PHPSECLIB 0.3.1 added to the project to support SFTP transfers of lab orders and...
authorRod Roark <rod@sunsetsystems.com>
Sun, 16 Dec 2012 05:00:17 +0000 (15 21:00 -0800)
committerRod Roark <rod@sunsetsystems.com>
Tue, 29 Jan 2013 18:17:09 +0000 (29 10:17 -0800)
17 files changed:
library/phpseclib/Crypt/AES.php [new file with mode: 0644]
library/phpseclib/Crypt/DES.php [new file with mode: 0644]
library/phpseclib/Crypt/Hash.php [new file with mode: 0644]
library/phpseclib/Crypt/RC4.php [new file with mode: 0644]
library/phpseclib/Crypt/RSA.php [new file with mode: 0644]
library/phpseclib/Crypt/Random.php [new file with mode: 0644]
library/phpseclib/Crypt/Rijndael.php [new file with mode: 0644]
library/phpseclib/Crypt/TripleDES.php [new file with mode: 0644]
library/phpseclib/File/ANSI.php [new file with mode: 0644]
library/phpseclib/File/ASN1.php [new file with mode: 0644]
library/phpseclib/File/X509.php [new file with mode: 0644]
library/phpseclib/Math/BigInteger.php [new file with mode: 0644]
library/phpseclib/Net/SFTP.php [new file with mode: 0644]
library/phpseclib/Net/SSH1.php [new file with mode: 0644]
library/phpseclib/Net/SSH2.php [new file with mode: 0644]
library/phpseclib/README.OpenEMR.txt [new file with mode: 0644]
library/phpseclib/openssl.cnf [new file with mode: 0644]

diff --git a/library/phpseclib/Crypt/AES.php b/library/phpseclib/Crypt/AES.php
new file mode 100644 (file)
index 0000000..74383cc
--- /dev/null
@@ -0,0 +1,611 @@
+<?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 <terrafrost@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
+ */
+if (!class_exists('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 <terrafrost@php.net>
+ * @version 0.1.0
+ * @access  public
+ * @package Crypt_AES
+ */
+class Crypt_AES extends Crypt_Rijndael {
+    /**
+     * mcrypt resource for encryption
+     *
+     * The mcrypt resource can be recreated every time something needs to be created or it can be created just once.
+     * Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode.
+     *
+     * @see Crypt_AES::encrypt()
+     * @var String
+     * @access private
+     */
+    var $enmcrypt;
+
+    /**
+     * mcrypt resource for decryption
+     *
+     * The mcrypt resource can be recreated every time something needs to be created or it can be created just once.
+     * Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode.
+     *
+     * @see Crypt_AES::decrypt()
+     * @var String
+     * @access private
+     */
+    var $demcrypt;
+
+    /**
+     * 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') && in_array('rijndael-128', mcrypt_list_algorithms()):
+                    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;
+    }
+
+
+    /**
+     * Sets the initialization vector. (optional)
+     *
+     * SetIV is not required when CRYPT_RIJNDAEL_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)
+    {
+        parent::setIV($iv);
+        if ( CRYPT_AES_MODE == CRYPT_AES_MODE_MCRYPT ) {
+            $this->changed = true;
+        }
+    }
+
+    /**
+     * 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:
diff --git a/library/phpseclib/Crypt/DES.php b/library/phpseclib/Crypt/DES.php
new file mode 100644 (file)
index 0000000..0d6dd00
--- /dev/null
@@ -0,0 +1,1295 @@
+<?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 <terrafrost@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 <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_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_DES_MODE_CBC)
+    {
+        if ( !defined('CRYPT_DES_MODE') ) {
+            switch (true) {
+                case extension_loaded('mcrypt') && in_array('des', mcrypt_list_algorithms()):
+                    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 password.
+     *
+     * Depending on what $method is set to, setPassword()'s (optional) parameters are as follows:
+     *     {@link http://en.wikipedia.org/wiki/PBKDF2 pbkdf2}:
+     *         $hash, $salt, $count
+     *
+     * @param String $password
+     * @param optional String $method
+     * @access public
+     */
+    function setPassword($password, $method = 'pbkdf2')
+    {
+        $key = '';
+
+        switch ($method) {
+            default: // 'pbkdf2'
+                list(, , $hash, $salt, $count) = func_get_args();
+                if (!isset($hash)) {
+                    $hash = 'sha1';
+                }
+                // WPA and WPA use the SSID as the salt
+                if (!isset($salt)) {
+                    $salt = 'phpseclib/salt';
+                }
+                // RFC2898#section-4.2 uses 1,000 iterations by default
+                // WPA and WPA2 use 4,096.
+                if (!isset($count)) {
+                    $count = 1000;
+                }
+
+                if (!class_exists('Crypt_Hash')) {
+                    require_once('Crypt/Hash.php');
+                }
+
+                $i = 1;
+                while (strlen($key) < 8) { // $dkLen == 8
+                    //$dk.= $this->_pbkdf($password, $salt, $count, $i++);
+                    $hmac = new Crypt_Hash();
+                    $hmac->setHash($hash);
+                    $hmac->setKey($password);
+                    $f = $u = $hmac->hash($salt . pack('N', $i++));
+                    for ($j = 2; $j <= $count; $j++) {
+                        $u = $hmac->hash($u);
+                        $f^= $u;
+                    }
+                    $key.= $f;
+                }
+        }
+
+        $this->setKey($key);
+    }
+
+    /**
+     * 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['encrypted'])) {
+                    for ($i = 0; $i < strlen($plaintext); $i+=8) {
+                        $block = substr($plaintext, $i, 8);
+                        $buffer['encrypted'].= $this->_processBlock($this->_generate_xor(8, $xor), CRYPT_DES_ENCRYPT);
+                        $key = $this->_string_shift($buffer['encrypted'], 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) {
+                        $buffer['encrypted'] = substr($key, $start) . $buffer['encrypted'];
+                    }
+                }
+                break;
+            case CRYPT_DES_MODE_CFB:
+                if (!empty($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->paddable ? $this->_unpad($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['ciphertext'])) {
+                    for ($i = 0; $i < strlen($ciphertext); $i+=8) {
+                        $block = substr($ciphertext, $i, 8);
+                        $buffer['ciphertext'].= $this->_processBlock($this->_generate_xor(8, $xor), CRYPT_DES_ENCRYPT);
+                        $key = $this->_string_shift($buffer['ciphertext'], 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) {
+                        $buffer['ciphertext'] = substr($key, $start) . $buffer['ciphertext'];
+                    }
+                }
+                break;
+            case CRYPT_DES_MODE_CFB:
+                if (!empty($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
diff --git a/library/phpseclib/Crypt/Hash.php b/library/phpseclib/Crypt/Hash.php
new file mode 100644 (file)
index 0000000..c5d314f
--- /dev/null
@@ -0,0 +1,825 @@
+<?php
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * Pure-PHP implementations of keyed-hash message authentication codes (HMACs) and various cryptographic hashing functions.
+ *
+ * Uses hash() or mhash() if available and an internal implementation, otherwise.  Currently supports the following:
+ *
+ * md2, md5, md5-96, sha1, sha1-96, sha256, sha384, and sha512
+ *
+ * If {@link Crypt_Hash::setKey() setKey()} is called, {@link Crypt_Hash::hash() hash()} will return the HMAC as opposed to
+ * the hash.  If no valid algorithm is provided, sha1 will be used.
+ *
+ * PHP versions 4 and 5
+ *
+ * {@internal The variable names are the same as those in 
+ * {@link http://tools.ietf.org/html/rfc2104#section-2 RFC2104}.}}
+ *
+ * Here's a short example of how to use this library:
+ * <code>
+ * <?php
+ *    include('Crypt/Hash.php');
+ *
+ *    $hash = new Crypt_Hash('sha1');
+ *
+ *    $hash->setKey('abcdefg');
+ *
+ *    echo base64_encode($hash->hash('abcdefg'));
+ * ?>
+ * </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_Hash
+ * @author     Jim Wigginton <terrafrost@php.net>
+ * @copyright  MMVII Jim Wigginton
+ * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @version    $Id: Hash.php,v 1.6 2009/11/23 23:37:07 terrafrost Exp $
+ * @link       http://phpseclib.sourceforge.net
+ */
+
+/**#@+
+ * @access private
+ * @see Crypt_Hash::Crypt_Hash()
+ */
+/**
+ * Toggles the internal implementation
+ */
+define('CRYPT_HASH_MODE_INTERNAL', 1);
+/**
+ * Toggles the mhash() implementation, which has been deprecated on PHP 5.3.0+.
+ */
+define('CRYPT_HASH_MODE_MHASH',    2);
+/**
+ * Toggles the hash() implementation, which works on PHP 5.1.2+.
+ */
+define('CRYPT_HASH_MODE_HASH',     3);
+/**#@-*/
+
+/**
+ * Pure-PHP implementations of keyed-hash message authentication codes (HMACs) and various cryptographic hashing functions.
+ *
+ * @author  Jim Wigginton <terrafrost@php.net>
+ * @version 0.1.0
+ * @access  public
+ * @package Crypt_Hash
+ */
+class Crypt_Hash {
+    /**
+     * Byte-length of compression blocks / key (Internal HMAC)
+     *
+     * @see Crypt_Hash::setAlgorithm()
+     * @var Integer
+     * @access private
+     */
+    var $b;
+
+    /**
+     * Byte-length of hash output (Internal HMAC)
+     *
+     * @see Crypt_Hash::setHash()
+     * @var Integer
+     * @access private
+     */
+    var $l = false;
+
+    /**
+     * Hash Algorithm
+     *
+     * @see Crypt_Hash::setHash()
+     * @var String
+     * @access private
+     */
+    var $hash;
+
+    /**
+     * Key
+     *
+     * @see Crypt_Hash::setKey()
+     * @var String
+     * @access private
+     */
+    var $key = false;
+
+    /**
+     * Outer XOR (Internal HMAC)
+     *
+     * @see Crypt_Hash::setKey()
+     * @var String
+     * @access private
+     */
+    var $opad;
+
+    /**
+     * Inner XOR (Internal HMAC)
+     *
+     * @see Crypt_Hash::setKey()
+     * @var String
+     * @access private
+     */
+    var $ipad;
+
+    /**
+     * Default Constructor.
+     *
+     * @param optional String $hash
+     * @return Crypt_Hash
+     * @access public
+     */
+    function Crypt_Hash($hash = 'sha1')
+    {
+        if ( !defined('CRYPT_HASH_MODE') ) {
+            switch (true) {
+                case extension_loaded('hash'):
+                    define('CRYPT_HASH_MODE', CRYPT_HASH_MODE_HASH);
+                    break;
+                case extension_loaded('mhash'):
+                    define('CRYPT_HASH_MODE', CRYPT_HASH_MODE_MHASH);
+                    break;
+                default:
+                    define('CRYPT_HASH_MODE', CRYPT_HASH_MODE_INTERNAL);
+            }
+        }
+
+        $this->setHash($hash);
+    }
+
+    /**
+     * Sets the key for HMACs
+     *
+     * Keys can be of any length.
+     *
+     * @access public
+     * @param String $key
+     */
+    function setKey($key = false)
+    {
+        $this->key = $key;
+    }
+
+    /**
+     * Sets the hash function.
+     *
+     * @access public
+     * @param String $hash
+     */
+    function setHash($hash)
+    {
+        $hash = strtolower($hash);
+        switch ($hash) {
+            case 'md5-96':
+            case 'sha1-96':
+                $this->l = 12; // 96 / 8 = 12
+                break;
+            case 'md2':
+            case 'md5':
+                $this->l = 16;
+                break;
+            case 'sha1':
+                $this->l = 20;
+                break;
+            case 'sha256':
+                $this->l = 32;
+                break;
+            case 'sha384':
+                $this->l = 48;
+                break;
+            case 'sha512':
+                $this->l = 64;
+        }
+
+        switch ($hash) {
+            case 'md2':
+                $mode = CRYPT_HASH_MODE == CRYPT_HASH_MODE_HASH && in_array('md2', hash_algos()) ?
+                    CRYPT_HASH_MODE_HASH : CRYPT_HASH_MODE_INTERNAL;
+                break;
+            case 'sha384':
+            case 'sha512':
+                $mode = CRYPT_HASH_MODE == CRYPT_HASH_MODE_MHASH ? CRYPT_HASH_MODE_INTERNAL : CRYPT_HASH_MODE;
+                break;
+            default:
+                $mode = CRYPT_HASH_MODE;
+        }
+
+        switch ( $mode ) {
+            case CRYPT_HASH_MODE_MHASH:
+                switch ($hash) {
+                    case 'md5':
+                    case 'md5-96':
+                        $this->hash = MHASH_MD5;
+                        break;
+                    case 'sha256':
+                        $this->hash = MHASH_SHA256;
+                        break;
+                    case 'sha1':
+                    case 'sha1-96':
+                    default:
+                        $this->hash = MHASH_SHA1;
+                }
+                return;
+            case CRYPT_HASH_MODE_HASH:
+                switch ($hash) {
+                    case 'md5':
+                    case 'md5-96':
+                        $this->hash = 'md5';
+                        return;
+                    case 'md2':
+                    case 'sha256':
+                    case 'sha384':
+                    case 'sha512':
+                        $this->hash = $hash;
+                        return;
+                    case 'sha1':
+                    case 'sha1-96':
+                    default:
+                        $this->hash = 'sha1';
+                }
+                return;
+        }
+
+        switch ($hash) {
+            case 'md2':
+                 $this->b = 16;
+                 $this->hash = array($this, '_md2');
+                 break;
+            case 'md5':
+            case 'md5-96':
+                 $this->b = 64;
+                 $this->hash = array($this, '_md5');
+                 break;
+            case 'sha256':
+                 $this->b = 64;
+                 $this->hash = array($this, '_sha256');
+                 break;
+            case 'sha384':
+            case 'sha512':
+                 $this->b = 128;
+                 $this->hash = array($this, '_sha512');
+                 break;
+            case 'sha1':
+            case 'sha1-96':
+            default:
+                 $this->b = 64;
+                 $this->hash = array($this, '_sha1');
+        }
+
+        $this->ipad = str_repeat(chr(0x36), $this->b);
+        $this->opad = str_repeat(chr(0x5C), $this->b);
+    }
+
+    /**
+     * Compute the HMAC.
+     *
+     * @access public
+     * @param String $text
+     * @return String
+     */
+    function hash($text)
+    {
+        $mode = is_array($this->hash) ? CRYPT_HASH_MODE_INTERNAL : CRYPT_HASH_MODE;
+
+        if (!empty($this->key) || is_string($this->key)) {
+            switch ( $mode ) {
+                case CRYPT_HASH_MODE_MHASH:
+                    $output = mhash($this->hash, $text, $this->key);
+                    break;
+                case CRYPT_HASH_MODE_HASH:
+                    $output = hash_hmac($this->hash, $text, $this->key, true);
+                    break;
+                case CRYPT_HASH_MODE_INTERNAL:
+                    /* "Applications that use keys longer than B bytes will first hash the key using H and then use the
+                        resultant L byte string as the actual key to HMAC."
+
+                        -- http://tools.ietf.org/html/rfc2104#section-2 */
+                    $key = strlen($this->key) > $this->b ? call_user_func($this->hash, $this->key) : $this->key;
+
+                    $key    = str_pad($key, $this->b, chr(0));      // step 1
+                    $temp   = $this->ipad ^ $key;                   // step 2
+                    $temp  .= $text;                                // step 3
+                    $temp   = call_user_func($this->hash, $temp);   // step 4
+                    $output = $this->opad ^ $key;                   // step 5
+                    $output.= $temp;                                // step 6
+                    $output = call_user_func($this->hash, $output); // step 7
+            }
+        } else {
+            switch ( $mode ) {
+                case CRYPT_HASH_MODE_MHASH:
+                    $output = mhash($this->hash, $text);
+                    break;
+                case CRYPT_HASH_MODE_HASH:
+                    $output = hash($this->hash, $text, true);
+                    break;
+                case CRYPT_HASH_MODE_INTERNAL:
+                    $output = call_user_func($this->hash, $text);
+            }
+        }
+
+        return substr($output, 0, $this->l);
+    }
+
+    /**
+     * Returns the hash length (in bytes)
+     *
+     * @access public
+     * @return Integer
+     */
+    function getLength()
+    {
+        return $this->l;
+    }
+
+    /**
+     * Wrapper for MD5
+     *
+     * @access private
+     * @param String $text
+     */
+    function _md5($m)
+    {
+        return pack('H*', md5($m));
+    }
+
+    /**
+     * Wrapper for SHA1
+     *
+     * @access private
+     * @param String $text
+     */
+    function _sha1($m)
+    {
+        return pack('H*', sha1($m));
+    }
+
+    /**
+     * Pure-PHP implementation of MD2
+     *
+     * See {@link http://tools.ietf.org/html/rfc1319 RFC1319}.
+     *
+     * @access private
+     * @param String $text
+     */
+    function _md2($m)
+    {
+        static $s = array(
+             41,  46,  67, 201, 162, 216, 124,   1,  61,  54,  84, 161, 236, 240, 6,
+             19,  98, 167,   5, 243, 192, 199, 115, 140, 152, 147,  43, 217, 188,
+             76, 130, 202,  30, 155,  87,  60, 253, 212, 224,  22, 103,  66, 111, 24,
+            138,  23, 229,  18, 190,  78, 196, 214, 218, 158, 222,  73, 160, 251,
+            245, 142, 187,  47, 238, 122, 169, 104, 121, 145,  21, 178,   7,  63,
+            148, 194,  16, 137,  11,  34,  95,  33, 128, 127,  93, 154,  90, 144, 50,
+             39,  53,  62, 204, 231, 191, 247, 151,   3, 255,  25,  48, 179,  72, 165,
+            181, 209, 215,  94, 146,  42, 172,  86, 170, 198,  79, 184,  56, 210,
+            150, 164, 125, 182, 118, 252, 107, 226, 156, 116,   4, 241,  69, 157,
+            112,  89, 100, 113, 135,  32, 134,  91, 207, 101, 230,  45, 168,   2, 27,
+             96,  37, 173, 174, 176, 185, 246,  28,  70,  97, 105,  52,  64, 126, 15,
+             85,  71, 163,  35, 221,  81, 175,  58, 195,  92, 249, 206, 186, 197,
+            234,  38,  44,  83,  13, 110, 133,  40, 132,   9, 211, 223, 205, 244, 65,
+            129,  77,  82, 106, 220,  55, 200, 108, 193, 171, 250,  36, 225, 123,
+              8,  12, 189, 177,  74, 120, 136, 149, 139, 227,  99, 232, 109, 233,
+            203, 213, 254,  59,   0,  29,  57, 242, 239, 183,  14, 102,  88, 208, 228,
+            166, 119, 114, 248, 235, 117,  75,  10,  49,  68,  80, 180, 143, 237,
+             31,  26, 219, 153, 141,  51, 159,  17, 131, 20
+        );
+
+        // Step 1. Append Padding Bytes
+        $pad = 16 - (strlen($m) & 0xF);
+        $m.= str_repeat(chr($pad), $pad);
+
+        $length = strlen($m);
+
+        // Step 2. Append Checksum
+        $c = str_repeat(chr(0), 16);
+        $l = chr(0);
+        for ($i = 0; $i < $length; $i+= 16) {
+            for ($j = 0; $j < 16; $j++) {
+                // RFC1319 incorrectly states that C[j] should be set to S[c xor L]
+                //$c[$j] = chr($s[ord($m[$i + $j] ^ $l)]);
+                // per <http://www.rfc-editor.org/errata_search.php?rfc=1319>, however, C[j] should be set to S[c xor L] xor C[j]
+                $c[$j] = chr($s[ord($m[$i + $j] ^ $l)] ^ ord($c[$j]));
+                $l = $c[$j];
+            }
+        }
+        $m.= $c;
+
+        $length+= 16;
+
+        // Step 3. Initialize MD Buffer
+        $x = str_repeat(chr(0), 48);
+
+        // Step 4. Process Message in 16-Byte Blocks
+        for ($i = 0; $i < $length; $i+= 16) {
+            for ($j = 0; $j < 16; $j++) {
+                $x[$j + 16] = $m[$i + $j];
+                $x[$j + 32] = $x[$j + 16] ^ $x[$j];
+            }
+            $t = chr(0);
+            for ($j = 0; $j < 18; $j++) {
+                for ($k = 0; $k < 48; $k++) {
+                    $x[$k] = $t = $x[$k] ^ chr($s[ord($t)]);
+                    //$t = $x[$k] = $x[$k] ^ chr($s[ord($t)]);
+                }
+                $t = chr(ord($t) + $j);
+            }
+        }
+
+        // Step 5. Output
+        return substr($x, 0, 16);
+    }
+
+    /**
+     * Pure-PHP implementation of SHA256
+     *
+     * See {@link http://en.wikipedia.org/wiki/SHA_hash_functions#SHA-256_.28a_SHA-2_variant.29_pseudocode SHA-256 (a SHA-2 variant) pseudocode - Wikipedia}.
