mirror of
https://github.com/LonamiWebs/Telethon.git
synced 2024-11-10 19:46:36 +03:00
381 lines
14 KiB
Python
381 lines
14 KiB
Python
import gzip
|
|
from datetime import timedelta
|
|
from threading import RLock
|
|
|
|
from .. import helpers as utils
|
|
from ..crypto import AES
|
|
from ..errors import BadMessageError, InvalidDCError, rpc_message_to_error
|
|
from ..tl.all_tlobjects import tlobjects
|
|
from ..tl.types import MsgsAck
|
|
from ..extensions import BinaryReader, BinaryWriter
|
|
|
|
import logging
|
|
logging.getLogger(__name__).addHandler(logging.NullHandler())
|
|
|
|
|
|
class MtProtoSender:
|
|
"""MTProto Mobile Protocol sender (https://core.telegram.org/mtproto/description)"""
|
|
|
|
def __init__(self, transport, session):
|
|
self._transport = transport
|
|
self.session = session
|
|
self._logger = logging.getLogger(__name__)
|
|
|
|
self._need_confirmation = [] # Message IDs that need confirmation
|
|
self._pending_receive = [] # Requests sent waiting to be received
|
|
|
|
# