view CHANGES @ 291:55a99934db87 DROPBEAR_0.48

0.48 bump
author Matt Johnston <>
date Thu, 09 Mar 2006 15:03:22 +0000
parents 94ee16f5b8a8
children 03f65e461915
line wrap: on
line source
0.48 - Thurs 9 March 2006

- Check that the circular buffer is properly empty before
  closing a channel, which could cause truncated transfers
  (thanks to Tomas Vanek for helping track it down)

- Implement per-IP pre-authentication connection limits 
  (after some poking from Pablo Fernandez)

- Exit gracefully if trying to connect to as SSH v1 server 
  (reported by Rushi Lala)

- Only read /dev/random once at startup when in non-inetd mode

- Allow ctrl-c to close a dbclient password prompt (may
  still have to press enter on some platforms)

- Merged in uClinux patch for inetd mode

- Updated to scp from OpenSSH 4.3p2 - fixes a security issue
  where use of system() could cause users to execute arbitrary
  code through malformed filenames, ref CVE-2006-0225

0.47 - Thurs Dec 8 2005

- 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).

- Fix channel handling code so that redirecting to /dev/null doesn't use
  100% CPU.

- Turn on zlib compression for dbclient.

- Set "low delay" TOS bit, can significantly improve interactivity
  over some links.

- Added client keyboard-interactive mode support, allows operation with
  newer OpenSSH servers in default config.

- Log when pubkey auth fails because of bad ~/.ssh/authorized_keys permissions

- Improve logging of assertions

- Added aes-256 cipher and sha1-96 hmac.

- Fix twofish so that it actually works.

- Improve PAM prompt comparison.

- Added -g (dbclient) and -a (dropbear server) options to allow
  connections to listening forwarded ports from remote machines.

- Various other minor fixes

- Compile fixes for glibc 2.1 (ss_family vs __ss_family) and NetBSD
  (netinet/in_systm.h needs to be included).

0.46 - Sat July 9 2005

- Fix long-standing bug which caused connections to be closed if an ssh-agent
  socket was no longer available

- Print a warning if we seem to be blocking on /dev/random 
  (suggested by Paul Fox)

- Fixed a memory leak in DSS code (thanks to Boris Berezovsky for the patch)

- dbclient -L no longer segfaults, allocate correct buffer size (thanks
  to David Cook for reporting it, and Christopher Faylor for independently
  sending in a patch)

- Added RSA blinding to signing code (suggested by Dan Kaminsky)

- Rearranged bignum reading/random generation code

- Reset the non-blocking status on stderr and stdout as well as stdin,
  fixes a problem where the shell running dbclient will exit (thanks to 
  Brent Roman for reporting it)

- Fix so that all file descriptors are closed so the child shell doesn't
  inherit descriptors (thanks to Linden May for the patch)

- Change signkey.c to avoid gcc 4 generating incorrect code

- After both sides of a file descriptor have been shutdown(), close()
  it to avoid leaking descriptors (thanks to Ari Hyttinen for a patch)

- Update to LibTomCrypt 1.05 and LibTomMath 0.35

0.45 - Mon March 7 2005

- Makefile no longer appends 'static' to statically linked binaries

- Add optional SSH_ASKPASS support to the client

- Respect HOST_LOOKUP option

- Fix accidentally removed "return;" statement which was removed in 0.44
  (causing clients which sent an empty terminal-modes string to fail to
  connect - including pssh,, danger hiptop). (patches
  independently from Paul Fox, David Horwitt and Sven-Ola Tuecke)

- Read "y/n" response for fingerprints from /dev/tty directly so that dbclient
  will work with scp.

0.44 - Mon Jan 3 2005

- SECURITY: Fix for PAM auth so that usernames are logged and conversation
  function responses are allocated correctly - all 0.44test4 users with PAM
  compiled in (not default) are advised to upgrade.

