significant improvements to server selector

ServerSelector/GameSettings.cs

@@ -0,0 +1,51 @@
+using System;
+using System.IO;
+using System.Text.Json;
+
+namespace ServerSelector
+{
+    public class GameSettings
+    {
+        private static GameSettings? _settings;
+        public string GameRoot { get; set; } = "C:\\Nikke";
+        public string LastIp { get; set; } = "127.0.0.1";
+        public int LastOffset { get; set; }
+
+        public static GameSettings Settings
+        {
+            get
+            {
+                if (_settings != null)
+                    return _settings;
+
+                string path = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "serverselectorsettings.json");
+
+                try
+                {
+                    if (File.Exists(path))
+                    {
+                        string json = File.ReadAllText(path);
+                        _settings = JsonSerializer.Deserialize<GameSettings>(json);
+                    }
+                }
+                catch
+                {
+
+                }
+
+                if (_settings == null)
+                {
+                    _settings = new();
+                }
+
+                return _settings;
+            }
+        }
+
+        public static void Save()
+        {
+            string path = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "serverselectorsettings.json");
+            File.WriteAllText(path, JsonSerializer.Serialize(_settings));
+        }
+    }
+}

ServerSelector/SearchReplace.cs

@@ -0,0 +1,128 @@
+// From: https://github.com/Ninka-Rex/CSharp-Search-and-Replace/blob/main/SearchReplace.cs
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+
+public static class PatchUtility
+{
+    // This method searches and replaces binary patterns in a given file
+    // It takes three parameters:
+    // - filePath: the path of the file to be patched
+    // - searchPatterns: an array of hexadecimal strings representing the patterns to be searched for
+    // - replacePatterns: an array of hexadecimal strings representing the patterns to be replaced with
+    // It returns true if the patching was successful, or false if there was an error or a pattern was not found
+    public static bool SearchAndReplace(string filePath, string[] searchPatterns, string[] replacePatterns)
+    {
+        try
+        {
+            // Check if the file exists
+            if (!File.Exists(filePath)) { Console.WriteLine("[ERROR] File not found: " + filePath); return false; }
+
+            // Read the binary data from the file as an array of bytes
+            byte[] fileData = File.ReadAllBytes(filePath);
+
+            // Backup the original file by copying it to a new file with a .bak extension
+            string backupFilePath = filePath + ".bak";
+            if (!File.Exists(backupFilePath))
+            {
+                File.Copy(filePath, backupFilePath);
+            }
+
+            // Loop through each pair of search and replace patterns and apply them to the file data
+            for (int k = 0; k < searchPatterns.Length; k++)
+            {
+                // Convert the hexadecimal strings to byte arrays using a helper method
+                byte[] searchBytes = HexStringToBytes(searchPatterns[k]);
+                byte[] replaceBytes = HexStringToBytes(replacePatterns[k]);
+
+                // Find the index of the first occurrence of the search pattern in the file data using another helper method
+                int index = FindPatternIndex(fileData, searchBytes)[1];
+
+                Console.WriteLine("offset: " + index.ToString("X"));
+
+                // If the index is -1, it means the pattern was not found, so we return false and log an error message
+                if (index == -1)
+                {
+                    Console.WriteLine("[ERROR] Search pattern not found: " + searchPatterns[k]);
+                    return false;
+                }
+
+                // Replace the pattern at the found index with the replace pattern, preserving original values when wildcards are encountered
+                // A wildcard is represented by either 00 or FF in the replace pattern, meaning that we keep the original value at that position
+                for (int i = 0; i < replaceBytes.Length; i++)
+                {
+                    if (replaceBytes[i] != 0x00 && replaceBytes[i] != 0xFF)
+                    {
+                        fileData[index + i] = replaceBytes[i];
+                    }
+                    else if (replaceBytes[i] == 0x00)
+                    {
+                        fileData[index + i] = 0x00;
+                    }
+                }
+
+                // Log a success message with the offset and file name where the patch was applied
+                string exeName = Path.GetFileName(filePath);
+                Console.WriteLine($"[Patch] Apply patch success at 0x{index:X} in {exeName}");
+            }
+
+            // Write the modified data back to the file, overwriting the original content
+            File.WriteAllBytes(filePath, fileData);
+
+            return true;
+        }
+        catch (Exception ex)
+        {
+            // If any exception occurs during the patching process, we return false and log an error message with the exception details
+            Console.WriteLine("[ERROR] An error occurred while writing the file: " + ex.Message);
+            return false;
+        }
+    }
+
+    // This helper method converts a hexadecimal string to a byte array
+    // It takes one parameter:
+    // - hex: a string of hexadecimal digits, optionally separated by spaces or question marks
+    // It returns a byte array corresponding to the hexadecimal values in the string
+    private static byte[] HexStringToBytes(string hex)
+    {
+        hex = hex.Replace(" ", "").Replace("??", "FF"); // Replace ?? with FF for wildcards
+        return Enumerable.Range(0, hex.Length)
+            .Where(x => x % 2 == 0) // Take every second character in the string
+            .Select(x => Convert.ToByte(hex.Substring(x, 2), 16)) // Convert each pair of characters to a byte value in base 16
+            .ToArray(); // Convert the result to an array of bytes
+    }
+
+    // This helper method finds the index of the first occurrence of a pattern in a data array
+    // It takes two parameters:
+    // - data: an array of bytes representing the data to be searched in
+    // - pattern: an array of bytes representing the pattern to be searched for
+    // It returns an integer representing the index where the pattern was found, or -1 if it was not found
+    private static List<int> FindPatternIndex(byte[] data, byte[] pattern)
+    {
+        List<int> points = [];
+        // Loop through each possible position in the data array where the pattern could start
+        for (int i = 0; i < data.Length - pattern.Length + 1; i++)
+        {
+            bool found = true; // Assume that the pattern is found until proven otherwise
+            // Loop through each byte in the pattern and compare it with the corresponding byte in the data array
+            for (int j = 0; j < pattern.Length; j++)
+            {
+                // If the pattern byte is not FF (wildcard) and it does not match the data byte, then the pattern is not found at this position
+                if (pattern[j] != 0xFF && data[i + j] != pattern[j])
+                {
+                    found = false;
+                    break;
+                }
+            }
+            // If the pattern was found at this position, return the index
+            if (found)
+            {
+                points.Add(i);
+            }
+        }
+        // If the pattern was not found in the entire data array, return -1
+        return points;
+    }
+}

