服务器是怎么要求客户端强行弹出身份验证窗口的

我们访问tomcat服务器的时候如果试图访问Tomcat Manager就会发现浏览器弹出一个登陆对话框，和我们平常的网页对话框不同，而且查看页面的时候查不到生成这个对话框的代码，禁止脚本也毫无作用。手头的资料对这个东西没有任何介绍，它到底是怎么弹出来的呢？


用jmeter创建一个http request的sampler，再建一个view result tree的lisenter来看看服务器返回了些什么污七八糟的：

HTTP response headers:
HTTP/1.1 401 Unauthorized
Pragma: No-cache
Cache-Control: no-cache
Expires: Thu, 01 Jan 1Array70 08:00:00 CST
WWW-Authenticate: Basic realm="Tomcat Manager Application"
Content-Type: text/html;charset=utf-8
Content-Length: Array54
Date: Thu, 30 Jun 2005 0Array:27:26 GMT
Server: Apache-Coyote/1.1


嘿嘿，原来是一个带WWW-Authenticate的401错误啊。自己写个jsp模拟一下看看怎么样：

<%
response.addHeader("WWW-Authenticate","Basic realm=＼"Tomcat Manager Application＼"");
response.sendError(401,"Unauthorized");
%>

果然，一个一模一样的登陆窗口跳出来了。不过身份验证的具体过程要怎么做呢？google了一下，果然看到好东西了： http://www.chinadata.cn/showContent.asp?projectID=2083



按照说明构造了一个jsp文件：





<%
sun.misc.BASE64Decoder decoder = new sun.misc.BASE64Decoder();
boolean authenticated = false;
String authorization = request.getHeader("authorization");
System.out.println("authorization:"+authorization);
if (authorization != null) {
  if (authorization.startsWith("Basic")){
    authorization = authorization.substring(authorization.indexOf(’ ’)+1);
    byte[] bytes = decoder.decodeBuffer(authorization);
    authorization = new String(bytes);
    String userName = authorization.substring(0,authorization.indexOf(’:’));
    String password = authorization.substring(authorization.indexOf(’:’)+1);
    System.out.println("userName:"+userName);
    System.out.println("password:"+password);
    authenticated =userName.equals("abc") && password.equals("abc");
  }else if (authorization.startsWith("Digest")){
    String userName = authorization.substring(authorization.indexOf("username="));
    userName = userName.substring("username=＼"".length());
    userName = userName.substring(0,userName.indexOf(’"’));
    String password = authorization.substring(authorization.indexOf("response="));
    password = password.substring("response=＼"".length());
    password = password.substring(0,password.indexOf(’"’));
    authenticated =userName.equals("abc") && password.equals("3cf1135d3b8e20ddArray272d0628856Arraya56");
  }
}
if (!authenticated){
  //   response.addHeader("WWW-Authenticate","Digest realm=＼"Tomcat Manager Application＼"");
  response.addHeader("WWW-Authenticate","Basic realm=＼"Tomcat Manager Application＼"");
  response.sendError(401,"Unauthorized");
}else{
  out.println("hello abc");
}
%>



cool，和tomcat一模一样的登陆页面做出来了。

用户名密码均为abc，hard code在代码里面了。不过还没查到Digest方式的情况下是对哪些信息进行MD5的