当前位置: 首页 > 图文教程 > 网络编程 > Javascript > base64编码/解码

Javascript
编辑浪子版表单验证类
JavaScript脚本语言在网页中的简单应用
getElementById在任意一款浏览器中都可以用吗的疑问回复
“增强js程序代码的健壮性”之我见大量示例代码
javascript之卸载鼠标事件的代码
静态页面下用javascript操作ACCESS数据库(读增改删)的代码
javascript操作文本框readOnly
用javascript实现gb2312转utf-8的脚本
网站被黑的假象--ARP欺骗之页面中加入一段js
(JS实现)MapBar中坐标的加密和解密的脚本
几款极品的javascript压缩混淆工具
[原创]由亿起发(eqifa.com)的页面发现顶部的http://16a.us/8.js想到的js解密
JavaScript中的new的使用方法与注意事项
分别用两个函数实现的菜单
非常不错的模拟打字效果,目前仅支持纯文本、BR标签、和P标签
用javascript实现的支持lrc歌词的播放器
JS加ASP二级域名转向的代码
效果直逼flash的Div+Css+Js菜单
input之怎么清除默认值
用xhtml+css写的相册自适应 - 类似九宫格[兼容 ff ie6 ie7 opear ]

Javascript 中的 base64编码/解码


出处:互联网   整理: 软晨网(RuanChen.com)   发布: 2009-08-10   浏览: 336 ::
收藏到网摘: n/a

编者:解决了对中文的不支持问题.
先用escape()对中文进行编码.然后再进行base64编码.
解码时,再加入unescape()对中文进行解码.

<html>
   <head>
      <title>base64 Encoding/Decoding</title>
   </head>

   <script type="text/javascript"><!--

   var keyStr = "ABCDEFGHIJKLMNOP" +
                "QRSTUVWXYZabcdef" +
                "ghijklmnopqrstuv" +
                "wxyz0123456789+/" +
                "=";

   function encode64(input) {
      input = escape(input);
      var output = "";
      var chr1, chr2, chr3 = "";
      var enc1, enc2, enc3, enc4 = "";
      var i = 0;

      do {
         chr1 = input.charCodeAt(i++);
         chr2 = input.charCodeAt(i++);
         chr3 = input.charCodeAt(i++);

         enc1 = chr1 >> 2;
         enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
         enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
         enc4 = chr3 & 63;

         if (isNaN(chr2)) {
            enc3 = enc4 = 64;
         } else if (isNaN(chr3)) {
            enc4 = 64;
         }

         output = output +
            keyStr.charAt(enc1) +
            keyStr.charAt(enc2) +
            keyStr.charAt(enc3) +
            keyStr.charAt(enc4);
         chr1 = chr2 = chr3 = "";
         enc1 = enc2 = enc3 = enc4 = "";
      } while (i < input.length);

      return output;
   }

   function decode64(input) {
      var output = "";
      var chr1, chr2, chr3 = "";
      var enc1, enc2, enc3, enc4 = "";
      var i = 0;

      // remove all characters that are not A-Z, a-z, 0-9, +, /, or =
      var base64test = /[^A-Za-z0-9\+\/\=]/g;
      if (base64test.exec(input)) {
         alert("There were invalid base64 characters in the input text.\n" +
               "Valid base64 characters are A-Z, a-z, 0-9, '+', '/', and '='\n" +
               "Expect errors in decoding.");
      }
      input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

      do {
         enc1 = keyStr.indexOf(input.charAt(i++));
         enc2 = keyStr.indexOf(input.charAt(i++));
         enc3 = keyStr.indexOf(input.charAt(i++));
         enc4 = keyStr.indexOf(input.charAt(i++));

         chr1 = (enc1 << 2) | (enc2 >> 4);
         chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
         chr3 = ((enc3 & 3) << 6) | enc4;

         output = output + String.fromCharCode(chr1);

         if (enc3 != 64) {
            output = output + String.fromCharCode(chr2);
         }
         if (enc4 != 64) {
            output = output + String.fromCharCode(chr3);
         }

         chr1 = chr2 = chr3 = "";
         enc1 = enc2 = enc3 = enc4 = "";

      } while (i < input.length);

      return unescape(output);
   }

   //--></script>

   <body>

      <form name="base64Form">

         Type in the message you want to encode in base64, or paste<br>
         base64 encoded text into the text field, select Encode or Decode, <br>
         and click the button!<br>

         <textarea name="theText" cols="40" rows="6"></textarea><br>

         <input type="button" name="encode" value="Encode to base64"
            onClick="document.base64Form.theText.value=encode64(document.base64Form.theText.value);">
         <input type="button" name="decode" value="Decode from base64"
            onClick="document.base64Form.theText.value=decode64(document.base64Form.theText.value);">

      </form>

   </body>
</html>


'