* setKey('abcdefgh'); * * $size = 10 * 1024; * $plaintext = ''; * for ($i = 0; $i < $size; $i++) { * $plaintext.= 'a'; * } * * echo $des->decrypt($des->encrypt($plaintext)); * ?> * * * 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_DES * @author Jim Wigginton * @copyright MMVII Jim Wigginton * @license http://www.gnu.org/licenses/lgpl.txt * @version $Id: DES.php,v 1.12 2010/02/09 06:10:26 terrafrost Exp $ * @link http://phpseclib.sourceforge.net */ /**#@+ * @access private * @see Crypt_DES::_prepareKey() * @see Crypt_DES::_processBlock() */ /** * Contains array_reverse($keys[CRYPT_DES_DECRYPT]) */ define('CRYPT_DES_ENCRYPT', 0); /** * Contains array_reverse($keys[CRYPT_DES_ENCRYPT]) */ define('CRYPT_DES_DECRYPT', 1); /**#@-*/ /**#@+ * @access public * @see Crypt_DES::encrypt() * @see Crypt_DES::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_DES_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_DES_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_DES_MODE_CBC', 2); /**#@-*/ /**#@+ * @access private * @see Crypt_DES::Crypt_DES() */ /** * Toggles the internal implementation */ define('CRYPT_DES_MODE_INTERNAL', 1); /** * Toggles the mcrypt implementation */ define('CRYPT_DES_MODE_MCRYPT', 2); /**#@-*/ /** * Pure-PHP implementation of DES. * * @author Jim Wigginton * @version 0.1.0 * @access public * @package Crypt_DES */ class Crypt_DES { /** * The Key Schedule * * @see Crypt_DES::setKey() * @var Array * @access private */ var $keys = "\0\0\0\0\0\0\0\0"; /** * The Encryption Mode * * @see Crypt_DES::Crypt_DES() * @var Integer * @access private */ var $mode; /** * Continuous Buffer status * * @see Crypt_DES::enableContinuousBuffer() * @var Boolean * @access private */ var $continuousBuffer = false; /** * Padding status * * @see Crypt_DES::enablePadding() * @var Boolean * @access private */ var $padding = true; /** * The Initialization Vector * * @see Crypt_DES::setIV() * @var String * @access private */ var $iv = "\0\0\0\0\0\0\0\0"; /** * A "sliding" Initialization Vector * * @see Crypt_DES::enableContinuousBuffer() * @var String * @access private */ var $encryptIV = "\0\0\0\0\0\0\0\0"; /** * A "sliding" Initialization Vector * * @see Crypt_DES::enableContinuousBuffer() * @var String * @access private */ var $decryptIV = "\0\0\0\0\0\0\0\0"; /** * 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; /** * Does the (en|de)mcrypt resource need to be (re)initialized? * * @see setKey() * @see setIV() * @var Boolean * @access private */ var $changed = true; /** * Default Constructor. * * Determines whether or not the mcrypt extension should be used. $mode should only, at present, be * CRYPT_DES_MODE_ECB or CRYPT_DES_MODE_CBC. If not explictly set, CRYPT_DES_MODE_CBC will be used. * * @param optional Integer $mode * @return Crypt_DES * @access public */ function Crypt_DES($mode = CRYPT_MODE_DES_CBC) { if ( !defined('CRYPT_DES_MODE') ) { switch (true) { case extension_loaded('mcrypt'): // i'd check to see if des 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_DES_MODE', CRYPT_DES_MODE_MCRYPT); break; default: define('CRYPT_DES_MODE', CRYPT_DES_MODE_INTERNAL); } } switch ( CRYPT_DES_MODE ) { case CRYPT_DES_MODE_MCRYPT: switch ($mode) { case CRYPT_DES_MODE_ECB: $this->mode = MCRYPT_MODE_ECB; break; case CRYPT_DES_MODE_CTR: $this->mode = 'ctr'; //$this->mode = in_array('ctr', mcrypt_list_modes()) ? 