| 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: |
| ============================================================================ |
| |
| Server 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. Beware of editors that split the key into multiple lines. |
| |
| NOTE: Dropbear ignores authorized_keys options such as those described in the |
| OpenSSH sshd manpage, and will not allow a login for these keys. |
| |
| ============================================================================ |
| |
| Client public key auth: |
| |
| Dropbear can do public key auth as a client, but you will have to convert |
| OpenSSH style keys to Dropbear format, or use dropbearkey to create them. |
| |
| If you have an OpenSSH-style private key ~/.ssh/id_rsa, you need to do: |
| |
| dropbearconvert openssh dropbear ~/.ssh/id_rsa ~/.ssh/id_rsa.db |
| dbclient -i ~/.ssh/id_rsa.db <hostname> |
| |
| Currently encrypted keys aren't supported, neither is agent forwarding. At some |
| stage both hopefully will be. |
| |
| ============================================================================ |
| |
| 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 by _PATH_SSH_PROGRAM in options.h . By default |
| the progress meter isn't compiled in to save space, you can enable it by |
| adding 'SCPPROGRESS=1' to the make commandline. |
