From cf5d87f7a7abb3822e4f606012d37b65d251f7de Mon Sep 17 00:00:00 2001
From: mkrsym1 <mkrsym1@gmail.com>
Date: Sun, 2 Jul 2023 23:21:17 +0300
Subject: [PATCH] Refuse to launch if the patcher is inside the game directory

---
 injector/src/dll.c | 40 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 38 insertions(+), 2 deletions(-)

diff --git a/injector/src/dll.c b/injector/src/dll.c
index 46f5f58..10776f5 100644
--- a/injector/src/dll.c
+++ b/injector/src/dll.c
@@ -5,6 +5,10 @@
 
 #include <game_p.h>
 
+typedef char *(*wgufn_t)(wchar_t* path); // wine_get_unix_file_name
+
+const char *J_MB_TITLE = "Jadeite Launcher Payload";
+
 BOOL WINAPI DllMain(HINSTANCE inst, DWORD reason, LPVOID reserved) {
     // Only listen for attach
     if (reason != DLL_PROCESS_ATTACH) {
@@ -25,6 +29,38 @@ BOOL WINAPI DllMain(HINSTANCE inst, DWORD reason, LPVOID reserved) {
     strcpy(workdir, targetExe);
     *(strrchr(workdir, '\\')) = '\0';
 
+    // SAFETY: verify that the injector is not inside the game directory
+    HMODULE kernel32 = GetModuleHandleA("kernel32.dll");
+    wgufn_t wine_get_unix_file_name = (wgufn_t)GetProcAddress(kernel32, "wine_get_unix_file_name");
+
+    if (wine_get_unix_file_name) {
+        wchar_t wInjectDll[MAX_PATH], wWorkdir[MAX_PATH];
+        MultiByteToWideChar(CP_UTF8, 0, injectDll, strlen(injectDll) + 1, wInjectDll, MAX_PATH);
+        MultiByteToWideChar(CP_UTF8, 0, workdir, strlen(workdir) + 1, wWorkdir, MAX_PATH);
+
+        char *unixInjectDll = wine_get_unix_file_name(wInjectDll);
+        char *unixWorkdir = wine_get_unix_file_name(wWorkdir);
+
+        char startsWith = 0;
+        while (*unixInjectDll != '\0' && *unixWorkdir != '\0') {
+            startsWith = *unixInjectDll == *unixWorkdir;
+            if (!startsWith) break;
+
+            unixInjectDll++, unixWorkdir++;
+        }
+
+        HANDLE heap = GetProcessHeap();
+        HeapFree(heap, 0, unixInjectDll);
+        HeapFree(heap, 0, unixWorkdir);
+
+        if (startsWith) {
+            MessageBoxA(NULL, "Putting the patcher (or any other foreign PE binaries) inside the game directory is dangerous! Please move it elsewhere.", J_MB_TITLE, MB_OK | MB_ICONERROR);
+            exit(1);
+        }
+    } else {
+        MessageBoxA(NULL, "Could not find wine_get_unix_file_name! Wine version too old?", J_MB_TITLE, MB_OK | MB_ICONWARNING);
+    }
+
     // Start the game
     STARTUPINFO si;
     ZeroMemory(&si, sizeof(si));
@@ -47,7 +83,7 @@ BOOL WINAPI DllMain(HINSTANCE inst, DWORD reason, LPVOID reserved) {
     )) {
         char message[64];
         sprintf(message, "Failed to start game process: %ld", GetLastError());
-        MessageBoxA(NULL, message, "Jadeite Launcher Payload", MB_OK | MB_ICONERROR);
+        MessageBoxA(NULL, message, J_MB_TITLE, MB_OK | MB_ICONERROR);
 
         exit(1);
     }
@@ -62,7 +98,7 @@ BOOL WINAPI DllMain(HINSTANCE inst, DWORD reason, LPVOID reserved) {
     if (waitEnabled && strcmp(waitEnabled, "") != 0) {
         char message[64];
         sprintf(message, "PID: %ld. Press OK to continue", pi.dwProcessId);
-        MessageBoxA(NULL, message, "Jadeite Launcher Payload", MB_OK | MB_ICONINFORMATION);
+        MessageBoxA(NULL, message, J_MB_TITLE, MB_OK | MB_ICONINFORMATION);
     }
 
     // Resume the process