Creating SSH key pairs

• First decide if you will be using SSH1 or SSH2 (or both). Most likely you'll want to stick with SSH1 (until OpenSSH is installed at PPPL, or until SSH2 is installed, etc).
• To generate public/private keypair for SSH1: ssh-keygen. This will generate ~/.ssh/identity and ~/.ssh/identity.pub.
• Do this on each machine you want to access (to/from) using ssh (only need to do this once on the PPPL unix cluster)
• Take all of the identity.pub files (which contain a public key on one line) and create an ~/.ssh/authorized_keys file by placing the contents of each separate identity.pub file on a single line of the ~/.ssh/authorized_keys file (then place on all sshable hosts).
• For SSH2, use ssh-keygen -t {rsa,dsa} (you choose between rsa keys or dsa keys, currently I use DSA), which will generate ~/.ssh/id_{dsa,rsa} and ~/.ssh/id_{dsa,rsa}.pub.
• Follow instructions for SSH1 keys, but instead generate a ~/.ssh/authorized_keys2 file using the id_{dsa,rsa}.pub files.