'ctr' : CRYPT_DES_MODE_CTR; break; case CRYPT_DES_MODE_CBC: default: $this->mode = MCRYPT_MODE_CBC; } break; default: switch ($mode) { case CRYPT_DES_MODE_ECB: case CRYPT_DES_MODE_CTR: case CRYPT_DES_MODE_CBC: $this->mode = $mode; break; default: $this->mode = CRYPT_DES_MODE_CBC; } } } /** * Sets the key. * * Keys can be of any length. DES, itself, uses 64-bit keys (eg. strlen($key) == 8), however, we * only use the first eight, if $key has more then eight characters in it, and pad $key with the * null byte if it is less then eight characters long. * * DES also requires that every eighth bit be a parity bit, however, we'll ignore that. * * If the key is not explicitly set, it'll be assumed to be all zero's. * * @access public * @param String $key */ function setKey($key) { $this->keys = ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT ) ? substr($key, 0, 8) : $this->_prepareKey($key); $this->changed = true; } /** * Sets the initialization vector. (optional) * * SetIV is not required when CRYPT_DES_MODE_ECB is being used. If not explictly set, it'll be assumed * to be all zero's. * * @access public * @param String $iv */ function setIV($iv) { $this->encryptIV = $this->decryptIV = $this->iv = str_pad(substr($iv, 0, 8), 8, chr(0)); $this->changed = true; } /** * Generate CTR XOR encryption key * * Encrypt the output of this and XOR it against the ciphertext / plaintext to get the * plaintext / ciphertext in CTR mode. * * @see Crypt_DES::decrypt() * @see Crypt_DES::encrypt() * @access public * @param Integer $length * @param String $iv */ function _generate_xor($length, &$iv) { $xor = ''; $num_blocks = ($length + 7) >> 3; for ($i = 0; $i < $num_blocks; $i++) { $xor.= $iv; for ($j = 4; $j <= 8; $j+=4) { $temp = substr($iv, -$j, 4); switch ($temp) { case "\xFF\xFF\xFF\xFF": $iv = substr_replace($iv, "\x00\x00\x00\x00", -$j, 4); break; case "\x7F\xFF\xFF\xFF": $iv = substr_replace($iv, "\x80\x00\x00\x00", -$j, 4); break 2; default: extract(unpack('Ncount', $temp)); $iv = substr_replace($iv, pack('N', $count + 1), -$j, 4); break 2; } } } return $xor; } /** * Encrypts a message. * * $plaintext will be padded with up to 8 additional bytes. Other DES implementations may or may not pad in the * same manner. Other common approaches to padding and the reasons why it's necessary are discussed in the following * URL: * * {@link http://www.di-mgt.com.au/cryptopad.html http://www.di-mgt.com.au/cryptopad.html} * * An alternative to padding is to, separately, send the length of the file. This is what SSH, in fact, does. * strlen($plaintext) will still need to be a multiple of 8, however, arbitrary values can be added to make it that * length. * * @see Crypt_DES::decrypt() * @access public * @param String $plaintext */ function encrypt($plaintext) { if ($this->mode != CRYPT_DES_MODE_CTR && $this->mode != 'ctr') { $plaintext = $this->_pad($plaintext); } if ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT ) { if ($this->changed) { if (!isset($this->enmcrypt)) { $this->enmcrypt = mcrypt_module_open(MCRYPT_DES, '', $this->mode, ''); } mcrypt_generic_init($this->enmcrypt, $this->keys, $this->encryptIV); $this->changed = false; } $ciphertext = mcrypt_generic($this->enmcrypt, $plaintext); if (!