Pam ssh agent auth

The PAM module allows a locally installed SSH key to authenticate for. This is useful for those who are not happy with completely passwordless sudo, but do not want to be frequently typing passwords.

Create SSH keys
Have each user that would like this capability to follow the guide on the SSH wiki page to create SSH keys.

PAM sudo file
Configure sudo to try using public keys, then fall back to normal password authentication:

Configure sudoers to preserve the environment variable SSH_AUTH_SOCK :

Add desired user's public key
Repeat this process for each user desired for sudo authentication: