SSH, The Secure Shell: The Definitive Guide, 2nd Edition
by Daniel J. Barrett, Richard E. Silverman, Robert G. Byrnes
Client Features: ssh, scp, and sftp
OpenSSH clients have new features pertaining to keyboard-interactive authentication, connection sharing, known-hosts handling, port forwarding, and command-line editing and history.
KbdInteractiveDevices Keyword
The KbdInteractiveDevices keyword was
undocumented in OpenSSH 3.9, but now it’s officially supported. It
determines the devices that the client will try for
keyboard-interactive authentication.
KbdInteractiveDevices = pam,skey,bsdauth
More Control for Connection Sharing
If you’re using the connection-sharing feature of ssh, you can now control the master process of that connection with the -O option. To check whether you’re using connection sharing, run the following:
$ ssh -O check server.example.com
To request the master process to exit, run the following:
$ ssh -O exit server.example.com
Hashing of Hostnames
In previous versions of OpenSSH, known_host files contain the hostnames and
IP addresses of the computer’s you’ve visited via SSH. If you’d like
to keep this information more private, use the new HashKnownHosts configuration keyword in your
client configuration file:
HashKnownHosts yes
SSH clients will now hash the hostnames so they look like random strings—for example:
|1|Un5Q61BdVPCq65Yj3ec/HH6r+zI=|2pPQE/qjP7rrPLblvS1epjYbUOs=
This feature is experimental at the moment, so use it at your own risk.
Port Forwarding
When you construct a port forwarding, you can now specify a bind address: the address on which the accepting side of the forwarding ...