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Posted to commits@vcl.apache.org by jf...@apache.org on 2011/06/16 22:18:37 UTC

svn commit: r1136647 [1/11] - in /incubator/vcl/trunk/web/.ht-inc/phpseclib: ./ Crypt/ Math/ Net/ PHP/ PHP/Compat/ PHP/Compat/Function/

Author: jfthomps
Date: Thu Jun 16 20:18:36 2011
New Revision: 1136647

URL: http://svn.apache.org/viewvc?rev=1136647&view=rev
Log:
VCL-479

inital check in of phpseclib - this is an encryption extension that uses mcrypt if available or native php if it is not

Added:
    incubator/vcl/trunk/web/.ht-inc/phpseclib/
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/AES.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/DES.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/Hash.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/RC4.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/RSA.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/Random.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/Rijndael.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/TripleDES.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Math/
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Math/BigInteger.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Net/
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Net/SFTP.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Net/SSH1.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/Net/SSH2.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/PHP/
    incubator/vcl/trunk/web/.ht-inc/phpseclib/PHP/Compat/
    incubator/vcl/trunk/web/.ht-inc/phpseclib/PHP/Compat/Function/
    incubator/vcl/trunk/web/.ht-inc/phpseclib/PHP/Compat/Function/array_fill.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/PHP/Compat/Function/bcpowmod.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/PHP/Compat/Function/str_split.php
    incubator/vcl/trunk/web/.ht-inc/phpseclib/crypt.html
    incubator/vcl/trunk/web/.ht-inc/phpseclib/docbook.css
    incubator/vcl/trunk/web/.ht-inc/phpseclib/index.html
    incubator/vcl/trunk/web/.ht-inc/phpseclib/intro.html
    incubator/vcl/trunk/web/.ht-inc/phpseclib/math.html
    incubator/vcl/trunk/web/.ht-inc/phpseclib/misc_crypt.html
    incubator/vcl/trunk/web/.ht-inc/phpseclib/net.html
    incubator/vcl/trunk/web/.ht-inc/phpseclib/sym_crypt.html

Added: incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/AES.php
URL: http://svn.apache.org/viewvc/incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/AES.php?rev=1136647&view=auto
==============================================================================
--- incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/AES.php (added)
+++ incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/AES.php Thu Jun 16 20:18:36 2011
@@ -0,0 +1,594 @@
+<?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: Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @category   Crypt
+ * @package    Crypt_AES
+ * @author     Jim Wigginton <te...@php.net>
+ * @copyright  MMVIII Jim Wigginton
+ * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @version    $Id: AES.php,v 1.7 2010/02/09 06:10:25 terrafrost Exp $
+ * @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);
+/**
+ * Encrypt / decrypt using the Cipher Feedback mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher_feedback_.28CFB.29
+ */
+define('CRYPT_AES_MODE_CFB', 3);
+/**
+ * Encrypt / decrypt using the Cipher Feedback mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Output_feedback_.28OFB.29
+ */
+define('CRYPT_AES_MODE_OFB', 4);
+/**#@-*/
+
+/**#@+
+ * @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 <te...@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;
+
+    /**
+     * mcrypt resource for CFB mode
+     *
+     * @see Crypt_AES::encrypt()
+     * @see Crypt_AES::decrypt()
+     * @var String
+     * @access private
+     */
+    var $ecb;
+
+    /**
+     * 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->paddable = true;
+                        $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_CFB:
+                        $this->mode = 'ncfb';
+                        break;
+                    case CRYPT_AES_MODE_OFB:
+                        $this->mode = MCRYPT_MODE_NOFB;
+                        break;
+                    case CRYPT_AES_MODE_CBC:
+                    default:
+                        $this->paddable = true;
+                        $this->mode = MCRYPT_MODE_CBC;
+                }
+
+                $this->debuffer = $this->enbuffer = '';
+
+                break;
+            default:
+                switch ($mode) {
+                    case CRYPT_AES_MODE_ECB:
+                        $this->paddable = true;
+                        $this->mode = CRYPT_RIJNDAEL_MODE_ECB;
+                        break;
+                    case CRYPT_AES_MODE_CTR:
+                        $this->mode = CRYPT_RIJNDAEL_MODE_CTR;
+                        break;
+                    case CRYPT_AES_MODE_CFB:
+                        $this->mode = CRYPT_RIJNDAEL_MODE_CFB;
+                        break;
+                    case CRYPT_AES_MODE_OFB:
+                        $this->mode = CRYPT_RIJNDAEL_MODE_OFB;
+                        break;
+                    case CRYPT_AES_MODE_CBC:
+                    default:
+                        $this->paddable = true;
+                        $this->mode = CRYPT_RIJNDAEL_MODE_CBC;
+                }
+        }
+
+        if (CRYPT_AES_MODE == CRYPT_AES_MODE_INTERNAL) {
+            parent::Crypt_Rijndael($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 ) {
+            $changed = $this->changed;
+            $this->_mcryptSetup();
+            /*
+            if ($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 $ciphertext;
+            }
+            */
+            // re: http://phpseclib.sourceforge.net/cfb-demo.phps
+            // using mcrypt's default handing of CFB the above would output two different things.  using phpseclib's
+            // rewritten CFB implementation the above outputs the same thing twice.
+            if ($this->mode == 'ncfb') {
+                if ($changed) {
+                    $this->ecb = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_ECB, '');
+                    mcrypt_generic_init($this->ecb, $this->key, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");
+                }
+
+                if (strlen($this->enbuffer)) {
+                    $ciphertext = $plaintext ^ substr($this->encryptIV, strlen($this->enbuffer));
+                    $this->enbuffer.= $ciphertext;
+                    if (strlen($this->enbuffer) == 16) {
+                        $this->encryptIV = $this->enbuffer;
+                        $this->enbuffer = '';
+                        mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV);
+                    }
+                    $plaintext = substr($plaintext, strlen($ciphertext));
+                } else {
+                    $ciphertext = '';
+                }
+
+                $last_pos = strlen($plaintext) & 0xFFFFFFF0;
+                $ciphertext.= $last_pos ? mcrypt_generic($this->enmcrypt, substr($plaintext, 0, $last_pos)) : '';
+
+                if (strlen($plaintext) & 0xF) {
+                    if (strlen($ciphertext)) {
+                        $this->encryptIV = substr($ciphertext, -16);
+                    }
+                    $this->encryptIV = mcrypt_generic($this->ecb, $this->encryptIV);
+                    $this->enbuffer = substr($plaintext, $last_pos) ^ $this->encryptIV;
+                    $ciphertext.= $this->enbuffer;
+                }
+
+                return $ciphertext;
+            }
+
+            if ($this->paddable) {
+                $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 ) {
+            $changed = $this->changed;
+            $this->_mcryptSetup();
+            /*
+            if ($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 == 'ncfb') {
+                if ($changed) {
+                    $this->ecb = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_ECB, '');
+                    mcrypt_generic_init($this->ecb, $this->key, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");
+                }
+
+                if (strlen($this->debuffer)) {
+                    $plaintext = $ciphertext ^ substr($this->decryptIV, strlen($this->debuffer));
+
+                    $this->debuffer.= substr($ciphertext, 0, strlen($plaintext));
+                    if (strlen($this->debuffer) == 16) {
+                        $this->decryptIV = $this->debuffer;
+                        $this->debuffer = '';
+                        mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV);
+                    }
+                    $ciphertext = substr($ciphertext, strlen($plaintext));
+                } else {
+                    $plaintext = '';
+                }
+
+                $last_pos = strlen($ciphertext) & 0xFFFFFFF0;
+                $plaintext.= $last_pos ? mdecrypt_generic($this->demcrypt, substr($ciphertext, 0, $last_pos)) : '';
+
+                if (strlen($ciphertext) & 0xF) {
+                    if (strlen($plaintext)) {
+                        $this->decryptIV = substr($ciphertext, $last_pos - 16, 16);
