bluez: implement pairing agent

dlech · dlech · commit 4e46255fe85a · 2022-11-18T11:34:23.000-06:00
diff --git a/bleak/backends/bluezdbus/agent.py b/bleak/backends/bluezdbus/agent.py
@@ -0,0 +1,171 @@
+"""
+Agent
+-----
+
+This module contains types associated with the BlueZ D-Bus `agent api
+<https://github.com/bluez/bluez/blob/master/doc/agent-api.txt>`.
+"""
+
+import asyncio
+import contextlib
+import logging
+import os
+from typing import Set, no_type_check
+
+from dbus_fast import DBusError, Message
+from dbus_fast.aio import MessageBus
+from dbus_fast.service import ServiceInterface, method
+
+from bleak.backends.device import BLEDevice
+
+from ...agent import BaseBleakAgentCallbacks
+from . import defs
+from .manager import get_global_bluez_manager
+from .utils import assert_reply
+
+logger = logging.getLogger(__name__)
+
+
+class Agent(ServiceInterface):
+    """
+    Implementation of the org.bluez.Agent1 D-Bus interface.
+    """
+
+    def __init__(self, callbacks: BaseBleakAgentCallbacks):
+        """
+        Args:
+        """
+        super().__init__(defs.AGENT_INTERFACE)
+        self._callbacks = callbacks
+        self._tasks: Set[asyncio.Task] = set()
+
+    async def _create_ble_device(self, device_path: str) -> BLEDevice:
+        manager = await get_global_bluez_manager()
+        props = manager.get_device_props(device_path)
+        return BLEDevice(
+            props["Address"], props["Alias"], {"path": device_path, "props": props}
+        )
+
+    @method()
+    def Release(self):
+        logger.debug("Release")
+
+    # REVISIT: mypy is broke, so we have to add redundant @no_type_check
+    # https://github.com/python/mypy/issues/6583
+
+    @method()
+    @no_type_check
+    async def RequestPinCode(self, device: "o") -> "s":  # noqa: F821
+        logger.debug("RequestPinCode %s", device)
+        raise NotImplementedError
+
+    @method()
+    @no_type_check
+    async def DisplayPinCode(self, device: "o", pincode: "s"):  # noqa: F821
+        logger.debug("DisplayPinCode %s %s", device, pincode)
+        raise NotImplementedError
+
+    @method()
+    @no_type_check
+    async def RequestPasskey(self, device: "o") -> "u":  # noqa: F821
+        logger.debug("RequestPasskey %s", device)
+
+        ble_device = await self._create_ble_device(device)
+
+        task = asyncio.create_task(self._callbacks.request_pin(ble_device))
+        self._tasks.add(task)
+
+        try:
+            pin = await task
+        except asyncio.CancelledError:
+            raise DBusError("org.bluez.Error.Canceled", "task canceled")
+        finally:
+            self._tasks.remove(task)
+
+        if not pin:
+            raise DBusError("org.bluez.Error.Rejected", "user rejected")
+
+        return int(pin)
+
+    @method()
+    @no_type_check
+    async def DisplayPasskey(
+        self, device: "o", passkey: "u", entered: "q"  # noqa: F821
+    ):
+        passkey = f"{passkey:06}"
+        logger.debug("DisplayPasskey %s %s %d", device, passkey, entered)
+        raise NotImplementedError
+
+    @method()
+    @no_type_check
+    async def RequestConfirmation(self, device: "o", passkey: "u"):  # noqa: F821
+        passkey = f"{passkey:06}"
+        logger.debug("RequestConfirmation %s %s", device, passkey)
+        raise NotImplementedError
+
+    @method()
+    @no_type_check
+    async def RequestAuthorization(self, device: "o"):  # noqa: F821
+        logger.debug("RequestAuthorization %s", device)
+        raise NotImplementedError
+
+    @method()
+    @no_type_check
+    async def AuthorizeService(self, device: "o", uuid: "s"):  # noqa: F821
+        logger.debug("AuthorizeService %s", device, uuid)
+        raise NotImplementedError
+
+    @method()
+    @no_type_check
+    def Cancel(self):  # noqa: F821
+        logger.debug("Cancel")
+        for t in self._tasks:
+            t.cancel()
+
+
+@contextlib.asynccontextmanager
+async def bluez_agent(bus: MessageBus, callbacks: BaseBleakAgentCallbacks):
+    agent = Agent(callbacks)
+
+    # REVISIT: implement passing capability if needed
+    # "DisplayOnly", "DisplayYesNo", "KeyboardOnly", "NoInputNoOutput", "KeyboardDisplay"
+    capability = ""
+
+    # this should be a unique path to allow multiple python interpreters
+    # running bleak and multiple agents at the same time
+    agent_path = f"/org/bleak/agent/{os.getpid()}/{id(agent)}"
+
+    bus.export(agent_path, agent)
+
+    try:
+        reply = await bus.call(
+            Message(
+                destination=defs.BLUEZ_SERVICE,
+                path="/org/bluez",
+                interface=defs.AGENT_MANAGER_INTERFACE,
+                member="RegisterAgent",
+                signature="os",
+                body=[agent_path, capability],
+            )
+        )
+
+        assert_reply(reply)
+
+        try:
+            yield
+        finally:
+            reply = await bus.call(
+                Message(
+                    destination=defs.BLUEZ_SERVICE,
+                    path="/org/bluez",
+                    interface=defs.AGENT_MANAGER_INTERFACE,
+                    member="UnregisterAgent",
+                    signature="o",
+                    body=[agent_path],
+                )
+            )
+
+            assert_reply(reply)
+
+    finally:
+        bus.unexport(agent_path, agent)
diff --git a/bleak/backends/bluezdbus/client.py b/bleak/backends/bluezdbus/client.py
@@ -3,6 +3,7 @@
 BLE Client for BlueZ on Linux
 """
 import asyncio
+import contextlib
 import logging
 import os
 import sys
@@ -22,12 +23,19 @@
 
