Merge branch 'testing' into 0.9.x

1 files changed, 1923 insertions, 339 deletions

diff --git a/plugins/OStatus/extlib/Crypt/RSA.php b/plugins/OStatus/extlib/Crypt/RSA.php
index 16dfa54d4..f0a75962c 100644
--- a/plugins/OStatus/extlib/Crypt/RSA.php
+++ b/plugins/OStatus/extlib/Crypt/RSA.php
@@ -1,524 +1,2108 @@
 <?php
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
 /**
- * Crypt_RSA allows to do following operations:
- *     - key pair generation
- *     - encryption and decryption
- *     - signing and sign validation
+ * Pure-PHP PKCS#1 (v2.1) compliant implementation of RSA.
  *
  * PHP versions 4 and 5
  *
- * LICENSE: This source file is subject to version 3.0 of the PHP license
- * that is available through the world-wide-web at the following URI:
- * http://www.php.net/license/3_0.txt.  If you did not receive a copy of
- * the PHP License and are unable to obtain it through the web, please
- * send a note to license@php.net so we can mail you a copy immediately.
+ * 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: This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
  *
- * @category   Encryption
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA  02111-1307  USA
+ *
+ * @category   Crypt
  * @package    Crypt_RSA
- * @author     Alexander Valyalkin <valyala@gmail.com>
- * @copyright  2005, 2006 Alexander Valyalkin
- * @license    http://www.php.net/license/3_0.txt  PHP License 3.0
- * @version    1.2.0b
- * @link       http://pear.php.net/package/Crypt_RSA
+ * @author     Jim Wigginton <terrafrost@php.net>
+ * @copyright  MMIX Jim Wigginton
+ * @license    http://www.gnu.org/licenses/lgpl.txt
+ * @version    $Id: RSA.php,v 1.14 2010/03/01 17:28:19 terrafrost Exp $
+ * @link       http://phpseclib.sourceforge.net
  */
 
 /**
- * RSA error handling facilities
+ * Include Math_BigInteger
  */
-require_once 'Crypt/RSA/ErrorHandler.php';
+require_once('Math/BigInteger.php');
 
 /**
- * loader for math wrappers
+ * Include Crypt_Random
  */
-require_once 'Crypt/RSA/MathLoader.php';
+require_once('Crypt/Random.php');
 
 /**
- * helper class for mange single key
+ * Include Crypt_Hash
  */
-require_once 'Crypt/RSA/Key.php';
+require_once('Crypt/Hash.php');
 
