<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
/**
* Pure-PHP implementation of DES.
*
* Uses mcrypt, if available, and an internal implementation, otherwise.
*
* PHP versions 4 and 5
*
* Useful resources are as follows:
*
* - {@link http://en.wikipedia.org/wiki/DES_supplementary_material Wikipedia: DES supplementary material}
* - {@link http://www.itl.nist.gov/fipspubs/fip46-2.htm FIPS 46-2 - (DES), Data Encryption Standard}
* - {@link http://www.cs.eku.edu/faculty/styer/460/Encrypt/JS-DES.html JavaScript DES Example}
*
* Here's a short example of how to use this library:
* <code>
* <?php
* include('Crypt/DES.php');
*
* $des = new Crypt_DES();
*
* $des->setKey('abcdefgh');
*
* $size = 10 * 1024;
* $plaintext = '';
* for ($i = 0; $i < $size; $i++) {
* $plaintext.= 'a';
* }
*
* echo $des->decrypt($des->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_DES
* @author Jim Wigginton <terrafrost@php.net>
* @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 <terrafrost@php.net>
* @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:
*
* <code>
* echo $des->encrypt(substr($plaintext, 0, 8));
* echo $des->encrypt(substr($plaintext, 8, 8));
* </code>
* <code>
* echo $des->encrypt($plaintext);
* </code>
*
* The solution is to enable the continuous buffer. Although this will resolve the above discrepancy, it creates
* another, as demonstrated with the following:
*
* <code>
* $des->encrypt(substr($plaintext, 0, 8));
* echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8)));
* </code>
* <code>
* echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8)));
* </code>
*
* 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:
