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941 lines
23 KiB
941 lines
23 KiB
<?php |
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/** |
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* CodeIgniter |
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* |
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* An open source application development framework for PHP |
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* |
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* This content is released under the MIT License (MIT) |
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* |
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* Copyright (c) 2014 - 2018, British Columbia Institute of Technology |
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* |
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* Permission is hereby granted, free of charge, to any person obtaining a copy |
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* of this software and associated documentation files (the "Software"), to deal |
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* in the Software without restriction, including without limitation the rights |
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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* copies of the Software, and to permit persons to whom the Software is |
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* furnished to do so, subject to the following conditions: |
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* |
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* The above copyright notice and this permission notice shall be included in |
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* all copies or substantial portions of the Software. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
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* THE SOFTWARE. |
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* |
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* @package CodeIgniter |
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* @author EllisLab Dev Team |
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* @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/) |
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* @copyright Copyright (c) 2014 - 2018, British Columbia Institute of Technology (http://bcit.ca/) |
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* @license http://opensource.org/licenses/MIT MIT License |
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* @link https://codeigniter.com |
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* @since Version 3.0.0 |
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* @filesource |
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*/ |
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defined('BASEPATH') OR exit('No direct script access allowed'); |
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|
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/** |
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* CodeIgniter Encryption Class |
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* |
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* Provides two-way keyed encryption via PHP's MCrypt and/or OpenSSL extensions. |
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* |
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* @package CodeIgniter |
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* @subpackage Libraries |
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* @category Libraries |
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* @author Andrey Andreev |
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* @link https://codeigniter.com/user_guide/libraries/encryption.html |
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*/ |
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class CI_Encryption { |
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/** |
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* Encryption cipher |
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* |
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* @var string |
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*/ |
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protected $_cipher = 'aes-128'; |
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|
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/** |
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* Cipher mode |
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* |
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* @var string |
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*/ |
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protected $_mode = 'cbc'; |
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|
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/** |
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* Cipher handle |
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* |
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* @var mixed |
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*/ |
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protected $_handle; |
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/** |
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* Encryption key |
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* |
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* @var string |
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*/ |
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protected $_key; |
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|
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/** |
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* PHP extension to be used |
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* |
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* @var string |
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*/ |
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protected $_driver; |
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|
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/** |
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* List of usable drivers (PHP extensions) |
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* |
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* @var array |
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*/ |
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protected $_drivers = array(); |
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|
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/** |
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* List of available modes |
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* |
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* @var array |
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*/ |
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protected $_modes = array( |
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'mcrypt' => array( |
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'cbc' => 'cbc', |
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'ecb' => 'ecb', |
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'ofb' => 'nofb', |
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'ofb8' => 'ofb', |
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'cfb' => 'ncfb', |
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'cfb8' => 'cfb', |
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'ctr' => 'ctr', |
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'stream' => 'stream' |
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), |
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'openssl' => array( |
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'cbc' => 'cbc', |
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'ecb' => 'ecb', |
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'ofb' => 'ofb', |
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'cfb' => 'cfb', |
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'cfb8' => 'cfb8', |
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'ctr' => 'ctr', |
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'stream' => '', |
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'xts' => 'xts' |
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) |
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); |
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|
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/** |
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* List of supported HMAC algorithms |
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* |
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* name => digest size pairs |
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* |
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* @var array |
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*/ |
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protected $_digests = array( |
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'sha224' => 28, |
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'sha256' => 32, |
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'sha384' => 48, |
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'sha512' => 64 |
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); |
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|
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/** |
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* mbstring.func_overload flag |
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* |
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* @var bool |
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*/ |
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protected static $func_overload; |
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|
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// -------------------------------------------------------------------- |
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|
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/** |
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* Class constructor |
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* |
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* @param array $params Configuration parameters |
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* @return void |
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*/ |
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public function __construct(array $params = array()) |
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{ |
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$this->_drivers = array( |
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'mcrypt' => defined('MCRYPT_DEV_URANDOM'), |
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'openssl' => extension_loaded('openssl') |
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); |
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|
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if ( ! $this->_drivers['mcrypt'] && ! $this->_drivers['openssl']) |
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{ |
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show_error('Encryption: Unable to find an available encryption driver.'); |
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} |
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|
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isset(self::$func_overload) OR self::$func_overload = (extension_loaded('mbstring') && ini_get('mbstring.func_overload')); |
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$this->initialize($params); |
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|
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if ( ! isset($this->_key) && self::strlen($key = config_item('encryption_key')) > 0) |
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{ |
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$this->_key = $key; |
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} |
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log_message('info', 'Encryption Class Initialized'); |
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} |
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// -------------------------------------------------------------------- |
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|
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/** |
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* Initialize |
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* |
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* @param array $params Configuration parameters |
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* @return CI_Encryption |
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*/ |
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public function initialize(array $params) |
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{ |
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if ( ! empty($params['driver'])) |
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{ |
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if (isset($this->_drivers[$params['driver']])) |
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{ |
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if ($this->_drivers[$params['driver']]) |