-/**
- * helper class for manage key pair
+/**#@+
+ * @access public
+ * @see Crypt_RSA::encrypt()
+ * @see Crypt_RSA::decrypt()
  */
-require_once 'Crypt/RSA/KeyPair.php';
-
 /**
- * Crypt_RSA class, derived from Crypt_RSA_ErrorHandler
+ * Use {@link http://en.wikipedia.org/wiki/Optimal_Asymmetric_Encryption_Padding Optimal Asymmetric Encryption Padding}
+ * (OAEP) for encryption / decryption.
  *
- * Provides the following functions:
- *  - setParams($params) - sets parameters of current object
- *  - encrypt($plain_data, $key = null) - encrypts data
- *  - decrypt($enc_data, $key = null) - decrypts data
- *  - createSign($doc, $private_key = null) - signs document by private key
- *  - validateSign($doc, $signature, $public_key = null) - validates signature of document
+ * Uses sha1 by default.
  *
- * Example usage:
- *     // creating an error handler
- *     $error_handler = create_function('$obj', 'echo "error: ", $obj->getMessage(), "\n"');
+ * @see Crypt_RSA::setHash()
+ * @see Crypt_RSA::setMGFHash()
+ */
+define('CRYPT_RSA_ENCRYPTION_OAEP',  1);
+/**
+ * Use PKCS#1 padding.
  *
- *     // 1024-bit key pair generation
- *     $key_pair = new Crypt_RSA_KeyPair(1024);
+ * 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
  *
- *     // check consistence of Crypt_RSA_KeyPair object
- *     $error_handler($key_pair);
+ * Uses sha1 by default.
  *
- *     // creating Crypt_RSA object
- *     $rsa_obj = new Crypt_RSA;
+ * @see Crypt_RSA::setSaltLength()
+ * @see Crypt_RSA::setMGFHash()
+ */
+define('CRYPT_RSA_SIGNATURE_PSS',  1);
+/**
+ * Use the PKCS#1 scheme by default.
  *
- *     // check consistence of Crypt_RSA object
- *     $error_handler($rsa_obj);
+ * 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
  *
- *     // set error handler on Crypt_RSA object ( see Crypt/RSA/ErrorHandler.php for details )
- *     $rsa_obj->setErrorHandler($error_handler);
+ * (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
  *
- *     // encryption (usually using public key)
- *     $enc_data = $rsa_obj->encrypt($plain_data, $key_pair->getPublicKey());
+ * Used by OpenSSH
+ */
+define('CRYPT_RSA_PRIVATE_FORMAT_PKCS1', 0);
+/**#@-*/
+
+/**#@+
+ * @access public
+ * @see Crypt_RSA::createKey()
+ * @see Crypt_RSA::setPublicKeyFormat()
+ */
+/**
+ * Raw public key
  *
- *     // decryption (usually using private key)
- *     $plain_data = $rsa_obj->decrypt($enc_data, $key_pair->getPrivateKey());
+ * An array containing two Math_BigInteger objects.
  *
- *     // signing
- *     $signature = $rsa_obj->createSign($document, $key_pair->getPrivateKey());
+ * The exponent can be indexed with any of the following:
  *
- *     // signature checking
- *     $is_valid = $rsa_obj->validateSign($document, $signature, $key_pair->getPublicKey());
+ * 0, e, exponent, publicExponent
  *
- *     // signing many documents by one private key
- *     $rsa_obj = new Crypt_RSA(array('private_key' => $key_pair->getPrivateKey()));
- *     // check consistence of Crypt_RSA object
- *     $error_handler($rsa_obj);
- *     // set error handler ( see Crypt/RSA/ErrorHandler.php for details )
- *     $rsa_obj->setErrorHandler($error_handler);
- *     // sign many documents
- *     $sign_1 = $rsa_obj->sign($doc_1);
- *     $sign_2 = $rsa_obj->sign($doc_2);
- *     //...
- *     $sign_n = $rsa_obj->sign($doc_n);
+ * The modulus can be indexed with any of the following:
  *
- *     // changing default hash function, which is used for sign
- *     // creating/validation
- *     $rsa_obj->setParams(array('hash_func' => 'md5'));
+ * 1, n, modulo, modulus
+ */
+define('CRYPT_RSA_PUBLIC_FORMAT_RAW', 1);
+/**
+ * PKCS#1 formatted public key
+ */
+define('CRYPT_RSA_PUBLIC_FORMAT_PKCS1', 2);
+/**
+ * OpenSSH formatted public key
  *
- *     // using factory() method instead of constructor (it returns PEAR_Error object on failure)
- *     $rsa_obj = &Crypt_RSA::factory();
- *     if (PEAR::isError($rsa_obj)) {
- *         echo "error: ", $rsa_obj->getMessage(), "\n";
- *     }
+ * Place in $HOME/.ssh/authorized_keys
+ */
+define('CRYPT_RSA_PUBLIC_FORMAT_OPENSSH', 3);
+/**#@-*/
+
+/**
+ * Pure-PHP PKCS#1 compliant implementation of RSA.
  *
- * @category   Encryption
- * @package    Crypt_RSA
- * @author     Alexander Valyalkin <valyala@gmail.com>
- * @copyright  2005, 2006 Alexander Valyalkin
- * @license    http://www.php.net/license/3_0.txt  PHP License 3.0
- * @link       http://pear.php.net/package/Crypt_RSA
- * @version    @package_version@
- * @access     public
+ * @author  Jim Wigginton <terrafrost@php.net>
+ * @version 0.1.0
+ * @access  public
+ * @package Crypt_RSA
  */
-class Crypt_RSA extends Crypt_RSA_ErrorHandler
-{
+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;
+
     /**
-     * Reference to math wrapper, which is used to
-     * manipulate large integers in RSA algorithm.
+     * Length of salt
      *
-     * @var object of Crypt_RSA_Math_* class
+     * @var Integer
      * @access private
      */
-    var $_math_obj;
+    var $sLen;
 
