479 lines
		
	
	
		
			17 KiB
		
	
	
	
		
			PHP
		
	
	
	
		
		
			
		
	
	
			479 lines
		
	
	
		
			17 KiB
		
	
	
	
		
			PHP
		
	
	
	
|  | <?php | ||
|  | /* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */ | ||
|  | 
 | ||
|  | /** | ||
|  |  * Pure-PHP implementation of AES. | ||
|  |  * | ||
|  |  * Uses mcrypt, if available, and an internal implementation, otherwise. | ||
|  |  * | ||
|  |  * PHP versions 4 and 5 | ||
|  |  * | ||
|  |  * If {@link Crypt_AES::setKeyLength() setKeyLength()} isn't called, it'll be calculated from | ||
|  |  * {@link Crypt_AES::setKey() setKey()}.  ie. if the key is 128-bits, the key length will be 128-bits.  If it's 136-bits | ||
|  |  * it'll be null-padded to 160-bits and 160 bits will be the key length until {@link Crypt_Rijndael::setKey() setKey()} | ||
|  |  * is called, again, at which point, it'll be recalculated. | ||
|  |  * | ||
|  |  * Since Crypt_AES extends Crypt_Rijndael, some functions are available to be called that, in the context of AES, don't | ||
|  |  * make a whole lot of sense.  {@link Crypt_AES::setBlockLength() setBlockLength()}, for instance.  Calling that function, | ||
|  |  * however possible, won't do anything (AES has a fixed block length whereas Rijndael has a variable one). | ||
|  |  * | ||
|  |  * Here's a short example of how to use this library: | ||
|  |  * <code> | ||
|  |  * <?php | ||
|  |  *    include('Crypt/AES.php'); | ||
|  |  * | ||
|  |  *    $aes = new Crypt_AES(); | ||
|  |  * | ||
|  |  *    $aes->setKey('abcdefghijklmnop'); | ||
|  |  * | ||
|  |  *    $size = 10 * 1024; | ||
|  |  *    $plaintext = ''; | ||
|  |  *    for ($i = 0; $i < $size; $i++) { | ||
|  |  *        $plaintext.= 'a'; | ||
|  |  *    } | ||
|  |  * | ||
|  |  *    echo $aes->decrypt($aes->encrypt($plaintext)); | ||
|  |  * ?>
 | ||
|  |  * </code> | ||
|  |  * | ||
|  |  * LICENSE: This library is free software; you can redistribute it and/or | ||
|  |  * modify it under the terms of the GNU Lesser General Public | ||
|  |  * License as published by the Free Software Foundation; either | ||
|  |  * version 2.1 of the License, or (at your option) any later version. | ||
|  |  * | ||
|  |  * This library is distributed in the hope that it will be useful, | ||
|  |  * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
|  |  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU | ||
|  |  * Lesser General Public License for more details. | ||
|  |  * | ||
|  |  * You should have received a copy of the GNU Lesser General Public | ||
|  |  * License along with this library; if not, write to the Free Software | ||
|  |  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, | ||
|  |  * MA  02111-1307  USA | ||
|  |  * | ||
|  |  * @category   Crypt | ||
|  |  * @package    Crypt_AES | ||
|  |  * @author     Jim Wigginton <terrafrost@php.net> | ||
|  |  * @copyright  MMVIII Jim Wigginton | ||
|  |  * @license    http://www.gnu.org/licenses/lgpl.txt | ||
|  |  * @version    $Id$ | ||
|  |  * @link       http://phpseclib.sourceforge.net | ||
|  |  */ | ||
|  | 
 | ||
|  | /** | ||
|  |  * Include Crypt_Rijndael | ||
|  |  */ | ||
|  | require_once 'Rijndael.php'; | ||
|  | 
 | ||
|  | /**#@+
 | ||
|  |  * @access public | ||
|  |  * @see Crypt_AES::encrypt() | ||
|  |  * @see Crypt_AES::decrypt() | ||
|  |  */ | ||
|  | /** | ||
|  |  * Encrypt / decrypt using the Counter mode. | ||
|  |  * | ||
|  |  * Set to -1 since that's what Crypt/Random.php uses to index the CTR mode. | ||
|  |  * | ||
|  |  * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Counter_.28CTR.29
 | ||
|  |  */ | ||
|  | define('CRYPT_AES_MODE_CTR', -1); | ||
|  | /** | ||
