481 lines
11 KiB
PHP
481 lines
11 KiB
PHP
<?php
|
|
/**
|
|
* CodeIgniter
|
|
*
|
|
* An open source application development framework for PHP
|
|
*
|
|
* This content is released under the MIT License (MIT)
|
|
*
|
|
* Copyright (c) 2014 - 2015, British Columbia Institute of Technology
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*
|
|
* @package CodeIgniter
|
|
* @author EllisLab Dev Team
|
|
* @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
|
|
* @copyright Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
|
|
* @license http://opensource.org/licenses/MIT MIT License
|
|
* @link http://codeigniter.com
|
|
* @since Version 1.0.0
|
|
* @filesource
|
|
*/
|
|
defined('BASEPATH') OR exit('No direct script access allowed');
|
|
|
|
/**
|
|
* CodeIgniter Encryption Class
|
|
*
|
|
* Provides two-way keyed encoding using Mcrypt
|
|
*
|
|
* @package CodeIgniter
|
|
* @subpackage Libraries
|
|
* @category Libraries
|
|
* @author EllisLab Dev Team
|
|
* @link http://codeigniter.com/user_guide/libraries/encryption.html
|
|
*/
|
|
class CI_Encrypt {
|
|
|
|
/**
|
|
* Reference to the user's encryption key
|
|
*
|
|
* @var string
|
|
*/
|
|
public $encryption_key = '';
|
|
|
|
/**
|
|
* Type of hash operation
|
|
*
|
|
* @var string
|
|
*/
|
|
protected $_hash_type = 'sha1';
|
|
|
|
/**
|
|
* Flag for the existance of mcrypt
|
|
*
|
|
* @var bool
|
|
*/
|
|
protected $_mcrypt_exists = FALSE;
|
|
|
|
/**
|
|
* Current cipher to be used with mcrypt
|
|
*
|
|
* @var string
|
|
*/
|
|
protected $_mcrypt_cipher;
|
|
|
|
/**
|
|
* Method for encrypting/decrypting data
|
|
*
|
|
* @var int
|
|
*/
|
|
protected $_mcrypt_mode;
|
|
|
|
/**
|
|
* Initialize Encryption class
|
|
*
|
|
* @return void
|
|
*/
|
|
public function __construct()
|
|
{
|
|
if (($this->_mcrypt_exists = function_exists('mcrypt_encrypt')) === FALSE)
|
|
{
|
|
show_error('The Encrypt library requires the Mcrypt extension.');
|
|
}
|
|
|
|
log_message('info', 'Encrypt Class Initialized');
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Fetch the encryption key
|
|
*
|
|
* Returns it as MD5 in order to have an exact-length 128 bit key.
|
|
* Mcrypt is sensitive to keys that are not the correct length
|
|
*
|
|
* @param string
|
|
* @return string
|
|
*/
|
|
public function get_key($key = '')
|
|
{
|
|
if ($key === '')
|
|
{
|
|
if ($this->encryption_key !== '')
|
|
{
|
|
return $this->encryption_key;
|
|
}
|
|
|
|
$key = config_item('encryption_key');
|
|
|
|
if ( ! strlen($key))
|
|
{
|
|
show_error('In order to use the encryption class requires that you set an encryption key in your config file.');
|
|
}
|
|
}
|
|
|
|
return md5($key);
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Set the encryption key
|
|
*
|
|
* @param string
|
|
* @return CI_Encrypt
|
|
*/
|
|
public function set_key($key = '')
|
|
{
|
|
$this->encryption_key = $key;
|
|
return $this;
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Encode
|
|
*
|
|
* Encodes the message string using bitwise XOR encoding.
|
|
* The key is combined with a random hash, and then it
|
|
* too gets converted using XOR. The whole thing is then run
|
|
* through mcrypt using the randomized key. The end result
|
|
* is a double-encrypted message string that is randomized
|
|
* with each call to this function, even if the supplied
|
|
* message and key are the same.
