After my successfull sudo test I was interested in 2fa for ssh. As a systemadministrator you are always scared about secure login just for you/your team.
Also ssh 2fa via yubikey is pretty straight forward. It needs some more work than just the sudo case but here we go.
Some days ago I thought about testing two factor authentication (2FA) with Yubikey. Yubikey is a hardware security key which can do a lot.
How to test 2FA on a local machine if you don’t want to log you out or destroy anything important? I decided to implement 2FA for
sudo command with yubikeys U2F feature. Be aware: This does not work for ssh.