如何判断串口是否被监控

Question

我做了一个小程序，向串口发送数据，如何才能判断我要发送数据的串口有没有被拦截，主要是不想让别人看见我发的数据，前问如何判断电脑上是否开了串口拦截软件？

Answer 1

下面是 hook comm的 例子/*
first call: "\\.\COM1 CreateFileW"
then  call: "\\.\COM1 CreateFileA"
*/ 
HANDLE WINAPI myCreateFileA(LPCSTR lpFileName, DWORD dwDesiredAccess, DWORD dwShareMode, 
 LPSECURITY_ATTRIBUTES lpSecurityAttributes, DWORD dwCreationDisposition,
 DWORD dwFlagsAndAttributes, HANDLE hTemplateFile)
{// unhook first          
g_HookApi.UnhookOneApi(&myapi_info[CREATEFILEA]);
HANDLE handle=CreateFileA(lpFileName, dwDesiredAccess, dwShareMode, lpSecurityAttributes,
     dwCreationDisposition, dwFlagsAndAttributes, hTemplateFile);
// hook again
g_HookApi.HookOneApi(&myapi_info[CREATEFILEA]);
//
if(handle != INVALID_HANDLE_VALUE)
{// handle
if(g_CommFile != handle)// not comes
{// because first call: "\\.\COM1 CreateFileW"
char *CommPort=0;
CommPort=strrchr(lpFileName,'\\');
if(CommPort) CommPort++;
else  CommPort=(char*)lpFileName;
if(strnicmp(CommPort,"COM",3)==0)
{//save handle and port name
g_CommFile=handle;
strcpy(g_CommStruc.CommName,CommPort);
#ifdef _DEBUG
SendData2Dialog(WM_CFA_MSG,(BYTE*)(g_CommStruc.CommName),strlen(g_CommStruc.CommName)+1);
#endif
}
}
}
return handle;
}
//
HANDLE WINAPI myCreateFileW(LPCWSTR lpFileName, DWORD dwDesiredAccess, DWORD dwShareMode,
LPSECURITY_ATTRIBUTES lpSecurityAttributes, DWORD dwCreationDisposition,
DWORD dwFlagsAndAttributes, HANDLE hTemplateFile)
{// unhook first
g_HookApi.UnhookOneApi(&myapi_info[CREATEFILEW]);
HANDLE handle=CreateFileW(lpFileName, dwDesiredAccess, dwShareMode, lpSecurityAttributes,
dwCreationDisposition, dwFlagsAndAttributes, hTemplateFile);
// hook again
g_HookApi.HookOneApi(&myapi_info[CREATEFILEW]);
//
if(handle != INVALID_HANDLE_VALUE)
{
if(g_CommFile != handle)
{
char fname[MAX_PATH]={0};//'\\.\COM1'
WideCharToMultiByte(CP_ACP, 0, lpFileName, -1, fname, MAX_PATH/2 ,NULL,NULL); 

char *CommPort=0;
CommPort=strrchr(fname,'\\');
if(CommPort) CommPort++;
else  CommPort=fname;
if(strnicmp(CommPort,"COM",3)==0)
{//save handle and port name
g_CommFile = handle;
strcpy(g_CommStruc.CommName,CommPort);
#ifdef _DEBUG
SendData2Dialog(WM_CFW_MSG,(BYTE*)(g_CommStruc.CommName),strlen(g_CommStruc.CommName)+1);
#endif
}
}
}
return handle;
}

Answer 2

https://download.csdn.net/download/schlafenhamster/5202391本程序 窥视 串口的 活动。主要 hook 了： {"KERNEL32.DLL", "CreateFileA","myCreateFileA",(FARPROC)myCreateFileA}, {"KERNEL32.DLL", "CreateFileW","myCreateFileW",(FARPROC)myCreateFileW}, {"KERNEL32.DLL", "GetCommState","myGetCommState",(FARPROC)myGetCommState}, {"KERNEL32.DLL", "ReadFile", "myReadFile", (FARPROC)myReadFile}, {"KERNEL32.DLL", "ReadFileEx", "myReadFileEx", (FARPROC)myReadFileEx}, {"KERNEL32.DLL", "WriteFile", "myWriteFile", (FARPROC)myWriteFile}, {"KERNEL32.DLL", "WriteFileEx","myWriteFileEx",(FARPROC)myWriteFileEx}, {"KERNEL32.DLL", "CloseHandle","myCloseHandle",(FARPROC)myCloseHandle},