add basic RPA support

bumble/device.py

@@ -259,8 +259,9 @@ DEVICE_DEFAULT_L2CAP_COC_MAX_CREDITS          = l2cap.L2CAP_LE_CREDIT_BASED_CONN
 DEVICE_DEFAULT_ADVERTISING_TX_POWER           = (
     HCI_LE_Set_Extended_Advertising_Parameters_Command.TX_POWER_NO_PREFERENCE
 )
-DEVICE_DEFAULT_PERIODIC_ADVERTISING_SYNC_SKIP    = 0
+DEVICE_DEFAULT_PERIODIC_ADVERTISING_SYNC_SKIP = 0
 DEVICE_DEFAULT_PERIODIC_ADVERTISING_SYNC_TIMEOUT = 5.0
+DEVICE_DEFAULT_LE_RPA_TIMEOUT                 = 15 * 60 # 15 minutes (in seconds)
 
 # fmt: on
 # pylint: enable=line-too-long
@@ -1567,8 +1568,9 @@ class DeviceConfiguration:
     advertising_interval_min: int = DEVICE_DEFAULT_ADVERTISING_INTERVAL
     advertising_interval_max: int = DEVICE_DEFAULT_ADVERTISING_INTERVAL
     le_enabled: bool = True
-    # LE host enable 2nd parameter
     le_simultaneous_enabled: bool = False
+    le_privacy_enabled: bool = False
+    le_rpa_timeout: int = DEVICE_DEFAULT_LE_RPA_TIMEOUT
     classic_enabled: bool = False
     classic_sc_enabled: bool = True
     classic_ssp_enabled: bool = True
@@ -1736,8 +1738,9 @@ device_host_event_handlers: List[str] = []
 # -----------------------------------------------------------------------------
 class Device(CompositeEventEmitter):
     # Incomplete list of fields.
-    random_address: Address
+    random_address: Address  # Random address that may change with RPA
-    public_address: Address
+    public_address: Address  # Public address (obtained from the controller)
+    static_address: Address  # Random address that can be set but does not change
     classic_enabled: bool
     name: str
     class_of_device: int
@@ -1867,15 +1870,19 @@ class Device(CompositeEventEmitter):
         config = config or DeviceConfiguration()
         self.config = config
 
-        self.public_address = Address('00:00:00:00:00:00')
         self.name = config.name
+        self.public_address = Address.ANY
         self.random_address = config.address
+        self.static_address = config.address
         self.class_of_device = config.class_of_device
         self.keystore = None
         self.irk = config.irk
         self.le_enabled = config.le_enabled
-        self.classic_enabled = config.classic_enabled
         self.le_simultaneous_enabled = config.le_simultaneous_enabled
+        self.le_privacy_enabled = config.le_privacy_enabled
+        self.le_rpa_timeout = config.le_rpa_timeout
+        self.le_rpa_periodic_update_task: Optional[asyncio.Task] = None
+        self.classic_enabled = config.classic_enabled
         self.cis_enabled = config.cis_enabled
         self.classic_sc_enabled = config.classic_sc_enabled
         self.classic_ssp_enabled = config.classic_ssp_enabled
@@ -1939,6 +1946,7 @@ class Device(CompositeEventEmitter):
             if isinstance(address, str):
                 address = Address(address)
             self.random_address = address
+            self.static_address = address
 
         # Setup SMP
         self.smp_manager = smp.Manager(
@@ -2170,6 +2178,16 @@ class Device(CompositeEventEmitter):
             )
 
         if self.le_enabled:
+            # If LE Privacy is enabled, generate an RPA
+            if self.le_privacy_enabled:
+                self.random_address = Address.generate_private_address(self.irk)
+                logger.info(f'Initial RPA: {self.random_address}')
+                if self.le_rpa_timeout > 0:
+                    # Start a task to periodically generate a new RPA
+                    self.le_rpa_periodic_update_task = asyncio.create_task(
+                        self._run_rpa_periodic_update()
+                    )
+
             # Set the controller address
             if self.random_address == Address.ANY_RANDOM:
                 # Try to use an address generated at random by the controller
@@ -2249,9 +2267,45 @@ class Device(CompositeEventEmitter):
 
     async def power_off(self) -> None:
         if self.powered_on:
+            if self.le_rpa_periodic_update_task:
+                self.le_rpa_periodic_update_task.cancel()
+
             await self.host.flush()
+
             self.powered_on = False
 
