/**
* Calculate a valid code given the shared secret key
*
* @param string $key The shared secret key to use for calculating code.
* @param mixed $step_count The time step used to calculate the code, which is the floor of time() divided by step size.
* @param int $digits The number of digits in the returned code.
* @param string $hash The hash used to calculate the code.
* @param int $time_step The size of the time step.
*
* @return string The totp code
*/
function calc_totp($key, $step_count = false, $digits = 6, $hash = 'sha1', $time_step = 30)
{
$secret = base32_decode($key);
if (false === $step_count) {
$step_count = floor(time() / $time_step);
}
$timestamp = pack64($step_count);
$hash = hash_hmac($hash, $timestamp, $secret, true);
$offset = ord($hash[19]) & 0xf;
$code = ((ord($hash[$offset + 0]) & 0x7f) << 24 | (ord($hash[$offset + 1]) & 0xff) << 16 | (ord($hash[$offset + 2]) & 0xff) << 8 | ord($hash[$offset + 3]) & 0xff) % pow(10, $digits);
return str_pad($code, $digits, '0', STR_PAD_LEFT);
}
<?
$encodedkey = "RmFzdGx5IFRva2VuIFRlc3Q=";
$interval = 60;
$key = base64_decode($encodedkey);
$number = pack64(intval(time()/$interval));
$token = base64_encode(hash_hmac('sha256', $number, $key, true));
$response = curl_get_contents("http://token.fastly.com/token");
$validation = curl_get_contents("http://token.fastly.com?$token");
print "Your Token: $token\n";
print "Fastly Token: $response\n";
print "Validation: $validation\n";
function pack64($value) {
$l = ($value & 0xffffffff00000000) >>32;
$r = $value & 0x00000000ffffffff;
return pack('VV', $r, $l);
}
function curl_get_contents($url)
{
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
$data = curl_exec($ch);
curl_close($ch);
