diff --git a/laravel/security/crypter.php b/laravel/security/crypter.php index 314a8cb0..3d4abdda 100644 --- a/laravel/security/crypter.php +++ b/laravel/security/crypter.php @@ -26,6 +26,9 @@ class Crypter { /** * Create a new Crypter instance. * + * A valid cipher and mode supported by the Mcrypt extension must be given to the constructor. + * Also, an encryption key (typically from the application configuration) must be specified. + * * @param string $cipher * @param string $mode * @param string $key @@ -33,9 +36,9 @@ class Crypter { */ public function __construct($cipher, $mode, $key) { - $this->cipher = $cipher; - $this->mode = $mode; $this->key = $key; + $this->mode = $mode; + $this->cipher = $cipher; if (trim((string) $this->key) === '') { @@ -46,48 +49,62 @@ class Crypter { /** * Encrypt a string using Mcrypt. * + * The string will be encrypted using the cipher and mode specified when the crypter + * instance was created, and the final result will be base64 encoded. + * + * + * // Encrypt a string using the Mcrypt PHP extension + * $encrypted = Crypter::encrpt('secret'); + * + * * @param string $value * @return string */ public function encrypt($value) { - $iv = mcrypt_create_iv($this->iv_size(), $this->randomizer()); + // Determine the most appropriate random number generator for the operating + // system and environment the application is running on. + if (defined('MCRYPT_DEV_URANDOM')) + { + $randomizer = MCRYPT_DEV_URANDOM; + } + elseif (defined('MCRYPT_DEV_RANDOM')) + { + $randomizer = MCRYPT_DEV_RANDOM; + } + else + { + $randomizer = MCRYPT_RAND; + } + + $iv = mcrypt_create_iv($this->iv_size(), $randomizer); return base64_encode($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 string using Mcrypt. * + * The string will be decrypted using the cipher and mode specified when the crypter was created. + * + * + * // Decrypt a string using the Mcrypt PHP extension + * $decrypted = Crypter::decrypt($secret); + * + * * @param string $value * @return string */ public function decrypt($value) { + // Since all encrypted strings generated by this class are base64 encoded, we will + // first attempt to base64 decode the string. If we can't do it, we'll bail out. if ( ! is_string($value = base64_decode($value, true))) { throw new \Exception('Decryption error. Input value is not valid base64 data.'); } + // Extract the input vector and the encrypted string from the value 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");