<?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_Mail

 * @subpackage Protocol

 * @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: Crammd5.php 22653 2010-07-22 18:41:39Z mabe $

 */

/**

 * @see Zend_Mail_Protocol_Smtp

 */

require_once 'Zend/Mail/Protocol/Smtp.php';

/**

 * Performs CRAM-MD5 authentication

 *

 * @category   Zend

 * @package    Zend_Mail

 * @subpackage Protocol

 * @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_Mail_Protocol_Smtp_Auth_Crammd5 extends Zend_Mail_Protocol_Smtp

{

    /**

     * Constructor.

     *

     * @param  string $host   (Default: 127.0.0.1)

     * @param  int    $port   (Default: null)

     * @param  array  $config Auth-specific parameters

     * @return void

     */

    public function __construct($host = '127.0.0.1', $port = null, $config = null)

    {

        if (is_array($config)) {

            if (isset($config['username'])) {

                $this->_username = $config['username'];

            }

            if (isset($config['password'])) {

                $this->_password = $config['password'];

            }

        }

        parent::__construct($host, $port, $config);

    }

    /**

     * @todo Perform CRAM-MD5 authentication with supplied credentials

     *

     * @return void

     */

    public function auth()

    {

        // Ensure AUTH has not already been initiated.

        parent::auth();

        $this->_send('AUTH CRAM-MD5');

        $challenge = $this->_expect(334);

        $challenge = base64_decode($challenge);

        $digest = $this->_hmacMd5($this->_password, $challenge);

        $this->_send(base64_encode($this->_username . ' ' . $digest));

        $this->_expect(235);

        $this->_auth = true;

    }

    /**

     * Prepare CRAM-MD5 response to server's ticket

     *

     * @param  string $key   Challenge key (usually password)

     * @param  string $data  Challenge data

     * @param  string $block Length of blocks

     * @return string

     */

    protected function _hmacMd5($key, $data, $block = 64)

    {

        if (strlen($key) > 64) {

            $key = pack('H32', md5($key));

        } elseif (strlen($key) < 64) {

            $key = str_pad($key, $block, "\0");

        }

        $k_ipad = substr($key, 0, 64) ^ str_repeat(chr(0x36), 64);

        $k_opad = substr($key, 0, 64) ^ str_repeat(chr(0x5C), 64);

        $inner = pack('H32', md5($k_ipad . $data));

        $digest = md5($k_opad . $inner);

        return $digest;

    }

}