/**
* Get the key as a packed binary string
*
* @return string
*/
protected function getKey()
{
// first create a sha256 hash of the key
$hash = hash('sha256', $this->key);
// create a binary string from the hash
$binary = hex2bin($hash);
// limit the key size based on our encryption method
$keySize = AesEnum::getKeySize($this->method);
$key = substr($binary, 0, $keySize);
return $key;
}
/**
* Get the openssl formatted encryption method
*
* @return string
*/
private function getEncryptionMethod()
{
$keySize = AesEnum::getKeySize($this->getMethod()) * 8;
return 'aes-' . $keySize . '-' . self::ENCRYPTION_MODE;
}
