try fix coverity build

--HG--
branch : coverity

.gitignore

@@ -0,0 +1,27 @@
+*~
+*.o
+*.a
+*.da
+*.bb
+*.bbg
+*.prof
+.*.swp
+/autom4te.cache
+/config.log
+/config.status
+/dbclient
+/dropbear
+/dropbearconvert
+/dropbearkey
+/dropbearmulti
+/fuzzcorpus
+/fuzzer-*
+/fuzzer-*.options
+/scp
+/scp-progress
+Makefile
+config.h
+config.h.in
+configure
+default_options_guard.h
+tags

.hgignore

@@ -0,0 +1,2 @@
+.*\.o
+.*~

.hgsigs

@@ -0,0 +1,29 @@
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.hgtags

@@ -0,0 +1,61 @@
+03f65e461915a940939e4cc689fc89721ffc40de DROPBEAR_0.48.1
+0f967bfef5cd0056b7ec60e2305d917e51cbf30d DROPBEAR_0.44
+170329dc8ce5dfcf6298e1ad6699f109bf78e73d DROPBEAR_0.51
+1dbd2473482f320ea59f76ce961385cb3a0150a9 DROPBEAR_0.46
+2098857ab826dd42ae05a9a22c3ce2cc835b9844 DROPBEAR_0.45
+36160290a1b27451178be36752ed038840f59cdd LTC_DB_0.46
+39d5d58461d6e93337636e69d4cdf184a09c8d24 LTC_1.05
+55a99934db873be2e63b5968fb6532e5d9bd02e4 DROPBEAR_0.48
+59400faa4b44708c5d0b595e81193bc621e752d3 libtomcrypt-1.05
+66087d87c3555c78b47cf01f32bb5a32054c3ceb DROPBEAR_0.44test4
+677843bfa734238a67636b461a02c110c462ffaf DROPBEAR_0.44test1
+7faae8f46238e23975430876547b8950b4e75481 t:ltc-0.95-orig
+8220862baae829ebc762587b99c662480d57bb23 DROPBEAR_0.53
+86e0b50a9b588239c3fc9cc9cfe255ef586df17b ltm-0.30-orig
+88e0a1ad951add46b795511dc2698e36b4aee922 DROPBEAR_0.44test3
+8e94663164c6e106ccc5c9e997dedf6e04d77dd2 LTM_DB_0.44
+91fbc376f01084037cd5f6a5bf2e2db4903e8e99 libtommath-0.35
+97db060d0ef5f8cf8e67eb602ef037055a185ca9 libtommath-0.40
+aa2f51a6b81d33de5e9898a7f27c792a173d9b26 DROPBEAR_0.53.1
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+cd1143579f00b0248c79f63ca70efee4a35a57e8 LTC_DB_0.44
+ce104c8b0be1ff3f2c2590b7cdc3fd6870c865cd DROPBEAR_0.52
+d5faf4814ddbc5abd9e209409bb9e7a4686c8cd7 libtomcrypt-1.16
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+d8254fc979e99560c93ca2cece77a6df31927ea5 LTM_0.35
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+e109027b9edfb02f0bdf96ec45bb1cd9ad41e7da LTM_DB_0.47
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+d354464b2aa6f6ba0bf44d43bcae5aa798435393 DROPBEAR_2012.55
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+0000000000000000000000000000000000000000 t:ltc-0.95-orig
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+0000000000000000000000000000000000000000 t:ltc-0.95-db-merge1
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+e894dbc015ba7ff4c3bf897ee20e28ca90c55a16 DROPBEAR_2013.61test
+3d1d7d151c0ce3a79da62e86463f5632fa2b144a DROPBEAR_2013.62
+2351b2da8e0d08dcc6e64fcc328b53b9630bda68 DROPBEAR_2014.63
+0d2d39957c029adb7f4327d37fe6b4900f0736d9 DROPBEAR_2014.64
+e9579816f20ea85affc6135e87f8477992808948 DROPBEAR_2014.65
+735511a4c761141416ad0e6728989d2dafa55bc2 DROPBEAR_2014.66
+cbd674d63cd4f3781464a8d4056a5506c8ae926f DROPBEAR_2015.67
+809feaa9408f036734129c77f2b3c7e779d4f099 DROPBEAR_2015.68
+1637dbd262124d113e52967df46afd6c715e4fad DROPBEAR_2015.69
+79a6ef02307d05cb9dda10465cb5b807baa8f62e DROPBEAR_2015.70
+9a944a243f08be6b22d32f166a0690eb4872462b DROPBEAR_2015.71
+78b12b6549be08b0bea3da329b2578060a76ca31 DROPBEAR_2016.72
+309e1c4a87682b6ca7d80b8555a1db416c3cb7ac DROPBEAR_2016.73
+0ed3d2bbf956cb8a9bf0f4b5a86b7dd9688205cb DROPBEAR_2016.74
+c31276613181c5cff7854e7ef586ace03424e55e DROPBEAR_2017.75
+1c66ca4f3791c82501c88e7637312182c7294978 DROPBEAR_2018.76
+6d1bbe7d5fa5827c7eae28bca044d691f7efa785 DROPBEAR_2019.77
+009d52ae26d35f3381c801e02318fa9be34be93c DROPBEAR_2019.78
+e2e4929d057b09422f2ea4556fb64209aff58161 DROPBEAR_2020.79

.travis.yml

@@ -0,0 +1,36 @@
+language: c
+
+git:
+  depth: 3
+
+env:
+  global:
+   # The next declaration is the encrypted COVERITY_SCAN_TOKEN, created
+   #   via the "travis encrypt" command using the project repo's public key
+   - secure: "F4rKQrHK/u58vPo3F9+x0WYXAeMFJvvtH9BIGZqx9yw8bUnL+gk0Ge9wnHHTXRcgCTqoc7B35uMS5njpH+Su/esVjrLAq85f/AmQctlRpmApwGK9LyxkIvx3UJN0nqfeeDXA90/8FUZ+n/qnCydXmYCEgqSaBCNydDxW1oqYUIc="
+   - BUNDLEDLIBTOM=--enable-bundled-libtom
+   - MULTI=1
+
+before_install:
+  - echo -n | openssl s_client -connect https://scan.coverity.com:443 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' | sudo tee -a /etc/ssl/certs/ca-
+
+addons:
+  apt:
+    packages:
+    # packages list: https://github.com/travis-ci/apt-package-whitelist/blob/master/ubuntu-precise
+    - zlib1g-dev
+    - libtomcrypt-dev
+    - libtommath-dev
+  coverity_scan:
+    project:
+      name: "mkj/dropbear"
+      description: "Dropbear SSH"
+    notification_email: matt@ucc.asn.au
+    build_command_prepend: autoconf && autoheader && ./configure --enable-bundled-libtom CFLAGS='-O2 -Wall -Wno-pointer-sign' --prefix=$HOME/inst
+    build_command: make MULTI=1
+    branch_pattern: coverity
+
+branches:
+  only:
+    - master
+    - coverity

CHANGES

@@ -1,3 +1,748 @@
+2020.80 - 26 June 2020
+
+- Don't block authorized_keys logins with no-X11-forwarding or no-agent-forwarding 
+  restrictions when X11 or agent forwarding are disabled at compile time.
+  This is more of a problem now X11 is disabled by default, reported by Guilhem Moulin
+
+- Reduce binary size by 4kB (x64) when using bundled libtommath
+
+- Define GNU_SOURCE for getrandom() on uclibc, reported by Laurent Bercot and
+  Fabrice Fontaine
+
+- Improve checking libtomcrypt version compatibility
+
+- Add some style notes to DEVELOPING.md
+
+2020.79 - 15 June 2020
+
+- Support ed25519 hostkeys and authorized_keys, many thanks to Vladislav Grishenko.
+  This also replaces curve25519 with a TweetNaCl implementation that reduces code size.
+
+- Add chacha20-poly1305 authenticated cipher. This will perform faster than AES
+  on many platforms. Thanks to Vladislav Grishenko
+
+- Support using rsa-sha2 signatures. No changes are needed to hostkeys/authorized_keys
+  entries, existing RSA keys can be used with the new signature format (signatures
+  are ephemeral within a session). Old ssh-rsa signatures will no longer
+  be supported by OpenSSH in future so upgrading is recommended.
+
+- Use getrandom() call on Linux to ensure sufficient entropy has been gathered at startup.
+  Dropbear now avoids reading from the random source at startup, instead waiting until
+  the first connection. It is possible that some platforms were running without enough 
+  entropy previously, those could potentially block at first boot generating host keys.
+  The dropbear "-R" option is one way to avoid that.
+
+- Upgrade libtomcrypt to 1.18.2 and libtommath to 1.2.0, many thanks to Steffen Jaeckel for
+  updating Dropbear to use the current API. Dropbear's configure script will check 
+  for sufficient system library versions, otherwise using the bundled versions.
+
+- CBC ciphers, 3DES, hmac-sha1-96, and x11 forwarding are now disabled by default.
+  They can be set in localoptions.h if required.
+  Blowfish has been removed.
+
+- Support AES GCM, patch from Vladislav Grishenko. This is disabled by default,
+  Dropbear doesn't currently use hardware accelerated AES.
+
+- Added an API for specifying user public keys as an authorized_keys replacement.
+  See pubkeyapi.h for details, thanks to Fabrizio Bertocci
+
+- Fix idle detection clashing with keepalives, thanks to jcmathews
+
+- Include IP addresses in more early exit messages making it easier for fail2ban
+  processing. Patch from Kevin Darbyshire-Bryant
+
+- scp fix for CVE-2018-20685 where a server could modify name of output files
+
+- SSH_ORIGINAL_COMMAND is set for "dropbear -c" forced command too
+
+- Fix writing key files on systems without hard links, from Matt Robinson
+
+- Compatibility fixes for IRIX from Kazuo Kuroi
+
+- Re-enable printing MOTD by default, was lost moving from options.h. Thanks to zciendor
+
+- Call fsync() is called on parent directory when writing key files to ensure they are flushed
+
+- Fix "make install" for manpages in out-of-tree builds, from Gabor Z. Papp
+
+- Some notes are added in DEVELOPING.md
+
+2019.78 - 27 March 2019
+
+- Fix dbclient regression in 2019.77. After exiting the terminal would be left
+  in a bad state. Reported by Ryan Woodsmall
+  
+2019.77 - 23 March 2019
+
+- Fix server -R option with ECDSA - only advertise one key size which will be accepted.
+  Reported by Peter Krefting, 2018.76 regression.
+
+- Fix server regression in 2018.76 where multiple client -R forwards were all forwarded 
+  to the first destination. Reported by Iddo Samet.
+
+- Make failure delay more consistent to avoid revealing valid usernames, set server password 
+  limit of 100 characters. Problem reported by usd responsible disclosure team
+
+- Change handling of failed authentication to avoid disclosing valid usernames,
+  CVE-2018-15599. 
+
+- Fix dbclient to reliably return the exit code from the remote server.
+  Reported by W. Mike Petullo
+
+- Fix export of 521-bit ECDSA keys, from Christian Hohnstädt
+
+- Add -o Port=xxx option to work with sshfs, from xcko
+
+- Merged fuzzing code, see FUZZER-NOTES.md
+
+- Add a DROPBEAR_SVR_MULTIUSER=0 compile option to run on 
+  single-user Linux kernels (CONFIG_MULTIUSER disabled). From Patrick Stewart
+
+- Increase allowed username to 100 characters, reported by W. Mike Petullo
+
+- Update config.sub and config.guess, should now work with RISC-V
+
+- Cygwin compile fix from karel-m
+
+- Don't require GNU sed (accidentally in 2018.76), reported by Samuel Hsu
+
+- Fix for IRIX and writev(), reported by Kazuo Kuroi
+
+- Other fixes and cleanups from François Perrad, Andre McCurdy, Konstantin Demin,
+  Michael Jones, Pawel Rapkiewicz
+
+
+2018.76 - 27 February 2018
+
+> > > Configuration/compatibility changes
+  IMPORTANT
+  Custom configuration is now specified in localoptions.h rather than options.h
+  Available options and defaults can be seen in default_options.h
+
+  To migrate your configuration, compare your customised options.h against the
+  upstream options.h from your relevant version. Any customised options should
+  be put in localoptions.h in the build directory.
+
+- "configure --enable-static" should now be used instead of "make STATIC=1"
+  This will avoid 'hardened build' flags that conflict with static binaries
+
+- Set 'hardened build' flags by default if supported by the compiler.
+  These can be disabled with configure --disable-harden if needed.
+  -Wl,-pie
+  -Wl,-z,now -Wl,-z,relro
+  -fstack-protector-strong
+  -D_FORTIFY_SOURCE=2
+  # spectre v2 mitigation
+  -mfunction-return=thunk
+  -mindirect-branch=thunk
+
+  Spectre patch from Loganaden Velvindron
+
+- "dropbear -r" option for hostkeys no longer attempts to load the default
+  hostkey paths as well. If desired these can be specified manually. 
+  Patch from CamVan Nguyen
+
+- group1-sha1 key exchange is disabled in the server by default since
+  the fixed 1024-bit group may be susceptible to attacks
+
+- twofish ciphers are now disabled in the default configuration
+
+- Default generated ECDSA key size is now 256 (rather than 521) 
+  for better interoperability
+
+- Minimum RSA key length has been increased to 1024 bits
+
+> > > Other features and fixes
+
+- Add runtime -T max_auth_tries option from Kevin Darbyshire-Bryant
+
+- Add 'dbclient -J &fd' to allow dbclient to connect over an existing socket.
+  See dbclient manpage for a socat example. Patch from Harald Becker
+
+- Add "-c forced_command" option. Patch from Jeremy Kerr
+
+- Restricted group -G option added with patch from stellarpower
+
+- Support server-chosen TCP forwarding ports, patch from houseofkodai
+
+- Allow choosing outgoing address for dbclient with -b [bind_address][:bind_port]
+  Patch from houseofkodai
+
+- Makefile will now rebuild object files when header files are modified
+
+- Add group14-256 and group16 key exchange options
+
+- curve25519-sha256 also supported without @libssh.org suffix
+
+- Update bundled libtomcrypt to 1.18.1, libtommath to 1.0.1
+  This fixes building with some recent versions of clang
+
+- Set PAM_RHOST which is needed by modules such as pam_abl
+
+- Improvements to DSS and RSA public key validation, found by OSS-Fuzz. 
+
+- Don't exit when an authorized_keys file has malformed entries. Found by OSS-Fuzz
+
+- Fix null-pointer crash with malformed ECDSA or DSS keys. Found by OSS-Fuzz
+
+- Numerous code cleanups and small issues fixed by Francois Perrad
+
+- Test for pkt_sched.h rather than SO_PRIORITY which was problematic with some musl
+  platforms. Reported by Oliver Schneider and Andrew Bainbridge
+
+- Fix some platform portability problems, from Ben Gardner
+
+- Add EXEEXT filename suffix for building dropbearmulti, from William Foster
+
+- Support --enable-<option> properly for configure, from Stefan Hauser
+
+- configure have_openpty result can be cached, from Eric Bénard
+
+- handle platforms that return close() < -1 on failure, from Marco Wenzel
+
+- Build and configuration cleanups from Michael Witten
+
+- Fix libtomcrypt/libtommath linking order, from Andre McCurdy
+
+- Fix old Linux platforms that have SYS_clock_gettime but not CLOCK_MONOTONIC
+
+- Update curve25519-donna implementation to current version
+
+2017.75 - 18 May 2017
+
+- Security: Fix double-free in server TCP listener cleanup
+  A double-free in the server could be triggered by an authenticated user if
+  dropbear is running with -a (Allow connections to forwarded ports from any host)
+  This could potentially allow arbitrary code execution as root by an authenticated user.
+  Affects versions 2013.56 to 2016.74. Thanks to Mark Shepard for reporting the crash.
+  CVE-2017-9078 https://secure.ucc.asn.au/hg/dropbear/rev/c8114a48837c
+
+- Security: Fix information disclosure with ~/.ssh/authorized_keys symlink.
+  Dropbear parsed authorized_keys as root, even if it were a symlink. The fix
+  is to switch to user permissions when opening authorized_keys
+
+  A user could symlink their ~/.ssh/authorized_keys to a root-owned file they
+  couldn't normally read. If they managed to get that file to contain valid
+  authorized_keys with command= options it might be possible to read other
+  contents of that file.
+  This information disclosure is to an already authenticated user.
+  Thanks to Jann Horn of Google Project Zero for reporting this.
+  CVE-2017-9079 https://secure.ucc.asn.au/hg/dropbear/rev/0d889b068123
+
+- Generate hostkeys with dropbearkey atomically and flush to disk with fsync
+  Thanks to Andrei Gherzan for a patch
+
+- Fix out of tree builds with bundled libtom
+  Thanks to Henrik Nordström and Peter Krefting for patches.
+
+2016.74 - 21 July 2016
+
+- Security: Message printout was vulnerable to format string injection.
+
+  If specific usernames including "%" symbols can be created on a system
+  (validated by getpwnam()) then an attacker could run arbitrary code as root
+  when connecting to Dropbear server.
+
+  A dbclient user who can control username or host arguments could potentially
+  run arbitrary code as the dbclient user. This could be a problem if scripts
+  or webpages pass untrusted input to the dbclient program.
+  CVE-2016-7406
+  https://secure.ucc.asn.au/hg/dropbear/rev/b66a483f3dcb
+
+- Security: dropbearconvert import of OpenSSH keys could run arbitrary code as
+  the local dropbearconvert user when parsing malicious key files
+  CVE-2016-7407
+  https://secure.ucc.asn.au/hg/dropbear/rev/34e6127ef02e
+
+- Security: dbclient could run arbitrary code as the local dbclient user if
+  particular -m or -c arguments are provided. This could be an issue where
+  dbclient is used in scripts.
+  CVE-2016-7408
+  https://secure.ucc.asn.au/hg/dropbear/rev/eed9376a4ad6
+
+- Security: dbclient or dropbear server could expose process memory to the
+  running user if compiled with DEBUG_TRACE and running with -v
+  CVE-2016-7409
+  https://secure.ucc.asn.au/hg/dropbear/rev/6a14b1f6dc04
+
+  The security issues were reported by an anonymous researcher working with
+  Beyond Security's SecuriTeam Secure Disclosure www.beyondsecurity.com/ssd.html
+
+- Fix port forwarding failure when connecting to domains that have both
+  IPv4 and IPv6 addresses. The bug was introduced in 2015.68
+
+- Fix 100% CPU use while waiting for rekey to complete. Thanks to Zhang Hui P
+  for the patch
+
+
+2016.73 - 18 March 2016
+
+- Support syslog in dbclient, option -o usesyslog=yes. Patch from Konstantin Tokarev
+
+- Kill a proxycommand when dbclient exits, patch from Konstantin Tokarev
+
+- Option to exit when a TCP forward fails, patch from Konstantin Tokarev
+
+- New "-o" option parsing from Konstantin Tokarev. This allows handling some extra options
+  in the style of OpenSSH, though implementing all OpenSSH options is not planned.
+
+- Fix crash when fallback initshells() is used, reported by Michael Nowak and Mike Tzou
+
+- Allow specifying commands eg "dropbearmulti dbclient ..." instead of symlinks
+
+- Various cleanups for issues found by a lint tool, patch from Francois Perrad
+
+- Fix tab indent consistency, patch from Francois Perrad
+
+- Fix issues found by cppcheck, reported by Mike Tzou
+
+- Use system memset_s() or explicit_bzero() if available to clear memory. Also make
+  libtomcrypt/libtommath routines use that (or Dropbear's own m_burn()).
+
+- Prevent scp failing when the local user doesn't exist. Based on patch from Michael Witten.
+
+- Improved Travis CI test running, thanks to Mike Tzou
+
+- Improve some code that was flagged by Coverity and Fortify Static Code Analyzer
+
+2016.72 - 9 March 2016
+
+- Validate X11 forwarding input. Could allow bypass of authorized_keys command= restrictions,
+  found by github.com/tintinweb. Thanks for Damien Miller for a patch. CVE-2016-3116
+  https://secure.ucc.asn.au/hg/dropbear/rev/a3e8389e01ff
+
+2015.71 - 3 December 2015
+
+- Fix "bad buf_incrpos" when data is transferred, broke in 2015.69
+
+- Fix crash on exit when -p address:port is used, broke in 2015.68, thanks to
+  Frank Stollenwerk for reporting and investigation
+
+- Fix building with only ENABLE_CLI_REMOTETCPFWD given, patch from Konstantin Tokarev
+
+- Fix bad configure script test which didn't work with dash shell, patch from Juergen Daubert,
+  broke in 2015.70
+
+- Fix server race condition that could cause sessions to hang on exit,
+  https://github.com/robotframework/SSHLibrary/issues/128
+
+2015.70 - 26 November 2015
+
+- Fix server password authentication on Linux, broke in 2015.69
+
+2015.69 - 25 November 2015
+
+- Fix crash when forwarded TCP connections fail to connect (bug introduced in 2015.68)
+
+- Avoid hang on session close when multiple sessions are started, affects Qt Creator
+  Patch from Andrzej Szombierski
+
+- Reduce per-channel memory consumption in common case, increase default
+  channel limit from 100 to 1000 which should improve SOCKS forwarding for modern
+  webpages
+
+- Handle multiple command line arguments in a single flag, thanks to Guilhem Moulin
+
+- Manpage improvements from Guilhem Moulin
+
+- Build fixes for Android from Mike Frysinger
+
+- Don't display the MOTD when an explicit command is run from Guilhem Moulin
+
+- Check curve25519 shared secret isn't zero
+
+2015.68 - Saturday 8 August 2015
+
+- Reduce local data copying for improved efficiency. Measured 30%
+  increase in throughput for connections to localhost
+
+- Forwarded TCP ports connect asynchronously and try all available addresses
+  (IPv4, IPv6, round robin DNS)
+
+- Fix all compile warnings, many patches from Gaël Portay
+  Note that configure with -Werror may not be successful on some platforms (OS X)
+  and some configuration options may still result in unused variable
+  warnings.
+
+- Use TCP Fast Open on Linux if available. Saves a round trip at connection
+  to hosts that have previously been connected. 
+  Needs a recent Linux kernel and possibly "sysctl -w net.ipv4.tcp_fastopen=3"
+  Client side is disabled by default pending further compatibility testing
+  with networks and systems.
+
+- Increase maximum command length to 9000 bytes
+
+- Free memory before exiting, patch from Thorsten Horstmann. Useful for
+  Dropbear ports to embedded systems and for checking memory leaks
+  with valgrind. Only partially implemented for dbclient.
+  This is disabled by default, enable with DROPBEAR_CLEANUP in sysoptions.h
+
+- DROPBEAR_DEFAULT_CLI_AUTHKEY setting now always prepends home directory unless
+  there is a leading slash (~ isn't treated specially)
+
+- Fix small ECC memory leaks
+
+- Tighten validation of Diffie-Hellman parameters, from Florent Daigniere of
+  Matta Consulting. Odds of bad values are around 2**-512 -- improbable.
+
+- Twofish-ctr cipher is supported though disabled by default
+
+- Fix pre-authentication timeout when waiting for client SSH-2.0 banner, thanks
+  to CL Ouyang
+
+- Fix null pointer crash with restrictions in authorized_keys without a command, patch from
+  Guilhem Moulin
+
+- Ensure authentication timeout is handled while reading the initial banner,
+  thanks to CL Ouyang for finding it.
+
+- Fix null pointer crash when handling bad ECC keys. Found by afl-fuzz
+
+2015.67 - Wednesday 28 January 2015
+
+- Call fsync() after generating private keys to ensure they aren't lost if a
+  reboot occurs. Thanks to Peter Korsgaard
+
+- Disable non-delayed zlib compression by default on the server. Can be
+  enabled if required for old clients with DROPBEAR_SERVER_DELAY_ZLIB
+
+- Default client key path ~/.ssh/id_dropbear
+
+- Prefer stronger algorithms by default, from Fedor Brunner. 
+  AES256 over 3DES
+  Diffie-hellman group14 over group1
+
+- Add option to disable CBC ciphers.
+
+- Disable twofish in default options.h
+
+- Enable sha2 HMAC algorithms by default, the code was already required
+  for ECC key exchange. sha1 is the first preference still for performance. 
+
+- Fix installing dropbear.8 in a separate build directory, from Like Ma
+
+- Allow configure to succeed if libtomcrypt/libtommath are missing, from Elan Ruusamäe
+
+- Don't crash if ssh-agent provides an unknown type of key. From Catalin Patulea
+
+- Minor bug fixes, a few issues found by Coverity scan
+
+2014.66 - Thursday 23 October 2014
+
+- Use the same keepalive handling behaviour as OpenSSH. This will work better 
+  with some SSH implementations that have different behaviour with unknown 
+  message types.
+
+- Don't reply with SSH_MSG_UNIMPLEMENTED when we receive a reply to our own 
+  keepalive message
+
+- Set $SSH_CLIENT to keep bash happy, patch from Ryan Cleere
+
+- Fix wtmp which broke since 2013.62, patch from Whoopie
+
+2014.65 - Friday 8 August 2014
+
+- Fix 2014.64 regression, server session hang on exit with scp (and probably
+  others), thanks to NiLuJe for tracking it down
+
+- Fix 2014.64 regression, clock_gettime() error handling which broke on older
+  Linux kernels, reported by NiLuJe
+
+- Fix 2014.64 regression, writev() could occassionally fail with EAGAIN which
+  wasn't caught
+
+- Avoid error message when trying to set QoS on proxycommand or multihop pipes
+
+- Use /usr/bin/xauth, thanks to Mike Frysinger
+
+- Don't exit the client if the local user entry can't be found, thanks to iquaba
+
+2014.64 - Sunday 27 July 2014
+
+- Fix compiling with ECDSA and DSS disabled
+
+- Don't exit abruptly if too many outgoing packets are queued for writev(). Patch
+  thanks to Ronny Meeus
+
+- The -K keepalive option now behaves more like OpenSSH's "ServerAliveInterval". 
+  If no response is received after 3 keepalives then the session is terminated. This
+  will close connections faster than waiting for a TCP timeout.
+
+- Rework TCP priority setting. New settings are
+	if (connecting || ptys || x11) tos = LOWDELAY
+	else if (tcp_forwards) tos = 0
+	else tos = BULK
+  Thanks to Catalin Patulea for the suggestion.
+
+- Improve handling of many concurrent new TCP forwarded connections, should now
+  be able to handle as many as MAX_CHANNELS. Thanks to Eduardo Silva for reporting
+  and investigating it.
+
+- Make sure that exit messages from the client are printed, regression in 2013.57
+
+- Use monotonic clock where available, timeouts won't be affected by system time
+  changes
+
+- Add -V for version
+
+2014.63 - Wednesday 19 February 2014
+
+- Fix ~. to terminate a client interactive session after waking a laptop
+  from sleep.
+
+- Changed port separator syntax again, now using host^port. This is because
+  IPv6 link-local addresses use %. Reported by Gui Iribarren
+
+- Avoid constantly relinking dropbearmulti target, fix "make install"
+  for multi target, thanks to Mike Frysinger
+
+- Avoid getting stuck in a loop writing huge key files, reported by Bruno
+  Thomsen
+
+- Don't link dropbearkey or dropbearconvert to libz or libutil, 
+  thanks to Nicolas Boos
+
+- Fix linking -lcrypt on systems without /usr/lib, thanks to Nicolas Boos
+
+- Avoid crash on exit due to cleaned up keys before last packets are sent,
+  debugged by Ronald Wahl
+
+- Fix a race condition in rekeying where Dropbear would exit if it received a
+  still-in-flight packet after initiating rekeying. Reported by Oliver Metz.
+  This is a longstanding bug but is triggered more easily since 2013.57
+
+- Fix README for ecdsa keys, from Catalin Patulea
+
+- Ensure that generated RSA keys are always exactly the length
+  requested. Previously Dropbear always generated N+16 or N+15 bit keys.
+  Thanks to Unit 193
+
+- Fix DROPBEAR_CLI_IMMEDIATE_AUTH mode which saves a network round trip if the
+  first public key succeeds. Still not enabled by default, needs more
+  compatibility testing with other implementations.
+
+- Fix for port 0 forwarding in the client and port forwarding with Apache MINA SSHD. Thanks to 
+
+- Fix for bad system linux/pkt-sched.h header file with older Linux
+kernels, from Steve Dover
+
+- Fix signal handlers so that errno is saved, thanks to Erik Ahlén for a patch
+  and Mark Wickham for independently spotting the same problem.
+
+2013.62 - Tuesday 3 December 2013
+
+- Disable "interactive" QoS connection options when a connection doesn't
+  have a PTY (eg scp, rsync). Thanks to Catalin Patulea for the patch.
+
+- Log when a hostkey is generated with -R, fix some bugs in handling server
+  hostkey commandline options
+
+- Fix crash in Dropbearconvert and 521 bit key, reported by NiLuJe
+
+- Update config.guess and config.sub again
+
+2013.61test - Thursday 14 November 2013
+
+- Default generated RSA key size changed from 1024 to 2048 bits
+
+- ECC (elliptic curve) support. Supports ECDSA hostkeys (requires new keys to
+  be generated) and ECDH for setting up encryption keys (no intervention
+  required). This is significantly faster.
+
+- curve25519-sha256@libssh.org support for setting up encryption keys. This is
+  another elliptic curve mode with less potential of NSA interference in
+  algorithm parameters. curve25519-donna code thanks to Adam Langley
+
+- -R option to automatically generate hostkeys. This is recommended for
+  embedded platforms since it allows the system random number device
+  /dev/urandom a longer startup time to generate a secure seed before the
+  hostkey is required.
+
+- Compile fixes for old vendor compilers like Tru64 from Daniel Richard G.
+
+- Make authorized_keys handling more robust, don't exit encountering
+  malformed lines. Thanks to Lorin Hochstein and Mark Stillwell 
+
+2013.60 - Wednesday 16 October 2013
+
+- Fix "make install" so that it doesn't always install to /bin and /sbin
+
+- Fix "make install MULTI=1", installing manpages failed
+
+- Fix "make install" when scp is included since it has no manpage
+
+- Make --disable-bundled-libtom work
+
+2013.59 - Friday 4 October 2013
+
+- Fix crash from -J command 
+  Thanks to Lluís Batlle i Rossell and Arnaud Mouiche for patches
+
+- Avoid reading too much from /proc/net/rt_cache since that causes
+  system slowness. 
+
+- Improve EOF handling for half-closed connections
+  Thanks to Catalin Patulea
+
+- Send a banner message to report PAM error messages intended for the user
+  Patch from Martin Donnelly
+
+- Limit the size of decompressed payloads, avoids memory exhaustion denial
+  of service 
+  Thanks to Logan Lamb for reporting and investigating it. CVE-2013-4421
+  https://secure.ucc.asn.au/hg/dropbear/rev/0bf76f54de6f
+
+- Avoid disclosing existence of valid users through inconsistent delays
+  Thanks to Logan Lamb for reporting. CVE-2013-4434
+  https://secure.ucc.asn.au/hg/dropbear/rev/d7784616409a
+
+- Update config.guess and config.sub for newer architectures
+
+- Avoid segfault in server for locked accounts
+
+- "make install" now installs manpages
+  dropbearkey.8 has been renamed to dropbearkey.1
+  manpage added for dropbearconvert
+
+- Get rid of one second delay when running non-interactive commands
+
+
+2013.58 - Thursday 18 April 2013
+
+- Fix building with Zlib disabled, thanks to Hans Harder and cuma@freetz
+
+- Use % as a separator for ports, fixes scp in multihop mode, from Hans Harder
+
+- Reject logins for other users when running as non-root, from Hans Harder
+
+- Disable client immediate authentication request by default, it prevents
+  passwordless logins from working
+
+2013.57 - Monday 15 April 2013
+
+- Decreased connection setup time particularly with high latency connections,
+  the number of round trips has been reduced for both client and server. 
+  CPU time hasn't been changed.
+
+- Client will send an initial key exchange guess to save a round trip.
+  Dropbear implements an extension kexguess2@matt.ucc.asn.au to allow the first
+  packet guess to succeed in wider circumstances than the standard behaviour.
+  When communicating with other implementations the standard behaviour is used.
+
+- Client side: when public key or password authentication with
+  $DROPBEAR_PASSWORD is used an initial authentication request will
+  be sent immediately rather than querying the list of available methods.
+  This behaviour is enabled by CLI_IMMEDIATE_AUTH option (on by default),
+  please let the Dropbear author know if it causes any interoperability
+  problems.
+
+- Implement client escape characters ~. (terminate session) and 
+  ~^Z (background session)
+
+- Server will more reliably clean up utmp when connection is closed, reported by
+  Mattias Walström
+
+- Don't crash if /dev/urandom isn't writable (RHEL5), thanks to Scott Case
+
+- Add "-y -y" client option to skip host key checking, thanks to Hans Harder
+
+- scp didn't work properly on systems using vfork(), thanks to Frank Van Uffelen
+
+- Added IUTF8 terminal mode support (Linux and Mac OS). Not standardised yet
+though probably will be soon
+
+- Some verbose DROPBEAR_TRACE output is now hidden unless $DROPBEAR_TRACE2
+  enviroment variable is set
+
+- Fix using asymmetric MAC algorithms (broke in )
+
+- Renamed configure.in to configure.ac to quieten autoconf, from Mike Frysinger
+
+2013.56 - Thursday 21 March 2013
+
+- Allow specifying cipher (-c) and MAC (-m) lists for dbclient
+
+- Allow using 'none' cipher or MAC (off by default, use options.h). Encryption
+  is used during authentication then disabled, similar to OpenSSH HPN mode
+
+- Allow a user in immediately if the account has a blank password and blank
+  passwords are enabled
+
+- Include a few extra sources of entropy from /proc on Linux, hash private keys
+  as well. Dropbear will also write gathered entropy back into /dev/urandom
+
+- Added hmac-sha2-256 and hmac-sha2-512 support (off by default, use options.h)
+
+- Don't sent bad address "localhost" for -R forward connections, 
+  reported by Denis Bider
+
+- Add "-B" runtime option to allow blank passwords
+
+- Allow using IPv6 bracket notation for addresses in server "-p" option, from Ben Jencks
+
+- A few improvements for Android from Reimar Döffinger
+
+- Fix memory leak for TCP forwarded connections to hosts that timed out,
+  reported by Norbert Benczúr. Appears to be a very long-standing bug.
+
+- Fix "make clean" for out of tree builds
+
+- Fix compilation when ENABLE_{SVR,CLI}_AGENTFWD are unset
+
+2012.55 - Wednesday 22 February 2012
+
+- Security: Fix use-after-free bug that could be triggered if command="..."
+  authorized_keys restrictions are used.  Could allow arbitrary code execution
+  or bypass of the command="..." restriction to an authenticated user.
+  This bug affects releases 0.52 onwards. Ref CVE-2012-0920.
+  Thanks to Danny Fullerton of Mantor Organization for reporting
+  the bug.
+  https://secure.ucc.asn.au/hg/dropbear/rev/818108bf7749
+
+- Compile fix, only apply IPV6 socket options if they are available in headers
+  Thanks to Gustavo Zacarias for the patch
+
+- Overwrite session key memory on exit
+
+- Fix minor memory leak in unusual PAM authentication configurations.
+  Thanks to Stathis Voukelatos
+
+- Other small code cleanups
+
+2011.54 - Tuesday 8 November 2011
+
+- Building statically works again, broke in 0.53 and 0.53.1
+
+- Fix crash when forwarding with -R
+
+- Fixed various leaks found by Klocwork analysis software, thanks to them for
+  running it
+
+- Set IPTOS_LOWDELAY for IPv6, thanks to Dave Taht
+
+- Bind to sockets with IPV6_V6ONLY so that it works properly on systems
+  regardless of the system-wide setting
+
+- Added ALLOW_BLANK_PASSWORD option. Dropbear also now allows public key logins
+  to accounts with a blank password. Thanks to Rob Landley
+
+- Fixed case where "-K 1" keepalive for dbclient would cause a SSH_MSG_IGNORE
+  packet to be sent
+
+- Avoid some memory allocations in big number maths routines, improves
+  performance slightly
+
+- Fix symlink target for installdropbearmulti with DESTDIR set, thanks to
+  Scottie Shore
+
+- When requesting server allocated remote ports (-R 0:host:port) print a
+  message informing what the port is, thanks to Ali Onur Uyar.
+
+- New version numbering scheme.
+
+Source repository has now migrated to Mercurial at 
+https://secure.ucc.asn.au/hg/dropbear/graph/default
+
 0.53.1 - Wednesday 2 March 2011
 
 - -lcrypt needs to be before object files for static linking
@@ -151,7 +896,7 @@
 
 - Security: dbclient previously would prompt to confirm a 
   mismatching hostkey but wouldn't warn loudly. It will now
-  exit upon a mismatch.
+  exit upon a mismatch. CVE-2007-1099
 
 - Compile fixes, make sure that all variable definitions are at the start
   of a scope.
@@ -213,7 +958,7 @@
   (thanks to Tomas Vanek for helping track it down)
 
 - Implement per-IP pre-authentication connection limits 
-  (after some poking from Pablo Fernandez)
+  (after some poking from Pablo Fernandez) CVE-2006-1206
 
 - Exit gracefully if trying to connect to as SSH v1 server 
   (reported by Rushi Lala)
@@ -234,7 +979,7 @@
 - SECURITY: fix for buffer allocation error in server code, could potentially
   allow authenticated users to gain elevated privileges. All multi-user systems
   running the server should upgrade (or apply the patch available on the
-  Dropbear webpage).
+  Dropbear webpage). CVE-2005-4178
 
 - Fix channel handling code so that redirecting to /dev/null doesn't use
   100% CPU.
@@ -441,7 +1186,7 @@
 - SECURITY: Don't try to free() uninitialised variables in DSS verification
   code. Thanks to Arne Bernin for pointing out this bug. This is possibly
   exploitable, all users with DSS and pubkey-auth compiled in are advised to
-  upgrade.
+  upgrade. CVE-2004-2486
 
 - Clean up agent forwarding socket files correctly, patch from Gerrit Pape.
 
@@ -565,7 +1310,7 @@
   Lobenstock and Mihnea Stoenescu
 
 - Use daemon() function if available (or our own copy) rather than separate
-  code (thanks to Frédéric Lavernhe for the report and debugging, and Bernard
+  code (thanks to Frédéric Lavernhe for the report and debugging, and Bernard
   Blackham for his suggestion on what to look at)
 
 - Fixed up support for first_kex_packet_follows, required to talk to ssh.com
@@ -684,7 +1429,7 @@
 - Various signedness fixes
 - Can listen on multiple ports
 - added option to disable openpty with configure script,
-  (from K.-P. Kirchdörfer <kapeka at epost.de>)
+  (from K.-P. Kirchdörfer <kapeka at epost.de>)
 - Various cleanups to bignum code
   (thanks to Tom St Denis <tomstdenis at iahu.ca>)
 - Fix compile error when disabling RSA

DEVELOPING.md

@@ -0,0 +1,75 @@
+# Developer Notes
+
+## Building
+
+See [INSTALL](INSTALL) for build instructions. 
+[SMALL](SMALL) has hints for building smaller binaries, also see comments
+in default_options.h.
+
+## Debug printing
+
+Set `#define DEBUG_TRACE 1` in localoptions.h to enable a `-v` option
+for dropbear and dbclient. That prints various details of the session. For
+development running `dropbear -F -E` is useful to run in the foreground. You
+can set `#define DEBUG_NOFORK 1` to make dropbear a one-shot server, easy to 
+run under a debugger.
+
+## Random sources
+
+Most cryptography requires a good random entropy source, both to generate secret
+keys and in the course of a session. Dropbear uses the Linux kernel's
+`getrandom()` syscall to ensure that the system RNG has been initialised before
+using it. On some systems there is insufficient entropy gathered during early
+boot - generating hostkeys then will block for some amount of time. 
+Dropbear has a `-R` option to generate hostkeys upon the first connection 
+as required - that will allow the system more time to gather entropy.
+
+## Algorithms
+
+Default algorithm lists are specified in [common-algo.c](common-algo.c).
+They are in priority order, the client's first matching choice is used
+(see rfc4253). 
+Dropbear client has `-c` and `-m` arguments to choose which are enabled at
+runtime (doesn't work for server as of June 2020).
+
+Enabling/disabling algorithms is done in [localoptions.h](localoptions.h),
+see [default_options.h](default_options.h).
+
+## Style
+
+Source code is indented with tabs, width set to 4 (though width shouldn't
+matter much). Braces are on the same line as functions/loops/if - try
+to keep consistency with existing code.
+
+All `if` statements should have braces, no exceptions.
+
+Avoid using pointer arithmetic, instead the functions in
+[buffer.h](buffer.h) should be used.
+
+Some Dropbear platforms have old compilers.
+Variable declarations must be at the top of a scope and
+comments must be `/* */` rather than `//`.
+
+Pointer variables should be initialised to NULL - it can reduce the
+severity of bugs.
+
+## Third party code
+
+Libtomcrypt and libtommath are periodically synced from upstream, so
+avoid making changes to that code which will need to be maintained.
+Improvements can be sent upstream to the libtom project.
+
+## Non-root user
+
+Dropbear server will run fine as a non-root user, allowing logins only for 
+that user. Password authentication probably won't work (can't read shadow 
+passwords). You will need to create hostkeys that are readable.
+
+## Connection setup 
+
+Dropbear implements first_kex_packet_follows to reduce 
+handshake latency (rfc 4253 7.1). Some less common implementations don't 
+handle that, it can be a cause of problems connecting. Note also that
+Dropbear may send several ssh packets within a single TCP packet - it's just a 
+stream.
+

FUZZER-NOTES.md

@@ -0,0 +1,77 @@
+# Fuzzing Dropbear
+
+Dropbear is process-per-session so it assumes calling `dropbear_exit()`
+is fine at any point to clean up. This makes fuzzing a bit trickier. 
+A few pieces of wrapping infrastructure are used to work around this.
+
+The [libfuzzer](http://llvm.org/docs/LibFuzzer.html#fuzz-target) harness
+expects a long running process to continually run a test function with 
+a string of crafted input. That process should not leak resources or exit.
+
+## longjmp
+
+When dropbear runs in fuzz mode it sets up a 
+[`setjmp()`](http://man7.org/linux/man-pages/man3/setjmp.3.html) target prior 
+to launching the code to be fuzzed, and then [`dropbear_exit()`](dbutil.c#L125)
+calls `longjmp()` back there. This avoids exiting though it doesn't free 
+memory or other resources.
+
+## malloc Wrapper
+
+Dropbear normally uses a [`m_malloc()`](dbmalloc.c) function that is the same as `malloc()` but
+exits if allocation fails. In fuzzing mode this is replaced with a tracking allocator
+that stores all allocations in a linked list. After the `longjmp()` occurs the fuzzer target
+calls [`m_malloc_free_epoch(1, 1)`](dbmalloc.c) to clean up any unreleased memory.
+
+If the fuzz target runs to completion it calls `m_malloc_free_epoch(1, 0)` which will reset 
+the tracked allocations but will not free memory - that allows libfuzzer's leak checking
+to detect leaks in normal operation.
+
+## File Descriptor Input
+
+As a network process Dropbear reads and writes from a socket. The wrappers for
+`read()`/`write()`/`select()` in [fuzz-wrapfd.c](fuzz-wrapfd.c) will read from the
+fuzzer input that has been set up with `wrapfd_add()`. `write()` output is
+currently discarded.
+These also test error paths such as EINTR and short reads with certain probabilities.
+
+This allows running the entire dropbear server process with network input provided by the
+fuzzer, without many modifications to the main code. At the time of writing this 
+only runs the pre-authentication stages, though post-authentication could be run similarly.
+
+## Encryption and Randomness
+
+When running in fuzzing mode Dropbear uses a [fixed seed](dbrandom.c#L185)
+every time so that failures can be reproduced. 
+
+Since the fuzzer cannot generate valid encrypted input the packet decryption and
+message authentication calls are disabled, see [packet.c](packet.c). 
+MAC failures are set to occur with a low probability to test that error path.
+
+## Fuzzers
+
+Current fuzzers are
+
+- [fuzzer-preauth](fuzzer-preauth.c) - the fuzzer input is treated as a stream of session input. This will
+  test key exchange, packet ordering, authentication attempts etc.
+
+- [fuzzer-preauth_nomaths](fuzzer-preauth_nomaths.c) - the same as fuzzer-preauth but with asymmetric crypto
+  routines replaced with dummies for faster runtime. corpora are shared 
+  between fuzzers by [oss-fuzz](https://github.com/google/oss-fuzz) so this 
+  will help fuzzer-preauth too.
+
+- [fuzzer-verify](fuzzer-verify.c) - read a key and signature from fuzzer input and verify that signature. 
+  It would not be expected to pass, though some keys with bad parameters are 
+  able to validate with a trivial signature - extra checks are added for that.
+
+- [fuzzer-pubkey](fuzzer-pubkey.c) - test parsing of an `authorized_keys` line.
+
+- [fuzzer-kexdh](fuzzer-kexdh.c) - test Diffie-Hellman key exchange where the fuzz input is the 
+  ephemeral public key that would be received over the network. This is testing `mp_expt_mod()`
+  and and other libtommath routines.
+
+- [fuzzer-kexecdh](fuzzer-kexecdh.c) - test Elliptic Curve Diffie-Hellman key exchange like fuzzer-kexdh.
+  This is testing libtommath ECC routines.
+
+- [fuzzer-kexcurve25519](fuzzer-kexcurve25519.c) - test Curve25519 Elliptic Curve Diffie-Hellman key exchange
+  like fuzzer-kexecdh. This is testing `dropbear_curve25519_scalarmult()` and other libtommath routines.

INSTALL

@@ -1,28 +1,42 @@
 Basic Dropbear build instructions:
 
-- Edit options.h to set which features you want.
-- Edit debug.h if you want any debug options (not usually required).
+- Edit localoptions.h to set which features you want. Available options
+  are described in default_options.h, these will be overridden by
+  anything set in localoptions.h
+  localoptions.h should be located in the build directory if you are
+  building out of tree.
 
-(If using a non-tarball copy, "autoconf; autoheader")
+- If using a Mercurial or Git checkout, "autoconf; autoheader"
 
-./configure      (optionally with --disable-zlib or --disable-syslog,
+- Configure for your system:
+  ./configure     (optionally with --disable-zlib or --disable-syslog,
                   or --help for other options)
 
-Now compile:
+- Compile:
 
-make PROGRAMS="dropbear dbclient dropbearkey dropbearconvert scp"
+  make PROGRAMS="dropbear dbclient dropbearkey dropbearconvert scp"
 
-And install (/usr/local/bin is usual default):
+- Optionally install, or copy the binaries another way
 
-make PROGRAMS="dropbear dbclient dropbearkey dropbearconvert scp" install
+  make install (/usr/local/bin is usual default):
+
+  or
+
+  make PROGRAMS="dropbear dbclient dropbearkey dropbearconvert scp" install
 
 (you can leave items out of the PROGRAMS list to avoid compiling them. If you
 recompile after changing the PROGRAMS list, you *MUST* "make clean" before
 recompiling - bad things will happen otherwise)
 
+DEVELOPING.md has some notes on other developer topics, including debugging.
+
 See MULTI for instructions on making all-in-one binaries.
 
-If you want to compile statically, add "STATIC=1" to the make command-line.
+If you want to compile statically use ./configure --enable-static
+
+By default Dropbear adds various build flags that improve robustness 
+against programming bugs (good for security). If these cause problems
+they can be disabled with ./configure --disable-harden
 
 Binaries can be stripped with "make strip"
 
@@ -44,7 +58,7 @@ Compiling for uClibc should be the same as normal, just set CC to the magic
 uClibc toolchain compiler (ie export CC=i386-uclibc-gcc or whatever).
 You can use "make STATIC=1" to make statically linked binaries, and it is
 advisable to strip the binaries too. If you're looking to make a small binary,
-you should remove unneeded ciphers and MD5, by editing options.h
+you should remove unneeded ciphers and MD5, by editing localoptions.h
 
 It is possible to compile zlib in, by copying zlib.h and zconf.h into a
 subdirectory (ie zlibincludes), and 

LICENSE

@@ -8,7 +8,7 @@ The majority of code is written by Matt Johnston, under the license below.
 Portions of the client-mode work are (c) 2004 Mihnea Stoenescu, under the
 same license:
 
-Copyright (c) 2002-2008 Matt Johnston
+Copyright (c) 2002-2020 Matt Johnston
 Portions copyright (c) 2004 Mihnea Stoenescu
 All rights reserved.
 
@@ -32,7 +32,8 @@ SOFTWARE.
 
 =====
 
-LibTomCrypt and LibTomMath are written by Tom St Denis, and are Public Domain.
+LibTomCrypt and LibTomMath are written by Tom St Denis and others, see
+libtomcrypt/LICENSE and libtommath/LICENSE.
 
 =====
 
@@ -87,3 +88,27 @@ NONINFRINGEMENT.  IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE
 FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
 CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+=====
+
+curve25519.c:
+
+Modified TweetNaCl version 20140427, a self-contained public-domain C library.
+https://tweetnacl.cr.yp.to/
+
+Contributors (alphabetical order)
+Daniel J. Bernstein, University of Illinois at Chicago and Technische
+Universiteit Eindhoven
+Bernard van Gastel, Radboud Universiteit Nijmegen
+Wesley Janssen, Radboud Universiteit Nijmegen
+Tanja Lange, Technische Universiteit Eindhoven
+Peter Schwabe, Radboud Universiteit Nijmegen
+Sjaak Smetsers, Radboud Universiteit Nijmegen
+
+Acknowledgments
+This work was supported by the U.S. National Science Foundation under grant
+1018836. "Any opinions, findings, and conclusions or recommendations expressed
+in this material are those of the author(s) and do not necessarily reflect the
+views of the National Science Foundation."
+This work was supported by the Netherlands Organisation for Scientific
+Research (NWO) under grant 639.073.005 and Veni 2013 project 13114.

MULTI

@@ -20,7 +20,3 @@ etc
 then execute as normal:
 
 ./dropbear <options here>
-
-"make install" doesn't currently work for multi-binary configuration, though
-in most situations where it is being used, the target and build systems will
-differ.

Makefile.in

@@ -2,73 +2,105 @@
 # @configure_input@
 
 # invocation:
-# make PROGRAMS="dropbear dbclient scp" MULTI=1 STATIC=1 SCPPROGRESS=1
+# make PROGRAMS="dropbear dbclient scp" MULTI=1 SCPPROGRESS=1
 #
-# to make a multiple-program statically linked binary "staticdropbearmulti".
+# to make a multiple-program binary "dropbearmulti".
 # This example will include dropbear, scp, dropbearkey, dropbearconvert, and
 # dbclient functionality, and includes the progress-bar functionality in scp.
-# Hopefully that seems intuitive.
 
 ifndef PROGRAMS
 	PROGRAMS=dropbear dbclient dropbearkey dropbearconvert
 endif
 
-LTC=libtomcrypt/libtomcrypt.a
-LTM=libtommath/libtommath.a
+STATIC_LTC=libtomcrypt/libtomcrypt.a
+STATIC_LTM=libtommath/libtommath.a
+
+LIBTOM_LIBS=@LIBTOM_LIBS@
 
 ifeq (@BUNDLED_LIBTOM@, 1)
-LIBTOM_DEPS=$(LTC) $(LTM)
-CFLAGS+=-I$(srcdir)/libtomcrypt/src/headers/ 
-LIBS+=$(LTC) $(LTM)
+LIBTOM_DEPS=$(STATIC_LTC) $(STATIC_LTM) 
+LIBTOM_CLEAN=ltc-clean ltm-clean
+CFLAGS+=-I$(srcdir)/libtomcrypt/src/headers/
+LIBTOM_LIBS=$(STATIC_LTC) $(STATIC_LTM)
 endif
 
-COMMONOBJS=dbutil.o buffer.o \
-		dss.o bignum.o \
-		signkey.o rsa.o random.o \
-		queue.o \
-		atomicio.o compat.o  fake-rfc2553.o 
+OPTION_HEADERS = default_options_guard.h sysoptions.h
+ifneq ($(wildcard localoptions.h),)
+CFLAGS+=-DLOCALOPTIONS_H_EXISTS
+OPTION_HEADERS += localoptions.h
+endif
 
-SVROBJS=@CRYPTLIB@ svr-kex.o svr-algo.o svr-auth.o sshpty.o \
+COMMONOBJS=dbutil.o buffer.o dbhelpers.o \
+		dss.o bignum.o \
+		signkey.o rsa.o dbrandom.o \
+		queue.o \
+		atomicio.o compat.o fake-rfc2553.o \
+		ltc_prng.o ecc.o ecdsa.o crypto_desc.o \
+		curve25519.o ed25519.o \
+		dbmalloc.o \
+		gensignkey.o gendss.o genrsa.o gened25519.o
+
+SVROBJS=svr-kex.o svr-auth.o sshpty.o \
 		svr-authpasswd.o svr-authpubkey.o svr-authpubkeyoptions.o svr-session.o svr-service.o \
 		svr-chansession.o svr-runopts.o svr-agentfwd.o svr-main.o svr-x11fwd.o\
 		svr-tcpfwd.o svr-authpam.o
 
-CLIOBJS=cli-algo.o cli-main.o cli-auth.o cli-authpasswd.o cli-kex.o \
-		cli-session.o cli-service.o cli-runopts.o cli-chansession.o \
+CLIOBJS=cli-main.o cli-auth.o cli-authpasswd.o cli-kex.o \
+		cli-session.o cli-runopts.o cli-chansession.o \
 		cli-authpubkey.o cli-tcpfwd.o cli-channel.o cli-authinteract.o \
-		cli-agentfwd.o list.o
+		cli-agentfwd.o 
 
 CLISVROBJS=common-session.o packet.o common-algo.o common-kex.o \
 			common-channel.o common-chansession.o termcodes.o loginrec.o \
-			tcp-accept.o listener.o process-packet.o \
-			common-runopts.o circbuffer.o
+			tcp-accept.o listener.o process-packet.o dh_groups.o \
+			common-runopts.o circbuffer.o list.o netio.o chachapoly.o gcm.o
 
-KEYOBJS=dropbearkey.o gendss.o genrsa.o
+KEYOBJS=dropbearkey.o
 
 CONVERTOBJS=dropbearconvert.o keyimport.o
 
 SCPOBJS=scp.o progressmeter.o atomicio.o scpmisc.o compat.o
 
-HEADERS=options.h dbutil.h session.h packet.h algo.h ssh.h buffer.h kex.h \
-		dss.h bignum.h signkey.h rsa.h random.h service.h auth.h \
-		debug.h channel.h chansession.h config.h queue.h sshpty.h \
-		termcodes.h gendss.h genrsa.h runopts.h includes.h \
-		loginrec.h atomicio.h x11fwd.h agentfwd.h tcpfwd.h compat.h \
-		listener.h fake-rfc2553.h
+ifeq (@DROPBEAR_FUZZ@, 1)
+	allobjs = $(COMMONOBJS) fuzz-common.o  fuzz-wrapfd.o $(CLISVROBJS) $(CLIOBJS) $(SVROBJS) @CRYPTLIB@
+	allobjs:=$(subst svr-main.o, ,$(allobjs))
+	allobjs:=$(subst cli-main.o, ,$(allobjs))
+	allobjs:=$(sort $(allobjs))
 
-dropbearobjs=$(COMMONOBJS) $(CLISVROBJS) $(SVROBJS) 
-dbclientobjs=$(COMMONOBJS) $(CLISVROBJS) $(CLIOBJS)
-dropbearkeyobjs=$(COMMONOBJS) $(KEYOBJS)
-dropbearconvertobjs=$(COMMONOBJS) $(CONVERTOBJS)
-scpobjs=$(SCPOBJS)
+	dropbearobjs=$(allobjs) svr-main.o
+	dbclientobjs=$(allobjs) cli-main.o
+	dropbearkeyobjs=$(allobjs) $(KEYOBJS)
+	dropbearconvertobjs=$(allobjs) $(CONVERTOBJS)
+	# CXX only set when fuzzing
+	CXX=@CXX@
+else
+	dropbearobjs=$(COMMONOBJS) $(CLISVROBJS) $(SVROBJS)
+	dbclientobjs=$(COMMONOBJS) $(CLISVROBJS) $(CLIOBJS)
+	dropbearkeyobjs=$(COMMONOBJS) $(KEYOBJS)
+	dropbearconvertobjs=$(COMMONOBJS) $(CONVERTOBJS)
+	scpobjs=$(SCPOBJS)
+endif
+
+ifeq (@DROPBEAR_PLUGIN@, 1)
+    # rdynamic makes all the global symbols of dropbear available to all the loaded shared libraries
+    # this allow a plugin to reuse existing crypto/utilities like base64_decode/base64_encode without
+    # the need to rewrite them.
+    PLUGIN_LIBS=-ldl -rdynamic
+else
+    PLUGIN_LIBS=
+endif
 
 VPATH=@srcdir@
 srcdir=@srcdir@
 
 prefix=@prefix@
-exec_prefix=${prefix}
-bindir=${exec_prefix}/bin
-sbindir=${exec_prefix}/sbin
+exec_prefix=@exec_prefix@
+datarootdir = @datarootdir@
+bindir=@bindir@
+sbindir=@sbindir@
+mandir=@mandir@
+
+.DELETE_ON_ERROR:
 
 CC=@CC@
 AR=@AR@
@@ -82,9 +114,10 @@ LDFLAGS=@LDFLAGS@
 
 EXEEXT=@EXEEXT@
 
+STATIC=@STATIC@
+
 # whether we're building client, server, or both for the common objects.
 # evilness so we detect 'dropbear' by itself as a word
-space:= $(empty) $(empty)
 ifneq (,$(strip $(foreach prog, $(PROGRAMS), $(findstring ZdropbearZ, Z$(prog)Z))))
 	CFLAGS+= -DDROPBEAR_SERVER
 endif
@@ -92,7 +125,6 @@ ifneq (,$(strip $(foreach prog, $(PROGRAMS), $(findstring ZdbclientZ, Z$(prog)Z)
 	CFLAGS+= -DDROPBEAR_CLIENT
 endif
 
-
 # these are exported so that libtomcrypt's makefile will use them
 export CC
 export CFLAGS
@@ -103,7 +135,7 @@ ifeq ($(STATIC), 1)
 endif
 
 ifeq ($(MULTI), 1)
-	TARGETS=dropbearmulti
+	TARGETS=dropbearmulti$(EXEEXT)
 else
 	TARGETS=$(PROGRAMS)
 endif
@@ -115,40 +147,50 @@ endif
 
 all: $(TARGETS)
 
+# for simplicity assume all source depends on all headers
+HEADERS=$(wildcard $(srcdir)/*.h *.h) $(OPTION_HEADERS)
+%.o : %.c $(HEADERS)
+	$(CC) -c $(CFLAGS) $(CPPFLAGS) $< -o $@
+
+default_options_guard.h: default_options.h
+	@echo Creating $@
+	@printf "/*\n > > > Do not edit this file (default_options_guard.h) < < <\nGenerated from "$^"\nLocal customisation goes in localoptions.h\n*/\n\n" > $@.tmp
+	@$(srcdir)/ifndef_wrapper.sh < $^ >> $@.tmp
+	@mv $@.tmp $@
+
 strip: $(TARGETS)
 	$(STRIP) $(addsuffix $(EXEEXT), $(TARGETS))
 
 install: $(addprefix inst_, $(TARGETS))
 
-installdropbearmulti: insdbmulti $(addprefix insmulti, $(PROGRAMS)) 
-
-insdbmulti: dropbearmulti
-	$(INSTALL) -d -m 755 $(DESTDIR)$(bindir)
-	$(INSTALL) -m 755 dropbearmulti$(EXEEXT) $(DESTDIR)$(bindir)
-	-chown root $(DESTDIR)$(bindir)/dropbearmulti$(EXEEXT)
-	-chgrp 0 $(DESTDIR)$(bindir)/dropbearmulti$(EXEEXT)
-
-insmultidropbear: dropbearmulti
+insmultidropbear: dropbearmulti$(EXEEXT)
+	$(INSTALL) -d $(DESTDIR)$(sbindir)
 	-rm -f $(DESTDIR)$(sbindir)/dropbear$(EXEEXT)
-	-ln -s $(DESTDIR)$(bindir)/dropbearmulti$(EXEEXT) $(DESTDIR)$(sbindir)/dropbear$(EXEEXT) 
+	-ln -s $(bindir)/dropbearmulti$(EXEEXT) $(DESTDIR)$(sbindir)/dropbear$(EXEEXT) 
+	$(INSTALL) -d $(DESTDIR)$(mandir)/man8
+	$(INSTALL) -m 644 $(srcdir)/dropbear.8  $(DESTDIR)$(mandir)/man8/dropbear.8
 
-insmulti%: dropbearmulti
+insmulti%: dropbearmulti$(EXEEXT)
+	$(INSTALL) -d $(DESTDIR)$(bindir)
 	-rm -f $(DESTDIR)$(bindir)/$*$(EXEEXT) 
-	-ln -s $(DESTDIR)$(bindir)/dropbearmulti$(EXEEXT) $(DESTDIR)$(bindir)/$*$(EXEEXT) 
+	-ln -s $(bindir)/dropbearmulti$(EXEEXT) $(DESTDIR)$(bindir)/$*$(EXEEXT) 
+	$(INSTALL) -d $(DESTDIR)$(mandir)/man1
+	if test -e $(srcdir)/$*.1; then $(INSTALL) -m 644 $(srcdir)/$*.1 $(DESTDIR)$(mandir)/man1/$*.1; fi
 
-# dropbear should go in sbin, so it needs a seperate rule
+# dropbear should go in sbin, so it needs a separate rule
 inst_dropbear: dropbear
-	$(INSTALL) -d -m 755 $(DESTDIR)$(sbindir)
-	$(INSTALL) -m 755 dropbear$(EXEEXT) $(DESTDIR)$(sbindir)
-	-chown root $(DESTDIR)$(sbindir)/dropbear$(EXEEXT)
-	-chgrp 0 $(DESTDIR)$(sbindir)/dropbear$(EXEEXT)
+	$(INSTALL) -d $(DESTDIR)$(sbindir)
+	$(INSTALL) dropbear$(EXEEXT) $(DESTDIR)$(sbindir)
+	$(INSTALL) -d $(DESTDIR)$(mandir)/man8
+	$(INSTALL) -m 644 $(srcdir)/dropbear.8 $(DESTDIR)$(mandir)/man8/dropbear.8
 
-inst_%: $*
-	$(INSTALL) -d -m 755 $(DESTDIR)$(bindir)
-	$(INSTALL) -m 755 $*$(EXEEXT) $(DESTDIR)$(bindir)
-	-chown root $(DESTDIR)$(bindir)/$*$(EXEEXT)
-	-chgrp 0 $(DESTDIR)$(bindir)/$*$(EXEEXT)
+inst_%: %
+	$(INSTALL) -d $(DESTDIR)$(bindir)
+	$(INSTALL) $*$(EXEEXT) $(DESTDIR)$(bindir)
+	$(INSTALL) -d $(DESTDIR)$(mandir)/man1
+	if test -e $(srcdir)/$*.1; then $(INSTALL) -m 644 $(srcdir)/$*.1 $(DESTDIR)$(mandir)/man1/$*.1; fi
 
+inst_dropbearmulti: $(addprefix insmulti, $(PROGRAMS)) 
 
 # for some reason the rule further down doesn't like $($@objs) as a prereq.
 dropbear: $(dropbearobjs)
@@ -156,8 +198,14 @@ dbclient: $(dbclientobjs)
 dropbearkey: $(dropbearkeyobjs)
 dropbearconvert: $(dropbearconvertobjs)
 
-dropbear dbclient dropbearkey dropbearconvert: $(HEADERS) $(LIBTOM_DEPS) Makefile
-	$(CC) $(LDFLAGS) -o $@$(EXEEXT) $($@objs) $(LIBS)
+dropbear: $(HEADERS) $(LIBTOM_DEPS) Makefile
+	$(CC) $(LDFLAGS) -o $@$(EXEEXT) $($@objs) $(LIBTOM_LIBS) $(LIBS) @CRYPTLIB@ $(PLUGIN_LIBS)
+
+dbclient: $(HEADERS) $(LIBTOM_DEPS) Makefile
+	$(CC) $(LDFLAGS) -o $@$(EXEEXT) $($@objs) $(LIBTOM_LIBS) $(LIBS)
+
+dropbearkey dropbearconvert: $(HEADERS) $(LIBTOM_DEPS) Makefile
+	$(CC) $(LDFLAGS) -o $@$(EXEEXT) $($@objs) $(LIBTOM_LIBS) $(LIBS)
 
 # scp doesn't use the libs so is special.
 scp: $(SCPOBJS)  $(HEADERS) Makefile
@@ -171,10 +219,10 @@ ifeq ($(MULTI),1)
 	CFLAGS+=$(addprefix -DDBMULTI_, $(PROGRAMS)) -DDROPBEAR_MULTI
 endif
 
-dropbearmulti: multilink 
+dropbearmulti$(EXEEXT): $(HEADERS) $(MULTIOBJS) $(LIBTOM_DEPS) Makefile
+	$(CC) $(LDFLAGS) -o $@ $(MULTIOBJS) $(LIBTOM_LIBS) $(LIBS) @CRYPTLIB@
 
-multibinary: $(HEADERS) $(MULTIOBJS) $(LIBTOM_DEPS) Makefile
-	$(CC) $(LDFLAGS) -o dropbearmulti$(EXEEXT) $(MULTIOBJS) $(LIBS)
+multibinary: dropbearmulti$(EXEEXT)
 
 multilink: multibinary $(addprefix link, $(PROGRAMS))
 
@@ -182,32 +230,104 @@ link%:
 	-rm -f $*$(EXEEXT)
 	-ln -s dropbearmulti$(EXEEXT) $*$(EXEEXT)
 
-$(LTC): options.h
-	cd libtomcrypt && $(MAKE) clean && $(MAKE)
+$(STATIC_LTC): $(OPTION_HEADERS)
+	$(MAKE) -C libtomcrypt
 
-$(LTM): options.h
-	cd libtommath && $(MAKE)
+$(STATIC_LTM): $(OPTION_HEADERS)
+	$(MAKE) -C libtommath
 
-.PHONY : clean sizes thisclean distclean tidy ltc-clean ltm-clean
+.PHONY : clean sizes thisclean distclean tidy ltc-clean ltm-clean lint
 
 ltc-clean:
-	cd libtomcrypt && $(MAKE) clean
+	$(MAKE) -C libtomcrypt clean
 
 ltm-clean:
-	cd libtommath && $(MAKE) clean
+	$(MAKE) -C libtommath clean
 
 sizes: dropbear
 	objdump -t dropbear|grep ".text"|cut -d "." -f 2|sort -rn
 
-clean: ltc-clean ltm-clean thisclean
+clean: $(LIBTOM_CLEAN) thisclean
 
 thisclean:
-	-rm -f dropbear dbclient dropbearkey dropbearconvert scp scp-progress \
-			dropbearmulti *.o *.da *.bb *.bbg *.prof 
+	-rm -f dropbear$(EXEEXT) dbclient$(EXEEXT) dropbearkey$(EXEEXT) \
+			dropbearconvert$(EXEEXT) scp$(EXEEXT) scp-progress$(EXEEXT) \
+			dropbearmulti$(EXEEXT) *.o *.da *.bb *.bbg *.prof
 
 distclean: clean tidy
 	-rm -f config.h
 	-rm -f Makefile
+	-rm -f default_options_guard.h
 
 tidy:
 	-rm -f *~ *.gcov */*~
+
+lint:
+	cd $(srcdir); ./dropbear_lint.sh
+
+## Fuzzing targets
+
+# list of fuzz targets
+FUZZ_TARGETS=fuzzer-preauth fuzzer-pubkey fuzzer-verify fuzzer-preauth_nomaths fuzzer-kexdh fuzzer-kexecdh fuzzer-kexcurve25519
+
+FUZZER_OPTIONS = $(addsuffix .options, $(FUZZ_TARGETS))
+
+list-fuzz-targets:
+	@echo $(FUZZ_TARGETS)
+
+# fuzzers that don't use libfuzzer, just a standalone harness that feeds inputs
+fuzzstandalone: FUZZLIB=fuzz-harness.o
+fuzzstandalone: fuzz-harness.o fuzz-targets
+
+# exclude svr-main.o to avoid duplicate main
+svrfuzzobjs=$(subst svr-main.o, ,$(dropbearobjs))
+
+fuzz-harness.o: $(HEADERS) $(LIBTOM_DEPS) Makefile $(svrfuzzobjs) fuzz-common.o
+
+# build all the fuzzers. This will require fail to link unless built with
+# make fuzz-targets FUZZLIB=-lFuzzer.a 
+# or similar - the library provides main().
+fuzz-targets: $(FUZZ_TARGETS) $(FUZZER_OPTIONS)
+
+fuzzer-preauth: fuzzer-preauth.o fuzz-harness.o
+	$(CXX) $(CXXFLAGS) $@.o $(LDFLAGS) $(svrfuzzobjs) -o $@$(EXEEXT) $(LIBTOM_LIBS) $(LIBS) $(FUZZLIB) @CRYPTLIB@
+
+fuzzer-preauth_nomaths: fuzzer-preauth_nomaths.o fuzz-harness.o
+	$(CXX) $(CXXFLAGS) $@.o $(LDFLAGS) $(svrfuzzobjs) -o $@$(EXEEXT) $(LIBTOM_LIBS) $(LIBS) $(FUZZLIB) @CRYPTLIB@
+
+fuzzer-pubkey: fuzzer-pubkey.o fuzz-harness.o
+	$(CXX) $(CXXFLAGS) $@.o $(LDFLAGS) $(svrfuzzobjs) -o $@$(EXEEXT) $(LIBTOM_LIBS) $(LIBS) $(FUZZLIB) @CRYPTLIB@
+
+fuzzer-verify: fuzzer-verify.o fuzz-harness.o
+	$(CXX) $(CXXFLAGS) $@.o $(LDFLAGS) $(svrfuzzobjs) -o $@$(EXEEXT) $(LIBTOM_LIBS) $(LIBS) $(FUZZLIB) @CRYPTLIB@
+
+fuzzer-kexdh: fuzzer-kexdh.o fuzz-harness.o
+	$(CXX) $(CXXFLAGS) $@.o $(LDFLAGS) $(svrfuzzobjs) -o $@$(EXEEXT) $(LIBTOM_LIBS) $(LIBS) $(FUZZLIB) @CRYPTLIB@
+
+fuzzer-kexecdh: fuzzer-kexecdh.o fuzz-harness.o
+	$(CXX) $(CXXFLAGS) $@.o $(LDFLAGS) $(svrfuzzobjs) -o $@$(EXEEXT) $(LIBTOM_LIBS) $(LIBS) $(FUZZLIB) @CRYPTLIB@
+
+fuzzer-kexcurve25519: fuzzer-kexcurve25519.o fuzz-harness.o
+	$(CXX) $(CXXFLAGS) $@.o $(LDFLAGS) $(svrfuzzobjs) -o $@$(EXEEXT) $(LIBTOM_LIBS) $(LIBS) $(FUZZLIB) @CRYPTLIB@
+
+fuzzer-%.options: Makefile
+	echo "[libfuzzer]"               > $@
+	echo "max_len = 50000"          >> $@
+
+# run this to update hardcoded hostkeys for for fuzzing. 
+# hostkeys.c is checked in to hg.
+fuzz-hostkeys:
+	dropbearkey -t rsa -f keyr
+	dropbearkey -t dss -f keyd
+	dropbearkey -t ecdsa -size 256 -f keye
+	dropbearkey -t ed25519 -f keyed25519
+	echo > hostkeys.c
+	/usr/bin/xxd -i -a keyr >> hostkeys.c
+	/usr/bin/xxd -i -a keye >> hostkeys.c
+	/usr/bin/xxd -i -a keyd >> hostkeys.c
+	/usr/bin/xxd -i -a keyed25519 >> hostkeys.c
+
+# to make coverity happy?
+test:
+	true
+

README

@@ -1,4 +1,5 @@
-This is Dropbear, a smallish SSH 2 server and client.
+This is Dropbear, a smallish SSH server and client.
+https://matt.ucc.asn.au/dropbear/dropbear.html
 
 INSTALL has compilation instructions.
 
@@ -7,8 +8,8 @@ which performs multiple tasks, to save disk space)
 
 SMALL has some tips on creating small binaries.
 
-See TODO for a few of the things I know need looking at, and please contact
-me if you have any questions/bugs found/features/ideas/comments etc :)
+Please contact me if you have any questions/bugs found/features/ideas/comments etc :)
+There is also a mailing list http://lists.ucc.gu.uwa.edu.au/mailman/listinfo/dropbear
 
 Matt Johnston
 matt@ucc.asn.au
@@ -27,8 +28,7 @@ ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAwVa6M6cGVmUcLl2cFzkxEoJd06Ub4bVDsYrWvXhvUV+Z
 You must make sure that ~/.ssh, and the key file, are only writable by the
 user. Beware of editors that split the key into multiple lines.
 
-NOTE: Dropbear ignores authorized_keys options such as those described in the
-OpenSSH sshd manpage, and will not allow a login for these keys. 
+Dropbear supports some options for authorized_keys entries, see the manpage.
 
 ============================================================================
 
@@ -42,8 +42,7 @@ If you have an OpenSSH-style private key ~/.ssh/id_rsa, you need to do:
 dropbearconvert openssh dropbear ~/.ssh/id_rsa  ~/.ssh/id_rsa.db
 dbclient -i ~/.ssh/id_rsa.db <hostname>
 
-Currently encrypted keys aren't supported, neither is agent forwarding. At some
-stage both hopefully will be.
+Dropbear does not support encrypted hostkeys though can connect to ssh-agent.
 
