Removing headers from the response

Question

I need to cloak certain headers generated by ASP.NET and IIS and returned in the responses from a ASP.NET WebAPI service. The headers I need to cloak are:

• Serv

Answer 1

For the benefit of those who land here through a google/bing search:: Here's the summary of steps:

Step 1: Create a class that derives from IHttpModule (and IDisposable to clean up when we're done):

    public class MyCustomModule : IHttpModule, IDisposable
    {
         private HttpApplication _httpApplication
private static readonly List HeadersToCloak = new List
            {
                "Server",
                "X-AspNet-Version",
                "X-AspNetMvc-Version",
                "X-Powered-By"
            };
    ..
    }

Step 2: Get a reference to the intrinsic context in the IHttpModule.Init method, and assign an event handler to the PreSendRequestHeaders event:

public void Init(HttpApplication context)
        {
            _httpApplication = context;

            context.PreSendRequestHeaders += OnPreSendRequestHeaders;
        }

Step 3: Now the headers can be removed like so:

private void OnPreSendRequestHeaders(object sender, EventArgs e)
        {
            if (null == _httpApplication)
            {
                return;
            }

            if (_httpApplication.Context != null)
            {
                var response = _httpApplication.Response;
                HeadersToCloak.ForEach(header => response.Headers.Remove(header));
            }
        }

Step 4: Now register this module in your root web.config under the system.webserver (if running IIS 7.0 integrated mode more details here):

Hope this helps!