11.网络游戏逆向分析与漏洞攻防-游戏网络架构逆向分析-接管游戏接收网络数据包的操作

内容参考于：易道云信息技术研究院VIP课

上一个内容：接管游戏发送数据的操作

 码云地址（master 分支）：https://gitee.com/dye_your_fingers/titan

码云版本号：8256eb53e8c16281bc1a29cb8d26d352bb5bbf4c

代码下载地址，在 titan 目录下，文件名为：titan-接管游戏接收网络数据包的操作.zip

链接：https://pan.baidu.com/s/1W-JpUcGOWbSJmMdmtMzYZg

提取码：q9n5

--来自百度网盘超级会员V4的分享

HOOK引擎，文件名为：黑兔sdk升级版.zip

链接：https://pan.baidu.com/s/1IB-Zs6hi3yU8LC2f-8hIEw

提取码：78h8

--来自百度网盘超级会员V4的分享

以 接管游戏发送数据的操作 它的代码为基础进行修改

通过 通过逆向分析确定游戏明文接收数据过程 分析得到 0x10617FD7 位置是调用recv函数之后接收到数据处理一个数据包的函数位置，它调用的函数不是虚函数表里的函数了，而是一个普通的函数，如下图红框位置，它调用的是0x10618480（0x10618480是函数地址）函数

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然后这个函数不知道是由于编译器优化还是什么原因，它是用eax传递的连接对象，但它本质上还是thiscall（一个类调用它的成员函数就是thiscall，Visual Studio里c++里的this就是取ecx寄存器里的值），所以调用的时候要特殊处理（因为类调用成员函数用的是ecx）

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用游戏生成一个接收到的数据包，这里的数据包时聊天数据的数据包，用于模拟服务器欺骗客户端

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游戏种发送的聊天数据：

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修改一下数据包：原本时0x31现在改成0x32

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效果图：成功欺骗了客户端，让客户端接收了伪造的数据

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GameProc.cpp文件的修改：修改了 InitInterface函数，新加 _OnRecv函数

#include "pch.h"
#include "GameProc.h"
#include "extern_all.h"// typedef bool(GameWinSock::* U)(char*, unsigned);bool _OnRecv(HOOKREFS2) {unsigned* _esp = (unsigned*)_ESP;_EAX = WinSock->RecvPoint;WinSock->OnRecving((char*)_esp[2], _esp[1]);return true;
}bool _OnConnect(HOOKREFS2) {/*根据虚函数表做HOOK的操作截取 ecx 获取 winsock 的值(指针)*/unsigned* vtable = (unsigned*)_EDX;//WinSock = (GameWinSock *)_ECX;/*联合体的特点是共用一个内存由于 GameWinSock::OnConnect 的 OnConnect函数是 GameWinSock类的成员函数直接 vtable[0x34 / 4] = (unsigned)&GameWinSock::OnConnect; 这样写语法不通过所以使用联合体，让语法通过*/union {unsigned value;bool(GameWinSock::* _proc)(char*, unsigned);} vproc;DWORD oldPro, backProc;VirtualProtect(vtable, 0x100, PAGE_EXECUTE_READWRITE, &oldPro);/*vproc._proc = &GameWinSock::OnConnect;  这一句是把我们自己写的调用connect函数的地址的出来*/ vproc._proc = &GameWinSock::OnConnect; /*InitClassProc函数里做的是给指针赋值的操作InitClassProc(&GameWinSock::_OnConnect, vtable[0x34/4]);这一句的意思是把GameWinSock类里的_OnConnect变量的值赋值成vtable[0x34/4]，这个 vtable[0x34/4] 是虚表里的函数vtable[0x34/4]是游戏中调用connect函数的函数地址，经过之前的分析调用connect是先调用了虚表中的一个函数，然后从这个函数中调用了connect函数*/InitClassProc(&GameWinSock::_OnConnect, vtable[0x34/4]);vtable[0x34 / 4] = vproc.value;vproc._proc = &GameWinSock::OnSend;InitClassProc(&GameWinSock::_OnSend, vtable[0x3C / 4]);vtable[0x3C / 4] = vproc.value;VirtualProtect(vtable, 0x100, oldPro, &backProc);return true;
}GameProc::GameProc()
{hooker = new htd::hook::htdHook2();Init();InitInterface();
}void GameProc::LoadBase()
{LoadLibraryA("fxnet2.dll");
}void GameProc::Init()
{
}void GameProc::InitInterface()
{LoadBase();// MessageBoxA(0, "1", "1", MB_OK);// 只会HOOK一次，一次性的HOOKhooker->SetHook((LPVOID)0x10617046, 0x1, _OnConnect, 0, true);/*第一个参数是HOOK的位置第二个参数是HOOK的位置的汇编代码的长度（用于保证执行的汇编代码完整）第三个参数是HOOK之后当游戏执行到第一个参数的位置的时候跳转的位置*/hooker->SetHook((LPVOID)0x10618480, 0x1, _OnRecv);/*在这里绑定游戏处理数据包函数（0x10618480函数）然后0x10618480函数在上面一行代码已经进行了HOOK所以在调用_OnRecv函数指针时，它就会进入我们HOOK*/InitClassProc(&GameWinSock::_OnRecv, 0x10618480);
}