|  |  * Encrypt / decrypt using the Electronic Code Book mode. | ||
|  |  * | ||
|  |  * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29
 | ||
|  |  */ | ||
|  | define('CRYPT_AES_MODE_ECB', 1); | ||
|  | /** | ||
|  |  * Encrypt / decrypt using the Code Book Chaining mode. | ||
|  |  * | ||
|  |  * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher-block_chaining_.28CBC.29
 | ||
|  |  */ | ||
|  | define('CRYPT_AES_MODE_CBC', 2); | ||
|  | /**#@-*/ | ||
|  | 
 | ||
|  | /**#@+
 | ||
|  |  * @access private | ||
|  |  * @see Crypt_AES::Crypt_AES() | ||
|  |  */ | ||
|  | /** | ||
|  |  * Toggles the internal implementation | ||
|  |  */ | ||
|  | define('CRYPT_AES_MODE_INTERNAL', 1); | ||
|  | /** | ||
|  |  * Toggles the mcrypt implementation | ||
|  |  */ | ||
|  | define('CRYPT_AES_MODE_MCRYPT', 2); | ||
|  | /**#@-*/ | ||
|  | 
 | ||
|  | /** | ||
|  |  * Pure-PHP implementation of AES. | ||
|  |  * | ||
|  |  * @author  Jim Wigginton <terrafrost@php.net> | ||
|  |  * @version 0.1.0 | ||
|  |  * @access  public | ||
|  |  * @package Crypt_AES | ||
|  |  */ | ||
|  | class Crypt_AES extends Crypt_Rijndael { | ||
|  |     /** | ||
|  |      * mcrypt resource for encryption | ||
|  |      * | ||
|  |      * The mcrypt resource can be recreated every time something needs to be created or it can be created just once. | ||
|  |      * Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode. | ||
|  |      * | ||
|  |      * @see Crypt_AES::encrypt() | ||
|  |      * @var String | ||
|  |      * @access private | ||
|  |      */ | ||
|  |     var $enmcrypt; | ||
|  | 
 | ||
|  |     /** | ||
|  |      * mcrypt resource for decryption | ||
|  |      * | ||
|  |      * The mcrypt resource can be recreated every time something needs to be created or it can be created just once. | ||
|  |      * Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode. | ||
|  |      * | ||
|  |      * @see Crypt_AES::decrypt() | ||
|  |      * @var String | ||
|  |      * @access private | ||
|  |      */ | ||
|  |     var $demcrypt; | ||
|  | 
 | ||
|  |     /** | ||
|  |      * Default Constructor. | ||
|  |      * | ||
|  |      * Determines whether or not the mcrypt extension should be used.  $mode should only, at present, be | ||
|  |      * CRYPT_AES_MODE_ECB or CRYPT_AES_MODE_CBC.  If not explictly set, CRYPT_AES_MODE_CBC will be used. | ||
|  |      * | ||
|  |      * @param optional Integer $mode | ||
|  |      * @return Crypt_AES | ||
|  |      * @access public | ||
|  |      */ | ||
|  |     function Crypt_AES($mode = CRYPT_AES_MODE_CBC) | ||
|  |     { | ||
|  |         if ( !defined('CRYPT_AES_MODE') ) { | ||
|  |             switch (true) { | ||
|  |                 case extension_loaded('mcrypt'): | ||
|  |                     // i'd check to see if aes was supported, by doing in_array('des', mcrypt_list_algorithms('')),
 | ||
|  |                     // but since that can be changed after the object has been created, there doesn't seem to be
 | ||
|  |                     // a lot of point...
 | ||
|  |                     define('CRYPT_AES_MODE', CRYPT_AES_MODE_MCRYPT); | ||
|  |                     break; | ||
|  |                 default: | ||
|  |                     define('CRYPT_AES_MODE', CRYPT_AES_MODE_INTERNAL); | ||
|  |             } | ||
|  |         } | ||
|  | 
 | ||
|  |         switch ( CRYPT_AES_MODE ) { | ||
|  |             case CRYPT_AES_MODE_MCRYPT: | ||
|  |                 switch ($mode) { | ||
|  |                     case CRYPT_AES_MODE_ECB: | ||
|  |                         $this->mode = MCRYPT_MODE_ECB; | ||
|  |                         break; | ||
|  |                     case CRYPT_AES_MODE_CTR: | ||
