How do I hook into the login process?

Hi!

I need to do two things during the facebook login process:

1) I need to amend the facebook permissions granted to have the user grant these four extended permissions: email, user_likes, user_location, and user_birthday

and

2) I need to send the facebook token to my analytics software as the login completes.

Ideally, I could hook into the login/registration process to amend the permissions simply and directly for the first. For the second, a hook into the login process after the fb token is set would allow me to run a function to send it to my analytics.

Thanks for your help!