SteamWeb.cs

using MihaZupan;
using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.IO;
using System.Net;
using System.Threading.Tasks;

namespace SteamAuth
{
    public class SteamWeb
    {


        /// <summary>
        /// Perform a mobile login request
        /// </summary>
        /// <param name="url">API url</param>
        /// <param name="method">GET or POST</param>
        /// <param name="data">Name-data pairs</param>
        /// <param name="cookies">current cookie container</param>
        /// <returns>response body</returns>
        public static string MobileLoginRequest(string url, string method, string proxy, int proxy_type, NameValueCollection data = null, CookieContainer cookies = null, NameValueCollection headers = null)
        {
            return Request(url, method, proxy, proxy_type, data, cookies, headers, APIEndpoints.COMMUNITY_BASE + "/mobilelogin?oauth_client_id=DE45CD61&oauth_scope=read_profile%20write_profile%20read_client%20write_client");
        }

        public static string Request(string url, string method, string proxy, int proxy_type, NameValueCollection data = null, CookieContainer cookies = null, NameValueCollection headers = null, string referer = APIEndpoints.COMMUNITY_BASE)
        {
            string query = (data == null ? string.Empty : string.Join("&", Array.ConvertAll(data.AllKeys, key => String.Format("{0}={1}", WebUtility.UrlEncode(key), WebUtility.UrlEncode(data[key])))));
            if (method == "GET")
            {
                url += (url.Contains("?") ? "&" : "?") + query;
            }

            return Request(url, method, proxy, proxy_type, query, cookies, headers, referer);
        }

        public static string Request(string url, string method, string proxy, int proxy_type, string dataString = null, CookieContainer cookies = null, NameValueCollection headers = null, string referer = APIEndpoints.COMMUNITY_BASE)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);

            string proxy_ip = null;
            int proxy_port = 0;
            string username = null;
            string password = null;

            if (!string.IsNullOrEmpty(proxy))
            {
                string[] mas = proxy.Split(':');

                if (mas.Length >= 2)
                {
                    proxy_ip = mas[0];
                    proxy_port = int.Parse(mas[1]);
                }

                if (mas.Length == 4)
                {
                    username = mas[2];
                    password = mas[3];
                }

                if (!string.IsNullOrEmpty(proxy_ip))
                    if (proxy_type == 1)
                    {
                        if (!string.IsNullOrEmpty(username))
                        {
                            ICredentials credentials = new NetworkCredential(username, password);
                            request.Proxy = new WebProxy(new Uri("http://" + proxy_ip + ":" + proxy_port.ToString()), false, null, credentials);
                        }
                        else
                            request.Proxy = new WebProxy(proxy_ip, proxy_port);
                    }
                    else
                    {
                        if (!string.IsNullOrEmpty(username))
                            request.Proxy = new HttpToSocks5Proxy(proxy_ip, proxy_port, username, password);
                        else
                            request.Proxy = new HttpToSocks5Proxy(proxy_ip, proxy_port);
                    }
            }

            request.Timeout = 30000;
            request.ReadWriteTimeout = 30000;
            request.ContinueTimeout = 30000;

            request.Method = method;
            request.Accept = "text/javascript, text/html, application/xml, text/xml, */*";
            request.UserAgent = "Mozilla/5.0 (Linux; U; Android 4.1.1; en-us; Google Nexus 4 - 4.1.1 - API 16 - 768x1280 Build/JRO03S) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30";
            request.AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip;
            request.Referer = referer;

            if (headers != null)
            {
                request.Headers.Add(headers);
            }

            if (cookies != null)
            {
                request.CookieContainer = cookies;
            }

            if (method == "POST")
            {
                request.ContentType = "application/x-www-form-urlencoded; charset=UTF-8";
                request.ContentLength = dataString.Length;

                StreamWriter requestStream = new StreamWriter(request.GetRequestStream());
                requestStream.Write(dataString);
                requestStream.Close();
            }

            try
            {
                using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
                {
                    if (response.StatusCode != HttpStatusCode.OK)
                    {
                        HandleFailedWebRequestResponse(response, url);
                        return null;
                    }

                    using (StreamReader responseStream = new StreamReader(response.GetResponseStream()))
                    {
                        string responseData = responseStream.ReadToEnd();
                        return responseData;
                    }
                }
            }
            catch (WebException e)
            {
                HandleFailedWebRequestResponse(e.Response as HttpWebResponse, url);
                return null;
            }
        }

        public static string Request(string url, string method, string proxy, int proxy_type, Dictionary<string, string> multipartData, CookieContainer cookies = null, NameValueCollection headers = null, string referer = APIEndpoints.COMMUNITY_BASE)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);

            string proxy_ip = null;
            int proxy_port = 0;
            string username = null;
            string password = null;

            if (!string.IsNullOrEmpty(proxy))
            {
                string[] mas = proxy.Split(':');

