[置顶] SSO单点登录系列6：cas单点登录防止登出退出后刷新后退ticket失效报500错

这个问题之前就发现过，最近有几个哥们一直在问我这个怎么搞，我手上在做另一个项目，cas就暂时搁浅了几周。现在我们来一起改一下你的应用(client2/3)的web.xml来解决这个2b问题，首先看下错误描述:

问题： 我登录了client2，又登录了client3，现在我把client2退出了，在client里面我F5刷新了一下，结果页面报错：

未能够识别出目标 'ST-41-2VcnVMguCDWJX5zHaaaD-cas01.example.org'票根

type Exception report

message org.jasig.cas.client.validation.TicketValidationException:

description The server encountered an internal error that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: org.jasig.cas.client.validation.TicketValidationException:
鏈兘澶熻瘑鍒嚭鐩爣 'ST-41-2VcnVMguCDWJX5zHaaaD-cas01.example.org'绁ㄦ牴

org.jasig.cas.client.validation.AbstractTicketValidationFilter.doFilter(AbstractTicketValidationFilter.java:155)
org.jasig.cas.client.session.SingleSignOutFilter.doFilter(SingleSignOutFilter.java:99)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
root cause

org.jasig.cas.client.validation.TicketValidationException:
鏈兘澶熻瘑鍒嚭鐩爣 'ST-41-2VcnVMguCDWJX5zHaaaD-cas01.example.org'绁ㄦ牴

org.jasig.cas.client.validation.Cas20ServiceTicketValidator.parseResponseFromServer(Cas20ServiceTicketValidator.java:73)
org.jasig.cas.client.validation.AbstractUrlBasedTicketValidator.validate(AbstractUrlBasedTicketValidator.java:188)
org.jasig.cas.client.validation.AbstractTicketValidationFilter.doFilter(AbstractTicketValidationFilter.java:132)
org.jasig.cas.client.session.SingleSignOutFilter.doFilter(SingleSignOutFilter.java:99)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.37 logs.

猜都能猜出来，我注销了，ticket已经失效了，现在我又发回到server端，它就报错了。（客户端发过去就报错了），以下就是cas ticket失效处理的一个很简单的解决办法，复杂的话，需要修改client源码进行异常处理。

1.所以针对这个情况，我只能在web.xml中下手了，（你也可以修改客户端的jar包中的一些java类，自己去做这个异常处理，接收所有在cas使用过程中会出错的处理，全部跳转到错误页面中，让掉线的人重新登录。在这里，我们采用web.xml配置一下）

2.这是官网解释：https://wiki.jasig.org/display/CASC/Configuring+the+Jasig+CAS+Client+for+Java+in+the+web.xml 它的解释：

The correct order of the filters in web.xml is necessary:

AuthenticationFilter

TicketValidationFilter (whichever one is chosen)

HttpServletRequestWrapperFilter

AssertionThreadLocalFilter

意思是说，过滤器链不要错，我之前的那篇教程里cas客户端配置web.xml没有使用这几个过滤器，现在我们重新使用它。

3.这是一个哥们之前解释的：我贴出来。

单点登出，客户端配置。我尝试使用SAML作为认证和Ticket校验，但是调试时发现单点登出取标识的方式只能识别CAS的认证和校验。
认证：org.jasig.cas.client.authentication.AuthenticationFilter
校验：org.jasig.cas.client.validation.Cas20ProxyReceivingTicketValidationFilter
过滤器顺序：
1. CAS Single Sign Out Filter
2. CAS Validation Filter
3. CAS Authentication Filter
4. CAS HttpServletRequest Wrapper Filter
5. CAS Assertion Thread Local Filter
特别注意Validation在Authentication之前，因为我使用的是Cas20ProxyReceivingTicketValidationFilter。根据CAS文档描述：If you are using proxy validation, you should map the validation filter before the authentication filter.

4.ok，放上我的web.xml文件，废掉之前的cas验证过滤器(CAS Filter)。使用另一个过滤器(CAS Authentication Filter)，并且增加另外三个过滤器（CAS Validation Filter,CAS HttpServletRequest Wrapper Filter,CAS Assertion Thread Local Filter），注意过滤器的顺序.

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.5"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee   http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> 
<!-- 解决中文乱码问题 -->
<filter>
<filter-name>spring filter</filter-name>
<filter-class>
org.springframework.web.filter.CharacterEncodingFilter
</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>spring filter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- 解决中文乱码问题 -->

<!--1.用于单点退出 -->
<listener>
<listener-class>
org.jasig.cas.client.session.SingleSignOutHttpSessionListener
</listener-class>
</listener>

<filter>
<filter-name>CAS Single Sign Out Filter</filter-name>
<filter-class>
org.jasig.cas.client.session.SingleSignOutFilter
</filter-class>
</filter>

<filter-mapping>
<filter-name>CAS Single Sign Out Filter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<!--2.负责Ticket校验-->
<filter>
<filter-name>CAS Validation Filter</filter-name>
<filter-class>
org.jasig.cas.client.validation.Cas20ProxyReceivingTicketValidationFilter
</filter-class>
<init-param>
<param-name>casServerUrlPrefix</param-name>
<param-value> http://192.168.168.141:8080/casServer </param-value>
</init-param>
<init-param>
<param-name>serverName</param-name>
<param-value>192.168.168.141:8080</param-value>
</init-param>
<init-param>
<param-name>useSession</param-name>
<param-value>true</param-value>
</init-param>