 ============================================================================
 
@@ -55,10 +54,16 @@ dropbearkey's '-y' option.
 To run the server, you need to generate server keys, this is one-off:
 ./dropbearkey -t rsa -f dropbear_rsa_host_key
 ./dropbearkey -t dss -f dropbear_dss_host_key
+./dropbearkey -t ecdsa -f dropbear_ecdsa_host_key
+./dropbearkey -t ed25519 -f dropbear_ed25519_host_key
 
 or alternatively convert OpenSSH keys to Dropbear:
 ./dropbearconvert openssh dropbear /etc/ssh/ssh_host_dsa_key dropbear_dss_host_key
 
+You can also get Dropbear to create keys when the first connection is made -
+this is preferable to generating keys when the system boots. Make sure 
+/etc/dropbear/ exists and then pass '-R' to the dropbear server.
+
 ============================================================================
 
 If the server is run as non-root, you most likely won't be able to allocate a

TODO

@@ -1,27 +0,0 @@
-Current:
-
-Things which might need doing:
-
-- default private dbclient keys
-
-- Make options.h generated from configure perhaps?
-
-- handle /etc/environment in AIX
-
-- check that there aren't timing issues with valid/invalid user authentication
-  feedback.
-
-- Binding to different interfaces
-
-- CTR mode
-- SSH_MSG_IGNORE sending to improve CBC security
-- DH Group Exchange possibly, or just add group14 (whatever it's called today)
-
-- fix scp.c for IRIX
-
-- Be able to use OpenSSH keys for the client? or at least have some form of 
-  encrypted keys.
-
-- Client agent forwarding
-
-- Handle restrictions in ~/.ssh/authorized_keys ?

agentfwd.h

@@ -21,8 +21,8 @@
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
-#ifndef _AGENTFWD_H_
-#define _AGENTFWD_H_
+#ifndef DROPBEAR_AGENTFWD_H_
+#define DROPBEAR_AGENTFWD_H_
 
 #include "includes.h"
 #include "chansession.h"
@@ -30,21 +30,21 @@
 #include "auth.h"
 #include "list.h"
 
+#if DROPBEAR_CLI_AGENTFWD
+
+/* From OpenSSH authfd.h */
+#define SSH_AGENT_RSA_SHA2_256          0x02
+
 /* An agent reply can be reasonably large, as it can
  * contain a list of all public keys held by the agent.
  * 10000 is arbitrary */
 #define MAX_AGENT_REPLY  10000
 
-int svr_agentreq(struct ChanSess * chansess);
-void svr_agentcleanup(struct ChanSess * chansess);
-void svr_agentset(struct ChanSess *chansess);
-
 /* client functions */
 void cli_load_agent_keys(m_list * ret_list);
 void agent_buf_sign(buffer *sigblob, sign_key *key, 
-    const unsigned char *data, unsigned int len);
-void cli_setup_agent(struct Channel *channel);
-
+		const buffer *data_buf, enum signature_type type);
+void cli_setup_agent(const struct Channel *channel);
 
 #ifdef __hpux
 #define seteuid(a)       setresuid(-1, (a), -1)
@@ -53,4 +53,14 @@ void cli_setup_agent(struct Channel *channel);
 
 extern const struct ChanType cli_chan_agent;
 
-#endif /* _AGENTFWD_H_ */
+#endif /* DROPBEAR_CLI_AGENTFWD */
+
+#if DROPBEAR_SVR_AGENTFWD
+
+int svr_agentreq(struct ChanSess * chansess);
+void svr_agentcleanup(struct ChanSess * chansess);
+void svr_agentset(const struct ChanSess *chansess);
+
+#endif /* DROPBEAR_SVR_AGENTFWD */
+
+#endif /* DROPBEAR_AGENTFWD_H_ */

algo.h

@@ -22,9 +22,9 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
-#ifndef _ALGO_H_
+#ifndef DROPBEAR_ALGO_H_
 
-#define _ALGO_H_
+#define DROPBEAR_ALGO_H_
 
 #include "includes.h"
 #include "buffer.h"
@@ -35,7 +35,7 @@
 
 struct Algo_Type {
 
-	unsigned char *name; /* identifying name */
+	const char *name; /* identifying name */
 	char val; /* a value for this cipher, or -1 for invalid */
 	const void *data; /* algorithm specific data */
 	char usable; /* whether we can use this algorithm */
@@ -47,10 +47,11 @@ typedef struct Algo_Type algo_type;
 
 /* lists mapping ssh types of algorithms to internal values */
 extern algo_type sshkex[];
-extern algo_type sshhostkey[];
+extern algo_type sigalgs[];
 extern algo_type sshciphers[];
 extern algo_type sshhashes[];
 extern algo_type ssh_compress[];
+extern algo_type ssh_delaycompress[];
 extern algo_type ssh_nocompress[];
 
 extern const struct dropbear_cipher dropbear_nocipher;
@@ -59,8 +60,8 @@ extern const struct dropbear_hash dropbear_nohash;
 
 struct dropbear_cipher {
 	const struct ltc_cipher_descriptor *cipherdesc;
-	unsigned long keysize;
-	unsigned char blocksize;
+	const unsigned long keysize;
+	const unsigned char blocksize;
 };
 
 struct dropbear_cipher_mode {
@@ -71,21 +72,76 @@ struct dropbear_cipher_mode {
 			unsigned long len, void *cipher_state);
 	int (*decrypt)(const unsigned char *ct, unsigned char *pt, 
 			unsigned long len, void *cipher_state);
+	int (*aead_crypt)(unsigned int seq,
+			const unsigned char *in, unsigned char *out,
+			unsigned long len, unsigned long taglen,
+			void *cipher_state, int direction);
+	int (*aead_getlength)(unsigned int seq,
+			const unsigned char *in, unsigned int *outlen,
+			unsigned long len, void *cipher_state);
+	const struct dropbear_hash *aead_mac;
 };
 
 struct dropbear_hash {
-	const struct ltc_hash_descriptor *hashdesc;
-	unsigned long keysize;
-	unsigned char hashsize;
+	const struct ltc_hash_descriptor *hash_desc;
+	const unsigned long keysize;
+	/* hashsize may be truncated from the size returned by hash_desc,
+	   eg sha1-96 */
+	const unsigned char hashsize;
 };
 
-void crypto_init();
-int have_algo(char* algo, size_t algolen, algo_type algos[]);
-void buf_put_algolist(buffer * buf, algo_type localalgos[]);
+enum dropbear_kex_mode {
+#if DROPBEAR_NORMAL_DH
+	DROPBEAR_KEX_NORMAL_DH,
+#endif
+#if DROPBEAR_ECDH
+	DROPBEAR_KEX_ECDH,
+#endif
+#if DROPBEAR_CURVE25519
+	DROPBEAR_KEX_CURVE25519,
+#endif
+};
 
-algo_type * svr_buf_match_algo(buffer* buf, algo_type localalgos[],
-		int *goodguess);
-algo_type * cli_buf_match_algo(buffer* buf, algo_type localalgos[],
-		int *goodguess);
+struct dropbear_kex {
+	enum dropbear_kex_mode mode;
+	
+	/* "normal" DH KEX */
+	const unsigned char *dh_p_bytes;
+	const int dh_p_len;
 
-#endif /* _ALGO_H_ */
+	/* elliptic curve DH KEX */
+#if DROPBEAR_ECDH
+	const struct dropbear_ecc_curve *ecc_curve;
+#else
+	const void* dummy;
+#endif
+
+	/* both */
+	const struct ltc_hash_descriptor *hash_desc;
+};
+
+/* Includes all algorithms is useall is set */
+void buf_put_algolist_all(buffer * buf, const algo_type localalgos[], int useall);
+/* Includes "usable" algorithms */
+void buf_put_algolist(buffer * buf, const algo_type localalgos[]);
+
+#define KEXGUESS2_ALGO_NAME "kexguess2@matt.ucc.asn.au"
+
+int buf_has_algo(buffer *buf, const char *algo);
+algo_type * first_usable_algo(algo_type algos[]);
+algo_type * buf_match_algo(buffer* buf, algo_type localalgos[],
+		int kexguess2, int *goodguess);
+
+#if DROPBEAR_USER_ALGO_LIST
+int check_user_algos(const char* user_algo_list, algo_type * algos, 
+		const char *algo_desc);
+char * algolist_string(const algo_type algos[]);
+#endif
+
+enum {
+	DROPBEAR_COMP_NONE,
+	DROPBEAR_COMP_ZLIB,
+	DROPBEAR_COMP_ZLIB_DELAY,
+};
+
+#endif /* DROPBEAR_ALGO_H_ */

atomicio.c

@@ -1,6 +1,8 @@
+/* $OpenBSD: atomicio.c,v 1.17 2006/04/01 05:51:34 djm Exp $ */
 /*
- * Copied from OpenSSH 3.6.1p2.
+ * Copied from OpenSSH/OpenBSD.
  * 
+ * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved.
  * Copyright (c) 1995,1999 Theo de Raadt.  All rights reserved.
  * All rights reserved.
  *
@@ -25,38 +27,32 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-/* RCSID("OpenBSD: atomicio.c,v 1.10 2001/05/08 22:48:07 markus Exp "); */
+#include "includes.h"
 
 #include "atomicio.h"
 
 /*
- * ensure all of data on socket comes through. f==read || f==write
+ * ensure all of data on socket comes through. f==read || f==vwrite
  */
-ssize_t
-atomicio(f, fd, _s, n)
-	ssize_t (*f) ();
-	int fd;
-	void *_s;
-	size_t n;
+size_t
+atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
 {
 	char *s = _s;
-	ssize_t res;
 	size_t pos = 0;
+	ssize_t res;
 
 	while (n > pos) {
 		res = (f) (fd, s + pos, n - pos);
 		switch (res) {
 		case -1:
-#ifdef EWOULDBLOCK
-			if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
-#else
 			if (errno == EINTR || errno == EAGAIN)
-#endif
 				continue;
+			return 0;
 		case 0:
-			return (res);
+			errno = EPIPE;
+			return pos;
 		default:
-			pos += res;
+			pos += (size_t)res;
 		}
 	}
 	return (pos);

atomicio.h

@@ -1,8 +1,7 @@
+/* $OpenBSD: atomicio.h,v 1.7 2006/03/25 22:22:42 djm Exp $ */
 
 /*
- * Copied from OpenSSH 3.6.1p2, required for loginrec.c
- *
- * $OpenBSD: atomicio.h,v 1.4 2001/06/26 06:32:46 itojun Exp $
+ * Copied from OpenSSH/OpenBSD, required for loginrec.c
  *
  * Copyright (c) 1995,1999 Theo de Raadt.  All rights reserved.
  * All rights reserved.
@@ -28,9 +27,9 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "includes.h"
-
 /*
- * Ensure all of data on socket comes through. f==read || f==write
+ * Ensure all of data on socket comes through. f==read || f==vwrite
  */
-ssize_t	atomicio(ssize_t (*)(), int, void *, size_t);
+size_t	atomicio(ssize_t (*)(int, void *, size_t), int, void *, size_t);
+
+#define vwrite (ssize_t (*)(int, void *, size_t))write

auth.h

@@ -22,31 +22,32 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
-#ifndef _AUTH_H_
-#define _AUTH_H_
+#ifndef DROPBEAR_AUTH_H_
+#define DROPBEAR_AUTH_H_
 
 #include "includes.h"
 #include "signkey.h"
 #include "chansession.h"
 
-void svr_authinitialise();
-void cli_authinitialise();
+void svr_authinitialise(void);
+void cli_authinitialise(void);
 
 /* Server functions */
-void recv_msg_userauth_request();
+void recv_msg_userauth_request(void);
 void send_msg_userauth_failure(int partial, int incrfail);
-void send_msg_userauth_success();
-void svr_auth_password();
-void svr_auth_pubkey();
-void svr_auth_pam();
+void send_msg_userauth_success(void);
+void send_msg_userauth_banner(const buffer *msg);
+void svr_auth_password(int valid_user);
+void svr_auth_pubkey(int valid_user);
+void svr_auth_pam(int valid_user);
 
-#ifdef ENABLE_SVR_PUBKEY_OPTIONS
-int svr_pubkey_allows_agentfwd();
-int svr_pubkey_allows_tcpfwd();
-int svr_pubkey_allows_x11fwd();
-int svr_pubkey_allows_pty();
+#if DROPBEAR_SVR_PUBKEY_OPTIONS_BUILT
+int svr_pubkey_allows_agentfwd(void);
+int svr_pubkey_allows_tcpfwd(void);
+int svr_pubkey_allows_x11fwd(void);
+int svr_pubkey_allows_pty(void);
 void svr_pubkey_set_forced_command(struct ChanSess *chansess);
-void svr_pubkey_options_cleanup();
+void svr_pubkey_options_cleanup(void);
 int svr_add_pubkey_options(buffer *options_buf, int line_num, const char* filename);
 #else
 /* no option : success */
@@ -55,34 +56,34 @@ int svr_add_pubkey_options(buffer *options_buf, int line_num, const char* filena
 #define svr_pubkey_allows_x11fwd() 1
 #define svr_pubkey_allows_pty() 1
 static inline void svr_pubkey_set_forced_command(struct ChanSess *chansess) { }
-static inline void svr_pubkey_options_cleanup() { }
+static inline void svr_pubkey_options_cleanup(void) { }
 #define svr_add_pubkey_options(x,y,z) DROPBEAR_SUCCESS
 #endif
 
 /* Client functions */
-void recv_msg_userauth_failure();
-void recv_msg_userauth_success();
-void recv_msg_userauth_specific_60();
-void recv_msg_userauth_pk_ok();
-void recv_msg_userauth_info_request();
-void cli_get_user();
-void cli_auth_getmethods();
-void cli_auth_try();
-void recv_msg_userauth_banner();
-void cli_pubkeyfail();
-void cli_auth_password();
-int cli_auth_pubkey();
-void cli_auth_interactive();
-char* getpass_or_cancel(char* prompt);
-void cli_auth_pubkey_cleanup();
+void recv_msg_userauth_failure(void);
+void recv_msg_userauth_success(void);
+void recv_msg_userauth_specific_60(void);
+void recv_msg_userauth_pk_ok(void);
+void recv_msg_userauth_info_request(void);
+void cli_get_user(void);
+void cli_auth_getmethods(void);
+int cli_auth_try(void);
+void recv_msg_userauth_banner(void);
+void cli_pubkeyfail(void);
+void cli_auth_password(void);
+int cli_auth_pubkey(void);
+void cli_auth_interactive(void);
+char* getpass_or_cancel(const char* prompt);
+void cli_auth_pubkey_cleanup(void);
 
 
-#define MAX_USERNAME_LEN 25 /* arbitrary for the moment */
+#define MAX_USERNAME_LEN 100 /* arbitrary for the moment */
 
 #define AUTH_TYPE_NONE      1
-#define AUTH_TYPE_PUBKEY    1 << 1
-#define AUTH_TYPE_PASSWORD  1 << 2
-#define AUTH_TYPE_INTERACT  1 << 3
+#define AUTH_TYPE_PUBKEY    (1 << 1)
+#define AUTH_TYPE_PASSWORD  (1 << 2)
+#define AUTH_TYPE_INTERACT  (1 << 3)
 
 #define AUTH_METHOD_NONE "none"
 #define AUTH_METHOD_NONE_LEN 4
@@ -104,12 +105,17 @@ struct AuthState {
 	unsigned char authtypes; /* Flags indicating which auth types are still 
 								valid */
 	unsigned int failcount; /* Number of (failed) authentication attempts.*/
-	unsigned authdone : 1; /* 0 if we haven't authed, 1 if we have. Applies for
-							  client and server (though has differing [obvious]
+	unsigned int authdone; /* 0 if we haven't authed, 1 if we have. Applies for
+							  client and server (though has differing 
 							  meanings). */
-	unsigned perm_warn : 1; /* Server only, set if bad permissions on 
+
+	unsigned int perm_warn; /* Server only, set if bad permissions on 
 							   ~/.ssh/authorized_keys have already been
 							   logged. */
+	unsigned int checkusername_failed;  /* Server only, set if checkusername
+	                                has already failed */
+	struct timespec auth_starttime; /* Server only, time of receiving current 
+									SSH_MSG_USERAUTH_REQUEST */
 
 	/* These are only used for the server */
 	uid_t pw_uid;
@@ -118,12 +124,12 @@ struct AuthState {
 	char *pw_shell;
 	char *pw_name;
 	char *pw_passwd;
-#ifdef ENABLE_SVR_PUBKEY_OPTIONS
+#if DROPBEAR_SVR_PUBKEY_OPTIONS_BUILT
 	struct PubKeyOptions* pubkey_options;
 #endif
 };
 
-#ifdef ENABLE_SVR_PUBKEY_OPTIONS
+#if DROPBEAR_SVR_PUBKEY_OPTIONS_BUILT
 struct PubKeyOptions;
 struct PubKeyOptions {
 	/* Flags */
@@ -132,9 +138,8 @@ struct PubKeyOptions {
 	int no_x11_forwarding_flag;
 	int no_pty_flag;
 	/* "command=" option. */
-	unsigned char * forced_command;
-	unsigned char * original_command;
+	char * forced_command;
 };
 #endif
 
-#endif /* _AUTH_H_ */
+#endif /* DROPBEAR_AUTH_H_ */

bignum.c

@@ -39,37 +39,66 @@ void m_mp_init(mp_int *mp) {
  * on error */
 void m_mp_init_multi(mp_int *mp, ...) 
 {
-    mp_int* cur_arg = mp;
-    va_list args;
+	mp_int* cur_arg = mp;
+	va_list args;
 
-    va_start(args, mp);        /* init args to next argument from caller */
-    while (cur_arg != NULL) {
-        if (mp_init(cur_arg) != MP_OKAY) {
+	va_start(args, mp);        /* init args to next argument from caller */
+	while (cur_arg != NULL) {
+		if (mp_init(cur_arg) != MP_OKAY) {
 			dropbear_exit("Mem alloc error");
-        }
-        cur_arg = va_arg(args, mp_int*);
-    }
-    va_end(args);
+		}
+		cur_arg = va_arg(args, mp_int*);
+	}
+	va_end(args);
+}
+
+void m_mp_alloc_init_multi(mp_int **mp, ...) 
+{
+	mp_int** cur_arg = mp;
+	va_list args;
+
+	va_start(args, mp);        /* init args to next argument from caller */
+	while (cur_arg != NULL) {
+		*cur_arg = m_malloc(sizeof(mp_int));
+		if (mp_init(*cur_arg) != MP_OKAY) {
+			dropbear_exit("Mem alloc error");
+		}
+		cur_arg = va_arg(args, mp_int**);
+	}
+	va_end(args);
+}
+
+void m_mp_free_multi(mp_int **mp, ...) 
+{
+	mp_int** cur_arg = mp;
+	va_list args;
+
+	va_start(args, mp);        /* init args to next argument from caller */
+	while (cur_arg != NULL) {
+		if (*cur_arg) {
+			mp_clear(*cur_arg);
+		}
+		m_free(*cur_arg);
+		cur_arg = va_arg(args, mp_int**);
+	}
+	va_end(args);
 }
 
 void bytes_to_mp(mp_int *mp, const unsigned char* bytes, unsigned int len) {
 
-	if (mp_read_unsigned_bin(mp, (unsigned char*)bytes, len) != MP_OKAY) {
+	if (mp_from_ubin(mp, (unsigned char*)bytes, len) != MP_OKAY) {
 		dropbear_exit("Mem alloc error");
 	}
 }
 
 /* hash the ssh representation of the mp_int mp */
-void sha1_process_mp(hash_state *hs, mp_int *mp) {
-
-	int i;
+void hash_process_mp(const struct ltc_hash_descriptor *hash_desc, 
+				hash_state *hs, mp_int *mp) {
 	buffer * buf;
 
 	buf = buf_new(512 + 20); /* max buffer is a 4096 bit key, 
 								plus header + some leeway*/
 	buf_putmpint(buf, mp);
-	i = buf->pos;
-	buf_setpos(buf, 0);
-	sha1_process(hs, buf_getptr(buf, i), i);
+	hash_desc->process(hs, buf->data, buf->len);
 	buf_free(buf);
 }

bignum.h

@@ -22,14 +22,17 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
-#ifndef _BIGNUM_H_
-#define _BIGNUM_H_
+#ifndef DROPBEAR_BIGNUM_H_
+#define DROPBEAR_BIGNUM_H_
 
-#include "includes.h"
+#include "dbhelpers.h"
 
 void m_mp_init(mp_int *mp);
-void m_mp_init_multi(mp_int *mp, ...);
+void m_mp_init_multi(mp_int *mp, ...) ATTRIB_SENTINEL;
+void m_mp_alloc_init_multi(mp_int **mp, ...) ATTRIB_SENTINEL;
+void m_mp_free_multi(mp_int **mp, ...)  ATTRIB_SENTINEL;
 void bytes_to_mp(mp_int *mp, const unsigned char* bytes, unsigned int len);
-void sha1_process_mp(hash_state *hs, mp_int *mp);
+void hash_process_mp(const struct ltc_hash_descriptor *hash_desc, 
+				hash_state *hs, mp_int *mp);
 
-#endif /* _BIGNUM_H_ */
+#endif /* DROPBEAR_BIGNUM_H_ */

buffer.c

@@ -46,17 +46,15 @@ buffer* buf_new(unsigned int size) {
 		dropbear_exit("buf->size too big");
 	}
 
-	buf = (buffer*)m_malloc(sizeof(buffer));
+	buf = (buffer*)m_malloc(sizeof(buffer)+size);
 
 	if (size > 0) {
-		buf->data = (unsigned char*)m_malloc(size);
+		buf->data = (unsigned char*)buf + sizeof(buffer);
 	} else {
 		buf->data = NULL;
 	}
 
 	buf->size = size;
-	buf->pos = 0;
-	buf->len = 0;
 
 	return buf;
 
@@ -65,12 +63,11 @@ buffer* buf_new(unsigned int size) {
 /* free the buffer's data and the buffer itself */
 void buf_free(buffer* buf) {
 
-	m_free(buf->data)
 	m_free(buf);
 }
 
 /* overwrite the contents of the buffer to clear it */
-void buf_burn(buffer* buf) {
+void buf_burn(const buffer* buf) {
 	
 	m_burn(buf->data, buf->size);
 
@@ -78,28 +75,31 @@ void buf_burn(buffer* buf) {
 
 /* resize a buffer, pos and len will be repositioned if required when
  * downsizing */
-void buf_resize(buffer *buf, unsigned int newsize) {
+buffer* buf_resize(buffer *buf, unsigned int newsize) {
 
 	if (newsize > BUF_MAX_SIZE) {
 		dropbear_exit("buf->size too big");
 	}
 
-	buf->data = m_realloc(buf->data, newsize);
+	buf = m_realloc(buf, sizeof(buffer)+newsize);
+	buf->data = (unsigned char*)buf + sizeof(buffer);
 	buf->size = newsize;
 	buf->len = MIN(newsize, buf->len);
 	buf->pos = MIN(newsize, buf->pos);
-
+	return buf;
 }
 
 /* Create a copy of buf, allocating required memory etc. */
 /* The new buffer is sized the same as the length of the source buffer. */
-buffer* buf_newcopy(buffer* buf) {
+buffer* buf_newcopy(const buffer* buf) {
 	
 	buffer* ret;
 
 	ret = buf_new(buf->len);
 	ret->len = buf->len;
-	memcpy(ret->data, buf->data, buf->len);
+	if (buf->len > 0) {
+		memcpy(ret->data, buf->data, buf->len);
+	}
 	return ret;
 }
 
@@ -109,6 +109,7 @@ void buf_setlen(buffer* buf, unsigned int len) {
 		dropbear_exit("Bad buf_setlen");
 	}
 	buf->len = len;
+	buf->pos = MIN(buf->pos, buf->len);
 }
 
 /* Increment the length of the buffer */
@@ -127,7 +128,7 @@ void buf_setpos(buffer* buf, unsigned int pos) {
 	buf->pos = pos;
 }
 
-/* increment the postion by incr, increasing the buffer length if required */
+/* increment the position by incr, increasing the buffer length if required */
 void buf_incrwritepos(buffer* buf, unsigned int incr) {
 	if (incr > BUF_MAX_INCR || buf->pos + incr > buf->size) {
 		dropbear_exit("Bad buf_incrwritepos");
@@ -141,9 +142,10 @@ void buf_incrwritepos(buffer* buf, unsigned int incr) {
 /* increment the position by incr, negative values are allowed, to
  * decrement the pos*/
 void buf_incrpos(buffer* buf,  int incr) {
-	if (incr > BUF_MAX_INCR ||
-			(unsigned int)((int)buf->pos + incr) > buf->len 
-			|| ((int)buf->pos + incr) < 0) {
+	if (incr > BUF_MAX_INCR 
+		|| incr < -BUF_MAX_INCR 
+		|| (unsigned int)((int)buf->pos + incr) > buf->len
+		|| ((int)buf->pos + incr) < 0) {
 		dropbear_exit("Bad buf_incrpos");
 	}
 	buf->pos += incr;
@@ -182,9 +184,9 @@ void buf_putbyte(buffer* buf, unsigned char val) {
 
 /* returns an in-place pointer to the buffer, checking that
  * the next len bytes from that position can be used */
-unsigned char* buf_getptr(buffer* buf, unsigned int len) {
+unsigned char* buf_getptr(const buffer* buf, unsigned int len) {
 
-	if (buf->pos + len > buf->len) {
+	if (len > BUF_MAX_INCR || buf->pos + len > buf->len) {
 		dropbear_exit("Bad buf_getptr");
 	}
 	return &buf->data[buf->pos];
@@ -192,9 +194,9 @@ unsigned char* buf_getptr(buffer* buf, unsigned int len) {
 
 /* like buf_getptr, but checks against total size, not used length.
  * This allows writing past the used length, but not past the size */
-unsigned char* buf_getwriteptr(buffer* buf, unsigned int len) {
+unsigned char* buf_getwriteptr(const buffer* buf, unsigned int len) {
 
-	if (buf->pos + len > buf->size) {
+	if (len > BUF_MAX_INCR || buf->pos + len > buf->size) {
 		dropbear_exit("Bad buf_getwriteptr");
 	}
 	return &buf->data[buf->pos];
@@ -203,10 +205,11 @@ unsigned char* buf_getwriteptr(buffer* buf, unsigned int len) {
 /* Return a null-terminated string, it is malloced, so must be free()ed
  * Note that the string isn't checked for null bytes, hence the retlen
  * may be longer than what is returned by strlen */
-unsigned char* buf_getstring(buffer* buf, unsigned int *retlen) {
+char* buf_getstring(buffer* buf, unsigned int *retlen) {
 
 	unsigned int len;
-	unsigned char* ret;
+	char* ret;
+	void* src = NULL;
 	len = buf_getint(buf);
 	if (len > MAX_STRING_LEN) {
 		dropbear_exit("String too long");
@@ -215,8 +218,9 @@ unsigned char* buf_getstring(buffer* buf, unsigned int *retlen) {
 	if (retlen != NULL) {
 		*retlen = len;
 	}
+	src = buf_getptr(buf, len);
 	ret = m_malloc(len+1);
-	memcpy(ret, buf_getptr(buf, len), len);
+	memcpy(ret, src, len);
 	buf_incrpos(buf, len);
 	ret[len] = '\0';
 
@@ -224,19 +228,37 @@ unsigned char* buf_getstring(buffer* buf, unsigned int *retlen) {
 }
 
 /* Return a string as a newly allocated buffer */
-buffer * buf_getstringbuf(buffer *buf) {
-	buffer *ret;
-	unsigned char* str;
-	unsigned int len;
-	str = buf_getstring(buf, &len);
-	ret = m_malloc(sizeof(*ret));
-	ret->data = str;
-	ret->len = len;
-	ret->size = len;
-	ret->pos = 0;
+static buffer * buf_getstringbuf_int(buffer *buf, int incllen) {
+	buffer *ret = NULL;
+	unsigned int len = buf_getint(buf);
+	int extra = 0;
+	if (len > MAX_STRING_LEN) {
+		dropbear_exit("String too long");
+	}
+	if (incllen) {
+		extra = 4;
+	}
+	ret = buf_new(len+extra);
+	if (incllen) {
+		buf_putint(ret, len);
+	}
+	memcpy(buf_getwriteptr(ret, len), buf_getptr(buf, len), len);
+	buf_incrpos(buf, len);
+	buf_incrlen(ret, len);
+	buf_setpos(ret, 0);
 	return ret;
 }
 
+/* Return a string as a newly allocated buffer */
+buffer * buf_getstringbuf(buffer *buf) {
+	return buf_getstringbuf_int(buf, 0);
+}
+
+/* Returns a string in a new buffer, including the length */
+buffer * buf_getbuf(buffer *buf) {
+	return buf_getstringbuf_int(buf, 1);
+}
+
 /* Just increment the buffer position the same as if we'd used buf_getstring,
  * but don't bother copying/malloc()ing for it */
 void buf_eatstring(buffer *buf) {
@@ -262,13 +284,18 @@ void buf_putint(buffer* buf, int unsigned val) {
 }
 
 /* put a SSH style string into the buffer, increasing buffer len if required */
-void buf_putstring(buffer* buf, const unsigned char* str, unsigned int len) {
+void buf_putstring(buffer* buf, const char* str, unsigned int len) {
 	
 	buf_putint(buf, len);
-	buf_putbytes(buf, str, len);
+	buf_putbytes(buf, (const unsigned char*)str, len);
 
 }
 
+/* puts an entire buffer as a SSH string. ignore pos of buf_str. */
+void buf_putbufstring(buffer *buf, const buffer* buf_str) {
+	buf_putstring(buf, (const char*)buf_str->data, buf_str->len);
+}
+
 /* put the set of len bytes into the buffer, incrementing the pos, increasing
  * len if required */
 void buf_putbytes(buffer *buf, const unsigned char *bytes, unsigned int len) {
@@ -280,18 +307,18 @@ void buf_putbytes(buffer *buf, const unsigned char *bytes, unsigned int len) {
 /* for our purposes we only need positive (or 0) numbers, so will
  * fail if we get negative numbers */
 void buf_putmpint(buffer* buf, mp_int * mp) {
-
+	size_t written;
 	unsigned int len, pad = 0;
-	TRACE(("enter buf_putmpint"))
+	TRACE2(("enter buf_putmpint"))
 
 	dropbear_assert(mp != NULL);
 
-	if (SIGN(mp) == MP_NEG) {
+	if (mp_isneg(mp)) {
 		dropbear_exit("negative bignum");
 	}
 
 	/* zero check */
-	if (USED(mp) == 1 && DIGIT(mp, 0) == 0) {
+	if (mp_iszero(mp)) {
 		len = 0;
 	} else {
 		/* SSH spec requires padding for mpints with the MSB set, this code
@@ -312,13 +339,13 @@ void buf_putmpint(buffer* buf, mp_int * mp) {
 		if (pad) {
 			buf_putbyte(buf, 0x00);
 		}
-		if (mp_to_unsigned_bin(mp, buf_getwriteptr(buf, len-pad)) != MP_OKAY) {
+		if (mp_to_ubin(mp, buf_getwriteptr(buf, len-pad), len-pad, &written) != MP_OKAY) {
 			dropbear_exit("mpint error");
 		}
-		buf_incrwritepos(buf, len-pad);
+		buf_incrwritepos(buf, written);
 	}
 
-	TRACE(("leave buf_putmpint"))
+	TRACE2(("leave buf_putmpint"))
 }
 
 /* Retrieve an mp_int from the buffer.
@@ -343,7 +370,7 @@ int buf_getmpint(buffer* buf, mp_int* mp) {
 		return DROPBEAR_FAILURE;
 	}
 
-	if (mp_read_unsigned_bin(mp, buf_getptr(buf, len), len) != MP_OKAY) {
+	if (mp_from_ubin(mp, buf_getptr(buf, len), len) != MP_OKAY) {
 		return DROPBEAR_FAILURE;
 	}
 

buffer.h

@@ -22,14 +22,15 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
-#ifndef _BUFFER_H_
+#ifndef DROPBEAR_BUFFER_H_
 
-#define _BUFFER_H_
+#define DROPBEAR_BUFFER_H_
 
 #include "includes.h"
 
 struct buf {
-
+	/* don't manipulate data member outside of buffer.c - it
+	is a pointer into the malloc holding buffer itself */
 	unsigned char * data;
 	unsigned int len; /* the used size */
 	unsigned int pos;
@@ -40,10 +41,11 @@ struct buf {
 typedef struct buf buffer;
 
 buffer * buf_new(unsigned int size);
-void buf_resize(buffer *buf, unsigned int newsize);
+/* Possibly returns a new buffer*, like realloc() */
+buffer * buf_resize(buffer *buf, unsigned int newsize);
 void buf_free(buffer* buf);
-void buf_burn(buffer* buf);
-buffer* buf_newcopy(buffer* buf);
+void buf_burn(const buffer* buf);
+buffer* buf_newcopy(const buffer* buf);
 void buf_setlen(buffer* buf, unsigned int len);
 void buf_incrlen(buffer* buf, unsigned int incr);
 void buf_setpos(buffer* buf, unsigned int pos);
@@ -52,16 +54,18 @@ void buf_incrwritepos(buffer* buf, unsigned int incr);
 unsigned char buf_getbyte(buffer* buf);
 unsigned char buf_getbool(buffer* buf);
 void buf_putbyte(buffer* buf, unsigned char val);
-unsigned char* buf_getptr(buffer* buf, unsigned int len);
-unsigned char* buf_getwriteptr(buffer* buf, unsigned int len);
-unsigned char* buf_getstring(buffer* buf, unsigned int *retlen);
+unsigned char* buf_getptr(const buffer* buf, unsigned int len);
+unsigned char* buf_getwriteptr(const buffer* buf, unsigned int len);
+char* buf_getstring(buffer* buf, unsigned int *retlen);
 buffer * buf_getstringbuf(buffer *buf);
+buffer * buf_getbuf(buffer *buf);
 void buf_eatstring(buffer *buf);
 void buf_putint(buffer* buf, unsigned int val);
-void buf_putstring(buffer* buf, const unsigned char* str, unsigned int len);
+void buf_putstring(buffer* buf, const char* str, unsigned int len);
+void buf_putbufstring(buffer *buf, const buffer* buf_str);
 void buf_putbytes(buffer *buf, const unsigned char *bytes, unsigned int len);
 void buf_putmpint(buffer* buf, mp_int * mp);
 int buf_getmpint(buffer* buf, mp_int* mp);
 unsigned int buf_getint(buffer* buf);
 
-#endif /* _BUFFER_H_ */
+#endif /* DROPBEAR_BUFFER_H_ */

chachapoly.c

@@ -0,0 +1,148 @@
+/*
+ * Dropbear SSH
+ * 
+ * Copyright (c) 2002,2003 Matt Johnston
+ * Copyright (c) 2020 by Vladislav Grishenko
+ * All rights reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE. */
+
+#include "includes.h"
+#include "algo.h"
+#include "dbutil.h"
+#include "chachapoly.h"
+
+#if DROPBEAR_CHACHA20POLY1305
+
+#define CHACHA20_KEY_LEN 32
+#define CHACHA20_BLOCKSIZE 8
+#define POLY1305_KEY_LEN 32
+#define POLY1305_TAG_LEN 16
+
+static const struct ltc_cipher_descriptor dummy = {.name = NULL};
+
+static const struct dropbear_hash dropbear_chachapoly_mac =
+	{NULL, POLY1305_KEY_LEN, POLY1305_TAG_LEN};
+
+const struct dropbear_cipher dropbear_chachapoly =
+	{&dummy, CHACHA20_KEY_LEN*2, CHACHA20_BLOCKSIZE};
+
+static int dropbear_chachapoly_start(int UNUSED(cipher), const unsigned char* UNUSED(IV),
+			const unsigned char *key, int keylen,
+			int UNUSED(num_rounds), dropbear_chachapoly_state *state) {
+	int err;
+
+	TRACE2(("enter dropbear_chachapoly_start"))
+
+	if (keylen != CHACHA20_KEY_LEN*2) {
+		return CRYPT_ERROR;
+	}
+
+	if ((err = chacha_setup(&state->chacha, key,
+				CHACHA20_KEY_LEN, 20)) != CRYPT_OK) {
+		return err;
+	}
+
+	if ((err = chacha_setup(&state->header, key + CHACHA20_KEY_LEN,
+				CHACHA20_KEY_LEN, 20) != CRYPT_OK)) {
+		return err;
+	}
+
+	TRACE2(("leave dropbear_chachapoly_start"))
+	return CRYPT_OK;
+}
+
+static int dropbear_chachapoly_crypt(unsigned int seq,
+			const unsigned char *in, unsigned char *out,
+			unsigned long len, unsigned long taglen,
+			dropbear_chachapoly_state *state, int direction) {
+	poly1305_state poly;
+	unsigned char seqbuf[8], key[POLY1305_KEY_LEN], tag[POLY1305_TAG_LEN];
+	int err;
+
+	TRACE2(("enter dropbear_chachapoly_crypt"))
+
+	if (len < 4 || taglen != POLY1305_TAG_LEN) {
+		return CRYPT_ERROR;
+	}
+
+	STORE64H((uint64_t)seq, seqbuf);
+	chacha_ivctr64(&state->chacha, seqbuf, sizeof(seqbuf), 0);
+	if ((err = chacha_keystream(&state->chacha, key, sizeof(key))) != CRYPT_OK) {
+		return err;
+	}
+
+	poly1305_init(&poly, key, sizeof(key));
+	if (direction == LTC_DECRYPT) {
+		poly1305_process(&poly, in, len);
+		poly1305_done(&poly, tag, &taglen);
+		if (constant_time_memcmp(in + len, tag, taglen) != 0) {
+			return CRYPT_ERROR;
+		}
+	}
+
+	chacha_ivctr64(&state->header, seqbuf, sizeof(seqbuf), 0);
+	if ((err = chacha_crypt(&state->header, in, 4, out)) != CRYPT_OK) {
+		return err;
+	}
+
+	chacha_ivctr64(&state->chacha, seqbuf, sizeof(seqbuf), 1);
+	if ((err = chacha_crypt(&state->chacha, in + 4, len - 4, out + 4)) != CRYPT_OK) {
+		return err;
+	}
+
+	if (direction == LTC_ENCRYPT) {
+		poly1305_process(&poly, out, len);
+		poly1305_done(&poly, out + len, &taglen);
+	}
+
+	TRACE2(("leave dropbear_chachapoly_crypt"))
+	return CRYPT_OK;
+}
+
+static int dropbear_chachapoly_getlength(unsigned int seq,
+			const unsigned char *in, unsigned int *outlen,
+			unsigned long len, dropbear_chachapoly_state *state) {
+	unsigned char seqbuf[8], buf[4];
+	int err;
+
+	TRACE2(("enter dropbear_chachapoly_getlength"))
+
+	if (len < sizeof(buf)) {
+		return CRYPT_ERROR;
+	}
+
+	STORE64H((uint64_t)seq, seqbuf);
+	chacha_ivctr64(&state->header, seqbuf, sizeof(seqbuf), 0);
+	if ((err = chacha_crypt(&state->header, in, sizeof(buf), buf)) != CRYPT_OK) {
+		return err;
+	}
+
+	LOAD32H(*outlen, buf);
+
+	TRACE2(("leave dropbear_chachapoly_getlength"))
+	return CRYPT_OK;
+}
+
+const struct dropbear_cipher_mode dropbear_mode_chachapoly =
+	{(void *)dropbear_chachapoly_start, NULL, NULL,
+	 (void *)dropbear_chachapoly_crypt,
+	 (void *)dropbear_chachapoly_getlength, &dropbear_chachapoly_mac};
+
+#endif /* DROPBEAR_CHACHA20POLY1305 */

chachapoly.h

@@ -0,0 +1,44 @@
+/*
+ * Dropbear SSH
+ * 
+ * Copyright (c) 2002,2003 Matt Johnston
+ * Copyright (c) 2020 by Vladislav Grishenko
+ * All rights reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE. */
+
+#ifndef DROPBEAR_DROPBEAR_CHACHAPOLY_H_
+#define DROPBEAR_DROPBEAR_CHACHAPOLY_H_
+
+#include "includes.h"
+#include "algo.h"
+
+#if DROPBEAR_CHACHA20POLY1305
+
+typedef struct {
+	chacha_state chacha;
+	chacha_state header;
+} dropbear_chachapoly_state;
+
+extern const struct dropbear_cipher dropbear_chachapoly;
+extern const struct dropbear_cipher_mode dropbear_mode_chachapoly;
+
+#endif /* DROPBEAR_CHACHA20POLY1305 */
+
+#endif /* DROPBEAR_DROPBEAR_CHACHAPOLY_H_ */

channel.h

@@ -22,21 +22,13 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
-#ifndef _CHANNEL_H_
-#define _CHANNEL_H_
+#ifndef DROPBEAR_CHANNEL_H_
+#define DROPBEAR_CHANNEL_H_
 
 #include "includes.h"
 #include "buffer.h"
 #include "circbuffer.h"
 
-/* channel->type values */
-#define CHANNEL_ID_NONE 0
-#define CHANNEL_ID_SESSION 1
-#define CHANNEL_ID_X11 2
-#define CHANNEL_ID_AGENT 3
-#define CHANNEL_ID_TCPDIRECT 4
-#define CHANNEL_ID_TCPFORWARDED 5
-
 #define SSH_OPEN_ADMINISTRATIVELY_PROHIBITED    1
 #define SSH_OPEN_CONNECT_FAILED                 2
 #define SSH_OPEN_UNKNOWN_CHANNEL_TYPE           3
@@ -49,6 +41,13 @@
 
 struct ChanType;
 
+enum dropbear_channel_prio {
+	DROPBEAR_CHANNEL_PRIO_INTERACTIVE, /* pty shell, x11 */
+	DROPBEAR_CHANNEL_PRIO_UNKNOWABLE, /* tcp - can't know what's being forwarded */
+	DROPBEAR_CHANNEL_PRIO_BULK, /* the rest - probably scp or something */
+	DROPBEAR_CHANNEL_PRIO_EARLY, /* channel is still being set up */
+};
+
 struct Channel {
 
 	unsigned int index; /* the local channel index */
@@ -61,7 +60,8 @@ struct Channel {
 	int readfd; /* read from insecure side, written to wire */
 	int errfd; /* used like writefd or readfd, depending if it's client or server.
 				  Doesn't exactly belong here, but is cleaner here */
-	circbuffer *writebuf; /* data from the wire, for local consumption */
+	circbuffer *writebuf; /* data from the wire, for local consumption. Can be
+							 initially NULL */
 	circbuffer *extrabuf; /* extended-data for the program - used like writebuf
 					     but for stderr */
 
@@ -69,6 +69,7 @@ struct Channel {
 	int sent_close, recv_close;
 	int recv_eof, sent_eof;
 
+	struct dropbear_progress_connection *conn_pending;
 	int initconn; /* used for TCP forwarding, whether the channel has been
 					 fully initialised */
 
@@ -78,51 +79,69 @@ struct Channel {
 
 	int flushing;
 
+	/* Used by client chansession to handle ~ escaping, NULL ignored otherwise */
+	void (*read_mangler)(const struct Channel*, const unsigned char* bytes, int *len);
+
 	const struct ChanType* type;
 
+	enum dropbear_channel_prio prio;
 };
 
 struct ChanType {
 
-	int sepfds; /* Whether this channel has seperate pipes for in/out or not */
-	char *name;
+	int sepfds; /* Whether this channel has separate pipes for in/out or not */
+	const char *name;
+	/* Sets up the channel */
 	int (*inithandler)(struct Channel*);
-	int (*check_close)(struct Channel*);
+	/* Called to check whether a channel should close, separately from the FD being closed.
+	Used for noticing process exiting */
+	int (*check_close)(const struct Channel*);
+	/* Handler for ssh_msg_channel_request */
 	void (*reqhandler)(struct Channel*);
-	void (*closehandler)(struct Channel*);
-
+	/* Called prior to sending ssh_msg_channel_close, used for sending exit status */
+	void (*closehandler)(const struct Channel*);
+	/* Frees resources, called just prior to channel being removed */
+	void (*cleanup)(const struct Channel*);
 };
 
-void chaninitialise(const struct ChanType *chantypes[]);
-void chancleanup();
-void setchannelfds(fd_set *readfd, fd_set *writefd);
-void channelio(fd_set *readfd, fd_set *writefd);
-struct Channel* getchannel();
-struct Channel* newchannel(unsigned int remotechan, 
-		const struct ChanType *type, 
-		unsigned int transwindow, unsigned int transmaxpacket);
+/* Callback for connect_remote */
+void channel_connect_done(int result, int sock, void* user_data, const char* errstring);
 
-void recv_msg_channel_open();
-void recv_msg_channel_request();
-void send_msg_channel_failure(struct Channel *channel);
-void send_msg_channel_success(struct Channel *channel);
-void recv_msg_channel_data();
-void recv_msg_channel_extended_data();
-void recv_msg_channel_window_adjust();
-void recv_msg_channel_close();
-void recv_msg_channel_eof();
+void chaninitialise(const struct ChanType *chantypes[]);
+void chancleanup(void);
+void setchannelfds(fd_set *readfds, fd_set *writefds, int allow_reads);
+void channelio(const fd_set *readfd, const fd_set *writefd);
+struct Channel* getchannel(void);
+/* Returns an arbitrary channel that is in a ready state - not
+being initialised and no EOF in either direction. NULL if none. */
+struct Channel* get_any_ready_channel(void);
+
+void recv_msg_channel_open(void);
+void recv_msg_channel_request(void);
+void send_msg_channel_failure(const struct Channel *channel);
+void send_msg_channel_success(const struct Channel *channel);
+void recv_msg_channel_data(void);
+void recv_msg_channel_extended_data(void);
+void recv_msg_channel_window_adjust(void);
+void recv_msg_channel_close(void);
+void recv_msg_channel_eof(void);
 
 void common_recv_msg_channel_data(struct Channel *channel, int fd, 
 		circbuffer * buf);
 
-#ifdef DROPBEAR_CLIENT
+#if DROPBEAR_CLIENT
 extern const struct ChanType clichansess;
 #endif
 
-#if defined(USING_LISTENERS) || defined(DROPBEAR_CLIENT)
+#if DROPBEAR_LISTENERS || DROPBEAR_CLIENT
 int send_msg_channel_open_init(int fd, const struct ChanType *type);
-void recv_msg_channel_open_confirmation();
-void recv_msg_channel_open_failure();
+void recv_msg_channel_open_confirmation(void);
+void recv_msg_channel_open_failure(void);
 #endif
+void start_send_channel_request(const struct Channel *channel, const char *type);
 
-#endif /* _CHANNEL_H_ */
+void send_msg_request_success(void);
+void send_msg_request_failure(void);
+
+
+#endif /* DROPBEAR_CHANNEL_H_ */

chansession.h

@@ -22,8 +22,8 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
-#ifndef _CHANSESSION_H_
-#define _CHANSESSION_H_
+#ifndef DROPBEAR_CHANSESSION_H_
+#define DROPBEAR_CHANSESSION_H_
 
 #include "loginrec.h"
 #include "channel.h"
@@ -39,23 +39,29 @@ struct exitinfo {
 
 struct ChanSess {
 
-	unsigned char * cmd; /* command to exec */
+	char * cmd; /* command to exec */
 	pid_t pid; /* child process pid */
+	/* command that was sent by the client, if authorized_keys command= or
+	dropbear -c was used */
+	char *original_command;
 
 	/* pty details */
 	int master; /* the master terminal fd*/
 	int slave;
-	unsigned char * tty;
-	unsigned char * term;
+	char * tty;
+	char * term;
 
 	/* exit details */
 	struct exitinfo exit;
 
-	/* Used to set $SSH_CONNECTION in the child session. 
-	Is only set temporarily before forking */
+
+	/* These are only set temporarily before forking */
+	/* Used to set $SSH_CONNECTION in the child session.  */
 	char *connection_string;
+	/* Used to set $SSH_CLIENT in the child session. */
+	char *client_string;
 	
-#ifndef DISABLE_X11FWD
+#if DROPBEAR_X11FWD
 	struct Listener * x11listener;
 	int x11port;
 	char * x11authprot;
@@ -64,7 +70,7 @@ struct ChanSess {
 	unsigned char x11singleconn;
 #endif
 
-#ifdef ENABLE_SVR_AGENTFWD
+#if DROPBEAR_SVR_AGENTFWD
 	struct Listener * agentlistener;
 	char * agentfile;
 	char * agentdir;
@@ -79,15 +85,15 @@ struct ChildPid {
 
 void addnewvar(const char* param, const char* var);
 
-void cli_send_chansess_request();
-void cli_tty_cleanup();
-void cli_chansess_winchange();
-#ifdef ENABLE_CLI_NETCAT
-void cli_send_netcat_request();
+void cli_send_chansess_request(void);
+void cli_tty_cleanup(void);
+void cli_chansess_winchange(void);
+#if DROPBEAR_CLI_NETCAT
+void cli_send_netcat_request(void);
 #endif
-void cli_start_send_channel_request(struct Channel *channel, unsigned char *type);
 
-void svr_chansessinitialise();
+void svr_chansessinitialise(void);
+void svr_chansess_checksignal(void);
 extern const struct ChanType svrchansess;
 
 struct SigMap {
@@ -97,4 +103,4 @@ struct SigMap {
 
 extern const struct SigMap signames[];
 
-#endif /* _CHANSESSION_H_ */
+#endif /* DROPBEAR_CHANSESSION_H_ */

circbuffer.c

@@ -37,7 +37,8 @@ circbuffer * cbuf_new(unsigned int size) {
 	}
 
 	cbuf = (circbuffer*)m_malloc(sizeof(circbuffer));
-	cbuf->data = (unsigned char*)m_malloc(size);
+	/* data is malloced on first write */
+	cbuf->data = NULL;
 	cbuf->used = 0;
 	cbuf->readpos = 0;
 	cbuf->writepos = 0;
@@ -48,40 +49,26 @@ circbuffer * cbuf_new(unsigned int size) {
 
 void cbuf_free(circbuffer * cbuf) {
 
-	m_free(cbuf->data);
+	if (cbuf->data) {
+		m_burn(cbuf->data, cbuf->size);
+		m_free(cbuf->data);
+	}
 	m_free(cbuf);
 }
 
-unsigned int cbuf_getused(circbuffer * cbuf) {
+unsigned int cbuf_getused(const circbuffer * cbuf) {
 
 	return cbuf->used;
 
 }
 
-unsigned int cbuf_getavail(circbuffer * cbuf) {
+unsigned int cbuf_getavail(const circbuffer * cbuf) {
 
 	return cbuf->size - cbuf->used;
 
 }
 
-unsigned int cbuf_readlen(circbuffer *cbuf) {
-
-	dropbear_assert(((2*cbuf->size)+cbuf->writepos-cbuf->readpos)%cbuf->size == cbuf->used%cbuf->size);
-	dropbear_assert(((2*cbuf->size)+cbuf->readpos-cbuf->writepos)%cbuf->size == (cbuf->size-cbuf->used)%cbuf->size);
-
-	if (cbuf->used == 0) {
-		TRACE(("cbuf_readlen: unused buffer"))
-		return 0;
-	}
-
-	if (cbuf->readpos < cbuf->writepos) {
-		return cbuf->writepos - cbuf->readpos;
-	}
-
-	return cbuf->size - cbuf->readpos;
-}
-
-unsigned int cbuf_writelen(circbuffer *cbuf) {
+unsigned int cbuf_writelen(const circbuffer *cbuf) {
 
 	dropbear_assert(cbuf->used <= cbuf->size);
 	dropbear_assert(((2*cbuf->size)+cbuf->writepos-cbuf->readpos)%cbuf->size == cbuf->used%cbuf->size);
@@ -99,12 +86,19 @@ unsigned int cbuf_writelen(circbuffer *cbuf) {
 	return cbuf->size - cbuf->writepos;
 }
 
-unsigned char* cbuf_readptr(circbuffer *cbuf, unsigned int len) {
-	if (len > cbuf_readlen(cbuf)) {
-		dropbear_exit("Bad cbuf read");
-	}
+void cbuf_readptrs(const circbuffer *cbuf,
+	unsigned char **p1, unsigned int *len1, 
+	unsigned char **p2, unsigned int *len2) {
+	*p1 = &cbuf->data[cbuf->readpos];
+	*len1 = MIN(cbuf->used, cbuf->size - cbuf->readpos);
 
-	return &cbuf->data[cbuf->readpos];
+	if (*len1 < cbuf->used) {
+		*p2 = cbuf->data;
+		*len2 = cbuf->used - *len1;
+	} else {
+		*p2 = NULL;
+		*len2 = 0;
+	}
 }
 
 unsigned char* cbuf_writeptr(circbuffer *cbuf, unsigned int len) {
@@ -113,6 +107,11 @@ unsigned char* cbuf_writeptr(circbuffer *cbuf, unsigned int len) {
 		dropbear_exit("Bad cbuf write");
 	}
 
+	if (!cbuf->data) {
+		/* lazy allocation */
+		cbuf->data = (unsigned char*)m_malloc(cbuf->size);
+	}
+
 	return &cbuf->data[cbuf->writepos];
 }
 
@@ -128,10 +127,6 @@ void cbuf_incrwrite(circbuffer *cbuf, unsigned int len) {
 
 
 void cbuf_incrread(circbuffer *cbuf, unsigned int len) {
-	if (len > cbuf_readlen(cbuf)) {
-		dropbear_exit("Bad cbuf read");
-	}
-
 	dropbear_assert(cbuf->used >= len);
 	cbuf->used -= len;
 	cbuf->readpos = (cbuf->readpos + len) % cbuf->size;

circbuffer.h

@@ -22,8 +22,8 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
-#ifndef _CIRCBUFFER_H_
-#define _CIRCBUFFER_H_
+#ifndef DROPBEAR_CIRCBUFFER_H_
+#define DROPBEAR_CIRCBUFFER_H_
 struct circbuf {
 
 	unsigned int size;
@@ -38,12 +38,14 @@ typedef struct circbuf circbuffer;
 circbuffer * cbuf_new(unsigned int size);
 void cbuf_free(circbuffer * cbuf);
 
-unsigned int cbuf_getused(circbuffer * cbuf); /* how much data stored */
-unsigned int cbuf_getavail(circbuffer * cbuf); /* how much we can write */
-unsigned int cbuf_readlen(circbuffer *cbuf); /* max linear read len */
-unsigned int cbuf_writelen(circbuffer *cbuf); /* max linear write len */
+unsigned int cbuf_getused(const circbuffer * cbuf); /* how much data stored */
+unsigned int cbuf_getavail(const circbuffer * cbuf); /* how much we can write */
+unsigned int cbuf_writelen(const circbuffer *cbuf); /* max linear write len */
 
-unsigned char* cbuf_readptr(circbuffer *cbuf, unsigned int len);
+/* returns pointers to the two portions of the circular buffer that can be read */
+void cbuf_readptrs(const circbuffer *cbuf,
+	unsigned char **p1, unsigned int *len1, 
+	unsigned char **p2, unsigned int *len2);
 unsigned char* cbuf_writeptr(circbuffer *cbuf, unsigned int len);
 void cbuf_incrwrite(circbuffer *cbuf, unsigned int len);
 void cbuf_incrread(circbuffer *cbuf, unsigned int len);

cli-agentfwd.c

@@ -24,7 +24,7 @@
 
 #include "includes.h"
 
-#ifdef ENABLE_CLI_AGENTFWD
+#if DROPBEAR_CLI_AGENTFWD
 
 #include "agentfwd.h"
 #include "session.h"
@@ -34,7 +34,7 @@
 #include "channel.h"
 #include "packet.h"
 #include "buffer.h"
-#include "random.h"
+#include "dbrandom.h"
 #include "listener.h"
 #include "runopts.h"
 #include "atomicio.h"
@@ -52,6 +52,7 @@ const struct ChanType cli_chan_agent = {
 	new_agent_chan,
 	NULL,
 	NULL,
+	NULL,
 	NULL
 };
 
@@ -73,8 +74,8 @@ static int connect_agent() {
 	return fd;
 }
 
-// handle a request for a connection to the locally running ssh-agent
-// or forward.
+/* handle a request for a connection to the locally running ssh-agent
+   or forward. */
 static int new_agent_chan(struct Channel * channel) {
 
 	int fd = -1;
@@ -83,7 +84,7 @@ static int new_agent_chan(struct Channel * channel) {
 		return SSH_OPEN_ADMINISTRATIVELY_PROHIBITED;
 
 	fd = connect_agent();
-	if (cli_opts.agent_fd < 0) {
+	if (fd < 0) {
 		return SSH_OPEN_CONNECT_FAILED;
 	}
 
@@ -94,7 +95,6 @@ static int new_agent_chan(struct Channel * channel) {
 	channel->readfd = fd;
 	channel->writefd = fd;
 
-	// success
 	return 0;
 }
 
@@ -109,7 +109,7 @@ static int new_agent_chan(struct Channel * channel) {
    data        Any data, depending on packet type.  Encoding as in the ssh packet
                protocol.
 */
-static buffer * agent_request(unsigned char type, buffer *data) {
+static buffer * agent_request(unsigned char type, const buffer *data) {
 
 	buffer * payload = NULL;
 	buffer * inbuf = NULL;
@@ -131,7 +131,7 @@ static buffer * agent_request(unsigned char type, buffer *data) {
 	}
 	buf_setpos(payload, 0);
 
-	ret = atomicio(write, fd, buf_getptr(payload, payload->len), payload->len);
+	ret = atomicio(vwrite, fd, buf_getptr(payload, payload->len), payload->len);
 	if ((size_t)ret != payload->len) {
 		TRACE(("write failed fd %d for agent_request, %s", fd, strerror(errno)))
 		goto out;
@@ -156,9 +156,7 @@ static buffer * agent_request(unsigned char type, buffer *data) {
 		goto out;
 	}
 	
-	TRACE(("agent_request readlen is %d", readlen))
-
-	buf_resize(inbuf, readlen);
+	inbuf = buf_resize(inbuf, readlen);
 	buf_setpos(inbuf, 0);
 	ret = atomicio(read, fd, buf_getwriteptr(inbuf, readlen), readlen);
 	if ((size_t)ret != readlen) {
@@ -167,7 +165,6 @@ static buffer * agent_request(unsigned char type, buffer *data) {
 	}
 	buf_incrwritepos(inbuf, readlen);
 	buf_setpos(inbuf, 0);
-	TRACE(("agent_request success, length %d", readlen))
 
 out:
 	if (payload)
@@ -205,7 +202,7 @@ static void agent_get_key_list(m_list * ret_list)
 	num = buf_getint(inbuf);
 	for (i = 0; i < num; i++) {
 		sign_key * pubkey = NULL;
-		int key_type = DROPBEAR_SIGNKEY_ANY;
+		enum signkey_type key_type = DROPBEAR_SIGNKEY_ANY;
 		buffer * key_buf;
 
 		/* each public key is encoded as a string */
@@ -214,13 +211,14 @@ static void agent_get_key_list(m_list * ret_list)
 		ret = buf_get_pub_key(key_buf, pubkey, &key_type);
 		buf_free(key_buf);
 		if (ret != DROPBEAR_SUCCESS) {
-			/* This is slack, properly would cleanup vars etc */
-			dropbear_exit("Bad pubkey received from agent");
-		}
-		pubkey->type = key_type;
-		pubkey->source = SIGNKEY_SOURCE_AGENT;
+			TRACE(("Skipping bad/unknown type pubkey from agent"));
+			sign_key_free(pubkey);
+		} else {
+			pubkey->type = key_type;
+			pubkey->source = SIGNKEY_SOURCE_AGENT;
 
-		list_append(ret_list, pubkey);
+			list_append(ret_list, pubkey);
+		}
 
 		/* We'll ignore the comment for now. might want it later.*/
 		buf_eatstring(inbuf);
@@ -233,12 +231,12 @@ out:
 	}
 }
 
-void cli_setup_agent(struct Channel *channel) {
+void cli_setup_agent(const struct Channel *channel) {
 	if (!getenv("SSH_AUTH_SOCK")) {
 		return;
 	}
 	
-	cli_start_send_channel_request(channel, "auth-agent-req@openssh.com");
+	start_send_channel_request(channel, "auth-agent-req@openssh.com");
 	/* Don't want replies */
 	buf_putbyte(ses.writepayload, 0);
 	encrypt_packet();
@@ -257,11 +255,12 @@ void cli_load_agent_keys(m_list *ret_list) {
 }
 
 void agent_buf_sign(buffer *sigblob, sign_key *key, 
-		const unsigned char *data, unsigned int len) {
-	buffer *request_data = buf_new(MAX_PUBKEY_SIZE + len + 12);
-	buffer *response;
-	unsigned int keylen, siglen;
+		const buffer *data_buf, enum signature_type sigtype) {
+	buffer *request_data = NULL;
+	buffer *response = NULL;
+	unsigned int siglen;
 	int packet_type;
+	int flags = 0;
 	
 	/* Request format
 	byte			SSH2_AGENTC_SIGN_REQUEST
@@ -269,19 +268,18 @@ void agent_buf_sign(buffer *sigblob, sign_key *key,
 	string			data
 	uint32			flags
 	*/
-	/* We write the key, then figure how long it was and write that */
-	//buf_putint(request_data, 0);
+	request_data = buf_new(MAX_PUBKEY_SIZE + data_buf->len + 12);
 	buf_put_pub_key(request_data, key, key->type);
-	keylen = request_data->len - 4;
-	//buf_setpos(request_data, 0);
-	//buf_putint(request_data, keylen);
 	
-	//buf_setpos(request_data, request_data->len);
-	buf_putstring(request_data, data, len);
-	buf_putint(request_data, 0);
+	buf_putbufstring(request_data, data_buf);
+#if DROPBEAR_RSA_SHA256
+	if (sigtype == DROPBEAR_SIGNATURE_RSA_SHA256) {
+		flags |= SSH_AGENT_RSA_SHA2_256;
+	}
+#endif
+	buf_putint(request_data, flags);
 	
 	response = agent_request(SSH2_AGENTC_SIGN_REQUEST, request_data);
-	buf_free(request_data);
 	
 	if (!response) {
 		goto fail;
@@ -298,14 +296,21 @@ void agent_buf_sign(buffer *sigblob, sign_key *key,
 	*/
 	siglen = buf_getint(response);
 	buf_putbytes(sigblob, buf_getptr(response, siglen), siglen);
-	buf_free(response);
+	goto cleanup;
 	
-	return;
 fail:
 	/* XXX don't fail badly here. instead propagate a failure code back up to
 	   the cli auth pubkey code, and just remove this key from the list of 
 	   ones to try. */
 	dropbear_exit("Agent failed signing key");
+
+cleanup:
+	if (request_data) {
+		buf_free(request_data);
+	}
+	if (response) {
+		buf_free(response);
+	}
 }
 
 #endif

cli-algo.c

@@ -1,99 +0,0 @@
-/*
- * Dropbear - a SSH2 server
- * SSH client implementation
- * 
- * Copyright (c) 2002,2003 Matt Johnston
- * Copyright (c) 2004 by Mihnea Stoenescu
- * All rights reserved.
- * 
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- * 
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- * 
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE. */
-
-#include "algo.h"
-#include "dbutil.h"
-
-
-/*
- * The chosen [encryption | MAC | compression] algorithm to each 
- * direction MUST be the first algorithm  on the client's list
- * that is also on the server's list.
- */
-algo_type * cli_buf_match_algo(buffer* buf, algo_type localalgos[],
-		int *goodguess) {
-
-	unsigned char * algolist = NULL;
-	unsigned char * remotealgos[MAX_PROPOSED_ALGO];
-	unsigned int len;
-	unsigned int count, i, j;
-	algo_type * ret = NULL;
-
-	*goodguess = 0;
-
-	/* get the comma-separated list from the buffer ie "algo1,algo2,algo3" */
-	algolist = buf_getstring(buf, &len);
-	TRACE(("cli_buf_match_algo: %s", algolist))
-	if (len > MAX_PROPOSED_ALGO*(MAX_NAME_LEN+1)) {
-		goto out; /* just a sanity check, no other use */
-	}
-
-	/* remotealgos will contain a list of the strings parsed out */
-	/* We will have at least one string (even if it's just "") */
-	remotealgos[0] = algolist;
-	count = 1;
-	/* Iterate through, replacing ','s with NULs, to split it into
-	 * words. */
-	for (i = 0; i < len; i++) {
-		if (algolist[i] == '\0') {
-			/* someone is trying something strange */
-			goto out;
-		}
-		if (algolist[i] == ',') {
-			algolist[i] = '\0';
-			remotealgos[count] = &algolist[i+1];
-			count++;
-		}
-		if (count == MAX_PROPOSED_ALGO) {
-			break;
-		}
-	}
-
-	/* iterate and find the first match */
-
-	for (j = 0; localalgos[j].name != NULL; j++) {
-		if (localalgos[j].usable) {
-		len = strlen(localalgos[j].name);
-			for (i = 0; i < count; i++) {
-				if (len == strlen(remotealgos[i]) 
-						&& strncmp(localalgos[j].name, 
-							remotealgos[i], len) == 0) {
-					if (i == 0 && j == 0) {
-						/* was a good guess */
-						*goodguess = 1;
-					}
-					ret = &localalgos[j];
-					goto out;
-				}
-			}
-		}
-	}
-
-out:
-	m_free(algolist);
-	return ret;
-}
-

cli-auth.c

@@ -40,28 +40,47 @@ void cli_authinitialise() {
 
 /* Send a "none" auth request to get available methods */
 void cli_auth_getmethods() {
-
 	TRACE(("enter cli_auth_getmethods"))
-
 	CHECKCLEARTOWRITE();
-
 	buf_putbyte(ses.writepayload, SSH_MSG_USERAUTH_REQUEST);
-	buf_putstring(ses.writepayload, cli_opts.username, 
+	buf_putstring(ses.writepayload, cli_opts.username,
 			strlen(cli_opts.username));
-	buf_putstring(ses.writepayload, SSH_SERVICE_CONNECTION, 
+	buf_putstring(ses.writepayload, SSH_SERVICE_CONNECTION,
 			SSH_SERVICE_CONNECTION_LEN);
 	buf_putstring(ses.writepayload, "none", 4); /* 'none' method */
 
 	encrypt_packet();
-	TRACE(("leave cli_auth_getmethods"))
 
+#if DROPBEAR_CLI_IMMEDIATE_AUTH
+	/* We can't haven't two auth requests in-flight with delayed zlib mode
+	since if the first one succeeds then the remote side will 
+	expect the second one to be compressed. 
+	Race described at
+	http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/zlib-openssh.html
+	*/
+	if (ses.keys->trans.algo_comp != DROPBEAR_COMP_ZLIB_DELAY) {
+		ses.authstate.authtypes = AUTH_TYPE_PUBKEY;
+#if DROPBEAR_USE_PASSWORD_ENV
+		if (getenv(DROPBEAR_PASSWORD_ENV)) {
+			ses.authstate.authtypes |= AUTH_TYPE_PASSWORD | AUTH_TYPE_INTERACT;
+		}
+#endif
+		if (cli_auth_try() == DROPBEAR_SUCCESS) {
+			TRACE(("skipped initial none auth query"))
+			/* Note that there will be two auth responses in-flight */
+			cli_ses.ignore_next_auth_response = 1;
+		}
+	}
+#endif
+	TRACE(("leave cli_auth_getmethods"))
 }
 
 void recv_msg_userauth_banner() {
 
-	unsigned char* banner = NULL;
+	char* banner = NULL;
 	unsigned int bannerlen;
 	unsigned int i, linecount;
+	int truncated = 0;
 
 	TRACE(("enter recv_msg_userauth_banner"))
 	if (ses.authstate.authdone) {
@@ -74,26 +93,29 @@ void recv_msg_userauth_banner() {
 
 	if (bannerlen > MAX_BANNER_SIZE) {
 		TRACE(("recv_msg_userauth_banner: bannerlen too long: %d", bannerlen))
-		goto out;
-	}
+		truncated = 1;
+	} else {
+		cleantext(banner);
 
-	cleantext(banner);
-
-	/* Limit to 25 lines */
-	linecount = 1;
-	for (i = 0; i < bannerlen; i++) {
-		if (banner[i] == '\n') {
-			if (linecount >= MAX_BANNER_LINES) {
-				banner[i] = '\0';
-				break;
+		/* Limit to 24 lines */
+		linecount = 1;
+		for (i = 0; i < bannerlen; i++) {
+			if (banner[i] == '\n') {
+				if (linecount >= MAX_BANNER_LINES) {
+					banner[i] = '\0';
+					truncated = 1;
+					break;
+				}
+				linecount++;
 			}
-			linecount++;
 		}
+		fprintf(stderr, "%s\n", banner);
 	}
 
-	fprintf(stderr, "%s\n", banner);
+	if (truncated) {
+		fprintf(stderr, "[Banner from the server is too long]\n");
+	}
 
-out:
 	m_free(banner);
 	TRACE(("leave recv_msg_userauth_banner"))
 }
@@ -105,21 +127,21 @@ out:
  * SSH_MSG_USERAUTH_INFO_REQUEST. */
 void recv_msg_userauth_specific_60() {
 
-#ifdef ENABLE_CLI_PUBKEY_AUTH
+#if DROPBEAR_CLI_PUBKEY_AUTH
 	if (cli_ses.lastauthtype == AUTH_TYPE_PUBKEY) {
 		recv_msg_userauth_pk_ok();
 		return;
 	}
 #endif
 
-#ifdef ENABLE_CLI_INTERACT_AUTH
+#if DROPBEAR_CLI_INTERACT_AUTH
 	if (cli_ses.lastauthtype == AUTH_TYPE_INTERACT) {
 		recv_msg_userauth_info_request();
 		return;
 	}
 #endif
 
-#ifdef ENABLE_CLI_PASSWORD_AUTH
+#if DROPBEAR_CLI_PASSWORD_AUTH
 	if (cli_ses.lastauthtype == AUTH_TYPE_PASSWORD) {
 		/* Eventually there could be proper password-changing
 		 * support. However currently few servers seem to
@@ -135,8 +157,8 @@ void recv_msg_userauth_specific_60() {
 
 void recv_msg_userauth_failure() {
 
-	unsigned char * methods = NULL;
-	unsigned char * tok = NULL;
+	char * methods = NULL;
+	char * tok = NULL;
 	unsigned int methlen = 0;
 	unsigned int partial = 0;
 	unsigned int i = 0;
@@ -144,31 +166,46 @@ void recv_msg_userauth_failure() {
 	TRACE(("<- MSG_USERAUTH_FAILURE"))
 	TRACE(("enter recv_msg_userauth_failure"))
 
+	if (ses.authstate.authdone) {
+		TRACE(("leave recv_msg_userauth_failure, already authdone."))
+		return;
+	}
+
 	if (cli_ses.state != USERAUTH_REQ_SENT) {
 		/* Perhaps we should be more fatal? */
 		dropbear_exit("Unexpected userauth failure");
 	}
 
-#ifdef ENABLE_CLI_PUBKEY_AUTH
-	/* If it was a pubkey auth request, we should cross that key 
-	 * off the list. */
-	if (cli_ses.lastauthtype == AUTH_TYPE_PUBKEY) {
-		cli_pubkeyfail();
-	}
+	/* When DROPBEAR_CLI_IMMEDIATE_AUTH is set there will be an initial response for 
+	the "none" auth request, and then a response to the immediate auth request. 
+	We need to be careful handling them. */
+	if (cli_ses.ignore_next_auth_response) {
+		cli_ses.state = USERAUTH_REQ_SENT;
+		cli_ses.ignore_next_auth_response = 0;
+		TRACE(("leave recv_msg_userauth_failure, ignored response, state set to USERAUTH_REQ_SENT"));
+		return;
+	} else  {
+#if DROPBEAR_CLI_PUBKEY_AUTH
+		/* If it was a pubkey auth request, we should cross that key 
+		 * off the list. */
+		if (cli_ses.lastauthtype == AUTH_TYPE_PUBKEY) {
+			cli_pubkeyfail();
+		}
 #endif
 
-#ifdef ENABLE_CLI_INTERACT_AUTH
-	/* If we get a failure message for keyboard interactive without
-	 * receiving any request info packet, then we don't bother trying
-	 * keyboard interactive again */
-	if (cli_ses.lastauthtype == AUTH_TYPE_INTERACT
-			&& !cli_ses.interact_request_received) {
-		TRACE(("setting auth_interact_failed = 1"))
-		cli_ses.auth_interact_failed = 1;
-	}
+#if DROPBEAR_CLI_INTERACT_AUTH
+		/* If we get a failure message for keyboard interactive without
+		 * receiving any request info packet, then we don't bother trying
+		 * keyboard interactive again */
+		if (cli_ses.lastauthtype == AUTH_TYPE_INTERACT
+				&& !cli_ses.interact_request_received) {
+			TRACE(("setting auth_interact_failed = 1"))
+			cli_ses.auth_interact_failed = 1;
+		}
 #endif
-
-	cli_ses.lastauthtype = AUTH_TYPE_NONE;
+		cli_ses.state = USERAUTH_FAIL_RCVD;
+		cli_ses.lastauthtype = AUTH_TYPE_NONE;
+	}
 
 	methods = buf_getstring(ses.payload, &methlen);
 
@@ -196,19 +233,19 @@ void recv_msg_userauth_failure() {
 	for (i = 0; i <= methlen; i++) {
 		if (methods[i] == '\0') {
 			TRACE(("auth method '%s'", tok))
-#ifdef ENABLE_CLI_PUBKEY_AUTH
+#if DROPBEAR_CLI_PUBKEY_AUTH
 			if (strncmp(AUTH_METHOD_PUBKEY, tok,
 				AUTH_METHOD_PUBKEY_LEN) == 0) {
 				ses.authstate.authtypes |= AUTH_TYPE_PUBKEY;
 			}
 #endif
-#ifdef ENABLE_CLI_INTERACT_AUTH
+#if DROPBEAR_CLI_INTERACT_AUTH
 			if (strncmp(AUTH_METHOD_INTERACT, tok,
 				AUTH_METHOD_INTERACT_LEN) == 0) {
 				ses.authstate.authtypes |= AUTH_TYPE_INTERACT;
 			}
 #endif
-#ifdef ENABLE_CLI_PASSWORD_AUTH
+#if DROPBEAR_CLI_PASSWORD_AUTH
 			if (strncmp(AUTH_METHOD_PASSWORD, tok,
 				AUTH_METHOD_PASSWORD_LEN) == 0) {
 				ses.authstate.authtypes |= AUTH_TYPE_PASSWORD;
@@ -221,13 +258,14 @@ void recv_msg_userauth_failure() {
 	}
 
 	m_free(methods);
-
-	cli_ses.state = USERAUTH_FAIL_RCVD;
 		
 	TRACE(("leave recv_msg_userauth_failure"))
 }
 
 void recv_msg_userauth_success() {
+	/* This function can validly get called multiple times
+	if DROPBEAR_CLI_IMMEDIATE_AUTH is set */
+
 	TRACE(("received msg_userauth_success"))
 	/* Note: in delayed-zlib mode, setting authdone here 
 	 * will enable compression in the transport layer */
@@ -235,12 +273,12 @@ void recv_msg_userauth_success() {
 	cli_ses.state = USERAUTH_SUCCESS_RCVD;
 	cli_ses.lastauthtype = AUTH_TYPE_NONE;
 
-#ifdef ENABLE_CLI_PUBKEY_AUTH
+#if DROPBEAR_CLI_PUBKEY_AUTH
 	cli_auth_pubkey_cleanup();
 #endif
 }
 
-void cli_auth_try() {
+int cli_auth_try() {
 
 	int finished = 0;
 	TRACE(("enter cli_auth_try"))
@@ -249,55 +287,63 @@ void cli_auth_try() {
 	
 	/* Order to try is pubkey, interactive, password.
 	 * As soon as "finished" is set for one, we don't do any more. */
-#ifdef ENABLE_CLI_PUBKEY_AUTH
+#if DROPBEAR_CLI_PUBKEY_AUTH
 	if (ses.authstate.authtypes & AUTH_TYPE_PUBKEY) {
 		finished = cli_auth_pubkey();
 		cli_ses.lastauthtype = AUTH_TYPE_PUBKEY;
 	}
 #endif
 
-#ifdef ENABLE_CLI_INTERACT_AUTH
-	if (!finished && ses.authstate.authtypes & AUTH_TYPE_INTERACT) {
-		if (cli_ses.auth_interact_failed) {
-			finished = 0;
+#if DROPBEAR_CLI_PASSWORD_AUTH
+	if (!finished && (ses.authstate.authtypes & AUTH_TYPE_PASSWORD)) {
+		if (ses.keys->trans.algo_crypt->cipherdesc == NULL) {
+			fprintf(stderr, "Sorry, I won't let you use password auth unencrypted.\n");
 		} else {
-			cli_auth_interactive();
-			cli_ses.lastauthtype = AUTH_TYPE_INTERACT;
+			cli_auth_password();
 			finished = 1;
+			cli_ses.lastauthtype = AUTH_TYPE_PASSWORD;
 		}
 	}
 #endif
 
-#ifdef ENABLE_CLI_PASSWORD_AUTH
-	if (!finished && ses.authstate.authtypes & AUTH_TYPE_PASSWORD) {
-		cli_auth_password();
-		finished = 1;
-		cli_ses.lastauthtype = AUTH_TYPE_PASSWORD;
+#if DROPBEAR_CLI_INTERACT_AUTH
+	if (!finished && (ses.authstate.authtypes & AUTH_TYPE_INTERACT)) {
+		if (ses.keys->trans.algo_crypt->cipherdesc == NULL) {
+			fprintf(stderr, "Sorry, I won't let you use interactive auth unencrypted.\n");
+		} else {
+			if (!cli_ses.auth_interact_failed) {
+				cli_auth_interactive();
+				cli_ses.lastauthtype = AUTH_TYPE_INTERACT;
+				finished = 1;
+			}
+		}
 	}
 #endif
 
 	TRACE(("cli_auth_try lastauthtype %d", cli_ses.lastauthtype))
 
-	if (!finished) {
-		dropbear_exit("No auth methods could be used.");
+	if (finished) {
+		TRACE(("leave cli_auth_try success"))
+		return DROPBEAR_SUCCESS;
 	}
-
-	TRACE(("leave cli_auth_try"))
+	TRACE(("leave cli_auth_try failure"))
+	return DROPBEAR_FAILURE;
 }
 
+#if DROPBEAR_CLI_PASSWORD_AUTH || DROPBEAR_CLI_INTERACT_AUTH
 /* A helper for getpass() that exits if the user cancels. The returned
  * password is statically allocated by getpass() */
-char* getpass_or_cancel(char* prompt)
+char* getpass_or_cancel(const char* prompt)
 {
 	char* password = NULL;
 	
-#ifdef DROPBEAR_PASSWORD_ENV
-    /* Password provided in an environment var */
-    password = getenv(DROPBEAR_PASSWORD_ENV);
-    if (password)
-    {
-        return password;
-    }
+#if DROPBEAR_USE_PASSWORD_ENV
+	/* Password provided in an environment var */
+	password = getenv(DROPBEAR_PASSWORD_ENV);
+	if (password)
+	{
+		return password;
+	}
 #endif
 
 	password = getpass(prompt);
@@ -308,3 +354,4 @@ char* getpass_or_cancel(char* prompt)
 	}
 	return password;
 }
+#endif

cli-authinteract.c

@@ -29,12 +29,12 @@
 #include "ssh.h"
 #include "runopts.h"
 
-#ifdef ENABLE_CLI_INTERACT_AUTH
+#if DROPBEAR_CLI_INTERACT_AUTH
 
-static unsigned char* get_response(unsigned char* prompt)
+static char* get_response(char* prompt)
 {
 	FILE* tty = NULL;
-	unsigned char* response = NULL;
+	char* response = NULL;
 	/* not a password, but a reasonable limit */
 	char buf[DROPBEAR_MAX_CLI_PASS];
 	char* ret = NULL;
@@ -50,13 +50,13 @@ static unsigned char* get_response(unsigned char* prompt)
 	}
 
 	if (ret == NULL) {
-		response = (unsigned char*)m_strdup("");
+		response = m_strdup("");
 	} else {
 		unsigned int buflen = strlen(buf);
 		/* fgets includes newlines */
 		if (buflen > 0 && buf[buflen-1] == '\n')
 			buf[buflen-1] = '\0';
-		response = (unsigned char*)m_strdup(buf);
+		response = m_strdup(buf);
 	}
 
 	m_burn(buf, sizeof(buf));
@@ -66,14 +66,14 @@ static unsigned char* get_response(unsigned char* prompt)
 
 void recv_msg_userauth_info_request() {
 
-	unsigned char *name = NULL;
-	unsigned char *instruction = NULL;
+	char *name = NULL;
+	char *instruction = NULL;
 	unsigned int num_prompts = 0;
 	unsigned int i;
 
-	unsigned char *prompt = NULL;
+	char *prompt = NULL;
 	unsigned int echo = 0;
-	unsigned char *response = NULL;
+	char *response = NULL;
 
 	TRACE(("enter recv_msg_recv_userauth_info_request"))
 
@@ -121,7 +121,7 @@ void recv_msg_userauth_info_request() {
 		echo = buf_getbool(ses.payload);
 
 		if (!echo) {
-			unsigned char* p = getpass_or_cancel(prompt);
+			char* p = getpass_or_cancel(prompt);
 			response = m_strdup(p);
 			m_burn(p, strlen(p));
 		} else {
@@ -131,6 +131,7 @@ void recv_msg_userauth_info_request() {
 		response_len = strlen(response);
 		buf_putstring(ses.writepayload, response, response_len);
 		m_burn(response, response_len);
+		m_free(prompt);
 		m_free(response);
 	}
 
@@ -152,7 +153,7 @@ void cli_auth_interactive() {
 			strlen(cli_opts.username));
 
 	/* service name */
-	buf_putstring(ses.writepayload, SSH_SERVICE_CONNECTION, 
+	buf_putstring(ses.writepayload, SSH_SERVICE_CONNECTION,
 			SSH_SERVICE_CONNECTION_LEN);
 
 	/* method */
@@ -171,4 +172,4 @@ void cli_auth_interactive() {
 	TRACE(("leave cli_auth_interactive"))
 