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{ |
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$this->_driver = $params['driver']; |
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} |
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else |
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{ |
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log_message('error', "Encryption: Driver '".$params['driver']."' is not available."); |
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} |
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} |
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else |
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{ |
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log_message('error', "Encryption: Unknown driver '".$params['driver']."' cannot be configured."); |
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} |
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} |
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|
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if (empty($this->_driver)) |
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{ |
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$this->_driver = ($this->_drivers['openssl'] === TRUE) |
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? 'openssl' |
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: 'mcrypt'; |
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|
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log_message('debug', "Encryption: Auto-configured driver '".$this->_driver."'."); |
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} |
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empty($params['cipher']) && $params['cipher'] = $this->_cipher; |
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empty($params['key']) OR $this->_key = $params['key']; |
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$this->{'_'.$this->_driver.'_initialize'}($params); |
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return $this; |
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} |
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// -------------------------------------------------------------------- |
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/** |
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* Initialize MCrypt |
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* |
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* @param array $params Configuration parameters |
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* @return void |
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*/ |
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protected function _mcrypt_initialize($params) |
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{ |
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if ( ! empty($params['cipher'])) |
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{ |
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$params['cipher'] = strtolower($params['cipher']); |
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$this->_cipher_alias($params['cipher']); |
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|
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if ( ! in_array($params['cipher'], mcrypt_list_algorithms(), TRUE)) |
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{ |
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log_message('error', 'Encryption: MCrypt cipher '.strtoupper($params['cipher']).' is not available.'); |
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} |
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else |
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{ |
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$this->_cipher = $params['cipher']; |
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} |
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} |
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if ( ! empty($params['mode'])) |
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{ |
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$params['mode'] = strtolower($params['mode']); |
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if ( ! isset($this->_modes['mcrypt'][$params['mode']])) |
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{ |
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log_message('error', 'Encryption: MCrypt mode '.strtoupper($params['mode']).' is not available.'); |
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} |
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else |
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{ |
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$this->_mode = $this->_modes['mcrypt'][$params['mode']]; |
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} |
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} |
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if (isset($this->_cipher, $this->_mode)) |
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{ |
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if (is_resource($this->_handle) |
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&& (strtolower(mcrypt_enc_get_algorithms_name($this->_handle)) !== $this->_cipher |
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OR strtolower(mcrypt_enc_get_modes_name($this->_handle)) !== $this->_mode) |
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) |
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{ |
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mcrypt_module_close($this->_handle); |
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} |
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if ($this->_handle = mcrypt_module_open($this->_cipher, '', $this->_mode, '')) |
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{ |
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log_message('info', 'Encryption: MCrypt cipher '.strtoupper($this->_cipher).' initialized in '.strtoupper($this->_mode).' mode.'); |
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} |
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else |
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{ |
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log_message('error', 'Encryption: Unable to initialize MCrypt with cipher '.strtoupper($this->_cipher).' in '.strtoupper($this->_mode).' mode.'); |
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} |
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} |
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} |
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// -------------------------------------------------------------------- |
