store api_id in session file. optional session_key (=api_hash by default) as encryption key

README.md

@@ -23,7 +23,7 @@ static async Task Main(string[] _)
     Console.WriteLine($"We are logged-in as {user.username ?? user.first_name + " " + user.last_name} (id {user.id})");
 }
 ```
-When run, this will prompt you interactively for your App **api_id** and **api_hash** (that you obtain through Telegram's [API development tools](https://my.telegram.org/apps) page) and try to connect to Telegram servers.
+When run, this will prompt you interactively for your App **api_hash** and **api_id** (that you obtain through Telegram's [API development tools](https://my.telegram.org/apps) page) and try to connect to Telegram servers.
 
 Then it will attempt to sign-in *(login)* as a user for which you must enter the **phone_number** and the **verification_code** that will be sent to this user (for example through SMS or another Telegram client app the user is connected to).
 
@@ -33,7 +33,7 @@ And that's it, you now have access to the **[full range of Telegram Client APIs]
 All those API methods are available *(with an underscore in the method name, instead of a dot)*, like this: `await client.Method_Name(...)`
 
 # Saved session
-If you run this program again, you will notice that only **api_id** and **api_hash** are requested, the other prompts are gone and you are automatically logged-on and ready to go.
+If you run this program again, you will notice that only **api_hash** is requested, the other prompts are gone and you are automatically logged-on and ready to go.
 
 This is because WTelegramClient saves (typically in the encrypted file **bin\WTelegram.session**) its state and the authentication keys that were negociated with Telegram so that you needn't sign-in again every time.
 
@@ -127,7 +127,7 @@ The Client class also offers an `Update` event that is triggered when Telegram s
 
 An invalid API request can result in a `RpcException` being raised, reflecting the [error code and status text](https://revgram.github.io/errors.html) of the problem.
 
-The other configuration items that you can override include: **session_pathname, server_address, device_model, system_version, app_version, system_lang_code, lang_pack, lang_code, user_id**
+The other configuration items that you can override include: **session_pathname, session_key, server_address, device_model, system_version, app_version, system_lang_code, lang_pack, lang_code, user_id**
 
 Optional API parameters have a default value of `null` when unset. Passing `null` for a required string/array is the same as *empty* (0-length). Required API parameters/fields can sometimes be set to 0 or `null` when unused (check API documentation or experiment).
 

src/Client.cs

@@ -50,9 +50,8 @@ namespace WTelegram
 		public delegate void ProgressCallback(long transmitted, long totalSize);
 
 		private readonly Func<string, string> _config;
-		private readonly int _apiId;
-		private readonly string _apiHash;
 		private readonly Session _session;
+		private string _apiHash;
 		private Session.DCSession _dcSession;
 		private TcpClient _tcpClient;
 		private Stream _networkStream;
@@ -89,9 +88,10 @@ namespace WTelegram
 		public Client(Func<string, string> configProvider = null)
 		{
 			_config = configProvider ?? DefaultConfigOrAsk;
-			_apiId = int.Parse(Config("api_id"));
+			var session_pathname = Config("session_pathname");
-			_apiHash = Config("api_hash");
+			var session_key = _config("session_key") ?? (_apiHash = Config("api_hash"));
-			_session = Session.LoadOrCreate(Config("session_pathname"), Convert.FromHexString(_apiHash));
+			_session = Session.LoadOrCreate(session_pathname, Convert.FromHexString(session_key));
+			if (_session.ApiId == 0) _session.ApiId = int.Parse(Config("api_id"));
 			if (_session.MainDC != 0) _session.DCSessions.TryGetValue(_session.MainDC, out _dcSession);
 			_dcSession ??= new() { Id = Helpers.RandomLong() };
 			_dcSession.Client = this;
@@ -102,8 +102,6 @@ namespace WTelegram
 		private Client(Client cloneOf, Session.DCSession dcSession)
 		{
 			_config = cloneOf._config;
-			_apiId = cloneOf._apiId;
-			_apiHash = cloneOf._apiHash;
 			_session = cloneOf._session;
 			TcpHandler = cloneOf.TcpHandler;
 			MTProxyUrl = cloneOf.MTProxyUrl;
@@ -127,8 +125,8 @@ namespace WTelegram
 			"server_address" => "149.154.167.50:443",	// DC 2
 #endif
 			"device_model" => Environment.Is64BitOperatingSystem ? "PC 64bit" : "PC 32bit",