 }
-#endif	/* ENABLE_CLI_INTERACT_AUTH */
+#endif	/* DROPBEAR_CLI_INTERACT_AUTH */

cli-authpasswd.c

@@ -29,9 +29,9 @@
 #include "ssh.h"
 #include "runopts.h"
 
-#ifdef ENABLE_CLI_PASSWORD_AUTH
+#if DROPBEAR_CLI_PASSWORD_AUTH
 
-#ifdef ENABLE_CLI_ASKPASS_HELPER
+#if DROPBEAR_CLI_ASKPASS_HELPER
 /* Returns 1 if we want to use the askpass program, 0 otherwise */
 static int want_askpass()
 {
@@ -113,7 +113,7 @@ static char *gui_getpass(const char *prompt) {
 	TRACE(("leave gui_getpass"))
 	return(buf);
 }
-#endif /* ENABLE_CLI_ASKPASS_HELPER */
+#endif /* DROPBEAR_CLI_ASKPASS_HELPER */
 
 void cli_auth_password() {
 
@@ -125,7 +125,7 @@ void cli_auth_password() {
 
 	snprintf(prompt, sizeof(prompt), "%s@%s's password: ", 
 				cli_opts.username, cli_opts.remotehost);
-#ifdef ENABLE_CLI_ASKPASS_HELPER
+#if DROPBEAR_CLI_ASKPASS_HELPER
 	if (want_askpass())
 	{
 		password = gui_getpass(prompt);
@@ -143,10 +143,10 @@ void cli_auth_password() {
 	buf_putstring(ses.writepayload, cli_opts.username,
 			strlen(cli_opts.username));
 
-	buf_putstring(ses.writepayload, SSH_SERVICE_CONNECTION, 
+	buf_putstring(ses.writepayload, SSH_SERVICE_CONNECTION,
 			SSH_SERVICE_CONNECTION_LEN);
 
-	buf_putstring(ses.writepayload, AUTH_METHOD_PASSWORD, 
+	buf_putstring(ses.writepayload, AUTH_METHOD_PASSWORD,
 			AUTH_METHOD_PASSWORD_LEN);
 
 	buf_putbyte(ses.writepayload, 0); /* FALSE - so says the spec */
@@ -158,4 +158,4 @@ void cli_auth_password() {
 
 	TRACE(("leave cli_auth_password"))
 }
-#endif	/* ENABLE_CLI_PASSWORD_AUTH */
+#endif	/* DROPBEAR_CLI_PASSWORD_AUTH */

cli-authpubkey.c

@@ -32,8 +32,8 @@
 #include "auth.h"
 #include "agentfwd.h"
 
-#ifdef ENABLE_CLI_PUBKEY_AUTH
-static void send_msg_userauth_pubkey(sign_key *key, int type, int realsign);
+#if DROPBEAR_CLI_PUBKEY_AUTH
+static void send_msg_userauth_pubkey(sign_key *key, enum signature_type sigtype, int realsign);
 
 /* Called when we receive a SSH_MSG_USERAUTH_FAILURE for a pubkey request.
  * We use it to remove the key we tried from the list */
@@ -58,14 +58,16 @@ void recv_msg_userauth_pk_ok() {
 	buffer* keybuf = NULL;
 	char* algotype = NULL;
 	unsigned int algolen;
-	int keytype;
+	enum signkey_type keytype;
+	enum signature_type sigtype;
 	unsigned int remotelen;
 
 	TRACE(("enter recv_msg_userauth_pk_ok"))
 
 	algotype = buf_getstring(ses.payload, &algolen);
-	keytype = signkey_type_from_name(algotype, algolen);
-	TRACE(("recv_msg_userauth_pk_ok: type %d", keytype))
+	sigtype = signature_type_from_name(algotype, algolen);
+	keytype = signkey_type_from_signature(sigtype);
+	TRACE(("recv_msg_userauth_pk_ok: type %d", sigtype))
 	m_free(algotype);
 
 	keybuf = buf_new(MAX_PUBKEY_SIZE);
@@ -112,7 +114,7 @@ void recv_msg_userauth_pk_ok() {
 		TRACE(("matching key"))
 		/* XXX TODO: if it's an encrypted key, here we ask for their
 		 * password */
-		send_msg_userauth_pubkey((sign_key*)iter->item, keytype, 1);
+		send_msg_userauth_pubkey((sign_key*)iter->item, sigtype, 1);
 	} else {
 		TRACE(("That was whacky. We got told that a key was valid, but it didn't match our list. Sounds like dodgy code on Dropbear's part"))
 	}
@@ -120,33 +122,32 @@ void recv_msg_userauth_pk_ok() {
 	TRACE(("leave recv_msg_userauth_pk_ok"))
 }
 
-void cli_buf_put_sign(buffer* buf, sign_key *key, int type, 
-			const unsigned char *data, unsigned int len)
-{
+static void cli_buf_put_sign(buffer* buf, sign_key *key, enum signature_type sigtype,
+			const buffer *data_buf) {
+#if DROPBEAR_CLI_AGENTFWD
+	// TODO: rsa-sha256 agent
 	if (key->source == SIGNKEY_SOURCE_AGENT) {
 		/* Format the agent signature ourselves, as buf_put_sign would. */
 		buffer *sigblob;
 		sigblob = buf_new(MAX_PUBKEY_SIZE);
-		agent_buf_sign(sigblob, key, data, len);
-		buf_setpos(sigblob, 0);
-		buf_putstring(buf, buf_getptr(sigblob, sigblob->len),
-				sigblob->len);
-
+		agent_buf_sign(sigblob, key, data_buf, sigtype);
+		buf_putbufstring(buf, sigblob);
 		buf_free(sigblob);
-	} else {
-		buf_put_sign(buf, key, type, data, len);
+	} else 
+#endif /* DROPBEAR_CLI_AGENTFWD */
+	{
+		buf_put_sign(buf, key, sigtype, data_buf);
 	}
-	
 }
 
-/* TODO: make it take an agent reference to use as well */
-static void send_msg_userauth_pubkey(sign_key *key, int type, int realsign) {
+static void send_msg_userauth_pubkey(sign_key *key, enum signature_type sigtype, int realsign) {
 
 	const char *algoname = NULL;
-	int algolen;
+	unsigned int algolen;
 	buffer* sigbuf = NULL;
+	enum signkey_type keytype = signkey_type_from_signature(sigtype);
 
-	TRACE(("enter send_msg_userauth_pubkey"))
+	TRACE(("enter send_msg_userauth_pubkey sigtype %d", sigtype))
 	CHECKCLEARTOWRITE();
 
 	buf_putbyte(ses.writepayload, SSH_MSG_USERAUTH_REQUEST);
@@ -154,27 +155,26 @@ static void send_msg_userauth_pubkey(sign_key *key, int type, int realsign) {
 	buf_putstring(ses.writepayload, cli_opts.username,
 			strlen(cli_opts.username));
 
-	buf_putstring(ses.writepayload, SSH_SERVICE_CONNECTION, 
+	buf_putstring(ses.writepayload, SSH_SERVICE_CONNECTION,
 			SSH_SERVICE_CONNECTION_LEN);
 
-	buf_putstring(ses.writepayload, AUTH_METHOD_PUBKEY, 
+	buf_putstring(ses.writepayload, AUTH_METHOD_PUBKEY,
 			AUTH_METHOD_PUBKEY_LEN);
 
 	buf_putbyte(ses.writepayload, realsign);
 
-	algoname = signkey_name_from_type(type, &algolen);
-
+	algoname = signature_name_from_type(sigtype, &algolen);
 	buf_putstring(ses.writepayload, algoname, algolen);
-	buf_put_pub_key(ses.writepayload, key, type);
+	buf_put_pub_key(ses.writepayload, key, keytype);
 
 	if (realsign) {
 		TRACE(("realsign"))
 		/* We put the signature as well - this contains string(session id), then
 		 * the contents of the write payload to this point */
-		sigbuf = buf_new(4 + SHA1_HASH_SIZE + ses.writepayload->len);
-		buf_putstring(sigbuf, ses.session_id, SHA1_HASH_SIZE);
+		sigbuf = buf_new(4 + ses.session_id->len + ses.writepayload->len);
+		buf_putbufstring(sigbuf, ses.session_id);
 		buf_putbytes(sigbuf, ses.writepayload->data, ses.writepayload->len);
-		cli_buf_put_sign(ses.writepayload, key, type, sigbuf->data, sigbuf->len);
+		cli_buf_put_sign(ses.writepayload, key, sigtype, sigbuf);
 		buf_free(sigbuf); /* Nothing confidential in the buffer */
 	}
 
@@ -184,19 +184,87 @@ static void send_msg_userauth_pubkey(sign_key *key, int type, int realsign) {
 
 /* Returns 1 if a key was tried */
 int cli_auth_pubkey() {
-
+	enum signature_type sigtype = DROPBEAR_SIGNATURE_NONE;
 	TRACE(("enter cli_auth_pubkey"))
 
+#if DROPBEAR_CLI_AGENTFWD
 	if (!cli_opts.agent_keys_loaded) {
 		/* get the list of available keys from the agent */
 		cli_load_agent_keys(cli_opts.privkeys);
 		cli_opts.agent_keys_loaded = 1;
+		TRACE(("cli_auth_pubkey: agent keys loaded"))
+	}
+#endif
+
+	/* iterate through privkeys to remove ones not allowed in server-sig-algs */
+ 	while (cli_opts.privkeys->first) {
+		sign_key * key = (sign_key*)cli_opts.privkeys->first->item;
+		if (cli_ses.server_sig_algs) {
+#if DROPBEAR_RSA
+			if (key->type == DROPBEAR_SIGNKEY_RSA) {
+#if DROPBEAR_RSA_SHA256
+				if (buf_has_algo(cli_ses.server_sig_algs, SSH_SIGNATURE_RSA_SHA256) 
+						== DROPBEAR_SUCCESS) {
+					sigtype = DROPBEAR_SIGNATURE_RSA_SHA256;
+					TRACE(("server-sig-algs allows rsa sha256"))
+					break;
+				}
+#endif /* DROPBEAR_RSA_SHA256 */
+#if DROPBEAR_RSA_SHA1
+				if (buf_has_algo(cli_ses.server_sig_algs, SSH_SIGNKEY_RSA)
+						== DROPBEAR_SUCCESS) {
+					sigtype = DROPBEAR_SIGNATURE_RSA_SHA1;
+					TRACE(("server-sig-algs allows rsa sha1"))
+					break;
+				}
+#endif /* DROPBEAR_RSA_SHA256 */
+			} else
+#endif /* DROPBEAR_RSA */
+			{
+				/* Not RSA */
+				const char *name = NULL;
+				sigtype = signature_type_from_signkey(key->type);
+				name = signature_name_from_type(sigtype, NULL);
+				if (buf_has_algo(cli_ses.server_sig_algs, name)
+						== DROPBEAR_SUCCESS) {
+					TRACE(("server-sig-algs allows %s", name))
+					break;
+				}
+			}
+
+			/* No match, skip this key */
+			TRACE(("server-sig-algs no match keytype %d, skipping", key->type))
+			key = list_remove(cli_opts.privkeys->first);
+			sign_key_free(key); 
+			continue;
+		} else {
+			/* Server didn't provide a server-sig-algs list, we'll 
+			   assume all except rsa-sha256 are OK. */
+#if DROPBEAR_RSA
+			if (key->type == DROPBEAR_SIGNKEY_RSA) {
+#if DROPBEAR_RSA_SHA1
+				sigtype = DROPBEAR_SIGNATURE_RSA_SHA1;
+				TRACE(("no server-sig-algs, using rsa sha1"))
+				break;
+#else
+				/* only support rsa-sha256, skip this key */
+				TRACE(("no server-sig-algs, skipping rsa sha256"))
+				key = list_remove(cli_opts.privkeys->first);
+				sign_key_free(key); 
+				continue;
+#endif
+			} /* key->type == DROPBEAR_SIGNKEY_RSA */
+#endif /* DROPBEAR_RSA */
+			sigtype = signature_type_from_signkey(key->type);
+			TRACE(("no server-sig-algs, using key"))
+			break;
+		}
 	}
 
 	if (cli_opts.privkeys->first) {
 		sign_key * key = (sign_key*)cli_opts.privkeys->first->item;
 		/* Send a trial request */
-		send_msg_userauth_pubkey(key, key->type, 0);
+		send_msg_userauth_pubkey(key, sigtype, 0);
 		cli_ses.lastprivkey = key;
 		TRACE(("leave cli_auth_pubkey-success"))
 		return 1;
@@ -209,7 +277,7 @@ int cli_auth_pubkey() {
 
 void cli_auth_pubkey_cleanup() {
 
-#ifdef ENABLE_CLI_AGENTFWD
+#if DROPBEAR_CLI_AGENTFWD
 	m_close(cli_opts.agent_fd);
 	cli_opts.agent_fd = -1;
 #endif

cli-chansession.c

@@ -35,14 +35,15 @@
 #include "chansession.h"
 #include "agentfwd.h"
 
-static void cli_closechansess(struct Channel *channel);
+static void cli_closechansess(const struct Channel *channel);
 static int cli_initchansess(struct Channel *channel);
 static void cli_chansessreq(struct Channel *channel);
+static void send_chansess_pty_req(const struct Channel *channel);
+static void send_chansess_shell_req(const struct Channel *channel);
+static void cli_escape_handler(const struct Channel *channel, const unsigned char* buf, int *len);
+static int cli_init_netcat(struct Channel *channel);
 
-static void send_chansess_pty_req(struct Channel *channel);
-static void send_chansess_shell_req(struct Channel *channel);
-
-static void cli_tty_setup();
+static void cli_tty_setup(void);
 
 const struct ChanType clichansess = {
 	0, /* sepfds */
@@ -51,11 +52,12 @@ const struct ChanType clichansess = {
 	NULL, /* checkclosehandler */
 	cli_chansessreq, /* reqhandler */
 	cli_closechansess, /* closehandler */
+	NULL, /* cleanup */
 };
 
 static void cli_chansessreq(struct Channel *channel) {
 
-	unsigned char* type = NULL;
+	char* type = NULL;
 	int wantreply;
 
 	TRACE(("enter cli_chansessreq"))
@@ -70,7 +72,9 @@ static void cli_chansessreq(struct Channel *channel) {
 		TRACE(("got exit-signal, ignoring it"))
 	} else {
 		TRACE(("unknown request '%s'", type))
-		send_msg_channel_failure(channel);
+		if (wantreply) {
+			send_msg_channel_failure(channel);
+		}
 		goto out;
 	}
 		
@@ -80,26 +84,13 @@ out:
 	
 
 /* If the main session goes, we close it up */
-static void cli_closechansess(struct Channel *UNUSED(channel)) {
+static void cli_closechansess(const struct Channel *UNUSED(channel)) {
+	cli_tty_cleanup(); /* Restore tty modes etc */
 
 	/* This channel hasn't gone yet, so we have > 1 */
 	if (ses.chancount > 1) {
 		dropbear_log(LOG_INFO, "Waiting for other channels to close...");
 	}
-
-	cli_tty_cleanup(); /* Restore tty modes etc */
-
-}
-
-void cli_start_send_channel_request(struct Channel *channel, 
-		unsigned char *type) {
-
-	CHECKCLEARTOWRITE();
-	buf_putbyte(ses.writepayload, SSH_MSG_CHANNEL_REQUEST);
-	buf_putint(ses.writepayload, channel->remotechan);
-
-	buf_putstring(ses.writepayload, type, strlen(type));
-
 }
 
 /* Taken from OpenSSH's sshtty.c:
@@ -280,13 +271,13 @@ void cli_chansess_winchange() {
 	cli_ses.winchange = 0;
 }
 
-static void send_chansess_pty_req(struct Channel *channel) {
+static void send_chansess_pty_req(const struct Channel *channel) {
 
-	unsigned char* term = NULL;
+	char* term = NULL;
 
 	TRACE(("enter send_chansess_pty_req"))
 
-	cli_start_send_channel_request(channel, "pty-req");
+	start_send_channel_request(channel, "pty-req");
 
 	/* Don't want replies */
 	buf_putbyte(ses.writepayload, 0);
@@ -313,9 +304,9 @@ static void send_chansess_pty_req(struct Channel *channel) {
 	TRACE(("leave send_chansess_pty_req"))
 }
 
-static void send_chansess_shell_req(struct Channel *channel) {
+static void send_chansess_shell_req(const struct Channel *channel) {
 
-	unsigned char* reqtype = NULL;
+	char* reqtype = NULL;
 
 	TRACE(("enter send_chansess_shell_req"))
 
@@ -329,7 +320,7 @@ static void send_chansess_shell_req(struct Channel *channel) {
 		reqtype = "shell";
 	}
 
-	cli_start_send_channel_request(channel, reqtype);
+	start_send_channel_request(channel, reqtype);
 
 	/* XXX TODO */
 	buf_putbyte(ses.writepayload, 0); /* Don't want replies */
@@ -356,11 +347,16 @@ static int cli_init_stdpipe_sess(struct Channel *channel) {
 	return 0;
 }
 
+static int cli_init_netcat(struct Channel *channel) {
+	channel->prio = DROPBEAR_CHANNEL_PRIO_UNKNOWABLE;
+	return cli_init_stdpipe_sess(channel);
+}
+
 static int cli_initchansess(struct Channel *channel) {
 
 	cli_init_stdpipe_sess(channel);
 
-#ifdef ENABLE_CLI_AGENTFWD
+#if DROPBEAR_CLI_AGENTFWD
 	if (cli_opts.agent_fwd) {
 		cli_setup_agent(channel);
 	}
@@ -368,33 +364,40 @@ static int cli_initchansess(struct Channel *channel) {
 
 	if (cli_opts.wantpty) {
 		send_chansess_pty_req(channel);
+		channel->prio = DROPBEAR_CHANNEL_PRIO_INTERACTIVE;
+	} else {
+		channel->prio = DROPBEAR_CHANNEL_PRIO_BULK;
 	}
 
 	send_chansess_shell_req(channel);
 
 	if (cli_opts.wantpty) {
 		cli_tty_setup();
-	}
+		channel->read_mangler = cli_escape_handler;
+		cli_ses.last_char = '\r';
+	}	
 
 	return 0; /* Success */
 }
 
-#ifdef ENABLE_CLI_NETCAT
+#if DROPBEAR_CLI_NETCAT
 
 static const struct ChanType cli_chan_netcat = {
 	0, /* sepfds */
 	"direct-tcpip",
-	cli_init_stdpipe_sess, /* inithandler */
+	cli_init_netcat, /* inithandler */
 	NULL,
 	NULL,
-	cli_closechansess
+	cli_closechansess,
+	NULL,
 };
 
 void cli_send_netcat_request() {
 
-	const unsigned char* source_host = "127.0.0.1";
+	const char* source_host = "127.0.0.1";
 	const int source_port = 22;
 
+	TRACE(("enter cli_send_netcat_request"))
 	cli_opts.wantpty = 0;
 
 	if (send_msg_channel_open_init(STDIN_FILENO, &cli_chan_netcat) 
@@ -402,7 +405,7 @@ void cli_send_netcat_request() {
 		dropbear_exit("Couldn't open initial channel");
 	}
 
-	buf_putstring(ses.writepayload, cli_opts.netcat_host, 
+	buf_putstring(ses.writepayload, cli_opts.netcat_host,
 			strlen(cli_opts.netcat_host));
 	buf_putint(ses.writepayload, cli_opts.netcat_port);
 
@@ -411,7 +414,7 @@ void cli_send_netcat_request() {
 	buf_putint(ses.writepayload, source_port);
 
 	encrypt_packet();
-	TRACE(("leave cli_send_chansess_request"))
+	TRACE(("leave cli_send_netcat_request"))
 }
 #endif
 
@@ -429,3 +432,58 @@ void cli_send_chansess_request() {
 	TRACE(("leave cli_send_chansess_request"))
 
 }
+
+/* returns 1 if the character should be consumed, 0 to pass through */
+static int
+do_escape(unsigned char c) {
+	switch (c) {
+		case '.':
+			dropbear_exit("Terminated");
+			return 1;
+		case 0x1a:
+			/* ctrl-z */
+			cli_tty_cleanup();
+			kill(getpid(), SIGTSTP);
+			/* after continuation */
+			cli_tty_setup();
+			cli_ses.winchange = 1;
+			return 1;
+		default:
+			return 0;
+	}
+}
+
+static
+void cli_escape_handler(const struct Channel* UNUSED(channel), const unsigned char* buf, int *len) {
+	char c;
+	int skip_char = 0;
+
+	/* only handle escape characters if they are read one at a time. simplifies 
+	   the code and avoids nasty people putting ~. at the start of a line to paste  */
+	if (*len != 1) {
+		cli_ses.last_char = 0x0;
+		return;
+	}
+
+	c = buf[0];
+
+	if (cli_ses.last_char == DROPBEAR_ESCAPE_CHAR) {
+		skip_char = do_escape(c);
+		cli_ses.last_char = 0x0;
+	} else {
+		if (c == DROPBEAR_ESCAPE_CHAR) {
+			if (cli_ses.last_char == '\r') {
+				cli_ses.last_char = DROPBEAR_ESCAPE_CHAR;
+				skip_char = 1;
+			} else {
+				cli_ses.last_char = 0x0;
+			}
+		} else {
+			cli_ses.last_char = c;
+		}
+	}
+
+	if (skip_char) {
+		*len = 0;
+	}
+}

cli-kex.c

@@ -33,46 +33,77 @@
 #include "ssh.h"
 #include "packet.h"
 #include "bignum.h"
-#include "random.h"
+#include "dbrandom.h"
 #include "runopts.h"
 #include "signkey.h"
+#include "ecc.h"
 
 
-static void checkhostkey(unsigned char* keyblob, unsigned int keybloblen);
+static void checkhostkey(const unsigned char* keyblob, unsigned int keybloblen);
 #define MAX_KNOWNHOSTS_LINE 4500
 
 void send_msg_kexdh_init() {
-
-	cli_ses.dh_e = (mp_int*)m_malloc(sizeof(mp_int));
-	cli_ses.dh_x = (mp_int*)m_malloc(sizeof(mp_int));
-	m_mp_init_multi(cli_ses.dh_e, cli_ses.dh_x, NULL);
-
-	gen_kexdh_vals(cli_ses.dh_e, cli_ses.dh_x);
+	TRACE(("send_msg_kexdh_init()"))	
 
 	CHECKCLEARTOWRITE();
 	buf_putbyte(ses.writepayload, SSH_MSG_KEXDH_INIT);
-	buf_putmpint(ses.writepayload, cli_ses.dh_e);
+	switch (ses.newkeys->algo_kex->mode) {
+#if DROPBEAR_NORMAL_DH
+		case DROPBEAR_KEX_NORMAL_DH:
+			if (ses.newkeys->algo_kex != cli_ses.param_kex_algo
+				|| !cli_ses.dh_param) {
+				if (cli_ses.dh_param) {
+					free_kexdh_param(cli_ses.dh_param);
+				}
+				cli_ses.dh_param = gen_kexdh_param();
+			}
+			buf_putmpint(ses.writepayload, &cli_ses.dh_param->pub);
+			break;
+#endif
+#if DROPBEAR_ECDH
+		case DROPBEAR_KEX_ECDH:
+			if (ses.newkeys->algo_kex != cli_ses.param_kex_algo
+				|| !cli_ses.ecdh_param) {
+				if (cli_ses.ecdh_param) {
+					free_kexecdh_param(cli_ses.ecdh_param);
+				}
+				cli_ses.ecdh_param = gen_kexecdh_param();
+			}
+			buf_put_ecc_raw_pubkey_string(ses.writepayload, &cli_ses.ecdh_param->key);
+			break;
+#endif
+#if DROPBEAR_CURVE25519
+		case DROPBEAR_KEX_CURVE25519:
+			if (ses.newkeys->algo_kex != cli_ses.param_kex_algo
+				|| !cli_ses.curve25519_param) {
+				if (cli_ses.curve25519_param) {
+					free_kexcurve25519_param(cli_ses.curve25519_param);
+				}
+				cli_ses.curve25519_param = gen_kexcurve25519_param();
+			}
+			buf_putstring(ses.writepayload, cli_ses.curve25519_param->pub, CURVE25519_LEN);
+			break;
+#endif
+	}
+
+	cli_ses.param_kex_algo = ses.newkeys->algo_kex;
 	encrypt_packet();
-	ses.requirenext = SSH_MSG_KEXDH_REPLY;
 }
 
 /* Handle a diffie-hellman key exchange reply. */
 void recv_msg_kexdh_reply() {
 
-	DEF_MP_INT(dh_f);
 	sign_key *hostkey = NULL;
-	unsigned int type, keybloblen;
+	unsigned int keytype, keybloblen;
 	unsigned char* keyblob = NULL;
 
-
 	TRACE(("enter recv_msg_kexdh_reply"))
 
 	if (cli_ses.kex_state != KEXDH_INIT_SENT) {
 		dropbear_exit("Received out-of-order kexdhreply");
 	}
-	m_mp_init(&dh_f);
-	type = ses.newkeys->algo_hostkey;
-	TRACE(("type is %d", type))
+	keytype = ses.newkeys->algo_hostkey;
+	TRACE(("keytype is %d", keytype))
 
 	hostkey = new_sign_key();
 	keybloblen = buf_getint(ses.payload);
@@ -83,24 +114,69 @@ void recv_msg_kexdh_reply() {
 		checkhostkey(keyblob, keybloblen);
 	}
 
-	if (buf_get_pub_key(ses.payload, hostkey, &type) != DROPBEAR_SUCCESS) {
+	if (buf_get_pub_key(ses.payload, hostkey, &keytype) != DROPBEAR_SUCCESS) {
 		TRACE(("failed getting pubkey"))
 		dropbear_exit("Bad KEX packet");
 	}
 
-	if (buf_getmpint(ses.payload, &dh_f) != DROPBEAR_SUCCESS) {
-		TRACE(("failed getting mpint"))
-		dropbear_exit("Bad KEX packet");
+	switch (ses.newkeys->algo_kex->mode) {
+#if DROPBEAR_NORMAL_DH
+		case DROPBEAR_KEX_NORMAL_DH:
+			{
+			DEF_MP_INT(dh_f);
+			m_mp_init(&dh_f);
+			if (buf_getmpint(ses.payload, &dh_f) != DROPBEAR_SUCCESS) {
+				TRACE(("failed getting mpint"))
+				dropbear_exit("Bad KEX packet");
+			}
+
+			kexdh_comb_key(cli_ses.dh_param, &dh_f, hostkey);
+			mp_clear(&dh_f);
+			}
+			break;
+#endif
+#if DROPBEAR_ECDH
+		case DROPBEAR_KEX_ECDH:
+			{
+			buffer *ecdh_qs = buf_getstringbuf(ses.payload);
+			kexecdh_comb_key(cli_ses.ecdh_param, ecdh_qs, hostkey);
+			buf_free(ecdh_qs);
+			}
+			break;
+#endif
+#if DROPBEAR_CURVE25519
+		case DROPBEAR_KEX_CURVE25519:
+			{
+			buffer *ecdh_qs = buf_getstringbuf(ses.payload);
+			kexcurve25519_comb_key(cli_ses.curve25519_param, ecdh_qs, hostkey);
+			buf_free(ecdh_qs);
+			}
+			break;
+#endif
 	}
 
-	kexdh_comb_key(cli_ses.dh_e, cli_ses.dh_x, &dh_f, hostkey);
-	mp_clear(&dh_f);
-	mp_clear_multi(cli_ses.dh_e, cli_ses.dh_x, NULL);
-	m_free(cli_ses.dh_e);
-	m_free(cli_ses.dh_x);
+#if DROPBEAR_NORMAL_DH
+	if (cli_ses.dh_param) {
+		free_kexdh_param(cli_ses.dh_param);
+		cli_ses.dh_param = NULL;
+	}
+#endif
+#if DROPBEAR_ECDH
+	if (cli_ses.ecdh_param) {
+		free_kexecdh_param(cli_ses.ecdh_param);
+		cli_ses.ecdh_param = NULL;
+	}
+#endif
+#if DROPBEAR_CURVE25519
+	if (cli_ses.curve25519_param) {
+		free_kexcurve25519_param(cli_ses.curve25519_param);
+		cli_ses.curve25519_param = NULL;
+	}
+#endif
 
-	if (buf_verify(ses.payload, hostkey, ses.hash, SHA1_HASH_SIZE) 
-			!= DROPBEAR_SUCCESS) {
+	cli_ses.param_kex_algo = NULL;
+	if (buf_verify(ses.payload, hostkey, ses.newkeys->algo_signature, 
+			ses.hash) != DROPBEAR_SUCCESS) {
 		dropbear_exit("Bad hostkey signature");
 	}
 
@@ -112,22 +188,25 @@ void recv_msg_kexdh_reply() {
 	TRACE(("leave recv_msg_kexdh_init"))
 }
 
-static void ask_to_confirm(unsigned char* keyblob, unsigned int keybloblen) {
+static void ask_to_confirm(const unsigned char* keyblob, unsigned int keybloblen,
+	const char* algoname) {
 
 	char* fp = NULL;
 	FILE *tty = NULL;
-	char response = 'z';
+	int response = 'z';
 
 	fp = sign_key_fingerprint(keyblob, keybloblen);
 	if (cli_opts.always_accept_key) {
-		fprintf(stderr, "\nHost '%s' key accepted unconditionally.\n(fingerprint %s)\n",
+		dropbear_log(LOG_INFO, "\nHost '%s' key accepted unconditionally.\n(%s fingerprint %s)\n",
 				cli_opts.remotehost,
+				algoname,
 				fp);
 		m_free(fp);
 		return;
 	}
-	fprintf(stderr, "\nHost '%s' is not in the trusted hosts file.\n(fingerprint %s)\nDo you want to continue connecting? (y/n) ", 
+	fprintf(stderr, "\nHost '%s' is not in the trusted hosts file.\n(%s fingerprint %s)\nDo you want to continue connecting? (y/n) ", 
 			cli_opts.remotehost, 
+			algoname,
 			fp);
 	m_free(fp);
 
@@ -206,7 +285,7 @@ out:
 	return hostsfile;
 }
 
-static void checkhostkey(unsigned char* keyblob, unsigned int keybloblen) {
+static void checkhostkey(const unsigned char* keyblob, unsigned int keybloblen) {
 
 	FILE *hostsfile = NULL;
 	int readonly = 0;
@@ -217,16 +296,22 @@ static void checkhostkey(unsigned char* keyblob, unsigned int keybloblen) {
 	buffer * line = NULL;
 	int ret;
 
+	if (cli_opts.no_hostkey_check) {
+		dropbear_log(LOG_INFO, "Caution, skipping hostkey check for %s\n", cli_opts.remotehost);
+		return;
+	}
+
+	algoname = signkey_name_from_type(ses.newkeys->algo_hostkey, &algolen);
+
 	hostsfile = open_known_hosts_file(&readonly);
 	if (!hostsfile)	{
-		ask_to_confirm(keyblob, keybloblen);
+		ask_to_confirm(keyblob, keybloblen, algoname);
 		/* ask_to_confirm will exit upon failure */
 		return;
 	}
 	
 	line = buf_new(MAX_KNOWNHOSTS_LINE);
 	hostlen = strlen(cli_opts.remotehost);
-	algoname = signkey_name_from_type(ses.newkeys->algo_hostkey, &algolen);
 
 	do {
 		if (buf_getline(line, hostsfile) == DROPBEAR_FAILURE) {
@@ -244,9 +329,8 @@ static void checkhostkey(unsigned char* keyblob, unsigned int keybloblen) {
 		}
 
 		/* Compare hostnames */
-		if (strncmp(cli_opts.remotehost, buf_getptr(line, hostlen),
+		if (strncmp(cli_opts.remotehost, (const char *) buf_getptr(line, hostlen),
 					hostlen) != 0) {
-			TRACE(("hosts don't match"))
 			continue;
 		}
 
@@ -257,7 +341,7 @@ static void checkhostkey(unsigned char* keyblob, unsigned int keybloblen) {
 			continue;
 		}
 
-		if (strncmp(buf_getptr(line, algolen), algoname, algolen) != 0) {
+		if (strncmp((const char *) buf_getptr(line, algolen), algoname, algolen) != 0) {
 			TRACE(("algo doesn't match"))
 			continue;
 		}
@@ -269,7 +353,7 @@ static void checkhostkey(unsigned char* keyblob, unsigned int keybloblen) {
 		}
 
 		/* Now we're at the interesting hostkey */
-		ret = cmp_base64_key(keyblob, keybloblen, algoname, algolen,
+		ret = cmp_base64_key(keyblob, keybloblen, (const unsigned char *) algoname, algolen,
 						line, &fingerprint);
 
 		if (ret == DROPBEAR_SUCCESS) {
@@ -280,17 +364,18 @@ static void checkhostkey(unsigned char* keyblob, unsigned int keybloblen) {
 
 		/* The keys didn't match. eep. Note that we're "leaking"
 		   the fingerprint strings here, but we're exiting anyway */
-		dropbear_exit("\n\nHost key mismatch for %s !\n"
+		dropbear_exit("\n\n%s host key mismatch for %s !\n"
 					"Fingerprint is %s\n"
 					"Expected %s\n"
 					"If you know that the host key is correct you can\nremove the bad entry from ~/.ssh/known_hosts", 
+					algoname,
 					cli_opts.remotehost,
 					sign_key_fingerprint(keyblob, keybloblen),
 					fingerprint ? fingerprint : "UNKNOWN");
 	} while (1); /* keep going 'til something happens */
 
 	/* Key doesn't exist yet */
-	ask_to_confirm(keyblob, keybloblen);
+	ask_to_confirm(keyblob, keybloblen, algoname);
 
 	/* If we get here, they said yes */
 
@@ -304,12 +389,11 @@ static void checkhostkey(unsigned char* keyblob, unsigned int keybloblen) {
 		fseek(hostsfile, 0, SEEK_END); /* In case it wasn't opened append */
 		buf_setpos(line, 0);
 		buf_setlen(line, 0);
-		buf_putbytes(line, cli_opts.remotehost, hostlen);
+		buf_putbytes(line, (const unsigned char *) cli_opts.remotehost, hostlen);
 		buf_putbyte(line, ' ');
-		buf_putbytes(line, algoname, algolen);
+		buf_putbytes(line, (const unsigned char *) algoname, algolen);
 		buf_putbyte(line, ' ');
 		len = line->size - line->pos;
-		TRACE(("keybloblen %d, len %d", keybloblen, len))
 		/* The only failure with base64 is buffer_overflow, but buf_getwriteptr
 		 * will die horribly in the case anyway */
 		base64_encode(keyblob, keybloblen, buf_getwriteptr(line, len), &len);
@@ -329,3 +413,38 @@ out:
 	}
 	m_free(fingerprint);
 }
+
+void recv_msg_ext_info(void) {
+	/* This message is not client-specific in the protocol but Dropbear only handles
+	a server-sent message at present. */
+	unsigned int num_ext;
+	unsigned int i;
+
+	TRACE(("enter recv_msg_ext_info"))
+
+	/* Must be after the first SSH_MSG_NEWKEYS */
+	TRACE(("last %d, donefirst %d, donescond %d", ses.lastpacket, ses.kexstate.donefirstkex, ses.kexstate.donesecondkex))
+	if (!(ses.lastpacket == SSH_MSG_NEWKEYS && !ses.kexstate.donesecondkex)) {
+		TRACE(("leave recv_msg_ext_info: ignoring packet received at the wrong time"))
+		return;
+	}
+
+	num_ext = buf_getint(ses.payload);
+	TRACE(("received SSH_MSG_EXT_INFO with %d items", num_ext))
+
+	for (i = 0; i < num_ext; i++) {
+		unsigned int name_len;
+		char *ext_name = buf_getstring(ses.payload, &name_len);
+		TRACE(("extension %d name '%s'", i, ext_name))
+		if (cli_ses.server_sig_algs == NULL
+				&& name_len == strlen(SSH_SERVER_SIG_ALGS)
+				&& strcmp(ext_name, SSH_SERVER_SIG_ALGS) == 0) {
+			cli_ses.server_sig_algs = buf_getbuf(ses.payload);
+		} else {
+			/* valid extension values could be >MAX_STRING_LEN */
+			buf_eatstring(ses.payload);
+		}
+		m_free(ext_name);
+	}
+	TRACE(("leave recv_msg_ext_info"))
+}

cli-main.c

@@ -28,55 +28,70 @@
 #include "dbutil.h"
 #include "runopts.h"
 #include "session.h"
+#include "dbrandom.h"
+#include "crypto_desc.h"
+#include "netio.h"
 
-static void cli_dropbear_exit(int exitcode, const char* format, va_list param);
+static void cli_dropbear_exit(int exitcode, const char* format, va_list param) ATTRIB_NORETURN;
 static void cli_dropbear_log(int priority, const char* format, va_list param);
 
-#ifdef ENABLE_CLI_PROXYCMD
-static void cli_proxy_cmd(int *sock_in, int *sock_out);
+#if DROPBEAR_CLI_PROXYCMD
+static void cli_proxy_cmd(int *sock_in, int *sock_out, pid_t *pid_out);
+static void kill_proxy_sighandler(int signo);
 #endif
 
-#if defined(DBMULTI_dbclient) || !defined(DROPBEAR_MULTI)
-#if defined(DBMULTI_dbclient) && defined(DROPBEAR_MULTI)
+#if defined(DBMULTI_dbclient) || !DROPBEAR_MULTI
+#if defined(DBMULTI_dbclient) && DROPBEAR_MULTI
 int cli_main(int argc, char ** argv) {
 #else
 int main(int argc, char ** argv) {
 #endif
 
 	int sock_in, sock_out;
-	char* error = NULL;
+	struct dropbear_progress_connection *progress = NULL;
 
 	_dropbear_exit = cli_dropbear_exit;
 	_dropbear_log = cli_dropbear_log;
 
 	disallow_core();
 
+	seedrandom();
+	crypto_init();
+
 	cli_getopts(argc, argv);
 
-	TRACE(("user='%s' host='%s' port='%s'", cli_opts.username,
-				cli_opts.remotehost, cli_opts.remoteport))
+#ifndef DISABLE_SYSLOG
+	if (opts.usingsyslog) {
+		startsyslog("dbclient");
+	}
+#endif
+
+	TRACE(("user='%s' host='%s' port='%s' bind_address='%s' bind_port='%s'", cli_opts.username,
+				cli_opts.remotehost, cli_opts.remoteport, cli_opts.bind_address, cli_opts.bind_port))
 
 	if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) {
 		dropbear_exit("signal() error");
 	}
 
-#ifdef ENABLE_CLI_PROXYCMD
+	pid_t proxy_cmd_pid = 0;
+#if DROPBEAR_CLI_PROXYCMD
 	if (cli_opts.proxycmd) {
-		cli_proxy_cmd(&sock_in, &sock_out);
+		cli_proxy_cmd(&sock_in, &sock_out, &proxy_cmd_pid);
 		m_free(cli_opts.proxycmd);
+		if (signal(SIGINT, kill_proxy_sighandler) == SIG_ERR ||
+			signal(SIGTERM, kill_proxy_sighandler) == SIG_ERR ||
+			signal(SIGHUP, kill_proxy_sighandler) == SIG_ERR) {
+			dropbear_exit("signal() error");
+		}
 	} else
 #endif
 	{
-		int sock = connect_remote(cli_opts.remotehost, cli_opts.remoteport, 
-				0, &error);
-		sock_in = sock_out = sock;
+		progress = connect_remote(cli_opts.remotehost, cli_opts.remoteport, 
+			cli_connected, &ses, cli_opts.bind_address, cli_opts.bind_port);
+		sock_in = sock_out = -1;
 	}
 
-	if (sock_in < 0) {
-		dropbear_exit("%s", error);
-	}
-
-	cli_session(sock_in, sock_out);
+	cli_session(sock_in, sock_out, progress, proxy_cmd_pid);
 
 	/* not reached */
 	return -1;
@@ -84,40 +99,58 @@ int main(int argc, char ** argv) {
 #endif /* DBMULTI stuff */
 
 static void cli_dropbear_exit(int exitcode, const char* format, va_list param) {
+	char exitmsg[150];
+	char fullmsg[300];
 
-	char fmtbuf[300];
+	/* Note that exit message must be rendered before session cleanup */
 
-	if (!sessinitdone) {
-		snprintf(fmtbuf, sizeof(fmtbuf), "Exited: %s",
-				format);
+	/* Render the formatted exit message */
+	vsnprintf(exitmsg, sizeof(exitmsg), format, param);
+	TRACE(("Exited, cleaning up: %s", exitmsg))
+
+	/* Add the prefix depending on session/auth state */
+	if (!ses.init_done) {
+		snprintf(fullmsg, sizeof(fullmsg), "Exited: %s", exitmsg);
 	} else {
-		snprintf(fmtbuf, sizeof(fmtbuf), 
+		snprintf(fullmsg, sizeof(fullmsg), 
 				"Connection to %s@%s:%s exited: %s", 
 				cli_opts.username, cli_opts.remotehost, 
-				cli_opts.remoteport, format);
+				cli_opts.remoteport, exitmsg);
 	}
 
 	/* Do the cleanup first, since then the terminal will be reset */
-	cli_session_cleanup();
-	common_session_cleanup();
-
-	_dropbear_log(LOG_INFO, fmtbuf, param);
+	session_cleanup();
+	/* Avoid printing onwards from terminal cruft */
+	fprintf(stderr, "\n");
 
+	dropbear_log(LOG_INFO, "%s", fullmsg);
 	exit(exitcode);
 }
 
-static void cli_dropbear_log(int UNUSED(priority), 
+static void cli_dropbear_log(int priority,
 		const char* format, va_list param) {
 
 	char printbuf[1024];
+	const char *name;
+
+	name = cli_opts.progname;
+	if (!name) {
+		name = "dbclient";
+	}
 
 	vsnprintf(printbuf, sizeof(printbuf), format, param);
 
-	fprintf(stderr, "%s: %s\n", cli_opts.progname, printbuf);
+#ifndef DISABLE_SYSLOG
+	if (opts.usingsyslog) {
+		syslog(priority, "%s", printbuf);
+	}
+#endif
 
+	fprintf(stderr, "%s: %s\n", name, printbuf);
+	fflush(stderr);
 }
 
-static void exec_proxy_cmd(void *user_data_cmd) {
+static void exec_proxy_cmd(const void *user_data_cmd) {
 	const char *cmd = user_data_cmd;
 	char *usershell;
 
@@ -126,17 +159,44 @@ static void exec_proxy_cmd(void *user_data_cmd) {
 	dropbear_exit("Failed to run '%s'\n", cmd);
 }
 
-#ifdef ENABLE_CLI_PROXYCMD
-static void cli_proxy_cmd(int *sock_in, int *sock_out) {
+#if DROPBEAR_CLI_PROXYCMD
+static void cli_proxy_cmd(int *sock_in, int *sock_out, pid_t *pid_out) {
+	char * ex_cmd = NULL;
+	size_t ex_cmdlen;
 	int ret;
 
+	/* File descriptor "-j &3" */
+	if (*cli_opts.proxycmd == '&') {
+		char *p = cli_opts.proxycmd + 1;
+		int sock = strtoul(p, &p, 10);
+		/* must be a single number, and not stdin/stdout/stderr */
+		if (sock > 2 && sock < 1024 && *p == '\0') {
+			*sock_in = sock;
+			*sock_out = sock;
+			return;
+		}
+	}
+
+	/* Normal proxycommand */
+
+	/* So that spawn_command knows which shell to run */
 	fill_passwd(cli_opts.own_user);
 
-	ret = spawn_command(exec_proxy_cmd, cli_opts.proxycmd,
-			sock_out, sock_in, NULL, NULL);
+	ex_cmdlen = strlen(cli_opts.proxycmd) + 6; /* "exec " + command + '\0' */
+	ex_cmd = m_malloc(ex_cmdlen);
+	snprintf(ex_cmd, ex_cmdlen, "exec %s", cli_opts.proxycmd);
+
+	ret = spawn_command(exec_proxy_cmd, ex_cmd,
+			sock_out, sock_in, NULL, pid_out);
+	m_free(ex_cmd);
 	if (ret == DROPBEAR_FAILURE) {
 		dropbear_exit("Failed running proxy command");
 		*sock_in = *sock_out = -1;
 	}
 }
-#endif // ENABLE_CLI_PROXYCMD
+
+static void kill_proxy_sighandler(int UNUSED(signo)) {
+	kill_proxy_command();
+	_exit(1);
+}
+#endif /* DROPBEAR_CLI_PROXYCMD */

cli-runopts.c

@@ -33,29 +33,29 @@
 
 cli_runopts cli_opts; /* GLOBAL */
 
-static void printhelp();
+static void printhelp(void);
 static void parse_hostname(const char* orighostarg);
 static void parse_multihop_hostname(const char* orighostarg, const char* argv0);
-static void fill_own_user();
-#ifdef ENABLE_CLI_PUBKEY_AUTH
-static void loadidentityfile(const char* filename);
+static void fill_own_user(void);
+#if DROPBEAR_CLI_PUBKEY_AUTH
+static void loadidentityfile(const char* filename, int warnfail);
 #endif
-#ifdef ENABLE_CLI_ANYTCPFWD
+#if DROPBEAR_CLI_ANYTCPFWD
 static void addforward(const char* str, m_list *fwdlist);
 #endif
-#ifdef ENABLE_CLI_NETCAT
+#if DROPBEAR_CLI_NETCAT
 static void add_netcat(const char *str);
 #endif
+static void add_extendedopt(const char *str);
 
 static void printhelp() {
 
-	fprintf(stderr, "Dropbear client v%s\n"
-#ifdef ENABLE_CLI_MULTIHOP
+	fprintf(stderr, "Dropbear SSH client v%s https://matt.ucc.asn.au/dropbear/dropbear.html\n"
+#if DROPBEAR_CLI_MULTIHOP
 					"Usage: %s [options] [user@]host[/port][,[user@]host/port],...] [command]\n"
 #else
 					"Usage: %s [options] [user@]host[/port] [command]\n"
 #endif
-					"Options are:\n"
 					"-p <remoteport>\n"
 					"-l <username>\n"
 					"-t    Allocate a pty\n"
@@ -63,59 +63,76 @@ static void printhelp() {
 					"-N    Don't run a remote command\n"
 					"-f    Run in background after auth\n"
 					"-y    Always accept remote host key if unknown\n"
-					"-s    Request a subsystem (use for sftp)\n"
-#ifdef ENABLE_CLI_PUBKEY_AUTH
-					"-i <identityfile>   (multiple allowed)\n"
+					"-y -y Don't perform any remote host key checking (caution)\n"
+					"-s    Request a subsystem (use by external sftp)\n"
+					"-o option     Set option in OpenSSH-like format ('-o help' to list options)\n"
+#if DROPBEAR_CLI_PUBKEY_AUTH
+					"-i <identityfile>   (multiple allowed, default %s)\n"
 #endif
-#ifdef ENABLE_CLI_AGENTFWD
+#if DROPBEAR_CLI_AGENTFWD
 					"-A    Enable agent auth forwarding\n"
 #endif
-#ifdef ENABLE_CLI_LOCALTCPFWD
+#if DROPBEAR_CLI_LOCALTCPFWD
 					"-L <[listenaddress:]listenport:remotehost:remoteport> Local port forwarding\n"
 					"-g    Allow remote hosts to connect to forwarded ports\n"
 #endif
-#ifdef ENABLE_CLI_REMOTETCPFWD
+#if DROPBEAR_CLI_REMOTETCPFWD
 					"-R <[listenaddress:]listenport:remotehost:remoteport> Remote port forwarding\n"
 #endif
 					"-W <receive_window_buffer> (default %d, larger may be faster, max 1MB)\n"
 					"-K <keepalive>  (0 is never, default %d)\n"
 					"-I <idle_timeout>  (0 is never, default %d)\n"
-#ifdef ENABLE_CLI_NETCAT
+#if DROPBEAR_CLI_NETCAT
 					"-B <endhost:endport> Netcat-alike forwarding\n"
 #endif				
-#ifdef ENABLE_CLI_PROXYCMD
+#if DROPBEAR_CLI_PROXYCMD
 					"-J <proxy_program> Use program pipe rather than TCP connection\n"
 #endif
-#ifdef DEBUG_TRACE
+#if DROPBEAR_USER_ALGO_LIST
+					"-c <cipher list> Specify preferred ciphers ('-c help' to list options)\n"
+					"-m <MAC list> Specify preferred MACs for packet verification (or '-m help')\n"
+#endif
+					"-b    [bind_address][:bind_port]\n"
+					"-V    Version\n"
+#if DEBUG_TRACE
 					"-v    verbose (compiled with DEBUG_TRACE)\n"
 #endif
 					,DROPBEAR_VERSION, cli_opts.progname,
+#if DROPBEAR_CLI_PUBKEY_AUTH
+					DROPBEAR_DEFAULT_CLI_AUTHKEY,
+#endif
 					DEFAULT_RECV_WINDOW, DEFAULT_KEEPALIVE, DEFAULT_IDLE_TIMEOUT);
 					
 }
 
 void cli_getopts(int argc, char ** argv) {
 	unsigned int i, j;
-	char ** next = 0;
+	char ** next = NULL;
+	enum {
+		OPT_EXTENDED_OPTIONS,
+#if DROPBEAR_CLI_PUBKEY_AUTH
+		OPT_AUTHKEY,
+#endif
+#if DROPBEAR_CLI_LOCALTCPFWD
+		OPT_LOCALTCPFWD,
+#endif
+#if DROPBEAR_CLI_REMOTETCPFWD
+		OPT_REMOTETCPFWD,
+#endif
+#if DROPBEAR_CLI_NETCAT
+		OPT_NETCAT,
+#endif
+		/* a flag (no arg) if 'next' is NULL, a string-valued option otherwise */
+		OPT_OTHER
+	} opt;
 	unsigned int cmdlen;
-#ifdef ENABLE_CLI_PUBKEY_AUTH
-	int nextiskey = 0; /* A flag if the next argument is a keyfile */
-#endif
-#ifdef ENABLE_CLI_LOCALTCPFWD
-	int nextislocal = 0;
-#endif
-#ifdef ENABLE_CLI_REMOTETCPFWD
-	int nextisremote = 0;
-#endif
-#ifdef ENABLE_CLI_NETCAT
-	int nextisnetcat = 0;
-#endif
-	char* dummy = NULL; /* Not used for anything real */
 
 	char* recv_window_arg = NULL;
 	char* keepalive_arg = NULL;
 	char* idle_timeout_arg = NULL;
 	char *host_arg = NULL;
+	char *bind_arg = NULL;
+	char c;
 
 	/* see printhelp() for options */
 	cli_opts.progname = argv[0];
@@ -127,97 +144,81 @@ void cli_getopts(int argc, char ** argv) {
 	cli_opts.backgrounded = 0;
 	cli_opts.wantpty = 9; /* 9 means "it hasn't been touched", gets set later */
 	cli_opts.always_accept_key = 0;
+	cli_opts.no_hostkey_check = 0;
 	cli_opts.is_subsystem = 0;
-#ifdef ENABLE_CLI_PUBKEY_AUTH
+#if DROPBEAR_CLI_PUBKEY_AUTH
 	cli_opts.privkeys = list_new();
 #endif
-#ifdef ENABLE_CLI_LOCALTCPFWD
+#if DROPBEAR_CLI_ANYTCPFWD
+	cli_opts.exit_on_fwd_failure = 0;
+#endif
+#if DROPBEAR_CLI_LOCALTCPFWD
 	cli_opts.localfwds = list_new();
 	opts.listen_fwd_all = 0;
 #endif
-#ifdef ENABLE_CLI_REMOTETCPFWD
+#if DROPBEAR_CLI_REMOTETCPFWD
 	cli_opts.remotefwds = list_new();
 #endif
-#ifdef ENABLE_CLI_AGENTFWD
+#if DROPBEAR_CLI_AGENTFWD
 	cli_opts.agent_fwd = 0;
+	cli_opts.agent_fd = -1;
 	cli_opts.agent_keys_loaded = 0;
 #endif
-#ifdef ENABLE_CLI_PROXYCMD
+#if DROPBEAR_CLI_PROXYCMD
 	cli_opts.proxycmd = NULL;
 #endif
+	cli_opts.bind_address = NULL;
+	cli_opts.bind_port = NULL;
 #ifndef DISABLE_ZLIB
-	opts.enable_compress = 1;
+	opts.compress_mode = DROPBEAR_COMPRESS_ON;
+#endif
+#if DROPBEAR_USER_ALGO_LIST
+	opts.cipher_list = NULL;
+	opts.mac_list = NULL;
+#endif
+#ifndef DISABLE_SYSLOG
+	opts.usingsyslog = 0;
 #endif
 	/* not yet
 	opts.ipv4 = 1;
 	opts.ipv6 = 1;
 	*/
 	opts.recv_window = DEFAULT_RECV_WINDOW;
+	opts.keepalive_secs = DEFAULT_KEEPALIVE;
+	opts.idle_timeout_secs = DEFAULT_IDLE_TIMEOUT;
 
 	fill_own_user();
 
-	/* Iterate all the arguments */
 	for (i = 1; i < (unsigned int)argc; i++) {
-#ifdef ENABLE_CLI_PUBKEY_AUTH
-		if (nextiskey) {
-			/* Load a hostkey since the previous argument was "-i" */
-			loadidentityfile(argv[i]);
-			nextiskey = 0;
-			continue;
-		}
-#endif
-#ifdef ENABLE_CLI_REMOTETCPFWD
-		if (nextisremote) {
-			TRACE(("nextisremote true"))
-			addforward(argv[i], cli_opts.remotefwds);
-			nextisremote = 0;
-			continue;
-		}
-#endif
-#ifdef ENABLE_CLI_LOCALTCPFWD
-		if (nextislocal) {
-			TRACE(("nextislocal true"))
-			addforward(argv[i], cli_opts.localfwds);
-			nextislocal = 0;
-			continue;
-		}
-#endif
-#ifdef ENABLE_CLI_NETCAT
-		if (nextisnetcat) {
-			TRACE(("nextisnetcat true"))
-			add_netcat(argv[i]);
-			nextisnetcat = 0;
-			continue;
-		}
-#endif
-		if (next) {
-			/* The previous flag set a value to assign */
-			*next = argv[i];
-			if (*next == NULL) {
-				dropbear_exit("Invalid null argument");
+		/* Handle non-flag arguments such as hostname or commands for the remote host */
+		if (argv[i][0] != '-')
+		{
+			if (host_arg == NULL) {
+				host_arg = argv[i];
+				continue;
 			}
-			next = NULL;
-			continue;
+			/* Commands to pass to the remote host. No more flag handling,
+			commands are consumed below */
+			break;
 		}
 
-		if (argv[i][0] == '-') {
-			/* A flag *waves* */
-
-			switch (argv[i][1]) {
+		/* Begins with '-' */
+		opt = OPT_OTHER;
+		for (j = 1; (c = argv[i][j]) != '\0' && !next && opt == OPT_OTHER; j++) {
+			switch (c) {
 				case 'y': /* always accept the remote hostkey */
+					if (cli_opts.always_accept_key) {
+						/* twice means no checking at all */
+						cli_opts.no_hostkey_check = 1;
+					}
 					cli_opts.always_accept_key = 1;
 					break;
 				case 'p': /* remoteport */
-					next = &cli_opts.remoteport;
+					next = (char**)&cli_opts.remoteport;
 					break;
-#ifdef ENABLE_CLI_PUBKEY_AUTH
+#if DROPBEAR_CLI_PUBKEY_AUTH
 				case 'i': /* an identityfile */
-					/* Keep scp happy when it changes "-i file" to "-ifile" */
-					if (strlen(argv[i]) > 2) {
-						loadidentityfile(&argv[i][2]);
-					} else  {
-						nextiskey = 1;
-					}
+					opt = OPT_AUTHKEY;
 					break;
 #endif
 				case 't': /* we want a pty */
@@ -235,25 +236,28 @@ void cli_getopts(int argc, char ** argv) {
 				case 's':
 					cli_opts.is_subsystem = 1;
 					break;
-#ifdef ENABLE_CLI_LOCALTCPFWD
+				case 'o':
+					opt = OPT_EXTENDED_OPTIONS;
+					break;
+#if DROPBEAR_CLI_LOCALTCPFWD
 				case 'L':
-					nextislocal = 1;
+					opt = OPT_LOCALTCPFWD;
 					break;
 				case 'g':
 					opts.listen_fwd_all = 1;
 					break;
 #endif
-#ifdef ENABLE_CLI_REMOTETCPFWD
+#if DROPBEAR_CLI_REMOTETCPFWD
 				case 'R':
-					nextisremote = 1;
+					opt = OPT_REMOTETCPFWD;
 					break;
 #endif
-#ifdef ENABLE_CLI_NETCAT
+#if DROPBEAR_CLI_NETCAT
 				case 'B':
-					nextisnetcat = 1;
+					opt = OPT_NETCAT;
 					break;
 #endif
-#ifdef ENABLE_CLI_PROXYCMD
+#if DROPBEAR_CLI_PROXYCMD
 				case 'J':
 					next = &cli_opts.proxycmd;
 					break;
@@ -277,88 +281,161 @@ void cli_getopts(int argc, char ** argv) {
 				case 'I':
 					next = &idle_timeout_arg;
 					break;
-#ifdef ENABLE_CLI_AGENTFWD
+#if DROPBEAR_CLI_AGENTFWD
 				case 'A':
 					cli_opts.agent_fwd = 1;
 					break;
 #endif
-#ifdef DEBUG_TRACE
+#if DROPBEAR_USER_ALGO_LIST
+				case 'c':
+					next = &opts.cipher_list;
+					break;
+				case 'm':
+					next = &opts.mac_list;
+					break;
+#endif
+#if DEBUG_TRACE
 				case 'v':
 					debug_trace = 1;
 					break;
 #endif
 				case 'F':
 				case 'e':
+#if !DROPBEAR_USER_ALGO_LIST
 				case 'c':
 				case 'm':
+#endif
 				case 'D':
-#ifndef ENABLE_CLI_REMOTETCPFWD
+#if !DROPBEAR_CLI_REMOTETCPFWD
 				case 'R':
 #endif
-#ifndef ENABLE_CLI_LOCALTCPFWD
+#if !DROPBEAR_CLI_LOCALTCPFWD
 				case 'L':
 #endif
-				case 'o':
+				case 'V':
+					print_version();
+					exit(EXIT_SUCCESS);
+					break;
 				case 'b':
-					next = &dummy;
+					next = &bind_arg;
+					break;
 				default:
-					fprintf(stderr, 
-						"WARNING: Ignoring unknown argument '%s'\n", argv[i]);
+					fprintf(stderr,
+						"WARNING: Ignoring unknown option -%c\n", c);
 					break;
 			} /* Switch */
-			
-			/* Now we handle args where they might be "-luser" (no spaces)*/
-			if (next && strlen(argv[i]) > 2) {
-				*next = &argv[i][2];
-				next = NULL;
-			}
-
-			continue; /* next argument */
-
-		} else {
-			TRACE(("non-flag arg: '%s'", argv[i]))
-
-			/* Either the hostname or commands */
-
-			if (host_arg == NULL) {
-				host_arg = argv[i];
-			} else {
-
-				/* this is part of the commands to send - after this we
-				 * don't parse any more options, and flags are sent as the
-				 * command */
-				cmdlen = 0;
-				for (j = i; j < (unsigned int)argc; j++) {
-					cmdlen += strlen(argv[j]) + 1; /* +1 for spaces */
-				}
-				/* Allocate the space */
-				cli_opts.cmd = (char*)m_malloc(cmdlen);
-				cli_opts.cmd[0] = '\0';
-
-				/* Append all the bits */
-				for (j = i; j < (unsigned int)argc; j++) {
-					strlcat(cli_opts.cmd, argv[j], cmdlen);
-					strlcat(cli_opts.cmd, " ", cmdlen);
-				}
-				/* It'll be null-terminated here */
-
-				/* We've eaten all the options and flags */
-				break;
-			}
 		}
+
+		if (!next && opt == OPT_OTHER) /* got a flag */
+			continue;
+
+		if (c == '\0') {
+			i++;
+			j = 0;
+			if (!argv[i])
+				dropbear_exit("Missing argument");
+		}
+
+		if (opt == OPT_EXTENDED_OPTIONS) {
+			TRACE(("opt extended"))
+			add_extendedopt(&argv[i][j]);
+		}
+		else
+#if DROPBEAR_CLI_PUBKEY_AUTH
+		if (opt == OPT_AUTHKEY) {
+			TRACE(("opt authkey"))
+			loadidentityfile(&argv[i][j], 1);
+		}
+		else
+#endif
+#if DROPBEAR_CLI_REMOTETCPFWD
+		if (opt == OPT_REMOTETCPFWD) {
+			TRACE(("opt remotetcpfwd"))
+			addforward(&argv[i][j], cli_opts.remotefwds);
+		}
+		else
+#endif
+#if DROPBEAR_CLI_LOCALTCPFWD
+		if (opt == OPT_LOCALTCPFWD) {
+			TRACE(("opt localtcpfwd"))
+			addforward(&argv[i][j], cli_opts.localfwds);
+		}
+		else
+#endif
+#if DROPBEAR_CLI_NETCAT
+		if (opt == OPT_NETCAT) {
+			TRACE(("opt netcat"))
+			add_netcat(&argv[i][j]);
+		}
+		else
+#endif
+		if (next) {
+			/* The previous flag set a value to assign */
+			*next = &argv[i][j];
+			if (*next == NULL)
+				dropbear_exit("Invalid null argument");
+			next = NULL;
+		}
+	}
+
+#if DROPBEAR_USER_ALGO_LIST
+	/* -c help doesn't need a hostname */
+	parse_ciphers_macs();
+#endif
+
+	/* Done with options/flags; now handle the hostname (which may not
+	 * start with a hyphen) and optional command */
+
+	if (host_arg == NULL) { /* missing hostname */
+		printhelp();
+		exit(EXIT_FAILURE);
+	}
+	TRACE(("host is: %s", host_arg))
+
+	if (i < (unsigned int)argc) {
+		/* Build the command to send */
+		cmdlen = 0;
+		for (j = i; j < (unsigned int)argc; j++)
+			cmdlen += strlen(argv[j]) + 1; /* +1 for spaces */
+
+		/* Allocate the space */
+		cli_opts.cmd = (char*)m_malloc(cmdlen);
+		cli_opts.cmd[0] = '\0';
+
+		/* Append all the bits */
+		for (j = i; j < (unsigned int)argc; j++) {
+			strlcat(cli_opts.cmd, argv[j], cmdlen);
+			strlcat(cli_opts.cmd, " ", cmdlen);
+		}
+		/* It'll be null-terminated here */
+		TRACE(("cmd is: %s", cli_opts.cmd))
 	}
 
 	/* And now a few sanity checks and setup */
 
-	if (host_arg == NULL) {
-		printhelp();
-		exit(EXIT_FAILURE);
+#if DROPBEAR_CLI_PROXYCMD                                                                                                                                   
+	if (cli_opts.proxycmd) {
+		/* To match the common path of m_freeing it */
+		cli_opts.proxycmd = m_strdup(cli_opts.proxycmd);
 	}
+#endif
 
 	if (cli_opts.remoteport == NULL) {
 		cli_opts.remoteport = "22";
 	}
 
+	if (bind_arg) {
+		/* split [host][:port] */
+		char *port = strrchr(bind_arg, ':');
+		if (port) {
+			cli_opts.bind_port = m_strdup(port+1);
+			*port = '\0';
+		}
+		if (strlen(bind_arg) > 0) {
+			cli_opts.bind_address = m_strdup(bind_arg);
+		}
+	}
+
 	/* If not explicitly specified with -t or -T, we don't want a pty if
 	 * there's a command, but we do otherwise */
 	if (cli_opts.wantpty == 9) {
@@ -396,31 +473,43 @@ void cli_getopts(int argc, char ** argv) {
 		opts.idle_timeout_secs = val;
 	}
 
-#ifdef ENABLE_CLI_NETCAT
+#if DROPBEAR_CLI_NETCAT
 	if (cli_opts.cmd && cli_opts.netcat_host) {
 		dropbear_log(LOG_INFO, "Ignoring command '%s' in netcat mode", cli_opts.cmd);
 	}
 #endif
 
+#if (DROPBEAR_CLI_PUBKEY_AUTH)
+	{
+		char *expand_path = expand_homedir_path(DROPBEAR_DEFAULT_CLI_AUTHKEY);
+		loadidentityfile(expand_path, 0);
+		m_free(expand_path);
+	}
+#endif
+
 	/* The hostname gets set up last, since
 	 * in multi-hop mode it will require knowledge
 	 * of other flags such as -i */
-#ifdef ENABLE_CLI_MULTIHOP
+#if DROPBEAR_CLI_MULTIHOP
 	parse_multihop_hostname(host_arg, argv[0]);
 #else
 	parse_hostname(host_arg);
 #endif
 }
 
-#ifdef ENABLE_CLI_PUBKEY_AUTH
-static void loadidentityfile(const char* filename) {
+#if DROPBEAR_CLI_PUBKEY_AUTH
+static void loadidentityfile(const char* filename, int warnfail) {
 	sign_key *key;
-	int keytype;
+	enum signkey_type keytype;
+
+	TRACE(("loadidentityfile %s", filename))
 
 	key = new_sign_key();
 	keytype = DROPBEAR_SIGNKEY_ANY;
 	if ( readhostkey(filename, key, &keytype) != DROPBEAR_SUCCESS ) {
-		fprintf(stderr, "Failed loading keyfile '%s'\n", filename);
+		if (warnfail) {
+			dropbear_log(LOG_WARNING, "Failed loading keyfile '%s'\n", filename);
+		}
 		sign_key_free(key);
 	} else {
 		key->type = keytype;
@@ -431,7 +520,7 @@ static void loadidentityfile(const char* filename) {
 }
 #endif
 
-#ifdef ENABLE_CLI_MULTIHOP
+#if DROPBEAR_CLI_MULTIHOP
 
 static char*
 multihop_passthrough_args() {
@@ -439,31 +528,53 @@ multihop_passthrough_args() {
 	int total;
 	unsigned int len = 0;
 	m_list_elem *iter;
-	/* Fill out -i and -W options that make sense for all
+	/* Fill out -i, -y, -W options that make sense for all
 	 * the intermediate processes */
+#if DROPBEAR_CLI_PUBKEY_AUTH
 	for (iter = cli_opts.privkeys->first; iter; iter = iter->next)
 	{
 		sign_key * key = (sign_key*)iter->item;
 		len += 3 + strlen(key->filename);
 	}
-	len += 20; // space for -W <size>, terminator.
+#endif /* DROPBEAR_CLI_PUBKEY_AUTH */
+
+	len += 30; /* space for -W <size>, terminator. */
 	ret = m_malloc(len);
 	total = 0;
 
-	if (opts.recv_window != DEFAULT_RECV_WINDOW)
+	if (cli_opts.no_hostkey_check)
 	{
-		int written = snprintf(ret+total, len-total, "-W %d", opts.recv_window);
+		int written = snprintf(ret+total, len-total, "-y -y ");
+		total += written;
+	}
+	else if (cli_opts.always_accept_key)
+	{
+		int written = snprintf(ret+total, len-total, "-y ");
 		total += written;
 	}
 
+	if (opts.recv_window != DEFAULT_RECV_WINDOW)
+	{
+		int written = snprintf(ret+total, len-total, "-W %u ", opts.recv_window);
+		total += written;
+	}
+
+#if DROPBEAR_CLI_PUBKEY_AUTH
 	for (iter = cli_opts.privkeys->first; iter; iter = iter->next)
 	{
 		sign_key * key = (sign_key*)iter->item;
 		const size_t size = len - total;
-		int written = snprintf(ret+total, size, "-i %s", key->filename);
+		int written = snprintf(ret+total, size, "-i %s ", key->filename);
 		dropbear_assert((unsigned int)written < size);
 		total += written;
 	}
+#endif /* DROPBEAR_CLI_PUBKEY_AUTH */
+
+	/* if args were passed, total will be not zero, and it will have a space at the end, so remove that */
+	if (total > 0) 
+	{
+		total--;
+	}
 
 	return ret;
 }
@@ -535,13 +646,13 @@ static void parse_multihop_hostname(const char* orighostarg, const char* argv0)
 				passthrough_args, remainder);
 #ifndef DISABLE_ZLIB
 		/* The stream will be incompressible since it's encrypted. */
-		opts.enable_compress = 0;
+		opts.compress_mode = DROPBEAR_COMPRESS_OFF;
 #endif
 		m_free(passthrough_args);
 	}
 	m_free(hostbuf);
 }
-#endif /* !ENABLE_CLI_MULTIHOP */
+#endif /* !DROPBEAR_CLI_MULTIHOP */
 
 /* Parses a [user@]hostname[/port] argument. */
 static void parse_hostname(const char* orighostarg) {
@@ -565,7 +676,11 @@ static void parse_hostname(const char* orighostarg) {
 		cli_opts.username = m_strdup(cli_opts.own_user);
 	}
 
-	port = strchr(cli_opts.remotehost, '/');
+	port = strchr(cli_opts.remotehost, '^');
+	if (!port)  {
+		/* legacy separator */
+		port = strchr(cli_opts.remotehost, '/');
+	}
 	if (port) {
 		*port = '\0';
 		cli_opts.remoteport = port+1;
@@ -576,7 +691,7 @@ static void parse_hostname(const char* orighostarg) {
 	}
 }
 
-#ifdef ENABLE_CLI_NETCAT
+#if DROPBEAR_CLI_NETCAT
 static void add_netcat(const char* origstr) {
 	char *portstr = NULL;
 	
@@ -620,14 +735,16 @@ static void fill_own_user() {
 	uid = getuid();
 
 	pw = getpwuid(uid);
-	if (pw == NULL || pw->pw_name == NULL) {
-		dropbear_exit("Unknown own user");
+	if (pw && pw->pw_name != NULL) {
+		cli_opts.own_user = m_strdup(pw->pw_name);
+	} else {
+		dropbear_log(LOG_INFO, "Warning: failed to identify current user. Trying anyway.");
+		cli_opts.own_user = m_strdup("unknown");
 	}
 
-	cli_opts.own_user = m_strdup(pw->pw_name);
 }
 
-#ifdef ENABLE_CLI_ANYTCPFWD
+#if DROPBEAR_CLI_ANYTCPFWD
 /* Turn a "[listenaddr:]listenport:remoteaddr:remoteport" string into into a forwarding
  * set, and add it to the forwarding list */
 static void addforward(const char* origstr, m_list *fwdlist) {
@@ -722,3 +839,82 @@ badport:
 	dropbear_exit("Bad TCP port in '%s'", origstr);
 }
 #endif
+
+static int match_extendedopt(const char** strptr, const char *optname) {
+	int seen_eq = 0;
+	int optlen = strlen(optname);
+	const char *str = *strptr;
+
+	while (isspace(*str)) {
+		++str;
+	}
+
+	if (strncasecmp(str, optname, optlen) != 0) {
+		return DROPBEAR_FAILURE;
+	}
+
+	str += optlen;
+
+	while (isspace(*str) || (!seen_eq && *str == '=')) {
+		if (*str == '=') {
+			seen_eq = 1;
+		}
+		++str;
+	}
+
+	if (str-*strptr == optlen) {
+		/* matched just a prefix of optname */
+		return DROPBEAR_FAILURE;
+	}
+
+	*strptr = str;
+	return DROPBEAR_SUCCESS;
+}
+
+static int parse_flag_value(const char *value) {
+	if (strcmp(value, "yes") == 0 || strcmp(value, "true") == 0) {
+		return 1;
+	} else if (strcmp(value, "no") == 0 || strcmp(value, "false") == 0) {
+		return 0;
+	}
+
+	dropbear_exit("Bad yes/no argument '%s'", value);
+}
+
+static void add_extendedopt(const char* origstr) {
+	const char *optstr = origstr;
+
+	if (strcmp(origstr, "help") == 0) {
+		dropbear_log(LOG_INFO, "Available options:\n"
+#if DROPBEAR_CLI_ANYTCPFWD
+			"\tExitOnForwardFailure\n"
+#endif
+#ifndef DISABLE_SYSLOG
+			"\tUseSyslog\n"
+#endif
+			"\tPort\n"
+		);
+		exit(EXIT_SUCCESS);
+	}
+
+#if DROPBEAR_CLI_ANYTCPFWD
+	if (match_extendedopt(&optstr, "ExitOnForwardFailure") == DROPBEAR_SUCCESS) {
+		cli_opts.exit_on_fwd_failure = parse_flag_value(optstr);
+		return;
+	}
+#endif
+
+#ifndef DISABLE_SYSLOG
+	if (match_extendedopt(&optstr, "UseSyslog") == DROPBEAR_SUCCESS) {
+		opts.usingsyslog = parse_flag_value(optstr);
+		return;
+	}
+#endif
+
+	if (match_extendedopt(&optstr, "Port") == DROPBEAR_SUCCESS) {
+		cli_opts.remoteport = optstr;
+		return;
+	}
+
+	dropbear_log(LOG_WARNING, "Ignoring unknown configuration option '%s'", origstr);
+}

cli-service.c

@@ -1,85 +0,0 @@
-/*
- * Dropbear SSH
- * 
- * Copyright (c) 2002,2003 Matt Johnston
- * Copyright (c) 2004 by Mihnea Stoenescu
- * All rights reserved.
- * 
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- * 
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- * 
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE. */
-
-#include "includes.h"
-#include "service.h"
-#include "dbutil.h"
-#include "packet.h"
-#include "buffer.h"
-#include "session.h"
-#include "ssh.h"
-
-void send_msg_service_request(char* servicename) {
-
-	TRACE(("enter send_msg_service_request: servicename='%s'", servicename))
-
-	CHECKCLEARTOWRITE();
-
-	buf_putbyte(ses.writepayload, SSH_MSG_SERVICE_REQUEST);
-	buf_putstring(ses.writepayload, servicename, strlen(servicename));
-
-	encrypt_packet();
-	TRACE(("leave send_msg_service_request"))
-}
-
-/* This just sets up the state variables right for the main client session loop
- * to deal with */
-void recv_msg_service_accept() {
-
-	unsigned char* servicename;
-	unsigned int len;
-
-	TRACE(("enter recv_msg_service_accept"))
-
-	servicename = buf_getstring(ses.payload, &len);
-
-	/* ssh-userauth */
-	if (cli_ses.state == SERVICE_AUTH_REQ_SENT
-			&& len == SSH_SERVICE_USERAUTH_LEN
-			&& strncmp(SSH_SERVICE_USERAUTH, servicename, len) == 0) {
-
-		cli_ses.state = SERVICE_AUTH_ACCEPT_RCVD;
-		m_free(servicename);
-		TRACE(("leave recv_msg_service_accept: done ssh-userauth"))
-		return;
-	}
-
-	/* ssh-connection */
-	if (cli_ses.state == SERVICE_CONN_REQ_SENT
-			&& len == SSH_SERVICE_CONNECTION_LEN 
-			&& strncmp(SSH_SERVICE_CONNECTION, servicename, len) == 0) {
-
-		if (ses.authstate.authdone != 1) {
-			dropbear_exit("Request for connection before auth");
-		}
-
-		cli_ses.state = SERVICE_CONN_ACCEPT_RCVD;
-		m_free(servicename);
-		TRACE(("leave recv_msg_service_accept: done ssh-connection"))
-		return;
-	}
-
-	dropbear_exit("Unrecognised service accept");
-}

cli-session.c

@@ -31,16 +31,21 @@
 #include "packet.h"
 #include "tcpfwd.h"
 #include "channel.h"
-#include "random.h"
+#include "dbrandom.h"
 #include "service.h"
 #include "runopts.h"
 #include "chansession.h"
 #include "agentfwd.h"
+#include "crypto_desc.h"
+#include "netio.h"
 
-static void cli_remoteclosed();
-static void cli_sessionloop();
-static void cli_session_init();
-static void cli_finished();
+static void cli_remoteclosed(void) ATTRIB_NORETURN;
+static void cli_sessionloop(void);
+static void cli_session_init(pid_t proxy_cmd_pid);
+static void cli_finished(void) ATTRIB_NORETURN;
+static void recv_msg_service_accept(void);
+static void cli_session_cleanup(void);
+static void recv_msg_global_request_cli(void);
 
 struct clientsession cli_ses; /* GLOBAL */
 
@@ -65,41 +70,61 @@ static const packettype cli_packettypes[] = {
 	{SSH_MSG_CHANNEL_OPEN_FAILURE, recv_msg_channel_open_failure},
 	{SSH_MSG_USERAUTH_BANNER, recv_msg_userauth_banner}, /* client */
 	{SSH_MSG_USERAUTH_SPECIFIC_60, recv_msg_userauth_specific_60}, /* client */
-#ifdef  ENABLE_CLI_REMOTETCPFWD
+	{SSH_MSG_GLOBAL_REQUEST, recv_msg_global_request_cli},
+	{SSH_MSG_CHANNEL_SUCCESS, ignore_recv_response},
+	{SSH_MSG_CHANNEL_FAILURE, ignore_recv_response},
+#if DROPBEAR_CLI_REMOTETCPFWD
 	{SSH_MSG_REQUEST_SUCCESS, cli_recv_msg_request_success}, /* client */
 	{SSH_MSG_REQUEST_FAILURE, cli_recv_msg_request_failure}, /* client */
+#else
+	/* For keepalive */
+	{SSH_MSG_REQUEST_SUCCESS, ignore_recv_response},
+	{SSH_MSG_REQUEST_FAILURE, ignore_recv_response},
 #endif
-	{0, 0} /* End */
+	{SSH_MSG_EXT_INFO, recv_msg_ext_info},
+	{0, NULL} /* End */
 };
 
 static const struct ChanType *cli_chantypes[] = {
-#ifdef ENABLE_CLI_REMOTETCPFWD
+#if DROPBEAR_CLI_REMOTETCPFWD
 	&cli_chan_tcpremote,
 #endif
-#ifdef ENABLE_CLI_AGENTFWD
+#if DROPBEAR_CLI_AGENTFWD
 	&cli_chan_agent,
 #endif
 	NULL /* Null termination */
 };
 
