http://us3.aminet.net/comm/tcp/openssh-bin.lha
OpenSSH comes with command line ssh.
That's for OS4. If you need one for 3.x, go here
http://www.chernoff.org/amiga/The only problem I have with it is CTRL-C breaks the CLI, not the remote session. Whoops. Mind you, I have never tried in anything other than the Amiga Shell.
EDIT: The AmiNet icon says OS4... I have not downloaded it to try, sorry.