- Fix calls to getnameinfo() for compatibility with Solaris

- Pristine compilation works (run 'configure' from a fresh dir and make it

- Fixes for compiling with most options disabled.

- Upgraded to LibTomCrypt 0.99 and LibTomMath 0.32

- Make sure that zeroing out of values in LTM and LTC won't get optimised away

- Removed unused functions from loginrec.c

- /dev/random is now the default entropy source rather than /dev/urandom

- Logging of IPs in auth success/failure messages for improved greppability

- Fix dbclient so that "scp -i keyfile" works. (It can handle "-ikeyfile

- Avoid a race in server shell-handling code which prevents the exit-code
  from being returned to the client in some circumstances.

- Makefile modified so that install target works correctly (doesn't try
  to install "all" binary) - patch from Juergen Daubert

- Various minor fixes and compile warnings.

0.44test4 - Tue Sept 14 2004 21:15:54 +0800

- Fix inetd mode so it actually loads the hostkeys (oops)

- Changed DROPBEAR_DEFPORT properly everywhere

- Fix a small memory leak in the auth code

- WCOREDUMP is only used on systems which support it (ie not cygwin or AIX)

- Check (and fail for) cases when we can't negotiate algorithms with the
  remote side successfully (rather than bombing out ungracefully)

- Handle authorized_keys files without a terminating newline

- Fiddle the channel receive window size for possibly better performance

- Added in the PAM authentication code (finally! thanks to Martin Carlsson)

0.44test3 - Fri Aug 27 22:20:54 +0800

- Fixed a bunch of warnings.

- scp works correctly when passed a username (fix for the dbclient program
  itself as well, "-lmatt" works as well as "-l matt").

- Remove unrequired debian files

- Exit with the remote process's return code for dbclient

- Display stderr messages from the server in the client

- Add circular buffering to the channel code. This should dramatically reduce
  the amount of backtraffic sent in response to traffic incoming to the
  Dropbear end - improves high-latency performance (ie dialup).

- Various other related channel-handling fixups.

- Allow leading lines in the banner when connecting to servers

- Fixed printing out errors onto the network socket with stderr (for inetd
  mode when using xinetd)

- Remove obselete documentation

- Fix a null-pointer exception when trying to free non-existant listeners
  at cleanup.

- DEBUG_TRACE now only works if you add "-v" to the program commandline

- Don't leave stdin non-blocking on exit - this caused the parent shell
  of dbclient to close when dbclient exited, for some shells in BusyBox

- Server connections no longer timeout after 5 minutes

- Fixed stupid DSS hostkey typo (server couldn't load host keys)

0.44test2 - Tues Aug 17 2004 17:43:54 +0800

- Fix up dropbearmulti targets in the Makefile - symlinks are now created

- Compile fake-rfc2553 even with dropbearconvert/dropbearkey - this 
  allows them to work on platforms without a native getaddrinfo()

- Create ~/.ssh/known_hosts properly if it doesn't exist

- Fix basename() function prototype

- Backport some local changes (more #ifdefs for termcodes.c, a fix for missing
  defines on AIX).

- Let dbclient be run as "ssh"

- Initialise mp_ints by default

0.44test1 - Sun Aug 16 2005 17:43:54 +0800

- TESTING RELEASE - this is the first public release of the client codebase,
  so there are sure to be bugs to be found. In addition, if you're just using
  the server portion, the final binary size probably will increase - I'll
  be trying to get it back down in future releases.

- Dropbear client added - lots of changes to the server code as well to 
  generalise things

- IPv6 support added for client, server, and forwarding

- New makefile with more generic support for multiple-program binaries

0.43 - Fri Jul 16 2004 17:44:54 +0800

- 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

- Clean up agent forwarding socket files correctly, patch from Gerrit Pape.

- Don't go into an infinite loop when portforwarding to servers which don't
  send any initial data/banner. Patch from Nikola Vladov

- Fix for network vs. host byte order in logging remote TCP ports, also
  from Gerrit Pape.

