<?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: Abstract.php 20096 2010-01-06 02:05:09Z bkarwin $

 */

/**

 * Zend_InfoCard_Xml_Element

 */

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

/**

 * Zend_InfoCard_Xml_KeyInfo

 */

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

/**

 * An abstract class representing a generic EncryptedData XML block. This class is extended

 * into a specific type of EncryptedData XML block (i.e. XmlEnc) as necessary

 *

 * @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

 */

abstract class Zend_InfoCard_Xml_EncryptedData_Abstract extends Zend_InfoCard_Xml_Element

{

    /**

     * Returns the KeyInfo Block

     *

     * @return Zend_InfoCard_Xml_KeyInfo_Abstract

     */

    public function getKeyInfo()

    {

        return Zend_InfoCard_Xml_KeyInfo::getInstance($this->KeyInfo[0]);

    }

    /**

     * Return the Encryption method used to encrypt the assertion document

     * (the symmetric cipher)

     *

     * @throws Zend_InfoCard_Xml_Exception

     * @return string The URI of the Symmetric Encryption Method used

     */

    public function getEncryptionMethod()

    {

        /**

         * @todo This is pretty hacky unless we can always be confident that the first

         * EncryptionMethod block is the correct one (the AES or compariable symetric algorithm)..

         * the second is the PK method if provided.

         */

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

        if(!($encryption_method instanceof Zend_InfoCard_Xml_Element)) {

            throw new Zend_InfoCard_Xml_Exception("Unable to find the enc:EncryptionMethod symmetric 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 value of the encrypted block

     *

     * @return string the value of the encrypted CipherValue block

     */

    abstract function getCipherValue();

}