+                    }
+                    $this->decryptIV = mcrypt_generic($this->ecb, $this->decryptIV);
+                    $this->debuffer = substr($ciphertext, $last_pos);
+                    $plaintext.= $this->debuffer ^ $this->decryptIV;
+                }
+
+                return $plaintext;
+            }
+
+            if ($this->paddable) {
+                // 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->paddable ? $this->_unpad($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;
+        }
+
+        $this->key = str_pad(substr($this->key, 0, $this->key_size), $this->key_size, chr(0));
+        $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:

Added: incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/DES.php
URL: http://svn.apache.org/viewvc/incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/DES.php?rev=1136647&view=auto
==============================================================================
--- incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/DES.php (added)
+++ incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/DES.php Thu Jun 16 20:18:36 2011
@@ -0,0 +1,1245 @@
+<?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: Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @category   Crypt
+ * @package    Crypt_DES
+ * @author     Jim Wigginton <te...@php.net>
+ * @copyright  MMVII Jim Wigginton
+ * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @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);
+/**
+ * Encrypt / decrypt using the Cipher Feedback mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher_feedback_.28CFB.29
+ */
+define('CRYPT_DES_MODE_CFB', 3);
+/**
+ * Encrypt / decrypt using the Cipher Feedback mode.
+ *
+ * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Output_feedback_.28OFB.29
+ */
+define('CRYPT_DES_MODE_OFB', 4);
+/**#@-*/
+
+/**#@+
+ * @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 <te...@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_DES::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_DES::decrypt()
+     * @var String
+     * @access private
+     */
+    var $demcrypt;
+
+    /**
+     * Does the enmcrypt resource need to be (re)initialized?
+     *
+     * @see Crypt_DES::setKey()
+     * @see Crypt_DES::setIV()
+     * @var Boolean
+     * @access private
+     */
+    var $enchanged = true;
+
+    /**
+     * Does the demcrypt resource need to be (re)initialized?
+     *
+     * @see Crypt_DES::setKey()
+     * @see Crypt_DES::setIV()
+     * @var Boolean
+     * @access private
+     */
+    var $dechanged = true;
+
+    /**
+     * Is the mode one that is paddable?
+     *
+     * @see Crypt_DES::Crypt_DES()
+     * @var Boolean
+     * @access private
+     */
+    var $paddable = false;
+
+    /**
+     * Encryption buffer for CTR, OFB and CFB modes
+     *
+     * @see Crypt_DES::encrypt()
+     * @var String
+     * @access private
+     */
+    var $enbuffer = '';
+
+    /**
+     * Decryption buffer for CTR, OFB and CFB modes
+     *
+     * @see Crypt_DES::decrypt()
+     * @var String
+     * @access private
+     */
+    var $debuffer = '';
+
+    /**
+     * mcrypt resource for CFB mode
+     *
+     * @see Crypt_DES::encrypt()
+     * @see Crypt_DES::decrypt()
+     * @var String
+     * @access private
+     */
+    var $ecb;
+
+    /**
+     * 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->paddable = true;
+                        $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_CFB:
+                        $this->mode = 'ncfb';
+                        break;
+                    case CRYPT_DES_MODE_OFB:
+                        $this->mode = MCRYPT_MODE_NOFB;
+                        break;
+                    case CRYPT_DES_MODE_CBC:
+                    default:
+                        $this->paddable = true;
+                        $this->mode = MCRYPT_MODE_CBC;
+                }
+
+                break;
+            default:
+                switch ($mode) {
+                    case CRYPT_DES_MODE_ECB:
+                    case CRYPT_DES_MODE_CBC:
+                        $this->paddable = true;
+                        $this->mode = $mode;
+                        break;
+                    case CRYPT_DES_MODE_CTR:
+                    case CRYPT_DES_MODE_CFB:
+                    case CRYPT_DES_MODE_OFB:
+                        $this->mode = $mode;
+                        break;
+                    default:
+                        $this->paddable = true;
+                        $this->mode = CRYPT_DES_MODE_CBC;
+                }
+        }
+    }
+
+    /**
+     * Sets the key.
