Spring Security整合CAS的示例代码

下面是我对于Spring Security整合CAS的示例代码的攻略：

前置知识

在开始讲解Spring Security整合CAS的示例代码之前，需要先了解以下几个概念：

CAS (Central Authentication Service)

CAS是一个单点登录协议，可以让用户在多个Web应用中进行统一认证和授权。对于用户进行登录的请求，CAS服务会将用户重定向到用户认证服务，等通过认证之后，CAS服务会将用户重定向回应用程序，并带上一个票据（Ticket）。应用程序可以通过这个票据，向CAS服务验证用户的身份。

Spring Security

Spring Security是一个基于Spring框架的安全框架，可以帮助开发者实现常用的安全功能，例如授权和认证。

整合流程

接下来，我们开始讲解Spring Security整合CAS的示例代码的完整攻略。

步骤1：在pom.xml中添加依赖

我们需要在pom.xml中添加以下依赖：

<dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-cas</artifactId>
    <version>5.5.0</version>
</dependency>
<dependency>
    <groupId>org.jasig.cas.client</groupId>
    <artifactId>cas-client-core</artifactId>
    <version>3.6.2</version>
</dependency>

这些依赖可以帮助我们使用Spring Security和CAS完成单点登录操作。

步骤2：修改Spring Security的配置

我们可以在Spring Security的配置文件中添加以下配置：

<security:http>
    <security:intercept-url pattern="/secure/**" access="ROLE_USER"/>
    <security:custom-filter ref="casAuthenticationFilter" position="CAS_FILTER"/>
</security:http>

<bean id="casAuthenticationFilter" class="org.springframework.security.cas.web.CasAuthenticationFilter">
    <property name="authenticationManager" ref="authenticationManager"/>
    <property name="authenticationSuccessHandler">
        <bean class="org.springframework.security.web.authentication.SavedRequestAwareAuthenticationSuccessHandler">
            <property name="defaultTargetUrl" value="/"/>
        </bean>
    </property>
</bean>

<bean id="casAuthenticationProvider" class="org.springframework.security.cas.authentication.CasAuthenticationProvider">
    <property name="key" value="casAuthenticationProvider"/>
    <property name="ticketValidator">
        <bean class="org.jasig.cas.client.validation.Cas20ServiceTicketValidator">
            <constructor-arg value="https://localhost:8443/cas"/>
        </bean>
    </property>
    <property name="serviceProperties" ref="serviceProperties"/>
    <property name="authenticationUserDetailsService">
        <bean class="org.springframework.security.core.userdetails.UserDetailsByNameServiceWrapper">
            <constructor-arg ref="inMemoryUserDetailsManager"/>
        </bean>
    </property>
</bean>

<bean id="serviceProperties" class="org.springframework.security.cas.ServiceProperties">
    <property name="service" value="http://localhost:8080/secure/userDetails.htm"/>
    <property name="sendRenew" value="false"/>
</bean>

<security:authentication-manager alias="authenticationManager">
    <security:authentication-provider ref="casAuthenticationProvider"/>
</security:authentication-manager>

<bean id="inMemoryUserDetailsManager" class="org.springframework.security.provisioning.InMemoryUserDetailsManager">
    <property name="userDetails">
        <list>
            <bean class="org.springframework.security.core.userdetails.User">
                <constructor-arg value="user"/>
                <constructor-arg value="password"/>
                <constructor-arg>
                    <array>
                        <bean class="org.springframework.security.core.authority.SimpleGrantedAuthority">
                            <constructor-arg value="ROLE_USER"/>
                        </bean>
                    </array>
                </constructor-arg>
            </bean>
        </list>
    </property>
</bean>

这些配置可以帮助Spring Security与CAS之间进行交互，完成单点登录操作。

示例1：自定义CAS登录页面

我们可以在上面的配置中添加以下配置：

<security:http>
    <security:intercept-url pattern="/cas/**" access="IS_AUTHENTICATED_ANONYMOUSLY"/>
    <security:custom-filter ref="casValidationFilter" position="CAS_FILTER"/>
    <security:custom-filter ref="casAuthenticationFilter" position="CAS_FILTER"/>
</security:http>

<bean id="casValidationFilter" class="org.jasig.cas.client.validation.Cas20ProxyReceivingTicketValidationFilter">
    <property name="redirectAfterValidation" value="true"/>
    <property name="exceptionOnValidationFailure" value="true"/>
    <property name="casServerUrlPrefix" value="https://localhost:8443/cas"/>
    <property name="proxyCallbackUrl" value="http://localhost:8080/cas/proxyCallback.do"/>
</bean>

<bean id="casAuthenticationFilter" class="org.springframework.security.cas.web.CasAuthenticationFilter">
    <property name="authenticationManager" ref="authenticationManager"/>
    <property name="authenticationSuccessHandler">
        <bean class="org.springframework.security.web.authentication.SavedRequestAwareAuthenticationSuccessHandler">
            <property name="defaultTargetUrl" value="/"/>
        </bean>
    </property>
    <property name="proxyCallbackUrl" value="http://localhost:8080/cas/proxyCallback.do"/>
    <property name="proxyReceptorUrl" value="/secure/receptor"/>
</bean>

<bean id="casAuthenticationEntryPoint" class="org.springframework.security.cas.web.CasAuthenticationEntryPoint">
    <property name="loginUrl" value="https://localhost:8443/cas/login"/>
    <property name="serviceProperties" ref="serviceProperties"/>
</bean>

<bean id="serviceProperties" class="org.springframework.security.cas.ServiceProperties">
    <property name="service" value="http://localhost:8080/cas/j_spring_cas_security_check"/>
    <property name="sendRenew" value="false"/>
</bean>

<bean id="customCasAuthenticationProvider" class="com.javabean.CustomCasAuthProvider" />

<security:authentication-manager alias="authenticationManager">
    <security:authentication-provider ref="customCasAuthenticationProvider"/>
</security:authentication-manager>

这些配置可以让我们自定义CAS登录页面。

示例2：自定义认证Provider