Mercurial > laserkard

     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 }
author	Robert McIntyre <rlm@mit.edu>
date	Sun, 25 Jul 2010 21:46:00 -0400
parents	021a9ab1ed5b
children