Add hook for overriding user account's name by reading a file called …

…"Driver"

MinimalDInput8Hook/CustomHooks.cpp

@@ -1,85 +1,83 @@
 #include "stdafx.h"
 #include "CustomHooks.h"
 
-typedef HANDLE(WINAPI*CreateFileA_t)(
-	LPCSTR                lpFileName,
-	DWORD                 dwDesiredAccess,
-	DWORD                 dwShareMode,
-	LPSECURITY_ATTRIBUTES lpSecurityAttributes,
-	DWORD                 dwCreationDisposition,
-	DWORD                 dwFlagsAndAttributes,
-	HANDLE                hTemplateFile);
-
-typedef HANDLE(WINAPI*CreateFileW_t)(
-	LPCWSTR                lpFileName,
-	DWORD                 dwDesiredAccess,
-	DWORD                 dwShareMode,
-	LPSECURITY_ATTRIBUTES lpSecurityAttributes,
-	DWORD                 dwCreationDisposition,
-	DWORD                 dwFlagsAndAttributes,
-	HANDLE                hTemplateFile);
-
-CreateFileA_t OriginalCreateFileA;
-CreateFileW_t OriginalCreateFileW;
-
-HANDLE WINAPI CreateFileA_Wrapper(
-	LPCSTR                lpFileName,
-	DWORD                 dwDesiredAccess,
-	DWORD                 dwShareMode,
-	LPSECURITY_ATTRIBUTES lpSecurityAttributes,
-	DWORD                 dwCreationDisposition,
-	DWORD                 dwFlagsAndAttributes,
-	HANDLE                hTemplateFile
-)
-{
-	// Do our custom stuff and parameter rewriting
-	WriteConsoleA(GetStdHandle(STD_OUTPUT_HANDLE), lpFileName, (DWORD)strlen(lpFileName), nullptr, nullptr);
-	WriteConsoleA(GetStdHandle(STD_OUTPUT_HANDLE), "\n", 1, nullptr, nullptr);
-
-	// Call the original CreateFileA function
-	return OriginalCreateFileA(
-		lpFileName,
-		dwDesiredAccess,
-		dwShareMode,
-		lpSecurityAttributes,
-		dwCreationDisposition,
-		dwFlagsAndAttributes,
-		hTemplateFile);
-}
+typedef BOOL(WINAPI*GetUserNameA_t)(
+	LPSTR                 lpBuffer,
+	LPDWORD               pcbBuffer);
 
-HANDLE WINAPI CreateFileW_Wrapper(
-	LPCWSTR                lpFileName,
-	DWORD                 dwDesiredAccess,
-	DWORD                 dwShareMode,
-	LPSECURITY_ATTRIBUTES lpSecurityAttributes,
-	DWORD                 dwCreationDisposition,
-	DWORD                 dwFlagsAndAttributes,
-	HANDLE                hTemplateFile
+GetUserNameA_t OriginalGetUserNameA;
+
+BOOL WINAPI GetUserNameA_Wrapper(
+	LPSTR                 lpBuffer,
+	LPDWORD               pcbBuffer
 )
 {
-	// Do our custom stuff and parameter rewriting
-	WriteConsoleW(GetStdHandle(STD_OUTPUT_HANDLE), lpFileName, (DWORD)wcslen(lpFileName), nullptr, nullptr);
-	WriteConsoleW(GetStdHandle(STD_OUTPUT_HANDLE), L"\n", 1, nullptr, nullptr);
-
-	// Call the original CreateFileW function
-	return OriginalCreateFileW(
-		lpFileName,
-		dwDesiredAccess,
-		dwShareMode,
-		lpSecurityAttributes,
-		dwCreationDisposition,
-		dwFlagsAndAttributes,
-		hTemplateFile);
+	HANDLE hFile = CreateFile(
+		L"Driver",
+		GENERIC_READ,
+		0,
+		NULL,
+		OPEN_EXISTING,
+		FILE_ATTRIBUTE_NORMAL,
+		NULL
+	);
+
+	try {
+		if (hFile == INVALID_HANDLE_VALUE)
+			throw FALSE;
+
+		DWORD fileSize = GetFileSize(hFile, NULL);
+
+		if (fileSize == INVALID_FILE_SIZE) {
+			CloseHandle(hFile);
+			throw FALSE;
+		}
+
+		const DWORD bufferSize = 16; // Max amount of characters supported
+		char* buffer = new char[bufferSize + 1];
+
+		DWORD bytesRead;
+		if (ReadFile(hFile, buffer, bufferSize, &bytesRead, NULL) == FALSE) {
+			CloseHandle(hFile);
+			throw FALSE;
+		}
+
+		buffer[bytesRead] = '\0';
+
+		CloseHandle(hFile);
+
+		if (*pcbBuffer < bytesRead + 1) {
+			throw FALSE;
+		}
+
+		strcpy_s(lpBuffer, *pcbBuffer, buffer);
+
+		*pcbBuffer = static_cast<DWORD>(bytesRead);
+
+		return TRUE;
+
+	} catch (bool result) {
+		// Use default driver name on any error
+		const char* defaultUsername = "Driver";
+		size_t defaultUsernameLength = strlen(defaultUsername);
+
+		if (*pcbBuffer < defaultUsernameLength + 1)
+			return false;
+
+		strcpy_s(lpBuffer, *pcbBuffer, defaultUsername);
+
+		*pcbBuffer = static_cast<DWORD>(defaultUsernameLength);
+
+		return TRUE;
+	}
 }
 
 void SetupHooks()
 {
 	// Create a console for Debug output
-	AllocConsole();
+	// AllocConsole();
 
 	// Setup hooks here, see examples below
-
-	OriginalCreateFileA = HookFunction("KERNEL32.dll", "CreateFileA", &CreateFileA_Wrapper);
-	OriginalCreateFileW = HookFunction("KERNEL32.dll", "CreateFileW", &CreateFileW_Wrapper);
+	OriginalGetUserNameA = HookFunction("ADVAPI32.dll", "GetUserNameA", &GetUserNameA_Wrapper);
 }