Vkontakte authorization without api in c#?

Question

In contact with

Friends who have a working VKontakte authorization code without api (via http)
There are several examples of implementation in c # on the Internet, but they are no longer working.
For example, here is one of them ctrockii.blogspot.ru/2012/07/c-http-api.html

public bool http_auth_vk(string login, string pass)
        {
            //*****************************
            //Получаем action_url
            //*****************************
            System.Net.ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };
            System.Net.WebRequest reqGET = System.Net.WebRequest.Create("http://m.vk.com/");
            System.Net.WebResponse resp = reqGET.GetResponse();
            System.IO.Stream stream = resp.GetResponseStream();
            System.IO.StreamReader sr = new System.IO.StreamReader(stream);
            string s = sr.ReadToEnd();


            //*****************************
            //Парсим
            //*****************************
            HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
            doc.LoadHtml(s);
            HtmlNode bodyNode = doc.DocumentNode.SelectSingleNode("//div[@class='cont']/form");
            string result1 = bodyNode.Attributes["action"].Value;

            //*****************************
            //POST запрос
            //*****************************
            var cookies = new CookieContainer();
            ServicePointManager.Expect100Continue = false;
            var request = (HttpWebRequest)WebRequest.Create(result1);
            request.CookieContainer = cookies;
            request.Method = "POST";
            request.ContentType = "application/x-www-form-urlencoded";
            using (var requestStream = request.GetRequestStream())
            using (var writer = new StreamWriter(requestStream))
            {
                writer.Write("email=" + login + "&pass=" + pass);
            }

            using (var responseStream = request.GetResponse().GetResponseStream())
            using (var reader = new StreamReader(responseStream))
            {
                var result = reader.ReadToEnd();

                //*****************************
                //Парсим, поиск ID
                //*****************************                 
                HtmlAgilityPack.HtmlDocument doc2 = new HtmlAgilityPack.HtmlDocument();                
                doc2.LoadHtml(result);
                string result2;
                try
                {                                     
                    
                    HtmlNode bodyNode2 = doc2.DocumentNode.SelectSingleNode("//div[@class='user_wrap']/a");
                    result2 = bodyNode2.Attributes["href"].Value.Substring(3);
                    //Если ID найден, то авторизация удалась
                    return true;
                }
                catch
                {
                    //Если ID не найден, то авторизация не удалась
                    MessageBox.Show("Ошибка авторизации, проверьте правильность введённых данных.\nВозможно там капча.");
                    return false;
                }
            }
        }

Answer 1

string AuthUrl = "https://m.vk.com/login";
string logoutId = "act=logout";
string MainUrl = "https://vk.com";

******************************
 httpHandler = new HttpClientHandler
                              {
                                  CookieContainer = new CookieContainer(),
                                  AllowAutoRedirect = true,
                                  AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip
                              };

 httpClient = new HttpClient(httpHandler) {Timeout = TimeSpan.FromSeconds(150)};
            httpClient.DefaultRequestHeaders.Add("Accept-Encoding", "gzip, deflate");
            httpClient.DefaultRequestHeaders.Add("Accept-Language", "ru-RU,ru;q=0.8,en-US;q=0.6,en;q=0.4");
            httpClient.DefaultRequestHeaders.Add("Cache-Control", "no-cache");
            httpClient.DefaultRequestHeaders.Add("Accept", "*/*");
            httpClient.DefaultRequestHeaders.Add("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36");

*************************************
Uri authUri = new Uri(AuthUrl);
            string data = await httpClient.GetStringAsync(authUri);
            IsAuth = data.Contains(logoutId);
            if (!IsAuth)
            {
                string result = data.Substring("<form method=\"post\" action=\"", "\"");//достаем ссылку для авторизации
                authUri = new Uri(result);
                var body = new Dictionary<string, string> {{"act", "login"}, {"email", Email}, {"pass", Pass}};//тут заполняем логин и пароль
                var response = await httpClient.PostAsync(authUri, new FormUrlEncodedContent(body));
                var page = await response.Content.ReadAsStringAsync();
                IsAuth = page.Contains(logoutId);//если вошли на странице появится ссыль для выхода :)
                Uri mainUri = new Uri(MainUrl);//переходим на главную страницу
                data = await httpClient.GetStringAsync(mainUri);
            }
            return IsAuth;

Answer 2

don't use http