IIS 7 Log Request Body

Question

I need to log the request post payload for requests made to IIS. Is this possible to configure the logging of request post payloads with the existing logging and advanced logging modules within IIS 7.5 or can anybody direct me to any custom modules that will allow me to log the post payload.

Answer 1

I managed to create a text file for my requests that contained the entire request (headers and response), I only used it to log specific post requests:

protected void Application_BeginRequest(Object Sender, EventArgs e)
{
    string uniqueid = Guid.NewGuid().ToString();
    string logfile = String.Format("C:\\path\\to\\folder\\requests\\{0}.txt", uniqueid);
    Request.SaveAs(logfile, true);
}

Hopefully this helps you!

Answer 2

It can actually be done, according to https://serverfault.com/a/90965

The IIS logs only record querystring and header information without any POST data.

If you're using IIS7, you can enabled Failed Request Tracing for status code 200. That will record all of the data and you can select which type of data to include.

Answer 3

Here is code of custom HTTP module we use to log HTTP POST request data.

using System;
using System.Web;

namespace MySolution.HttpModules
{
    public class HttpPOSTLogger : IHttpModule
    {

        public void Dispose()
        {
        }

        public void Init(HttpApplication context)
        {
            context.BeginRequest += new EventHandler(context_BeginRequest);
        }

        private void context_BeginRequest(object sender, EventArgs e)
        {
            if (sender != null && sender is HttpApplication)
            {
                var request = (sender as HttpApplication).Request;
                var response = (sender as HttpApplication).Response;

                if (request != null && response != null && request.HttpMethod.ToUpper() == "POST")
                {
                    var body = HttpUtility.UrlDecode(request.Form.ToString());
                    if (!string.IsNullOrWhiteSpace(body))
                        response.AppendToLog(body);
                }
            }
        }

    }
}

Do not forget to register it in web.config of you application.

Use system.WebServer section for IIS Integrated Model

<system.webServer>
    <modules>
      <add name="HttpPOSTLogger" type="MySolution.HttpModules.HttpPOSTLogger, MySolution.HttpModules" />
    </modules>
</system.webServer>

Use system.web section for IIS Classic Model

<system.web>
    <httpModules>
        <add name="HttpPOSTLogger" type="MySolution.HttpModules.HttpPOSTLogger, MySolution.HttpModules"/>
    </httpModules>
</system.web>

IIS log Before applying module:

::1, -, 10/31/2017, 10:53:20, W3SVC1, machine-name, ::1, 5, 681, 662, 200, 0, POST, /MySolution/MyService.svc/MyMethod, -,

IIS log After applying module:

::1, -, 10/31/2017, 10:53:20, W3SVC1, machine-name, ::1, 5, 681, 662, 200, 0, POST, /MySolution/MyService.svc/MyMethod, {"model":{"Platform":"Mobile","EntityID":"420003"}},

Full article:

https://www.codeproject.com/Tips/1213108/HttpModule-for-logging-HTTP-POST-data-in-IIS-Log