chameleond/utils/pairing_agent.py

# -*- coding: utf-8 -*-
# Copyright 2020 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""This module provides the functionality of a bluez pairing agent."""

from __future__ import print_function

import logging              # pylint: disable=cros-logging-import

import dbus                 # pylint: disable=import-error
import dbus.service         # pylint: disable=import-error
import dbus.mainloop.glib   # pylint: disable=import-error

try:
  from gi.repository import GObject
except ImportError:
  import gobject as GObject


BUS_NAME = 'org.bluez'
AGENT_INTERFACE = 'org.bluez.Agent1'
AGENT_MANAGER_INTERFACE = 'org.bluez.AgentManager1'
DEVICE_INTERFACE = 'org.bluez.Device1'
PROP_INTERFACE = 'org.freedesktop.DBus.Properties'

BLUEZ_OBJECT_PATH = dbus.ObjectPath('/org/bluez')
AGENT_PATH = dbus.ObjectPath('/test/agent')

agent = None
bus = None
mainloop = None


class Agent(dbus.service.Object):
  """A Pairing Agent"""

  PASSKEY = dbus.UInt32(123456)
  PIN = dbus.String('0000')

  def __init__(self, *args, **kwargs):
    super(Agent, self).__init__(*args, **kwargs)
    self._passkey = None
    self._pin = None


  def SetPin(self, pin):
    self._pin = dbus.String(pin)


  def SetPasskey(self, passkey):
    self._passkey = dbus.UInt32(passkey)


  def SetTrusted(self, path):
    props = dbus.Interface(bus.get_object(BUS_NAME, path), PROP_INTERFACE)
    props.Set(DEVICE_INTERFACE, 'Trusted', True)


  @dbus.service.method(AGENT_INTERFACE, in_signature='', out_signature='')
  def Release(self):
    global mainloop   # pylint: disable=global-statement

    logging.info('Release')
    mainloop.quit()
    mainloop = None
    logging.debug('mainloop quit')


  @dbus.service.method(AGENT_INTERFACE, in_signature='os', out_signature='')
  def AuthorizeService(self, device, uuid):
    logging.info('AuthorizeService (%s, %s)', device, uuid)


  @dbus.service.method(AGENT_INTERFACE, in_signature='o', out_signature='s')
  def RequestPinCode(self, device):
    logging.info('RequestPinCode (%s)', device)
    self.SetTrusted(device)
    return self._pin or self.PIN


  @dbus.service.method(AGENT_INTERFACE, in_signature='o', out_signature='u')
  def RequestPasskey(self, device):
    logging.info('RequestPasskey (%s)', device)
    self.SetTrusted(device)
    return self._passkey or self.PASSKEY


  @dbus.service.method(AGENT_INTERFACE, in_signature='ouq', out_signature='')
  def DisplayPasskey(self, device, passkey, entered):
    logging.info('DisplayPasskey (%s, %06u entered %u)',
                 device, passkey, entered)


  @dbus.service.method(AGENT_INTERFACE, in_signature='os', out_signature='')
  def DisplayPinCode(self, device, pincode):
    logging.info('DisplayPinCode (%s, %s)', device, pincode)


  @dbus.service.method(AGENT_INTERFACE, in_signature='ou', out_signature='')
  def RequestConfirmation(self, device, passkey):
    logging.info('RequestConfirmation (%s, %06d)', device, passkey)
    self.SetTrusted(device)


  @dbus.service.method(AGENT_INTERFACE, in_signature='o', out_signature='')
  def RequestAuthorization(self, device):
    logging.info('RequestAuthorization (%s)', device)


  @dbus.service.method(AGENT_INTERFACE, in_signature='', out_signature='')
  def Cancel(self):
    logging.info('Cancel')


def SetupAgent(capability):
  """Setup a pairing agent.

  Args:
    capability: the capability of the device. The capability parameter can
                have the values: DisplayOnly, DisplayYesNo, KeyboardOnly,
                NoInputNoOutput and KeyboardDisplay.
  """
  global agent      # pylint: disable=global-statement
  global bus        # pylint: disable=global-statement
  global mainloop   # pylint: disable=global-statement

  dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
  bus = dbus.SystemBus()
  agent = Agent(bus, AGENT_PATH)
  mainloop = GObject.MainLoop()

  bluez_obj = bus.get_object(BUS_NAME, BLUEZ_OBJECT_PATH)
  agent_manager = dbus.Interface(bluez_obj, AGENT_MANAGER_INTERFACE)
  agent_manager.RegisterAgent(AGENT_PATH, dbus.String(capability))
  logging.info('Agent registered')

  agent_manager.RequestDefaultAgent(AGENT_PATH)
  mainloop.run()

  agent_manager.UnregisterAgent(AGENT_PATH)
  logging.info('Agent unregistered')


def StopAgent():
  global agent      # pylint: disable=global-statement

  agent.Release()
  agent = None


if __name__ == '__main__':
  SetupAgent('NoInputNoOutput')