- Initialise many pointers to NULL, for general safety. Also checked cleanup
  code for mp_ints (related to security issues above).

0.42 - Wed Jun 16 2004 12:44:54 +0800

- Updated to Gerrit Pape's official Debian subdirectory

- Fixed bad check when opening /dev/urandom - thanks to Danny Sung.

- Added -i inetd mode flag, and associated options in options.h . Dropbear
  can be compiled with either normal mode, inetd, or both modes. Thanks
  to Gerrit Pape for basic patch and motivation.

- Use <dirent.h> rather than <sys/dir.h> for POSIX compliance. Thanks to Bill

- Fixed a TCP forwarding (client-local, -L style) bug which caused the whole
  session to close if the TCP connection failed. Thanks to Andrew Braund for
  reporting it and helping track it down.

- Re-enable sigpipe for child processes. Thanks to Gerrit Pape for some
  suggestions, and BSD manpages for a clearer explanation of the behaviour.

- Added manpages, thanks to Gerrit Pape.

- Changed license text for LibTomCrypt and LibTomMath.

- Added strip-static target

- Fixed a bug in agent-forwarding cleanup handler - would segfault
  (dereferencing a null pointer) if agent forwarding had failed.

- Fix behaviour of authorized_keys parsing, so larger (>1024 bit) DSA keys will
  work. Thanks to Dr. Markus Waldeck for the report. 

- Fixed local port forwarding code so that the "-j" option will make forwarding
  attempts fail more gracefully.

- Allow repeated requests in a single session if previous ones fail - this fixes  PuTTY and some other SCP clients, which try SFTP, then fall-back to SCP if it
  isn't available. Thanks to Stirling Westrup for the report.

- Updated to LibTomCrypt 0.96 and LibTomMath 0.30. The AES code now uses
  smaller non-precomputed tables if DROPBEAR_SMALL_CODE is defined in
  options.h, leading to a significant reduction in the binary size.

0.41 - Mon Jan 19 2004 22:40:19 +0800

- Fix in configure so that cross-compiling works, thanks to numerous people for
  reporting and testing

- Terminal mode parsing now handles empty terminal mode strings (sent by
  Windows clients), thanks to Ricardo Derbes for the report

- Handling is improved for users with no shell specified in /etc/passwd,
  thanks again to Ricardo Derbes

- Fix for compiling with --disable-syslog, thanks to gordonfh

- Various minor fixes allow scp to work with irix, thanks to Paul Marinceu for
  fixing it up

- Use <stropts.h> not <sys/stropts.h>, since the former seems more common

0.40 - Tue Jan 13 2004 21:05:19 +0800

- Remote TCP forwarding (-R) style implemented

- Local and remote TCP forwarding can each be disabled at runtime (-k and -j

- Fix for problems detecting openpty() with uClibc - many thanks to various
  people for reporting and testing fixes, including (in random order) Cristian
  Ionescu-Idbohrn, James Ewing, Steve Dover, Thomas Lundquist and Frederic

- Improved portability for IRIX, thanks to Paul Marinceu

- AIX and HPUX portability fixes, thanks to Darren Tucker for patches

- prngd should now work correctly, thanks to Darren Tucker for the patch

- scp compilation on systems without strlcpy() is fixed, thanks to Peter
  Jannesen and David Muse for reporting it (independently and simultaneously :)

- Merged in new LibTomCrypt 0.92 and LibTomMath 0.28

0.39 - Tue Dec 16 2003 15:19:19 +0800

- Better checking of key lengths and parameters for DSS and RSA auth

- Print fingerprint of keys used for pubkey auth

- More consistent logging of usernames and IPs

- Added option to disable password auth (or just for root) at runtime

- Avoid including bignum functions which don't give much speed benefit but
  take up binary size

- Added a stripped down version of OpenSSH's scp binary

- Added additional supporting functions for Irix, thanks to Paul Marinceu

- Don't check for unused libraries in configure script

- Removed trailing comma in algorithm lists (thanks to Mihnea Stoenescu)

- Fixed up channel close handling, always send close packet in response
  (also thanks to Mihnea Stoenescu)

- Various makefile improvements for cross-compiling, thanks to Friedrich
  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
  Blackham for his suggestion on what to look at)

- Fixed up support for first_kex_packet_follows, required to talk to
  clients. Thanks to Marian Stagarescu for the bug report.

