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trezor-firmware/trezorlib/transport_hid.py
2016-06-28 09:51:57 +02:00

145 lines
4.3 KiB
Python

'''USB HID implementation of Transport.'''
import hid
import time
from .transport import TransportV1, TransportV2, ConnectionError
def enumerate():
"""
Return a list of available TREZOR devices.
"""
devices = {}
for d in hid.enumerate(0, 0):
vendor_id = d['vendor_id']
product_id = d['product_id']
serial_number = d['serial_number']
interface_number = d['interface_number']
path = d['path']
# HIDAPI on Mac cannot detect correct HID interfaces, so device with
# DebugLink doesn't work on Mac...
if devices.get(serial_number) != None and devices[serial_number][0] == path:
raise Exception("Two devices with the same path and S/N found. This is Mac, right? :-/")
if (vendor_id, product_id) in DEVICE_IDS:
devices.setdefault(serial_number, [None, None])
if interface_number == 0 or interface_number == -1: # normal link
devices[serial_number][0] = path
elif interface_number == 1: # debug link
devices[serial_number][1] = path
# List of two-tuples (path_normal, path_debuglink)
return list(devices.values())
def path_to_transport(path):
try:
device = [ d for d in hid.enumerate(0, 0) if d['path'] == path ][0]
except IndexError:
raise ConnectionError("Connection failed")
# VID/PID found, let's find proper transport
try:
transport = DEVICE_TRANSPORTS[(device['vendor_id'], device['product_id'])]
except IndexError:
raise Exception("Unknown transport for VID:PID %04x:%04x" % (vid, pid))
return transport
class _HidTransport(object):
def __init__(self, device, *args, **kwargs):
self.hid = None
self.hid_version = None
device = device[int(bool(kwargs.get('debug_link')))]
super(_HidTransport, self).__init__(device, *args, **kwargs)
def is_connected(self):
"""
Check if the device is still connected.
"""
for d in hid.enumerate(0, 0):
if d['path'] == self.device:
return True
return False
def _open(self):
self.hid = hid.device()
self.hid.open_path(self.device)
self.hid.set_nonblocking(True)
# determine hid_version
r = self.hid.write([0, 63, ] + [0xFF] * 63)
if r == 65:
self.hid_version = 2
return
r = self.hid.write([63, ] + [0xFF] * 63)
if r == 64:
self.hid_version = 1
return
raise ConnectionError("Unknown HID version")
def _close(self):
self.hid.close()
self.hid = None
def _write_chunk(self, chunk):
if len(chunk) != 64:
raise Exception("Unexpected data length")
if self.hid_version == 2:
self.hid.write(b'\0' + chunk)
else:
self.hid.write(chunk)
def _read_chunk(self):
start = time.time()
while True:
data = self.hid.read(64)
if not len(data):
if time.time() - start > 10:
# Over 10 s of no response, let's check if
# device is still alive
if not self.is_connected():
raise ConnectionError("Connection failed")
# Restart timer
start = time.time()
time.sleep(0.001)
continue
break
if len(data) != 64:
raise Exception("Unexpected chunk size: %d" % len(data))
return bytearray(data)
class HidTransportV1(_HidTransport, TransportV1):
pass
class HidTransportV2(_HidTransport, TransportV2):
pass
DEVICE_IDS = [
(0x534c, 0x0001), # TREZOR
(0x1209, 0x53C0), # TREZORv2 Bootloader
(0x1209, 0x53C1), # TREZORv2
]
DEVICE_TRANSPORTS = {
(0x534c, 0x0001): HidTransportV1, # TREZOR
(0x1209, 0x53C0): HidTransportV2, # TREZORv2 Bootloader
(0x1209, 0x53C1): HidTransportV2, # TREZORv2
}
# Backward compatible wrapper, decides for proper transport
# based on VID/PID of given path
def HidTransport(device, *args, **kwargs):
transport = path_to_transport(device[0])
return transport(device, *args, **kwargs)
# Backward compatibility hack; HidTransport is a function, not a class like before
HidTransport.enumerate = enumerate