NewAutPost.cs

public class WebClientEx : WebClient
{
    private CookieContainer _cookieContainer = new CookieContainer();

    protected override WebRequest GetWebRequest(Uri address)
    {
        WebRequest request = base.GetWebRequest(address);
        if (request is HttpWebRequest)
        {
            (request as HttpWebRequest).CookieContainer = _cookieContainer;
        }
        return request;
    }
}

class Program
{
    static void Main()
    {
        using (var client = new WebClientEx())
        {
            var response1 = client.DownloadString("https://myJazzServer.com:9092/jazz/authenticated/identity");

            var data = new NameValueCollection
            {
                { "j_username", "myUser" },
                { "j_password", "MyPass" },
            };
            var response2 = client.UploadValues("https://myJazzServer.com:9092/jazz/authenticated/j_security_check", data);
            Console.WriteLine(Encoding.Default.GetString(response2));
        }
    }
}