-void cli_session(int sock_in, int sock_out) {
+void cli_connected(int result, int sock, void* userdata, const char *errstring)
+{
+	struct sshsession *myses = userdata;
+	if (result == DROPBEAR_FAILURE) {
+		dropbear_exit("Connect failed: %s", errstring);
+	}
+	myses->sock_in = myses->sock_out = sock;
+	update_channel_prio();
+}
 
-	seedrandom();
-
-	crypto_init();
+void cli_session(int sock_in, int sock_out, struct dropbear_progress_connection *progress, pid_t proxy_cmd_pid) {
 
 	common_session_init(sock_in, sock_out);
 
+	if (progress) {
+		connect_set_writequeue(progress, &ses.writequeue);
+	}
+
 	chaninitialise(cli_chantypes);
 
 	/* Set up cli_ses vars */
-	cli_session_init();
+	cli_session_init(proxy_cmd_pid);
 
 	/* Ready to go */
-	sessinitdone = 1;
+	ses.init_done = 1;
 
 	/* Exchange identification */
-	session_identification();
+	send_session_identification();
+
+	kexfirstinitialise(); /* initialise the kex state */
 
 	send_msg_kexinit();
 
@@ -109,7 +134,13 @@ void cli_session(int sock_in, int sock_out) {
 
 }
 
-static void cli_session_init() {
+#if DROPBEAR_KEX_FIRST_FOLLOWS
+static void cli_send_kex_first_guess() {
+	send_msg_kexdh_init();
+}
+#endif
+
+static void cli_session_init(pid_t proxy_cmd_pid) {
 
 	cli_ses.state = STATE_NOTHING;
 	cli_ses.kex_state = KEX_NOTHING;
@@ -128,6 +159,8 @@ static void cli_session_init() {
 
 	cli_ses.retval = EXIT_SUCCESS; /* Assume it's clean if we don't get a
 									  specific exit status */
+	cli_ses.proxy_cmd_pid = proxy_cmd_pid;
+	TRACE(("proxy command PID='%d'", proxy_cmd_pid));
 
 	/* Auth */
 	cli_ses.lastprivkey = NULL;
@@ -135,37 +168,61 @@ static void cli_session_init() {
 
 	/* For printing "remote host closed" for the user */
 	ses.remoteclosed = cli_remoteclosed;
-	ses.buf_match_algo = cli_buf_match_algo;
+
+	ses.extra_session_cleanup = cli_session_cleanup;
 
 	/* packet handlers */
 	ses.packettypes = cli_packettypes;
 
 	ses.isserver = 0;
+
+#if DROPBEAR_KEX_FIRST_FOLLOWS
+	ses.send_kex_first_guess = cli_send_kex_first_guess;
+#endif
+
+}
+
+static void send_msg_service_request(const char* servicename) {
+
+	TRACE(("enter send_msg_service_request: servicename='%s'", servicename))
+
+	CHECKCLEARTOWRITE();
+
+	buf_putbyte(ses.writepayload, SSH_MSG_SERVICE_REQUEST);
+	buf_putstring(ses.writepayload, servicename, strlen(servicename));
+
+	encrypt_packet();
+	TRACE(("leave send_msg_service_request"))
+}
+
+static void recv_msg_service_accept(void) {
+	/* do nothing, if it failed then the server MUST have disconnected */
 }
 
 /* This function drives the progress of the session - it initiates KEX,
  * service, userauth and channel requests */
 static void cli_sessionloop() {
 
-	TRACE(("enter cli_sessionloop"))
+	TRACE2(("enter cli_sessionloop"))
 
-	if (ses.lastpacket == SSH_MSG_KEXINIT && cli_ses.kex_state == KEX_NOTHING) {
-		cli_ses.kex_state = KEXINIT_RCVD;
+	if (ses.lastpacket == 0) {
+		TRACE2(("exit cli_sessionloop: no real packets yet"))
+		return;
 	}
 
-	if (cli_ses.kex_state == KEXINIT_RCVD) {
-
+	if (ses.lastpacket == SSH_MSG_KEXINIT && cli_ses.kex_state == KEX_NOTHING) {
 		/* We initiate the KEXDH. If DH wasn't the correct type, the KEXINIT
 		 * negotiation would have failed. */
-		send_msg_kexdh_init();
-		cli_ses.kex_state = KEXDH_INIT_SENT;
+		if (!ses.kexstate.our_first_follows_matches) {
+			send_msg_kexdh_init();
+		}
+		cli_ses.kex_state = KEXDH_INIT_SENT;			
 		TRACE(("leave cli_sessionloop: done with KEXINIT_RCVD"))
 		return;
 	}
 
 	/* A KEX has finished, so we should go back to our KEX_NOTHING state */
-	if (cli_ses.kex_state != KEX_NOTHING && ses.kexstate.recvkexinit == 0
-			&& ses.kexstate.sentkexinit == 0) {
+	if (cli_ses.kex_state != KEX_NOTHING && ses.kexstate.sentnewkeys) {
 		cli_ses.kex_state = KEX_NOTHING;
 	}
 
@@ -175,10 +232,10 @@ static void cli_sessionloop() {
 		return;
 	}
 
-	/* We should exit if we haven't donefirstkex: we shouldn't reach here
-	 * in normal operation */
 	if (ses.kexstate.donefirstkex == 0) {
-		TRACE(("XXX XXX might be bad! leave cli_sessionloop: haven't donefirstkex"))
+		/* We might reach here if we have partial packet reads or have
+		 * received SSG_MSG_IGNORE etc. Just skip it */
+		TRACE2(("donefirstkex false\n"))
 		return;
 	}
 
@@ -188,30 +245,35 @@ static void cli_sessionloop() {
 			/* We've got the transport layer sorted, we now need to request
 			 * userauth */
 			send_msg_service_request(SSH_SERVICE_USERAUTH);
-			cli_ses.state = SERVICE_AUTH_REQ_SENT;
-			TRACE(("leave cli_sessionloop: sent userauth service req"))
-			return;
-
-		/* userauth code */
-		case SERVICE_AUTH_ACCEPT_RCVD:
 			cli_auth_getmethods();
 			cli_ses.state = USERAUTH_REQ_SENT;
 			TRACE(("leave cli_sessionloop: sent userauth methods req"))
 			return;
+
+		case USERAUTH_REQ_SENT:
+			TRACE(("leave cli_sessionloop: waiting, req_sent"))
+			return;
 			
 		case USERAUTH_FAIL_RCVD:
-			cli_auth_try();
+			if (cli_auth_try() == DROPBEAR_FAILURE) {
+				dropbear_exit("No auth methods could be used.");
+			}
 			cli_ses.state = USERAUTH_REQ_SENT;
 			TRACE(("leave cli_sessionloop: cli_auth_try"))
 			return;
 
 		case USERAUTH_SUCCESS_RCVD:
+#ifndef DISABLE_SYSLOG
+			if (opts.usingsyslog) {
+				dropbear_log(LOG_INFO, "Authentication succeeded.");
+			}
+#endif
 
 			if (cli_opts.backgrounded) {
 				int devnull;
 				/* keeping stdin open steals input from the terminal and
 				   is confusing, though stdout/stderr could be useful. */
-				devnull = open(_PATH_DEVNULL, O_RDONLY);
+				devnull = open(DROPBEAR_PATH_DEVNULL, O_RDONLY);
 				if (devnull < 0) {
 					dropbear_exit("Opening /dev/null: %d %s",
 							errno, strerror(errno));
@@ -223,14 +285,7 @@ static void cli_sessionloop() {
 				}
 			}
 			
-#ifdef ENABLE_CLI_LOCALTCPFWD
-			setup_localtcp();
-#endif
-#ifdef ENABLE_CLI_REMOTETCPFWD
-			setup_remotetcp();
-#endif
-
-#ifdef ENABLE_CLI_NETCAT
+#if DROPBEAR_CLI_NETCAT
 			if (cli_opts.netcat_host) {
 				cli_send_netcat_request();
 			} else 
@@ -238,6 +293,14 @@ static void cli_sessionloop() {
 			if (!cli_opts.no_cmd) {
 				cli_send_chansess_request();
 			}
+
+#if DROPBEAR_CLI_LOCALTCPFWD
+			setup_localtcp();
+#endif
+#if DROPBEAR_CLI_REMOTETCPFWD
+			setup_remotetcp();
+#endif
+
 			TRACE(("leave cli_sessionloop: running"))
 			cli_ses.state = SESSION_RUNNING;
 			return;
@@ -259,30 +322,46 @@ static void cli_sessionloop() {
 		break;
 	}
 
-	TRACE(("leave cli_sessionloop: fell out"))
+	TRACE2(("leave cli_sessionloop: fell out"))
 
 }
 
-void cli_session_cleanup() {
+void kill_proxy_command(void) {
+	/*
+	 * Send SIGHUP to proxy command if used. We don't wait() in
+	 * case it hangs and instead rely on init to reap the child
+	 */
+	if (cli_ses.proxy_cmd_pid > 1) {
+		TRACE(("killing proxy command with PID='%d'", cli_ses.proxy_cmd_pid));
+		kill(cli_ses.proxy_cmd_pid, SIGHUP);
+	}
+}
 
-	if (!sessinitdone) {
+static void cli_session_cleanup(void) {
+
+	if (!ses.init_done) {
 		return;
 	}
 
+	kill_proxy_command();
+
 	/* Set std{in,out,err} back to non-blocking - busybox ash dies nastily if
 	 * we don't revert the flags */
-	fcntl(cli_ses.stdincopy, F_SETFL, cli_ses.stdinflags);
-	fcntl(cli_ses.stdoutcopy, F_SETFL, cli_ses.stdoutflags);
-	fcntl(cli_ses.stderrcopy, F_SETFL, cli_ses.stderrflags);
+	/* Ignore return value since there's nothing we can do */
+	(void)fcntl(cli_ses.stdincopy, F_SETFL, cli_ses.stdinflags);
+	(void)fcntl(cli_ses.stdoutcopy, F_SETFL, cli_ses.stdoutflags);
+	(void)fcntl(cli_ses.stderrcopy, F_SETFL, cli_ses.stderrflags);
 
 	cli_tty_cleanup();
-
+	if (cli_ses.server_sig_algs) {
+		buf_free(cli_ses.server_sig_algs);
+	}
 }
 
 static void cli_finished() {
+	TRACE(("cli_finished()"))
 
-	cli_session_cleanup();
-	common_session_cleanup();
+	session_cleanup();
 	fprintf(stderr, "Connection to %s@%s:%s closed.\n", cli_opts.username,
 			cli_opts.remotehost, cli_opts.remoteport);
 	exit(cli_ses.retval);
@@ -304,10 +383,10 @@ static void cli_remoteclosed() {
 /* Operates in-place turning dirty (untrusted potentially containing control
  * characters) text into clean text. 
  * Note: this is safe only with ascii - other charsets could have problems. */
-void cleantext(unsigned char* dirtytext) {
+void cleantext(char* dirtytext) {
 
 	unsigned int i, j;
-	unsigned char c;
+	char c;
 
 	j = 0;
 	for (i = 0; dirtytext[i] != '\0'; i++) {
@@ -322,3 +401,9 @@ void cleantext(unsigned char* dirtytext) {
 	/* Null terminate */
 	dirtytext[j] = '\0';
 }
+
+static void recv_msg_global_request_cli(void) {
+	TRACE(("recv_msg_global_request_cli"))
+	/* Send a proper rejection */
+	send_msg_request_failure();
+}

cli-tcpfwd.c

@@ -23,15 +23,15 @@
  * SOFTWARE. */
 
 #include "includes.h"
-#include "options.h"
 #include "dbutil.h"
 #include "tcpfwd.h"
 #include "channel.h"
 #include "runopts.h"
 #include "session.h"
 #include "ssh.h"
+#include "netio.h"
 
-#ifdef ENABLE_CLI_REMOTETCPFWD
+#if DROPBEAR_CLI_REMOTETCPFWD
 static int newtcpforwarded(struct Channel * channel);
 
 const struct ChanType cli_chan_tcpremote = {
@@ -40,11 +40,12 @@ const struct ChanType cli_chan_tcpremote = {
 	newtcpforwarded,
 	NULL,
 	NULL,
+	NULL,
 	NULL
 };
 #endif
 
-#ifdef ENABLE_CLI_LOCALTCPFWD
+#if DROPBEAR_CLI_LOCALTCPFWD
 static int cli_localtcp(const char* listenaddr, 
 		unsigned int listenport, 
 		const char* remoteaddr,
@@ -52,6 +53,7 @@ static int cli_localtcp(const char* listenaddr,
 static const struct ChanType cli_chan_tcplocal = {
 	1, /* sepfds */
 	"direct-tcpip",
+	tcp_prio_inithandler,
 	NULL,
 	NULL,
 	NULL,
@@ -59,7 +61,24 @@ static const struct ChanType cli_chan_tcplocal = {
 };
 #endif
 
-#ifdef ENABLE_CLI_LOCALTCPFWD
+#if DROPBEAR_CLI_ANYTCPFWD
+static void fwd_failed(const char* format, ...) ATTRIB_PRINTF(1,2);
+static void fwd_failed(const char* format, ...)
+{
+	va_list param;
+	va_start(param, format);
+
+	if (cli_opts.exit_on_fwd_failure) {
+		_dropbear_exit(EXIT_FAILURE, format, param);
+	} else {
+		_dropbear_log(LOG_WARNING, format, param);
+	}
+
+	va_end(param);
+}
+#endif
+
+#if DROPBEAR_CLI_LOCALTCPFWD
 void setup_localtcp() {
 	m_list_elem *iter;
 	int ret;
@@ -74,7 +93,7 @@ void setup_localtcp() {
 				fwd->connectaddr,
 				fwd->connectport);
 		if (ret == DROPBEAR_FAILURE) {
-			dropbear_log(LOG_WARNING, "Failed local port forward %s:%d:%s:%d",
+			fwd_failed("Failed local port forward %s:%d:%s:%d",
 					fwd->listenaddr,
 					fwd->listenport,
 					fwd->connectaddr,
@@ -118,7 +137,7 @@ static int cli_localtcp(const char* listenaddr,
 	tcpinfo->chantype = &cli_chan_tcplocal;
 	tcpinfo->tcp_type = direct;
 
-	ret = listen_tcpfwd(tcpinfo);
+	ret = listen_tcpfwd(tcpinfo, NULL);
 
 	if (ret == DROPBEAR_FAILURE) {
 		m_free(tcpinfo);
@@ -126,9 +145,9 @@ static int cli_localtcp(const char* listenaddr,
 	TRACE(("leave cli_localtcp: %d", ret))
 	return ret;
 }
-#endif /* ENABLE_CLI_LOCALTCPFWD */
+#endif /* DROPBEAR_CLI_LOCALTCPFWD */
 
-#ifdef  ENABLE_CLI_REMOTETCPFWD
+#if DROPBEAR_CLI_REMOTETCPFWD
 static void send_msg_global_request_remotetcp(const char *addr, int port) {
 
 	TRACE(("enter send_msg_global_request_remotetcp"))
@@ -148,15 +167,27 @@ static void send_msg_global_request_remotetcp(const char *addr, int port) {
 /* The only global success/failure messages are for remotetcp.
  * Since there isn't any identifier in these messages, we have to rely on them
  * being in the same order as we sent the requests. This is the ordering
- * of the cli_opts.remotefwds list */
+ * of the cli_opts.remotefwds list.
+ * If the requested remote port is 0 the listen port will be
+ * dynamically allocated by the server and the port number will be returned
+ * to client and the port number reported to the user. */
 void cli_recv_msg_request_success() {
-	/* Nothing in the packet. We just mark off that we have received the reply,
+	/* We just mark off that we have received the reply,
 	 * so that we can report failure for later ones. */
 	m_list_elem * iter = NULL;
 	for (iter = cli_opts.remotefwds->first; iter; iter = iter->next) {
 		struct TCPFwdEntry *fwd = (struct TCPFwdEntry*)iter->item;
 		if (!fwd->have_reply) {
 			fwd->have_reply = 1;
+			if (fwd->listenport == 0) {
+				/* The server should let us know which port was allocated if we requested port 0 */
+				int allocport = buf_getint(ses.payload);
+				if (allocport > 0) {
+					fwd->listenport = allocport;
+					dropbear_log(LOG_INFO, "Allocated port %d for remote forward to %s:%d", 
+							allocport, fwd->connectaddr, fwd->connectport);
+				}
+			}
 			return;
 		}
 	}
@@ -168,7 +199,10 @@ void cli_recv_msg_request_failure() {
 		struct TCPFwdEntry *fwd = (struct TCPFwdEntry*)iter->item;
 		if (!fwd->have_reply) {
 			fwd->have_reply = 1;
-			dropbear_log(LOG_WARNING, "Remote TCP forward request failed (port %d -> %s:%d)", fwd->listenport, fwd->connectaddr, fwd->connectport);
+			fwd_failed("Remote TCP forward request failed (port %d -> %s:%d)",
+					fwd->listenport,
+					fwd->connectaddr,
+					fwd->connectport);
 			return;
 		}
 	}
@@ -182,8 +216,8 @@ void setup_remotetcp() {
 		struct TCPFwdEntry *fwd = (struct TCPFwdEntry*)iter->item;
 		if (!fwd->listenaddr)
 		{
-			// we store the addresses so that we can compare them
-			// when the server sends them back
+			/* we store the addresses so that we can compare them
+			   when the server sends them back */
 			if (opts.listen_fwd_all) {
 				fwd->listenaddr = m_strdup("");
 			} else {
@@ -198,48 +232,52 @@ void setup_remotetcp() {
 
 static int newtcpforwarded(struct Channel * channel) {
 
-    char *origaddr = NULL;
+	char *origaddr = NULL;
 	unsigned int origport;
 	m_list_elem * iter = NULL;
-	struct TCPFwdEntry *fwd;
+	struct TCPFwdEntry *fwd = NULL;
 	char portstring[NI_MAXSERV];
-	int sock;
 	int err = SSH_OPEN_ADMINISTRATIVELY_PROHIBITED;
 
 	origaddr = buf_getstring(ses.payload, NULL);
 	origport = buf_getint(ses.payload);
 
-	/* Find which port corresponds */
+	/* Find which port corresponds. First try and match address as well as port,
+	in case they want to forward different ports separately ... */
 	for (iter = cli_opts.remotefwds->first; iter; iter = iter->next) {
 		fwd = (struct TCPFwdEntry*)iter->item;
 		if (origport == fwd->listenport
-				&& (strcmp(origaddr, fwd->listenaddr) == 0)) {
+				&& strcmp(origaddr, fwd->listenaddr) == 0) {
 			break;
 		}
 	}
 
-	if (iter == NULL) {
+	if (!iter)
+	{
+		/* ... otherwise try to generically match the only forwarded port 
+		without address (also handles ::1 vs 127.0.0.1 vs localhost case).
+		rfc4254 is vague about the definition of "address that was connected" */
+		for (iter = cli_opts.remotefwds->first; iter; iter = iter->next) {
+			fwd = (struct TCPFwdEntry*)iter->item;
+			if (origport == fwd->listenport) {
+				break;
+			}
+		}
+	}
+
+
+	if (iter == NULL || fwd == NULL) {
 		/* We didn't request forwarding on that port */
-        cleantext(origaddr);
+		cleantext(origaddr);
 		dropbear_log(LOG_INFO, "Server sent unrequested forward from \"%s:%d\"", 
                 origaddr, origport);
 		goto out;
 	}
 	
-	snprintf(portstring, sizeof(portstring), "%d", fwd->connectport);
-	sock = connect_remote(fwd->connectaddr, portstring, 1, NULL);
-	if (sock < 0) {
-		TRACE(("leave newtcpdirect: sock failed"))
-		err = SSH_OPEN_CONNECT_FAILED;
-		goto out;
-	}
+	snprintf(portstring, sizeof(portstring), "%u", fwd->connectport);
+	channel->conn_pending = connect_remote(fwd->connectaddr, portstring, channel_connect_done, channel, NULL, NULL);
 
-	ses.maxfd = MAX(ses.maxfd, sock);
-
-	/* We don't set readfd, that will get set after the connection's
-	 * progress succeeds */
-	channel->writefd = sock;
-	channel->initconn = 1;
+	channel->prio = DROPBEAR_CHANNEL_PRIO_UNKNOWABLE;
 	
 	err = SSH_OPEN_IN_PROGRESS;
 
@@ -248,4 +286,4 @@ out:
 	TRACE(("leave newtcpdirect: err %d", err))
 	return err;
 }
-#endif /* ENABLE_CLI_REMOTETCPFWD */
+#endif /* DROPBEAR_CLI_REMOTETCPFWD */

common-algo.c

@@ -23,52 +23,56 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
+#include "includes.h"
 #include "algo.h"
+#include "session.h"
 #include "dbutil.h"
+#include "dh_groups.h"
+#include "ltc_prng.h"
+#include "ecc.h"
+#include "gcm.h"
+#include "chachapoly.h"
+#include "ssh.h"
 
 /* This file (algo.c) organises the ciphers which can be used, and is used to
  * decide which ciphers/hashes/compression/signing to use during key exchange*/
 
 static int void_cipher(const unsigned char* in, unsigned char* out,
-		unsigned long len, void *cipher_state) {
+		unsigned long len, void* UNUSED(cipher_state)) {
 	if (in != out) {
 		memmove(out, in, len);
 	}
 	return CRYPT_OK;
 }
 
-static int void_start(int cipher, const unsigned char *IV, 
-			const unsigned char *key, 
-			int keylen, int num_rounds, void *cipher_state) {
+static int void_start(int UNUSED(cipher), const unsigned char* UNUSED(IV), 
+			const unsigned char* UNUSED(key), 
+			int UNUSED(keylen), int UNUSED(num_rounds), void* UNUSED(cipher_state)) {
 	return CRYPT_OK;
 }
 
 /* Mappings for ciphers, parameters are
    {&cipher_desc, keysize, blocksize} */
-/* NOTE: if keysize > 2*SHA1_HASH_SIZE, code such as hashkeys()
-   needs revisiting */
 
-#ifdef DROPBEAR_AES256
+/* Remember to add new ciphers/hashes to regciphers/reghashes too */
+
+#if DROPBEAR_AES256
 static const struct dropbear_cipher dropbear_aes256 = 
 	{&aes_desc, 32, 16};
 #endif
-#ifdef DROPBEAR_AES128
+#if DROPBEAR_AES128
 static const struct dropbear_cipher dropbear_aes128 = 
 	{&aes_desc, 16, 16};
 #endif
-#ifdef DROPBEAR_BLOWFISH
-static const struct dropbear_cipher dropbear_blowfish = 
-	{&blowfish_desc, 16, 8};
-#endif
-#ifdef DROPBEAR_TWOFISH256
+#if DROPBEAR_TWOFISH256
 static const struct dropbear_cipher dropbear_twofish256 = 
 	{&twofish_desc, 32, 16};
 #endif
-#ifdef DROPBEAR_TWOFISH128
+#if DROPBEAR_TWOFISH128
 static const struct dropbear_cipher dropbear_twofish128 = 
 	{&twofish_desc, 16, 16};
 #endif
-#ifdef DROPBEAR_3DES
+#if DROPBEAR_3DES
 static const struct dropbear_cipher dropbear_3des = 
 	{&des3_desc, 24, 8};
 #endif
@@ -79,11 +83,15 @@ const struct dropbear_cipher dropbear_nocipher =
 
 /* A few void* s are required to silence warnings
  * about the symmetric_CBC vs symmetric_CTR cipher_state pointer */
+#if DROPBEAR_ENABLE_CBC_MODE
 const struct dropbear_cipher_mode dropbear_mode_cbc =
-	{(void*)cbc_start, (void*)cbc_encrypt, (void*)cbc_decrypt};
+	{(void*)cbc_start, (void*)cbc_encrypt, (void*)cbc_decrypt, NULL, NULL, NULL};
+#endif /* DROPBEAR_ENABLE_CBC_MODE */
+
 const struct dropbear_cipher_mode dropbear_mode_none =
-	{void_start, void_cipher, void_cipher};
-#ifdef DROPBEAR_ENABLE_CTR_MODE
+	{void_start, void_cipher, void_cipher, NULL, NULL, NULL};
+
+#if DROPBEAR_ENABLE_CTR_MODE
 /* a wrapper to make ctr_start and cbc_start look the same */
 static int dropbear_big_endian_ctr_start(int cipher, 
 		const unsigned char *IV, 
@@ -92,21 +100,29 @@ static int dropbear_big_endian_ctr_start(int cipher,
 	return ctr_start(cipher, IV, key, keylen, num_rounds, CTR_COUNTER_BIG_ENDIAN, ctr);
 }
 const struct dropbear_cipher_mode dropbear_mode_ctr =
-	{(void*)dropbear_big_endian_ctr_start, (void*)ctr_encrypt, (void*)ctr_decrypt};
-#endif
+	{(void*)dropbear_big_endian_ctr_start, (void*)ctr_encrypt, (void*)ctr_decrypt, NULL, NULL, NULL};
+#endif /* DROPBEAR_ENABLE_CTR_MODE */
 
 /* Mapping of ssh hashes to libtomcrypt hashes, including keysize etc.
    {&hash_desc, keysize, hashsize} */
 
-#ifdef DROPBEAR_SHA1_HMAC
+#if DROPBEAR_SHA1_HMAC
 static const struct dropbear_hash dropbear_sha1 = 
 	{&sha1_desc, 20, 20};
 #endif
-#ifdef DROPBEAR_SHA1_96_HMAC
+#if DROPBEAR_SHA1_96_HMAC
 static const struct dropbear_hash dropbear_sha1_96 = 
 	{&sha1_desc, 20, 12};
 #endif
-#ifdef DROPBEAR_MD5_HMAC
+#if DROPBEAR_SHA2_256_HMAC
+static const struct dropbear_hash dropbear_sha2_256 = 
+	{&sha256_desc, 32, 32};
+#endif
+#if DROPBEAR_SHA2_512_HMAC
+static const struct dropbear_hash dropbear_sha2_512 =
+	{&sha512_desc, 64, 64};
+#endif
+#if DROPBEAR_MD5_HMAC
 static const struct dropbear_hash dropbear_md5 = 
 	{&md5_desc, 16, 16};
 #endif
@@ -120,57 +136,95 @@ const struct dropbear_hash dropbear_nohash =
  * that is also supported by the server will get used. */
 
 algo_type sshciphers[] = {
-#ifdef DROPBEAR_ENABLE_CTR_MODE
-#ifdef DROPBEAR_AES128
+#if DROPBEAR_CHACHA20POLY1305
+	{"chacha20-poly1305@openssh.com", 0, &dropbear_chachapoly, 1, &dropbear_mode_chachapoly},
+#endif
+
+#if DROPBEAR_ENABLE_GCM_MODE
+#if DROPBEAR_AES128
+	{"aes128-gcm@openssh.com", 0, &dropbear_aes128, 1, &dropbear_mode_gcm},
+#endif
+#if DROPBEAR_AES256
+	{"aes256-gcm@openssh.com", 0, &dropbear_aes256, 1, &dropbear_mode_gcm},
+#endif
+#endif /* DROPBEAR_ENABLE_GCM_MODE */
+
+#if DROPBEAR_ENABLE_CTR_MODE
+#if DROPBEAR_AES128
 	{"aes128-ctr", 0, &dropbear_aes128, 1, &dropbear_mode_ctr},
 #endif
-#ifdef DROPBEAR_3DES
-	{"3des-ctr", 0, &dropbear_3des, 1, &dropbear_mode_ctr},
-#endif
-#ifdef DROPBEAR_AES256
+#if DROPBEAR_AES256
 	{"aes256-ctr", 0, &dropbear_aes256, 1, &dropbear_mode_ctr},
 #endif
+#if DROPBEAR_TWOFISH_CTR
+/* twofish ctr is conditional as it hasn't been tested for interoperability, see options.h */
+#if DROPBEAR_TWOFISH256
+	{"twofish256-ctr", 0, &dropbear_twofish256, 1, &dropbear_mode_ctr},
+#endif
+#if DROPBEAR_TWOFISH128
+	{"twofish128-ctr", 0, &dropbear_twofish128, 1, &dropbear_mode_ctr},
+#endif
+#endif /* DROPBEAR_TWOFISH_CTR */
 #endif /* DROPBEAR_ENABLE_CTR_MODE */
 
-/* CBC modes are always enabled */
-#ifdef DROPBEAR_AES128
+#if DROPBEAR_ENABLE_CBC_MODE
+#if DROPBEAR_AES128
 	{"aes128-cbc", 0, &dropbear_aes128, 1, &dropbear_mode_cbc},
 #endif
-#ifdef DROPBEAR_3DES
-	{"3des-cbc", 0, &dropbear_3des, 1, &dropbear_mode_cbc},
-#endif
-#ifdef DROPBEAR_AES256
+#if DROPBEAR_AES256
 	{"aes256-cbc", 0, &dropbear_aes256, 1, &dropbear_mode_cbc},
 #endif
-#ifdef DROPBEAR_TWOFISH256
+#if DROPBEAR_TWOFISH256
 	{"twofish256-cbc", 0, &dropbear_twofish256, 1, &dropbear_mode_cbc},
 	{"twofish-cbc", 0, &dropbear_twofish256, 1, &dropbear_mode_cbc},
 #endif
-#ifdef DROPBEAR_TWOFISH128
+#if DROPBEAR_TWOFISH128
 	{"twofish128-cbc", 0, &dropbear_twofish128, 1, &dropbear_mode_cbc},
 #endif
-#ifdef DROPBEAR_BLOWFISH
-	{"blowfish-cbc", 0, &dropbear_blowfish, 1, &dropbear_mode_cbc},
+#endif /* DROPBEAR_ENABLE_CBC_MODE */
+
+#if DROPBEAR_3DES
+#if DROPBEAR_ENABLE_CTR_MODE
+	{"3des-ctr", 0, &dropbear_3des, 1, &dropbear_mode_ctr},
 #endif
+#if DROPBEAR_ENABLE_CBC_MODE
+	{"3des-cbc", 0, &dropbear_3des, 1, &dropbear_mode_cbc},
+#endif
+#endif /* DROPBEAR_3DES */
+
+#if DROPBEAR_ENABLE_CBC_MODE
+#endif /* DROPBEAR_ENABLE_CBC_MODE */
 	{NULL, 0, NULL, 0, NULL}
 };
 
 algo_type sshhashes[] = {
-#ifdef DROPBEAR_SHA1_96_HMAC
+#if DROPBEAR_SHA1_96_HMAC
 	{"hmac-sha1-96", 0, &dropbear_sha1_96, 1, NULL},
 #endif
-#ifdef DROPBEAR_SHA1_HMAC
+#if DROPBEAR_SHA1_HMAC
 	{"hmac-sha1", 0, &dropbear_sha1, 1, NULL},
 #endif
-#ifdef DROPBEAR_MD5_HMAC
-	{"hmac-md5", 0, &dropbear_md5, 1, NULL},
+#if DROPBEAR_SHA2_256_HMAC
+	{"hmac-sha2-256", 0, &dropbear_sha2_256, 1, NULL},
+#endif
+#if DROPBEAR_SHA2_512_HMAC
+	{"hmac-sha2-512", 0, &dropbear_sha2_512, 1, NULL},
+#endif
+#if DROPBEAR_MD5_HMAC
+	{"hmac-md5", 0, (void*)&dropbear_md5, 1, NULL},
 #endif
 	{NULL, 0, NULL, 0, NULL}
 };
 
 #ifndef DISABLE_ZLIB
 algo_type ssh_compress[] = {
+	{"zlib@openssh.com", DROPBEAR_COMP_ZLIB_DELAY, NULL, 1, NULL},
 	{"zlib", DROPBEAR_COMP_ZLIB, NULL, 1, NULL},
+	{"none", DROPBEAR_COMP_NONE, NULL, 1, NULL},
+	{NULL, 0, NULL, 0, NULL}
+};
+
+algo_type ssh_delaycompress[] = {
 	{"zlib@openssh.com", DROPBEAR_COMP_ZLIB_DELAY, NULL, 1, NULL},
 	{"none", DROPBEAR_COMP_NONE, NULL, 1, NULL},
 	{NULL, 0, NULL, 0, NULL}
@@ -182,103 +236,369 @@ algo_type ssh_nocompress[] = {
 	{NULL, 0, NULL, 0, NULL}
 };
 
-algo_type sshhostkey[] = {
-#ifdef DROPBEAR_RSA
-	{"ssh-rsa", DROPBEAR_SIGNKEY_RSA, NULL, 1, NULL},
+algo_type sigalgs[] = {
+#if DROPBEAR_ED25519
+	{"ssh-ed25519", DROPBEAR_SIGNATURE_ED25519, NULL, 1, NULL},
 #endif
-#ifdef DROPBEAR_DSS
-	{"ssh-dss", DROPBEAR_SIGNKEY_DSS, NULL, 1, NULL},
+#if DROPBEAR_ECDSA
+#if DROPBEAR_ECC_256
+	{"ecdsa-sha2-nistp256", DROPBEAR_SIGNATURE_ECDSA_NISTP256, NULL, 1, NULL},
+#endif
+#if DROPBEAR_ECC_384
+	{"ecdsa-sha2-nistp384", DROPBEAR_SIGNATURE_ECDSA_NISTP384, NULL, 1, NULL},
+#endif
+#if DROPBEAR_ECC_521
+	{"ecdsa-sha2-nistp521", DROPBEAR_SIGNATURE_ECDSA_NISTP521, NULL, 1, NULL},
+#endif
+#endif
+#if DROPBEAR_RSA
+#if DROPBEAR_RSA_SHA256
+	{"rsa-sha2-256", DROPBEAR_SIGNATURE_RSA_SHA256, NULL, 1, NULL},
+#endif
+#if DROPBEAR_RSA_SHA1
+	{"ssh-rsa", DROPBEAR_SIGNATURE_RSA_SHA1, NULL, 1, NULL},
+#endif
+#endif
+#if DROPBEAR_DSS
+	{"ssh-dss", DROPBEAR_SIGNATURE_DSS, NULL, 1, NULL},
 #endif
 	{NULL, 0, NULL, 0, NULL}
 };
 
+#if DROPBEAR_DH_GROUP1
+static const struct dropbear_kex kex_dh_group1 = {DROPBEAR_KEX_NORMAL_DH, dh_p_1, DH_P_1_LEN, NULL, &sha1_desc };
+#endif
+#if DROPBEAR_DH_GROUP14_SHA1
+static const struct dropbear_kex kex_dh_group14_sha1 = {DROPBEAR_KEX_NORMAL_DH, dh_p_14, DH_P_14_LEN, NULL, &sha1_desc };
+#endif
+#if DROPBEAR_DH_GROUP14_SHA256
+static const struct dropbear_kex kex_dh_group14_sha256 = {DROPBEAR_KEX_NORMAL_DH, dh_p_14, DH_P_14_LEN, NULL, &sha256_desc };
+#endif
+#if DROPBEAR_DH_GROUP16
+static const struct dropbear_kex kex_dh_group16_sha512 = {DROPBEAR_KEX_NORMAL_DH, dh_p_16, DH_P_16_LEN, NULL, &sha512_desc };
+#endif
+
+#if DROPBEAR_ECDH
+#if DROPBEAR_ECC_256
+static const struct dropbear_kex kex_ecdh_nistp256 = {DROPBEAR_KEX_ECDH, NULL, 0, &ecc_curve_nistp256, &sha256_desc };
+#endif
+#if DROPBEAR_ECC_384
+static const struct dropbear_kex kex_ecdh_nistp384 = {DROPBEAR_KEX_ECDH, NULL, 0, &ecc_curve_nistp384, &sha384_desc };
+#endif
+#if DROPBEAR_ECC_521
+static const struct dropbear_kex kex_ecdh_nistp521 = {DROPBEAR_KEX_ECDH, NULL, 0, &ecc_curve_nistp521, &sha512_desc };
+#endif
+#endif /* DROPBEAR_ECDH */
+
+#if DROPBEAR_CURVE25519
+/* Referred to directly */
+static const struct dropbear_kex kex_curve25519 = {DROPBEAR_KEX_CURVE25519, NULL, 0, NULL, &sha256_desc };
+#endif
+
+/* data == NULL for non-kex algorithm identifiers */
 algo_type sshkex[] = {
-	{"diffie-hellman-group1-sha1", DROPBEAR_KEX_DH_GROUP1, NULL, 1, NULL},
-	{"diffie-hellman-group14-sha1", DROPBEAR_KEX_DH_GROUP14, NULL, 1, NULL},
+#if DROPBEAR_CURVE25519
+	{"curve25519-sha256", 0, &kex_curve25519, 1, NULL},
+	{"curve25519-sha256@libssh.org", 0, &kex_curve25519, 1, NULL},
+#endif
+#if DROPBEAR_ECDH
+#if DROPBEAR_ECC_521
+	{"ecdh-sha2-nistp521", 0, &kex_ecdh_nistp521, 1, NULL},
+#endif
+#if DROPBEAR_ECC_384
+	{"ecdh-sha2-nistp384", 0, &kex_ecdh_nistp384, 1, NULL},
+#endif
+#if DROPBEAR_ECC_256
+	{"ecdh-sha2-nistp256", 0, &kex_ecdh_nistp256, 1, NULL},
+#endif
+#endif
+#if DROPBEAR_DH_GROUP14_SHA256
+	{"diffie-hellman-group14-sha256", 0, &kex_dh_group14_sha256, 1, NULL},
+#endif
+#if DROPBEAR_DH_GROUP14_SHA1
+	{"diffie-hellman-group14-sha1", 0, &kex_dh_group14_sha1, 1, NULL},
+#endif
+#if DROPBEAR_DH_GROUP1
+	{"diffie-hellman-group1-sha1", 0, &kex_dh_group1, 1, NULL},
+#endif
+#if DROPBEAR_DH_GROUP16
+	{"diffie-hellman-group16-sha512", 0, &kex_dh_group16_sha512, 1, NULL},
+#endif
+#if DROPBEAR_KEXGUESS2
+	{KEXGUESS2_ALGO_NAME, 0, NULL, 1, NULL},
+#endif
+#if DROPBEAR_EXT_INFO
+#if DROPBEAR_CLIENT
+	/* Set unusable by svr_algos_initialise() */
+	{SSH_EXT_INFO_C, 0, NULL, 1, NULL},
+#endif
+#endif
 	{NULL, 0, NULL, 0, NULL}
 };
 
-
-/* Register the compiled in ciphers.
- * This should be run before using any of the ciphers/hashes */
-void crypto_init() {
-
-	const struct ltc_cipher_descriptor *regciphers[] = {
-#ifdef DROPBEAR_AES
-		&aes_desc,
-#endif
-#ifdef DROPBEAR_BLOWFISH
-		&blowfish_desc,
-#endif
-#ifdef DROPBEAR_TWOFISH
-		&twofish_desc,
-#endif
-#ifdef DROPBEAR_3DES
-		&des3_desc,
-#endif
-		NULL
-	};
-
-	const struct ltc_hash_descriptor *reghashes[] = {
-		/* we need sha1 for hostkey stuff regardless */
-		&sha1_desc,
-#ifdef DROPBEAR_MD5_HMAC
-		&md5_desc,
-#endif
-		NULL
-	};	
-	int i;
-	
-	for (i = 0; regciphers[i] != NULL; i++) {
-		if (register_cipher(regciphers[i]) == -1) {
-			dropbear_exit("Error registering crypto");
-		}
-	}
-
-	for (i = 0; reghashes[i] != NULL; i++) {
-		if (register_hash(reghashes[i]) == -1) {
-			dropbear_exit("Error registering crypto");
-		}
-	}
-}
-
-/* algolen specifies the length of algo, algos is our local list to match
- * against.
- * Returns DROPBEAR_SUCCESS if we have a match for algo, DROPBEAR_FAILURE
- * otherwise */
-int have_algo(char* algo, size_t algolen, algo_type algos[]) {
-
-	int i;
-
-	for (i = 0; algos[i].name != NULL; i++) {
-		if (strlen(algos[i].name) == algolen
-				&& (strncmp(algos[i].name, algo, algolen) == 0)) {
-			return DROPBEAR_SUCCESS;
-		}
-	}
-
-	return DROPBEAR_FAILURE;
-}
-
-
-
 /* Output a comma separated list of algorithms to a buffer */
-void buf_put_algolist(buffer * buf, algo_type localalgos[]) {
-
+void buf_put_algolist_all(buffer * buf, const algo_type localalgos[], int useall) {
 	unsigned int i, len;
 	unsigned int donefirst = 0;
-	buffer *algolist = NULL;
+	unsigned int startpos;
 
-	algolist = buf_new(160);
+	startpos = buf->pos;
+	/* Placeholder for length */
+	buf_putint(buf, 0); 
 	for (i = 0; localalgos[i].name != NULL; i++) {
-		if (localalgos[i].usable) {
-			if (donefirst)
-				buf_putbyte(algolist, ',');
+		if (localalgos[i].usable || useall) {
+			if (donefirst) {
+				buf_putbyte(buf, ',');
+			}
 			donefirst = 1;
 			len = strlen(localalgos[i].name);
-			buf_putbytes(algolist, localalgos[i].name, len);
+			buf_putbytes(buf, (const unsigned char *) localalgos[i].name, len);
 		}
 	}
-	buf_putstring(buf, algolist->data, algolist->len);
-	buf_free(algolist);
+	/* Fill out the length */
+	len = buf->pos - startpos - 4;
+	buf_setpos(buf, startpos);
+	buf_putint(buf, len);
+	TRACE(("algolist add %d '%*s'", len, len, buf_getptr(buf, len)))
+	buf_incrwritepos(buf, len);
 }
+
+void buf_put_algolist(buffer * buf, const algo_type localalgos[]) {
+	buf_put_algolist_all(buf, localalgos, 0);
+}
+
+/* returns a list of pointers into algolist, of null-terminated names.
+   ret_list should be passed in with space for *ret_count elements,
+   on return *ret_count has the number of names filled.
+   algolist is modified. */
+static void get_algolist(char* algolist, unsigned int algolist_len,
+				const char* *ret_list, unsigned int *ret_count) {
+	unsigned int max_count = *ret_count;
+	unsigned int i;
+
+	if (*ret_count == 0) {
+		return;
+	}
+	if (algolist_len > MAX_PROPOSED_ALGO*(MAX_NAME_LEN+1)) {
+		*ret_count = 0;
+		}
+
+	/* ret_list will contain a list of the strings parsed out.
+	   We will have at least one string (even if it's just "") */
+	ret_list[0] = algolist;
+	*ret_count = 1;
+	for (i = 0; i < algolist_len; i++) {
+		if (algolist[i] == '\0') {
+			/* someone is trying something strange */
+			*ret_count = 0;
+			return;
+	}
+
+		if (algolist[i] == ',') {
+			if (*ret_count >= max_count) {
+				/* Too many */
+				*ret_count = 0;
+				return;
+			}
+			algolist[i] = '\0';
+			ret_list[*ret_count] = &algolist[i+1];
+			(*ret_count)++;
+		}
+	}
+}
+
+/* Return DROPBEAR_SUCCESS if the namelist contains algo,
+DROPBEAR_FAILURE otherwise. buf position is not incremented. */
+int buf_has_algo(buffer *buf, const char *algo) {
+	unsigned char* algolist = NULL;
+	unsigned int orig_pos = buf->pos;
+	unsigned int len, remotecount, i;
+	const char *remotenames[MAX_PROPOSED_ALGO];
+	int ret = DROPBEAR_FAILURE;
+
+	algolist = buf_getstring(buf, &len);
+	remotecount = MAX_PROPOSED_ALGO;
+	get_algolist(algolist, len, remotenames, &remotecount);
+	for (i = 0; i < remotecount; i++)
+	{
+		if (strcmp(remotenames[i], algo) == 0) {
+			ret = DROPBEAR_SUCCESS;
+			break;
+		}
+	}
+	if (algolist) {
+		m_free(algolist);
+	}
+	buf_setpos(buf, orig_pos);
+	return ret;
+}
+
+algo_type * first_usable_algo(algo_type algos[]) {
+	int i;
+	for (i = 0; algos[i].name != NULL; i++) {
+		if (algos[i].usable) {
+			return &algos[i];
+		}
+	}
+	return NULL;
+}
+
+/* match the first algorithm in the comma-separated list in buf which is
+ * also in localalgos[], or return NULL on failure.
+ * (*goodguess) is set to 1 if the preferred client/server algos match,
+ * 0 otherwise. This is used for checking if the kexalgo/hostkeyalgos are
+ * guessed correctly */
+algo_type * buf_match_algo(buffer* buf, algo_type localalgos[],
+		int kexguess2, int *goodguess) {
+	char * algolist = NULL;
+	const char *remotenames[MAX_PROPOSED_ALGO], *localnames[MAX_PROPOSED_ALGO];
+	unsigned int len;
+	unsigned int remotecount, localcount, clicount, servcount, i, j;
+	algo_type * ret = NULL;
+	const char **clinames, **servnames;
+
+	if (goodguess) {
+		*goodguess = 0;
+	}
+
+	/* get the comma-separated list from the buffer ie "algo1,algo2,algo3" */
+	algolist = buf_getstring(buf, &len);
+	TRACE(("buf_match_algo: %s", algolist))
+	remotecount = MAX_PROPOSED_ALGO;
+	get_algolist(algolist, len, remotenames, &remotecount);
+
+	for (i = 0; localalgos[i].name != NULL; i++) {
+		if (localalgos[i].usable) {
+			localnames[i] = localalgos[i].name;
+		} else {
+			localnames[i] = NULL;
+		}
+	}
+	localcount = i;
+
+	if (IS_DROPBEAR_SERVER) {
+		clinames = remotenames;
+		clicount = remotecount;
+		servnames = localnames;
+		servcount = localcount;
+	} else {
+		clinames = localnames;
+		clicount = localcount;
+		servnames = remotenames;
+		servcount = remotecount;
+	}
+
+	/* iterate and find the first match */
+	for (i = 0; i < clicount; i++) {
+		for (j = 0; j < servcount; j++) {
+			if (!(servnames[j] && clinames[i])) {
+				/* unusable algos are NULL */
+				continue;
+			}
+			if (strcmp(servnames[j], clinames[i]) == 0) {
+				/* set if it was a good guess */
+				if (goodguess != NULL) {
+					if (kexguess2) {
+						if (i == 0) {
+							*goodguess = 1;
+						}
+					} else {
+						if (i == 0 && j == 0) {
+							*goodguess = 1;
+						}
+					}
+				}
+				/* set the algo to return */
+				if (IS_DROPBEAR_SERVER) {
+					ret = &localalgos[j];
+				} else {
+					ret = &localalgos[i];
+				}
+				goto out;
+			}
+		}
+	}
+
+out:
+	m_free(algolist);
+	return ret;
+}
+
+#if DROPBEAR_USER_ALGO_LIST
+
+char *
+algolist_string(const algo_type algos[])
+{
+	char *ret_list;
+	buffer *b = buf_new(200);
+	buf_put_algolist(b, algos);
+	buf_setpos(b, b->len);
+	buf_putbyte(b, '\0');
+	buf_setpos(b, 4);
+	ret_list = m_strdup((const char *) buf_getptr(b, b->len - b->pos));
+	buf_free(b);
+	return ret_list;
+}
+
+static algo_type*
+check_algo(const char* algo_name, algo_type *algos)
+{
+	algo_type *a;
+	for (a = algos; a->name != NULL; a++)
+	{
+		if (strcmp(a->name, algo_name) == 0)
+		{
+			return a;
+		}
+	}
+
+	return NULL;
+}
+
+/* Checks a user provided comma-separated algorithm list for available
+ * options. Any that are not acceptable are removed in-place. Returns the
+ * number of valid algorithms. */
+int
+check_user_algos(const char* user_algo_list, algo_type * algos, 
+		const char *algo_desc)
+{
+	algo_type new_algos[MAX_PROPOSED_ALGO+1];
+	char *work_list = m_strdup(user_algo_list);
+	char *start = work_list;
+	char *c;
+	int n;
+	/* So we can iterate and look for null terminator */
+	memset(new_algos, 0x0, sizeof(new_algos));
+	for (c = work_list, n = 0; ; c++)
+	{
+		char oc = *c;
+		if (n >= MAX_PROPOSED_ALGO) {
+			dropbear_exit("Too many algorithms '%s'", user_algo_list);
+		}
+		if (*c == ',' || *c == '\0') {
+			algo_type *match_algo = NULL;
+			*c = '\0';
+			match_algo = check_algo(start, algos);
+			if (match_algo) {
+				if (check_algo(start, new_algos)) {
+					TRACE(("Skip repeated algorithm '%s'", start))
+				} else {
+					new_algos[n] = *match_algo;
+					n++;
+				}
+			} else {
+				dropbear_log(LOG_WARNING, "This Dropbear program does not support '%s' %s algorithm", start, algo_desc);
+			}
+			c++;
+			start = c;
+		}
+		if (oc == '\0') {
+			break;
+		}
+	}
+	m_free(work_list);
+	/* n+1 to include a null terminator */
+	memcpy(algos, new_algos, sizeof(*new_algos) * (n+1));
+	return n;
+}
+#endif /* DROPBEAR_USER_ALGO_LIST */

common-channel.c

@@ -32,25 +32,24 @@
 #include "circbuffer.h"
 #include "dbutil.h"
 #include "channel.h"
-#include "ssh.h"
 #include "listener.h"
 #include "runopts.h"
+#include "netio.h"
 
 static void send_msg_channel_open_failure(unsigned int remotechan, int reason,
-		const unsigned char *text, const unsigned char *lang);
-static void send_msg_channel_open_confirmation(struct Channel* channel,
+		const char *text, const char *lang);
+static void send_msg_channel_open_confirmation(const struct Channel* channel,
 		unsigned int recvwindow, 
 		unsigned int recvmaxpacket);
-static void writechannel(struct Channel* channel, int fd, circbuffer *cbuf);
-static void send_msg_channel_window_adjust(struct Channel *channel, 
+static int writechannel(struct Channel* channel, int fd, circbuffer *cbuf,
+	const unsigned char *moredata, unsigned int *morelen);
+static void send_msg_channel_window_adjust(const struct Channel *channel,
 		unsigned int incr);
 static void send_msg_channel_data(struct Channel *channel, int isextended);
 static void send_msg_channel_eof(struct Channel *channel);
 static void send_msg_channel_close(struct Channel *channel);
 static void remove_channel(struct Channel *channel);
-static void delete_channel(struct Channel *channel);
-static void check_in_progress(struct Channel *channel);
-static unsigned int write_pending(struct Channel * channel);
+static unsigned int write_pending(const struct Channel * channel);
 static void check_close(struct Channel *channel);
 static void close_chan_fd(struct Channel *channel, int fd, int how);
 
@@ -60,6 +59,13 @@ static void close_chan_fd(struct Channel *channel, int fd, int how);
 #define ERRFD_IS_READ(channel) ((channel)->extrabuf == NULL)
 #define ERRFD_IS_WRITE(channel) (!ERRFD_IS_READ(channel))
 
+/* allow space for:
+ * 1 byte  byte      SSH_MSG_CHANNEL_DATA
+ * 4 bytes uint32    recipient channel
+ * 4 bytes string    data
+ */
+#define RECV_MAX_CHANNEL_DATA_LEN (RECV_MAX_PAYLOAD_LEN-(1+4+4))
+
 /* Initialise all the channels */
 void chaninitialise(const struct ChanType *chantypes[]) {
 
@@ -71,7 +77,7 @@ void chaninitialise(const struct ChanType *chantypes[]) {
 
 	ses.chantypes = chantypes;
 
-#ifdef USING_LISTENERS
+#if DROPBEAR_LISTENERS
 	listeners_initialise();
 #endif
 
@@ -97,7 +103,7 @@ void chancleanup() {
 /* If remotechan, transwindow and transmaxpacket are not know (for a new
  * outgoing connection, with them to be filled on confirmation), they should
  * all be set to 0 */
-struct Channel* newchannel(unsigned int remotechan, 
+static struct Channel* newchannel(unsigned int remotechan, 
 		const struct ChanType *type, 
 		unsigned int transwindow, unsigned int transmaxpacket) {
 
@@ -147,15 +153,17 @@ struct Channel* newchannel(unsigned int remotechan,
 	newchan->writefd = FD_UNINIT;
 	newchan->readfd = FD_UNINIT;
 	newchan->errfd = FD_CLOSED; /* this isn't always set to start with */
-	newchan->initconn = 0;
 	newchan->await_open = 0;
 	newchan->flushing = 0;
 
 	newchan->writebuf = cbuf_new(opts.recv_window);
-	newchan->extrabuf = NULL; /* The user code can set it up */
 	newchan->recvwindow = opts.recv_window;
+
+	newchan->extrabuf = NULL; /* The user code can set it up */
 	newchan->recvdonelen = 0;
-	newchan->recvmaxpacket = RECV_MAX_PAYLOAD_LEN;
+	newchan->recvmaxpacket = RECV_MAX_CHANNEL_DATA_LEN;
+
+	newchan->prio = DROPBEAR_CHANNEL_PRIO_EARLY; /* inithandler sets it */
 
 	ses.channels[i] = newchan;
 	ses.chancount++;
@@ -189,13 +197,16 @@ struct Channel* getchannel() {
 }
 
 /* Iterate through the channels, performing IO if available */
-void channelio(fd_set *readfds, fd_set *writefds) {
+void channelio(const fd_set *readfds, const fd_set *writefds) {
 
+	/* Listeners such as TCP, X11, agent-auth */
 	struct Channel *channel;
 	unsigned int i;
 
 	/* foreach channel */
 	for (i = 0; i < ses.chansize; i++) {
+		/* Close checking only needs to occur for channels that had IO events */
+		int do_check_close = 0;
 
 		channel = ses.channels[i];
 		if (channel == NULL) {
@@ -207,6 +218,7 @@ void channelio(fd_set *readfds, fd_set *writefds) {
 		if (channel->readfd >= 0 && FD_ISSET(channel->readfd, readfds)) {
 			TRACE(("send normal readfd"))
 			send_msg_channel_data(channel, 0);
+			do_check_close = 1;
 		}
 
 		/* read stderr data and send it over the wire */
@@ -214,32 +226,34 @@ void channelio(fd_set *readfds, fd_set *writefds) {
 			&& FD_ISSET(channel->errfd, readfds)) {
 				TRACE(("send normal errfd"))
 				send_msg_channel_data(channel, 1);
+			do_check_close = 1;
 		}
 
 		/* write to program/pipe stdin */
 		if (channel->writefd >= 0 && FD_ISSET(channel->writefd, writefds)) {
-			if (channel->initconn) {
-				/* XXX should this go somewhere cleaner? */
-				check_in_progress(channel);
-				continue; /* Important not to use the channel after
-							 check_in_progress(), as it may be NULL */
-			}
-			writechannel(channel, channel->writefd, channel->writebuf);
+			writechannel(channel, channel->writefd, channel->writebuf, NULL, NULL);
+			do_check_close = 1;
 		}
 		
 		/* stderr for client mode */
 		if (ERRFD_IS_WRITE(channel)
 				&& channel->errfd >= 0 && FD_ISSET(channel->errfd, writefds)) {
-			writechannel(channel, channel->errfd, channel->extrabuf);
+			writechannel(channel, channel->errfd, channel->extrabuf, NULL, NULL);
+			do_check_close = 1;
+		}
+
+		if (ses.channel_signal_pending) {
+			/* SIGCHLD can change channel state for server sessions */
+			do_check_close = 1;
 		}
 	
 		/* handle any channel closing etc */
-		check_close(channel);
-
+		if (do_check_close) {
+			check_close(channel);
+		}
 	}
 
-	/* Listeners such as TCP, X11, agent-auth */
-#ifdef USING_LISTENERS
+#if DROPBEAR_LISTENERS
 	handle_listeners(readfds);
 #endif
 }
@@ -247,7 +261,7 @@ void channelio(fd_set *readfds, fd_set *writefds) {
 
 /* Returns true if there is data remaining to be written to stdin or
  * stderr of a channel's endpoint. */
-static unsigned int write_pending(struct Channel * channel) {
+static unsigned int write_pending(const struct Channel * channel) {
 
 	if (channel->writefd >= 0 && cbuf_getused(channel->writebuf) > 0) {
 		return 1;
@@ -263,14 +277,16 @@ static unsigned int write_pending(struct Channel * channel) {
 static void check_close(struct Channel *channel) {
 	int close_allowed = 0;
 
-	TRACE(("check_close: writefd %d, readfd %d, errfd %d, sent_close %d, recv_close %d",
+	TRACE2(("check_close: writefd %d, readfd %d, errfd %d, sent_close %d, recv_close %d",
 				channel->writefd, channel->readfd,
 				channel->errfd, channel->sent_close, channel->recv_close))
-	TRACE(("writebuf size %d extrabuf size %d",
-				cbuf_getused(channel->writebuf),
+	TRACE2(("writebuf size %d extrabuf size %d",
+				channel->writebuf ? cbuf_getused(channel->writebuf) : 0,
 				channel->extrabuf ? cbuf_getused(channel->extrabuf) : 0))
 
-	if (!channel->flushing && channel->type->check_close
+	if (!channel->flushing 
+		&& !channel->sent_close
+		&& channel->type->check_close
 		&& channel->type->check_close(channel))
 	{
 		channel->flushing = 1;
@@ -281,7 +297,8 @@ static void check_close(struct Channel *channel) {
 	   channel, to ensure that the shell has exited (and the exit status 
 	   retrieved) before we close things up. */
 	if (!channel->type->check_close	
-			|| channel->type->check_close(channel)) {
+		|| channel->sent_close
+		|| channel->type->check_close(channel)) {
 		close_allowed = 1;
 	}
 
@@ -294,7 +311,9 @@ static void check_close(struct Channel *channel) {
 		return;
 	}
 
-	if (channel->recv_eof && !write_pending(channel)) {
+	if ((channel->recv_eof && !write_pending(channel))
+		/* have a server "session" and child has exited */
+		|| (channel->type->check_close && close_allowed)) {
 		close_chan_fd(channel, channel->writefd, SHUT_WR);
 	}
 
@@ -323,6 +342,7 @@ static void check_close(struct Channel *channel) {
 
 	/* And if we can't receive any more data from them either, close up */
 	if (channel->readfd == FD_CLOSED
+			&& channel->writefd == FD_CLOSED
 			&& (ERRFD_IS_WRITE(channel) || channel->errfd == FD_CLOSED)
 			&& !channel->sent_close
 			&& close_allowed
@@ -336,26 +356,26 @@ static void check_close(struct Channel *channel) {
  * if so, set up the channel properly. Otherwise, the channel is cleaned up, so
  * it is important that the channel reference isn't used after a call to this
  * function */
-static void check_in_progress(struct Channel *channel) {
+void channel_connect_done(int result, int sock, void* user_data, const char* UNUSED(errstring)) {
 
-	int val;
-	socklen_t vallen = sizeof(val);
+	struct Channel *channel = user_data;
 
-	TRACE(("enter check_in_progress"))
+	TRACE(("enter channel_connect_done"))
 
-	if (getsockopt(channel->writefd, SOL_SOCKET, SO_ERROR, &val, &vallen)
-			|| val != 0) {
-		send_msg_channel_open_failure(channel->remotechan,
-				SSH_OPEN_CONNECT_FAILED, "", "");
-		close(channel->writefd);
-		delete_channel(channel);
-		TRACE(("leave check_in_progress: fail"))
-	} else {
+	if (result == DROPBEAR_SUCCESS)
+	{
+		channel->readfd = channel->writefd = sock;
+		channel->conn_pending = NULL;
 		send_msg_channel_open_confirmation(channel, channel->recvwindow,
 				channel->recvmaxpacket);
-		channel->readfd = channel->writefd;
-		channel->initconn = 0;
-		TRACE(("leave check_in_progress: success"))
+		TRACE(("leave channel_connect_done: success"))
+	}
+	else
+	{
+		send_msg_channel_open_failure(channel->remotechan,
+				SSH_OPEN_CONNECT_FAILED, "", "");
+		remove_channel(channel);
+		TRACE(("leave check_in_progress: fail"))
 	}
 }
 
@@ -363,7 +383,7 @@ static void check_in_progress(struct Channel *channel) {
 /* Send the close message and set the channel as closed */
 static void send_msg_channel_close(struct Channel *channel) {
 
-	TRACE(("enter send_msg_channel_close"))
+	TRACE(("enter send_msg_channel_close %p", (void*)channel))
 	if (channel->type->closehandler) {
 		channel->type->closehandler(channel);
 	}
@@ -399,35 +419,120 @@ static void send_msg_channel_eof(struct Channel *channel) {
 	TRACE(("leave send_msg_channel_eof"))
 }
 
-/* Called to write data out to the local side of the channel. 
- * Only called when we know we can write to a channel, writes as much as
- * possible */
-static void writechannel(struct Channel* channel, int fd, circbuffer *cbuf) {
+#ifndef HAVE_WRITEV
+static int writechannel_fallback(struct Channel* channel, int fd, circbuffer *cbuf,
+	const unsigned char *UNUSED(moredata), unsigned int *morelen) {
 
-	int len, maxlen;
+	unsigned char *circ_p1, *circ_p2;
+	unsigned int circ_len1, circ_len2;
+	ssize_t written;
 
-	TRACE(("enter writechannel fd %d", fd))
-
-	maxlen = cbuf_readlen(cbuf);
-
-	/* Write the data out */
-	len = write(fd, cbuf_readptr(cbuf, maxlen), maxlen);
-	if (len <= 0) {
-		TRACE(("errno %d len %d", errno, len))
-		if (len < 0 && errno != EINTR) {
-			close_chan_fd(channel, fd, SHUT_WR);
-		}
-		TRACE(("leave writechannel: len <= 0"))
-		return;
+	if (morelen) {
+		/* fallback doesn't consume moredata */
+		*morelen = 0;
 	}
-	TRACE(("writechannel wrote %d", len))
 
-	cbuf_incrread(cbuf, len);
-	channel->recvdonelen += len;
+	/* Write the first portion of the circular buffer */
+	cbuf_readptrs(cbuf, &circ_p1, &circ_len1, &circ_p2, &circ_len2);
+	written = write(fd, circ_p1, circ_len1);
+	if (written < 0) {
+		if (errno != EINTR && errno != EAGAIN) {
+			TRACE(("channel IO write error fd %d %s", fd, strerror(errno)))
+			close_chan_fd(channel, fd, SHUT_WR);
+			return DROPBEAR_FAILURE;
+		}
+	} else {
+		cbuf_incrread(cbuf, written);
+		channel->recvdonelen += written;
+	}
+	return DROPBEAR_SUCCESS;
+}
+#endif /* !HAVE_WRITEV */
+
+#ifdef HAVE_WRITEV
+static int writechannel_writev(struct Channel* channel, int fd, circbuffer *cbuf,
+	const unsigned char *moredata, unsigned int *morelen) {
+
+	struct iovec iov[3];
+	unsigned char *circ_p1, *circ_p2;
+	unsigned int circ_len1, circ_len2;
+	int io_count = 0;
+
+	ssize_t written;
+
+	cbuf_readptrs(cbuf, &circ_p1, &circ_len1, &circ_p2, &circ_len2);
+
+	if (circ_len1 > 0) {
+		TRACE(("circ1 %d", circ_len1))
+		iov[io_count].iov_base = circ_p1;
+		iov[io_count].iov_len = circ_len1;
+		io_count++;
+	}
+
+	if (circ_len2 > 0) {
+		TRACE(("circ2 %d", circ_len2))
+		iov[io_count].iov_base = circ_p2;
+		iov[io_count].iov_len = circ_len2;
+		io_count++;
+	}
+
+	if (morelen) {
+		assert(moredata);
+		TRACE(("more %d", *morelen))
+		iov[io_count].iov_base = (void*)moredata;
+		iov[io_count].iov_len  = *morelen;
+		io_count++;
+	}
+
+	if (io_count == 0) {
+		/* writechannel may sometimes be called twice in a main loop iteration.
+		From common_recv_msg_channel_data() then channelio().
+		The second call may not have any data to write, so we just return. */
+		TRACE(("leave writechannel, no data"))
+		return DROPBEAR_SUCCESS;
+	}
+
+	if (morelen) {
+		/* Default return value, none consumed */
+		*morelen = 0;
+	}
+
+	written = writev(fd, iov, io_count);
+
+	if (written < 0) {
+		if (errno != EINTR && errno != EAGAIN) {
+			TRACE(("channel IO write error fd %d %s", fd, strerror(errno)))
+			close_chan_fd(channel, fd, SHUT_WR);
+			return DROPBEAR_FAILURE;
+		}
+	} else {
+		int cbuf_written = MIN(circ_len1+circ_len2, (unsigned int)written);
+		cbuf_incrread(cbuf, cbuf_written);
+		if (morelen) {
+			*morelen = written - cbuf_written;
+		}
+		channel->recvdonelen += written;
+	}
+	return DROPBEAR_SUCCESS;
+}
+#endif /* HAVE_WRITEV */
+
+/* Called to write data out to the local side of the channel. 
+   Writes the circular buffer contents and also the "moredata" buffer
+   if not null. Will ignore EAGAIN.
+   Returns DROPBEAR_FAILURE if writing to fd had an error and the channel is being closed, DROPBEAR_SUCCESS otherwise */
+static int writechannel(struct Channel* channel, int fd, circbuffer *cbuf,
+	const unsigned char *moredata, unsigned int *morelen) {
+	int ret = DROPBEAR_SUCCESS;
+	TRACE(("enter writechannel fd %d", fd))
+#ifdef HAVE_WRITEV
+	ret = writechannel_writev(channel, fd, cbuf, moredata, morelen);
+#else
+	ret = writechannel_fallback(channel, fd, cbuf, moredata, morelen);
+#endif
 
 	/* Window adjust handling */
 	if (channel->recvdonelen >= RECV_WINDOWEXTEND) {
-		/* Set it back to max window */
 		send_msg_channel_window_adjust(channel, channel->recvdonelen);
 		channel->recvwindow += channel->recvdonelen;
 		channel->recvdonelen = 0;
@@ -439,11 +544,13 @@ static void writechannel(struct Channel* channel, int fd, circbuffer *cbuf) {
 			channel->recvwindow <= cbuf_getavail(channel->extrabuf));
 	
 	TRACE(("leave writechannel"))
+	return ret;
 }
 
+
 /* Set the file descriptors for the main select in session.c
  * This avoid channels which don't have any window available, are closed, etc*/
-void setchannelfds(fd_set *readfds, fd_set *writefds) {
+void setchannelfds(fd_set *readfds, fd_set *writefds, int allow_reads) {
 	
 	unsigned int i;
 	struct Channel * channel;
@@ -455,8 +562,13 @@ void setchannelfds(fd_set *readfds, fd_set *writefds) {
 			continue;
 		}
 
-		/* Stuff to put over the wire */
-		if (channel->transwindow > 0) {
+		/* Stuff to put over the wire. 
+		Avoid queueing data to send if we're in the middle of a 
+		key re-exchange (!dataallowed), but still read from the 
+		FD if there's the possibility of "~."" to kill an 
+		interactive session (the read_mangler) */
+		if (channel->transwindow > 0
+		   && ((ses.dataallowed && allow_reads) || channel->read_mangler)) {
 
 			if (channel->readfd >= 0) {
 				FD_SET(channel->readfd, readfds);
@@ -468,19 +580,18 @@ void setchannelfds(fd_set *readfds, fd_set *writefds) {
 		}
 
 		/* Stuff from the wire */
-		if ((channel->writefd >= 0 && cbuf_getused(channel->writebuf) > 0 )
-				|| channel->initconn) {
+		if (channel->writefd >= 0 && cbuf_getused(channel->writebuf) > 0) {
 				FD_SET(channel->writefd, writefds);
 		}
 
 		if (ERRFD_IS_WRITE(channel) && channel->errfd >= 0 
-				&& cbuf_getused(channel->extrabuf) > 0 ) {
+				&& cbuf_getused(channel->extrabuf) > 0) {
 				FD_SET(channel->errfd, writefds);
 		}
 
 	} /* foreach channel */
 
-#ifdef USING_LISTENERS
+#if DROPBEAR_LISTENERS
 	set_listener_fds(readfds);
 #endif
 
@@ -536,31 +647,33 @@ static void remove_channel(struct Channel * channel) {
 	}
 
 
-	/* close the FDs in case they haven't been done
-	 * yet (they might have been shutdown etc) */
-	TRACE(("CLOSE writefd %d", channel->writefd))
-	close(channel->writefd);
-	TRACE(("CLOSE readfd %d", channel->readfd))
-	close(channel->readfd);
-	TRACE(("CLOSE errfd %d", channel->errfd))
-	close(channel->errfd);
+	if (IS_DROPBEAR_SERVER || (channel->writefd != STDOUT_FILENO)) {
+		/* close the FDs in case they haven't been done
+		 * yet (they might have been shutdown etc) */
+		TRACE(("CLOSE writefd %d", channel->writefd))
+		m_close(channel->writefd);
+		TRACE(("CLOSE readfd %d", channel->readfd))
+		m_close(channel->readfd);
+		TRACE(("CLOSE errfd %d", channel->errfd))
+		m_close(channel->errfd);
+	}
 
-	channel->typedata = NULL;
+	if (channel->type->cleanup) {
+		channel->type->cleanup(channel);
+	}
 
-	delete_channel(channel);
-
-	TRACE(("leave remove_channel"))
-}
-
-/* Remove a channel entry */
-static void delete_channel(struct Channel *channel) {
+	if (channel->conn_pending) {
+		cancel_connect(channel->conn_pending);
+	}
 
 	ses.channels[channel->index] = NULL;
 	m_free(channel);
 	ses.chancount--;
-	
-}
 
+	update_channel_prio();
+
+	TRACE(("leave remove_channel"))
+}
 
 /* Handle channel specific requests, passing off to corresponding handlers
  * such as chansession or x11fwd */
@@ -568,19 +681,19 @@ void recv_msg_channel_request() {
 
 	struct Channel *channel;
 
-	TRACE(("enter recv_msg_channel_request"))
-	
 	channel = getchannel();
 
-	if (channel->sent_close) {
-		TRACE(("leave recv_msg_channel_request: already closed channel"))
-		return;
-	}
+	TRACE(("enter recv_msg_channel_request %p", (void*)channel))
 
 	if (channel->type->reqhandler) {
 		channel->type->reqhandler(channel);
 	} else {
-		send_msg_channel_failure(channel);
+		int wantreply;
+		buf_eatstring(ses.payload);
+		wantreply = buf_getbool(ses.payload);
+		if (wantreply) {
+			send_msg_channel_failure(channel);
+		}
 	}
 
 	TRACE(("leave recv_msg_channel_request"))
@@ -616,7 +729,7 @@ static void send_msg_channel_data(struct Channel *channel, int isextended) {
 	 * exttype if is extended */
 	maxlen = MIN(maxlen, 
 			ses.writepayload->size - 1 - 4 - 4 - (isextended ? 4 : 0));
-	TRACE(("maxlen %d", maxlen))
+	TRACE(("maxlen %zd", maxlen))
 	if (maxlen == 0) {
 		TRACE(("leave send_msg_channel_data: no window"))
 		return;
@@ -634,6 +747,7 @@ static void send_msg_channel_data(struct Channel *channel, int isextended) {
 
 	/* read the data */
 	len = read(fd, buf_getwriteptr(ses.writepayload, maxlen), maxlen);
+
 	if (len <= 0) {
 		if (len == 0 || errno != EINTR) {
 			/* This will also get hit in the case of EAGAIN. The only
@@ -641,11 +755,23 @@ static void send_msg_channel_data(struct Channel *channel, int isextended) {
 			in which case it can be treated the same as EOF */
 			close_chan_fd(channel, fd, SHUT_RD);
 		}
-		ses.writepayload->len = ses.writepayload->pos = 0;
+		buf_setpos(ses.writepayload, 0);
+		buf_setlen(ses.writepayload, 0);
 		TRACE(("leave send_msg_channel_data: len %d read err %d or EOF for fd %d", 
 					len, errno, fd))
 		return;
 	}
+
+	if (channel->read_mangler) {
+		channel->read_mangler(channel, buf_getwriteptr(ses.writepayload, len), &len);
+		if (len == 0) {
+			buf_setpos(ses.writepayload, 0);
+			buf_setlen(ses.writepayload, 0);
+			return;
+		}
+	}
+
+	TRACE(("send_msg_channel_data: len %d fd %d", len, fd))
 	buf_incrwritepos(ses.writepayload, len);
 	/* ... real size here */
 	buf_setpos(ses.writepayload, size_pos);
@@ -684,6 +810,8 @@ void common_recv_msg_channel_data(struct Channel *channel, int fd,
 	unsigned int maxdata;
 	unsigned int buflen;
 	unsigned int len;
+	unsigned int consumed;
+	int res;
 
 	TRACE(("enter recv_msg_channel_data"))
 
@@ -691,7 +819,7 @@ void common_recv_msg_channel_data(struct Channel *channel, int fd,
 		dropbear_exit("Received data after eof");
 	}
 
-	if (fd < 0) {
+	if (fd < 0 || !cbuf) {
 		/* If we have encountered failed write, the far side might still
 		 * be sending data without having yet received our close notification.
 		 * We just drop the data. */
@@ -710,25 +838,36 @@ void common_recv_msg_channel_data(struct Channel *channel, int fd,
 		dropbear_exit("Oversized packet");
 	}
 
-	/* We may have to run throught twice, if the buffer wraps around. Can't
-	 * just "leave it for next time" like with writechannel, since this
-	 * is payload data */
-	len = datalen;
-	while (len > 0) {
-		buflen = cbuf_writelen(cbuf);
-		buflen = MIN(buflen, len);
-
-		memcpy(cbuf_writeptr(cbuf, buflen), 
-				buf_getptr(ses.payload, buflen), buflen);
-		cbuf_incrwrite(cbuf, buflen);
-		buf_incrpos(ses.payload, buflen);
-		len -= buflen;
-	}
-
 	dropbear_assert(channel->recvwindow >= datalen);
 	channel->recvwindow -= datalen;
 	dropbear_assert(channel->recvwindow <= opts.recv_window);
 
+	/* Attempt to write the data immediately without having to put it in the circular buffer */
+	consumed = datalen;
+	res = writechannel(channel, fd, cbuf, buf_getptr(ses.payload, datalen), &consumed);
+
+	datalen -= consumed;
+	buf_incrpos(ses.payload, consumed);
+
+
+	/* We may have to run throught twice, if the buffer wraps around. Can't
+	 * just "leave it for next time" like with writechannel, since this
+	 * is payload data.
+	 * If the writechannel() failed then remaining data is discarded */
+	if (res == DROPBEAR_SUCCESS) {
+		len = datalen;
+		while (len > 0) {
+			buflen = cbuf_writelen(cbuf);
+			buflen = MIN(buflen, len);
+
+			memcpy(cbuf_writeptr(cbuf, buflen), 
+					buf_getptr(ses.payload, buflen), buflen);
+			cbuf_incrwrite(cbuf, buflen);
+			buf_incrpos(ses.payload, buflen);
+			len -= buflen;
+		}
+	}
+
 	TRACE(("leave recv_msg_channel_data"))
 }
 
@@ -753,7 +892,7 @@ void recv_msg_channel_window_adjust() {
 
 /* Increment the incoming data window for a channel, and let the remote
  * end know */
-static void send_msg_channel_window_adjust(struct Channel* channel, 
+static void send_msg_channel_window_adjust(const struct Channel* channel,
 		unsigned int incr) {
 
 	TRACE(("sending window adjust %d", incr))
@@ -769,7 +908,7 @@ static void send_msg_channel_window_adjust(struct Channel* channel,
 /* Handle a new channel request, performing any channel-type-specific setup */
 void recv_msg_channel_open() {
 
-	unsigned char *type;
+	char *type;
 	unsigned int typelen;
 	unsigned int remotechan, transwindow, transmaxpacket;
 	struct Channel *channel;
@@ -818,6 +957,7 @@ void recv_msg_channel_open() {
 
 	if (channel == NULL) {
 		TRACE(("newchannel returned NULL"))
+		errtype = SSH_OPEN_RESOURCE_SHORTAGE;
 		goto failure;
 	}
 
@@ -829,12 +969,16 @@ void recv_msg_channel_open() {
 		}
 		if (ret > 0) {
 			errtype = ret;
-			delete_channel(channel);
+			remove_channel(channel);
 			TRACE(("inithandler returned failure %d", ret))
 			goto failure;
 		}
 	}
 
+	if (channel->prio == DROPBEAR_CHANNEL_PRIO_EARLY) {
+		channel->prio = DROPBEAR_CHANNEL_PRIO_BULK;
+	}
+
 	/* success */
 	send_msg_channel_open_confirmation(channel, channel->recvwindow,
 			channel->recvmaxpacket);
@@ -846,14 +990,21 @@ failure:
 
 cleanup:
 	m_free(type);
+	
+	update_channel_prio();
 
 	TRACE(("leave recv_msg_channel_open"))
 }
 
 /* Send a failure message */
-void send_msg_channel_failure(struct Channel *channel) {
+void send_msg_channel_failure(const struct Channel *channel) {
 
 	TRACE(("enter send_msg_channel_failure"))
+
+	if (channel->sent_close) {
+		TRACE(("Skipping sending msg_channel_failure for closed channel"))
+		return;
+	}
 	CHECKCLEARTOWRITE();
 
 	buf_putbyte(ses.writepayload, SSH_MSG_CHANNEL_FAILURE);
@@ -864,9 +1015,13 @@ void send_msg_channel_failure(struct Channel *channel) {
 }
 
 /* Send a success message */
-void send_msg_channel_success(struct Channel *channel) {
+void send_msg_channel_success(const struct Channel *channel) {
 
