key = $key; $this->mode = $mode; $this->cipher = $cipher; if (trim((string) $this->key) === '') { throw new \Exception('The encryption class may not be used without an encryption key.'); } } /** * 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) { // 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)); } /** * 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, $iv), "\0"); } /** * Get the input vector size for the cipher and mode. * * Different ciphers and modes use varying lengths of input vectors. * * @return int */ private function iv_size() { return mcrypt_get_iv_size($this->cipher, $this->mode); } }