This ColdFusion CAS client is written as a component (CFC) and meant to be saved as an object in the Session scope. The included example is an Application.cfc, but it can be used with an Application.cfm with some work.
This was written/tested in ColdFusion 8 with CAS Server 3.3.x
Validates the user is logged in, if not send to CAS login or validate ST
Returns the value of of cas:user after a successful authentication
Returns a struct of all the cas:attributes included in the ST validation response
Returns the value of the requested attribute or "" if it doesn't exist
Sends the user to the CAS login page.
Sends the user to the CAS logout page.
Invalidates the CAS session for this application, but does not destroy session variables
Checks if the current request is a Single Sign Out request and destroys the corresponding session
Validates the provided ST and sets the user and attributes if successful