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