Make TLMessage always have a valid TLObject

This simplifies the flow instead of having separate request/body
attributes, and also means that BinaryReader.tgread_object() can
be used without so many special cases.
This commit is contained in:
Lonami Exo 2018-06-09 13:48:27 +02:00
parent f7e8907c6f
commit be279ce3f5
6 changed files with 98 additions and 91 deletions

View File

@ -12,14 +12,15 @@ class TypeNotFoundError(Exception):
Occurs when a type is not found, for example,
when trying to read a TLObject with an invalid constructor code.
"""
def __init__(self, invalid_constructor_id):
def __init__(self, invalid_constructor_id, remaining):
super().__init__(
'Could not find a matching Constructor ID for the TLObject '
'that was supposed to be read with ID {}. Most likely, a TLObject '
'was trying to be read when it should not be read.'
.format(hex(invalid_constructor_id)))
'that was supposed to be read with ID {:08x}. Most likely, '
'a TLObject was trying to be read when it should not be read. '
'Remaining bytes: {!r}'.format(invalid_constructor_id, remaining))
self.invalid_constructor_id = invalid_constructor_id
self.remaining = remaining
class InvalidChecksumError(Exception):

View File

@ -141,7 +141,10 @@ class BinaryReader:
if clazz is None:
# If there was still no luck, give up
self.seek(-4) # Go back
raise TypeNotFoundError(constructor_id)
pos = self.tell_position()
error = TypeNotFoundError(constructor_id, self.read())
self.set_position(pos)
raise error
return clazz.from_reader(self)

