arno
/
trezor-firmware
mirror of https://github.com/trezor/trezor-firmware.git
1
0
Fork 0
Code Issues Releases Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Branches Tags
${ item.name }
Create tag ${ searchTerm }
Create branch ${ searchTerm }
from '50fe43646a'
${ noResults }
trezor-firmware/core/src/trezor/wire/thp/channel.py

787 lines
28 KiB
Raw Blame History

import ustruct # pyright: ignore[reportMissingModuleSource]
from micropython import const # pyright: ignore[reportMissingModuleSource]
from typing import TYPE_CHECKING # pyright:ignore[reportShadowedImports]
import usb
from storage import cache_thp
from storage.cache_thp import KEY_LENGTH, SESSION_ID_LENGTH, TAG_LENGTH, ChannelCache
from trezor import log, loop, protobuf, utils, workflow
from trezor.enums import FailureType, MessageType
from trezor.messages import (
Failure,
ThpCreateNewSession,
ThpHandshakeCompletionReqNoisePayload,
)
from trezor.wire import message_handler
from trezor.wire.thp import ack_handler, thp_messages
from ..protocol_common import Context, MessageWithType
from . import ChannelState, SessionState, checksum, crypto
from . import thp_session as THP
from .checksum import CHECKSUM_LENGTH
from .crypto import PUBKEY_LENGTH
from .thp_messages import (
ACK_MESSAGE,
CONTINUATION_PACKET,
ENCRYPTED_TRANSPORT,
ERROR,
HANDSHAKE_COMP_REQ,
HANDSHAKE_COMP_RES,
HANDSHAKE_INIT_REQ,
HANDSHAKE_INIT_RES,
InitHeader,
)
from .thp_session import ThpError
from .writer import (
CONT_DATA_OFFSET,
INIT_DATA_OFFSET,
REPORT_LENGTH,
write_payload_to_wire,
)
if TYPE_CHECKING:
from trezorio import WireInterface # pyright:ignore[reportMissingImports]
_WIRE_INTERFACE_USB = b"\x01"
_MOCK_INTERFACE_HID = b"\x00"
MESSAGE_TYPE_LENGTH = const(2)
MAX_PAYLOAD_LEN = const(60000)
class Channel(Context):
def __init__(self, channel_cache: ChannelCache) -> None:
if __debug__:
log.debug(__name__, "channel initialization")
iface = _decode_iface(channel_cache.iface)
super().__init__(iface, channel_cache.channel_id)
self.channel_cache = channel_cache
self.buffer: utils.BufferType
self.waiting_for_ack_timeout: loop.spawn | None = None
self.write_task_spawn: loop.spawn | None = None
self.is_cont_packet_expected: bool = False
self.expected_payload_length: int = 0
self.bytes_read: int = 0
self.selected_pairing_methods = []
from trezor.wire.thp.session_context import load_cached_sessions
self.connection_context = None
self.sessions = load_cached_sessions(self)
@classmethod
def create_new_channel(
cls, iface: WireInterface, buffer: utils.BufferType
) -> "Channel":
channel_cache = cache_thp.get_new_unauthenticated_channel(_encode_iface(iface))
r = cls(channel_cache)
r.set_buffer(buffer)
r.set_channel_state(ChannelState.TH1)
return r
# ACCESS TO CHANNEL_DATA
def get_channel_state(self) -> int:
state = int.from_bytes(self.channel_cache.state, "big")
if __debug__:
log.debug(__name__, "get_channel_state: %s", _state_to_str(state))
return state
def get_channel_id_int(self) -> int:
return int.from_bytes(self.channel_id, "big")
def set_channel_state(self, state: ChannelState) -> None:
if __debug__:
log.debug(__name__, "set_channel_state: %s", _state_to_str(state))
self.channel_cache.state = bytearray(state.to_bytes(1, "big"))
def set_buffer(self, buffer: utils.BufferType) -> None:
self.buffer = buffer
if __debug__:
log.debug(__name__, "set_buffer: %s", type(self.buffer))
# CALLED BY THP_MAIN_LOOP
async def receive_packet(self, packet: utils.BufferType):
if __debug__:
log.debug(__name__, "receive_packet")
await self._handle_received_packet(packet)
if __debug__:
log.debug(__name__, "self.buffer: %s", utils.get_bytes_as_str(self.buffer))
if self.expected_payload_length + INIT_DATA_OFFSET == self.bytes_read:
self._finish_message()
await self._handle_completed_message()
elif self.expected_payload_length + INIT_DATA_OFFSET > self.bytes_read:
self.is_cont_packet_expected = True
else:
raise ThpError(
"Read more bytes than is the expected length of the message, this should not happen!"
)
async def _handle_received_packet(self, packet: utils.BufferType) -> None:
ctrl_byte = packet[0]
if _is_ctrl_byte_continuation(ctrl_byte):
await self._handle_cont_packet(packet)
else:
await self._handle_init_packet(packet)
async def _handle_init_packet(self, packet: utils.BufferType) -> None:
if __debug__:
log.debug(__name__, "handle_init_packet")
ctrl_byte, _, payload_length = ustruct.unpack(">BHH", packet)
self.expected_payload_length = payload_length
packet_payload = packet[5:]
# If the channel does not "own" the buffer lock, decrypt first packet
# TODO do it only when needed!
if _is_ctrl_byte_encrypted_transport(ctrl_byte):
packet_payload = self._decrypt_single_packet_payload(packet_payload)
self._select_buffer(packet_payload, payload_length)
await self._buffer_packet_data(self.buffer, packet, 0)
if __debug__:
log.debug(__name__, "handle_init_packet - payload len: %d", payload_length)
log.debug(__name__, "handle_init_packet - buffer len: %d", len(self.buffer))
def _select_buffer(
self, packet_payload: utils.BufferType, payload_length: int
) -> None:
state = self.get_channel_state()
if state is ChannelState.ENCRYPTED_TRANSPORT:
session_id = packet_payload[0]
if session_id == 0:
pass
# TODO use small buffer
else:
pass
# TODO use big buffer but only if the channel owns the buffer lock.
# Otherwise send BUSY message and return
else:
pass
# TODO use small buffer
try:
# TODO for now, we create a new big buffer every time. It should be changed
self.buffer: utils.BufferType = _get_buffer_for_message(
payload_length, self.buffer
)
except Exception as e:
if __debug__:
log.exception(__name__, e)
async def _handle_cont_packet(self, packet: utils.BufferType) -> None:
if __debug__:
log.debug(__name__, "handle_cont_packet")
if not self.is_cont_packet_expected:
raise ThpError("Continuation packet is not expected, ignoring")
await self._buffer_packet_data(self.buffer, packet, CONT_DATA_OFFSET)
async def _handle_completed_message(self) -> None:
if __debug__:
log.debug(__name__, "handle_completed_message")
ctrl_byte, _, payload_length = ustruct.unpack(">BHH", self.buffer)
message_length = payload_length + INIT_DATA_OFFSET
self._check_checksum(message_length)
# Synchronization process
sync_bit = (ctrl_byte & 0x10) >> 4
if __debug__:
log.debug(
__name__,
"handle_completed_message - sync bit of message: %d",
sync_bit,
)
# 1: Handle ACKs
if _is_ctrl_byte_ack(ctrl_byte):
await self._handle_ack(sync_bit)
return
if (
self._should_have_ctrl_byte_encrypted_transport()
and not _is_ctrl_byte_encrypted_transport(ctrl_byte)
):
self._todo_clear_buffer()
raise ThpError("Message is not encrypted. Ignoring")
# 2: Handle message with unexpected synchronization bit
if sync_bit != THP.sync_get_receive_expected_bit(self.channel_cache):
if __debug__:
log.debug(
__name__, "Received message with an unexpected synchronization bit"
)
await self._send_ack(sync_bit)
raise ThpError("Received message with an unexpected synchronization bit")
# 3: Send ACK in response
await self._send_ack(sync_bit)
THP.sync_set_receive_expected_bit(self.channel_cache, 1 - sync_bit)
await self._handle_message_to_app_or_channel(
payload_length, message_length, ctrl_byte, sync_bit
)
if __debug__:
log.debug(__name__, "handle_completed_message - end")
async def _handle_ack(self, sync_bit: int):
if not ack_handler.is_ack_valid(self.channel_cache, sync_bit):
return
# ACK is expected and it has correct sync bit
if __debug__:
log.debug(__name__, "Received ACK message with correct sync bit")
if self.waiting_for_ack_timeout is not None:
self.waiting_for_ack_timeout.close()
if __debug__:
log.debug(__name__, 'Closed "waiting for ack" task')
THP.sync_set_can_send_message(self.channel_cache, True)
if self.write_task_spawn is not None:
if __debug__:
log.debug(__name__, 'Control to "write_encrypted_payload_loop" task')
await self.write_task_spawn
# Note that no the write_task_spawn could result in loop.clear(),
# which will result in terminations of this function - any code after
# this await might not be executed
def _check_checksum(self, message_length: int):
if __debug__:
log.debug(__name__, "check_checksum")
if not checksum.is_valid(
checksum=self.buffer[message_length - CHECKSUM_LENGTH : message_length],
data=self.buffer[: message_length - CHECKSUM_LENGTH],
):
self._todo_clear_buffer()
if __debug__:
log.debug(__name__, "Invalid checksum, ignoring message.")
raise ThpError("Invalid checksum, ignoring message.")
async def _handle_message_to_app_or_channel(
self, payload_length: int, message_length: int, ctrl_byte: int, sync_bit: int
) -> None:
state = self.get_channel_state()
if __debug__:
log.debug(__name__, "state: %s", _state_to_str(state))
if state is ChannelState.ENCRYPTED_TRANSPORT:
await self._handle_state_ENCRYPTED_TRANSPORT(message_length)
return
if state is ChannelState.TH1:
await self._handle_state_TH1(
payload_length, message_length, ctrl_byte, sync_bit
)
return
if state is ChannelState.TH2:
await self._handle_state_TH2(message_length, ctrl_byte, sync_bit)
return
if is_channel_state_pairing(state):
await self._handle_pairing(message_length)
return
raise ThpError("Unimplemented channel state")
async def _handle_state_TH1(
self, payload_length: int, message_length: int, ctrl_byte: int, sync_bit: int
) -> None:
if __debug__:
log.debug(__name__, "handle_state_TH1")
if not _is_ctrl_byte_handshake_init_req(ctrl_byte):
raise ThpError("Message received is not a handshake init request!")
if not payload_length == PUBKEY_LENGTH + CHECKSUM_LENGTH:
raise ThpError("Message received is not a valid handshake init request!")
host_ephemeral_key = bytearray(
self.buffer[INIT_DATA_OFFSET : message_length - CHECKSUM_LENGTH]
)
cache_thp.set_channel_host_ephemeral_key(self.channel_cache, host_ephemeral_key)
# send handshake init response message
self._prepare_write()
self.write_task_spawn = loop.spawn(
self._write_encrypted_payload_loop(
HANDSHAKE_INIT_RES, thp_messages.get_handshake_init_response()
)
)
self.set_channel_state(ChannelState.TH2)
return
async def _handle_state_TH2(
self, message_length: int, ctrl_byte: int, sync_bit: int
) -> None:
if __debug__:
log.debug(__name__, "handle_state_TH2")
if not _is_ctrl_byte_handshake_comp_req(ctrl_byte):
raise ThpError("Message received is not a handshake completion request!")
host_encrypted_static_pubkey = self.buffer[
INIT_DATA_OFFSET : INIT_DATA_OFFSET + KEY_LENGTH + TAG_LENGTH
]
handshake_completion_request_noise_payload = self.buffer[
INIT_DATA_OFFSET
+ KEY_LENGTH
+ TAG_LENGTH : message_length
- CHECKSUM_LENGTH
]
noise_payload = thp_messages.decode_message(
self.buffer[
INIT_DATA_OFFSET
+ KEY_LENGTH
+ TAG_LENGTH : message_length
- CHECKSUM_LENGTH
- TAG_LENGTH
],
0,
"ThpHandshakeCompletionReqNoisePayload",
)
if TYPE_CHECKING:
assert ThpHandshakeCompletionReqNoisePayload.is_type_of(noise_payload)
for i in noise_payload.pairing_methods:
self.selected_pairing_methods.append(i)
if __debug__:
log.debug(
__name__,
"host static pubkey: %s, noise payload: %s",
utils.get_bytes_as_str(host_encrypted_static_pubkey),
utils.get_bytes_as_str(handshake_completion_request_noise_payload),
)
# TODO add credential recognition
paired: bool = False # TODO should be output from credential check
# send hanshake completion response
self._prepare_write()
self.write_task_spawn = loop.spawn(
self._write_encrypted_payload_loop(
HANDSHAKE_COMP_RES,
thp_messages.get_handshake_completion_response(paired=paired),
)
)
if paired:
self.set_channel_state(ChannelState.ENCRYPTED_TRANSPORT)
else:
self.set_channel_state(ChannelState.TP1)
async def _handle_state_ENCRYPTED_TRANSPORT(self, message_length: int) -> None:
if __debug__:
log.debug(__name__, "handle_state_ENCRYPTED_TRANSPORT")
self._decrypt_buffer(message_length)
session_id, message_type = ustruct.unpack(">BH", self.buffer[INIT_DATA_OFFSET:])
if session_id == 0:
await self._handle_channel_message(message_length, message_type)
return
if session_id not in self.sessions:
await self.write_error(
FailureType.ThpUnallocatedSession, "Unallocated session"
)
raise ThpError("Unalloacted session")
session_state = self.sessions[session_id].get_session_state()
if session_state is SessionState.UNALLOCATED:
await self.write_error(
FailureType.ThpUnallocatedSession, "Unallocated session"
)
raise ThpError("Unalloacted session")
self.sessions[session_id].incoming_message.publish(
MessageWithType(
message_type,
self.buffer[
INIT_DATA_OFFSET
+ MESSAGE_TYPE_LENGTH
+ SESSION_ID_LENGTH : message_length
- CHECKSUM_LENGTH
- TAG_LENGTH
],
)
)
async def _handle_pairing(self, message_length: int) -> None:
from .pairing_context import PairingContext
if self.connection_context is None:
self.connection_context = PairingContext(self)
loop.schedule(self.connection_context.handle())
self._decrypt_buffer(message_length)
message_type = ustruct.unpack(
">H", self.buffer[INIT_DATA_OFFSET + SESSION_ID_LENGTH :]
)[0]
self.connection_context.incoming_message.publish(
MessageWithType(
message_type,
self.buffer[
INIT_DATA_OFFSET
+ MESSAGE_TYPE_LENGTH
+ SESSION_ID_LENGTH : message_length
- CHECKSUM_LENGTH
- TAG_LENGTH
],
)
)
# 1. Check that message is expected with respect to the current state
# 2. Handle the message
pass
def _should_have_ctrl_byte_encrypted_transport(self) -> bool:
if self.get_channel_state() in [
ChannelState.UNALLOCATED,
ChannelState.TH1,
ChannelState.TH2,
]:
return False
return True
async def _handle_channel_message(
self, message_length: int, message_type: int
) -> None:
buf = self.buffer[
INIT_DATA_OFFSET + 3 : message_length - CHECKSUM_LENGTH - TAG_LENGTH
]
expected_type = protobuf.type_for_wire(message_type)
message = message_handler.wrap_protobuf_load(buf, expected_type)
if not ThpCreateNewSession.is_type_of(message):
raise ThpError(
"This message cannot be handled by channel itself. It must be send to allocated session."
)
# TODO handle other messages than CreateNewSession
from trezor.wire.thp.handler_provider import get_handler_for_channel_message
handler = get_handler_for_channel_message(message)
task = handler(self, message)
response_message = await task
# TODO handle
await self.write(response_message)
if __debug__:
log.debug(__name__, "_handle_channel_message - end")
def _decrypt_single_packet_payload(self, payload: bytes) -> bytearray:
payload_buffer = bytearray(payload)
crypto.decrypt(b"\x00", b"\x00", payload_buffer, INIT_DATA_OFFSET, len(payload))
return payload_buffer
def _decrypt_buffer(self, message_length: int) -> None:
if not isinstance(self.buffer, bytearray):
self.buffer = bytearray(self.buffer)
crypto.decrypt(
b"\x00",
b"\x00",
self.buffer,
INIT_DATA_OFFSET,
message_length - INIT_DATA_OFFSET - CHECKSUM_LENGTH,
)
def _encrypt(self, buffer: bytearray, noise_payload_len: int) -> None:
if __debug__:
log.debug(__name__, "encrypt")
min_required_length = noise_payload_len + TAG_LENGTH + CHECKSUM_LENGTH
if len(buffer) < min_required_length or not isinstance(buffer, bytearray):
new_buffer = bytearray(min_required_length)
utils.memcpy(new_buffer, 0, buffer, 0)
buffer = new_buffer
tag = crypto.encrypt(
b"\x00",
b"\x00",
buffer,
0,
noise_payload_len,
)
buffer[noise_payload_len : noise_payload_len + TAG_LENGTH] = tag
async def _buffer_packet_data(
self, payload_buffer: utils.BufferType, packet: utils.BufferType, offset: int
):
self.bytes_read += utils.memcpy(payload_buffer, self.bytes_read, packet, offset)
def _finish_message(self):
self.bytes_read = 0
self.expected_payload_length = 0
self.is_cont_packet_expected = False
async def _send_ack(self, ack_bit: int) -> None:
ctrl_byte = self._add_sync_bit_to_ctrl_byte(ACK_MESSAGE, ack_bit)
header = InitHeader(ctrl_byte, self.get_channel_id_int(), CHECKSUM_LENGTH)
chksum = checksum.compute(header.to_bytes())
if __debug__:
log.debug(
__name__,
"Writing ACK message to a channel with id: %d, sync bit: %d",
self.get_channel_id_int(),
ack_bit,
)
await write_payload_to_wire(self.iface, header, chksum)
def _add_sync_bit_to_ctrl_byte(self, ctrl_byte, sync_bit):
if sync_bit == 0:
return ctrl_byte & 0xEF
if sync_bit == 1:
return ctrl_byte | 0x10
raise ThpError("Unexpected synchronization bit")
# CALLED BY WORKFLOW / SESSION CONTEXT
async def write(self, msg: protobuf.MessageType, session_id: int = 0) -> None:
if __debug__:
log.debug(__name__, "write message: %s", msg.MESSAGE_NAME)
noise_payload_len = self._encode_into_buffer(msg, session_id)
await self.write_and_encrypt(self.buffer[:noise_payload_len])
async def write_error(self, err_type: FailureType, message: str) -> None:
if __debug__:
log.debug(__name__, "write_error")
msg_size = self._encode_error_into_buffer(err_type, message)
data_length = MESSAGE_TYPE_LENGTH + msg_size
header: InitHeader = InitHeader(
ERROR, self.get_channel_id_int(), data_length + CHECKSUM_LENGTH
)
chksum = checksum.compute(
header.to_bytes() + memoryview(self.buffer[:data_length])
)
utils.memcpy(self.buffer, data_length, chksum, 0)
await write_payload_to_wire(
self.iface, header, memoryview(self.buffer[: data_length + CHECKSUM_LENGTH])
)
async def write_and_encrypt(self, payload: bytes) -> None:
payload_length = len(payload)
if not isinstance(self.buffer, bytearray):
self.buffer = bytearray(self.buffer)
self._encrypt(self.buffer, payload_length)
payload_length = payload_length + TAG_LENGTH
if self.write_task_spawn is not None:
self.write_task_spawn.close() # UPS TODO migh break something
print("\nCLOSED\n")
self._prepare_write()
self.write_task_spawn = loop.spawn(
self._write_encrypted_payload_loop(
ENCRYPTED_TRANSPORT, memoryview(self.buffer[:payload_length])
)
)
def _prepare_write(self) -> None:
# TODO add condition that disallows to write when can_send_message is false
THP.sync_set_can_send_message(self.channel_cache, False)
async def _write_encrypted_payload_loop(
self, ctrl_byte: int, payload: bytes
) -> None:
if __debug__:
log.debug(__name__, "write_encrypted_payload_loop")
payload_len = len(payload) + CHECKSUM_LENGTH
sync_bit = THP.sync_get_send_bit(self.channel_cache)
ctrl_byte = self._add_sync_bit_to_ctrl_byte(ctrl_byte, sync_bit)
header = InitHeader(ctrl_byte, self.get_channel_id_int(), payload_len)
chksum = checksum.compute(header.to_bytes() + payload)
payload = payload + chksum
while True:
if __debug__:
log.debug(
__name__,
"write_encrypted_payload_loop - loop start, sync_bit: %d, sync_send_bit: %d",
(header.ctrl_byte & 0x10) >> 4,
THP.sync_get_send_bit(self.channel_cache),
)
await write_payload_to_wire(self.iface, header, payload)
self.waiting_for_ack_timeout = loop.spawn(self._wait_for_ack())
try:
if THP.sync_can_send_message(self.channel_cache):
# TODO This can happen when ack is received before the message was sent,
# but after it was scheduled to be sent (i.e. ACK was already expected)
# This case should be removed or improved upon before production.
break
else:
await self.waiting_for_ack_timeout
except loop.TaskClosed:
break
THP.sync_set_send_bit_to_opposite(self.channel_cache)
# Let the main loop be restarted and clear loop, if there is no other
# workflow and the state is ENCRYPTED_TRANSPORT
if self._can_clear_loop():
if __debug__:
log.debug(__name__, "clearing loop from channel")
loop.clear()
def _can_clear_loop(self) -> bool:
return (
not workflow.tasks
) and self.get_channel_state() is ChannelState.ENCRYPTED_TRANSPORT
async def _wait_for_ack(self) -> None:
await loop.sleep(1000)
def _encode_into_buffer(self, msg: protobuf.MessageType, session_id: int) -> int:
# cannot write message without wire type
assert msg.MESSAGE_WIRE_TYPE is not None
msg_size = protobuf.encoded_length(msg)
payload_size = SESSION_ID_LENGTH + MESSAGE_TYPE_LENGTH + msg_size
required_min_size = payload_size + CHECKSUM_LENGTH + TAG_LENGTH
if required_min_size > len(self.buffer):
# message is too big, we need to allocate a new buffer
self.buffer = bytearray(required_min_size)
buffer = self.buffer
_encode_session_into_buffer(memoryview(buffer), session_id)
_encode_message_type_into_buffer(
memoryview(buffer), msg.MESSAGE_WIRE_TYPE, SESSION_ID_LENGTH
)
_encode_message_into_buffer(
memoryview(buffer), msg, SESSION_ID_LENGTH + MESSAGE_TYPE_LENGTH
)
return payload_size
def _encode_error_into_buffer(self, err_code: FailureType, message: str) -> int:
error_message: protobuf.MessageType = Failure(code=err_code, message=message)
_encode_message_type_into_buffer(memoryview(self.buffer), MessageType.Failure)
_encode_message_into_buffer(
memoryview(self.buffer), error_message, MESSAGE_TYPE_LENGTH
)
return protobuf.encoded_length(error_message)
def _todo_clear_buffer(self):
# TODO Buffer clearing not implemented
pass
def load_cached_channels(buffer: utils.BufferType) -> dict[int, Channel]: # TODO
channels: dict[int, Channel] = {}
cached_channels = cache_thp.get_all_allocated_channels()
for c in cached_channels:
channels[int.from_bytes(c.channel_id, "big")] = Channel(c)
for c in channels.values():
c.set_buffer(buffer)
return channels
def _decode_iface(cached_iface: bytes) -> WireInterface:
if cached_iface == _WIRE_INTERFACE_USB:
iface = usb.iface_wire
if iface is None:
raise RuntimeError("There is no valid USB WireInterface")
return iface
if __debug__ and cached_iface == _MOCK_INTERFACE_HID:
raise NotImplementedError("Should return MockHID WireInterface")
# TODO implement bluetooth interface
raise Exception("Unknown WireInterface")
def _encode_iface(iface: WireInterface) -> bytes:
if iface is usb.iface_wire:
return _WIRE_INTERFACE_USB
# TODO implement bluetooth interface
if __debug__:
return _MOCK_INTERFACE_HID
raise Exception("Unknown WireInterface")
def _get_buffer_for_message(
payload_length: int, existing_buffer: utils.BufferType, max_length=MAX_PAYLOAD_LEN
) -> utils.BufferType:
length = payload_length + INIT_DATA_OFFSET
if __debug__:
log.debug(
__name__,
"get_buffer_for_message - length: %d, %s %s",
length,
"existing buffer type:",
type(existing_buffer),
)
if length > max_length:
raise ThpError("Message too large")
if length > len(existing_buffer):
# allocate a new buffer to fit the message
try:
payload: utils.BufferType = bytearray(length)
except MemoryError:
payload = bytearray(REPORT_LENGTH)
raise ThpError("Message too large")
return payload
# reuse a part of the supplied buffer
return memoryview(existing_buffer)[:length]
def _is_ctrl_byte_continuation(ctrl_byte: int) -> bool:
return ctrl_byte & 0x80 == CONTINUATION_PACKET
def _is_ctrl_byte_encrypted_transport(ctrl_byte: int) -> bool:
return ctrl_byte & 0xEF == ENCRYPTED_TRANSPORT
def _is_ctrl_byte_handshake_init_req(ctrl_byte: int) -> bool:
return ctrl_byte & 0xEF == HANDSHAKE_INIT_REQ
def _is_ctrl_byte_handshake_comp_req(ctrl_byte: int) -> bool:
return ctrl_byte & 0xEF == HANDSHAKE_COMP_REQ
def _is_ctrl_byte_ack(ctrl_byte: int) -> bool:
return ctrl_byte & 0xEF == ACK_MESSAGE
def is_channel_state_pairing(state: int) -> bool:
if state in (
ChannelState.TP1,
ChannelState.TP2,
ChannelState.TP3,
ChannelState.TP4,
ChannelState.TC1,
):
return True
return False
def _encode_session_into_buffer(
buffer: memoryview, session_id: int, buffer_offset: int = 0
) -> None:
session_id_bytes = int.to_bytes(session_id, SESSION_ID_LENGTH, "big")
utils.memcpy(buffer, buffer_offset, session_id_bytes, 0)
def _encode_message_type_into_buffer(
buffer: memoryview, message_type: int, offset: int = 0
) -> None:
msg_type_bytes = int.to_bytes(message_type, MESSAGE_TYPE_LENGTH, "big")
utils.memcpy(buffer, offset, msg_type_bytes, 0)
def _encode_message_into_buffer(
buffer: memoryview, message: protobuf.MessageType, buffer_offset: int = 0
) -> None:
protobuf.encode(memoryview(buffer[buffer_offset:]), message)
def _state_to_str(state: int) -> str:
name = {
v: k for k, v in ChannelState.__dict__.items() if not k.startswith("__")
}.get(state)
if name is not None:
return name
return "UNKNOWN_STATE"
Reference in new issue View Git Blame Copy Permalink