Calling Twilio API from C#/.NET through a Proxy Server

Question

I am trying to run the C# sample twilio application from behind a proxy web server. My proxy server needs authentication. Using the code below, I am able to authenticate successfully to the proxy server and make the Twilio call. However, Twilio returns me a code 20003 (Permission Denied). My AccountSID and AuthToken are correct. The below code (without the proxy settings) works just fine in a different environment that does not require a web proxy server.

My issue is similar to the issue and solution posted here , using Java, but I am unable to replicate the Java fix using C#/.NET. I am using .NET SDK 4.5

using System;
using Twilio;
using System.Net;

namespace TestTwilio
{
    class Program
    {
        static void Main(string[] args)
        {
            var accountSid = "xx";
            var authToken = "yy";

                var twilio = new TwilioRestClient(accountSid, authToken);twilio.Proxy = new System.Net.WebProxy("proxy.mycompany.com", 8080);
                    twilio.Proxy.Credentials = new NetworkCredential(“username”, “password”);

                var message = twilio.SendMessage("+1xxxxxxxxxx","+1xxxxxxxxxx", "Hello from C#");

            if (message.RestException != null)
            {
                var error = message.RestException.Message;
                Console.WriteLine(error);
                Console.WriteLine(message.RestException.MoreInfo);
                Console.WriteLine(message.Uri);
                Console.WriteLine(message.AccountSid);
                Console.Write("Press any key to continue.");
                Console.ReadKey();
            }
        }
    }
}

Thanks for helping out.

Answer 1

I was able to bypass the issue using a direct API call. Is not an elegant solution to the original problem... so still looking for the right way to do this. Below is the code that worked.

using System;
using System.Net;
using RestSharp;

namespace TestTwilio
{
    class Program
    {
        static void Main(string[] args)
        {
            var client = new RestClient("https://api.twilio.com/2010-04-01/Accounts/{yourTwilioAccountSID}/SMS/Messages.json");
            client.Proxy = new System.Net.WebProxy("proxy.mycompany.com", 8080);
            client.Proxy.Credentials = new NetworkCredential("<<proxyServerUserName>>", "<<proxyServerPassword>>", "<<proxyServerDomain>>");
            var request = new RestRequest(Method.POST);
            request.Credentials = new NetworkCredential("<<your Twilio AccountSID>>", "<<your Twilio AuthToken>>");
            request.AddParameter("From", "+1xxxxxxxxxx");
            request.AddParameter("To", "+1xxxxxxxxxx");
            request.AddParameter("Body", "Testing from C# after authenticating with a Proxy");
            IRestResponse response = client.Execute(request);
            Console.WriteLine(response.Content);
            Console.ReadKey();
        }
    }
}