extractedContentSha256 := extractedSignedHeaders.Get("x-amz-content-sha256")
	// "host" header value from the extracted result.
	extractedHost := extractedSignedHeaders.Get("host")
	//  "x-amz-date" header from the extracted result.
	extractedDate := extractedSignedHeaders.Get("x-amz-date")
	// extracted `expect` header.
	extractedExpect := extractedSignedHeaders.Get("expect")

	if payload != req.Header.Get(xhttp.AmzContentSha256) {
		return cred, "", "", time.Time{}, ErrContentSHA256Mismatch
	}

	// Extract all the signed headers along with its values.
	extractedSignedHeaders, errCode := extractSignedHeaders(signV4Values.SignedHeaders, r)
	if errCode != ErrNone {
		return cred, "", "", time.Time{}, errCode
	}

	cred, _, errCode = checkKeyValid(r, signV4Values.Credential.accessKey)

	// "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)