$this->continuousBuffer) { mcrypt_generic_init($this->enmcrypt, $this->keys, $this->encryptIV); } return $ciphertext; } if (!is_array($this->keys)) { $this->keys = $this->_prepareKey("\0\0\0\0\0\0\0\0"); } $ciphertext = ''; switch ($this->mode) { case CRYPT_DES_MODE_ECB: for ($i = 0; $i < strlen($plaintext); $i+=8) { $ciphertext.= $this->_processBlock(substr($plaintext, $i, 8), CRYPT_DES_ENCRYPT); } break; case CRYPT_DES_MODE_CBC: $xor = $this->encryptIV; for ($i = 0; $i < strlen($plaintext); $i+=8) { $block = substr($plaintext, $i, 8); $block = $this->_processBlock($block ^ $xor, CRYPT_DES_ENCRYPT); $xor = $block; $ciphertext.= $block; } if ($this->continuousBuffer) { $this->encryptIV = $xor; } break; case CRYPT_DES_MODE_CTR: $xor = $this->encryptIV; for ($i = 0; $i < strlen($plaintext); $i+=8) { $block = substr($plaintext, $i, 8); $key = $this->_processBlock($this->_generate_xor(8, $xor), CRYPT_DES_ENCRYPT); $ciphertext.= $block ^ $key; } if ($this->continuousBuffer) { $this->encryptIV = $xor; } } return $ciphertext; } /** * Decrypts a message. * * If strlen($ciphertext) is not a multiple of 8, null bytes will be added to the end of the string until it is. * * @see Crypt_DES::encrypt() * @access public * @param String $ciphertext */ function decrypt($ciphertext) { if ($this->mode != CRYPT_DES_MODE_CTR && $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($ciphertext) + 7) & 0xFFFFFFF8, chr(0)); } if ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT ) { if ($this->changed) { if (!isset($this->demcrypt)) { $this->demcrypt = mcrypt_module_open(MCRYPT_DES, '', $this->mode, ''); } mcrypt_generic_init($this->demcrypt, $this->keys, $this->decryptIV); $this->changed = false; } $plaintext = mdecrypt_generic($this->demcrypt, $ciphertext); if (!$this->continuousBuffer) { mcrypt_generic_init($this->demcrypt, $this->keys, $this->decryptIV); } return $this->mode != 'ctr' ? $this->_unpad($plaintext) : $plaintext; } if (!is_array($this->keys)) { $this->keys = $this->_prepareKey("\0\0\0\0\0\0\0\0"); } $plaintext = ''; switch ($this->mode) { case CRYPT_DES_MODE_ECB: for ($i = 0; $i < strlen($ciphertext); $i+=8) { $plaintext.= $this->_processBlock(substr($ciphertext, $i, 8), CRYPT_DES_DECRYPT); } break; case CRYPT_DES_MODE_CBC: $xor = $this->decryptIV; for ($i = 0; $i < strlen($ciphertext); $i+=8) { $block = substr($ciphertext, $i, 8); $plaintext.= $this->_processBlock($block, CRYPT_DES_DECRYPT) ^ $xor; $xor = $block; } if ($this->continuousBuffer) { $this->decryptIV = $xor; } break; case CRYPT_DES_MODE_CTR: $xor = $this->decryptIV; for ($i = 0; $i < strlen($ciphertext); $i+=8) { $block = substr($ciphertext, $i, 8); $key = $this->_processBlock($this->_generate_xor(8, $xor), CRYPT_DES_ENCRYPT); $plaintext.