title: Oauth2 Client Application authorization, using Symfony
body: <p>I would like to protect some end-point of the API only to be accessed by "Client Application" (instead of for a user with a role). The system is using Oauth2, and I have access and can modify the Authorization Server and the Client Application. </p>
  
  <p>I am using Symfony2 and there is an example <a href="http://symfony.com/doc/current/cookbook/security/api_key_authentication.html" rel="nofollow">How to Authenticate Users with API Keys </a>, but the example is only for the user's token (Using ApiKeyUserProvider) this made me think that maybe Is not the right approach.</p>
  
  <p>Do you know any example for this problem, should I try other approach?</p>