Ejemplo n.º 1
0
BOOL
vncClientThread::InitAuthenticate()
{
	// Retrieve the local password
	char password[MAXPWLEN];
	m_server->GetPassword(password);
	vncPasswd::ToText plain(password);

	// Verify the peer host name against the AuthHosts string
	vncServer::AcceptQueryReject verified;
	if (m_auth) {
		verified = vncServer::aqrAccept;
	} else {
		verified = m_server->VerifyHost(m_socket->GetPeerName());
	}
	
	// If necessary, query the connection with a timed dialog
	if (verified == vncServer::aqrQuery) {
		vncAcceptDialog *acceptDlg = new vncAcceptDialog(m_server->QueryTimeout(), m_socket->GetPeerName());
		if ((acceptDlg == 0) || (!(acceptDlg->DoDialog())))
			verified = vncServer::aqrReject;
	}
	if (verified == vncServer::aqrReject) {
		CARD32 auth_val = Swap32IfLE(rfbConnFailed);
		char *errmsg = "Your connection has been rejected.";
		CARD32 errlen = Swap32IfLE(strlen(errmsg));
		if (!m_socket->SendExact((char *)&auth_val, sizeof(auth_val)))
			return FALSE;
		if (!m_socket->SendExact((char *)&errlen, sizeof(errlen)))
			return FALSE;
		m_socket->SendExact(errmsg, strlen(errmsg));
		return FALSE;
	}

	// By default we disallow passwordless workstations!
	if ((strlen(plain) == 0) && m_server->AuthRequired())
	{
		vnclog.Print(LL_CONNERR, VNCLOG("no password specified for server - client rejected\n"));

		// Send an error message to the client
		CARD32 auth_val = Swap32IfLE(rfbConnFailed);
		char *errmsg =
			"This server does not have a valid password enabled.  "
			"Until a password is set, incoming connections cannot be accepted.";
		CARD32 errlen = Swap32IfLE(strlen(errmsg));

		if (!m_socket->SendExact((char *)&auth_val, sizeof(auth_val)))
			return FALSE;
		if (!m_socket->SendExact((char *)&errlen, sizeof(errlen)))
			return FALSE;
		m_socket->SendExact(errmsg, strlen(errmsg));

		return FALSE;
	}

	// By default we filter out local loop connections, because they're pointless
	if (!m_server->LoopbackOk())
	{
		char *localname = strdup(m_socket->GetSockName());
		char *remotename = strdup(m_socket->GetPeerName());

		// Check that the local & remote names are different!
		if ((localname != NULL) && (remotename != NULL))
		{
			BOOL ok = strcmp(localname, remotename) != 0;

			if (localname != NULL)
				free(localname);

			if (remotename != NULL)
				free(remotename);

			if (!ok)
			{
				vnclog.Print(LL_CONNERR, VNCLOG("loopback connection attempted - client rejected\n"));
				
				// Send an error message to the client
				CARD32 auth_val = Swap32IfLE(rfbConnFailed);
				char *errmsg = "Local loop-back connections are disabled.";
				CARD32 errlen = Swap32IfLE(strlen(errmsg));

				if (!m_socket->SendExact((char *)&auth_val, sizeof(auth_val)))
					return FALSE;
				if (!m_socket->SendExact((char *)&errlen, sizeof(errlen)))
					return FALSE;
				m_socket->SendExact(errmsg, strlen(errmsg));

				return FALSE;
			}
		}
	}

	// Authenticate the connection, if required
	if (m_auth || (strlen(plain) == 0))
	{
		// Send no-auth-required message
		CARD32 auth_val = Swap32IfLE(rfbNoAuth);
		if (!m_socket->SendExact((char *)&auth_val, sizeof(auth_val)))
			return FALSE;
	}
	else
	{
		// Send auth-required message
		CARD32 auth_val = Swap32IfLE(rfbVncAuth);
		if (!m_socket->SendExact((char *)&auth_val, sizeof(auth_val)))
			return FALSE;

		BOOL auth_ok = TRUE;
		{
			// Now create a 16-byte challenge
			char challenge[16];
			vncRandomBytes((BYTE *)&challenge);

			// Send the challenge to the client
			if (!m_socket->SendExact(challenge, sizeof(challenge)))
				return FALSE;

			// Read the response
			char response[16];
			if (!m_socket->ReadExact(response, sizeof(response)))\
				return FALSE;

			// Encrypt the challenge bytes
			vncEncryptBytes((BYTE *)&challenge, plain);

			// Compare them to the response
			for (int i=0; i<sizeof(challenge); i++)
			{
				if (challenge[i] != response[i])
				{
					auth_ok = FALSE;
					break;
				}
			}
		}

		// Did the authentication work?
		CARD32 authmsg;
		if (!auth_ok)
		{
			vnclog.Print(LL_CONNERR, VNCLOG("authentication failed\n"));

			authmsg = Swap32IfLE(rfbVncAuthFailed);
			m_socket->SendExact((char *)&authmsg, sizeof(authmsg));
			return FALSE;
		}
		else
		{
			// Tell the client we're ok
			authmsg = Swap32IfLE(rfbVncAuthOK);
			if (!m_socket->SendExact((char *)&authmsg, sizeof(authmsg)))
				return FALSE;
		}
	}

	// Read the client's initialisation message
	rfbClientInitMsg client_ini;
	if (!m_socket->ReadExact((char *)&client_ini, sz_rfbClientInitMsg))
		return FALSE;

	// If the client wishes to have exclusive access then remove other clients
	if (!client_ini.shared && !m_shared)
	{
		// Which client takes priority, existing or incoming?
		if (m_server->ConnectPriority() < 1)
		{
			// Incoming
			vnclog.Print(LL_INTINFO, VNCLOG("non-shared connection - disconnecting old clients\n"));
			m_server->KillAuthClients();
		} else if (m_server->ConnectPriority() > 1)
		{
			// Existing
			if (m_server->AuthClientCount() > 0)
			{
				vnclog.Print(LL_CLIENTS, VNCLOG("connections already exist - client rejected\n"));
				return FALSE;
			}
		}
	}

	// Tell the server that this client is ok
	return m_server->Authenticated(m_client->GetClientId());
}
Ejemplo n.º 2
0
void *
vncDesktopThread::run_undetached(void *arg)
{
	// Save the thread's "home" desktop, under NT (no effect under 9x)
	HDESK home_desktop = GetThreadDesktop(GetCurrentThreadId());

	// Attempt to initialise and return success or failure
	if (!m_desktop->Startup())
	{
		vncService::SelectHDESK(home_desktop);
		ReturnVal(FALSE);
		return NULL;
	}

  // Grab the initial display contents
  // *** m_desktop->m_buffer.GrabRegion(m_desktop->m_bmrect);
  // *** m_desktop->m_buffer.Clear(m_desktop->m_bmrect);

	// Succeeded to initialise ok
	ReturnVal(TRUE);

	// START PROCESSING DESKTOP MESSAGES

	// We set a flag inside the desktop handler here, to indicate it's now safe
	// to handle clipboard messages
	m_desktop->SetClipboardActive(TRUE);

	// All changes in the state of the display are stored in a local
	// UpdateTracker object, and are flushed to the vncServer whenever
	// client updates are about to be triggered
	rfb::SimpleUpdateTracker clipped_updates;
	rfb::ClippedUpdateTracker updates(clipped_updates, m_desktop->m_bmrect);
	clipped_updates.enable_copyrect(true);

	// Incoming update messages are collated into a single region cache
	// The region cache areas are checked for changes before an update
	// is triggered, and the changed areas are passed to the UpdateTracker
	rfb::Region2D rgncache = m_desktop->m_bmrect;

	// The previous cursor position is stored, to allow us to erase the
	// old instance whenever it moves.
	rfb::Point oldcursorpos;

	// Set the hook thread to a high priority
	// *** set_priority(omni_thread::PRIORITY_HIGH);