- Avoid using MAXPATHLEN, pointer from Ian Morris

- Improved input sanity checking

0.38 - Sat Oct 11 2003 16:28:13 +0800

- Default hostkey path changed to /etc/dropbear/dropbear_{rsa,dss}_host_key
  rather than /etc/dropbear_{rsa,dss}_host_key

- Added SMALL and MULTI text files which have info on compiling for multiple
  binaries or small binaries

- Allow for commandline definition of some options.h settings
  (without warnings)

- Be more careful handling EINTR

- More fixes for channel closing

- Added multi-binary support

- Improved logging of IPs, now get logged in all cases

- Don't chew cpu when waiting for version identification string, also
  make sure that we kick off people if they don't auth within 5 minutes.

- Various small fixes, warnings etc

- Display MOTD if requested - suggested by
  Trent Lloyd <lathiat at> and
  Zach White <zwhite at>

- sftp support works (relies on OpenSSH sftp binary or similar)

- Added --disable-shadow option (requested by the floppyfw guys)

0.37 - Wed Sept 24 2003 19:42:12 +0800

- Various portability fixes, fixes for Solaris 9, Tru64 5.1, Mac OS X 10.2,

- Updated LibTomMath to 0.27 and LibTomCrypt to 0.90

- Renamed util.{c,h} to dbutil.{c,h} to avoid conflicts with system util.h

- Added some small changes so it'll work with AIX (plus Linux Affinity).
  Thanks to Shig for them.

- Improved the closing messages, so a clean exit is "Exited normally"

- Added some more robust integer/size checking in buffer.c as a backstop for
  integer overflows

- X11 forwarding fixed for OSX, path for xauth changed to /usr/X11R6/bin/xauth

- Channel code handles closing more nicely, doesn't sit waiting for an extra
  keystroke on BSD/OSX platforms, and data is flushed fully before closing
  child processes (thanks to 
  Cristian Ionescu-Idbohrn <cristian.ionescu-idbohrn at> for
  pointing that out).

- Changed "DISABLE_TCPFWD" to "ENABLE_TCPFWD" (and for x11/auth) so
  "disable DISABLE_TCPWD" isn't so confusing.

- Fix authorized_keys handling (don't crash on too-long keys, and
  use fgetc not getc to avoid strange macro-related issues), thanks to
  Cristian Ionescu-Idbohrn <cristian.ionescu-idbohrn at> 
  and Steve Rodgers <hwstar at> for reporting and testing.

- Fixes to the README with regard to uClibc systems, thanks to 
  Cristian Ionescu-Idbohrn <cristian.ionescu-idbohrn at>,
  as well as general improvements to documentation (split README/INSTALL)

- Fixed up some compilation problems with dropbearconvert/dropbearkey if
  DSS or RSA were disabled, reported by Patrik Karlsson <patrik at>

- Fix double-free bug for hostkeys, reported by
  Vincent Sanders <vince at>

- Fix up missing \ns from dropbearconvert help message,
  thanks to Mordy Ovits <movits at> for the patch

0.36 - Tue August 19 2003 12:16:23 +0800

- Fix uninitialised temporary variable in DSS signing code
  (thanks to Matthew Franz <mdfranz at> for reporting, and the authors
  of Valgrind for making it easy to track down)
- Fix remote version-string parsing error
  (thanks to Bernard Blackham <bernard at> for noticing)
- Improved host-algorithm-matching algorithm in algo.c
- Decreased MAX_STRING_LEN to a more realistic value
- Fix incorrect version (0.34) in this CHANGES file for the previous release.