     /**
-     * key for encryption, which is used by encrypt() method
+     * Hash function for the Mask Generation Function
      *
-     * @var object of Crypt_RSA_KEY class
+     * @var Crypt_Hash
      * @access private
      */
-    var $_enc_key;
+    var $mgfHash;
 
     /**
-     * key for decryption, which is used by decrypt() method
+     * Length of MGF hash function output
      *
-     * @var object of Crypt_RSA_KEY class
+     * @var Integer
      * @access private
      */
-    var $_dec_key;
+    var $mgfHLen;
 
     /**
-     * public key, which is used by validateSign() method
+     * Encryption mode
      *
-     * @var object of Crypt_RSA_KEY class
+     * @var Integer
      * @access private
      */
-    var $_public_key;
+    var $encryptionMode = CRYPT_RSA_ENCRYPTION_OAEP;
 
     /**
-     * private key, which is used by createSign() method
+     * Signature mode
      *
-     * @var object of Crypt_RSA_KEY class
+     * @var Integer
      * @access private
      */
-    var $_private_key;
+    var $signatureMode = CRYPT_RSA_SIGNATURE_PSS;
 
     /**
-     * name of hash function, which is used by validateSign()
-     * and createSign() methods. Default hash function is SHA-1
+     * Public Exponent
      *
-     * @var string
+     * @var Mixed
      * @access private
      */
-    var $_hash_func = 'sha1';
+    var $publicExponent = false;
+
+    /**
+     * Password
+     *
+     * @var String
+     * @access private
+     */
+    var $password = '';
+
+    /**
+     * 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();
+    }
 
     /**
-     * Crypt_RSA constructor.
+     * Create public / private key pair
      *
-     * @param array $params
-     *        Optional associative array of parameters, such as:
-     *        enc_key, dec_key, private_key, public_key, hash_func.
-     *        See setParams() method for more detailed description of
-     *        these parameters.
-     * @param string $wrapper_name
-     *        Name of math wrapper, which will be used to
-     *        perform different operations with big integers.
-     *        See contents of Crypt/RSA/Math folder for examples of wrappers.
-     *        Read docs/Crypt_RSA/docs/math_wrappers.txt for details.
-     * @param string $error_handler   name of error handler function
+     * 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 $p
      */
-    function Crypt_RSA($params = null, $wrapper_name = 'default', $error_handler = '')
+    function createKey($bits = 1024, $timeout = false, $partial = array())
     {
-        // set error handler
-        $this->setErrorHandler($error_handler);
-        // try to load math wrapper
-        $obj = &Crypt_RSA_MathLoader::loadWrapper($wrapper_name);
-        if ($this->isError($obj)) {
-            // error during loading of math wrapper
-            // Crypt_RSA object is partially constructed.
-            $this->pushError($obj);
-            return;
+        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
+            );
         }
-        $this->_math_obj = &$obj;
 
-        if (!is_null($params)) {
-            if (!$this->setParams($params)) {
-                // error in Crypt_RSA::setParams() function
-                return;
+        $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 serialize(array(
+                            'privatekey' => '',
+                            'publickey'  => '',
+                            'partialkey' => 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[$i] === false) { // if we've reached the timeout
+                    return array(
+                        'privatekey' => '',
+                        'publickey'  => '',
+                        'partialkey' => empty($primes) ? '' : serialize(array(
+                            'primes' => array_slice($primes, 0, $i - 1),
+                            'coefficients' => $coefficients,
+                            'lcm' => $lcm,
+                            'exponents' => $exponents
+                        ))
+                    );
+                }
+
+                // 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 . $iv)); // 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 '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
+                    );
+                }
         }
     }
 
