在jsp中作HTTP认证的方法

【 tulaoshi.com - Java 】

    最近研究了jsp中作HTTP认证的问题，它的工作方式如下：

1、server发送一个要求认证代码401和一个头信息WWW-authenticate，激发browser弹出一个认证窗口

2、server取得browser送来的认证头"Authorization",它是加密的了，要用Base64方法解密，取得明文的用户名和密码

3、检查用户名和密码，根据结果传送不同的页面

以下是jsp的片断，你也可以把它做成include文件。和Base64的加解密的class源码。
如有兴趣可与我联系：unixboy@yeah.net

<jsp:useBean id="base64"scope="page"class="Base64"/
<%
if(request.getHeader("Authorization")==null){
   response.setStatus(401);
   response.setHeader("WWW-authenticate","Basic realm="unixboy.com"");
}else{
   String encoded=(request.getHeader("Authorization"));
   String tmp=encoded.substring(6);
   String up=Base64.decode(tmp);
   String user="";
   String password="";
   if(up!=null){
        user=up.substring(0,up.indexOf(":"));
    password=up.substring(up.indexOf(":")+1);
   }
   if(user.equals("unixboy")&&password.equals("123456")){
        //认证成功
   }else{
        //认证失败
   }
}
%

//消息加解密class
public class Base64
{
        /** decode a Base 64 encoded String.
          *<p<h4String to byte conversion</h4
          * This method uses a naive String to byte interpretation, it simply gets each
          * char of the String and calls it a byte.</p
          *<pSince we should be dealing with Base64 encoded Strings that is a reasonable
          * assumption.</p
          *<p<h4End of data</h4
          * We don''t try to stop the converion when we find the"="end of data padding char.
          * We simply add zero bytes to the unencode buffer.</p
        */
        public static String decode(String encoded)
        {
                StringBuffer sb=new StringBuffer();
                int maxturns;
                //work out how long to loop for.
                if(encoded.length()%3==0)
                maxturns=encoded.length();
                else
                maxturns=encoded.length()+(3-(encoded.length()%3));
                //tells us whether to include the char in the unencode
                boolean skip;
                //the unencode buffer
                byte[] unenc=new byte[4];
   &n