|
|
*
|
|
* @param string the string to encode
|
|
* @param string the key
|
|
* @return string
|
|
*/
|
|
public function encode($string, $key = '')
|
|
{
|
|
return base64_encode($this->mcrypt_encode($string, $this->get_key($key)));
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Decode
|
|
*
|
|
* Reverses the above process
|
|
*
|
|
* @param string
|
|
* @param string
|
|
* @return string
|
|
*/
|
|
public function decode($string, $key = '')
|
|
{
|
|
if (preg_match('/[^a-zA-Z0-9\/\+=]/', $string) OR base64_encode(base64_decode($string)) !== $string)
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
return $this->mcrypt_decode(base64_decode($string), $this->get_key($key));
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Encode from Legacy
|
|
*
|
|
* Takes an encoded string from the original Encryption class algorithms and
|
|
* returns a newly encoded string using the improved method added in 2.0.0
|
|
* This allows for backwards compatibility and a method to transition to the
|
|
* new encryption algorithms.
|
|
*
|
|
* For more details, see http://codeigniter.com/user_guide/installation/upgrade_200.html#encryption
|
|
*
|
|
* @param string
|
|
* @param int (mcrypt mode constant)
|
|
* @param string
|
|
* @return string
|
|
*/
|
|
public function encode_from_legacy($string, $legacy_mode = MCRYPT_MODE_ECB, $key = '')
|
|
{
|
|
if (preg_match('/[^a-zA-Z0-9\/\+=]/', $string))
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
// decode it first
|
|
// set mode temporarily to what it was when string was encoded with the legacy
|
|
// algorithm - typically MCRYPT_MODE_ECB
|
|
$current_mode = $this->_get_mode();
|
|
$this->set_mode($legacy_mode);
|
|
|
|
$key = $this->get_key($key);
|
|
$dec = base64_decode($string);
|
|
if (($dec = $this->mcrypt_decode($dec, $key)) === FALSE)
|
|
{
|
|
$this->set_mode($current_mode);
|
|
return FALSE;
|
|
}
|
|
|
|
$dec = $this->_xor_decode($dec, $key);
|
|
|
|
// set the mcrypt mode back to what it should be, typically MCRYPT_MODE_CBC
|
|
$this->set_mode($current_mode);
|
|
|
|
// and re-encode
|
|
return base64_encode($this->mcrypt_encode($dec, $key));
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* XOR Decode
|
|
*
|
|
* Takes an encoded string and key as input and generates the
|
|
* plain-text original message
|
|
*
|
|
* @param string
|
|
* @param string
|
|
* @return string
|
|
*/
|
|
protected function _xor_decode($string, $key)
|
|
{
|
|
$string = $this->_xor_merge($string, $key);
|
|
|
|
$dec = '';
|
|
for ($i = 0, $l = strlen($string); $i < $l; $i++)
|
|
{
|
|
$dec .= ($string[$i++] ^ $string[$i]);
|
|
}
|
|
|
|
return $dec;
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* XOR key + string Combiner
|
|
*
|
|
* Takes a string and key as input and computes the difference using XOR
|
|
*
|
|
* @param string
|
|
* @param string
|
|
* @return string
|
|
*/
|
|
protected function _xor_merge($string, $key)
|
|
{
|
|
$hash = $this->hash($key);
|
|
$str = '';
|
|
for ($i = 0, $ls = strlen($string), $lh = strlen($hash); $i < $ls; $i++)
|
|
{
|
|
$str .= $string[$i] ^ $hash[($i % $lh)];
|
|
}
|
|
|
|
return $str;
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Encrypt using Mcrypt
|
|
*
|
|
* @param string
|
|
* @param string
|
|
* @return string
|
|
*/
|
|
public function mcrypt_encode($data, $key)
|
|
{
|
|
$init_size = mcrypt_get_iv_size($this->_get_cipher(), $this->_get_mode());
|
|
$init_vect = mcrypt_create_iv($init_size, MCRYPT_RAND);
|
|
