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

svn commit: r1136647 [3/11] - in /incubator/vcl/trunk/web/.ht-inc/phpseclib: ./ Crypt/ Math/ Net/ PHP/ PHP/Compat/ PHP/Compat/Function/

Added: incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/RSA.php
URL: http://svn.apache.org/viewvc/incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/RSA.php?rev=1136647&view=auto
==============================================================================
--- incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/RSA.php (added)
+++ incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/RSA.php Thu Jun 16 20:18:36 2011
@@ -0,0 +1,2356 @@
+<?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 <te...@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
+ */
+require_once('Math/BigInteger.php');
+
+/**
+ * Include Crypt_Random
+ */
+require_once('Crypt/Random.php');
+
+/**
+ * Include 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 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
+ */
+define('CRYPT_RSA_PUBLIC_FORMAT_PKCS1', 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);
+/**#@-*/
+
+/**
+ * Pure-PHP PKCS#1 compliant implementation of RSA.
+ *
+ * @author  Jim Wigginton <te...@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 = '';
+
+    /**
+     * 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);
+            }
+        }
+
+        $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 ( CRYPT_RSA_MODE == CRYPT_RSA_MODE_OPENSSL ) {
+            $rsa = openssl_pkey_new(array('private_key_bits' => $bits));
+            openssl_pkey_export($rsa, $privatekey);
+            $publickey = openssl_pkey_get_details($rsa);
+            $publickey = $publickey['key'];
+
+            if ($this->privateKeyFormat != CRYPT_RSA_PRIVATE_FORMAT_PKCS1) {
+                $privatekey = call_user_func_array(array($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)));
+            }
+
+            return array(
+                'privatekey' => $privatekey,
+                'publickey' => $publickey,
+                'partialkey' => false
+            );
+        }
+
+        static $e;
+        if (!isset($e)) {
+            if (!defined('CRYPT_RSA_EXPONENT')) {
+                // http://en.wikipedia.org/wiki/65537_%28number%29
+                define('CRYPT_RSA_EXPONENT', '65537');
+            }
+            if (!defined('CRYPT_RSA_COMMENT')) {
+                define('CRYPT_RSA_COMMENT', 'phpseclib-generated-key');
+            }
+            // per <http://cseweb.ucsd.edu/~hovav/dist/survey.pdf#page=5>, this number ought not result in primes smaller
+            // than 256 bits.
+            if (!defined('CRYPT_RSA_SMALLEST_PRIME')) {
+                define('CRYPT_RSA_SMALLEST_PRIME', 4096);
+            }
+
+            $e = new Math_BigInteger(CRYPT_RSA_EXPONENT);
+        }
+
+        extract($this->_generateMinMax($bits));
+        $absoluteMin = $min;
+        $temp = $bits >> 1;
+        if ($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) {
+            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)) {
+                    $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_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
+                // 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']
+                );
+
+                $RSAPublicKey = "-----BEGIN PUBLIC KEY-----\r\n" .
+                                 chunk_split(base64_encode($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, $type)
+    {
+        switch ($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 $components;
+            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($key));
+                if ($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));
+                    $this->_string_shift($key); // skip over the BIT STRING tag
+                    $this->_decodeLength($key); // skip over the BIT 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 teh 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)
+                    $this->_string_shift($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";
+
+                extract(unpack('Nlength', $this->_string_shift($key, 4)));
+                $publicExponent = new Math_BigInteger($this->_string_shift($key, $length), -256);
+                extract(unpack('Nlength', $this->_string_shift($key, 4)));
+                $modulus = new Math_BigInteger($this->_string_shift($key, $length), -256);
+
+                if ($cleanup && strlen($key)) {
+                    extract(unpack('Nlength', $this->_string_shift($key, 4)));
+                    return array(
+                        'modulus' => new Math_BigInteger($this->_string_shift($key, $length), -256),
+                        'publicExponent' => $modulus
+                    );
+                } else {
+                    return 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 $this->components;
+            // 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)));
+                $components['privateExponent'] = new Math_BigInteger($this->_string_shift($private, $length), -256);
+                extract(unpack('Nlength', $this->_string_shift($private, 4)));
+                $components['primes'] = array(1 => new Math_BigInteger($this->_string_shift($private, $length), -256));
+                extract(unpack('Nlength', $this->_string_shift($private, 4)));
+                $components['primes'][] = new Math_BigInteger($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)));
+                $components['coefficients'] = array(2 => new Math_BigInteger($this->_string_shift($private, $length), -256));
+
+                return $components;
+        }
+    }
+
+    /**
+     * 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 true.
+     *
+     * @see createKey()
+     * @see loadKey()
+     * @access public
+     * @param String $password
+     */
+    function setPassword($password)
+    {
+        $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
+     * @param Integer $type optional
+     * @return Boolean
+     */
+    function setPublicKey($key, $type = CRYPT_RSA_PUBLIC_FORMAT_PKCS1)
+    {
+        $components = $this->_parseKey($key, $type);
+
+        if (empty($this->modulus) || !$this->modulus->equals($components['modulus'])) {
+            user_error('Trying to load a public key?  Use loadKey() instead.  It\'s called loadKey() and not loadPrivateKey() for a reason.', E_USER_NOTICE);
+            return false;
+        }
+
+        $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;
+    }
+
+    /**
+     * 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)
+    {
+        $temp = '';
+        if ($nonzero) {
+            for ($i = 0; $i < $bytes; $i++) {
+                $temp.= chr(crypt_random(1, 255));
+            }
+        } else {
+            $ints = ($bytes + 1) >> 2;
+            for ($i = 0; $i < $ints; $i++) {
+                $temp.= pack('N', crypt_random());
+            }
+            $temp = substr($temp, 0, $bytes);
+        }
+        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;
+    }
+
+    /**
+     * 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 $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 $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);
+        }
+    }
+}
\ No newline at end of file

Added: incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/Random.php
URL: http://svn.apache.org/viewvc/incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/Random.php?rev=1136647&view=auto
==============================================================================
--- incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/Random.php (added)
+++ incubator/vcl/trunk/web/.ht-inc/phpseclib/Crypt/Random.php Thu Jun 16 20:18:36 2011
@@ -0,0 +1,133 @@
+<?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 <te...@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;
+    }
+
+    // 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/branches/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;
+}
+?>
\ No newline at end of file