|  |                         // ctr doesn't have a constant associated with it even though it appears to be fairly widely
 | ||
|  |                         // supported.  in lieu of knowing just how widely supported it is, i've, for now, opted not to
 | ||
|  |                         // include a compatibility layer.  the layer has been implemented but, for now, is commented out.
 | ||
|  |                         $this->mode = 'ctr'; | ||
|  |                         //$this->mode = in_array('ctr', mcrypt_list_modes()) ? 'ctr' : CRYPT_AES_MODE_CTR;
 | ||
|  |                         break; | ||
|  |                     case CRYPT_AES_MODE_CBC: | ||
|  |                     default: | ||
|  |                         $this->mode = MCRYPT_MODE_CBC; | ||
|  |                 } | ||
|  | 
 | ||
|  |                 break; | ||
|  |             default: | ||
|  |                 switch ($mode) { | ||
|  |                     case CRYPT_AES_MODE_ECB: | ||
|  |                         $this->mode = CRYPT_RIJNDAEL_MODE_ECB; | ||
|  |                         break; | ||
|  |                     case CRYPT_AES_MODE_CTR: | ||
|  |                         $this->mode = CRYPT_RIJNDAEL_MODE_CTR; | ||
|  |                         break; | ||
|  |                     case CRYPT_AES_MODE_CBC: | ||
|  |                     default: | ||
|  |                         $this->mode = CRYPT_RIJNDAEL_MODE_CBC; | ||
|  |                 } | ||
|  |         } | ||
|  | 
 | ||
|  |         if (CRYPT_AES_MODE == CRYPT_AES_MODE_INTERNAL) { | ||
|  |             parent::Crypt_Rijndael($this->mode); | ||
|  |         } | ||
|  |     } | ||
|  | 
 | ||
|  |     /** | ||
|  |      * Dummy function
 | ||
|  |      * | ||
|  |      * Since Crypt_AES extends Crypt_Rijndael, this function is, technically, available, but it doesn't do anything. | ||
|  |      * | ||
|  |      * @access public | ||
|  |      * @param Integer $length | ||
|  |      */ | ||
|  |     function setBlockLength($length) | ||
|  |     { | ||
|  |         return; | ||
|  |     } | ||
|  | 
 | ||
|  |     /** | ||
|  |      * Encrypts a message. | ||
|  |      * | ||
|  |      * $plaintext will be padded with up to 16 additional bytes.  Other AES implementations may or may not pad in the | ||
|  |      * same manner.  Other common approaches to padding and the reasons why it's necessary are discussed in the following | ||
|  |      * URL: | ||
|  |      * | ||
|  |      * {@link http://www.di-mgt.com.au/cryptopad.html http://www.di-mgt.com.au/cryptopad.html} | ||
|  |      * | ||
|  |      * An alternative to padding is to, separately, send the length of the file.  This is what SSH, in fact, does. | ||
|  |      * strlen($plaintext) will still need to be a multiple of 16, however, arbitrary values can be added to make it that | ||
|  |      * length. | ||
|  |      * | ||
|  |      * @see Crypt_AES::decrypt() | ||
|  |      * @access public | ||
|  |      * @param String $plaintext | ||
|  |      */ | ||
|  |     function encrypt($plaintext) | ||
|  |     { | ||
|  |         if ( CRYPT_AES_MODE == CRYPT_AES_MODE_MCRYPT ) { | ||
|  |             $this->_mcryptSetup(); | ||
|  |             /* | ||
|  |             if ($this->mode == CRYPT_AES_MODE_CTR) { | ||
|  |                 $iv = $this->encryptIV; | ||
|  |                 $xor = mcrypt_generic($this->enmcrypt, $this->_generate_xor(strlen($plaintext), $iv)); | ||
|  |                 $ciphertext = $plaintext ^ $xor; | ||
|  |                 if ($this->continuousBuffer) { | ||
|  |                     $this->encryptIV = $iv; | ||
|  |                 } | ||
|  |                 return $ciphertext; | ||
|  |             } | ||
|  |             */ | ||