     /**
-     * Crypt_RSA factory.
+     * 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 = CRYPT_RSA_PRIVATE_FORMAT_PKCS1)
+    {
+        $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.
      *
-     * @param array $params
-     *        Optional associative array of parameters, such as:
-     *        enc_key, dec_key, private_key, public_key, hash_func.
-     *        See setParams() method for more detailed description of
-     *        these parameters.
-     * @param string $wrapper_name
-     *        Name of math wrapper, which will be used to
-     *        perform different operations with big integers.
-     *        See contents of Crypt/RSA/Math folder for examples of wrappers.
-     *        Read docs/Crypt_RSA/docs/math_wrappers.txt for details.
-     * @param string $error_handler   name of error handler function
+     * Returns true on success, false on failure
      *
-     * @return object  new Crypt_RSA object on success or PEAR_Error object on failure
+     * @see getPublicKey()
      * @access public
+     * @param String $key
+     * @param Integer $type optional
+     * @return Boolean
      */
-    function &factory($params = null, $wrapper_name = 'default', $error_handler = '')
+    function setPublicKey($key, $type = CRYPT_RSA_PUBLIC_FORMAT_PKCS1)
     {
-        $obj = &new Crypt_RSA($params, $wrapper_name, $error_handler);
-        if ($obj->isError()) {
-            // error during creating a new object. Retrurn PEAR_Error object
-            return $obj->getLastError();
+        $components = $this->_parseKey($key, $type);
+        if (empty($this->modulus) || !$this->modulus->equals($components['modulus'])) {
+            return false;
         }
-        // object created successfully. Return it
-        return $obj;
+        $this->publicExponent = $components['publicExponent'];
     }
 
     /**
-     * Accepts any combination of available parameters as associative array:
-     *     enc_key - encryption key for encrypt() method
-     *     dec_key - decryption key for decrypt() method
-     *     public_key - key for validateSign() method
-     *     private_key - key for createSign() method
-     *     hash_func - name of hash function, which will be used to create and validate sign
+     * Returns the public key
      *
-     * @param array $params
-     *        associative array of permitted parameters (see above)
+     * 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.
      *
-     * @return bool   true on success or false on error
+     * @see getPublicKey()
      * @access public
+     * @param String $key
+     * @param Integer $type optional
      */
-    function setParams($params)
+    function getPublicKey($type = CRYPT_RSA_PUBLIC_FORMAT_PKCS1)
     {
-        if (!is_array($params)) {
-            $this->pushError('parameters must be passed to function as associative array', CRYPT_RSA_ERROR_WRONG_PARAMS);
+        if (empty($this->modulus) || empty($this->publicExponent)) {
             return false;
         }
 
-        if (isset($params['enc_key'])) {
-            if (Crypt_RSA_Key::isValid($params['enc_key'])) {
-                $this->_enc_key = $params['enc_key'];
-            }
-            else {
-                $this->pushError('wrong encryption key. It must be an object of Crypt_RSA_Key class', CRYPT_RSA_ERROR_WRONG_KEY);
-                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 {
+            $min[0] = chr(0x80);
         }
-        if (isset($params['dec_key'])) {
-            if (Crypt_RSA_Key::isValid($params['dec_key'])) {
-                $this->_dec_key = $params['dec_key'];
-            }
-            else {
-                $this->pushError('wrong decryption key. It must be an object of Crypt_RSA_Key class', CRYPT_RSA_ERROR_WRONG_KEY);
-                return false;
-            }
+
+        return array(
+            'min' => new Math_BigInteger($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));
         }
-        if (isset($params['private_key'])) {
-            if (Crypt_RSA_Key::isValid($params['private_key'])) {
-                if ($params['private_key']->getKeyType() != 'private') {
-                    $this->pushError('private key must have "private" attribute', CRYPT_RSA_ERROR_WRONG_KEY_TYPE);
-                    return false;
-                }
-                $this->_private_key = $params['private_key'];
+        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 {
-                $this->pushError('wrong private key. It must be an object of Crypt_RSA_Key class', CRYPT_RSA_ERROR_WRONG_KEY);
-                return false;
+        } else {
+            $ints = ($bytes + 1) >> 2;
+            for ($i = 0; $i < $ints; $i++) {
+                $temp.= pack('N', crypt_random());
             }
+            $temp = substr($temp, 0, $bytes);
         }
-        if (isset($params['public_key'])) {
-            if (Crypt_RSA_Key::isValid($params['public_key'])) {
-                if ($params['public_key']->getKeyType() != 'public') {
-                    $this->pushError('public key must have "public" attribute', CRYPT_RSA_ERROR_WRONG_KEY_TYPE);
-                    return false;
+        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];
                 }
-                $this->_public_key = $params['public_key'];
             }
-            else {
-                $this->pushError('wrong public key. It must be an object of Crypt_RSA_Key class', CRYPT_RSA_ERROR_WRONG_KEY);
-                return false;
+
+            $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($h));
             }
         }
-        if (isset($params['hash_func'])) {
-            if (!function_exists($params['hash_func'])) {
-                $this->pushError('cannot find hash function with name [' . $params['hash_func'] . ']', CRYPT_RSA_ERROR_WRONG_HASH_FUNC);
-                return false;
-            }
-            $this->_hash_func = $params['hash_func'];
+
+        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 true; // all ok
+        return $this->_exponentiate($m);
     }
 