ServerSelector/ServerSwitcher.cs

@@ -7,11 +7,9 @@ namespace ServerSelector
 {
     public class ServerSwitcher
     {
-        private static int GameAssemblySodiumIntegrityFuncHint = 0x6014080;
-        public static string PatchGameVersion = "131.10.2";
-
-        private static byte[] GameAssemblySodiumIntegrityFuncOrg = [0x40, 0x53, 0x56, 0x57, 0x41];
-        private static byte[] GameAssemblySodiumIntegrityFuncPatch = [0xb0, 0x01, 0xc3, 0x90, 0x90];
+        private static string[] GameAssemblySodiumIntegrityFuncHint = ["40 53 56 57 41 54 41 55 41 56 41 57 48 81 EC C0 00 00 00 80 3d ?? ?? ?? ?? 00 0f 85 ?? 00 00 00 48"];
+        public static bool GameAssemblyNeedsPatch = true; // Set to false if running on versions before v124
+        private static string[] GameAssemblySodiumIntegrityFuncPatch = ["b0 01 c3 90 90"];
         private const string HostsStartMarker = "# begin ServerSelector entries";
         private const string HostsEndMarker = "# end ServerSelector entries";
 
@@ -67,8 +65,7 @@ namespace ServerSelector
             {
                 var certList1 = await File.ReadAllTextAsync(launcherCertList);
 
-                int goodSslIndex1 = certList1.IndexOf("Good SSL Ca");
-                if (goodSslIndex1 == -1)
+                if (!certList1.Contains("Good SSL Ca"))
                     return "Patch missing";
             }
 
@@ -76,8 +73,7 @@ namespace ServerSelector
             {
                 var certList2 = await File.ReadAllTextAsync(gameCertList);
 
-                int goodSslIndex2 = certList2.IndexOf("Good SSL Ca");
-                if (goodSslIndex2 == -1)
+                if (!certList2.Contains("Good SSL Ca"))
                     return "Patch missing";
             }
 