+     *
+     * @access private
+     * @param String $text
+     */
+    function _sha256($m)
+    {
+        if (extension_loaded('suhosin')) {
+            return pack('H*', sha256($m));
+        }
+
+        // Initialize variables
+        $hash = array(
+            0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
+        );
+        // Initialize table of round constants
+        // (first 32 bits of the fractional parts of the cube roots of the first 64 primes 2..311)
+        static $k = array(
+            0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
+            0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
+            0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+            0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
+            0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
+            0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+            0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
+            0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
+        );
+
+        // Pre-processing
+        $length = strlen($m);
+        // to round to nearest 56 mod 64, we'll add 64 - (length + (64 - 56)) % 64
+        $m.= str_repeat(chr(0), 64 - (($length + 8) & 0x3F));
+        $m[$length] = chr(0x80);
+        // we don't support hashing strings 512MB long
+        $m.= pack('N2', 0, $length << 3);
+
+        // Process the message in successive 512-bit chunks
+        $chunks = str_split($m, 64);
+        foreach ($chunks as $chunk) {
+            $w = array();
+            for ($i = 0; $i < 16; $i++) {
+                extract(unpack('Ntemp', $this->_string_shift($chunk, 4)));
+                $w[] = $temp;
+            }
+
+            // Extend the sixteen 32-bit words into sixty-four 32-bit words
+            for ($i = 16; $i < 64; $i++) {
+                $s0 = $this->_rightRotate($w[$i - 15],  7) ^
+                      $this->_rightRotate($w[$i - 15], 18) ^
+                      $this->_rightShift( $w[$i - 15],  3);
+                $s1 = $this->_rightRotate($w[$i - 2], 17) ^
+                      $this->_rightRotate($w[$i - 2], 19) ^
+                      $this->_rightShift( $w[$i - 2], 10);
+                $w[$i] = $this->_add($w[$i - 16], $s0, $w[$i - 7], $s1);
+
+            }
+
+            // Initialize hash value for this chunk
+            list($a, $b, $c, $d, $e, $f, $g, $h) = $hash;
+
+            // Main loop
+            for ($i = 0; $i < 64; $i++) {
+                $s0 = $this->_rightRotate($a,  2) ^
+                      $this->_rightRotate($a, 13) ^
+                      $this->_rightRotate($a, 22);
+                $maj = ($a & $b) ^
+                       ($a & $c) ^
+                       ($b & $c);
+                $t2 = $this->_add($s0, $maj);
+
+                $s1 = $this->_rightRotate($e,  6) ^
+                      $this->_rightRotate($e, 11) ^
+                      $this->_rightRotate($e, 25);
+                $ch = ($e & $f) ^
+                      ($this->_not($e) & $g);
+                $t1 = $this->_add($h, $s1, $ch, $k[$i], $w[$i]);
+
+                $h = $g;
+                $g = $f;
+                $f = $e;
+                $e = $this->_add($d, $t1);
+                $d = $c;
+                $c = $b;
+                $b = $a;
+                $a = $this->_add($t1, $t2);
+            }
+
+            // Add this chunk's hash to result so far
+            $hash = array(
+                $this->_add($hash[0], $a),
+                $this->_add($hash[1], $b),
+                $this->_add($hash[2], $c),
+                $this->_add($hash[3], $d),
+                $this->_add($hash[4], $e),
+                $this->_add($hash[5], $f),
+                $this->_add($hash[6], $g),
+                $this->_add($hash[7], $h)
+            );
+        }
+
+        // Produce the final hash value (big-endian)
+        return pack('N8', $hash[0], $hash[1], $hash[2], $hash[3], $hash[4], $hash[5], $hash[6], $hash[7]);
+    }
+
+    /**
+     * Pure-PHP implementation of SHA384 and SHA512
+     *
+     * @access private
+     * @param String $text
+     */
+    function _sha512($m)
+    {
+        if (!class_exists('Math_BigInteger')) {
+            require_once('Math/BigInteger.php');
+        }
+
+        static $init384, $init512, $k;
+
+        if (!isset($k)) {
+            // Initialize variables
+            $init384 = array( // initial values for SHA384
+                'cbbb9d5dc1059ed8', '629a292a367cd507', '9159015a3070dd17', '152fecd8f70e5939', 
+                '67332667ffc00b31', '8eb44a8768581511', 'db0c2e0d64f98fa7', '47b5481dbefa4fa4'
+            );
+            $init512 = array( // initial values for SHA512
+                '6a09e667f3bcc908', 'bb67ae8584caa73b', '3c6ef372fe94f82b', 'a54ff53a5f1d36f1', 
+                '510e527fade682d1', '9b05688c2b3e6c1f', '1f83d9abfb41bd6b', '5be0cd19137e2179'
+            );
+
+            for ($i = 0; $i < 8; $i++) {
+                $init384[$i] = new Math_BigInteger($init384[$i], 16);
+                $init384[$i]->setPrecision(64);
+                $init512[$i] = new Math_BigInteger($init512[$i], 16);
+                $init512[$i]->setPrecision(64);
+            }
+
+            // Initialize table of round constants
+            // (first 64 bits of the fractional parts of the cube roots of the first 80 primes 2..409)
+            $k = array(
+                '428a2f98d728ae22', '7137449123ef65cd', 'b5c0fbcfec4d3b2f', 'e9b5dba58189dbbc',
+                '3956c25bf348b538', '59f111f1b605d019', '923f82a4af194f9b', 'ab1c5ed5da6d8118',
+                'd807aa98a3030242', '12835b0145706fbe', '243185be4ee4b28c', '550c7dc3d5ffb4e2',
+                '72be5d74f27b896f', '80deb1fe3b1696b1', '9bdc06a725c71235', 'c19bf174cf692694',
+                'e49b69c19ef14ad2', 'efbe4786384f25e3', '0fc19dc68b8cd5b5', '240ca1cc77ac9c65',
+                '2de92c6f592b0275', '4a7484aa6ea6e483', '5cb0a9dcbd41fbd4', '76f988da831153b5',
+                '983e5152ee66dfab', 'a831c66d2db43210', 'b00327c898fb213f', 'bf597fc7beef0ee4',
+                'c6e00bf33da88fc2', 'd5a79147930aa725', '06ca6351e003826f', '142929670a0e6e70',
+                '27b70a8546d22ffc', '2e1b21385c26c926', '4d2c6dfc5ac42aed', '53380d139d95b3df',
+                '650a73548baf63de', '766a0abb3c77b2a8', '81c2c92e47edaee6', '92722c851482353b',
+                'a2bfe8a14cf10364', 'a81a664bbc423001', 'c24b8b70d0f89791', 'c76c51a30654be30',
+                'd192e819d6ef5218', 'd69906245565a910', 'f40e35855771202a', '106aa07032bbd1b8',
+                '19a4c116b8d2d0c8', '1e376c085141ab53', '2748774cdf8eeb99', '34b0bcb5e19b48a8',
+                '391c0cb3c5c95a63', '4ed8aa4ae3418acb', '5b9cca4f7763e373', '682e6ff3d6b2b8a3',
+                '748f82ee5defb2fc', '78a5636f43172f60', '84c87814a1f0ab72', '8cc702081a6439ec',
+                '90befffa23631e28', 'a4506cebde82bde9', 'bef9a3f7b2c67915', 'c67178f2e372532b',
+                'ca273eceea26619c', 'd186b8c721c0c207', 'eada7dd6cde0eb1e', 'f57d4f7fee6ed178',
+                '06f067aa72176fba', '0a637dc5a2c898a6', '113f9804bef90dae', '1b710b35131c471b',
+                '28db77f523047d84', '32caab7b40c72493', '3c9ebe0a15c9bebc', '431d67c49c100d4c',
+                '4cc5d4becb3e42b6', '597f299cfc657e2a', '5fcb6fab3ad6faec', '6c44198c4a475817'
+            );
+
+            for ($i = 0; $i < 80; $i++) {
+                $k[$i] = new Math_BigInteger($k[$i], 16);
+            }
+        }
+
+        $hash = $this->l == 48 ? $init384 : $init512;
+
+        // Pre-processing
+        $length = strlen($m);
+        // to round to nearest 112 mod 128, we'll add 128 - (length + (128 - 112)) % 128
+        $m.= str_repeat(chr(0), 128 - (($length + 16) & 0x7F));
+        $m[$length] = chr(0x80);
+        // we don't support hashing strings 512MB long
+        $m.= pack('N4', 0, 0, 0, $length << 3);
+
+        // Process the message in successive 1024-bit chunks
+        $chunks = str_split($m, 128);
+        foreach ($chunks as $chunk) {
+            $w = array();
+            for ($i = 0; $i < 16; $i++) {
+                $temp = new Math_BigInteger($this->_string_shift($chunk, 8), 256);
+                $temp->setPrecision(64);
+                $w[] = $temp;
+            }
+
+            // Extend the sixteen 32-bit words into eighty 32-bit words
+            for ($i = 16; $i < 80; $i++) {
+                $temp = array(
+                          $w[$i - 15]->bitwise_rightRotate(1),
+                          $w[$i - 15]->bitwise_rightRotate(8),
+                          $w[$i - 15]->bitwise_rightShift(7)
+                );
+                $s0 = $temp[0]->bitwise_xor($temp[1]);
+                $s0 = $s0->bitwise_xor($temp[2]);
+                $temp = array(
+                          $w[$i - 2]->bitwise_rightRotate(19),
+                          $w[$i - 2]->bitwise_rightRotate(61),
+                          $w[$i - 2]->bitwise_rightShift(6)
+                );
+                $s1 = $temp[0]->bitwise_xor($temp[1]);
+                $s1 = $s1->bitwise_xor($temp[2]);
+                $w[$i] = $w[$i - 16]->copy();
+                $w[$i] = $w[$i]->add($s0);
+                $w[$i] = $w[$i]->add($w[$i - 7]);
+                $w[$i] = $w[$i]->add($s1);
+            }
+
+            // Initialize hash value for this chunk
+            $a = $hash[0]->copy();
+            $b = $hash[1]->copy();
+            $c = $hash[2]->copy();
+            $d = $hash[3]->copy();
+            $e = $hash[4]->copy();
+            $f = $hash[5]->copy();
+            $g = $hash[6]->copy();
+            $h = $hash[7]->copy();
+
+            // Main loop
+            for ($i = 0; $i < 80; $i++) {
+                $temp = array(
+                    $a->bitwise_rightRotate(28),
+                    $a->bitwise_rightRotate(34),
+                    $a->bitwise_rightRotate(39)
+                );
+                $s0 = $temp[0]->bitwise_xor($temp[1]);
+                $s0 = $s0->bitwise_xor($temp[2]);
+                $temp = array(
+                    $a->bitwise_and($b),
+                    $a->bitwise_and($c),
+                    $b->bitwise_and($c)
+                );
+                $maj = $temp[0]->bitwise_xor($temp[1]);
+                $maj = $maj->bitwise_xor($temp[2]);
+                $t2 = $s0->add($maj);
+
+                $temp = array(
+                    $e->bitwise_rightRotate(14),
+                    $e->bitwise_rightRotate(18),
+                    $e->bitwise_rightRotate(41)
+                );
+                $s1 = $temp[0]->bitwise_xor($temp[1]);
+                $s1 = $s1->bitwise_xor($temp[2]);
+                $temp = array(
+                    $e->bitwise_and($f),
+                    $g->bitwise_and($e->bitwise_not())
+                );
+                $ch = $temp[0]->bitwise_xor($temp[1]);
+                $t1 = $h->add($s1);
+                $t1 = $t1->add($ch);
+                $t1 = $t1->add($k[$i]);
+                $t1 = $t1->add($w[$i]);
+
+                $h = $g->copy();
+                $g = $f->copy();
+                $f = $e->copy();
+                $e = $d->add($t1);
+                $d = $c->copy();
+                $c = $b->copy();
+                $b = $a->copy();
+                $a = $t1->add($t2);
+            }
+
+            // Add this chunk's hash to result so far
+            $hash = array(
+                $hash[0]->add($a),
+                $hash[1]->add($b),
+                $hash[2]->add($c),
+                $hash[3]->add($d),
+                $hash[4]->add($e),
+                $hash[5]->add($f),
+                $hash[6]->add($g),
+                $hash[7]->add($h)
+            );
+        }
+
+        // Produce the final hash value (big-endian)
+        // (Crypt_Hash::hash() trims the output for hashes but not for HMACs.  as such, we trim the output here)
+        $temp = $hash[0]->toBytes() . $hash[1]->toBytes() . $hash[2]->toBytes() . $hash[3]->toBytes() .
+                $hash[4]->toBytes() . $hash[5]->toBytes();
+        if ($this->l != 48) {
+            $temp.= $hash[6]->toBytes() . $hash[7]->toBytes();
+        }
+
+        return $temp;
+    }
+
+    /**
+     * Right Rotate
+     *
+     * @access private
+     * @param Integer $int
+     * @param Integer $amt
+     * @see _sha256()
+     * @return Integer
+     */
+    function _rightRotate($int, $amt)
+    {
+        $invamt = 32 - $amt;
+        $mask = (1 << $invamt) - 1;
+        return (($int << $invamt) & 0xFFFFFFFF) | (($int >> $amt) & $mask);
+    }
+
+    /**
+     * Right Shift
+     *
+     * @access private
+     * @param Integer $int
+     * @param Integer $amt
+     * @see _sha256()
+     * @return Integer
+     */
+    function _rightShift($int, $amt)
+    {
+        $mask = (1 << (32 - $amt)) - 1;
+        return ($int >> $amt) & $mask;
+    }
+
+    /**
+     * Not
+     *
+     * @access private
+     * @param Integer $int
+     * @see _sha256()
+     * @return Integer
+     */
+    function _not($int)
+    {
+        return ~$int & 0xFFFFFFFF;
+    }
+
+    /**
+     * Add
+     *
+     * _sha256() adds multiple unsigned 32-bit integers.  Since PHP doesn't support unsigned integers and since the
+     * possibility of overflow exists, care has to be taken.  Math_BigInteger() could be used but this should be faster.
+     *
+     * @param String $string
+     * @param optional Integer $index
+     * @return String
+     * @see _sha256()
+     * @access private
+     */
+    function _add()
+    {
+        static $mod;
+        if (!isset($mod)) {
+            $mod = pow(2, 32);
+        }
+
+        $result = 0;
+        $arguments = func_get_args();
+        foreach ($arguments as $argument) {
+            $result+= $argument < 0 ? ($argument & 0x7FFFFFFF) + 0x80000000 : $argument;
+        }
+
+        return fmod($result, $mod);
+    }
+
+    /**
+     * 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;
+    }
+}
diff --git a/library/phpseclib/Crypt/RC4.php b/library/phpseclib/Crypt/RC4.php
new file mode 100644 (file)
index 0000000..94cb691
--- /dev/null
@@ -0,0 +1,531 @@
+<?php
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * Pure-PHP implementation of RC4.
+ *
+ * Uses mcrypt, if available, and an internal implementation, otherwise.
+ *
+ * PHP versions 4 and 5
+ *
+ * Useful resources are as follows:
+ *
+ *  - {@link http://www.mozilla.org/projects/security/pki/nss/draft-kaukonen-cipher-arcfour-03.txt ARCFOUR Algorithm}
+ *  - {@link http://en.wikipedia.org/wiki/RC4 - Wikipedia: RC4}
+ *
+ * RC4 is also known as ARCFOUR or ARC4.  The reason is elaborated upon at Wikipedia.  This class is named RC4 and not
+ * ARCFOUR or ARC4 because RC4 is how it is refered to in the SSH1 specification.
+ *
+ * Here's a short example of how to use this library:
+ * <code>
+ * <?php
+ *    include('Crypt/RC4.php');
+ *
+ *    $rc4 = new Crypt_RC4();
+ *
+ *    $rc4->setKey('abcdefgh');
+ *
+ *    $size = 10 * 1024;
+ *    $plaintext = '';
+ *    for ($i = 0; $i < $size; $i++) {
+ *        $plaintext.= 'a';
+ *    }
+ *
+ *    echo $rc4->decrypt($rc4->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_RC4
+ * @author     Jim Wigginton <terrafrost@php.net>
+ * @copyright  MMVII Jim Wigginton
+ * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @version    $Id: RC4.php,v 1.8 2009/06/09 04:00:38 terrafrost Exp $
+ * @link       http://phpseclib.sourceforge.net
+ */
+
+/**#@+
+ * @access private
+ * @see Crypt_RC4::Crypt_RC4()
+ */
+/**
+ * Toggles the internal implementation
+ */
+define('CRYPT_RC4_MODE_INTERNAL', 1);
+/**
+ * Toggles the mcrypt implementation
+ */
+define('CRYPT_RC4_MODE_MCRYPT', 2);
+/**#@-*/
+
+/**#@+
+ * @access private
+ * @see Crypt_RC4::_crypt()
+ */
+define('CRYPT_RC4_ENCRYPT', 0);
+define('CRYPT_RC4_DECRYPT', 1);
+/**#@-*/
+
+/**
+ * Pure-PHP implementation of RC4.
+ *
+ * @author  Jim Wigginton <terrafrost@php.net>
+ * @version 0.1.0
+ * @access  public
+ * @package Crypt_RC4
+ */
+class Crypt_RC4 {
+    /**
+     * The Key
+     *
+     * @see Crypt_RC4::setKey()
+     * @var String
+     * @access private
+     */
+    var $key = "\0";
+
+    /**
+     * The Key Stream for encryption
+     *
+     * If CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT, this will be equal to the mcrypt object
+     *
+     * @see Crypt_RC4::setKey()
+     * @var Array
+     * @access private
+     */
+    var $encryptStream = false;
+
+    /**
+     * The Key Stream for decryption
+     *
+     * If CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT, this will be equal to the mcrypt object
+     *
+     * @see Crypt_RC4::setKey()
+     * @var Array
+     * @access private
+     */
+    var $decryptStream = false;
+
+    /**
+     * The $i and $j indexes for encryption
+     *
+     * @see Crypt_RC4::_crypt()
+     * @var Integer
+     * @access private
+     */
+    var $encryptIndex = 0;
+
+    /**
+     * The $i and $j indexes for decryption
+     *
+     * @see Crypt_RC4::_crypt()
+     * @var Integer
+     * @access private
+     */
+    var $decryptIndex = 0;
+
+    /**
+     * The Encryption Algorithm
+     *
+     * Only used if CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT.  Only possible values are MCRYPT_RC4 or MCRYPT_ARCFOUR.
+     *
+     * @see Crypt_RC4::Crypt_RC4()
+     * @var Integer
+     * @access private
+     */
+    var $mode;
+
+    /**
+     * Continuous Buffer status
+     *
+     * @see Crypt_RC4::enableContinuousBuffer()
+     * @var Boolean
+     * @access private
+     */
+    var $continuousBuffer = false;
+
+    /**
+     * Default Constructor.
+     *
+     * Determines whether or not the mcrypt extension should be used.
+     *
+     * @param optional Integer $mode
+     * @return Crypt_RC4
+     * @access public
+     */
+    function Crypt_RC4()
+    {
+        if ( !defined('CRYPT_RC4_MODE') ) {
+            switch (true) {
+                case extension_loaded('mcrypt') && (defined('MCRYPT_ARCFOUR') || defined('MCRYPT_RC4')) && in_array('arcfour', mcrypt_list_algorithms()):
+                    define('CRYPT_RC4_MODE', CRYPT_RC4_MODE_MCRYPT);
+                    break;
+                default:
+                    define('CRYPT_RC4_MODE', CRYPT_RC4_MODE_INTERNAL);
+            }
+        }
+
+        switch ( CRYPT_RC4_MODE ) {
+            case CRYPT_RC4_MODE_MCRYPT:
+                switch (true) {
+                    case defined('MCRYPT_ARCFOUR'):
+                        $this->mode = MCRYPT_ARCFOUR;
+                        break;
+                    case defined('MCRYPT_RC4');
+                        $this->mode = MCRYPT_RC4;
+                }
+        }
+    }
+
+    /**
+     * Sets the key.
+     *
+     * Keys can be between 1 and 256 bytes long.  If they are longer then 256 bytes, the first 256 bytes will
+     * be used.  If no key is explicitly set, it'll be assumed to be a single null byte.
+     *
+     * @access public
+     * @param String $key
+     */
+    function setKey($key)
+    {
+        $this->key = $key;
+
+        if ( CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT ) {
+            return;
+        }
+
+        $keyLength = strlen($key);
+        $keyStream = array();
+        for ($i = 0; $i < 256; $i++) {
+            $keyStream[$i] = $i;
+        }
+        $j = 0;
+        for ($i = 0; $i < 256; $i++) {
+            $j = ($j + $keyStream[$i] + ord($key[$i % $keyLength])) & 255;
+            $temp = $keyStream[$i];
+            $keyStream[$i] = $keyStream[$j];
+            $keyStream[$j] = $temp;
+        }
+
+        $this->encryptIndex = $this->decryptIndex = array(0, 0);
+        $this->encryptStream = $this->decryptStream = $keyStream;
+    }
+
+    /**
+     * Sets the password.
+     *
+     * Depending on what $method is set to, setPassword()'s (optional) parameters are as follows:
+     *     {@link http://en.wikipedia.org/wiki/PBKDF2 pbkdf2}:
+     *         $hash, $salt, $count, $dkLen
+     *
+     * @param String $password
+     * @param optional String $method
+     * @access public
+     */
+    function setPassword($password, $method = 'pbkdf2')
+    {
+        $key = '';
+
+        switch ($method) {
+            default: // 'pbkdf2'
+                list(, , $hash, $salt, $count) = func_get_args();
+                if (!isset($hash)) {
+                    $hash = 'sha1';
+                }
+                // WPA and WPA use the SSID as the salt
+                if (!isset($salt)) {
+                    $salt = 'phpseclib/salt';
+                }
+                // RFC2898#section-4.2 uses 1,000 iterations by default
+                // WPA and WPA2 use 4,096.
+                if (!isset($count)) {
+                    $count = 1000;
+                }
+                if (!isset($dkLen)) {
+                    $dkLen = 128;
+                }
+
+                if (!class_exists('Crypt_Hash')) {
+                    require_once('Crypt/Hash.php');
+                }
+
+                $i = 1;
+                while (strlen($key) < $dkLen) {
+                    //$dk.= $this->_pbkdf($password, $salt, $count, $i++);
+                    $hmac = new Crypt_Hash();
+                    $hmac->setHash($hash);
+                    $hmac->setKey($password);
+                    $f = $u = $hmac->hash($salt . pack('N', $i++));
+                    for ($j = 2; $j <= $count; $j++) {
+                        $u = $hmac->hash($u);
+                        $f^= $u;
+                    }
+                    $key.= $f;
+                }
+        }
+
+        $this->setKey(substr($key, 0, $dkLen));
+    }
+
+    /**
+     * Dummy function.
+     *
+     * Some protocols, such as WEP, prepend an "initialization vector" to the key, effectively creating a new key [1].
+     * If you need to use an initialization vector in this manner, feel free to prepend it to the key, yourself, before
+     * calling setKey().
+     *
+     * [1] WEP's initialization vectors (IV's) are used in a somewhat insecure way.  Since, in that protocol,
+     * the IV's are relatively easy to predict, an attack described by
+     * {@link http://www.drizzle.com/~aboba/IEEE/rc4_ksaproc.pdf Scott Fluhrer, Itsik Mantin, and Adi Shamir}
+     * can be used to quickly guess at the rest of the key.  The following links elaborate:
+     *
+     * {@link http://www.rsa.com/rsalabs/node.asp?id=2009 http://www.rsa.com/rsalabs/node.asp?id=2009}
+     * {@link http://en.wikipedia.org/wiki/Related_key_attack http://en.wikipedia.org/wiki/Related_key_attack}
+     *
+     * @param String $iv
+     * @see Crypt_RC4::setKey()
+     * @access public
+     */
+    function setIV($iv)
+    {
+    }
+
+    /**
+     * Encrypts a message.
+     *
+     * @see Crypt_RC4::_crypt()
+     * @access public
+     * @param String $plaintext
+     */
+    function encrypt($plaintext)
+    {
+        return $this->_crypt($plaintext, CRYPT_RC4_ENCRYPT);
+    }
+
+    /**
+     * Decrypts a message.
+     *
+     * $this->decrypt($this->encrypt($plaintext)) == $this->encrypt($this->encrypt($plaintext)).
+     * Atleast if the continuous buffer is disabled.
+     *
+     * @see Crypt_RC4::_crypt()
+     * @access public
+     * @param String $ciphertext
+     */
+    function decrypt($ciphertext)
+    {
+        return $this->_crypt($ciphertext, CRYPT_RC4_DECRYPT);
+    }
+
+    /**
+     * Encrypts or decrypts a message.
+     *
+     * @see Crypt_RC4::encrypt()
+     * @see Crypt_RC4::decrypt()
+     * @access private
+     * @param String $text
+     * @param Integer $mode
+     */
+    function _crypt($text, $mode)
+    {
+        if ( CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT ) {
+            $keyStream = $mode == CRYPT_RC4_ENCRYPT ? 'encryptStream' : 'decryptStream';
+
+            if ($this->$keyStream === false) {
+                $this->$keyStream = mcrypt_module_open($this->mode, '', MCRYPT_MODE_STREAM, '');
+                mcrypt_generic_init($this->$keyStream, $this->key, '');
+            } else if (!$this->continuousBuffer) {
+                mcrypt_generic_init($this->$keyStream, $this->key, '');
+            }
+            $newText = mcrypt_generic($this->$keyStream, $text);
+            if (!$this->continuousBuffer) {
+                mcrypt_generic_deinit($this->$keyStream);
+            }
+
+            return $newText;
+        }
+
+        if ($this->encryptStream === false) {
+            $this->setKey($this->key);
+        }
+
+        switch ($mode) {
+            case CRYPT_RC4_ENCRYPT:
+                $keyStream = $this->encryptStream;
+                list($i, $j) = $this->encryptIndex;
+                break;
+            case CRYPT_RC4_DECRYPT:
+                $keyStream = $this->decryptStream;
+                list($i, $j) = $this->decryptIndex;
+        }
+
+        $newText = '';
+        for ($k = 0; $k < strlen($text); $k++) {
+            $i = ($i + 1) & 255;
+            $j = ($j + $keyStream[$i]) & 255;
+            $temp = $keyStream[$i];
+            $keyStream[$i] = $keyStream[$j];
+            $keyStream[$j] = $temp;
+            $temp = $keyStream[($keyStream[$i] + $keyStream[$j]) & 255];
+            $newText.= chr(ord($text[$k]) ^ $temp);
+        }
+
+        if ($this->continuousBuffer) {
+            switch ($mode) {
+                case CRYPT_RC4_ENCRYPT:
+                    $this->encryptStream = $keyStream;
+                    $this->encryptIndex = array($i, $j);
+                    break;
+                case CRYPT_RC4_DECRYPT:
+                    $this->decryptStream = $keyStream;
+                    $this->decryptIndex = array($i, $j);
+            }
+        }
+
+        return $newText;
+    }
+
+    /**
+     * 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 $rc4->encrypt(substr($plaintext, 0, 8));
+     *    echo $rc4->encrypt(substr($plaintext, 8, 8));
+     * </code>
+     * <code>
+     *    echo $rc4->encrypt($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>
+     *    $rc4->encrypt(substr($plaintext, 0, 8));
+     *    echo $rc4->decrypt($des->encrypt(substr($plaintext, 8, 8)));
+     * </code>
+     * <code>
+     *    echo $rc4->decrypt($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_RC4::disableContinuousBuffer()
+     * @access public
+     */
+    function enableContinuousBuffer()
+    {
+        $this->continuousBuffer = true;
+    }
+
+    /**
+     * Treat consecutive packets as if they are a discontinuous buffer.
+     *
+     * The default behavior.
+     *
+     * @see Crypt_RC4::enableContinuousBuffer()
+     * @access public
+     */
+    function disableContinuousBuffer()
+    {
+        if ( CRYPT_RC4_MODE == CRYPT_RC4_MODE_INTERNAL ) {
+            $this->encryptIndex = $this->decryptIndex = array(0, 0);
+            $this->setKey($this->key);
+        }
+
+        $this->continuousBuffer = false;
+    }
+
+    /**
+     * Dummy function.
+     *
+     * Since RC4 is a stream cipher and not a block cipher, no padding is necessary.  The only reason this function is
+     * included is so that you can switch between a block cipher and a stream cipher transparently.
+     *
+     * @see Crypt_RC4::disablePadding()
+     * @access public
+     */
+    function enablePadding()
+    {
+    }
+
+    /**
+     * Dummy function.
+     *
+     * @see Crypt_RC4::enablePadding()
+     * @access public
+     */
+    function disablePadding()
+    {
+    }
+
+    /**
+     * Class destructor.
+     *
+     * Will be called, automatically, if you're using PHP5.  If you're using PHP4, call it yourself.  Only really
+     * needs to be called if mcrypt is being used.
+     *
+     * @access public
+     */
+    function __destruct()
+    {
+        if ( CRYPT_RC4_MODE == CRYPT_RC4_MODE_MCRYPT ) {
+            $this->_closeMCrypt();
+        }
+    }
+
+    /**
+     * Properly close the MCrypt objects.
+     *
+     * @access prviate
+     */
+    function _closeMCrypt()
+    {
+        if ( $this->encryptStream !== false ) {
+            if ( $this->continuousBuffer ) {
+                mcrypt_generic_deinit($this->encryptStream);
+            }
+
+            mcrypt_module_close($this->encryptStream);
+
+            $this->encryptStream = false;
+        }
+
+        if ( $this->decryptStream !== false ) {
+            if ( $this->continuousBuffer ) {
+                mcrypt_generic_deinit($this->decryptStream);
+            }
+
+            mcrypt_module_close($this->decryptStream);
+
+            $this->decryptStream = false;
+        }
+    }
+}
diff --git a/library/phpseclib/Crypt/RSA.php b/library/phpseclib/Crypt/RSA.php
new file mode 100644 (file)
index 0000000..7df1ded
--- /dev/null
@@ -0,0 +1,2640 @@
+<?php
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * Pure-PHP PKCS#1 (v2.1) compliant implementation of RSA.
+ *
+ * PHP versions 4 and 5
+ *
+ * Here's an example of how to encrypt and decrypt text with this library:
+ * <code>
+ * <?php
+ *    include('Crypt/RSA.php');
+ *
+ *    $rsa = new Crypt_RSA();
+ *    extract($rsa->createKey());
+ *
+ *    $plaintext = 'terrafrost';
+ *
+ *    $rsa->loadKey($privatekey);
+ *    $ciphertext = $rsa->encrypt($plaintext);
+ *
+ *    $rsa->loadKey($publickey);
+ *    echo $rsa->decrypt($ciphertext);
+ * ?>
+ * </code>
+ *
+ * Here's an example of how to create signatures and verify signatures with this library:
+ * <code>
+ * <?php
+ *    include('Crypt/RSA.php');
+ *
+ *    $rsa = new Crypt_RSA();
+ *    extract($rsa->createKey());
+ *
+ *    $plaintext = 'terrafrost';
+ *
+ *    $rsa->loadKey($privatekey);
+ *    $signature = $rsa->sign($plaintext);
+ *
+ *    $rsa->loadKey($publickey);
+ *    echo $rsa->verify($plaintext, $signature) ? 'verified' : 'unverified';
+ * ?>
+ * </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_RSA
+ * @author     Jim Wigginton <terrafrost@php.net>
+ * @copyright  MMIX Jim Wigginton
+ * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @version    $Id: RSA.php,v 1.19 2010/09/12 21:58:54 terrafrost Exp $
+ * @link       http://phpseclib.sourceforge.net
+ */
+
+/**
+ * Include Math_BigInteger
+ */
+if (!class_exists('Math_BigInteger')) {
+    require_once('Math/BigInteger.php');
+}
+
+/**
+ * Include Crypt_Random
+ */
+// the class_exists() will only be called if the crypt_random function hasn't been defined and
+// will trigger a call to __autoload() if you're wanting to auto-load classes
+// call function_exists() a second time to stop the require_once from being called outside
+// of the auto loader
+if (!function_exists('crypt_random') && !class_exists('Crypt_Random') && !function_exists('crypt_random')) {
+    require_once('Crypt/Random.php');
+}
+
+/**
+ * Include Crypt_Hash
+ */
+if (!class_exists('Crypt_Hash')) {
+    require_once('Crypt/Hash.php');
+}
+
+/**#@+
+ * @access public
+ * @see Crypt_RSA::encrypt()
+ * @see Crypt_RSA::decrypt()
+ */
+/**
+ * Use {@link http://en.wikipedia.org/wiki/Optimal_Asymmetric_Encryption_Padding Optimal Asymmetric Encryption Padding}
+ * (OAEP) for encryption / decryption.
+ *
+ * Uses sha1 by default.
+ *
+ * @see Crypt_RSA::setHash()
+ * @see Crypt_RSA::setMGFHash()
+ */
+define('CRYPT_RSA_ENCRYPTION_OAEP',  1);
+/**
+ * Use PKCS#1 padding.
+ *
+ * Although CRYPT_RSA_ENCRYPTION_OAEP offers more security, including PKCS#1 padding is necessary for purposes of backwards
+ * compatability with protocols (like SSH-1) written before OAEP's introduction.
+ */
+define('CRYPT_RSA_ENCRYPTION_PKCS1', 2);
+/**#@-*/
+
+/**#@+
+ * @access public
+ * @see Crypt_RSA::sign()
+ * @see Crypt_RSA::verify()
+ * @see Crypt_RSA::setHash()
+ */
+/**
+ * Use the Probabilistic Signature Scheme for signing
+ *
+ * Uses sha1 by default.
+ *
+ * @see Crypt_RSA::setSaltLength()
+ * @see Crypt_RSA::setMGFHash()
+ */
+define('CRYPT_RSA_SIGNATURE_PSS',  1);
+/**
+ * Use the PKCS#1 scheme by default.
+ *
+ * Although CRYPT_RSA_SIGNATURE_PSS offers more security, including PKCS#1 signing is necessary for purposes of backwards
+ * compatability with protocols (like SSH-2) written before PSS's introduction.
+ */
+define('CRYPT_RSA_SIGNATURE_PKCS1', 2);
+/**#@-*/
+
+/**#@+
+ * @access private
+ * @see Crypt_RSA::createKey()
+ */
+/**
+ * ASN1 Integer
+ */
+define('CRYPT_RSA_ASN1_INTEGER',   2);
+/**
+ * ASN1 Bit String
+ */
+define('CRYPT_RSA_ASN1_BITSTRING', 3); 
+/**
+ * ASN1 Sequence (with the constucted bit set)
+ */
+define('CRYPT_RSA_ASN1_SEQUENCE', 48);
+/**#@-*/
+
+/**#@+
+ * @access private
+ * @see Crypt_RSA::Crypt_RSA()
+ */
+/**
+ * To use the pure-PHP implementation
+ */
+define('CRYPT_RSA_MODE_INTERNAL', 1);
+/**
+ * To use the OpenSSL library
+ *
+ * (if enabled; otherwise, the internal implementation will be used)
+ */
+define('CRYPT_RSA_MODE_OPENSSL', 2);
+/**#@-*/
+
+/**#@+
+ * @access public
+ * @see Crypt_RSA::createKey()
+ * @see Crypt_RSA::setPrivateKeyFormat()
+ */
+/**
+ * PKCS#1 formatted private key
+ *
+ * Used by OpenSSH
+ */
+define('CRYPT_RSA_PRIVATE_FORMAT_PKCS1', 0);
+/**
+ * PuTTY formatted private key
+ */
+define('CRYPT_RSA_PRIVATE_FORMAT_PUTTY', 1);
+/**
+ * XML formatted private key
+ */
+define('CRYPT_RSA_PRIVATE_FORMAT_XML', 2);
+/**#@-*/
+
+/**#@+
+ * @access public
+ * @see Crypt_RSA::createKey()
+ * @see Crypt_RSA::setPublicKeyFormat()
+ */
+/**
+ * Raw public key
+ *
+ * An array containing two Math_BigInteger objects.
+ *
+ * The exponent can be indexed with any of the following:
+ *
+ * 0, e, exponent, publicExponent
+ *
+ * The modulus can be indexed with any of the following:
+ *
+ * 1, n, modulo, modulus
+ */
+define('CRYPT_RSA_PUBLIC_FORMAT_RAW', 3);
+/**
+ * PKCS#1 formatted public key (raw)
+ *
+ * Used by File/X509.php
+ */
+define('CRYPT_RSA_PUBLIC_FORMAT_PKCS1_RAW', 4);
+/**
+ * XML formatted public key
+ */
+define('CRYPT_RSA_PUBLIC_FORMAT_XML', 5);
+/**
+ * OpenSSH formatted public key
+ *
+ * Place in $HOME/.ssh/authorized_keys
+ */
+define('CRYPT_RSA_PUBLIC_FORMAT_OPENSSH', 6);
+/**
+ * PKCS#1 formatted public key (encapsulated)
+ *
+ * Used by PHP's openssl_public_encrypt() and openssl's rsautl (when -pubin is set)
+ */
+define('CRYPT_RSA_PUBLIC_FORMAT_PKCS1', 7);
+/**#@-*/
+
+/**
+ * Pure-PHP PKCS#1 compliant implementation of RSA.
+ *
+ * @author  Jim Wigginton <terrafrost@php.net>
+ * @version 0.1.0
+ * @access  public
+ * @package Crypt_RSA
+ */
+class Crypt_RSA {
+    /**
+     * Precomputed Zero
+     *
+     * @var Array
+     * @access private
+     */
+    var $zero;
+
+    /**
+     * Precomputed One
+     *
+     * @var Array
+     * @access private
+     */
+    var $one;
+
+    /**
+     * Private Key Format
+     *
+     * @var Integer
+     * @access private
+     */
+    var $privateKeyFormat = CRYPT_RSA_PRIVATE_FORMAT_PKCS1;
+
+    /**
+     * Public Key Format
+     *
+     * @var Integer
+     * @access public
+     */
+    var $publicKeyFormat = CRYPT_RSA_PUBLIC_FORMAT_PKCS1;
+
+    /**
+     * Modulus (ie. n)
+     *
+     * @var Math_BigInteger
+     * @access private
+     */
+    var $modulus;
+
+    /**
+     * Modulus length
+     *
+     * @var Math_BigInteger
+     * @access private
+     */
+    var $k;
+
+    /**
+     * Exponent (ie. e or d)
+     *
+     * @var Math_BigInteger
+     * @access private
+     */
+    var $exponent;
+
+    /**
+     * Primes for Chinese Remainder Theorem (ie. p and q)
+     *
+     * @var Array
+     * @access private
+     */
+    var $primes;
+
+    /**
+     * Exponents for Chinese Remainder Theorem (ie. dP and dQ)
+     *
+     * @var Array
+     * @access private
+     */
+    var $exponents;
+
+    /**
+     * Coefficients for Chinese Remainder Theorem (ie. qInv)
+     *
+     * @var Array
+     * @access private
+     */
+    var $coefficients;
+
+    /**
+     * Hash name
+     *
+     * @var String
+     * @access private
+     */
+    var $hashName;
+
+    /**
+     * Hash function
+     *
+     * @var Crypt_Hash
+     * @access private
+     */
+    var $hash;
+
+    /**
+     * Length of hash function output
+     *
+     * @var Integer
+     * @access private
+     */
+    var $hLen;
+
+    /**
+     * Length of salt
+     *
+     * @var Integer
+     * @access private
+     */
+    var $sLen;
+
+    /**
+     * Hash function for the Mask Generation Function
+     *
+     * @var Crypt_Hash
+     * @access private
+     */
+    var $mgfHash;
+
+    /**
+     * Length of MGF hash function output
+     *
+     * @var Integer
+     * @access private
+     */
+    var $mgfHLen;
+
+    /**
+     * Encryption mode
+     *
+     * @var Integer
+     * @access private
+     */
+    var $encryptionMode = CRYPT_RSA_ENCRYPTION_OAEP;
+
+    /**
+     * Signature mode
+     *
+     * @var Integer
+     * @access private
+     */
+    var $signatureMode = CRYPT_RSA_SIGNATURE_PSS;
+
+    /**
+     * Public Exponent
+     *
+     * @var Mixed
+     * @access private
+     */
+    var $publicExponent = false;
+
+    /**
+     * Password
+     *
+     * @var String
+     * @access private
+     */
+    var $password = false;
+
+    /**
+     * Components
+     *
+     * For use with parsing XML formatted keys.  PHP's XML Parser functions use utilized - instead of PHP's DOM functions -
+     * because PHP's XML Parser functions work on PHP4 whereas PHP's DOM functions - although surperior - don't.
+     *
+     * @see Crypt_RSA::_start_element_handler()
+     * @var Array
+     * @access private
+     */
+    var $components = array();
+
+    /**
+     * Current String
+     *
+     * For use with parsing XML formatted keys.
+     *
+     * @see Crypt_RSA::_character_handler()
+     * @see Crypt_RSA::_stop_element_handler()
+     * @var Mixed
+     * @access private
+     */
+    var $current;
+
+    /**
+     * The constructor
+     *
+     * If you want to make use of the openssl extension, you'll need to set the mode manually, yourself.  The reason
+     * Crypt_RSA doesn't do it is because OpenSSL doesn't fail gracefully.  openssl_pkey_new(), in particular, requires
+     * openssl.cnf be present somewhere and, unfortunately, the only real way to find out is too late.
+     *
+     * @return Crypt_RSA
+     * @access public
+     */
+    function Crypt_RSA()
+    {
+        if ( !defined('CRYPT_RSA_MODE') ) {
+            switch (true) {
+                case extension_loaded('openssl') && version_compare(PHP_VERSION, '4.2.0', '>='):
+                    define('CRYPT_RSA_MODE', CRYPT_RSA_MODE_OPENSSL);
+                    break;
+                default:
+                    define('CRYPT_RSA_MODE', CRYPT_RSA_MODE_INTERNAL);
+            }
+        }
+
+        if (!defined('CRYPT_RSA_COMMENT')) {
+            define('CRYPT_RSA_COMMENT', 'phpseclib-generated-key');
+        }
+
+        $this->zero = new Math_BigInteger();
+        $this->one = new Math_BigInteger(1);
+
+        $this->hash = new Crypt_Hash('sha1');
+        $this->hLen = $this->hash->getLength();
+        $this->hashName = 'sha1';
+        $this->mgfHash = new Crypt_Hash('sha1');
+        $this->mgfHLen = $this->mgfHash->getLength();
+    }
+
+    /**
+     * Create public / private key pair
+     *
+     * Returns an array with the following three elements:
+     *  - 'privatekey': The private key.
+     *  - 'publickey':  The public key.
+     *  - 'partialkey': A partially computed key (if the execution time exceeded $timeout).
+     *                  Will need to be passed back to Crypt_RSA::createKey() as the third parameter for further processing.
+     *
+     * @access public
+     * @param optional Integer $bits
+     * @param optional Integer $timeout
+     * @param optional Math_BigInteger $p
+     */
+    function createKey($bits = 1024, $timeout = false, $partial = array())
+    {
+        if (!defined('CRYPT_RSA_EXPONENT')) {
+            // http://en.wikipedia.org/wiki/65537_%28number%29
+            define('CRYPT_RSA_EXPONENT', '65537');
+        }
+        // per <http://cseweb.ucsd.edu/~hovav/dist/survey.pdf#page=5>, this number ought not result in primes smaller
+        // than 256 bits. as a consequence if the key you're trying to create is 1024 bits and you've set CRYPT_RSA_SMALLEST_PRIME
+        // to 384 bits then you're going to get a 384 bit prime and a 640 bit prime (384 + 1024 % 384). at least if
+        // CRYPT_RSA_MODE is set to CRYPT_RSA_MODE_INTERNAL. if CRYPT_RSA_MODE is set to CRYPT_RSA_MODE_OPENSSL then
+        // CRYPT_RSA_SMALLEST_PRIME is ignored (ie. multi-prime RSA support is more intended as a way to speed up RSA key
+        // generation when there's a chance neither gmp nor OpenSSL are installed)
+        if (!defined('CRYPT_RSA_SMALLEST_PRIME')) {
+            define('CRYPT_RSA_SMALLEST_PRIME', 4096);
+        }
+
+        // OpenSSL uses 65537 as the exponent and requires RSA keys be 384 bits minimum
+        if ( CRYPT_RSA_MODE == CRYPT_RSA_MODE_OPENSSL && $bits >= 384 && CRYPT_RSA_EXPONENT == 65537) {
+            $rsa = openssl_pkey_new(array(
+                'private_key_bits' => $bits,
+                'config' => dirname(__FILE__) . '/../openssl.cnf'
+            ));
+
+            openssl_pkey_export($rsa, $privatekey, NULL, array('config' => dirname(__FILE__) . '/../openssl.cnf'));
+            $publickey = openssl_pkey_get_details($rsa);
+            $publickey = $publickey['key'];
+
+            $privatekey = call_user_func_array(array($this, '_convertPrivateKey'), array_values($this->_parseKey($privatekey, CRYPT_RSA_PRIVATE_FORMAT_PKCS1)));
+            $publickey = call_user_func_array(array($this, '_convertPublicKey'), array_values($this->_parseKey($publickey, CRYPT_RSA_PUBLIC_FORMAT_PKCS1)));
+
+            // clear the buffer of error strings stemming from a minimalistic openssl.cnf
+            while (openssl_error_string() !== false);
+
+            return array(
+                'privatekey' => $privatekey,
+                'publickey' => $publickey,
+                'partialkey' => false
+            );
+        }
+
+        static $e;
+        if (!isset($e)) {
+            $e = new Math_BigInteger(CRYPT_RSA_EXPONENT);
+        }
+
+        extract($this->_generateMinMax($bits));
+        $absoluteMin = $min;
+        $temp = $bits >> 1; // divide by two to see how many bits P and Q would be
+        if ($temp > CRYPT_RSA_SMALLEST_PRIME) {
+            $num_primes = floor($bits / CRYPT_RSA_SMALLEST_PRIME);
+            $temp = CRYPT_RSA_SMALLEST_PRIME;
+        } else {
+            $num_primes = 2;
+        }
+        extract($this->_generateMinMax($temp + $bits % $temp));
+        $finalMax = $max;
+        extract($this->_generateMinMax($temp));
+
+        $generator = new Math_BigInteger();
+        $generator->setRandomGenerator('crypt_random');
+
+        $n = $this->one->copy();
+        if (!empty($partial)) {
+            extract(unserialize($partial));
+        } else {
+            $exponents = $coefficients = $primes = array();
+            $lcm = array(
+                'top' => $this->one->copy(),
+                'bottom' => false
+            );
+        }
+
+        $start = time();
+        $i0 = count($primes) + 1;
+
+        do {
+            for ($i = $i0; $i <= $num_primes; $i++) {
+                if ($timeout !== false) {
+                    $timeout-= time() - $start;
+                    $start = time();
+                    if ($timeout <= 0) {
+                        return array(
+                            'privatekey' => '',
+                            'publickey'  => '',
+                            'partialkey' => serialize(array(
+                                'primes' => $primes,
+                                'coefficients' => $coefficients,
+                                'lcm' => $lcm,
+                                'exponents' => $exponents
+                            ))
+                        );
+                    }
+                }
+
+                if ($i == $num_primes) {
+                    list($min, $temp) = $absoluteMin->divide($n);
+                    if (!$temp->equals($this->zero)) {
+                        $min = $min->add($this->one); // ie. ceil()
+                    }
+                    $primes[$i] = $generator->randomPrime($min, $finalMax, $timeout);
+                } else {
+                    $primes[$i] = $generator->randomPrime($min, $max, $timeout);
+                }
+
+                if ($primes[$i] === false) { // if we've reached the timeout
+                    if (count($primes) > 1) {
+                        $partialkey = '';
+                    } else {
+                        array_pop($primes);
+                        $partialkey = serialize(array(
+                            'primes' => $primes,
+                            'coefficients' => $coefficients,
+                            'lcm' => $lcm,
+                            'exponents' => $exponents
+                        ));
+                    }
+
+                    return array(
+                        'privatekey' => '',
+                        'publickey'  => '',
+                        'partialkey' => $partialkey
+                    );
+                }
+
+                // the first coefficient is calculated differently from the rest
+                // ie. instead of being $primes[1]->modInverse($primes[2]), it's $primes[2]->modInverse($primes[1])
+                if ($i > 2) {
+                    $coefficients[$i] = $n->modInverse($primes[$i]);
+                }
+
+                $n = $n->multiply($primes[$i]);
+
+                $temp = $primes[$i]->subtract($this->one);
+
+                // textbook RSA implementations use Euler's totient function instead of the least common multiple.
+                // see http://en.wikipedia.org/wiki/Euler%27s_totient_function
+                $lcm['top'] = $lcm['top']->multiply($temp);
+                $lcm['bottom'] = $lcm['bottom'] === false ? $temp : $lcm['bottom']->gcd($temp);
+
+                $exponents[$i] = $e->modInverse($temp);
+            }
+
+            list($lcm) = $lcm['top']->divide($lcm['bottom']);
+            $gcd = $lcm->gcd($e);
+            $i0 = 1;
+        } while (!$gcd->equals($this->one));
+
+        $d = $e->modInverse($lcm);
+
+        $coefficients[2] = $primes[2]->modInverse($primes[1]);
+
+        // from <http://tools.ietf.org/html/rfc3447#appendix-A.1.2>:
+        // RSAPrivateKey ::= SEQUENCE {
+        //     version           Version,
+        //     modulus           INTEGER,  -- n
+        //     publicExponent    INTEGER,  -- e
+        //     privateExponent   INTEGER,  -- d
+        //     prime1            INTEGER,  -- p
+        //     prime2            INTEGER,  -- q
+        //     exponent1         INTEGER,  -- d mod (p-1)
+        //     exponent2         INTEGER,  -- d mod (q-1)
+        //     coefficient       INTEGER,  -- (inverse of q) mod p
+        //     otherPrimeInfos   OtherPrimeInfos OPTIONAL
+        // }
+
+        return array(
+            'privatekey' => $this->_convertPrivateKey($n, $e, $d, $primes, $exponents, $coefficients),
+            'publickey'  => $this->_convertPublicKey($n, $e),
+            'partialkey' => false
+        );
+    }
+
+    /**
+     * Convert a private key to the appropriate format.
+     *
+     * @access private
+     * @see setPrivateKeyFormat()
+     * @param String $RSAPrivateKey
+     * @return String
+     */
+    function _convertPrivateKey($n, $e, $d, $primes, $exponents, $coefficients)
+    {
+        $num_primes = count($primes);
+        $raw = array(
+            'version' => $num_primes == 2 ? chr(0) : chr(1), // two-prime vs. multi
+            'modulus' => $n->toBytes(true),
+            'publicExponent' => $e->toBytes(true),
+            'privateExponent' => $d->toBytes(true),
+            'prime1' => $primes[1]->toBytes(true),
+            'prime2' => $primes[2]->toBytes(true),
+            'exponent1' => $exponents[1]->toBytes(true),
+            'exponent2' => $exponents[2]->toBytes(true),
+            'coefficient' => $coefficients[2]->toBytes(true)
+        );
+
+        // if the format in question does not support multi-prime rsa and multi-prime rsa was used,
+        // call _convertPublicKey() instead.
+        switch ($this->privateKeyFormat) {
+            case CRYPT_RSA_PRIVATE_FORMAT_XML:
+                if ($num_primes != 2) {
+                    return false;
+                }
+                return "<RSAKeyValue>\r\n" .
+                       '  <Modulus>' . base64_encode($raw['modulus']) . "</Modulus>\r\n" .
+                       '  <Exponent>' . base64_encode($raw['publicExponent']) . "</Exponent>\r\n" .
+                       '  <P>' . base64_encode($raw['prime1']) . "</P>\r\n" .
+                       '  <Q>' . base64_encode($raw['prime2']) . "</Q>\r\n" .
+                       '  <DP>' . base64_encode($raw['exponent1']) . "</DP>\r\n" .
+                       '  <DQ>' . base64_encode($raw['exponent2']) . "</DQ>\r\n" .
+                       '  <InverseQ>' . base64_encode($raw['coefficient']) . "</InverseQ>\r\n" .
+                       '  <D>' . base64_encode($raw['privateExponent']) . "</D>\r\n" .
+                       '</RSAKeyValue>';
+                break;
+            case CRYPT_RSA_PRIVATE_FORMAT_PUTTY:
+                if ($num_primes != 2) {
+                    return false;
+                }
+                $key = "PuTTY-User-Key-File-2: ssh-rsa\r\nEncryption: ";
+                $encryption = (!empty($this->password) || is_string($this->password)) ? 'aes256-cbc' : 'none';
+                $key.= $encryption;
+                $key.= "\r\nComment: " . CRYPT_RSA_COMMENT . "\r\n";
+                $public = pack('Na*Na*Na*',
+                    strlen('ssh-rsa'), 'ssh-rsa', strlen($raw['publicExponent']), $raw['publicExponent'], strlen($raw['modulus']), $raw['modulus']
+                );
+                $source = pack('Na*Na*Na*Na*',
+                              strlen('ssh-rsa'), 'ssh-rsa', strlen($encryption), $encryption,
+                              strlen(CRYPT_RSA_COMMENT), CRYPT_RSA_COMMENT, strlen($public), $public
+                );
+                $public = base64_encode($public);
+                $key.= "Public-Lines: " . ((strlen($public) + 32) >> 6) . "\r\n";
+                $key.= chunk_split($public, 64);
+                $private = pack('Na*Na*Na*Na*',
+                    strlen($raw['privateExponent']), $raw['privateExponent'], strlen($raw['prime1']), $raw['prime1'],
+                    strlen($raw['prime2']), $raw['prime2'], strlen($raw['coefficient']), $raw['coefficient']
+                );
+                if (empty($this->password) && !is_string($this->password)) {
+                    $source.= pack('Na*', strlen($private), $private);
+                    $hashkey = 'putty-private-key-file-mac-key';
+                } else {
+                    $private.= $this->_random(16 - (strlen($private) & 15));
+                    $source.= pack('Na*', strlen($private), $private);
+                    if (!class_exists('Crypt_AES')) {
+                        require_once('Crypt/AES.php');
+                    }
+                    $sequence = 0;
+                    $symkey = '';
+                    while (strlen($symkey) < 32) {
+                        $temp = pack('Na*', $sequence++, $this->password);
+                        $symkey.= pack('H*', sha1($temp));
+                    }
+                    $symkey = substr($symkey, 0, 32);
+                    $crypto = new Crypt_AES();
+
+                    $crypto->setKey($symkey);
+                    $crypto->disablePadding();
+                    $private = $crypto->encrypt($private);
+                    $hashkey = 'putty-private-key-file-mac-key' . $this->password;
+                }
+
+                $private = base64_encode($private);
+                $key.= 'Private-Lines: ' . ((strlen($private) + 32) >> 6) . "\r\n";
+                $key.= chunk_split($private, 64);
+                if (!class_exists('Crypt_Hash')) {
+                    require_once('Crypt/Hash.php');
+                }
+                $hash = new Crypt_Hash('sha1');
+                $hash->setKey(pack('H*', sha1($hashkey)));
+                $key.= 'Private-MAC: ' . bin2hex($hash->hash($source)) . "\r\n";
+
+                return $key;
+            default: // eg. CRYPT_RSA_PRIVATE_FORMAT_PKCS1
+                $components = array();
+                foreach ($raw as $name => $value) {
+                    $components[$name] = pack('Ca*a*', CRYPT_RSA_ASN1_INTEGER, $this->_encodeLength(strlen($value)), $value);
+                }
+
+                $RSAPrivateKey = implode('', $components);
+
+                if ($num_primes > 2) {
+                    $OtherPrimeInfos = '';
+                    for ($i = 3; $i <= $num_primes; $i++) {
+                        // OtherPrimeInfos ::= SEQUENCE SIZE(1..MAX) OF OtherPrimeInfo
+                        //
+                        // OtherPrimeInfo ::= SEQUENCE {
+                        //     prime             INTEGER,  -- ri
+                        //     exponent          INTEGER,  -- di
+                        //     coefficient       INTEGER   -- ti
+                        // }
+                        $OtherPrimeInfo = pack('Ca*a*', CRYPT_RSA_ASN1_INTEGER, $this->_encodeLength(strlen($primes[$i]->toBytes(true))), $primes[$i]->toBytes(true));
+                        $OtherPrimeInfo.= pack('Ca*a*', CRYPT_RSA_ASN1_INTEGER, $this->_encodeLength(strlen($exponents[$i]->toBytes(true))), $exponents[$i]->toBytes(true));
+                        $OtherPrimeInfo.= pack('Ca*a*', CRYPT_RSA_ASN1_INTEGER, $this->_encodeLength(strlen($coefficients[$i]->toBytes(true))), $coefficients[$i]->toBytes(true));
+                        $OtherPrimeInfos.= pack('Ca*a*', CRYPT_RSA_ASN1_SEQUENCE, $this->_encodeLength(strlen($OtherPrimeInfo)), $OtherPrimeInfo);
+                    }
+                    $RSAPrivateKey.= pack('Ca*a*', CRYPT_RSA_ASN1_SEQUENCE, $this->_encodeLength(strlen($OtherPrimeInfos)), $OtherPrimeInfos);
+                }
+
+                $RSAPrivateKey = pack('Ca*a*', CRYPT_RSA_ASN1_SEQUENCE, $this->_encodeLength(strlen($RSAPrivateKey)), $RSAPrivateKey);
+
+                if (!empty($this->password) || is_string($this->password)) {
+                    $iv = $this->_random(8);
+                    $symkey = pack('H*', md5($this->password . $iv)); // symkey is short for symmetric key
+                    $symkey.= substr(pack('H*', md5($symkey . $this->password . $iv)), 0, 8);
+                    if (!class_exists('Crypt_TripleDES')) {
+                        require_once('Crypt/TripleDES.php');
+                    }
+                    $des = new Crypt_TripleDES();
+                    $des->setKey($symkey);
+                    $des->setIV($iv);
+                    $iv = strtoupper(bin2hex($iv));
+                    $RSAPrivateKey = "-----BEGIN RSA PRIVATE KEY-----\r\n" .
