Write CHANGES since last release

CHANGES

@@ -1,9 +1,125 @@
-- The following config paths are now relative to a home directory if
-  starting with "~". Thanks to Begley Brothers Inc
-  *_PRIV_FILENAME
-  DROPBEAR_PIDFILE
-  SFTPSERVER_PATH
-  MOTD_FILENAME
+Future Release
+Features and Changes:
+
+- Implement OpenSSH format private key handling for dropbearconvert.
+  Keys can be read in OpenSSH format or the old PEM format, they will be
+  written in OpenSSH format. (DSS has not been implemented).
+  ED25519 support is now correct.
+
+- Use SHA256 for key fingerprints
+
+- Reworked -v verbose printing, specifying multiple times will increase
+  verbosity. -vvvv is equivalent to the old DEBUG_TRACE -v level, it
+  can be configured at compile time in localoptions.h (see default_options.h)
+  Lower -v options can be used to check connection progress or algorithm
+  negotiation.
+  Thanks to Hans Harder for the implementation
+
+  > > localoptions.h DEBUG_TRACE should be set to 4 for the same result as the
+  previous DEBUG_TRACE 1.
+
+- Added server support for U2F/FIDO keys (ecdsa-sk and ed25519-sk) in
+  authorized_keys. no-touch-required option isn't allowed yet.
+  Thanks to Egor Duda for the implementation
+
+- autoconf output (configure script etc) is now committed to version control.
+  It isn't necessary to run "autoconf" any more on a checkout.
+
+- sha1 will be omitted from the build if KEX/signing/MAC algorithms don't
+  require it. Instead sha256 is used for random number generation.
+  See sysoptions.h to see which algorithms require which hashes.
+
+- Set SSH_PUBKEYINFO environment variable based on the authorized_keys
+  entry used for auth. The first word of the comment after the key is used
+  (must only have characters a-z A-Z 0-9 .,_-+@)
+  Patch from Hans Harder, modified by Matt Johnston
+
+- Allow home-directory relative paths ~/path for various settings
+  and command line options.
+  *_PRIV_FILENAME DROPBEAR_PIDFILE SFTPSERVER_PATH MOTD_FILENAME
+  Thanks to Begley Brothers Inc
+
+  > > The default DROPBEAR_DEFAULT_CLI_AUTHKEY has now changed, it now needs
+  a tilde prefix.
+
+- LANG environment variable is carried over from the Dropbear server process
+  From Maxim Kochetkov
+
+- Add /usr/sbin and /sbin to $PATH when logging in as root.
+  Patch from Raphaël Hertzog
+  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=903403
+
+- Added client option "-o DisableTrivialAuth". This can be used to prevent
+  the server immediately allowing successful authentication (before any auth
+  request) which could cause UI confusion and security issues with agent
+  forwarding - it isn't clear which host is prompting to use a key.
+  Thanks to Manfred Kaiser from Austrian MilCERT
+
+- Add -q client option to hide remote banner, from Hans Harder
+
+- Add -e option to pass all server environment variables to child processes.
+  This should be used with caution.
+  Patch from Roland Vollgraf (github #118)
+
+- Use DSCP for QoS traffic classes. Priority (tty) traffic is now set to
+  AF21 "interactive". Previously TOS classes were used, they are not used by
+  modern traffic classifiers. Non-tty traffic is left at default priority.
+
+- Disable dh-group1 key exchange by default. It has been disabled server
+  side by default since 2018.
+
+- Removed Twofish cipher
+
+Fixes:
+
+- Fix flushing channel data when pty was allocated (github #85)
+  Data wasn't completely transmitted at channel close.
+  Reported and initial patch thanks to Yousong Zhou
+
+- Dropbear now re-executes itself rather than just forking for each connection
+  (only on Linux). This allows ASLR to randomise address space for each
+  connection as a security mitigation. It should not have any visible impact
+  - if there are any performance impacts in the wild please report it.
+
+- Check authorized_keys permissions as the user, fixes NFS squash root.
+  Patch from Chris Dragan (github #107)
+
+- A missing home directory is now non-fatal, starting in / instead
+
+- Improve error logging so that they are logged on the server rather than being
+  sent to the client over the connection
+
+- Max window size is increased to 10MB, more graceful fallback if it's invalid.
+
+- Fix correctness of Dropbear's handling of global requests.
+  Patch from Dirkjan Bussink
+
+- Fix some small bugs found by fuzzers, null pointer dereference crash and leaks
+  (post authentication)
+
+- $HOME variable is used before /etc/passwd when expanding paths such as
+  ~/.ssh/id_dropbear (for the client). Patch from Matt Robinson
+
+- C89 build fixes from Guillaume Picquet
+
+Infrastructure:
+
+- Improvements to fuzzers. Added post-auth fuzzer, and a mutator that can
+  handle the structure of SSH packet streams. Added cifuzz to run on commits
+  and pull requests.
+
+- Dropbear source tarballs generated by release.sh are now reproducible from a
+  Git or Mercurial checkout, they will be identical on any system. Tested
+  on ubuntu and macos.
+
+- Added some integration testing using pytest. Currently this has tests
+  for various channel handling edge cases, ASLR fork randomisation,
+  dropbearconvert, and SSH_PUBKEYINFO
+
+- Set up github actions. This runs the pytest suite and other checks.
+  - build matrix includes c89, dropbearmulti, bundled libtom, macos, DEBUG_TRACE
+  - test for configure script regeneration
+  - build a tarball for external reproducibility
 
 2020.81 - 29 October 2020