OtpAlgorithm::isStringsEqual

protected function isStringsEqual($expected, $actual)
{
	if (!is_string($expected))
	{
		throw new ArgumentTypeException('expected', 'string');
	}

	if (!is_string($actual))
	{
		throw new ArgumentTypeException('actual', 'string');
	}

	$lenExpected = strlen($expected);
	$lenActual = strlen($actual);

	$status = $lenExpected ^ $lenActual;
	$len = min($lenExpected, $lenActual);
	for ($i = 0; $i < $len; $i++)
	{
		$status |= ord($expected[$i]) ^ ord($actual[$i]);
	}

	return $status === 0;
}