|  | 
 | ||
|  |             if ($this->mode != 'ctr') { | ||
|  |                 $plaintext = $this->_pad($plaintext); | ||
|  |             } | ||
|  | 
 | ||
|  |             $ciphertext = mcrypt_generic($this->enmcrypt, $plaintext); | ||
|  | 
 | ||
|  |             if (!$this->continuousBuffer) { | ||
|  |                 mcrypt_generic_init($this->enmcrypt, $this->key, $this->iv); | ||
|  |             } | ||
|  | 
 | ||
|  |             return $ciphertext; | ||
|  |         } | ||
|  | 
 | ||
|  |         return parent::encrypt($plaintext); | ||
|  |     } | ||
|  | 
 | ||
|  |     /** | ||
|  |      * Decrypts a message. | ||
|  |      * | ||
|  |      * If strlen($ciphertext) is not a multiple of 16, null bytes will be added to the end of the string until it is. | ||
|  |      * | ||
|  |      * @see Crypt_AES::encrypt() | ||
|  |      * @access public | ||
|  |      * @param String $ciphertext | ||
|  |      */ | ||
|  |     function decrypt($ciphertext) | ||
|  |     { | ||
|  |         if ( CRYPT_AES_MODE == CRYPT_AES_MODE_MCRYPT ) { | ||
|  |             $this->_mcryptSetup(); | ||
|  |             /* | ||
|  |             if ($this->mode == CRYPT_AES_MODE_CTR) { | ||
|  |                 $iv = $this->decryptIV; | ||
|  |                 $xor = mcrypt_generic($this->enmcrypt, $this->_generate_xor(strlen($ciphertext), $iv)); | ||
|  |                 $plaintext = $ciphertext ^ $xor; | ||
|  |                 if ($this->continuousBuffer) { | ||
|  |                     $this->decryptIV = $iv; | ||
|  |                 } | ||
|  |                 return $plaintext; | ||
|  |             } | ||
|  |             */ | ||
|  | 
 | ||
|  |             if ($this->mode != 'ctr') { | ||
|  |                 // we pad with chr(0) since that's what mcrypt_generic does.  to quote from http://php.net/function.mcrypt-generic :
 | ||
|  |                 // "The data is padded with "\0" to make sure the length of the data is n * blocksize."
 | ||
|  |                 $ciphertext = str_pad($ciphertext, (strlen($ciphertext) + 15) & 0xFFFFFFF0, chr(0)); | ||
|  |             } | ||
|  | 
 | ||
|  |             $plaintext = mdecrypt_generic($this->demcrypt, $ciphertext); | ||
|  | 
 | ||
|  |             if (!$this->continuousBuffer) { | ||
|  |                 mcrypt_generic_init($this->demcrypt, $this->key, $this->iv); | ||
|  |             } | ||
|  | 
 | ||
|  |             return $this->mode != 'ctr' ? $this->_unpad($plaintext) : $plaintext; | ||
|  |         } | ||
|  | 
 | ||
|  |         return parent::decrypt($ciphertext); | ||
|  |     } | ||
|  | 
 | ||
|  |     /** | ||
|  |      * Setup mcrypt | ||
|  |      * | ||
|  |      * Validates all the variables. | ||
|  |      * | ||
|  |      * @access private | ||
|  |      */ | ||
|  |     function _mcryptSetup() | ||
|  |     { | ||
|  |         if (!$this->changed) { | ||
|  |             return; | ||
|  |         } | ||
|  | 
 | ||
|  |         if (!$this->explicit_key_length) { | ||
|  |             // this just copied from Crypt_Rijndael::_setup()
 | ||
|  |             $length = strlen($this->key) >> 2; | ||
|  |             if ($length > 8) { | ||
|  |                 $length = 8; | ||
|  |             } else if ($length < 4) { | ||
|  |                 $length = 4; | ||
|  |             } | ||
|  |             $this->Nk = $length; | ||
|  |             $this->key_size = $length << 2; | ||
|  |         } | ||
|  | 
 | ||
|  |         switch ($this->Nk) { | ||
|  |             case 4: // 128
 | ||
|  |                 $this->key_size = 16; | ||
|  |                 break; | ||
|  |             case 5: // 160
 | ||
|  |             case 6: // 192
 | ||
