I have a webpage that gets a user’s access token and userId (using the js api).
I want to send the fb userId I got to a login page on my site, but obviously I need to make sure that the user is really who says he is.
The question is: is it enough to check https://graph.facebook.com/me?access_token=ACCESS_TOKEN
and compare the userId I got and the one in the page above?
If you used the FB login functions you can’t be sure the user is who he claims to be.
After that, you just have to retrieve the users session to get he’s details again.
Note that you can use client side and server side code without the need for reauthentication.