AnalogFeelings / HookPlusPlus

HookPlusPlus is a lightweight 2-file C++ library for hooking in Windows-based systems, licensed under GPL v3.0.

HookPlusPlus - Hooking made easy.

HookPlusPlus is a lightweight 2-file C++ library for hooking in Windows-based systems! No more looking around Google for any way to hook under both x86_64 and x86, because HookPlusPlus does both.

Important

Please read SECURITY.md before using.

Usage is very simple, and below you can find some example code.

Example

Say you have a DLL you want to attach whenever you want to debug something. In this case, here's the example code, with comments for your leisure.

#include "hookplusplus.h"

// Define hooks.
HookPlusPlus::Hook* MessageBoxHookW = NULL;
HookPlusPlus::Hook* MessageBoxHookA = NULL;

// REMEMBER! The impostor function's signature must match 1:1 the function you're trying to hook!
DWORD WINAPI HookedMessageBowW(HWND hWnd, LPCWSTR lpText, LPCWSTR lpCaption, UINT uType)
{
    // Unperform patch to be able to call the original function.
    MessageBoxHookW->UnperformPatch();

    DWORD returnCode = MessageBoxW(hWnd, L"Ah sorry mate, I just hooked this message box!\n- HookPlusPlus", L"Sorry!", uType);

    // Perform it again.
    MessageBoxHookW->PerformPatch();
    
    return returnCode;
}

// REMEMBER! The impostor function's signature must match 1:1 the function you're trying to hook!
DWORD WINAPI HookedMessageBowA(HWND hWnd, LPCSTR lpText, LPCSTR lpCaption, UINT uType)
{
    // Unperform patch to be able to call the original function.
    MessageBoxHookA->UnperformPatch();

    DWORD returnCode = MessageBoxA(hWnd, "Ah sorry mate, I just hooked this message box!\n- HookPlusPlus", "Sorry!", uType);

    // Perform it again.
    MessageBoxHookA->PerformPatch();

    return returnCode;
}

BOOL APIENTRY DllMain(HMODULE hModule, DWORD callReason, LPVOID lpReserved)
{
    switch (callReason)
    {
    case DLL_PROCESS_ATTACH:
        // Create the hooks.
        MessageBoxHookW = new HookPlusPlus::Hook("user32.dll", "MessageBoxW", &HookedMessageBowW);
        MessageBoxHookA = new HookPlusPlus::Hook("user32.dll", "MessageBoxA", &HookedMessageBowA);

        // Perform the patches.
        MessageBoxHookW->PerformPatch();
        MessageBoxHookA->PerformPatch();

        break;
    case DLL_PROCESS_DETACH:
        // Remember: deleting hooks automatically unperforms patches.
        delete MessageBoxHookW;
        delete MessageBoxHookA;

        break;
    }

    return TRUE;
}