Password incorrect when using SSH with public/private key

Question

I enabled logging to my remote Kubuntu computer with a public/private key following this short tutorial, and now logging is easy and doesn't ask for password.

Anyway, I noticed when I try to sudo, I'm asked for a password and when entered it says it's incorrect. And since I cannot sudo, I cannot modify the sshd_config or other root files.

I even cannot login to the physical machine using my own password, so all in all, I'm stuck.

How do I enable back the password authentication? (knowing that I cannot use sudo now) Thanks.

Answer 1

The relevant part of the tutorial is this:

At this point, user’s account on the server can be locked for password authentication. On Linux systems, one can make:

root@apanela.com:~# passwd -l ornellas

So, if you followed this part of the tutorial you've locked your password. The only way to resolve this is either to use a root account to unlock your password, or boot with a rescue disk and fix up the passwd/shadow file directly:

passwd -u ornellas