-			"system_version" => System.Runtime.InteropServices.RuntimeInformation.OSDescription,
+			"system_version" => Helpers.GetSystemVersion(),
-			"app_version" => (Assembly.GetEntryAssembly() ?? AppDomain.CurrentDomain.GetAssemblies().FirstOrDefault(a => a.EntryPoint != null))?.GetName().Version.ToString() ?? "0.0",
+			"app_version" => Helpers.GetAppVersion(),
 			"system_lang_code" => CultureInfo.InstalledUICulture.TwoLetterISOLanguageName,
 			"lang_pack" => "",
 			"lang_code" => CultureInfo.CurrentUICulture.TwoLetterISOLanguageName,
@@ -141,7 +139,8 @@ namespace WTelegram
 
 		private static string AskConfig(string config)
 		{
-			if (config == "api_id") Console.WriteLine("Welcome! You can obtain your api_id/api_hash at https://my.telegram.org/apps");
+			if (config == "session_key") return null;
+			if (config == "api_hash") Console.WriteLine("Welcome! You can obtain your api_id/api_hash at https://my.telegram.org/apps");
 			Console.Write($"Enter {config.Replace('_', ' ')}: ");
 			return Console.ReadLine();
 		}
@@ -340,7 +339,7 @@ namespace WTelegram
 				TLConfig = await this.InvokeWithLayer(Layer.Version,
 					new TL.Methods.InitConnection<Config>
 					{
-						api_id = _apiId,
+						api_id = _session.ApiId,
 						device_model = Config("device_model"),
 						system_version = Config("system_version"),
 						app_version = Config("app_version"),
@@ -1082,7 +1081,7 @@ namespace WTelegram
 				await this.Auth_LogOut();
 				_session.UserId = _dcSession.UserId = 0;
 			}
-			var authorization = await this.Auth_ImportBotAuthorization(0, _apiId, _apiHash, botToken);
+			var authorization = await this.Auth_ImportBotAuthorization(0, _session.ApiId, _apiHash ??= Config("api_hash"), botToken);
 			return LoginAlreadyDone(authorization);
 		}
 
@@ -1122,11 +1121,11 @@ namespace WTelegram
 			Auth_SentCode sentCode;
 			try
 			{
-				sentCode = await this.Auth_SendCode(phone_number, _apiId, _apiHash, settings ??= new());
+				sentCode = await this.Auth_SendCode(phone_number, _session.ApiId, _apiHash ??= Config("api_hash"), settings ??= new());
 			}
 			catch (RpcException ex) when (ex.Code == 500 && ex.Message == "AUTH_RESTART")
 			{
-				sentCode = await this.Auth_SendCode(phone_number, _apiId, _apiHash, settings ??= new());
+				sentCode = await this.Auth_SendCode(phone_number, _session.ApiId, _apiHash, settings);
 			}
 		resent:
 			var timeout = DateTime.UtcNow + TimeSpan.FromSeconds(sentCode.timeout);

src/Helpers.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Numerics;
+using System.Reflection;
 using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
@@ -253,6 +254,16 @@ namespace WTelegram
 			0x3f, 0x00
 		};
 
+		internal static string GetSystemVersion()
+		{
+			var os = System.Runtime.InteropServices.RuntimeInformation.OSDescription;
+			int space = os.IndexOf(' ') + 1, dot = os.IndexOf('.');
+			return os[(os.IndexOf(' ', space) < 0 ? 0 : space)..(dot < 0 ? os.Length : dot)];
+		}
+
+		internal static string GetAppVersion()
+			=> (Assembly.GetEntryAssembly() ?? Array.Find(AppDomain.CurrentDomain.GetAssemblies(), a => a.EntryPoint != null))?.GetName().Version.ToString() ?? "0.0";
+
 		public class IndirectStream : Stream
 		{
 			public IndirectStream(Stream innerStream) => _innerStream = innerStream;

src/Session.cs

@@ -11,6 +11,7 @@ namespace WTelegram
 {
 	internal class Session
 	{
+		public int ApiId;
 		public long UserId;
 		public int MainDC;
 		public Dictionary<int, DCSession> DCSessions = new();

src/TL.Schema.cs

@@ -5572,9 +5572,9 @@ namespace TL
 		/// <summary>App version</summary>
 		public string app_version;
 		/// <summary>When was the session created</summary>
-		public int date_created;
+		public DateTime date_created;
 		/// <summary>When was the session last active</summary>
-		public int date_active;
+		public DateTime date_active;
 		/// <summary>Last known IP</summary>
 		public string ip;
 		/// <summary>Country determined from IP</summary>
@@ -9542,9 +9542,9 @@ namespace TL
 		/// <summary>Platform</summary>
 		public string platform;
 		/// <summary>When was the web session created</summary>
-		public int date_created;
+		public DateTime date_created;
 		/// <summary>When was the web session last active</summary>
-		public int date_active;
+		public DateTime date_active;
 		/// <summary>IP address</summary>
 		public string ip;
 		/// <summary>Region, determined from IP address</summary>