From 0d99caf2b077843c4b9bacdf3bdf2767e153f2b4 Mon Sep 17 00:00:00 2001
From: Jan Nedbal <jan.nedbal@apertia.cz>
Date: Wed, 15 Apr 2026 11:40:57 +0200
Subject: [PATCH] launcher: deliver m2pack runtime key + auto-pick metin wine
 prefix

GameProcess now reads runtime-key.json from the install dir and forwards
master_key_hex / sign_public_key_hex / key_id to the spawned Metin2.exe via
the M2PACK_MASTER_KEY_HEX, M2PACK_SIGN_PUBKEY_HEX, M2PACK_KEY_ID env vars
the new MinGW client loader expects. Without this the m2p loader bails out
with "Invalid M2PACK_MASTER_KEY_HEX".

Also defaults WINEPREFIX to ~/metin/wine-metin when the parent shell hasn't
set one. The default ~/.wine prefix lacks tahoma + d3dx9 + vcrun, which
makes the client run with invisible fonts; the metin-specific prefix is
prepared by m2dev-client/scripts/setup-wine-prefix.sh.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 src/Metin2Launcher/GameLaunch/GameProcess.cs | 63 +++++++++++++++++---
 1 file changed, 55 insertions(+), 8 deletions(-)

diff --git a/src/Metin2Launcher/GameLaunch/GameProcess.cs b/src/Metin2Launcher/GameLaunch/GameProcess.cs
index ced668f..3de0ac1 100644
--- a/src/Metin2Launcher/GameLaunch/GameProcess.cs
+++ b/src/Metin2Launcher/GameLaunch/GameProcess.cs
@@ -1,4 +1,5 @@
 using System.Diagnostics;
+using System.Text.Json;
 using Metin2Launcher.Logging;
 
 namespace Metin2Launcher.GameLaunch;
@@ -53,23 +54,69 @@ public static class GameProcess
     /// </summary>
     public static ProcessStartInfo BuildStartInfo(string exePath, string workingDirectory)
     {
+        ProcessStartInfo psi;
         if (OperatingSystem.IsLinux())
         {
-            var psi = new ProcessStartInfo
+            psi = new ProcessStartInfo
             {
                 FileName = "wine",
                 WorkingDirectory = workingDirectory,
                 UseShellExecute = false,
             };
             psi.ArgumentList.Add(exePath);
-            return psi;
+            // The default ~/.wine prefix lacks tahoma + d3dx9 + vcrun, which makes
+            // the client run with invisible fonts and missing renderer DLLs. We
+            // honor WINEPREFIX from the parent env if set; otherwise prefer a
+            // metin-specific prefix that setup-wine-prefix.sh prepares.
+            if (string.IsNullOrEmpty(Environment.GetEnvironmentVariable("WINEPREFIX")))
+            {
+                var home = Environment.GetEnvironmentVariable("HOME") ?? "/home/jann";
+                var metinPrefix = Path.Combine(home, "metin", "wine-metin");
+                if (Directory.Exists(metinPrefix))
+                    psi.Environment["WINEPREFIX"] = metinPrefix;
+            }
         }
-
-        return new ProcessStartInfo
+        else
         {
-            FileName = exePath,
-            WorkingDirectory = workingDirectory,
-            UseShellExecute = false,
-        };
+            psi = new ProcessStartInfo
+            {
+                FileName = exePath,
+                WorkingDirectory = workingDirectory,
+                UseShellExecute = false,
+            };
+        }
+        ApplyM2PackRuntimeKey(psi, workingDirectory);
+        return psi;
+    }
+
+    // m2pack-secure: the new client refuses to load .m2p archives unless a
+    // runtime master key is delivered out-of-band. The release ships
+    // runtime-key.json next to the exe; we read it and pass the values via
+    // env vars (M2PACK_MASTER_KEY_HEX et al) which the loader picks up.
+    // If the file is missing we just don't set the vars — useful for legacy
+    // releases that still have the static client.
+    private static void ApplyM2PackRuntimeKey(ProcessStartInfo psi, string clientRoot)
+    {
+        var keyFile = Path.Combine(clientRoot, "runtime-key.json");
+        if (!File.Exists(keyFile))
+        {
+            return;
+        }
+        try
+        {
+            using var doc = JsonDocument.Parse(File.ReadAllText(keyFile));
+            var root = doc.RootElement;
+            if (root.TryGetProperty("master_key_hex", out var mk))
+                psi.Environment["M2PACK_MASTER_KEY_HEX"] = mk.GetString() ?? "";
+            if (root.TryGetProperty("sign_public_key_hex", out var pk))
+                psi.Environment["M2PACK_SIGN_PUBKEY_HEX"] = pk.GetString() ?? "";
+            if (root.TryGetProperty("key_id", out var kid))
+                psi.Environment["M2PACK_KEY_ID"] = kid.GetInt32().ToString();
+            Log.Info("m2pack runtime key loaded from runtime-key.json");
+        }
+        catch (Exception ex)
+        {
+            Log.Error("failed to load runtime-key.json", ex);
+        }
     }
 }