/**
* Generate a HOTP key collection based on a timestamp and window size
* all keys that could exist between a start and end time will be included
* in the returned array
* @param string $key the key to use for hashing
* @param int $window the size of the window a key is valid for in seconds
* @param int $min the minimum window to accept before $timestamp
* @param int $max the maximum window to accept after $timestamp
* @param int $timestamp a timestamp to calculate for, defaults to time()
* @return array of HOTPResult
*/
public static function generateByTimeWindow($key, $window, $min = -1, $max = 1, $timestamp = false)
{
if (!$timestamp && $timestamp !== 0) {
$timestamp = HOTP::getTime();
}
$counter = intval($timestamp / $window);
$window = range($min, $max);
$out = array();
for ($i = 0; $i < count($window); $i++) {
$shift_counter = $window[$i];
$out[$shift_counter] = HOTP::generateByCounter($key, $counter + $shift_counter);
}
return $out;
}
/**
* {@inheritdoc}
*/
public function validate($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;
}
public function testCheck1()
{
$hotp = new HOTP(new HOTPSecret("3132333435363738393031323334353637383930", HOTPSecret::FORMAT_HEX));
$this->assertSame(-1, $hotp->check("359152", 0, 1));
$this->assertSame(1, $hotp->check("359152", 1, 1));
$this->assertSame(0, $hotp->check("359152", 2, 1));
$this->assertSame(-1, $hotp->check("359152", 3, 1));
$this->assertSame(-1, $hotp->check("359152", 4, 1));
$this->assertSame(-1, $hotp->check("359152", 5, 1));
}
echo ' ';
$method = 'to' . ucfirst(str_replace('HMAC', 'string', $type));
echo str_pad($calc == $hotp->{$method}(6) ? '[OK]' : '[FAIL]', 9, ' ', STR_PAD_LEFT);
echo "\n";
}
}
echo <<<DOCBLOCK
TOTP Tests:
DOCBLOCK;
echo "Time (sec) Value Pass/Fail\n";
echo "----------------------------------------------------------------------\n";
// now echo over the TOTP table
foreach ($table['TOTP'] as $seed => $results) {
$totp = HOTP::generateByTime($key, 30, $seed);
$first = true;
foreach ($results as $type => $calc) {
if ($first) {
echo str_pad($seed, 10, ' ', STR_PAD_LEFT);
$first = false;
} else {
echo ' ';
}
echo ' ';
echo str_pad($calc, 47, ' ', STR_PAD_RIGHT);
echo ' ';
$method = 'to' . ucfirst(str_replace('totp', 'hotp', $type));
echo str_pad($calc == $totp->{$method}(8) ? '[OK]' : '[FAIL]', 9, ' ', STR_PAD_LEFT);
echo "\n";
}
