
Hands-On Spring Security 5 for Reactive Applications
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The
Central Authentication Service (CAS)
is a single-sign-on/single-sign-off protocol for the web. It permits a user to access multiple applications while providing their credentials (such as userid and password) only once to a central CAS Server application.
– CAS Protocol Specification
CAS is an open source, platform-independent, central single sign-on (SSO) service supporting a variety of well-known protocols. Spring Security has first-class support for CAS, and the implementation is quite simple for an enterprise having a central CAS server. CAS is based on Spring Framework, and the architecture is quite simple, as shown in the following diagram:
Figure 1: CAS architecture (figure adapted from https://apereo.github.io)
The CAS server is a Java servlet-based application built on Spring Framework (Spring MVC and Spring Web Flow). It authenticates and grants access to CAS-enabled services.
Upon the successful login of the user, an SSO session is created, and the server issues a ticket-granting...