= $block ^ $key; } if ($this->continuousBuffer) { $this->decryptIV = $xor; } } return $this->mode != CRYPT_DES_MODE_CTR ? $this->_unpad($plaintext) : $plaintext; } /** * Treat consecutive "packets" as if they are a continuous buffer. * * Say you have a 16-byte plaintext $plaintext. Using the default behavior, the two following code snippets * will yield different outputs: * * * echo $des->encrypt(substr($plaintext, 0, 8)); * echo $des->encrypt(substr($plaintext, 8, 8)); * * * echo $des->encrypt($plaintext); * * * The solution is to enable the continuous buffer. Although this will resolve the above discrepancy, it creates * another, as demonstrated with the following: * * * $des->encrypt(substr($plaintext, 0, 8)); * echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8))); * * * echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8))); * * * With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different * outputs. The reason is due to the fact that the initialization vector's change after every encryption / * decryption round when the continuous buffer is enabled. When it's disabled, they remain constant. * * Put another way, when the continuous buffer is enabled, the state of the Crypt_DES() object changes after each * encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that * continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them), * however, they are also less intuitive and more likely to cause you problems. * * @see Crypt_DES::disableContinuousBuffer() * @access public */ function enableContinuousBuffer() { $this->continuousBuffer = true; } /** * Treat consecutive packets as if they are a discontinuous buffer. * * The default behavior. * * @see Crypt_DES::enableContinuousBuffer() * @access public */ function disableContinuousBuffer() { $this->continuousBuffer = false; $this->encryptIV = $this->iv; $this->decryptIV = $this->iv; } /** * Pad "packets". * * DES works by encrypting eight bytes at a time. If you ever need to encrypt or decrypt something that's not * a multiple of eight, it becomes necessary to pad the input so that it's length is a multiple of eight. * * Padding is enabled by default. Sometimes, however, it is undesirable to pad strings. Such is the case in SSH1, * where "packets" are padded with random bytes before being encrypted. Unpad these packets and you risk stripping * away characters that shouldn't be stripped away. (SSH knows how many bytes are added because the length is * transmitted separately) * * @see Crypt_DES::disablePadding() * @access public */ function enablePadding() { $this->padding = true; } /** * Do not pad packets. * * @see Crypt_DES::enablePadding() * @access public */ function disablePadding() { $this->padding = false; } /** * Pads a string * * Pads a string using the RSA PKCS padding standards so that its length is a multiple of the blocksize (8). * 8 - (strlen($text) & 7) bytes are added, each of which is equal to chr(8 - (strlen($text) & 7) * * If padding is disabled and $text is not a multiple of the blocksize, the string will be padded regardless * and padding will, hence forth, be enabled. * * @see Crypt_DES::_unpad() * @access private */ function _pad($text) { $length = strlen($text); if (!$this->padding) { if (($length & 7) == 0) { return $text; } else { user_error("The plaintext's length ($length) is not a multiple of the block size (8)", E_USER_NOTICE); $this->padding = true; } } $pad = 8 - ($length & 7); return str_pad($text, $length + $pad, chr($pad)); } /** * Unpads a string * * If padding is enabled and the reported padding length is invalid the encryption key will be assumed to be wrong * and false will be returned. * * @see Crypt_DES::_pad() * @access private */ function _unpad($text) { if (!