+     *
+     * Keys can be of any length.  DES, itself, uses 64-bit keys (eg. strlen($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)
+    {
+        $this->keys = ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT ) ? str_pad(substr($key, 0, 8), 8, chr(0)) : $this->_prepareKey($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->paddable) {
+            $plaintext = $this->_pad($plaintext);
+        }
+
+        if ( CRYPT_DES_MODE == CRYPT_DES_MODE_MCRYPT ) {
+            if ($this->enchanged) {
+                if (!isset($this->enmcrypt)) {
+                    $this->enmcrypt = mcrypt_module_open(MCRYPT_DES, '', $this->mode, '');
+                }
+                mcrypt_generic_init($this->enmcrypt, $this->keys, $this->encryptIV);
+                if ($this->mode != 'ncfb') {
+                    $this->enchanged = false;
+                }
+            }
+
+            if ($this->mode != 'ncfb') {
+                $ciphertext = mcrypt_generic($this->enmcrypt, $plaintext);
+            } else {
+                if ($this->enchanged) {
+                    $this->ecb = mcrypt_module_open(MCRYPT_DES, '', MCRYPT_MODE_ECB, '');
+                    mcrypt_generic_init($this->ecb, $this->keys, "\0\0\0\0\0\0\0\0");
+                    $this->enchanged = false;
+                }
+
+                if (strlen($this->enbuffer)) {
+                    $ciphertext = $plaintext ^ substr($this->encryptIV, strlen($this->enbuffer));
+                    $this->enbuffer.= $ciphertext;
+                    if (strlen($this->enbuffer) == 8) {
+                        $this->encryptIV = $this->enbuffer;
+                        $this->enbuffer = '';
+                        mcrypt_generic_init($this->enmcrypt, $this->keys, $this->encryptIV);
+                    }
+                    $plaintext = substr($plaintext, strlen($ciphertext));
+                } else {
+                    $ciphertext = '';
+                }
+
+                $last_pos = strlen($plaintext) & 0xFFFFFFF8;
+                $ciphertext.= $last_pos ? mcrypt_generic($this->enmcrypt, substr($plaintext, 0, $last_pos)) : '';
+
+                if (strlen($plaintext) & 0x7) {
+                    if (strlen($ciphertext)) {
+                        $this->encryptIV = substr($ciphertext, -8);
+                    }
+                    $this->encryptIV = mcrypt_generic($this->ecb, $this->encryptIV);
+                    $this->enbuffer = substr($plaintext, $last_pos) ^ $this->encryptIV;
+                    $ciphertext.= $this->enbuffer;
+                }
+            }
+
+            if (!$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");
+        }
+
+        $buffer = &$this->enbuffer;
+        $continuousBuffer = $this->continuousBuffer;
+        $ciphertext = '';
+        switch ($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 = $this->encryptIV;
+                if (strlen($buffer)) {
+                    for ($i = 0; $i < strlen($plaintext); $i+=8) {
+                        $block = substr($plaintext, $i, 8);
+                        $buffer.= $this->_processBlock($this->_generate_xor(8, $xor), CRYPT_DES_ENCRYPT);
+                        $key = $this->_string_shift($buffer, 8);
+                        $ciphertext.= $block ^ $key;
+                    }
+                } else {
+                    for ($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 = $xor;
+                    if ($start = strlen($plaintext) & 7) {
+                        $buffer = substr($key, $start) . $buffer;
+                    }
+                }
+                break;
+            case CRYPT_DES_MODE_CFB:
+                if (!empty($buffer['xor'])) {
+                    $ciphertext = $plaintext ^ $buffer['xor'];
+                    $iv = $buffer['encrypted'] . $ciphertext;
+                    $start = strlen($ciphertext);
+                    $buffer['encrypted'].= $ciphertext;
+                    $buffer['xor'] = substr($buffer['xor'], strlen($ciphertext));
+                } else {
+                    $ciphertext = '';
+                    $iv = $this->encryptIV;
