add passkey delegate

2026-04-16 00:25:31 +00:00 · 2025-06-09 12:20:06 -04:00
parent 8614e075b6
commit d631156f6c
3 changed files with 157 additions and 31 deletions
--- a/examples/run_gatt_server_with_pairing_delegate.py
+++ b/examples/run_gatt_server_with_pairing_delegate.py
@@ -0,0 +1,111 @@
+# Copyright 2021-2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# -----------------------------------------------------------------------------
+# Imports
+# -----------------------------------------------------------------------------
+import asyncio
+import sys
+import os
+import logging
+
+from bumble.device import Device
+from bumble.transport import open_transport_or_link
+from bumble.gatt import (
+    Service,
+    Characteristic,
+)
+from bumble.pairing import PairingConfig, PairingDelegate
+
+
+# -----------------------------------------------------------------------------
+class FixedPinPairingDelegate(PairingDelegate):
+    """
+    A PairingDelegate that declares that the device only has the ability to display
+    a passkey but not to enter or confirm one. When asked for the passkey to use for
+    pairing, this delegate returns a fixed value (instead of the default, which  is
+    to generate a random value each time). This is obviously not a secure way to do
+    pairing, but it used here as an illustration of how a delegate can override the
+    default passkey generation.
+    """
+
+    def __init__(self, passkey: int) -> None:
+        super().__init__(io_capability=PairingDelegate.IoCapability.DISPLAY_OUTPUT_ONLY)
+        self.passkey = passkey
+
+    async def generate_passkey(self) -> int:
+        return self.passkey
+
+
+# -----------------------------------------------------------------------------
+async def main() -> None:
+    if len(sys.argv) < 3:
+        print(
+            'Usage: run_gatt_server_with_pairing_delegate.py <device-config> <transport-spec> '
+        )
+        print('example: run_gatt_server_with_pairing_delegate.py device1.json usb:0')
+        return
+
+    print('<<< connecting to HCI...')
+    async with await open_transport_or_link(sys.argv[2]) as hci_transport:
+        print('<<< connected')
+
+        # Create a device to manage the host
+        device = Device.from_config_file_with_hci(
+            sys.argv[1], hci_transport.source, hci_transport.sink
+        )
+
+        # Add a service with a single characteristic.
+        # The characteristic requires authentication, so reading it on a non-paired
+        # connection will return an error.
+        custom_service1 = Service(
+            '50DB505C-8AC4-4738-8448-3B1D9CC09CC5',
+            [
+                Characteristic(
+                    '486F64C6-4B5F-4B3B-8AFF-EDE134A8446A',
+                    Characteristic.Properties.READ,
+                    Characteristic.READABLE
+                    | Characteristic.READ_REQUIRES_AUTHENTICATION,
+                    bytes('hello', 'utf-8'),
+                ),
+            ],
+        )
+        device.add_services([custom_service1])
+
+        # Debug print
+        for attribute in device.gatt_server.attributes:
+            print(attribute)
+
+        # Setup pairing
+        device.pairing_config_factory = lambda connection: PairingConfig(
+            delegate=FixedPinPairingDelegate(123456)
+        )
+
+        # Get things going
+        await device.power_on()
+
+        # Connect to a peer
+        if len(sys.argv) > 3:
+            target_address = sys.argv[3]
+            print(f'=== Connecting to {target_address}...')
+            await device.connect(target_address)
+        else:
+            await device.start_advertising(auto_restart=True)
+
+        await hci_transport.source.wait_for_termination()
+
+
+# -----------------------------------------------------------------------------
+logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'DEBUG').upper())
+asyncio.run(main())