How would i go about linking someones gamer-tag? Basically, i am wanting to make sure a user actually owns that account. MLG Game battles does the same thing, where you click a link, then you are redirected to Microsoft's Xbox Live website. Once i login, i am redirected back to MLG Game battles, and my account is then Linked. After that, i would save the gamer-tag into a Database for latter reference. How would i do this?
With Reference to James Comment:
*OAuth 2.0
Live Connect implements the OAuth 2.0 protocol to authenticate users. This topic describes both the authorization flows that Live Connect uses and the supported extension parameters. In this topic, we assume that you are familiar with OAuth 2.0 and OAuth terminology. If you're new to OAuth, we recommend that you check out the OAuth 2.0 spec first, or refer to it when you come across a term or idea that's unfamiliar to you.
Source https://msdn.microsoft.com/en-us/library/hh243647.aspx (correct as of 13th September 2016)
If you read through their documentation I'm sure you can get the finer details and work it into you project