|  |                 $this->key_size = 24; | ||
|  |                 break; | ||
|  |             case 7: // 224
 | ||
|  |             case 8: // 256
 | ||
|  |                 $this->key_size = 32; | ||
|  |         } | ||
|  | 
 | ||
|  |         $this->key = substr($this->key, 0, $this->key_size); | ||
|  |         $this->encryptIV = $this->decryptIV = $this->iv = str_pad(substr($this->iv, 0, 16), 16, chr(0)); | ||
|  | 
 | ||
|  |         if (!isset($this->enmcrypt)) { | ||
|  |             $mode = $this->mode; | ||
|  |             //$mode = $this->mode == CRYPT_AES_MODE_CTR ? MCRYPT_MODE_ECB : $this->mode;
 | ||
|  | 
 | ||
|  |             $this->demcrypt = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', $mode, ''); | ||
|  |             $this->enmcrypt = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', $mode, ''); | ||
|  |         } // else should mcrypt_generic_deinit be called?
 | ||
|  | 
 | ||
|  |         mcrypt_generic_init($this->demcrypt, $this->key, $this->iv); | ||
|  |         mcrypt_generic_init($this->enmcrypt, $this->key, $this->iv); | ||
|  | 
 | ||
|  |         $this->changed = false; | ||
|  |     } | ||
|  | 
 | ||
|  |     /** | ||
|  |      * Encrypts a block | ||
|  |      * | ||
|  |      * Optimized over Crypt_Rijndael's implementation by means of loop unrolling. | ||
|  |      * | ||
|  |      * @see Crypt_Rijndael::_encryptBlock() | ||
|  |      * @access private | ||
|  |      * @param String $in | ||
|  |      * @return String | ||
|  |      */ | ||
|  |     function _encryptBlock($in) | ||
|  |     { | ||
|  |         $state = unpack('N*word', $in); | ||
|  | 
 | ||
|  |         $Nr = $this->Nr; | ||
|  |         $w = $this->w; | ||
|  |         $t0 = $this->t0; | ||
|  |         $t1 = $this->t1; | ||
|  |         $t2 = $this->t2; | ||
|  |         $t3 = $this->t3; | ||
|  | 
 | ||
|  |         // addRoundKey and reindex $state
 | ||
|  |         $state = array( | ||
|  |             $state['word1'] ^ $w[0][0], | ||
|  |             $state['word2'] ^ $w[0][1], | ||
|  |             $state['word3'] ^ $w[0][2], | ||
|  |             $state['word4'] ^ $w[0][3] | ||
|  |         ); | ||
|  | 
 | ||
|  |         // shiftRows + subWord + mixColumns + addRoundKey
 | ||
|  |         // we could loop unroll this and use if statements to do more rounds as necessary, but, in my tests, that yields
 | ||
|  |         // only a marginal improvement.  since that also, imho, hinders the readability of the code, i've opted not to do it.
 | ||
|  |         for ($round = 1; $round < $this->Nr; $round++) { | ||
|  |             $state = array( | ||
|  |                 $t0[$state[0] & 0xFF000000] ^ $t1[$state[1] & 0x00FF0000] ^ $t2[$state[2] & 0x0000FF00] ^ $t3[$state[3] & 0x000000FF] ^ $w[$round][0], | ||
|  |                 $t0[$state[1] & 0xFF000000] ^ $t1[$state[2] & 0x00FF0000] ^ $t2[$state[3] & 0x0000FF00] ^ $t3[$state[0] & 0x000000FF] ^ $w[$round][1], | ||
|  |                 $t0[$state[2] & 0xFF000000] ^ $t1[$state[3] & 0x00FF0000] ^ $t2[$state[0] & 0x0000FF00] ^ $t3[$state[1] & 0x000000FF] ^ $w[$round][2], | ||
|  |                 $t0[$state[3] & 0xFF000000] ^ $t1[$state[0] & 0x00FF0000] ^ $t2[$state[1] & 0x0000FF00] ^ $t3[$state[2] & 0x000000FF] ^ $w[$round][3] | ||
|  |             ); | ||
|  | 
 | ||
|  |         } | ||
|  | 
 | ||
|  |         // subWord
 | ||
|  |         $state = array( | ||
|  |             $this->_subWord($state[0]), | ||
|  |             $this->_subWord($state[1]), | ||
|  |             $this->_subWord($state[2]), | ||
|  |             $this->_subWord($state[3]) | ||
|  |         ); | ||
|  | 
 | ||
|  |         // shiftRows + addRoundKey
 | ||
|  |         $state = array( | ||
