MIF_E31222691/system/crypter.php

118 lines
2.3 KiB
PHP

<?php namespace System;
class Crypter {
/**
* The encryption cipher.
*
* @var string
*/
public $cipher;
/**
* The encryption mode.
*
* @var string
*/
public $mode;
/**
* Create a new Crypter instance.
*
* @param string $cipher
* @param string $mode
* @return void
*/
public function __construct($cipher = 'rijndael-256', $mode = 'cbc')
{
$this->cipher = $cipher;
$this->mode = $mode;
}
/**
* Create a new Crypter instance.
*
* @param string $cipher
* @param string $mode
* @return Crypt
*/
public static function make($cipher = 'rijndael-256', $mode = 'cbc')
{
return new static($cipher, $mode);
}
/**
* Encrypt a value using the MCrypt library.
*
* @param string $value
* @return string
*/
public function encrypt($value)
{
$iv = mcrypt_create_iv($this->iv_size(), $this->randomizer());
return base64_encode($iv.mcrypt_encrypt($this->cipher, $this->key(), $value, $this->mode, $iv));
}
/**
* Get the random number source available to the OS.
*
* @return int
*/
protected function randomizer()
{
if (defined('MCRYPT_DEV_URANDOM'))
{
return MCRYPT_DEV_URANDOM;
}
elseif (defined('MCRYPT_DEV_RANDOM'))
{
return MCRYPT_DEV_RANDOM;
}
return MCRYPT_RAND;
}
/**
* Decrypt a value using the MCrypt library.
*
* @param string $value
* @return string
*/
public function decrypt($value)
{
if ( ! is_string($value = base64_decode($value, true)))
{
throw new \Exception('Decryption error. Input value is not valid base64 data.');
}
list($iv, $value) = array(substr($value, 0, $this->iv_size()), substr($value, $this->iv_size()));
return rtrim(mcrypt_decrypt($this->cipher, $this->key(), $value, $this->mode, $iv), "\0");
}
/**
* Get the application key from the application configuration file.
*
* @return string
*/
private function key()
{
if ( ! is_null($key = Config::get('application.key')) and $key !== '') return $key;
throw new \Exception("The encryption class can not be used without an encryption key.");
}
/**
* Get the input vector size for the cipher and mode.
*
* Different ciphers and modes use varying lengths of input vectors.
*
* @return int
*/
private function iv_size()
{
return mcrypt_get_iv_size($this->cipher, $this->mode);
}
}