These changes were identified by building with and without
-D_TIME_BITS=64 -D_FILE_OFFSET_BITS=64
on 32-bit arm, logging warnings to files.
-Wconversion was added to CFLAGS in both builds.
Then a "diff -I Wconversion log1 log2" shows new warnings that appear
with the 64-bit time_t. There are a few false positives that have been
fixed for quietness.
struct logininfo and struct wtmp are still problematic, those will
need to be handled by libc.
Since re-exec change in 2022.82 Dropbear count
treat authenticated sessions towards the unauthenticated
session limit. This is fixed by passing the childpipe FD
through to the re-execed process.
This allows ASLR to re-randomize the address
space for every connection, preventing some
vulnerabilities from being exploitable by
repeated probing.
Overhead (memory and time) is yet to be confirmed.
At present this is only enabled on Linux. Other BSD platforms
with fexecve() would probably also work though have not been tested.
* Implemented dynamic loading of an external plug-in shared library to delegate public key authentication
* Moved conditional compilation of the plugin infrastructure into the configure.ac script to be able to add -ldl to dropbear build only when the flag is enabled
* Added tags file to the ignore list
* Updated API to have the constructor to return function pointers in the pliugin instance. Added support for passing user name to the checkpubkey function. Added options to the session returned by the plugin and have dropbear to parse and process them
* Added -rdynamic to the linker flags when EPKA is enabled
* Changed the API to pass a previously created session to the checkPubKey function (created during preauth)
* Added documentation to the API
* Added parameter addrstring to plugin creation function
* Modified the API to retrieve the auth options. Instead of having them as field of the EPKASession struct, they are stored internally (plugin-dependent) in the plugin/session and retrieved through a pointer to a function (in the session)
* Changed option string to be a simple char * instead of unsigned char *
For the sake of review, this commit alters only the code; the affiliated
comments within the source files also need to be updated, but doing so
now would obscure the operational changes that have been made here.
* All on/off options have been switched to the numeric `#if' variant;
that is the only way to make this `default_options.h.in' thing work
in a reasonable manner.
* There is now some very minor compile-time checking of the user's
choice of options.
* NO_FAST_EXPTMOD doesn't seem to be used, so it has been removed.
* ENABLE_USER_ALGO_LIST was supposed to be renamed DROPBEAR_USER_ALGO_LIST,
and this commit completes that work.
* DROPBEAR_FUZZ seems to be a relatively new, as-yet undocumented option,
which was added by the following commit:
commit 6e0b539e9c
Author: Matt Johnston <matt@ucc.asn.au>
Date: Tue May 23 22:29:21 2017 +0800
split out checkpubkey_line() separately
It has now been added to `sysoptions.h' and defined as `0' by default.
* The configuration option `DROPBEAR_PASSWORD_ENV' is no longer listed in
`default_options.h.in'; it is no longer meant to be set by the user, and
is instead left to be defined in `sysoptions.h' (where it was already being
defined) as merely the name of the environment variable in question:
DROPBEAR_PASSWORD
To enable or disable use of that environment variable, the user must now
toggle `DROPBEAR_USE_DROPBEAR_PASSWORD'.
* The sFTP support is now toggled by setting `DROPBEAR_SFTPSERVER', and the
path of the sFTP server program is set independently through the usual
SFTPSERVER_PATH.
Add support for '-T n' for a run-time specification for maximum number
of authentication attempts where 'n' is between 1 and compile time
option MAX_AUTH_TRIES.
A default number of tries can be specified at compile time using
'DEFAULT_AUTH_TRIES' which itself defaults to MAX_AUTH_TRIES for
backwards compatibility.
Signed-off-by: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>
This change adds a -c option to dropbear, to force the session to use a
specific command, in a similar fashion to OpenSSH's ForceCommand
configuration option.
This is useful to provide a simple fixed service over ssh, without
requiring an authorized key file for the per-key forced_command option.
This setting takes precedence over the channel session's provided
command, and the per-key forced_command setting.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
