[C ++挂钩winsock

Question

我正在尝试挂钩winsock send和recv以便读取进程的所有流量。我将以下代码作为dll注入目标进程中]

#include "dll.h"
#include <windows.h>
#include <winsock2.h>
#include <iostream>
#include <fstream>

#pragma comment(lib, "ws2_32.lib")

using namespace std;

DllClass::DllClass()
{

}


DllClass::~DllClass ()
{

}

BYTE hook[6];
BYTE hook2[6];
BYTE jmp[6] = { 0xe9,0x00, 0x00, 0x00, 0x00 ,0xc3 };  
ofstream myfile;
ofstream myfile2;

DWORD HookFunction(LPCSTR lpModule, LPCSTR lpFuncName, LPVOID lpFunction, unsigned char *lpBackup)
{  
      DWORD dwAddr = (DWORD)GetProcAddress(GetModuleHandle(lpModule), lpFuncName);
      ReadProcessMemory(GetCurrentProcess(), (LPVOID)dwAddr, lpBackup, 6, 0);
      DWORD dwCalc = ((DWORD)lpFunction - dwAddr - 5);
      memcpy(&jmp[1], &dwCalc, 4);
      WriteProcessMemory(GetCurrentProcess(), (LPVOID)dwAddr, jmp, 6, 0);
      return dwAddr;
}    

BOOL UnHookFunction(LPCSTR lpModule, LPCSTR lpFuncName, unsigned char *lpBackup)
{
DWORD dwAddr = (DWORD)GetProcAddress(GetModuleHandle(lpModule), lpFuncName);
if (WriteProcessMemory(GetCurrentProcess(), (LPVOID)dwAddr, lpBackup, 6, 0))
        return TRUE;
return FALSE;  
}

int nSend(SOCKET s, const char *buf, int len,int flags){
UnHookFunction("ws2_32.dll", "send", hook);


int result = send(s,buf,len,flags);


  myfile.open ("C:\\tmp\\log.txt",ios::app | ios::binary);
  myfile << buf;
  myfile.close();




HookFunction("ws2_32.dll", "send", (LPVOID*) nSend, hook);
return result;
} 

int nRecv(SOCKET s, char* buf, int len, int flags)
{
    UnHookFunction("ws2_32.dll", "recv", hook2);
    DWORD tmp;

    len = recv(s, buf, len, flags);

    if (len > 0)
    {

        myfile2.open ("C:\\tmp\\log.txt",ios::app | ios::binary);
        myfile2 << buf;
        myfile2.close();
    }
   HookFunction("ws2_32.dll", "recv", (LPVOID*) nRecv, hook2);
    return len;
}
void fun(){ // <-- this is called after the DLL has been injected
HookFunction("ws2_32.dll", "send", (LPVOID*) nSend, hook);
HookFunction("ws2_32.dll", "recv", (LPVOID*) nRecv, hook2);
}

BOOL APIENTRY DllMain(HMODULE hModule, DWORD ul_reason_for_call, LPVOID lpReserved)
{
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:

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

[在某些情况下有效，在某些情况下则无效。如果我将其注入到filezilla ftp中，它的工作原理就像一个超级按钮，并将发送或接收的所有内容写入文件。

但是在几乎所有其他程序上（Internet Explorer，firefoxusw。），它只是将一些字节写入文件，然后进程崩溃...

有人知道出了什么问题吗？

Answer 1

好即使启用了DataExecutionPrevention，它现在也可以工作。如果将来有人遇到类似的问题，请使用以下工作代码：

dllmain.cpp：

#include "dll.h"
#include <windows.h>
#include <winsock2.h>
#include <iostream>
#include <fstream>

#pragma comment(lib, "ws2_32.lib")

using namespace std;

DllClass::DllClass()
{

}


DllClass::~DllClass ()
{

}

BYTE hook[6];
BYTE hook2[6];
BYTE jmp[6] = { 0xe9,0x00, 0x00, 0x00, 0x00 ,0xc3 };  
ofstream myfile;
ofstream myfile2;
DWORD pPrevious;

