title: Any examples of a MessageHandler for WebAPI Forms Authentication?
body: <p>As a follow-up to this question: </p>
  
  <p><a href="https://stackoverflow.com/questions/15994857/webapi-forms-authentication-simplemembershipprovider-using-windowsidentity-w">WebAPI + Forms Authentication + SimpleMembershipProvider using WindowsIdentity when it shouldn&#39;t</a></p>
  
  <p>I'm now trying to implement a message handler that sets the principal on each request, but I'm not sure how to tie this in with simpleMembershipProvider.  I'm looking for an example that sets the principal and performs authentication against simpleMembership. </p>