h1. Overview

CAS is an enterprise Single Sign-On solution for web services. _Single Sign-On_ (SSO) means a better user experience when running a multitude of web services, each with it's own means of authentication. With a SSO solution, different web services may authenticate to one authorative source of trust, that the user needs to log in to, instead of requiring the end-user to log in into each separate service.


JA-SIG produces an enterprise-wide single sign on system known as CAS. Unlike other initiatives, JA-SIG's Central Authentication Service is open source, widely used, simple to understand, platform independent, and supports proxy capabilities. Petals View could be connected to a CAS server to provide single sign on.

{color:#333333}Somewhere in your enterprise you will need to setup a CAS server. The CAS server is simply a standard WAR file, so there isn't anything difficult about setting up your server. Inside the WAR file you will customise the login and other single sign on pages displayed to users.{color}

You can learn more about CAS at [http://www.ja-sig.org/cas]. You will also need to visit this site to download the CAS Server files.

Then edit the file located in : *PETALSVIEW_ROOT{*}*/WEB-INF/spring/petals-view-security.xml*

Comment the "Classical authent" section and uncomment the "CAS authent" section. An exemple *petals-view-security.xml* is provided here : 
{code:lang=xml}
<beans xmlns:security="http://www.springframework.org/schema/security"
xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.0.xsd">

<!--
########################## CAS authent
##########################
-->

<security:http entry-point-ref="casEntryPoint">
<security:intercept-url pattern="/petals-view/pg/pages/Welcome"
access="ROLE_AUTH" />
<security:intercept-url pattern="/petals-view/**"
access="ROLE_AUTH" />
<security:anonymous />
<security:logout logout-success-url="${cas.server.url}${cas.logout.path}" />
<security:custom-filter ref="casAuthenticationFilter"
after="CAS_FILTER" />
</security:http>
<bean id="casAuthenticationFilter"
class="org.springframework.security.cas.web.CasAuthenticationFilter">
<property name="authenticationManager" ref="authenticationManager" />
</bean>
<bean id="casEntryPoint"
class="org.springframework.security.cas.web.CasAuthenticationEntryPoint">
<property name="loginUrl" value="${cas.server.url}${cas.login.path}" />
<property name="serviceProperties" ref="serviceProperties" />
</bean>

<bean id="serviceProperties" class="org.springframework.security.cas.ServiceProperties">
<!--
<property name="service"
value="${webapp.url}/j_spring_cas_security_check" />
-->
<property name="service" value="${webapp.url}/j_spring_cas_security_check" />
<property name="sendRenew" value="false" />
</bean>

<security:authentication-manager alias="authenticationManager">
<security:authentication-provider
ref="casAuthenticationProvider" />
</security:authentication-manager>
<bean id="casAuthenticationProvider"
class="org.springframework.security.cas.authentication.CasAuthenticationProvider">
<property name="authenticationUserDetailsService" ref="myUserDetailsService" />
<property name="serviceProperties" ref="serviceProperties" />
<property name="ticketValidator">
<bean class="org.jasig.cas.client.validation.Cas20ServiceTicketValidator">
<constructor-arg index="0" value="${cas.server.url}" />
</bean>
</property>
<property name="key" value="an_id_for_this_auth_provider_only" />
</bean>

<bean id="myUserDetailsService"
class="com.ebmwebsourcing.petalsview.util.FullAccessRightsUserDetailsService">
<property name="rolesResource">
<value>${role.list.file.url}</value>
</property>
</bean>

<!--
########################## End of CAS authent
##########################
-->