1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
#!/usr/bin/env python3
#
# SPDX-FileCopyrightText: © 2019 The usbmon-tools Authors
# SPDX-FileCopyrightText: © 2019 The freestyle-hid Authors
#
# SPDX-License-Identifier: Apache-2.0
import logging
import sys
from typing import BinaryIO, Optional, Sequence
import click
import click_log
import construct
import usbmon
import usbmon.pcapng
from usbmon.tools import _utils
logger = logging.getLogger()
click_log.basic_config(logger)
_SERIAL_NUMBER_RESPONSE_TYPE = 0x06
_ENCRYPTION_SETUP_REQ_TYPE = 0x14
_ENCRYPTION_SETUP_RESP_TYPE = 0x33
_START_AUTHORIZE_CMD = 0x11
_CHALLENGE_CMD = 0x16
_CHALLENGE_RESPONSE_CMD = 0x17
_ABBOTT_VENDOR_ID = 0x1A61
_LIBRE2_PRODUCT_ID = 0x3950
_SERIAL_NO = construct.Struct(
message_type=construct.Const(_SERIAL_NUMBER_RESPONSE_TYPE, construct.Byte),
length=construct.Const(14, construct.Byte),
serial_number=construct.PaddedString(13, "ascii"),
termination=construct.Const(0, construct.Byte),
)
_CHALLENGE = construct.Struct(
message_type=construct.Const(_ENCRYPTION_SETUP_RESP_TYPE, construct.Byte),
length=construct.Const(16, construct.Byte),
subcmd=construct.Const(_CHALLENGE_CMD, construct.Byte),
challenge=construct.Bytes(8),
iv=construct.Bytes(7),
)
_CHALLENGE_RESPONSE = construct.Struct(
message_type=construct.Const(_ENCRYPTION_SETUP_REQ_TYPE, construct.Byte),
length=construct.Const(26, construct.Byte),
subcmd=construct.Const(_CHALLENGE_RESPONSE_CMD, construct.Byte),
challenge_response_encrypted=construct.Bytes(16),
const=construct.Const(1, construct.Byte),
mac=construct.Bytes(8),
)
@click.command()
@click_log.simple_verbosity_option(logger, "--vlog")
@click.option(
"--device-address",
help=(
"Device address (busnum.devnum) of the device to extract capture"
" of. If none provided, device descriptors will be relied on."
),
type=_utils.DeviceAddressType(),
)
@click.argument(
"pcap-files",
type=click.File(mode="rb"),
nargs=None,
)
def main(
*,
device_address: Optional[usbmon.addresses.DeviceAddress],
pcap_files: Sequence[BinaryIO],
):
if sys.version_info < (3, 7):
raise Exception("Unsupported Python version, please use at least Python 3.7.")
for pcap_file in pcap_files:
session = usbmon.pcapng.parse_stream(pcap_file, retag_urbs=False)
if not device_address:
for descriptor in session.device_descriptors.values():
if (
descriptor.vendor_id == _ABBOTT_VENDOR_ID
and descriptor.product_id == _LIBRE2_PRODUCT_ID
):
if device_address and device_address != descriptor.address:
raise Exception(
"Multiple Libre2 devices present in capture, please"
" provide a --device-address flag."
)
device_address = descriptor.address
else:
device_address = descriptor.address
assert device_address is not None
if device_address in session.device_descriptors:
descriptor = session.device_descriptors[device_address]
assert descriptor.vendor_id == _ABBOTT_VENDOR_ID
assert descriptor.product_id == _LIBRE2_PRODUCT_ID
serial_number = "UNKNOWN"
challenge = "UNKNOWN"
iv = "UNKNOWN"
encrypted_challenge = "UNKNOWN"
mac = "UNKNOWN"
for first, second in session.in_pairs():
# Ignore stray callbacks/errors.
if not first.type == usbmon.constants.PacketType.SUBMISSION:
continue
if not first.address.device_address == device_address:
# No need to check second, they will be linked.
continue
if first.xfer_type == usbmon.constants.XferType.INTERRUPT:
pass
elif (
first.xfer_type == usbmon.constants.XferType.CONTROL
and not first.setup_packet
or first.setup_packet.type == usbmon.setup.Type.CLASS # type: ignore
):
pass
else:
continue
if first.direction == usbmon.constants.Direction.OUT:
packet = first
else:
assert second is not None
packet = second
if not packet.payload:
continue
assert len(packet.payload) >= 2
message_type = packet.payload[0]
if message_type == _SERIAL_NUMBER_RESPONSE_TYPE:
obj = _SERIAL_NO.parse(packet.payload)
serial_number = obj.serial_number
elif (
message_type == _ENCRYPTION_SETUP_RESP_TYPE
and packet.payload[2] == _CHALLENGE_CMD
):
obj = _CHALLENGE.parse(packet.payload)
challenge = obj.challenge.hex()
iv = obj.iv.hex()
elif (
message_type == _ENCRYPTION_SETUP_REQ_TYPE
and packet.payload[2] == _CHALLENGE_RESPONSE_CMD
):
obj = _CHALLENGE_RESPONSE.parse(packet.payload)
encrypted_challenge = obj.challenge_response_encrypted.hex()
mac = obj.mac.hex()
print(f"{serial_number},{challenge},{iv},{encrypted_challenge},{mac}")
if __name__ == "__main__":
main()
|
