title: iOS & node.js: how to verify passed access token?
body: <p>I have an iOS which uses OAuth and OAuth2 providers (Facebook, google, twitter, etc) to validate a user and provide access tokens. Apart from minimal data such as name and email address, the app doesn't uses these services for anything except authentication.</p>
  
  <p>The app then sends the access token to a server to indicate that the user is authenticated.</p>
  
  <p>The server is written in Node.js and before doing anything it needs to validate the supplied access token against the correct OAuth* service. </p>
  
  <p>I've been looking around, but so far all the node.js authentication modules I've found appear to be for logging in and authenticating through web pages supplied by the server. </p>
  
  <p>Does anyone know any node.js modules that can do simple validation of a supplied access token?</p>