Test case 3. Junior C# Developer

using HtmlAgilityPack;
using System;
using System.Collections.Specialized;
using System.IO;
using System.Net;
using System.Text;
using System.Threading.Tasks;

namespace SemanticForce.TestProject2
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.OutputEncoding = CodePagesEncodingProvider.Instance.GetEncoding(1251);
            const string baseUrl = "https://forum.0day.kiev.ua";
            const string loginUrl = "https://forum.0day.kiev.ua/index.php?act=Login&CODE=01&CookieDate=1";

            //step 1 get cookie
            HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(baseUrl);
            //webRequest.Proxy = new WebProxy("127.0.0.1", 8888);
            webRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.80 Safari/5";
            webRequest.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*";
            webRequest.Headers.Add("accept-language","uk");
            webRequest.ContentType = "application/x-www-form-urlencoded";
            HttpWebResponse webResponse = (HttpWebResponse)webRequest.GetResponse();
            string sCookies = String.IsNullOrEmpty(webResponse.Headers["Set-Cookie"])?
                "":webResponse.Headers["Set-Cookie"];

            //step 2 send post request for authorization
            webRequest = (HttpWebRequest)WebRequest.Create(loginUrl);
            webRequest.Method = "POST";
            webRequest.Referer = baseUrl;
            webRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.80 Safari/5";
            webRequest.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*";
            webRequest.Headers.Add("accept-language", "uk");
            webRequest.ContentType = "application/x-www-form-urlencoded";
            webRequest.Headers.Add(HttpRequestHeader.Cookie, sCookies);
            webRequest.AllowAutoRedirect = false;
            string sQueryString = "UserName=DarkWarrior&PassWord=mSGes4i7yG3XRzU";
            byte[] byteArr = CodePagesEncodingProvider.Instance.GetEncoding(1251).GetBytes(sQueryString);
            webRequest.ContentLength = byteArr.Length;
            webRequest.GetRequestStream().Write(byteArr, 0, byteArr.Length);
            try
            {
                webResponse = (HttpWebResponse)webRequest.GetResponse();
            }
            catch (WebException e) {
                if (e.Message.Contains("302"))
                   webResponse = (HttpWebResponse)e.Response;
            }

            //step 3 load data
            string sLocation = webResponse.Headers["Location"];
            sCookies = "";
            if (!String.IsNullOrEmpty(webResponse.Headers["Set-Cookie"]))
            {
                sCookies = webResponse.Headers["Set-Cookie"];
            }
            webRequest = (HttpWebRequest)HttpWebRequest.Create(loginUrl);
            webRequest.Referer = loginUrl;
            webRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.80 Safari/5";
            webRequest.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*";
            webRequest.Headers.Add("accept-language", "uk");
            webRequest.ContentType = "application/x-www-form-urlencoded";
            if (!String.IsNullOrEmpty(sCookies))
            {
                webRequest.Headers.Add(HttpRequestHeader.Cookie, sCookies);
            }
            webResponse = (HttpWebResponse)webRequest.GetResponse();
            StreamReader myStreamReader = new StreamReader(webResponse.GetResponseStream(), CodePagesEncodingProvider.Instance.GetEncoding(1251));
            HtmlDocument htmlDoc = new HtmlDocument();
            htmlDoc.LoadHtml(myStreamReader.ReadToEnd());
            var data = htmlDoc.DocumentNode.SelectSingleNode("//div[@id='userlinks']");
            Console.WriteLine(data.InnerHtml);
            Console.ReadKey();
        }
    }
}