Passwordless ssh login

To create a passwordless ssh login, first generate a new authentication key:

ssh-keygen -t rsa

It will prompt you to specify a filename for the key, choose something unique. Skip setting a passphrase by hitting return.

Next copy the public key to the remote server, adding it to the list of authorized keys.

cat ~/.ssh/ | ssh username@servername "cat >> ~/.ssh/authorized_keys"

If either the .ssh directory or authorized_keys file don’t exist, create them with the following permissions:

chmod 700 ~/.ssh
chmod 600 ~/.ssh/authorized_keys

Now, when logging into the server specify which key to use by setting the -i flag.

ssh -i $HOME/.ssh/unique_key_name username@servername

Finally, create an entry in your ~/.ssh/config file to allow for a more simple login.

Host mellowalias
    Hostname servername
    IdentityFile ~/.ssh/unique_key_name
    User username