js/webtoolkit.base64.js

   1 /**
   2 *
   3 *  Base64 encode / decode
   4 *  http://www.webtoolkit.info/
   5 *
   6 **/
   7
   8 var Base64 = {
   9
  10         // private property
  11         _keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
  12
  13         // public method for encoding
  14         encode : function (input) {
  15                 var output = "";
  16                 var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
  17                 var i = 0;
  18
  19                 input = Base64._utf8_encode(input);
  20
  21                 while (i < input.length) {
  22
  23                         chr1 = input.charCodeAt(i++);
  24                         chr2 = input.charCodeAt(i++);
  25                         chr3 = input.charCodeAt(i++);
  26
  27                         enc1 = chr1 >> 2;
  28                         enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
  29                         enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
  30                         enc4 = chr3 & 63;
  31
  32                         if (isNaN(chr2)) {
  33                                 enc3 = enc4 = 64;
  34                         } else if (isNaN(chr3)) {
  35                                 enc4 = 64;
  36                         }
  37
  38                         output = output +
  39                         this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
  40                         this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4);
  41
  42                 }
  43
  44                 return output;
  45         },
  46
  47         // public method for decoding
  48         decode : function (input) {
  49                 var output = "";
  50                 var chr1, chr2, chr3;
  51                 var enc1, enc2, enc3, enc4;
  52                 var i = 0;
  53
  54                 input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
  55
  56                 while (i < input.length) {
  57
  58                         enc1 = this._keyStr.indexOf(input.charAt(i++));
  59                         enc2 = this._keyStr.indexOf(input.charAt(i++));
  60                         enc3 = this._keyStr.indexOf(input.charAt(i++));
  61                         enc4 = this._keyStr.indexOf(input.charAt(i++));
  62
  63                         chr1 = (enc1 << 2) | (enc2 >> 4);
  64                         chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
  65                         chr3 = ((enc3 & 3) << 6) | enc4;
  66
  67                         output = output + String.fromCharCode(chr1);
  68
  69                         if (enc3 != 64) {
  70                                 output = output + String.fromCharCode(chr2);
  71                         }
  72                         if (enc4 != 64) {
  73                                 output = output + String.fromCharCode(chr3);
  74                         }
  75
  76                 }
  77
  78                 output = Base64._utf8_decode(output);
  79
  80                 return output;
  81
  82         },
  83
  84         // private method for UTF-8 encoding
  85         _utf8_encode : function (string) {
  86                 string = string.replace(/\r\n/g,"\n");
  87                 var utftext = "";
  88
  89                 for (var n = 0; n < string.length; n++) {
  90
  91                         var c = string.charCodeAt(n);
  92
  93                         if (c < 128) {
  94                                 utftext += String.fromCharCode(c);
  95                         }
  96                         else if((c > 127) && (c < 2048)) {
  97                                 utftext += String.fromCharCode((c >> 6) | 192);
  98                                 utftext += String.fromCharCode((c & 63) | 128);
  99                         }
 100                         else {
 101                                 utftext += String.fromCharCode((c >> 12) | 224);
 102                                 utftext += String.fromCharCode(((c >> 6) & 63) | 128);
 103                                 utftext += String.fromCharCode((c & 63) | 128);
 104                         }
 105
 106                 }
 107
 108                 return utftext;
 109         },
 110
 111         // private method for UTF-8 decoding
 112         _utf8_decode : function (utftext) {
 113                 var string = "";
 114                 var i = 0;
 115                 var c = c1 = c2 = 0;
 116
 117                 while ( i < utftext.length ) {
 118
 119                         c = utftext.charCodeAt(i);
 120
 121                         if (c < 128) {
 122                                 string += String.fromCharCode(c);
 123                                 i++;
 124                         }
 125                         else if((c > 191) && (c < 224)) {
 126                                 c2 = utftext.charCodeAt(i+1);
 127                                 string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
 128                                 i += 2;
 129                         }
 130                         else {
 131                                 c2 = utftext.charCodeAt(i+1);
 132                                 c3 = utftext.charCodeAt(i+2);
 133                                 string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
 134                                 i += 3;
 135                         }
 136
 137                 }
 138
 139                 return string;
 140         }
 141
 142 }