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mirror of https://github.com/trezor/trezor-firmware.git synced 2024-12-18 20:38:10 +00:00
trezor-firmware/python/src/trezorlib/debuglink.py
matejcik a58823cc0c refactor(python): rework trezorlib protobuf codec
API-compatibility with the original one is retained.

Now that we don't need to keep code parity with core, we could do some
changes that make life easier.

All generated classes are now in one file. This makes github diffs more
readable, at the cost of somewhat complicating inspecting individual
classes; however, that is something we shouldn't be doing anyway.

Enums are now implemented as enum.IntEnum.

The original class-level FIELDS member was restored.

Each field is now defined via protobuf.Field, which is easier to work
with in the codec, AND we're not stuffing defaults and flags into the
same field.
2021-06-08 09:55:19 +02:00

668 lines
22 KiB
Python

# This file is part of the Trezor project.
#
# Copyright (C) 2012-2019 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>.
import logging
import textwrap
from collections import namedtuple
from copy import deepcopy
from enum import IntEnum
from mnemonic import Mnemonic
from . import mapping, messages, protobuf
from .client import TrezorClient
from .exceptions import TrezorFailure
from .log import DUMP_BYTES
from .tools import expect
EXPECTED_RESPONSES_CONTEXT_LINES = 3
LayoutLines = namedtuple("LayoutLines", "lines text")
LOG = logging.getLogger(__name__)
def layout_lines(lines):
return LayoutLines(lines, " ".join(lines))
class DebugLink:
def __init__(self, transport, auto_interact=True):
self.transport = transport
self.allow_interactions = auto_interact
def open(self):
self.transport.begin_session()
def close(self):
self.transport.end_session()
def _call(self, msg, nowait=False):
LOG.debug(
"sending message: {}".format(msg.__class__.__name__),
extra={"protobuf": msg},
)
msg_type, msg_bytes = mapping.encode(msg)
LOG.log(
DUMP_BYTES,
"encoded as type {} ({} bytes): {}".format(
msg_type, len(msg_bytes), msg_bytes.hex()
),
)
self.transport.write(msg_type, msg_bytes)
if nowait:
return None
ret_type, ret_bytes = self.transport.read()
LOG.log(
DUMP_BYTES,
"received type {} ({} bytes): {}".format(
msg_type, len(msg_bytes), msg_bytes.hex()
),
)
msg = mapping.decode(ret_type, ret_bytes)
LOG.debug(
"received message: {}".format(msg.__class__.__name__),
extra={"protobuf": msg},
)
return msg
def state(self):
return self._call(messages.DebugLinkGetState())
def read_layout(self):
return layout_lines(self.state().layout_lines)
def wait_layout(self):
obj = self._call(messages.DebugLinkGetState(wait_layout=True))
if isinstance(obj, messages.Failure):
raise TrezorFailure(obj)
return layout_lines(obj.layout_lines)
def watch_layout(self, watch: bool) -> None:
"""Enable or disable watching layouts.
If disabled, wait_layout will not work.
The message is missing on T1. Use `TrezorClientDebugLink.watch_layout` for
cross-version compatibility.
"""
self._call(messages.DebugLinkWatchLayout(watch=watch))
def encode_pin(self, pin, matrix=None):
"""Transform correct PIN according to the displayed matrix."""
if matrix is None:
matrix = self.state().matrix
if matrix is None:
# we are on trezor-core
return pin
return "".join([str(matrix.index(p) + 1) for p in pin])
def read_recovery_word(self):
state = self.state()
return (state.recovery_fake_word, state.recovery_word_pos)
def read_reset_word(self):
state = self._call(messages.DebugLinkGetState(wait_word_list=True))
return state.reset_word
def read_reset_word_pos(self):
state = self._call(messages.DebugLinkGetState(wait_word_pos=True))
return state.reset_word_pos
def input(
self,
word=None,
button=None,
swipe=None,
x=None,
y=None,
wait=False,
hold_ms=None,
):
if not self.allow_interactions:
return
args = sum(a is not None for a in (word, button, swipe, x))
if args != 1:
raise ValueError("Invalid input - must use one of word, button, swipe")
decision = messages.DebugLinkDecision(
yes_no=button, swipe=swipe, input=word, x=x, y=y, wait=wait, hold_ms=hold_ms
)
ret = self._call(decision, nowait=not wait)
if ret is not None:
return layout_lines(ret.lines)
def click(self, click, wait=False):
x, y = click
return self.input(x=x, y=y, wait=wait)
def press_yes(self):
self.input(button=True)
def press_no(self):
self.input(button=False)
def swipe_up(self):
self.input(swipe=messages.DebugSwipeDirection.UP)
def swipe_down(self):
self.input(swipe=messages.DebugSwipeDirection.DOWN)
def swipe_right(self):
self.input(swipe=messages.DebugSwipeDirection.RIGHT)
def swipe_left(self):
self.input(swipe=messages.DebugSwipeDirection.LEFT)
def stop(self):
self._call(messages.DebugLinkStop(), nowait=True)
def reseed(self, value):
return self._call(messages.DebugLinkReseedRandom(value=value))
def start_recording(self, directory):
self._call(messages.DebugLinkRecordScreen(target_directory=directory))
def stop_recording(self):
self._call(messages.DebugLinkRecordScreen(target_directory=None))
@expect(messages.DebugLinkMemory, field="memory")
def memory_read(self, address, length):
return self._call(messages.DebugLinkMemoryRead(address=address, length=length))
def memory_write(self, address, memory, flash=False):
self._call(
messages.DebugLinkMemoryWrite(address=address, memory=memory, flash=flash),
nowait=True,
)
def flash_erase(self, sector):
self._call(messages.DebugLinkFlashErase(sector=sector), nowait=True)
@expect(messages.Success)
def erase_sd_card(self, format=True):
return self._call(messages.DebugLinkEraseSdCard(format=format))
class NullDebugLink(DebugLink):
def __init__(self):
super().__init__(None)
def open(self):
pass
def close(self):
pass
def _call(self, msg, nowait=False):
if not nowait:
if isinstance(msg, messages.DebugLinkGetState):
return messages.DebugLinkState()
else:
raise RuntimeError("unexpected call to a fake debuglink")
class DebugUI:
INPUT_FLOW_DONE = object()
def __init__(self, debuglink: DebugLink):
self.debuglink = debuglink
self.clear()
def clear(self):
self.pins = None
self.passphrase = ""
self.input_flow = None
def button_request(self, code):
if self.input_flow is None:
if code == messages.ButtonRequestType.PinEntry:
self.debuglink.input(self.get_pin())
else:
self.debuglink.press_yes()
elif self.input_flow is self.INPUT_FLOW_DONE:
raise AssertionError("input flow ended prematurely")
else:
try:
self.input_flow.send(code)
except StopIteration:
self.input_flow = self.INPUT_FLOW_DONE
def get_pin(self, code=None):
if self.pins is None:
raise RuntimeError("PIN requested but no sequence was configured")
try:
return self.debuglink.encode_pin(next(self.pins))
except StopIteration:
raise AssertionError("PIN sequence ended prematurely")
def get_passphrase(self, available_on_device):
return self.passphrase
class MessageFilter:
def __init__(self, message_type, **fields):
self.message_type = message_type
self.fields = {}
self.update_fields(**fields)
def update_fields(self, **fields):
for name, value in fields.items():
try:
self.fields[name] = self.from_message_or_type(value)
except TypeError:
self.fields[name] = value
return self
@classmethod
def from_message_or_type(cls, message_or_type):
if isinstance(message_or_type, cls):
return message_or_type
if isinstance(message_or_type, protobuf.MessageType):
return cls.from_message(message_or_type)
if isinstance(message_or_type, type) and issubclass(
message_or_type, protobuf.MessageType
):
return cls(message_or_type)
raise TypeError("Invalid kind of expected response")
@classmethod
def from_message(cls, message):
fields = {}
for field in message.FIELDS.values():
value = getattr(message, field.name)
if value in (None, [], protobuf.REQUIRED_FIELD_PLACEHOLDER):
continue
fields[field.name] = value
return cls(type(message), **fields)
def match(self, message):
if type(message) != self.message_type:
return False
for field, expected_value in self.fields.items():
actual_value = getattr(message, field, None)
if isinstance(expected_value, MessageFilter):
if not expected_value.match(actual_value):
return False
elif expected_value != actual_value:
return False
return True
def format(self, maxwidth=80):
fields = []
for field in self.message_type.FIELDS.values():
if field.name not in self.fields:
continue
value = self.fields[field.name]
if isinstance(value, IntEnum):
field_str = value.name
elif isinstance(value, MessageFilter):
field_str = value.format(maxwidth - 4)
elif isinstance(value, protobuf.MessageType):
field_str = protobuf.format_message(value)
else:
field_str = repr(value)
field_str = textwrap.indent(field_str, " ").lstrip()
fields.append((field.name, field_str))
pairs = ["{}={}".format(k, v) for k, v in fields]
oneline_str = ", ".join(pairs)
if len(oneline_str) < maxwidth:
return "{}({})".format(self.message_type.__name__, oneline_str)
else:
item = []
item.append("{}(".format(self.message_type.__name__))
for pair in pairs:
item.append(" {}".format(pair))
item.append(")")
return "\n".join(item)
class MessageFilterGenerator:
def __getattr__(self, key):
message_type = getattr(messages, key)
return MessageFilter(message_type).update_fields
message_filters = MessageFilterGenerator()
class TrezorClientDebugLink(TrezorClient):
# This class implements automatic responses
# and other functionality for unit tests
# for various callbacks, created in order
# to automatically pass unit tests.
#
# This mixing should be used only for purposes
# of unit testing, because it will fail to work
# without special DebugLink interface provided
# by the device.
def __init__(self, transport, auto_interact=True):
try:
debug_transport = transport.find_debug()
self.debug = DebugLink(debug_transport, auto_interact)
# try to open debuglink, see if it works
self.debug.open()
self.debug.close()
except Exception:
if not auto_interact:
self.debug = NullDebugLink()
else:
raise
self.ui = DebugUI(self.debug)
self.in_with_statement = 0
self.screenshot_id = 0
self.filters = {}
# Do not expect any specific response from device
self.expected_responses = None
self.current_response = None
super().__init__(transport, ui=self.ui)
def open(self):
super().open()
if self.session_counter == 1:
self.debug.open()
def close(self):
if self.session_counter == 1:
self.debug.close()
super().close()
def set_filter(self, message_type, callback):
"""Configure a filter function for a specified message type.
The `callback` must be a function that accepts a protobuf message, and returns
a (possibly modified) protobuf message of the same type. Whenever a message
is sent or received that matches `message_type`, `callback` is invoked on the
message and its result is substituted for the original.
Useful for test scenarios with an active malicious actor on the wire.
"""
self.filters[message_type] = callback
def _filter_message(self, msg):
message_type = msg.__class__
callback = self.filters.get(message_type)
if callable(callback):
return callback(deepcopy(msg))
else:
return msg
def set_input_flow(self, input_flow):
"""Configure a sequence of input events for the current with-block.
The `input_flow` must be a generator function. A `yield` statement in the
input flow function waits for a ButtonRequest from the device, and returns
its code.
Example usage:
>>> def input_flow():
>>> # wait for first button prompt
>>> code = yield
>>> assert code == ButtonRequestType.Other
>>> # press No
>>> client.debug.press_no()
>>>
>>> # wait for second button prompt
>>> yield
>>> # press Yes
>>> client.debug.press_yes()
>>>
>>> with client:
>>> client.set_input_flow(input_flow)
>>> some_call(client)
"""
if not self.in_with_statement:
raise RuntimeError("Must be called inside 'with' statement")
if callable(input_flow):
input_flow = input_flow()
if not hasattr(input_flow, "send"):
raise RuntimeError("input_flow should be a generator function")
self.ui.input_flow = input_flow
input_flow.send(None) # start the generator
def watch_layout(self, watch: bool = True) -> None:
"""Enable or disable watching layout changes.
Since trezor-core v2.3.2, it is necessary to call `watch_layout()` before
using `debug.wait_layout()`, otherwise layout changes are not reported.
"""
if self.version >= (2, 3, 2):
# version check is necessary because otherwise we cannot reliably detect
# whether and where to wait for reply:
# - T1 reports unknown debuglink messages on the wirelink
# - TT < 2.3.0 does not reply to unknown debuglink messages due to a bug
self.debug.watch_layout(watch)
def __enter__(self):
# For usage in with/expected_responses
self.in_with_statement += 1
return self
def __exit__(self, _type, value, traceback):
self.in_with_statement -= 1
# Clear input flow.
try:
if _type is not None:
# Another exception raised
return False
if self.expected_responses is None:
# no need to check anything else
return False
# Evaluate missed responses in 'with' statement
if self.current_response < len(self.expected_responses):
self._raise_unexpected_response(None)
finally:
# Cleanup
self.expected_responses = None
self.current_response = None
self.ui.clear()
self.watch_layout(False)
return False
def set_expected_responses(self, expected):
"""Set a sequence of expected responses to client calls.
Within a given with-block, the list of received responses from device must
match the list of expected responses, otherwise an AssertionError is raised.
If an expected response is given a field value other than None, that field value
must exactly match the received field value. If a given field is None
(or unspecified) in the expected response, the received field value is not
checked.
Each expected response can also be a tuple (bool, message). In that case, the
expected response is only evaluated if the first field is True.
This is useful for differentiating sequences between Trezor models:
>>> trezor_one = client.features.model == "1"
>>> client.set_expected_responses([
>>> messages.ButtonRequest(code=ConfirmOutput),
>>> (trezor_one, messages.ButtonRequest(code=ConfirmOutput)),
>>> messages.Success(),
>>> ])
"""
if not self.in_with_statement:
raise RuntimeError("Must be called inside 'with' statement")
# make sure all items are (bool, message) tuples
expected_with_validity = (
e if isinstance(e, tuple) else (True, e) for e in expected
)
# only apply those items that are (True, message)
self.expected_responses = [
MessageFilter.from_message_or_type(expected)
for valid, expected in expected_with_validity
if valid
]
self.current_response = 0
def use_pin_sequence(self, pins):
"""Respond to PIN prompts from device with the provided PINs.
The sequence must be at least as long as the expected number of PIN prompts.
"""
self.ui.pins = iter(pins)
def use_passphrase(self, passphrase):
"""Respond to passphrase prompts from device with the provided passphrase."""
self.ui.passphrase = Mnemonic.normalize_string(passphrase)
def use_mnemonic(self, mnemonic):
"""Use the provided mnemonic to respond to device.
Only applies to T1, where device prompts the host for mnemonic words."""
self.mnemonic = Mnemonic.normalize_string(mnemonic).split(" ")
def _raw_read(self):
__tracebackhide__ = True # for pytest # pylint: disable=W0612
resp = super()._raw_read()
resp = self._filter_message(resp)
self._check_request(resp)
return resp
def _raw_write(self, msg):
return super()._raw_write(self._filter_message(msg))
def _raise_unexpected_response(self, msg):
__tracebackhide__ = True # for pytest # pylint: disable=W0612
start_at = max(self.current_response - EXPECTED_RESPONSES_CONTEXT_LINES, 0)
stop_at = min(
self.current_response + EXPECTED_RESPONSES_CONTEXT_LINES + 1,
len(self.expected_responses),
)
output = []
output.append("Expected responses:")
if start_at > 0:
output.append(" (...{} previous responses omitted)".format(start_at))
for i in range(start_at, stop_at):
exp = self.expected_responses[i]
prefix = " " if i != self.current_response else ">>> "
output.append(textwrap.indent(exp.format(), prefix))
if stop_at < len(self.expected_responses):
omitted = len(self.expected_responses) - stop_at
output.append(" (...{} following responses omitted)".format(omitted))
output.append("")
if msg is not None:
output.append("Actually received:")
output.append(textwrap.indent(protobuf.format_message(msg), " "))
else:
output.append("This message was never received.")
raise AssertionError("\n".join(output))
def _check_request(self, msg):
__tracebackhide__ = True # for pytest # pylint: disable=W0612
if self.expected_responses is None:
return
if self.current_response >= len(self.expected_responses):
raise AssertionError(
"No more messages were expected, but we got:\n"
+ protobuf.format_message(msg)
)
expected = self.expected_responses[self.current_response]
if not expected.match(msg):
self._raise_unexpected_response(msg)
self.current_response += 1
def mnemonic_callback(self, _):
word, pos = self.debug.read_recovery_word()
if word != "":
return word
if pos != 0:
return self.mnemonic[pos - 1]
raise RuntimeError("Unexpected call")
@expect(messages.Success, field="message")
def load_device(
client,
mnemonic,
pin,
passphrase_protection,
label,
language="en-US",
skip_checksum=False,
needs_backup=False,
no_backup=False,
):
if not isinstance(mnemonic, (list, tuple)):
mnemonic = [mnemonic]
mnemonics = [Mnemonic.normalize_string(m) for m in mnemonic]
if client.features.initialized:
raise RuntimeError(
"Device is initialized already. Call device.wipe() and try again."
)
resp = client.call(
messages.LoadDevice(
mnemonics=mnemonics,
pin=pin,
passphrase_protection=passphrase_protection,
language=language,
label=label,
skip_checksum=skip_checksum,
needs_backup=needs_backup,
no_backup=no_backup,
)
)
client.init_device()
return resp
# keep the old name for compatibility
load_device_by_mnemonic = load_device
@expect(messages.Success, field="message")
def self_test(client):
if client.features.bootloader_mode is not True:
raise RuntimeError("Device must be in bootloader mode")
return client.call(
messages.SelfTest(
payload=b"\x00\xFF\x55\xAA\x66\x99\x33\xCCABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!\x00\xFF\x55\xAA\x66\x99\x33\xCC"
)
)