/**
* {@inheritdoc}
*/
public function validate($otp, $counter = null)
{
if ($counter === null) {
$counter = time();
}
$window = $this->getWindow();
$counter = self::timestampToCounter($counter, $this->getTimeStep());
$valid = false;
$offset = null;
$counterLow = max(0, $counter - intval(floor($window / 2)));
$counterHigh = max(0, $counter + intval(ceil($window / 2)));
for ($current = $counterLow; $current <= $counterHigh; ++$current) {
if ($otp === parent::calculate($current)) {
$valid = true;
$offset = $current - $counter;
break;
}
}
$this->lastCounterOffset = $offset;
return $valid;
}