+                                     "Proc-Type: 4,ENCRYPTED\r\n" .
+                                     "DEK-Info: DES-EDE3-CBC,$iv\r\n" .
+                                     "\r\n" .
+                                     chunk_split(base64_encode($des->encrypt($RSAPrivateKey))) .
+                                     '-----END RSA PRIVATE KEY-----';
+                } else {
+                    $RSAPrivateKey = "-----BEGIN RSA PRIVATE KEY-----\r\n" .
+                                     chunk_split(base64_encode($RSAPrivateKey)) .
+                                     '-----END RSA PRIVATE KEY-----';
+                }
+
+                return $RSAPrivateKey;
+        }
+    }
+
+    /**
+     * Convert a public key to the appropriate format
+     *
+     * @access private
+     * @see setPublicKeyFormat()
+     * @param String $RSAPrivateKey
+     * @return String
+     */
+    function _convertPublicKey($n, $e)
+    {
+        $modulus = $n->toBytes(true);
+        $publicExponent = $e->toBytes(true);
+
+        switch ($this->publicKeyFormat) {
+            case CRYPT_RSA_PUBLIC_FORMAT_RAW:
+                return array('e' => $e->copy(), 'n' => $n->copy());
+            case CRYPT_RSA_PUBLIC_FORMAT_XML:
+                return "<RSAKeyValue>\r\n" .
+                       '  <Modulus>' . base64_encode($modulus) . "</Modulus>\r\n" .
+                       '  <Exponent>' . base64_encode($publicExponent) . "</Exponent>\r\n" .
+                       '</RSAKeyValue>';
+                break;
+            case CRYPT_RSA_PUBLIC_FORMAT_OPENSSH:
+                // from <http://tools.ietf.org/html/rfc4253#page-15>:
+                // string    "ssh-rsa"
+                // mpint     e
+                // mpint     n
+                $RSAPublicKey = pack('Na*Na*Na*', strlen('ssh-rsa'), 'ssh-rsa', strlen($publicExponent), $publicExponent, strlen($modulus), $modulus);
+                $RSAPublicKey = 'ssh-rsa ' . base64_encode($RSAPublicKey) . ' ' . CRYPT_RSA_COMMENT;
+
+                return $RSAPublicKey;
+            default: // eg. CRYPT_RSA_PUBLIC_FORMAT_PKCS1_RAW or CRYPT_RSA_PUBLIC_FORMAT_PKCS1
+                // from <http://tools.ietf.org/html/rfc3447#appendix-A.1.1>:
+                // RSAPublicKey ::= SEQUENCE {
+                //     modulus           INTEGER,  -- n
+                //     publicExponent    INTEGER   -- e
+                // }
+                $components = array(
+                    'modulus' => pack('Ca*a*', CRYPT_RSA_ASN1_INTEGER, $this->_encodeLength(strlen($modulus)), $modulus),
+                    'publicExponent' => pack('Ca*a*', CRYPT_RSA_ASN1_INTEGER, $this->_encodeLength(strlen($publicExponent)), $publicExponent)
+                );
+
+                $RSAPublicKey = pack('Ca*a*a*',
+                    CRYPT_RSA_ASN1_SEQUENCE, $this->_encodeLength(strlen($components['modulus']) + strlen($components['publicExponent'])),
+                    $components['modulus'], $components['publicExponent']
+                );
+
+                if ($this->publicKeyFormat == CRYPT_RSA_PUBLIC_FORMAT_PKCS1) {
+                    // sequence(oid(1.2.840.113549.1.1.1), null)) = rsaEncryption.
+                    $rsaOID = pack('H*', '300d06092a864886f70d0101010500'); // hex version of MA0GCSqGSIb3DQEBAQUA
+                    $RSAPublicKey = chr(0) . $RSAPublicKey;
+                    $RSAPublicKey = chr(3) . $this->_encodeLength(strlen($RSAPublicKey)) . $RSAPublicKey;
+
+                    $RSAPublicKey = pack('Ca*a*',
+                        CRYPT_RSA_ASN1_SEQUENCE, $this->_encodeLength(strlen($rsaOID . $RSAPublicKey)), $rsaOID . $RSAPublicKey
+                    );
+                }
+
+                $RSAPublicKey = "-----BEGIN PUBLIC KEY-----\r\n" .
+                                 chunk_split(base64_encode($RSAPublicKey)) .
+                                 '-----END PUBLIC KEY-----';
+
+                return $RSAPublicKey;
+        }
+    }
+
+    /**
+     * Break a public or private key down into its constituant components
+     *
+     * @access private
+     * @see _convertPublicKey()
+     * @see _convertPrivateKey()
+     * @param String $key
+     * @param Integer $type
+     * @return Array
+     */
+    function _parseKey($key, $type)
+    {
+        if ($type != CRYPT_RSA_PUBLIC_FORMAT_RAW && !is_string($key)) {
+            return false;
+        }
+
+        switch ($type) {
+            case CRYPT_RSA_PUBLIC_FORMAT_RAW:
+                if (!is_array($key)) {
+                    return false;
+                }
+                $components = array();
+                switch (true) {
+                    case isset($key['e']):
+                        $components['publicExponent'] = $key['e']->copy();
+                        break;
+                    case isset($key['exponent']):
+                        $components['publicExponent'] = $key['exponent']->copy();
+                        break;
+                    case isset($key['publicExponent']):
+                        $components['publicExponent'] = $key['publicExponent']->copy();
+                        break;
+                    case isset($key[0]):
+                        $components['publicExponent'] = $key[0]->copy();
+                }
+                switch (true) {
+                    case isset($key['n']):
+                        $components['modulus'] = $key['n']->copy();
+                        break;
+                    case isset($key['modulo']):
+                        $components['modulus'] = $key['modulo']->copy();
+                        break;
+                    case isset($key['modulus']):
+                        $components['modulus'] = $key['modulus']->copy();
+                        break;
+                    case isset($key[1]):
+                        $components['modulus'] = $key[1]->copy();
+                }
+                return isset($components['modulus']) && isset($components['publicExponent']) ? $components : false;
+            case CRYPT_RSA_PRIVATE_FORMAT_PKCS1:
+            case CRYPT_RSA_PUBLIC_FORMAT_PKCS1:
+                /* Although PKCS#1 proposes a format that public and private keys can use, encrypting them is
+                   "outside the scope" of PKCS#1.  PKCS#1 then refers you to PKCS#12 and PKCS#15 if you're wanting to
+                   protect private keys, however, that's not what OpenSSL* does.  OpenSSL protects private keys by adding
+                   two new "fields" to the key - DEK-Info and Proc-Type.  These fields are discussed here:
+
+                   http://tools.ietf.org/html/rfc1421#section-4.6.1.1
+                   http://tools.ietf.org/html/rfc1421#section-4.6.1.3
+
+                   DES-EDE3-CBC as an algorithm, however, is not discussed anywhere, near as I can tell.
+                   DES-CBC and DES-EDE are discussed in RFC1423, however, DES-EDE3-CBC isn't, nor is its key derivation
+                   function.  As is, the definitive authority on this encoding scheme isn't the IETF but rather OpenSSL's
+                   own implementation.  ie. the implementation *is* the standard and any bugs that may exist in that 
+                   implementation are part of the standard, as well.
+
+                   * OpenSSL is the de facto standard.  It's utilized by OpenSSH and other projects */
+                if (preg_match('#DEK-Info: (.+),(.+)#', $key, $matches)) {
+                    $iv = pack('H*', trim($matches[2]));
+                    $symkey = pack('H*', md5($this->password . substr($iv, 0, 8))); // symkey is short for symmetric key
+                    $symkey.= substr(pack('H*', md5($symkey . $this->password . $iv)), 0, 8);
+                    $ciphertext = preg_replace('#.+(\r|\n|\r\n)\1|[\r\n]|-.+-| #s', '', $key);
+                    $ciphertext = preg_match('#^[a-zA-Z\d/+]*={0,2}$#', $ciphertext) ? base64_decode($ciphertext) : false;
+                    if ($ciphertext === false) {
+                        $ciphertext = $key;
+                    }
+                    switch ($matches[1]) {
+                        case 'AES-128-CBC':
+                            if (!class_exists('Crypt_AES')) {
+                                require_once('Crypt/AES.php');
+                            }
+                            $symkey = substr($symkey, 0, 16);
+                            $crypto = new Crypt_AES();
+                            break;
+                        case 'DES-EDE3-CFB':
+                            if (!class_exists('Crypt_TripleDES')) {
+                                require_once('Crypt/TripleDES.php');
+                            }
+                            $crypto = new Crypt_TripleDES(CRYPT_DES_MODE_CFB);
+                            break;
+                        case 'DES-EDE3-CBC':
+                            if (!class_exists('Crypt_TripleDES')) {
+                                require_once('Crypt/TripleDES.php');
+                            }
+                            $crypto = new Crypt_TripleDES();
+                            break;
+                        case 'DES-CBC':
+                            if (!class_exists('Crypt_DES')) {
+                                require_once('Crypt/DES.php');
+                            }
+                            $crypto = new Crypt_DES();
+                            break;
+                        default:
+                            return false;
+                    }
+                    $crypto->setKey($symkey);
+                    $crypto->setIV($iv);
+                    $decoded = $crypto->decrypt($ciphertext);
+                } else {
+                    $decoded = preg_replace('#-.+-|[\r\n]| #', '', $key);
+                    $decoded = preg_match('#^[a-zA-Z\d/+]*={0,2}$#', $decoded) ? base64_decode($decoded) : false;
+                }
+
+                if ($decoded !== false) {
+                    $key = $decoded;
+                }
+
+                $components = array();
+
+                if (ord($this->_string_shift($key)) != CRYPT_RSA_ASN1_SEQUENCE) {
+                    return false;
+                }
+                if ($this->_decodeLength($key) != strlen($key)) {
+                    return false;
+                }
+
+                $tag = ord($this->_string_shift($key));
+                /* intended for keys for which OpenSSL's asn1parse returns the following:
+
+                    0:d=0  hl=4 l= 631 cons: SEQUENCE
+                    4:d=1  hl=2 l=   1 prim:  INTEGER           :00
+                    7:d=1  hl=2 l=  13 cons:  SEQUENCE
+                    9:d=2  hl=2 l=   9 prim:   OBJECT            :rsaEncryption
+                   20:d=2  hl=2 l=   0 prim:   NULL
+                   22:d=1  hl=4 l= 609 prim:  OCTET STRING */
+
+                if ($tag == CRYPT_RSA_ASN1_INTEGER && substr($key, 0, 3) == "\x01\x00\x30") {
+                    $this->_string_shift($key, 3);
+                    $tag = CRYPT_RSA_ASN1_SEQUENCE;
+                }
+
+                if ($tag == CRYPT_RSA_ASN1_SEQUENCE) {
+                    /* intended for keys for which OpenSSL's asn1parse returns the following:
+
+                        0:d=0  hl=4 l= 290 cons: SEQUENCE
+                        4:d=1  hl=2 l=  13 cons:  SEQUENCE
+                        6:d=2  hl=2 l=   9 prim:   OBJECT            :rsaEncryption
+                       17:d=2  hl=2 l=   0 prim:   NULL
+                       19:d=1  hl=4 l= 271 prim:  BIT STRING */
+                    $this->_string_shift($key, $this->_decodeLength($key));
+                    $tag = ord($this->_string_shift($key)); // skip over the BIT STRING / OCTET STRING tag
+                    $this->_decodeLength($key); // skip over the BIT STRING / OCTET STRING length
+                    // "The initial octet shall encode, as an unsigned binary integer wtih bit 1 as the least significant bit, the number of
+                    //  unused bits in the final subsequent octet. The number shall be in the range zero to seven."
+                    //  -- http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf (section 8.6.2.2)
+                    if ($tag == CRYPT_RSA_ASN1_BITSTRING) {
+                        $this->_string_shift($key);
+                    }
+                    if (ord($this->_string_shift($key)) != CRYPT_RSA_ASN1_SEQUENCE) {
+                        return false;
+                    }
+                    if ($this->_decodeLength($key) != strlen($key)) {
+                        return false;
+                    }
+                    $tag = ord($this->_string_shift($key));
+                }
+                if ($tag != CRYPT_RSA_ASN1_INTEGER) {
+                    return false;
+                }
+
+                $length = $this->_decodeLength($key);
+                $temp = $this->_string_shift($key, $length);
+                if (strlen($temp) != 1 || ord($temp) > 2) {
+                    $components['modulus'] = new Math_BigInteger($temp, 256);
+                    $this->_string_shift($key); // skip over CRYPT_RSA_ASN1_INTEGER
+                    $length = $this->_decodeLength($key);
+                    $components[$type == CRYPT_RSA_PUBLIC_FORMAT_PKCS1 ? 'publicExponent' : 'privateExponent'] = new Math_BigInteger($this->_string_shift($key, $length), 256);
+
+                    return $components;
+                }
+                if (ord($this->_string_shift($key)) != CRYPT_RSA_ASN1_INTEGER) {
+                    return false;
+                }
+                $length = $this->_decodeLength($key);
+                $components['modulus'] = new Math_BigInteger($this->_string_shift($key, $length), 256);
+                $this->_string_shift($key);
+                $length = $this->_decodeLength($key);
+                $components['publicExponent'] = new Math_BigInteger($this->_string_shift($key, $length), 256);
+                $this->_string_shift($key);
+                $length = $this->_decodeLength($key);
+                $components['privateExponent'] = new Math_BigInteger($this->_string_shift($key, $length), 256);
+                $this->_string_shift($key);
+                $length = $this->_decodeLength($key);
+                $components['primes'] = array(1 => new Math_BigInteger($this->_string_shift($key, $length), 256));
+                $this->_string_shift($key);
+                $length = $this->_decodeLength($key);
+                $components['primes'][] = new Math_BigInteger($this->_string_shift($key, $length), 256);
+                $this->_string_shift($key);
+                $length = $this->_decodeLength($key);
+                $components['exponents'] = array(1 => new Math_BigInteger($this->_string_shift($key, $length), 256));
+                $this->_string_shift($key);
+                $length = $this->_decodeLength($key);
+                $components['exponents'][] = new Math_BigInteger($this->_string_shift($key, $length), 256);
+                $this->_string_shift($key);
+                $length = $this->_decodeLength($key);
+                $components['coefficients'] = array(2 => new Math_BigInteger($this->_string_shift($key, $length), 256));
+
+                if (!empty($key)) {
+                    if (ord($this->_string_shift($key)) != CRYPT_RSA_ASN1_SEQUENCE) {
+                        return false;
+                    }
+                    $this->_decodeLength($key);
+                    while (!empty($key)) {
+                        if (ord($this->_string_shift($key)) != CRYPT_RSA_ASN1_SEQUENCE) {
+                            return false;
+                        }
+                        $this->_decodeLength($key);
+                        $key = substr($key, 1);
+                        $length = $this->_decodeLength($key);
+                        $components['primes'][] = new Math_BigInteger($this->_string_shift($key, $length), 256);
+                        $this->_string_shift($key);
+                        $length = $this->_decodeLength($key);
+                        $components['exponents'][] = new Math_BigInteger($this->_string_shift($key, $length), 256);
+                        $this->_string_shift($key);
+                        $length = $this->_decodeLength($key);
+                        $components['coefficients'][] = new Math_BigInteger($this->_string_shift($key, $length), 256);
+                    }
+                }
+
+                return $components;
+            case CRYPT_RSA_PUBLIC_FORMAT_OPENSSH:
+                $key = base64_decode(preg_replace('#^ssh-rsa | .+$#', '', $key));
+                if ($key === false) {
+                    return false;
+                }
+
+                $cleanup = substr($key, 0, 11) == "\0\0\0\7ssh-rsa";
+
+                if (strlen($key) <= 4) {
+                    return false;
+                }
+                extract(unpack('Nlength', $this->_string_shift($key, 4)));
+                $publicExponent = new Math_BigInteger($this->_string_shift($key, $length), -256);
+                if (strlen($key) <= 4) {
+                    return false;
+                }
+                extract(unpack('Nlength', $this->_string_shift($key, 4)));
+                $modulus = new Math_BigInteger($this->_string_shift($key, $length), -256);
+
+                if ($cleanup && strlen($key)) {
+                    if (strlen($key) <= 4) {
+                        return false;
+                    }
+                    extract(unpack('Nlength', $this->_string_shift($key, 4)));
+                    $realModulus = new Math_BigInteger($this->_string_shift($key, $length), -256);
+                    return strlen($key) ? false : array(
+                        'modulus' => $realModulus,
+                        'publicExponent' => $modulus
+                    );
+                } else {
+                    return strlen($key) ? false : array(
+                        'modulus' => $modulus,
+                        'publicExponent' => $publicExponent
+                    );
+                }
+            // http://www.w3.org/TR/xmldsig-core/#sec-RSAKeyValue
+            // http://en.wikipedia.org/wiki/XML_Signature
+            case CRYPT_RSA_PRIVATE_FORMAT_XML:
+            case CRYPT_RSA_PUBLIC_FORMAT_XML:
+                $this->components = array();
+
+                $xml = xml_parser_create('UTF-8');
+                xml_set_object($xml, $this);
+                xml_set_element_handler($xml, '_start_element_handler', '_stop_element_handler');
+                xml_set_character_data_handler($xml, '_data_handler');
+                if (!xml_parse($xml, $key)) {
+                    return false;
+                }
+
+                return isset($this->components['modulus']) && isset($this->components['publicExponent']) ? $this->components : false;
+            // from PuTTY's SSHPUBK.C
+            case CRYPT_RSA_PRIVATE_FORMAT_PUTTY:
+                $components = array();
+                $key = preg_split('#\r\n|\r|\n#', $key);
+                $type = trim(preg_replace('#PuTTY-User-Key-File-2: (.+)#', '$1', $key[0]));
+                if ($type != 'ssh-rsa') {
+                    return false;
+                }
+                $encryption = trim(preg_replace('#Encryption: (.+)#', '$1', $key[1]));
+
+                $publicLength = trim(preg_replace('#Public-Lines: (\d+)#', '$1', $key[3]));
+                $public = base64_decode(implode('', array_map('trim', array_slice($key, 4, $publicLength))));
+                $public = substr($public, 11);
+                extract(unpack('Nlength', $this->_string_shift($public, 4)));
+                $components['publicExponent'] = new Math_BigInteger($this->_string_shift($public, $length), -256);
+                extract(unpack('Nlength', $this->_string_shift($public, 4)));
+                $components['modulus'] = new Math_BigInteger($this->_string_shift($public, $length), -256);
+
+                $privateLength = trim(preg_replace('#Private-Lines: (\d+)#', '$1', $key[$publicLength + 4]));
+                $private = base64_decode(implode('', array_map('trim', array_slice($key, $publicLength + 5, $privateLength))));
+
+                switch ($encryption) {
+                    case 'aes256-cbc':
+                        if (!class_exists('Crypt_AES')) {
+                            require_once('Crypt/AES.php');
+                        }
+                        $symkey = '';
+                        $sequence = 0;
+                        while (strlen($symkey) < 32) {
+                            $temp = pack('Na*', $sequence++, $this->password);
+                            $symkey.= pack('H*', sha1($temp));
+                        }
+                        $symkey = substr($symkey, 0, 32);
+                        $crypto = new Crypt_AES();
+                }
+
+                if ($encryption != 'none') {
+                    $crypto->setKey($symkey);
+                    $crypto->disablePadding();
+                    $private = $crypto->decrypt($private);
+                    if ($private === false) {
+                        return false;
+                    }
+                }
+
+                extract(unpack('Nlength', $this->_string_shift($private, 4)));
+                if (strlen($private) < $length) {
+                    return false;
+                }
+                $components['privateExponent'] = new Math_BigInteger($this->_string_shift($private, $length), -256);
+                extract(unpack('Nlength', $this->_string_shift($private, 4)));
+                if (strlen($private) < $length) {
+                    return false;
+                }
+                $components['primes'] = array(1 => new Math_BigInteger($this->_string_shift($private, $length), -256));
+                extract(unpack('Nlength', $this->_string_shift($private, 4)));
+                if (strlen($private) < $length) {
+                    return false;
+                }
+                $components['primes'][] = new Math_BigInteger($this->_string_shift($private, $length), -256);
+
+                $temp = $components['primes'][1]->subtract($this->one);
+                $components['exponents'] = array(1 => $components['publicExponent']->modInverse($temp));
+                $temp = $components['primes'][2]->subtract($this->one);
+                $components['exponents'][] = $components['publicExponent']->modInverse($temp);
+
+                extract(unpack('Nlength', $this->_string_shift($private, 4)));
+                if (strlen($private) < $length) {
+                    return false;
+                }
+                $components['coefficients'] = array(2 => new Math_BigInteger($this->_string_shift($private, $length), -256));
+
+                return $components;
+        }
+    }
+
+    /**
+     * Returns the key size
+     *
+     * More specifically, this returns the size of the modulo in bits.
+     *
+     * @access public
+     * @return Integer
+     */
+    function getSize()
+    {
+        return !isset($this->modulus) ? 0 : strlen($this->modulus->toBits());
+    }
+
+    /**
+     * Start Element Handler
+     *
+     * Called by xml_set_element_handler()
+     *
+     * @access private
+     * @param Resource $parser
+     * @param String $name
+     * @param Array $attribs
+     */
+    function _start_element_handler($parser, $name, $attribs)
+    {
+        //$name = strtoupper($name);
+        switch ($name) {
+            case 'MODULUS':
+                $this->current = &$this->components['modulus'];
+                break;
+            case 'EXPONENT':
+                $this->current = &$this->components['publicExponent'];
+                break;
+            case 'P':
+                $this->current = &$this->components['primes'][1];
+                break;
+            case 'Q':
+                $this->current = &$this->components['primes'][2];
+                break;
+            case 'DP':
+                $this->current = &$this->components['exponents'][1];
+                break;
+            case 'DQ':
+                $this->current = &$this->components['exponents'][2];
+                break;
+            case 'INVERSEQ':
+                $this->current = &$this->components['coefficients'][2];
+                break;
+            case 'D':
+                $this->current = &$this->components['privateExponent'];
+                break;
+            default:
+                unset($this->current);
+        }
+        $this->current = '';
+    }
+
+    /**
+     * Stop Element Handler
+     *
+     * Called by xml_set_element_handler()
+     *
+     * @access private
+     * @param Resource $parser
+     * @param String $name
+     */
+    function _stop_element_handler($parser, $name)
+    {
+        //$name = strtoupper($name);
+        if ($name == 'RSAKEYVALUE') {
+            return;
+        }
+        $this->current = new Math_BigInteger(base64_decode($this->current), 256);
+    }
+
+    /**
+     * Data Handler
+     *
+     * Called by xml_set_character_data_handler()
+     *
+     * @access private
+     * @param Resource $parser
+     * @param String $data
+     */
+    function _data_handler($parser, $data)
+    {
+        if (!isset($this->current) || is_object($this->current)) {
+            return;
+        }
+        $this->current.= trim($data);
+    }
+
+    /**
+     * Loads a public or private key
+     *
+     * Returns true on success and false on failure (ie. an incorrect password was provided or the key was malformed)
+     *
+     * @access public
+     * @param String $key
+     * @param Integer $type optional
+     */
+    function loadKey($key, $type = false)
+    {
+        if ($type === false) {
+            $types = array(
+                CRYPT_RSA_PUBLIC_FORMAT_RAW,
+                CRYPT_RSA_PRIVATE_FORMAT_PKCS1,
+                CRYPT_RSA_PRIVATE_FORMAT_XML,
+                CRYPT_RSA_PRIVATE_FORMAT_PUTTY,
+                CRYPT_RSA_PUBLIC_FORMAT_OPENSSH
+            );
+            foreach ($types as $type) {
+                $components = $this->_parseKey($key, $type);
+                if ($components !== false) {
+                    break;
+                }
+            }
+            
+        } else {
+            $components = $this->_parseKey($key, $type);
+        }
+
+        if ($components === false) {
+            return false;
+        }
+
+        $this->modulus = $components['modulus'];
+        $this->k = strlen($this->modulus->toBytes());
+        $this->exponent = isset($components['privateExponent']) ? $components['privateExponent'] : $components['publicExponent'];
+        if (isset($components['primes'])) {
+            $this->primes = $components['primes'];
+            $this->exponents = $components['exponents'];
+            $this->coefficients = $components['coefficients'];
+            $this->publicExponent = $components['publicExponent'];
+        } else {
+            $this->primes = array();
+            $this->exponents = array();
+            $this->coefficients = array();
+            $this->publicExponent = false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Sets the password
+     *
+     * Private keys can be encrypted with a password.  To unset the password, pass in the empty string or false.
+     * Or rather, pass in $password such that empty($password) && !is_string($password) is true.