	BOOL idle_skip = TRUE;
	ULONG idle_skip_count = 0;
	MSG msg;
	while (TRUE)
	{
		if (!PeekMessage(&msg, NULL, NULL, NULL, PM_REMOVE)) {
			//
			// - MESSAGE QUEUE EMPTY
			// Whenever the message queue becomes empty, we check to see whether
			// there are updates to be passed to clients.
			if (idle_skip) {
				idle_skip = FALSE;
				if (idle_skip_count++ < 4) {
					Sleep(5);
					continue;
				}
			}
			idle_skip_count = 0;

			// Clear the triggered flag
			m_desktop->m_update_triggered = FALSE;

			//
			// CHECK SCREEN FORMAT
			// First, we must check that the screen hasnt changed too much.
			if (m_desktop->m_displaychanged || !vncService::InputDesktopSelected())
			{
				rfbServerInitMsg oldscrinfo = m_desktop->m_scrinfo;
				m_desktop->m_displaychanged = FALSE;

				// Attempt to close the old hooks
				if (!m_desktop->Shutdown())
				{
					m_server->KillAuthClients();
					break;
				}

				// Now attempt to re-install them!
				if (!m_desktop->Startup())
				{
					m_server->KillAuthClients();
					break;
				}

				// Check that the screen info hasn't changed
				//vnclog.Print(LL_INTINFO, VNCLOG("SCR: old screen format %dx%dx%d\n"),
				//	oldscrinfo.framebufferWidth,
				//	oldscrinfo.framebufferHeight,
				//	oldscrinfo.format.bitsPerPixel);
				//vnclog.Print(LL_INTINFO, VNCLOG("SCR: new screen format %dx%dx%d\n"),
				//	m_desktop->m_scrinfo.framebufferWidth,
				//	m_desktop->m_scrinfo.framebufferHeight,
				//	m_desktop->m_scrinfo.format.bitsPerPixel);
				if ((m_desktop->m_scrinfo.framebufferWidth != oldscrinfo.framebufferWidth) ||
					(m_desktop->m_scrinfo.framebufferHeight != oldscrinfo.framebufferHeight))
				{
					m_server->KillAuthClients();
					break;
				} else if (memcmp(&m_desktop->m_scrinfo.format, &oldscrinfo.format, sizeof(rfbPixelFormat)) != 0)
				{
					m_server->UpdateLocalFormat();
				}

				// Adjust the UpdateTracker clip region
				updates.set_clip_region(m_desktop->m_bmrect);

				// Add a full screen update to all the clients
				rgncache = rgncache.union_(rfb::Region2D(m_desktop->m_bmrect));
				m_server->UpdatePalette();
			}
	
			//
			// CALCULATE CHANGES
			//

			if (m_desktop->m_server->UpdateWanted())
			{
				// POLL PROBLEM AREAS
				// We add specific areas of the screen to the region cache,
				// causing them to be fetched for processing.
				if (m_desktop->m_server->PollFullScreen())
				{
					rfb::Rect rect = m_desktop->m_qtrscreen;
					rect = rect.translate(rfb::Point(0, m_desktop->m_pollingcycle * m_desktop->m_qtrscreen.br.y));
					rgncache = rgncache.union_(rfb::Region2D(rect));
					m_desktop->m_pollingcycle = (m_desktop->m_pollingcycle + 1) % 4;
				}
				if (m_desktop->m_server->PollForeground())
				{
					// Get the window rectangle for the currently selected window
					HWND hwnd = GetForegroundWindow();
					if (hwnd != NULL)
						PollWindow(rgncache, hwnd);
				}
				if (m_desktop->m_server->PollUnderCursor())
				{
					// Find the mouse position
					POINT mousepos;
					if (GetCursorPos(&mousepos))
					{
						// Find the window under the mouse
						HWND hwnd = WindowFromPoint(mousepos);
						if (hwnd != NULL)
							PollWindow(rgncache, hwnd);
					}
				}

				// PROCESS THE MOUSE POINTER
				// Some of the hard work is done in clients, some here
				// This code fetches the desktop under the old pointer position
				// but the client is responsible for actually encoding and sending
				// it when required.
				// This code also renders the pointer and saves the rendered position
				// Clients include this when rendering updates.
				// The code is complicated in this way because we wish to avoid 
				// rendering parts of the screen the mouse moved through between
				// client updates, since in practice they will probably not have changed.