View File

@ -351,29 +351,27 @@ class MTProtoSender:
__log__.warning('Security error while unpacking a '
'received message:'.format(e))
continue
except TypeNotFoundError as e:
# The payload inside the message was not a known TLObject.
__log__.info('Server replied with an unknown type {:08x}: {!r}'
.format(e.invalid_constructor_id, e.remaining))
else:
try:
with BinaryReader(message.body) as reader:
obj = reader.tgread_object()
except TypeNotFoundError as e:
__log__.warning('Could not decode received message: {}, '
'raw bytes: {!r}'.format(e, message))
else:
await self._process_message(message, obj)
await self._process_message(message)
# Response Handlers
async def _process_message(self, message, obj):
async def _process_message(self, message):
"""
Adds the given message to the list of messages that must be
acknowledged and dispatches control to different ``_handle_*``
method based on its type.
"""
self._pending_ack.add(message.msg_id)
handler = self._handlers.get(obj.CONSTRUCTOR_ID, self._handle_update)
await handler(message, obj)
handler = self._handlers.get(message.obj.CONSTRUCTOR_ID,
self._handle_update)
await handler(message)
async def _handle_rpc_result(self, message, rpc_result):
async def _handle_rpc_result(self, message):
"""
Handles the result for Remote Procedure Calls:
@ -381,6 +379,7 @@ class MTProtoSender:
This is where the future results for sent requests are set.
"""
rpc_result = message.obj
message = self._pending_messages.pop(rpc_result.req_msg_id, None)
__log__.debug('Handling RPC result for message {}'
.format(rpc_result.req_msg_id))
@ -397,7 +396,7 @@ class MTProtoSender:
return
elif message:
with BinaryReader(rpc_result.body) as reader:
result = message.request.read_result(reader)
result = message.obj.read_result(reader)
# TODO Process entities
if not message.future.cancelled():
@ -408,35 +407,35 @@ class MTProtoSender:
__log__.info('Received response without parent request: {}'
.format(rpc_result.body))
async def _handle_container(self, message, container):
async def _handle_container(self, message):
"""
Processes the inner messages of a container with many of them:
msg_container#73f1f8dc messages:vector<%Message> = MessageContainer;
"""
__log__.debug('Handling container')
for inner_message in container.messages:
with BinaryReader(inner_message.body) as reader:
inner_obj = reader.tgread_object()
await self._process_message(inner_message, inner_obj)
for inner_message in message.obj.messages:
await self._process_message(inner_message)
async def _handle_gzip_packed(self, message, gzip_packed):
async def _handle_gzip_packed(self, message):
"""
Unpacks the data from a gzipped object and processes it:
gzip_packed#3072cfa1 packed_data:bytes = Object;
"""
__log__.debug('Handling gzipped data')
with BinaryReader(gzip_packed.data) as reader:
await self._process_message(message, reader.tgread_object())
with BinaryReader(message.obj.data) as reader:
message.obj = reader.tgread_object()
await self._process_message(message)
async def _handle_update(self, message, update):
__log__.debug('Handling update {}'.format(update.__class__.__name__))
async def _handle_update(self, message):
__log__.debug('Handling update {}'
.format(message.obj.__class__.__name__))
# TODO Further handling of the update
# TODO Process entities
async def _handle_pong(self, message, pong):
async def _handle_pong(self, message):
"""
Handles pong results, which don't come inside a ``rpc_result``
but are still sent through a request:
@ -444,11 +443,12 @@ class MTProtoSender:
pong#347773c5 msg_id:long ping_id:long = Pong;
"""
__log__.debug('Handling pong')
pong = message.obj
message = self._pending_messages.pop(pong.msg_id, None)
if message:
message.future.set_result(pong)
message.future.set_result(pong.obj)
async def _handle_bad_server_salt(self, message, bad_salt):
async def _handle_bad_server_salt(self, message):
"""
Corrects the currently used server salt to use the right value
before enqueuing the rejected message to be re-sent:
@ -457,10 +457,11 @@ class MTProtoSender:
error_code:int new_server_salt:long = BadMsgNotification;
"""
__log__.debug('Handling bad salt')
bad_salt = message.obj
self.state.salt = bad_salt.new_server_salt
await self._send_queue.put(self._pending_messages[bad_salt.bad_msg_id])
async def _handle_bad_notification(self, message, bad_msg):
async def _handle_bad_notification(self, message):
"""
Adjusts the current state to be correct based on the
received bad message notification whenever possible:
@ -469,6 +470,7 @@ class MTProtoSender:
error_code:int = BadMsgNotification;
"""
__log__.debug('Handling bad message')
bad_msg = message.obj
if bad_msg.error_code in (16, 17):
# Sent msg_id too low or too high (respectively).
# Use the current msg_id to determine the right time offset.
@ -489,7 +491,7 @@ class MTProtoSender:
# Messages are to be re-sent once we've corrected the issue
await self._send_queue.put(self._pending_messages[bad_msg.bad_msg_id])
async def _handle_detailed_info(self, message, detailed_info):
async def _handle_detailed_info(self, message):
"""
Updates the current status with the received detailed information:
@ -498,9 +500,9 @@ class MTProtoSender:
"""
# TODO https://goo.gl/VvpCC6
__log__.debug('Handling detailed info')
self._pending_ack.add(detailed_info.answer_msg_id)
self._pending_ack.add(message.obj.answer_msg_id)
async def _handle_new_detailed_info(self, message, new_detailed_info):
async def _handle_new_detailed_info(self, message):
"""
Updates the current status with the received detailed information:
@ -509,9 +511,9 @@ class MTProtoSender:
"""
# TODO https://goo.gl/G7DPsR
__log__.debug('Handling new detailed info')
self._pending_ack.add(new_detailed_info.answer_msg_id)
self._pending_ack.add(message.obj.answer_msg_id)
async def _handle_new_session_created(self, message, new_session):
async def _handle_new_session_created(self, message):
"""
Updates the current status with the received session information:
@ -520,7 +522,7 @@ class MTProtoSender:
"""
# TODO https://goo.gl/LMyN7A
__log__.debug('Handling new session created')
self.state.salt = new_session.server_salt
self.state.salt = message.obj.server_salt
def _clean_containers(self, msg_ids):
"""
@ -533,13 +535,13 @@ class MTProtoSender:
"""
for i in reversed(range(len(self._pending_containers))):
message = self._pending_containers[i]
for msg in message.request.messages:
for msg in message.obj.messages:
if msg.msg_id in msg_ids:
del self._pending_containers[i]
del self._pending_messages[message.msg_id]
break
async def _handle_ack(self, message, ack):
async def _handle_ack(self, message):
"""
Handles a server acknowledge about our messages. Normally
these can be ignored except in the case of ``auth.logOut``:
@ -555,16 +557,17 @@ class MTProtoSender:
messages are acknowledged.
"""
__log__.debug('Handling acknowledge')
ack = message.obj
if self._pending_containers:
self._clean_containers(ack.msg_ids)
for msg_id in ack.msg_ids:
msg = self._pending_messages.get(msg_id, None)
if msg and isinstance(msg.request, LogOutRequest):
if msg and isinstance(msg.obj, LogOutRequest):
del self._pending_messages[msg_id]
msg.future.set_result(True)
async def _handle_future_salts(self, message, salts):
async def _handle_future_salts(self, message):
"""
Handles future salt results, which don't come inside a
``rpc_result`` but are still sent through a request:
@ -577,7 +580,7 @@ class MTProtoSender:
__log__.debug('Handling future salts')
msg = self._pending_messages.pop(message.msg_id, None)
if msg:
msg.future.set_result(salts)
msg.future.set_result(message.obj)
class _ContainerQueue(asyncio.Queue):
@ -593,13 +596,13 @@ class _ContainerQueue(asyncio.Queue):
"""
async def get(self):
result = await super().get()
if self.empty() or isinstance(result.request, MessageContainer):
if self.empty() or isinstance(result.obj, MessageContainer):
return result
result = [result]
while not self.empty():
item = self.get_nowait()
if isinstance(item.request, MessageContainer):
if isinstance(item.obj, MessageContainer):
await self.put(item)
break
else:

View File

@ -1,3 +1,4 @@
import logging
import os
import struct
import time
@ -8,6 +9,8 @@ from ..errors import SecurityError, BrokenAuthKeyError
from ..extensions import BinaryReader
from ..tl.core import TLMessage
__log__ = logging.getLogger(__name__)
class MTProtoState:
"""
@ -33,15 +36,15 @@ class MTProtoState:
self._sequence = 0
self._last_msg_id = 0
def create_message(self, request, after=None):
def create_message(self, obj, after=None):
"""
Creates a new `telethon.tl.tl_message.TLMessage` from
the given `telethon.tl.tlobject.TLObject` instance.
"""
return TLMessage(
msg_id=self._get_new_msg_id(),
seq_no=self._get_seq_no(request.content_related),
request=request,
seq_no=self._get_seq_no(obj.content_related),
obj=obj,
after_id=after.msg_id if after else None
)
@ -100,25 +103,31 @@ class MTProtoState:
msg_key = body[8:24]
aes_key, aes_iv = self._calc_key(self.auth_key.key, msg_key, False)
data = BinaryReader(AES.decrypt_ige(body[24:], aes_key, aes_iv))
data.read_long() # remote_salt
if data.read_long() != self.id:
raise SecurityError('Server replied with a wrong session ID')
remote_msg_id = data.read_long()
remote_sequence = data.read_int()
msg_len = data.read_int()
message = data.read(msg_len)
body = AES.decrypt_ige(body[24:], aes_key, aes_iv)
# https://core.telegram.org/mtproto/security_guidelines
# Sections "checking sha256 hash" and "message length"
our_key = sha256(self.auth_key.key[96:96 + 32] + data.get_bytes())
our_key = sha256(self.auth_key.key[96:96 + 32] + body)
if msg_key != our_key.digest()[8:24]:
raise SecurityError(
"Received msg_key doesn't match with expected one")
return TLMessage(remote_msg_id, remote_sequence, body=message)
reader = BinaryReader(body)
reader.read_long() # remote_salt
if reader.read_long() != self.id:
raise SecurityError('Server replied with a wrong session ID')
remote_msg_id = reader.read_long()
remote_sequence = reader.read_int()
msg_len = reader.read_int()
before = reader.tell_position()
obj = reader.tgread_object()
if reader.tell_position() != before + msg_len:
reader.set_position(before)
__log__.warning('Data left after TLObject {}: {!r}'
.format(obj, reader.read(msg_len)))
return TLMessage(remote_msg_id, remote_sequence, obj)
def _get_new_msg_id(self):
"""

