Check Z-Order for making content accessible on the lock screen.

source/api.py

@@ -237,7 +237,10 @@ def setReviewPosition(
 	@param isCaret: Whether the review position is changed due to caret following.
 	@param isMouse: Whether the review position is changed due to mouse following.
 	"""
-	if _isSecureObjectWhileLockScreenActivated(reviewPosition.obj):
+	reviewObj = reviewPosition.obj
+	if isinstance(reviewObj, treeInterceptorHandler.TreeInterceptor):
+		reviewObj = reviewObj.rootNVDAObject
+	if _isSecureObjectWhileLockScreenActivated(reviewObj):
 		return False
 	globalVars.reviewPosition=reviewPosition.copy()
 	globalVars.reviewPositionObj=reviewPosition.obj

source/baseObject.py

@@ -1,24 +1,39 @@
 # A part of NonVisual Desktop Access (NVDA)
-# Copyright (C) 2007-2020 NV Access Limited, Christopher Toth, Babbage B.V., Julien Cochuyt
+# Copyright (C) 2007-2022 NV Access Limited, Christopher Toth, Babbage B.V., Julien Cochuyt
 # This file is covered by the GNU General Public License.
 # See the file COPYING for more details.
 
 """Contains the base classes that many of NVDA's classes such as NVDAObjects, virtualBuffers, appModules, synthDrivers inherit from. These base classes provide such things as auto properties, and methods and properties for scripting and key binding.
 """
 
+from typing import (
+	Any,
+	Callable,
+	Optional,
+	Set,
+	Union,
+)
 import weakref
 import garbageHandler
 from logHandler import log
 from abc import ABCMeta, abstractproperty
 
+GetterReturnT = Any
+GetterMethodT = Callable[["AutoPropertyObject"], GetterReturnT]
+
+
 class Getter(object):
 
 	def __init__(self,fget, abstract=False):
 		self.fget=fget
 		if abstract:
 			self._abstract = self.__isabstractmethod__ = abstract
 
-	def __get__(self,instance,owner):
+	def __get__(
+			self,
+			instance: Union[Any, None, "AutoPropertyObject"],
+			owner,
+	) -> Union[GetterReturnT, "Getter"]:
 		if isinstance(self.fget, classmethod):
 			return self.fget.__get__(instance, owner)()
 		elif instance is None:
@@ -31,16 +46,22 @@ def setter(self,func):
 	def deleter(self,func):
 		return (abstractproperty if self._abstract else property)(fget=self.fget,fdel=func)
 
+
 class CachingGetter(Getter):
 
-	def __get__(self, instance, owner):
+	def __get__(
+			self,
+			instance: Union[Any, None, "AutoPropertyObject"],
+			owner,
+	) -> Union[GetterReturnT, "CachingGetter"]:
 		if isinstance(self.fget, classmethod):
 			log.warning("Class properties do not support caching")
 			return self.fget.__get__(instance, owner)()
 		elif instance is None:
 			return self
 		return instance._getPropertyViaCache(self.fget)
 
+
 class AutoPropertyType(ABCMeta):
 
 	def __init__(self,name,bases,dict):
@@ -125,6 +146,7 @@ class AutoPropertyObject(garbageHandler.TrackedObject, metaclass=AutoPropertyTyp
 	#: @type: bool
 	cachePropertiesByDefault = False
 
+	_propertyCache: Set[GetterMethodT]
 
 	def __new__(cls, *args, **kwargs):
 		self = super(AutoPropertyObject, cls).__new__(cls)
@@ -134,7 +156,7 @@ def __new__(cls, *args, **kwargs):
 		self.__instances[self]=None
 		return self
 