@@ -127,7 +123,7 @@ namespace ServerSelector
                     endIdx = txt.IndexOf(endIndexStr) + endIndexStr.Length;
                 }
 
-                txt = txt.Substring(0, startIdx) + txt.Substring(endIdx);
+                txt = string.Concat(txt.AsSpan(0, startIdx), txt.AsSpan(endIdx));
 
 
                 await File.WriteAllTextAsync(hostsFilePath, txt);
@@ -138,6 +134,24 @@ namespace ServerSelector
             }
         }
 
+        public static bool PatchGameAssembly(string dll, bool install)
+        {
+            if (!GameAssemblyNeedsPatch) return true;
+
+            bool backupExists = File.Exists(dll + ".bak");
+
+            if (install && !backupExists)
+            {
+                return PatchUtility.SearchAndReplace(dll, GameAssemblySodiumIntegrityFuncHint, GameAssemblySodiumIntegrityFuncPatch);
+            }
+            else if (backupExists)
+            {
+                File.Move(dll + ".bak", dll, true);
+            }
+
+            return true;
+        }
+
         public static async Task<ServerSwitchResult> SaveCfg(bool useOffical, string gamePath, string launcherPath, string ip, bool offlineMode)
         {
             string sodiumLib = AppDomain.CurrentDomain.BaseDirectory + "sodium.dll";
@@ -172,7 +186,7 @@ namespace ServerSelector
                     // remove cert
                     if (OperatingSystem.IsWindows())
                     {
-                        X509Store store = new X509Store(StoreName.Root, StoreLocation.LocalMachine);
+                        X509Store store = new(StoreName.Root, StoreLocation.LocalMachine);
                         store.Open(OpenFlags.ReadWrite);
                         store.Remove(new X509Certificate2(X509Certificate.CreateFromCertFile(AppDomain.CurrentDomain.BaseDirectory + "myCA.pfx")));
                         store.Close();
@@ -186,39 +200,13 @@ namespace ServerSelector
                 // restore sodium
                 if (!File.Exists(sodiumBackup))
                 {
-                    throw new Exception("sodium backup does not exist");
+                    throw new Exception("sodium backup does not exist. Repair the game in the launcher and switch to local server and back to official.");
                 }
                 File.Copy(sodiumBackup, gameSodium, true);
 
-                // revert gameassembly changes
-                var gameAssemblyBytes = await File.ReadAllBytesAsync(gameAssembly);
-                var i = GameAssemblySodiumIntegrityFuncHint;
-                if (gameAssemblyBytes[i] == GameAssemblySodiumIntegrityFuncOrg[0] &&
-        gameAssemblyBytes[i + 1] == GameAssemblySodiumIntegrityFuncOrg[1] &&
-        gameAssemblyBytes[i + 2] == GameAssemblySodiumIntegrityFuncOrg[2] &&
-        gameAssemblyBytes[i + 3] == GameAssemblySodiumIntegrityFuncOrg[3] &&
-        gameAssemblyBytes[i + 4] == GameAssemblySodiumIntegrityFuncOrg[4])
+                if (!PatchGameAssembly(gameAssembly, false))
                 {
-
-                }
-                else if (gameAssemblyBytes[i] == GameAssemblySodiumIntegrityFuncPatch[0] &&
-                    gameAssemblyBytes[i + 1] == GameAssemblySodiumIntegrityFuncPatch[1] &&
-                    gameAssemblyBytes[i + 2] == GameAssemblySodiumIntegrityFuncPatch[2] &&
-                    gameAssemblyBytes[i + 3] == GameAssemblySodiumIntegrityFuncPatch[3] &&
-                    gameAssemblyBytes[i + 4] == GameAssemblySodiumIntegrityFuncPatch[4])
-                {
-                    gameAssemblyBytes[i] = GameAssemblySodiumIntegrityFuncOrg[0];
-                    gameAssemblyBytes[i + 1] = GameAssemblySodiumIntegrityFuncOrg[1];
-                    gameAssemblyBytes[i + 2] = GameAssemblySodiumIntegrityFuncOrg[2];
-                    gameAssemblyBytes[i + 3] = GameAssemblySodiumIntegrityFuncOrg[3];
-                    gameAssemblyBytes[i + 4] = GameAssemblySodiumIntegrityFuncOrg[4];
-
-                    File.WriteAllBytes(gameAssembly, gameAssemblyBytes);
-                }
-                else
-                {
-                    // TODO: unsupported version
-                    supported = false;
+                    throw new Exception("Failed to restore GameAssembly.dll. Please repair the game in the launcher.");
                 }
 