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|
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/** |
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* Initialize OpenSSL |
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* |
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* @param array $params Configuration parameters |
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* @return void |
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*/ |
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protected function _openssl_initialize($params) |
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{ |
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if ( ! empty($params['cipher'])) |
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{ |
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$params['cipher'] = strtolower($params['cipher']); |
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$this->_cipher_alias($params['cipher']); |
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$this->_cipher = $params['cipher']; |
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} |
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|
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if ( ! empty($params['mode'])) |
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{ |
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$params['mode'] = strtolower($params['mode']); |
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if ( ! isset($this->_modes['openssl'][$params['mode']])) |
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{ |
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log_message('error', 'Encryption: OpenSSL mode '.strtoupper($params['mode']).' is not available.'); |
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} |
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else |
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{ |
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$this->_mode = $this->_modes['openssl'][$params['mode']]; |
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} |
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} |
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|
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if (isset($this->_cipher, $this->_mode)) |
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{ |
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// This is mostly for the stream mode, which doesn't get suffixed in OpenSSL |
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$handle = empty($this->_mode) |
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? $this->_cipher |
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: $this->_cipher.'-'.$this->_mode; |
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|
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if ( ! in_array($handle, openssl_get_cipher_methods(), TRUE)) |
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{ |
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$this->_handle = NULL; |
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log_message('error', 'Encryption: Unable to initialize OpenSSL with method '.strtoupper($handle).'.'); |
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} |
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else |
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{ |
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$this->_handle = $handle; |
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log_message('info', 'Encryption: OpenSSL initialized with method '.strtoupper($handle).'.'); |
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} |
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} |
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} |
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|
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// -------------------------------------------------------------------- |
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|
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/** |
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* Create a random key |
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* |
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* @param int $length Output length |
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* @return string |
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*/ |
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public function create_key($length) |
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{ |
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if (function_exists('random_bytes')) |
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{ |
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try |
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{ |
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return random_bytes((int) $length); |
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} |
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catch (Exception $e) |
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{ |
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log_message('error', $e->getMessage()); |
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return FALSE; |
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} |
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} |
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elseif (defined('MCRYPT_DEV_URANDOM')) |
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{ |
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return mcrypt_create_iv($length, MCRYPT_DEV_URANDOM); |
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} |
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|
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$is_secure = NULL; |
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$key = openssl_random_pseudo_bytes($length, $is_secure); |
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return ($is_secure === TRUE) |
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? $key |
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: FALSE; |
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} |
|
|
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// -------------------------------------------------------------------- |
|
|
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/** |
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* Encrypt |
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* |
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* @param string $data Input data |
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* @param array $params Input parameters |
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* @return string |
