CRM/Utils/Crypt.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | CiviCRM version 5                                                  |
   5  +--------------------------------------------------------------------+
   6  | Copyright CiviCRM LLC (c) 2004-2020                                |
   7  +--------------------------------------------------------------------+
   8  | This file is a part of CiviCRM.                                    |
   9  |                                                                    |
  10  | CiviCRM is free software; you can copy, modify, and distribute it  |
  11  | under the terms of the GNU Affero General Public License           |
  12  | Version 3, 19 November 2007 and the CiviCRM Licensing Exception.   |
  13  |                                                                    |
  14  | CiviCRM is distributed in the hope that it will be useful, but     |
  15  | WITHOUT ANY WARRANTY; without even the implied warranty of         |
  16  | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.               |
  17  | See the GNU Affero General Public License for more details.        |
  18  |                                                                    |
  19  | You should have received a copy of the GNU Affero General Public   |
  20  | License and the CiviCRM Licensing Exception along                  |
  21  | with this program; if not, contact CiviCRM LLC                     |
  22  | at info[AT]civicrm[DOT]org. If you have questions about the        |
  23  | GNU Affero General Public License or the licensing of CiviCRM,     |
  24  | see the CiviCRM license FAQ at http://civicrm.org/licensing        |
  25  +--------------------------------------------------------------------+
  26  */
  27
  28 /**
  29  *
  30  * @package CRM
  31  * @copyright CiviCRM LLC (c) 2004-2020
  32  */
  33 class CRM_Utils_Crypt {
  34
  35   /**
  36    * Encrypts a string using AES256 in ECB mode, if encryption is enabled.
  37    *
  38    * After encrypting the string, it is base64 encoded.
  39    *
  40    * If encryption is not enabled, either due to CIVICRM_SITE_KEY being
  41    * undefined or due to unavailability of the mcrypt module, the string is
  42    * merely base64 encoded and is not encrypted at all.
  43    *
  44    * @param string $string
  45    *   Plaintext to be encrypted.
  46    * @return string
  47    *   Base64-encoded ciphertext, or base64-encoded plaintext if encryption is
  48    *   disabled or unavailable.
  49    */
  50   public static function encrypt($string) {
  51     if (empty($string)) {
  52       return $string;
  53     }
  54
  55     if (function_exists('mcrypt_module_open') &&
  56       defined('CIVICRM_SITE_KEY')
  57     ) {
  58       // phpcs:disable
  59       $td = mcrypt_module_open(MCRYPT_RIJNDAEL_256, '', MCRYPT_MODE_ECB, '');
  60       // ECB mode - iv not needed - CRM-8198
  61       $iv = '00000000000000000000000000000000';
  62       $ks = mcrypt_enc_get_key_size($td);
  63       $key = substr(sha1(CIVICRM_SITE_KEY), 0, $ks);
  64
  65       mcrypt_generic_init($td, $key, $iv);
  66       $string = mcrypt_generic($td, $string);
  67       mcrypt_generic_deinit($td);
  68       mcrypt_module_close($td);
  69     }
  70     // phpcs:enable
  71     return base64_encode($string);
  72   }
  73
  74   /**
  75    * Decrypts ciphertext encrypted with AES256 in ECB mode, if possible.
  76    *
  77    * If the mcrypt module is not available or if CIVICRM_SITE_KEY is not set,
  78    * the provided ciphertext is only base64-decoded, not decrypted.
  79    *
  80    * @param string $string
  81    *   Ciphertext to be decrypted.
  82    * @return string
  83    *   Plaintext, or base64-decoded ciphertext if encryption is disabled or
  84    *   unavailable.
  85    */
  86   public static function decrypt($string) {
  87     if (empty($string)) {
  88       return $string;
  89     }
  90
  91     $string = base64_decode($string);
  92     if (empty($string)) {
  93       return $string;
  94     }
  95
  96     if (function_exists('mcrypt_module_open') &&
  97       defined('CIVICRM_SITE_KEY')
  98     ) {
  99       // phpcs:disable
 100       $td = mcrypt_module_open(MCRYPT_RIJNDAEL_256, '', MCRYPT_MODE_ECB, '');
 101       // ECB mode - iv not needed - CRM-8198
 102       $iv = '00000000000000000000000000000000';
 103       $ks = mcrypt_enc_get_key_size($td);
 104       $key = substr(sha1(CIVICRM_SITE_KEY), 0, $ks);
 105
 106       mcrypt_generic_init($td, $key, $iv);
 107       $string = rtrim(mdecrypt_generic($td, $string));
 108       mcrypt_generic_deinit($td);
 109       mcrypt_module_close($td);
 110       // phpcs:enable
 111     }
 112
 113     return $string;
 114   }
 115
 116 }