 from ... import BleakScanner
 from ...agent import BaseBleakAgentCallbacks
-from ...exc import BleakDBusError, BleakError, BleakDeviceNotFoundError
+from ...exc import (
+    BleakDBusError,
+    BleakDeviceNotFoundError,
+    BleakError,
+    BleakPairingCancelledError,
+    BleakPairingFailedError,
+)
 from ..characteristic import BleakGATTCharacteristic
 from ..client import BaseBleakClient, NotifyCallback
 from ..device import BLEDevice
 from ..service import BleakGATTServiceCollection
 from . import defs
+from .agent import bluez_agent
 from .characteristic import BleakGATTCharacteristicBlueZDBus
 from .manager import get_global_bluez_manager
 from .scanner import BleakScannerBlueZDBus
@@ -343,9 +351,6 @@ async def pair(
         Pair with the peripheral.
         """
 
-        if callbacks:
-            raise NotImplementedError
-
         # See if it is already paired.
         reply = await self._bus.call(
             Message(
@@ -377,29 +382,31 @@ async def pair(
 
         logger.debug("Pairing to BLE device @ %s", self.address)
 
-        reply = await self._bus.call(
-            Message(
-                destination=defs.BLUEZ_SERVICE,
-                path=self._device_path,
-                interface=defs.DEVICE_INTERFACE,
-                member="Pair",
+        async with contextlib.nullcontext() if callbacks is None else bluez_agent(
+            self._bus, callbacks
+        ):
+            reply = await self._bus.call(
+                Message(
+                    destination=defs.BLUEZ_SERVICE,
+                    path=self._device_path,
+                    interface=defs.DEVICE_INTERFACE,
+                    member="Pair",
+                )
             )
-        )
-        assert_reply(reply)
 
-        reply = await self._bus.call(
-            Message(
-                destination=defs.BLUEZ_SERVICE,
-                path=self._device_path,
-                interface=defs.PROPERTIES_INTERFACE,
-                member="Get",
-                signature="ss",
-                body=[defs.DEVICE_INTERFACE, "Paired"],
-            )
-        )
-        assert_reply(reply)
+            try:
+                assert_reply(reply)
+            except BleakDBusError as e:
+                if e.dbus_error == "org.bluez.Error.AuthenticationCanceled":
+                    raise BleakPairingCancelledError from e
+
+                if e.dbus_error == "org.bluez.Error.AuthenticationFailed":
+                    raise BleakPairingFailedError from e
 
-        return reply.body[0].value
+                raise
+
+        # for backwards compatibility
+        return True
 
     async def unpair(self) -> bool:
         """Unpair with the peripheral.
diff --git a/bleak/backends/bluezdbus/defs.py b/bleak/backends/bluezdbus/defs.py
@@ -17,6 +17,8 @@
 ADAPTER_INTERFACE = "org.bluez.Adapter1"
 ADVERTISEMENT_MONITOR_INTERFACE = "org.bluez.AdvertisementMonitor1"
 ADVERTISEMENT_MONITOR_MANAGER_INTERFACE = "org.bluez.AdvertisementMonitorManager1"
+AGENT_INTERFACE = "org.bluez.Agent1"
+AGENT_MANAGER_INTERFACE = "org.bluez.AgentManager1"
 DEVICE_INTERFACE = "org.bluez.Device1"
 BATTERY_INTERFACE = "org.bluez.Battery1"
 
diff --git a/bleak/backends/bluezdbus/manager.py b/bleak/backends/bluezdbus/manager.py
@@ -621,6 +621,20 @@ async def get_services(
 
         return services
 
+    def get_device_props(self, device_path: str) -> Device1:
+        """
+        Gets the current properties of a device.
+
+        Args:
+            device_path: The D-Bus object path of the device.
+
+        Returns:
+            The current properties.
+        """
+        return cast(
+            Device1, self._properties[device_path][defs.DEVICE_INTERFACE].copy()
+        )
+
     def get_device_name(self, device_path: str) -> str:
         """
         Gets the value of the "Name" property for a device.
