Message all steam friends - Steam Authentication Optional

using System;
using System.IO;
using System.Security.Cryptography;
using System.Threading;
using SteamKit2;

namespace Friends_Auth
{
    class Program
    {
        static SteamClient steamClient;
        static CallbackManager manager;

        static SteamUser steamUser;
        static SteamFriends steamFriends;

        static bool isRunning, steamAuth;

        static string user, pass, message;
        static string authCode, twoFactorAuth;

        static void Main(string[] args)
        {
            if (args.Length < 2)
            {
                Console.WriteLine("Sample4: No username and password specified!");
                return;
            }

            // save our logon details
            user = args[0];
            pass = args[1];
            message = args[2];
            steamAuth = Boolean.Parse(args[3]);

            // create our steamclient instance
            steamClient = new SteamClient(System.Net.Sockets.ProtocolType.Tcp);
            // create the callback manager which will route callbacks to function calls
            manager = new CallbackManager(steamClient);

            // get the steamuser handler, which is used for logging on after successfully connecting
            steamUser = steamClient.GetHandler<SteamUser>();
            // get the steam friends handler, which is used for interacting with friends on the network after logging on
            steamFriends = steamClient.GetHandler<SteamFriends>();

            // register a few callbacks we're interested in
            // these are registered upon creation to a callback manager, which will then route the callbacks
            // to the functions specified
            manager.Subscribe<SteamClient.ConnectedCallback>(OnConnected);
            manager.Subscribe<SteamClient.DisconnectedCallback>(OnDisconnected);

            manager.Subscribe<SteamUser.LoggedOnCallback>(OnLoggedOn);
            manager.Subscribe<SteamUser.LoggedOffCallback>(OnLoggedOff);

            if(steamAuth)
                // this callback is triggered when the steam servers wish for the client to store the sentry file
                manager.Subscribe<SteamUser.UpdateMachineAuthCallback>(OnMachineAuth);

            // we use the following callbacks for friends related activities
            manager.Subscribe<SteamUser.AccountInfoCallback>(OnAccountInfo);
            manager.Subscribe<SteamFriends.FriendsListCallback>(OnFriendsList);
            manager.Subscribe<SteamFriends.PersonaStateCallback>(OnPersonaState);
            manager.Subscribe<SteamFriends.FriendAddedCallback>(OnFriendAdded);

            isRunning = true;

            Console.WriteLine("Connecting to Steam...");

            // initiate the connection
            steamClient.Connect();
            // create our callback handling loop
            while (isRunning)
            {
                // in order for the callbacks to get routed, they need to be handled by the manager
                manager.RunWaitCallbacks(TimeSpan.FromSeconds(1));

            }
        }

        static void OnConnected(SteamClient.ConnectedCallback callback)
        {
            if (callback.Result != EResult.OK)
            {
                Console.WriteLine("Unable to connect to Steam: {0}", callback.Result);

                isRunning = false;
                return;
            }

            Console.WriteLine("Connected to Steam! Logging in '{0}'...", user);

            if(steamAuth)
            {
                byte[] sentryHash = null;
                if (File.Exists("sentry.bin"))
                {
                    // if we have a saved sentry file, read and sha-1 hash it
                    byte[] sentryFile = File.ReadAllBytes("sentry.bin");
                    sentryHash = CryptoHelper.SHAHash(sentryFile);
                }

                steamUser.LogOn(new SteamUser.LogOnDetails
                {
                    Username = user,
                    Password = pass,

                    // in this sample, we pass in an additional authcode
                    // this value will be null (which is the default) for our first logon attempt
                    AuthCode = authCode,

                    // if the account is using 2-factor auth, we'll provide the two factor code instead
                    // this will also be null on our first logon attempt
                    TwoFactorCode = twoFactorAuth,

                    // our subsequent logons use the hash of the sentry file as proof of ownership of the file
                    // this will also be null for our first (no authcode) and second (authcode only) logon attempts
                    SentryFileHash = sentryHash,
                });
            }
            else
            {
                steamUser.LogOn(new SteamUser.LogOnDetails
                {
                    Username = user,
                    Password = pass,
                });
            }

        }

        static void OnDisconnected(SteamClient.DisconnectedCallback callback)
        {
            Console.WriteLine("Disconnected from Steam, reconnecting in 5...");