$this->padding) { return $text; } $length = ord($text[strlen($text) - 1]); if (!$length || $length > 8) { return false; } return substr($text, 0, -$length); } /** * Encrypts or decrypts a 64-bit block * * $mode should be either CRYPT_DES_ENCRYPT or CRYPT_DES_DECRYPT. See * {@link http://en.wikipedia.org/wiki/Image:Feistel.png Feistel.png} to get a general * idea of what this function does. * * @access private * @param String $block * @param Integer $mode * @return String */ function _processBlock($block, $mode) { // s-boxes. in the official DES docs, they're described as being matrices that // one accesses by using the first and last bits to determine the row and the // middle four bits to determine the column. in this implementation, they've // been converted to vectors static $sbox = array( array( 14, 0, 4, 15, 13, 7, 1, 4, 2, 14, 15, 2, 11, 13, 8, 1, 3, 10 ,10, 6, 6, 12, 12, 11, 5, 9, 9, 5, 0, 3, 7, 8, 4, 15, 1, 12, 14, 8, 8, 2, 13, 4, 6, 9, 2, 1, 11, 7, 15, 5, 12, 11, 9, 3, 7, 14, 3, 10, 10, 0, 5, 6, 0, 13 ), array( 15, 3, 1, 13, 8, 4, 14, 7, 6, 15, 11, 2, 3, 8, 4, 14, 9, 12, 7, 0, 2, 1, 13, 10, 12, 6, 0, 9, 5, 11, 10, 5, 0, 13, 14, 8, 7, 10, 11, 1, 10, 3, 4, 15, 13, 4, 1, 2, 5, 11, 8, 6, 12, 7, 6, 12, 9, 0, 3, 5, 2, 14, 15, 9 ), array( 10, 13, 0, 7, 9, 0, 14, 9, 6, 3, 3, 4, 15, 6, 5, 10, 1, 2, 13, 8, 12, 5, 7, 14, 11, 12, 4, 11, 2, 15, 8, 1, 13, 1, 6, 10, 4, 13, 9, 0, 8, 6, 15, 9, 3, 8, 0, 7, 11, 4, 1, 15, 2, 14, 12, 3, 5, 11, 10, 5, 14, 2, 7, 12 ), array( 7, 13, 13, 8, 14, 11, 3, 5, 0, 6, 6, 15, 9, 0, 10, 3, 1, 4, 2, 7, 8, 2, 5, 12, 11, 1, 12, 10, 4, 14, 15, 9, 10, 3, 6, 15, 9, 0, 0, 6, 12, 10, 11, 1, 7, 13, 13, 8, 15, 9, 1, 4, 3, 5, 14, 11, 5, 12, 2, 7, 8, 2, 4, 14 ), array( 2, 14, 12, 11, 4, 2, 1, 12, 7, 4, 10, 7, 11, 13, 6, 1, 8, 5, 5, 0, 3, 15, 15, 10, 13, 3, 0, 9, 14, 8, 9, 6, 4, 11, 2, 8, 1, 12, 11, 7, 10, 1, 13, 14, 7, 2, 8, 13, 15, 6, 9, 15, 12, 0, 5, 9, 6, 10, 3, 4, 0, 5, 14, 3 ), array( 12, 10, 1, 15, 10, 4, 15, 2, 9, 7, 2, 12, 6, 9, 8, 5, 0, 6, 13, 1, 3, 13, 4, 14, 14, 0, 7, 11, 5, 3, 11, 8, 9, 4, 14, 3, 15, 2, 5, 12, 2, 9, 8, 5, 12, 15, 3, 10, 7, 11, 0, 14, 4, 1, 10, 7, 1, 6, 13, 0, 11, 8, 6, 13 ), array( 4, 13, 11, 0, 2, 11, 14, 7, 15, 4, 0, 9, 8, 1, 13, 10, 3, 14, 12, 3, 9, 5, 7, 12, 5, 2, 10, 15, 6, 8, 1, 6, 1, 6, 4, 11, 11, 13, 13, 8, 12, 1, 3, 4, 7, 10, 14, 7, 10, 9, 15, 5, 6, 0, 8, 15, 0, 14, 5, 2, 9, 3, 2, 12 ), array( 13, 1, 2, 15, 8, 13, 4, 8, 6, 10, 15, 3, 11, 7, 1, 4, 10, 12, 9, 5, 3, 6, 14, 11, 5, 0, 0, 14, 12, 9, 7, 2, 7, 2, 11, 1, 4, 14, 1, 7, 9, 4, 12, 10, 14, 8, 2, 13, 0, 15, 6, 12, 10, 9, 13, 0, 15, 3, 3, 5, 5, 6, 8, 11 ) ); $keys = $this->keys; $temp = unpack('Na/Nb', $block); $block = array($temp['a'], $temp['b']); // because php does arithmetic right shifts, if the most significant bits are set, right // shifting those into the correct position will add 1's - not 0's. this will intefere // with the | operation unless a second & is done. so we isolate these bits and left shift // them into place. we then & each block with 0x7FFFFFFF to prevennt 1's from being added // for any other shifts. $msb = array( ($block[0] >> 31) & 1, ($block[1] >> 31) & 1 ); $block[0] &= 0x7FFFFFFF; $block[1] &= 0x7FFFFFFF; // we isolate the appropriate bit in the appropriate integer and shift