I have a Lenovo X131e running Ubuntu Server 18.04.1 LTS and I wanted to be sure that I am doing all I can to secure the connection between the Ubuntu-book and my Mac Mini at home. I will be using the Ubuntu-book to remote back into my Mac while on campus.
Ive set up public key authentication and it appears to work; however, to force the use of the key on the Mac, I needed to modify the ssh_config file to the following...
PubKeyAuthentication yes PasswordAuthentication no ChallengeResponseAuthentication yes usePam no
!! - with usePam enabled, the Mac would allow password authentication despite having PasswordAuthentication disabled.
My main question is whether disabling PAM is opening up a vulnerability elsewhere?