File indexing completed on 2024-11-24 05:19:04

 <?php
 /**
  * file server - part of Opendesktop.org platform project <https://www.opendesktop.org>.
  *
  * Copyright (c) 2016 pling GmbH.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
 namespace Ocs\Url;
 
 use DateTime;
 use Exception;
 
 class UrlSigner
 {
 
     /**
      * Sign a URL
      *
      * @param string $url
      * @param string $private_key
      * @param int    $expireMin
      *
      * @return string Signed URL
      * @throws Exception
      */
     public static function getSignedUrl(string $url, string $private_key, int $expireMin = 30): string
     {
         $join = parse_url($url, PHP_URL_QUERY) ? '&' : '?';
         $expiration = self::getExpirationTimestamp($expireMin);
 
         return $url . $join . 'signature=' . self::getUrlSignature($url, $private_key, $expiration) . '&expires=' . $expiration;
     }
 
     /**
      * @throws Exception
      */
     private static function getExpirationTimestamp($expiration): string
     {
         if (is_int($expiration)) {
             $expiration = (new DateTime())->modify((int)$expiration . ' minutes');
         }
 
         if (!$expiration instanceof DateTime) {
             throw new Exception('Expiration date must be an instance of DateTime or an integer');
         }
 
         if (!self::isFuture($expiration->getTimestamp())) {
             throw new Exception('Expiration date must be in the future');
         }
 
         return (string)$expiration->getTimestamp();
     }
 
     private static function isFuture($timestamp): bool
     {
         return ((int)$timestamp) >= (new DateTime())->getTimestamp();
     }
 
     /**
      * Get the signature for the given URL
      *
      * @param string $url
      * @param string $private_key
      * @param        $expiration
      *
      * @return string URL signature string
      */
     private static function getUrlSignature(string $url, string $private_key, $expiration): string
     {
         return md5($url . ':' . $expiration . ':' . $private_key);
     }
 
     /**
      * Check that the given URL is correctly signed
      *
      * @param string $url
      * @param string $private_key
      *
      * @return bool True if URL contains valid signature, false otherwise
      */
     public static function verifySignedUrl(string $url, string $private_key): bool
     {
 
         $param_expires = preg_quote('expires');
         if (!preg_match($regex1 = "/(:?&|\?)?{$param_expires}=([0-9]{10})/", $url, $matches)) {
             return false;
         }
         // Get the expires param
         $expiration = $matches[2];
 
 
         if (!self::isFuture($expiration)) {
             return false;
         }
         $param_name = preg_quote('signature');
         if (!preg_match($regex2 = "/(:?&|\?)?{$param_name}=([0-9a-f]{32})/", $url, $matches)) {
             return false;
         }
         // Get the signature param
         $passed_sig = $matches[2];
 
         // Strip signature from the given URL
         $url = preg_replace($regex1, '', $url);
         $url = preg_replace($regex2, '', $url);
 
         // Check that the given signature matches the correct one
         return self::getUrlSignature($url, $private_key, $expiration) === $passed_sig;
     }
 }