Using the excellent phpCAS library, we have created a small Drupal module to allow single sign-on with CAS.
phpCAS is a fantastic library for integrating Central Authentication Services into PHP applications. The library is well-documented and is licensed under the LGPL. CAS is a Java-based single sign-on solution originally developed at Yale and later placed under the auspices of JA-SIG (Java Architectures - Special Interest Group). CAS has quickly become the most popular single sign-on solution for universities. In its most simple use (CAS can also proxy single sign-on), CAS authenticates users and sends the user to the requested application with a ticket. The application is then responsible for authenticating the ticket (behind the scenes, with a tool like cURL) and automatically logging the user in if the ticket is valid.
LDAP & CAS Attributes Integration
Integration with LDAP and CAS attributes is provided by a separate CAS Attributes module maintained by the same developers.
We are currently seeking a co-maintainer, especially for the CAS Server component.
Please read the release notes before upgrading from CAS 6.x-2.x to CAS 6.x-3.0. In particular, note that the database schema has changed in such a way that you cannot revert to CAS 6.x-2.x after the upgrade.