<?php
namespace Illuminate\Encryption;
use RuntimeException;
use Illuminate\Contracts\Encryption\DecryptException;
use Illuminate\Contracts\Encryption\EncryptException;
use Illuminate\Contracts\Encryption\Encrypter as EncrypterContract;
class Encrypter extends BaseEncrypter implements EncrypterContract
{
/**
* The algorithm used for encryption.
*
* @var string
*/
protected $cipher;
/**
* Create a new encrypter instance.
*
* @param string $key
* @param string $cipher
* @return void
*
* @throws \RuntimeException
*/
public function __construct($key, $cipher = 'AES-128-CBC')
{
$key = (string) $key;
if (static::supported($key, $cipher)) {
$this->key = $key;
$this->cipher = $cipher;
} else {
throw new RuntimeException('The only supported ciphers are AES-128-CBC and AES-256-CBC with the correct key lengths.');
}
}
/**
* Determine if the given key and cipher combination is valid.
*
* @param string $key
* @param string $cipher
* @return bool
*/
public static function supported($key, $cipher)
{
$length = mb_strlen($key, '8bit');
return ($cipher === 'AES-128-CBC' && $length === 16) || ($cipher === 'AES-256-CBC' && $length === 32);
}
/**
* Encrypt the given value.
*
* @param string $value
* @return string
*
* @throws \Illuminate\Contracts\Encryption\EncryptException
*/
public function encrypt($value)
{
$iv = random_bytes($this->getIvSize());
$value = \openssl_encrypt(serialize($value), $this->cipher, $this->key, 0, $iv);
if ($value === false) {
throw new EncryptException('Could not encrypt the data.');
}
// Once we have the encrypted value we will go ahead base64_encode the input
// vector and create the MAC for the encrypted value so we can verify its
// authenticity. Then, we'll JSON encode the data in a "payload" array.
$mac = $this->hash($iv = base64_encode($iv), $value);
$json = json_encode(compact('iv', 'value', 'mac'));
if (! is_string($json)) {
throw new EncryptException('Could not encrypt the data.');
}
return base64_encode($json);
}
/**
* Decrypt the given value.
*
* @param string $payload
* @return string
*
* @throws \Illuminate\Contracts\Encryption\DecryptException
*/
public function decrypt($payload)
{
$payload = $this->getJsonPayload($payload);
$iv = base64_decode($payload['iv']);
$decrypted = \openssl_decrypt($payload['value'], $this->cipher, $this->key, 0, $iv);
if ($decrypted === false) {
throw new DecryptException('Could not decrypt the data.');
}
return unserialize($decrypted);
}
/**
* Get the IV size for the cipher.
*
* @return int
*/
protected function getIvSize()
{
return 16;
}
}