阻止SPY++类似的程序捕捉软件窗口

我以前用Spy++能轻易捕捉360软件界面,除了一些应用DHTML制作的窗体.昨天我再用Spy++捕捉的时候捕捉不到了,甚至连最外围的对话框都捕捉不到,显然是做了类似拦截API的处理.下面我也模拟一下这种效果,让自己的程序窗口不能被捕捉.
Spy++之类的程序一般通过API函数WindowFromPoint和ChildWindowFromPoint来获取指定位置的窗口句柄。拦截一下WindowFromPoint函数,如果捕捉到的是自己程序的窗口,而且实施捕捉的进程不是自己程序的进程,那就直接返回NULL(这样自己的程序捕捉自己的窗口就不会受影响).拦截API我直接用微软的Detour库,使用起来方便.
由于是拦截所有进程地址空间的WindowFromPoint函数,我借助于全局WH_SHELL钩子，因此拦截操作放在一单独的DLL项目中.先封装一下Detour操作CInterceptSpyFun类:
////////////////////h文件///////////////////////////

class CInterceptSpyFun
{
private:
//是否已经拦截
BOOL  m_bIntercepted;

public:
//保存要屏蔽WindowFromPoint函数的进程ID
static  DWORD  m_dwValidProcessID;

public:
CInterceptSpyFun( );
~CInterceptSpyFun( );

BOOL  IsIntercepted()
{
return this->m_bIntercepted;
}

/*
* 拦截操作
* dwValidProcessID: 待屏蔽WindowFromPoint函数的进程ID
* 返回拦截成功与否
*/
BOOL  Intercept( DWORD dwValidProcessID  );

/*
* 取消拦截,还原成原先的操作
*/
void    UnIntercept();
};

///////////////////////////cpp////////////////////////////

DWORD  CInterceptSpyFun::m_dwValidProcessID   =  0;

//让Real_WindowFromPoint指针指向实际上的WindowFromPoint函数地址
DETOUR_TRAMPOLINE( HWND WINAPI Real_WindowFromPoint( POINT pt ), WindowFromPoint );

/*
* 自定义WindowFromPoint函数的处理
*/
HWND WINAPI Mine_WindowFromPoint( POINT pt )
{
//调用实际上的WindowFromPoint函数,取得窗口句柄
HWND  hWnd =  Real_WindowFromPoint( pt );

//获取窗口所属的进程ID
DWORD  dwProcessID(0);
::GetWindowThreadProcessId( hWnd, &dwProcessID );

if( ( CInterceptSpyFun::m_dwValidProcessID == dwProcessID ) && ( ::GetCurrentProcessId() != CInterceptSpyFun::m_dwValidProcessID ) )
{    //如果窗口属于指定的进程并且是被不是指定进程的其他进程调用WindowFromPoint访问时,返回NULL
return NULL;
}

return hWnd;
}

CInterceptSpyFun::CInterceptSpyFun( )
{
m_bIntercepted  =  FALSE;
}

CInterceptSpyFun::~CInterceptSpyFun( )
{
}

BOOL  CInterceptSpyFun::Intercept( DWORD dwValidProcessID )
{
CInterceptSpyFun::m_dwValidProcessID   =  dwValidProcessID;
//Detour库拦截处理
m_bIntercepted  =  DetourFunctionWithTrampoline( (PBYTE)Real_WindowFromPoint,  (PBYTE)Mine_WindowFromPoint );
return m_bIntercepted;
}

void    CInterceptSpyFun::UnIntercept()
{
if( m_bIntercepted )
{
//取消拦截
DetourRemove( (PBYTE)Real_WindowFromPoint,(PBYTE)Mine_WindowFromPoint );
m_bIntercepted  =  FALSE;
}
}

dwValidProcessID(要拦截WindowFromPoint函数的进程ID)需要在LoadLibrary之后,安装钩子之前传递,并且需要保存到共享节中以达到在所有的进程中数据共享的目的.
#pragma data_seg(".unspy")
HHOOK hHook = NULL;
DWORD dwValidProcessID = 0;
#pragma data_seg()
#pragma comment(linker,"/section:.unspy,rws")

HOOK句柄和dwValidProcessID 都保存到共享节”.unspy”中。

设置dwValidProcessID 的导出函数：
extern"C" __declspec( dllexport ) void SetValidProcessID( DWORD dwProcessID )
{
dwValidProcessID = dwProcessID;
}

声明拦截类的全局变量:
CInterceptSpyFun interceptSpy;
HMODULE hDllModule = NULL; //保存DLL模块句柄

SHELL钩子处理:

LRESULT CALLBACK CustomShellProc (int nCode, WPARAM wParam, LPARAM lParam)
{
if( !interceptSpy.IsIntercepted() )
{  //拦截API
interceptSpy.Intercept( dwValidProcessID );
}

return ::CallNextHookEx( hHook, nCode, wParam, lParam );
}

extern"C" __declspec( dllexport ) void InstallHook( )
{
hHook = ::SetWindowsHookEx( WH_SHELL , CustomShellProc ,(HINSTANCE)hDllModule, 0 );
}

extern"C" __declspec( dllexport ) void UninstallHook()
{
if( hHook != NULL )
{
::UnhookWindowsHookEx( hHook );
}
hHook = NULL;
}

取消拦截操作应在卸载DLL的时候:

BOOL APIENTRY DllMain( HMODULE hModule,  DWORD  ul_reason_for_call,   LPVOID lpReserved  )
{
hDllModule   =   hModule;
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
break;
case DLL_THREAD_ATTACH:
break;
case DLL_THREAD_DETACH:
break;
case DLL_PROCESS_DETACH:
{
interceptSpy.UnIntercept();
}
break;
}

return TRUE;
}

至此,DLL部分已经完成.在需要屏蔽WindowFromPoint函数的程序中需加载该DLL,调用DLL的SetValidProcessID,将当前的进程ID传入,随后安装钩子:

m_hInstance  = ::LoadLibrary(_T("AvoidSpyLib.dll"));
if ( m_hInstance == NULL )
{
::MessageBox(NULL,_T("LoadLibrary Failed"),_T(""),MB_OK);
}

if( m_hInstance == NULL )
return 0;

typedef void (*PSetValidProcessID)( DWORD  dwProcessID );
PSetValidProcessID pSetFunc;
pSetFunc = (PSetValidProcessID)::GetProcAddress( m_hInstance , "SetValidProcessID");
if ( pSetFunc != NULL )
{
(*pSetFunc)( ::GetCurrentProcessId() );
}

typedef void (*PInstallHook)( );
PInstallHook pInstallFunc;
pInstallFunc = (PInstallHook)::GetProcAddress( m_hInstance , "InstallHook");
if ( pInstallFunc != NULL )
{
(*pInstallFunc)();
}
//卸载钩子
if( m_hInstance != NULL )
{
typedef void (*PUninstallHook)( );
PUninstallHook pFunc;
pFunc = (PUninstallHook)::GetProcAddress( m_hInstance , "UninstallHook");
if ( pFunc != NULL )
{
(*pFunc)();
}

::FreeLibrary( m_hInstance );
}

全部完工,运行了一下,呵呵,和360软件的效果一样,Spy++再也捕捉不到界面的任何东西了.