For a server I manage, I explicitly want to receive notification emails of successful ssh logins. I've enabled this, and allow-listed my own fixed IP address.
My customer can login to one account using ssh, but doesn't have a fixed ip. Is there a way to allow-list the public ssh key he's using?
An example of such notification would be:
Nov 28 13:05:51 srv sshd[3474329]: Accepted publickey for shops-live from 6X.X5.1X1.XX port 24X47 ssh2: RSA SHA256:EXXhaPXXXXXX+wXXXXXXb3CI3XXXXXXT5jYOXXXXXZMg