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*/ |
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public function encrypt($data, array $params = NULL) |
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{ |
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if (($params = $this->_get_params($params)) === FALSE) |
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{ |
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return FALSE; |
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} |
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|
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isset($params['key']) OR $params['key'] = $this->hkdf($this->_key, 'sha512', NULL, self::strlen($this->_key), 'encryption'); |
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|
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if (($data = $this->{'_'.$this->_driver.'_encrypt'}($data, $params)) === FALSE) |
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{ |
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return FALSE; |
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} |
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|
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$params['base64'] && $data = base64_encode($data); |
|
|
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if (isset($params['hmac_digest'])) |
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{ |
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isset($params['hmac_key']) OR $params['hmac_key'] = $this->hkdf($this->_key, 'sha512', NULL, NULL, 'authentication'); |
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return hash_hmac($params['hmac_digest'], $data, $params['hmac_key'], ! $params['base64']).$data; |
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} |
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|
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return $data; |
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} |
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|
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// -------------------------------------------------------------------- |
|
|
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/** |
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* Encrypt via MCrypt |
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* |
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* @param string $data Input data |
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* @param array $params Input parameters |
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* @return string |
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*/ |
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protected function _mcrypt_encrypt($data, $params) |
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{ |
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if ( ! is_resource($params['handle'])) |
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{ |
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return FALSE; |
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} |
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|
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// The greater-than-1 comparison is mostly a work-around for a bug, |
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// where 1 is returned for ARCFour instead of 0. |
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$iv = (($iv_size = mcrypt_enc_get_iv_size($params['handle'])) > 1) |
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? $this->create_key($iv_size) |
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: NULL; |
|
|
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if (mcrypt_generic_init($params['handle'], $params['key'], $iv) < 0) |
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{ |
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if ($params['handle'] !== $this->_handle) |
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{ |
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mcrypt_module_close($params['handle']); |
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} |
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|
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return FALSE; |
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} |
|
|
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// Use PKCS#7 padding in order to ensure compatibility with OpenSSL |
|
// and other implementations outside of PHP. |
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if (in_array(strtolower(mcrypt_enc_get_modes_name($params['handle'])), array('cbc', 'ecb'), TRUE)) |
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{ |
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$block_size = mcrypt_enc_get_block_size($params['handle']); |
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$pad = $block_size - (self::strlen($data) % $block_size); |
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$data .= str_repeat(chr($pad), $pad); |
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} |
|
|
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// Work-around for yet another strange behavior in MCrypt. |
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// |
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// When encrypting in ECB mode, the IV is ignored. Yet |
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// mcrypt_enc_get_iv_size() returns a value larger than 0 |
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// even if ECB is used AND mcrypt_generic_init() complains |
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// if you don't pass an IV with length equal to the said |
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// return value. |
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// |
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// This probably would've been fine (even though still wasteful), |
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// but OpenSSL isn't that dumb and we need to make the process |
|
// portable, so ... |
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$data = (mcrypt_enc_get_modes_name($params['handle']) !== 'ECB') |
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? $iv.mcrypt_generic($params['handle'], $data) |
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: mcrypt_generic($params['handle'], $data); |
|
|
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mcrypt_generic_deinit($params['handle']); |
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if ($params['handle'] !== $this->_handle) |
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{ |