+     *
+     * @see createKey()
+     * @see loadKey()
+     * @access public
+     * @param String $password
+     */
+    function setPassword($password = false)
+    {
+        $this->password = $password;
+    }
+
+    /**
+     * Defines the public key
+     *
+     * Some private key formats define the public exponent and some don't.  Those that don't define it are problematic when
+     * used in certain contexts.  For example, in SSH-2, RSA authentication works by sending the public key along with a
+     * message signed by the private key to the server.  The SSH-2 server looks the public key up in an index of public keys
+     * and if it's present then proceeds to verify the signature.  Problem is, if your private key doesn't include the public
+     * exponent this won't work unless you manually add the public exponent.
+     *
+     * Do note that when a new key is loaded the index will be cleared.
+     *
+     * Returns true on success, false on failure
+     *
+     * @see getPublicKey()
+     * @access public
+     * @param String $key optional
+     * @param Integer $type optional
+     * @return Boolean
+     */
+    function setPublicKey($key = false, $type = false)
+    {
+        if ($key === false && !empty($this->modulus)) {
+            $this->publicExponent = $this->exponent;
+            return true;
+        }
+
+        if ($type === false) {
+            $types = array(
+                CRYPT_RSA_PUBLIC_FORMAT_RAW,
+                CRYPT_RSA_PUBLIC_FORMAT_PKCS1,
+                CRYPT_RSA_PUBLIC_FORMAT_XML,
+                CRYPT_RSA_PUBLIC_FORMAT_OPENSSH
+            );
+            foreach ($types as $type) {
+                $components = $this->_parseKey($key, $type);
+                if ($components !== false) {
+                    break;
+                }
+            }
+        } else {
+            $components = $this->_parseKey($key, $type);
+        }
+
+        if ($components === false) {
+            return false;
+        }
+
+        if (empty($this->modulus) || !$this->modulus->equals($components['modulus'])) {
+            $this->modulus = $components['modulus'];
+            $this->exponent = $this->publicExponent = $components['publicExponent'];
+            return true;
+        }
+
+        $this->publicExponent = $components['publicExponent'];
+
+        return true;
+    }
+
+    /**
+     * Returns the public key
+     *
+     * The public key is only returned under two circumstances - if the private key had the public key embedded within it
+     * or if the public key was set via setPublicKey().  If the currently loaded key is supposed to be the public key this
+     * function won't return it since this library, for the most part, doesn't distinguish between public and private keys.
+     *
+     * @see getPublicKey()
+     * @access public
+     * @param String $key
+     * @param Integer $type optional
+     */
+    function getPublicKey($type = CRYPT_RSA_PUBLIC_FORMAT_PKCS1)
+    {
+        if (empty($this->modulus) || empty($this->publicExponent)) {
+            return false;
+        }
+
+        $oldFormat = $this->publicKeyFormat;
+        $this->publicKeyFormat = $type;
+        $temp = $this->_convertPublicKey($this->modulus, $this->publicExponent);
+        $this->publicKeyFormat = $oldFormat;
+        return $temp;
+    }
+
+    /**
+     * Returns the private key
+     *
+     * The private key is only returned if the currently loaded key contains the constituent prime numbers.
+     *
+     * @see getPublicKey()
+     * @access public
+     * @param String $key
+     * @param Integer $type optional
+     */
+    function getPrivateKey($type = CRYPT_RSA_PUBLIC_FORMAT_PKCS1)
+    {
+        if (empty($this->primes)) {
+            return false;
+        }
+
+        $oldFormat = $this->privateKeyFormat;
+        $this->privateKeyFormat = $type;
+        $temp = $this->_convertPrivateKey($this->modulus, $this->publicExponent, $this->exponent, $this->primes, $this->exponents, $this->coefficients);
+        $this->privateKeyFormat = $oldFormat;
+        return $temp;
+    }
+
+    /**
+     * Returns a minimalistic private key
+     *
+     * Returns the private key without the prime number constituants.  Structurally identical to a public key that
+     * hasn't been set as the public key
+     *
+     * @see getPrivateKey()
+     * @access private
+     * @param String $key
+     * @param Integer $type optional
+     */
+    function _getPrivatePublicKey($mode = CRYPT_RSA_PUBLIC_FORMAT_PKCS1)
+    {
+        if (empty($this->modulus) || empty($this->exponent)) {
+            return false;
+        }
+
+        $oldFormat = $this->publicKeyFormat;
+        $this->publicKeyFormat = $mode;
+        $temp = $this->_convertPublicKey($this->modulus, $this->exponent);
+        $this->publicKeyFormat = $oldFormat;
+        return $temp;
+    }
+
+    /**
+     *  __toString() magic method
+     *
+     * @access public
+     */
+    function __toString()
+    {
+        $key = $this->getPrivateKey($this->privateKeyFormat);
+        if ($key !== false) {
+            return $key;
+        }
+        $key = $this->_getPrivatePublicKey($this->publicKeyFormat);
+        return $key !== false ? $key : '';
+    }
+
+    /**
+     * Generates the smallest and largest numbers requiring $bits bits
+     *
+     * @access private
+     * @param Integer $bits
+     * @return Array
+     */
+    function _generateMinMax($bits)
+    {
+        $bytes = $bits >> 3;
+        $min = str_repeat(chr(0), $bytes);
+        $max = str_repeat(chr(0xFF), $bytes);
+        $msb = $bits & 7;
+        if ($msb) {
+            $min = chr(1 << ($msb - 1)) . $min;
+            $max = chr((1 << $msb) - 1) . $max;
+        } else {
+            $min[0] = chr(0x80);
+        }
+
+        return array(
+            'min' => new Math_BigInteger($min, 256),
+            'max' => new Math_BigInteger($max, 256)
+        );
+    }
+
+    /**
+     * DER-decode the length
+     *
+     * DER supports lengths up to (2**8)**127, however, we'll only support lengths up to (2**8)**4.  See
+     * {@link http://itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf#p=13 X.690 § 8.1.3} for more information.
+     *
+     * @access private
+     * @param String $string
+     * @return Integer
+     */
+    function _decodeLength(&$string)
+    {
+        $length = ord($this->_string_shift($string));
+        if ( $length & 0x80 ) { // definite length, long form
+            $length&= 0x7F;
+            $temp = $this->_string_shift($string, $length);
+            list(, $length) = unpack('N', substr(str_pad($temp, 4, chr(0), STR_PAD_LEFT), -4));
+        }
+        return $length;
+    }
+
+    /**
+     * DER-encode the length
+     *
+     * DER supports lengths up to (2**8)**127, however, we'll only support lengths up to (2**8)**4.  See
+     * {@link http://itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf#p=13 X.690 § 8.1.3} for more information.
+     *
+     * @access private
+     * @param Integer $length
+     * @return String
+     */
+    function _encodeLength($length)
+    {
+        if ($length <= 0x7F) {
+            return chr($length);
+        }
+
+        $temp = ltrim(pack('N', $length), chr(0));
+        return pack('Ca*', 0x80 | strlen($temp), $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;
+    }
+
+    /**
+     * Determines the private key format
+     *
+     * @see createKey()
+     * @access public
+     * @param Integer $format
+     */
+    function setPrivateKeyFormat($format)
+    {
+        $this->privateKeyFormat = $format;
+    }
+
+    /**
+     * Determines the public key format
+     *
+     * @see createKey()
+     * @access public
+     * @param Integer $format
+     */
+    function setPublicKeyFormat($format)
+    {
+        $this->publicKeyFormat = $format;
+    }
+
+    /**
+     * Determines which hashing function should be used
+     *
+     * Used with signature production / verification and (if the encryption mode is CRYPT_RSA_ENCRYPTION_OAEP) encryption and
+     * decryption.  If $hash isn't supported, sha1 is used.
+     *
+     * @access public
+     * @param String $hash
+     */
+    function setHash($hash)
+    {
+        // Crypt_Hash supports algorithms that PKCS#1 doesn't support.  md5-96 and sha1-96, for example.
+        switch ($hash) {
+            case 'md2':
+            case 'md5':
+            case 'sha1':
+            case 'sha256':
+            case 'sha384':
+            case 'sha512':
+                $this->hash = new Crypt_Hash($hash);
+                $this->hashName = $hash;
+                break;
+            default:
+                $this->hash = new Crypt_Hash('sha1');
+                $this->hashName = 'sha1';
+        }
+        $this->hLen = $this->hash->getLength();
+    }
+
+    /**
+     * Determines which hashing function should be used for the mask generation function
+     *
+     * The mask generation function is used by CRYPT_RSA_ENCRYPTION_OAEP and CRYPT_RSA_SIGNATURE_PSS and although it's
+     * best if Hash and MGFHash are set to the same thing this is not a requirement.
+     *
+     * @access public
+     * @param String $hash
+     */
+    function setMGFHash($hash)
+    {
+        // Crypt_Hash supports algorithms that PKCS#1 doesn't support.  md5-96 and sha1-96, for example.
+        switch ($hash) {
+            case 'md2':
+            case 'md5':
+            case 'sha1':
+            case 'sha256':
+            case 'sha384':
+            case 'sha512':
+                $this->mgfHash = new Crypt_Hash($hash);
+                break;
+            default:
+                $this->mgfHash = new Crypt_Hash('sha1');
+        }
+        $this->mgfHLen = $this->mgfHash->getLength();
+    }
+
+    /**
+     * Determines the salt length
+     *
+     * To quote from {@link http://tools.ietf.org/html/rfc3447#page-38 RFC3447#page-38}:
+     *
+     *    Typical salt lengths in octets are hLen (the length of the output
+     *    of the hash function Hash) and 0.
+     *
+     * @access public
+     * @param Integer $format
+     */
+    function setSaltLength($sLen)
+    {
+        $this->sLen = $sLen;
+    }
+
+    /**
+     * Generates a random string x bytes long
+     *
+     * @access public
+     * @param Integer $bytes
+     * @param optional Integer $nonzero
+     * @return String
+     */
+    function _random($bytes, $nonzero = false)
+    {
+        $temp = '';
+        for ($i = 0; $i < $bytes; $i++) {
+            $temp.= chr(crypt_random($nonzero, 255));
+        }
+        return $temp;
+    }
+
+    /**
+     * Integer-to-Octet-String primitive
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-4.1 RFC3447#section-4.1}.
+     *
+     * @access private
+     * @param Math_BigInteger $x
+     * @param Integer $xLen
+     * @return String
+     */
+    function _i2osp($x, $xLen)
+    {
+        $x = $x->toBytes();
+        if (strlen($x) > $xLen) {
+            user_error('Integer too large', E_USER_NOTICE);
+            return false;
+        }
+        return str_pad($x, $xLen, chr(0), STR_PAD_LEFT);
+    }
+
+    /**
+     * Octet-String-to-Integer primitive
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-4.2 RFC3447#section-4.2}.
+     *
+     * @access private
+     * @param String $x
+     * @return Math_BigInteger
+     */
+    function _os2ip($x)
+    {
+        return new Math_BigInteger($x, 256);
+    }
+
+    /**
+     * Exponentiate with or without Chinese Remainder Theorem
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-5.1.1 RFC3447#section-5.1.2}.
+     *
+     * @access private
+     * @param Math_BigInteger $x
+     * @return Math_BigInteger
+     */
+    function _exponentiate($x)
+    {
+        if (empty($this->primes) || empty($this->coefficients) || empty($this->exponents)) {
+            return $x->modPow($this->exponent, $this->modulus);
+        }
+
+        $num_primes = count($this->primes);
+
+        if (defined('CRYPT_RSA_DISABLE_BLINDING')) {
+            $m_i = array(
+                1 => $x->modPow($this->exponents[1], $this->primes[1]),
+                2 => $x->modPow($this->exponents[2], $this->primes[2])
+            );
+            $h = $m_i[1]->subtract($m_i[2]);
+            $h = $h->multiply($this->coefficients[2]);
+            list(, $h) = $h->divide($this->primes[1]);
+            $m = $m_i[2]->add($h->multiply($this->primes[2]));
+
+            $r = $this->primes[1];
+            for ($i = 3; $i <= $num_primes; $i++) {
+                $m_i = $x->modPow($this->exponents[$i], $this->primes[$i]);
+
+                $r = $r->multiply($this->primes[$i - 1]);
+
+                $h = $m_i->subtract($m);
+                $h = $h->multiply($this->coefficients[$i]);
+                list(, $h) = $h->divide($this->primes[$i]);
+
+                $m = $m->add($r->multiply($h));
+            }
+        } else {
+            $smallest = $this->primes[1];
+            for ($i = 2; $i <= $num_primes; $i++) {
+                if ($smallest->compare($this->primes[$i]) > 0) {
+                    $smallest = $this->primes[$i];
+                }
+            }
+
+            $one = new Math_BigInteger(1);
+            $one->setRandomGenerator('crypt_random');
+
+            $r = $one->random($one, $smallest->subtract($one));
+
+            $m_i = array(
+                1 => $this->_blind($x, $r, 1),
+                2 => $this->_blind($x, $r, 2)
+            );
+            $h = $m_i[1]->subtract($m_i[2]);
+            $h = $h->multiply($this->coefficients[2]);
+            list(, $h) = $h->divide($this->primes[1]);
+            $m = $m_i[2]->add($h->multiply($this->primes[2]));
+
+            $r = $this->primes[1];
+            for ($i = 3; $i <= $num_primes; $i++) {
+                $m_i = $this->_blind($x, $r, $i);
+
+                $r = $r->multiply($this->primes[$i - 1]);
+
+                $h = $m_i->subtract($m);
+                $h = $h->multiply($this->coefficients[$i]);
+                list(, $h) = $h->divide($this->primes[$i]);
+
+                $m = $m->add($r->multiply($h));
+            }
+        }
+
+        return $m;
+    }
+
+    /**
+     * Performs RSA Blinding
+     *
+     * Protects against timing attacks by employing RSA Blinding.
+     * Returns $x->modPow($this->exponents[$i], $this->primes[$i])
+     *
+     * @access private
+     * @param Math_BigInteger $x
+     * @param Math_BigInteger $r
+     * @param Integer $i
+     * @return Math_BigInteger
+     */
+    function _blind($x, $r, $i)
+    {
+        $x = $x->multiply($r->modPow($this->publicExponent, $this->primes[$i]));
+        $x = $x->modPow($this->exponents[$i], $this->primes[$i]);
+
+        $r = $r->modInverse($this->primes[$i]);
+        $x = $x->multiply($r);
+        list(, $x) = $x->divide($this->primes[$i]);
+
+        return $x;
+    }
+
+    /**
+     * Performs blinded RSA equality testing
+     *
+     * Protects against a particular type of timing attack described.
+     *
+     * See {@link http://codahale.com/a-lesson-in-timing-attacks/ A Lesson In Timing Attacks (or, Don’t use MessageDigest.isEquals)}
+     *
+     * Thanks for the heads up singpolyma!
+     *
+     * @access private
+     * @param String $x
+     * @param String $y
+     * @return Boolean
+     */
+    function _equals($x, $y)
+    {
+        if (strlen($x) != strlen($y)) {
+            return false;
+        }
+
+        $result = 0;
+        for ($i = 0; $i < strlen($x); $i++) {
+            $result |= ord($x[$i]) ^ ord($y[$i]);
+        }
+
+        return $result == 0;
+    }
+
+    /**
+     * RSAEP
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-5.1.1 RFC3447#section-5.1.1}.
+     *
+     * @access private
+     * @param Math_BigInteger $m
+     * @return Math_BigInteger
+     */
+    function _rsaep($m)
+    {
+        if ($m->compare($this->zero) < 0 || $m->compare($this->modulus) > 0) {
+            user_error('Message representative out of range', E_USER_NOTICE);
+            return false;
+        }
+        return $this->_exponentiate($m);
+    }
+
+    /**
+     * RSADP
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-5.1.2 RFC3447#section-5.1.2}.
+     *
+     * @access private
+     * @param Math_BigInteger $c
+     * @return Math_BigInteger
+     */
+    function _rsadp($c)
+    {
+        if ($c->compare($this->zero) < 0 || $c->compare($this->modulus) > 0) {
+            user_error('Ciphertext representative out of range', E_USER_NOTICE);
+            return false;
+        }
+        return $this->_exponentiate($c);
+    }
+
+    /**
+     * RSASP1
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-5.2.1 RFC3447#section-5.2.1}.
+     *
+     * @access private
+     * @param Math_BigInteger $m
+     * @return Math_BigInteger
+     */
+    function _rsasp1($m)
+    {
+        if ($m->compare($this->zero) < 0 || $m->compare($this->modulus) > 0) {
+            user_error('Message representative out of range', E_USER_NOTICE);
+            return false;
+        }
+        return $this->_exponentiate($m);
+    }
+
+    /**
+     * RSAVP1
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-5.2.2 RFC3447#section-5.2.2}.
+     *
+     * @access private
+     * @param Math_BigInteger $s
+     * @return Math_BigInteger
+     */
+    function _rsavp1($s)
+    {
+        if ($s->compare($this->zero) < 0 || $s->compare($this->modulus) > 0) {
+            user_error('Signature representative out of range', E_USER_NOTICE);
+            return false;
+        }
+        return $this->_exponentiate($s);
+    }
+
+    /**
+     * MGF1
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#appendix-B.2.1 RFC3447#appendix-B.2.1}.
+     *
+     * @access private
+     * @param String $mgfSeed
+     * @param Integer $mgfLen
+     * @return String
+     */
+    function _mgf1($mgfSeed, $maskLen)
+    {
+        // if $maskLen would yield strings larger than 4GB, PKCS#1 suggests a "Mask too long" error be output.
+
+        $t = '';
+        $count = ceil($maskLen / $this->mgfHLen);
+        for ($i = 0; $i < $count; $i++) {
+            $c = pack('N', $i);
+            $t.= $this->mgfHash->hash($mgfSeed . $c);
+        }
+
+        return substr($t, 0, $maskLen);
+    }
+
+    /**
+     * RSAES-OAEP-ENCRYPT
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-7.1.1 RFC3447#section-7.1.1} and
+     * {http://en.wikipedia.org/wiki/Optimal_Asymmetric_Encryption_Padding OAES}.
+     *
+     * @access private
+     * @param String $m
+     * @param String $l
+     * @return String
+     */
+    function _rsaes_oaep_encrypt($m, $l = '')
+    {
+        $mLen = strlen($m);
+
+        // Length checking
+
+        // if $l is larger than two million terrabytes and you're using sha1, PKCS#1 suggests a "Label too long" error
+        // be output.
+
+        if ($mLen > $this->k - 2 * $this->hLen - 2) {
+            user_error('Message too long', E_USER_NOTICE);
+            return false;
+        }
+
+        // EME-OAEP encoding
+
+        $lHash = $this->hash->hash($l);
+        $ps = str_repeat(chr(0), $this->k - $mLen - 2 * $this->hLen - 2);
+        $db = $lHash . $ps . chr(1) . $m;
+        $seed = $this->_random($this->hLen);
+        $dbMask = $this->_mgf1($seed, $this->k - $this->hLen - 1);
+        $maskedDB = $db ^ $dbMask;
+        $seedMask = $this->_mgf1($maskedDB, $this->hLen);
+        $maskedSeed = $seed ^ $seedMask;
+        $em = chr(0) . $maskedSeed . $maskedDB;
+
+        // RSA encryption
+
+        $m = $this->_os2ip($em);
+        $c = $this->_rsaep($m);
+        $c = $this->_i2osp($c, $this->k);
+
+        // Output the ciphertext C
+
+        return $c;
+    }
+
+    /**
+     * RSAES-OAEP-DECRYPT
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-7.1.2 RFC3447#section-7.1.2}.  The fact that the error
+     * messages aren't distinguishable from one another hinders debugging, but, to quote from RFC3447#section-7.1.2:
+     * 
+     *    Note.  Care must be taken to ensure that an opponent cannot
+     *    distinguish the different error conditions in Step 3.g, whether by
+     *    error message or timing, or, more generally, learn partial
+     *    information about the encoded message EM.  Otherwise an opponent may
+     *    be able to obtain useful information about the decryption of the
+     *    ciphertext C, leading to a chosen-ciphertext attack such as the one
+     *    observed by Manger [36].
+     *
+     * As for $l...  to quote from {@link http://tools.ietf.org/html/rfc3447#page-17 RFC3447#page-17}:
+     *
+     *    Both the encryption and the decryption operations of RSAES-OAEP take
+     *    the value of a label L as input.  In this version of PKCS #1, L is
+     *    the empty string; other uses of the label are outside the scope of
+     *    this document.
+     *
+     * @access private
+     * @param String $c
+     * @param String $l
+     * @return String
+     */
+    function _rsaes_oaep_decrypt($c, $l = '')
+    {
+        // Length checking
+
+        // if $l is larger than two million terrabytes and you're using sha1, PKCS#1 suggests a "Label too long" error
+        // be output.
+
+        if (strlen($c) != $this->k || $this->k < 2 * $this->hLen + 2) {
+            user_error('Decryption error', E_USER_NOTICE);
+            return false;
+        }
+
+        // RSA decryption
+
+        $c = $this->_os2ip($c);
+        $m = $this->_rsadp($c);
+        if ($m === false) {
+            user_error('Decryption error', E_USER_NOTICE);
+            return false;
+        }
+        $em = $this->_i2osp($m, $this->k);
+
+        // EME-OAEP decoding
+
+        $lHash = $this->hash->hash($l);
+        $y = ord($em[0]);
+        $maskedSeed = substr($em, 1, $this->hLen);
+        $maskedDB = substr($em, $this->hLen + 1);
+        $seedMask = $this->_mgf1($maskedDB, $this->hLen);
+        $seed = $maskedSeed ^ $seedMask;
+        $dbMask = $this->_mgf1($seed, $this->k - $this->hLen - 1);
+        $db = $maskedDB ^ $dbMask;
+        $lHash2 = substr($db, 0, $this->hLen);
+        $m = substr($db, $this->hLen);
+        if ($lHash != $lHash2) {
+            user_error('Decryption error', E_USER_NOTICE);
+            return false;
+        }
+        $m = ltrim($m, chr(0));
+        if (ord($m[0]) != 1) {
+            user_error('Decryption error', E_USER_NOTICE);
+            return false;
+        }
+
+        // Output the message M
+
+        return substr($m, 1);
+    }
+
+    /**
+     * RSAES-PKCS1-V1_5-ENCRYPT
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-7.2.1 RFC3447#section-7.2.1}.
+     *
+     * @access private
+     * @param String $m
+     * @return String
+     */
+    function _rsaes_pkcs1_v1_5_encrypt($m)
+    {
+        $mLen = strlen($m);
+
+        // Length checking
+
+        if ($mLen > $this->k - 11) {
+            user_error('Message too long', E_USER_NOTICE);
+            return false;
+        }
+
+        // EME-PKCS1-v1_5 encoding
+
+        $ps = $this->_random($this->k - $mLen - 3, true);
+        $em = chr(0) . chr(2) . $ps . chr(0) . $m;
+
+        // RSA encryption
+        $m = $this->_os2ip($em);
+        $c = $this->_rsaep($m);
+        $c = $this->_i2osp($c, $this->k);
+
+        // Output the ciphertext C
+
+        return $c;
+    }
+
+    /**
+     * RSAES-PKCS1-V1_5-DECRYPT
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-7.2.2 RFC3447#section-7.2.2}.
+     *
+     * For compatability purposes, this function departs slightly from the description given in RFC3447.
+     * The reason being that RFC2313#section-8.1 (PKCS#1 v1.5) states that ciphertext's encrypted by the
+     * private key should have the second byte set to either 0 or 1 and that ciphertext's encrypted by the
+     * public key should have the second byte set to 2.  In RFC3447 (PKCS#1 v2.1), the second byte is supposed
+     * to be 2 regardless of which key is used.  For compatability purposes, we'll just check to make sure the
+     * second byte is 2 or less.  If it is, we'll accept the decrypted string as valid.
+     *
+     * As a consequence of this, a private key encrypted ciphertext produced with Crypt_RSA may not decrypt
+     * with a strictly PKCS#1 v1.5 compliant RSA implementation.  Public key encrypted ciphertext's should but
+     * not private key encrypted ciphertext's.
+     *
+     * @access private
+     * @param String $c
+     * @return String
+     */
+    function _rsaes_pkcs1_v1_5_decrypt($c)
+    {
+        // Length checking
+
+        if (strlen($c) != $this->k) { // or if k < 11
+            user_error('Decryption error', E_USER_NOTICE);
+            return false;
+        }
+
+        // RSA decryption
+
+        $c = $this->_os2ip($c);
+        $m = $this->_rsadp($c);
+
+        if ($m === false) {
+            user_error('Decryption error', E_USER_NOTICE);
+            return false;
+        }
+        $em = $this->_i2osp($m, $this->k);
+
+        // EME-PKCS1-v1_5 decoding
+
+        if (ord($em[0]) != 0 || ord($em[1]) > 2) {
+            user_error('Decryption error', E_USER_NOTICE);
+            return false;
+        }
+
+        $ps = substr($em, 2, strpos($em, chr(0), 2) - 2);
+        $m = substr($em, strlen($ps) + 3);
+
+        if (strlen($ps) < 8) {
+            user_error('Decryption error', E_USER_NOTICE);
+            return false;
+        }
+
+        // Output M
+
+        return $m;
+    }
+
+    /**
+     * EMSA-PSS-ENCODE
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-9.1.1 RFC3447#section-9.1.1}.
+     *
+     * @access private
+     * @param String $m
+     * @param Integer $emBits
+     */
+    function _emsa_pss_encode($m, $emBits)
+    {
+        // if $m is larger than two million terrabytes and you're using sha1, PKCS#1 suggests a "Label too long" error
+        // be output.
