<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_InfoCard

 * @subpackage Zend_InfoCard_Cipher

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: Rsa.php 20096 2010-01-06 02:05:09Z bkarwin $

 */

/**

 * Zend_InfoCard_Cipher_Pki_Adapter_Abstract

 */

require_once 'Zend/InfoCard/Cipher/Pki/Adapter/Abstract.php';

/**

 * Zend_InfoCard_Cipher_Pki_Rsa_Interface

 */

require_once 'Zend/InfoCard/Cipher/Pki/Rsa/Interface.php';

/**

 * RSA Public Key Encryption Cipher Object for the InfoCard component. Relies on OpenSSL

 * to implement the RSA algorithm

 *

 * @category   Zend

 * @package    Zend_InfoCard

 * @subpackage Zend_InfoCard_Cipher

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_InfoCard_Cipher_Pki_Adapter_Rsa

    extends Zend_InfoCard_Cipher_Pki_Adapter_Abstract

    implements Zend_InfoCard_Cipher_Pki_Rsa_Interface

{

    /**

     * Object Constructor

     *

     * @param integer $padding The type of Padding to use

     */

    public function __construct($padding = Zend_InfoCard_Cipher_Pki_Adapter_Abstract::NO_PADDING)

    {

        // Can't test this..

        // @codeCoverageIgnoreStart

        if(!extension_loaded('openssl')) {

            require_once 'Zend/InfoCard/Cipher/Exception.php';

            throw new Zend_InfoCard_Cipher_Exception("Use of this PKI RSA Adapter requires the openssl extension loaded");

        }

        // @codeCoverageIgnoreEnd

        $this->setPadding($padding);

    }

    /**

     * Decrypts RSA encrypted data using the given private key

     *

     * @throws Zend_InfoCard_Cipher_Exception

     * @param string $encryptedData The encrypted data in binary format

     * @param string $privateKey The private key in binary format

     * @param string $password The private key passphrase

     * @param integer $padding The padding to use during decryption (of not provided object value will be used)

     * @return string The decrypted data

     */

    public function decrypt($encryptedData, $privateKey, $password = null, $padding = null)

    {

        $private_key = openssl_pkey_get_private(array($privateKey, $password));

        if(!$private_key) {

            require_once 'Zend/InfoCard/Cipher/Exception.php';

            throw new Zend_InfoCard_Cipher_Exception("Failed to load private key");

        }

        if($padding !== null) {

            try {

                $this->setPadding($padding);

            } catch(Exception $e) {

                openssl_free_key($private_key);

                throw $e;

            }

        }

        switch($this->getPadding()) {

            case self::NO_PADDING:

                $openssl_padding = OPENSSL_NO_PADDING;

                break;

            case self::OAEP_PADDING:

                $openssl_padding = OPENSSL_PKCS1_OAEP_PADDING;

                break;

        }

        $result = openssl_private_decrypt($encryptedData, $decryptedData, $private_key, $openssl_padding);

        openssl_free_key($private_key);

        if(!$result) {

            require_once 'Zend/InfoCard/Cipher/Exception.php';

            throw new Zend_InfoCard_Cipher_Exception("Unable to Decrypt Value using provided private key");

        }

        if($this->getPadding() == self::NO_PADDING) {

            $decryptedData = substr($decryptedData, 2);

            $start = strpos($decryptedData, 0) + 1;

            $decryptedData = substr($decryptedData, $start);

        }

        return $decryptedData;

    }

}