title: How can I implement a custom challenge handler in Xamarin for iOS using IBM MobileFirst?
body: <p>I'm trying to implement an adapter-based authentication using IBM MobileFirst Platform Foundation 6.3 and Xamarin in iOS.</p>
  
  <p>I have followed the IBM documentation on how to setup a customSecurityTest, adding realms and equivalent loginModules within authenticationConfig.xml. I have then setup 2 adapter procedures: </p>
  
  <ul>
  <li><code>authenticateUser</code> with <code>securityTest="wl_unprotected"</code>, and another </li>
  <li><code>HelloFromServer</code> with a <code>securityTest="SingleStepAuthAdapter"</code> that actually does a user authentication, and executing <code>WL.Server.setActiveUser("SingleStepAuthRealm", userIdentity)</code> to create the user identity.</li>
  </ul>
  
  <p>I have then created an iOS app using Xamarin Studio. Tried to invoke <code>HelloFromServer</code>, which as expected runs my ChallengeHandler module BUT within the <code>HandleChallenge</code> method while trying to invoke the <code>authenticateUser</code> procedure on the server, it respond back with another <code>authRequired=TRUE</code>.</p>
  
  <p>Anybody having the same problem?</p>