                 if (File.Exists(launcherCertList))
@@ -227,7 +215,7 @@ namespace ServerSelector
 
                     int goodSslIndex1 = certList1.IndexOf("Good SSL Ca");
                     if (goodSslIndex1 != -1)
-                        await File.WriteAllTextAsync(launcherCertList, certList1.Substring(0, goodSslIndex1));
+                        await File.WriteAllTextAsync(launcherCertList, certList1[..goodSslIndex1]);
                 }
 
                 if (File.Exists(gameCertList))
@@ -236,7 +224,7 @@ namespace ServerSelector
 
                     int goodSslIndex2 = certList2.IndexOf("Good SSL Ca");
                     if (goodSslIndex2 != -1)
-                        await File.WriteAllTextAsync(gameCertList, certList2.Substring(0, goodSslIndex2));
+                        await File.WriteAllTextAsync(gameCertList, certList2[..goodSslIndex2]);
                 }
             }
             else
@@ -323,38 +311,7 @@ namespace ServerSelector
                 await File.WriteAllBytesAsync(gameSodium, await File.ReadAllBytesAsync(sodiumLib));
 
                 // patch gameassembly to remove sodium IntegrityUtility Check introduced in v124.6.10
-                var gameAssemblyBytes = await File.ReadAllBytesAsync(gameAssembly);
-
-                var i = GameAssemblySodiumIntegrityFuncHint;
-                if (gameAssemblyBytes[i] == GameAssemblySodiumIntegrityFuncOrg[0] &&
-                    gameAssemblyBytes[i + 1] == GameAssemblySodiumIntegrityFuncOrg[1] &&
-                    gameAssemblyBytes[i + 2] == GameAssemblySodiumIntegrityFuncOrg[2] &&
-                    gameAssemblyBytes[i + 3] == GameAssemblySodiumIntegrityFuncOrg[3] &&
-                    gameAssemblyBytes[i + 4] == GameAssemblySodiumIntegrityFuncOrg[4])
-                {
-                    gameAssemblyBytes[i] = GameAssemblySodiumIntegrityFuncPatch[0]; // MOV ax, 1
-                    gameAssemblyBytes[i + 1] = GameAssemblySodiumIntegrityFuncPatch[1];
-                    gameAssemblyBytes[i + 2] = GameAssemblySodiumIntegrityFuncPatch[2]; // NOP
-                    gameAssemblyBytes[i + 3] = GameAssemblySodiumIntegrityFuncPatch[3]; // NOP
-                    gameAssemblyBytes[i + 4] = GameAssemblySodiumIntegrityFuncPatch[4]; // NOP
-
-                    await File.WriteAllBytesAsync(gameAssembly, gameAssemblyBytes);
-                }
-                else if (gameAssemblyBytes[i] == GameAssemblySodiumIntegrityFuncPatch[0] &&
-                    gameAssemblyBytes[i + 1] == GameAssemblySodiumIntegrityFuncPatch[1] &&
-                    gameAssemblyBytes[i + 2] == GameAssemblySodiumIntegrityFuncPatch[2] &&
-                    gameAssemblyBytes[i + 3] == GameAssemblySodiumIntegrityFuncPatch[3] &&
-                    gameAssemblyBytes[i + 4] == GameAssemblySodiumIntegrityFuncPatch[4])
-                {
-                    // was already patched
-                }
-                else
-                {
-                    // TODO: unsupported version
-                    supported = false;
-                }
-
-
+                supported = PatchGameAssembly(gameAssembly, true);
 
                 // update launcher/game ca cert list
 
@@ -373,17 +330,10 @@ namespace ServerSelector
         }
     }
 
-    public class ServerSwitchResult
+    public class ServerSwitchResult(bool ok, Exception? exception, bool isSupported)
     {
-        public bool Ok { get; set; }
-        public Exception? Exception { get; set; }
-        public bool IsSupported { get; set; }
-
-        public ServerSwitchResult(bool ok, Exception? exception, bool isSupported)
-        {
-            this.Ok = ok;
-            this.Exception = exception;
-            this.IsSupported = isSupported;
-        }
+        public bool Ok { get; set; } = ok;
+        public Exception? Exception { get; set; } = exception;
+        public bool IsSupported { get; set; } = isSupported;
     }
 }