+
+        $emLen = ($emBits + 1) >> 3; // ie. ceil($emBits / 8)
+        $sLen = $this->sLen == false ? $this->hLen : $this->sLen;
+
+        $mHash = $this->hash->hash($m);
+        if ($emLen < $this->hLen + $sLen + 2) {
+            user_error('Encoding error', E_USER_NOTICE);
+            return false;
+        }
+
+        $salt = $this->_random($sLen);
+        $m2 = "\0\0\0\0\0\0\0\0" . $mHash . $salt;
+        $h = $this->hash->hash($m2);
+        $ps = str_repeat(chr(0), $emLen - $sLen - $this->hLen - 2);
+        $db = $ps . chr(1) . $salt;
+        $dbMask = $this->_mgf1($h, $emLen - $this->hLen - 1);
+        $maskedDB = $db ^ $dbMask;
+        $maskedDB[0] = ~chr(0xFF << ($emBits & 7)) & $maskedDB[0];
+        $em = $maskedDB . $h . chr(0xBC);
+
+        return $em;
+    }
+
+    /**
+     * EMSA-PSS-VERIFY
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-9.1.2 RFC3447#section-9.1.2}.
+     *
+     * @access private
+     * @param String $m
+     * @param String $em
+     * @param Integer $emBits
+     * @return String
+     */
+    function _emsa_pss_verify($m, $em, $emBits)
+    {
+        // if $m is larger than two million terrabytes and you're using sha1, PKCS#1 suggests a "Label too long" error
+        // be output.
+
+        $emLen = ($emBits + 1) >> 3; // ie. ceil($emBits / 8);
+        $sLen = $this->sLen == false ? $this->hLen : $this->sLen;
+
+        $mHash = $this->hash->hash($m);
+        if ($emLen < $this->hLen + $sLen + 2) {
+            return false;
+        }
+
+        if ($em[strlen($em) - 1] != chr(0xBC)) {
+            return false;
+        }
+
+        $maskedDB = substr($em, 0, -$this->hLen - 1);
+        $h = substr($em, -$this->hLen - 1, $this->hLen);
+        $temp = chr(0xFF << ($emBits & 7));
+        if ((~$maskedDB[0] & $temp) != $temp) {
+            return false;
+        }
+        $dbMask = $this->_mgf1($h, $emLen - $this->hLen - 1);
+        $db = $maskedDB ^ $dbMask;
+        $db[0] = ~chr(0xFF << ($emBits & 7)) & $db[0];
+        $temp = $emLen - $this->hLen - $sLen - 2;
+        if (substr($db, 0, $temp) != str_repeat(chr(0), $temp) || ord($db[$temp]) != 1) {
+            return false;
+        }
+        $salt = substr($db, $temp + 1); // should be $sLen long
+        $m2 = "\0\0\0\0\0\0\0\0" . $mHash . $salt;
+        $h2 = $this->hash->hash($m2);
+        return $this->_equals($h, $h2);
+    }
+
+    /**
+     * RSASSA-PSS-SIGN
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-8.1.1 RFC3447#section-8.1.1}.
+     *
+     * @access private
+     * @param String $m
+     * @return String
+     */
+    function _rsassa_pss_sign($m)
+    {
+        // EMSA-PSS encoding
+
+        $em = $this->_emsa_pss_encode($m, 8 * $this->k - 1);
+
+        // RSA signature
+
+        $m = $this->_os2ip($em);
+        $s = $this->_rsasp1($m);
+        $s = $this->_i2osp($s, $this->k);
+
+        // Output the signature S
+
+        return $s;
+    }
+
+    /**
+     * RSASSA-PSS-VERIFY
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-8.1.2 RFC3447#section-8.1.2}.
+     *
+     * @access private
+     * @param String $m
+     * @param String $s
+     * @return String
+     */
+    function _rsassa_pss_verify($m, $s)
+    {
+        // Length checking
+
+        if (strlen($s) != $this->k) {
+            user_error('Invalid signature', E_USER_NOTICE);
+            return false;
+        }
+
+        // RSA verification
+
+        $modBits = 8 * $this->k;
+
+        $s2 = $this->_os2ip($s);
+        $m2 = $this->_rsavp1($s2);
+        if ($m2 === false) {
+            user_error('Invalid signature', E_USER_NOTICE);
+            return false;
+        }
+        $em = $this->_i2osp($m2, $modBits >> 3);
+        if ($em === false) {
+            user_error('Invalid signature', E_USER_NOTICE);
+            return false;
+        }
+
+        // EMSA-PSS verification
+
+        return $this->_emsa_pss_verify($m, $em, $modBits - 1);
+    }
+
+    /**
+     * EMSA-PKCS1-V1_5-ENCODE
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-9.2 RFC3447#section-9.2}.
+     *
+     * @access private
+     * @param String $m
+     * @param Integer $emLen
+     * @return String
+     */
+    function _emsa_pkcs1_v1_5_encode($m, $emLen)
+    {
+        $h = $this->hash->hash($m);
+        if ($h === false) {
+            return false;
+        }
+
+        // see http://tools.ietf.org/html/rfc3447#page-43
+        switch ($this->hashName) {
+            case 'md2':
+                $t = pack('H*', '3020300c06082a864886f70d020205000410');
+                break;
+            case 'md5':
+                $t = pack('H*', '3020300c06082a864886f70d020505000410');
+                break;
+            case 'sha1':
+                $t = pack('H*', '3021300906052b0e03021a05000414');
+                break;
+            case 'sha256':
+                $t = pack('H*', '3031300d060960864801650304020105000420');
+                break;
+            case 'sha384':
+                $t = pack('H*', '3041300d060960864801650304020205000430');
+                break;
+            case 'sha512':
+                $t = pack('H*', '3051300d060960864801650304020305000440');
+        }
+        $t.= $h;
+        $tLen = strlen($t);
+
+        if ($emLen < $tLen + 11) {
+            user_error('Intended encoded message length too short', E_USER_NOTICE);
+            return false;
+        }
+
+        $ps = str_repeat(chr(0xFF), $emLen - $tLen - 3);
+
+        $em = "\0\1$ps\0$t";
+
+        return $em;
+    }
+
+    /**
+     * RSASSA-PKCS1-V1_5-SIGN
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-8.2.1 RFC3447#section-8.2.1}.
+     *
+     * @access private
+     * @param String $m
+     * @return String
+     */
+    function _rsassa_pkcs1_v1_5_sign($m)
+    {
+        // EMSA-PKCS1-v1_5 encoding
+
+        $em = $this->_emsa_pkcs1_v1_5_encode($m, $this->k);
+        if ($em === false) {
+            user_error('RSA modulus too short', E_USER_NOTICE);
+            return false;
+        }
+
+        // RSA signature
+
+        $m = $this->_os2ip($em);
+        $s = $this->_rsasp1($m);
+        $s = $this->_i2osp($s, $this->k);
+
+        // Output the signature S
+
+        return $s;
+    }
+
+    /**
+     * RSASSA-PKCS1-V1_5-VERIFY
+     *
+     * See {@link http://tools.ietf.org/html/rfc3447#section-8.2.2 RFC3447#section-8.2.2}.
+     *
+     * @access private
+     * @param String $m
+     * @return String
+     */
+    function _rsassa_pkcs1_v1_5_verify($m, $s)
+    {
+        // Length checking
+
+        if (strlen($s) != $this->k) {
+            user_error('Invalid signature', E_USER_NOTICE);
+            return false;
+        }
+
+        // RSA verification
+
+        $s = $this->_os2ip($s);
+        $m2 = $this->_rsavp1($s);
+        if ($m2 === false) {
+            user_error('Invalid signature', E_USER_NOTICE);
+            return false;
+        }
+        $em = $this->_i2osp($m2, $this->k);
+        if ($em === false) {
+            user_error('Invalid signature', E_USER_NOTICE);
+            return false;
+        }
+
+        // EMSA-PKCS1-v1_5 encoding
+
+        $em2 = $this->_emsa_pkcs1_v1_5_encode($m, $this->k);
+        if ($em2 === false) {
+            user_error('RSA modulus too short', E_USER_NOTICE);
+            return false;
+        }
+
+        // Compare
+
+        return $this->_equals($em, $em2);
+    }
+
+    /**
+     * Set Encryption Mode
+     *
+     * Valid values include CRYPT_RSA_ENCRYPTION_OAEP and CRYPT_RSA_ENCRYPTION_PKCS1.
+     *
+     * @access public
+     * @param Integer $mode
+     */
+    function setEncryptionMode($mode)
+    {
+        $this->encryptionMode = $mode;
+    }
+
+    /**
+     * Set Signature Mode
+     *
+     * Valid values include CRYPT_RSA_SIGNATURE_PSS and CRYPT_RSA_SIGNATURE_PKCS1
+     *
+     * @access public
+     * @param Integer $mode
+     */
+    function setSignatureMode($mode)
+    {
+        $this->signatureMode = $mode;
+    }
+
+    /**
+     * Encryption
+     *
+     * Both CRYPT_RSA_ENCRYPTION_OAEP and CRYPT_RSA_ENCRYPTION_PKCS1 both place limits on how long $plaintext can be.
+     * If $plaintext exceeds those limits it will be broken up so that it does and the resultant ciphertext's will
+     * be concatenated together.
+     *
+     * @see decrypt()
+     * @access public
+     * @param String $plaintext
+     * @return String
+     */
+    function encrypt($plaintext)
+    {
+        switch ($this->encryptionMode) {
+            case CRYPT_RSA_ENCRYPTION_PKCS1:
+                $length = $this->k - 11;
+                if ($length <= 0) {
+                    return false;
+                }
+
+                $plaintext = str_split($plaintext, $length);
+                $ciphertext = '';
+                foreach ($plaintext as $m) {
+                    $ciphertext.= $this->_rsaes_pkcs1_v1_5_encrypt($m);
+                }
+                return $ciphertext;
+            //case CRYPT_RSA_ENCRYPTION_OAEP:
+            default:
+                $length = $this->k - 2 * $this->hLen - 2;
+                if ($length <= 0) {
+                    return false;
+                }
+
+                $plaintext = str_split($plaintext, $length);
+                $ciphertext = '';
+                foreach ($plaintext as $m) {
+                    $ciphertext.= $this->_rsaes_oaep_encrypt($m);
+                }
+                return $ciphertext;
+        }
+    }
+
+    /**
+     * Decryption
+     *
+     * @see encrypt()
+     * @access public
+     * @param String $plaintext
+     * @return String
+     */
+    function decrypt($ciphertext)
+    {
+        if ($this->k <= 0) {
+            return false;
+        }
+
+        $ciphertext = str_split($ciphertext, $this->k);
+        $plaintext = '';
+
+        switch ($this->encryptionMode) {
+            case CRYPT_RSA_ENCRYPTION_PKCS1:
+                $decrypt = '_rsaes_pkcs1_v1_5_decrypt';
+                break;
+            //case CRYPT_RSA_ENCRYPTION_OAEP:
+            default:
+                $decrypt = '_rsaes_oaep_decrypt';
+        }
+
+        foreach ($ciphertext as $c) {
+            $temp = $this->$decrypt($c);
+            if ($temp === false) {
+                return false;
+            }
+            $plaintext.= $temp;
+        }
+
+        return $plaintext;
+    }
+
+    /**
+     * Create a signature
+     *
+     * @see verify()
+     * @access public
+     * @param String $message
+     * @return String
+     */
+    function sign($message)
+    {
+        if (empty($this->modulus) || empty($this->exponent)) {
+            return false;
+        }
+
+        switch ($this->signatureMode) {
+            case CRYPT_RSA_SIGNATURE_PKCS1:
+                return $this->_rsassa_pkcs1_v1_5_sign($message);
+            //case CRYPT_RSA_SIGNATURE_PSS:
+            default:
+                return $this->_rsassa_pss_sign($message);
+        }
+    }
+
+    /**
+     * Verifies a signature
+     *
+     * @see sign()
+     * @access public
+     * @param String $message
+     * @param String $signature
+     * @return Boolean
+     */
+    function verify($message, $signature)
+    {
+        if (empty($this->modulus) || empty($this->exponent)) {
+            return false;
+        }
+
+        switch ($this->signatureMode) {
+            case CRYPT_RSA_SIGNATURE_PKCS1:
+                return $this->_rsassa_pkcs1_v1_5_verify($message, $signature);
+            //case CRYPT_RSA_SIGNATURE_PSS:
+            default:
+                return $this->_rsassa_pss_verify($message, $signature);
+        }
+    }
+}
diff --git a/library/phpseclib/Crypt/Random.php b/library/phpseclib/Crypt/Random.php
new file mode 100644 (file)
index 0000000..3e14edd
--- /dev/null
@@ -0,0 +1,142 @@
+<?php
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * Random Number Generator
+ *
+ * PHP versions 4 and 5
+ *
+ * Here's a short example of how to use this library:
+ * <code>
+ * <?php
+ *    include('Crypt/Random.php');
+ *
+ *    echo crypt_random();
+ * ?>
+ * </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_Random
+ * @author     Jim Wigginton <terrafrost@php.net>
+ * @copyright  MMVII Jim Wigginton
+ * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @version    $Id: Random.php,v 1.9 2010/04/24 06:40:48 terrafrost Exp $
+ * @link       http://phpseclib.sourceforge.net
+ */
+
+/**
+ * Generate a random value.
+ *
+ * On 32-bit machines, the largest distance that can exist between $min and $max is 2**31.
+ * If $min and $max are farther apart than that then the last ($max - range) numbers.
+ *
+ * Depending on how this is being used, it may be worth while to write a replacement.  For example,
+ * a PHP-based web app that stores its data in an SQL database can collect more entropy than this function
+ * can.
+ *
+ * @param optional Integer $min
+ * @param optional Integer $max
+ * @return Integer
+ * @access public
+ */
+function crypt_random($min = 0, $max = 0x7FFFFFFF)
+{
+    if ($min == $max) {
+        return $min;
+    }
+
+    if (function_exists('openssl_random_pseudo_bytes')) {
+        // openssl_random_pseudo_bytes() is slow on windows per the following:
+        // http://stackoverflow.com/questions/1940168/openssl-random-pseudo-bytes-is-slow-php
+        if ((PHP_OS & "\xDF\xDF\xDF") !== 'WIN') { // PHP_OS & "\xDF\xDF\xDF" == strtoupper(substr(PHP_OS, 0, 3)), but a lot faster
+            extract(unpack('Nrandom', openssl_random_pseudo_bytes(4)));
+
+            return abs($random) % ($max - $min) + $min; 
+        }
+    }
+
+    // see http://en.wikipedia.org/wiki//dev/random
+    static $urandom = true;
+    if ($urandom === true) {
+        // Warning's will be output unles the error suppression operator is used.  Errors such as
+        // "open_basedir restriction in effect", "Permission denied", "No such file or directory", etc.
+        $urandom = @fopen('/dev/urandom', 'rb');
+    }
+    if (!is_bool($urandom)) {
+        extract(unpack('Nrandom', fread($urandom, 4)));
+
+        // say $min = 0 and $max = 3.  if we didn't do abs() then we could have stuff like this:
+        // -4 % 3 + 0 = -1, even though -1 < $min
+        return abs($random) % ($max - $min) + $min;
+    }
+
+    /* Prior to PHP 4.2.0, mt_srand() had to be called before mt_rand() could be called.
+       Prior to PHP 5.2.6, mt_rand()'s automatic seeding was subpar, as elaborated here:
+
+       http://www.suspekt.org/2008/08/17/mt_srand-and-not-so-random-numbers/
+
+       The seeding routine is pretty much ripped from PHP's own internal GENERATE_SEED() macro:
+
+       http://svn.php.net/viewvc/php/php-src/tags/php_5_3_2/ext/standard/php_rand.h?view=markup */
+    if (version_compare(PHP_VERSION, '5.2.5', '<=')) { 
+        static $seeded;
+        if (!isset($seeded)) {
+            $seeded = true;
+            mt_srand(fmod(time() * getmypid(), 0x7FFFFFFF) ^ fmod(1000000 * lcg_value(), 0x7FFFFFFF));
+        }
+    }
+
+    static $crypto;
+
+    // The CSPRNG's Yarrow and Fortuna periodically reseed.  This function can be reseeded by hitting F5
+    // in the browser and reloading the page.
+
+    if (!isset($crypto)) {
+        $key = $iv = '';
+        for ($i = 0; $i < 8; $i++) {
+            $key.= pack('n', mt_rand(0, 0xFFFF));
+            $iv .= pack('n', mt_rand(0, 0xFFFF));
+        }
+        switch (true) {
+            case class_exists('Crypt_AES'):
+                $crypto = new Crypt_AES(CRYPT_AES_MODE_CTR);
+                break;
+            case class_exists('Crypt_TripleDES'):
+                $crypto = new Crypt_TripleDES(CRYPT_DES_MODE_CTR);
+                break;
+            case class_exists('Crypt_DES'):
+                $crypto = new Crypt_DES(CRYPT_DES_MODE_CTR);
+                break;
+            case class_exists('Crypt_RC4'):
+                $crypto = new Crypt_RC4();
+                break;
+            default:
+                extract(unpack('Nrandom', pack('H*', sha1(mt_rand(0, 0x7FFFFFFF)))));
+                return abs($random) % ($max - $min) + $min;
+        }
+        $crypto->setKey($key);
+        $crypto->setIV($iv);
+        $crypto->enableContinuousBuffer();
+    }
+
+    extract(unpack('Nrandom', $crypto->encrypt("\0\0\0\0")));
+    return abs($random) % ($max - $min) + $min;
+}
diff --git a/library/phpseclib/Crypt/Rijndael.php b/library/phpseclib/Crypt/Rijndael.php
new file mode 100644 (file)
index 0000000..e7f17a6
--- /dev/null
@@ -0,0 +1,1478 @@
+<?php
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * Pure-PHP implementation of Rijndael.
+ *
+ * Does not use mcrypt, even when available, for reasons that are explained below.
+ *
+ * PHP versions 4 and 5
+ *
+ * If {@link Crypt_Rijndael::setBlockLength() setBlockLength()} isn't called, it'll be assumed to be 128 bits.  If 
+ * {@link Crypt_Rijndael::setKeyLength() setKeyLength()} isn't called, it'll be calculated from 
+ * {@link Crypt_Rijndael::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.
+ *
+ * Not all Rijndael implementations may support 160-bits or 224-bits as the block length / key length.  mcrypt, for example,
+ * does not.  AES, itself, only supports block lengths of 128 and key lengths of 128, 192, and 256.
+ * {@link http://csrc.nist.gov/archive/aes/rijndael/Rijndael-ammended.pdf#page=10 Rijndael-ammended.pdf#page=10} defines the
+ * algorithm for block lengths of 192 and 256 but not for block lengths / key lengths of 160 and 224.  Indeed, 160 and 224
+ * are first defined as valid key / block lengths in 
+ * {@link http://csrc.nist.gov/archive/aes/rijndael/Rijndael-ammended.pdf#page=44 Rijndael-ammended.pdf#page=44}: 
+ * Extensions: Other block and Cipher Key lengths.
+ *
+ * {@internal The variable names are the same as those in 
+ * {@link http://www.csrc.nist.gov/publications/fips/fips197/fips-197.pdf#page=10 fips-197.pdf#page=10}.}}
+ *
+ * Here's a short example of how to use this library:
+ * <code>
+ * <?php
+ *    include('Crypt/Rijndael.php');
+ *
+ *    $rijndael = new Crypt_Rijndael();
+ *
+ *    $rijndael->setKey('abcdefghijklmnop');
+ *
+ *    $size = 10 * 1024;
+ *    $plaintext = '';
+ *    for ($i = 0; $i < $size; $i++) {
+ *        $plaintext.= 'a';
+ *    }
+ *
+ *    echo $rijndael->decrypt($rijndael->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_Rijndael
+ * @author     Jim Wigginton <terrafrost@php.net>
+ * @copyright  MMVIII Jim Wigginton
+ * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @version    $Id: Rijndael.php,v 1.12 2010/02/09 06:10:26 terrafrost Exp $
+ * @link       http://phpseclib.sourceforge.net
+ */
+
+/**#@+
+ * @access public
+ * @see Crypt_Rijndael::encrypt()
+ * @see Crypt_Rijndael::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_RIJNDAEL_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_RIJNDAEL_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_RIJNDAEL_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_RIJNDAEL_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_RIJNDAEL_MODE_OFB', 4);
+/**#@-*/
+
+/**#@+
+ * @access private
+ * @see Crypt_Rijndael::Crypt_Rijndael()
+ */
+/**
+ * Toggles the internal implementation
+ */
+define('CRYPT_RIJNDAEL_MODE_INTERNAL', 1);
+/**
+ * Toggles the mcrypt implementation
+ */
+define('CRYPT_RIJNDAEL_MODE_MCRYPT', 2);
+/**#@-*/
+
+/**
+ * Pure-PHP implementation of Rijndael.
+ *
+ * @author  Jim Wigginton <terrafrost@php.net>
+ * @version 0.1.0
+ * @access  public
+ * @package Crypt_Rijndael
+ */
+class Crypt_Rijndael {
+    /**
+     * The Encryption Mode
+     *
+     * @see Crypt_Rijndael::Crypt_Rijndael()
+     * @var Integer
+     * @access private
+     */
+    var $mode;
+
+    /**
+     * The Key
+     *
+     * @see Crypt_Rijndael::setKey()
+     * @var String
+     * @access private
+     */
+    var $key = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
+
+    /**
+     * The Initialization Vector
+     *
+     * @see Crypt_Rijndael::setIV()
+     * @var String
+     * @access private
+     */
+    var $iv = '';
+
+    /**
+     * A "sliding" Initialization Vector
+     *
+     * @see Crypt_Rijndael::enableContinuousBuffer()
+     * @var String
+     * @access private
+     */
+    var $encryptIV = '';
+
+    /**
+     * A "sliding" Initialization Vector
+     *
+     * @see Crypt_Rijndael::enableContinuousBuffer()
+     * @var String
+     * @access private
+     */
+    var $decryptIV = '';
+
+    /**
+     * Continuous Buffer status
+     *
+     * @see Crypt_Rijndael::enableContinuousBuffer()
+     * @var Boolean
+     * @access private
+     */
+    var $continuousBuffer = false;
+
+    /**
+     * Padding status
+     *
+     * @see Crypt_Rijndael::enablePadding()
+     * @var Boolean
+     * @access private
+     */
+    var $padding = true;
+
+    /**
+     * Does the key schedule need to be (re)calculated?
+     *
+     * @see setKey()
+     * @see setBlockLength()
+     * @see setKeyLength()
+     * @var Boolean
+     * @access private
+     */
+    var $changed = true;
+
+    /**
+     * Has the key length explicitly been set or should it be derived from the key, itself?
+     *
+     * @see setKeyLength()
+     * @var Boolean
+     * @access private
+     */
+    var $explicit_key_length = false;
+
+    /**
+     * The Key Schedule
+     *
+     * @see _setup()
+     * @var Array
+     * @access private
+     */
+    var $w;
+
+    /**
+     * The Inverse Key Schedule
+     *
+     * @see _setup()
+     * @var Array
+     * @access private
+     */
+    var $dw;
+
+    /**
+     * The Block Length
+     *
+     * @see setBlockLength()
+     * @var Integer
+     * @access private
+     * @internal The max value is 32, the min value is 16.  All valid values are multiples of 4.  Exists in conjunction with
+     *     $Nb because we need this value and not $Nb to pad strings appropriately.  
+     */
+    var $block_size = 16;
+
+    /**
+     * The Block Length divided by 32
+     *
+     * @see setBlockLength()
+     * @var Integer
+     * @access private
+     * @internal The max value is 256 / 32 = 8, the min value is 128 / 32 = 4.  Exists in conjunction with $block_size 
+     *    because the encryption / decryption / key schedule creation requires this number and not $block_size.  We could 
+     *    derive this from $block_size or vice versa, but that'd mean we'd have to do multiple shift operations, so in lieu
+     *    of that, we'll just precompute it once.
+     *
+     */
+    var $Nb = 4;
+
+    /**
+     * The Key Length
+     *
+     * @see setKeyLength()
+     * @var Integer
+     * @access private
+     * @internal The max value is 256 / 8 = 32, the min value is 128 / 8 = 16.  Exists in conjunction with $key_size
+     *    because the encryption / decryption / key schedule creation requires this number and not $key_size.  We could 
+     *    derive this from $key_size or vice versa, but that'd mean we'd have to do multiple shift operations, so in lieu
+     *    of that, we'll just precompute it once.
+     */
+    var $key_size = 16;
+
+    /**
+     * The Key Length divided by 32
+     *
+     * @see setKeyLength()
+     * @var Integer
+     * @access private
+     * @internal The max value is 256 / 32 = 8, the min value is 128 / 32 = 4
+     */
+    var $Nk = 4;
+
+    /**
+     * The Number of Rounds
+     *
+     * @var Integer
+     * @access private
+     * @internal The max value is 14, the min value is 10.
+     */
+    var $Nr;
+
+    /**
+     * Shift offsets
+     *
+     * @var Array
+     * @access private
+     */
+    var $c;
+
+    /**
+     * Precomputed mixColumns table
+     *
+     * @see Crypt_Rijndael()
+     * @var Array
+     * @access private
+     */
+    var $t0;
+
+    /**
+     * Precomputed mixColumns table
+     *
+     * @see Crypt_Rijndael()
+     * @var Array
+     * @access private
+     */
+    var $t1;
+
+    /**
+     * Precomputed mixColumns table
+     *
+     * @see Crypt_Rijndael()
+     * @var Array
+     * @access private
+     */
+    var $t2;
+
+    /**
+     * Precomputed mixColumns table
+     *
+     * @see Crypt_Rijndael()
+     * @var Array
+     * @access private
+     */
+    var $t3;
+
+    /**
+     * Precomputed invMixColumns table
+     *
+     * @see Crypt_Rijndael()
+     * @var Array
+     * @access private
+     */
+    var $dt0;
+
+    /**
+     * Precomputed invMixColumns table
+     *
+     * @see Crypt_Rijndael()
+     * @var Array
+     * @access private
+     */
+    var $dt1;
+
+    /**
+     * Precomputed invMixColumns table
+     *
+     * @see Crypt_Rijndael()
+     * @var Array
+     * @access private
+     */
+    var $dt2;
+
+    /**
+     * Precomputed invMixColumns table
+     *
+     * @see Crypt_Rijndael()
+     * @var Array
+     * @access private
+     */
+    var $dt3;
+
+    /**
+     * Is the mode one that is paddable?
