title: Authentication via headers in WCF REST service
body: <p>I am new to WCF services and currently testing out things.</p>
  
  <p>I have got a little REST API, which has several methods. Some of them require a user context (session), some others don't. At login, each user gets a session token. The client should supply this token and his user ID on every request <em>via HTTP headers</em>.</p>
  
  <p>At the moment, I wrote a method for getting those two headers and validate the session, calling it on every method which will need a user context. This seems kinda nasty if the API gets bigger.</p>
  
  <p>Is there a better approach for doing this?</p>