				// Re-render the mouse's old location if it's moved
				BOOL cursormoved = FALSE;
				POINT cursorpos;
				if (GetCursorPos(&cursorpos) && 
					((cursorpos.x != oldcursorpos.x) ||
					(cursorpos.y != oldcursorpos.y))) {
					cursormoved = TRUE;
					oldcursorpos = rfb::Point(cursorpos);
				}
				if (cursormoved) {
					if (!m_desktop->m_cursorpos.is_empty())
						rgncache = rgncache.union_(rfb::Region2D(m_desktop->m_cursorpos));
				}

				{
					// Prevent any clients from accessing the Buffer
					omni_mutex_lock l(m_desktop->m_update_lock);

					// CHECK FOR COPYRECTS
					// This actually just checks where the Foreground window is
					m_desktop->CalcCopyRects(updates);

					// GRAB THE DISPLAY
					// Fetch data from the display to our display cache.
					m_desktop->m_buffer.GrabRegion(rgncache);
				  // Render the mouse
				  m_desktop->m_buffer.GrabMouse();
					if (cursormoved) {
						// Inform clients that it has moved
						m_desktop->m_server->UpdateMouse();
						// Get the buffer to fetch the pointer bitmap
						if (!m_desktop->m_cursorpos.is_empty())
							rgncache = rgncache.union_(rfb::Region2D(m_desktop->m_cursorpos));
					}

					// SCAN THE CHANGED REGION FOR ACTUAL CHANGES
					// The hooks return hints as to areas that may have changed.
					// We check the suggested areas, and just send the ones that
					// have actually changed.
					// Note that we deliberately don't check the copyrect destination
					// here, to reduce the overhead & the likelihood of corrupting the
					// backbuffer contents.
					rfb::Region2D checkrgn = rgncache.subtract(clipped_updates.get_copied_region());
					rgncache = clipped_updates.get_copied_region();
					rfb::Region2D changedrgn;
					m_desktop->m_buffer.CheckRegion(changedrgn, checkrgn);

					// FLUSH UPDATES TO CLIENTS
					// Add the bits that have really changed to their update regions
					// Note that the cursor is NOT included - they must do that
					// themselves, for the reasons above.
					// This call implicitly kicks clients to update themselves

					updates.add_changed(changedrgn);
					clipped_updates.get_update(m_server->GetUpdateTracker());
				}

				// Clear the update tracker and region cache
				clipped_updates.clear();
			}

			// Now wait for more messages to be queued
			if (!WaitMessage()) {
				//vnclog.Print(LL_INTERR, VNCLOG("WaitMessage() failed\n"));
				break;
			}
		} else if (msg.message == RFB_SCREEN_UPDATE) {
			// Process an incoming update event

			// An area of the screen has changed
			rfb::Rect rect;
			rect.tl = rfb::Point((SHORT)LOWORD(msg.wParam), (SHORT)HIWORD(msg.wParam));
			rect.br = rfb::Point((SHORT)LOWORD(msg.lParam), (SHORT)HIWORD(msg.lParam));
			rect = rect.intersect(m_desktop->m_bmrect);
			if (!rect.is_empty()) {
				rgncache = rgncache.union_(rfb::Region2D(rect));
			}

			idle_skip = TRUE;
		} else if (msg.message == RFB_MOUSE_UPDATE) {
			// Process an incoming mouse event

			// Save the cursor ID
			m_desktop->SetCursor((HCURSOR) msg.wParam);

			idle_skip = TRUE;
		} else if (msg.message == WM_QUIT) {
			break;
		} else {
			// Process any other messages normally
			DispatchMessage(&msg);

			idle_skip = TRUE;
		}
	}

	m_desktop->SetClipboardActive(FALSE);
	
	//vnclog.Print(LL_INTINFO, VNCLOG("quitting desktop server thread\n"));

	// Clear all the hooks and close windows, etc.
	m_desktop->Shutdown();

	// Clear the shift modifier keys, now that there are no remote clients
	vncKeymap::ClearShiftKeys();

	// Switch back into our home desktop, under NT (no effect under 9x)
	vncService::SelectHDESK(home_desktop);

	return NULL;
}