0.35 - Sun August 17 2003 05:37:47 +0800

- Fix for remotely exploitable format string buffer overflow.
  (thanks to Joel Eriksson <je at>)

0.34 - Fri August 15 2003 15:10:00 +0800

- Made syslog optional, both at compile time and as a compile option
  (suggested by Laurent Bercot <ska at>)
- Fixup for bad base64 parsing in authorized_keys
  (noticed by Davyd Madeley <davyd at>)
- Added initial tcp forwarding code, only -L (local) at this stage
- Improved "make install" with DESTDIR and changing ownership seperately,
  don't check for setpgrp on Linux for crosscompiling.
  (from Erik Andersen <andersen at>)
- More commenting, fix minor compile warnings, make return values more
  consistent etc
- Various signedness fixes
- Can listen on multiple ports
- added option to disable openpty with configure script,
  (from K.-P. Kirchdörfer <kapeka at>)
- Various cleanups to bignum code
  (thanks to Tom St Denis <tomstdenis at>)
- Fix compile error when disabling RSA
  (from Marc Kleine-Budde <kleine-budde at>)
- Other cleanups, splitting large functions for packet and kex handling etc

0.33 - Sun June 22 2003 22:24:12 +0800

- Fixed some invalid assertions in the channel code, fixing the server dying
  when forwarding X11 connections.
- Add dropbearconvert to convert to/from OpenSSH host keys and Dropbear keys
- RSA keys now keep p and q parameters for compatibility -- old Dropbear keys
  still work, but can't be converted to OpenSSH etc.
- Debian packaging directory added, thanks to 
  Grahame (grahame at
- 'install' target added to the makefile
- general tidying, improve consistency of functions etc
- If RSA or DSS hostkeys don't exist, that algorithm won't be used.
- Improved RSA and DSS key generation, more efficient and fixed some minor bugs
  (thanks to Tom St Denis for the advice)
- Merged new versions of LibTomCrypt (0.86) and LibTomMath (0.21)

0.32 - Sat May 24 2003 12:44:11 +0800

- Don't compile unused code from libtomcrypt (test vectors etc)
- Updated to libtommath 0.17 and libtomcrypt 0.83. New libtommath results
  in smaller binary size, due to not linking unrequired code
- X11 forwarding added
- Agent forwarding added (for ssh client/agent)
- Fix incorrect buffer freeing when banners are used
- Hostname resolution works
- Various minor bugfixes/code size improvements etc

0.31 - Fri May 9 2003 17:57:16 +0800

- Improved syslog messages - IP logging etc
- Strip control characters from log messages (specified username currently)
- Login recording (utmp/wtmp) support, so last/w/who work - taken from OpenSSH
- Shell is started as a proper login shell, so /etc/profile etc is sourced
- Ptys work on Solaris (2.8 x86 tested) now
- Fixed bug in specifying the rsa hostkey
- Fixed bug in compression code, could trigger if compression resulted in
  larger output than input (uncommon but possible).

0.30 - Thu Apr 17 2003 18:46:15 +0800

- SECURITY: buffer.c had bad checking for buffer increment length - fixed
- channel code now closes properly on EOF - scp processes don't hang around
- syslog support added - improved auth/login/failure messages
- general code tidying, made return codes more consistent
- Makefile fixed for dependencies and makes libtomcrypt as well
- Implemented sending SSH_MSG_UNIMPLEMENTED :)

0.29 - Wed Apr 9 2003

- Fixed a stupid bug in 0.28 release, 'newstr = strdup(oldstr)',
  not 'newstr=oldstr'

0.28 - Sun Apr 6 2003

- Initial public release

Development was started in October 2002