Shell Programming and Scripting

Setting up keys for passwordless authentication isn't rocket science. On the machine you want to connect from run

Code:

ssh-keygen -t dsa < /dev/null

That will create a private and a public key called ~/.ssh/id_dsa and id_dsa.pub. Now, copy the contents of id_dsa.pub into the file ~/.ssh/authorized_keys2 on the machine you want to connect to, eg

Code:

cat ~/.ssh/id_dsa.pub | ssh user@remote 'mkdir -p .ssh; cat >> .ssh/authorized_keys2'

If you connect afterward, you shouldn't be promped for a password. If you try to connect from a machine that hasn't got the private key, you'll still be asked for a password.

IMHO, it's more secure than passwords in scripts. They're impossible to guess, easy to revoke (just remove the entry from the authorized_keys2 file), and you can even tie access to a specific user on a specific machine (just allow only that one unique key). if you're uncomfortable with the procedure, experiment on some non-critical machines first (eg. some development machines or VMs)

maybe something like this?

Code:

#!/usr/bin/expect
set timeout 20
spawn  ssh [server-ip]
expect "[something from the login prompt]"
send "[username]\r"
expect "[something from the passwd prompt]"
send "[passwd]\r"