We are currently introducing facebook and twitter login functionality for our users both on our website as well as mobile app.
The current issue I have is with facebook tokens, I have noticed that when a user tries logging through facebook the token returned on my website and mobile app are different.
What is the best way to manage these tokens to prevent duplicate registration of users. Each user when logs in creates a basic profile in our database which is linked to the access token. I also use offline_access permission.
Now when this user uses the mobile app a different token is returned and a duplicate profile may be created. How do I prevent this situation, I need the same profile to be detected on the website as well as mobile.