-	def _getPropertyViaCache(self,getterMethod=None):
+	def _getPropertyViaCache(self, getterMethod: Optional[GetterMethodT] = None) -> GetterReturnT:
 		if not getterMethod:
 			raise ValueError("getterMethod is None")
 		missing=False

source/core.py

@@ -601,7 +601,6 @@ def onEndSession(evt):
 		wx.CallAfter(audioDucking.initialize)
 
 	from winAPI.messageWindow import WindowMessage
-	from winAPI import sessionTracking
 	import winUser
 	# #3763: In wxPython 3, the class name of frame windows changed from wxWindowClassNR to wxWindowNR.
 	# NVDA uses the main frame to check for and quit another instance of NVDA.
@@ -630,27 +629,12 @@ def __init__(self, windowName=None):
 			self.orientationCoordsCache = (0,0)
 			self.handlePowerStatusChange()
 
-			# Call must be paired with a call to sessionTracking.unregister
-			if not sessionTracking.register(self.handle):
-				import utils.security
-				wx.CallAfter(utils.security.warnSessionLockStateUnknown)
-
-		def destroy(self):
-			"""
-			NVDA must unregister session tracking before destroying the message window.
-			"""
-			# Requires an active message window and a handle to unregister.
-			sessionTracking.unregister(self.handle)
-			super().destroy()
-
 		def windowProc(self, hwnd, msg, wParam, lParam):
 			post_windowMessageReceipt.notify(msg=msg, wParam=wParam, lParam=lParam)
 			if msg == WindowMessage.POWER_BROADCAST and wParam == self.PBT_APMPOWERSTATUSCHANGE:
 				self.handlePowerStatusChange()
 			elif msg == winUser.WM_DISPLAYCHANGE:
 				self.handleScreenOrientationChange(lParam)
-			elif msg == WindowMessage.WTS_SESSION_CHANGE:
-				sessionTracking.handleSessionChange(sessionTracking.WindowsTrackedSession(wParam), lParam)
 
 		def handleScreenOrientationChange(self, lParam):
 			# TODO: move to winAPI
@@ -809,7 +793,8 @@ def run(self):
 				mouseHandler.pumpAll()
 				braille.pumpAll()
 				vision.pumpAll()
-			except:
+				sessionTracking.pumpAll()
+			except Exception:
 				log.exception("errors in this core pump cycle")
 			baseObject.AutoPropertyObject.invalidateCaches()
 			watchdog.asleep()
@@ -832,6 +817,9 @@ def run(self):
 		log.debug("initializing updateCheck")
 		updateCheck.initialize()
 
+	from winAPI import sessionTracking
+	sessionTracking.initialize()
+
 	_TrackNVDAInitialization.markInitializationComplete()
 
 	log.info("NVDA initialized")

source/globalVars.py

@@ -21,6 +21,7 @@
 
 if typing.TYPE_CHECKING:
 	import NVDAObjects  # noqa: F401 used for type checking only
+	import textInfos  # noqa: F401 used for type checking only
 
 
 class DefaultAppArgs(argparse.Namespace):
@@ -70,7 +71,7 @@ class DefaultAppArgs(argparse.Namespace):
 mouseOldY=None
 navigatorObject: typing.Optional['NVDAObjects.NVDAObject'] = None
 reviewPosition=None
-reviewPositionObj=None
+reviewPositionObj: typing.Optional["textInfos.TextInfoObjT"] = None
 lastProgressValue=0
 appArgs = DefaultAppArgs()
 unknownAppArgs: typing.List[str] = []

source/nvda.pyw

@@ -350,13 +350,19 @@ if mutex is None:
 	sys.exit(1)
 
 
-if _isSecureDesktop():
+def _serviceDebugEnabled() -> bool:
 	import winreg
 	try:
 		k = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, r"SOFTWARE\NVDA")
-		if not winreg.QueryValueEx(k, u"serviceDebug")[0]:
-			globalVars.appArgs.secure = True
+		if winreg.QueryValueEx(k, "serviceDebug")[0]:
+			return True
 	except WindowsError:
+		pass
+	return False
+
+
+if _isSecureDesktop():
+	if not _serviceDebugEnabled():
 		globalVars.appArgs.secure = True
 	globalVars.appArgs.changeScreenReaderFlag = False
 	globalVars.appArgs.minimal = True

source/textInfos/__init__.py

@@ -1,7 +1,7 @@
 # A part of NonVisual Desktop Access (NVDA)
 # This file is covered by the GNU General Public License.
 # See the file COPYING for more details.
-# Copyright (C) 2006-2021 NV Access Limited, Babbage B.V., Accessolutions, Julien Cochuyt
+# Copyright (C) 2006-2022 NV Access Limited, Babbage B.V., Accessolutions, Julien Cochuyt
 
