if s3Err != ErrNone {
		return s3Err
	}

	// Make sure the request has not expired.
	expiresInt, err := strconv.ParseInt(expires, 10, 64)
	if err != nil {
		return ErrMalformedExpires
	}

	// Check if the presigned URL has expired.
	if expiresInt < UTCNow().Unix() {
		return ErrExpiredPresignRequest
	}