<init-param>
<param-name>exceptionOnValidationFailure</param-name>
<param-value>false</param-value>
</init-param>

<init-param>
<param-name>redirectAfterValidation</param-name>
<param-value>true</param-value>
</init-param>
</filter>

<filter-mapping>
<filter-name>CAS Validation Filter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<!-- 3. 单点登录验证 -->

<filter>
<filter-name>CAS Authentication Filter</filter-name>
<filter-class>
org.jasig.cas.client.authentication.AuthenticationFilter
</filter-class>
<init-param>
<param-name>casServerLoginUrl</param-name>
<param-value> http://192.168.168.141:8080/casServer/login </param-value>
</init-param>
<init-param>
<param-name>serverName</param-name>
<param-value>http://192.168.168.141:8080</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CAS Authentication Filter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<!-- 3.用于单点登录 去服务器端认证(之前使用的这种)
<filter>
<filter-name>CAS Filter</filter-name>
<filter-class>
edu.yale.its.tp.cas.client.filter.CASFilter
</filter-class>
<init-param>
<param-name>
edu.yale.its.tp.cas.client.filter.loginUrl
</param-name>
<param-value> http://192.168.168.141:8080/casServer/login </param-value>
</init-param>
<init-param>
<param-name>
edu.yale.its.tp.cas.client.filter.validateUrl
</param-name>
<param-value> http://192.168.168.141:8080/casServer/serviceValidate </param-value>
</init-param>
<init-param>
<param-name>
edu.yale.its.tp.cas.client.filter.serverName
</param-name>
<param-value>192.168.168.141:8080</param-value>
</init-param>
</filter>
-->

<!--4.  CAS HttpServletRequest Wrapper Filter 这个是HttpServletRequet的包裹类，让他支持getUserPrincipal，getRemoteUser方法来取得用户信息-->

<filter>
<filter-name>CAS HttpServletRequest Wrapper Filter</filter-name>
<filter-class>
org.jasig.cas.client.util.HttpServletRequestWrapperFilter
</filter-class>
</filter>

<filter-mapping>
<filter-name>CAS HttpServletRequest Wrapper Filter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<!--5. CAS Assertion Thread Local Filter  这个类把Assertion信息放在ThreadLocal变量中，这样应用程序不在web层也能够获取到当前登录信息-->

<filter>
<filter-name>CAS Assertion Thread Local Filter</filter-name>
<filter-class>
org.jasig.cas.client.util.AssertionThreadLocalFilter
</filter-class>
</filter>

<filter-mapping>
<filter-name>CAS Assertion Thread Local Filter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<servlet>
<servlet-name>Query</servlet-name>
<servlet-class>servlet.Query</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>Query</servlet-name>
<url-pattern>/query</url-pattern>
</servlet-mapping>

<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>

5.如果这样做了，你还需要一件事情，就是前台获取用户信息的方式改了，我的index.jsp改成了这个：

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@page import="edu.yale.its.tp.cas.client.filter.CASFilter"%>
<%@page import="org.jasig.cas.client.util.AssertionThreadLocalFilter"%>
<%@page import="org.jasig.cas.client.util.HttpServletRequestWrapperFilter"%>
<%@page import="org.jasig.cas.client.authentication.AttributePrincipal"%>
<%@page import="org.jasig.cas.client.util.AbstractCasFilter"%>
<%@page import="org.jasig.cas.client.validation.Assertion"%>

<body>

<h1>
登录成功，这是客户端2
</h1>
<br />

欢迎您:

<%
//String username = (String) session.getAttribute(CASFilter.CAS_FILTER_USER);
//String username2 = (String)AssertionHolder.getAssertion().getPrincipal().getName();
String username = "";
AttributePrincipal principal = (AttributePrincipal) request.getUserPrincipal();
if(principal != null){
username = principal.getName();//获取用户名
}

%>
用户名：<%=username%>

ok,我的应用之间如果一个退出，另一个就算带ticket参数也不不再报错了，就算是测试组的兄弟拿到那段ticket复制粘贴到另一个浏览器中进行访问，也不会报错。

ps：

也有兄弟说可以通过修改C:\tomcat7\webapps\casServer\WEB-INF\spring-configuration\ticketExpirationPolicies.xml这个文件中的

<!-- Expiration policies -->
<util:constant id="SECONDS" static-field="java.util.concurrent.TimeUnit.SECONDS"/>
<bean id="serviceTicketExpirationPolicy" class="org.jasig.cas.ticket.support.MultiTimeUseOrTimeoutExpirationPolicy"
c:numberOfUses="1" c:timeToKill="${st.timeToKillInSeconds:10}" c:timeUnit-ref="SECONDS"/>

其中那个

c:numberOfUses="1" //使用ticket多少次

c:timeToKill="${st.timeToKillInSeconds:10}" //多少秒过期，默认10秒，你把这个改成10分钟玩玩。

这个方法我没有尝试，所以希望想尝试想折腾和想玩的兄弟狠狠的点击这个链接：http://bbs.csdn.net/topics/390111112

落雨

2013年7月26日13:37:05