encodedQuery = splits[1]
		}
	}

	unescapedQueries, err := unescapeQueries(encodedQuery)
	if err != nil {
		return err
	}

	// Get presigned string to sign.
	stringToSign := getStringToSignV2(req.Method, encodedResource, strings.Join(unescapedQueries, "&"), req.Header, expiresStr)
	hm := hmac.New(sha1.New, []byte(secretAccessKey))
	hm.Write([]byte(stringToSign))

	// Calculate signature.