 	TRACE(("enter send_msg_channel_success"))
+	if (channel->sent_close) {
+		TRACE(("Skipping sending msg_channel_success for closed channel"))
+		return;
+	}
 	CHECKCLEARTOWRITE();
 
 	buf_putbyte(ses.writepayload, SSH_MSG_CHANNEL_SUCCESS);
@@ -879,7 +1034,7 @@ void send_msg_channel_success(struct Channel *channel) {
 /* Send a channel open failure message, with a corresponding reason
  * code (usually resource shortage or unknown chan type) */
 static void send_msg_channel_open_failure(unsigned int remotechan, 
-		int reason, const unsigned char *text, const unsigned char *lang) {
+		int reason, const char *text, const char *lang) {
 
 	TRACE(("enter send_msg_channel_open_failure"))
 	CHECKCLEARTOWRITE();
@@ -887,8 +1042,8 @@ static void send_msg_channel_open_failure(unsigned int remotechan,
 	buf_putbyte(ses.writepayload, SSH_MSG_CHANNEL_OPEN_FAILURE);
 	buf_putint(ses.writepayload, remotechan);
 	buf_putint(ses.writepayload, reason);
-	buf_putstring(ses.writepayload, text, strlen((char*)text));
-	buf_putstring(ses.writepayload, lang, strlen((char*)lang));
+	buf_putstring(ses.writepayload, text, strlen(text));
+	buf_putstring(ses.writepayload, lang, strlen(lang));
 
 	encrypt_packet();
 	TRACE(("leave send_msg_channel_open_failure"))
@@ -896,7 +1051,7 @@ static void send_msg_channel_open_failure(unsigned int remotechan,
 
 /* Confirm a channel open, and let the remote end know what number we've
  * allocated and the receive parameters */
-static void send_msg_channel_open_confirmation(struct Channel* channel,
+static void send_msg_channel_open_confirmation(const struct Channel* channel,
 		unsigned int recvwindow, 
 		unsigned int recvmaxpacket) {
 
@@ -928,7 +1083,7 @@ static void close_chan_fd(struct Channel *channel, int fd, int how) {
 		}
 	} else {
 		TRACE(("CLOSE some fd %d", fd))
-		close(fd);
+		m_close(fd);
 		closein = closeout = 1;
 	}
 
@@ -951,17 +1106,17 @@ static void close_chan_fd(struct Channel *channel, int fd, int how) {
 	if (channel->type->sepfds && channel->readfd == FD_CLOSED 
 		&& channel->writefd == FD_CLOSED && channel->errfd == FD_CLOSED) {
 		TRACE(("CLOSE (finally) of %d", fd))
-		close(fd);
+		m_close(fd);
 	}
 }
 
 
-#if defined(USING_LISTENERS) || defined(DROPBEAR_CLIENT)
+#if (DROPBEAR_LISTENERS) || (DROPBEAR_CLIENT)
 /* Create a new channel, and start the open request. This is intended
  * for X11, agent, tcp forwarding, and should be filled with channel-specific
  * options, with the calling function calling encrypt_packet() after
  * completion. It is mandatory for the caller to encrypt_packet() if
- * DROPBEAR_SUCCESS is returned */
+ * a channel is returned. NULL is returned on failure. */
 int send_msg_channel_open_init(int fd, const struct ChanType *type) {
 
 	struct Channel* chan;
@@ -973,6 +1128,9 @@ int send_msg_channel_open_init(int fd, const struct ChanType *type) {
 		return DROPBEAR_FAILURE;
 	}
 
+	/* Outbound opened channels don't make use of in-progress connections,
+	 * we can set it up straight away */
+
 	/* set fd non-blocking */
 	setnonblocking(fd);
 
@@ -988,7 +1146,7 @@ int send_msg_channel_open_init(int fd, const struct ChanType *type) {
 	buf_putstring(ses.writepayload, type->name, strlen(type->name));
 	buf_putint(ses.writepayload, chan->index);
 	buf_putint(ses.writepayload, opts.recv_window);
-	buf_putint(ses.writepayload, RECV_MAX_PAYLOAD_LEN);
+	buf_putint(ses.writepayload, RECV_MAX_CHANNEL_DATA_LEN);
 
 	TRACE(("leave send_msg_channel_open_init()"))
 	return DROPBEAR_SUCCESS;
@@ -1023,9 +1181,14 @@ void recv_msg_channel_open_confirmation() {
 		if (ret > 0) {
 			remove_channel(channel);
 			TRACE(("inithandler returned failure %d", ret))
+			return;
 		}
 	}
 
+	if (channel->prio == DROPBEAR_CHANNEL_PRIO_EARLY) {
+		channel->prio = DROPBEAR_CHANNEL_PRIO_BULK;
+	}
+	update_channel_prio();
 	
 	TRACE(("leave recv_msg_channel_open_confirmation"))
 }
@@ -1044,4 +1207,43 @@ void recv_msg_channel_open_failure() {
 
 	remove_channel(channel);
 }
-#endif /* USING_LISTENERS */
+#endif /* DROPBEAR_LISTENERS */
+
+void send_msg_request_success() {
+	CHECKCLEARTOWRITE();
+	buf_putbyte(ses.writepayload, SSH_MSG_REQUEST_SUCCESS);
+	encrypt_packet();
+}
+
+void send_msg_request_failure() {
+	CHECKCLEARTOWRITE();
+	buf_putbyte(ses.writepayload, SSH_MSG_REQUEST_FAILURE);
+	encrypt_packet();
+}
+
+struct Channel* get_any_ready_channel() {
+	size_t i;
+	if (ses.chancount == 0) {
+		return NULL;
+	}
+	for (i = 0; i < ses.chansize; i++) {
+		struct Channel *chan = ses.channels[i];
+		if (chan
+				&& !(chan->sent_eof || chan->recv_eof)
+				&& !(chan->await_open)) {
+			return chan;
+		}
+	}
+	return NULL;
+}
+
+void start_send_channel_request(const struct Channel *channel,
+		const char *type) {
+
+	CHECKCLEARTOWRITE();
+	buf_putbyte(ses.writepayload, SSH_MSG_CHANNEL_REQUEST);
+	buf_putint(ses.writepayload, channel->remotechan);
+
+	buf_putstring(ses.writepayload, type, strlen(type));
+
+}

common-runopts.c

@@ -28,12 +28,15 @@
 #include "buffer.h"
 #include "dbutil.h"
 #include "auth.h"
+#include "algo.h"
+#include "dbrandom.h"
 
 runopts opts; /* GLOBAL */
 
 /* returns success or failure, and the keytype in *type. If we want
  * to restrict the type, type can contain a type to return */
-int readhostkey(const char * filename, sign_key * hostkey, int *type) {
+int readhostkey(const char * filename, sign_key * hostkey, 
+	enum signkey_type *type) {
 
 	int ret = DROPBEAR_FAILURE;
 	buffer *buf;
@@ -44,6 +47,9 @@ int readhostkey(const char * filename, sign_key * hostkey, int *type) {
 		goto out;
 	}
 	buf_setpos(buf, 0);
+
+	addrandom(buf_getptr(buf, buf->len), buf->len);
+
 	if (buf_get_priv_key(buf, hostkey, type) == DROPBEAR_FAILURE) {
 		goto out;
 	}
@@ -55,3 +61,44 @@ out:
 	buf_free(buf);
 	return ret;
 }
+
+#if DROPBEAR_USER_ALGO_LIST
+void
+parse_ciphers_macs() {
+	int printed_help = 0;
+	if (opts.cipher_list) {
+		if (strcmp(opts.cipher_list, "help") == 0) {
+			char *ciphers = algolist_string(sshciphers);
+			dropbear_log(LOG_INFO, "Available ciphers: %s", ciphers);
+			m_free(ciphers);
+			printed_help = 1;
+		} else {
+			if (check_user_algos(opts.cipher_list, sshciphers, "cipher") == 0) {
+				dropbear_exit("No valid ciphers specified for '-c'");
+			}
+		}
+	}
+
+	if (opts.mac_list) {
+		if (strcmp(opts.mac_list, "help") == 0) {
+			char *macs = algolist_string(sshhashes);
+			dropbear_log(LOG_INFO, "Available MACs: %s", macs);
+			m_free(macs);
+			printed_help = 1;
+		} else {
+			if (check_user_algos(opts.mac_list, sshhashes, "MAC") == 0) {
+				dropbear_exit("No valid MACs specified for '-m'");
+			}
+		}
+	}
+	if (printed_help) {
+		dropbear_exit(".");
+	}
+}
+#endif
+
+void print_version() {
+	fprintf(stderr, "Dropbear v%s\n", DROPBEAR_VERSION);
+}
+
+

common-session.c

@@ -1,7 +1,7 @@
 /*
  * Dropbear - a SSH2 server
  * 
- * Copyright (c) 2002,2003 Matt Johnston
+ * Copyright (c) Matt Johnston
  * All rights reserved.
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -30,29 +30,26 @@
 #include "buffer.h"
 #include "dss.h"
 #include "ssh.h"
-#include "random.h"
+#include "dbrandom.h"
 #include "kex.h"
 #include "channel.h"
-#include "atomicio.h"
 #include "runopts.h"
+#include "netio.h"
 
-static void checktimeouts();
-static long select_timeout();
+static void checktimeouts(void);
+static long select_timeout(void);
 static int ident_readln(int fd, char* buf, int count);
+static void read_session_identification(void);
 
 struct sshsession ses; /* GLOBAL */
 
-/* need to know if the session struct has been initialised, this way isn't the
- * cleanest, but works OK */
-int sessinitdone = 0; /* GLOBAL */
-
-/* this is set when we get SIGINT or SIGTERM, the handler is in main.c */
-int exitflag = 0; /* GLOBAL */
-
-
-
 /* called only at the start of a session, set up initial state */
 void common_session_init(int sock_in, int sock_out) {
+	time_t now;
+
+#if DEBUG_TRACE
+	debug_start_net();
+#endif
 
 	TRACE(("enter session_init"))
 
@@ -60,21 +57,47 @@ void common_session_init(int sock_in, int sock_out) {
 	ses.sock_out = sock_out;
 	ses.maxfd = MAX(sock_in, sock_out);
 
-	ses.connect_time = 0;
-	ses.last_trx_packet_time = 0;
-	ses.last_packet_time = 0;
+	if (sock_in >= 0) {
+		setnonblocking(sock_in);
+	}
+	if (sock_out >= 0) {
+		setnonblocking(sock_out);
+	}
+
+	ses.socket_prio = DROPBEAR_PRIO_DEFAULT;
+	/* Sets it to lowdelay */
+	update_channel_prio();
+
+#if !DROPBEAR_SVR_MULTIUSER
+	/* A sanity check to prevent an accidental configuration option
+	   leaving multiuser systems exposed */
+	errno = 0;
+	getuid();
+	if (errno != ENOSYS) {
+		dropbear_exit("Non-multiuser Dropbear requires a non-multiuser kernel");
+	}
+#endif
+
+	now = monotonic_now();
+	ses.connect_time = now;
+	ses.last_packet_time_keepalive_recv = now;
+	ses.last_packet_time_idle = now;
+	ses.last_packet_time_any_sent = 0;
+	ses.last_packet_time_keepalive_sent = 0;
 	
+#if DROPBEAR_FUZZ
+	if (!fuzz.fuzzing)
+#endif
+	{
 	if (pipe(ses.signal_pipe) < 0) {
 		dropbear_exit("Signal pipe failed");
 	}
 	setnonblocking(ses.signal_pipe[0]);
 	setnonblocking(ses.signal_pipe[1]);
-
 	ses.maxfd = MAX(ses.maxfd, ses.signal_pipe[0]);
 	ses.maxfd = MAX(ses.maxfd, ses.signal_pipe[1]);
+	}
 	
-	kexfirstinitialise(); /* initialise the kex state */
-
 	ses.writepayload = buf_new(TRANS_MAX_PAYLOAD_LEN);
 	ses.transseq = 0;
 
@@ -103,7 +126,7 @@ void common_session_init(int sock_in, int sock_out) {
 	ses.keys->recv.algo_mac = &dropbear_nohash;
 	ses.keys->trans.algo_mac = &dropbear_nohash;
 
-	ses.keys->algo_kex = -1;
+	ses.keys->algo_kex = NULL;
 	ses.keys->algo_hostkey = -1;
 	ses.keys->recv.algo_comp = DROPBEAR_COMP_NONE;
 	ses.keys->trans.algo_comp = DROPBEAR_COMP_NONE;
@@ -124,10 +147,14 @@ void common_session_init(int sock_in, int sock_out) {
 
 	ses.allowprivport = 0;
 
+#if DROPBEAR_PLUGIN
+        ses.plugin_session = NULL;
+#endif
+
 	TRACE(("leave session_init"))
 }
 
-void session_loop(void(*loophandler)()) {
+void session_loop(void(*loophandler)(void)) {
 
 	fd_set readfd, writefd;
 	struct timeval timeout;
@@ -135,30 +162,51 @@ void session_loop(void(*loophandler)()) {
 
 	/* main loop, select()s for all sockets in use */
 	for(;;) {
+		const int writequeue_has_space = (ses.writequeue_len <= 2*TRANS_MAX_PAYLOAD_LEN);
 
 		timeout.tv_sec = select_timeout();
 		timeout.tv_usec = 0;
-		FD_ZERO(&writefd);
-		FD_ZERO(&readfd);
+		DROPBEAR_FD_ZERO(&writefd);
+		DROPBEAR_FD_ZERO(&readfd);
+
 		dropbear_assert(ses.payload == NULL);
-		if (ses.sock_in != -1) {
+
+		/* We get woken up when signal handlers write to this pipe.
+		   SIGCHLD in svr-chansession is the only one currently. */
+#if DROPBEAR_FUZZ
+		if (!fuzz.fuzzing) 
+#endif
+		{
+		FD_SET(ses.signal_pipe[0], &readfd);
+		}
+
+		/* set up for channels which can be read/written */
+		setchannelfds(&readfd, &writefd, writequeue_has_space);
+
+		/* Pending connections to test */
+		set_connect_fds(&writefd);
+
+		/* We delay reading from the input socket during initial setup until
+		after we have written out our initial KEXINIT packet (empty writequeue). 
+		This means our initial packet can be in-flight while we're doing a blocking
+		read for the remote ident.
+		We also avoid reading from the socket if the writequeue is full, that avoids
+		replies backing up */
+		if (ses.sock_in != -1 
+			&& (ses.remoteident || isempty(&ses.writequeue)) 
+			&& writequeue_has_space) {
 			FD_SET(ses.sock_in, &readfd);
 		}
+
+		/* Ordering is important, this test must occur after any other function
+		might have queued packets (such as connection handlers) */
 		if (ses.sock_out != -1 && !isempty(&ses.writequeue)) {
 			FD_SET(ses.sock_out, &writefd);
 		}
-		
-		/* We get woken up when signal handlers write to this pipe.
-		   SIGCHLD in svr-chansession is the only one currently. */
-		FD_SET(ses.signal_pipe[0], &readfd);
 
-		/* set up for channels which require reading/writing */
-		if (ses.dataallowed) {
-			setchannelfds(&readfd, &writefd);
-		}
 		val = select(ses.maxfd+1, &readfd, &writefd, NULL, &timeout);
 
-		if (exitflag) {
+		if (ses.exitflag) {
 			dropbear_exit("Terminated by signal");
 		}
 		
@@ -171,31 +219,33 @@ void session_loop(void(*loophandler)()) {
 			 * want to iterate over channels etc for reading, to handle
 			 * server processes exiting etc. 
 			 * We don't want to read/write FDs. */
-			FD_ZERO(&writefd);
-			FD_ZERO(&readfd);
+			DROPBEAR_FD_ZERO(&writefd);
+			DROPBEAR_FD_ZERO(&readfd);
 		}
 		
 		/* We'll just empty out the pipe if required. We don't do
 		any thing with the data, since the pipe's purpose is purely to
 		wake up the select() above. */
+		ses.channel_signal_pending = 0;
 		if (FD_ISSET(ses.signal_pipe[0], &readfd)) {
 			char x;
+			TRACE(("signal pipe set"))
 			while (read(ses.signal_pipe[0], &x, 1) > 0) {}
+			ses.channel_signal_pending = 1;
 		}
 
 		/* check for auth timeout, rekeying required etc */
 		checktimeouts();
 
-		/* process session socket's incoming/outgoing data */
-		if (ses.sock_out != -1) {
-			if (FD_ISSET(ses.sock_out, &writefd) && !isempty(&ses.writequeue)) {
-				write_packet();
-			}
-		}
-
+		/* process session socket's incoming data */
 		if (ses.sock_in != -1) {
 			if (FD_ISSET(ses.sock_in, &readfd)) {
-				read_packet();
+				if (!ses.remoteident) {
+					/* blocking read of the version string */
+					read_session_identification();
+				} else {
+					read_packet();
+				}
 			}
 			
 			/* Process the decrypted packet. After this, the read buffer
@@ -204,19 +254,26 @@ void session_loop(void(*loophandler)()) {
 				process_packet();
 			}
 		}
-		
+
 		/* if required, flush out any queued reply packets that
 		were being held up during a KEX */
 		maybe_flush_reply_queue();
 
+		handle_connect_fds(&writefd);
+
+		/* loop handler prior to channelio, in case the server loophandler closes
+		channels on process exit */
+		loophandler();
+
 		/* process pipes etc for the channels, ses.dataallowed == 0
 		 * during rekeying ) */
-		if (ses.dataallowed) {
-			channelio(&readfd, &writefd);
-		}
+		channelio(&readfd, &writefd);
 
-		if (loophandler) {
-			loophandler();
+		/* process session socket's outgoing data */
+		if (ses.sock_out != -1) {
+			if (!isempty(&ses.writequeue)) {
+				write_packet();
+			}
 		}
 
 	} /* for(;;) */
@@ -224,43 +281,100 @@ void session_loop(void(*loophandler)()) {
 	/* Not reached */
 }
 
+static void cleanup_buf(buffer **buf) {
+	if (!*buf) {
+		return;
+	}
+	buf_burn(*buf);
+	buf_free(*buf);
+	*buf = NULL;
+}
+
 /* clean up a session on exit */
-void common_session_cleanup() {
+void session_cleanup() {
 	
 	TRACE(("enter session_cleanup"))
 	
 	/* we can't cleanup if we don't know the session state */
-	if (!sessinitdone) {
-		TRACE(("leave session_cleanup: !sessinitdone"))
+	if (!ses.init_done) {
+		TRACE(("leave session_cleanup: !ses.init_done"))
 		return;
 	}
-	
-	m_free(ses.session_id);
+
+	/* BEWARE of changing order of functions here. */
+
+	/* Must be before extra_session_cleanup() */
+	chancleanup();
+
+	if (ses.extra_session_cleanup) {
+		ses.extra_session_cleanup();
+	}
+
+	/* After these are freed most functions will fail */
+#if DROPBEAR_CLEANUP
+	/* listeners call cleanup functions, this should occur before
+	other session state is freed. */
+	remove_all_listeners();
+
+	remove_connect_pending();
+
+	while (!isempty(&ses.writequeue)) {
+		buf_free(dequeue(&ses.writequeue));
+	}
+
+	m_free(ses.newkeys);
+#ifndef DISABLE_ZLIB
+	if (ses.keys->recv.zstream != NULL) {
+		if (inflateEnd(ses.keys->recv.zstream) == Z_STREAM_ERROR) {
+			dropbear_exit("Crypto error");
+		}
+		m_free(ses.keys->recv.zstream);
+	}
+#endif
+
+	m_free(ses.remoteident);
+	m_free(ses.authstate.pw_dir);
+	m_free(ses.authstate.pw_name);
+	m_free(ses.authstate.pw_shell);
+	m_free(ses.authstate.pw_passwd);
+	m_free(ses.authstate.username);
+#endif
+
+	cleanup_buf(&ses.session_id);
+	cleanup_buf(&ses.hash);
+	cleanup_buf(&ses.payload);
+	cleanup_buf(&ses.readbuf);
+	cleanup_buf(&ses.writepayload);
+	cleanup_buf(&ses.kexhashbuf);
+	cleanup_buf(&ses.transkexinit);
+	if (ses.dh_K) {
+		mp_clear(ses.dh_K);
+	}
+	m_free(ses.dh_K);
+
 	m_burn(ses.keys, sizeof(struct key_context));
 	m_free(ses.keys);
 
-	chancleanup();
-
 	TRACE(("leave session_cleanup"))
 }
 
+void send_session_identification() {
+	buffer *writebuf = buf_new(strlen(LOCAL_IDENT "\r\n") + 1);
+	buf_putbytes(writebuf, (const unsigned char *) LOCAL_IDENT "\r\n", strlen(LOCAL_IDENT "\r\n"));
+	writebuf_enqueue(writebuf);
+}
 
-void session_identification() {
-
+static void read_session_identification() {
 	/* max length of 255 chars */
 	char linebuf[256];
 	int len = 0;
 	char done = 0;
 	int i;
 
-	/* write our version string, this blocks */
-	if (atomicio(write, ses.sock_out, LOCAL_IDENT "\r\n",
-				strlen(LOCAL_IDENT "\r\n")) == DROPBEAR_FAILURE) {
-		ses.remoteclosed();
-	}
-
-	/* If they send more than 50 lines, something is wrong */
-	for (i = 0; i < 50; i++) {
+	/* Servers may send other lines of data before sending the
+	 * version string, client must be able to process such lines.
+	 * If they send more than 50 lines, something is wrong */
+	for (i = IS_DROPBEAR_CLIENT ? 50 : 1; i > 0; i--) {
 		len = ident_readln(ses.sock_in, linebuf, sizeof(linebuf));
 
 		if (len < 0 && errno != EINTR) {
@@ -276,7 +390,7 @@ void session_identification() {
 	}
 
 	if (!done) {
-		TRACE(("err: %s for '%s'\n", strerror(errno), linebuf))
+		TRACE(("error reading remote ident: %s\n", strerror(errno)))
 		ses.remoteclosed();
 	} else {
 		/* linebuf is already null terminated */
@@ -310,7 +424,7 @@ static int ident_readln(int fd, char* buf, int count) {
 		return -1;
 	}
 
-	FD_ZERO(&fds);
+	DROPBEAR_FD_ZERO(&fds);
 
 	/* select since it's a non-blocking fd */
 	
@@ -368,11 +482,37 @@ static int ident_readln(int fd, char* buf, int count) {
 	return pos+1;
 }
 
-void send_msg_ignore() {
+void ignore_recv_response() {
+	/* Do nothing */
+	TRACE(("Ignored msg_request_response"))
+}
+
+static void send_msg_keepalive() {
+	time_t old_time_idle = ses.last_packet_time_idle;
+	struct Channel *chan = get_any_ready_channel();
+
 	CHECKCLEARTOWRITE();
-	buf_putbyte(ses.writepayload, SSH_MSG_IGNORE);
-	buf_putstring(ses.writepayload, "", 0);
+
+	if (chan) {
+		/* Channel requests are preferable, more implementations
+		handle them than SSH_MSG_GLOBAL_REQUEST */
+		TRACE(("keepalive channel request %d", chan->index))
+		start_send_channel_request(chan, DROPBEAR_KEEPALIVE_STRING);
+	} else {
+		TRACE(("keepalive global request"))
+		/* Some peers will reply with SSH_MSG_REQUEST_FAILURE, 
+		some will reply with SSH_MSG_UNIMPLEMENTED, some will exit. */
+		buf_putbyte(ses.writepayload, SSH_MSG_GLOBAL_REQUEST); 
+		buf_putstring(ses.writepayload, DROPBEAR_KEEPALIVE_STRING,
+			strlen(DROPBEAR_KEEPALIVE_STRING));
+	}
+	buf_putbyte(ses.writepayload, 1); /* want_reply */
 	encrypt_packet();
+
+	ses.last_packet_time_keepalive_sent = monotonic_now();
+
+	/* keepalives shouldn't update idle timeout, reset it back */
+	ses.last_packet_time_idle = old_time_idle;
 }
 
 /* Check all timeouts which are required. Currently these are the time for
@@ -380,10 +520,10 @@ void send_msg_ignore() {
 static void checktimeouts() {
 
 	time_t now;
-
-	now = time(NULL);
+	now = monotonic_now();
 	
-	if (ses.connect_time != 0 && now - ses.connect_time >= AUTH_TIMEOUT) {
+	if (IS_DROPBEAR_SERVER && ses.connect_time != 0
+		&& now - ses.connect_time >= AUTH_TIMEOUT) {
 			dropbear_close("Timeout before auth");
 	}
 
@@ -399,30 +539,69 @@ static void checktimeouts() {
 		send_msg_kexinit();
 	}
 	
-	if (opts.keepalive_secs > 0 
-			&& now - ses.last_trx_packet_time >= opts.keepalive_secs) {
-		send_msg_ignore();
+	if (opts.keepalive_secs > 0 && ses.authstate.authdone) {
+		/* Avoid sending keepalives prior to auth - those are
+		not valid pre-auth packet types */
+
+		/* Send keepalives if we've been idle */
+		if (now - ses.last_packet_time_any_sent >= opts.keepalive_secs) {
+			send_msg_keepalive();
+		}
+
+		/* Also send an explicit keepalive message to trigger a response
+		if the remote end hasn't sent us anything */
+		if (now - ses.last_packet_time_keepalive_recv >= opts.keepalive_secs
+			&& now - ses.last_packet_time_keepalive_sent >= opts.keepalive_secs) {
+			send_msg_keepalive();
+		}
+
+		if (now - ses.last_packet_time_keepalive_recv 
+			>= opts.keepalive_secs * DEFAULT_KEEPALIVE_LIMIT) {
+			dropbear_exit("Keepalive timeout");
+		}
 	}
 
-	if (opts.idle_timeout_secs > 0 && ses.last_packet_time > 0
-			&& now - ses.last_packet_time >= opts.idle_timeout_secs) {
+	if (opts.idle_timeout_secs > 0 
+			&& now - ses.last_packet_time_idle >= opts.idle_timeout_secs) {
 		dropbear_close("Idle timeout");
 	}
 }
 
+static void update_timeout(long limit, long now, long last_event, long * timeout) {
+	TRACE2(("update_timeout limit %ld, now %ld, last %ld, timeout %ld",
+		limit, now, last_event, *timeout))
+	if (last_event > 0 && limit > 0) {
+		*timeout = MIN(*timeout, last_event+limit-now);
+		TRACE2(("new timeout %ld", *timeout))
+	}
+}
+
 static long select_timeout() {
 	/* determine the minimum timeout that might be required, so
 	as to avoid waking when unneccessary */
-	long ret = LONG_MAX;
-	if (KEX_REKEY_TIMEOUT > 0)
-		ret = MIN(KEX_REKEY_TIMEOUT, ret);
-	if (AUTH_TIMEOUT > 0)
-		ret = MIN(AUTH_TIMEOUT, ret);
-	if (opts.keepalive_secs > 0)
-		ret = MIN(opts.keepalive_secs, ret);
-    if (opts.idle_timeout_secs > 0)
-        ret = MIN(opts.idle_timeout_secs, ret);
-	return ret;
+	long timeout = KEX_REKEY_TIMEOUT;
+	long now = monotonic_now();
+
+	if (!ses.kexstate.sentkexinit) {
+		update_timeout(KEX_REKEY_TIMEOUT, now, ses.kexstate.lastkextime, &timeout);
+	}
+
+	if (ses.authstate.authdone != 1 && IS_DROPBEAR_SERVER) {
+		/* AUTH_TIMEOUT is only relevant before authdone */
+		update_timeout(AUTH_TIMEOUT, now, ses.connect_time, &timeout);
+	}
+
+	if (ses.authstate.authdone) {
+		update_timeout(opts.keepalive_secs, now, 
+			MAX(ses.last_packet_time_keepalive_recv, ses.last_packet_time_keepalive_sent),
+			&timeout);
+	}
+
+	update_timeout(opts.idle_timeout_secs, now, ses.last_packet_time_idle,
+		&timeout);
+
+	/* clamp negative timeouts to zero - event has already triggered */
+	return MAX(timeout, 0);
 }
 
 const char* get_user_shell() {
@@ -453,6 +632,69 @@ void fill_passwd(const char* username) {
 	ses.authstate.pw_name = m_strdup(pw->pw_name);
 	ses.authstate.pw_dir = m_strdup(pw->pw_dir);
 	ses.authstate.pw_shell = m_strdup(pw->pw_shell);
-	ses.authstate.pw_passwd = m_strdup(pw->pw_passwd);
+	{
+		char *passwd_crypt = pw->pw_passwd;
+#ifdef HAVE_SHADOW_H
+		/* get the shadow password if possible */
+		struct spwd *spasswd = getspnam(ses.authstate.pw_name);
+		if (spasswd && spasswd->sp_pwdp) {
+			passwd_crypt = spasswd->sp_pwdp;
+		}
+#endif
+		if (!passwd_crypt) {
+			/* android supposedly returns NULL */
+			passwd_crypt = "!!";
+		}
+		ses.authstate.pw_passwd = m_strdup(passwd_crypt);
+	}
+}
+
+/* Called when channels are modified */
+void update_channel_prio() {
+	enum dropbear_prio new_prio;
+	int any = 0;
+	unsigned int i;
+
+	TRACE(("update_channel_prio"))
+
+	if (ses.sock_out < 0) {
+		TRACE(("leave update_channel_prio: no socket"))
+		return;
+	}
+
+	new_prio = DROPBEAR_PRIO_BULK;
+	for (i = 0; i < ses.chansize; i++) {
+		struct Channel *channel = ses.channels[i];
+		if (!channel || channel->prio == DROPBEAR_CHANNEL_PRIO_EARLY) {
+			if (channel && channel->prio == DROPBEAR_CHANNEL_PRIO_EARLY) {
+				TRACE(("update_channel_prio: early %d", channel->index))
+			}
+			continue;
+		}
+		any = 1;
+		if (channel->prio == DROPBEAR_CHANNEL_PRIO_INTERACTIVE)
+		{
+			TRACE(("update_channel_prio: lowdelay %d", channel->index))
+			new_prio = DROPBEAR_PRIO_LOWDELAY;
+			break;
+		} else if (channel->prio == DROPBEAR_CHANNEL_PRIO_UNKNOWABLE
+			&& new_prio == DROPBEAR_PRIO_BULK)
+		{
+			TRACE(("update_channel_prio: unknowable %d", channel->index))
+			new_prio = DROPBEAR_PRIO_DEFAULT;
+		}
+	}
+
+	if (any == 0) {
+		/* lowdelay during setup */
+		TRACE(("update_channel_prio: not any"))
+		new_prio = DROPBEAR_PRIO_LOWDELAY;
+	}
+
+	if (new_prio != ses.socket_prio) {
+		TRACE(("Dropbear priority transitioning %d -> %d", ses.socket_prio, new_prio))
+		set_sock_priority(ses.sock_out, new_prio);
+		ses.socket_prio = new_prio;
+	}
 }
 

compat.c

@@ -114,8 +114,8 @@ size_t strlcpy(char *dst, const char *src, size_t size) {
 #endif /* HAVE_STRLCPY */
 
 #ifndef HAVE_STRLCAT
-/* taken from openbsd-compat for OpenSSH 3.6.1p1 */
-/* "$OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $"
+/* taken from openbsd-compat for OpenSSH 7.2p2 */
+/* "$OpenBSD: strlcat.c,v 1.13 2005/08/08 08:05:37 espie Exp $"
  *
  * Appends src to string dst of size siz (unlike strncat, siz is the
  * full size of dst, not space left).  At most siz-1 characters
@@ -123,15 +123,12 @@ size_t strlcpy(char *dst, const char *src, size_t size) {
  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
  * If retval >= siz, truncation occurred.
  */
-	size_t
-strlcat(dst, src, siz)
-	char *dst;
-	const char *src;
-	size_t siz;
+size_t
+strlcat(char *dst, const char *src, size_t siz)
 {
-	register char *d = dst;
-	register const char *s = src;
-	register size_t n = siz;
+	char *d = dst;
+	const char *s = src;
+	size_t n = siz;
 	size_t dlen;
 
 	/* Find the end of dst and adjust bytes left but don't go past end */
@@ -177,7 +174,7 @@ int daemon(int nochdir, int noclose) {
 	if (!nochdir)
 		(void)chdir("/");
 
-	if (!noclose && (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
+	if (!noclose && (fd = open(DROPBEAR_PATH_DEVNULL, O_RDWR, 0)) != -1) {
 		(void)dup2(fd, STDIN_FILENO);
 		(void)dup2(fd, STDOUT_FILENO);
 		(void)dup2(fd, STDERR_FILENO);
@@ -193,6 +190,10 @@ int daemon(int nochdir, int noclose) {
 char *basename(const char *path) {
 
 	char *foo = strrchr(path, '/');
+	if (!foo)
+	{
+		return path;
+	}
 	return ++foo;
 }
 
@@ -231,7 +232,7 @@ void setusershell() {
 
 static char **initshells() {
 	/* don't touch this list. */
-	const char *okshells[] = { "/bin/sh", "/bin/csh", NULL };
+	static const char *okshells[] = { "/bin/sh", "/bin/csh", NULL };
 	register char **sp, *cp;
 	register FILE *fp;
 	struct stat statb;

compat.h

@@ -22,8 +22,8 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
-#ifndef _COMPAT_H_
-#define _COMPAT_H_
+#ifndef DROPBEAR_COMPAT_H_
+#define DROPBEAR_COMPAT_H_
 
 #include "includes.h"
 
@@ -44,13 +44,13 @@ char *basename(const char* path);
 #endif
 
 #ifndef HAVE_GETUSERSHELL
-char *getusershell();
-void setusershell();
-void endusershell();
+char *getusershell(void);
+void setusershell(void);
+void endusershell(void);
 #endif
 
-#ifndef _PATH_DEVNULL
-#define _PATH_DEVNULL "/dev/null"
+#ifndef DROPBEAR_PATH_DEVNULL
+#define DROPBEAR_PATH_DEVNULL "/dev/null"
 #endif
 
-#endif /* _COMPAT_H_ */
+#endif /* DROPBEAR_COMPAT_H_ */

configure.ac

@@ -5,24 +5,125 @@
 # of the platform checks have been taken straight from OpenSSH's configure.ac
 # Huge thanks to them for dealing with the horrible platform-specifics :)
 
-AC_PREREQ(2.50)
-AC_INIT(buffer.c)
+AC_PREREQ(2.59)
+AC_INIT
+AC_CONFIG_SRCDIR(buffer.c)
 
-OLDCFLAGS=$CFLAGS
+# Record which revision is being built
+if test -s "`which hg`" && test -d "$srcdir/.hg"; then
+	hgrev=`hg id -i -R "$srcdir"`
+	AC_MSG_NOTICE([Source directory Mercurial base revision $hgrev])
+fi
+
+ORIGCFLAGS="$CFLAGS"
 # Checks for programs.
 AC_PROG_CC
-AC_PROG_MAKE_SET
 
 if test -z "$LD" ; then
 	LD=$CC
 fi
 AC_SUBST(LD)	
 
-if test -z "$OLDCFLAGS" && test "$GCC" = "yes"; then
+AC_DEFUN(DB_TRYADDCFLAGS, 
+[{
+		OLDFLAGS="$CFLAGS"
+		TESTFLAGS="$1"
+		CFLAGS="$CFLAGS $TESTFLAGS"
+		AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])], 
+			[AC_MSG_NOTICE([Setting $TESTFLAGS])], 
+			[AC_MSG_NOTICE([Not setting $TESTFLAGS]); CFLAGS="$OLDFLAGS" ]
+			)
+}])
+
+# set compile flags prior to other tests
+if test -z "$ORIGCFLAGS" && test "$GCC" = "yes"; then
 	AC_MSG_NOTICE(No \$CFLAGS set... using "-Os -W -Wall" for GCC)
 	CFLAGS="-Os -W -Wall"
 fi
 
+AC_MSG_NOTICE([Checking if compiler '$CC' supports -Wno-pointer-sign])
+DB_TRYADDCFLAGS([-Wno-pointer-sign])
+
+AC_MSG_NOTICE([Checking if compiler '$CC' supports -fno-strict-overflow])
+DB_TRYADDCFLAGS([-fno-strict-overflow])
+
+STATIC=0
+AC_ARG_ENABLE(static,
+	[  --enable-static         Build static binaries],
+	[
+		if test "x$enableval" = "xyes"; then
+			STATIC=1
+			AC_MSG_NOTICE(Static Build)
+		fi
+	], [])
+AC_SUBST(STATIC)
+
+hardenbuild=1
+AC_ARG_ENABLE(harden,
+	[  --disable-harden        Don't set hardened build flags],
+	[
+		if test "x$enableval" = "xno"; then
+			hardenbuild=0
+			AC_MSG_NOTICE(Disabling hardened build flags)
+		fi
+	], [])
+
+if test "$hardenbuild" -eq 1; then
+	AC_MSG_NOTICE(Checking for available hardened build flags:)
+	# relocation flags don't make sense for static builds
+	if test "$STATIC" -ne 1; then
+		# pie
+		DB_TRYADDCFLAGS([-fPIE])
+
+		OLDLDFLAGS="$LDFLAGS"
+		TESTFLAGS="-Wl,-pie"
+		LDFLAGS="$LDFLAGS $TESTFLAGS"
+		AC_LINK_IFELSE([AC_LANG_PROGRAM([])], 
+			[AC_MSG_NOTICE([Setting $TESTFLAGS])], 
+			[
+				LDFLAGS="$OLDLDFLAGS"
+				TESTFLAGS="-pie"
+				LDFLAGS="$LDFLAGS $TESTFLAGS"
+				AC_LINK_IFELSE([AC_LANG_PROGRAM([])], 
+					[AC_MSG_NOTICE([Setting $TESTFLAGS])], 
+					[AC_MSG_NOTICE([Not setting $TESTFLAGS]); LDFLAGS="$OLDLDFLAGS" ]
+					)
+			]
+			)
+		# readonly elf relocation sections (relro)
+		OLDLDFLAGS="$LDFLAGS"
+		TESTFLAGS="-Wl,-z,now -Wl,-z,relro"
+		LDFLAGS="$LDFLAGS $TESTFLAGS"
+		AC_LINK_IFELSE([AC_LANG_PROGRAM([])], 
+			[AC_MSG_NOTICE([Setting $TESTFLAGS])], 
+			[AC_MSG_NOTICE([Not setting $TESTFLAGS]); LDFLAGS="$OLDLDFLAGS" ]
+			)
+	fi # non-static
+	# stack protector. -strong is good but only in gcc 4.9 or later
+	OLDCFLAGS="$CFLAGS"
+	TESTFLAGS="-fstack-protector-strong"
+	CFLAGS="$CFLAGS $TESTFLAGS"
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])], 
+	    [AC_MSG_NOTICE([Setting $TESTFLAGS])], 
+	    [
+			CFLAGS="$OLDCFLAGS"
+			TESTFLAGS="-fstack-protector --param=ssp-buffer-size=4"
+			CFLAGS="$CFLAGS $TESTFLAGS"
+			AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])], 
+			    [AC_MSG_NOTICE([Setting $TESTFLAGS])], 
+			    [AC_MSG_NOTICE([Not setting $TESTFLAGS]); CFLAGS="$OLDCFLAGS" ]
+			    )
+	    ]
+	    )
+	# FORTIFY_SOURCE
+	DB_TRYADDCFLAGS([-D_FORTIFY_SOURCE=2])
+
+	# Spectre v2 mitigations
+	DB_TRYADDCFLAGS([-mfunction-return=thunk])
+	DB_TRYADDCFLAGS([-mindirect-branch=thunk])
+
+fi
+
 # large file support is useful for scp
 AC_SYS_LARGEFILE
 
@@ -44,8 +145,8 @@ case "$host" in
 	sol2ver=`echo "$host"| sed -e 's/.*[[0-9]]\.//'`
 	if test "$sol2ver" -ge 8; then
 		AC_MSG_RESULT(yes)
-		AC_DEFINE(DISABLE_UTMP,,Disable utmp)
-		AC_DEFINE(DISABLE_WTMP,,Disable wtmp)
+		AC_DEFINE(DISABLE_UTMP,1,Disable utmp)
+		AC_DEFINE(DISABLE_WTMP,1,Disable wtmp)
 	else
 		AC_MSG_RESULT(no)
 	fi
@@ -54,18 +155,18 @@ case "$host" in
 	;;
 
 *-*-aix*)
-	AC_DEFINE(AIX,,Using AIX)
+	AC_DEFINE(AIX,1,Using AIX)
 	# OpenSSH thinks it's broken. If it isn't, let me know.
-	AC_DEFINE(BROKEN_GETADDRINFO,,Broken getaddrinfo)
+	AC_DEFINE(BROKEN_GETADDRINFO,1,Broken getaddrinfo)
 	;;
 	
 *-*-hpux*)
 	LIBS="$LIBS -lsec"
 	# It's probably broken.
-	AC_DEFINE(BROKEN_GETADDRINFO,,Broken getaddrinfo)
+	AC_DEFINE(BROKEN_GETADDRINFO,1,Broken getaddrinfo)
 	;;
 *-dec-osf*)
-	AC_DEFINE(BROKEN_GETADDRINFO,,Broken getaddrinfo)
+	AC_DEFINE(BROKEN_GETADDRINFO,1,Broken getaddrinfo)
 	;;
 esac
 
@@ -79,11 +180,21 @@ AC_CHECK_DECL(__UCLIBC__,
 	[
 	no_loginfunc_check=1
 	AC_MSG_NOTICE([Using uClibc - login() and logout() probably don't work, so we won't use them.])
-	],,,)
+	],,)
 
-# Checks for libraries.
-AC_CHECK_LIB(crypt, crypt, CRYPTLIB="-lcrypt")
+dnl We test for crypt() specially. On Linux (and others?) it resides in libcrypt
+dnl but we don't want link all binaries to -lcrypt, just dropbear server.
+dnl OS X doesn't need -lcrypt 
+AC_CHECK_FUNC(crypt, found_crypt_func=here)
+AC_CHECK_LIB(crypt, crypt, 
+	[
+	CRYPTLIB="-lcrypt"
+	found_crypt_func=here
+	])
 AC_SUBST(CRYPTLIB)	
+if test "t$found_crypt_func" = there; then
+AC_DEFINE(HAVE_CRYPT, 1, [crypt() function])
+fi
 
 # Check if zlib is needed
 AC_ARG_WITH(zlib,
@@ -107,7 +218,7 @@ AC_ARG_ENABLE(zlib,
 	[  --disable-zlib          Don't include zlib support],
 	[
 		if test "x$enableval" = "xno"; then
-			AC_DEFINE(DISABLE_ZLIB,, Use zlib)
+			AC_DEFINE(DISABLE_ZLIB,1,Use zlib)
 			AC_MSG_NOTICE(Disabling zlib)
 		else
 			AC_CHECK_LIB(z, deflate, , AC_MSG_ERROR([*** zlib missing - install first or check config.log ***]))
@@ -141,20 +252,20 @@ AC_ARG_WITH(pam,
 
 
 AC_ARG_ENABLE(pam,
-	[  --enable-pam          Try to include PAM support],
+	[  --enable-pam            Try to include PAM support],
 	[
 		if test "x$enableval" = "xyes"; then
 			AC_CHECK_LIB(pam, pam_authenticate, , AC_MSG_ERROR([*** PAM missing - install first or check config.log ***]))
 			AC_MSG_NOTICE(Enabling PAM)
 			AC_CHECK_FUNCS(pam_fail_delay)
 		else
-			AC_DEFINE(DISABLE_PAM,, Use PAM)
+			AC_DEFINE(DISABLE_PAM,1,Use PAM)
 			AC_MSG_NOTICE(Disabling PAM)
 		fi
 	],
 	[
 		# disable it by default
-		AC_DEFINE(DISABLE_PAM,, Use PAM)
+		AC_DEFINE(DISABLE_PAM,1,Use PAM)
 		AC_MSG_NOTICE(Disabling PAM)
 	]
 )
@@ -166,21 +277,26 @@ AC_ARG_ENABLE(openpty,
 			AC_MSG_NOTICE(Not using openpty)
 		else
 			AC_MSG_NOTICE(Using openpty if available)
-			AC_SEARCH_LIBS(openpty, util, [AC_DEFINE(HAVE_OPENPTY,,Have openpty() function)])
+			AC_SEARCH_LIBS(openpty, util, [dropbear_cv_func_have_openpty=yes])
 		fi
 	],
 	[
 		AC_MSG_NOTICE(Using openpty if available)
-		AC_SEARCH_LIBS(openpty, util, [AC_DEFINE(HAVE_OPENPTY)])
+		AC_SEARCH_LIBS(openpty, util, [dropbear_cv_func_have_openpty=yes])
 	]
 )
-		
+
+if test "x$dropbear_cv_func_have_openpty" = "xyes"; then
+	AC_DEFINE(HAVE_OPENPTY,,Have openpty() function)
+	no_ptc_check=yes
+	no_ptmx_check=yes
+fi
 
 AC_ARG_ENABLE(syslog,
 	[  --disable-syslog        Don't include syslog support],
 	[
 		if test "x$enableval" = "xno"; then
-			AC_DEFINE(DISABLE_SYSLOG,, Using syslog)
+			AC_DEFINE(DISABLE_SYSLOG,1,Using syslog)
 			AC_MSG_NOTICE(Disabling syslog)
 		else
 			AC_MSG_NOTICE(Enabling syslog)
@@ -206,12 +322,56 @@ AC_ARG_ENABLE(shadow,
 		AC_MSG_NOTICE(Using shadow passwords if available)
 	]
 )
-			
+
+AC_ARG_ENABLE(plugin,
+	[  --enable-plugin         Enable support for External Public Key Authentication plug-in],
+	[
+		AC_DEFINE(DROPBEAR_PLUGIN, 1, External Public Key Authentication)
+		AC_MSG_NOTICE(Enabling support for External Public Key Authentication)
+		DROPBEAR_PLUGIN=1
+	],
+	[
+		AC_DEFINE(DROPBEAR_PLUGIN, 0, External Public Key Authentication)
+		DROPBEAR_PLUGIN=0
+	]
+
+)
+AC_SUBST(DROPBEAR_PLUGIN)
+
+AC_ARG_ENABLE(fuzz,
+	[  --enable-fuzz           Build fuzzing. Not recommended for deployment.],
+	[
+		if test "x$enableval" = "xyes"; then
+            AC_DEFINE(DROPBEAR_FUZZ, 1, Fuzzing)
+            AC_MSG_NOTICE(Enabling fuzzing)
+            DROPBEAR_FUZZ=1
+            # libfuzzer needs linking with c++ libraries
+            AC_PROG_CXX
+        else
+            AC_DEFINE(DROPBEAR_FUZZ, 0, Fuzzing)
+            AC_MSG_NOTICE(Disabling fuzzing)
+            DROPBEAR_FUZZ=0
+        fi
+	],
+	[
+		AC_DEFINE(DROPBEAR_FUZZ, 0, Fuzzing)
+		AC_MSG_NOTICE(Disabling fuzzing)
+		DROPBEAR_FUZZ=0
+	]
+
+)
+AC_SUBST(DROPBEAR_FUZZ)
+AC_SUBST(CXX)
 
 # Checks for header files.
 AC_HEADER_STDC
 AC_HEADER_SYS_WAIT
-AC_CHECK_HEADERS([fcntl.h limits.h netinet/in.h netinet/tcp.h stdlib.h string.h sys/socket.h sys/time.h termios.h unistd.h crypt.h pty.h ioctl.h libutil.h libgen.h inttypes.h stropts.h utmp.h utmpx.h lastlog.h paths.h util.h netdb.h security/pam_appl.h pam/pam_appl.h netinet/in_systm.h])
+AC_CHECK_HEADERS([netinet/in.h netinet/tcp.h \
+	crypt.h \
+	pty.h libutil.h libgen.h inttypes.h stropts.h utmp.h \
+	utmpx.h lastlog.h paths.h util.h netdb.h security/pam_appl.h \
+	pam/pam_appl.h netinet/in_systm.h sys/uio.h linux/pkt_sched.h \
+	sys/random.h])
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST
@@ -221,7 +381,8 @@ AC_TYPE_PID_T
 AC_TYPE_SIZE_T
 AC_HEADER_TIME
 
-AC_CHECK_TYPES([uint16_t, u_int16_t, struct sockaddr_storage])
+AC_CHECK_TYPES([uint8_t, u_int8_t, uint16_t, u_int16_t, uint32_t, u_int32_t])
+AC_CHECK_TYPES([struct sockaddr_storage])
 AC_CHECK_TYPE([socklen_t], ,[
 	AC_MSG_CHECKING([for socklen_t equivalent])
 	AC_CACHE_VAL([curl_cv_socklen_t_equiv],
@@ -231,15 +392,15 @@ AC_CHECK_TYPE([socklen_t], ,[
 	curl_cv_socklen_t_equiv=
 	for arg2 in "struct sockaddr" void; do
 		for t in int size_t unsigned long "unsigned long"; do
-		AC_TRY_COMPILE([
-			#include <sys/types.h>
-			#include <sys/socket.h>
+		AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <sys/socket.h>
 
 			int getpeername (int, $arg2 *, $t *);
-		],[
+		]],[[
 			$t len;
 			getpeername(0,0,&len);
-		],[
+		]])],[
 			curl_cv_socklen_t_equiv="$t"
 			break
 		])
@@ -259,12 +420,11 @@ AC_CHECK_TYPE([socklen_t], ,[
 # for the fake-rfc2553 stuff - straight from OpenSSH
 
 AC_CACHE_CHECK([for struct sockaddr_storage], ac_cv_have_struct_sockaddr_storage, [
-	AC_TRY_COMPILE(
-		[
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h>
 #include <sys/socket.h>
-		],
-		[ struct sockaddr_storage s; ],
+		]],
+		[[ if (sizeof(struct sockaddr_storage)) return 0 ]])],
 		[ ac_cv_have_struct_sockaddr_storage="yes" ],
 		[ ac_cv_have_struct_sockaddr_storage="no" ]
 	)
@@ -274,64 +434,61 @@ if test "x$ac_cv_have_struct_sockaddr_storage" = "xyes" ; then
 fi
 
 AC_CACHE_CHECK([for struct sockaddr_in6], ac_cv_have_struct_sockaddr_in6, [
-	AC_TRY_COMPILE(
-		[
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h>
 #include <netinet/in.h>
-		],
-		[ struct sockaddr_in6 s; s.sin6_family = 0; ],
+		]],
+		[[ if (sizeof(struct sockaddr_in6)) return 0 ]])],
 		[ ac_cv_have_struct_sockaddr_in6="yes" ],
 		[ ac_cv_have_struct_sockaddr_in6="no" ]
 	)
 ])
 if test "x$ac_cv_have_struct_sockaddr_in6" = "xyes" ; then
-	AC_DEFINE(HAVE_STRUCT_SOCKADDR_IN6,,Have struct sockaddr_in6)
+	AC_DEFINE(HAVE_STRUCT_SOCKADDR_IN6,1,Have struct sockaddr_in6)
 fi
 
 AC_CACHE_CHECK([for struct in6_addr], ac_cv_have_struct_in6_addr, [
-	AC_TRY_COMPILE(
-		[
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h>
 #include <netinet/in.h>
-		],
-		[ struct in6_addr s; s.s6_addr[0] = 0; ],
+		]],
+		[[ if (sizeof(struct in6_addr)) return 0 ]])],
 		[ ac_cv_have_struct_in6_addr="yes" ],
 		[ ac_cv_have_struct_in6_addr="no" ]
 	)
 ])
 if test "x$ac_cv_have_struct_in6_addr" = "xyes" ; then
-	AC_DEFINE(HAVE_STRUCT_IN6_ADDR,,Have struct in6_addr)
+	AC_DEFINE(HAVE_STRUCT_IN6_ADDR,1,Have struct in6_addr)
 fi
 
 AC_CACHE_CHECK([for struct addrinfo], ac_cv_have_struct_addrinfo, [
-	AC_TRY_COMPILE(
-		[
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netdb.h>
-		],
-		[ struct addrinfo s; s.ai_flags = AI_PASSIVE; ],
+		]],
+		[[ if (sizeof(struct addrinfo)) return 0 ]])],
 		[ ac_cv_have_struct_addrinfo="yes" ],
 		[ ac_cv_have_struct_addrinfo="no" ]
 	)
 ])
 if test "x$ac_cv_have_struct_addrinfo" = "xyes" ; then
-	AC_DEFINE(HAVE_STRUCT_ADDRINFO,,Have struct addrinfo)
+	AC_DEFINE(HAVE_STRUCT_ADDRINFO,1,Have struct addrinfo)
 fi
 
 
 # IRIX has a const char return value for gai_strerror()
 AC_CHECK_FUNCS(gai_strerror,[
 	AC_DEFINE(HAVE_GAI_STRERROR)
-	AC_TRY_COMPILE([
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netdb.h>
 
-const char *gai_strerror(int);],[
+const char *gai_strerror(int);]],[[
 char *str;
 
-str = gai_strerror(0);],[
+str = gai_strerror(0);]])],[
 		AC_DEFINE(HAVE_CONST_GAI_STRERROR_PROTO, 1,
 		[Define if gai_strerror() returns const char *])])])
 
@@ -363,23 +520,44 @@ AC_CHECK_FUNCS(endutxent getutxent getutxid getutxline pututxline )
 AC_CHECK_FUNCS(setutxent utmpxname)
 AC_CHECK_FUNCS(logout updwtmp logwtmp)
 
+# POSIX monotonic time
+AC_CHECK_FUNCS(clock_gettime)
+
+# OS X monotonic time
+AC_CHECK_HEADERS([mach/mach_time.h])
+AC_CHECK_FUNCS(mach_absolute_time)
+
+AC_CHECK_FUNCS(explicit_bzero memset_s getrandom)
+
 AC_ARG_ENABLE(bundled-libtom,
-	[  --enable-bundled-libtom       Use bundled libtomcrypt/libtommath even if a system version exists],
-	[ 
-		BUNDLED_LIBTOM=1
-		AC_MSG_NOTICE(Forcing bundled libtom*)
+[  --enable-bundled-libtom       Force using bundled libtomcrypt/libtommath even if a system version exists.
+  --disable-bundled-libtom      Force using system libtomcrypt/libtommath, fail if it does not exist.
+                                Default is to use system if available, otherwise bundled.
+                                Dropbear requires system libtommath >= 1.2.0 and libtomcrypt >= 1.18.0],
+	[
+		if test "x$enableval" = "xyes"; then
+			BUNDLED_LIBTOM=1
+			AC_MSG_NOTICE(Forcing bundled libtom*)
+		else
+			BUNDLED_LIBTOM=0
+			AC_CHECK_LIB(tommath, mp_to_ubin, LIBTOM_LIBS="-ltommath $LIBTOM_LIBS",
+				[AC_MSG_ERROR([Missing/old system libtommath and --disable-bundled-libtom was specified])] )
+			AC_CHECK_LIB(tomcrypt, poly1305_init, LIBTOM_LIBS="-ltomcrypt $LIBTOM_LIBS",
+				[AC_MSG_ERROR([Missing/old system libtomcrypt and --disable-bundled-libtom was specified])] )
+		fi
 	],
 	[
 		BUNDLED_LIBTOM=0
-		AC_CHECK_LIB(tomcrypt, register_cipher, , BUNDLED_LIBTOM=1)
-		AC_CHECK_LIB(tommath, mp_exptmod, , BUNDLED_LIBTOM=1)
+		AC_CHECK_LIB(tommath, mp_to_ubin, LIBTOM_LIBS="-ltommath $LIBTOM_LIBS", BUNDLED_LIBTOM=1)
+		AC_CHECK_LIB(tomcrypt, poly1305_init, LIBTOM_LIBS="-ltomcrypt $LIBTOM_LIBS", BUNDLED_LIBTOM=1)
 	]
 )
 
 if test $BUNDLED_LIBTOM = 1 ; then
-	AC_DEFINE(BUNDLED_LIBTOM,,Use bundled libtom) 
+	AC_DEFINE(BUNDLED_LIBTOM,1,Use bundled libtom) 
 fi
 
+AC_SUBST(LIBTOM_LIBS)
 AC_SUBST(BUNDLED_LIBTOM)
 
 dnl Added from OpenSSH 3.6.1p2's configure.ac
@@ -387,36 +565,64 @@ dnl Added from OpenSSH 3.6.1p2's configure.ac
 dnl allow user to disable some login recording features
 AC_ARG_ENABLE(lastlog,
 	[  --disable-lastlog       Disable use of lastlog even if detected [no]],
-	[ AC_DEFINE(DISABLE_LASTLOG,,Disable use of lastlog()) ]
+	[
+		if test "x$enableval" = "xno" ; then
+			AC_DEFINE(DISABLE_LASTLOG,1,Disable use of lastlog())
+		fi
+	]
 )
 AC_ARG_ENABLE(utmp,
 	[  --disable-utmp          Disable use of utmp even if detected [no]],
-	[ AC_DEFINE(DISABLE_UTMP,,Disable use of utmp) ]
+	[
+		if test "x$enableval" = "xno" ; then
+			AC_DEFINE(DISABLE_UTMP,1,Disable use of utmp)
+		fi
+	]
 )
 AC_ARG_ENABLE(utmpx,
 	[  --disable-utmpx         Disable use of utmpx even if detected [no]],
-	[ AC_DEFINE(DISABLE_UTMPX,,Disable use of utmpx) ]
+	[
+		if test "x$enableval" = "xno" ; then
+			AC_DEFINE(DISABLE_UTMPX,1,Disable use of utmpx)
+		fi
+	]
 )
 AC_ARG_ENABLE(wtmp,
 	[  --disable-wtmp          Disable use of wtmp even if detected [no]],
-	[ AC_DEFINE(DISABLE_WTMP,,Disable use of wtmp) ]
+	[
+		if test "x$enableval" = "xno" ; then
+			AC_DEFINE(DISABLE_WTMP,1,Disable use of wtmp)
+		fi
+	]
 )
 AC_ARG_ENABLE(wtmpx,
 	[  --disable-wtmpx         Disable use of wtmpx even if detected [no]],
-	[ AC_DEFINE(DISABLE_WTMPX,,Disable use of wtmpx) ]
+	[
+		if test "x$enableval" = "xno" ; then
+			AC_DEFINE(DISABLE_WTMPX,1,Disable use of wtmpx)
+		fi
+	]
 )
 AC_ARG_ENABLE(loginfunc,
 	[  --disable-loginfunc     Disable use of login() etc. [no]],
 	[ no_loginfunc_check=1
-	AC_MSG_NOTICE(Not using login() etc) ]
+	AC_MSG_NOTICE([Not using login() etc]) ]
 )
 AC_ARG_ENABLE(pututline,
 	[  --disable-pututline     Disable use of pututline() etc. ([uw]tmp) [no]],
-	[ AC_DEFINE(DISABLE_PUTUTLINE,,Disable use of pututline()) ]
+	[
+		if test "x$enableval" = "xno" ; then
+			AC_DEFINE(DISABLE_PUTUTLINE,1,Disable use of pututline())
+		fi
+	]
 )
 AC_ARG_ENABLE(pututxline,
 	[  --disable-pututxline    Disable use of pututxline() etc. ([uw]tmpx) [no]],
-	[ AC_DEFINE(DISABLE_PUTUTXLINE,,Disable use of pututxline()) ]
+	[
+		if test "x$enableval" = "xno" ; then
+			AC_DEFINE(DISABLE_PUTUTXLINE,1,Disable use of pututxline())
+		fi
+	]
 )
 AC_ARG_WITH(lastlog,
   [  --with-lastlog=FILE|DIR specify lastlog location [common locations]],
@@ -431,7 +637,7 @@ AC_ARG_WITH(lastlog,
 
 if test -z "$no_loginfunc_check"; then
 	dnl    Checks for libutil functions (login(), logout() etc, not openpty() )
-	AC_SEARCH_LIBS(login, util bsd, [AC_DEFINE(HAVE_LOGIN,,Have login() function)])
+	AC_SEARCH_LIBS(login, util bsd, [AC_DEFINE(HAVE_LOGIN,1,[Have login() function])])
 	AC_CHECK_FUNCS(logout updwtmp logwtmp)
 fi
 
@@ -443,7 +649,7 @@ dnl lastlog and [uw]tmp are subject to a file search if all else fails
 dnl lastlog detection
 dnl  NOTE: the code itself will detect if lastlog is a directory
 AC_MSG_CHECKING([if your system defines LASTLOG_FILE])
-AC_TRY_COMPILE([
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h>
 #include <utmp.h>
 #ifdef HAVE_LASTLOG_H
@@ -455,13 +661,13 @@ AC_TRY_COMPILE([
 #ifdef HAVE_LOGIN_H
 # include <login.h>
 #endif
-	],
-	[ char *lastlog = LASTLOG_FILE; ],
+	]],
+	[[ char *lastlog = LASTLOG_FILE; ]])],
 	[ AC_MSG_RESULT(yes) ],
 	[
 		AC_MSG_RESULT(no)
 		AC_MSG_CHECKING([if your system defines _PATH_LASTLOG])
-		AC_TRY_COMPILE([
+		AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h>
 #include <utmp.h>
 #ifdef HAVE_LASTLOG_H
@@ -470,8 +676,8 @@ AC_TRY_COMPILE([
 #ifdef HAVE_PATHS_H
 #  include <paths.h>
 #endif
-		],
-		[ char *lastlog = _PATH_LASTLOG; ],
+		]],
+		[[ char *lastlog = _PATH_LASTLOG; ]])],
 		[ AC_MSG_RESULT(yes) ],
 		[
 			AC_MSG_RESULT(no)
@@ -500,14 +706,14 @@ fi
 
 dnl utmp detection
 AC_MSG_CHECKING([if your system defines UTMP_FILE])
-AC_TRY_COMPILE([
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h>
 #include <utmp.h>
 #ifdef HAVE_PATHS_H
 #  include <paths.h>
 #endif
-	],
-	[ char *utmp = UTMP_FILE; ],
+	]],
+	[[ char *utmp = UTMP_FILE; ]])],
 	[ AC_MSG_RESULT(yes) ],
 	[ AC_MSG_RESULT(no)
 	  system_utmp_path=no ]
@@ -530,14 +736,16 @@ fi
 
 dnl wtmp detection
 AC_MSG_CHECKING([if your system defines WTMP_FILE])
-AC_TRY_COMPILE([
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h>
-#include <utmp.h>
+#ifdef HAVE_UTMP_H
+#  include <utmp.h>
+#endif
 #ifdef HAVE_PATHS_H
 #  include <paths.h>
 #endif
-	],
-	[ char *wtmp = WTMP_FILE; ],
+	]],
+	[[ char *wtmp = WTMP_FILE; ]])],
 	[ AC_MSG_RESULT(yes) ],
 	[ AC_MSG_RESULT(no)
 	  system_wtmp_path=no ]
@@ -563,7 +771,7 @@ dnl utmpx detection - I don't know any system so perverse as to require
 dnl  utmpx, but not define UTMPX_FILE (ditto wtmpx.) No doubt it's out
 dnl  there, though.
 AC_MSG_CHECKING([if your system defines UTMPX_FILE])
-AC_TRY_COMPILE([
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h>
 #include <utmp.h>
 #ifdef HAVE_UTMPX_H
@@ -572,8 +780,8 @@ AC_TRY_COMPILE([
 #ifdef HAVE_PATHS_H
 #  include <paths.h>
 #endif
-	],
-	[ char *utmpx = UTMPX_FILE; ],
+	]],
+	[[ char *utmpx = UTMPX_FILE; ]])],
 	[ AC_MSG_RESULT(yes) ],
 	[ AC_MSG_RESULT(no)
 	  system_utmpx_path=no ]
@@ -588,17 +796,19 @@ fi
 
 dnl wtmpx detection
 AC_MSG_CHECKING([if your system defines WTMPX_FILE])
-AC_TRY_COMPILE([
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h>
-#include <utmp.h>
+#ifdef HAVE_UTMP_H
+#  include <utmp.h>
+#endif
 #ifdef HAVE_UTMPX_H
-#include <utmpx.h>
+#  include <utmpx.h>
 #endif
 #ifdef HAVE_PATHS_H
 #  include <paths.h>
 #endif
-	],
-	[ char *wtmpx = WTMPX_FILE; ],
+	]],
+	[[ char *wtmpx = WTMPX_FILE; ]])],
 	[ AC_MSG_RESULT(yes) ],
 	[ AC_MSG_RESULT(no)
 	  system_wtmpx_path=no ]
@@ -615,15 +825,18 @@ fi
 AC_PROG_GCC_TRADITIONAL
 AC_FUNC_MEMCMP
 AC_FUNC_SELECT_ARGTYPES
-AC_TYPE_SIGNAL
-AC_CHECK_FUNCS([dup2 getspnam getusershell memset putenv select socket strdup clearenv strlcpy strlcat daemon basename _getpty getaddrinfo freeaddrinfo getnameinfo])
+AC_CHECK_FUNCS([getpass getspnam getusershell putenv])
+AC_CHECK_FUNCS([clearenv strlcpy strlcat daemon basename _getpty getaddrinfo ])
+AC_CHECK_FUNCS([freeaddrinfo getnameinfo fork writev getgrouplist])
 
 AC_SEARCH_LIBS(basename, gen, AC_DEFINE(HAVE_BASENAME))
 
 # Solaris needs ptmx
 if test -z "$no_ptmx_check" ; then
 	if test x"$cross_compiling" = x"no" ; then
-		AC_CHECK_FILE("/dev/ptmx", AC_DEFINE(USE_DEV_PTMX,,Use /dev/ptmx))
+		if test -e /dev/ptmx ; then
+			AC_DEFINE(USE_DEV_PTMX,1,Use /dev/ptmx)
+		fi
 	else
 		AC_MSG_NOTICE([Not checking for /dev/ptmx, we're cross-compiling])
 	fi
@@ -631,7 +844,9 @@ fi
 
 if test -z "$no_ptc_check" ; then
 	if test x"$cross_compiling" = x"no" ; then
-		AC_CHECK_FILE("/dev/ptc", AC_DEFINE(HAVE_DEV_PTS_AND_PTC,,Use /dev/ptc & /dev/pts))
+		if test -e /dev/ptc ; then
+			AC_DEFINE(HAVE_DEV_PTS_AND_PTC,1,Use /dev/ptc & /dev/pts)
+		fi
 	else
 		AC_MSG_NOTICE([Not checking for /dev/ptc & /dev/pts since we're cross-compiling])
 	fi
@@ -639,64 +854,32 @@ fi
 
 AC_EXEEXT
 
-# XXX there must be a nicer way to do this
-AS_MKDIR_P(libtomcrypt/src/ciphers/aes)
-AS_MKDIR_P(libtomcrypt/src/ciphers/safer)
-AS_MKDIR_P(libtomcrypt/src/ciphers/twofish)
-AS_MKDIR_P(libtomcrypt/src/encauth/ccm)
-AS_MKDIR_P(libtomcrypt/src/encauth/eax)
-AS_MKDIR_P(libtomcrypt/src/encauth/gcm)
-AS_MKDIR_P(libtomcrypt/src/encauth/ocb)
-AS_MKDIR_P(libtomcrypt/src/hashes)
-AS_MKDIR_P(libtomcrypt/src/hashes/chc)
-AS_MKDIR_P(libtomcrypt/src/hashes/helper)
-AS_MKDIR_P(libtomcrypt/src/hashes/sha2)
-AS_MKDIR_P(libtomcrypt/src/hashes/whirl)
-AS_MKDIR_P(libtomcrypt/src/mac/hmac)
-AS_MKDIR_P(libtomcrypt/src/mac/omac)
-AS_MKDIR_P(libtomcrypt/src/mac/pelican)
-AS_MKDIR_P(libtomcrypt/src/mac/pmac)
-AS_MKDIR_P(libtomcrypt/src/mac/f9)
-AS_MKDIR_P(libtomcrypt/src/mac/xcbc)
-AS_MKDIR_P(libtomcrypt/src/math/fp)
-AS_MKDIR_P(libtomcrypt/src/misc/base64)
-AS_MKDIR_P(libtomcrypt/src/misc/crypt)
-AS_MKDIR_P(libtomcrypt/src/misc/mpi)
-AS_MKDIR_P(libtomcrypt/src/misc/pkcs5)
-AS_MKDIR_P(libtomcrypt/src/modes/cbc)
-AS_MKDIR_P(libtomcrypt/src/modes/cfb)
-AS_MKDIR_P(libtomcrypt/src/modes/ctr)
-AS_MKDIR_P(libtomcrypt/src/modes/ecb)
-AS_MKDIR_P(libtomcrypt/src/modes/ofb)
-AS_MKDIR_P(libtomcrypt/src/modes/f8)
-AS_MKDIR_P(libtomcrypt/src/modes/lrw)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/bit)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/choice)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/ia5)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/integer)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/object_identifier)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/octet)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/printable_string)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/sequence)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/short_integer)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/utctime)
-AS_MKDIR_P(libtomcrypt/src/pk/dh)
-AS_MKDIR_P(libtomcrypt/src/pk/dsa)
-AS_MKDIR_P(libtomcrypt/src/pk/ecc)
-AS_MKDIR_P(libtomcrypt/src/pk/pkcs1)
-AS_MKDIR_P(libtomcrypt/src/pk/rsa)
-AS_MKDIR_P(libtomcrypt/src/prng)
+if test $BUNDLED_LIBTOM = 1 ; then
+(cd $srcdir; find libtomcrypt -type d) | xargs mkdir -pv 
+LIBTOM_FILES="libtomcrypt/Makefile libtommath/Makefile"
+fi
+
 AC_CONFIG_HEADER(config.h)
-AC_OUTPUT(Makefile)
-AC_OUTPUT(libtomcrypt/Makefile)
-AC_OUTPUT(libtommath/Makefile)
+AC_CONFIG_FILES(Makefile $LIBTOM_FILES)
+AC_OUTPUT
 
 AC_MSG_NOTICE()
 if test $BUNDLED_LIBTOM = 1 ; then
-AC_MSG_NOTICE(Using bundled libtomcrypt and libtommath)
+AC_MSG_NOTICE([Using bundled libtomcrypt and libtommath])
 else
-AC_MSG_NOTICE(Using system libtomcrypt and libtommath)
+AC_MSG_NOTICE([Using system libtomcrypt and libtommath])
+fi
+
+
+if test "x$ac_cv_func_getpass" != xyes; then
+AC_MSG_NOTICE()
+AC_MSG_NOTICE([getpass() not available, dbclient will only have public-key authentication])
+fi
+
+if test "t$found_crypt_func" != there; then
+AC_MSG_NOTICE()
+AC_MSG_NOTICE([crypt() not available, dropbear server will not have password authentication])
 fi
 
 AC_MSG_NOTICE()
-AC_MSG_NOTICE(Now edit options.h to choose features.)
+AC_MSG_NOTICE([Now edit localoptions.h to choose features.])

