逆向 | 通过inlinehook opengl实现cs1.6透视

之前一直想弄没弄的，今天给弄了。
inlinehook的原理与上一篇文章基本相同。https://www.cnblogs.com/Mz1-rc/p/16586411.html

cs1.6可以是对d3d可以是opengl，先调成opengl，然后开始下面的操作。
主要就是hook glBegin这个函数，然后判断一下mode，对实体强行渲染一下，就可以了。

被注入的dll代码如下：

// inject_dll.cpp : Defines the entry point for the DLL application.
//

#include "stdafx.h"
#include <stdio.h>
#include <gl/glut.h>


DWORD g_dwOldAddr;         // 原始函数地址
DWORD g_dwNewAddr;         // Hook函数地址
DWORD g_dwHookFlag;     // 标志有没有被hook


#define PATCH_LENGTH 5

DWORD dwRetAddress;
BOOL setInlineHook(DWORD dwOldAddr, DWORD dwNewAddr){
	BOOL bRet = FALSE;
	dwRetAddress = dwOldAddr + PATCH_LENGTH;       // hook结束以后的返回地址
	BYTE byJmpCode[PATCH_LENGTH] = {0xe9};
	DWORD dwOldProtect;
	
	// 之前的字节码
	static BYTE byOriginalCode[PATCH_LENGTH] = {0};
	static BOOL bHookFlag = FALSE;

	// 测试用
	char buf[1024] = {0};

	
	// 1. 初始化byJmpCode
	memset(&byJmpCode[1], 0x90, PATCH_LENGTH-1);
	
	// 2. 存储跳转地址
	*(DWORD*)&byJmpCode[1] = (DWORD)dwNewAddr - (DWORD)dwOldAddr - 5;
	
	// 3. 备份被覆盖的code
	memcpy(byOriginalCode, (LPVOID)dwOldAddr, PATCH_LENGTH);
	

	// 4. 开始patch
	if (!bHookFlag)
	{
		// hook
		VirtualProtect((LPVOID)dwOldAddr,
			PATCH_LENGTH, PAGE_EXECUTE_READWRITE, &dwOldProtect);     // 这个是成功执行的

		// 好了它又没问题了，不知道咋回事之前会崩溃
		memcpy((LPVOID)dwOldAddr, byJmpCode, PATCH_LENGTH);     // 这里拷贝的时候有问题，会出现不可写的问题

		
		VirtualProtect((LPVOID)dwOldAddr, PATCH_LENGTH, dwOldProtect, 0);
		bHookFlag = TRUE;
		bRet = TRUE;
	}else{
		// 取消hook
		VirtualProtect((LPVOID)dwOldAddr,
			PATCH_LENGTH, PAGE_EXECUTE_READWRITE, &dwOldProtect);
		memcpy((LPVOID)dwOldAddr, byOriginalCode, PATCH_LENGTH);
		VirtualProtect((LPVOID)dwOldAddr, PATCH_LENGTH, dwOldProtect, 0);
		bHookFlag = FALSE;
		bRet = TRUE;
	}

	return bRet;
}

char szNewText[] = "Hook!";
void __declspec(naked) MyglBegin(GLenum mode){
	// GL_TRIANGLE_STRIP 0x0005
	// GL_TRIANGLE_FAN 0x0006
	__asm{
		// 1. 保存寄存器
		pushad;
		pushfd;
		// 2. 修改数据
		
		// 判断mode 原[esp+8] 现在的[esp+32+4+4]
		mov eax, dword ptr [esp+32+4+4];   // eax=mode
		cmp eax, 5;
		jz disable;
		cmp eax, 6;
		jz disable;
		jmp back_to_func;
	}
disable:
	// 调用glDisable
	glDisable(GL_DEPTH_TEST);
	__asm{

back_to_func:
		// 3. 恢复寄存器
		popfd;
		popad;
		// 4. 执行覆盖的代码
		mov edi, edi;
		push ebp;
		mov ebp, esp;
		// 5. 返回执行
		jmp dwRetAddress;
	}
}


/*
void WINAPI MyglBegin(GLenum mode)
{
	MessageBox(0,"获取到调用",0,0);
	if(mode==GL_TRIANGLE_STRIP||mode==GL_TRIANGLE_FAN)
	{
		glDisable(GL_DEPTH_TEST);
		MessageBox(0,"获取到调用",0,0);
	} 
	
	glBegin(mode);
}
*/


// 线程函数
DWORD WINAPI ThreadProc(LPVOID lpParameter){
	// 保存原始函数地址
	DWORD pOldFuncAddr = (DWORD)GetProcAddress(LoadLibrary("opengl32.dll"), "glBegin");
	//DWORD pOldFuncAddr = (DWORD)GetProcAddress(LoadLibrary("user32.dll"), "MessageBoxA");
	char buf[1024] = {0};
	sprintf(buf, "获取到函数地址：%p ", pOldFuncAddr);
	MessageBox(0, buf, 0, 0);
	
	// 安装或者卸载HOOK
	BOOL ret;
	if (!g_dwHookFlag){
		ret = setInlineHook(pOldFuncAddr, (DWORD)MyglBegin);
		if (ret){
			MessageBox(0, "安装hook成功！", 0, 0);
		}else{
			MessageBox(0, "安装hook失败！", 0, 0);
		}
		
	}

	return 0;
}




BOOL APIENTRY DllMain( HANDLE hModule, 
                       DWORD  ul_reason_for_call, 
                       LPVOID lpReserved
					 )
{
	switch ( ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
        CreateThread(NULL,0,
            (LPTHREAD_START_ROUTINE)ThreadProc,
            NULL, 0,NULL);//创建新线程执行代码
        break;
    case DLL_PROCESS_DETACH:
        break;
    case DLL_THREAD_ATTACH:
        break;
    case DLL_THREAD_DETACH:
        break;
	}
    return TRUE;
}