func isRequestSignatureV4(r *http.Request) bool {
	return strings.HasPrefix(r.Header.Get(xhttp.Authorization), signV4Algorithm)
}

// Verify if request has AWS Signature Version '2'.
func isRequestSignatureV2(r *http.Request) bool {
	return (!strings.HasPrefix(r.Header.Get(xhttp.Authorization), signV4Algorithm) &&
		strings.HasPrefix(r.Header.Get(xhttp.Authorization), signV2Algorithm))
}

	}
	return false
}

// Check if client is sending a malicious request.
func hasMultipleAuth(r *http.Request) bool {
	authTypeCount := 0
	for _, hasValidAuth := range []func(*http.Request) bool{
		isRequestSignatureV2, isRequestPresignedSignatureV2,
		isRequestSignatureV4, isRequestPresignedSignatureV4,
		isRequestJWT, isRequestPostPolicySignatureV4,
	} {
		if hasValidAuth(r) {
			authTypeCount++
		}
	}