I've used this thrice in three days, so I'm just keeping a copy for myself.
Sourced (i.e. blatant copy-paste) from: http://arbib.it/tag/shortest-passwordless-ssh-tutorial/
That in turn got it from http://blogs.translucentcode.org/mick/archives/000230.html
local$ ssh-keygen -t dsa local$ scp ~/.ssh/id_dsa.pub remote:~/ local$ ssh username@remote remote$ cat ~/id_dsa.pub >> ~/.ssh/authorized_keys remote$ chmod 644 ~/.ssh/authorized_keys remote$ exit local$ ssh username@remote
Now instead of the normal password you should be asked for the password you entered for your dsa key. This isn't passwordless yet but shows that ssh is using the key.
Note: Leave Key password blank to have passwordless authentication
Fixes for possible problems:
chmod 0600 authorized_keys ln -s authorized_keys2 authorized_keys (or viceversa)