005-ssh-hardening

Tues Sept 21, 2021

Just a quick note/reminder that one of the FIRST things you should ALWAYS do on a new machine is make sure:

1. root cannot log in (PermitRootLogin no)
2. passwords are not accepted (ssh-key only -- PasswordAuthentication no)

Both these are set under /etc/ssh/sshd_config. Make sure to upload your ~/.ssh/id_rsa.pub first to ~/.ssh/authorized_keys (so as not to lock yourself out!) and then make the edits and reload the daemon:

# rcctl reload sshd

We waited literally only 4 hrs to do this and we already had script kiddies knocking down our /var/log/authlog :(

If my old coworker Joe was right about one thing, it's that the internet these days is a cesspool.