|  |             ($state[0] & 0xFF000000) ^ ($state[1] & 0x00FF0000) ^ ($state[2] & 0x0000FF00) ^ ($state[3] & 0x000000FF) ^ $this->w[$this->Nr][0], | ||
|  |             ($state[1] & 0xFF000000) ^ ($state[2] & 0x00FF0000) ^ ($state[3] & 0x0000FF00) ^ ($state[0] & 0x000000FF) ^ $this->w[$this->Nr][1], | ||
|  |             ($state[2] & 0xFF000000) ^ ($state[3] & 0x00FF0000) ^ ($state[0] & 0x0000FF00) ^ ($state[1] & 0x000000FF) ^ $this->w[$this->Nr][2], | ||
|  |             ($state[3] & 0xFF000000) ^ ($state[0] & 0x00FF0000) ^ ($state[1] & 0x0000FF00) ^ ($state[2] & 0x000000FF) ^ $this->w[$this->Nr][3] | ||
|  |         ); | ||
|  | 
 | ||
|  |         return pack('N*', $state[0], $state[1], $state[2], $state[3]); | ||
|  |     } | ||
|  | 
 | ||
|  |     /** | ||
|  |      * Decrypts a block | ||
|  |      * | ||
|  |      * Optimized over Crypt_Rijndael's implementation by means of loop unrolling. | ||
|  |      * | ||
|  |      * @see Crypt_Rijndael::_decryptBlock() | ||
|  |      * @access private | ||
|  |      * @param String $in | ||
|  |      * @return String | ||
|  |      */ | ||
|  |     function _decryptBlock($in) | ||
|  |     { | ||
|  |         $state = unpack('N*word', $in); | ||
|  | 
 | ||
|  |         $Nr = $this->Nr; | ||
|  |         $dw = $this->dw; | ||
|  |         $dt0 = $this->dt0; | ||
|  |         $dt1 = $this->dt1; | ||
|  |         $dt2 = $this->dt2; | ||
|  |         $dt3 = $this->dt3; | ||
|  | 
 | ||
|  |         // addRoundKey and reindex $state
 | ||
|  |         $state = array( | ||
|  |             $state['word1'] ^ $dw[$this->Nr][0], | ||
|  |             $state['word2'] ^ $dw[$this->Nr][1], | ||
|  |             $state['word3'] ^ $dw[$this->Nr][2], | ||
|  |             $state['word4'] ^ $dw[$this->Nr][3] | ||
|  |         ); | ||
|  | 
 | ||
|  | 
 | ||
|  |         // invShiftRows + invSubBytes + invMixColumns + addRoundKey
 | ||
|  |         for ($round = $this->Nr - 1; $round > 0; $round--) { | ||
|  |             $state = array( | ||
|  |                 $dt0[$state[0] & 0xFF000000] ^ $dt1[$state[3] & 0x00FF0000] ^ $dt2[$state[2] & 0x0000FF00] ^ $dt3[$state[1] & 0x000000FF] ^ $dw[$round][0], | ||
|  |                 $dt0[$state[1] & 0xFF000000] ^ $dt1[$state[0] & 0x00FF0000] ^ $dt2[$state[3] & 0x0000FF00] ^ $dt3[$state[2] & 0x000000FF] ^ $dw[$round][1], | ||
|  |                 $dt0[$state[2] & 0xFF000000] ^ $dt1[$state[1] & 0x00FF0000] ^ $dt2[$state[0] & 0x0000FF00] ^ $dt3[$state[3] & 0x000000FF] ^ $dw[$round][2], | ||
|  |                 $dt0[$state[3] & 0xFF000000] ^ $dt1[$state[2] & 0x00FF0000] ^ $dt2[$state[1] & 0x0000FF00] ^ $dt3[$state[0] & 0x000000FF] ^ $dw[$round][3] | ||
|  |             ); | ||
|  |         } | ||
|  | 
 | ||
|  |         // invShiftRows + invSubWord + addRoundKey
 | ||
|  |         $state = array( | ||
|  |             $this->_invSubWord(($state[0] & 0xFF000000) ^ ($state[3] & 0x00FF0000) ^ ($state[2] & 0x0000FF00) ^ ($state[1] & 0x000000FF)) ^ $dw[0][0], | ||
|  |             $this->_invSubWord(($state[1] & 0xFF000000) ^ ($state[0] & 0x00FF0000) ^ ($state[3] & 0x0000FF00) ^ ($state[2] & 0x000000FF)) ^ $dw[0][1], | ||
|  |             $this->_invSubWord(($state[2] & 0xFF000000) ^ ($state[1] & 0x00FF0000) ^ ($state[0] & 0x0000FF00) ^ ($state[3] & 0x000000FF)) ^ $dw[0][2], | ||
|  |             $this->_invSubWord(($state[3] & 0xFF000000) ^ ($state[2] & 0x00FF0000) ^ ($state[1] & 0x0000FF00) ^ ($state[0] & 0x000000FF)) ^ $dw[0][3] | ||
|  |         ); | ||
|  | 
 | ||
|  |         return pack('N*', $state[0], $state[1], $state[2], $state[3]); | ||
|  |     } | ||
|  | } | ||
|  | 
 | ||
|  | // vim: ts=4:sw=4:et:
 | ||
|  | // vim6: fdl=1:
 |