Dropbear SSH Server

Download releases - latest is 0.31 - .tar.bz2 .tar.gz Changelog

Dropbear 0.31 is the latest version, with various improvements. In particular logging is improved, and login recording works (so last/w/who will work). Note that 0.29 and earlier are insecure, so if you're using them, please upgrade.

Given this software is still in development, it is advisable to check back here from time to time for new releases.

I was looking for a small SSH 2 server to fit on a laptop with 4 megs ram and no hard disk, and couldn't find one which was satisfactory. I decided to write my own, and Dropbear is the result. It is close to ssh2 compliant, implementing most required parts of the IETF drafts. On the todo list are X11/tcp/agent forwarding, pam, and a few other things.

Platforms I have tested are:

It shouldn't be hard to get it to work on other POSIX platforms, its mostly a case of setting up the configure options correctly.

Dropbear is stable enough for personal use, though hasn't been widely tested, so if you want to use it for something important - do some testing first.

The crypto algorithms are based on Tom St Denis's LibTomCrypt, and use his LibTomMath library for the bignum stuff. Some parts such as the pty code are taken from OpenSSH (from Tatu Ylönen's original ssh), login recording (utmp/wtmp) code is from OpenSSH by Andre Lucas, and some of the other code was based on ideas from PuTTY.

A package for LEAF Bering is in the leaf-bering subdirectory.

My email address is matt (at) ucc.gu.uwa.edu.au if you want to give me feedback - I want to know how well it does (or doesn't) work.
Matt Johnston

Note: Export of cryptographic software from Australia is subject to export controls - you should ensure that you are not breaching these controls. see Crypto Law Survey.