Files
trezor-agent/libagent/device/trezor.py
2020-04-09 14:41:56 +02:00

138 lines
5.2 KiB
Python

"""TREZOR-related code (see http://bitcointrezor.com/)."""
import binascii
import logging
import semver
from . import interface
log = logging.getLogger(__name__)
class Trezor(interface.Device):
"""Connection to TREZOR device."""
@classmethod
def package_name(cls):
"""Python package name (at PyPI)."""
return 'trezor-agent'
@property
def _defs(self):
from . import trezor_defs
return trezor_defs
required_version = '>=1.4.0'
ui = None # can be overridden by device's users
cached_session_id = None
def _verify_version(self, connection):
f = connection.features
log.debug('connected to %s %s', self, f.device_id)
log.debug('label : %s', f.label)
log.debug('vendor : %s', f.vendor)
current_version = '{}.{}.{}'.format(f.major_version,
f.minor_version,
f.patch_version)
log.debug('version : %s', current_version)
log.debug('revision : %s', binascii.hexlify(f.revision))
if not semver.match(current_version, self.required_version):
fmt = ('Please upgrade your {} firmware to {} version'
' (current: {})')
raise ValueError(fmt.format(self, self.required_version,
current_version))
def connect(self):
"""Enumerate and connect to the first available interface."""
transport = self._defs.find_device()
if not transport:
raise interface.NotFoundError('{} not connected'.format(self))
log.debug('using transport: %s', transport)
for _ in range(5): # Retry a few times in case of PIN failures
connection = self._defs.Client(transport=transport,
ui=self.ui,
session_id=self.__class__.cached_session_id)
self._verify_version(connection)
try:
# unlock PIN and passphrase
self._defs.get_address(connection,
"Testnet",
self._defs.PASSPHRASE_TEST_PATH)
return connection
except (self._defs.PinException, ValueError) as e:
log.error('Invalid PIN: %s, retrying...', e)
continue
except Exception as e:
log.exception('ping failed: %s', e)
connection.close() # so the next HID open() will succeed
raise
def close(self):
"""Close connection."""
self.__class__.cached_session_id = self.conn.session_id
super().close()
def pubkey(self, identity, ecdh=False):
"""Return public key."""
curve_name = identity.get_curve_name(ecdh=ecdh)
log.debug('"%s" getting public key (%s) from %s',
identity.to_string(), curve_name, self)
addr = identity.get_bip32_address(ecdh=ecdh)
result = self._defs.get_public_node(
self.conn,
n=addr,
ecdsa_curve_name=curve_name)
log.debug('result: %s', result)
return bytes(result.node.public_key)
def _identity_proto(self, identity):
result = self._defs.IdentityType()
for name, value in identity.items():
setattr(result, name, value)
return result
def sign(self, identity, blob):
"""Sign given blob and return the signature (as bytes)."""
curve_name = identity.get_curve_name(ecdh=False)
log.debug('"%s" signing %r (%s) on %s',
identity.to_string(), blob, curve_name, self)
try:
result = self._defs.sign_identity(
self.conn,
identity=self._identity_proto(identity),
challenge_hidden=blob,
challenge_visual='',
ecdsa_curve_name=curve_name)
log.debug('result: %s', result)
assert len(result.signature) == 65
assert result.signature[:1] == b'\x00'
return bytes(result.signature[1:])
except self._defs.TrezorFailure as e:
msg = '{} error: {}'.format(self, e)
log.debug(msg, exc_info=True)
raise interface.DeviceError(msg)
def ecdh(self, identity, pubkey):
"""Get shared session key using Elliptic Curve Diffie-Hellman."""
curve_name = identity.get_curve_name(ecdh=True)
log.debug('"%s" shared session key (%s) for %r from %s',
identity.to_string(), curve_name, pubkey, self)
try:
result = self._defs.get_ecdh_session_key(
self.conn,
identity=self._identity_proto(identity),
peer_public_key=pubkey,
ecdsa_curve_name=curve_name)
log.debug('result: %s', result)
assert len(result.session_key) in {65, 33} # NIST256 or Curve25519
assert result.session_key[:1] == b'\x04'
return bytes(result.session_key)
except self._defs.TrezorFailure as e:
msg = '{} error: {}'.format(self, e)
log.debug(msg, exc_info=True)
raise interface.DeviceError(msg)