HttpListener Access Denied

Randall Flagg picture Randall Flagg · Oct 26, 2010 · Viewed 148.1k times · Source

I am writing an HTTP server in C#.

When I try to execute the function HttpListener.Start() I get an HttpListenerException saying

"Access Denied".

When I run the app in admin mode in windows 7 it works fine.

Can I make it run without admin mode? if yes how? If not how can I make the app change to admin mode after start running?

using System;
using System.Net;

namespace ConsoleApplication1
{
    class Program
    {
        private HttpListener httpListener = null;

        static void Main(string[] args)
        {
            Program p = new Program();
            p.Server();
        }

        public void Server()
        {
            this.httpListener = new HttpListener();

            if (httpListener.IsListening)
                throw new InvalidOperationException("Server is currently running.");

            httpListener.Prefixes.Clear();
            httpListener.Prefixes.Add("http://*:4444/");

            try
            {
                httpListener.Start(); //Throws Exception
            }
            catch (HttpListenerException ex)
            {
                if (ex.Message.Contains("Access is denied"))
                {
                    return;
                }
                else
                {
                    throw;
                }
            }
        }
    }
}

Answer

Darrel Miller picture Darrel Miller · Nov 6, 2010

Yes you can run HttpListener in non-admin mode. All you need to do is grant permissions to the particular URL. e.g.

netsh http add urlacl url=http://+:80/MyUri user=DOMAIN\user

Documentation is here.