DWORD HookFunction(LPCSTR lpModule, LPCSTR lpFuncName, LPVOID lpFunction, unsigned char *lpBackup)
{  
      DWORD dwAddr = (DWORD)GetProcAddress(GetModuleHandle(lpModule), lpFuncName);
      ReadProcessMemory(GetCurrentProcess(), (LPVOID)dwAddr, lpBackup, 6, 0);
      DWORD dwCalc = ((DWORD)lpFunction - dwAddr - 5);
      VirtualProtect((void*) dwAddr, 6, PAGE_EXECUTE_READWRITE, &pPrevious);
      memcpy(&jmp[1], &dwCalc, 4);
      WriteProcessMemory(GetCurrentProcess(), (LPVOID)dwAddr, jmp, 6, 0);
      VirtualProtect((void*) dwAddr, 6, pPrevious, &pPrevious);
      FlushInstructionCache(GetCurrentProcess(),0,0);
      return dwAddr;
}    

BOOL UnHookFunction(LPCSTR lpModule, LPCSTR lpFuncName, unsigned char *lpBackup)
{
DWORD dwAddr = (DWORD)GetProcAddress(GetModuleHandle(lpModule), lpFuncName);

if (WriteProcessMemory(GetCurrentProcess(), (LPVOID)dwAddr, lpBackup, 6, 0))
        return TRUE;
        FlushInstructionCache(GetCurrentProcess(),0,0);

return FALSE;  
}

int __stdcall nSend(SOCKET s, const char *buf, int len,int flags){
UnHookFunction("ws2_32.dll", "send", hook);


int result = send(s,buf,len,flags);


  myfile.open ("C:\\tmp\\log.txt",ios::app | ios::binary);
  myfile << buf;
  myfile.close();




HookFunction("ws2_32.dll", "send", (LPVOID*) nSend, hook);
return result;
} 

int __stdcall nRecv(SOCKET s, char* buf, int len, int flags)
{
    UnHookFunction("ws2_32.dll", "recv", hook2);
    DWORD tmp;

    len = recv(s, buf, len, flags);

    if (len > 0)
    {

        myfile2.open ("C:\\tmp\\log.txt",ios::app | ios::binary);
        myfile2 << buf;
        myfile2.close();
    }
   HookFunction("ws2_32.dll", "recv", (LPVOID*) nRecv, hook2);
    return len;
}
void fun(){
HookFunction("ws2_32.dll", "send", (LPVOID*) nSend, hook);
HookFunction("ws2_32.dll", "recv", (LPVOID*) nRecv, hook2);
}

BOOL APIENTRY DllMain(HMODULE hModule, DWORD ul_reason_for_call, LPVOID lpReserved)
{
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
HookFunction("ws2_32.dll", "send", (LPVOID*) nSend, hook);
HookFunction("ws2_32.dll", "recv", (LPVOID*) nRecv, hook2);
case DLL_THREAD_ATTACH:
case DLL_THREAD_DETACH:
case DLL_PROCESS_DETACH:
break;
}
return TRUE;
}

dll.h

#ifndef _DLL_H_
#define _DLL_H_

#if BUILDING_DLL
# define DLLIMPORT __declspec (dllexport)
#else /* Not BUILDING_DLL */
# define DLLIMPORT __declspec (dllimport)
#endif /* Not BUILDING_DLL */


class DLLIMPORT DllClass
{
  public:
    DllClass();
    virtual ~DllClass(void);

  private:

};
extern "C" __declspec(dllexport) void fun();

#endif /* _DLL_H_ */

[在Win XP 32bit上几乎所有程序以及在Win 7 x64上某些程序都经过测试并可以使用

Answer 2

请确保在挂钩函数上使用正确的调用约定。默认的调用约定通常是__cdecl。但是，“发送”和“接收”使用__stdcall（#define WINAPI __stdcall）

两者的主要区别是：

[当函数使用__cdecl时，调用者负责堆栈清理。但是，当一个函数使用__stdcall时，被调用函数负责堆栈清理。

int WINAPI nSend(SOCKET s, const char *buf, int len,int flags);
int WINAPI nRecv(SOCKET s, char* buf, int len, int flags)

请参阅here以获取更多信息。

Answer 3

多线程并发操作时会出现问题吗？