 """Framework for accessing text content in widgets.
 The core component of this framework is the L{TextInfo} class.
@@ -32,6 +32,7 @@
 
 if typing.TYPE_CHECKING:
 	import NVDAObjects
+	import treeInterceptorHandler  # noqa: F401 used for type checking only
 
 SpeechSequence = List[Union[Any, str]]
 
@@ -287,6 +288,9 @@ def _logBadSequenceTypes(sequence: SpeechSequence, shouldRaise: bool = True):
 	return speech.types.logBadSequenceTypes(sequence, raiseExceptionOnError=shouldRaise)
 
 
+TextInfoObjT = Union["NVDAObjects.NVDAObject", "treeInterceptorHandler.TreeInterceptor"]
+
+
 class TextInfo(baseObject.AutoPropertyObject):
 	"""Provides information about a range of text in an object and facilitates access to all text in the widget.
 	A TextInfo represents a specific range of text, providing access to the text itself, as well as information about the text such as its formatting and any associated controls.
@@ -307,7 +311,11 @@ class TextInfo(baseObject.AutoPropertyObject):
 	@type bookmark: L{Bookmark}
 	"""
 
-	def __init__(self,obj,position):
+	def __init__(
+			self,
+			obj: TextInfoObjT,
+			position
+	):
 		"""Constructor.
 		Subclasses must extend this, calling the superclass method first.
 		@param position: The initial position of this range; one of the POSITION_* constants or a position object supported by the implementation.
@@ -338,9 +346,9 @@ def _set_end(self, otherEndpoint: "TextInfoEndpoint"):
 		self.end.moveTo(otherEndpoint)
 
 	#: Typing information for auto-property: _get_obj
-	obj: "NVDAObjects.NVDAObject"
+	obj: TextInfoObjT
 
-	def _get_obj(self) -> "NVDAObjects.NVDAObject":
+	def _get_obj(self) -> TextInfoObjT:
 		"""The object containing the range of text being represented."""
 		return self._obj()
 

source/treeInterceptorHandler.py

@@ -1,10 +1,13 @@
-# treeInterceptorHandler.py
 # A part of NonVisual Desktop Access (NVDA)
-# Copyright (C) 2006-2020 NV Access Limited, Davy Kager, Accessolutions, Julien Cochuyt
+# Copyright (C) 2006-2022 NV Access Limited, Davy Kager, Accessolutions, Julien Cochuyt
 # This file is covered by the GNU General Public License.
 # See the file COPYING for more details.
 
-from typing import Optional, Dict
+from typing import (
+	TYPE_CHECKING,
+	Dict,
+	Optional,
+)
 
 from logHandler import log
 import baseObject
@@ -18,6 +21,10 @@
 from speech.types import SpeechSequence
 from controlTypes import OutputReason
 
+if TYPE_CHECKING:
+	import NVDAObjects
+
+
 runningTable=set()
 
 def getTreeInterceptor(obj):
@@ -84,12 +91,11 @@ class TreeInterceptor(baseObject.ScriptableObject):
 
 	shouldTrapNonCommandGestures=False #: If true then gestures that do not have a script and are not a command gesture should be trapped from going through to Windows.
 
-	def __init__(self, rootNVDAObject):
+	def __init__(self, rootNVDAObject: "NVDAObjects.NVDAObject"):
 		super(TreeInterceptor, self).__init__()
 		self._passThrough = False
 		#: The root object of the tree wherein events and scripts are intercepted.
-		#: @type: L{NVDAObjects.NVDAObject}
-		self.rootNVDAObject = rootNVDAObject
+		self.rootNVDAObject: "NVDAObjects.NVDAObject" = rootNVDAObject
 
 	def terminate(self):
 		"""Terminate this interceptor.

source/utils/security.py

@@ -14,13 +14,14 @@
 import winUser
 
 if typing.TYPE_CHECKING:
-	import appModuleHandler
+	import appModuleHandler  # noqa: F401, use for typing
 	import scriptHandler  # noqa: F401, use for typing
-	import NVDAObjects
+	import NVDAObjects  # noqa: F401, use for typing
 
 
 postSessionLockStateChanged = extensionPoints.Action()
 """
+# TODO: maintain backwards compat
 Notifies when a session lock or unlock event occurs.
 
