This is Dropbear, a smallish SSH 2 server and client. INSTALL has compilation instructions. MULTI has instructions on making a multi-purpose binary (ie a single binary 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 :) Matt Johnston matt@ucc.asn.au In the absence of detailed documentation, some notes follow: ============================================================================ Public key auth: You can use ~/.ssh/authorized_keys in the same way as with OpenSSH, just put the key entries in that file. They should be of the form: ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAwVa6M6cGVmUcLl2cFzkxEoJd06Ub4bVDsYrWvXhvUV+ZAM9uGuewZBDoAqNKJxoIn0Hyd0Nk/yU99UVv6NWV/5YSHtnf35LKds56j7cuzoQpFIdjNwdxAN0PCET/MG8qyskG/2IE2DPNIaJ3Wy+Ws4IZEgdJgPlTYUBWWtCWOGc= someone@hostname You must make sure that ~/.ssh, and the key file, are only writable by the user. NOTE: Dropbear ignores authorized_keys options such as those described in the OpenSSH sshd manpage, and will not allow a login for these keys. ============================================================================ If you want to get the public-key portion of a Dropbear private key, look at 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 or alternatively convert OpenSSH keys to Dropbear: ./dropbearconvert openssh dropbear /etc/ssh/ssh_host_dsa_key dropbear_dss_host_key ============================================================================ If the server is run as non-root, you most likely won't be able to allocate a pty, and you cannot login as any user other than that running the daemon (obviously). Shadow passwords will also be unusable as non-root. ============================================================================ The Dropbear distribution includes a standalone version of OpenSSH's scp program. You can compile it with "make scp", you may want to change the path of the ssh binary, specified near the top of the scp.c file. By default the progress meter isn't compiled in to save space, you can enable it by adding 'SCPPROGRESS=1' to the make commandline.