7.5. Summary

In this chapter, we studied the SSH protocol, a drop-in replacement for telnet, ftp, and the BSD r-commands. The protocol has two incompatible versions, but most implementations support them both.

SSHv1, the older protocol version, can provide a secure remote shell session, a secure channel between any two distributed applications—whether or not they are SSH-aware—X11 and port forwarding, and the secure file copy utility, scp. The server and user authentication mechanisms that SSHv1 uses ensure that the SSH client is talking to the correct server, and that the user is authorized to connect to the server.