 Usage:
@@ -141,7 +142,13 @@ def _isSecureObjectWhileLockScreenActivated(
 	As such, NVDA must prevent accessing and reading objects outside of the lockscreen when Windows is locked.
 	@return: C{True} if the Windows 10/11 lockscreen is active and C{obj} is outside of the lock screen.
 	"""
-	if isWindowsLocked() and not isObjectAboveLockScreen(obj):
+	try:
+		isObjectInSecure = isWindowsLocked() and not isObjectAboveLockScreen(obj)
+	except Exception:
+		log.exception()
+		return False
+
+	if isObjectInSecure:
 		if shouldLog and log.isEnabledFor(log.DEBUG):
 			devInfo = '\n'.join(obj.devInfo)
 			log.debug(f"Attempt at navigating to a secure object: {devInfo}")
@@ -155,7 +162,6 @@ def isObjectAboveLockScreen(obj: "NVDAObjects.NVDAObject") -> bool:
 	When Windows is locked, the foreground Window is usually LockApp,
 	but other Windows can be focused (e.g. Windows Magnifier).
 	"""
-	import appModuleHandler
 	from IAccessibleHandler import SecureDesktopNVDAObject
 	from NVDAObjects.IAccessible import TaskListIcon
 
@@ -176,19 +182,44 @@ def isObjectAboveLockScreen(obj: "NVDAObjects.NVDAObject") -> bool:
 		or isinstance(obj, SecureDesktopNVDAObject)
 	):
 		return True
+	return _isObjectAboveLockScreenCheckZOrder(obj)
 
+
+def _isObjectAboveLockScreenCheckZOrder(obj: "NVDAObjects.NVDAObject") -> bool:
+	"""
+	This is a risky hack.
+	If the order is incorrectly detected,
+	the Windows UX may become inaccessible
+	or secure information may become accessible.
+
+	If these functions fail, where possible,
+	NVDA should make NVDA objects accessible.
+	"""
+	import appModuleHandler
+	from NVDAObjects.window import Window
+	if not isinstance(obj, Window):
+		# must be a window to get its HWNDVal
+		return True
 	runningAppModules = appModuleHandler.runningTable.values()
 	lockAppModule = next(filter(_isLockAppAndAlive, runningAppModules), None)
 
 	if lockAppModule is None:
 		# lockAppModule not running/registered by NVDA yet
-		log.debugWarning(
+		log.debug(
 			"lockAppModule not detected when Windows is locked. "
-			"Cannot detect if object is in lock app, considering object as insecure. "
+			"Cannot detect if object is in lock app, considering object as safe. "
 		)
-	elif lockAppModule is not None and obj.processID == lockAppModule.processID:
 		return True
 
+	desktopWindow = winUser.getDesktopWindow()
+	nextWindow = winUser.getTopWindow(desktopWindow)
+	while nextWindow:
+		windowProcessId = winUser.getWindowThreadProcessID(nextWindow)
+		if nextWindow == obj.windowHandle:
+			return True
+		elif windowProcessId == lockAppModule.processID:
+			return False
+		nextWindow = winUser.getWindow(nextWindow, winUser.GW_HWNDNEXT)
 	return False
 
 

source/winAPI/messageWindow.py

@@ -21,6 +21,4 @@ class WindowMessage(enum.IntEnum):
 	"""
 	WM_WTSSESSION_CHANGE
 	Windows Message for when a Session State Changes.
-	Receiving these messages is registered by sessionTracking.register.
-	handleSessionChange handles these messages.
 	"""