博客

一、加密方法

function Base64() { 
   
    // private property 
    _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="; 
     
    // public method for encoding 
    this.encode = function (input) { 
      var output = ""; 
      var chr1, chr2, chr3, enc1, enc2, enc3, enc4; 
      var i = 0; 
      input = _utf8_encode(input); 
      while (i < input.length) { 
        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); 
      } 
      return output; 
    } 
     
    // public method for decoding 
    this.decode = function (input) { 
      var output = ""; 
      var chr1, chr2, chr3; 
      var enc1, enc2, enc3, enc4; 
      var i = 0; 
      input = input.replace(/[^A-Za-z0-9\+\/\=]/g, ""); 
      while (i < input.length) { 
        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); 
        } 
      } 
      output = _utf8_decode(output); 
      return output; 
    } 
     
    // private method for UTF-8 encoding 
    _utf8_encode = function (string) { 
      string = string.replace(/\r\n/g,"\n"); 
      var utftext = ""; 
      for (var n = 0; n < string.length; n++) { 
        var c = string.charCodeAt(n); 
        if (c < 128) { 
          utftext += String.fromCharCode(c); 
        } else if((c > 127) && (c < 2048)) { 
          utftext += String.fromCharCode((c >> 6) | 192); 
          utftext += String.fromCharCode((c & 63) | 128); 
        } else { 
          utftext += String.fromCharCode((c >> 12) | 224); 
          utftext += String.fromCharCode(((c >> 6) & 63) | 128); 
          utftext += String.fromCharCode((c & 63) | 128); 
        } 
     
      } 
      return utftext; 
    } 
     
    // private method for UTF-8 decoding 
    _utf8_decode = function (utftext) { 
      var string = ""; 
      var i = 0; 
      var c = c1 = c2 = 0; 
      while ( i < utftext.length ) { 
        c = utftext.charCodeAt(i); 
        if (c < 128) { 
          string += String.fromCharCode(c); 
          i++; 
        } else if((c > 191) && (c < 224)) { 
          c2 = utftext.charCodeAt(i+1); 
          string += String.fromCharCode(((c & 31) << 6) | (c2 & 63)); 
          i += 2; 
        } else { 
          c2 = utftext.charCodeAt(i+1); 
          c3 = utftext.charCodeAt(i+2); 
          string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63)); 
          i += 3; 
        } 
      } 
      return string; 
    } 
}

二、方法调用

var str = '124中文内容'; 
var base = new Base64(); 
 var stampInfoXml = base.encode(str ); //加密
 str  = base.decode(stampInfoXml ); //解密