passwordless ssh, this is how I set up for linux to freebsd
a@A:~> ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/a/.ssh/id_rsa):
Created directory ‘/home/a/.ssh’.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/a/.ssh/id_rsa.
Your public key has been saved in /home/a/.ssh/id_rsa.pub.
The key fingerprint is:
3e:4f:05:79:3a:9f:96:7c:3b:ad:e9:58:37:bc:37:e4 a@A
a@A:~> ssh b@B mkdir -p .ssh
b@B’s password:
a@A:~> cat .ssh/id_rsa.pub | ssh b@B ‘cat >> .ssh/authorized_keys’
b@B’s password:
Put the public key in .ssh/authorized_keys2
Change the permissions of .ssh to 700
Change the permissions of .ssh/authorized_keys2 to 640