ssh

Creating an RSA key

$ ssh-keygen -t rsa

By default, this will create two files at ~/.ssh: id_rsa and id_rsa.pub

Copying the public key to a server

$ ssh-copy-id -i .ssh/id_rsa.pub user@server

Setting the authorized_keys file

$ cat id_rsa.pub >> authorized_keys

Make sure files permissions are right

$ chmod 700 ~/.ssh

$ chmod 600 ~/.ssh/authorized_keys