js/src/t/string-base64.js

   1 /* ***** BEGIN LICENSE BLOCK *****
   2  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   3  *
   4  * The contents of this file are subject to the Mozilla Public License Version
   5  * 1.1 (the "License"); you may not use this file except in compliance with
   6  * the License. You may obtain a copy of the License at
   7  * http://www.mozilla.org/MPL/
   8  *
   9  * Software distributed under the License is distributed on an "AS IS" basis,
  10  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  11  * for the specific language governing rights and limitations under the
  12  * License.
  13  *
  14  * The Original Code is Mozilla XML-RPC Client component.
  15  *
  16  * The Initial Developer of the Original Code is
  17  * Digital Creations 2, Inc.
  18  * Portions created by the Initial Developer are Copyright (C) 2000
  19  * the Initial Developer. All Rights Reserved.
  20  *
  21  * Contributor(s):
  22  *   Martijn Pieters <mj@digicool.com> (original author)
  23  *   Samuel Sieb <samuel@sieb.net>
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either the GNU General Public License Version 2 or later (the "GPL"), or
  27  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28  * in which case the provisions of the GPL or the LGPL are applicable instead
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  34  * the provisions above, a recipient may use your version of this file under
  35  * the terms of any one of the MPL, the GPL or the LGPL.
  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 // From: http://lxr.mozilla.org/mozilla/source/extensions/xml-rpc/src/nsXmlRpcClient.js#956
  40
  41 /* Convert data (an array of integers) to a Base64 string. */
  42 var toBase64Table = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
  43 var base64Pad = '=';
  44
  45 function toBase64(data) {
  46     var result = '';
  47     var length = data.length;
  48     var i;
  49     // Convert every three bytes to 4 ascii characters.
  50     for (i = 0; i < (length - 2); i += 3) {
  51         result += toBase64Table[data[i] >> 2];
  52         result += toBase64Table[((data[i] & 0x03) << 4) + (data[i+1] >> 4)];
  53         result += toBase64Table[((data[i+1] & 0x0f) << 2) + (data[i+2] >> 6)];
  54         result += toBase64Table[data[i+2] & 0x3f];
  55     }
  56
  57     // Convert the remaining 1 or 2 bytes, pad out to 4 characters.
  58     if (length%3) {
  59         i = length - (length%3);
  60         result += toBase64Table[data[i] >> 2];
  61         if ((length%3) == 2) {
  62             result += toBase64Table[((data[i] & 0x03) << 4) + (data[i+1] >> 4)];
  63             result += toBase64Table[(data[i+1] & 0x0f) << 2];
  64             result += base64Pad;
  65         } else {
  66             result += toBase64Table[(data[i] & 0x03) << 4];
  67             result += base64Pad + base64Pad;
  68         }
  69     }
  70
  71     return result;
  72 }
  73
  74 /* Convert Base64 data to a string */
  75 var toBinaryTable = [
  76     -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
  77     -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
  78     -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63,
  79     52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1, 0,-1,-1,
  80     -1, 0, 1, 2,  3, 4, 5, 6,  7, 8, 9,10, 11,12,13,14,
  81     15,16,17,18, 19,20,21,22, 23,24,25,-1, -1,-1,-1,-1,
  82     -1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
  83     41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1
  84 ];
  85
  86 function base64ToString(data) {
  87     var result = '';
  88     var leftbits = 0; // number of bits decoded, but yet to be appended
  89     var leftdata = 0; // bits decoded, but yet to be appended
  90
  91     // Convert one by one.
  92     for (var i = 0; i < data.length; i++) {
  93         var c = toBinaryTable[data.charCodeAt(i) & 0x7f];
  94         var padding = (data[i] == base64Pad);
  95         // Skip illegal characters and whitespace
  96         if (c == -1) continue;
  97
  98         // Collect data into leftdata, update bitcount
  99         leftdata = (leftdata << 6) | c;
 100         leftbits += 6;
 101
 102         // If we have 8 or more bits, append 8 bits to the result
 103         if (leftbits >= 8) {
 104             leftbits -= 8;
 105             // Append if not padding.
 106             if (!padding)
 107                 result += String.fromCharCode((leftdata >> leftbits) & 0xff);
 108             leftdata &= (1 << leftbits) - 1;
 109         }
 110     }
 111
 112     // If there are any bits left, the base64 string was corrupted
 113     if (leftbits)
 114         throw Components.Exception('Corrupted base64 string');
 115
 116     return result;
 117 }
 118
 119 var str = "";
 120
 121 for ( var i = 0; i < 8192; i++ )
 122         str += String.fromCharCode( (25 * Math.random()) + 97 );
 123
 124 for ( var i = 8192; i <= 16384; i *= 2 ) {
 125
 126     var base64;
 127
 128     base64 = toBase64(str);
 129     base64ToString(base64);
 130
 131     // Double the string
 132     str += str;
 133 }
 134
 135 toBinaryTable = null;