Merge f141828 into 4b339e2

LeonarddeR · web-flow · commit 88fcb449fb8b · 2022-02-18T17:35:08.000+10:00
diff --git a/source/UIAHandler/__init__.py b/source/UIAHandler/__init__.py
@@ -798,21 +798,23 @@ def _isUIAWindowHelper(self,hwnd):
 				and not config.conf['UIA']['useInMSExcelWhenAvailable']
 			):
 				return False
-			# Unless explicitly allowed, all Chromium implementations (including Edge) should not be UIA,
-			# As their IA2 implementation is still better at the moment.
-			elif (
-				windowClass == "Chrome_RenderWidgetHostHWND"
-				and (
+			elif windowClass == "Chrome_RenderWidgetHostHWND":
+				# Unless explicitly allowed, all Chromium implementations (including Edge) should not be UIA,
+				# As their IA2 implementation is still better at the moment.
+				# However, in cases where Chromium is running under another logon session,
+				# the IAccessible2 implementation is unavailable.
+				hasAccessToIA2 = not appModule.isRunningUnderDifferentLogonSession
+				if (
 					AllowUiaInChromium.getConfig() == AllowUiaInChromium.NO
 					# Disabling is only useful if we can inject in-process (and use our older code)
 					or (
 						canUseOlderInProcessApproach
+						and hasAccessToIA2
 						and AllowUiaInChromium.getConfig() != AllowUiaInChromium.YES  # Users can prefer to use UIA
 					)
-				)
-			):
-				return False
-			if windowClass == "ConsoleWindowClass":
+				):
+					return False
+			elif windowClass == "ConsoleWindowClass":
 				return utils._shouldUseUIAConsole(hwnd)
 		return bool(res)
 
diff --git a/source/appModuleHandler.py b/source/appModuleHandler.py
@@ -37,11 +37,15 @@
 import exceptions
 import extensionPoints
 from fileUtils import getFileVersionInfo
+from typing import Optional
+from systemUtils import getProcessTokenOrigin
 
 # Dictionary of processID:appModule pairs used to hold the currently running modules
 runningTable: Dict[int, AppModule] = {}
 #: The process ID of NVDA itself.
 NVDAProcessID=None
+#: The logon session ID under which NVDA was started.
+NVDAProcessLogonSessionID: Optional[int] = None
 _importers=None
 _getAppModuleLock=threading.RLock()
 #: Notifies when another application is taking foreground.
@@ -230,8 +234,12 @@ def reloadAppModules():
 def initialize():
 	"""Initializes the appModule subsystem. 
 	"""
-	global NVDAProcessID,_importers
+	global NVDAProcessID, NVDAProcessLogonSessionID, _importers
 	NVDAProcessID=os.getpid()
+	try:
+		NVDAProcessLogonSessionID = getProcessTokenOrigin(winKernel.GetCurrentProcess())
+	except WindowsError:
+		log.error("Couldn't get NVDAProcessLogonSessionID", exc_info=True)
 	config.addConfigDirsToPythonPackagePath(appModules)
 	_importers=list(pkgutil.iter_importers("appModules.__init__"))
 
@@ -520,6 +528,20 @@ def _get_isWindowsStoreApp(self):
 		self.isWindowsStoreApp = False
 		return self.isWindowsStoreApp
 
+	def _get_isRunningUnderDifferentLogonSession(self) -> bool:
+		"""Returns whether the application for this appModule was started under a different logon session.
+		This applies to applications started with the Windows runas command
+		or when choosing "run as a different user" from an application's (shortcut) context menu.
+		"""
+		try:
+			self.isRunningUnderDifferentLogonSession = (
+				NVDAProcessLogonSessionID != getProcessTokenOrigin(self.processHandle)
+			)
+		except WindowsError:
+			log.error(f"Couldn't get logon session ID for {self}", exc_info=True)
+			self.isRunningUnderDifferentLogonSession = False
+		return self.isRunningUnderDifferentLogonSession
+
 	def _get_appArchitecture(self):
 		"""Returns the target architecture for the specified app.
 		This is useful for detecting X86/X64 apps running on ARM64 releases of Windows 10.
diff --git a/source/systemUtils.py b/source/systemUtils.py
@@ -63,6 +63,36 @@ def hasUiAccess():
 		ctypes.windll.kernel32.CloseHandle(token)
 
 
+TokenOrigin = 17
+
+
+class TOKEN_ORIGIN(ctypes.Structure):
+	_fields_ = [("OriginatingLogonSession", ctypes.c_ulonglong)]
+
+
+def getProcessTokenOrigin(processHandle):
+	token = ctypes.wintypes.HANDLE()
+	if not ctypes.windll.advapi32.OpenProcessToken(
+		processHandle,
+		winKernel.MAXIMUM_ALLOWED,
+		ctypes.byref(token)
+	):
+		raise ctypes.WinError()
+	try:
+		val = TOKEN_ORIGIN()
+		if not ctypes.windll.advapi32.GetTokenInformation(
+			token,
+			TokenOrigin,
+			ctypes.byref(val),
+			ctypes.sizeof(val),
+			ctypes.byref(ctypes.wintypes.DWORD())
+		):
+			raise ctypes.WinError()
+		return val.OriginatingLogonSession
+	finally:
+		ctypes.windll.kernel32.CloseHandle(token)
+
+
 def execElevated(path, params=None, wait=False, handleAlreadyElevated=False):
 	import subprocess
 	if params is not None:
