title: How to turn a Rails app with Devise into a SSO/CAS server?
body: <p>I realized from a <a href="https://stackoverflow.com/questions/25878009/how-to-turn-a-rails-app-with-devise-into-an-oauth-provider">previous question</a> that I had been asking the wrong question...I would like to turn my application into a CAS server so that admins of the application may use this same authentication mechanism to log into other applications that we develop for the organization. </p>
  
  <p>Have you done this before? Is there a plugin which adds the ability to Devise to be able to act as a CAS server? What do I need to change/add in order to turn the app into a CAS server?</p>