Project abandoned.
This module is still in the early development phase - nothing much to see here yet. If you're not sure what CAS (Central Authentication Service) is, this module probably isn't for you.
This module allows a Drupal instance to restrict registration to those who can successfully authenticate via CAS (as configured by the site admin). Unlike the CAS module, which creates a Drupal user account or logs into an existing Drupal user account when an individual authenticates via CAS, this module does not interface with Drupal's user authentication system. Instead, it sends an invitation via email (in the same manner that the Invite module does) to register on the Drupal site (like normal) to users who successfully authenticate via CAS. In this way, CAS is used as part of the registration process, but not to log in.
Read the README.txt before installing. An external library (phpCAS) and specific PHP modules (curl, openssl, dom, zlib) are required.