as appropriate. in // some cases, there are going to be multiple bits in the same integer that need to be shifted // in the same way. we combine those into one shift operation. $block = array( (($block[1] & 0x00000040) << 25) | (($block[1] & 0x00004000) << 16) | (($block[1] & 0x00400001) << 7) | (($block[1] & 0x40000100) >> 2) | (($block[0] & 0x00000040) << 21) | (($block[0] & 0x00004000) << 12) | (($block[0] & 0x00400001) << 3) | (($block[0] & 0x40000100) >> 6) | (($block[1] & 0x00000010) << 19) | (($block[1] & 0x00001000) << 10) | (($block[1] & 0x00100000) << 1) | (($block[1] & 0x10000000) >> 8) | (($block[0] & 0x00000010) << 15) | (($block[0] & 0x00001000) << 6) | (($block[0] & 0x00100000) >> 3) | (($block[0] & 0x10000000) >> 12) | (($block[1] & 0x00000004) << 13) | (($block[1] & 0x00000400) << 4) | (($block[1] & 0x00040000) >> 5) | (($block[1] & 0x04000000) >> 14) | (($block[0] & 0x00000004) << 9) | ( $block[0] & 0x00000400 ) | (($block[0] & 0x00040000) >> 9) | (($block[0] & 0x04000000) >> 18) | (($block[1] & 0x00010000) >> 11) | (($block[1] & 0x01000000) >> 20) | (($block[0] & 0x00010000) >> 15) | (($block[0] & 0x01000000) >> 24) , (($block[1] & 0x00000080) << 24) | (($block[1] & 0x00008000) << 15) | (($block[1] & 0x00800002) << 6) | (($block[0] & 0x00000080) << 20) | (($block[0] & 0x00008000) << 11) | (($block[0] & 0x00800002) << 2) | (($block[1] & 0x00000020) << 18) | (($block[1] & 0x00002000) << 9) | ( $block[1] & 0x00200000 ) | (($block[1] & 0x20000000) >> 9) | (($block[0] & 0x00000020) << 14) | (($block[0] & 0x00002000) << 5) | (($block[0] & 0x00200000) >> 4) | (($block[0] & 0x20000000) >> 13) | (($block[1] & 0x00000008) << 12) | (($block[1] & 0x00000800) << 3) | (($block[1] & 0x00080000) >> 6) | (($block[1] & 0x08000000) >> 15) | (($block[0] & 0x00000008) << 8) | (($block[0] & 0x00000800) >> 1) | (($block[0] & 0x00080000) >> 10) | (($block[0] & 0x08000000) >> 19) | (($block[1] & 0x00000200) >> 3) | (($block[0] & 0x00000200) >> 7) | (($block[1] & 0x00020000) >> 12) | (($block[1] & 0x02000000) >> 21) | (($block[0] & 0x00020000) >> 16) | (($block[0] & 0x02000000) >> 25) | ($msb[1] << 28) | ($msb[0] << 24) ); for ($i = 0; $i < 16; $i++) { // start of "the Feistel (F) function" - see the following URL: // http://en.wikipedia.org/wiki/Image:Data_Encryption_Standard_InfoBox_Diagram.png $temp = (($sbox[0][((($block[1] >> 27) & 0x1F) | (($block[1] & 1) << 5)) ^ $keys[$mode][$i][0]]) << 28) | (($sbox[1][(($block[1] & 0x1F800000) >> 23) ^ $keys[$mode][$i][1]]) << 24) | (($sbox[2][(($block[1] & 0x01F80000) >> 19) ^ $keys[$mode][$i][2]]) << 20) | (($sbox[3][(($block[1] & 0x001F8000) >> 15) ^ $keys[$mode][$i][3]]) << 16) | (($sbox[4][(($block[1] & 0x0001F800) >> 11) ^ $keys[$mode][$i][4]]) << 12) | (($sbox[5][(($block[1] & 0x00001F80) >> 7) ^ $keys[$mode][$i][5]]) << 8) | (($sbox[6][(($block[1] & 0x000001F8) >> 3) ^ $keys[$mode][$i][6]]) << 4) | ( $sbox[7][((($block[1] & 0x1F) << 1) | (($block[1] >> 31) & 1)) ^ $keys[$mode][$i][7]]); $msb = ($temp >> 31) & 1; $temp &= 0x7FFFFFFF; $newBlock = (($temp & 0x00010000) << 15) | (($temp & 0x02020120) << 5) | (($temp & 0x00001800) << 17) | (($temp & 0x01000000) >> 10) | (($temp & 0x00000008) << 24) | (($temp & 0x00100000) << 6) | (($temp & 0x00000010) << 21) | (($temp & 