// "host" is the only header required to be signed for Presigned URLs.
	extractedSignedHeaders := make(http.Header)
	extractedSignedHeaders.Set("host", req.Host)

	queryStr := strings.ReplaceAll(query.Encode(), "+", "%20")
	canonicalRequest := getCanonicalRequest(extractedSignedHeaders, unsignedPayload, queryStr, req.URL.Path, req.Method)
	stringToSign := getStringToSign(canonicalRequest, date, scope)