     /**
-     * Ecnrypts $plain_data by the key $this->_enc_key or $key.
+     * RSADP
      *
-     * @param string $plain_data  data, which must be encrypted
-     * @param object $key         encryption key (object of Crypt_RSA_Key class)
-     * @return mixed
-     *         encrypted data as string on success or false on error
+     * See {@link http://tools.ietf.org/html/rfc3447#section-5.1.2 RFC3447#section-5.1.2}.
      *
-     * @access public
+     * @access private
+     * @param Math_BigInteger $c
+     * @return Math_BigInteger
      */
-    function encrypt($plain_data, $key = null)
+    function _rsadp($c)
     {
-        $enc_data = $this->encryptBinary($plain_data, $key);
-        if ($enc_data !== false) {
-            return base64_encode($enc_data);
+        if ($c->compare($this->zero) < 0 || $c->compare($this->modulus) > 0) {
+            user_error('Ciphertext representative out of range', E_USER_NOTICE);
+            return false;
         }
-        // error during encripting data
-        return false;
+        return $this->_exponentiate($c);
     }
 
     /**
-     * Ecnrypts $plain_data by the key $this->_enc_key or $key.
+     * RSASP1
      *
-     * @param string $plain_data  data, which must be encrypted
-     * @param object $key         encryption key (object of Crypt_RSA_Key class)
-     * @return mixed
-     *         encrypted data as binary string on success or false on error
+     * See {@link http://tools.ietf.org/html/rfc3447#section-5.2.1 RFC3447#section-5.2.1}.
      *
-     * @access public
+     * @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 $mgfLen
+     * @return String
      */
-    function encryptBinary($plain_data, $key = null)
+    function _mgf1($mgfSeed, $maskLen)
     {
-        if (is_null($key)) {
-            // use current encryption key
-            $key = $this->_enc_key;
+        // 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 . $c);
         }
-        else if (!Crypt_RSA_Key::isValid($key)) {
-            $this->pushError('invalid encryption key. It must be an object of Crypt_RSA_Key class', CRYPT_RSA_ERROR_WRONG_KEY);
+
+        return substr($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;
         }
 
-        // append tail \x01 to plain data. It needs for correctly decrypting of data
-        $plain_data .= "\x01";
+        // EME-OAEP encoding
 
-        $plain_data = $this->_math_obj->bin2int($plain_data);
-        $exp = $this->_math_obj->bin2int($key->getExponent());
-        $modulus = $this->_math_obj->bin2int($key->getModulus());
+        $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;
 
-        // divide plain data into chunks
-        $data_len = $this->_math_obj->bitLen($plain_data);
-        $chunk_len = $key->getKeyLength() - 1;
-        $block_len = (int) ceil($chunk_len / 8);
-        $curr_pos = 0;
-        $enc_data = '';
-        while ($curr_pos < $data_len) {
-            $tmp = $this->_math_obj->subint($plain_data, $curr_pos, $chunk_len);
-            $enc_data .= str_pad(
-                $this->_math_obj->int2bin($this->_math_obj->powmod($tmp, $exp, $modulus)),
-                $block_len,
-                "\0"
-            );
-            $curr_pos += $chunk_len;
+        // 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;
         }
-        return $enc_data;
+
+        // Output the message M
+
+        return substr($m, 1);
     }
 
