title: Mixed authentication for OWIN
body: <p>I have two authenticate users in two ways:</p>
  
  <ol>
  <li>If they are an internal user we authenticate through Windows' active directory</li>
  <li>If they registered with the site they authenticate through Forms Authentication</li>
  </ol>
  
  <p>In MVC 3/4 I was able to accomplish this by implementing a custom membership provider and custom role provider. </p>
  
  <p>Is the same possible in MVC 5 using OWIN and Identity and how can it be done?</p>