I recently made my own VPN Server (OpenVPN) on my Linux Debian vServer. Now, in order to make it more secure I figured it would be a good idea to add 2-Factor-Authentication. So installed Google Authenticator using this tutorial: https://ubuntu.com/tutorials/configure-ssh-2fa#2-installing-and-configuring-required-packages
Everything went well until I got to the step where you are supposed to edit the ssh_config in /etc/ssh/. After opening the config I couldn't find any line saying something like 'ChallengeResponseAuthentication', so I simply added it. After saving, my SSH Client (Termius) crashed and I got logged out. Now my main Problem is I don't know how to log back in. I changed my Root Password once but I dont know if I changed it correctly (from what Ive noted). So now I got 3 possible Passwords: The old standart Root Password, One new Root Password (which I changed via the 'passwd' command in the SSh-Client and lastly the Root Password I changed via the Web Interface of the vServer. None of them work. Of course I also tried logging in via Authentication code on my phone but that didn't work either. It would be nice to know how to log back onto my server even though all systems (Mailserver and VPN-Server) are still working normally.
Some Data that might be useful: Linux Version: Linux Debian 9.5.0 Minimal
Status Online Type kvm Nodename vnode003 Hostname v1613952.v-server.me
Hosted by Avoro.eu Bandwidth 11.66 GB of 5 TB Used / 4.99 TB Free Also keep in mind that I cant access the server at all (at least as far as I am aware of)