I have set up 2 factor authentication. I had added the following line to the end of /etc/pam.d/common-auth:
auth required pam_google_authenticator.so
All was working well, except for the fact that I did not get prompted for a verification code. According to this tutorial the line should be added above:
auth [success=1 default=ignore] pam_unix.so nullok_secure
I misread and put it beneath this line. After logging out I tried to login but now my password was no longer working. I got the error message that my password was incorrect. I am 100% sure the password is correct as I have used it many times every day. My change in the common-auth file must have corrupted the login.
Is there any way to rollback this change? I am working on a dual-boot machine and have windows installed as well. Maybe I could use the windows install to access the common-auth file and change it?