<?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_Xml

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

 */

/**

 * Zend_InfoCard_Xml_Element

 */

require_once 'Zend/InfoCard/Xml/Element.php';

/**

 * Zend_InfoCard_Xml_EncryptedKey

 */

require_once 'Zend/InfoCard/Xml/EncryptedKey.php';

/**

 * Zend_InfoCard_Xml_KeyInfo_Interface

 */

require_once 'Zend/InfoCard/Xml/KeyInfo/Interface.php';

/**

 * An object representing an Xml EncryptedKEy block

 *

 * @category   Zend

 * @package    Zend_InfoCard

 * @subpackage Zend_InfoCard_Xml

 * @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_Xml_EncryptedKey

    extends Zend_InfoCard_Xml_Element

    implements Zend_InfoCard_Xml_KeyInfo_Interface

{

    /**

     * Return an instance of the object based on input XML Data

     *

     * @throws Zend_InfoCard_Xml_Exception

     * @param string $xmlData The EncryptedKey XML Block

     * @return Zend_InfoCard_Xml_EncryptedKey

     */

    static public function getInstance($xmlData)

    {

        if($xmlData instanceof Zend_InfoCard_Xml_Element) {

            $strXmlData = $xmlData->asXML();

        } else if (is_string($xmlData)) {

            $strXmlData = $xmlData;

        } else {

            throw new Zend_InfoCard_Xml_Exception("Invalid Data provided to create instance");

        }

        $sxe = simplexml_load_string($strXmlData);

        if($sxe->getName() != "EncryptedKey") {

            throw new Zend_InfoCard_Xml_Exception("Invalid XML Block provided for EncryptedKey");

        }

        return simplexml_load_string($strXmlData, "Zend_InfoCard_Xml_EncryptedKey");

    }

    /**

     * Returns the Encyption Method Algorithm URI of the block

     *

     * @throws Zend_InfoCard_Xml_Exception

     * @return string the Encryption method algorithm URI

     */

    public function getEncryptionMethod()

    {

        $this->registerXPathNamespace('e', 'http://www.w3.org/2001/04/xmlenc#');

        list($encryption_method) = $this->xpath("//e:EncryptionMethod");

        if(!($encryption_method instanceof Zend_InfoCard_Xml_Element)) {

            throw new Zend_InfoCard_Xml_Exception("Unable to find the e:EncryptionMethod KeyInfo encryption block");

        }

        $dom = self::convertToDOM($encryption_method);

        if(!$dom->hasAttribute('Algorithm')) {

            throw new Zend_InfoCard_Xml_Exception("Unable to determine the encryption algorithm in the Symmetric enc:EncryptionMethod XML block");

        }

        return $dom->getAttribute('Algorithm');

    }

    /**

     * Returns the Digest Method Algorithm URI used

     *

     * @throws Zend_InfoCard_Xml_Exception

     * @return string the Digest Method Algorithm URI

     */

    public function getDigestMethod()

    {

        $this->registerXPathNamespace('e', 'http://www.w3.org/2001/04/xmlenc#');

        list($encryption_method) = $this->xpath("//e:EncryptionMethod");

        if(!($encryption_method instanceof Zend_InfoCard_Xml_Element)) {

            throw new Zend_InfoCard_Xml_Exception("Unable to find the e:EncryptionMethod KeyInfo encryption block");

        }

        if(!($encryption_method->DigestMethod instanceof Zend_InfoCard_Xml_Element)) {

            throw new Zend_InfoCard_Xml_Exception("Unable to find the DigestMethod block");

        }

        $dom = self::convertToDOM($encryption_method->DigestMethod);

        if(!$dom->hasAttribute('Algorithm')) {

            throw new Zend_InfoCard_Xml_Exception("Unable to determine the digest algorithm for the symmetric Keyinfo");

        }

        return $dom->getAttribute('Algorithm');

    }

    /**

     * Returns the KeyInfo block object

     *

     * @throws Zend_InfoCard_Xml_Exception

     * @return Zend_InfoCard_Xml_KeyInfo_Abstract

     */

    public function getKeyInfo()

    {

        if(isset($this->KeyInfo)) {

            return Zend_InfoCard_Xml_KeyInfo::getInstance($this->KeyInfo);

        }

        throw new Zend_InfoCard_Xml_Exception("Unable to locate a KeyInfo block");

    }

    /**

     * Return the encrypted value of the block in base64 format

     *

     * @throws Zend_InfoCard_Xml_Exception

     * @return string The Value of the CipherValue block in base64 format

     */

    public function getCipherValue()

    {

        $this->registerXPathNamespace('e', 'http://www.w3.org/2001/04/xmlenc#');

        list($cipherdata) = $this->xpath("//e:CipherData");

        if(!($cipherdata instanceof Zend_InfoCard_Xml_Element)) {

            throw new Zend_InfoCard_Xml_Exception("Unable to find the e:CipherData block");

        }

        $cipherdata->registerXPathNameSpace('enc', 'http://www.w3.org/2001/04/xmlenc#');

        list($ciphervalue) = $cipherdata->xpath("//enc:CipherValue");

        if(!($ciphervalue instanceof Zend_InfoCard_Xml_Element)) {

            throw new Zend_InfoCard_Xml_Exception("Unable to fidn the enc:CipherValue block");

        }

        return (string)$ciphervalue;

    }

}