GameWinSock.h文件的修改：新加 _OnRecv函数指针变量，OnRecving函数、OnRecv函数、vatble变量、un变量、RecvPoint变量

#pragma once
class GameWinSock
{typedef bool(GameWinSock::* PROC)(char*, unsigned);
public:unsigned* vatble;// 虚函数表unsigned un[17];unsigned RecvPoint; // 游戏recv之后调用处理一个数据包函数时的eax，这里偏移是0x48
public:static PROC _OnConnect;static PROC _OnSend;static PROC _OnRecv;bool OnConnect(char* ip, unsigned port);bool OnSend(char* buff, unsigned len);bool OnRecving(char* buff, unsigned len);bool OnRecv(char* buff, unsigned len);
};

GameWinSock.cpp文件的修改：新加 _OnRecv函数指针变量，OnRecving函数、OnRecv函数、vatble变量、un变量、RecvPoint变量

#include "pch.h"
#include "GameWinSock.h"
#include "extern_all.h"GameWinSock::PROC GameWinSock::_OnConnect{};
GameWinSock::PROC GameWinSock::_OnSend{};
GameWinSock::PROC GameWinSock::_OnRecv{};
// 这个函数拦截了游戏的连接
bool GameWinSock::OnConnect(char* ip, unsigned port)
{// this是ecx，HOOK的点已经有ecx了WinSock = this;bool b = (this->*_OnConnect)(ip, port);// 下方注释的代码时为了防止多次注入，导致虚函数地址不恢复问题导致死循环，通过一次性HOOK也能解决/*unsigned* vtable = (unsigned*)this;vtable = (unsigned*)vtable[0];union {unsigned value;bool(GameWinSock::* _proc)(char*, unsigned);} vproc;vproc._proc = _OnConnect;DWORD oldPro, backProc;VirtualProtect(vtable, 0x10x00, PAGE_EXECUTE_READWRITE, &oldPro);vtable[0x34 / 4] = vproc.value;VirtualProtect(vtable, 0x10x00, oldPro, &backProc);*/return b;
}bool GameWinSock::OnSend(char* buff, unsigned len)
{/*这里就可以监控游戏发送的数据了*/return (this->*_OnSend)(buff, len);
}bool GameWinSock::OnRecving(char* buff, unsigned len)
{// MessageBoxA(0, "11111111111111", "0", MB_OK);/*监控游戏接收的数据包*/return true;
}bool GameWinSock::OnRecv(char* buff, unsigned len)
{//AfxMessageBox(L"%s", buff);return (this->*_OnRecv)(buff, len);
}

CUIWnd_0.cpp文件的修改：修改了 OnBnClickedButton1函数（按钮点击事件处理函数）

// CUIWnd_0.cpp: 实现文件
//#include "pch.h"
#include "htdMfcDll.h"
#include "CUIWnd_0.h"
#include "afxdialogex.h"
#include "extern_all.h"// CUIWnd_0 对话框IMPLEMENT_DYNAMIC(CUIWnd_0, CDialogEx)CUIWnd_0::CUIWnd_0(CWnd* pParent /*=nullptr*/): CDialogEx(IDD_PAGE_0, pParent)
{}CUIWnd_0::~CUIWnd_0()
{
}void CUIWnd_0::DoDataExchange(CDataExchange* pDX)
{CDialogEx::DoDataExchange(pDX);
}BEGIN_MESSAGE_MAP(CUIWnd_0, CDialogEx)ON_BN_CLICKED(IDC_BUTTON1, &CUIWnd_0::OnBnClickedButton1)
END_MESSAGE_MAP()// CUIWnd_0 消息处理程序void CUIWnd_0::OnBnClickedButton1()
{/*char buff[] = {0xA, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,0x00, 0x00, 0x00, 0x00, 0x00, 0x4, 0x00, 0x02, 0x01, 0x00, 0x00, 0x00, 0x02, 0x01, 00 ,0x00,0x00, 0x07, 0x0E, 0x00, 0x00, 0x00, 0x31, 0x00, 0x32, 0x00, 0x33, 0x00, 0x31, 0x00, 0x32 ,0x00,0x33, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};WinSock->OnSend(buff, sizeof(buff));*/char buff[] = {0x27, 0x46, 0x92, 0x02, 0x00, 0x00, 0x89, 0x02, 0x00, 0x00, 0x06, 0x00, 0x06, 0x05, 0x00, 0x00, 0x00, 0x63, 0x68, 0x61, 0x74, 0x00, 0x02, 0x01, 0x00, 0x00, 0x00, 0x07, 0x0A, 0x00, 0x00, 0x00, 0x34, 0x00, 0x33, 0x00, 0x39, 0x00, 0x39, 0x00, 0x00, 0x00, 0x07, 0x5A, 0x02, 0x00, 0x00, 0x31, 0x00, 0x32, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x31, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x32, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33,0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x33, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x35, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x34, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36,0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x36, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x37, 0x00, 0x38, 0x00, 0x00, 0x00, 0x02, 0x01, 0x00, 0x00, 0x00, 0x02, 0x01, 0x00, 0x00, 0x00};WinSock->OnRecv(buff, sizeof(buff));
}

 

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