return
		}

		// Version in policy must not be empty
		if sessionPolicy.Version == "" {
			writeSTSErrorResponse(ctx, w, ErrSTSInvalidParameterValue, fmt.Errorf("Version cannot be empty expecting '2012-10-17'"))
			return
		}
	}

	duration, err := openid.GetDefaultExpiration(r.Form.Get(stsDurationSeconds))
	if err != nil {
		writeSTSErrorResponse(ctx, w, ErrSTSInvalidParameterValue, err)
		return
	}