What Does This Have to do With Portals?

A portal is a special multi-tier application. To "portalize" an existing application that requires authentication, the portal must stand in as the client in a way that is convincing to the server. While a monolithic application that requires a-priori credentials (userid/password) would still need these, if the application utilizes CAS, a more appealing option exists.

Goals:
The portal should not hold user primary credentials.
The authentication should be at least as strong as two-party CAS.