return
	}

	durationParam := r.Form.Get(stsDurationSeconds)
	var requestedDuration int
	if durationParam != "" {
		var err error
		requestedDuration, err = strconv.Atoi(durationParam)
		if err != nil {
			writeSTSErrorResponse(ctx, w, ErrSTSInvalidParameterValue, fmt.Errorf("Invalid requested duration: %s", durationParam))