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mcrypt_module_close($params['handle']); |
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} |
|
|
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return $data; |
|
} |
|
|
|
// -------------------------------------------------------------------- |
|
|
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/** |
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* Encrypt via OpenSSL |
|
* |
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* @param string $data Input data |
|
* @param array $params Input parameters |
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* @return string |
|
*/ |
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protected function _openssl_encrypt($data, $params) |
|
{ |
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if (empty($params['handle'])) |
|
{ |
|
return FALSE; |
|
} |
|
|
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$iv = ($iv_size = openssl_cipher_iv_length($params['handle'])) |
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? $this->create_key($iv_size) |
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: NULL; |
|
|
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$data = openssl_encrypt( |
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$data, |
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$params['handle'], |
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$params['key'], |
|
1, // DO NOT TOUCH! |
|
$iv |
|
); |
|
|
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if ($data === FALSE) |
|
{ |
|
return FALSE; |
|
} |
|
|
|
return $iv.$data; |
|
} |
|
|
|
// -------------------------------------------------------------------- |
|
|
|
/** |
|
* Decrypt |
|
* |
|
* @param string $data Encrypted data |
|
* @param array $params Input parameters |
|
* @return string |
|
*/ |
|
public function decrypt($data, array $params = NULL) |
|
{ |
|
if (($params = $this->_get_params($params)) === FALSE) |
|
{ |
|
return FALSE; |
|
} |
|
|
|
if (isset($params['hmac_digest'])) |
|
{ |
|
// This might look illogical, but it is done during encryption as well ... |
|
// The 'base64' value is effectively an inverted "raw data" parameter |
|
$digest_size = ($params['base64']) |
|
? $this->_digests[$params['hmac_digest']] * 2 |
|
: $this->_digests[$params['hmac_digest']]; |
|
|
|
if (self::strlen($data) <= $digest_size) |
|
{ |
|
return FALSE; |
|
} |
|
|
|
$hmac_input = self::substr($data, 0, $digest_size); |
|
$data = self::substr($data, $digest_size); |
|
|
|
isset($params['hmac_key']) OR $params['hmac_key'] = $this->hkdf($this->_key, 'sha512', NULL, NULL, 'authentication'); |
|
$hmac_check = hash_hmac($params['hmac_digest'], $data, $params['hmac_key'], ! $params['base64']); |
|
|
|
// Time-attack-safe comparison |
|
$diff = 0; |
|
for ($i = 0; $i < $digest_size; $i++) |
|
{ |
|
$diff |= ord($hmac_input[$i]) ^ ord($hmac_check[$i]); |
|
} |
|
|
|
if ($diff !== 0) |
|
{ |
|
return FALSE; |
|
} |
|
} |
|
|
|
if ($params['base64']) |
|
{ |
|
$data = base64_decode($data); |
|
} |
|
|
|
isset($params['key']) OR $params['key'] = $this->hkdf($this->_key, 'sha512', NULL, self::strlen($this->_key), 'encryption'); |
|
|
|
return $this->{'_'.$this->_driver.'_decrypt'}($data, $params); |
|
} |
|
|
|
// -------------------------------------------------------------------- |
|
|
|
/** |
|
* Decrypt via MCrypt |
|
* |
|
* @param string $data Encrypted data |
|
* @param array $params Input parameters |
|
* @return string |
|
*/ |
|
protected function _mcrypt_decrypt($data, $params) |
|
{ |
|
if ( ! is_resource($params['handle'])) |
|
{ |
|
return FALSE; |
|
} |
|
|
|
// The greater-than-1 comparison is mostly a work-around for a bug, |
|
// where 1 is returned for ARCFour instead of 0. |
|
if (($iv_size = mcrypt_enc_get_iv_size($params['handle'])) > 1) |
|
{ |
|
if (mcrypt_enc_get_modes_name($params['handle']) !== 'ECB') |
|
{ |
|
$iv = self::substr($data, 0, $iv_size); |
|
$data = self::substr($data, $iv_size); |
|
} |
|
else |
|
{ |
|
// MCrypt is dumb and this is ignored, only size matters |
|
$iv = str_repeat("\x0", $iv_size); |
|
} |
|
} |
|
else |
|
{ |
|
$iv = NULL; |
|
} |
|
|
|
if (mcrypt_generic_init($params['handle'], $params['key'], $iv) < 0) |
|
{ |
|
if ($params['handle'] !== $this->_handle) |
|
{ |
|
mcrypt_module_close($params['handle']); |
|
} |
|
|
|
return FALSE; |
|
} |
|
|
|
$data = mdecrypt_generic($params['handle'], $data); |
|
// Remove PKCS#7 padding, if necessary |
|
if (in_array(strtolower(mcrypt_enc_get_modes_name($params['handle'])), array('cbc', 'ecb'), TRUE)) |
|
{ |
|
$data = self::substr($data, 0, -ord($data[self::strlen($data)-1])); |
|
} |
|
|
|
mcrypt_generic_deinit($params['handle']); |
|
if ($params['handle'] !== $this->_handle) |
|
{ |
|
mcrypt_module_close($params['handle']); |
|
} |
|
|
|
return $data; |
|
} |
|
|
|
// -------------------------------------------------------------------- |
|
|
|
/** |
|
* Decrypt via OpenSSL |
|
* |
|
* @param string $data Encrypted data |
|
* @param array $params Input parameters |
|
* @return string |
|
*/ |
|
protected function _openssl_decrypt($data, $params) |
|
{ |
|
if ($iv_size = openssl_cipher_iv_length($params['handle'])) |
|
{ |
|
$iv = self::substr($data, 0, $iv_size); |
|
$data = self::substr($data, $iv_size); |
|
} |
|
else |
|
{ |
|
$iv = NULL; |
|
} |
|
|
|
return empty($params['handle']) |
|
? FALSE |
|
: openssl_decrypt( |
|
$data, |
|
$params['handle'], |
|
$params['key'], |
|
1, // DO NOT TOUCH! |
|
$iv |
|
); |
|
} |
|
|
|
// -------------------------------------------------------------------- |
|
|
|
/** |
|
* Get params |
|
* |
|
* @param array $params Input parameters |
|
* @return array |
|
*/ |
|
protected function _get_params($params) |
|
{ |
|
if (empty($params)) |
|
{ |
|
return isset($this->_cipher, $this->_mode, $this->_key, $this->_handle) |
|
? array( |
|
'handle' => $this->_handle, |
|
'cipher' => $this->_cipher, |
|
'mode' => $this->_mode, |
|
'key' => NULL, |
|
'base64' => TRUE, |
|
'hmac_digest' => 'sha512', |
|
'hmac_key' => NULL |
|
) |
|
: FALSE; |
|
} |
|
elseif ( ! isset($params['cipher'], $params['mode'], $params['key'])) |
|
{ |
|
return FALSE; |
|
} |
|
|
|
if (isset($params['mode'])) |
|
{ |
|
$params['mode'] = strtolower($params['mode']); |
|
if ( ! isset($this->_modes[$this->_driver][$params['mode']])) |
|
{ |
|
return FALSE; |
|
} |
|
|
|
$params['mode'] = $this->_modes[$this->_driver][$params['mode']]; |
|
} |
|
|
|
if (isset($params['hmac']) && $params['hmac'] === FALSE) |
|
{ |
|
$params['hmac_digest'] = $params['hmac_key'] = NULL; |
|
} |
|
else |
|
{ |
|
if ( ! isset($params['hmac_key'])) |
|
{ |
|
return FALSE; |
|
} |
|
elseif (isset($params['hmac_digest'])) |
|
{ |
|
