CAS (2) —— Mac下配置CAS到Tomcat（客户端）

tomcat版本: tomcat-8.0.29

jdk版本: jdk1.8.0_65

cas版本: cas4.1.2
cas-client-3.4.1

参考来源:

CAS实现单点登录（SSO）经典完整教程

CAS 4.0 配置开发手册

cas客户端应用实现

使用 CAS 在 Tomcat 中实现单点登录

Tomcat (1) —— Mac下配置Tomcat Https/SSL

【高可用HA】Apache (2) —— Mac下安装多个Apache Tomcat实例

目标架构

下载

首先登陆jasig网站http://downloads.jasig.org/，下载相应的cas版本。

由于网站只提供源码包而不提供发布包，所以需要自己下载来编译。

cas会为不同的客户端消费者提供client包，这里我们选择java-client作为演示。

编译客户端所需要的jar

java-cas-client-cas-client-3.4.1 Richard$ mvn clean install -Dmaven.test.skip

然后下载供测试的客户端示例代码(jasig在github上为我们提供了一个简易的客户端demo)

$ git clone https://github.com/UniconLabs/cas-sample-java-webapp.git

配置

客户端

设置

参照以下文章为Tomcat配置好Https

Tomcat (1) —— Mac下配置Tomcat Https/SSL

【高可用HA】Apache (2) —— Mac下安装多个Apache Tomcat实例

编译部署

然后编译我们的示例项目

:cas-sample-java-webapp Richard$ mvn clean install -Dmaven.test.skip

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>iamlabs.unicon.net</groupId>
<artifactId>cas-sample-java-webapp</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<name>CAS Example Java Web App</name>
<description>A sample web application that exercises the CAS protocol features via the Java CAS Client.</description>
<build>
	<finalName>cas-sample-java-webapp</finalName>
	<plugins>
		<plugin>
			<groupId>org.apache.maven.plugins</groupId>
			<artifactId>maven-compiler-plugin</artifactId>
			<version>2.5.1</version>
			<configuration>
				<source>1.6</source>
				<target>1.6</target>
			</configuration>
		</plugin>
	</plugins>
</build>

<dependencies>

	<dependency>
		<groupId>commons-logging</groupId>
		<artifactId>commons-logging</artifactId>
		<version>1.1.1</version>
	</dependency>

	<dependency>
		<groupId>log4j</groupId>
		<artifactId>log4j</artifactId>
		<version>1.2.16</version>
	</dependency>
	<dependency>
		<groupId>org.opensaml</groupId>
		<artifactId>opensaml1</artifactId>
		<version>1.1</version>
	</dependency>
	
	<dependency>
		<groupId>javax.servlet</groupId>
		<artifactId>javax.servlet-api</artifactId>
		<version>3.1.0</version>
		<scope>provided</scope>
	</dependency>

	<dependency>
		<groupId>org.jasig.cas.client</groupId>
		<artifactId>cas-client-core</artifactId>
  		<version>3.2.1</version>
		<exclusions>
			<exclusion>
				<groupId>javax.servlet</groupId>
				<artifactId>servlet-api</artifactId>
			</exclusion>
		</exclusions>
	</dependency>

	<dependency>
		<groupId>commons-codec</groupId>
		<artifactId>commons-codec</artifactId>
		<version>1.6</version>
	</dependency>

	<dependency>
		<groupId>org.apache.santuario</groupId>
		<artifactId>xmlsec</artifactId>
		<version>1.4.3</version>
	</dependency>
</dependencies>

将编译生成的war包部署到我们的Tomcat容器中:

项目主要包括两个页面

index.jsp(供登陆)

<%@page contentType="text/html"%>
<%@page pageEncoding="UTF-8"%>
<%@ page import="java.util.Map" %>
<%@ page import="java.util.Iterator" %>
<%@ page import="java.util.List" %>
<%@ page import="org.jasig.cas.client.authentication.AttributePrincipal" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
	"http://www.w3.org/TR/html4/loose.dtd">

<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>CAS Example Java Web App</title>
</head>
<body>

<h1>CAS Example Java Web App</h1>
<p>A sample web application that exercises the CAS protocol features via the Java CAS Client.</p>
<hr>

<p><b>Authenticated User Id:</b> <a href="../cas1/logout.jsp" title="Click here to log out"><%= request.getRemoteUser() %></a></p>

<%
if (request.getUserPrincipal() != null) {
  AttributePrincipal principal = (AttributePrincipal) request.getUserPrincipal();
  
  /*
  final String password = principal.getPassword();
  if (password != null) {
    out.println("<p><b>User Credentials:</b> " + password + "</p>");
  }
  */
  
  final Map attributes = principal.getAttributes();
  
  if (attributes != null) {
    Iterator attributeNames = attributes.keySet().iterator();
    out.println("<b>Attributes:</b>");
    
    if (attributeNames.hasNext()) {
      out.println("<hr><table border='3pt' width='100%'>");
      out.println("<th colspan='2'>Attributes</th>");
      out.println("<tr><td><b>Key</b></td><td><b>Value</b></td></tr>");

      for (; attributeNames.hasNext();) {
        out.println("<tr><td>");
        String attributeName = (String) attributeNames.next();
        out.println(attributeName);
        out.println("</td><td>");
        final Object attributeValue = attributes.get(attributeName);

        if (attributeValue instanceof List) {
          final List values = (List) attributeValue;
          out.println("<strong>Multi-valued attribute: " + values.size() + "</strong>");
          out.println("<ul>");
          for (Object value: values) {
            out.println("<li>" + value + "</li>");
          }
          out.println("</ul>");
        } else {
          out.println(attributeValue);
        }
        out.println("</td></tr>");
      }
      out.println("</table>");
    } else {
      out.print("No attributes are supplied by the CAS server.</p>");
    }
  } else {
    out.println("<pre>The attribute map is empty. Review your CAS filter configurations.</pre>");
  }
} else {
    out.println("<pre>The user principal is empty from the request object. Review the wrapper filter configuration.</pre>");
}
%>