     /**
-     * Decrypts $enc_data by the key $this->_dec_key or $key.
+     * RSAES-PKCS1-V1_5-ENCRYPT
      *
-     * @param string $enc_data  encrypted data as string
-     * @param object $key       decryption key (object of RSA_Crypt_Key class)
-     * @return mixed
-     *         decrypted data as string on success or false on error
+     * See {@link http://tools.ietf.org/html/rfc3447#section-7.2.1 RFC3447#section-7.2.1}.
      *
-     * @access public
+     * @access private
+     * @param String $m
+     * @return String
      */
-    function decrypt($enc_data, $key = null)
+    function _rsaes_pkcs1_v1_5_encrypt($m)
     {
-        $enc_data = base64_decode($enc_data);
-        return $this->decryptBinary($enc_data, $key);
+        $mLen = strlen($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;
     }
 
     /**
-     * Decrypts $enc_data by the key $this->_dec_key or $key.
+     * RSAES-PKCS1-V1_5-DECRYPT
      *
-     * @param string $enc_data  encrypted data as binary string
-     * @param object $key       decryption key (object of RSA_Crypt_Key class)
-     * @return mixed
-     *         decrypted data as string on success or false on error
+     * See {@link http://tools.ietf.org/html/rfc3447#section-7.2.2 RFC3447#section-7.2.2}.
      *
-     * @access public
+     * @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 $emBits
      */
-    function decryptBinary($enc_data, $key = null)
+    function _emsa_pss_encode($m, $emBits)
     {
-        if (is_null($key)) {
-            // use current decryption key
-            $key = $this->_dec_key;
+        // 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($em) - 1] != chr(0xBC)) {
+            return false;
         }
-        else if (!Crypt_RSA_Key::isValid($key)) {
-            $this->pushError('invalid decryption key. It must be an object of Crypt_RSA_Key class', CRYPT_RSA_ERROR_WRONG_KEY);
+
+        $maskedDB = substr($em, 0, $em - $this->hLen - 1);
+        $h = substr($em, $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
 
-        $exp = $this->_math_obj->bin2int($key->getExponent());
-        $modulus = $this->_math_obj->bin2int($key->getModulus());
+        $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
 
-        $data_len = strlen($enc_data);
-        $chunk_len = $key->getKeyLength() - 1;
-        $block_len = (int) ceil($chunk_len / 8);
-        $curr_pos = 0;
-        $bit_pos = 0;
-        $plain_data = $this->_math_obj->bin2int("\0");
-        while ($curr_pos < $data_len) {
-            $tmp = $this->_math_obj->bin2int(substr($enc_data, $curr_pos, $block_len));
-            $tmp = $this->_math_obj->powmod($tmp, $exp, $modulus);
-            $plain_data = $this->_math_obj->bitOr($plain_data, $tmp, $bit_pos);
-            $bit_pos += $chunk_len;
-            $curr_pos += $block_len;
+        if (strlen($s) != $this->k) {
+            user_error('Invalid signature', E_USER_NOTICE);
+            return false;
         }
-        $result = $this->_math_obj->int2bin($plain_data);
 
-        // delete tail, containing of \x01
-        $tail = ord($result{strlen($result) - 1});
-        if ($tail != 1) {
-            $this->pushError("Error tail of decrypted text = {$tail}. Expected 1", CRYPT_RSA_ERROR_WRONG_TAIL);
+        // RSA verification
+
+        $modBits = 8 * $this->k;
+
+        $s2 = $this->_os2ip($s);
+        $m2 = $this->_rsavp1($s2);
+        if ($m2 === false) {
+            user_error('Invalid signature', E_USER_NOTICE);
             return false;
         }
-        return substr($result, 0, -1);
+        $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);
     }
 