0x00008000) << 9) | (($temp & 0x00000200) << 12) | (($temp & 0x10000000) >> 27) | (($temp & 0x00000040) << 14) | (($temp & 0x08000000) >> 8) | (($temp & 0x00004000) << 4) | (($temp & 0x00000002) << 16) | (($temp & 0x00442000) >> 6) | (($temp & 0x40800000) >> 15) | (($temp & 0x00000001) << 11) | (($temp & 0x20000000) >> 20) | (($temp & 0x00080000) >> 13) | (($temp & 0x00000004) << 3) | (($temp & 0x04000000) >> 22) | (($temp & 0x00000480) >> 7) | (($temp & 0x00200000) >> 19) | ($msb << 23); // end of "the Feistel (F) function" - $newBlock is F's output $temp = $block[1]; $block[1] = $block[0] ^ $newBlock; $block[0] = $temp; } $msb = array( ($block[0] >> 31) & 1, ($block[1] >> 31) & 1 ); $block[0] &= 0x7FFFFFFF; $block[1] &= 0x7FFFFFFF; $block = array( (($block[0] & 0x01000004) << 7) | (($block[1] & 0x01000004) << 6) | (($block[0] & 0x00010000) << 13) | (($block[1] & 0x00010000) << 12) | (($block[0] & 0x00000100) << 19) | (($block[1] & 0x00000100) << 18) | (($block[0] & 0x00000001) << 25) | (($block[1] & 0x00000001) << 24) | (($block[0] & 0x02000008) >> 2) | (($block[1] & 0x02000008) >> 3) | (($block[0] & 0x00020000) << 4) | (($block[1] & 0x00020000) << 3) | (($block[0] & 0x00000200) << 10) | (($block[1] & 0x00000200) << 9) | (($block[0] & 0x00000002) << 16) | (($block[1] & 0x00000002) << 15) | (($block[0] & 0x04000000) >> 11) | (($block[1] & 0x04000000) >> 12) | (($block[0] & 0x00040000) >> 5) | (($block[1] & 0x00040000) >> 6) | (($block[0] & 0x00000400) << 1) | ( $block[1] & 0x00000400 ) | (($block[0] & 0x08000000) >> 20) | (($block[1] & 0x08000000) >> 21) | (($block[0] & 0x00080000) >> 14) | (($block[1] & 0x00080000) >> 15) | (($block[0] & 0x00000800) >> 8) | (($block[1] & 0x00000800) >> 9) , (($block[0] & 0x10000040) << 3) | (($block[1] & 0x10000040) << 2) | (($block[0] & 0x00100000) << 9) | (($block[1] & 0x00100000) << 8) | (($block[0] & 0x00001000) << 15) | (($block[1] & 0x00001000) << 14) | (($block[0] & 0x00000010) << 21) | (($block[1] & 0x00000010) << 20) | (($block[0] & 0x20000080) >> 6) | (($block[1] & 0x20000080) >> 7) | ( $block[0] & 0x00200000 ) | (($block[1] & 0x00200000) >> 1) | (($block[0] & 0x00002000) << 6) | (($block[1] & 0x00002000) << 5) | (($block[0] & 0x00000020) << 12) | (($block[1] & 0x00000020) << 11) | (($block[0] & 0x40000000) >> 15) | (($block[1] & 0x40000000) >> 16) | (($block[0] & 0x00400000) >> 9) | (($block[1] & 0x00400000) >> 10) | (($block[0] & 0x00004000) >> 3) | (($block[1] & 0x00004000) >> 4) | (($block[0] & 0x00800000) >> 18) | (($block[1] & 0x00800000) >> 19) | (($block[0] & 0x00008000) >> 12) | (($block[1] & 0x00008000) >> 13) | ($msb[0] << 7) | ($msb[1] << 6) ); return pack('NN', $block[0], $block[1]); } /** * Creates the key schedule. * * @access private * @param String $key * @return Array */ function _prepareKey($key) { static $shifts = array( // number of key bits shifted per round 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 ); // pad the key and remove extra characters as appropriate. $key = str_pad(substr($key, 0, 8), 8, chr(0)); $temp = unpack('Na/Nb', $key); $key = array($temp['a'], $temp['b']); $msb = array( ($key[0] >> 31) & 1, ($key[1] >> 31) & 1 ); $key[0] &= 0x7FFFFFFF; $key[1] &= 0x7FFFFFFF; $key = array( (($key[1] & 0x00000002) << 26) | (($key[1] & 