                if (mas.Length >= 2)
                {
                    proxy_ip = mas[0];
                    proxy_port = int.Parse(mas[1]);
                }

                if (mas.Length == 4)
                {
                    username = mas[2];
                    password = mas[3];
                }

                if (!string.IsNullOrEmpty(proxy_ip))
                    if (proxy_type == 1)
                    {
                        if (!string.IsNullOrEmpty(username))
                        {
                            ICredentials credentials = new NetworkCredential(username, password);
                            request.Proxy = new WebProxy(new Uri("http://" + proxy_ip + ":" + proxy_port.ToString()), false, null, credentials);
                        }
                        else
                            request.Proxy = new WebProxy(proxy_ip, proxy_port);
                    }
                    else
                    {
                        if (!string.IsNullOrEmpty(username))
                            request.Proxy = new HttpToSocks5Proxy(proxy_ip, proxy_port, username, password);
                        else
                            request.Proxy = new HttpToSocks5Proxy(proxy_ip, proxy_port);
                    }
            }

            request.Timeout = 30000;
            request.ReadWriteTimeout = 30000;
            request.ContinueTimeout = 30000;

            request.Method = method;
            request.Accept = "text/javascript, text/html, application/xml, text/xml, */*";
            request.UserAgent = "Mozilla/5.0 (Linux; U; Android 4.1.1; en-us; Google Nexus 4 - 4.1.1 - API 16 - 768x1280 Build/JRO03S) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30";
            request.AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip;
            request.Referer = referer;

            if (headers != null)
            {
                request.Headers.Add(headers);
            }

            if (cookies != null)
            {
                request.CookieContainer = cookies;
            }

            
            if (method == "POST")
            {
                string boundary = CreateFormDataBoundary();
                request.ContentType = "multipart/form-data; boundary=" + boundary;
                Stream requestStream = request.GetRequestStream();

                multipartData.WriteMultipartFormData(requestStream, boundary);

                byte[] endBytes = System.Text.Encoding.UTF8.GetBytes("--" + boundary + "--");
                requestStream.Write(endBytes, 0, endBytes.Length);
                requestStream.Close();
            }

            try
            {
                using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
                {
                    if (response.StatusCode != HttpStatusCode.OK)
                    {
                        HandleFailedWebRequestResponse(response, url);
                        return null;
                    }

                    using (StreamReader responseStream = new StreamReader(response.GetResponseStream()))
                    {
                        string responseData = responseStream.ReadToEnd();
                        return responseData;
                    }
                }
            }
            catch (WebException e)
            {
                HandleFailedWebRequestResponse(e.Response as HttpWebResponse, url);
                return null;
            }
        }



        /// <summary>
        /// Raise exceptions relevant to this HttpWebResponse -- EG, to signal that our oauth token has expired.
        /// </summary>
        private static void HandleFailedWebRequestResponse(HttpWebResponse response, string requestURL)
        {
            if (response == null) return;

            //Redirecting -- likely to a steammobile:// URI
            if (response.StatusCode == HttpStatusCode.Found)
            {
                var location = response.Headers.Get("Location");
                if (!string.IsNullOrEmpty(location))
                {
                    //Our OAuth token has expired. This is given both when we must refresh our session, or the entire OAuth Token cannot be refreshed anymore.
                    //Thus, we should only throw this exception when we're attempting to refresh our session.
                    if (location == "steammobile://lostauth" && requestURL == APIEndpoints.MOBILEAUTH_GETWGTOKEN)
                    {
                        throw new SteamGuardAccount.WGTokenExpiredException();
                    }
                }
            }
        }



        public static string CreateFormDataBoundary()
        {
            return "---------------------------" + DateTime.Now.Ticks.ToString("x");
        }
    }

    public static class DictionaryExtensions
    {
        public const string FormDataTemplate = "--{0}\r\nContent-Disposition: form-data; name=\"{1}\"\r\n\r\n{2}\r\n";

        public static void WriteMultipartFormData(this Dictionary<string, string> dictionary, Stream stream, string mimeBoundary)
        {
            if (dictionary == null || dictionary.Count == 0)
            {
                return;
            }
            if (stream == null)
            {
                throw new ArgumentNullException("stream");
            }
            if (mimeBoundary == null)
            {
                throw new ArgumentNullException("mimeBoundary");
            }
            if (mimeBoundary.Length == 0)
            {
                throw new ArgumentException("MIME boundary may not be empty.", "mimeBoundary");
            }
            foreach (string key in dictionary.Keys)
            {
                string item = String.Format(FormDataTemplate, mimeBoundary, key, dictionary[key]);
                byte[] itemBytes = System.Text.Encoding.UTF8.GetBytes(item);
                stream.Write(itemBytes, 0, itemBytes.Length);
            }
        }
    }
}