+    async def update_rpa(self) -> bool:
+        """
+        Try to update the RPA.
+
+        Returns:
+          True if the RPA was updated, False if it could not be updated.
+        """
+
+        # Check if this is a good time to rotate the address
+        if self.is_advertising or self.is_scanning or self.is_le_connecting:
+            logger.debug('skipping RPA update')
+            return False
+
+        random_address = Address.generate_private_address(self.irk)
+        response = await self.send_command(
+            HCI_LE_Set_Random_Address_Command(random_address=self.random_address)
+        )
+        if response.return_parameters == HCI_SUCCESS:
+            logger.info(f'new RPA: {random_address}')
+            self.random_address = random_address
+            return True
+        else:
+            logger.warning(f'failed to set RPA: {response.return_parameters}')
+            return False
+
+    async def _run_rpa_periodic_update(self) -> None:
+        """Update the RPA periodically"""
+        while self.le_rpa_timeout != 0:
+            await asyncio.sleep(self.le_rpa_timeout)
+            if not self.update_rpa():
+                logger.debug("periodic RPA update failed")
+
     async def refresh_resolving_list(self) -> None:
         assert self.keystore is not None
 
@@ -4871,5 +4925,6 @@ class Device(CompositeEventEmitter):
         return (
             f'Device(name="{self.name}", '
             f'random_address="{self.random_address}", '
-            f'public_address="{self.public_address}")'
+            f'public_address="{self.public_address}", '
+            f'static_address="{self.static_address}")'
         )

bumble/smp.py

@@ -1076,9 +1076,9 @@ class Session:
 
     def send_identity_address_command(self) -> None:
         identity_address = {
-            None: self.connection.self_address,
+            None: self.manager.device.static_address,
             Address.PUBLIC_DEVICE_ADDRESS: self.manager.device.public_address,
-            Address.RANDOM_DEVICE_ADDRESS: self.manager.device.random_address,
+            Address.RANDOM_DEVICE_ADDRESS: self.manager.device.static_address,
         }[self.pairing_config.identity_address_type]
         self.send_command(
             SMP_Identity_Address_Information_Command(

examples/device_with_rpa.json

@@ -0,0 +1,7 @@
+{
+    "name": "Bumble",
+    "address": "F0:F1:F2:F3:F4:F5",
+    "keystore": "JsonKeyStore",
+    "irk": "865F81FF5A8B486EAAE29A27AD9F77DC",
+    "le_privacy_enabled": true
+}

tests/device_test.py

@@ -276,34 +276,6 @@ async def test_legacy_advertising():
     assert not device.is_advertising
 
 
-# -----------------------------------------------------------------------------
-@pytest.mark.parametrize(
-    'own_address_type,',
-    (OwnAddressType.PUBLIC, OwnAddressType.RANDOM),
-)
-@pytest.mark.asyncio
-async def test_legacy_advertising_connection(own_address_type):
-    device = Device(host=mock.AsyncMock(Host))
-    peer_address = Address('F0:F1:F2:F3:F4:F5')
-
-    # Start advertising
-    await device.start_advertising()
-    device.on_connection(
-        0x0001,
-        BT_LE_TRANSPORT,
-        peer_address,
-        BT_PERIPHERAL_ROLE,
-        ConnectionParameters(0, 0, 0),
-    )
-
-    if own_address_type == OwnAddressType.PUBLIC:
-        assert device.lookup_connection(0x0001).self_address == device.public_address
-    else:
-        assert device.lookup_connection(0x0001).self_address == device.random_address
-
-    await async_barrier()
-
-
 # -----------------------------------------------------------------------------
 @pytest.mark.parametrize(
     'auto_restart,',