NTLM negotiation logged as ERROR

Elastic Observability APM
1

Environment

Windows
.NET Framework 4.8 WebApp

Describe the bug

The situation I came across is when my web application receives a request and that request triggers a request/transaction using HttpWebRequest (System.Net) with NTLM authentication.
This transaction is logged as an error (401) which is the NTLM negotiation response despite the transaction actually giving 200.

Expected behavior

The transaction will be logged as success instead of the current error state

2 
using System;
using System.Net;
using System.IO;

public class NtlmAuthExample
{
    public static void Main()
    {
        string url = "https://your-api-endpoint.com/resource";
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
        request.Credentials = CredentialCache.DefaultCredentials; // Use NTLM authentication

        try
        {
            using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
            {
                if (response.StatusCode == HttpStatusCode.OK)
                {
                    // Successfully authenticated and received a 200 response
                    using (Stream dataStream = response.GetResponseStream())
                    using (StreamReader reader = new StreamReader(dataStream))
                    {
                        string responseFromServer = reader.ReadToEnd();
                        Console.WriteLine("Response received: " + responseFromServer);
                        // Log the successful transaction here
                        LogTransaction(true, response.StatusCode, responseFromServer);
                    }
                }
                else
                {
                    // Handle other status codes if necessary
                    LogTransaction(false, response.StatusCode, "Unexpected status code");
                }
            }
        }
        catch (WebException ex)
        {
            if (ex.Response != null)
            {
                using (HttpWebResponse errorResponse = (HttpWebResponse)ex.Response)
                {
                    if (errorResponse.StatusCode == HttpStatusCode.Unauthorized)
                    {
                        // This is part of the NTLM handshake, not an actual error
                        Console.WriteLine("NTLM negotiation in progress...");
                        // You can choose to log this as an informational message rather than an error
                        LogTransaction(false, errorResponse.StatusCode, "NTLM negotiation");
                    }
                    else
                    {
                        // Handle other web exceptions
                        LogTransaction(false, errorResponse.StatusCode, ex.Message);
                    }
                }
            }
            else
            {
                // Handle other exceptions
                LogTransaction(false, HttpStatusCode.InternalServerError, ex.Message);
            }
        }
    }

    private static void LogTransaction(bool isSuccess, HttpStatusCode statusCode, string message)
    {
        // Implement your logging logic here
        // For example, you can use a logging framework like NLog, log4net, or simply write to a file
        string logMessage = $"Transaction Success: {isSuccess}, Status Code: {statusCode}, Message: {message}";
        Console.WriteLine(logMessage);
        // Example: Write to a file
        File.AppendAllText("transaction_log.txt", logMessage + Environment.NewLine);
    }
}