* @link http://www.doophp.com/
* @copyright Copyright © 2009 Leng Sheng Hong
* @license http://www.doophp.com/license
*/
/**
* Handles HTTP digest authentication
*
* HTTP digest authentication can be used with the URI router.
* HTTP digest is much more recommended over the use of HTTP Basic auth which doesn't provide any encryption.
* If you are running PHP on Apache in CGI/FastCGI mode, you would need to
* add the following line to your .htaccess for digest auth to work correctly.
* RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization},L]
*
* This class is tested under Apache 2.2 and Cherokee web server. It should work in both mod_php and cgi mode.
*
* @author Leng Sheng Hong
* @version $Id: DooDigestAuth.php 1000 2009-07-7 18:27:22
* @package doo.auth
* @since 1.0
*/
class DooDigestAuth{
/**
* Authenticate against a list of username and passwords.
*
* HTTP Digest Authentication doesn't work with PHP in CGI mode,
* you have to add this into your .htaccess RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization},L]
*
* @param string $realm Name of the authentication session
* @param array $users An assoc array of username and password: array('uname1'=>'pwd1', 'uname2'=>'pwd2')
* @param string $fail_msg Message to be displayed if the User cancel the login
* @param string $fail_url URL to be redirect if the User cancel the login
* @return string The username if login success.
*/
public static function http_auth($realm, $users, $fail_msg=NULL, $fail_url=NULL){
$realm = "Restricted area - $realm";
//user => password
//$users = array('admin' => '1234', 'guest' => 'guest');
if(!empty($_SERVER['REDIRECT_HTTP_AUTHORIZATION']) && strpos($_SERVER['REDIRECT_HTTP_AUTHORIZATION'], 'Digest')===0){
$_SERVER['PHP_AUTH_DIGEST'] = $_SERVER['REDIRECT_HTTP_AUTHORIZATION'];
}
if (empty($_SERVER['PHP_AUTH_DIGEST'])) {
header('WWW-Authenticate: Digest realm="'.$realm.
'",qop="auth",nonce="'.uniqid().'",opaque="'.md5($realm).'"');
header('HTTP/1.1 401 Unauthorized');
if($fail_msg!=NULL)
die($fail_msg);
if($fail_url!=NULL)
die("");
exit;
}
// analyze the PHP_AUTH_DIGEST variable
if (!($data = self::http_digest_parse($_SERVER['PHP_AUTH_DIGEST'])) || !isset($users[$data['username']])){
header('WWW-Authenticate: Digest realm="'.$realm.
'",qop="auth",nonce="'.uniqid().'",opaque="'.md5($realm).'"');
header('HTTP/1.1 401 Unauthorized');
if($fail_msg!=NULL)
die($fail_msg);
if($fail_url!=NULL)
die("");
exit;
}
// generate the valid response
$A1 = md5($data['username'] . ':' . $realm . ':' . $users[$data['username']]);
$A2 = md5($_SERVER['REQUEST_METHOD'].':'.$data['uri']);
$valid_response = md5($A1.':'.$data['nonce'].':'.$data['nc'].':'.$data['cnonce'].':'.$data['qop'].':'.$A2);
if ($data['response'] != $valid_response){
header('HTTP/1.1 401 Unauthorized');
header('WWW-Authenticate: Digest realm="'.$realm.
'",qop="auth",nonce="'.uniqid().'",opaque="'.md5($realm).'"');
if($fail_msg!=NULL)
die($fail_msg);
if($fail_url!=NULL)
die("");
exit;
}
// ok, valid username & password
return $data['username'];
}
/**
* Method to parse the http auth header, works with IE.
*
* Internet Explorer returns a qop="xxxxxxxxxxx" in the header instead of qop=xxxxxxxxxxx as most browsers do.
*
* @param string $txt header string to parse
* @return array An assoc array of the digest auth session
*/
private static function http_digest_parse($txt)
{
$res = preg_match("/username=\"([^\"]+)\"/i", $txt, $match);
$data['username'] = (isset($match[1]))?$match[1]:null;
$res = preg_match('/nonce=\"([^\"]+)\"/i', $txt, $match);
$data['nonce'] = $match[1];
$res = preg_match('/nc=([0-9]+)/i', $txt, $match);
$data['nc'] = $match[1];
$res = preg_match('/cnonce=\"([^\"]+)\"/i', $txt, $match);
$data['cnonce'] = $match[1];
$res = preg_match('/qop=([^,]+)/i', $txt, $match);
$data['qop'] = str_replace('"','',$match[1]);
$res = preg_match('/uri=\"([^\"]+)\"/i', $txt, $match);
$data['uri'] = $match[1];
$res = preg_match('/response=\"([^\"]+)\"/i', $txt, $match);
$data['response'] = $match[1];
return $data;
}
}