<?php

/*

 * This file is part of the Symfony package.

 *

 * (c) Fabien Potencier <fabien@symfony.com>

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */

namespace Symfony\Component\Security\Http\EntryPoint;

use Symfony\Component\Security\Core\Exception\AuthenticationException;

use Symfony\Component\Security\Http\EntryPoint\AuthenticationEntryPointInterface;

use Symfony\Component\Security\Core\Exception\NonceExpiredException;

use Symfony\Component\HttpFoundation\Response;

use Symfony\Component\HttpFoundation\Request;

use Symfony\Component\HttpKernel\Log\LoggerInterface;

/**

 * DigestAuthenticationEntryPoint starts an HTTP Digest authentication.

 *

 * @author Fabien Potencier <fabien@symfony.com>

 */

class DigestAuthenticationEntryPoint implements AuthenticationEntryPointInterface

{

    private $key;

    private $realmName;

    private $nonceValiditySeconds;

    private $logger;

    public function __construct($realmName, $key, $nonceValiditySeconds = 300, LoggerInterface $logger = null)

    {

        $this->realmName = $realmName;

        $this->key = $key;

        $this->nonceValiditySeconds = $nonceValiditySeconds;

        $this->logger = $logger;

    }

    public function start(Request $request, AuthenticationException $authException = null)

    {

        $expiryTime = microtime(true) + $this->nonceValiditySeconds * 1000;

        $signatureValue = md5($expiryTime.':'.$this->key);

        $nonceValue = $expiryTime.':'.$signatureValue;

        $nonceValueBase64 = base64_encode($nonceValue);

        $authenticateHeader = sprintf('Digest realm="%s", qop="auth", nonce="%s"', $this->realmName, $nonceValueBase64);

        if ($authException instanceof NonceExpiredException) {

            $authenticateHeader = $authenticateHeader.', stale="true"';

        }

        if (null !== $this->logger) {

            $this->logger->debug(sprintf('WWW-Authenticate header sent to user agent: "%s"', $authenticateHeader));

        }

        $response = new Response();

        $response->headers->set('WWW-Authenticate', $authenticateHeader);

        $response->setStatusCode(401, $authException ? $authException->getMessage() : null);

        return $response;

    }

}