def check_pin_trust(self, environ):
        """Checks if the request passed the pin test.  This returns `True` if the
        request is trusted on a pin/cookie basis and returns `False` if not.
        Additionally if the cookie's stored pin hash is wrong it will return
        `None` so that appropriate action can be taken.
        """
        if self.pin is None:
            return True
        val = parse_cookie(environ).get(self.pin_cookie_name)
        if not val or "|" not in val:
            return False
        ts, pin_hash = val.split("|", 1)
        if not ts.isdigit():
            return False
        if pin_hash != hash_pin(self.pin):
            return None
        return (time.time() - PIN_TIME) < int(ts)