     /**
-     * Creates sign for document $document, using $this->_private_key or $private_key
-     * as private key and $this->_hash_func or $hash_func as hash function.
+     * EMSA-PKCS1-V1_5-ENCODE
      *
-     * @param string $document     document, which must be signed
-     * @param object $private_key  private key (object of Crypt_RSA_Key type)
-     * @param string $hash_func    name of hash function, which will be used during signing
-     * @return mixed
-     *         signature of $document as string on success or false on error
+     * See {@link http://tools.ietf.org/html/rfc3447#section-9.2 RFC3447#section-9.2}.
      *
-     * @access public
+     * @access private
+     * @param String $m
+     * @param Integer $emLen
+     * @return String
      */
-    function createSign($document, $private_key = null, $hash_func = null)
+    function _emsa_pkcs1_v1_5_encode($m, $emLen)
     {
-        // check private key
-        if (is_null($private_key)) {
-            $private_key = $this->_private_key;
+        $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 < $tLen + 11) {
+            user_error('Intended encoded message length too short', E_USER_NOTICE);
+            return false;
         }
-        else if (!Crypt_RSA_Key::isValid($private_key)) {
-            $this->pushError('invalid private key. It must be an object of Crypt_RSA_Key class', CRYPT_RSA_ERROR_WRONG_KEY);
+
+        $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;
         }
-        if ($private_key->getKeyType() != 'private') {
-            $this->pushError('signing key must be private', CRYPT_RSA_ERROR_NEED_PRV_KEY);
+
+        // 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;
         }
 
-        // check hash_func
-        if (is_null($hash_func)) {
-            $hash_func = $this->_hash_func;
+        // 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;
         }
-        if (!function_exists($hash_func)) {
-            $this->pushError("cannot find hash function with name [$hash_func]", CRYPT_RSA_ERROR_WRONG_HASH_FUNC);
+
+        // 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;
         }
 
-        return $this->encrypt($hash_func($document), $private_key);
+        // 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;
     }
 
     /**
-     * Validates $signature for document $document with public key $this->_public_key
-     * or $public_key and hash function $this->_hash_func or $hash_func.
+     * Encryption
      *
-     * @param string $document    document, signature of which must be validated
-     * @param string $signature   signature, which must be validated
-     * @param object $public_key  public key (object of Crypt_RSA_Key class)
-     * @param string $hash_func   hash function, which will be used during validating signature
-     * @return mixed
-     *         true, if signature of document is valid
-     *         false, if signature of document is invalid
-     *         null on error
+     * 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 $plaintext
+     * @return String
      */
-    function validateSign($document, $signature, $public_key = null, $hash_func = null)
+    function encrypt($plaintext)
     {
-        // check public key
-        if (is_null($public_key)) {
-            $public_key = $this->_public_key;
+        switch ($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 $ciphertext;
         }
-        else if (!Crypt_RSA_Key::isValid($public_key)) {
-            $this->pushError('invalid public key. It must be an object of Crypt_RSA_Key class', CRYPT_RSA_ERROR_WRONG_KEY);
-            return null;
+    }
+
+    /**
+     * Decryption
+     *
+     * @see encrypt()
+     * @access public
+     * @param String $plaintext
+     * @return String
+     */
+    function decrypt($ciphertext)
+    {
+        if ($this->k <= 0) {
+            return false;
         }
-        if ($public_key->getKeyType() != 'public') {
-            $this->pushError('validating key must be public', CRYPT_RSA_ERROR_NEED_PUB_KEY);
-            return null;
+
+        $ciphertext = str_split($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';
         }
 
-        // check hash_func
-        if (is_null($hash_func)) {
-            $hash_func = $this->_hash_func;
+        foreach ($ciphertext as $c) {
+            $temp = $this->$decrypt($c);
+            if ($temp === false) {
+                return false;
+            }
+            $plaintext.= $temp;
         }
-        if (!function_exists($hash_func)) {
-            $this->pushError("cannot find hash function with name [$hash_func]", CRYPT_RSA_ERROR_WRONG_HASH_FUNC);
-            return null;
+
+        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;
         }
 
-        return $hash_func($document) == $this->decrypt($signature, $public_key);
+        switch ($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);
+        }
     }
-}
 
-?>
\ No newline at end of file
+    /**
+     * 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