c++ - 如何在注入(inject)的dll中调用函数

Question

我正在尝试使用注入(inject)的 dll 从另一个进程获取键盘消息，但我不知道在我自己的程序中必须在哪里调用函数。这是我注入(inject)的 dll 函数:

//this is my dll main function  
BOOL APIENTRY DllMain(HANDLE hModule,DWORD  ul_reason_for_call,LPVOID   lpReserved)
      {
        /* open file */
        FILE *file;
        fopen_s(&file, "d:\\dll\\temp.txt", "a+");

        switch (ul_reason_for_call) {
        case DLL_PROCESS_ATTACH:
            hInst = (HINSTANCE)hModule;
// should be function calling be here????
            installhook(); 
            break;
        case DLL_PROCESS_DETACH:
            fprintf(file, "DLL detach function called.\n");
            break;
        case DLL_THREAD_ATTACH:
            fprintf(file, "DLL thread attach function called.\n");
            break;
        case DLL_THREAD_DETACH:
            fprintf(file, "DLL thread detach function called.\n");
            break;
        }
        hInst = (HINSTANCE)hModule;
        /* close file */
        fclose(file);
        return TRUE;
    }

这是我安装 keyboardproc 来处理的安装 Hook 函数

   BOOL __declspec(dllexport)__stdcall installhook()
        {
            HWND targetWnd;
            HANDLE hProcess;
            unsigned long processID = 0;
            hkb = SetWindowsHookEx(WH_KEYBOARD, (HOOKPROC)KeyboardProc, hInst, GetCurrentThreadId());
            return TRUE;
        }

这是我的 keyboardproc 函数体

LRESULT __declspec(dllexport)__stdcall  CALLBACK KeyboardProc(int nCode, WPARAM wParam, LPARAM lParam)
{
    char ch;
    MessageBoxA(nullptr, "key touched\n", "DLL_PROCESS_ATTACH", MB_OK | MB_ICONWARNING);
    do
    {
        if (((DWORD)lParam & 0x40000000) && (HC_ACTION == nCode))
        {
            if ((wParam == VK_SPACE) || (wParam == VK_RETURN) || (wParam >= 0x2f) && (wParam <= 0x100))
            {
                FILE *file;
                fopen_s(&file, "d:\\dll\\temp.txt", "a+");
                fprintf(file, nCode + ".\n");
            }
        }
    } while (0);
    return CallNextHookEx(hkb, nCode, wParam, lParam);
}

最后这是我的主程序，我将 dll 注入(inject)目标进程

int procID = 9448;
    HANDLE process = OpenProcess(PROCESS_ALL_ACCESS, FALSE, procID);
    if (process == NULL) {
        printf("Error: the specified process couldn't be found.\n");
    }

    /*
    * Get address of the LoadLibrary function.
    */
    LPVOID addr = (LPVOID)GetProcAddress(GetModuleHandle(L"kernel32.dll"), "LoadLibraryA");
    if (addr == NULL) {
        printf("Error: the LoadLibraryA function was not found inside kernel32.dll library.\n");
    }

    /*
    * Allocate new memory region inside the process's address space.
    */
    LPVOID arg = (LPVOID)VirtualAllocEx(process, NULL, strlen(buffer), MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
    if (arg == NULL) {
        printf("Error: the memory could not be allocated inside the chosen process.\n");
    }

    /*
    * Write the argument to LoadLibraryA to the process's newly allocated memory region.
    */
    int n = WriteProcessMemory(process, arg, buffer, strlen(buffer), NULL);
    if (n == 0) {
        printf("Error: there was no bytes written to the process's address space.\n");
    }

    cout << procID << "\nhandle:" << process << "\nAddress:" << addr << "\nVirtualArg:" << arg << "\nWM:"<<n<<"\n";


    /*
    * Inject our DLL into the process's address space.
    */
    HANDLE threadID = CreateRemoteThread(process, NULL, 0, (LPTHREAD_START_ROUTINE)addr, arg, NULL, NULL);
    if (threadID == NULL) {
        printf("Error: the remote thread could not be created.\n");
    }
    else {
        printf("Success: the remote thread was successfully created.\n");
    }

    /*
    * Close the handle to the process, becuase we've already injected the DLL.
    */
    CloseHandle(process);

我的代码有什么问题，必须更改哪里才能获得预期的结果!

Answer 1

是的，它可以从 DLL_PROCESS_ATTACH 调用。但是根据msdn

hMod [in] Type: HINSTANCE A handle to the DLL containing the hook procedure pointed to by the lpfn parameter. The hMod parameter must be set to NULL if the dwThreadId parameter specifies a thread created by the current process and if the hook procedure is within the code associated with the current process.

所以把hMod改成NULL

hkb = SetWindowsHookEx(WH_KEYBOARD, (HOOKPROC)KeyboardProc, NULL, GetCurrentThreadId());