crypto_desc.c

@@ -0,0 +1,75 @@
+#include "includes.h"
+#include "dbutil.h"
+#include "crypto_desc.h"
+#include "ltc_prng.h"
+#include "ecc.h"
+
+#if DROPBEAR_LTC_PRNG
+	int dropbear_ltc_prng = -1;
+#endif
+
+
+/* Register the compiled in ciphers.
+ * This should be run before using any of the ciphers/hashes */
+void crypto_init() {
+
+	const struct ltc_cipher_descriptor *regciphers[] = {
+#if DROPBEAR_AES
+		&aes_desc,
+#endif
+#if DROPBEAR_BLOWFISH
+		&blowfish_desc,
+#endif
+#if DROPBEAR_TWOFISH
+		&twofish_desc,
+#endif
+#if DROPBEAR_3DES
+		&des3_desc,
+#endif
+		NULL
+	};
+
+	const struct ltc_hash_descriptor *reghashes[] = {
+		/* we need sha1 for hostkey stuff regardless */
+		&sha1_desc,
+#if DROPBEAR_MD5_HMAC
+		&md5_desc,
+#endif
+#if DROPBEAR_SHA256
+		&sha256_desc,
+#endif
+#if DROPBEAR_SHA384
+		&sha384_desc,
+#endif
+#if DROPBEAR_SHA512
+		&sha512_desc,
+#endif
+		NULL
+	};	
+	int i;
+	
+	for (i = 0; regciphers[i] != NULL; i++) {
+		if (register_cipher(regciphers[i]) == -1) {
+			dropbear_exit("Error registering crypto");
+		}
+	}
+
+	for (i = 0; reghashes[i] != NULL; i++) {
+		if (register_hash(reghashes[i]) == -1) {
+			dropbear_exit("Error registering crypto");
+		}
+	}
+
+#if DROPBEAR_LTC_PRNG
+	dropbear_ltc_prng = register_prng(&dropbear_prng_desc);
+	if (dropbear_ltc_prng == -1) {
+		dropbear_exit("Error registering crypto");
+	}
+#endif
+
+#if DROPBEAR_ECC
+	ltc_mp = ltm_desc;
+	dropbear_ecc_fill_dp();
+#endif
+}
+

crypto_desc.h

@@ -0,0 +1,9 @@
+#ifndef DROPBEAR_CRYPTO_DESC_H
+#define DROPBEAR_CRYPTO_DESC_H
+
+void crypto_init(void);
+
+extern int dropbear_ltc_prng;
+
+#endif /* DROPBEAR_CRYPTO_DESC_H */
+

curve25519.c

@@ -0,0 +1,497 @@
+/*
+ * Dropbear - a SSH2 server
+ * 
+ * Copyright (c) 2002,2003 Matt Johnston
+ * All rights reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE. */
+
+#include "includes.h"
+#include "dbrandom.h"
+#include "curve25519.h"
+
+#if DROPBEAR_CURVE25519 || DROPBEAR_ED25519
+
+/* Modified TweetNaCl version 20140427, a self-contained public-domain C library.
+ * https://tweetnacl.cr.yp.to/ */
+
+#define FOR(i,n) for (i = 0;i < n;++i)
+#define sv static void
+
+typedef unsigned char u8;
+typedef unsigned long u32;
+typedef unsigned long long u64;
+typedef long long i64;
+typedef i64 gf[16];
+
+#if DROPBEAR_CURVE25519
+static const gf
+  _121665 = {0xDB41,1};
+#endif /* DROPBEAR_CURVE25519 */
+#if DROPBEAR_ED25519
+static const gf
+  gf0,
+  gf1 = {1},
+  D2 = {0xf159, 0x26b2, 0x9b94, 0xebd6, 0xb156, 0x8283, 0x149a, 0x00e0, 0xd130, 0xeef3, 0x80f2, 0x198e, 0xfce7, 0x56df, 0xd9dc, 0x2406},
+  X = {0xd51a, 0x8f25, 0x2d60, 0xc956, 0xa7b2, 0x9525, 0xc760, 0x692c, 0xdc5c, 0xfdd6, 0xe231, 0xc0a4, 0x53fe, 0xcd6e, 0x36d3, 0x2169},
+  Y = {0x6658, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666};
+#if DROPBEAR_SIGNKEY_VERIFY
+static const gf
+  D = {0x78a3, 0x1359, 0x4dca, 0x75eb, 0xd8ab, 0x4141, 0x0a4d, 0x0070, 0xe898, 0x7779, 0x4079, 0x8cc7, 0xfe73, 0x2b6f, 0x6cee, 0x5203},
+  I = {0xa0b0, 0x4a0e, 0x1b27, 0xc4ee, 0xe478, 0xad2f, 0x1806, 0x2f43, 0xd7a7, 0x3dfb, 0x0099, 0x2b4d, 0xdf0b, 0x4fc1, 0x2480, 0x2b83};
+#endif /* DROPBEAR_SIGNKEY_VERIFY */
+#endif /* DROPBEAR_ED25519 */
+
+#if DROPBEAR_ED25519
+#if DROPBEAR_SIGNKEY_VERIFY
+static int vn(const u8 *x,const u8 *y,u32 n)
+{
+  u32 i,d = 0;
+  FOR(i,n) d |= x[i]^y[i];
+  return (1 & ((d - 1) >> 8)) - 1;
+}
+
+static int crypto_verify_32(const u8 *x,const u8 *y)
+{
+  return vn(x,y,32);
+}
+#endif /* DROPBEAR_SIGNKEY_VERIFY */
+
+sv set25519(gf r, const gf a)
+{
+  int i;
+  FOR(i,16) r[i]=a[i];
+}
+#endif /* DROPBEAR_ED25519 */
+
+sv car25519(gf o)
+{
+  int i;
+  i64 c;
+  FOR(i,16) {
+    o[i]+=(1LL<<16);
+    c=o[i]>>16;
+    o[(i+1)*(i<15)]+=c-1+37*(c-1)*(i==15);
+    o[i]-=c<<16;
+  }
+}
+
+sv sel25519(gf p,gf q,int b)
+{
+  i64 t,i,c=~(b-1);
+  FOR(i,16) {
+    t= c&(p[i]^q[i]);
+    p[i]^=t;
+    q[i]^=t;
+  }
+}
+
+sv pack25519(u8 *o,const gf n)
+{
+  int i,j,b;
+  gf m,t;
+  FOR(i,16) t[i]=n[i];
+  car25519(t);
+  car25519(t);
+  car25519(t);
+  FOR(j,2) {
+    m[0]=t[0]-0xffed;
+    for(i=1;i<15;i++) {
+      m[i]=t[i]-0xffff-((m[i-1]>>16)&1);
+      m[i-1]&=0xffff;
+    }
+    m[15]=t[15]-0x7fff-((m[14]>>16)&1);
+    b=(m[15]>>16)&1;
+    m[14]&=0xffff;
+    sel25519(t,m,1-b);
+  }
+  FOR(i,16) {
+    o[2*i]=t[i]&0xff;
+    o[2*i+1]=t[i]>>8;
+  }
+}
+
+#if DROPBEAR_ED25519
+#if DROPBEAR_SIGNKEY_VERIFY
+static int neq25519(const gf a, const gf b)
+{
+  u8 c[32],d[32];
+  pack25519(c,a);
+  pack25519(d,b);
+  return crypto_verify_32(c,d);
+}
+#endif /* DROPBEAR_SIGNKEY_VERIFY */
+
+static u8 par25519(const gf a)
+{
+  u8 d[32];
+  pack25519(d,a);
+  return d[0]&1;
+}
+#endif /* DROPBEAR_ED25519 */
+
+sv unpack25519(gf o, const u8 *n)
+{
+  int i;
+  FOR(i,16) o[i]=n[2*i]+((i64)n[2*i+1]<<8);
+  o[15]&=0x7fff;
+}
+
+sv A(gf o,const gf a,const gf b)
+{
+  int i;
+  FOR(i,16) o[i]=a[i]+b[i];
+}
+
+sv Z(gf o,const gf a,const gf b)
+{
+  int i;
+  FOR(i,16) o[i]=a[i]-b[i];
+}
+
+sv M(gf o,const gf a,const gf b)
+{
+  i64 i,j,t[31];
+  FOR(i,31) t[i]=0;
+  FOR(i,16) FOR(j,16) t[i+j]+=a[i]*b[j];
+  FOR(i,15) t[i]+=38*t[i+16];
+  FOR(i,16) o[i]=t[i];
+  car25519(o);
+  car25519(o);
+}
+
+sv S(gf o,const gf a)
+{
+  M(o,a,a);
+}
+
+sv inv25519(gf o,const gf i)
+{
+  gf c;
+  int a;
+  FOR(a,16) c[a]=i[a];
+  for(a=253;a>=0;a--) {
+    S(c,c);
+    if(a!=2&&a!=4) M(c,c,i);
+  }
+  FOR(a,16) o[a]=c[a];
+}
+
+#if DROPBEAR_ED25519 && DROPBEAR_SIGNKEY_VERIFY
+sv pow2523(gf o,const gf i)
+{
+  gf c;
+  int a;
+  FOR(a,16) c[a]=i[a];
+  for(a=250;a>=0;a--) {
+    S(c,c);
+    if(a!=1) M(c,c,i);
+  }
+  FOR(a,16) o[a]=c[a];
+}
+#endif /* DROPBEAR_ED25519 && DROPBEAR_SIGNKEY_VERIFY */
+
+#if DROPBEAR_CURVE25519
+void dropbear_curve25519_scalarmult(u8 *q,const u8 *n,const u8 *p)
+{
+  u8 z[32];
+  i64 x[80],r,i;
+  gf a,b,c,d,e,f;
+  FOR(i,31) z[i]=n[i];
+  z[31]=(n[31]&127)|64;
+  z[0]&=248;
+  unpack25519(x,p);
+  FOR(i,16) {
+    b[i]=x[i];
+    d[i]=a[i]=c[i]=0;
+  }
+  a[0]=d[0]=1;
+  for(i=254;i>=0;--i) {
+    r=(z[i>>3]>>(i&7))&1;
+    sel25519(a,b,r);
+    sel25519(c,d,r);
+    A(e,a,c);
+    Z(a,a,c);
+    A(c,b,d);
+    Z(b,b,d);
+    S(d,e);
+    S(f,a);
+    M(a,c,a);
+    M(c,b,e);
+    A(e,a,c);
+    Z(a,a,c);
+    S(b,a);
+    Z(c,d,f);
+    M(a,c,_121665);
+    A(a,a,d);
+    M(c,c,a);
+    M(a,d,f);
+    M(d,b,x);
+    S(b,e);
+    sel25519(a,b,r);
+    sel25519(c,d,r);
+  }
+  FOR(i,16) {
+    x[i+16]=a[i];
+    x[i+32]=c[i];
+    x[i+48]=b[i];
+    x[i+64]=d[i];
+  }
+  inv25519(x+32,x+32);
+  M(x+16,x+16,x+32);
+  pack25519(q,x+16);
+}
+#endif /* DROPBEAR_CURVE25519 */
+
+#if DROPBEAR_ED25519
+static int crypto_hash(u8 *out,const u8 *m,u64 n)
+{
+  hash_state hs;
+
+  sha512_init(&hs);
+  sha512_process(&hs, m, n);
+  return sha512_done(&hs, out);
+}
+
+sv add(gf p[4],gf q[4])
+{
+  gf a,b,c,d,t,e,f,g,h;
+  
+  Z(a, p[1], p[0]);
+  Z(t, q[1], q[0]);
+  M(a, a, t);
+  A(b, p[0], p[1]);
+  A(t, q[0], q[1]);
+  M(b, b, t);
+  M(c, p[3], q[3]);
+  M(c, c, D2);
+  M(d, p[2], q[2]);
+  A(d, d, d);
+  Z(e, b, a);
+  Z(f, d, c);
+  A(g, d, c);
+  A(h, b, a);
+
+  M(p[0], e, f);
+  M(p[1], h, g);
+  M(p[2], g, f);
+  M(p[3], e, h);
+}
+
+sv cswap(gf p[4],gf q[4],u8 b)
+{
+  int i;
+  FOR(i,4)
+    sel25519(p[i],q[i],b);
+}
+
+sv pack(u8 *r,gf p[4])
+{
+  gf tx, ty, zi;
+  inv25519(zi, p[2]); 
+  M(tx, p[0], zi);
+  M(ty, p[1], zi);
+  pack25519(r, ty);
+  r[31] ^= par25519(tx) << 7;
+}
+
+sv scalarmult(gf p[4],gf q[4],const u8 *s)
+{
+  int i;
+  set25519(p[0],gf0);
+  set25519(p[1],gf1);
+  set25519(p[2],gf1);
+  set25519(p[3],gf0);
+  for (i = 255;i >= 0;--i) {
+    u8 b = (s[i/8]>>(i&7))&1;
+    cswap(p,q,b);
+    add(q,p);
+    add(p,p);
+    cswap(p,q,b);
+  }
+}
+
+sv scalarbase(gf p[4],const u8 *s)
+{
+  gf q[4];
+  set25519(q[0],X);
+  set25519(q[1],Y);
+  set25519(q[2],gf1);
+  M(q[3],X,Y);
+  scalarmult(p,q,s);
+}
+
+void dropbear_ed25519_make_key(u8 *pk,u8 *sk)
+{
+  u8 d[64];
+  gf p[4];
+
+  genrandom(sk, 32);
+
+  crypto_hash(d, sk, 32);
+  d[0] &= 248;
+  d[31] &= 127;
+  d[31] |= 64;
+
+  scalarbase(p,d);
+  pack(pk,p);
+}
+
+static const u64 L[32] = {0xed, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58, 0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x10};
+
+sv modL(u8 *r,i64 x[64])
+{
+  i64 carry,i,j;
+  for (i = 63;i >= 32;--i) {
+    carry = 0;
+    for (j = i - 32;j < i - 12;++j) {
+      x[j] += carry - 16 * x[i] * L[j - (i - 32)];
+      carry = (x[j] + 128) >> 8;
+      x[j] -= carry << 8;
+    }
+    x[j] += carry;
+    x[i] = 0;
+  }
+  carry = 0;
+  FOR(j,32) {
+    x[j] += carry - (x[31] >> 4) * L[j];
+    carry = x[j] >> 8;
+    x[j] &= 255;
+  }
+  FOR(j,32) x[j] -= carry * L[j];
+  FOR(i,32) {
+    x[i+1] += x[i] >> 8;
+    r[i] = x[i] & 255;
+  }
+}
+
+sv reduce(u8 *r)
+{
+  i64 x[64],i;
+  FOR(i,64) x[i] = (u64) r[i];
+  FOR(i,64) r[i] = 0;
+  modL(r,x);
+}
+
+void dropbear_ed25519_sign(const u8 *m,u32 mlen,u8 *s,u32 *slen,const u8 *sk, const u8 *pk)
+{
+  hash_state hs;
+  u8 d[64],h[64],r[64];
+  i64 x[64];
+  gf p[4];
+  u32 i,j;
+
+  crypto_hash(d, sk, 32);
+  d[0] &= 248;
+  d[31] &= 127;
+  d[31] |= 64;
+
+  *slen = 64;
+
+  sha512_init(&hs);
+  sha512_process(&hs,d + 32,32);
+  sha512_process(&hs,m,mlen);
+  sha512_done(&hs,r);
+  reduce(r);
+  scalarbase(p,r);
+  pack(s,p);
+
+  sha512_init(&hs);
+  sha512_process(&hs,s,32);
+  sha512_process(&hs,pk,32);
+  sha512_process(&hs,m,mlen);
+  sha512_done(&hs,h);
+  reduce(h);
+
+  FOR(i,64) x[i] = 0;
+  FOR(i,32) x[i] = (u64) r[i];
+  FOR(i,32) FOR(j,32) x[i+j] += h[i] * (u64) d[j];
+  modL(s + 32,x);
+}
+
+#if DROPBEAR_SIGNKEY_VERIFY
+static int unpackneg(gf r[4],const u8 p[32])
+{
+  gf t, chk, num, den, den2, den4, den6;
+  set25519(r[2],gf1);
+  unpack25519(r[1],p);
+  S(num,r[1]);
+  M(den,num,D);
+  Z(num,num,r[2]);
+  A(den,r[2],den);
+
+  S(den2,den);
+  S(den4,den2);
+  M(den6,den4,den2);
+  M(t,den6,num);
+  M(t,t,den);
+
+  pow2523(t,t);
+  M(t,t,num);
+  M(t,t,den);
+  M(t,t,den);
+  M(r[0],t,den);
+
+  S(chk,r[0]);
+  M(chk,chk,den);
+  if (neq25519(chk, num)) M(r[0],r[0],I);
+
+  S(chk,r[0]);
+  M(chk,chk,den);
+  if (neq25519(chk, num)) return -1;
+
+  if (par25519(r[0]) == (p[31]>>7)) Z(r[0],gf0,r[0]);
+
+  M(r[3],r[0],r[1]);
+  return 0;
+}
+
+int dropbear_ed25519_verify(const u8 *m,u32 mlen,const u8 *s,u32 slen,const u8 *pk)
+{
+  hash_state hs;
+  u8 t[32],h[64];
+  gf p[4],q[4];
+
+  if (slen < 64) return -1;
+
+  if (unpackneg(q,pk)) return -1;
+
+  sha512_init(&hs);
+  sha512_process(&hs,s,32);
+  sha512_process(&hs,pk,32);
+  sha512_process(&hs,m,mlen);
+  sha512_done(&hs,h);
+
+  reduce(h);
+  scalarmult(p,q,h);
+
+  scalarbase(q,s + 32);
+  add(p,q);
+  pack(t,p);
+
+  if (crypto_verify_32(s, t))
+    return -1;
+
+  return 0;
+}
+#endif /* DROPBEAR_SIGNKEY_VERIFY */
+
+#endif /* DROPBEAR_ED25519 */
+
+#endif /* DROPBEAR_CURVE25519 || DROPBEAR_ED25519 */

curve25519.h

@@ -0,0 +1,37 @@
+/*
+ * Dropbear - a SSH2 server
+ * 
+ * Copyright (c) 2002,2003 Matt Johnston
+ * All rights reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE. */
+
+#ifndef DROPBEAR_CURVE25519_H
+#define DROPBEAR_CURVE25519_H
+
+void dropbear_curve25519_scalarmult(unsigned char *q, const unsigned char *n, const unsigned char *p);
+void dropbear_ed25519_make_key(unsigned char *pk, unsigned char  *sk);
+void dropbear_ed25519_sign(const unsigned char *m, unsigned long mlen,
+			  unsigned char *s, unsigned long *slen,
+			  const unsigned char *sk, const unsigned char *pk);
+int dropbear_ed25519_verify(const unsigned char *m, unsigned long mlen,
+			    const unsigned char *s, unsigned long slen,
+			    const unsigned char *pk);
+
+#endif /* DROPBEAR_CURVE25519_H */

dbclient.1

@@ -1,42 +1,48 @@
 .TH dbclient 1
 .SH NAME
-dbclient \- lightweight SSH2 client
+dbclient \- lightweight SSH client
 .SH SYNOPSIS
 .B dbclient
-[\-Tt] [\-p
+[\fIflag arguments\fR] [\-p
 .I port\fR] [\-i
 .I id\fR] [\-L
-.I l\fR:\fIh\fR:\fIr\fR] [\-R
-.I l\fR:\fIh\fR:\fIr\fR] [\-l
+.I l\fR:\fIh\fR:\fIp\fR] [\-R
+.I l\fR:\fIh\fR:\fIp\fR] [\-l
 .IR user ]
 .I host
+.RI [ \fImore\ flags\fR ]
 .RI [ command ]
 
 .B dbclient
-[
-.I args ]
-.I [user1]@host1[/port1],[user2]@host2[/port2],...
+[\fIargs\fR]
+[\fIuser1\fR]@\fIhost1\fR[^\fIport1\fR],[\fIuser2\fR]@\fIhost2\fR[^\fIport2\fR],...
 
 .SH DESCRIPTION
 .B dbclient
-is a SSH 2 client designed to be small enough to be used in small memory
-environments, while still being functional and secure enough for general use.
+is a small SSH client 
 .SH OPTIONS
 .TP
+.TP
+.B command
+A command to run on the remote host. This will normally be run by the remote host
+using the user's shell. The command begins at the first hyphen argument after the 
+host argument. If no command is specified an interactive terminal will be opened
+(see -t and -T).
+.TP
 .B \-p \fIport
-Remote port.
-Connect to port
+Connect to 
 .I port
-on the remote host.
+on the remote host. Alternatively a port can be specified as hostname^port.
 Default is 22.
 .TP
 .B \-i \fIidfile
 Identity file.
-Read the identity from file
+Read the identity key from file
 .I idfile
-(multiple allowed).
+(multiple allowed). This file is created with dropbearkey(1) or converted
+from OpenSSH with dropbearconvert(1). The default path ~/.ssh/id_dropbear is used
 .TP
-.B \-L [\fIlistenaddress\fR]:\fIlistenport\fR:\fIhost\fR:\fIport\fR
+.B \-L\fR [\fIlistenaddress\fR]:\fIlistenport\fR:\fIhost\fR:\fIport\fR
 Local port forwarding.
 Forward the port
 .I listenport
@@ -45,7 +51,7 @@ on the local host through the SSH connection to port
 on the host
 .IR host .
 .TP
-.B \-R [\fIlistenaddress\fR]:\fIlistenport\fR:\fIhost\fR:\fIport\fR
+.B \-R\fR [\fIlistenaddress\fR]:\fIlistenport\fR:\fIhost\fR:\fIport\fR
 Remote port forwarding.
 Forward the port
 .I listenport
@@ -61,10 +67,12 @@ Login as
 on the remote host.
 .TP
 .B \-t
-Allocate a pty.
+Allocate a PTY. This is the default when no command is given, it gives a full
+interactive remote session. The main effect is that keystrokes are sent remotely 
+immediately as opposed to local line-based editing.
 .TP
 .B \-T
-Don't allocate a pty.
+Don't allocate a PTY. This is the default a command is given. See -t.
 .TP
 .B \-N
 Don't request a remote shell or run any commands. Any command arguments are ignored.
@@ -80,7 +88,8 @@ by the ssh server.
 .TP
 .B \-y
 Always accept hostkeys if they are unknown. If a hostkey mismatch occurs the
-connection will abort as normal.
+connection will abort as normal. If specified a second time no host key checking
+is performed at all, this is usually undesirable.
 .TP
 .B \-A
 Forward agent connections to the remote host. dbclient will use any
@@ -97,26 +106,71 @@ Ensure that traffic is transmitted at a certain interval in seconds. This is
 useful for working around firewalls or routers that drop connections after
 a certain period of inactivity. The trade-off is that a session may be
 closed if there is a temporary lapse of network connectivity. A setting
-if 0 disables keepalives.
+if 0 disables keepalives. If no response is received for 3 consecutive keepalives the connection will be closed.
 .TP
 .B \-I \fIidle_timeout
 Disconnect the session if no traffic is transmitted or received for \fIidle_timeout\fR seconds.
 .TP
+
+.\" TODO: how to avoid a line break between these two -J arguments?
 .B \-J \fIproxy_command
+.TP
+.B \-J \fI&fd
+.br
 Use the standard input/output of the program \fIproxy_command\fR rather than using
 a normal TCP connection. A hostname should be still be provided, as this is used for
-comparing saved hostkeys.
+comparing saved hostkeys. This command will be executed as "exec proxy_command ..." with the
+default shell.
+
+The second form &fd will make dbclient use the numeric file descriptor as a socket. This
+can be used for more complex tunnelling scenarios. Example usage with socat is
+
+socat EXEC:'dbclient -J &38 ev',fdin=38,fdout=38 TCP4:host.example.com:22
+
 .TP
 .B \-B \fIendhost:endport
 "Netcat-alike" mode, where Dropbear will connect to the given host, then create a
 forwarded connection to \fIendhost\fR. This will then be presented as dbclient's
 standard input/output.
+.TP
+.B \-c \fIcipherlist
+Specify a comma separated list of ciphers to enable. Use \fI-c help\fR to list possibilities.
+.TP
+.B \-m \fIMAClist
+Specify a comma separated list of authentication MACs to enable. Use \fI-m help\fR to list possibilities.
+.TP
+.B \-o \fIoption
+Can be used to give options in the format used by OpenSSH config file. This is
+useful for specifying options for which there is no separate command-line flag.
+For full details of the options listed below, and their possible values, see
+ssh_config(5).
+The following options have currently been implemented:
 
+.RS
+.TP
+.B ExitOnForwardFailure
+Specifies whether dbclient should terminate the connection if it cannot set up all requested local and remote port forwardings. The argument must be “yes” or “no”.  The default is “no”.
+.TP
+.B UseSyslog
+Send dbclient log messages to syslog in addition to stderr.
+.RE
+.TP
+.B \-s 
+The specified command will be requested as a subsystem, used for sftp. Dropbear doesn't implement sftp itself but the OpenSSH sftp client can be used eg \fIsftp -S dbclient user@host\fR
+.TP
+.B \-b \fI[address][:port]
+Bind to a specific local address when connecting to the remote host. This can be used to choose from
+multiple outgoing interfaces. Either address or port (or both) can be given.
+.TP
+.B \-V
+Print the version
+
+.SH MULTI-HOP
 Dropbear will also allow multiple "hops" to be specified, separated by commas. In
 this case a connection will be made to the first host, then a TCP forwarded 
 connection will be made through that to the second host, and so on. Hosts other than
 the final destination will not see anything other than the encrypted SSH stream. 
-A port for a host can be specified with a slash (eg matt@martello/44 ).
+A port for a host can be specified with a caret (eg matt@martello^44 ).
 This syntax can also be used with scp or rsync (specifying dbclient as the 
 ssh/rsh command). A file can be "bounced" through multiple SSH hops, eg
 
@@ -126,6 +180,11 @@ Note that hostnames are resolved by the prior hop (so "canyons" would be resolve
 in the example above, the same way as other -L TCP forwarded hosts are. Host keys are 
 checked locally based on the given hostname.
 
+.SH ESCAPE CHARACTERS
+Typing a newline followed by the  key sequence \fI~.\fR (tilde, dot) will terminate a connection.
+The sequence \fI~^Z\fR (tilde, ctrl-z) will background the connection. This behaviour only
+applies when a PTY is used.
+
 .SH ENVIRONMENT
 .TP
 .B DROPBEAR_PASSWORD
@@ -139,6 +198,10 @@ SSH_ASKPASS should be set to the path of a program that will return a password
 on standard output. This program will only be used if either DISPLAY is set and
 standard input is not a TTY, or the environment variable SSH_ASKPASS_ALWAYS is
 set.
+.SH NOTES
+If compiled with zlib support and if the server supports it, dbclient will
+always use compression.
+
 .SH AUTHOR
 Matt Johnston (matt@ucc.asn.au).
 .br
@@ -146,6 +209,6 @@ Mihnea Stoenescu wrote initial Dropbear client support
 .br
 Gerrit Pape (pape@smarden.org) wrote this manual page.
 .SH SEE ALSO
-dropbear(8), dropbearkey(8)
+dropbear(8), dropbearkey(1)
 .P
-http://matt.ucc.asn.au/dropbear/dropbear.html
+https://matt.ucc.asn.au/dropbear/dropbear.html

dbhelpers.c

@@ -0,0 +1,18 @@
+#include "dbhelpers.h"
+#include "includes.h"
+
+/* Erase data */
+void m_burn(void *data, unsigned int len) {
+
+#if defined(HAVE_MEMSET_S)
+	memset_s(data, len, 0x0, len);
+#elif defined(HAVE_EXPLICIT_BZERO)
+	explicit_bzero(data, len);
+#else
+	/* This must be volatile to avoid compiler optimisation */
+	volatile void *p = data;
+	memset((void*)p, 0x0, len);
+#endif
+}
+
+

dbhelpers.h

@@ -0,0 +1,21 @@
+#ifndef DROPBEAR_DBHELPERS_H_
+#define DROPBEAR_DBHELPERS_H_
+
+/* This header defines some things that are also used by libtomcrypt/math. 
+   We avoid including normal include.h since that can result in conflicting 
+   definitions - only include config.h */
+#include "config.h"
+
+#ifdef __GNUC__
+#define ATTRIB_PRINTF(fmt,args) __attribute__((format(printf, fmt, args))) 
+#define ATTRIB_NORETURN __attribute__((noreturn))
+#define ATTRIB_SENTINEL __attribute__((sentinel))
+#else
+#define ATTRIB_PRINTF(fmt,args)
+#define ATTRIB_NORETURN
+#define ATTRIB_SENTINEL
+#endif
+
+void m_burn(void* data, unsigned int len);
+
+#endif /* DROPBEAR_DBHELPERS_H_ */

dbmalloc.c

@@ -0,0 +1,192 @@
+#include "dbmalloc.h"
+#include "dbutil.h"
+
+
+void * m_calloc(size_t nmemb, size_t size) {
+    if (SIZE_T_MAX / nmemb < size) {
+        dropbear_exit("m_calloc failed");
+    }
+    return m_malloc(nmemb*size);
+}
+
+void * m_strdup(const char * str) {
+    char* ret;
+    unsigned int len;
+    len = strlen(str);
+
+    ret = m_malloc(len+1);
+    if (ret == NULL) {
+        dropbear_exit("m_strdup failed");
+    }
+    memcpy(ret, str, len+1);
+    return ret;
+}
+
+#if !DROPBEAR_TRACKING_MALLOC
+
+/* Simple wrappers around malloc etc */
+void * m_malloc(size_t size) {
+
+	void* ret;
+
+	if (size == 0) {
+		dropbear_exit("m_malloc failed");
+	}
+	ret = calloc(1, size);
+	if (ret == NULL) {
+		dropbear_exit("m_malloc failed");
+	}
+	return ret;
+
+}
+
+void * m_realloc(void* ptr, size_t size) {
+
+	void *ret;
+
+	if (size == 0) {
+		dropbear_exit("m_realloc failed");
+	}
+	ret = realloc(ptr, size);
+	if (ret == NULL) {
+		dropbear_exit("m_realloc failed");
+	}
+	return ret;
+}
+
+
+#else
+
+/* For fuzzing */
+
+struct dbmalloc_header {
+    unsigned int epoch;
+    struct dbmalloc_header *prev;
+    struct dbmalloc_header *next;
+};
+
+static void put_alloc(struct dbmalloc_header *header);
+static void remove_alloc(struct dbmalloc_header *header);
+
+/* end of the linked list */
+static struct dbmalloc_header* staple;
+
+unsigned int current_epoch = 0;
+
+void m_malloc_set_epoch(unsigned int epoch) {
+    current_epoch = epoch;
+}
+
+void m_malloc_free_epoch(unsigned int epoch, int dofree) {
+    struct dbmalloc_header* header;
+    struct dbmalloc_header* nextheader = NULL;
+    struct dbmalloc_header* oldstaple = staple;
+    staple = NULL;
+    /* free allocations from this epoch, create a new staple-anchored list from
+    the remainder */
+    for (header = oldstaple; header; header = nextheader)
+    {
+        nextheader = header->next;
+        if (header->epoch == epoch) {
+            if (dofree) {
+                free(header);
+            }
+        } else {
+            header->prev = NULL;
+            header->next = NULL;
+            put_alloc(header);
+        }
+    }
+}
+
+static void put_alloc(struct dbmalloc_header *header) {
+    assert(header->next == NULL);
+    assert(header->prev == NULL);
+    if (staple) {
+        staple->prev = header;
+    }
+    header->next = staple;
+    staple = header;
+}
+
+static void remove_alloc(struct dbmalloc_header *header) {
+    if (header->prev) {
+        header->prev->next = header->next;
+    }
+    if (header->next) {
+        header->next->prev = header->prev;
+    }
+    if (staple == header) {
+        staple = header->next;
+    }
+    header->prev = NULL;
+    header->next = NULL;
+}
+
+static struct dbmalloc_header* get_header(void* ptr) {
+    char* bptr = ptr;
+    return (struct dbmalloc_header*)&bptr[-sizeof(struct dbmalloc_header)];
+}
+
+void * m_malloc(size_t size) {
+    char* mem = NULL;
+    struct dbmalloc_header* header = NULL;
+
+    if (size == 0 || size > 1e9) {
+        dropbear_exit("m_malloc failed");
+    }
+
+    size = size + sizeof(struct dbmalloc_header);
+
+    mem = calloc(1, size);
+    if (mem == NULL) {
+        dropbear_exit("m_malloc failed");
+    }
+    header = (struct dbmalloc_header*)mem;
+    put_alloc(header);
+    header->epoch = current_epoch;
+    return &mem[sizeof(struct dbmalloc_header)];
+}
+
+void * m_realloc(void* ptr, size_t size) {
+    char* mem = NULL;
+    struct dbmalloc_header* header = NULL;
+    if (size == 0 || size > 1e9) {
+        dropbear_exit("m_realloc failed");
+    }
+
+    header = get_header(ptr);
+    remove_alloc(header);
+
+    size = size + sizeof(struct dbmalloc_header);
+    mem = realloc(header, size);
+    if (mem == NULL) {
+        dropbear_exit("m_realloc failed");
+    }
+
+    header = (struct dbmalloc_header*)mem;
+    put_alloc(header);
+    return &mem[sizeof(struct dbmalloc_header)];
+}
+
+void m_free_direct(void* ptr) {
+    struct dbmalloc_header* header = NULL;
+    if (!ptr) {
+        return;
+    }
+    header = get_header(ptr);
+    remove_alloc(header);
+    free(header);
+}
+
+#endif /* DROPBEAR_TRACKING_MALLOC */
+
+void * m_realloc_ltm(void* ptr, size_t oldsize, size_t newsize) {
+   (void)oldsize;
+   return m_realloc(ptr, newsize);
+}
+
+void m_free_ltm(void *mem, size_t size) {
+   (void)size;
+   m_free_direct(mem);
+}

dbmalloc.h

@@ -0,0 +1,27 @@
+#ifndef DBMALLOC_H_
+#define DBMALLOC_H_
+
+#include "stdint.h"
+#include "stdlib.h"
+#include "options.h"
+
+void * m_malloc(size_t size);
+void * m_calloc(size_t nmemb, size_t size);
+void * m_strdup(const char * str);
+void * m_realloc(void* ptr, size_t size);
+
+#if DROPBEAR_TRACKING_MALLOC
+void m_free_direct(void* ptr);
+void m_malloc_set_epoch(unsigned int epoch);
+void m_malloc_free_epoch(unsigned int epoch, int dofree);
+
+#else
+/* plain wrapper */
+#define m_free_direct free
+
+#endif
+
+#define m_free(X) do {m_free_direct(X); (X) = NULL;} while (0)
+
+
+#endif /* DBMALLOC_H_ */

dbmulti.c

@@ -26,17 +26,13 @@
 
 /* definitions are cleanest if we just put them here */
 int dropbear_main(int argc, char ** argv);
+int cli_main(int argc, char ** argv);
 int dropbearkey_main(int argc, char ** argv);
 int dropbearconvert_main(int argc, char ** argv);
 int scp_main(int argc, char ** argv);
 
-int main(int argc, char ** argv) {
-
-	char * progname;
-
-	if (argc > 0) {
-		/* figure which form we're being called as */
-		progname = basename(argv[0]);
+static int runprog(const char *progname, int argc, char ** argv, int *match) {
+	*match = DROPBEAR_SUCCESS;
 
 #ifdef DBMULTI_dropbear
 		if (strcmp(progname, "dropbear") == 0) {
@@ -64,10 +60,28 @@ int main(int argc, char ** argv) {
 			return scp_main(argc, argv);
 		}
 #endif
+	*match = DROPBEAR_FAILURE;
+	return 1;
+}
+
+int main(int argc, char ** argv) {
+	int i;
+	for (i = 0; i < 2; i++) {
+		/* Try symlink first, then try as an argument eg "dropbearmulti dbclient host ..." */
+		if (argc > i) {
+			int match, res;
+			/* figure which form we're being called as */
+			const char* progname = basename(argv[i]);
+			res = runprog(progname, argc-i, &argv[i], &match);
+			if (match == DROPBEAR_SUCCESS) {
+				return res;
+			}
+		}
 	}
 
-	fprintf(stderr, "Dropbear multi-purpose version %s\n"
-			"Make a symlink pointing at this binary with one of the following names:\n"
+	fprintf(stderr, "Dropbear SSH multi-purpose v%s\n"
+			"Make a symlink pointing at this binary with one of the\n"
+			"following names or run 'dropbearmulti <command>'.\n"
 #ifdef DBMULTI_dropbear
 			"'dropbear' - the Dropbear server\n"
 #endif

dbrandom.c

@@ -0,0 +1,378 @@
+/*
+ * Dropbear - a SSH2 server
+ * 
+ * Copyright (c) 2002,2003 Matt Johnston
+ * All rights reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE. */
+
+#include "includes.h"
+#include "buffer.h"
+#include "dbutil.h"
+#include "bignum.h"
+#include "dbrandom.h"
+#include "runopts.h"
+
+/* this is used to generate unique output from the same hashpool */
+static uint32_t counter = 0;
+/* the max value for the counter, so it won't integer overflow */
+#define MAX_COUNTER (1<<30)
+
+static unsigned char hashpool[SHA1_HASH_SIZE] = {0};
+static int donerandinit = 0;
+
+#define INIT_SEED_SIZE 32 /* 256 bits */
+
+/* The basic setup is we read some data from /dev/(u)random or prngd and hash it
+ * into hashpool. To read data, we hash together current hashpool contents,
+ * and a counter. We feed more data in by hashing the current pool and new
+ * data into the pool.
+ *
+ * It is important to ensure that counter doesn't wrap around before we
+ * feed in new entropy.
+ *
+ */
+
+/* Pass wantlen=0 to hash an entire file */
+static int
+process_file(hash_state *hs, const char *filename,
+		unsigned int wantlen, int prngd) {
+	int readfd = -1;
+	unsigned int readcount;
+	int ret = DROPBEAR_FAILURE;
+
+	if (prngd) {
+#if DROPBEAR_USE_PRNGD
+		readfd = connect_unix(filename);
+#endif
+	} else {
+		readfd = open(filename, O_RDONLY);
+	}
+
+	if (readfd < 0) {
+		goto out;
+	}
+
+	readcount = 0;
+	while (wantlen == 0 || readcount < wantlen) {
+		int readlen, wantread;
+		unsigned char readbuf[4096];
+		if (wantlen == 0) {
+			wantread = sizeof(readbuf);
+		} else {
+			wantread = MIN(sizeof(readbuf), wantlen-readcount);
+		}
+
+#if DROPBEAR_USE_PRNGD
+		if (prngd) {
+			char egdcmd[2];
+			egdcmd[0] = 0x02;	/* blocking read */
+			egdcmd[1] = (unsigned char)wantread;
+			if (write(readfd, egdcmd, 2) < 0) {
+				dropbear_exit("Can't send command to egd");
+			}
+		}
+#endif
+		readlen = read(readfd, readbuf, wantread);
+		if (readlen <= 0) {
+			if (readlen < 0 && errno == EINTR) {
+				continue;
+			}
+			if (readlen == 0 && wantlen == 0) {
+				/* whole file was read as requested */
+				break;
+			}
+			goto out;
+		}
+		sha1_process(hs, readbuf, readlen);
+		readcount += readlen;
+	}
+	ret = DROPBEAR_SUCCESS;
+out:
+	close(readfd);
+	return ret;
+}
+
+void addrandom(const unsigned char * buf, unsigned int len)
+{
+	hash_state hs;
+
+#if DROPBEAR_FUZZ
+	if (fuzz.fuzzing) {
+		return;
+	}
+#endif
+
+	/* hash in the new seed data */
+	sha1_init(&hs);
+	/* existing state (zeroes on startup) */
+	sha1_process(&hs, (void*)hashpool, sizeof(hashpool));
+
+	/* new */
+	sha1_process(&hs, buf, len);
+	sha1_done(&hs, hashpool);
+}
+
+static void write_urandom()
+{
+#if DROPBEAR_FUZZ
+	if (fuzz.fuzzing) {
+		return;
+	}
+#endif
+#if !DROPBEAR_USE_PRNGD
+	/* This is opportunistic, don't worry about failure */
+	unsigned char buf[INIT_SEED_SIZE];
+	FILE *f = fopen(DROPBEAR_URANDOM_DEV, "w");
+	if (!f) {
+		return;
+	}
+	genrandom(buf, sizeof(buf));
+	fwrite(buf, sizeof(buf), 1, f);
+	fclose(f);
+#endif
+}
+
+#if DROPBEAR_FUZZ
+void fuzz_seed(void) {
+	hash_state hs;
+	sha1_init(&hs);
+	sha1_process(&hs, "fuzzfuzzfuzz", strlen("fuzzfuzzfuzz"));
+	sha1_done(&hs, hashpool);
+
+	counter = 0;
+	donerandinit = 1;
+}
+#endif
+
+
+#ifdef HAVE_GETRANDOM
+/* Reads entropy seed with getrandom(). 
+ * May block if the kernel isn't ready.
+ * Return DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
+static int process_getrandom(hash_state *hs) {
+	char buf[INIT_SEED_SIZE];
+	ssize_t ret;
+
+	/* First try non-blocking so that we can warn about waiting */
+	ret = getrandom(buf, sizeof(buf), GRND_NONBLOCK);
+	if (ret == -1) {
+		if (errno == ENOSYS) {
+			/* Old kernel */
+			return DROPBEAR_FAILURE;
+		}
+		/* Other errors fall through to blocking getrandom() */
+		TRACE(("first getrandom() failed: %d %s", errno, strerror(errno)))
+		if (errno == EAGAIN) {
+			dropbear_log(LOG_WARNING, "Waiting for kernel randomness to be initialised...");
+		}
+	}
+
+	/* Wait blocking if needed. Loop in case we get EINTR */
+	while (ret != sizeof(buf)) {
+		ret = getrandom(buf, sizeof(buf), 0);
+
+		if (ret == sizeof(buf)) {
+			/* Success */
+			break;
+		}
+		if (ret == -1 && errno == EINTR) {
+			/* Try again. */
+			continue;
+		}
+		if (ret >= 0) {
+			TRACE(("Short read %zd from getrandom() shouldn't happen", ret))
+			/* Try again? */
+			continue;
+		}
+
+		/* Unexpected problem, fall back to /dev/urandom */
+		TRACE(("2nd getrandom() failed: %d %s", errno, strerror(errno)))
+		break;
+	}
+
+	if (ret == sizeof(buf)) {
+		/* Success, stir in the entropy */
+		sha1_process(hs, (void*)buf, sizeof(buf));
+		return DROPBEAR_SUCCESS;
+	}
+
+	return DROPBEAR_FAILURE;
+
+}
+#endif /* HAVE_GETRANDOM */
+
+/* Initialise the prng from /dev/urandom or prngd. This function can
+ * be called multiple times */
+void seedrandom() {
+		
+	hash_state hs;
+
+	pid_t pid;
+	struct timeval tv;
+	clock_t clockval;
+	int urandom_seeded = 0;
+
+#if DROPBEAR_FUZZ
+	if (fuzz.fuzzing) {
+		return;
+	}
+#endif
+
+	/* hash in the new seed data */
+	sha1_init(&hs);
+
+	/* existing state */
+	sha1_process(&hs, (void*)hashpool, sizeof(hashpool));
+
+#ifdef HAVE_GETRANDOM
+	if (process_getrandom(&hs) == DROPBEAR_SUCCESS) {
+		urandom_seeded = 1;
+	}
+#endif
+
+	if (!urandom_seeded) {
+#if DROPBEAR_USE_PRNGD
+		if (process_file(&hs, DROPBEAR_PRNGD_SOCKET, INIT_SEED_SIZE, 1) 
+				!= DROPBEAR_SUCCESS) {
+			dropbear_exit("Failure reading random device %s", 
+					DROPBEAR_PRNGD_SOCKET);
+			urandom_seeded = 1;
+		}
+#else
+		/* non-blocking random source (probably /dev/urandom) */
+		if (process_file(&hs, DROPBEAR_URANDOM_DEV, INIT_SEED_SIZE, 0) 
+				!= DROPBEAR_SUCCESS) {
+			dropbear_exit("Failure reading random device %s", 
+					DROPBEAR_URANDOM_DEV);
+			urandom_seeded = 1;
+		}
+#endif
+	} /* urandom_seeded */
+
+	/* A few other sources to fall back on. 
+	 * Add more here for other platforms */
+#ifdef __linux__
+	/* Seems to be a reasonable source of entropy from timers. Possibly hard
+	 * for even local attackers to reproduce */
+	process_file(&hs, "/proc/timer_list", 0, 0);
+	/* Might help on systems with wireless */
+	process_file(&hs, "/proc/interrupts", 0, 0);
+
+	process_file(&hs, "/proc/loadavg", 0, 0);
+	process_file(&hs, "/proc/sys/kernel/random/entropy_avail", 0, 0);
+
+	/* Mostly network visible but useful in some situations.
+	 * Limit size to avoid slowdowns on systems with lots of routes */
+	process_file(&hs, "/proc/net/netstat", 4096, 0);
+	process_file(&hs, "/proc/net/dev", 4096, 0);
+	process_file(&hs, "/proc/net/tcp", 4096, 0);
+	/* Also includes interface lo */
+	process_file(&hs, "/proc/net/rt_cache", 4096, 0);
+	process_file(&hs, "/proc/vmstat", 0, 0);
+#endif
+
+	pid = getpid();
+	sha1_process(&hs, (void*)&pid, sizeof(pid));
+
+	/* gettimeofday() doesn't completely fill out struct timeval on 
+	   OS X (10.8.3), avoid valgrind warnings by clearing it first */
+	memset(&tv, 0x0, sizeof(tv));
+	gettimeofday(&tv, NULL);
+	sha1_process(&hs, (void*)&tv, sizeof(tv));
+
+	clockval = clock();
+	sha1_process(&hs, (void*)&clockval, sizeof(clockval));
+
+	/* When a private key is read by the client or server it will
+	 * be added to the hashpool - see runopts.c */
+
+	sha1_done(&hs, hashpool);
+
+	counter = 0;
+	donerandinit = 1;
+
+	/* Feed it all back into /dev/urandom - this might help if Dropbear
+	 * is running from inetd and gets new state each time */
+	write_urandom();
+}
+
+/* return len bytes of pseudo-random data */
+void genrandom(unsigned char* buf, unsigned int len) {
+
+	hash_state hs;
+	unsigned char hash[SHA1_HASH_SIZE];
+	unsigned int copylen;
+
+	if (!donerandinit) {
+		dropbear_exit("seedrandom not done");
+	}
+
+	while (len > 0) {
+		sha1_init(&hs);
+		sha1_process(&hs, (void*)hashpool, sizeof(hashpool));
+		sha1_process(&hs, (void*)&counter, sizeof(counter));
+		sha1_done(&hs, hash);
+
+		counter++;
+		if (counter > MAX_COUNTER) {
+			seedrandom();
+		}
+
+		copylen = MIN(len, SHA1_HASH_SIZE);
+		memcpy(buf, hash, copylen);
+		len -= copylen;
+		buf += copylen;
+	}
+	m_burn(hash, sizeof(hash));
+}
+
+/* Generates a random mp_int. 
+ * max is a *mp_int specifying an upper bound.
+ * rand must be an initialised *mp_int for the result.
+ * the result rand satisfies:  0 < rand < max 
+ * */
+void gen_random_mpint(mp_int *max, mp_int *rand) {
+
+	unsigned char *randbuf = NULL;
+	unsigned int len = 0;
+	const unsigned char masks[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
+
+	const int size_bits = mp_count_bits(max);
+
+	len = size_bits / 8;
+	if ((size_bits % 8) != 0) {
+		len += 1;
+	}
+
+	randbuf = (unsigned char*)m_malloc(len);
+	do {
+		genrandom(randbuf, len);
+		/* Mask out the unrequired bits - mp_read_unsigned_bin expects
+		 * MSB first.*/
+		randbuf[0] &= masks[size_bits % 8];
+
+		bytes_to_mp(rand, randbuf, len);
+
+		/* keep regenerating until we get one satisfying
+		 * 0 < rand < max    */
+	} while (!(mp_cmp(rand, max) == MP_LT && mp_cmp_d(rand, 0) == MP_GT));
+	m_burn(randbuf, len);
+	m_free(randbuf);
+}

dbrandom.h

@@ -22,15 +22,14 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
-#ifndef _RANDOM_H_
-#define _RANDOM_H_
+#ifndef DROPBEAR_RANDOM_H_
+#define DROPBEAR_RANDOM_H_
 
-struct mp_int;
+#include "includes.h"
 
-void seedrandom();
-void reseedrandom();
-void genrandom(unsigned char* buf, int len);
-void addrandom(unsigned char* buf, int len);
+void seedrandom(void);
+void genrandom(unsigned char* buf, unsigned int len);
+void addrandom(const unsigned char * buf, unsigned int len);
 void gen_random_mpint(mp_int *max, mp_int *rand);
 
-#endif /* _RANDOM_H_ */
+#endif /* DROPBEAR_RANDOM_H_ */

dbutil.c

@@ -48,6 +48,19 @@
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
 
+#include "config.h"
+
+#ifdef __linux__
+#define _GNU_SOURCE
+/* To call clock_gettime() directly */
+#include <sys/syscall.h>
+#endif /* __linux */
+
+#ifdef HAVE_MACH_MACH_TIME_H
+#include <mach/mach_time.h>
+#include <mach/mach.h>
+#endif
+
 #include "includes.h"
 #include "dbutil.h"
 #include "buffer.h"
@@ -57,23 +70,23 @@
 #define MAX_FMT 100
 
 static void generic_dropbear_exit(int exitcode, const char* format, 
-		va_list param);
+		va_list param) ATTRIB_NORETURN;
 static void generic_dropbear_log(int priority, const char* format, 
 		va_list param);
 
-void (*_dropbear_exit)(int exitcode, const char* format, va_list param) 
+void (*_dropbear_exit)(int exitcode, const char* format, va_list param) ATTRIB_NORETURN
 						= generic_dropbear_exit;
 void (*_dropbear_log)(int priority, const char* format, va_list param)
 						= generic_dropbear_log;
 
-#ifdef DEBUG_TRACE
+#if DEBUG_TRACE
 int debug_trace = 0;
 #endif
 
 #ifndef DISABLE_SYSLOG
-void startsyslog() {
+void startsyslog(const char *ident) {
 
-	openlog(PROGNAME, LOG_PID, LOG_AUTHPRIV);
+	openlog(ident, LOG_PID, LOG_AUTHPRIV);
 
 }
 #endif /* DISABLE_SYSLOG */
@@ -107,6 +120,13 @@ static void generic_dropbear_exit(int exitcode, const char* format,
 
 	_dropbear_log(LOG_INFO, fmtbuf, param);
 
+#if DROPBEAR_FUZZ
+	/* longjmp before cleaning up svr_opts */
+    if (fuzz.do_jmp) {
+        longjmp(fuzz.jmp, 1);
+    }
+#endif
+
 	exit(exitcode);
 }
 
@@ -136,9 +156,37 @@ void dropbear_log(int priority, const char* format, ...) {
 }
 
 
-#ifdef DEBUG_TRACE
-void dropbear_trace(const char* format, ...) {
+#if DEBUG_TRACE
 
+static double debug_start_time = -1;
+
+void debug_start_net()
+{
+	if (getenv("DROPBEAR_DEBUG_NET_TIMESTAMP"))
+	{
+		/* Timestamps start from first network activity */
+		struct timeval tv;
+		gettimeofday(&tv, NULL);
+		debug_start_time = tv.tv_sec + (tv.tv_usec / 1000000.0);
+		TRACE(("Resetting Dropbear TRACE timestamps"))
+	}
+}
+
+static double time_since_start()
+{
+	double nowf;
+	struct timeval tv;
+	gettimeofday(&tv, NULL);
+	nowf = tv.tv_sec + (tv.tv_usec / 1000000.0);
+	if (debug_start_time < 0)
+	{
+		debug_start_time = nowf;
+		return 0;
+	}
+	return nowf - debug_start_time;
+}
+
+void dropbear_trace(const char* format, ...) {
 	va_list param;
 
 	if (!debug_trace) {
@@ -146,157 +194,34 @@ void dropbear_trace(const char* format, ...) {
 	}
 
 	va_start(param, format);
-	fprintf(stderr, "TRACE (%d): ", getpid());
+	fprintf(stderr, "TRACE  (%d) %f: ", getpid(), time_since_start());
+	vfprintf(stderr, format, param);
+	fprintf(stderr, "\n");
+	va_end(param);
+}
+
+void dropbear_trace2(const char* format, ...) {
+	static int trace_env = -1;
+	va_list param;
+
+	if (trace_env == -1) {
+		trace_env = getenv("DROPBEAR_TRACE2") ? 1 : 0;
+	}
+
+	if (!(debug_trace && trace_env)) {
+		return;
+	}
+
+	va_start(param, format);
+	fprintf(stderr, "TRACE2 (%d) %f: ", getpid(), time_since_start());
 	vfprintf(stderr, format, param);
 	fprintf(stderr, "\n");
 	va_end(param);
 }
 #endif /* DEBUG_TRACE */
 
-static void set_sock_priority(int sock) {
-
-	int val;
-
-	/* disable nagle */
-	val = 1;
-	setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (void*)&val, sizeof(val));
-
-	/* set the TOS bit. note that this will fail for ipv6, I can't find any
-	 * equivalent. */
-#ifdef IPTOS_LOWDELAY
-	val = IPTOS_LOWDELAY;
-	setsockopt(sock, IPPROTO_IP, IP_TOS, (void*)&val, sizeof(val));
-#endif
-
-#ifdef SO_PRIORITY
-	/* linux specific, sets QoS class.
-	 * 6 looks to be optimal for interactive traffic (see tc-prio(8) ). */
-	val = 6;
-	setsockopt(sock, SOL_SOCKET, SO_PRIORITY, (void*) &val, sizeof(val));
-#endif
-
-}
-
-/* Listen on address:port. 
- * Special cases are address of "" listening on everything,
- * and address of NULL listening on localhost only.
- * Returns the number of sockets bound on success, or -1 on failure. On
- * failure, if errstring wasn't NULL, it'll be a newly malloced error
- * string.*/
-int dropbear_listen(const char* address, const char* port,
-		int *socks, unsigned int sockcount, char **errstring, int *maxfd) {
-
-	struct addrinfo hints, *res = NULL, *res0 = NULL;
-	int err;
-	unsigned int nsock;
-	struct linger linger;
-	int val;
-	int sock;
-
-	TRACE(("enter dropbear_listen"))
-	
-	memset(&hints, 0, sizeof(hints));
-	hints.ai_family = AF_UNSPEC; /* TODO: let them flag v4 only etc */
-	hints.ai_socktype = SOCK_STREAM;
-
-	/* for calling getaddrinfo:
-	 address == NULL and !AI_PASSIVE: local loopback
-	 address == NULL and AI_PASSIVE: all interfaces
-	 address != NULL: whatever the address says */
-	if (!address) {
-		TRACE(("dropbear_listen: local loopback"))
-	} else {
-		if (address[0] == '\0') {
-			TRACE(("dropbear_listen: all interfaces"))
-			address = NULL;
-		}
-		hints.ai_flags = AI_PASSIVE;
-	}
-	err = getaddrinfo(address, port, &hints, &res0);
-
-	if (err) {
-		if (errstring != NULL && *errstring == NULL) {
-			int len;
-			len = 20 + strlen(gai_strerror(err));
-			*errstring = (char*)m_malloc(len);
-			snprintf(*errstring, len, "Error resolving: %s", gai_strerror(err));
-		}
-		if (res0) {
-			freeaddrinfo(res0);
-			res0 = NULL;
-		}
-		TRACE(("leave dropbear_listen: failed resolving"))
-		return -1;
-	}
-
-
-	nsock = 0;
-	for (res = res0; res != NULL && nsock < sockcount;
-			res = res->ai_next) {
-
-		/* Get a socket */
-		socks[nsock] = socket(res->ai_family, res->ai_socktype,
-				res->ai_protocol);
-
-		sock = socks[nsock]; /* For clarity */
-
-		if (sock < 0) {
-			err = errno;
-			TRACE(("socket() failed"))
-			continue;
-		}
-
-		/* Various useful socket options */
-		val = 1;
-		/* set to reuse, quick timeout */
-		setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void*) &val, sizeof(val));
-		linger.l_onoff = 1;
-		linger.l_linger = 5;
-		setsockopt(sock, SOL_SOCKET, SO_LINGER, (void*)&linger, sizeof(linger));
-
-		set_sock_priority(sock);
-
-		if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
-			err = errno;
-			close(sock);
-			TRACE(("bind(%s) failed", port))
-			continue;
-		}
-
-		if (listen(sock, 20) < 0) {
-			err = errno;
-			close(sock);
-			TRACE(("listen() failed"))
-			continue;
-		}
-
-		*maxfd = MAX(*maxfd, sock);
-
-		nsock++;
-	}
-
-	if (res0) {
-		freeaddrinfo(res0);
-		res0 = NULL;
-	}
-
-	if (nsock == 0) {
-		if (errstring != NULL && *errstring == NULL) {
-			int len;
-			len = 20 + strlen(strerror(err));
-			*errstring = (char*)m_malloc(len);
-			snprintf(*errstring, len, "Error listening: %s", strerror(err));
-		}
-		TRACE(("leave dropbear_listen: failure, %s", strerror(err)))
-		return -1;
-	}
-
-	TRACE(("leave dropbear_listen: success, %d socks bound", nsock))
-	return nsock;
-}
-
 /* Connect to a given unix socket. The socket is blocking */
-#ifdef ENABLE_CONNECT_UNIX
+#if ENABLE_CONNECT_UNIX
 int connect_unix(const char* path) {
 	struct sockaddr_un addr;
 	int fd = -1;
@@ -311,105 +236,19 @@ int connect_unix(const char* path) {
 	}
 	if (connect(fd, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
 		TRACE(("Failed to connect to '%s' socket", path))
+		m_close(fd);
 		return -1;
 	}
 	return fd;
 }
 #endif
 
-/* Connect via TCP to a host. Connection will try ipv4 or ipv6, will
- * return immediately if nonblocking is set. On failure, if errstring
- * wasn't null, it will be a newly malloced error message */
-
-/* TODO: maxfd */
-int connect_remote(const char* remotehost, const char* remoteport,
-		int nonblocking, char ** errstring) {
-
-	struct addrinfo *res0 = NULL, *res = NULL, hints;
-	int sock;
-	int err;
-
-	TRACE(("enter connect_remote"))
-
-	if (errstring != NULL) {
-		*errstring = NULL;
-	}
-
-	memset(&hints, 0, sizeof(hints));
-	hints.ai_socktype = SOCK_STREAM;
-	hints.ai_family = PF_UNSPEC;
-
-	err = getaddrinfo(remotehost, remoteport, &hints, &res0);
-	if (err) {
-		if (errstring != NULL && *errstring == NULL) {
-			int len;
-			len = 100 + strlen(gai_strerror(err));
-			*errstring = (char*)m_malloc(len);
-			snprintf(*errstring, len, "Error resolving '%s' port '%s'. %s", 
-					remotehost, remoteport, gai_strerror(err));
-		}
-		TRACE(("Error resolving: %s", gai_strerror(err)))
-		return -1;
-	}
-
-	sock = -1;
-	err = EADDRNOTAVAIL;
-	for (res = res0; res; res = res->ai_next) {
-
-		sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
-		if (sock < 0) {
-			err = errno;
-			continue;
-		}
-
-		if (nonblocking) {
-			setnonblocking(sock);
-		}
-
-		if (connect(sock, res->ai_addr, res->ai_addrlen) < 0) {
-			if (errno == EINPROGRESS && nonblocking) {
-				TRACE(("Connect in progress"))
-				break;
-			} else {
-				err = errno;
-				close(sock);
-				sock = -1;
-				continue;
-			}
-		}
-
-		break; /* Success */
-	}
-
-	if (sock < 0 && !(errno == EINPROGRESS && nonblocking)) {
-		/* Failed */
-		if (errstring != NULL && *errstring == NULL) {
-			int len;
-			len = 20 + strlen(strerror(err));
-			*errstring = (char*)m_malloc(len);
-			snprintf(*errstring, len, "Error connecting: %s", strerror(err));
-		}
-		TRACE(("Error connecting: %s", strerror(err)))
-	} else {
-		/* Success */
-		set_sock_priority(sock);
-	}
-
-	freeaddrinfo(res0);
-	if (sock > 0 && errstring != NULL && *errstring != NULL) {
-		m_free(*errstring);
-	}
-
-	TRACE(("leave connect_remote: sock %d\n", sock))
-	return sock;
-}
-
 /* Sets up a pipe for a, returning three non-blocking file descriptors
  * and the pid. exec_fn is the function that will actually execute the child process,
  * it will be run after the child has fork()ed, and is passed exec_data.
  * If ret_errfd == NULL then stderr will not be captured.
  * ret_pid can be passed as  NULL to discard the pid. */
-int spawn_command(void(*exec_fn)(void *user_data), void *exec_data,
+int spawn_command(void(*exec_fn)(const void *user_data), const void *exec_data,
 		int *ret_writefd, int *ret_readfd, int *ret_errfd, pid_t *ret_pid) {
 	int infds[2];
 	int outfds[2];
@@ -430,7 +269,7 @@ int spawn_command(void(*exec_fn)(void *user_data), void *exec_data,
 		return DROPBEAR_FAILURE;
 	}
 
-#ifdef __uClinux__
+#if DROPBEAR_VFORK
 	pid = vfork();
 #else
 	pid = fork();
@@ -539,89 +378,7 @@ void run_shell_command(const char* cmd, unsigned int maxfd, char* usershell) {
 	execv(usershell, argv);
 }
 
-void get_socket_address(int fd, char **local_host, char **local_port,
-						char **remote_host, char **remote_port, int host_lookup)
-{
-	struct sockaddr_storage addr;
-	socklen_t addrlen;
-	
-	if (local_host || local_port) {
-		addrlen = sizeof(addr);
-		if (getsockname(fd, (struct sockaddr*)&addr, &addrlen) < 0) {
-			dropbear_exit("Failed socket address: %s", strerror(errno));
-		}
-		getaddrstring(&addr, local_host, local_port, host_lookup);		
-	}
-	if (remote_host || remote_port) {
-		addrlen = sizeof(addr);
-		if (getpeername(fd, (struct sockaddr*)&addr, &addrlen) < 0) {
-			dropbear_exit("Failed socket address: %s", strerror(errno));
-		}
-		getaddrstring(&addr, remote_host, remote_port, host_lookup);		
-	}
-}
-
-/* Return a string representation of the socket address passed. The return
- * value is allocated with malloc() */
-void getaddrstring(struct sockaddr_storage* addr, 
-			char **ret_host, char **ret_port,
-			int host_lookup) {
-
-	char host[NI_MAXHOST+1], serv[NI_MAXSERV+1];
-	unsigned int len;
-	int ret;
-	
-	int flags = NI_NUMERICSERV | NI_NUMERICHOST;
-
-#ifndef DO_HOST_LOOKUP
-	host_lookup = 0;
-#endif
-	
-	if (host_lookup) {
-		flags = NI_NUMERICSERV;
-	}
-
-	len = sizeof(struct sockaddr_storage);
-	/* Some platforms such as Solaris 8 require that len is the length
-	 * of the specific structure. Some older linux systems (glibc 2.1.3
-	 * such as debian potato) have sockaddr_storage.__ss_family instead
-	 * but we'll ignore them */
-#ifdef HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY
-	if (addr->ss_family == AF_INET) {
-		len = sizeof(struct sockaddr_in);
-	}
-#ifdef AF_INET6
-	if (addr->ss_family == AF_INET6) {
-		len = sizeof(struct sockaddr_in6);
-	}
-#endif
-#endif
-
-	ret = getnameinfo((struct sockaddr*)addr, len, host, sizeof(host)-1, 
-			serv, sizeof(serv)-1, flags);
-
-	if (ret != 0) {
-		if (host_lookup) {
-			/* On some systems (Darwin does it) we get EINTR from getnameinfo
-			 * somehow. Eew. So we'll just return the IP, since that doesn't seem
-			 * to exhibit that behaviour. */
-			getaddrstring(addr, ret_host, ret_port, 0);
-			return;
-		} else {
-			/* if we can't do a numeric lookup, something's gone terribly wrong */
-			dropbear_exit("Failed lookup: %s", gai_strerror(ret));
-		}
-	}
-
-	if (ret_host) {
-		*ret_host = m_strdup(host);
-	}
-	if (ret_port) {
-		*ret_port = m_strdup(serv);
-	}
-}
-
-#ifdef DEBUG_TRACE
+#if DEBUG_TRACE
 void printhex(const char * label, const unsigned char * buf, int len) {
 
 	int i;
@@ -638,6 +395,15 @@ void printhex(const char * label, const unsigned char * buf, int len) {
 	}
 	fprintf(stderr, "\n");
 }
+
+void printmpint(const char *label, mp_int *mp) {
+	buffer *buf = buf_new(1000);
+	buf_putmpint(buf, mp);
+	fprintf(stderr, "%d bits ", mp_count_bits(mp));
+	printhex(label, buf->data, buf->len);
+	buf_free(buf);
+
+}
 #endif
 
 /* Strip all control characters from text (a null-terminated string), except
@@ -707,13 +473,11 @@ out:
  * authkeys file.
  * Will return DROPBEAR_SUCCESS if data is read, or DROPBEAR_FAILURE on EOF.*/
 /* Only used for ~/.ssh/known_hosts and ~/.ssh/authorized_keys */
-#if defined(DROPBEAR_CLIENT) || defined(ENABLE_SVR_PUBKEY_AUTH)
+#if DROPBEAR_CLIENT || DROPBEAR_SVR_PUBKEY_AUTH
 int buf_getline(buffer * line, FILE * authfile) {
 
 	int c = EOF;
 
-	TRACE(("enter buf_getline"))
-
 	buf_setpos(line, 0);
 	buf_setlen(line, 0);
 
@@ -737,10 +501,8 @@ out:
 
 	/* if we didn't read anything before EOF or error, exit */
 	if (c == EOF && line->pos == 0) {
-		TRACE(("leave buf_getline: failure"))
 		return DROPBEAR_FAILURE;
 	} else {
-		TRACE(("leave buf_getline: success"))
 		buf_setpos(line, 0);
 		return DROPBEAR_SUCCESS;
 	}
@@ -750,8 +512,12 @@ out:
 
 /* make sure that the socket closes */
 void m_close(int fd) {
-
 	int val;
+
+	if (fd < 0) {
+		return;
+	}
+
 	do {
 		val = close(fd);
 	} while (val < 0 && errno == EINTR);
@@ -762,78 +528,26 @@ void m_close(int fd) {
 	}
 }
 	
-void * m_malloc(size_t size) {
-
-	void* ret;
-
-	if (size == 0) {
-		dropbear_exit("m_malloc failed");
-	}
-	ret = calloc(1, size);
-	if (ret == NULL) {
-		dropbear_exit("m_malloc failed");
-	}
-	return ret;
-
-}
-
-void * m_strdup(const char * str) {
-	char* ret;
-
-	ret = strdup(str);
-	if (ret == NULL) {
-		dropbear_exit("m_strdup failed");
-	}
-	return ret;
-}
-
-void __m_free(void* ptr) {
-	if (ptr != NULL) {
-		free(ptr);
-	}
-}
-
-void * m_realloc(void* ptr, size_t size) {
-
-	void *ret;
-
-	if (size == 0) {
-		dropbear_exit("m_realloc failed");
-	}
-	ret = realloc(ptr, size);
-	if (ret == NULL) {
-		dropbear_exit("m_realloc failed");
-	}
-	return ret;
-}
-
-/* Clear the data, based on the method in David Wheeler's
- * "Secure Programming for Linux and Unix HOWTO" */
-/* Beware of calling this from within dbutil.c - things might get
- * optimised away */
-void m_burn(void *data, unsigned int len) {
-	volatile char *p = data;
-
-	if (data == NULL)
-		return;
-	while (len--) {
-		*p++ = 0x66;
-	}
-}
-
-
 void setnonblocking(int fd) {
 
 	TRACE(("setnonblocking: %d", fd))
 
+#if DROPBEAR_FUZZ
+	if (fuzz.fuzzing) {
+		return;
+	}
+#endif
+
 	if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) {
 		if (errno == ENODEV) {
 			/* Some devices (like /dev/null redirected in)
 			 * can't be set to non-blocking */
 			TRACE(("ignoring ENODEV for setnonblocking"))
 		} else {
+		{
 			dropbear_exit("Couldn't set nonblocking");
 		}
+		}
 	}
 	TRACE(("leave setnonblocking"))
 }
@@ -846,14 +560,129 @@ void disallow_core() {
 
 /* Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE, with the result in *val */
 int m_str_to_uint(const char* str, unsigned int *val) {
+	unsigned long l;
 	errno = 0;
-	*val = strtoul(str, NULL, 10);
+	l = strtoul(str, NULL, 10);
 	/* The c99 spec doesn't actually seem to define EINVAL, but most platforms
 	 * I've looked at mention it in their manpage */
-	if ((*val == 0 && errno == EINVAL)
-		|| (*val == ULONG_MAX && errno == ERANGE)) {
+	if ((l == 0 && errno == EINVAL)
+		|| (l == ULONG_MAX && errno == ERANGE)
+		|| (l > UINT_MAX)) {
 		return DROPBEAR_FAILURE;
 	} else {
+		*val = l;
 		return DROPBEAR_SUCCESS;
 	}
 }
+
+/* Returns malloced path. inpath beginning with '/' is returned as-is,
+otherwise home directory is prepended */
+char * expand_homedir_path(const char *inpath) {
+	struct passwd *pw = NULL;
+	if (inpath[0] != '/') {
+		pw = getpwuid(getuid());
+		if (pw && pw->pw_dir) {
+			int len = strlen(inpath) + strlen(pw->pw_dir) + 2;
+			char *buf = m_malloc(len);
+			snprintf(buf, len, "%s/%s", pw->pw_dir, inpath);
+			return buf;
+		}
+	}
+
+	/* Fallback */
+	return m_strdup(inpath);
+}
+
+int constant_time_memcmp(const void* a, const void *b, size_t n)
+{
+	const char *xa = a, *xb = b;
+	uint8_t c = 0;
+	size_t i;
+	for (i = 0; i < n; i++)
+	{
+		c |= (xa[i] ^ xb[i]);
+	}
+	return c;
+}
+
+/* higher-resolution monotonic timestamp, falls back to gettimeofday */
+void gettime_wrapper(struct timespec *now) {
+	struct timeval tv;
+#if DROPBEAR_FUZZ
+	if (fuzz.fuzzing) {
+		/* time stands still when fuzzing */
+		now->tv_sec = 5;
+		now->tv_nsec = 0;
+	}
+#endif
+
+#if defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
+	/* POSIX monotonic clock. Newer Linux, BSD, MacOSX >10.12 */
+	if (clock_gettime(CLOCK_MONOTONIC, now) == 0) {
+		return;
+	}
+#endif
+
+#if defined(__linux__) && defined(SYS_clock_gettime)
+	{
+	/* Old linux toolchain - kernel might support it but not the build headers */
+	/* Also glibc <2.17 requires -lrt which we neglect to add */
+	static int linux_monotonic_failed = 0;
+	if (!linux_monotonic_failed) {
+		/* CLOCK_MONOTONIC isn't in some headers */
+		int clock_source_monotonic = 1; 
+		if (syscall(SYS_clock_gettime, clock_source_monotonic, now) == 0) {
+			return;
+		} else {
+			/* Don't try again */
+			linux_monotonic_failed = 1;
+		}
+	}
+	}
+#endif /* linux fallback clock_gettime */
+
+#if defined(HAVE_MACH_ABSOLUTE_TIME)
+	{
+	/* OS X pre 10.12, see https://developer.apple.com/library/mac/qa/qa1398/_index.html */
+	static mach_timebase_info_data_t timebase_info;
+	uint64_t scaled_time;
+	if (timebase_info.denom == 0) {
+		mach_timebase_info(&timebase_info);
+	}
+	scaled_time = mach_absolute_time() * timebase_info.numer / timebase_info.denom;
+	now->tv_sec = scaled_time / 1000000000;
+	now->tv_nsec = scaled_time % 1000000000;
+	}
+#endif /* osx mach_absolute_time */
+
+	/* Fallback for everything else - this will sometimes go backwards */
+	gettimeofday(&tv, NULL);
+	now->tv_sec = tv.tv_sec;
+	now->tv_nsec = 1000*tv.tv_usec;
+}
+
+/* second-resolution monotonic timestamp */
+time_t monotonic_now() {
+	struct timespec ts;
+	gettime_wrapper(&ts);
+	return ts.tv_sec;
+}
+
+void fsync_parent_dir(const char* fn) {
+#ifdef HAVE_LIBGEN_H
+	char *fn_dir = m_strdup(fn);
+	char *dir = dirname(fn_dir);
+	int dirfd = open(dir, O_RDONLY);
+
+	if (dirfd != -1) {
+		if (fsync(dirfd) != 0) {
+			TRACE(("fsync of directory %s failed: %s", dir, strerror(errno)))
+		}
+		m_close(dirfd);
+	} else {
+		TRACE(("error opening directory %s for fsync: %s", dir, strerror(errno)))
+	}
+
+	m_free(fn_dir);
+#endif
+}

dbutil.h

@@ -22,56 +22,53 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
-#ifndef _DBUTIL_H_
+#ifndef DROPBEAR_DBUTIL_H_
 
-#define _DBUTIL_H_
+#define DROPBEAR_DBUTIL_H_
 
 #include "includes.h"
 #include "buffer.h"
+#include "queue.h"
+#include "dbhelpers.h"
+#include "dbmalloc.h"
 
 #ifndef DISABLE_SYSLOG
-void startsyslog();
+void startsyslog(const char *ident);
 #endif
 
-extern void (*_dropbear_exit)(int exitcode, const char* format, va_list param);
+extern void (*_dropbear_exit)(int exitcode, const char* format, va_list param) ATTRIB_NORETURN;
 extern void (*_dropbear_log)(int priority, const char* format, va_list param);
 
-void dropbear_exit(const char* format, ...);
-void dropbear_close(const char* format, ...);
-void dropbear_log(int priority, const char* format, ...);
-void fail_assert(const char* expr, const char* file, int line);
-#ifdef DEBUG_TRACE
-void dropbear_trace(const char* format, ...);
+void dropbear_exit(const char* format, ...) ATTRIB_PRINTF(1,2) ATTRIB_NORETURN;
+
+void dropbear_close(const char* format, ...) ATTRIB_PRINTF(1,2) ;
+void dropbear_log(int priority, const char* format, ...) ATTRIB_PRINTF(2,3) ;
+
+void fail_assert(const char* expr, const char* file, int line) ATTRIB_NORETURN;
+
+#if DEBUG_TRACE
+void dropbear_trace(const char* format, ...) ATTRIB_PRINTF(1,2);
+void dropbear_trace2(const char* format, ...) ATTRIB_PRINTF(1,2);
 void printhex(const char * label, const unsigned char * buf, int len);
+void printmpint(const char *label, mp_int *mp);
+void debug_start_net(void);
 extern int debug_trace;
 #endif
+
 char * stripcontrol(const char * text);
-void get_socket_address(int fd, char **local_host, char **local_port,
-		char **remote_host, char **remote_port, int host_lookup);
-void getaddrstring(struct sockaddr_storage* addr, 
-		char **ret_host, char **ret_port, int host_lookup);
-int dropbear_listen(const char* address, const char* port,
-		int *socks, unsigned int sockcount, char **errstring, int *maxfd);
-int spawn_command(void(*exec_fn)(void *user_data), void *exec_data,
+
+int spawn_command(void(*exec_fn)(const void *user_data), const void *exec_data,
 		int *writefd, int *readfd, int *errfd, pid_t *pid);
 void run_shell_command(const char* cmd, unsigned int maxfd, char* usershell);
-#ifdef ENABLE_CONNECT_UNIX
+#if ENABLE_CONNECT_UNIX
 int connect_unix(const char* addr);
 #endif
-int connect_remote(const char* remotehost, const char* remoteport,
-		int nonblocking, char ** errstring);
 int buf_readfile(buffer* buf, const char* filename);
 int buf_getline(buffer * line, FILE * authfile);
 
 void m_close(int fd);
-void * m_malloc(size_t size);
-void * m_strdup(const char * str);
-void * m_realloc(void* ptr, size_t size);
-#define m_free(X) __m_free(X); (X) = NULL;
-void __m_free(void* ptr);
-void m_burn(void* data, unsigned int len);
 void setnonblocking(int fd);
-void disallow_core();
+void disallow_core(void);
 int m_str_to_uint(const char* str, unsigned int *val);
 
 /* Used to force mp_ints to be initialised */
@@ -80,4 +77,24 @@ int m_str_to_uint(const char* str, unsigned int *val);
 /* Dropbear assertion */
 #define dropbear_assert(X) do { if (!(X)) { fail_assert(#X, __FILE__, __LINE__); } } while (0)
 
-#endif /* _DBUTIL_H_ */
+/* Returns 0 if a and b have the same contents */
+int constant_time_memcmp(const void* a, const void *b, size_t n);
+
+/* Returns a time in seconds that doesn't go backwards - does not correspond to
+a real-world clock */
+time_t monotonic_now(void);
+/* Higher resolution clock_gettime(CLOCK_MONOTONIC) wrapper */
+void gettime_wrapper(struct timespec *now);
+
+char * expand_homedir_path(const char *inpath);
+
+void fsync_parent_dir(const char* fn);
+
+#if DROPBEAR_MSAN
+/* FD_ZERO seems to leave some memory uninitialized. clear it to avoid false positives */
+#define DROPBEAR_FD_ZERO(fds) do { memset((fds), 0x0, sizeof(fd_set)); FD_ZERO(fds); } while(0)
+#else
+#define DROPBEAR_FD_ZERO(fds) FD_ZERO(fds)
+#endif
+
+#endif /* DROPBEAR_DBUTIL_H_ */

debian/changelog

@@ -1,3 +1,148 @@
+dropbear (2020.79-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Mon, 15 Jun 2020 22:51:57 +0800
+
+dropbear (2019.78-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Wed, 27 Mar 2019 22:51:57 +0800
+
+dropbear (2019.77-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Sat, 23 Mar 2019 22:51:57 +0800
+
+dropbear (2018.76-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Tue, 27 Feb 2018 22:51:57 +0800
+
+dropbear (2017.75-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Thu, 18 May 2017 22:51:57 +0800
+
+dropbear (2016.74-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Thu, 21 Jul 2016 22:51:57 +0800
+
+dropbear (2016.73-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Fri, 18 Mar 2016 22:52:58 +0800
+
+dropbear (2016.72-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Wed, 10 Mar 2016 22:52:58 +0800
+
+dropbear (2015.70-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Thu, 26 Nov 2015 22:52:58 +0800
+
+dropbear (2015.69-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Wed, 25 Nov 2015 22:52:58 +0800
+
+dropbear (2015.68-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Sat, 8 Aug 2015 22:52:58 +0800
+
+dropbear (2015.67-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Wed, 28 Jan 2015 22:53:59 +0800
+
+dropbear (2014.66-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Thu, 23 Oct 2014 22:54:00 +0800
+
+dropbear (2014.65-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Fri, 8 Aug 2014 22:54:00 +0800
+
+dropbear (2014.64-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Sun, 27 Jul 2014 22:54:00 +0800
+
+dropbear (2014.63-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Wed, 19 Feb 2014 22:54:00 +0800
+
+dropbear (2013.62) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Tue, 7 Dec 2013 22:54:00 +0800
+
+dropbear (2013.60-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Wed, 16 Oct 2013 22:54:00 +0800
+
+dropbear (2013.59-0.1) unstable; urgency=low
+
+  * New upstream release.
+  * Build with DEB_BUILD_MAINT_OPTIONS = hardening=+all
+
+ -- Matt Johnston <matt@ucc.asn.au>  Fri, 4 Oct 2013 22:54:00 +0800
+
+dropbear (2013.58-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Thu, 18 Apr 2013 22:54:00 +0800
+
+dropbear (2013.57-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Mon, 15 Apr 2013 22:54:00 +0800
+
+dropbear (2013.56-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Thu, 21 Mar 2013 22:54:00 +0800
+
+dropbear (2012.55-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Wed, 22 Feb 2012 22:54:00 +0800
+
+dropbear (2011.54-0.1) unstable; urgency=low
+
+  * New upstream release.
+
+ -- Matt Johnston <matt@ucc.asn.au>  Tues, 8 Nov 2011 22:54:00 +0800
+
 dropbear (0.53.1-0.1) unstable; urgency=low
 
   * New upstream release.

debian/dropbear.docs

@@ -1,4 +1,3 @@
 README
-TODO
 debian/README.runit
 debian/README.Debian.diet

debian/dropbear.init

@@ -5,6 +5,7 @@
 # Required-Stop:     $remote_fs $syslog
 # Default-Start:     2 3 4 5
 # Default-Stop:      0 1 6
+# Short-Description: Dropbear SSH server
 ### END INIT INFO
 #
 # Do not configure this file. Edit /etc/default/dropbear instead!

debian/rules

@@ -1,5 +1,9 @@
 #!/usr/bin/make -f
 
+export DEB_BUILD_MAINT_OPTIONS = hardening=+all
+DPKG_EXPORT_BUILDFLAGS = 1
+include /usr/share/dpkg/buildflags.mk
+
 #export DH_OPTIONS
 DEB_HOST_GNU_TYPE ?=$(shell dpkg-architecture -qDEB_HOST_GNU_TYPE)
 DEB_BUILD_GNU_TYPE ?=$(shell dpkg-architecture -qDEB_BUILD_GNU_TYPE)
@@ -9,13 +13,6 @@ ifneq (,$(findstring nostrip,$(DEB_BUILD_OPTIONS)))
   STRIP =: nostrip
 endif
 
-CFLAGS =-Wall -g
-ifneq (,$(findstring noopt,$(DEB_BUILD_OPTIONS)))
-  CFLAGS +=-O0
-else
-  CFLAGS +=-O2
-endif
-
 CONFFLAGS =
 CC =gcc
 ifneq (,$(findstring diet,$(DEB_BUILD_OPTIONS)))
@@ -79,12 +76,12 @@ install: deb-checkdir deb-checkuid build-stamp
 	ln -s /var/log/dropbear '$(DIR)'/etc/dropbear/log/main
 	# man pages
 	install -d -m0755 '$(DIR)'/usr/share/man/man8
-	for i in dropbear.8 dropbearkey.8; do \
-	  install -m644 $$i '$(DIR)'/usr/share/man/man8/ || exit 1; \
+	install -d -m0755 '$(DIR)'/usr/share/man/man1
+	install -m644 dropbear.8 '$(DIR)'/usr/share/man/man8/
+	for i in dbclient.1 dropbearkey.1 dropbearconvert.1; do \
+	  install -m644 $$i '$(DIR)'/usr/share/man/man1/ || exit 1; \
 	done
 	gzip -9 '$(DIR)'/usr/share/man/man8/*.8
-	install -d -m0755 '$(DIR)'/usr/share/man/man1
-	install -m644 dbclient.1 '$(DIR)'/usr/share/man/man1/
 	gzip -9 '$(DIR)'/usr/share/man/man1/*.1
 	# copyright, changelog
 	cat debian/copyright.in LICENSE >debian/copyright

debug.h

@@ -22,8 +22,8 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
-#ifndef _DEBUG_H_
-#define _DEBUG_H_
+#ifndef DROPBEAR_DEBUG_H_
+#define DROPBEAR_DEBUG_H_
 
 #include "includes.h"
 
@@ -33,27 +33,15 @@
  * etc. Don't use this normally, it might cause problems */
 /* #define DEBUG_VALGRIND */
 
-/* Define this to compile in trace debugging printf()s. 
- * You'll need to run programs with "-v" to turn this on.
- *
- * Caution: Don't use this in an unfriendly environment (ie unfirewalled),
- * since the printing may not sanitise strings etc. This will add a reasonable
- * amount to your executable size. */
-/*#define DEBUG_TRACE */
-
 /* All functions writing to the cleartext payload buffer call
  * CHECKCLEARTOWRITE() before writing. This is only really useful if you're
  * attempting to track down a problem */
 /*#define CHECKCLEARTOWRITE() assert(ses.writepayload->len == 0 && \
 		ses.writepayload->pos == 0)*/
 
+#ifndef CHECKCLEARTOWRITE
 #define CHECKCLEARTOWRITE()
-
-/* Define this, compile with -pg and set GMON_OUT_PREFIX=gmon to get gmon
- * output when Dropbear forks. This will allow it gprof to be used.
- * It's useful to run dropbear -F, so you don't fork as much */
-/* (This is Linux specific) */
-/*#define DEBUG_FORKGPROF*/
+#endif
 
 /* A couple of flags, not usually useful, and mightn't do anything */
 
@@ -61,15 +49,20 @@
 /*#define DEBUG_RSA*/
 
 /* you don't need to touch this block */
-#ifdef DEBUG_TRACE
+#if DEBUG_TRACE
+extern int debug_trace;
 #define TRACE(X) dropbear_trace X;
+#define TRACE2(X) dropbear_trace2 X;
 #else /*DEBUG_TRACE*/
 #define TRACE(X)
+#define TRACE2(X)
 #endif /*DEBUG_TRACE*/
 
 /* To debug with GDB it is easier to run with no forking of child processes.
    You will need to pass "-F" as well. */
-/* #define DEBUG_NOFORK */
+#ifndef DEBUG_NOFORK
+#define DEBUG_NOFORK 0
+#endif
 