+                    $start = 0;
+                }
+
+                for ($i = $start; $i < strlen($plaintext); $i+=8) {
+                    $block = substr($plaintext, $i, 8);
+                    $xor = $this->_processBlock($iv, CRYPT_DES_ENCRYPT);
+                    $iv = $block ^ $xor;
+                    if ($continuousBuffer && strlen($iv) != 8) {
+                        $buffer = array(
+                            'encrypted' => $iv,
+                            'xor' => substr($xor, strlen($iv))
+                        );
+                    }
+                    $ciphertext.= $iv;
+                }
+
+                if ($this->continuousBuffer) {
+                    $this->encryptIV = $iv;
+                }
+                break;
+            case CRYPT_DES_MODE_OFB:
+                $xor = $this->encryptIV;
+                if (strlen($buffer)) {
+                    for ($i = 0; $i < strlen($plaintext); $i+=8) {
+                        $xor = $this->_processBlock($xor, CRYPT_DES_ENCRYPT);
+                        $buffer.= $xor;
+                        $key = $this->_string_shift($buffer, 8);
+                        $ciphertext.= substr($plaintext, $i, 8) ^ $key;
+                    }
+                } else {
+                    for ($i = 0; $i < strlen($plaintext); $i+=8) {
+                        $xor = $this->_processBlock($xor, CRYPT_DES_ENCRYPT);
+                        $ciphertext.= substr($plaintext, $i, 8) ^ $xor;
+                    }
+                    $key = $xor;
+                }
+                if ($this->continuousBuffer) {
+                    $this->encryptIV = $xor;
+                    if ($start = strlen($plaintext) & 7) {
+                         $buffer = substr($key, $start) . $buffer;
+                    }
+                }
+        }
+
+        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->paddable) {
+            // 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->dechanged) {
+                if (!isset($this->demcrypt)) {
+                    $this->demcrypt = mcrypt_module_open(MCRYPT_DES, '', $this->mode, '');
+                }
+                mcrypt_generic_init($this->demcrypt, $this->keys, $this->decryptIV);
+                if ($this->mode != 'ncfb') {
+                    $this->dechanged = false;
+                }
+            }
+
+            if ($this->mode != 'ncfb') {
+                $plaintext = mdecrypt_generic($this->demcrypt, $ciphertext);
+            } else {
+                if ($this->dechanged) {
+                    $this->ecb = mcrypt_module_open(MCRYPT_DES, '', MCRYPT_MODE_ECB, '');
+                    mcrypt_generic_init($this->ecb, $this->keys, "\0\0\0\0\0\0\0\0");
+                    $this->dechanged = false;
+                }
+
+                if (strlen($this->debuffer)) {
+                    $plaintext = $ciphertext ^ substr($this->decryptIV, strlen($this->debuffer));
+
+                    $this->debuffer.= substr($ciphertext, 0, strlen($plaintext));
+                    if (strlen($this->debuffer) == 8) {
+                        $this->decryptIV = $this->debuffer;
+                        $this->debuffer = '';
+                        mcrypt_generic_init($this->demcrypt, $this->keys, $this->decryptIV);
+                    }
+                    $ciphertext = substr($ciphertext, strlen($plaintext));
+                } else {
+                    $plaintext = '';
+                }
+
+                $last_pos = strlen($ciphertext) & 0xFFFFFFF8;
+                $plaintext.= $last_pos ? mdecrypt_generic($this->demcrypt, substr($ciphertext, 0, $last_pos)) : '';
+
+                if (strlen($ciphertext) & 0x7) {
+                    if (strlen($plaintext)) {
+                        $this->decryptIV = substr($ciphertext, $last_pos - 8, 8);
+                    }
+                    $this->decryptIV = mcrypt_generic($this->ecb, $this->decryptIV);
+                    $this->debuffer = substr($ciphertext, $last_pos);
+                    $plaintext.= $this->debuffer ^ $this->decryptIV;
+                }
+
+                return $plaintext;
+            }
+
