backends/winrt/client: handle arbitrary access denied

We had a hard-coded list of services know to return an access denied
error when attempting to enumerate characteristics. However, since
we don't know Windows internals, the list was not exhaustive and it
could also change in the future.

Instead, we can just check for the access denied error and skip any
service that returns that error which should also handle additional
services we don't know about yet.

Fixes: #1291

CHANGELOG.rst

@@ -14,6 +14,10 @@ Changed
 -------
 - Improved error messages when failing to get services in WinRT backend.
 
+Fixed
+-----
+- Fix handling all access denied errors when enumerating characteristics on Windows. Fixes #1291.
+
 `0.20.2`_ (2023-04-19)
 ======================
 

bleak/backends/winrt/client.py

@@ -68,11 +68,6 @@
 
 logger = logging.getLogger(__name__)
 
-_ACCESS_DENIED_SERVICES = list(
-    uuid.UUID(u)
-    for u in ("00001812-0000-1000-8000-00805f9b34fb",)  # Human Interface Device Service
-)
-
 # TODO: we can use this when minimum Python is 3.8
 # class _Result(typing.Protocol):
 #     status: GattCommunicationStatus
@@ -652,8 +647,6 @@ async def get_services(
         if cache_mode is not None:
             args.append(cache_mode)
 
-        logger.debug("calling get_gatt_services_async")
-
         def dispose_on_cancel(future):
             if future._cancel_requested and future._result is not None:
                 logger.debug("disposing services object because of cancel")
@@ -688,44 +681,39 @@ def dispose_on_cancel(future):
                     )
                 )
 
-        logger.debug("returned from get_gatt_services_async")
-
         try:
             for service in services:
-                # Windows returns an ACCESS_DENIED error when trying to enumerate
-                # characteristics of services used by the OS, like the HID service
-                # so we have to exclude those services.
-                if service.uuid in _ACCESS_DENIED_SERVICES:
-                    continue
 
-                new_services.add_service(BleakGATTServiceWinRT(service))
+                result = await FutureLike(service.get_characteristics_async(*args))
 
-                logger.debug("calling get_characteristics_async")
+                if result.status == GattCommunicationStatus.ACCESS_DENIED:
+                    # Windows does not allow access to services "owned" by the
+                    # OS. This includes services like HID and Bond Manager.
+                    logger.debug(
+                        "skipping service %s due to access denied", service.uuid
+                    )
+                    continue
 
                 characteristics: Sequence[GattCharacteristic] = _ensure_success(
-                    await FutureLike(service.get_characteristics_async(*args)),
+                    result,
                     "characteristics",
                     f"Could not get GATT characteristics for service {service.uuid} ({service.attribute_handle})",
                 )
 
-                logger.debug("returned from get_characteristics_async")
+                new_services.add_service(BleakGATTServiceWinRT(service))
 
                 for characteristic in characteristics:
-                    new_services.add_characteristic(
-                        BleakGATTCharacteristicWinRT(
-                            characteristic, self._session.max_pdu_size - 3
-                        )
-                    )
-
-                    logger.debug("calling get_descriptors_async")
-
                     descriptors: Sequence[GattDescriptor] = _ensure_success(
                         await FutureLike(characteristic.get_descriptors_async(*args)),
                         "descriptors",
                         f"Could not get GATT descriptors for characteristic {characteristic.uuid} ({characteristic.attribute_handle})",
                     )
 
-                    logger.debug("returned from get_descriptors_async")
+                    new_services.add_characteristic(
+                        BleakGATTCharacteristicWinRT(
+                            characteristic, self._session.max_pdu_size - 3
+                        )
+                    )
 
                     for descriptor in descriptors:
                         new_services.add_descriptor(