CAS在客户端进行验证

1.原理：

用户在发起登录请求，把自己的用户名和密码传到后台，后台使用httpclient进行模拟登录

登录成功后，CAS服务器会给httpclient发一个cookie（TGT，ticket granting ticket），

服务器会把这个cookie返回给用户，完成一次模拟登录的过程。

2.核心代码：

001 package ecen.mip.sys.action;
002
003 import java.io.BufferedReader;
004 import java.io.IOException;
005 import java.io.InputStreamReader;
006 import java.util.ArrayList;
007 import java.util.List;
008
009 import org.apache.http.HttpEntity;
010 import org.apache.http.HttpResponse;
011 import org.apache.http.NameValuePair;
012 import org.apache.http.client.entity.UrlEncodedFormEntity;
013 import org.apache.http.client.methods.HttpGet;
014 import org.apache.http.client.methods.HttpPost;
015 import org.apache.http.cookie.Cookie;
016 import org.apache.http.impl.client.DefaultHttpClient;
017 import org.apache.http.message.BasicNameValuePair;
018 import org.apache.http.protocol.HTTP;
019 import org.apache.log4j.Logger;
020 import org.apache.struts2.convention.annotation.Action;
021 import org.apache.struts2.convention.annotation.Namespace;
022 import org.apache.struts2.convention.annotation.Result;
023 import org.apache.struts2.convention.annotation.Results;
024 import org.springframework.stereotype.Component;
025
026 @Namespace("/")
027 @Action("sysSingleSignOnAction")
028 @Component("sysSingleSignOnAction")
029 @Results({ @Result(name = "SUCCESS", location = "/sys/sys_new_index.jsp") })
030 public class SysSingleSignOnAction extends BaseAction {
031
032     private static final long serialVersionUID = -2096730223578871319L;
033     private static final Logger log = Logger.getLogger(SysSingleSignOnAction.class);
034     final String server = "http://192.168.0.142:8080/cas/login";
035     private String username;
036     private String password;
037
038     @Override
039     public String execute() throws Exception {
040         Cookie cookie = getTicketGrantingTicket(server, username, password);
041         if(cookie!=null){
042             getResponse().addCookie(convertToServletCookie(cookie));
043             log.info("The user authenticated successfully whose nickname code is "+username+" ! ");
044             return "SUCCESS";
045         }
046         return super.execute();
047     }
048
049
050     private Cookie getTicketGrantingTicket(final String server,final String username, final String password) throws IOException {
051         DefaultHttpClient client = new DefaultHttpClient();
052         HttpPost post = new HttpPost(server);
053
054         List <NameValuePair> nvps = new ArrayList <NameValuePair>();
055         nvps.add(new BasicNameValuePair("username", username));
056         nvps.add(new BasicNameValuePair("password", password));
057         nvps.add(new BasicNameValuePair("lt", doCasLoginRequest(client, server)));
058         nvps.add(new BasicNameValuePair("_eventId", "submit"));
059         post.setEntity(new UrlEncodedFormEntity(nvps, HTTP.UTF_8));
060         try {
061             HttpResponse response = client.execute(post);
062             HttpEntity entity = response.getEntity();
063             if(entity!=null){
064                 Cookie cookie = getCookieValue(client, "CASTGC");
065                 entity.consumeContent();
066                 return cookie;
067             }
068         } catch (Exception e) {
069             e.printStackTrace();
070         }
071         return null;
072     }
073
074
075     private Cookie getCookieValue(DefaultHttpClient httpclient, String name) {
076         List<Cookie> cookies = httpclient.getCookieStore().getCookies();
077         if (cookies.isEmpty()) {
078             return null;
079         } else {
080             for (int i = 0; i < cookies.size(); i++) {
081                 Cookie cookie = cookies.get(i);
082                 if (cookie.getName().equalsIgnoreCase(name)) {
083                     return cookie;
084                 }
085             }
086         }
087         return null;
088     }
089
090
091     private String doCasLoginRequest(DefaultHttpClient httpclient, String url) throws IOException {
092              String result = "";
093              HttpGet httpget = new HttpGet(url);
094                 HttpResponse response = httpclient.execute(httpget);
095                 HttpEntity entity = response.getEntity();
096                 BufferedReader rd = new BufferedReader(new InputStreamReader(entity.getContent(), "UTF-8"));
097                 String tempLine = rd.readLine();
098                 String s = "<input type=\"hidden\" name=\"lt\" value=\"";
099                 while (tempLine != null){
100                   int index = tempLine.indexOf(s);
101                      if(index != -1) {
102                       String s1 = tempLine.substring(index + s.length());
103                      int index1 = s1.indexOf("\"");
104                      if(index1 != -1)
105                       result = s1.substring(0, index1);
106                      }
107                     tempLine = rd.readLine();
108                 }
109                 if (entity != null) {
110                     entity.consumeContent();
111                 }
112                 return result;
113             }
114
115
116     private javax.servlet.http.Cookie convertToServletCookie(Cookie cookie){
117         javax.servlet.http.Cookie retCookie = new javax.servlet.http.Cookie(cookie.getName(), cookie.getValue());
118         retCookie.setComment(cookie.getComment());
119         retCookie.setDomain(cookie.getDomain());
120         retCookie.setHttpOnly(false);
121         retCookie.setSecure(false);
122         retCookie.setPath(cookie.getPath());
123         retCookie.setVersion(cookie.getVersion());
124         retCookie.setMaxAge((int) ((cookie.getExpiryDate().getTime()-System.currentTimeMillis())/1000));
125         return retCookie;
126     }
127
128     public String getUsername() {
129         return username;
130     }
131
132     public void setUsername(String username) {
133         this.username = username;
134     }
135
136     public String getPassword() {
137         return password;
138     }
139
140     public void setPassword(String password) {
141         this.password = password;
142     }
143
144 }

 

 

写完就贴上来了，所以没写注释，不过，应该都能看懂吧

3.注意事项：

通过这种途径登录后，request.getRemoteUser()不能使用，具体原因还不知道。