CAS is the Central Authentification Service. CAS is very useful for developing webs where companies wish to integrate several client services (services offered by independent tools) and offering that services avoiding that clients have to insert login and password several times (one for independent platform). In other words, CAS allows to deploy a Single Sign On among several tools.
I have installed CAS (using the esup-cas-server) integrated with LDAP. Now, i’m trying to test integration between Typo3 CMS and CAS. By now, i have developed a service and a frontend plugin that allows to redirect to CAS login page and then, using the service, a user can access to Typo3 without authentication on Typo3.

The following steps will be to improve the frontend plugin to show the CAS login page inside of Typo3, to avoid users to exit from Typo3 to CAS. With this improvement, the full scenario will be:

1. A user will see public pages as anonymous user. The CMS will show an IFRAME with CAS login page.
2. If the user wants to access to private contents, the user must introduce username and password on CAS login page.
3. CAS login page redirects to CMS to log in the user and IFRAME will show the username and a button to log out.
4. The user will be able to access to all private services and contents to which user has permissions.

Reference:

• CAS: http://www.ja-sig.org/products/cas/
• Typo3: http://www.typo3.org