+     *
+     * @see Crypt_Rijndael::Crypt_Rijndael()
+     * @var Boolean
+     * @access private
+     */
+    var $paddable = false;
+
+    /**
+     * Encryption buffer for CTR, OFB and CFB modes
+     *
+     * @see Crypt_Rijndael::encrypt()
+     * @var String
+     * @access private
+     */
+    var $enbuffer = array('encrypted' => '', 'xor' => '');
+
+    /**
+     * Decryption buffer for CTR, OFB and CFB modes
+     *
+     * @see Crypt_Rijndael::decrypt()
+     * @var String
+     * @access private
+     */
+    var $debuffer = array('ciphertext' => '');
+
+    /**
+     * Default Constructor.
+     *
+     * Determines whether or not the mcrypt extension should be used.  $mode should only, at present, be
+     * CRYPT_RIJNDAEL_MODE_ECB or CRYPT_RIJNDAEL_MODE_CBC.  If not explictly set, CRYPT_RIJNDAEL_MODE_CBC will be used.
+     *
+     * @param optional Integer $mode
+     * @return Crypt_Rijndael
+     * @access public
+     */
+    function Crypt_Rijndael($mode = CRYPT_RIJNDAEL_MODE_CBC)
+    {
+        switch ($mode) {
+            case CRYPT_RIJNDAEL_MODE_ECB:
+            case CRYPT_RIJNDAEL_MODE_CBC:
+                $this->paddable = true;
+                $this->mode = $mode;
+                break;
+            case CRYPT_RIJNDAEL_MODE_CTR:
+            case CRYPT_RIJNDAEL_MODE_CFB:
+            case CRYPT_RIJNDAEL_MODE_OFB:
+                $this->mode = $mode;
+                break;
+            default:
+                $this->paddable = true;
+                $this->mode = CRYPT_RIJNDAEL_MODE_CBC;
+        }
+
+        $t3 = &$this->t3;
+        $t2 = &$this->t2;
+        $t1 = &$this->t1;
+        $t0 = &$this->t0;
+
+        $dt3 = &$this->dt3;
+        $dt2 = &$this->dt2;
+        $dt1 = &$this->dt1;
+        $dt0 = &$this->dt0;
+
+        // according to <http://csrc.nist.gov/archive/aes/rijndael/Rijndael-ammended.pdf#page=19> (section 5.2.1), 
+        // precomputed tables can be used in the mixColumns phase.  in that example, they're assigned t0...t3, so
+        // those are the names we'll use.
+        $t3 = array(
+            0x6363A5C6, 0x7C7C84F8, 0x777799EE, 0x7B7B8DF6, 0xF2F20DFF, 0x6B6BBDD6, 0x6F6FB1DE, 0xC5C55491, 
+            0x30305060, 0x01010302, 0x6767A9CE, 0x2B2B7D56, 0xFEFE19E7, 0xD7D762B5, 0xABABE64D, 0x76769AEC, 
+            0xCACA458F, 0x82829D1F, 0xC9C94089, 0x7D7D87FA, 0xFAFA15EF, 0x5959EBB2, 0x4747C98E, 0xF0F00BFB, 
+            0xADADEC41, 0xD4D467B3, 0xA2A2FD5F, 0xAFAFEA45, 0x9C9CBF23, 0xA4A4F753, 0x727296E4, 0xC0C05B9B, 
+            0xB7B7C275, 0xFDFD1CE1, 0x9393AE3D, 0x26266A4C, 0x36365A6C, 0x3F3F417E, 0xF7F702F5, 0xCCCC4F83, 
+            0x34345C68, 0xA5A5F451, 0xE5E534D1, 0xF1F108F9, 0x717193E2, 0xD8D873AB, 0x31315362, 0x15153F2A, 
+            0x04040C08, 0xC7C75295, 0x23236546, 0xC3C35E9D, 0x18182830, 0x9696A137, 0x05050F0A, 0x9A9AB52F, 
+            0x0707090E, 0x12123624, 0x80809B1B, 0xE2E23DDF, 0xEBEB26CD, 0x2727694E, 0xB2B2CD7F, 0x75759FEA, 
+            0x09091B12, 0x83839E1D, 0x2C2C7458, 0x1A1A2E34, 0x1B1B2D36, 0x6E6EB2DC, 0x5A5AEEB4, 0xA0A0FB5B, 
+            0x5252F6A4, 0x3B3B4D76, 0xD6D661B7, 0xB3B3CE7D, 0x29297B52, 0xE3E33EDD, 0x2F2F715E, 0x84849713, 
+            0x5353F5A6, 0xD1D168B9, 0x00000000, 0xEDED2CC1, 0x20206040, 0xFCFC1FE3, 0xB1B1C879, 0x5B5BEDB6, 
+            0x6A6ABED4, 0xCBCB468D, 0xBEBED967, 0x39394B72, 0x4A4ADE94, 0x4C4CD498, 0x5858E8B0, 0xCFCF4A85, 
+            0xD0D06BBB, 0xEFEF2AC5, 0xAAAAE54F, 0xFBFB16ED, 0x4343C586, 0x4D4DD79A, 0x33335566, 0x85859411, 
+            0x4545CF8A, 0xF9F910E9, 0x02020604, 0x7F7F81FE, 0x5050F0A0, 0x3C3C4478, 0x9F9FBA25, 0xA8A8E34B, 
+            0x5151F3A2, 0xA3A3FE5D, 0x4040C080, 0x8F8F8A05, 0x9292AD3F, 0x9D9DBC21, 0x38384870, 0xF5F504F1, 
+            0xBCBCDF63, 0xB6B6C177, 0xDADA75AF, 0x21216342, 0x10103020, 0xFFFF1AE5, 0xF3F30EFD, 0xD2D26DBF, 
+            0xCDCD4C81, 0x0C0C1418, 0x13133526, 0xECEC2FC3, 0x5F5FE1BE, 0x9797A235, 0x4444CC88, 0x1717392E, 
+            0xC4C45793, 0xA7A7F255, 0x7E7E82FC, 0x3D3D477A, 0x6464ACC8, 0x5D5DE7BA, 0x19192B32, 0x737395E6, 
+            0x6060A0C0, 0x81819819, 0x4F4FD19E, 0xDCDC7FA3, 0x22226644, 0x2A2A7E54, 0x9090AB3B, 0x8888830B, 
+            0x4646CA8C, 0xEEEE29C7, 0xB8B8D36B, 0x14143C28, 0xDEDE79A7, 0x5E5EE2BC, 0x0B0B1D16, 0xDBDB76AD, 
+            0xE0E03BDB, 0x32325664, 0x3A3A4E74, 0x0A0A1E14, 0x4949DB92, 0x06060A0C, 0x24246C48, 0x5C5CE4B8, 
+            0xC2C25D9F, 0xD3D36EBD, 0xACACEF43, 0x6262A6C4, 0x9191A839, 0x9595A431, 0xE4E437D3, 0x79798BF2, 
+            0xE7E732D5, 0xC8C8438B, 0x3737596E, 0x6D6DB7DA, 0x8D8D8C01, 0xD5D564B1, 0x4E4ED29C, 0xA9A9E049, 
+            0x6C6CB4D8, 0x5656FAAC, 0xF4F407F3, 0xEAEA25CF, 0x6565AFCA, 0x7A7A8EF4, 0xAEAEE947, 0x08081810, 
+            0xBABAD56F, 0x787888F0, 0x25256F4A, 0x2E2E725C, 0x1C1C2438, 0xA6A6F157, 0xB4B4C773, 0xC6C65197, 
+            0xE8E823CB, 0xDDDD7CA1, 0x74749CE8, 0x1F1F213E, 0x4B4BDD96, 0xBDBDDC61, 0x8B8B860D, 0x8A8A850F, 
+            0x707090E0, 0x3E3E427C, 0xB5B5C471, 0x6666AACC, 0x4848D890, 0x03030506, 0xF6F601F7, 0x0E0E121C, 
+            0x6161A3C2, 0x35355F6A, 0x5757F9AE, 0xB9B9D069, 0x86869117, 0xC1C15899, 0x1D1D273A, 0x9E9EB927, 
+            0xE1E138D9, 0xF8F813EB, 0x9898B32B, 0x11113322, 0x6969BBD2, 0xD9D970A9, 0x8E8E8907, 0x9494A733, 
+            0x9B9BB62D, 0x1E1E223C, 0x87879215, 0xE9E920C9, 0xCECE4987, 0x5555FFAA, 0x28287850, 0xDFDF7AA5, 
+            0x8C8C8F03, 0xA1A1F859, 0x89898009, 0x0D0D171A, 0xBFBFDA65, 0xE6E631D7, 0x4242C684, 0x6868B8D0, 
+            0x4141C382, 0x9999B029, 0x2D2D775A, 0x0F0F111E, 0xB0B0CB7B, 0x5454FCA8, 0xBBBBD66D, 0x16163A2C
+        );
+
+        $dt3 = array(
+            0xF4A75051, 0x4165537E, 0x17A4C31A, 0x275E963A, 0xAB6BCB3B, 0x9D45F11F, 0xFA58ABAC, 0xE303934B, 
+            0x30FA5520, 0x766DF6AD, 0xCC769188, 0x024C25F5, 0xE5D7FC4F, 0x2ACBD7C5, 0x35448026, 0x62A38FB5, 
+            0xB15A49DE, 0xBA1B6725, 0xEA0E9845, 0xFEC0E15D, 0x2F7502C3, 0x4CF01281, 0x4697A38D, 0xD3F9C66B, 
+            0x8F5FE703, 0x929C9515, 0x6D7AEBBF, 0x5259DA95, 0xBE832DD4, 0x7421D358, 0xE0692949, 0xC9C8448E, 
+            0xC2896A75, 0x8E7978F4, 0x583E6B99, 0xB971DD27, 0xE14FB6BE, 0x88AD17F0, 0x20AC66C9, 0xCE3AB47D, 
+            0xDF4A1863, 0x1A3182E5, 0x51336097, 0x537F4562, 0x6477E0B1, 0x6BAE84BB, 0x81A01CFE, 0x082B94F9, 
+            0x48685870, 0x45FD198F, 0xDE6C8794, 0x7BF8B752, 0x73D323AB, 0x4B02E272, 0x1F8F57E3, 0x55AB2A66, 
+            0xEB2807B2, 0xB5C2032F, 0xC57B9A86, 0x3708A5D3, 0x2887F230, 0xBFA5B223, 0x036ABA02, 0x16825CED, 
+            0xCF1C2B8A, 0x79B492A7, 0x07F2F0F3, 0x69E2A14E, 0xDAF4CD65, 0x05BED506, 0x34621FD1, 0xA6FE8AC4, 
+            0x2E539D34, 0xF355A0A2, 0x8AE13205, 0xF6EB75A4, 0x83EC390B, 0x60EFAA40, 0x719F065E, 0x6E1051BD, 
+            0x218AF93E, 0xDD063D96, 0x3E05AEDD, 0xE6BD464D, 0x548DB591, 0xC45D0571, 0x06D46F04, 0x5015FF60, 
+            0x98FB2419, 0xBDE997D6, 0x4043CC89, 0xD99E7767, 0xE842BDB0, 0x898B8807, 0x195B38E7, 0xC8EEDB79, 
+            0x7C0A47A1, 0x420FE97C, 0x841EC9F8, 0x00000000, 0x80868309, 0x2BED4832, 0x1170AC1E, 0x5A724E6C, 
+            0x0EFFFBFD, 0x8538560F, 0xAED51E3D, 0x2D392736, 0x0FD9640A, 0x5CA62168, 0x5B54D19B, 0x362E3A24, 
+            0x0A67B10C, 0x57E70F93, 0xEE96D2B4, 0x9B919E1B, 0xC0C54F80, 0xDC20A261, 0x774B695A, 0x121A161C, 
+            0x93BA0AE2, 0xA02AE5C0, 0x22E0433C, 0x1B171D12, 0x090D0B0E, 0x8BC7ADF2, 0xB6A8B92D, 0x1EA9C814, 
+            0xF1198557, 0x75074CAF, 0x99DDBBEE, 0x7F60FDA3, 0x01269FF7, 0x72F5BC5C, 0x663BC544, 0xFB7E345B, 
+            0x4329768B, 0x23C6DCCB, 0xEDFC68B6, 0xE4F163B8, 0x31DCCAD7, 0x63851042, 0x97224013, 0xC6112084, 
+            0x4A247D85, 0xBB3DF8D2, 0xF93211AE, 0x29A16DC7, 0x9E2F4B1D, 0xB230F3DC, 0x8652EC0D, 0xC1E3D077, 
+            0xB3166C2B, 0x70B999A9, 0x9448FA11, 0xE9642247, 0xFC8CC4A8, 0xF03F1AA0, 0x7D2CD856, 0x3390EF22, 
+            0x494EC787, 0x38D1C1D9, 0xCAA2FE8C, 0xD40B3698, 0xF581CFA6, 0x7ADE28A5, 0xB78E26DA, 0xADBFA43F, 
+            0x3A9DE42C, 0x78920D50, 0x5FCC9B6A, 0x7E466254, 0x8D13C2F6, 0xD8B8E890, 0x39F75E2E, 0xC3AFF582, 
+            0x5D80BE9F, 0xD0937C69, 0xD52DA96F, 0x2512B3CF, 0xAC993BC8, 0x187DA710, 0x9C636EE8, 0x3BBB7BDB, 
+            0x267809CD, 0x5918F46E, 0x9AB701EC, 0x4F9AA883, 0x956E65E6, 0xFFE67EAA, 0xBCCF0821, 0x15E8E6EF, 
+            0xE79BD9BA, 0x6F36CE4A, 0x9F09D4EA, 0xB07CD629, 0xA4B2AF31, 0x3F23312A, 0xA59430C6, 0xA266C035, 
+            0x4EBC3774, 0x82CAA6FC, 0x90D0B0E0, 0xA7D81533, 0x04984AF1, 0xECDAF741, 0xCD500E7F, 0x91F62F17, 
+            0x4DD68D76, 0xEFB04D43, 0xAA4D54CC, 0x9604DFE4, 0xD1B5E39E, 0x6A881B4C, 0x2C1FB8C1, 0x65517F46, 
+            0x5EEA049D, 0x8C355D01, 0x877473FA, 0x0B412EFB, 0x671D5AB3, 0xDBD25292, 0x105633E9, 0xD647136D, 
+            0xD7618C9A, 0xA10C7A37, 0xF8148E59, 0x133C89EB, 0xA927EECE, 0x61C935B7, 0x1CE5EDE1, 0x47B13C7A, 
+            0xD2DF599C, 0xF2733F55, 0x14CE7918, 0xC737BF73, 0xF7CDEA53, 0xFDAA5B5F, 0x3D6F14DF, 0x44DB8678, 
+            0xAFF381CA, 0x68C43EB9, 0x24342C38, 0xA3405FC2, 0x1DC37216, 0xE2250CBC, 0x3C498B28, 0x0D9541FF, 
+            0xA8017139, 0x0CB3DE08, 0xB4E49CD8, 0x56C19064, 0xCB84617B, 0x32B670D5, 0x6C5C7448, 0xB85742D0
+        );
+
+        for ($i = 0; $i < 256; $i++) {
+            $t2[$i <<  8] = (($t3[$i] <<  8) & 0xFFFFFF00) | (($t3[$i] >> 24) & 0x000000FF);
+            $t1[$i << 16] = (($t3[$i] << 16) & 0xFFFF0000) | (($t3[$i] >> 16) & 0x0000FFFF);
+            $t0[$i << 24] = (($t3[$i] << 24) & 0xFF000000) | (($t3[$i] >>  8) & 0x00FFFFFF);
+
+            $dt2[$i <<  8] = (($this->dt3[$i] <<  8) & 0xFFFFFF00) | (($dt3[$i] >> 24) & 0x000000FF);
+            $dt1[$i << 16] = (($this->dt3[$i] << 16) & 0xFFFF0000) | (($dt3[$i] >> 16) & 0x0000FFFF);
+            $dt0[$i << 24] = (($this->dt3[$i] << 24) & 0xFF000000) | (($dt3[$i] >>  8) & 0x00FFFFFF);
+        }
+    }
+
+    /**
+     * Sets the key.
+     *
+     * Keys can be of any length.  Rijndael, itself, requires the use of a key that's between 128-bits and 256-bits long and
+     * whose length is a multiple of 32.  If the key is less than 256-bits and the key length isn't set, we round the length
+     * up to the closest valid key length, padding $key with null bytes.  If the key is more than 256-bits, we trim the
+     * excess bits.
+     *
+     * If the key is not explicitly set, it'll be assumed to be all null bytes.
+     *
+     * @access public
+     * @param String $key
+     */
+    function setKey($key)
+    {
+        $this->key = $key;
+        $this->changed = true;
+    }
+
+    /**
+     * Sets the initialization vector. (optional)
+     *
+     * SetIV is not required when CRYPT_RIJNDAEL_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, $this->block_size), $this->block_size, chr(0));
+    }
+
+    /**
+     * Sets the key length
+     *
+     * Valid key lengths are 128, 160, 192, 224, and 256.  If the length is less than 128, it will be rounded up to
+     * 128.  If the length is greater then 128 and invalid, it will be rounded down to the closest valid amount.
+     *
+     * @access public
+     * @param Integer $length
+     */
+    function setKeyLength($length)
+    {
+        $length >>= 5;
+        if ($length > 8) {
+            $length = 8;
+        } else if ($length < 4) {
+            $length = 4;
+        }
+        $this->Nk = $length;
+        $this->key_size = $length << 2;
+
+        $this->explicit_key_length = true;
+        $this->changed = true;
+    }
+
+    /**
+     * Sets the password.
+     *
+     * Depending on what $method is set to, setPassword()'s (optional) parameters are as follows:
+     *     {@link http://en.wikipedia.org/wiki/PBKDF2 pbkdf2}:
+     *         $hash, $salt, $count
+     *     Set $dkLen by calling setKeyLength()
+     *
+     * @param String $password
+     * @param optional String $method
+     * @access public
+     */
+    function setPassword($password, $method = 'pbkdf2')
+    {
+        $key = '';
+
+        switch ($method) {
+            default: // 'pbkdf2'
+                list(, , $hash, $salt, $count) = func_get_args();
+                if (!isset($hash)) {
+                    $hash = 'sha1';
+                }
+                // WPA and WPA use the SSID as the salt
+                if (!isset($salt)) {
+                    $salt = 'phpseclib/salt';
+                }
+                // RFC2898#section-4.2 uses 1,000 iterations by default
+                // WPA and WPA2 use 4,096.
+                if (!isset($count)) {
+                    $count = 1000;
+                }
+
+                if (!class_exists('Crypt_Hash')) {
+                    require_once('Crypt/Hash.php');
+                }
+
+                $i = 1;
+                while (strlen($key) < $this->key_size) { // $dkLen == $this->key_size
+                    //$dk.= $this->_pbkdf($password, $salt, $count, $i++);
+                    $hmac = new Crypt_Hash();
+                    $hmac->setHash($hash);
+                    $hmac->setKey($password);
+                    $f = $u = $hmac->hash($salt . pack('N', $i++));
+                    for ($j = 2; $j <= $count; $j++) {
+                        $u = $hmac->hash($u);
+                        $f^= $u;
+                    }
+                    $key.= $f;
+                }
+        }
+
+        $this->setKey(substr($key, 0, $this->key_size));
+    }
+
+    /**
+     * Sets the block length
+     *
+     * Valid block lengths are 128, 160, 192, 224, and 256.  If the length is less than 128, it will be rounded up to
+     * 128.  If the length is greater then 128 and invalid, it will be rounded down to the closest valid amount.
+     *
+     * @access public
+     * @param Integer $length
+     */
+    function setBlockLength($length)
+    {
+        $length >>= 5;
+        if ($length > 8) {
+            $length = 8;
+        } else if ($length < 4) {
+            $length = 4;
+        }
+        $this->Nb = $length;
+        $this->block_size = $length << 2;
+        $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_Rijndael::decrypt()
+     * @see Crypt_Rijndael::encrypt()
+     * @access public
+     * @param Integer $length
+     * @param String $iv
+     */
+    function _generate_xor($length, &$iv)
+    {
+        $xor = '';
+        $block_size = $this->block_size;
+        $num_blocks = floor(($length + ($block_size - 1)) / $block_size);
+        for ($i = 0; $i < $num_blocks; $i++) {
+            $xor.= $iv;
+            for ($j = 4; $j <= $block_size; $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.
+     *
+     * $plaintext will be padded with additional bytes such that it's length is a multiple of the block size.  Other Rjindael
+     * implementations may or may not pad in the same manner.  Other common approaches to padding and the reasons why it's
+     * necessary are discussed in the following
+     * URL:
+     *
+     * {@link http://www.di-mgt.com.au/cryptopad.html http://www.di-mgt.com.au/cryptopad.html}
+     *
+     * An alternative to padding is to, separately, send the length of the file.  This is what SSH, in fact, does.
+     * strlen($plaintext) will still need to be a multiple of 8, however, arbitrary values can be added to make it that
+     * length.
+     *
+     * @see Crypt_Rijndael::decrypt()
+     * @access public
+     * @param String $plaintext
+     */
+    function encrypt($plaintext)
+    {
+        $this->_setup();
+        if ($this->paddable) {
+            $plaintext = $this->_pad($plaintext);
+        }
+
+        $block_size = $this->block_size;
+        $buffer = &$this->enbuffer;
+        $continuousBuffer = $this->continuousBuffer;
+        $ciphertext = '';
+        switch ($this->mode) {
+            case CRYPT_RIJNDAEL_MODE_ECB:
+                for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
+                    $ciphertext.= $this->_encryptBlock(substr($plaintext, $i, $block_size));
+                }
+                break;
+            case CRYPT_RIJNDAEL_MODE_CBC:
+                $xor = $this->encryptIV;
+                for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
+                    $block = substr($plaintext, $i, $block_size);
+                    $block = $this->_encryptBlock($block ^ $xor);
+                    $xor = $block;
+                    $ciphertext.= $block;
+                }
+                if ($this->continuousBuffer) {
+                    $this->encryptIV = $xor;
+                }
+                break;
+            case CRYPT_RIJNDAEL_MODE_CTR:
+                $xor = $this->encryptIV;
+                if (!empty($buffer['encrypted'])) {
+                    for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
+                        $block = substr($plaintext, $i, $block_size);
+                        $buffer['encrypted'].= $this->_encryptBlock($this->_generate_xor($block_size, $xor));
+                        $key = $this->_string_shift($buffer['encrypted'], $block_size);
+                        $ciphertext.= $block ^ $key;
+                    }
+                } else {
+                    for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
+                        $block = substr($plaintext, $i, $block_size);
+                        $key = $this->_encryptBlock($this->_generate_xor($block_size, $xor));
+                        $ciphertext.= $block ^ $key;
+                    }
+                }
+                if ($this->continuousBuffer) {
+                    $this->encryptIV = $xor;
+                    if ($start = strlen($plaintext) % $block_size) {
+                        $buffer['encrypted'] = substr($key, $start) . $buffer['encrypted'];
+                    }
+                }
+                break;
+            case CRYPT_RIJNDAEL_MODE_CFB:
+                if (!empty($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); $i+=$block_size) {
+                    $block = substr($plaintext, $i, $block_size);
+                    $xor = $this->_encryptBlock($iv);
+                    $iv = $block ^ $xor;
+                    if ($continuousBuffer && strlen($iv) != $block_size) {
+                        $buffer = array(
+                            'encrypted' => $iv,
+                            'xor' => substr($xor, strlen($iv))
+                        );
+                    }
+                    $ciphertext.= $iv;
+                }
+
+                if ($this->continuousBuffer) {
+                    $this->encryptIV = $iv;
+                }
+                break;
+            case CRYPT_RIJNDAEL_MODE_OFB:
+                $xor = $this->encryptIV;
+                if (strlen($buffer)) {
+                    for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
+                        $xor = $this->_encryptBlock($xor);
+                        $buffer.= $xor;
+                        $key = $this->_string_shift($buffer, $block_size);
+                        $ciphertext.= substr($plaintext, $i, $block_size) ^ $key;
+                    }
+                } else {
+                    for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
+                        $xor = $this->_encryptBlock($xor);
+                        $ciphertext.= substr($plaintext, $i, $block_size) ^ $xor;
+                    }
+                    $key = $xor;
+                }
+                if ($this->continuousBuffer) {
+                    $this->encryptIV = $xor;
+                    if ($start = strlen($plaintext) % $block_size) {
+                         $buffer = substr($key, $start) . $buffer;
+                    }
+                }
+        }
+
+        return $ciphertext;
+    }
+
+    /**
+     * Decrypts a message.
+     *
+     * If strlen($ciphertext) is not a multiple of the block size, null bytes will be added to the end of the string until
+     * it is.
