#!/usr/bin/env python3 # Enable NFC on Linux (CCID/PCSCD) # Dell E7470 # Dell ControlVault2 # BCM20795 (20795A1) import binascii import logging import math import struct import sys import time import usb.core import usb.util SUPPORTED_DEVICES = [ {'idVendor': 0x0A5C, 'idProduct': 0x5834}, ] logging.basicConfig(level=logging.DEBUG) logger = logging.getLogger(__name__) def to_hex(val): return ' '.join([bytes([i]).hex() for i in val]) class BcmCommunicator: def __init__(self, device, bulk_in, bulk_out): self.logger = logging.getLogger(__name__) self.device = device self.bulk_in = bulk_in self.bulk_out = bulk_out def ctrl_transfer(self, *args, **kwargs): self.logger.debug('Control: {} {}'.format(args, kwargs)) return self.device.ctrl_transfer(*args, **kwargs) def write(self, *args, **kwargs): return self.bulk_out.write(*args, **kwargs) def read(self, *args, **kwargs): return self.bulk_in.read(*args, **kwargs) def send_packet(self, payload): packet_type = 0x01 unknown1 = 0x00 length = len(payload) packet = struct.pack('>BBH', packet_type, unknown1, length) + payload self.logger.debug('Put: {}'.format(to_hex(packet))) self.write(packet) def recv_packet(self): packet = self.read(64, timeout=5000).tobytes() tag = packet[0:2] if tag != b'\x00\x00': raise Exception('Unknown tag: {}'.format(tag.hex())) length = packet[2:4] length = struct.unpack('>H', length)[0] for i in range(0, math.ceil(length/64) - 1): packet += self.read(64).tobytes() self.logger.debug('Got: {}'.format(to_hex(packet))) return packet[4:] def talk(self, exchange): for packet in exchange: self.send_packet(bytes.fromhex(packet)) data = self.recv_packet() if data[1] == 0x61: packet = self.recv_packet() @staticmethod def _dev_match(template, candidate): for prop, value in template.items(): if prop not in candidate.__dict__ or candidate.__dict__[prop] != value: return False return True @classmethod def _dev_matcher(cls, dev): for device in SUPPORTED_DEVICES: if cls._dev_match(device, dev): return True return False @classmethod def find(cls): logger = logging.getLogger(__name__) logger.info('Looking for BCM device...') device = usb.core.find(custom_match=cls._dev_matcher) if device is None: raise Exception('Cannot find BCM device - check list of supported devices') logger.info('Found {:04X}:{:04X}'.format(device.idVendor, device.idProduct)) logger.debug('Enumerating interfaces...') configuration = device.get_active_configuration() bcm_interface = None for interface in configuration: if interface.bInterfaceClass == 0xff and interface.iInterface == 0x08: if bcm_interface is not None: raise Exception('More than one vendor-specific interface found!') bcm_interface = interface if bcm_interface is None: raise Exception('Cannot find vendor-specific interface') logger.debug('Interface found: {}'.format(bcm_interface._str())) logger.debug('Enumerating endpoints...') bulk_in = None bulk_out = None for endpoint in bcm_interface: if endpoint.bmAttributes & usb.util._ENDPOINT_TRANSFER_TYPE_MASK == usb.util.ENDPOINT_TYPE_BULK: if endpoint.bEndpointAddress & usb.util._ENDPOINT_DIR_MASK == usb.util.ENDPOINT_IN: if bulk_in is not None: raise Exception('More than one BULK IN endpoint found!') bulk_in = endpoint logger.debug('BULK IN found: {}'.format(bulk_in._str())) if endpoint.bEndpointAddress & usb.util._ENDPOINT_DIR_MASK == usb.util.ENDPOINT_OUT: if bulk_out is not None: raise Exception('More than one BULK OUT endpoint found!') bulk_out = endpoint logger.debug('BULK OUT found: {}'.format(bulk_out._str())) if bulk_in is None: raise Exception('BULK IN endpoint not found!') if bulk_out is None: raise Exception('BULK OUT endpoint not found!') logger.debug('Returning {} object...'.format(cls.__name__)) return cls(device, bulk_in, bulk_out) turn_on_seq1 = [ "10 2f 04 00", "10 2f 1d 03 05 90 65", "10 2f 2d 00", "10 2f 11 01 f7", "01 27 fc 0c 08 00 01 00 01 00 00 00 00 00 00 00", ] turn_on_seq2 = [ "10 20 00 01 01", "10 20 01 02 01 00", "10 20 02 67 01 b9 64 01 00 ff ff 50 00 8b 13 00 10 00 06 00 00 00 00 00 ff 00 00 00 ff 00 00 04 00 00 00 00 03 00 00 00 03 00 0c 00 00 0d 00 00 00 00 00 00 00 00 00 00 33 23 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 03 00 02 53 3b 0f 00 00 00 00 00 00 00 00 00 00 00 00 04 00 00 00 00 00 00 00", "10 20 02 90 0a ca 05 00 00 00 00 2c 80 01 01 b0 05 01 03 03 03 08 b5 03 01 03 ff c9 0d 24 00 00 00 01 00 bb 00 e4 00 0a 01 02 d6 0d 01 02 00 00 00 00 00 01 00 01 5a 00 8a b2 02 e8 03 c8 1e 06 1f 00 0a 00 30 00 04 24 00 1c 00 75 00 77 00 76 00 1c 00 03 00 0a 00 56 01 00 00 40 04 d7 01 07 dd 32 00 00 00 29 16 08 08 06 04 00 00 00 1f 27 0a 6d 20 00 52 20 00 00 00 01 85 00 00 32 1f 00 00 02 0a 16 00 02 55 55 55 55 55 55 55 55 55 55 55 55 55 1e", "10 20 02 06 01 b7 03 02 00 01", "10 2f 06 01 01", "10 20 02 0e 02 51 08 20 79 ff ff ff ff ff ff 58 01 07", "10 21 00 07 02 04 03 02 05 03 03", "10 20 02 17 01 29 14 46 66 6d 01 01 11 02 02 07 ff 03 02 00 13 04 01 64 07 01 03", "10 20 02 1a 02 61 14 46 66 6d 01 01 11 02 02 07 ff 03 02 00 13 04 01 64 07 01 03 60 01 07", "10 20 02 10 05 30 01 04 31 01 00 32 01 40 38 01 00 50 01 02", "10 20 02 05 01 00 02 fa 00", "10 20 02 0b 01 c2 08 01 08 00 04 80 c3 c9 01", "10 21 03 0d 06 00 01 01 01 02 01 80 01 82 01 06 01", ] def turn_on(communicator): communicator.ctrl_transfer(0x41, 0, 1, 3) communicator.talk(turn_on_seq1) communicator.ctrl_transfer(0x41, 1, 0, 3) communicator.talk(turn_on_seq2) communicator.ctrl_transfer(0x41, 1, 1, 3) def turn_off(communicator): communicator.ctrl_transfer(0x41, 1, 0, 3) communicator.ctrl_transfer(0x41, 0, 0, 3) if __name__ == "__main__": if len(sys.argv) < 2: print('Usage: {} [on|off]'.format(sys.argv[0])) sys.exit(2) communicator = BcmCommunicator.find() if sys.argv[1] == 'on': logger.info('Turning NFC on...') turn_on(communicator) logger.info('NFC should be turned on now!') elif sys.argv[1] == 'off': logger.info('Turning NFC off...') turn_off(communicator) logger.info('NFC should be turned off now!') else: raise Exception('Unknown option: {}'.format(sys.argv[1]))