include/base64.js

   1 /*
   2  * Modified from:
   3  * http://lxr.mozilla.org/mozilla/source/extensions/xml-rpc/src/nsXmlRpcClient.js#956
   4  */
   5
   6 /* ***** BEGIN LICENSE BLOCK *****
   7  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   8  *
   9  * The contents of this file are subject to the Mozilla Public License Version
  10  * 1.1 (the "License"); you may not use this file except in compliance with
  11  * the License. You may obtain a copy of the License at
  12  * http://www.mozilla.org/MPL/
  13  *
  14  * Software distributed under the License is distributed on an "AS IS" basis,
  15  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  16  * for the specific language governing rights and limitations under the
  17  * License.
  18  *
  19  * The Original Code is Mozilla XML-RPC Client component.
  20  *
  21  * The Initial Developer of the Original Code is
  22  * Digital Creations 2, Inc.
  23  * Portions created by the Initial Developer are Copyright (C) 2000
  24  * the Initial Developer. All Rights Reserved.
  25  *
  26  * Contributor(s):
  27  *   Martijn Pieters <mj@digicool.com> (original author)
  28  *   Samuel Sieb <samuel@sieb.net>
  29  *
  30  * Alternatively, the contents of this file may be used under the terms of
  31  * either the GNU General Public License Version 2 or later (the "GPL"), or
  32  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  33  * in which case the provisions of the GPL or the LGPL are applicable instead
  34  * of those above. If you wish to allow use of your version of this file only
  35  * under the terms of either the GPL or the LGPL, and not to allow others to
  36  * use your version of this file under the terms of the MPL, indicate your
  37  * decision by deleting the provisions above and replace them with the notice
  38  * and other provisions required by the GPL or the LGPL. If you do not delete
  39  * the provisions above, a recipient may use your version of this file under
  40  * the terms of any one of the MPL, the GPL or the LGPL.
  41  *
  42  * ***** END LICENSE BLOCK ***** */
  43
  44 Base64 = {
  45
  46 /* Convert data (an array of integers) to a Base64 string. */
  47 toBase64Table : 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/',
  48 base64Pad     : '=',
  49
  50 encode: function (data) {
  51     var result = '';
  52     var chrTable = Base64.toBase64Table.split('');
  53     var pad = Base64.base64Pad;
  54     var length = data.length;
  55     var i;
  56     // Convert every three bytes to 4 ascii characters.
  57     for (i = 0; i < (length - 2); i += 3) {
  58         result += chrTable[data[i] >> 2];
  59         result += chrTable[((data[i] & 0x03) << 4) + (data[i+1] >> 4)];
  60         result += chrTable[((data[i+1] & 0x0f) << 2) + (data[i+2] >> 6)];
  61         result += chrTable[data[i+2] & 0x3f];
  62     }
  63
  64     // Convert the remaining 1 or 2 bytes, pad out to 4 characters.
  65     if (length%3) {
  66         i = length - (length%3);
  67         result += chrTable[data[i] >> 2];
  68         if ((length%3) == 2) {
  69             result += chrTable[((data[i] & 0x03) << 4) + (data[i+1] >> 4)];
  70             result += chrTable[(data[i+1] & 0x0f) << 2];
  71             result += pad;
  72         } else {
  73             result += chrTable[(data[i] & 0x03) << 4];
  74             result += pad + pad;
  75         }
  76     }
  77
  78     return result;
  79 },
  80
  81 /* Convert Base64 data to a string */
  82 toBinaryTable : [
  83     -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
  84     -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
  85     -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63,
  86     52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1, 0,-1,-1,
  87     -1, 0, 1, 2,  3, 4, 5, 6,  7, 8, 9,10, 11,12,13,14,
  88     15,16,17,18, 19,20,21,22, 23,24,25,-1, -1,-1,-1,-1,
  89     -1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
  90     41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1
  91 ],
  92
  93 decode: function (data, offset) {
  94     offset = typeof(offset) != 'undefined' ? offset : 0;
  95     var binTable = Base64.toBinaryTable;
  96     var pad = Base64.base64Pad;
  97     var leftbits = 0; // number of bits decoded, but yet to be appended
  98     var leftdata = 0; // bits decoded, but yet to be appended
  99
 100     /* Every four characters is 3 resulting numbers */
 101     var data_length = data.indexOf('=') - offset;
 102     if (data_length < 0) data_length = data.length - offset;
 103
 104     var result_length = (data_length >> 2) * 3 + Math.floor((data_length%4)/1.5);
 105     var result = new Array(result_length);
 106
 107     // Convert one by one.
 108     var idx = 0;
 109     for (var i = offset; i < data.length; i++) {
 110         var c = binTable[data.charCodeAt(i) & 0x7f];
 111         var padding = (data.charAt(i) == pad);
 112         // Skip illegal characters and whitespace
 113         if (c == -1) {
 114             console.log("Illegal character '" + data.charCodeAt(i) + "'");
 115             continue;
 116         }
 117
 118         // Collect data into leftdata, update bitcount
 119         leftdata = (leftdata << 6) | c;
 120         leftbits += 6;
 121
 122         // If we have 8 or more bits, append 8 bits to the result
 123         if (leftbits >= 8) {
 124             leftbits -= 8;
 125             // Append if not padding.
 126             if (!padding)
 127                 result[idx++] = (leftdata >> leftbits) & 0xff;
 128             leftdata &= (1 << leftbits) - 1;
 129         }
 130     }
 131
 132     // If there are any bits left, the base64 string was corrupted
 133     if (leftbits)
 134         throw {name: 'Base64-Error',
 135                message: 'Corrupted base64 string'};
 136
 137     return result;
 138 }
 139
 140 }; /* End of Base64 namespace */