/**
* Generates Session ID
*
* Generates a session ID to use. Checks existing sessions to avoid conflict.
*
* @return string
*/
public static function generateSID()
{
$key = null;
while (Session::isSession($key) || $key === null) {
$key = sha1(time() . '-' . microtime(true) . '-' . rand(0, PHP_INT_MAX) . filter_input(INPUT_SERVER, 'HTTP_USER_AGENT'));
}
return $key;
}