 
 /* For testing as non-root on shadowed systems, include the crypt of a password

default_options.h

@@ -0,0 +1,314 @@
+#ifndef DROPBEAR_DEFAULT_OPTIONS_H_
+#define DROPBEAR_DEFAULT_OPTIONS_H_
+/*
+                     > > > Read This < < <
+
+default_options.h  documents compile-time options, and provides default values.
+
+Local customisation should be added to localoptions.h which is
+used if it exists in the build directory. Options defined there will override 
+any options in this file.
+
+Options can also be defined with -DDROPBEAR_XXX=[0,1] in Makefile CFLAGS
+
+IMPORTANT: Some options will require "make clean" after changes */
+
+#define DROPBEAR_DEFPORT "22"
+
+/* Listen on all interfaces */
+#define DROPBEAR_DEFADDRESS ""
+
+/* Default hostkey paths - these can be specified on the command line */
+#define DSS_PRIV_FILENAME "/etc/dropbear/dropbear_dss_host_key"
+#define RSA_PRIV_FILENAME "/etc/dropbear/dropbear_rsa_host_key"
+#define ECDSA_PRIV_FILENAME "/etc/dropbear/dropbear_ecdsa_host_key"
+#define ED25519_PRIV_FILENAME "/etc/dropbear/dropbear_ed25519_host_key"
+
+/* Set NON_INETD_MODE if you require daemon functionality (ie Dropbear listens
+ * on chosen ports and keeps accepting connections. This is the default.
+ *
+ * Set INETD_MODE if you want to be able to run Dropbear with inetd (or
+ * similar), where it will use stdin/stdout for connections, and each process
+ * lasts for a single connection. Dropbear should be invoked with the -i flag
+ * for inetd, and can only accept IPv4 connections.
+ *
+ * Both of these flags can be defined at once, don't compile without at least
+ * one of them. */
+#define NON_INETD_MODE 1
+#define INETD_MODE 1
+
+/* Include verbose debug output, enabled with -v at runtime. 
+ * This will add a reasonable amount to your executable size. */
+#define DEBUG_TRACE 0
+
+/* Set this if you want to use the DROPBEAR_SMALL_CODE option. This can save
+ * several kB in binary size however will make the symmetrical ciphers and hashes
+ * slower, perhaps by 50%. Recommended for small systems that aren't doing
+ * much traffic. */
+#define DROPBEAR_SMALL_CODE 1
+
+/* Enable X11 Forwarding - server only */
+#define DROPBEAR_X11FWD 0
+
+/* Enable TCP Fowarding */
+/* 'Local' is "-L" style (client listening port forwarded via server)
+ * 'Remote' is "-R" style (server listening port forwarded via client) */
+#define DROPBEAR_CLI_LOCALTCPFWD 1
+#define DROPBEAR_CLI_REMOTETCPFWD 1
+
+#define DROPBEAR_SVR_LOCALTCPFWD 1
+#define DROPBEAR_SVR_REMOTETCPFWD 1
+
+/* Enable Authentication Agent Forwarding */
+#define DROPBEAR_SVR_AGENTFWD 1
+#define DROPBEAR_CLI_AGENTFWD 1
+
+/* Note: Both DROPBEAR_CLI_PROXYCMD and DROPBEAR_CLI_NETCAT must be set to
+ * allow multihop dbclient connections */
+
+/* Allow using -J <proxycommand> to run the connection through a 
+   pipe to a program, rather the normal TCP connection */
+#define DROPBEAR_CLI_PROXYCMD 1
+
+/* Enable "Netcat mode" option. This will forward standard input/output
+ * to a remote TCP-forwarded connection */
+#define DROPBEAR_CLI_NETCAT 1
+
+/* Whether to support "-c" and "-m" flags to choose ciphers/MACs at runtime */
+#define DROPBEAR_USER_ALGO_LIST 1
+
+/* Encryption - at least one required.
+ * AES128 should be enabled, some very old implementations might only
+ * support 3DES.
+ * Including both AES keysize variants (128 and 256) will result in 
+ * a minimal size increase */
+#define DROPBEAR_AES128 1
+#define DROPBEAR_AES256 1
+#define DROPBEAR_3DES 0
+#define DROPBEAR_TWOFISH256 0
+#define DROPBEAR_TWOFISH128 0
+
+/* Enable Chacha20-Poly1305 authenticated encryption mode. This is
+ * generally faster than AES256 on CPU w/o dedicated AES instructions,
+ * having the same key size. Recommended.
+ * Compiling in will add ~5,5kB to binary size on x86-64 */
+#define DROPBEAR_CHACHA20POLY1305 1
+
+/* Enable "Counter Mode" for ciphers. Recommended. */
+#define DROPBEAR_ENABLE_CTR_MODE 1
+
+/* Enable CBC mode for ciphers. This has security issues though
+   may be required for compatibility with old implementations */
+#define DROPBEAR_ENABLE_CBC_MODE 0
+
+/* Enable "Galois/Counter Mode" for ciphers. This authenticated
+ * encryption mode is combination of CTR mode and GHASH. Recommended
+ * for security and forwards compatibility, but slower than CTR on
+ * CPU w/o dedicated AES/GHASH instructions.
+ * Compiling in will add ~6kB to binary size on x86-64 */
+#define DROPBEAR_ENABLE_GCM_MODE 0
+
+/* Message integrity. sha2-256 is recommended as a default, 
+   sha1 for compatibility */
+#define DROPBEAR_SHA1_HMAC 1
+#define DROPBEAR_SHA2_256_HMAC 1
+#define DROPBEAR_SHA1_96_HMAC 0
+
+/* Hostkey/public key algorithms - at least one required, these are used
+ * for hostkey as well as for verifying signatures with pubkey auth.
+ * Removing either of these won't save very much space.
+ * RSA is recommended
+ * DSS may be necessary to connect to some systems though
+   is not recommended for new keys */
+#define DROPBEAR_RSA 1
+#define DROPBEAR_DSS 1
+/* ECDSA is significantly faster than RSA or DSS. Compiling in ECC
+ * code (either ECDSA or ECDH) increases binary size - around 30kB
+ * on x86-64 */
+#define DROPBEAR_ECDSA 1
+/* Ed25519 is faster than ECDSA. Compiling in Ed25519 code increases
+   binary size - around 7,5kB on x86-64 */
+#define DROPBEAR_ED25519 1
+
+/* RSA must be >=1024 */
+#define DROPBEAR_DEFAULT_RSA_SIZE 2048
+/* DSS is always 1024 */
+/* ECDSA defaults to largest size configured, usually 521 */
+/* Ed25519 is always 256 */
+
+/* Add runtime flag "-R" to generate hostkeys as-needed when the first 
+   connection using that key type occurs.
+   This avoids the need to otherwise run "dropbearkey" and avoids some problems
+   with badly seeded /dev/urandom when systems first boot. */
+#define DROPBEAR_DELAY_HOSTKEY 1
+
+
+/* Key exchange algorithm.
+
+ * group14_sha1 - 2048 bit, sha1
+ * group14_sha256 - 2048 bit, sha2-256
+ * group16 - 4096 bit, sha2-512
+ * group1 - 1024 bit, sha1
+ * curve25519 - elliptic curve DH
+ * ecdh - NIST elliptic curve DH (256, 384, 521)
+ *
+ * group1 is too small for security though is necessary if you need 
+     compatibility with some implementations such as Dropbear versions < 0.53
+ * group14 is supported by most implementations.
+ * group16 provides a greater strength level but is slower and increases binary size
+ * curve25519 and ecdh algorithms are faster than non-elliptic curve methods
+ * curve25519 increases binary size by ~2,5kB on x86-64
+ * including either ECDH or ECDSA increases binary size by ~30kB on x86-64
+
+ * Small systems should generally include either curve25519 or ecdh for performance.
+ * curve25519 is less widely supported but is faster
+ */ 
+#define DROPBEAR_DH_GROUP14_SHA1 1
+#define DROPBEAR_DH_GROUP14_SHA256 1
+#define DROPBEAR_DH_GROUP16 0
+#define DROPBEAR_CURVE25519 1
+#define DROPBEAR_ECDH 1
+#define DROPBEAR_DH_GROUP1 1
+
+/* When group1 is enabled it will only be allowed by Dropbear client
+not as a server, due to concerns over its strength. Set to 0 to allow
+group1 in Dropbear server too */
+#define DROPBEAR_DH_GROUP1_CLIENTONLY 1
+
+/* Control the memory/performance/compression tradeoff for zlib.
+ * Set windowBits=8 for least memory usage, see your system's
+ * zlib.h for full details.
+ * Default settings (windowBits=15) will use 256kB for compression
+ * windowBits=8 will use 129kB for compression.
+ * Both modes will use ~35kB for decompression (using windowBits=15 for
+ * interoperability) */
+#define DROPBEAR_ZLIB_WINDOW_BITS 15 
+
+/* Whether to do reverse DNS lookups. */
+#define DO_HOST_LOOKUP 0
+
+/* Whether to print the message of the day (MOTD). */
+#define DO_MOTD 1
+#define MOTD_FILENAME "/etc/motd"
+
+/* Authentication Types - at least one required.
+   RFC Draft requires pubkey auth, and recommends password */
+#define DROPBEAR_SVR_PASSWORD_AUTH 1
+
+/* Note: PAM auth is quite simple and only works for PAM modules which just do
+ * a simple "Login: " "Password: " (you can edit the strings in svr-authpam.c).
+ * It's useful for systems like OS X where standard password crypts don't work
+ * but there's an interface via a PAM module. It won't work for more complex
+ * PAM challenge/response.
+ * You can't enable both PASSWORD and PAM. */
+#define DROPBEAR_SVR_PAM_AUTH 0
+
+/* ~/.ssh/authorized_keys authentication */
+#define DROPBEAR_SVR_PUBKEY_AUTH 1
+
+/* Whether to take public key options in 
+ * authorized_keys file into account */
+#define DROPBEAR_SVR_PUBKEY_OPTIONS 1
+
+/* Set this to 0 if your system does not have multiple user support.
+   (Linux kernel CONFIG_MULTIUSER option)
+   The resulting binary will not run on a normal system. */
+#define DROPBEAR_SVR_MULTIUSER 1
+
+/* Client authentication options */
+#define DROPBEAR_CLI_PASSWORD_AUTH 1
+#define DROPBEAR_CLI_PUBKEY_AUTH 1
+
+/* A default argument for dbclient -i <privatekey>. 
+Homedir is prepended unless path begins with / */
+#define DROPBEAR_DEFAULT_CLI_AUTHKEY ".ssh/id_dropbear"
+
+/* Allow specifying the password for dbclient via the DROPBEAR_PASSWORD
+ * environment variable. */
+#define DROPBEAR_USE_PASSWORD_ENV 1
+
+/* Define this (as well as DROPBEAR_CLI_PASSWORD_AUTH) to allow the use of
+ * a helper program for the ssh client. The helper program should be
+ * specified in the SSH_ASKPASS environment variable, and dbclient
+ * should be run with DISPLAY set and no tty. The program should
+ * return the password on standard output */
+#define DROPBEAR_CLI_ASKPASS_HELPER 0
+
+/* Save a network roundtrip by sendng a real auth request immediately after
+ * sending a query for the available methods. This is not yet enabled by default 
+ since it could cause problems with non-compliant servers */ 
+#define DROPBEAR_CLI_IMMEDIATE_AUTH 0
+
+/* Set this to use PRNGD or EGD instead of /dev/urandom */
+#define DROPBEAR_USE_PRNGD 0
+#define DROPBEAR_PRNGD_SOCKET "/var/run/dropbear-rng"
+
+/* Specify the number of clients we will allow to be connected but
+ * not yet authenticated. After this limit, connections are rejected */
+/* The first setting is per-IP, to avoid denial of service */
+#define MAX_UNAUTH_PER_IP 5
+
+/* And then a global limit to avoid chewing memory if connections 
+ * come from many IPs */
+#define MAX_UNAUTH_CLIENTS 30
+
+/* Default maximum number of failed authentication tries (server option) */
+/* -T server option overrides */
+#define MAX_AUTH_TRIES 10
+
+/* The default file to store the daemon's process ID, for shutdown
+   scripts etc. This can be overridden with the -P flag */
+#define DROPBEAR_PIDFILE "/var/run/dropbear.pid"
+
+/* The command to invoke for xauth when using X11 forwarding.
+ * "-q" for quiet */
+#define XAUTH_COMMAND "/usr/bin/xauth -q"
+
+
+/* if you want to enable running an sftp server (such as the one included with
+ * OpenSSH), set the path below and set DROPBEAR_SFTPSERVER. 
+ * The sftp-server program is not provided by Dropbear itself */
+#define DROPBEAR_SFTPSERVER 1
+#define SFTPSERVER_PATH "/usr/libexec/sftp-server"
+
+/* This is used by the scp binary when used as a client binary. If you're
+ * not using the Dropbear client, you'll need to change it */
+#define DROPBEAR_PATH_SSH_PROGRAM "/usr/bin/dbclient"
+
+/* Whether to log commands executed by a client. This only logs the 
+ * (single) command sent to the server, not what a user did in a 
+ * shell/sftp session etc. */
+#define LOG_COMMANDS 0
+
+/* Window size limits. These tend to be a trade-off between memory
+   usage and network performance: */
+/* Size of the network receive window. This amount of memory is allocated
+   as a per-channel receive buffer. Increasing this value can make a
+   significant difference to network performance. 24kB was empirically
+   chosen for a 100mbit ethernet network. The value can be altered at
+   runtime with the -W argument. */
+#define DEFAULT_RECV_WINDOW 24576
+/* Maximum size of a received SSH data packet - this _MUST_ be >= 32768
+   in order to interoperate with other implementations */
+#define RECV_MAX_PAYLOAD_LEN 32768
+/* Maximum size of a transmitted data packet - this can be any value,
+   though increasing it may not make a significant difference. */
+#define TRANS_MAX_PAYLOAD_LEN 16384
+
+/* Ensure that data is transmitted every KEEPALIVE seconds. This can
+be overridden at runtime with -K. 0 disables keepalives */
+#define DEFAULT_KEEPALIVE 0
+
+/* If this many KEEPALIVES are sent with no packets received from the
+other side, exit. Not run-time configurable - if you have a need
+for runtime configuration please mail the Dropbear list */
+#define DEFAULT_KEEPALIVE_LIMIT 3
+
+/* Ensure that data is received within IDLE_TIMEOUT seconds. This can
+be overridden at runtime with -I. 0 disables idle timeouts */
+#define DEFAULT_IDLE_TIMEOUT 0
+
+/* The default path. This will often get replaced by the shell */
+#define DEFAULT_PATH "/usr/bin:/bin"
+
+#endif /* DROPBEAR_DEFAULT_OPTIONS_H_ */

dh_groups.c

@@ -0,0 +1,97 @@
+#include "options.h"
+#include "dh_groups.h"
+
+#if DROPBEAR_NORMAL_DH
+
+#if DROPBEAR_DH_GROUP1
+/* diffie-hellman-group1-sha1 value for p */
+const unsigned char dh_p_1[DH_P_1_LEN] = {
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC9, 0x0F, 0xDA, 0xA2,
+	0x21, 0x68, 0xC2, 0x34, 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1,
+	0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, 0x02, 0x0B, 0xBE, 0xA6,
+	0x3B, 0x13, 0x9B, 0x22, 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD,
+	0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B, 0x30, 0x2B, 0x0A, 0x6D,
+	0xF2, 0x5F, 0x14, 0x37, 0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45,
+	0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6, 0xF4, 0x4C, 0x42, 0xE9,
+	0xA6, 0x37, 0xED, 0x6B, 0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED,
+	0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5, 0xAE, 0x9F, 0x24, 0x11,
+	0x7C, 0x4B, 0x1F, 0xE6, 0x49, 0x28, 0x66, 0x51, 0xEC, 0xE6, 0x53, 0x81,
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+#endif /* DROPBEAR_DH_GROUP1 */
+
+#if DROPBEAR_DH_GROUP14
+/* diffie-hellman-group14-sha1 value for p */
+const unsigned char dh_p_14[DH_P_14_LEN] = {
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC9, 0x0F, 0xDA, 0xA2, 
+	0x21, 0x68, 0xC2, 0x34, 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1, 
+	0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, 0x02, 0x0B, 0xBE, 0xA6,
+	0x3B, 0x13, 0x9B, 0x22, 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD,
+	0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B, 0x30, 0x2B, 0x0A, 0x6D,
+	0xF2, 0x5F, 0x14, 0x37, 0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45,
+	0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6, 0xF4, 0x4C, 0x42, 0xE9,
+	0xA6, 0x37, 0xED, 0x6B, 0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED,
+	0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5, 0xAE, 0x9F, 0x24, 0x11,
+	0x7C, 0x4B, 0x1F, 0xE6, 0x49, 0x28, 0x66, 0x51, 0xEC, 0xE4, 0x5B, 0x3D,
+	0xC2, 0x00, 0x7C, 0xB8, 0xA1, 0x63, 0xBF, 0x05, 0x98, 0xDA, 0x48, 0x36,
+	0x1C, 0x55, 0xD3, 0x9A, 0x69, 0x16, 0x3F, 0xA8, 0xFD, 0x24, 0xCF, 0x5F,
+	0x83, 0x65, 0x5D, 0x23, 0xDC, 0xA3, 0xAD, 0x96, 0x1C, 0x62, 0xF3, 0x56,
+	0x20, 0x85, 0x52, 0xBB, 0x9E, 0xD5, 0x29, 0x07, 0x70, 0x96, 0x96, 0x6D,
+	0x67, 0x0C, 0x35, 0x4E, 0x4A, 0xBC, 0x98, 0x04, 0xF1, 0x74, 0x6C, 0x08,
+	0xCA, 0x18, 0x21, 0x7C, 0x32, 0x90, 0x5E, 0x46, 0x2E, 0x36, 0xCE, 0x3B,
+	0xE3, 0x9E, 0x77, 0x2C, 0x18, 0x0E, 0x86, 0x03, 0x9B, 0x27, 0x83, 0xA2,
+	0xEC, 0x07, 0xA2, 0x8F, 0xB5, 0xC5, 0x5D, 0xF0, 0x6F, 0x4C, 0x52, 0xC9,
+	0xDE, 0x2B, 0xCB, 0xF6, 0x95, 0x58, 0x17, 0x18, 0x39, 0x95, 0x49, 0x7C,
+	0xEA, 0x95, 0x6A, 0xE5, 0x15, 0xD2, 0x26, 0x18, 0x98, 0xFA, 0x05, 0x10,
+	0x15, 0x72, 0x8E, 0x5A, 0x8A, 0xAC, 0xAA, 0x68, 0xFF, 0xFF, 0xFF, 0xFF,
+	0xFF, 0xFF, 0xFF, 0xFF};
+#endif /* DROPBEAR_DH_GROUP14 */
+
+#if DROPBEAR_DH_GROUP16
+/* diffie-hellman-group16-256 value for p */
+const unsigned char dh_p_16[DH_P_16_LEN] = {
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC9, 0x0F, 0xDA, 0xA2, 0x21,
+	0x68, 0xC2, 0x34, 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1, 0x29, 0x02,
+	0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, 0x02, 0x0B, 0xBE, 0xA6, 0x3B, 0x13, 0x9B,
+	0x22, 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD, 0xEF, 0x95, 0x19, 0xB3,
+	0xCD, 0x3A, 0x43, 0x1B, 0x30, 0x2B, 0x0A, 0x6D, 0xF2, 0x5F, 0x14, 0x37, 0x4F,
+	0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45, 0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E,
+	0x7E, 0xC6, 0xF4, 0x4C, 0x42, 0xE9, 0xA6, 0x37, 0xED, 0x6B, 0x0B, 0xFF, 0x5C,
+	0xB6, 0xF4, 0x06, 0xB7, 0xED, 0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5,
+	0xAE, 0x9F, 0x24, 0x11, 0x7C, 0x4B, 0x1F, 0xE6, 0x49, 0x28, 0x66, 0x51, 0xEC,
+	0xE4, 0x5B, 0x3D, 0xC2, 0x00, 0x7C, 0xB8, 0xA1, 0x63, 0xBF, 0x05, 0x98, 0xDA,
+	0x48, 0x36, 0x1C, 0x55, 0xD3, 0x9A, 0x69, 0x16, 0x3F, 0xA8, 0xFD, 0x24, 0xCF,
+	0x5F, 0x83, 0x65, 0x5D, 0x23, 0xDC, 0xA3, 0xAD, 0x96, 0x1C, 0x62, 0xF3, 0x56,
+	0x20, 0x85, 0x52, 0xBB, 0x9E, 0xD5, 0x29, 0x07, 0x70, 0x96, 0x96, 0x6D, 0x67,
+	0x0C, 0x35, 0x4E, 0x4A, 0xBC, 0x98, 0x04, 0xF1, 0x74, 0x6C, 0x08, 0xCA, 0x18,
+	0x21, 0x7C, 0x32, 0x90, 0x5E, 0x46, 0x2E, 0x36, 0xCE, 0x3B, 0xE3, 0x9E, 0x77,
+	0x2C, 0x18, 0x0E, 0x86, 0x03, 0x9B, 0x27, 0x83, 0xA2, 0xEC, 0x07, 0xA2, 0x8F,
+	0xB5, 0xC5, 0x5D, 0xF0, 0x6F, 0x4C, 0x52, 0xC9, 0xDE, 0x2B, 0xCB, 0xF6, 0x95,
+	0x58, 0x17, 0x18, 0x39, 0x95, 0x49, 0x7C, 0xEA, 0x95, 0x6A, 0xE5, 0x15, 0xD2,
+	0x26, 0x18, 0x98, 0xFA, 0x05, 0x10, 0x15, 0x72, 0x8E, 0x5A, 0x8A, 0xAA, 0xC4,
+	0x2D, 0xAD, 0x33, 0x17, 0x0D, 0x04, 0x50, 0x7A, 0x33, 0xA8, 0x55, 0x21, 0xAB,
+	0xDF, 0x1C, 0xBA, 0x64, 0xEC, 0xFB, 0x85, 0x04, 0x58, 0xDB, 0xEF, 0x0A, 0x8A,
+	0xEA, 0x71, 0x57, 0x5D, 0x06, 0x0C, 0x7D, 0xB3, 0x97, 0x0F, 0x85, 0xA6, 0xE1,
+	0xE4, 0xC7, 0xAB, 0xF5, 0xAE, 0x8C, 0xDB, 0x09, 0x33, 0xD7, 0x1E, 0x8C, 0x94,
+	0xE0, 0x4A, 0x25, 0x61, 0x9D, 0xCE, 0xE3, 0xD2, 0x26, 0x1A, 0xD2, 0xEE, 0x6B,
+	0xF1, 0x2F, 0xFA, 0x06, 0xD9, 0x8A, 0x08, 0x64, 0xD8, 0x76, 0x02, 0x73, 0x3E,
+	0xC8, 0x6A, 0x64, 0x52, 0x1F, 0x2B, 0x18, 0x17, 0x7B, 0x20, 0x0C, 0xBB, 0xE1,
+	0x17, 0x57, 0x7A, 0x61, 0x5D, 0x6C, 0x77, 0x09, 0x88, 0xC0, 0xBA, 0xD9, 0x46,
+	0xE2, 0x08, 0xE2, 0x4F, 0xA0, 0x74, 0xE5, 0xAB, 0x31, 0x43, 0xDB, 0x5B, 0xFC,
+	0xE0, 0xFD, 0x10, 0x8E, 0x4B, 0x82, 0xD1, 0x20, 0xA9, 0x21, 0x08, 0x01, 0x1A,
+	0x72, 0x3C, 0x12, 0xA7, 0x87, 0xE6, 0xD7, 0x88, 0x71, 0x9A, 0x10, 0xBD, 0xBA,
+	0x5B, 0x26, 0x99, 0xC3, 0x27, 0x18, 0x6A, 0xF4, 0xE2, 0x3C, 0x1A, 0x94, 0x68,
+	0x34, 0xB6, 0x15, 0x0B, 0xDA, 0x25, 0x83, 0xE9, 0xCA, 0x2A, 0xD4, 0x4C, 0xE8,
+	0xDB, 0xBB, 0xC2, 0xDB, 0x04, 0xDE, 0x8E, 0xF9, 0x2E, 0x8E, 0xFC, 0x14, 0x1F,
+	0xBE, 0xCA, 0xA6, 0x28, 0x7C, 0x59, 0x47, 0x4E, 0x6B, 0xC0, 0x5D, 0x99, 0xB2,
+	0x96, 0x4F, 0xA0, 0x90, 0xC3, 0xA2, 0x23, 0x3B, 0xA1, 0x86, 0x51, 0x5B, 0xE7,
+	0xED, 0x1F, 0x61, 0x29, 0x70, 0xCE, 0xE2, 0xD7, 0xAF, 0xB8, 0x1B, 0xDD, 0x76,
+	0x21, 0x70, 0x48, 0x1C, 0xD0, 0x06, 0x91, 0x27, 0xD5, 0xB0, 0x5A, 0xA9, 0x93,
+	0xB4, 0xEA, 0x98, 0x8D, 0x8F, 0xDD, 0xC1, 0x86, 0xFF, 0xB7, 0xDC, 0x90, 0xA6,
+	0xC0, 0x8F, 0x4D, 0xF4, 0x35, 0xC9, 0x34, 0x06, 0x31, 0x99, 0xFF, 0xFF, 0xFF,
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+#endif /* DROPBEAR_DH_GROUP16 */
+
+/* Same for all groups */
+const int DH_G_VAL = 2;
+
+#endif /* DROPBEAR_NORMAL_DH */

dh_groups.h

@@ -0,0 +1,26 @@
+#ifndef DROPBEAR_DH_GROUPS_H
+#define DROPBEAR_DH_GROUPS_H
+#include "options.h"
+
+#if DROPBEAR_NORMAL_DH
+
+#if DROPBEAR_DH_GROUP1
+#define DH_P_1_LEN 128
+extern const unsigned char dh_p_1[DH_P_1_LEN];
+#endif
+
+#if DROPBEAR_DH_GROUP14
+#define DH_P_14_LEN 256
+extern const unsigned char dh_p_14[DH_P_14_LEN];
+#endif
+
+#if DROPBEAR_DH_GROUP16
+#define DH_P_16_LEN 512
+extern const unsigned char dh_p_16[DH_P_16_LEN];
+#endif
+
+extern const int DH_G_VAL;
+
+#endif /* DROPBEAR_NORMAL_DH */
+
+#endif

dropbear.8

@@ -1,17 +1,15 @@
 .TH dropbear 8
 .SH NAME
-dropbear \- lightweight SSH2 server
+dropbear \- lightweight SSH server
 .SH SYNOPSIS
 .B dropbear
-[\-FEmwsgjki] [\-b
-.I banner\fR] [\-d
-.I dsskey\fR] [\-r
-.I rsakey\fR] [\-p
-.IR [address:]port ]
+[\fIflag arguments\fR] [\-b
+.I banner\fR] 
+[\-r
+.I hostkeyfile\fR] [\-p [\fIaddress\fR:]\fIport\fR]
 .SH DESCRIPTION
 .B dropbear
-is a SSH 2 server designed to be small enough to be used in small memory
-environments, while still being functional and secure enough for general use.
+is a small SSH server 
 .SH OPTIONS
 .TP
 .B \-b \fIbanner
@@ -20,24 +18,16 @@ Display the contents of the file
 .I banner
 before user login (default: none).
 .TP
-.B \-d \fIdsskey
-dsskeyfile.
+.B \-r \fIhostkey
 Use the contents of the file
-.I dsskey
-for the DSS host key (default: /etc/dropbear/dropbear_dss_host_key). 
-Note that 
-some SSH implementations
-use the term "DSA" rather than "DSS", they mean the same thing.
+.I hostkey
+for the SSH hostkey.
 This file is generated with
-.BR dropbearkey (8).
+.BR dropbearkey (1) 
+or automatically with the '-R' option. See "Host Key Files" below.
 .TP
-.B \-r \fIrsakey
-rsakeyfile.
-Use the contents of the file
-.I rsakey
-for the rsa host key (default: /etc/dropbear/dropbear_rsa_host_key).
-This file is generated with
-.BR dropbearkey (8).
+.B \-R
+Generate hostkeys automatically. See "Host Key Files" below.
 .TP
 .B \-F
 Don't fork into background.
@@ -63,7 +53,7 @@ Disable local port forwarding.
 .B \-k
 Disable remote port forwarding.
 .TP
-.B \-p \fI[address:]port
+.B \-p\fR [\fIaddress\fR:]\fIport
 Listen on specified 
 .I address
 and TCP
@@ -96,16 +86,28 @@ Ensure that traffic is transmitted at a certain interval in seconds. This is
 useful for working around firewalls or routers that drop connections after
 a certain period of inactivity. The trade-off is that a session may be
 closed if there is a temporary lapse of network connectivity. A setting
-if 0 disables keepalives.
+if 0 disables keepalives. If no response is received for 3 consecutive keepalives the connection will be closed.
 .TP
 .B \-I \fIidle_timeout
 Disconnect the session if no traffic is transmitted or received for \fIidle_timeout\fR seconds.
+.TP
+.B \-T \fImax_authentication_attempts
+Set the number of authentication attempts allowed per connection. If unspecified the default is 10 (MAX_AUTH_TRIES)
+.TP
+.B \-c \fIforced_command
+Disregard the command provided by the user and always run \fIforced_command\fR. This also
+overrides any authorized_keys command= option.
+.TP
+.B \-V
+Print the version
+
 .SH FILES
 
 .TP
 Authorized Keys
 
-~/.ssh/authorized_keys can be set up to allow remote login with a RSA or DSS
+~/.ssh/authorized_keys can be set up to allow remote login with a RSA,
+ECDSA, Ed25519 or DSS
 key. Each line is of the form
 .TP
 [restrictions] ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIgAsp... [comment]
@@ -132,8 +134,9 @@ Disable PTY allocation. Note that a user can still obtain most of the
 same functionality with other means even if no-pty is set.
 
 .TP
-.B command="\fIforced_command\fR"
+.B command=\fR"\fIforced_command\fR"
 Disregard the command provided by the user and always run \fIforced_command\fR.
+The -c command line option overrides this.
 
 The authorized_keys file and its containing ~/.ssh directory must only be
 writable by the user, otherwise Dropbear will not allow a login using public
@@ -143,9 +146,15 @@ key authentication.
 Host Key Files
 
 Host key files are read at startup from a standard location, by default
-/etc/dropbear/dropbear_dss_host_key and /etc/dropbear/dropbear_rsa_host_key
-or specified on the commandline with -d or -r. These are of the form generated
-by dropbearkey.
+/etc/dropbear/dropbear_dss_host_key, /etc/dropbear/dropbear_rsa_host_key,
+/etc/dropbear/dropbear_ecdsa_host_key and /etc/dropbear/dropbear_ed25519_host_key
+
+If the -r command line option is specified the default files are not loaded.
+Host key files are of the form generated by dropbearkey. 
+The -R option can be used to automatically generate keys
+in the default location - keys will be generated after startup when the first
+connection is established. This had the benefit that the system /dev/urandom
+random number source has a better chance of being securely seeded.
 
 .TP
 Message Of The Day
@@ -180,13 +189,14 @@ in this variable. If a shell was requested this is set to an empty value.
 .B SSH_AUTH_SOCK
 Set to a forwarded ssh-agent connection.
 
-
+.SH NOTES
+Dropbear only supports SSH protocol version 2.
 
 .SH AUTHOR
 Matt Johnston (matt@ucc.asn.au).
 .br
 Gerrit Pape (pape@smarden.org) wrote this manual page.
 .SH SEE ALSO
-dropbearkey(8), dbclient(1)
+dropbearkey(1), dbclient(1), dropbearconvert(1)
 .P
-http://matt.ucc.asn.au/dropbear/dropbear.html
+https://matt.ucc.asn.au/dropbear/dropbear.html

dropbear_lint.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+
+EXITCODE=0
+
+# #ifdef instead of #if
+grep '#ifdef DROPBEAR' -I *.c *.h && EXITCODE=1
+
+exit $EXITCODE

dropbearconvert.1

@@ -0,0 +1,50 @@
+.TH dropbearconvert 1
+.SH NAME
+dropbearconvert \- convert between Dropbear and OpenSSH private key formats
+.SH SYNOPSIS
+.B dropbearconvert
+.I input_type
+.I output_type
+.I input_file
+.I output_file
+.SH DESCRIPTION
+.B Dropbear
+and 
+.B OpenSSH
+SSH implementations have different private key formats.
+.B dropbearconvert
+can convert between the two.
+.P
+Dropbear uses the same SSH public key format as OpenSSH, it can be extracted
+from a private key by using
+.B dropbearkey \-y
+.P
+Encrypted private keys are not supported, use ssh-keygen(1) to decrypt them
+first.
+.SH ARGUMENTS
+.TP
+.I input_type
+Either 
+.I dropbear
+or 
+.I openssh
+.TP
+.I output_type
+Either 
+.I dropbear
+or 
+.I openssh
+.TP
+.I input_file
+An existing Dropbear or OpenSSH private key file
+.TP
+.I output_file
+The path to write the converted private key file. For client authentication ~/.ssh/id_dropbear is loaded by default
+.SH EXAMPLE
+ # dropbearconvert openssh dropbear ~/.ssh/id_rsa ~/.ssh/id_dropbear
+.SH AUTHOR
+Matt Johnston (matt@ucc.asn.au).
+.SH SEE ALSO
+ dropbearkey(1), ssh-keygen(1)
+.P
+https://matt.ucc.asn.au/dropbear/dropbear.html

dropbearconvert.c

@@ -28,6 +28,8 @@
 #include "buffer.h"
 #include "dbutil.h"
 #include "keyimport.h"
+#include "crypto_desc.h" 
+#include "dbrandom.h" 
 
 
 static int do_convert(int intype, const char* infile, int outtype,
@@ -51,8 +53,8 @@ static void printhelp(char * progname) {
 					progname);
 }
 
-#if defined(DBMULTI_dropbearconvert) || !defined(DROPBEAR_MULTI)
-#if defined(DBMULTI_dropbearconvert) && defined(DROPBEAR_MULTI)
+#if defined(DBMULTI_dropbearconvert) || !DROPBEAR_MULTI
+#if defined(DBMULTI_dropbearconvert) && DROPBEAR_MULTI
 int dropbearconvert_main(int argc, char ** argv) {
 #else 
 int main(int argc, char ** argv) {
@@ -62,7 +64,10 @@ int main(int argc, char ** argv) {
 	const char* infile;
 	const char* outfile;
 
-#ifdef DEBUG_TRACE
+	crypto_init();
+	seedrandom();
+
+#if DEBUG_TRACE
 	/* It's hard for it to get in the way _too_ much */
 	debug_trace = 1;
 #endif
@@ -111,7 +116,7 @@ static int do_convert(int intype, const char* infile, int outtype,
 		const char* outfile) {
 
 	sign_key * key = NULL;
-	char * keytype = NULL;
+	const char * keytype = NULL;
 	int ret = 1;
 
 	key = import_read(infile, NULL, intype);
@@ -121,16 +126,7 @@ static int do_convert(int intype, const char* infile, int outtype,
 		goto out;
 	}
 
-#ifdef DROPBEAR_RSA
-	if (key->rsakey != NULL) {
-		keytype = "RSA";
-	}
-#endif
-#ifdef DROPBEAR_DSS
-	if (key->dsskey != NULL) {
-		keytype = "DSS";
-	}
-#endif
+	keytype = signkey_name_from_type(key->type, NULL);
 
 	fprintf(stderr, "Key is a %s key\n", keytype);
 

dropbearkey.1

@@ -0,0 +1,61 @@
+.TH dropbearkey 1
+.SH NAME
+dropbearkey \- create private keys for the use with dropbear(8) or dbclient(1)
+.SH SYNOPSIS
+.B dropbearkey
+\-t
+.I type
+\-f
+.I file
+[\-s
+.IR bits ]
+[\-y]
+.SH DESCRIPTION
+.B dropbearkey
+generates a
+\fIRSA\fR, \fIDSS\fR, \fIECDSA\fR, or \fIEd25519\fR
+format SSH private key, and saves it to a file for the use with the
+Dropbear client or server.
+Note that 
+some SSH implementations
+use the term "DSA" rather than "DSS", they mean the same thing.
+.SH OPTIONS
+.TP
+.B \-t \fItype
+Type of key to generate.
+Must be one of
+.I rsa
+.I ecdsa
+.I ed25519
+or
+.IR dss .
+.TP
+.B \-f \fIfile
+Write the secret key to the file
+\fIfile\fR. For client authentication ~/.ssh/id_dropbear is loaded by default
+.TP
+.B \-s \fIbits
+Set the key size to
+.I bits
+bits, should be multiple of 8 (optional). 
+.TP
+.B \-y
+Just print the publickey and fingerprint for the private key in \fIfile\fR.
+.SH NOTES
+The program dropbearconvert(1) can be used to convert between Dropbear and OpenSSH key formats.
+.P
+Dropbear does not support encrypted keys. 
+.SH EXAMPLE
+generate a host-key:
+ # dropbearkey -t rsa -f /etc/dropbear/dropbear_rsa_host_key
+
+extract a public key suitable for authorized_keys from private key:
+ # dropbearkey -y -f id_rsa | grep "^ssh-rsa " >> authorized_keys
+.SH AUTHOR
+Matt Johnston (matt@ucc.asn.au).
+.br
+Gerrit Pape (pape@smarden.org) wrote this manual page.
+.SH SEE ALSO
+dropbear(8), dbclient(1), dropbearconvert(1)
+.P
+https://matt.ucc.asn.au/dropbear/dropbear.html

dropbearkey.8

@@ -1,50 +0,0 @@
-.TH dropbearkey 8
-.SH NAME
-dropbearkey \- create private keys for the use with dropbear(8)
-.SH SYNOPSIS
-.B dropbearkey
-\-t
-.I type
-\-f
-.I file
-[\-s
-.IR bits ]
-.SH DESCRIPTION
-.B dropbearkey
-generates a
-.I RSA
-or
-.I DSS
-format SSH private key, and saves it to a file for the use with the
-.BR dropbear (8)
-SSH 2 server.
-Note that 
-some SSH implementations
-use the term "DSA" rather than "DSS", they mean the same thing.
-.SH OPTIONS
-.TP
-.B \-t \fItype
-Type of key to generate.
-Must be one of
-.I rsa
-or
-.IR dss .
-.TP
-.B \-f \fIfile
-Write the secret key to the file
-.IR file .
-.TP
-.B \-s \fIbits
-Set the key size to
-.I bits
-bits, should be multiple of 8 (optional).
-.SH EXAMPLE
- # dropbearkey -t rsa -f /etc/dropbear/dropbear_rsa_host_key
-.SH AUTHOR
-Matt Johnston (matt@ucc.asn.au).
-.br
-Gerrit Pape (pape@smarden.org) wrote this manual page.
-.SH SEE ALSO
-dropbear(8), dbclient(1)
-.P
-http://matt.ucc.asn.au/dropbear/dropbear.html

dropbearkey.c

@@ -43,6 +43,10 @@
  * mp_int	y
  * mp_int	x
  *
+ * Ed25519:
+ * string	"ssh-ed25519"
+ * string	k (32 bytes) + A (32 bytes)
+ *
  */
 #include "includes.h"
 #include "signkey.h"
@@ -51,57 +55,115 @@
 
 #include "genrsa.h"
 #include "gendss.h"
+#include "gened25519.h"
+#include "ecdsa.h"
+#include "crypto_desc.h"
+#include "dbrandom.h"
+#include "gensignkey.h"
 
 static void printhelp(char * progname);
 
-#define RSA_SIZE (1024/8) /* 1024 bit */
-#define DSS_SIZE (1024/8) /* 1024 bit */
 
-static void buf_writefile(buffer * buf, const char * filename);
 static void printpubkey(sign_key * key, int keytype);
-static void justprintpub(const char* filename);
+static int printpubfile(const char* filename);
 
 /* Print a help message */
 static void printhelp(char * progname) {
 
 	fprintf(stderr, "Usage: %s -t <type> -f <filename> [-s bits]\n"
-					"Options are:\n"
 					"-t type	Type of key to generate. One of:\n"
-#ifdef DROPBEAR_RSA
+#if DROPBEAR_RSA
 					"		rsa\n"
 #endif
-#ifdef DROPBEAR_DSS
+#if DROPBEAR_DSS
 					"		dss\n"
 #endif
-					"-f filename	Use filename for the secret key\n"
+#if DROPBEAR_ECDSA
+					"		ecdsa\n"
+#endif
+#if DROPBEAR_ED25519
+					"		ed25519\n"
+#endif
+					"-f filename    Use filename for the secret key.\n"
+					"               ~/.ssh/id_dropbear is recommended for client keys.\n"
 					"-s bits	Key size in bits, should be a multiple of 8 (optional)\n"
-					"           (DSS has a fixed size of 1024 bits)\n"
+#if DROPBEAR_DSS
+					"           DSS has a fixed size of 1024 bits\n"
+#endif
+#if DROPBEAR_ECDSA
+					"           ECDSA has sizes "
+#if DROPBEAR_ECC_256
+					"256 "
+#endif
+#if DROPBEAR_ECC_384
+					"384 "
+#endif
+#if DROPBEAR_ECC_521
+					"521 "
+#endif
+					"\n"
+#endif
+#if DROPBEAR_ED25519
+					"           Ed25519 has a fixed size of 256 bits\n"
+#endif
 					"-y		Just print the publickey and fingerprint for the\n		private key in <filename>.\n"
-#ifdef DEBUG_TRACE
+#if DEBUG_TRACE
 					"-v		verbose\n"
 #endif
 					,progname);
 }
 
-#if defined(DBMULTI_dropbearkey) || !defined(DROPBEAR_MULTI)
-#if defined(DBMULTI_dropbearkey) && defined(DROPBEAR_MULTI)
+/* fails fatally */
+static void check_signkey_bits(enum signkey_type type, int bits)
+{
+	switch (type) {
+#if DROPBEAR_ED25519
+		case DROPBEAR_SIGNKEY_ED25519:
+			if (bits != 256) {
+				dropbear_exit("Ed25519 keys have a fixed size of 256 bits\n");
+				exit(EXIT_FAILURE);
+			}
+			break;
+#endif
+#if DROPBEAR_RSA
+		case DROPBEAR_SIGNKEY_RSA:
+			if (bits < 512 || bits > 4096 || (bits % 8 != 0)) {
+				dropbear_exit("Bits must satisfy 512 <= bits <= 4096, and be a"
+				              " multiple of 8\n");
+			}
+			break;
+#endif
+#if DROPEAR_DSS
+		case DROPBEAR_SIGNKEY_DSS:
+			if (bits != 1024) {
+				dropbear_exit("DSS keys have a fixed size of 1024 bits\n");
+				exit(EXIT_FAILURE);
+			}
+#endif
+		default:
+			(void)0; /* quiet, compiler. ecdsa handles checks itself */
+	}
+}
+
+#if defined(DBMULTI_dropbearkey) || !DROPBEAR_MULTI
+#if defined(DBMULTI_dropbearkey) && DROPBEAR_MULTI
 int dropbearkey_main(int argc, char ** argv) {
 #else
 int main(int argc, char ** argv) {
 #endif
 
 	int i;
-	char ** next = 0;
-	sign_key *key = NULL;
-	buffer *buf = NULL;
+	char ** next = NULL;
 	char * filename = NULL;
-	int keytype = -1;
+	enum signkey_type keytype = DROPBEAR_SIGNKEY_NONE;
 	char * typetext = NULL;
 	char * sizetext = NULL;
-	unsigned int bits;
-	unsigned int keysize;
+	unsigned int bits = 0, genbits;
 	int printpub = 0;
 
+	crypto_init();
+	seedrandom();
+
 	/* get the commandline options */
 	for (i = 1; i < argc; i++) {
 		if (argv[i] == NULL) {
@@ -131,7 +193,7 @@ int main(int argc, char ** argv) {
 					printhelp(argv[0]);
 					exit(EXIT_SUCCESS);
 					break;
-#ifdef DEBUG_TRACE
+#if DEBUG_TRACE
 				case 'v':
 					debug_trace = 1;
 					break;
@@ -152,8 +214,8 @@ int main(int argc, char ** argv) {
 	}
 
 	if (printpub) {
-		justprintpub(filename);
-		/* Not reached */
+		int ret = printpubfile(filename);
+		exit(ret);
 	}
 
 	/* check/parse args */
@@ -163,21 +225,32 @@ int main(int argc, char ** argv) {
 		exit(EXIT_FAILURE);
 	}
 
-	if (strlen(typetext) == 3) {
-#ifdef DROPBEAR_RSA
-		if (strncmp(typetext, "rsa", 3) == 0) {
-			keytype = DROPBEAR_SIGNKEY_RSA;
-			TRACE(("type is rsa"))
-		}
-#endif
-#ifdef DROPBEAR_DSS
-		if (strncmp(typetext, "dss", 3) == 0) {
-			keytype = DROPBEAR_SIGNKEY_DSS;
-			TRACE(("type is dss"))
-		}
-#endif
+#if DROPBEAR_RSA
+	if (strcmp(typetext, "rsa") == 0)
+	{
+		keytype = DROPBEAR_SIGNKEY_RSA;
 	}
-	if (keytype == -1) {
+#endif
+#if DROPBEAR_DSS
+	if (strcmp(typetext, "dss") == 0)
+	{
+		keytype = DROPBEAR_SIGNKEY_DSS;
+	}
+#endif
+#if DROPBEAR_ECDSA
+	if (strcmp(typetext, "ecdsa") == 0)
+	{
+		keytype = DROPBEAR_SIGNKEY_ECDSA_KEYGEN;
+	}
+#endif
+#if DROPBEAR_ED25519
+	if (strcmp(typetext, "ed25519") == 0)
+	{
+		keytype = DROPBEAR_SIGNKEY_ED25519;
+	}
+#endif
+
+	if (keytype == DROPBEAR_SIGNKEY_NONE) {
 		fprintf(stderr, "Unknown key type '%s'\n", typetext);
 		printhelp(argv[0]);
 		exit(EXIT_FAILURE);
@@ -189,75 +262,27 @@ int main(int argc, char ** argv) {
 			exit(EXIT_FAILURE);
 		}
 		
-		if (keytype == DROPBEAR_SIGNKEY_DSS && bits != 1024) {
-			fprintf(stderr, "DSS keys have a fixed size of 1024 bits\n");
-			exit(EXIT_FAILURE);			
-		} else if (bits < 512 || bits > 4096 || (bits % 8 != 0)) {
-			fprintf(stderr, "Bits must satisfy 512 <= bits <= 4096, and be a"
-					" multiple of 8\n");
-			exit(EXIT_FAILURE);
-		}
-
-		keysize = bits / 8;
-	} else {
-		if (keytype == DROPBEAR_SIGNKEY_DSS) {
-			keysize = DSS_SIZE;
-		} else if (keytype == DROPBEAR_SIGNKEY_RSA) {
-			keysize = RSA_SIZE;
-		} else {
-			exit(EXIT_FAILURE); /* not reached */
-		}
+		check_signkey_bits(keytype, bits);;
 	}
 
-
-	fprintf(stderr, "Will output %d bit %s secret key to '%s'\n", keysize*8,
-			typetext, filename);
-
-	/* don't want the file readable by others */
-	umask(077);
-
-	/* now we can generate the key */
-	key = new_sign_key();
-	
-	fprintf(stderr, "Generating key, this may take a while...\n");
-	switch(keytype) {
-#ifdef DROPBEAR_RSA
-		case DROPBEAR_SIGNKEY_RSA:
-			key->rsakey = gen_rsa_priv_key(keysize); /* 128 bytes = 1024 bit */
-			break;
-#endif
-#ifdef DROPBEAR_DSS
-		case DROPBEAR_SIGNKEY_DSS:
-			key->dsskey = gen_dss_priv_key(keysize); /* 128 bytes = 1024 bit */
-			break;
-#endif
-		default:
-			fprintf(stderr, "Internal error, bad key type\n");
-			exit(EXIT_FAILURE);
+	genbits = signkey_generate_get_bits(keytype, bits);
+	fprintf(stderr, "Generating %u bit %s key, this may take a while...\n", genbits, typetext);
+	if (signkey_generate(keytype, bits, filename, 0) == DROPBEAR_FAILURE)
+	{
+		dropbear_exit("Failed to generate key.\n");
 	}
 
-	buf = buf_new(MAX_PRIVKEY_SIZE); 
-
-	buf_put_priv_key(buf, key, keytype);
-	buf_setpos(buf, 0);
-	buf_writefile(buf, filename);
-
-	buf_burn(buf);
-	buf_free(buf);
-
-	printpubkey(key, keytype);
-
-	sign_key_free(key);
+	printpubfile(filename);
 
 	return EXIT_SUCCESS;
 }
 #endif
 
-static void justprintpub(const char* filename) {
+static int printpubfile(const char* filename) {
 
 	buffer *buf = NULL;
 	sign_key *key = NULL;
-	int keytype;
+	enum signkey_type keytype;
 	int ret;
 	int err = DROPBEAR_FAILURE;
 
@@ -291,7 +316,7 @@ out:
 		sign_key_free(key);
 		key = NULL;
 	}
-	exit(err);
+	return err;
 }
 
 static void printpubkey(sign_key * key, int keytype) {
@@ -320,7 +345,7 @@ static void printpubkey(sign_key * key, int keytype) {
 		fprintf(stderr, "base64 failed");
 	}
 
-	typestring = signkey_name_from_type(keytype, &err);
+	typestring = signkey_name_from_type(keytype, NULL);
 
 	fp = sign_key_fingerprint(buf_getptr(buf, len), len);
 
@@ -340,35 +365,3 @@ static void printpubkey(sign_key * key, int keytype) {
 	m_free(fp);
 	buf_free(buf);
 }
-
-/* Write a buffer to a file specified, failing if the file exists */
-static void buf_writefile(buffer * buf, const char * filename) {
-
-	int fd;
-	int len;
-
-	fd = open(filename, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
-	if (fd < 0) {
-		fprintf(stderr, "Couldn't create new file %s\n", filename);
-		perror("Reason");
-		buf_burn(buf);
-		exit(EXIT_FAILURE);
-	}
-
-	/* write the file now */
-	while (buf->pos != buf->len) {
-		len = write(fd, buf_getptr(buf, buf->len - buf->pos),
-				buf->len - buf->pos);
-		if (errno == EINTR) {
-			continue;
-		}
-		if (len <= 0) {
-			fprintf(stderr, "Failed writing file '%s'\n",filename);
-			perror("Reason");
-			exit(EXIT_FAILURE);
-		}
-		buf_incrpos(buf, len);
-	}
-
-	close(fd);
-}

dss.c

@@ -28,7 +28,7 @@
 #include "dss.h"
 #include "buffer.h"
 #include "ssh.h"
-#include "random.h"
+#include "dbrandom.h"
 
 /* Handle DSS (Digital Signature Standard), aka DSA (D.S. Algorithm),
  * operations, such as key reading, signing, verification. Key generation
@@ -37,21 +37,18 @@
  * See FIPS186 or the Handbook of Applied Cryptography for details of the
  * algorithm */
 
-#ifdef DROPBEAR_DSS 
+#if DROPBEAR_DSS 
 
 /* Load a dss key from a buffer, initialising the values.
  * The key will have the same format as buf_put_dss_key.
  * These should be freed with dss_key_free.
  * Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
 int buf_get_dss_pub_key(buffer* buf, dropbear_dss_key *key) {
+	int ret = DROPBEAR_FAILURE;
 
 	TRACE(("enter buf_get_dss_pub_key"))
 	dropbear_assert(key != NULL);
-	key->p = m_malloc(sizeof(mp_int));
-	key->q = m_malloc(sizeof(mp_int));
-	key->g = m_malloc(sizeof(mp_int));
-	key->y = m_malloc(sizeof(mp_int));
-	m_mp_init_multi(key->p, key->q, key->g, key->y, NULL);
+	m_mp_alloc_init_multi(&key->p, &key->q, &key->g, &key->y, NULL);
 	key->x = NULL;
 
 	buf_incrpos(buf, 4+SSH_SIGNKEY_DSS_LEN); /* int + "ssh-dss" */
@@ -60,17 +57,41 @@ int buf_get_dss_pub_key(buffer* buf, dropbear_dss_key *key) {
 	 || buf_getmpint(buf, key->g) == DROPBEAR_FAILURE
 	 || buf_getmpint(buf, key->y) == DROPBEAR_FAILURE) {
 		TRACE(("leave buf_get_dss_pub_key: failed reading mpints"))
-		return DROPBEAR_FAILURE;
+		ret = DROPBEAR_FAILURE;
+		goto out;
 	}
 
-	if (mp_count_bits(key->p) < MIN_DSS_KEYLEN) {
-		dropbear_log(LOG_WARNING, "DSS key too short");
-		TRACE(("leave buf_get_dss_pub_key: short key"))
-		return DROPBEAR_FAILURE;
+	if (mp_count_bits(key->p) != DSS_P_BITS) {
+		dropbear_log(LOG_WARNING, "Bad DSS p");
+		ret = DROPBEAR_FAILURE;
+		goto out;
 	}
 
+	if (mp_count_bits(key->q) != DSS_Q_BITS) {
+		dropbear_log(LOG_WARNING, "Bad DSS q");
+		ret = DROPBEAR_FAILURE;
+		goto out;
+	}
+
+	/* test 1 < g < p */
+	if (mp_cmp_d(key->g, 1) != MP_GT) {
+		dropbear_log(LOG_WARNING, "Bad DSS g");
+		ret = DROPBEAR_FAILURE;
+		goto out;
+	}
+	if (mp_cmp(key->g, key->p) != MP_LT) {
+		dropbear_log(LOG_WARNING, "Bad DSS g");
+		ret = DROPBEAR_FAILURE;
+		goto out;
+	}
+
+	ret = DROPBEAR_SUCCESS;
 	TRACE(("leave buf_get_dss_pub_key: success"))
-	return DROPBEAR_SUCCESS;
+out:
+	if (ret == DROPBEAR_FAILURE) {
+		m_mp_free_multi(&key->p, &key->q, &key->g, &key->y, NULL);
+	}
+	return ret;
 }
 
 /* Same as buf_get_dss_pub_key, but reads a private "x" key at the end.
@@ -87,11 +108,10 @@ int buf_get_dss_priv_key(buffer* buf, dropbear_dss_key *key) {
 		return DROPBEAR_FAILURE;
 	}
 
-	key->x = m_malloc(sizeof(mp_int));
-	m_mp_init(key->x);
+	m_mp_alloc_init_multi(&key->x, NULL);
 	ret = buf_getmpint(buf, key->x);
 	if (ret == DROPBEAR_FAILURE) {
-		m_free(key->x);
+		m_mp_free_multi(&key->x, NULL);
 	}
 
 	return ret;
@@ -101,33 +121,14 @@ int buf_get_dss_priv_key(buffer* buf, dropbear_dss_key *key) {
 /* Clear and free the memory used by a public or private key */
 void dss_key_free(dropbear_dss_key *key) {
 
-	TRACE(("enter dsa_key_free"))
+	TRACE2(("enter dsa_key_free"))
 	if (key == NULL) {
-		TRACE(("enter dsa_key_free: key == NULL"))
+		TRACE2(("enter dsa_key_free: key == NULL"))
 		return;
 	}
-	if (key->p) {
-		mp_clear(key->p);
-		m_free(key->p);
-	}
-	if (key->q) {
-		mp_clear(key->q);
-		m_free(key->q);
-	}
-	if (key->g) {
-		mp_clear(key->g);
-		m_free(key->g);
-	}
-	if (key->y) {
-		mp_clear(key->y);
-		m_free(key->y);
-	}
-	if (key->x) {
-		mp_clear(key->x);
-		m_free(key->x);
-	}
+	m_mp_free_multi(&key->p, &key->q, &key->g, &key->y, &key->x, NULL);
 	m_free(key);
-	TRACE(("leave dsa_key_free"))
+	TRACE2(("leave dsa_key_free"))
 }
 
 /* put the dss public key into the buffer in the required format:
@@ -138,7 +139,7 @@ void dss_key_free(dropbear_dss_key *key) {
  * mpint	g
  * mpint	y
  */
-void buf_put_dss_pub_key(buffer* buf, dropbear_dss_key *key) {
+void buf_put_dss_pub_key(buffer* buf, const dropbear_dss_key *key) {
 
 	dropbear_assert(key != NULL);
 	buf_putstring(buf, SSH_SIGNKEY_DSS, SSH_SIGNKEY_DSS_LEN);
@@ -150,7 +151,7 @@ void buf_put_dss_pub_key(buffer* buf, dropbear_dss_key *key) {
 }
 
 /* Same as buf_put_dss_pub_key, but with the private "x" key appended */
-void buf_put_dss_priv_key(buffer* buf, dropbear_dss_key *key) {
+void buf_put_dss_priv_key(buffer* buf, const dropbear_dss_key *key) {
 
 	dropbear_assert(key != NULL);
 	buf_put_dss_pub_key(buf, key);
@@ -158,12 +159,10 @@ void buf_put_dss_priv_key(buffer* buf, dropbear_dss_key *key) {
 
 }
 
-#ifdef DROPBEAR_SIGNKEY_VERIFY
+#if DROPBEAR_SIGNKEY_VERIFY
 /* Verify a DSS signature (in buf) made on data by the key given. 
  * returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
-int buf_dss_verify(buffer* buf, dropbear_dss_key *key, const unsigned char* data,
-		unsigned int len) {
-
+int buf_dss_verify(buffer* buf, const dropbear_dss_key *key, const buffer *data_buf) {
 	unsigned char msghash[SHA1_HASH_SIZE];
 	hash_state hs;
 	int ret = DROPBEAR_FAILURE;
@@ -172,7 +171,7 @@ int buf_dss_verify(buffer* buf, dropbear_dss_key *key, const unsigned char* data
 	DEF_MP_INT(val3);
 	DEF_MP_INT(val4);
 	char * string = NULL;
-	int stringlen;
+	unsigned int stringlen;
 
 	TRACE(("enter buf_dss_verify"))
 	dropbear_assert(key != NULL);
@@ -185,20 +184,34 @@ int buf_dss_verify(buffer* buf, dropbear_dss_key *key, const unsigned char* data
 		goto out;
 	}
 
+#if DEBUG_DSS_VERIFY
+	printmpint("dss verify p", key->p);
+	printmpint("dss verify q", key->q);
+	printmpint("dss verify g", key->g);
+	printmpint("dss verify y", key->y);
+#endif
+
 	/* hash the data */
 	sha1_init(&hs);
-	sha1_process(&hs, data, len);
+	sha1_process(&hs, data_buf->data, data_buf->len);
 	sha1_done(&hs, msghash);
 
 	/* create the signature - s' and r' are the received signatures in buf */
 	/* w = (s')-1 mod q */
 	/* let val1 = s' */
-	bytes_to_mp(&val1, &string[SHA1_HASH_SIZE], SHA1_HASH_SIZE);
+	bytes_to_mp(&val1, (const unsigned char*) &string[SHA1_HASH_SIZE], SHA1_HASH_SIZE);
+#if DEBUG_DSS_VERIFY
+	printmpint("dss verify s'", &val1);
+#endif
 
 	if (mp_cmp(&val1, key->q) != MP_LT) {
 		TRACE(("verify failed, s' >= q"))
 		goto out;
 	}
+	if (mp_cmp_d(&val1, 0) != MP_GT) {
+		TRACE(("verify failed, s' <= 0"))
+		goto out;
+	}
 	/* let val2 = w = (s')^-1 mod q*/
 	if (mp_invmod(&val1, key->q, &val2) != MP_OKAY) {
 		goto out;
@@ -207,6 +220,9 @@ int buf_dss_verify(buffer* buf, dropbear_dss_key *key, const unsigned char* data
 	/* u1 = ((SHA(M')w) mod q */
 	/* let val1 = SHA(M') = msghash */
 	bytes_to_mp(&val1, msghash, SHA1_HASH_SIZE);
+#if DEBUG_DSS_VERIFY
+	printmpint("dss verify r'", &val1);
+#endif
 
 	/* let val3 = u1 = ((SHA(M')w) mod q */
 	if (mp_mulmod(&val1, &val2, key->q, &val3) != MP_OKAY) {
@@ -215,11 +231,15 @@ int buf_dss_verify(buffer* buf, dropbear_dss_key *key, const unsigned char* data
 
 	/* u2 = ((r')w) mod q */
 	/* let val1 = r' */
-	bytes_to_mp(&val1, &string[0], SHA1_HASH_SIZE);
+	bytes_to_mp(&val1, (const unsigned char*) &string[0], SHA1_HASH_SIZE);
 	if (mp_cmp(&val1, key->q) != MP_LT) {
 		TRACE(("verify failed, r' >= q"))
 		goto out;
 	}
+	if (mp_cmp_d(&val1, 0) != MP_GT) {
+		TRACE(("verify failed, r' <= 0"))
+		goto out;
+	}
 	/* let val4 = u2 = ((r')w) mod q */
 	if (mp_mulmod(&val1, &val2, key->q, &val4) != MP_OKAY) {
 		goto out;
@@ -258,52 +278,13 @@ out:
 }
 #endif /* DROPBEAR_SIGNKEY_VERIFY */
 
-#ifdef DSS_PROTOK	
-/* convert an unsigned mp into an array of bytes, malloced.
- * This array must be freed after use, len contains the length of the array,
- * if len != NULL */
-static unsigned char* mptobytes(mp_int *mp, int *len) {
-	
-	unsigned char* ret;
-	int size;
-
-	size = mp_unsigned_bin_size(mp);
-	ret = m_malloc(size);
-	if (mp_to_unsigned_bin(mp, ret) != MP_OKAY) {
-		dropbear_exit("Mem alloc error");
-	}
-	if (len != NULL) {
-		*len = size;
-	}
-	return ret;
-}
-#endif
-
 /* Sign the data presented with key, writing the signature contents
- * to the buffer
- *
- * When DSS_PROTOK is #defined:
- * The alternate k generation method is based on the method used in PuTTY. 
- * In particular to avoid being vulnerable to attacks using flaws in random
- * generation of k, we use the following:
- *
- * proto_k = SHA512 ( SHA512(x) || SHA160(message) )
- * k = proto_k mod q
- *
- * Now we aren't relying on the random number generation to protect the private
- * key x, which is a long term secret */
-void buf_put_dss_sign(buffer* buf, dropbear_dss_key *key, const unsigned char* data,
-		unsigned int len) {
-
+ * to the buffer */
+void buf_put_dss_sign(buffer* buf, const dropbear_dss_key *key, const buffer *data_buf) {
 	unsigned char msghash[SHA1_HASH_SIZE];
 	unsigned int writelen;
 	unsigned int i;
-#ifdef DSS_PROTOK
-	unsigned char privkeyhash[SHA512_HASH_SIZE];
-	unsigned char *privkeytmp;
-	unsigned char proto_k[SHA512_HASH_SIZE];
-	DEF_MP_INT(dss_protok);
-#endif
+	size_t written;
 	DEF_MP_INT(dss_k);
 	DEF_MP_INT(dss_m);
 	DEF_MP_INT(dss_temp1);
@@ -317,38 +298,14 @@ void buf_put_dss_sign(buffer* buf, dropbear_dss_key *key, const unsigned char* d
 	
 	/* hash the data */
 	sha1_init(&hs);
-	sha1_process(&hs, data, len);
+	sha1_process(&hs, data_buf->data, data_buf->len);
 	sha1_done(&hs, msghash);
 
 	m_mp_init_multi(&dss_k, &dss_temp1, &dss_temp2, &dss_r, &dss_s,
 			&dss_m, NULL);
-#ifdef DSS_PROTOK	
-	/* hash the privkey */
-	privkeytmp = mptobytes(key->x, &i);
-	sha512_init(&hs);
-	sha512_process(&hs, "the quick brown fox jumped over the lazy dog", 44);
-	sha512_process(&hs, privkeytmp, i);
-	sha512_done(&hs, privkeyhash);
-	m_burn(privkeytmp, i);
-	m_free(privkeytmp);
-
-	/* calculate proto_k */
-	sha512_init(&hs);
-	sha512_process(&hs, privkeyhash, SHA512_HASH_SIZE);
-	sha512_process(&hs, msghash, SHA1_HASH_SIZE);
-	sha512_done(&hs, proto_k);
-
-	/* generate k */
-	m_mp_init(&dss_protok);
-	bytes_to_mp(&dss_protok, proto_k, SHA512_HASH_SIZE);
-	if (mp_mod(&dss_protok, key->q, &dss_k) != MP_OKAY) {
-		dropbear_exit("DSS error");
-	}
-	mp_clear(&dss_protok);
-	m_burn(proto_k, SHA512_HASH_SIZE);
-#else /* DSS_PROTOK not defined*/
+	/* the random number generator's input has included the private key which
+	 * avoids DSS's problem of private key exposure due to low entropy */
 	gen_random_mpint(key->q, &dss_k);
-#endif
 
 	/* now generate the actual signature */
 	bytes_to_mp(&dss_m, msghash, SHA1_HASH_SIZE);
@@ -384,31 +341,31 @@ void buf_put_dss_sign(buffer* buf, dropbear_dss_key *key, const unsigned char* d
 	buf_putstring(buf, SSH_SIGNKEY_DSS, SSH_SIGNKEY_DSS_LEN);
 	buf_putint(buf, 2*SHA1_HASH_SIZE);
 
-	writelen = mp_unsigned_bin_size(&dss_r);
+	writelen = mp_ubin_size(&dss_r);
 	dropbear_assert(writelen <= SHA1_HASH_SIZE);
 	/* need to pad to 160 bits with leading zeros */
 	for (i = 0; i < SHA1_HASH_SIZE - writelen; i++) {
 		buf_putbyte(buf, 0);
 	}
-	if (mp_to_unsigned_bin(&dss_r, buf_getwriteptr(buf, writelen)) 
+	if (mp_to_ubin(&dss_r, buf_getwriteptr(buf, writelen), writelen, &written)
 			!= MP_OKAY) {
 		dropbear_exit("DSS error");
 	}
 	mp_clear(&dss_r);
-	buf_incrwritepos(buf, writelen);
+	buf_incrwritepos(buf, written);
 
-	writelen = mp_unsigned_bin_size(&dss_s);
+	writelen = mp_ubin_size(&dss_s);
 	dropbear_assert(writelen <= SHA1_HASH_SIZE);
 	/* need to pad to 160 bits with leading zeros */
 	for (i = 0; i < SHA1_HASH_SIZE - writelen; i++) {
 		buf_putbyte(buf, 0);
 	}
-	if (mp_to_unsigned_bin(&dss_s, buf_getwriteptr(buf, writelen)) 
+	if (mp_to_ubin(&dss_s, buf_getwriteptr(buf, writelen), writelen, &written)
 			!= MP_OKAY) {
 		dropbear_exit("DSS error");
 	}
 	mp_clear(&dss_s);
-	buf_incrwritepos(buf, writelen);
+	buf_incrwritepos(buf, written);
 
 	mp_clear_multi(&dss_k, &dss_temp1, &dss_temp2, &dss_r, &dss_s,
 			&dss_m, NULL);

dss.h

@@ -22,17 +22,15 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
-#ifndef _DSS_H_
-#define _DSS_H_
+#ifndef DROPBEAR_DSS_H_
+#define DROPBEAR_DSS_H_
 
 #include "includes.h"
 #include "buffer.h"
 
-#ifdef DROPBEAR_DSS 
+#if DROPBEAR_DSS 
 
-#define DSS_SIGNATURE_SIZE 4+SSH_SIGNKEY_DSS_LEN+4+2*SHA1_HASH_SIZE
-
-typedef struct {
+typedef struct dropbear_DSS_Key {
 
 	mp_int* p;
 	mp_int* q;
@@ -43,18 +41,19 @@ typedef struct {
 
 } dropbear_dss_key;
 
-void buf_put_dss_sign(buffer* buf, dropbear_dss_key *key, const unsigned char* data,
-		unsigned int len);
-#ifdef DROPBEAR_SIGNKEY_VERIFY
-int buf_dss_verify(buffer* buf, dropbear_dss_key *key, const unsigned char* data,
-		unsigned int len);
+#define DSS_P_BITS 1024
+#define DSS_Q_BITS 160
+
+void buf_put_dss_sign(buffer* buf, const dropbear_dss_key *key, const buffer *data_buf);
+#if DROPBEAR_SIGNKEY_VERIFY
+int buf_dss_verify(buffer* buf, const dropbear_dss_key *key, const buffer *data_buf);
 #endif
 int buf_get_dss_pub_key(buffer* buf, dropbear_dss_key *key);
 int buf_get_dss_priv_key(buffer* buf, dropbear_dss_key *key);
-void buf_put_dss_pub_key(buffer* buf, dropbear_dss_key *key);
-void buf_put_dss_priv_key(buffer* buf, dropbear_dss_key *key);
+void buf_put_dss_pub_key(buffer* buf, const dropbear_dss_key *key);
+void buf_put_dss_priv_key(buffer* buf, const dropbear_dss_key *key);
 void dss_key_free(dropbear_dss_key *key);
 
