Simple authentication with CAS

A knowledge base article about Simple authentication with CAS provided by the UC Berkeley IT Service Hub - Knowledge Portal

Simple Authentication with CAS

Quick CAS Overview

  • Originally developed at Yale and now an Apereo Foundation project.
  • Provides client support for many languages and platforms, including Ruby, Perl, Java, ASP, PHP, uPortal, Apache, Tomcat, and more.
  • The CAS Protocol emulates the central security concepts of the Kerberos protocol.

CAS Protocol

  • The CAS Protocol is based on the Kerberos Protocol.
  • It utilizes basic HTTP GET for requests and responses, with optional POST support for responses.
  • All CAS responses are returned in XML format.
  • CAS can be configured to perform either Single Sign-On (SSO) or Re-Authentication (forcing a fresh login).

Simple Authentication

CAS simple authentication provides Single Sign-On (SSO) capabilities for the campus community:

  1. CAS redirects browsers visiting an application or service to the central CAS server for authentication.
  2. Upon return from CAS, the application must validate the browser data presented.
  3. The application takes the "Service Ticket" presented by the browser and queries the CAS server to verify the ticket's validity for that specific service URL.
  4. CAS responds with an XML success or failure message.

Technical Resources