View File

@ -1,7 +1,10 @@
import logging
import struct
from ..tlobject import TLObject
from .tlmessage import TLMessage
from ..tlobject import TLObject
__log__ = logging.getLogger(__name__)
class MessageContainer(TLObject):
@ -26,17 +29,6 @@ class MessageContainer(TLObject):
'<Ii', MessageContainer.CONSTRUCTOR_ID, len(self.messages)
) + b''.join(bytes(m) for m in self.messages)
@staticmethod
def iter_read(reader):
reader.read_int(signed=False) # code
size = reader.read_int()
for _ in range(size):
inner_msg_id = reader.read_long()
inner_sequence = reader.read_int()
inner_length = reader.read_int()
yield TLMessage(inner_msg_id, inner_sequence,
body=reader.read(inner_length))
def __str__(self):
return TLObject.pretty_format(self)
@ -46,8 +38,16 @@ class MessageContainer(TLObject):
@classmethod
def from_reader(cls, reader):
# This assumes that .read_* calls are done in the order they appear
return MessageContainer([TLMessage(
msg_id=reader.read_long(),
seq_no=reader.read_int(),
body=reader.read(reader.read_int())
) for _ in range(reader.read_int())])
messages = []
for _ in range(reader.read_int()):
msg_id = reader.read_long()
seq_no = reader.read_int()
length = reader.read_int()
before = reader.tell_position()
obj = reader.tgread_object()
messages.append(TLMessage(msg_id, seq_no, obj))
if reader.tell_position() != before + length:
reader.set_position(before)
__log__.warning('Data left after TLObject {}: {!r}'
.format(obj, reader.read(length)))
return MessageContainer(messages)

View File

@ -21,23 +21,14 @@ class TLMessage(TLObject):
sent `TLMessage`, and this result can be represented as a `Future`
that will eventually be set with either a result, error or cancelled.
"""
def __init__(self, msg_id, seq_no, body=None, request=None, after_id=0):
def __init__(self, msg_id, seq_no, obj=None, after_id=0):
super().__init__()
self.msg_id = msg_id
self.seq_no = seq_no
self.obj = obj
self.container_msg_id = None
self.future = asyncio.Future()
# TODO Perhaps it's possible to merge body and request?
# We need things like rpc_result and gzip_packed to
# be readable by the ``BinaryReader`` for such purpose.
# Used for incoming, not-decoded messages
self.body = body
# Used for outgoing, not-encoded messages
self.request = request
# After which message ID this one should run. We do this so
# InvokeAfterMsgRequest is transparent to the user and we can
# easily invoke after while confirming the original request.
@ -47,17 +38,17 @@ class TLMessage(TLObject):
return {
'msg_id': self.msg_id,
'seq_no': self.seq_no,
'request': self.request,
'obj': self.obj,
'container_msg_id': self.container_msg_id,
'after_id': self.after_id
}
def __bytes__(self):
if self.after_id is None:
body = GzipPacked.gzip_if_smaller(self.request)
body = GzipPacked.gzip_if_smaller(self.obj)
else:
body = GzipPacked.gzip_if_smaller(
InvokeAfterMsgRequest(self.after_id, self.request))
InvokeAfterMsgRequest(self.after_id, self.obj))
return struct.pack('<qii', self.msg_id, self.seq_no, len(body)) + body