Авторизация через webBrowser1

private void button1_Click(object sender, EventArgs e)
        {
 
            // Начальная страница
            webBrowser1.Navigate("http://server/application/login/");
            pause_wb();
            webBrowser1.Document.GetElementById("username").InnerText = "user1";
            pause_wb();             
            webBrowser1.Document.GetElementById("password").SetAttribute("value", "pass1");
            pause_wb();
 
            webBrowser1.Document.GetElementById("userSignIn").InvokeMember("click");
            pause_wb();
 
            // Страница на которую нужно перейти после авторизации
            webBrowser1.Navigate("http://server/application/obj/");
         }
 
// Пауза для прогрузки webBrowser
protected void pause_wb()
        {
            while (webBrowser1.ReadyState != WebBrowserReadyState.Complete)
            {
                Application.DoEvents();
            }
        }

string g_cook = "";
        [DllImport("wininet.dll", CharSet = CharSet.Auto, SetLastError = true)]
        public static extern bool InternetSetCookie(string lpszUrlName, string lbszCookieName, string lpszCookieData);

g_cook = webBrowser1.Document.Cookie.ToString();
            
 
            InternetSetCookie("http://server/application/", null, g_cook);
            webBrowser1.Navigate("http://server/application/obj");

[System.ComponentModel.DesignerCategory("Code")]
class CookieWebClient : WebClient
{
    readonly CookieContainer _cookies = new CookieContainer();
 
    public CookieContainer Cookies { get { return _cookies; } }
 
    protected override WebRequest GetWebRequest(Uri address)
    {
        WebRequest request = base.GetWebRequest(address);
        HttpWebRequest httpRequest = request as HttpWebRequest;
        if (httpRequest != null)
        {
            httpRequest.CookieContainer = _cookies;
        }
        return request;
    }
}

private void button3_Click(object sender, EventArgs e)
        {
 
            using (var webClient = new CookieWebClient())
            {
 
                webClient.UploadString("http://server/application/login/", "username=user1&password=pass1");
 
                string answer = webClient.DownloadString("http://server/application/obj/");
                richTextBox1.AppendText(answer);
 
            }
 
           
        }

webClient.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";

webClient.Headers.Remove(HttpRequestHeader.ContentType)

private void button3_Click(object sender, EventArgs e)
{
 
    using (var webClient = new CookieAwareWebClient())
    {
        //webClient.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";
        webClient.UploadString("http://server/app/login/", "username=user1&password=pass1");
        //webClient.Headers.Remove(HttpRequestHeader.ContentType);
 
        string answer = webClient.DownloadString("http://server/app/obj/");
        richTextBox1.AppendText(answer);
 
    }
 
}

public class CookieAwareWebClient : WebClient
{
    public void Login(string loginPageAddress, NameValueCollection loginData)
    {
        CookieContainer container;
 
        var request = (HttpWebRequest)WebRequest.Create(loginPageAddress);
 
        request.Method = "POST";
        request.ContentType = "application/x-www-form-urlencoded";
 
        var query = string.Join("&",
          loginData.Cast<string>().Select(key => $"{key}={loginData[key]}"));
 
        var buffer = Encoding.ASCII.GetBytes(query);
        request.ContentLength = buffer.Length;
        var requestStream = request.GetRequestStream();
        requestStream.Write(buffer, 0, buffer.Length);
        requestStream.Close();
 
        container = request.CookieContainer = new CookieContainer();
 
        var response = request.GetResponse();
        response.Close();
        CookieContainer = container;
    }
 
    public CookieAwareWebClient(CookieContainer container)
    {
        CookieContainer = container;
    }
 
    public CookieAwareWebClient()
      : this(new CookieContainer())
    { }
 
    public CookieContainer CookieContainer { get; private set; }
 
    protected override WebRequest GetWebRequest(Uri address)
    {
        var request = (HttpWebRequest)base.GetWebRequest(address);
        request.CookieContainer = CookieContainer;
        return request;
    }
}

webClient.UploadString("http://server/app/login/", "username=user1&password=pass1&urlParams=params");

private void button3_Click(object sender, EventArgs e)
        {
 
 
             using (var webClient = new CookieAwareWebClient())
              {
                 var loginData = new NameValueCollection
                 {
                   { "username", "user1" },
                   { "password", "pass1" }
                   
                 };
                var loginAddress = "http://server/app/login/doLogin";               
 
                webClient.Login(loginAddress,loginData);
                string t= webClient.GetHomePage("http://server/app/obj/");
                
                richTextBox1.AppendText(t);
 
            }

public class CookieAwareWebClient : WebClient
{
    public void Login(string loginPageAddress, NameValueCollection loginData)
    {
        CookieContainer container;
 
        var request = (HttpWebRequest)WebRequest.Create(loginPageAddress);
 
        request.Method = "POST";
        request.ContentType = "application/x-www-form-urlencoded";
        request.Referer = loginPageAddress;
        
        var query = string.Join("&",
          loginData.Cast<string>().Select(key => $"{key}={loginData[key]}"));
 
        var buffer = Encoding.ASCII.GetBytes(query);
        request.ContentLength = buffer.Length;
        var requestStream = request.GetRequestStream();
        requestStream.Write(buffer, 0, buffer.Length);
        requestStream.Close();
 
        container = request.CookieContainer = new CookieContainer();
 
        var response = request.GetResponse();
        response.Close();
        CookieContainer = container;        
    }
 
    public CookieAwareWebClient(CookieContainer container)
    {
        CookieContainer = container;
    }
 
    public CookieAwareWebClient()
      : this(new CookieContainer())
    { }
 
    public CookieContainer CookieContainer { get; private set; }
 
    protected override WebRequest GetWebRequest(Uri address)    
    {
        var request = (HttpWebRequest)base.GetWebRequest(address);
        request.CookieContainer = CookieContainer;        
        return request;
    }
    public string GetHomePage(string url)
    {
        
        var webRequest = this.GetWebRequest(new Uri(url));
 
        string src = "";
        using (var webResponse = (HttpWebResponse)webRequest.GetResponse())
        {
            src = new StreamReader(webResponse.GetResponseStream()).ReadToEnd();
            return src;
        }
    }
}