0x00000204) << 17) | (($key[1] & 0x00020408) << 8) | (($key[1] & 0x02040800) >> 1) | (($key[0] & 0x00000002) << 22) | (($key[0] & 0x00000204) << 13) | (($key[0] & 0x00020408) << 4) | (($key[0] & 0x02040800) >> 5) | (($key[1] & 0x04080000) >> 10) | (($key[0] & 0x04080000) >> 14) | (($key[1] & 0x08000000) >> 19) | (($key[0] & 0x08000000) >> 23) | (($key[0] & 0x00000010) >> 1) | (($key[0] & 0x00001000) >> 10) | (($key[0] & 0x00100000) >> 19) | (($key[0] & 0x10000000) >> 28) , (($key[1] & 0x00000080) << 20) | (($key[1] & 0x00008000) << 11) | (($key[1] & 0x00800000) << 2) | (($key[0] & 0x00000080) << 16) | (($key[0] & 0x00008000) << 7) | (($key[0] & 0x00800000) >> 2) | (($key[1] & 0x00000040) << 13) | (($key[1] & 0x00004000) << 4) | (($key[1] & 0x00400000) >> 5) | (($key[1] & 0x40000000) >> 14) | (($key[0] & 0x00000040) << 9) | ( $key[0] & 0x00004000 ) | (($key[0] & 0x00400000) >> 9) | (($key[0] & 0x40000000) >> 18) | (($key[1] & 0x00000020) << 6) | (($key[1] & 0x00002000) >> 3) | (($key[1] & 0x00200000) >> 12) | (($key[1] & 0x20000000) >> 21) | (($key[0] & 0x00000020) << 2) | (($key[0] & 0x00002000) >> 7) | (($key[0] & 0x00200000) >> 16) | (($key[0] & 0x20000000) >> 25) | (($key[1] & 0x00000010) >> 1) | (($key[1] & 0x00001000) >> 10) | (($key[1] & 0x00100000) >> 19) | (($key[1] & 0x10000000) >> 28) | ($msb[1] << 24) | ($msb[0] << 20) ); $keys = array(); for ($i = 0; $i < 16; $i++) { $key[0] <<= $shifts[$i]; $temp = ($key[0] & 0xF0000000) >> 28; $key[0] = ($key[0] | $temp) & 0x0FFFFFFF; $key[1] <<= $shifts[$i]; $temp = ($key[1] & 0xF0000000) >> 28; $key[1] = ($key[1] | $temp) & 0x0FFFFFFF; $temp = array( (($key[1] & 0x00004000) >> 9) | (($key[1] & 0x00000800) >> 7) | (($key[1] & 0x00020000) >> 14) | (($key[1] & 0x00000010) >> 2) | (($key[1] & 0x08000000) >> 26) | (($key[1] & 0x00800000) >> 23) , (($key[1] & 0x02400000) >> 20) | (($key[1] & 0x00000001) << 4) | (($key[1] & 0x00002000) >> 10) | (($key[1] & 0x00040000) >> 18) | (($key[1] & 0x00000080) >> 6) , ( $key[1] & 0x00000020 ) | (($key[1] & 0x00000200) >> 5) | (($key[1] & 0x00010000) >> 13) | (($key[1] & 0x01000000) >> 22) | (($key[1] & 0x00000004) >> 1) | (($key[1] & 0x00100000) >> 20) , (($key[1] & 0x00001000) >> 7) | (($key[1] & 0x00200000) >> 17) | (($key[1] & 0x00000002) << 2) | (($key[1] & 0x00000100) >> 6) | (($key[1] & 0x00008000) >> 14) | (($key[1] & 0x04000000) >> 26) , (($key[0] & 0x00008000) >> 10) | ( $key[0] & 0x00000010 ) | (($key[0] & 0x02000000) >> 22) | (($key[0] & 0x00080000) >> 17) | (($key[0] & 0x00000200) >> 8) | (($key[0] & 0x00000002) >> 1) , (($key[0] & 0x04000000) >> 21) | (($key[0] & 0x00010000) >> 12) | (($key[0] & 0x00000020) >> 2) | (($key[0] & 0x00000800) >> 9) | (($key[0] & 0x00800000) >> 22) | (($key[0] & 0x00000100) >> 8) , (($key[0] & 0x00001000) >> 7) | (($key[0] & 0x00000088) >> 3) | (($key[0] & 0x00020000) >> 14) | (($key[0] & 0x00000001) << 2) | (($key[0] & 0x00400000) >> 21) , (($key[0] & 0x00000400) >> 5) | (($key[0] & 0x00004000) >> 10) | (($key[0] & 0x00000040) >> 3) | (($key[0] & 0x00100000) >> 18) | (($key[0] & 0x08000000) >> 26) | (($key[0] & 0x01000000) >> 24) ); $keys[] = $temp; } $temp = array( CRYPT_DES_ENCRYPT => $keys, CRYPT_DES_DECRYPT => array_reverse($keys) ); return $temp; } } // vim: ts=4:sw=4:et: // vim6: fdl=1: