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mirror of https://github.com/trezor/trezor-firmware.git synced 2025-05-21 00:08:46 +00:00
trezor-firmware/python/src/trezorlib/transport/bridge.py
2025-04-22 09:19:07 +02:00

235 lines
7.6 KiB
Python

# This file is part of the Trezor project.
#
# Copyright (C) 2012-2022 SatoshiLabs and contributors
#
# This library is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3
# as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the License along with this library.
# If not, see <https://www.gnu.org/licenses/lgpl-3.0.html>.
from __future__ import annotations
import logging
import typing as t
import requests
from typing_extensions import Self
from ..client import ProtocolVersion
from ..log import DUMP_PACKETS
from . import DeviceIsBusy, Transport, TransportException
if t.TYPE_CHECKING:
from ..models import TrezorModel
LOG = logging.getLogger(__name__)
TREZORD_HOST = "http://127.0.0.1:21325"
TREZORD_ORIGIN_HEADER = {"Origin": "https://python.trezor.io"}
TREZORD_VERSION_MODERN = (2, 0, 25)
TREZORD_VERSION_THP_SUPPORT = (2, 0, 31) # TODO add correct value
CONNECTION = requests.Session()
CONNECTION.headers.update(TREZORD_ORIGIN_HEADER)
class BridgeException(TransportException):
def __init__(self, path: str, status: int, message: str) -> None:
self.path = path
self.status = status
self.message = message
super().__init__(f"trezord: {path} failed with code {status}: {message}")
def call_bridge(
path: str, data: str | None = None, timeout: float | None = None
) -> requests.Response:
url = TREZORD_HOST + "/" + path
r = CONNECTION.post(url, data=data, timeout=timeout)
if r.status_code != 200:
raise BridgeException(path, r.status_code, r.json()["error"])
return r
def get_bridge_version() -> t.Tuple[int, ...]:
config = call_bridge("configure").json()
return tuple(map(int, config["version"].split(".")))
def is_legacy_bridge() -> bool:
return get_bridge_version() < TREZORD_VERSION_MODERN
def supports_protocolV2() -> bool:
return get_bridge_version() >= TREZORD_VERSION_THP_SUPPORT
def detect_protocol_version(transport: "BridgeTransport") -> int:
from .. import mapping, messages
from ..messages import FailureType
protocol_version = ProtocolVersion.PROTOCOL_V1
request_type, request_data = mapping.DEFAULT_MAPPING.encode(messages.Initialize())
transport.open()
transport.write_chunk(request_type.to_bytes(2, "big") + request_data)
response = transport.read_chunk()
response_type = int.from_bytes(response[:2], "big")
response_data = response[2:]
response = mapping.DEFAULT_MAPPING.decode(response_type, response_data)
if isinstance(response, messages.Failure):
if response.code == FailureType.InvalidProtocol:
LOG.debug("Protocol V2 detected")
protocol_version = ProtocolVersion.PROTOCOL_V2
return protocol_version
def _is_transport_valid(transport: "BridgeTransport") -> bool:
is_valid = detect_protocol_version(transport) == ProtocolVersion.PROTOCOL_V1
if not is_valid:
LOG.warning("Detected unsupported Bridge transport!")
return is_valid
def filter_invalid_bridge_transports(
transports: t.Iterable["BridgeTransport"],
) -> t.Sequence["BridgeTransport"]:
"""Filters out invalid bridge transports. Keeps only valid ones."""
return [t for t in transports if _is_transport_valid(t)]
class BridgeHandle:
def __init__(self, transport: "BridgeTransport") -> None:
self.transport = transport
def read_buf(self, timeout: float | None = None) -> bytes:
raise NotImplementedError
def write_buf(self, buf: bytes) -> None:
raise NotImplementedError
class BridgeHandleModern(BridgeHandle):
def write_buf(self, buf: bytes) -> None:
LOG.log(DUMP_PACKETS, f"sending message: {buf.hex()}")
self.transport._call("post", data=buf.hex())
def read_buf(self, timeout: float | None = None) -> bytes:
data = self.transport._call("read", timeout=timeout)
LOG.log(DUMP_PACKETS, f"received message: {data.text}")
return bytes.fromhex(data.text)
class BridgeHandleLegacy(BridgeHandle):
def __init__(self, transport: "BridgeTransport") -> None:
super().__init__(transport)
self.request: str | None = None
def write_buf(self, buf: bytes) -> None:
if self.request is not None:
raise TransportException("Can't write twice on legacy Bridge")
self.request = buf.hex()
def read_buf(self, timeout: float | None = None) -> bytes:
if self.request is None:
raise TransportException("Can't read without write on legacy Bridge")
try:
LOG.log(DUMP_PACKETS, f"calling with message: {self.request}")
data = self.transport._call("call", data=self.request, timeout=timeout)
LOG.log(DUMP_PACKETS, f"received response: {data.text}")
return bytes.fromhex(data.text)
finally:
self.request = None
class BridgeTransport(Transport):
"""
BridgeTransport implements transport through Trezor Bridge (aka trezord).
"""
PATH_PREFIX = "bridge"
ENABLED: bool = True
CHUNK_SIZE = None
def __init__(
self, device: dict[str, t.Any], legacy: bool, debug: bool = False
) -> None:
if legacy and debug:
raise TransportException("Debugging not supported on legacy Bridge")
self.device = device
self.session: str | None = device["session"]
self.debug = debug
self.legacy = legacy
if legacy:
self.handle: BridgeHandle = BridgeHandleLegacy(self)
else:
self.handle = BridgeHandleModern(self)
def get_path(self) -> str:
return f"{self.PATH_PREFIX}:{self.device['path']}"
def find_debug(self) -> Self:
if not self.device.get("debug"):
raise TransportException("Debug device not available")
return self.__class__(self.device, self.legacy, debug=True)
def _call(
self,
action: str,
data: str | None = None,
timeout: float | None = None,
) -> requests.Response:
session = self.session or "null"
uri = action + "/" + str(session)
if self.debug:
uri = "debug/" + uri
return call_bridge(uri, data=data, timeout=timeout)
@classmethod
def enumerate(
cls, _models: t.Iterable[TrezorModel] | None = None
) -> t.Iterable["BridgeTransport"]:
try:
legacy = is_legacy_bridge()
return filter_invalid_bridge_transports(
[
BridgeTransport(dev, legacy)
for dev in call_bridge("enumerate").json()
]
)
except Exception:
return []
def open(self) -> None:
try:
data = self._call("acquire/" + self.device["path"])
except BridgeException as e:
if e.message == "wrong previous session":
raise DeviceIsBusy(self.device["path"]) from e
raise
self.session = data.json()["session"]
def close(self) -> None:
if not self.session:
return
self._call("release")
self.session = None
def write_chunk(self, chunk: bytes) -> None:
self.handle.write_buf(chunk)
def read_chunk(self, timeout: float | None = None) -> bytes:
return self.handle.read_buf(timeout=timeout)
def ping(self) -> bool:
return self.session is not None