ServerSelector/Views/MainView.axaml

@@ -114,7 +114,7 @@
 					</Grid.RowDefinitions>
 
 
-					<TextBlock VerticalAlignment="Center" Margin="5" Grid.Row="0" Grid.Column="0">Game path: </TextBlock>
+					<TextBlock VerticalAlignment="Center" Margin="5" Grid.Row="0" Grid.Column="0" ToolTip.Tip="The folder with the game and launcher folders.">Game root path: </TextBlock>
 					<TextBox x:Name="txtGamePath" Grid.Row="0" Grid.Column="1" TextChanged="GamePath_TextChanged" ToolTip.Tip="The folder with the game and launcher folders.">C:\NIKKE\</TextBox>
 					<Button x:Name="btnSelectGamePath" Grid.Row="0" Grid.Column="2" Classes="utility" Click="BtnSelectGamePath_Click">...</Button>
 

ServerSelector/Views/MainView.axaml.cs

@@ -34,11 +34,14 @@ public partial class MainView : UserControl
             {
                 VerticalAlignment = Avalonia.Layout.VerticalAlignment.Center,
                 HorizontalAlignment = Avalonia.Layout.HorizontalAlignment.Center,
-                Text = "Root is required to change servers."
+                Text = "Root is required to change servers in order to modify /etc/hosts."
             };
         }
 
         UpdateIntegrityLabel();
+
+        txtGamePath.Text = GameSettings.Settings.GameRoot;
+        TxtIpAddress.Text = GameSettings.Settings.LastIp;
     }
 
     private void SetGamePathValid(bool isValid)
@@ -83,7 +86,7 @@ public partial class MainView : UserControl
         {
             SetGamePathValid(false);
             if (showMessage)
-                ShowWarningMsg("Game path does not exist", "Error");
+                ShowWarningMsg("game folder does not exist in the game root folder", "Error");
             return false;
         }
 
@@ -91,7 +94,7 @@ public partial class MainView : UserControl
         {
             SetGamePathValid(false);
             if (showMessage)
-                ShowWarningMsg("Launcher path is invalid. Make sure that nikke_launcher.exe exists in the launcher folder", "Error");
+                ShowWarningMsg("Game path is invalid. Make sure that nikke_launcher.exe exists in the <Game Path>/launcher folder", "Error");
 
             return false;
         }
@@ -130,15 +133,18 @@ public partial class MainView : UserControl
         if (!ValidatePaths(true) || txtGamePath.Text == null || GamePath == null || LauncherPath == null)
             return;
 
-        if (CmbServerSelection.SelectedIndex == 1)
+        if (CmbServerSelection.SelectedIndex == 1 && !IPAddress.TryParse(TxtIpAddress.Text, out _))
         {
-            if (!IPAddress.TryParse(TxtIpAddress.Text, out _))
-            {
-                ShowWarningMsg("Invalid IP address. The entered IP address should be IPv4 or IPv6.", "Error");
-                return;
-            }
+            ShowWarningMsg("Invalid IP address. The entered IP address should be IPv4 or IPv6.", "Error");
+            return;
         }
-        if (TxtIpAddress.Text == null) TxtIpAddress.Text = "";
+
+        GameSettings.Settings.GameRoot = txtGamePath.Text;
+        GameSettings.Settings.LastIp = TxtIpAddress.Text ?? "127.0.0.1";
+
+        TxtIpAddress.Text ??= "";
+
+        GameSettings.Save();
 
         SetLoadingScreenVisible(true);
         try
@@ -170,7 +176,7 @@ public partial class MainView : UserControl
 
     public static void ShowWarningMsg(string text, string title)
     {
-        ContentDialog dlg = new ContentDialog() { Title = title, Content = text, PrimaryButtonText = "OK" };
+        ContentDialog dlg = new() { Title = title, Content = text, PrimaryButtonText = "OK" };
         dlg.ShowAsync();
     }