public static function getDynamicSessionSignature($glt_cookie, $timeoutInSeconds, $secret)
{
// cookie format:
// <expiration time in unix time format>_BASE64(HMACSHA1(secret key, <login token>_<expiration time in unix time format>))
$expirationTimeUnixMS = SigUtils::currentTimeMillis() / 1000 + $timeoutInSeconds;
$expirationTimeUnix = (string) floor($expirationTimeUnixMS);
$unsignedExpString = $glt_cookie . "_" . $expirationTimeUnix;
$signedExpString = SigUtils::calcSignature($unsignedExpString, $secret);
// sign the base string using the secret key
$ret = $expirationTimeUnix . '_' . $signedExpString;
// define the cookie value
return $ret;
}
