Thanks Curtis.
Yes, I'm aware of those documentation. But I am not able to figure out how to implement those hooks.
Currently, what I'm able to do is to use PAM authentication to get logged in user's work preserved (stored) in the server, so that when the user logs in again next time from a different computer, the tutorial goes to where the user is left off.
But, to use PAM authentication, I need to create users manually in the server. I would like to use google authentication to achieve the same behavior. Is that possible?