# CAS architecture

## Introduction

The CAS is a Single Sign On protocol for the web. This protocol allows users to access multiple applications by providing their credentials.

The response will be a JSON or XML


## Single Log-in

The single log-in is usually initiated by the application server. The typical UML use case is as follows:

[![image-1661327423181.png](https://bookstack.soffid.com/uploads/images/gallery/2022-08/scaled-1680-/image-1661327423181.png)](https://bookstack.soffid.com/uploads/images/gallery/2022-08/image-1661327423181.png)

## Proxy web flow diagram

[![image-1661327695882.png](https://bookstack.soffid.com/uploads/images/gallery/2022-08/scaled-1680-/image-1661327695882.png)](https://bookstack.soffid.com/uploads/images/gallery/2022-08/image-1661327695882.png)

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*[https://en.wikipedia.org/wiki/Central\_Authentication\_Service](https://en.wikipedia.org/wiki/Central_Authentication_Service)*