In the first part of this article, I shared my implementation of the Cental Authentication Service (CAS) protocol using the Jifty framework, CAS+. That article covered the basic details of how this single sign-on (SSO) system was implemented to include basic login and how a user's credentials are passed back to another web service. This covered most aspects of the CAS 1.0 protocol.
However, the CAS protocol provides much more than robust single sign-on. CAS 2.0 provides additional features for authentication by proxy. By using this extension, a web service may pass identity credentials on to additional services allowing services that are not directly web accessible, such as IMAP, SMTP, or other applications. CAS+ implements these extensions as well and this article will share, and this article will explain how those are implemented in Jifty.