</body>
</html>

logout.jsp(注销)

<%@page contentType="text/html"%>
<%@page pageEncoding="UTF-8"%>
<%@ page import="java.util.Map" %>
<%@ page import="java.util.Iterator" %>
<%@ page import="org.jasig.cas.client.authentication.AttributePrincipal" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
	"http://www.w3.org/TR/html4/loose.dtd">

<%
	session.invalidate();
%>

<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>CAS Example Java Web App</title>
</head>
<body>
	<h1>CAS Example Java Web App</h1>
    <p>Application session is now invalidated. You may also issue a request to "/cas/logout" to destroy the CAS SSO Session as well.</p>
    <hr>
    
	<a href="../cas1/index.jsp">Back to Home</a>
</body>
</html>

配置CAS Authentication Filter

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<filter>
	<filter-name>CAS Authentication Filter</filter-name>
	<filter-class>org.jasig.cas.client.authentication.AuthenticationFilter</filter-class>
	<!-- <filter-class>org.jasig.cas.client.authentication.Saml11AuthenticationFilter</filter-class> -->
	<!-- <filter-class>org.jasig.cas.client.authentication.AuthenticationFilter</filter-class> -->
	<init-param>
		<param-name>casServerLoginUrl</param-name>
		<param-value>https://sso.hoau.com:8433/cas/login</param-value>
	</init-param>
	<init-param>
		<param-name>serverName</param-name>
		<param-value>https://app1.hoau.com:8413</param-value>
	</init-param>
</filter>

<filter>
	<filter-name>CAS Validation Filter</filter-name>
	<filter-class>org.jasig.cas.client.validation.Cas20ProxyReceivingTicketValidationFilter</filter-class>
	<!-- <filter-class>org.jasig.cas.client.validation.Saml11TicketValidationFilter</filter-class> -->	
	<!-- <filter-class>org.jasig.cas.client.validation.Cas20ProxyReceivingTicketValidationFilter</filter-class>	-->	
	<init-param>
		<param-name>casServerUrlPrefix</param-name>
		<param-value>https://sso.hoau.com:8433/cas</param-value>
	</init-param>
	<init-param>
		<param-name>serverName</param-name>
		<param-value>https://app1.hoau.com:8413</param-value>
	</init-param>
	<init-param>
		<param-name>redirectAfterValidation</param-name>
		<param-value>true</param-value>
	</init-param>
	<init-param>
		<param-name>useSession</param-name>
		<param-value>true</param-value>
	</init-param>
	<init-param>
		<param-name>acceptAnyProxy</param-name>
		<param-value>true</param-value>
	</init-param>
	<!--
	<init-param>
		<param-name>proxyReceptorUrl</param-name>
		<param-value>/cas1/proxyUrl</param-value>
	</init-param>
	<init-param>
		<param-name>proxyCallbackUrl</param-name>
		<param-value>https://app1.hoau.com:8413/cas1/index.jsp</param-value>
	</init-param>
	-->
</filter>

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

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

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

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

* 以上web.xml配置中有四处需要注意的地方

cas目标服务器登陆页面的配置

 <init-param>
 	<param-name>casServerLoginUrl</param-name>
 	<param-value>https://sso.hoau.com:8433/cas/login</param-value>
 </init-param>

本机服务器的地址（即当前node-a）

 <init-param>
 	<param-name>serverName</param-name>
 	<param-value>https://app1.hoau.com:8413</param-value>
 </init-param>

"Cas20ProxyReceivingTicketValidationFilter"

2.x和3.x以前也有其他的Ticket校验方式，这里官方推荐用Cas20Proxy

 <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>https://sso.hoau.com:8433/cas</param-value>
 </init-param>
 <init-param>
 	<param-name>serverName</param-name>
 	<param-value>https://app1.hoau.com:8413</param-value>
 </init-param>

暂时将proxyReceptorUrl和proxyCallbackUrl注释掉，因为这里没有使用代理

 <!--
 <init-param>
 	<param-name>proxyReceptorUrl</param-name>
 	<param-value>/cas1/proxyUrl</param-value>
 </init-param>
 <init-param>
 	<param-name>proxyCallbackUrl</param-name>
 	<param-value>https://app1.hoau.com:8413/cas1/index.jsp</param-value>
 </init-param>
 -->

测试

尝试访问

https://app1.hoau.com:8413/cas1

* 抱歉此处配图为node-b的

并使用我们在数据库里面预埋的数据"test01/psw01"登陆

使用相同方式将cas2部署到node-b节点，并指向cas的SSO服务器

*扩展

我们清空浏览器的cache和cookie，按照下列步骤操作

访问"https://app1.hoau.com:8413/cas1"

系统会将我们重定向到"https://sso.hoau.com:8433/cas/login"。
输入用户名密码"test01/psw01"

登陆成功
访问"https://app2.hoau.com:8423/cas2"

系统会自动登陆使用用户名密码"test01/psw01"。

问题来了

这就是达到了SSO的效果，但是为什么是这样，原理是什么