+     *
+     * @see Crypt_Rijndael::encrypt()
+     * @access public
+     * @param String $ciphertext
+     */
+    function decrypt($ciphertext)
+    {
+        $this->_setup();
+
+        if ($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($ciphertext) + ($this->block_size - strlen($ciphertext) % $this->block_size) % $this->block_size, chr(0));
+        }
+
+        $block_size = $this->block_size;
+        $buffer = &$this->debuffer;
+        $continuousBuffer = $this->continuousBuffer;
+        $plaintext = '';
+        switch ($this->mode) {
+            case CRYPT_RIJNDAEL_MODE_ECB:
+                for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
+                    $plaintext.= $this->_decryptBlock(substr($ciphertext, $i, $block_size));
+                }
+                break;
+            case CRYPT_RIJNDAEL_MODE_CBC:
+                $xor = $this->decryptIV;
+                for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
+                    $block = substr($ciphertext, $i, $block_size);
+                    $plaintext.= $this->_decryptBlock($block) ^ $xor;
+                    $xor = $block;
+                }
+                if ($this->continuousBuffer) {
+                    $this->decryptIV = $xor;
+                }
+                break;
+            case CRYPT_RIJNDAEL_MODE_CTR:
+                $xor = $this->decryptIV;
+                if (!empty($buffer['ciphertext'])) {
+                    for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
+                        $block = substr($ciphertext, $i, $block_size);
+                        $buffer['ciphertext'].= $this->_encryptBlock($this->_generate_xor($block_size, $xor));
+                        $key = $this->_string_shift($buffer['ciphertext'], $block_size);
+                        $plaintext.= $block ^ $key;
+                    }
+                } else {
+                    for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
+                        $block = substr($ciphertext, $i, $block_size);
+                        $key = $this->_encryptBlock($this->_generate_xor($block_size, $xor));
+                        $plaintext.= $block ^ $key;
+                    }
+                }
+                if ($this->continuousBuffer) {
+                    $this->decryptIV = $xor;
+                    if ($start = strlen($ciphertext) % $block_size) {
+                        $buffer['ciphertext'] = substr($key, $start) . $buffer['encrypted'];
+                    }
+                }
+                break;
+            case CRYPT_RIJNDAEL_MODE_CFB:
+                if (!empty($buffer['ciphertext'])) {
+                    $plaintext = $ciphertext ^ substr($this->decryptIV, strlen($buffer['ciphertext']));
+                    $buffer['ciphertext'].= substr($ciphertext, 0, strlen($plaintext));
+                    if (strlen($buffer['ciphertext']) == $block_size) {
+                        $xor = $this->_encryptBlock($buffer['ciphertext']);
+                        $buffer['ciphertext'] = '';
+                    }
+                    $start = strlen($plaintext);
+                    $block = $this->decryptIV;
+                } else {
+                    $plaintext = '';
+                    $xor = $this->_encryptBlock($this->decryptIV);
+                    $start = 0;
+                }
+
+                for ($i = $start; $i < strlen($ciphertext); $i+=$block_size) {
+                    $block = substr($ciphertext, $i, $block_size);
+                    $plaintext.= $block ^ $xor;
+                    if ($continuousBuffer && strlen($block) != $block_size) {
+                        $buffer['ciphertext'].= $block;
+                        $block = $xor;
+                    } else if (strlen($block) == $block_size) {
+                        $xor = $this->_encryptBlock($block);
+                    }
+                }
+                if ($this->continuousBuffer) {
+                    $this->decryptIV = $block;
+                }
+                break;
+            case CRYPT_RIJNDAEL_MODE_OFB:
+                $xor = $this->decryptIV;
+                if (strlen($buffer)) {
+                    for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
+                        $xor = $this->_encryptBlock($xor);
+                        $buffer.= $xor;
+                        $key = $this->_string_shift($buffer, $block_size);
+                        $plaintext.= substr($ciphertext, $i, $block_size) ^ $key;
+                    }
+                } else {
+                    for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
+                        $xor = $this->_encryptBlock($xor);
+                        $plaintext.= substr($ciphertext, $i, $block_size) ^ $xor;
+                    }
+                    $key = $xor;
+                }
+                if ($this->continuousBuffer) {
+                    $this->decryptIV = $xor;
+                    if ($start = strlen($ciphertext) % $block_size) {
+                         $buffer = substr($key, $start) . $buffer;
+                    }
+                }
+        }
+
+        return $this->paddable ? $this->_unpad($plaintext) : $plaintext;
+    }
+
+    /**
+     * Encrypts a block
+     *
+     * @access private
+     * @param String $in
+     * @return String
+     */
+    function _encryptBlock($in)
+    {
+        $state = array();
+        $words = unpack('N*word', $in);
+
+        $w = $this->w;
+        $t0 = $this->t0;
+        $t1 = $this->t1;
+        $t2 = $this->t2;
+        $t3 = $this->t3;
+        $Nb = $this->Nb;
+        $Nr = $this->Nr;
+        $c = $this->c;
+
+        // addRoundKey
+        $i = 0;
+        foreach ($words as $word) {
+            $state[] = $word ^ $w[0][$i++];
+        }
+
+        // fips-197.pdf#page=19, "Figure 5. Pseudo Code for the Cipher", states that this loop has four components - 
+        // subBytes, shiftRows, mixColumns, and addRoundKey. fips-197.pdf#page=30, "Implementation Suggestions Regarding 
+        // Various Platforms" suggests that performs enhanced implementations are described in Rijndael-ammended.pdf.
+        // Rijndael-ammended.pdf#page=20, "Implementation aspects / 32-bit processor", discusses such an optimization.
+        // Unfortunately, the description given there is not quite correct.  Per aes.spec.v316.pdf#page=19 [1], 
+        // equation (7.4.7) is supposed to use addition instead of subtraction, so we'll do that here, as well.
+
+        // [1] http://fp.gladman.plus.com/cryptography_technology/rijndael/aes.spec.v316.pdf
+        $temp = array();
+        for ($round = 1; $round < $Nr; $round++) {
+            $i = 0; // $c[0] == 0
+            $j = $c[1];
+            $k = $c[2];
+            $l = $c[3];
+
+            while ($i < $this->Nb) {
+                $temp[$i] = $t0[$state[$i] & 0xFF000000] ^ 
+                            $t1[$state[$j] & 0x00FF0000] ^ 
+                            $t2[$state[$k] & 0x0000FF00] ^ 
+                            $t3[$state[$l] & 0x000000FF] ^ 
+                            $w[$round][$i];
+                $i++;
+                $j = ($j + 1) % $Nb;
+                $k = ($k + 1) % $Nb;
+                $l = ($l + 1) % $Nb;
+            }
+
+            for ($i = 0; $i < $Nb; $i++) {
+                $state[$i] = $temp[$i];
+            }
+        }
+
+        // subWord
+        for ($i = 0; $i < $Nb; $i++) {
+            $state[$i] = $this->_subWord($state[$i]);
+        }
+
+        // shiftRows + addRoundKey
+        $i = 0; // $c[0] == 0
+        $j = $c[1];
+        $k = $c[2];
+        $l = $c[3];
+        while ($i < $this->Nb) {
+            $temp[$i] = ($state[$i] & 0xFF000000) ^ 
+                        ($state[$j] & 0x00FF0000) ^ 
+                        ($state[$k] & 0x0000FF00) ^ 
+                        ($state[$l] & 0x000000FF) ^
+                         $w[$Nr][$i];
+            $i++;
+            $j = ($j + 1) % $Nb;
+            $k = ($k + 1) % $Nb;
+            $l = ($l + 1) % $Nb;
+        }
+        $state = $temp;
+
+        array_unshift($state, 'N*');
+
+        return call_user_func_array('pack', $state);
+    }
+
+    /**
+     * Decrypts a block
+     *
+     * @access private
+     * @param String $in
+     * @return String
+     */
+    function _decryptBlock($in)
+    {
+        $state = array();
+        $words = unpack('N*word', $in);
+
+        $num_states = count($state);
+        $dw = $this->dw;
+        $dt0 = $this->dt0;
+        $dt1 = $this->dt1;
+        $dt2 = $this->dt2;
+        $dt3 = $this->dt3;
+        $Nb = $this->Nb;
+        $Nr = $this->Nr;
+        $c = $this->c;
+
+        // addRoundKey
+        $i = 0;
+        foreach ($words as $word) {
+            $state[] = $word ^ $dw[$Nr][$i++];
+        }
+
+        $temp = array();
+        for ($round = $Nr - 1; $round > 0; $round--) {
+            $i = 0; // $c[0] == 0
+            $j = $Nb - $c[1];
+            $k = $Nb - $c[2];
+            $l = $Nb - $c[3];
+
+            while ($i < $Nb) {
+                $temp[$i] = $dt0[$state[$i] & 0xFF000000] ^ 
+                            $dt1[$state[$j] & 0x00FF0000] ^ 
+                            $dt2[$state[$k] & 0x0000FF00] ^ 
+                            $dt3[$state[$l] & 0x000000FF] ^ 
+                            $dw[$round][$i];
+                $i++;
+                $j = ($j + 1) % $Nb;
+                $k = ($k + 1) % $Nb;
+                $l = ($l + 1) % $Nb;
+            }
+
+            for ($i = 0; $i < $Nb; $i++) {
+                $state[$i] = $temp[$i];
+            }
+        }
+
+        // invShiftRows + invSubWord + addRoundKey
+        $i = 0; // $c[0] == 0
+        $j = $Nb - $c[1];
+        $k = $Nb - $c[2];
+        $l = $Nb - $c[3];
+
+        while ($i < $Nb) {
+            $temp[$i] = $dw[0][$i] ^ 
+                        $this->_invSubWord(($state[$i] & 0xFF000000) | 
+                                           ($state[$j] & 0x00FF0000) | 
+                                           ($state[$k] & 0x0000FF00) | 
+                                           ($state[$l] & 0x000000FF));
+            $i++;
+            $j = ($j + 1) % $Nb;
+            $k = ($k + 1) % $Nb;
+            $l = ($l + 1) % $Nb;
+        }
+
+        $state = $temp;
+
+        array_unshift($state, 'N*');
+
+        return call_user_func_array('pack', $state);
+    }
+
+    /**
+     * Setup Rijndael
+     *
+     * Validates all the variables and calculates $Nr - the number of rounds that need to be performed - and $w - the key
+     * key schedule.
+     *
+     * @access private
+     */
+    function _setup()
+    {
+        // Each number in $rcon is equal to the previous number multiplied by two in Rijndael's finite field.
+        // See http://en.wikipedia.org/wiki/Finite_field_arithmetic#Multiplicative_inverse
+        static $rcon = array(0,
+            0x01000000, 0x02000000, 0x04000000, 0x08000000, 0x10000000,
+            0x20000000, 0x40000000, 0x80000000, 0x1B000000, 0x36000000,
+            0x6C000000, 0xD8000000, 0xAB000000, 0x4D000000, 0x9A000000,
+            0x2F000000, 0x5E000000, 0xBC000000, 0x63000000, 0xC6000000,
+            0x97000000, 0x35000000, 0x6A000000, 0xD4000000, 0xB3000000,
+            0x7D000000, 0xFA000000, 0xEF000000, 0xC5000000, 0x91000000
+        );
+
+        if (!$this->changed) {
+            return;
+        }
+
+        if (!$this->explicit_key_length) {
+            // we do >> 2, here, and not >> 5, as we do above, since strlen($this->key) tells us the number of bytes - not bits
+            $length = strlen($this->key) >> 2;
+            if ($length > 8) {
+                $length = 8;
+            } else if ($length < 4) {
+                $length = 4;
+            }
+            $this->Nk = $length;
+            $this->key_size = $length << 2;
+        }
+
+        $this->key = str_pad(substr($this->key, 0, $this->key_size), $this->key_size, chr(0));
+        $this->encryptIV = $this->decryptIV = $this->iv = str_pad(substr($this->iv, 0, $this->block_size), $this->block_size, chr(0));
+
+        // see Rijndael-ammended.pdf#page=44
+        $this->Nr = max($this->Nk, $this->Nb) + 6;
+
+        // shift offsets for Nb = 5, 7 are defined in Rijndael-ammended.pdf#page=44,
+        //     "Table 8: Shift offsets in Shiftrow for the alternative block lengths"
+        // shift offsets for Nb = 4, 6, 8 are defined in Rijndael-ammended.pdf#page=14,
+        //     "Table 2: Shift offsets for different block lengths"
+        switch ($this->Nb) {
+            case 4:
+            case 5:
+            case 6:
+                $this->c = array(0, 1, 2, 3);
+                break;
+            case 7:
+                $this->c = array(0, 1, 2, 4);
+                break;
+            case 8:
+                $this->c = array(0, 1, 3, 4);
+        }
+
+        $key = $this->key;
+
+        $w = array_values(unpack('N*words', $key));
+
+        $length = $this->Nb * ($this->Nr + 1);
+        for ($i = $this->Nk; $i < $length; $i++) {
+            $temp = $w[$i - 1];
+            if ($i % $this->Nk == 0) {
+                // according to <http://php.net/language.types.integer>, "the size of an integer is platform-dependent".
+                // on a 32-bit machine, it's 32-bits, and on a 64-bit machine, it's 64-bits. on a 32-bit machine,
+                // 0xFFFFFFFF << 8 == 0xFFFFFF00, but on a 64-bit machine, it equals 0xFFFFFFFF00. as such, doing 'and'
+                // with 0xFFFFFFFF (or 0xFFFFFF00) on a 32-bit machine is unnecessary, but on a 64-bit machine, it is.
+                $temp = (($temp << 8) & 0xFFFFFF00) | (($temp >> 24) & 0x000000FF); // rotWord
+                $temp = $this->_subWord($temp) ^ $rcon[$i / $this->Nk];
+            } else if ($this->Nk > 6 && $i % $this->Nk == 4) {
+                $temp = $this->_subWord($temp);
+            }
+            $w[$i] = $w[$i - $this->Nk] ^ $temp;
+        }
+
+        // convert the key schedule from a vector of $Nb * ($Nr + 1) length to a matrix with $Nr + 1 rows and $Nb columns
+        // and generate the inverse key schedule.  more specifically,
+        // according to <http://csrc.nist.gov/archive/aes/rijndael/Rijndael-ammended.pdf#page=23> (section 5.3.3), 
+        // "The key expansion for the Inverse Cipher is defined as follows:
+        //        1. Apply the Key Expansion.
+        //        2. Apply InvMixColumn to all Round Keys except the first and the last one."
+        // also, see fips-197.pdf#page=27, "5.3.5 Equivalent Inverse Cipher"
+        $temp = array();
+        for ($i = $row = $col = 0; $i < $length; $i++, $col++) {
+            if ($col == $this->Nb) {
+                if ($row == 0) {
+                    $this->dw[0] = $this->w[0];
+                } else {
+                    // subWord + invMixColumn + invSubWord = invMixColumn
+                    $j = 0;
+                    while ($j < $this->Nb) {
+                        $dw = $this->_subWord($this->w[$row][$j]);
+                        $temp[$j] = $this->dt0[$dw & 0xFF000000] ^ 
+                                    $this->dt1[$dw & 0x00FF0000] ^ 
+                                    $this->dt2[$dw & 0x0000FF00] ^ 
+                                    $this->dt3[$dw & 0x000000FF];
+                        $j++;
+                    }
+                    $this->dw[$row] = $temp;
+                }
+
+                $col = 0;
+                $row++;
+            }
+            $this->w[$row][$col] = $w[$i];
+        }
+
+        $this->dw[$row] = $this->w[$row];
+
+        $this->changed = false;
+    }
+
+    /**
+     * Performs S-Box substitutions
+     *
+     * @access private
+     */
+    function _subWord($word)
+    {
+        static $sbox0, $sbox1, $sbox2, $sbox3;
+
+        if (empty($sbox0)) {
+            $sbox0 = array(
+                0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76,
+                0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0,
+                0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15,
+                0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75,
+                0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
+                0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF,
+                0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8,
+                0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2,
+                0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73,
+                0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
+                0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79,
+                0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08,
+                0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A,
+                0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E,
+                0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
+                0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16
+            );
+
+            $sbox1 = array();
+            $sbox2 = array();
+            $sbox3 = array();
+
+            for ($i = 0; $i < 256; $i++) {
+                $sbox1[$i <<  8] = $sbox0[$i] <<  8;
+                $sbox2[$i << 16] = $sbox0[$i] << 16;
+                $sbox3[$i << 24] = $sbox0[$i] << 24;
+            }
+        }
+
+        return $sbox0[$word & 0x000000FF] | 
+               $sbox1[$word & 0x0000FF00] | 
+               $sbox2[$word & 0x00FF0000] | 
+               $sbox3[$word & 0xFF000000];
+    }
+
+    /**
+     * Performs inverse S-Box substitutions
+     *
+     * @access private
+     */
+    function _invSubWord($word)
+    {
+        static $sbox0, $sbox1, $sbox2, $sbox3;
+
+        if (empty($sbox0)) {
+            $sbox0 = array(
+                0x52, 0x09, 0x6A, 0xD5, 0x30, 0x36, 0xA5, 0x38, 0xBF, 0x40, 0xA3, 0x9E, 0x81, 0xF3, 0xD7, 0xFB,
+                0x7C, 0xE3, 0x39, 0x82, 0x9B, 0x2F, 0xFF, 0x87, 0x34, 0x8E, 0x43, 0x44, 0xC4, 0xDE, 0xE9, 0xCB,
+                0x54, 0x7B, 0x94, 0x32, 0xA6, 0xC2, 0x23, 0x3D, 0xEE, 0x4C, 0x95, 0x0B, 0x42, 0xFA, 0xC3, 0x4E,
+                0x08, 0x2E, 0xA1, 0x66, 0x28, 0xD9, 0x24, 0xB2, 0x76, 0x5B, 0xA2, 0x49, 0x6D, 0x8B, 0xD1, 0x25,
+                0x72, 0xF8, 0xF6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xD4, 0xA4, 0x5C, 0xCC, 0x5D, 0x65, 0xB6, 0x92,
+                0x6C, 0x70, 0x48, 0x50, 0xFD, 0xED, 0xB9, 0xDA, 0x5E, 0x15, 0x46, 0x57, 0xA7, 0x8D, 0x9D, 0x84,
+                0x90, 0xD8, 0xAB, 0x00, 0x8C, 0xBC, 0xD3, 0x0A, 0xF7, 0xE4, 0x58, 0x05, 0xB8, 0xB3, 0x45, 0x06,
+                0xD0, 0x2C, 0x1E, 0x8F, 0xCA, 0x3F, 0x0F, 0x02, 0xC1, 0xAF, 0xBD, 0x03, 0x01, 0x13, 0x8A, 0x6B,
+                0x3A, 0x91, 0x11, 0x41, 0x4F, 0x67, 0xDC, 0xEA, 0x97, 0xF2, 0xCF, 0xCE, 0xF0, 0xB4, 0xE6, 0x73,
+                0x96, 0xAC, 0x74, 0x22, 0xE7, 0xAD, 0x35, 0x85, 0xE2, 0xF9, 0x37, 0xE8, 0x1C, 0x75, 0xDF, 0x6E,
+                0x47, 0xF1, 0x1A, 0x71, 0x1D, 0x29, 0xC5, 0x89, 0x6F, 0xB7, 0x62, 0x0E, 0xAA, 0x18, 0xBE, 0x1B,
+                0xFC, 0x56, 0x3E, 0x4B, 0xC6, 0xD2, 0x79, 0x20, 0x9A, 0xDB, 0xC0, 0xFE, 0x78, 0xCD, 0x5A, 0xF4,
+                0x1F, 0xDD, 0xA8, 0x33, 0x88, 0x07, 0xC7, 0x31, 0xB1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xEC, 0x5F,
+                0x60, 0x51, 0x7F, 0xA9, 0x19, 0xB5, 0x4A, 0x0D, 0x2D, 0xE5, 0x7A, 0x9F, 0x93, 0xC9, 0x9C, 0xEF,
+                0xA0, 0xE0, 0x3B, 0x4D, 0xAE, 0x2A, 0xF5, 0xB0, 0xC8, 0xEB, 0xBB, 0x3C, 0x83, 0x53, 0x99, 0x61,
+                0x17, 0x2B, 0x04, 0x7E, 0xBA, 0x77, 0xD6, 0x26, 0xE1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0C, 0x7D
+            );
+
+            $sbox1 = array();
+            $sbox2 = array();
+            $sbox3 = array();
+
+            for ($i = 0; $i < 256; $i++) {
+                $sbox1[$i <<  8] = $sbox0[$i] <<  8;
+                $sbox2[$i << 16] = $sbox0[$i] << 16;
+                $sbox3[$i << 24] = $sbox0[$i] << 24;
+            }
+        }
+
+        return $sbox0[$word & 0x000000FF] | 
+               $sbox1[$word & 0x0000FF00] | 
+               $sbox2[$word & 0x00FF0000] | 
+               $sbox3[$word & 0xFF000000];
+    }
+
+    /**
+     * Pad "packets".
+     *
+     * Rijndael works by encrypting between sixteen and thirty-two bytes at a time, provided that number is also a multiple
+     * of four.  If you ever need to encrypt or decrypt something that isn't of the proper length, it becomes necessary to
+     * pad the input so that it is of the proper length.
+     *
+     * Padding is enabled by default.  Sometimes, however, it is undesirable to pad strings.  Such is the case in SSH,
+     * 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_Rijndael::disablePadding()
+     * @access public
+     */
+    function enablePadding()
+    {
+        $this->padding = true;
+    }
+
+    /**
+     * Do not pad packets.
+     *
+     * @see Crypt_Rijndael::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.
+     * $block_size - (strlen($text) % $block_size) bytes are added, each of which is equal to 
+     * chr($block_size - (strlen($text) % $block_size)
+     *
+     * If padding is disabled and $text is not a multiple of the blocksize, the string will be padded regardless
+     * and padding will, hence forth, be enabled.
+     *
+     * @see Crypt_Rijndael::_unpad()
+     * @access private
+     */
+    function _pad($text)
+    {
+        $length = strlen($text);
+
+        if (!$this->padding) {
+            if ($length % $this->block_size == 0) {
+                return $text;
+            } else {
+                user_error("The plaintext's length ($length) is not a multiple of the block size ({$this->block_size})", E_USER_NOTICE);
+                $this->padding = true;
+            }
+        }
+
+        $pad = $this->block_size - ($length % $this->block_size);
+
+        return str_pad($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_Rijndael::_pad()
+     * @access private
+     */
+    function _unpad($text)
+    {
+        if (!$this->padding) {
+            return $text;
+        }
+
+        $length = ord($text[strlen($text) - 1]);
+
+        if (!$length || $length > $this->block_size) {
+            return false;
+        }
+
+        return substr($text, 0, -$length);
+    }
+
+    /**
+     * Treat consecutive "packets" as if they are a continuous buffer.
+     *
+     * Say you have a 32-byte plaintext $plaintext.  Using the default behavior, the two following code snippets
+     * will yield different outputs:
+     *
+     * <code>
+     *    echo $rijndael->encrypt(substr($plaintext,  0, 16));
+     *    echo $rijndael->encrypt(substr($plaintext, 16, 16));
+     * </code>
+     * <code>
+     *    echo $rijndael->encrypt($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>
+     *    $rijndael->encrypt(substr($plaintext, 0, 16));
+     *    echo $rijndael->decrypt($des->encrypt(substr($plaintext, 16, 16)));
+     * </code>
+     * <code>
+     *    echo $rijndael->decrypt($des->encrypt(substr($plaintext, 16, 16)));
+     * </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_Rijndael() 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_Rijndael::disableContinuousBuffer()
+     * @access public
+     */
+    function enableContinuousBuffer()
+    {
+        $this->continuousBuffer = true;
+    }
+
+    /**
+     * Treat consecutive packets as if they are a discontinuous buffer.
+     *
+     * The default behavior.
+     *
+     * @see Crypt_Rijndael::enableContinuousBuffer()
+     * @access public
+     */
+    function disableContinuousBuffer()
+    {
+        $this->continuousBuffer = false;
+        $this->encryptIV = $this->iv;
+        $this->decryptIV = $this->iv;
+    }
+
+    /**
+     * 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:
diff --git a/library/phpseclib/Crypt/TripleDES.php b/library/phpseclib/Crypt/TripleDES.php
new file mode 100644 (file)
index 0000000..faf8c18
--- /dev/null
@@ -0,0 +1,1061 @@
+<?php
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * Pure-PHP implementation of Triple DES.
+ *
+ * Uses mcrypt, if available, and an internal implementation, otherwise.  Operates in the EDE3 mode (encrypt-decrypt-encrypt).
+ *
+ * PHP versions 4 and 5
+ *
+ * Here's a short example of how to use this library:
+ * <code>
+ * <?php
+ *    include('Crypt/TripleDES.php');
+ *
+ *    $des = new Crypt_TripleDES();
+ *
+ *    $des->setKey('abcdefghijklmnopqrstuvwx');
+ *
+ *    $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_TripleDES
+ * @author     Jim Wigginton <terrafrost@php.net>
+ * @copyright  MMVII Jim Wigginton
+ * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @version    $Id: TripleDES.php,v 1.13 2010/02/26 03:40:25 terrafrost Exp $
+ * @link       http://phpseclib.sourceforge.net
+ */
+
+/**
+ * Include Crypt_DES
+ */
+if (!class_exists('Crypt_DES')) {
+    require_once('DES.php');
+}
+
+/**
+ * Encrypt / decrypt using inner chaining
+ *
+ * Inner chaining is used by SSH-1 and is generally considered to be less secure then outer chaining (CRYPT_DES_MODE_CBC3).
+ */
+define('CRYPT_DES_MODE_3CBC', -2);
+
+/**
+ * Encrypt / decrypt using outer chaining
+ *
+ * Outer chaining is used by SSH-2 and when the mode is set to CRYPT_DES_MODE_CBC.
+ */
+define('CRYPT_DES_MODE_CBC3', CRYPT_DES_MODE_CBC);
+
+/**
+ * Pure-PHP implementation of Triple DES.
+ *
+ * @author  Jim Wigginton <terrafrost@php.net>
+ * @version 0.1.0
+ * @access  public
+ * @package Crypt_TerraDES
+ */
+class Crypt_TripleDES {
+    /**
+     * The Three Keys
+     *
+     * @see Crypt_TripleDES::setKey()
+     * @var String
+     * @access private
+     */
+    var $key = "\0\0\0\0\0\0\0\0";
+
+    /**
+     * The Encryption Mode
+     *
+     * @see Crypt_TripleDES::Crypt_TripleDES()
+     * @var Integer
+     * @access private
+     */
+    var $mode = CRYPT_DES_MODE_CBC;
+
+    /**
+     * Continuous Buffer status
+     *
+     * @see Crypt_TripleDES::enableContinuousBuffer()
+     * @var Boolean
+     * @access private
+     */
+    var $continuousBuffer = false;
+
+    /**
+     * Padding status
+     *
+     * @see Crypt_TripleDES::enablePadding()
+     * @var Boolean
+     * @access private
+     */
+    var $padding = true;
+
+    /**
+     * The Initialization Vector
+     *
+     * @see Crypt_TripleDES::setIV()
+     * @var String
+     * @access private
+     */
+    var $iv = "\0\0\0\0\0\0\0\0";
+
+    /**
+     * A "sliding" Initialization Vector
+     *
+     * @see Crypt_TripleDES::enableContinuousBuffer()
+     * @var String
+     * @access private
+     */
+