HttpWebRequest using Basic authentication

I'm trying to go through an authentication request that mimics the "basic auth request" we're used to seeing when setting up IIS for this behavior.

The URL is: https://telematicoprova.agenziadogane.it/TelematicoServiziDiUtilitaWeb/ServiziDiUtilitaAutServlet?UC=22&SC=1&ST=2
(warning: https!)

This server is running under UNIX and Java as application server.

This is the code I use to connect to this server:

CookieContainer myContainer = new CookieContainer();
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://telematicoprova.agenziadogane.it/TelematicoServiziDiUtilitaWeb/ServiziDiUtilitaAutServlet?UC=22&SC=1&ST=2");
request.Credentials = new NetworkCredential(xxx,xxx);
request.CookieContainer = myContainer;
request.PreAuthenticate = true;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();

(I copied this from another post on this site). But I receive this answer from the server:

The underlying connection was closed: An unexpected error occurred on a send.

I think I tried every possible task my knowledge on C# has to offer me, but nothing...

You can also just add the authorization header yourself.

Just make the name "Authorization" and the value "Basic BASE64({USERNAME:PASSWORD})"

var username   = "abc";
var password   = "123";
string encoded = System.Convert.ToBase64String(Encoding.GetEncoding("ISO-8859-1")
                               .GetBytes(username + ":" + password));
httpWebRequest.Headers.Add("Authorization", "Basic " + encoded);

Edit

Switched the encoding from UTF-8 to ISO 8859-1 per What encoding should I use for HTTP Basic Authentication? and Jeroen's comment.

I finally got it!

string url = @"https://telematicoprova.agenziadogane.it/TelematicoServiziDiUtilitaWeb/ServiziDiUtilitaAutServlet?UC=22&SC=1&ST=2";
WebRequest request = WebRequest.Create(url);
request.Credentials = GetCredential();
request.PreAuthenticate = true;

and this is GetCredential()

private CredentialCache GetCredential()
{
    string url = @"https://telematicoprova.agenziadogane.it/TelematicoServiziDiUtilitaWeb/ServiziDiUtilitaAutServlet?UC=22&SC=1&ST=2";
    ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;
    CredentialCache credentialCache = new CredentialCache();
    credentialCache.Add(new System.Uri(url), "Basic", new NetworkCredential(ConfigurationManager.AppSettings["ead_username"], ConfigurationManager.AppSettings["ead_password"]));
    return credentialCache;
}

YAY!

If you can use the WebClient class, using basic authentication becomes simple:

var client = new WebClient {Credentials = new NetworkCredential("user_name", "password")};
var response = client.DownloadString("https://telematicoprova.agenziadogane.it/TelematicoServiziDiUtilitaWeb/ServiziDiUtilitaAutServlet?UC=22&SC=1&ST=2");

Try this:

System.Net.CredentialCache credentialCache = new System.Net.CredentialCache(); 
credentialCache.Add(
    new System.Uri("http://www.yoururl.com/"),
    "Basic", 
    new System.Net.NetworkCredential("username", "password")
);

...
...

httpWebRequest.Credentials = credentialCache;