return $this->_add_cipher_noise($init_vect.mcrypt_encrypt($this->_get_cipher(), $key, $data, $this->_get_mode(), $init_vect), $key);
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Decrypt using Mcrypt
|
|
*
|
|
* @param string
|
|
* @param string
|
|
* @return string
|
|
*/
|
|
public function mcrypt_decode($data, $key)
|
|
{
|
|
$data = $this->_remove_cipher_noise($data, $key);
|
|
$init_size = mcrypt_get_iv_size($this->_get_cipher(), $this->_get_mode());
|
|
|
|
if ($init_size > strlen($data))
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
$init_vect = substr($data, 0, $init_size);
|
|
$data = substr($data, $init_size);
|
|
return rtrim(mcrypt_decrypt($this->_get_cipher(), $key, $data, $this->_get_mode(), $init_vect), "\0");
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Adds permuted noise to the IV + encrypted data to protect
|
|
* against Man-in-the-middle attacks on CBC mode ciphers
|
|
* http://www.ciphersbyritter.com/GLOSSARY.HTM#IV
|
|
*
|
|
* @param string
|
|
* @param string
|
|
* @return string
|
|
*/
|
|
protected function _add_cipher_noise($data, $key)
|
|
{
|
|
$key = $this->hash($key);
|
|
$str = '';
|
|
|
|
for ($i = 0, $j = 0, $ld = strlen($data), $lk = strlen($key); $i < $ld; ++$i, ++$j)
|
|
{
|
|
if ($j >= $lk)
|
|
{
|
|
$j = 0;
|
|
}
|
|
|
|
$str .= chr((ord($data[$i]) + ord($key[$j])) % 256);
|
|
}
|
|
|
|
return $str;
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Removes permuted noise from the IV + encrypted data, reversing
|
|
* _add_cipher_noise()
|
|
*
|
|
* Function description
|
|
*
|
|
* @param string $data
|
|
* @param string $key
|
|
* @return string
|
|
*/
|
|
protected function _remove_cipher_noise($data, $key)
|
|
{
|
|
$key = $this->hash($key);
|
|
$str = '';
|
|
|
|
for ($i = 0, $j = 0, $ld = strlen($data), $lk = strlen($key); $i < $ld; ++$i, ++$j)
|
|
{
|
|
if ($j >= $lk)
|
|
{
|
|
$j = 0;
|
|
}
|
|
|
|
$temp = ord($data[$i]) - ord($key[$j]);
|
|
|
|
if ($temp < 0)
|
|
{
|
|
$temp += 256;
|
|
}
|
|
|
|
$str .= chr($temp);
|
|
}
|
|
|
|
return $str;
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Set the Mcrypt Cipher
|
|
*
|
|
* @param int
|
|
* @return CI_Encrypt
|
|
*/
|
|
public function set_cipher($cipher)
|
|
{
|
|
$this->_mcrypt_cipher = $cipher;
|
|
return $this;
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Set the Mcrypt Mode
|
|
*
|
|
* @param int
|
|
* @return CI_Encrypt
|
|
*/
|
|
public function set_mode($mode)
|
|
{
|
|
$this->_mcrypt_mode = $mode;
|
|
return $this;
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Get Mcrypt cipher Value
|
|
*
|
|
* @return int
|
|
*/
|
|
protected function _get_cipher()
|
|
{
|
|
if ($this->_mcrypt_cipher === NULL)
|
|
{
|
|
return $this->_mcrypt_cipher = MCRYPT_RIJNDAEL_256;
|
|
}
|
|
|
|
return $this->_mcrypt_cipher;
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Get Mcrypt Mode Value
|
|
*
|
|
* @return int
|
|
*/
|
|
protected function _get_mode()
|
|
{
|
|
if ($this->_mcrypt_mode === NULL)
|
|
{
|
|
return $this->_mcrypt_mode = MCRYPT_MODE_CBC;
|
|
}
|
|
|
|
return $this->_mcrypt_mode;
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Set the Hash type
|
|
*
|
|
* @param string
|
|
* @return void
|
|
*/
|
|
public function set_hash($type = 'sha1')
|
|
{
|
|
$this->_hash_type = in_array($type, hash_algos()) ? $type : 'sha1';
|
|
}
|
|
|
|
// --------------------------------------------------------------------
|
|
|
|
/**
|
|
* Hash encode a string
|
|
*
|
|
* @param string
|
|
* @return string
|
|
*/
|
|
public function hash($str)
|
|
{
|
|
return hash($this->_hash_type, $str);
|
|
}
|
|
|
|
}
|