 #endif /* DROPBEAR_DSS */
 
-#endif /* _DSS_H_ */
+#endif /* DROPBEAR_DSS_H_ */

ecc.c

@@ -0,0 +1,264 @@
+#include "includes.h"
+#include "ecc.h"
+#include "dbutil.h"
+#include "bignum.h"
+
+#if DROPBEAR_ECC
+
+/* .dp members are filled out by dropbear_ecc_fill_dp() at startup */
+#if DROPBEAR_ECC_256
+struct dropbear_ecc_curve ecc_curve_nistp256 = {
+	32,		/* .ltc_size	*/
+	NULL,		/* .dp		*/
+	&sha256_desc,	/* .hash_desc	*/
+	"nistp256"	/* .name	*/
+};
+#endif
+#if DROPBEAR_ECC_384
+struct dropbear_ecc_curve ecc_curve_nistp384 = {
+	48,		/* .ltc_size	*/
+	NULL,		/* .dp		*/
+	&sha384_desc,	/* .hash_desc	*/
+	"nistp384"	/* .name	*/
+};
+#endif
+#if DROPBEAR_ECC_521
+struct dropbear_ecc_curve ecc_curve_nistp521 = {
+	66,		/* .ltc_size	*/
+	NULL,		/* .dp		*/
+	&sha512_desc,	/* .hash_desc	*/
+	"nistp521"	/* .name	*/
+};
+#endif
+
+struct dropbear_ecc_curve *dropbear_ecc_curves[] = {
+#if DROPBEAR_ECC_256
+	&ecc_curve_nistp256,
+#endif
+#if DROPBEAR_ECC_384
+	&ecc_curve_nistp384,
+#endif
+#if DROPBEAR_ECC_521
+	&ecc_curve_nistp521,
+#endif
+	NULL
+};
+
+void dropbear_ecc_fill_dp() {
+	struct dropbear_ecc_curve **curve;
+	/* libtomcrypt guarantees they're ordered by size */
+	const ltc_ecc_set_type *dp = ltc_ecc_sets;
+	for (curve = dropbear_ecc_curves; *curve; curve++) {
+		for (;dp->size > 0; dp++) {
+			if (dp->size == (*curve)->ltc_size) {
+				(*curve)->dp = dp;
+				break;
+			}
+		}
+		if (!(*curve)->dp) {
+			dropbear_exit("Missing ECC params %s", (*curve)->name);
+		}
+	}
+}
+
+struct dropbear_ecc_curve* curve_for_dp(const ltc_ecc_set_type *dp) {
+	struct dropbear_ecc_curve **curve = NULL;
+	for (curve = dropbear_ecc_curves; *curve; curve++) {
+		if ((*curve)->dp == dp) {
+			break;
+		}
+	}
+	assert(*curve);
+	return *curve;
+}
+
+ecc_key * new_ecc_key(void) {
+	ecc_key *key = m_malloc(sizeof(*key));
+	m_mp_alloc_init_multi((mp_int**)&key->pubkey.x, (mp_int**)&key->pubkey.y, 
+		(mp_int**)&key->pubkey.z, (mp_int**)&key->k, NULL);
+	return key;
+}
+
+/* Copied from libtomcrypt ecc_import.c (version there is static), modified
+   for different mp_int pointer without LTC_SOURCE */
+static int ecc_is_point(const ecc_key *key)
+{
+	mp_int *prime, *b, *t1, *t2;
+	int err;
+	
+	m_mp_alloc_init_multi(&prime, &b, &t1, &t2, NULL);
+	
+   /* load prime and b */
+	if ((err = mp_read_radix(prime, key->dp->prime, 16)) != CRYPT_OK)                          { goto error; }
+	if ((err = mp_read_radix(b, key->dp->B, 16)) != CRYPT_OK)                                  { goto error; }
+	
+   /* compute y^2 */
+	if ((err = mp_sqr(key->pubkey.y, t1)) != CRYPT_OK)                                         { goto error; }
+	
+   /* compute x^3 */
+	if ((err = mp_sqr(key->pubkey.x, t2)) != CRYPT_OK)                                         { goto error; }
+	if ((err = mp_mod(t2, prime, t2)) != CRYPT_OK)                                             { goto error; }
+	if ((err = mp_mul(key->pubkey.x, t2, t2)) != CRYPT_OK)                                     { goto error; }
+	
+   /* compute y^2 - x^3 */
+	if ((err = mp_sub(t1, t2, t1)) != CRYPT_OK)                                                { goto error; }
+	
+   /* compute y^2 - x^3 + 3x */
+	if ((err = mp_add(t1, key->pubkey.x, t1)) != CRYPT_OK)                                     { goto error; }
+	if ((err = mp_add(t1, key->pubkey.x, t1)) != CRYPT_OK)                                     { goto error; }
+	if ((err = mp_add(t1, key->pubkey.x, t1)) != CRYPT_OK)                                     { goto error; }
+	if ((err = mp_mod(t1, prime, t1)) != CRYPT_OK)                                             { goto error; }
+	while (mp_cmp_d(t1, 0) == LTC_MP_LT) {
+		if ((err = mp_add(t1, prime, t1)) != CRYPT_OK)                                          { goto error; }
+	}
+	while (mp_cmp(t1, prime) != LTC_MP_LT) {
+		if ((err = mp_sub(t1, prime, t1)) != CRYPT_OK)                                          { goto error; }
+	}
+	
+   /* compare to b */
+	if (mp_cmp(t1, b) != LTC_MP_EQ) {
+		err = CRYPT_INVALID_PACKET;
+	} else {
+		err = CRYPT_OK;
+	}
+	
+	error:
+	mp_clear_multi(prime, b, t1, t2, NULL);
+	m_free(prime);
+	m_free(b);
+	m_free(t1);
+	m_free(t2);
+	return err;
+}
+
+/* For the "ephemeral public key octet string" in ECDH (rfc5656 section 4) */
+void buf_put_ecc_raw_pubkey_string(buffer *buf, ecc_key *key) {
+	unsigned long len = key->dp->size*2 + 1;
+	int err;
+	buf_putint(buf, len);
+	err = ecc_ansi_x963_export(key, buf_getwriteptr(buf, len), &len);
+	if (err != CRYPT_OK) {
+		dropbear_exit("ECC error");
+	}
+	buf_incrwritepos(buf, len);
+}
+
+/* For the "ephemeral public key octet string" in ECDH (rfc5656 section 4) */
+ecc_key * buf_get_ecc_raw_pubkey(buffer *buf, const struct dropbear_ecc_curve *curve) {
+	ecc_key *key = NULL;
+	int ret = DROPBEAR_FAILURE;
+	const unsigned int size = curve->dp->size;
+	unsigned char first;
+
+	TRACE(("enter buf_get_ecc_raw_pubkey"))
+
+	buf_setpos(buf, 0);
+	first = buf_getbyte(buf);
+	if (first == 2 || first == 3) {
+		dropbear_log(LOG_WARNING, "Dropbear doesn't support ECC point compression");
+		return NULL;
+	}
+	if (first != 4 || buf->len != 1+2*size) {
+		TRACE(("leave, wrong size"))
+		return NULL;
+	}
+
+	key = new_ecc_key();
+	key->dp = curve->dp;
+
+	if (mp_from_ubin(key->pubkey.x, buf_getptr(buf, size), size) != MP_OKAY) {
+		TRACE(("failed to read x"))
+		goto out;
+	}
+	buf_incrpos(buf, size);
+
+	if (mp_from_ubin(key->pubkey.y, buf_getptr(buf, size), size) != MP_OKAY) {
+		TRACE(("failed to read y"))
+		goto out;
+	}
+	buf_incrpos(buf, size);
+
+	mp_set(key->pubkey.z, 1);
+
+	if (ecc_is_point(key) != CRYPT_OK) {
+		TRACE(("failed, not a point"))
+		goto out;
+	}
+
+   /* SEC1 3.2.3.1 Check that Q != 0 */
+	if (mp_cmp_d(key->pubkey.x, 0) == LTC_MP_EQ) {
+		TRACE(("failed, x == 0"))
+		goto out;
+	}
+	if (mp_cmp_d(key->pubkey.y, 0) == LTC_MP_EQ) {
+		TRACE(("failed, y == 0"))
+		goto out;
+	}
+
+	ret = DROPBEAR_SUCCESS;
+
+	out:
+	if (ret == DROPBEAR_FAILURE) {
+		if (key) {
+			ecc_free(key);
+			m_free(key);
+			key = NULL;
+		}
+	}
+
+	return key;
+
+}
+
+/* a modified version of libtomcrypt's "ecc_shared_secret" to output
+   a mp_int instead. */
+mp_int * dropbear_ecc_shared_secret(ecc_key *public_key, const ecc_key *private_key)
+{
+	ecc_point *result = NULL;
+	mp_int *prime = NULL, *shared_secret = NULL;
+	int err = DROPBEAR_FAILURE;
+
+   /* type valid? */
+	if (private_key->type != PK_PRIVATE) {
+		goto out;
+	}
+
+	if (private_key->dp != public_key->dp) {
+		goto out;
+	}
+
+   /* make new point */
+	result = ltc_ecc_new_point();
+	if (result == NULL) {
+		goto out;
+	}
+
+	prime = m_malloc(sizeof(*prime));
+	m_mp_init(prime);
+
+	if (mp_read_radix(prime, (char *)private_key->dp->prime, 16) != CRYPT_OK) { 
+		goto out;
+	}
+	if (ltc_mp.ecc_ptmul(private_key->k, &public_key->pubkey, result, prime, 1) != CRYPT_OK) { 
+		goto out;
+	}
+
+	shared_secret = m_malloc(sizeof(*shared_secret));
+	m_mp_init(shared_secret);
+	if (mp_copy(result->x, shared_secret) != CRYPT_OK) {
+		goto out;
+	}
+
+	mp_clear(prime);
+	m_free(prime);
+	ltc_ecc_del_point(result);
+
+	err = DROPBEAR_SUCCESS;
+	out:
+	if (err == DROPBEAR_FAILURE) {
+		dropbear_exit("ECC error");
+	}
+	return shared_secret;
+}
+
+#endif

ecc.h

@@ -0,0 +1,35 @@
+#ifndef DROPBEAR_DROPBEAR_ECC_H
+#define DROPBEAR_DROPBEAR_ECC_H
+
+#include "includes.h"
+
+#include "buffer.h"
+
+#if DROPBEAR_ECC
+
+struct dropbear_ecc_curve {
+	int ltc_size; /* to match the byte sizes in ltc_ecc_sets[] */
+	const ltc_ecc_set_type *dp; /* curve domain parameters */
+	const struct ltc_hash_descriptor *hash_desc;
+	const char *name;
+};
+
+extern struct dropbear_ecc_curve ecc_curve_nistp256;
+extern struct dropbear_ecc_curve ecc_curve_nistp384;
+extern struct dropbear_ecc_curve ecc_curve_nistp521;
+extern struct dropbear_ecc_curve *dropbear_ecc_curves[];
+
+void dropbear_ecc_fill_dp(void);
+struct dropbear_ecc_curve* curve_for_dp(const ltc_ecc_set_type *dp);
+
+/* "pubkey" refers to a point, but LTC uses ecc_key structure for both public
+   and private keys */
+void buf_put_ecc_raw_pubkey_string(buffer *buf, ecc_key *key);
+ecc_key * buf_get_ecc_raw_pubkey(buffer *buf, const struct dropbear_ecc_curve *curve);
+int buf_get_ecc_privkey_string(buffer *buf, ecc_key *key);
+
+mp_int * dropbear_ecc_shared_secret(ecc_key *pub_key, const ecc_key *priv_key);
+
+#endif
+
+#endif /* DROPBEAR_DROPBEAR_ECC_H */

ecdsa.c

@@ -0,0 +1,420 @@
+#include "includes.h"
+#include "dbutil.h"
+#include "crypto_desc.h"
+#include "ecc.h"
+#include "ecdsa.h"
+#include "signkey.h"
+
+#if DROPBEAR_ECDSA
+
+int signkey_is_ecdsa(enum signkey_type type)
+{
+	return type == DROPBEAR_SIGNKEY_ECDSA_NISTP256
+		|| type == DROPBEAR_SIGNKEY_ECDSA_NISTP384
+		|| type == DROPBEAR_SIGNKEY_ECDSA_NISTP521;
+}
+
+enum signkey_type ecdsa_signkey_type(const ecc_key * key) {
+#if DROPBEAR_ECC_256
+	if (key->dp == ecc_curve_nistp256.dp) {
+		return DROPBEAR_SIGNKEY_ECDSA_NISTP256;
+	}
+#endif
+#if DROPBEAR_ECC_384
+	if (key->dp == ecc_curve_nistp384.dp) {
+		return DROPBEAR_SIGNKEY_ECDSA_NISTP384;
+	}
+#endif
+#if DROPBEAR_ECC_521
+	if (key->dp == ecc_curve_nistp521.dp) {
+		return DROPBEAR_SIGNKEY_ECDSA_NISTP521;
+	}
+#endif
+	return DROPBEAR_SIGNKEY_NONE;
+}
+
+ecc_key *gen_ecdsa_priv_key(unsigned int bit_size) {
+	const ltc_ecc_set_type *dp = NULL; /* curve domain parameters */
+	ecc_key *new_key = NULL;
+	switch (bit_size) {
+#if DROPBEAR_ECC_256
+		case 256:
+			dp = ecc_curve_nistp256.dp;
+			break;
+#endif
+#if DROPBEAR_ECC_384
+		case 384:
+			dp = ecc_curve_nistp384.dp;
+			break;
+#endif
+#if DROPBEAR_ECC_521
+		case 521:
+			dp = ecc_curve_nistp521.dp;
+			break;
+#endif
+	}
+	if (!dp) {
+		dropbear_exit("Key size %d isn't valid. Try "
+#if DROPBEAR_ECC_256
+			"256 "
+#endif
+#if DROPBEAR_ECC_384
+			"384 "
+#endif
+#if DROPBEAR_ECC_521
+			"521 "
+#endif
+			, bit_size);
+	}
+
+	new_key = m_malloc(sizeof(*new_key));
+	if (ecc_make_key_ex(NULL, dropbear_ltc_prng, new_key, dp) != CRYPT_OK) {
+		dropbear_exit("ECC error");
+	}
+	return new_key;
+}
+
+ecc_key *buf_get_ecdsa_pub_key(buffer* buf) {
+	unsigned char *key_ident = NULL, *identifier = NULL;
+	unsigned int key_ident_len, identifier_len;
+	buffer *q_buf = NULL;
+	struct dropbear_ecc_curve **curve;
+	ecc_key *new_key = NULL;
+
+	/* string   "ecdsa-sha2-[identifier]" */
+	key_ident = (unsigned char*)buf_getstring(buf, &key_ident_len);
+	/* string   "[identifier]" */
+	identifier = (unsigned char*)buf_getstring(buf, &identifier_len);
+
+	if (key_ident_len != identifier_len + strlen("ecdsa-sha2-")) {
+		TRACE(("Bad identifier lengths"))
+		goto out;
+	}
+	if (memcmp(&key_ident[strlen("ecdsa-sha2-")], identifier, identifier_len) != 0) {
+		TRACE(("mismatching identifiers"))
+		goto out;
+	}
+
+	for (curve = dropbear_ecc_curves; *curve; curve++) {
+		if (memcmp(identifier, (char*)(*curve)->name, strlen((char*)(*curve)->name)) == 0) {
+			break;
+		}
+	}
+	if (!*curve) {
+		TRACE(("couldn't match ecc curve"))
+		goto out;
+	}
+
+	/* string Q */
+	q_buf = buf_getstringbuf(buf);
+	new_key = buf_get_ecc_raw_pubkey(q_buf, *curve);
+
+out:
+	m_free(key_ident);
+	m_free(identifier);
+	if (q_buf) {
+		buf_free(q_buf);
+		q_buf = NULL;
+	}
+	TRACE(("leave buf_get_ecdsa_pub_key"))	
+	return new_key;
+}
+
+ecc_key *buf_get_ecdsa_priv_key(buffer *buf) {
+	ecc_key *new_key = NULL;
+	TRACE(("enter buf_get_ecdsa_priv_key"))
+	new_key = buf_get_ecdsa_pub_key(buf);
+	if (!new_key) {
+		return NULL;
+	}
+
+	if (buf_getmpint(buf, new_key->k) != DROPBEAR_SUCCESS) {
+		ecc_free(new_key);
+		m_free(new_key);
+		return NULL;
+	}
+
+	return new_key;
+}
+
+void buf_put_ecdsa_pub_key(buffer *buf, ecc_key *key) {
+	struct dropbear_ecc_curve *curve = NULL;
+	char key_ident[30];
+
+	curve = curve_for_dp(key->dp);
+	snprintf(key_ident, sizeof(key_ident), "ecdsa-sha2-%s", curve->name);
+	buf_putstring(buf, key_ident, strlen(key_ident));
+	buf_putstring(buf, curve->name, strlen(curve->name));
+	buf_put_ecc_raw_pubkey_string(buf, key);
+}
+
+void buf_put_ecdsa_priv_key(buffer *buf, ecc_key *key) {
+	buf_put_ecdsa_pub_key(buf, key);
+	buf_putmpint(buf, key->k);
+}
+
+void buf_put_ecdsa_sign(buffer *buf, const ecc_key *key, const buffer *data_buf) {
+	/* Based on libtomcrypt's ecc_sign_hash but without the asn1 */
+	int err = DROPBEAR_FAILURE;
+	struct dropbear_ecc_curve *curve = NULL;
+	hash_state hs;
+	unsigned char hash[64];
+	void *e = NULL, *p = NULL, *s = NULL, *r;
+	char key_ident[30];
+	buffer *sigbuf = NULL;
+
+	TRACE(("buf_put_ecdsa_sign"))
+	curve = curve_for_dp(key->dp);
+
+	if (ltc_init_multi(&r, &s, &p, &e, NULL) != CRYPT_OK) { 
+		goto out;
+	}
+
+	curve->hash_desc->init(&hs);
+	curve->hash_desc->process(&hs, data_buf->data, data_buf->len);
+	curve->hash_desc->done(&hs, hash);
+
+	if (ltc_mp.unsigned_read(e, hash, curve->hash_desc->hashsize) != CRYPT_OK) {
+		goto out;
+	}
+
+	if (ltc_mp.read_radix(p, (char *)key->dp->order, 16) != CRYPT_OK) { 
+		goto out; 
+	}
+
+	for (;;) {
+		ecc_key R_key; /* ephemeral key */
+		if (ecc_make_key_ex(NULL, dropbear_ltc_prng, &R_key, key->dp) != CRYPT_OK) {
+			goto out;
+		}
+		if (ltc_mp.mpdiv(R_key.pubkey.x, p, NULL, r) != CRYPT_OK) {
+			goto out;
+		}
+		if (ltc_mp.compare_d(r, 0) == LTC_MP_EQ) {
+			/* try again */
+			ecc_free(&R_key);
+			continue;
+		}
+		/* k = 1/k */
+		if (ltc_mp.invmod(R_key.k, p, R_key.k) != CRYPT_OK) {
+			goto out;
+		}
+		/* s = xr */
+		if (ltc_mp.mulmod(key->k, r, p, s) != CRYPT_OK) {
+			goto out;
+		}
+		/* s = e +  xr */
+		if (ltc_mp.add(e, s, s) != CRYPT_OK) {
+			goto out;
+		}
+		if (ltc_mp.mpdiv(s, p, NULL, s) != CRYPT_OK) {
+			goto out;
+		}
+		/* s = (e + xr)/k */
+		if (ltc_mp.mulmod(s, R_key.k, p, s) != CRYPT_OK) {
+			goto out;
+		}
+		ecc_free(&R_key);
+
+		if (ltc_mp.compare_d(s, 0) != LTC_MP_EQ) {
+			break;
+		}
+	}
+
+	snprintf(key_ident, sizeof(key_ident), "ecdsa-sha2-%s", curve->name);
+	buf_putstring(buf, key_ident, strlen(key_ident));
+	/* enough for nistp521 */
+	sigbuf = buf_new(200);
+	buf_putmpint(sigbuf, (mp_int*)r);
+	buf_putmpint(sigbuf, (mp_int*)s);
+	buf_putbufstring(buf, sigbuf);
+
+	err = DROPBEAR_SUCCESS;
+
+out:
+	if (r && s && p && e) {
+		ltc_deinit_multi(r, s, p, e, NULL);
+	}
+
+	if (sigbuf) {
+		buf_free(sigbuf);
+	}
+
+	if (err == DROPBEAR_FAILURE) {
+		dropbear_exit("ECC error");
+	}
+}
+
+/* returns values in s and r
+   returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
+static int buf_get_ecdsa_verify_params(buffer *buf,
+			void *r, void* s) {
+	int ret = DROPBEAR_FAILURE;
+	unsigned int sig_len;
+	unsigned int sig_pos;
+
+	sig_len = buf_getint(buf);
+	sig_pos = buf->pos;
+	if (buf_getmpint(buf, r) != DROPBEAR_SUCCESS) {
+		goto out;
+	}
+	if (buf_getmpint(buf, s) != DROPBEAR_SUCCESS) {
+		goto out;
+	}
+	if (buf->pos - sig_pos != sig_len) {
+		goto out;
+	}
+	ret = DROPBEAR_SUCCESS;
+
+out:
+	return ret;
+}
+
+
+int buf_ecdsa_verify(buffer *buf, const ecc_key *key, const buffer *data_buf) {
+	/* Based on libtomcrypt's ecc_verify_hash but without the asn1 */
+	int ret = DROPBEAR_FAILURE;
+	hash_state hs;
+	struct dropbear_ecc_curve *curve = NULL;
+	unsigned char hash[64];
+	ecc_point *mG = NULL, *mQ = NULL;
+	void *r = NULL, *s = NULL, *v = NULL, *w = NULL, *u1 = NULL, *u2 = NULL, 
+		*e = NULL, *p = NULL, *m = NULL;
+	void *mp = NULL;
+
+	/* verify 
+	 *
+	 * w  = s^-1 mod n
+	 * u1 = xw 
+	 * u2 = rw
+	 * X = u1*G + u2*Q
+	 * v = X_x1 mod n
+	 * accept if v == r
+	 */
+
+	TRACE(("buf_ecdsa_verify"))
+	curve = curve_for_dp(key->dp);
+
+	mG = ltc_ecc_new_point();
+	mQ = ltc_ecc_new_point();
+	if (ltc_init_multi(&r, &s, &v, &w, &u1, &u2, &p, &e, &m, NULL) != CRYPT_OK
+		|| !mG
+		|| !mQ) {
+		dropbear_exit("ECC error");
+	}
+
+	if (buf_get_ecdsa_verify_params(buf, r, s) != DROPBEAR_SUCCESS) {
+		goto out;
+	}
+
+	curve->hash_desc->init(&hs);
+	curve->hash_desc->process(&hs, data_buf->data, data_buf->len);
+	curve->hash_desc->done(&hs, hash);
+
+	if (ltc_mp.unsigned_read(e, hash, curve->hash_desc->hashsize) != CRYPT_OK) {
+		goto out;
+	}
+
+   /* get the order */
+	if (ltc_mp.read_radix(p, (char *)key->dp->order, 16) != CRYPT_OK) { 
+		goto out; 
+	}
+
+   /* get the modulus */
+	if (ltc_mp.read_radix(m, (char *)key->dp->prime, 16) != CRYPT_OK) { 
+		goto out; 
+	}
+
+   /* check for zero */
+	if (ltc_mp.compare_d(r, 0) == LTC_MP_EQ 
+		|| ltc_mp.compare_d(s, 0) == LTC_MP_EQ 
+		|| ltc_mp.compare(r, p) != LTC_MP_LT 
+		|| ltc_mp.compare(s, p) != LTC_MP_LT) {
+		goto out;
+	}
+
+   /*  w  = s^-1 mod n */
+	if (ltc_mp.invmod(s, p, w) != CRYPT_OK) { 
+		goto out; 
+	}
+
+   /* u1 = ew */
+	if (ltc_mp.mulmod(e, w, p, u1) != CRYPT_OK) { 
+		goto out; 
+	}
+
+   /* u2 = rw */
+	if (ltc_mp.mulmod(r, w, p, u2) != CRYPT_OK) { 
+		goto out; 
+	}
+
+   /* find mG and mQ */
+	if (ltc_mp.read_radix(mG->x, (char *)key->dp->Gx, 16) != CRYPT_OK) { 
+		goto out; 
+	}
+	if (ltc_mp.read_radix(mG->y, (char *)key->dp->Gy, 16) != CRYPT_OK) { 
+		goto out; 
+	}
+	if (ltc_mp.set_int(mG->z, 1) != CRYPT_OK) { 
+		goto out; 
+	}
+
+	if (ltc_mp.copy(key->pubkey.x, mQ->x) != CRYPT_OK
+		|| ltc_mp.copy(key->pubkey.y, mQ->y) != CRYPT_OK
+		|| ltc_mp.copy(key->pubkey.z, mQ->z) != CRYPT_OK) { 
+		goto out; 
+	}
+
+   /* compute u1*mG + u2*mQ = mG */
+	if (ltc_mp.ecc_mul2add == NULL) {
+		if (ltc_mp.ecc_ptmul(u1, mG, mG, m, 0) != CRYPT_OK) { 
+			goto out; 
+		}
+		if (ltc_mp.ecc_ptmul(u2, mQ, mQ, m, 0) != CRYPT_OK) {
+			goto out; 
+		}
+
+		/* find the montgomery mp */
+		if (ltc_mp.montgomery_setup(m, &mp) != CRYPT_OK) { 
+			goto out; 
+		}
+
+		/* add them */
+		if (ltc_mp.ecc_ptadd(mQ, mG, mG, m, mp) != CRYPT_OK) { 
+			goto out; 
+		}
+
+		/* reduce */
+		if (ltc_mp.ecc_map(mG, m, mp) != CRYPT_OK) { 
+			goto out; 
+		}
+	} else {
+		/* use Shamir's trick to compute u1*mG + u2*mQ using half of the doubles */
+		if (ltc_mp.ecc_mul2add(mG, u1, mQ, u2, mG, m) != CRYPT_OK) { 
+			goto out; 
+		}
+	}
+
+   /* v = X_x1 mod n */
+	if (ltc_mp.mpdiv(mG->x, p, NULL, v) != CRYPT_OK) { 
+		goto out; 
+	}
+
+   /* does v == r */
+	if (ltc_mp.compare(v, r) == LTC_MP_EQ) {
+		ret = DROPBEAR_SUCCESS;
+	}
+
+out:
+	ltc_ecc_del_point(mG);
+	ltc_ecc_del_point(mQ);
+	ltc_deinit_multi(r, s, v, w, u1, u2, p, e, m, NULL);
+	if (mp != NULL) { 
+		ltc_mp.montgomery_deinit(mp);
+	}
+	return ret;
+}
+
+
+
+#endif /* DROPBEAR_ECDSA */

ecdsa.h

@@ -0,0 +1,36 @@
+#ifndef DROPBEAR_ECDSA_H_
+#define DROPBEAR_ECDSA_H_
+
+#include "includes.h"
+#include "buffer.h"
+#include "signkey.h"
+
+#if DROPBEAR_ECDSA
+
+/* prefer 256 or 384 since those are SHOULD for
+   draft-ietf-curdle-ssh-kex-sha2.txt */
+#if DROPBEAR_ECC_256
+#define ECDSA_DEFAULT_SIZE 256
+#elif DROPBEAR_ECC_384
+#define ECDSA_DEFAULT_SIZE 384
+#elif DROPBEAR_ECC_521
+#define ECDSA_DEFAULT_SIZE 521
+#else
+#error ECDSA cannot be enabled without enabling at least one size (256, 384, 521)
+#endif
+
+ecc_key *gen_ecdsa_priv_key(unsigned int bit_size);
+ecc_key *buf_get_ecdsa_pub_key(buffer* buf);
+ecc_key *buf_get_ecdsa_priv_key(buffer *buf);
+void buf_put_ecdsa_pub_key(buffer *buf, ecc_key *key);
+void buf_put_ecdsa_priv_key(buffer *buf, ecc_key *key);
+enum signkey_type ecdsa_signkey_type(const ecc_key * key);
+
+void buf_put_ecdsa_sign(buffer *buf, const ecc_key *key, const buffer *data_buf);
+int buf_ecdsa_verify(buffer *buf, const ecc_key *key, const buffer *data_buf);
+/* Returns 1 on success */
+int signkey_is_ecdsa(enum signkey_type type);
+
+#endif
+
+#endif /* DROPBEAR_ECDSA_H_ */

ed25519.c

@@ -0,0 +1,182 @@
+/*
+ * Dropbear - a SSH2 server
+ * 
+ * Copyright (c) 2002,2003 Matt Johnston
+ * All rights reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE. */
+
+/* Perform Ed25519 operations on data, including reading keys, signing and
+ * verification. */
+
+#include "includes.h"
+#include "dbutil.h"
+#include "buffer.h"
+#include "ssh.h"
+#include "curve25519.h"
+#include "ed25519.h"
+
+#if DROPBEAR_ED25519
+
+/* Load a public ed25519 key from a buffer, initialising the values.
+ * The key will have the same format as buf_put_ed25519_key.
+ * These should be freed with ed25519_key_free.
+ * Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
+int buf_get_ed25519_pub_key(buffer *buf, dropbear_ed25519_key *key) {
+
+	unsigned int len;
+
+	TRACE(("enter buf_get_ed25519_pub_key"))
+	dropbear_assert(key != NULL);
+
+	buf_incrpos(buf, 4+SSH_SIGNKEY_ED25519_LEN); /* int + "ssh-ed25519" */
+
+	len = buf_getint(buf);
+	if (len != CURVE25519_LEN || buf->len - buf->pos < len) {
+		TRACE(("leave buf_get_ed25519_pub_key: failure"))
+		return DROPBEAR_FAILURE;
+	}
+
+	m_burn(key->priv, CURVE25519_LEN);
+	memcpy(key->pub, buf_getptr(buf, CURVE25519_LEN), CURVE25519_LEN);
+	buf_incrpos(buf, CURVE25519_LEN);
+
+	TRACE(("leave buf_get_ed25519_pub_key: success"))
+	return DROPBEAR_SUCCESS;
+}
+
+/* Same as buf_get_ed25519_pub_key, but reads private key at the end.
+ * Loads a public and private ed25519 key from a buffer
+ * Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
+int buf_get_ed25519_priv_key(buffer *buf, dropbear_ed25519_key *key) {
+
+	unsigned int len;
+
+	TRACE(("enter buf_get_ed25519_priv_key"))
+	dropbear_assert(key != NULL);
+
+	buf_incrpos(buf, 4+SSH_SIGNKEY_ED25519_LEN); /* int + "ssh-ed25519" */
+
+	len = buf_getint(buf);
+	if (len != CURVE25519_LEN*2 || buf->len - buf->pos < len) {
+		TRACE(("leave buf_get_ed25519_priv_key: failure"))
+		return DROPBEAR_FAILURE;
+	}
+
+	memcpy(key->priv, buf_getptr(buf, CURVE25519_LEN), CURVE25519_LEN);
+	buf_incrpos(buf, CURVE25519_LEN);
+	memcpy(key->pub, buf_getptr(buf, CURVE25519_LEN), CURVE25519_LEN);
+	buf_incrpos(buf, CURVE25519_LEN);
+
+	TRACE(("leave buf_get_ed25519_priv_key: success"))
+	return DROPBEAR_SUCCESS;
+}
+
+/* Clear and free the memory used by a public or private key */
+void ed25519_key_free(dropbear_ed25519_key *key) {
+
+	TRACE2(("enter ed25519_key_free"))
+
+	if (key == NULL) {
+		TRACE2(("leave ed25519_key_free: key == NULL"))
+		return;
+	}
+	m_burn(key->priv, CURVE25519_LEN);
+	m_free(key);
+
+	TRACE2(("leave ed25519_key_free"))
+}
+
+/* Put the public ed25519 key into the buffer in the required format */
+void buf_put_ed25519_pub_key(buffer *buf, const dropbear_ed25519_key *key) {
+
+	TRACE(("enter buf_put_ed25519_pub_key"))
+	dropbear_assert(key != NULL);
+
+	buf_putstring(buf, SSH_SIGNKEY_ED25519, SSH_SIGNKEY_ED25519_LEN);
+	buf_putstring(buf, key->pub, CURVE25519_LEN);
+
+	TRACE(("leave buf_put_ed25519_pub_key"))
+}
+
+/* Put the public and private ed25519 key into the buffer in the required format */
+void buf_put_ed25519_priv_key(buffer *buf, const dropbear_ed25519_key *key) {
+
+	TRACE(("enter buf_put_ed25519_priv_key"))
+	dropbear_assert(key != NULL);
+
+	buf_putstring(buf, SSH_SIGNKEY_ED25519, SSH_SIGNKEY_ED25519_LEN);
+	buf_putint(buf, CURVE25519_LEN*2);
+	buf_putbytes(buf, key->priv, CURVE25519_LEN);
+	buf_putbytes(buf, key->pub, CURVE25519_LEN);
+
+	TRACE(("leave buf_put_ed25519_priv_key"))
+}
+
+/* Sign the data presented with key, writing the signature contents
+ * to the buffer */
+void buf_put_ed25519_sign(buffer* buf, const dropbear_ed25519_key *key, const buffer *data_buf) {
+
+	unsigned char s[64];
+	unsigned long slen = sizeof(s);
+
+	TRACE(("enter buf_put_ed25519_sign"))
+	dropbear_assert(key != NULL);
+
+	dropbear_ed25519_sign(data_buf->data, data_buf->len, s, &slen, key->priv, key->pub);
+	buf_putstring(buf, SSH_SIGNKEY_ED25519, SSH_SIGNKEY_ED25519_LEN);
+	buf_putstring(buf, s, slen);
+
+	TRACE(("leave buf_put_ed25519_sign"))
+}
+
+#if DROPBEAR_SIGNKEY_VERIFY
+/* Verify a signature in buf, made on data by the key given.
+ * Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
+int buf_ed25519_verify(buffer *buf, const dropbear_ed25519_key *key, const buffer *data_buf) {
+
+	int ret = DROPBEAR_FAILURE;
+	unsigned char *s;
+	unsigned long slen;
+
+	TRACE(("enter buf_ed25519_verify"))
+	dropbear_assert(key != NULL);
+
+	slen = buf_getint(buf);
+	if (slen != 64 || buf->len - buf->pos < slen) {
+		TRACE(("leave buf_ed25519_verify: bad size"))
+		goto out;
+	}
+	s = buf_getptr(buf, slen);
+
+	if (dropbear_ed25519_verify(data_buf->data, data_buf->len,
+				    s, slen, key->pub) == 0) {
+		/* signature is valid */
+		TRACE(("leave buf_ed25519_verify: success!"))
+		ret = DROPBEAR_SUCCESS;
+	}
+
+out:
+	TRACE(("leave buf_ed25519_verify: ret %d", ret))
+	return ret;
+}
+
+#endif /* DROPBEAR_SIGNKEY_VERIFY */
+
+#endif /* DROPBEAR_ED25519 */

ed25519.h

@@ -0,0 +1,54 @@
+/*
+ * Dropbear - a SSH2 server
+ * 
+ * Copyright (c) 2002,2003 Matt Johnston
+ * All rights reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE. */
+
+#ifndef DROPBEAR_ED25519_H_
+#define DROPBEAR_ED25519_H_
+
+#include "includes.h"
+#include "buffer.h"
+
+#if DROPBEAR_ED25519 
+
+#define CURVE25519_LEN 32
+
+typedef struct dropbear_ED25519_Key {
+
+	unsigned char priv[CURVE25519_LEN];
+	unsigned char pub[CURVE25519_LEN];
+
+} dropbear_ed25519_key;
+
+void buf_put_ed25519_sign(buffer* buf, const dropbear_ed25519_key *key, const buffer *data_buf);
+#if DROPBEAR_SIGNKEY_VERIFY
+int buf_ed25519_verify(buffer * buf, const dropbear_ed25519_key *key, const buffer *data_buf);
+#endif
+int buf_get_ed25519_pub_key(buffer* buf, dropbear_ed25519_key *key);
+int buf_get_ed25519_priv_key(buffer* buf, dropbear_ed25519_key *key);
+void buf_put_ed25519_pub_key(buffer* buf, const dropbear_ed25519_key *key);
+void buf_put_ed25519_priv_key(buffer* buf, const dropbear_ed25519_key *key);
+void ed25519_key_free(dropbear_ed25519_key *key);
+
+#endif /* DROPBEAR_ED25519 */
+
+#endif /* DROPBEAR_ED25519_H_ */

fake-rfc2553.h

@@ -39,8 +39,8 @@
  * that ai_family is AF_INET. Don't use it for another purpose.
  */
 
-#ifndef _FAKE_RFC2553_H
-#define _FAKE_RFC2553_H
+#ifndef DROPBEAR_FAKE_RFC2553_H
+#define DROPBEAR_FAKE_RFC2553_H
 
 #include "includes.h"
 #include <sys/types.h>

filelist.txt

@@ -99,6 +99,10 @@ rsa.c			RSA asymmetric crypto routines
 
 dss.c			DSS asymmetric crypto routines
 
+ed25519.c		Ed25519 asymmetric crypto routines
+
+gened25519.c		Ed25519 key generation
+
 gendss.c		DSS key generation
 
 genrsa.c		RSA key generation

fuzz-common.c

@@ -0,0 +1,209 @@
+#include "includes.h"
+
+#include "includes.h"
+#include "fuzz.h"
+#include "dbutil.h"
+#include "runopts.h"
+#include "crypto_desc.h"
+#include "session.h"
+#include "dbrandom.h"
+#include "bignum.h"
+#include "fuzz-wrapfd.h"
+
+struct dropbear_fuzz_options fuzz;
+
+static void fuzz_dropbear_log(int UNUSED(priority), const char* format, va_list param);
+static void load_fixed_hostkeys(void);
+
+void fuzz_common_setup(void) {
+    fuzz.fuzzing = 1;
+    fuzz.wrapfds = 1;
+    fuzz.do_jmp = 1;
+    fuzz.input = m_malloc(sizeof(buffer));
+    _dropbear_log = fuzz_dropbear_log;
+    crypto_init();
+    fuzz_seed();
+    /* let any messages get flushed */
+    setlinebuf(stdout);
+}
+
+int fuzz_set_input(const uint8_t *Data, size_t Size) {
+
+    fuzz.input->data = (unsigned char*)Data;
+    fuzz.input->size = Size;
+    fuzz.input->len = Size;
+    fuzz.input->pos = 0;
+
+    memset(&ses, 0x0, sizeof(ses));
+    memset(&svr_ses, 0x0, sizeof(svr_ses));
+    wrapfd_setup();
+
+    fuzz_seed();
+
+    return DROPBEAR_SUCCESS;
+}
+
+#if DEBUG_TRACE
+static void fuzz_dropbear_log(int UNUSED(priority), const char* format, va_list param) {
+    if (debug_trace) {
+        char printbuf[1024];
+        vsnprintf(printbuf, sizeof(printbuf), format, param);
+        fprintf(stderr, "%s\n", printbuf);
+    }
+}
+#else
+static void fuzz_dropbear_log(int UNUSED(priority), const char* UNUSED(format), va_list UNUSED(param)) {
+    /* No print */
+}
+#endif /* DEBUG_TRACE */
+
+void fuzz_svr_setup(void) {
+    fuzz_common_setup();
+    
+    _dropbear_exit = svr_dropbear_exit;
+
+    char *argv[] = { 
+        "-E", 
+    };
+
+    int argc = sizeof(argv) / sizeof(*argv);
+    svr_getopts(argc, argv);
+
+    /* user lookups might be slow, cache it */
+    fuzz.pw_name = m_strdup("person");
+    fuzz.pw_dir = m_strdup("/tmp");
+    fuzz.pw_shell = m_strdup("/bin/zsh");
+    fuzz.pw_passwd = m_strdup("!!zzznope");
+
+    load_fixed_hostkeys();
+}
+
+static void load_fixed_hostkeys(void) {
+#include "fuzz-hostkeys.c"   
+
+    buffer *b = buf_new(3000);
+    enum signkey_type type;
+
+    TRACE(("load fixed hostkeys"))
+
+    svr_opts.hostkey = new_sign_key();
+
+    buf_setlen(b, 0);
+    buf_putbytes(b, keyr, keyr_len);
+    buf_setpos(b, 0);
+    type = DROPBEAR_SIGNKEY_RSA;
+    if (buf_get_priv_key(b, svr_opts.hostkey, &type) == DROPBEAR_FAILURE) {
+        dropbear_exit("failed fixed rsa hostkey");
+    }
+
+    buf_setlen(b, 0);
+    buf_putbytes(b, keyd, keyd_len);
+    buf_setpos(b, 0);
+    type = DROPBEAR_SIGNKEY_DSS;
+    if (buf_get_priv_key(b, svr_opts.hostkey, &type) == DROPBEAR_FAILURE) {
+        dropbear_exit("failed fixed dss hostkey");
+    }
+
+    buf_setlen(b, 0);
+    buf_putbytes(b, keye, keye_len);
+    buf_setpos(b, 0);
+    type = DROPBEAR_SIGNKEY_ECDSA_NISTP256;
+    if (buf_get_priv_key(b, svr_opts.hostkey, &type) == DROPBEAR_FAILURE) {
+        dropbear_exit("failed fixed ecdsa hostkey");
+    }
+
+    buf_setlen(b, 0);
+    buf_putbytes(b, keyed25519, keyed25519_len);
+    buf_setpos(b, 0);
+    type = DROPBEAR_SIGNKEY_ED25519;
+    if (buf_get_priv_key(b, svr_opts.hostkey, &type) == DROPBEAR_FAILURE) {
+        dropbear_exit("failed fixed ed25519 hostkey");
+    }
+
+    buf_free(b);
+}
+
+void fuzz_kex_fakealgos(void) {
+    ses.newkeys->recv.crypt_mode = &dropbear_mode_none;
+}
+
+void fuzz_get_socket_address(int UNUSED(fd), char **local_host, char **local_port,
+                        char **remote_host, char **remote_port, int UNUSED(host_lookup)) {
+    if (local_host) {
+        *local_host = m_strdup("fuzzlocalhost");
+    }
+    if (local_port) {
+        *local_port = m_strdup("1234");
+    }
+    if (remote_host) {
+        *remote_host = m_strdup("fuzzremotehost");
+    }
+    if (remote_port) {
+        *remote_port = m_strdup("9876");
+    }
+}
+
+/* cut down version of svr_send_msg_kexdh_reply() that skips slow maths. Still populates structures */
+void fuzz_fake_send_kexdh_reply(void) {
+    assert(!ses.dh_K);
+    m_mp_alloc_init_multi(&ses.dh_K, NULL);
+    mp_set_ul(ses.dh_K, 12345678uL);
+    finish_kexhashbuf();
+}
+
+int fuzz_run_preauth(const uint8_t *Data, size_t Size, int skip_kexmaths) {
+    static int once = 0;
+    if (!once) {
+        fuzz_svr_setup();
+        fuzz.skip_kexmaths = skip_kexmaths;
+        once = 1;
+    }
+
+    if (fuzz_set_input(Data, Size) == DROPBEAR_FAILURE) {
+        return 0;
+    }
+
+    /*
+      get prefix. input format is
+      string prefix
+          uint32 wrapfd seed
+          ... to be extended later
+      [bytes] ssh input stream
+    */
+
+    /* be careful to avoid triggering buffer.c assertions */
+    if (fuzz.input->len < 8) {
+        return 0;
+    }
+    size_t prefix_size = buf_getint(fuzz.input);
+    if (prefix_size != 4) {
+        return 0;
+    }
+    uint32_t wrapseed = buf_getint(fuzz.input);
+    wrapfd_setseed(wrapseed);
+
+    int fakesock = 20;
+    wrapfd_add(fakesock, fuzz.input, PLAIN);
+
+    m_malloc_set_epoch(1);
+    if (setjmp(fuzz.jmp) == 0) {
+        svr_session(fakesock, fakesock);
+        m_malloc_free_epoch(1, 0);
+    } else {
+        m_malloc_free_epoch(1, 1);
+        TRACE(("dropbear_exit longjmped"))
+        /* dropbear_exit jumped here */
+    }
+
+    return 0;
+}
+
+const void* fuzz_get_algo(const algo_type *algos, const char* name) {
+    const algo_type *t;
+    for (t = algos; t->name; t++) {
+        if (strcmp(t->name, name) == 0) {
+            return t->data;
+        }
+    }
+    assert(0);
+}

fuzz-harness.c

@@ -0,0 +1,48 @@
+#include "includes.h"
+#include "buffer.h"
+#include "dbutil.h"
+
+extern int LLVMFuzzerTestOneInput(const unsigned char *data, size_t size);
+
+int main(int argc, char ** argv) {
+    int i;
+    buffer *input = buf_new(100000);
+
+    for (i = 1; i < argc; i++) {
+        printf("arg %s\n", argv[i]);
+#if DEBUG_TRACE
+        if (strcmp(argv[i], "-v") == 0) {
+            debug_trace = 1;
+            TRACE(("debug printing on"))
+        }
+#endif
+    }
+
+    int old_fuzz_wrapfds = 0;
+    for (i = 1; i < argc; i++) {
+        if (argv[i][0] == '-') {
+            /* ignore arguments */
+            continue;
+        }
+
+        char* fn = argv[i];
+        buf_setlen(input, 0);
+        buf_readfile(input, fn);
+        buf_setpos(input, 0);
+
+        fuzz.wrapfds = old_fuzz_wrapfds;
+        printf("Running %s once \n", fn);
+        LLVMFuzzerTestOneInput(input->data, input->len);
+        printf("Running %s twice \n", fn);
+        LLVMFuzzerTestOneInput(input->data, input->len);
+        printf("Done %s\n", fn);
+
+        /* Disable wrapfd so it won't interfere with buf_readfile() above */
+        old_fuzz_wrapfds = fuzz.wrapfds;
+        fuzz.wrapfds = 0;
+    }
+
+    printf("Finished\n");
+
+    return 0;
+}

fuzz-hostkeys.c

@@ -0,0 +1,139 @@
+
+unsigned char keyr[] = {
+  0x00, 0x00, 0x00, 0x07, 0x73, 0x73, 0x68, 0x2d, 0x72, 0x73, 0x61, 0x00,
+  0x00, 0x00, 0x03, 0x01, 0x00, 0x01, 0x00, 0x00, 0x01, 0x01, 0x00, 0xb1,
+  0x06, 0x95, 0xc9, 0xa8, 0x38, 0xb9, 0x99, 0x91, 0xb5, 0x17, 0x39, 0xb9,
+  0xfa, 0xa4, 0x49, 0xf8, 0x2a, 0x4c, 0x14, 0xbd, 0xb6, 0x85, 0xdb, 0x38,
+  0x99, 0x44, 0xfa, 0xd6, 0xaa, 0x67, 0xef, 0x00, 0x75, 0x2b, 0x6a, 0x5c,
+  0x1b, 0x50, 0xa8, 0x52, 0xf9, 0xa7, 0xee, 0xe2, 0xb3, 0x80, 0x38, 0x92,
+  0x20, 0x86, 0x7c, 0xe5, 0x89, 0xb3, 0x06, 0xe4, 0x3b, 0xd1, 0xe2, 0x45,
+  0xea, 0xc1, 0xd5, 0x8e, 0x05, 0xfb, 0x90, 0x29, 0xd9, 0x41, 0xb3, 0x05,
+  0x31, 0x1e, 0xcc, 0xeb, 0x89, 0xdc, 0xd2, 0x6a, 0x99, 0x23, 0xbd, 0x7a,
+  0xbe, 0x8c, 0xe3, 0x3f, 0xa1, 0xe8, 0xf5, 0xb4, 0x51, 0x40, 0xb4, 0xb1,
+  0xc1, 0x16, 0x9f, 0x07, 0xbb, 0x99, 0xaa, 0x4b, 0x8f, 0x11, 0x19, 0x3c,
+  0x18, 0xbd, 0x6e, 0xce, 0x14, 0x54, 0x2c, 0x16, 0x4a, 0x5f, 0x89, 0xe4,
+  0x6b, 0x9f, 0x55, 0x68, 0xcc, 0x09, 0x8e, 0x4b, 0x92, 0xc8, 0x87, 0xfe,
+  0x09, 0xed, 0x53, 0x6e, 0xff, 0x5f, 0x15, 0x0d, 0x19, 0x9d, 0xa6, 0x54,
+  0xd2, 0xea, 0x59, 0x4f, 0xa1, 0x7c, 0xf6, 0xf5, 0x7f, 0x32, 0x23, 0xed,
+  0x72, 0xa8, 0x96, 0x17, 0x87, 0x06, 0xf2, 0xc7, 0xcd, 0xda, 0x4a, 0x10,
+  0xd1, 0xfd, 0xb8, 0xf1, 0xaf, 0x25, 0x55, 0x32, 0x45, 0x39, 0x95, 0xec,
+  0x0c, 0xa9, 0xf0, 0x47, 0x8b, 0x66, 0xe0, 0xb7, 0xa2, 0xf6, 0x35, 0x50,
+  0x27, 0xe7, 0x2f, 0x90, 0x35, 0x5b, 0xd5, 0x62, 0x19, 0xb4, 0x41, 0xd4,
+  0x52, 0xe7, 0x7f, 0x97, 0xfc, 0x5b, 0x4a, 0x5b, 0x19, 0x06, 0x65, 0x2d,
+  0x23, 0x29, 0x15, 0x8b, 0x05, 0xaf, 0xbe, 0xd3, 0x4a, 0x27, 0x5b, 0xc9,
+  0xc0, 0xd0, 0xd2, 0xba, 0x8b, 0x00, 0x7a, 0x2f, 0x39, 0xa0, 0x13, 0xb9,
+  0xe6, 0xf5, 0x4b, 0x21, 0x54, 0x57, 0xb3, 0xf9, 0x6c, 0x6f, 0xd0, 0x17,
+  0xf4, 0x50, 0x9d, 0x00, 0x00, 0x01, 0x00, 0x01, 0xf2, 0xda, 0x5f, 0xfb,
+  0xe2, 0xda, 0xfc, 0xe0, 0xdf, 0x3a, 0x0e, 0x14, 0x18, 0xc1, 0xd9, 0x1f,
+  0x43, 0xe3, 0x65, 0x3e, 0x07, 0xe7, 0x8d, 0xdc, 0x1d, 0x11, 0xc1, 0xd6,
+  0xc0, 0xd8, 0xda, 0x53, 0xf5, 0x04, 0x73, 0x51, 0x1b, 0x26, 0xef, 0x4e,
+  0xf5, 0xce, 0x3d, 0x77, 0x21, 0x94, 0xd0, 0xc7, 0xc1, 0xda, 0x19, 0x7d,
+  0xf8, 0xc5, 0x4c, 0xc8, 0xee, 0x7d, 0xd1, 0xbb, 0x02, 0x90, 0x2b, 0xff,
+  0x4e, 0x4d, 0xd7, 0x9d, 0x72, 0x0c, 0x60, 0x0f, 0x4b, 0x83, 0xf5, 0xc2,
+  0x26, 0xd6, 0x22, 0xb8, 0x60, 0x3a, 0xf9, 0x2f, 0x92, 0x2a, 0x2e, 0x14,
+  0xa7, 0x56, 0x1c, 0x56, 0x05, 0x41, 0x92, 0xac, 0xb1, 0x4e, 0x44, 0x1e,
+  0x70, 0x42, 0xda, 0xc7, 0xc8, 0x9c, 0xae, 0x29, 0x2d, 0x0c, 0x3a, 0xff,
+  0x9b, 0xb6, 0xad, 0xb4, 0xfb, 0x49, 0x28, 0x96, 0x74, 0xf5, 0x94, 0x74,
+  0xb7, 0x40, 0x93, 0x2b, 0x34, 0x29, 0xd2, 0x8a, 0xf3, 0x99, 0xf9, 0xe9,
+  0xd8, 0xcc, 0x48, 0x1d, 0x3e, 0xc1, 0x82, 0x35, 0x4f, 0xef, 0xb1, 0x81,
+  0x3c, 0xe1, 0xa1, 0x03, 0x65, 0xac, 0x21, 0x21, 0x40, 0x61, 0xfb, 0xd3,
+  0x54, 0xac, 0xa1, 0xf2, 0xf0, 0x61, 0xd9, 0x01, 0x4e, 0xc2, 0x28, 0xb1,
+  0x7c, 0x27, 0x6e, 0x56, 0x68, 0x69, 0x8f, 0xc5, 0xfd, 0xca, 0x39, 0x6e,
+  0x22, 0x09, 0xf1, 0xb4, 0xd5, 0xac, 0xb8, 0xe0, 0x1b, 0x21, 0x86, 0xf4,
+  0xc8, 0x15, 0xc6, 0x1f, 0x21, 0xae, 0xcb, 0xab, 0x5a, 0x09, 0x30, 0x9e,
+  0xdd, 0x6c, 0x38, 0x59, 0xec, 0x59, 0x3a, 0x08, 0xee, 0x46, 0x7b, 0x78,
+  0x23, 0xbc, 0xfc, 0xe2, 0xda, 0xe8, 0x1a, 0x65, 0xe6, 0xe0, 0x78, 0xd3,
+  0xb0, 0x03, 0x2e, 0xf1, 0xb8, 0xca, 0x8e, 0x90, 0x75, 0xaf, 0xf7, 0xa8,
+  0x48, 0xed, 0x82, 0xc9, 0xcf, 0x44, 0x56, 0xfc, 0x05, 0xfd, 0x6b, 0x00,
+  0x00, 0x00, 0x81, 0x00, 0xfc, 0x94, 0xdf, 0x42, 0xc7, 0x9a, 0xa2, 0xff,
+  0x32, 0xdf, 0x06, 0xb6, 0x4d, 0x90, 0x31, 0x28, 0x28, 0xdb, 0x03, 0xf9,
+  0xa6, 0xb3, 0xa2, 0x91, 0x4c, 0xdf, 0x6e, 0xf6, 0xb9, 0x44, 0x3b, 0xdd,
+  0x17, 0xc1, 0xc8, 0x1d, 0xd1, 0xc0, 0xc0, 0x30, 0x22, 0xbe, 0x24, 0x2e,
+  0x0e, 0xdf, 0xe0, 0x18, 0x37, 0x3e, 0xb8, 0x7f, 0xb2, 0x50, 0x34, 0xc4,
+  0x08, 0x5e, 0x69, 0x1f, 0xd5, 0xc9, 0xce, 0x47, 0x7d, 0x75, 0x5e, 0x3b,
+  0x87, 0xdd, 0x46, 0x35, 0x01, 0x0f, 0x17, 0x8a, 0xf1, 0xf1, 0xc4, 0xa9,
+  0x94, 0xa7, 0x6e, 0xce, 0x80, 0xe3, 0x17, 0x2e, 0xb0, 0xef, 0x63, 0xa7,
+  0x11, 0x86, 0x96, 0x4a, 0x63, 0x2d, 0x9e, 0x92, 0x62, 0x43, 0x43, 0x72,
+  0xa5, 0xdc, 0xa0, 0xcd, 0x19, 0x93, 0xd7, 0xe0, 0x80, 0x41, 0x27, 0xea,
+  0xe4, 0xe8, 0xc1, 0x91, 0x9e, 0x13, 0xb3, 0x9c, 0xd1, 0xed, 0xcb, 0xbf,
+  0x00, 0x00, 0x00, 0x81, 0x00, 0xb3, 0x6b, 0xee, 0xa4, 0x70, 0x4e, 0xfb,
+  0xf9, 0x7e, 0x2e, 0x74, 0x5d, 0x3e, 0x8b, 0x3f, 0xff, 0x8c, 0xde, 0x68,
+  0x38, 0xda, 0xce, 0xc0, 0x66, 0x4b, 0xca, 0x35, 0xc3, 0x97, 0xa8, 0xf0,
+  0x00, 0x8e, 0xb3, 0x46, 0x60, 0xd0, 0x4d, 0x7e, 0x7b, 0xdf, 0x17, 0x7b,
+  0x2f, 0xc4, 0x16, 0xee, 0x45, 0xdb, 0xa5, 0x5d, 0xc0, 0x72, 0xe9, 0xc6,
+  0x91, 0x0f, 0xd9, 0x30, 0x74, 0x6c, 0xde, 0x93, 0xb5, 0xb6, 0xaf, 0x52,
+  0x53, 0x3c, 0x08, 0x55, 0xea, 0xb8, 0x66, 0x07, 0xbe, 0xce, 0xf9, 0x80,
+  0x8d, 0xe0, 0xca, 0xdc, 0x63, 0xe8, 0x58, 0x94, 0x22, 0x4f, 0x08, 0x66,
+  0x13, 0x9e, 0x63, 0x2e, 0x92, 0x7a, 0xb6, 0x66, 0x94, 0x9b, 0x71, 0x66,
+  0xd3, 0x08, 0xc9, 0x89, 0xea, 0x78, 0x35, 0x0d, 0xf2, 0x25, 0x55, 0xd4,
+  0xb0, 0x9b, 0xea, 0x18, 0x77, 0xf6, 0x25, 0x02, 0xb4, 0x5e, 0x71, 0xea,
+  0xa3
+};
+unsigned int keyr_len = 805;
+unsigned char keye[] = {
+  0x00, 0x00, 0x00, 0x13, 0x65, 0x63, 0x64, 0x73, 0x61, 0x2d, 0x73, 0x68,
+  0x61, 0x32, 0x2d, 0x6e, 0x69, 0x73, 0x74, 0x70, 0x32, 0x35, 0x36, 0x00,
+  0x00, 0x00, 0x08, 0x6e, 0x69, 0x73, 0x74, 0x70, 0x32, 0x35, 0x36, 0x00,
+  0x00, 0x00, 0x41, 0x04, 0x0a, 0x00, 0x6c, 0x7c, 0x1c, 0xc4, 0x03, 0x44,
+  0x46, 0x70, 0xba, 0x00, 0x7c, 0x79, 0x89, 0x7b, 0xc3, 0xd6, 0x32, 0x98,
+  0x34, 0xe7, 0x1c, 0x60, 0x04, 0x73, 0xd9, 0xb5, 0x7e, 0x94, 0x04, 0x04,
+  0xea, 0xc8, 0xb8, 0xfb, 0xd4, 0x70, 0x9f, 0x29, 0xa7, 0x8d, 0x9a, 0x64,
+  0x3a, 0x8c, 0x45, 0x23, 0x37, 0x5a, 0x2b, 0x4f, 0x54, 0x91, 0x80, 0xf1,
+  0xac, 0x3a, 0xf5, 0x6d, 0xfa, 0xe8, 0x76, 0x20, 0x00, 0x00, 0x00, 0x21,
+  0x00, 0xc2, 0xaf, 0xbe, 0xdc, 0x06, 0xff, 0x3d, 0x08, 0x9b, 0x73, 0xe0,
+  0x3c, 0x58, 0x28, 0x70, 0x9b, 0x23, 0x39, 0x51, 0xd7, 0xbc, 0xa7, 0x1a,
+  0xf5, 0xb4, 0x23, 0xd3, 0xf6, 0x17, 0xa6, 0x9c, 0x02
+};
+unsigned int keye_len = 141;
+unsigned char keyd[] = {
+  0x00, 0x00, 0x00, 0x07, 0x73, 0x73, 0x68, 0x2d, 0x64, 0x73, 0x73, 0x00,
+  0x00, 0x00, 0x81, 0x00, 0xb0, 0x02, 0x19, 0x8b, 0xf3, 0x46, 0xf9, 0xc5,
+  0x47, 0x78, 0x3d, 0x7f, 0x04, 0x10, 0x0a, 0x43, 0x8e, 0x00, 0x9e, 0xa4,
+  0x30, 0xfd, 0x47, 0xb9, 0x05, 0x9e, 0x95, 0xaa, 0x37, 0x9a, 0x91, 0xbf,
+  0xf8, 0xb9, 0xe0, 0x8d, 0x97, 0x49, 0x87, 0xe2, 0xe6, 0x90, 0xc1, 0xe4,
+  0x61, 0x57, 0x77, 0xfd, 0x91, 0x1d, 0xe1, 0x4b, 0xa0, 0xb2, 0xbc, 0xa1,
+  0x6a, 0x6a, 0xdd, 0x31, 0xda, 0xe7, 0x54, 0x03, 0xfd, 0x48, 0x62, 0x8a,
+  0x1d, 0x1d, 0xe2, 0x26, 0x76, 0x29, 0x08, 0xab, 0x65, 0x88, 0x74, 0x02,
+  0x1e, 0xa9, 0x29, 0x1b, 0x69, 0x3b, 0xb4, 0x5f, 0x62, 0x80, 0xa3, 0xa6,
+  0x4b, 0xc3, 0x0e, 0x89, 0x24, 0xe4, 0x8a, 0x31, 0xae, 0x89, 0x7a, 0x7a,
+  0x58, 0x44, 0x46, 0x77, 0x62, 0x33, 0xa2, 0x5d, 0x17, 0x0e, 0x0b, 0x64,
+  0xee, 0x1a, 0x02, 0xbd, 0xf8, 0x27, 0x86, 0xe1, 0x87, 0x92, 0x84, 0xc7,
+  0x00, 0x00, 0x00, 0x15, 0x00, 0xb3, 0x8b, 0x81, 0x39, 0x9c, 0xba, 0xe1,
+  0x1d, 0x9a, 0x8b, 0x89, 0xb3, 0x08, 0x9b, 0x12, 0xa8, 0x7b, 0xea, 0x25,
+  0x8d, 0x00, 0x00, 0x00, 0x80, 0x76, 0x3f, 0x72, 0xb2, 0xef, 0xc3, 0x16,
+  0xd8, 0x09, 0x36, 0x23, 0x03, 0xf9, 0x5c, 0xac, 0x8b, 0x51, 0x35, 0x2e,
+  0x36, 0xba, 0x39, 0xd0, 0x57, 0x19, 0x4f, 0x14, 0x8b, 0xea, 0x32, 0xfc,
+  0x86, 0x41, 0xea, 0x85, 0x71, 0x4d, 0x52, 0x0c, 0xff, 0xc1, 0xd3, 0xd5,
+  0xcd, 0x2e, 0x37, 0xcc, 0xe1, 0xcc, 0x22, 0x38, 0xa8, 0x47, 0x16, 0x34,
+  0x3b, 0x32, 0x9c, 0x2f, 0x0f, 0xcd, 0x5f, 0x7f, 0x06, 0x64, 0x89, 0xc5,
+  0x02, 0x4f, 0x9a, 0x70, 0x11, 0xf0, 0xaa, 0xe1, 0x7a, 0x75, 0x49, 0x8d,
+  0x0f, 0x8d, 0x5b, 0x54, 0xe2, 0xe7, 0x10, 0x6e, 0xe5, 0xbd, 0xb7, 0x62,
+  0xf7, 0x40, 0x59, 0x39, 0x31, 0xd9, 0x13, 0x7b, 0xa3, 0xdf, 0x0d, 0x31,
+  0x52, 0x43, 0xe0, 0xaf, 0x19, 0x12, 0x15, 0x12, 0x34, 0x01, 0x6f, 0xcf,
+  0x62, 0x21, 0xe4, 0xc8, 0x34, 0x69, 0xc9, 0x85, 0xe3, 0xde, 0xd7, 0x0c,
+  0xac, 0x00, 0x00, 0x00, 0x80, 0x41, 0xa3, 0xc5, 0xa4, 0x89, 0x86, 0xc8,
+  0x17, 0xf3, 0x8e, 0x68, 0x72, 0xbe, 0x13, 0x8b, 0x63, 0xe3, 0x07, 0xe3,
+  0xd5, 0xa4, 0xa2, 0xd3, 0x2c, 0x2f, 0xbe, 0x16, 0x71, 0xc9, 0x79, 0x64,
+  0x5a, 0x1e, 0x19, 0x82, 0x07, 0xe2, 0x93, 0xda, 0x22, 0xcf, 0x6d, 0xdd,
+  0x38, 0xcb, 0x6e, 0x6b, 0x0f, 0x95, 0x8d, 0xfa, 0x3f, 0xbb, 0xb8, 0x6a,
+  0x7d, 0xc3, 0x22, 0x1e, 0x49, 0xcf, 0x98, 0x73, 0x05, 0x5d, 0x97, 0xfa,
+  0x4c, 0xf2, 0x82, 0x3d, 0x98, 0x61, 0x4e, 0x96, 0x80, 0x26, 0x79, 0xda,
+  0x24, 0xf8, 0xa1, 0x9c, 0x71, 0x82, 0xe6, 0xc7, 0xdc, 0xc2, 0xa5, 0xd0,
+  0xf4, 0x36, 0xba, 0xaa, 0xee, 0xd3, 0x43, 0x46, 0x1d, 0xaa, 0x53, 0xea,
+  0x85, 0x2c, 0x1b, 0xc8, 0x7c, 0x3c, 0xe7, 0x06, 0x44, 0xab, 0x16, 0xad,
+  0xc6, 0x54, 0x91, 0x9a, 0xb9, 0xc0, 0xeb, 0x93, 0x8c, 0xca, 0x39, 0xcf,
+  0x6f, 0x00, 0x00, 0x00, 0x15, 0x00, 0x90, 0x26, 0x0a, 0xfc, 0x15, 0x99,
+  0x7b, 0xac, 0xaa, 0x0c, 0xa2, 0xca, 0x7b, 0xa8, 0xd4, 0xdf, 0x68, 0x56,
+  0xf9, 0x39
+};
+unsigned int keyd_len = 458;
+unsigned char keyed25519[] = {
+  0x00, 0x00, 0x00, 0x0b, 0x73, 0x73, 0x68, 0x2d, 0x65, 0x64, 0x32, 0x35,
+  0x35, 0x31, 0x39, 0x00, 0x00, 0x00, 0x40, 0x10, 0xb3, 0x79, 0x06, 0xe5,
+  0x9b, 0xe7, 0xe4, 0x6e, 0xec, 0xfe, 0xa5, 0x39, 0x21, 0x7c, 0xf6, 0x66,
+  0x8c, 0x0b, 0x6a, 0x01, 0x09, 0x05, 0xc7, 0x4f, 0x64, 0xa8, 0x24, 0xd2,
+  0x8d, 0xbd, 0xdd, 0xc6, 0x3c, 0x99, 0x1b, 0x2d, 0x3e, 0x33, 0x90, 0x19,
+  0xa4, 0xd5, 0xe9, 0x23, 0xfe, 0x8e, 0xd6, 0xd4, 0xf9, 0xb1, 0x11, 0x69,
+  0x7c, 0x57, 0x52, 0x0e, 0x41, 0xdb, 0x1b, 0x12, 0x87, 0xfa, 0xc9
+};
+unsigned int keyed25519_len = 83;

fuzz-wrapfd.c

@@ -0,0 +1,246 @@
+#define FUZZ_SKIP_WRAP 1
+#include "includes.h"
+#include "fuzz-wrapfd.h"
+
+#include "dbutil.h"
+
+#include "fuzz.h"
+
+#define IOWRAP_MAXFD (FD_SETSIZE-1)
+static const int MAX_RANDOM_IN = 50000;
+static const double CHANCE_CLOSE = 1.0 / 600;
+static const double CHANCE_INTR = 1.0 / 900;
+static const double CHANCE_READ1 = 0.96;
+static const double CHANCE_READ2 = 0.5;
+static const double CHANCE_WRITE1 = 0.96;
+static const double CHANCE_WRITE2 = 0.5;
+
+struct fdwrap {
+	enum wrapfd_mode mode;
+	buffer *buf;
+	int closein;
+	int closeout;
+};
+
+static struct fdwrap wrap_fds[IOWRAP_MAXFD+1];
+/* for quick selection of in-use descriptors */
+static int wrap_used[IOWRAP_MAXFD+1];
+static unsigned int nused;
+static unsigned short rand_state[3];
+
+void wrapfd_setup(void) {
+	TRACE(("wrapfd_setup"))
+	nused = 0;
+	memset(wrap_fds, 0x0, sizeof(wrap_fds));
+	memset(wrap_used, 0x0, sizeof(wrap_used));
+
+	memset(rand_state, 0x0, sizeof(rand_state));
+	wrapfd_setseed(50);
+}
+
+void wrapfd_setseed(uint32_t seed) {
+	memcpy(rand_state, &seed, sizeof(seed));
+	nrand48(rand_state);
+}
+
+void wrapfd_add(int fd, buffer *buf, enum wrapfd_mode mode) {
+	TRACE(("wrapfd_add %d buf %p mode %d", fd, buf, mode))
+	assert(fd >= 0);
+	assert(fd <= IOWRAP_MAXFD);
+	assert(wrap_fds[fd].mode == UNUSED);
+	assert(buf || mode == RANDOMIN);
+
+	wrap_fds[fd].mode = mode;
+	wrap_fds[fd].buf = buf;
+	wrap_fds[fd].closein = 0;
+	wrap_fds[fd].closeout = 0;
+	wrap_used[nused] = fd;
+
+	nused++;
+}
+
+void wrapfd_remove(int fd) {
+	unsigned int i, j;
+	TRACE(("wrapfd_remove %d", fd))
+	assert(fd >= 0);
+	assert(fd <= IOWRAP_MAXFD);
+	assert(wrap_fds[fd].mode != UNUSED);
+	wrap_fds[fd].mode = UNUSED;
+
+
+	/* remove from used list */
+	for (i = 0, j = 0; i < nused; i++) {
+		if (wrap_used[i] != fd) {
+			wrap_used[j] = wrap_used[i];
+			j++;
+		}
+	}
+	nused--;
+}
+
+int wrapfd_close(int fd) {
+	if (fd >= 0 && fd <= IOWRAP_MAXFD && wrap_fds[fd].mode != UNUSED) {
+		wrapfd_remove(fd);
+		return 0;
+	} else {
+		return close(fd);
+	}
+}
+
+int wrapfd_read(int fd, void *out, size_t count) {
+	size_t maxread;
+	buffer *buf;
+
+	if (!fuzz.wrapfds) {
+		return read(fd, out, count);
+	}
+
+	if (fd < 0 || fd > IOWRAP_MAXFD || wrap_fds[fd].mode == UNUSED) {
+		/* XXX - assertion failure? */
+		TRACE(("Bad read descriptor %d\n", fd))
+		errno = EBADF;
+		return -1;
+	}
+
+	assert(count != 0);
+
+	if (wrap_fds[fd].closein || erand48(rand_state) < CHANCE_CLOSE) {
+		wrap_fds[fd].closein = 1;
+		errno = ECONNRESET;
+		return -1;
+	}
+
+	if (erand48(rand_state) < CHANCE_INTR) {
+		errno = EINTR;
+		return -1;
+	}
+
+	buf = wrap_fds[fd].buf;
+	if (buf) {
+		maxread = MIN(buf->len - buf->pos, count);
+		/* returns 0 if buf is EOF, as intended */
+		if (maxread > 0) {
+			maxread = nrand48(rand_state) % maxread + 1;
+		}
+		memcpy(out, buf_getptr(buf, maxread), maxread);
+		buf_incrpos(buf, maxread);
+		return maxread;
+	}
+
+	maxread = MIN(MAX_RANDOM_IN, count);
+	maxread = nrand48(rand_state) % maxread + 1;
+	memset(out, 0xef, maxread);
+	return maxread;
+}
+
+int wrapfd_write(int fd, const void* in, size_t count) {
+	unsigned const volatile char* volin = in;
+	unsigned int i;
+
+	if (!fuzz.wrapfds) {
+		return write(fd, in, count);
+	}
+
+	if (fd < 0 || fd > IOWRAP_MAXFD || wrap_fds[fd].mode == UNUSED) {
+		/* XXX - assertion failure? */
+		TRACE(("Bad read descriptor %d\n", fd))
+		errno = EBADF;
+		return -1;
+	}
+
+	assert(count != 0);
+
+	/* force read to exercise sanitisers */
+	for (i = 0; i < count; i++) {
+		(void)volin[i];
+	}
+
+	if (wrap_fds[fd].closeout || erand48(rand_state) < CHANCE_CLOSE) {
+		wrap_fds[fd].closeout = 1;
+		errno = ECONNRESET;
+		return -1;
+	}
+
+	if (erand48(rand_state) < CHANCE_INTR) {
+		errno = EINTR;
+		return -1;
+	}
+
+	return nrand48(rand_state) % (count+1);
+}
+
+int wrapfd_select(int nfds, fd_set *readfds, fd_set *writefds, 
+	fd_set *exceptfds, struct timeval *timeout) {
+	int i, nset, sel;
+	int ret = 0;
+	int fdlist[IOWRAP_MAXFD+1];
+
+	memset(fdlist, 0x0, sizeof(fdlist));
+
+	if (!fuzz.wrapfds) {
+		return select(nfds, readfds, writefds, exceptfds, timeout);
+	}
+
+	assert(nfds <= IOWRAP_MAXFD+1);
+
+	if (erand48(rand_state) < CHANCE_INTR) {
+		errno = EINTR;
+		return -1;
+	}
+
+	/* read */
+	if (readfds != NULL && erand48(rand_state) < CHANCE_READ1) {
+		for (i = 0, nset = 0; i < nfds; i++) {
+			if (FD_ISSET(i, readfds)) {
+				assert(wrap_fds[i].mode != UNUSED);
+				fdlist[nset] = i;
+				nset++;
+			}
+		}
+		DROPBEAR_FD_ZERO(readfds);
+
+		if (nset > 0) {
+			/* set one */
+			sel = fdlist[nrand48(rand_state) % nset];
+			FD_SET(sel, readfds);
+			ret++;
+
+			if (erand48(rand_state) < CHANCE_READ2) {
+				sel = fdlist[nrand48(rand_state) % nset];
+				if (!FD_ISSET(sel, readfds)) {
+					FD_SET(sel, readfds);
+					ret++;
+				}
+			}
+		}
+	}
+
+	/* write */
+	if (writefds != NULL && erand48(rand_state) < CHANCE_WRITE1) {
+		for (i = 0, nset = 0; i < nfds; i++) {
+			if (FD_ISSET(i, writefds)) {
+				assert(wrap_fds[i].mode != UNUSED);
+				fdlist[nset] = i;
+				nset++;
+			}
+		}
+		DROPBEAR_FD_ZERO(writefds);
+
+		/* set one */
+		if (nset > 0) {
+			sel = fdlist[nrand48(rand_state) % nset];
+			FD_SET(sel, writefds);
+			ret++;
+
+			if (erand48(rand_state) < CHANCE_WRITE2) {
+				sel = fdlist[nrand48(rand_state) % nset];
+				if (!FD_ISSET(sel, writefds)) {
+					FD_SET(sel, writefds);
+					ret++;
+				}
+			}
+		}
+	}
+	return ret;
+}
+

fuzz-wrapfd.h

@@ -0,0 +1,25 @@
+#ifndef FUZZ_WRAPFD_H
+#define FUZZ_WRAPFD_H
+
+#include "buffer.h"
+
+enum wrapfd_mode {
+    UNUSED = 0,
+    PLAIN,
+    INPROGRESS,
+    RANDOMIN
+};
+
+void wrapfd_setup(void);
+void wrapfd_setseed(uint32_t seed);
+// doesn't take ownership of buf. buf is optional.
+void wrapfd_add(int fd, buffer *buf, enum wrapfd_mode mode);
+
+// called via #defines for read/write/select
+int wrapfd_read(int fd, void *out, size_t count);
+int wrapfd_write(int fd, const void* in, size_t count);
+int wrapfd_select(int nfds, fd_set *readfds, fd_set *writefds, 
+    fd_set *exceptfds, struct timeval *timeout);
+int wrapfd_close(int fd);
+
+#endif // FUZZ_WRAPFD_H

fuzz.h

@@ -0,0 +1,72 @@
+#ifndef DROPBEAR_FUZZ_H
+#define DROPBEAR_FUZZ_H
+
+#include "config.h"
+
+#if DROPBEAR_FUZZ
+
+#include "includes.h"
+#include "buffer.h"
+#include "algo.h"
+#include "fuzz-wrapfd.h"
+
+// once per process
+void fuzz_common_setup(void);
+void fuzz_svr_setup(void);
+
+// must be called once per fuzz iteration. 
+// returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE
+int fuzz_set_input(const uint8_t *Data, size_t Size);
+
+int fuzz_run_preauth(const uint8_t *Data, size_t Size, int skip_kexmaths);
+const void* fuzz_get_algo(const algo_type *algos, const char* name);
+
+// fuzzer functions that intrude into general code
+void fuzz_kex_fakealgos(void);
+int fuzz_checkpubkey_line(buffer* line, int line_num, char* filename,
+        const char* algo, unsigned int algolen,
+        const unsigned char* keyblob, unsigned int keybloblen);
+extern const char * const * fuzz_signkey_names;
+void fuzz_seed(void);
+void fuzz_get_socket_address(int fd, char **local_host, char **local_port,
+                        char **remote_host, char **remote_port, int host_lookup);
+void fuzz_fake_send_kexdh_reply(void);
+
+// fake IO wrappers
+#ifndef FUZZ_SKIP_WRAP
+#define select(nfds, readfds, writefds, exceptfds, timeout) \
+        wrapfd_select(nfds, readfds, writefds, exceptfds, timeout)
+#define write(fd, buf, count) wrapfd_write(fd, buf, count)
+#define read(fd, buf, count) wrapfd_read(fd, buf, count)
+#define close(fd) wrapfd_close(fd)
+#endif // FUZZ_SKIP_WRAP
+
+struct dropbear_fuzz_options {
+    int fuzzing;
+
+    // fuzzing input
+    buffer *input;
+    struct dropbear_cipher recv_cipher;
+    struct dropbear_hash recv_mac;
+    int wrapfds;
+
+    // whether to skip slow bignum maths
+    int skip_kexmaths;
+
+    // dropbear_exit() jumps back
+    int do_jmp;
+    sigjmp_buf jmp;
+
+    uid_t pw_uid;
+    gid_t pw_gid;
+    char* pw_name;
+    char* pw_dir;
+    char* pw_shell;
+    char* pw_passwd;
+};
+
+extern struct dropbear_fuzz_options fuzz;
+
+#endif // DROPBEAR_FUZZ
+
+#endif /* DROPBEAR_FUZZ_H */

fuzzer-kexcurve25519.c

@@ -0,0 +1,72 @@
+#include "fuzz.h"
+#include "session.h"
+#include "fuzz-wrapfd.h"
+#include "debug.h"
+#include "runopts.h"
+#include "algo.h"
+#include "bignum.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+	static int once = 0;
+	static struct key_context* keep_newkeys = NULL;
+	/* number of generated parameters is limited by the timeout for the first run.
+	   TODO move this to the libfuzzer initialiser function instead if the timeout
+	   doesn't apply there */
+	#define NUM_PARAMS 20
+	static struct kex_curve25519_param *curve25519_params[NUM_PARAMS];
+
+	if (!once) {
+		fuzz_common_setup();
+		fuzz_svr_setup();
+
+		keep_newkeys = (struct key_context*)m_malloc(sizeof(struct key_context));
+		keep_newkeys->algo_kex = fuzz_get_algo(sshkex, "curve25519-sha256");
+		keep_newkeys->algo_hostkey = DROPBEAR_SIGNKEY_ED25519;
+		ses.newkeys = keep_newkeys;
+
+		/* Pre-generate parameters */
+		int i;
+		for (i = 0; i < NUM_PARAMS; i++) {
+			curve25519_params[i] = gen_kexcurve25519_param();
+		}
+
+		once = 1;
+	}
+
+	if (fuzz_set_input(Data, Size) == DROPBEAR_FAILURE) {
+		return 0;
+	}
+
+	m_malloc_set_epoch(1);
+
+	if (setjmp(fuzz.jmp) == 0) {
+		/* Based on recv_msg_kexdh_init()/send_msg_kexdh_reply() 
+		with DROPBEAR_KEX_CURVE25519 */
+		ses.newkeys = keep_newkeys;
+
+		/* Choose from the collection of curve25519 params */
+		unsigned int e = buf_getint(fuzz.input);
+		struct kex_curve25519_param *curve25519_param = curve25519_params[e % NUM_PARAMS];
+
+		buffer * ecdh_qs = buf_getstringbuf(fuzz.input);
+
+		ses.kexhashbuf = buf_new(KEXHASHBUF_MAX_INTS);
+		kexcurve25519_comb_key(curve25519_param, ecdh_qs, svr_opts.hostkey);
+
+		mp_clear(ses.dh_K);
+		m_free(ses.dh_K);
+		buf_free(ecdh_qs);
+
+		buf_free(ses.hash);
+		buf_free(ses.session_id);
+		/* kexhashbuf is freed in kexdh_comb_key */
+
+		m_malloc_free_epoch(1, 0);
+	} else {
+		m_malloc_free_epoch(1, 1);
+		TRACE(("dropbear_exit longjmped"))
+		/* dropbear_exit jumped here */
+	}
+
+	return 0;
+}

fuzzer-kexdh.c

@@ -0,0 +1,76 @@
+#include "fuzz.h"
+#include "session.h"
+#include "fuzz-wrapfd.h"
+#include "debug.h"
+#include "runopts.h"
+#include "algo.h"
+#include "bignum.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+	static int once = 0;
+	static struct key_context* keep_newkeys = NULL;
+	/* number of generated parameters is limited by the timeout for the first run.
+	   TODO move this to the libfuzzer initialiser function instead if the timeout
+	   doesn't apply there */
+	#define NUM_PARAMS 20
+	static struct kex_dh_param *dh_params[NUM_PARAMS];
+
+	if (!once) {
+		fuzz_common_setup();
+		fuzz_svr_setup();
+
+		keep_newkeys = (struct key_context*)m_malloc(sizeof(struct key_context));
+		keep_newkeys->algo_kex = fuzz_get_algo(sshkex, "diffie-hellman-group14-sha256");
+		keep_newkeys->algo_hostkey = DROPBEAR_SIGNKEY_ECDSA_NISTP256;
+		ses.newkeys = keep_newkeys;
+
+		/* Pre-generate parameters */
+		int i;
+		for (i = 0; i < NUM_PARAMS; i++) {
+			dh_params[i] = gen_kexdh_param();
+		}
+
+		once = 1;
+	}
+
+	if (fuzz_set_input(Data, Size) == DROPBEAR_FAILURE) {
+		return 0;
+	}
+
+	m_malloc_set_epoch(1);
+
+	if (setjmp(fuzz.jmp) == 0) {
+		/* Based on recv_msg_kexdh_init()/send_msg_kexdh_reply() 
+		with DROPBEAR_KEX_NORMAL_DH */
+		ses.newkeys = keep_newkeys;
+
+		/* Choose from the collection of ecdh params */
+		unsigned int e = buf_getint(fuzz.input);
+		struct kex_dh_param * dh_param = dh_params[e % NUM_PARAMS];
+
+		DEF_MP_INT(dh_e);
+		m_mp_init(&dh_e);
+		if (buf_getmpint(fuzz.input, &dh_e) != DROPBEAR_SUCCESS) {
+			dropbear_exit("Bad kex value");
+		}
+
+		ses.kexhashbuf = buf_new(KEXHASHBUF_MAX_INTS);
+		kexdh_comb_key(dh_param, &dh_e, svr_opts.hostkey);
+
+		mp_clear(ses.dh_K);
+		m_free(ses.dh_K);
+		mp_clear(&dh_e);
+
+		buf_free(ses.hash);
+		buf_free(ses.session_id);
+		/* kexhashbuf is freed in kexdh_comb_key */
+
+		m_malloc_free_epoch(1, 0);
+	} else {
+		m_malloc_free_epoch(1, 1);
+		TRACE(("dropbear_exit longjmped"))
+		/* dropbear_exit jumped here */
+	}
+
+	return 0;
+}

fuzzer-kexecdh.c

@@ -0,0 +1,82 @@
+#include "fuzz.h"
+#include "session.h"
+#include "fuzz-wrapfd.h"
+#include "debug.h"
+#include "runopts.h"
+#include "algo.h"
+#include "bignum.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+	static int once = 0;
+	static const struct dropbear_kex *ecdh[3]; /* 256, 384, 521 */
+	static struct key_context* keep_newkeys = NULL;
+	/* number of generated parameters is limited by the timeout for the first run */
+	#define NUM_PARAMS 80
+	static struct kex_ecdh_param *ecdh_params[NUM_PARAMS];
+
+	if (!once) {
+		fuzz_common_setup();
+		fuzz_svr_setup();
+
+		/* ses gets zeroed by fuzz_set_input */
+		keep_newkeys = (struct key_context*)m_malloc(sizeof(struct key_context));
+		ecdh[0] = fuzz_get_algo(sshkex, "ecdh-sha2-nistp256");
+		ecdh[1] = fuzz_get_algo(sshkex, "ecdh-sha2-nistp384");
+		ecdh[2] = fuzz_get_algo(sshkex, "ecdh-sha2-nistp521");
+		assert(ecdh[0]);
+		assert(ecdh[1]);
+		assert(ecdh[2]);
+		keep_newkeys->algo_hostkey = DROPBEAR_SIGNKEY_ECDSA_NISTP256;
+		ses.newkeys = keep_newkeys;
+
+		/* Pre-generate parameters */
+		int i;
+		for (i = 0; i < NUM_PARAMS; i++) {
+			ses.newkeys->algo_kex = ecdh[i % 3];
+			ecdh_params[i] = gen_kexecdh_param();
+		}
+
+		once = 1;
+	}
+
+	if (fuzz_set_input(Data, Size) == DROPBEAR_FAILURE) {
+		return 0;
+	}
+
+	m_malloc_set_epoch(1);
+
+	if (setjmp(fuzz.jmp) == 0) {
+		/* Based on recv_msg_kexdh_init()/send_msg_kexdh_reply() 
+		with DROPBEAR_KEX_ECDH */
+		ses.newkeys = keep_newkeys;
+
+		/* random choice of ecdh 256, 384, 521 */
+		unsigned char b = buf_getbyte(fuzz.input);
+		ses.newkeys->algo_kex = ecdh[b % 3];
+
+		/* Choose from the collection of ecdh params */
+		unsigned int e = buf_getint(fuzz.input);
+		struct kex_ecdh_param *ecdh_param = ecdh_params[e % NUM_PARAMS];
+
+		buffer * ecdh_qs = buf_getstringbuf(fuzz.input);
+
+		ses.kexhashbuf = buf_new(KEXHASHBUF_MAX_INTS);
+		kexecdh_comb_key(ecdh_param, ecdh_qs, svr_opts.hostkey);
+
+		mp_clear(ses.dh_K);
+		m_free(ses.dh_K);
+		buf_free(ecdh_qs);
+
+		buf_free(ses.hash);
+		buf_free(ses.session_id);
+		/* kexhashbuf is freed in kexdh_comb_key */
+
+		m_malloc_free_epoch(1, 0);
+	} else {
+		m_malloc_free_epoch(1, 1);
+		TRACE(("dropbear_exit longjmped"))
+		/* dropbear_exit jumped here */
+	}
+
+	return 0;
+}