$params['hmac_digest'] = strtolower($params['hmac_digest']); |
|
if ( ! isset($this->_digests[$params['hmac_digest']])) |
|
{ |
|
return FALSE; |
|
} |
|
} |
|
else |
|
{ |
|
$params['hmac_digest'] = 'sha512'; |
|
} |
|
} |
|
|
|
$params = array( |
|
'handle' => NULL, |
|
'cipher' => $params['cipher'], |
|
'mode' => $params['mode'], |
|
'key' => $params['key'], |
|
'base64' => isset($params['raw_data']) ? ! $params['raw_data'] : FALSE, |
|
'hmac_digest' => $params['hmac_digest'], |
|
'hmac_key' => $params['hmac_key'] |
|
); |
|
|
|
$this->_cipher_alias($params['cipher']); |
|
$params['handle'] = ($params['cipher'] !== $this->_cipher OR $params['mode'] !== $this->_mode) |
|
? $this->{'_'.$this->_driver.'_get_handle'}($params['cipher'], $params['mode']) |
|
: $this->_handle; |
|
|
|
return $params; |
|
} |
|
|
|
// -------------------------------------------------------------------- |
|
|
|
/** |
|
* Get MCrypt handle |
|
* |
|
* @param string $cipher Cipher name |
|
* @param string $mode Encryption mode |
|
* @return resource |
|
*/ |
|
protected function _mcrypt_get_handle($cipher, $mode) |
|
{ |
|
return mcrypt_module_open($cipher, '', $mode, ''); |
|
} |
|
|
|
// -------------------------------------------------------------------- |
|
|
|
/** |
|
* Get OpenSSL handle |
|
* |
|
* @param string $cipher Cipher name |
|
* @param string $mode Encryption mode |
|
* @return string |
|
*/ |
|
protected function _openssl_get_handle($cipher, $mode) |
|
{ |
|
// OpenSSL methods aren't suffixed with '-stream' for this mode |
|
return ($mode === 'stream') |
|
? $cipher |
|
: $cipher.'-'.$mode; |
|
} |
|
|
|
// -------------------------------------------------------------------- |
|
|
|
/** |
|
* Cipher alias |
|
* |
|
* Tries to translate cipher names between MCrypt and OpenSSL's "dialects". |
|
* |
|
* @param string $cipher Cipher name |
|
* @return void |
|
*/ |
|
protected function _cipher_alias(&$cipher) |
|
{ |
|
static $dictionary; |
|
|
|
if (empty($dictionary)) |
|
{ |
|
$dictionary = array( |
|
'mcrypt' => array( |
|
'aes-128' => 'rijndael-128', |
|
'aes-192' => 'rijndael-128', |
|
'aes-256' => 'rijndael-128', |
|
'des3-ede3' => 'tripledes', |
|
'bf' => 'blowfish', |
|
'cast5' => 'cast-128', |
|
'rc4' => 'arcfour', |
|
'rc4-40' => 'arcfour' |
|
), |
|
'openssl' => array( |
|
'rijndael-128' => 'aes-128', |
|
'tripledes' => 'des-ede3', |
|
'blowfish' => 'bf', |
|
'cast-128' => 'cast5', |
|
'arcfour' => 'rc4-40', |
|
'rc4' => 'rc4-40' |
|
) |
|
); |
|
|
|
// Notes: |
|
// |
|
// - Rijndael-128 is, at the same time all three of AES-128, |
|
// AES-192 and AES-256. The only difference between them is |
|
// the key size. Rijndael-192, Rijndael-256 on the other hand |
|
// also have different block sizes and are NOT AES-compatible. |
|
// |
|
// - Blowfish is said to be supporting key sizes between |
|
// 4 and 56 bytes, but it appears that between MCrypt and |
|
// OpenSSL, only those of 16 and more bytes are compatible. |
|
// Also, don't know what MCrypt's 'blowfish-compat' is. |
|
// |
|
// - CAST-128/CAST5 produces a longer cipher when encrypted via |
|
// OpenSSL, but (strangely enough) can be decrypted by either |
|
// extension anyway. |
|
// Also, it appears that OpenSSL uses 16 rounds regardless of |
|
// the key size, while RFC2144 says that for key sizes lower |
|
// than 11 bytes, only 12 rounds should be used. This makes |
|
// it portable only with keys of between 11 and 16 bytes. |
|
// |
|
// - RC4 (ARCFour) has a strange implementation under OpenSSL. |
|
// Its 'rc4-40' cipher method seems to work flawlessly, yet |
|
// there's another one, 'rc4' that only works with a 16-byte key. |
|
// |
|
// - DES is compatible, but doesn't need an alias. |
|
// |
|
// Other seemingly matching ciphers between MCrypt, OpenSSL: |
|
// |
|
// - RC2 is NOT compatible and only an obscure forum post |
|
// confirms that it is MCrypt's fault. |
|
} |
|
|
|
if (isset($dictionary[$this->_driver][$cipher])) |
|
{ |
|
$cipher = $dictionary[$this->_driver][$cipher]; |
|
} |
|
} |
|
|
|
// -------------------------------------------------------------------- |
|
|
|
/** |
|
* HKDF |
|
* |
|
* @link https://tools.ietf.org/rfc/rfc5869.txt |
|
* @param $key Input key |
|
* @param $digest A SHA-2 hashing algorithm |
|
* @param $salt Optional salt |
|
* @param $length Output length (defaults to the selected digest size) |
|
* @param $info Optional context/application-specific info |
|
* @return string A pseudo-random key |
|
*/ |
|
public function hkdf($key, $digest = 'sha512', $salt = NULL, $length = NULL, $info = '') |
|
{ |
|
if ( ! isset($this->_digests[$digest])) |
|
{ |
|
return FALSE; |
|
} |
|
|
|
if (empty($length) OR ! is_int($length)) |
|
{ |
|
$length = $this->_digests[$digest]; |
|
} |
|
elseif ($length > (255 * $this->_digests[$digest])) |
|
{ |
|
return FALSE; |
|
} |
|
|
|
self::strlen($salt) OR $salt = str_repeat("\0", $this->_digests[$digest]); |
|
|
|
$prk = hash_hmac($digest, $key, $salt, TRUE); |
|
$key = ''; |
|
for ($key_block = '', $block_index = 1; self::strlen($key) < $length; $block_index++) |
|
{ |
|
$key_block = hash_hmac($digest, $key_block.$info.chr($block_index), $prk, TRUE); |
|
$key .= $key_block; |
|
} |
|
|
|
return self::substr($key, 0, $length); |
|
} |
|
|
|
// -------------------------------------------------------------------- |
|
|
|
/** |
|
* __get() magic |
|
* |
|
* @param string $key Property name |
|
* @return mixed |
|
*/ |
|
public function __get($key) |
|
{ |
|
// Because aliases |
|
if ($key === 'mode') |
|
{ |
|
return array_search($this->_mode, $this->_modes[$this->_driver], TRUE); |
|
} |
|
elseif (in_array($key, array('cipher', 'driver', 'drivers', 'digests'), TRUE)) |
|
{ |
|
return $this->{'_'.$key}; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
// -------------------------------------------------------------------- |
|
|
|
/** |
|
* Byte-safe strlen() |
|
* |
|
* @param string $str |
|
* @return int |
|
*/ |
|
protected static function strlen($str) |
|
{ |
|
return (self::$func_overload) |
|
? mb_strlen($str, '8bit') |
|
: strlen($str); |
|
} |
|
|
|
// -------------------------------------------------------------------- |
|
|
|
/** |
|
* Byte-safe substr() |
|
* |
|
* @param string $str |
|
* @param int $start |
|
* @param int $length |
|
* @return string |
|
*/ |
|
protected static function substr($str, $start, $length = NULL) |
|
{ |
|
if (self::$func_overload) |
|
{ |
|
// mb_substr($str, $start, null, '8bit') returns an empty |
|
// string on PHP 5.3 |
|
isset($length) OR $length = ($start >= 0 ? self::strlen($str) - $start : -$start); |
|
return mb_substr($str, $start, $length, '8bit'); |
|
} |
|
|
|
return isset($length) |
|
? substr($str, $start, $length) |
|
: substr($str, $start); |
|
} |
|
}
|
|
|