c++ - SetWindowshookEx 有时在 dll 注入(inject)后不起作用

Question

我正在使用这个库 http://code.google.com/p/injex/注入(inject)一个包含键盘钩子(Hook)函数的dll。 dll 很简单，只需创建一个线程并使用“setWindowsHookEx”函数即可。

注入(inject)总是成功的，但键盘钩子(Hook)并不适用于所有情况。

1. 我编写了一个简单的“hello world”win32 应用程序，并使用 injex.exe 将键盘钩子(Hook) dll 注入(inject)其中。一切都按预期工作。

2. 如果选择复杂的程序注入(inject)(delphi写的游戏)，dll注入(inject)成功(可以看到注入(inject)的主窗体)，但是hook键盘失败。

所以我的问题是:

1. 键盘钩子(Hook)失效是注入(inject)方式的问题，还是键盘钩子(Hook)函数的问题？

2. 是否可以注入(inject)dll，但不能保证其功能？

所以欢迎任何建议。

这是dll代码:

// dllmain.cpp : Defines the entry point for the DLL application.
#include "stdafx.h"

#include <Windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <tchar.h>

//GUI==============================================================================
#define MYMENU_EXIT         (WM_APP + 101)
#define MYMENU_MESSAGEBOX   (WM_APP + 102) 

HINSTANCE  inj_hModule;          //Injected Modules Handle
HWND       prnt_hWnd;            //Parent Window Handle

//WndProc for the new window
LRESULT CALLBACK DLLWindowProc (HWND, UINT, WPARAM, LPARAM);

//Register our windows Class
BOOL RegisterDLLWindowClass(wchar_t szClassName[])
{
    WNDCLASSEX wc;
    wc.hInstance =  inj_hModule;
    wc.lpszClassName = (LPCWSTR)L"InjectedDLLWindowClass";
    wc.lpszClassName = (LPCWSTR)szClassName;
    wc.lpfnWndProc = DLLWindowProc;
    wc.style = CS_DBLCLKS;
    wc.cbSize = sizeof (WNDCLASSEX);
    wc.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wc.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor (NULL, IDC_ARROW);
    wc.lpszMenuName = NULL;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hbrBackground = (HBRUSH) COLOR_BACKGROUND;
    if (!RegisterClassEx (&wc))
        return 0;
}
//Creating our windows Menu
HMENU CreateDLLWindowMenu()
{
    HMENU hMenu;
    hMenu = CreateMenu();
    HMENU hMenuPopup;
    if(hMenu==NULL)
        return FALSE;
    hMenuPopup = CreatePopupMenu();
    AppendMenu (hMenuPopup, MF_STRING, MYMENU_EXIT, TEXT("Exit"));
    AppendMenu (hMenu, MF_POPUP, (UINT_PTR) hMenuPopup, TEXT("File")); 

    hMenuPopup = CreatePopupMenu();
    AppendMenu (hMenuPopup, MF_STRING,MYMENU_MESSAGEBOX, TEXT("MessageBox")); 
    AppendMenu (hMenu, MF_POPUP, (UINT_PTR) hMenuPopup, TEXT("Test")); 
    return hMenu;
}


//Our new windows proc
LRESULT CALLBACK DLLWindowProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
        case WM_KEYDOWN:
            if(wParam == VK_HOME) {
            //TextOut(hdc,15, 15, keydown, _tcslen(keydown));
            // etc.
                MessageBox(NULL, _T("Call to RegisterClassEx failed!"), _T("Win32 Guided Tour"), NULL);
            }
        break;
        case WM_COMMAND:
               switch(wParam)
               {
                    case MYMENU_EXIT:
                        SendMessage(hwnd, WM_CLOSE, 0, 0);
                        break;
                    case MYMENU_MESSAGEBOX:
                        MessageBox(hwnd, L"Test", L"MessageBox",MB_OK);
                        break;
               }
               break;
        case WM_DESTROY:
            PostQuitMessage (0);
            break;
        default:
            return DefWindowProc (hwnd, message, wParam, lParam);
    }
    return 0;
}

//HOOK LIB=====================================================================================================
// This will be called when keys are pressed.

HHOOK g_kbHook=NULL;

LRESULT CALLBACK KeyboardHook(int nCode,WPARAM wParam,LPARAM lParam)
{
    KBDLLHOOKSTRUCT* key;
    if(wParam == WM_KEYDOWN || wParam == WM_SYSKEYDOWN){
        key = (KBDLLHOOKSTRUCT*)lParam;
        if(key->vkCode == VkKeyScan('a')){
            //odprintf("You pressed 'a'");
            MessageBox(NULL, _T("Pressed a"), _T("Win32 Guided Tour"), NULL);
        }

        if(key->vkCode == VK_F1){
            MessageBox(NULL, _T("Pressed F1"), _T("Win32 Guided Tour"), NULL);
            //odprintf("You pressed F1");
        }
    }

    return 0;
}

LRESULT CALLBACK _KeyboardHookProc(int nCode,WPARAM wParam,LPARAM lParam){
    //g_kbHookFunction(nCode,wParam,lParam);
    KeyboardHook(nCode,wParam,lParam);
    return CallNextHookEx(g_kbHook,nCode,wParam,lParam);
};

//ENTRY POINT================================================================================================
//our start function, start everything here

DWORD WINAPI start(LPVOID lpParam){
    // START YOUR CODE HERE...

    // Lay some hooks, season libraly with pwnsauce.
    // Do whatever you want here, this is your thread to play with.
    // NOTE: This is used as the starting function in most examples.

    // STOP HERE.

    MSG messages;
    wchar_t *pString = reinterpret_cast<wchar_t * > (lpParam);
    HMENU hMenu = CreateDLLWindowMenu();
    RegisterDLLWindowClass(L"InjectedDLLWindowClass");
    prnt_hWnd = FindWindow(L"Window Injected Into ClassName", L"Window Injected Into Caption");
    HWND hwnd = CreateWindowEx (0, L"InjectedDLLWindowClass", L"mywindow", WS_EX_PALETTEWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 400, 300, prnt_hWnd, hMenu,inj_hModule, NULL );
    ShowWindow (hwnd, SW_SHOWNORMAL);

    g_kbHook = SetWindowsHookEx(WH_KEYBOARD_LL,_KeyboardHookProc,GetModuleHandle(NULL),0);
    if (!g_kbHook) {

    }

    while (GetMessage (&messages, NULL, 0, 0))
    {
        TranslateMessage(&messages);
        DispatchMessage(&messages);
    }
    return 1;
    g_kbHook = NULL;
}


BOOL APIENTRY DllMain( HMODULE hModule, DWORD  ul_reason_for_call, LPVOID lpReserved) {
    switch (ul_reason_for_call) {
        case DLL_PROCESS_ATTACH:
            // We create a new thread to do our bidding in, this way we don't hold the loader lock.
            // We close the handle to the thread for various reasons.
            inj_hModule = hModule;
            CloseHandle(CreateThread(NULL, 0, start, (LPVOID)hModule, 0, NULL));

        break;
        case DLL_THREAD_ATTACH:
        case DLL_THREAD_DETACH:
        case DLL_PROCESS_DETACH:
        break;
    }

    return TRUE;
}

Answer 1

如果您尝试 Hook 的进程已经安装了自己的键盘 Hook ，则该 Hook 可能不会调用 CallNextHookEx() 将消息传递给您的 Hook 。请参阅 MSDN 处的说明(注意返回值部分的解释)。如果这确实是您的问题的原因，您唯一的选择可能是在进程安装自己的 Hook 之前安装您的 Hook 。