            Thread.Sleep(TimeSpan.FromSeconds(5));

            steamClient.Connect();
        }

        static void OnLoggedOn(SteamUser.LoggedOnCallback callback)
        {
            if(steamAuth)
            {
                bool isSteamGuard = callback.Result == EResult.AccountLogonDenied;
                bool is2FA = callback.Result == EResult.AccountLoginDeniedNeedTwoFactor;

                if (isSteamGuard || is2FA)
                {
                    Console.WriteLine("This account is SteamGuard protected!");

                    if (is2FA)
                    {
                        Console.Write("Please enter your 2 factor auth code from your authenticator app: ");
                        twoFactorAuth = Console.ReadLine();
                    }
                    else
                    {
                        Console.Write("Please enter the auth code sent to the email at {0}: ", callback.EmailDomain);
                        authCode = Console.ReadLine();
                    }

                    return;
                }


            }
            else
            {
                if (callback.Result != EResult.OK)
                {
                    if (callback.Result == EResult.AccountLogonDenied)
                    {
                        // if we recieve AccountLogonDenied or one of it's flavors (AccountLogonDeniedNoMailSent, etc)
                        // then the account we're logging into is SteamGuard protected
                        // see sample 5 for how SteamGuard can be handled

                        Console.WriteLine("Unable to logon to Steam: This account is SteamGuard protected.");

                        isRunning = false;
                        return;
                    }
                }
            }

            if (callback.Result != EResult.OK)
            {
                Console.WriteLine("Unable to logon to Steam: {0} / {1}", callback.Result, callback.ExtendedResult);

                isRunning = false;
                return;
            }
            Console.WriteLine("Successfully logged on!");

            // at this point, we'd be able to perform actions on Steam
        }

        static void OnAccountInfo(SteamUser.AccountInfoCallback callback)
        {
            // before being able to interact with friends, you must wait for the account info callback
            // this callback is posted shortly after a successful logon

            // at this point, we can go online on friends, so lets do that
            steamFriends.SetPersonaState(EPersonaState.Online);
        }

        static void OnFriendsList(SteamFriends.FriendsListCallback callback)
        {
            // at this point, the client has received it's friends list

            int friendCount = steamFriends.GetFriendCount();

            Console.WriteLine("We have {0} friends", friendCount);

            for (int x = 0; x < friendCount; x++)
            {
                // steamids identify objects that exist on the steam network, such as friends, as an example
                SteamID steamIdFriend = steamFriends.GetFriendByIndex(x);
                // we'll just display the STEAM_ rendered version
                Console.WriteLine("Friend: {0}", steamIdFriend.Render());
            }

            // we can also iterate over our friendslist to accept or decline any pending invites
            bool hasErrored = false;
            try
            {
                foreach (var friend in callback.FriendList)
                {
                    if (friend.Relationship == EFriendRelationship.Friend)
                    {
                        steamFriends.SendChatMessage(friend.SteamID, EChatEntryType.ChatMsg, message);
                    }
                }
            }
            catch(Exception e)
            {
                hasErrored = true;
            }

            if(!hasErrored)
                Console.WriteLine("Messaged all friends!");
        }


        static void OnFriendAdded(SteamFriends.FriendAddedCallback callback)
        {
            // someone accepted our friend request, or we accepted one
            Console.WriteLine("{0} is now a friend", callback.PersonaName);
        }

        static void OnPersonaState(SteamFriends.PersonaStateCallback callback)
        {
            // this callback is received when the persona state (friend information) of a friend changes

            // for this sample we'll simply display the names of the friends
            Console.WriteLine("State change: {0}", callback.Name);
        }

        static void OnLoggedOff(SteamUser.LoggedOffCallback callback)
        {
            Console.WriteLine("Logged off of Steam: {0}", callback.Result);
        }

        static void OnMachineAuth(SteamUser.UpdateMachineAuthCallback callback)
        {
            Console.WriteLine("Updating sentryfile...");

            // write out our sentry file
            // ideally we'd want to write to the filename specified in the callback
            // but then this sample would require more code to find the correct sentry file to read during logon
            // for the sake of simplicity, we'll just use "sentry.bin"

            int fileSize;
            byte[] sentryHash;
            using (var fs = File.Open("sentry.bin", FileMode.OpenOrCreate, FileAccess.ReadWrite))
            {
                fs.Seek(callback.Offset, SeekOrigin.Begin);
                fs.Write(callback.Data, 0, callback.BytesToWrite);
                fileSize = (int)fs.Length;

                fs.Seek(0, SeekOrigin.Begin);
                using (var sha = new SHA1CryptoServiceProvider())
                {
                    sentryHash = sha.ComputeHash(fs);
                }
            }

            // inform the steam servers that we're accepting this sentry file
            steamUser.SendMachineAuthResponse(new SteamUser.MachineAuthDetails
            {
                JobID = callback.JobID,

                FileName = callback.FileName,

                BytesWritten = callback.BytesToWrite,
                FileSize = fileSize,
                Offset = callback.Offset,

                Result = EResult.OK,
                LastError = 0,

                OneTimePassword = callback.OneTimePassword,

                SentryFileHash = sentryHash,
            });

            Console.WriteLine("Done!");
        }
    }
}