title: Restrict Login Email with Google OAuth2.0 to Specific Domain Name
body: <p>I can't seem to find any documentation on how to restrict the login to my web application (which uses OAuth2.0 and Google APIs) to only accept authentication requests from users with an email on a specific domain name or set of domain names. I would like to whitelist as opposed to blacklist.</p>
  
  <p>Does anyone have suggestions on how to do this, documentation on the officially accepted method of doing so, or an easy, secure work around?</p>
  
  <p>For the record, I do not know any info about the user until they attempt to log in through Google's OAuth authentication. All I receive back is the basic user info and email.</p>