crm.fsf.org/20131203/files/sites/all/modules-new/civicrm/vendor/phpseclib/phpseclib/phpseclib/Crypt/AES.php

   1 <?php
   2
   3 /**
   4  * Pure-PHP implementation of AES.
   5  *
   6  * Uses mcrypt, if available/possible, and an internal implementation, otherwise.
   7  *
   8  * PHP versions 4 and 5
   9  *
  10  * If {@link Crypt_AES::setKeyLength() setKeyLength()} isn't called, it'll be calculated from
  11  * {@link Crypt_AES::setKey() setKey()}.  ie. if the key is 128-bits, the key length will be 128-bits.  If it's 136-bits
  12  * it'll be null-padded to 192-bits and 192 bits will be the key length until {@link Crypt_AES::setKey() setKey()}
  13  * is called, again, at which point, it'll be recalculated.
  14  *
  15  * Since Crypt_AES extends Crypt_Rijndael, some functions are available to be called that, in the context of AES, don't
  16  * make a whole lot of sense.  {@link Crypt_AES::setBlockLength() setBlockLength()}, for instance.  Calling that function,
  17  * however possible, won't do anything (AES has a fixed block length whereas Rijndael has a variable one).
  18  *
  19  * Here's a short example of how to use this library:
  20  * <code>
  21  * <?php
  22  *    include 'Crypt/AES.php';
  23  *
  24  *    $aes = new Crypt_AES();
  25  *
  26  *    $aes->setKey('abcdefghijklmnop');
  27  *
  28  *    $size = 10 * 1024;
  29  *    $plaintext = '';
  30  *    for ($i = 0; $i < $size; $i++) {
  31  *        $plaintext.= 'a';
  32  *    }
  33  *
  34  *    echo $aes->decrypt($aes->encrypt($plaintext));
  35  * ?>
  36  * </code>
  37  *
  38  * LICENSE: Permission is hereby granted, free of charge, to any person obtaining a copy
  39  * of this software and associated documentation files (the "Software"), to deal
  40  * in the Software without restriction, including without limitation the rights
  41  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  42  * copies of the Software, and to permit persons to whom the Software is
  43  * furnished to do so, subject to the following conditions:
  44  *
  45  * The above copyright notice and this permission notice shall be included in
  46  * all copies or substantial portions of the Software.
  47  *
  48  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  49  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  50  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  51  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  52  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  53  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  54  * THE SOFTWARE.
  55  *
  56  * @category  Crypt
  57  * @package   Crypt_AES
  58  * @author    Jim Wigginton <terrafrost@php.net>
  59  * @copyright 2008 Jim Wigginton
  60  * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
  61  * @link      http://phpseclib.sourceforge.net
  62  */
  63
  64 /**
  65  * Include Crypt_Rijndael
  66  */
  67 if (!class_exists('Crypt_Rijndael')) {
  68     include_once 'Rijndael.php';
  69 }
  70
  71 /**#@+
  72  * @access public
  73  * @see Crypt_AES::encrypt()
  74  * @see Crypt_AES::decrypt()
  75  */
  76 /**
  77  * Encrypt / decrypt using the Counter mode.
  78  *
  79  * Set to -1 since that's what Crypt/Random.php uses to index the CTR mode.
  80  *
  81  * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Counter_.28CTR.29
  82  */
  83 define('CRYPT_AES_MODE_CTR', CRYPT_MODE_CTR);
  84 /**
  85  * Encrypt / decrypt using the Electronic Code Book mode.
  86  *
  87  * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29
  88  */
  89 define('CRYPT_AES_MODE_ECB', CRYPT_MODE_ECB);
  90 /**
  91  * Encrypt / decrypt using the Code Book Chaining mode.
  92  *
  93  * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher-block_chaining_.28CBC.29
  94  */
  95 define('CRYPT_AES_MODE_CBC', CRYPT_MODE_CBC);
  96 /**
  97  * Encrypt / decrypt using the Cipher Feedback mode.
  98  *
  99  * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher_feedback_.28CFB.29
 100  */
 101 define('CRYPT_AES_MODE_CFB', CRYPT_MODE_CFB);
 102 /**
 103  * Encrypt / decrypt using the Cipher Feedback mode.
 104  *
 105  * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Output_feedback_.28OFB.29
 106  */
 107 define('CRYPT_AES_MODE_OFB', CRYPT_MODE_OFB);
 108 /**#@-*/
 109
 110 /**#@+
 111  * @access private
 112  * @see Crypt_Base::Crypt_Base()
 113  */
 114 /**
 115  * Toggles the internal implementation
 116  */
 117 define('CRYPT_AES_MODE_INTERNAL', CRYPT_MODE_INTERNAL);
 118 /**
 119  * Toggles the mcrypt implementation
 120  */
 121 define('CRYPT_AES_MODE_MCRYPT', CRYPT_MODE_MCRYPT);
 122 /**#@-*/
 123
 124 /**
 125  * Pure-PHP implementation of AES.
 126  *
 127  * @package Crypt_AES
 128  * @author  Jim Wigginton <terrafrost@php.net>
 129  * @access  public
 130  */
 131 class Crypt_AES extends Crypt_Rijndael
 132 {
 133     /**
 134      * The namespace used by the cipher for its constants.
 135      *
 136      * @see Crypt_Base::const_namespace
 137      * @var String
 138      * @access private
 139      */
 140     var $const_namespace = 'AES';
 141
 142     /**
 143      * Dummy function
 144      *
 145      * Since Crypt_AES extends Crypt_Rijndael, this function is, technically, available, but it doesn't do anything.
 146      *
 147      * @see Crypt_Rijndael::setBlockLength()
 148      * @access public
 149      * @param Integer $length
 150      */
 151     function setBlockLength($length)
 152     {
 153         return;
 154     }
 155
 156     /**
 157      * Sets the key length
 158      *
 159      * Valid key lengths are 128, 192, and 256.  If the length is less than 128, it will be rounded up to
 160      * 128.  If the length is greater than 128 and invalid, it will be rounded down to the closest valid amount.
 161      *
 162      * @see Crypt_Rijndael:setKeyLength()
 163      * @access public
 164      * @param Integer $length
 165      */
 166     function setKeyLength($length)
 167     {
 168         switch ($length) {
 169             case 160:
 170                 $length = 192;
 171                 break;
 172             case 224:
 173                 $length = 256;
 174         }
 175         parent::setKeyLength($length);
 176     }
 177
 178     /**
 179      * Sets the key.
 180      *
 181      * Rijndael supports five different key lengths, AES only supports three.
 182      *
 183      * @see Crypt_Rijndael:setKey()
 184      * @see setKeyLength()
 185      * @access public
 186      * @param String $key
 187      */
 188     function setKey($key)
 189     {
 190         parent::setKey($key);
 191
 192         if (!$this->explicit_key_length) {
 193             $length = strlen($key);
 194             switch (true) {
 195                 case $length <= 16:
 196                     $this->key_size = 16;
 197                     break;
 198                 case $length <= 24:
 199                     $this->key_size = 24;
 200                     break;
 201                 default:
 202                     $this->key_size = 32;
 203             }
 204             $this->_setupEngine();
 205         }
 206     }
 207 }