int TcpExchangeChallenge (SOCKET s, int seed, int nVersion, const char *key)
{
FILETIME ft;
struct S_Challenge Out1, In1, Out2, In2;
int Rc;
int Ark;
GetSystemTimeAsFileTime (&ft);
srand (ft.dwLowDateTime + seed + (unsigned) s);
for (Ark=0 ; Ark< sizeof Out1.challenge ; Ark++)
Out1.challenge[Ark] = (unsigned char) (rand () & 0xFF);
Out1.pad = 0;
Out1.version = nVersion;
Rc = TcpPPSend ( s, (char *) & Out1, sizeof Out1, INVALID_FILE_HANDLE );
if (Rc<0) return Rc;
Rc = TcpPPRecv ( s, (char *) & In1, sizeof In1, 10, INVALID_FILE_HANDLE );
if (Rc<0)
{int Ark = WSAGetLastError ();
LogToMonitor ("Error %d receiving on socket %d\n", Ark, s);
return Rc;
}
/* verify version */
if (In1.version != nVersion) return TCP4U_VERSION_ERROR;
/* 'crypt' challenge */
Out2 = In1;
sym_crypt ( Out2.challenge, sizeof Out2.challenge, key );
/* resend frame */
Rc = TcpPPSend ( s, (char *)& Out2, sizeof Out2, INVALID_FILE_HANDLE );
if (Rc<0) return Rc;
/* wait for our Challenge (*/
Rc = TcpPPRecv ( s, (char *)& In2, sizeof In2, 10, INVALID_FILE_HANDLE );
if (Rc<0) return Rc;
/* un crypt In2 and compare with Out1 */
sym_crypt ( In2.challenge, sizeof In2.challenge, key );
return memcmp (In2.challenge, Out1.challenge, sizeof Out1.challenge)==0 ? TCP4U_SUCCESS : TCP4U_BAD_AUTHENT ;
} // TcpExchangeChallenge
void TftpdConsole (void *param)
{
SOCKET sDlg;
int Rc;
int nTriggeredEvent;
static struct S_ConsoleMsg msg;
enum e_Events { EV_TOGUI, EV_FROMGUI, EV_NUMBER };
HANDLE tEvents [EV_NUMBER];
// open logging facility
StartAsyncMessagingFacility ( );
do
{
LogToMonitor ("opening comm socket\n");
SetGuiStatus (NOT_CONNECTED);
sDlg = WaitForGuiConnection (); // fail only if thread ends
if (sDlg==INVALID_SOCKET) continue;
// Verify Versions
LogToMonitor ("Verify Console/GUI parameters\n");
Rc = TcpExchangeChallenge (sDlg, 0x56AE, CURRENT_PROTOCOL_VERSION, NULL, sSettings.szConsolePwd);
if ( Rc < 0 )
{
Sleep (1000);
continue;
}
LogToMonitor ( "Version check OK\n" );
SetGuiStatus (CONNECTED);
// Startup blocking service by creating
// one event and one semaphore to code the blocking sendmsgrequest
hMsgRequestSemaf = CreateMutex(NULL, 0, NULL);
hEvMsgSent = CreateEvent(NULL,FALSE,FALSE,NULL);
if (hMsgRequestSemaf==NULL)
CMsgBox (NULL, "Can not create resource", APPLICATION, MB_OK | MB_ICONERROR);
tThreads[TH_CONSOLE].bInit = TRUE; // inits OK
// Create Socket Event
tEvents [EV_FROMGUI] = WSACreateEvent();
WSAEventSelect (sDlg, tEvents[EV_FROMGUI], FD_READ | FD_CLOSE);
do
{
// waits either internal sollicitation or msg reception
tEvents[EV_TOGUI] = tThreads[TH_CONSOLE].hEv;
nTriggeredEvent = WaitForMultipleObjects (EV_NUMBER, tEvents, FALSE, INFINITE);
switch (nTriggeredEvent)
{
case EV_FROMGUI :
// WSA events should be manually reset
WSAEventSelect (sDlg, 0, 0);
ResetEvent (tEvents[EV_FROMGUI]);
Rc = TcpPPRecv (sDlg, (void *) &msg, sizeof msg, 10, INVALID_HANDLE_VALUE);
if (Rc>0) LOG (9, "received %d bytes from console", Rc);
if (Rc>0) ProcessMsg (sDlg, &msg);
else LogToMonitor ("rcvd error %d/%d in console\n", Rc, GetLastError ());
WSAEventSelect (sDlg, tEvents[EV_FROMGUI], FD_READ | FD_CLOSE);
break;
// message to be sent to Gui (except logs)
case EV_TOGUI :
ProcessAsyncMessages ( sDlg, hEvMsgSent );
break;
} // switch signalled events
}
while (tThreads[TH_CONSOLE].gRunning && (Rc>0 || Rc==TCP4U_TIMEOUT) );
WSACloseEvent (tEvents [EV_FROMGUI]); tEvents [EV_FROMGUI] = INVALID_HANDLE_VALUE;
closesocket (sDlg);
// blocking service not available
CloseHandle (hEvMsgSent); hEvMsgSent = INVALID_HANDLE_VALUE;
CloseHandle (hMsgRequestSemaf); hMsgRequestSemaf = INVALID_HANDLE_VALUE;
LogToMonitor ("end of GUI session\n");
}
while ( tThreads[TH_CONSOLE].gRunning );
// terminate therad : don't listen anymore
// closesocket (sListen);
// unblock some threads
SetEvent (hEvMsgSent); Sleep (10); SetEvent (hEvMsgSent);
// stop logging service
StopAsyncMessagingFacility ();
LogToMonitor ("End of console thread\n");
_endthread ();
} // TftpdConsole