+            if (!$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");
+        }
+
+        $buffer = &$this->debuffer;
+        $continuousBuffer = $this->continuousBuffer;
+        $plaintext = '';
+        switch ($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 = $this->decryptIV;
+                if (strlen($buffer)) {
+                    for ($i = 0; $i < strlen($ciphertext); $i+=8) {
+                        $block = substr($ciphertext, $i, 8);
+                        $buffer.= $this->_processBlock($this->_generate_xor(8, $xor), CRYPT_DES_ENCRYPT);
+                        $key = $this->_string_shift($buffer, 8);
+                        $plaintext.= $block ^ $key;
+                    }
+                } else {
+                    for ($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 = $xor;
+                    if ($start = strlen($ciphertext) % 8) {
+                        $buffer = substr($key, $start) . $buffer;
+                    }
+                }
+                break;
+            case CRYPT_DES_MODE_CFB:
+                if (!empty($buffer['ciphertext'])) {
+                    $plaintext = $ciphertext ^ substr($this->decryptIV, strlen($buffer['ciphertext']));
+                    $buffer['ciphertext'].= substr($ciphertext, 0, strlen($plaintext));
+                    if (strlen($buffer['ciphertext']) == 8) {
+                        $xor = $this->_processBlock($buffer['ciphertext'], CRYPT_DES_ENCRYPT);
+                        $buffer['ciphertext'] = '';
+                    }
+                    $start = strlen($plaintext);
+                    $block = $this->decryptIV;
+                } else {
+                    $plaintext = '';
+                    $xor = $this->_processBlock($this->decryptIV, CRYPT_DES_ENCRYPT);
+                    $start = 0;
+                }
+
+                for ($i = $start; $i < strlen($ciphertext); $i+=8) {
+                    $block = substr($ciphertext, $i, 8);
+                    $plaintext.= $block ^ $xor;
+                    if ($continuousBuffer && strlen($block) != 8) {
+                        $buffer['ciphertext'].= $block;
+                        $block = $xor;
+                    } else if (strlen($block) == 8) {
+                        $xor = $this->_processBlock($block, CRYPT_DES_ENCRYPT);
+                    }
+                }
+                if ($this->continuousBuffer) {
+                    $this->decryptIV = $block;
+                }
+                break;
+            case CRYPT_DES_MODE_OFB:
+                $xor = $this->decryptIV;
+                if (strlen($buffer)) {
+                    for ($i = 0; $i < strlen($ciphertext); $i+=8) {
+                        $xor = $this->_processBlock($xor, CRYPT_DES_ENCRYPT);
+                        $buffer.= $xor;
+                        $key = $this->_string_shift($buffer, 8);
+                        $plaintext.= substr($ciphertext, $i, 8) ^ $key;
+                    }
+                } else {
+                    for ($i = 0; $i < strlen($ciphertext); $i+=8) {
+                        $xor = $this->_processBlock($xor, CRYPT_DES_ENCRYPT);
+                        $plaintext.= substr($ciphertext, $i, 8) ^ $xor;
+                    }
+                    $key = $xor;
+                }
+                if ($this->continuousBuffer) {
+                    $this->decryptIV = $xor;
+                    if ($start = strlen($ciphertext) % 8) {
+                         $buffer = substr($key, $start) . $buffer;
+                    }
+                }
+        }
+
+        return $this->paddable ? $this->_unpad($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;
+    }
+
+    /**
+     * String Shift
+     *
+     * Inspired by array_shift
+     *
+     * @param String $string
+     * @param optional Integer $index
+     * @return String
+     * @access private
+     */
+    function _string_shift(&$string, $index = 1)
+    {
+        $substr = substr($string, 0, $index);
+        $string = substr($string, $index);
+        return $substr;
+    }
+}
+
+// vim: ts=4:sw=4:et:
+// vim6: fdl=1:
\ No newline at end of file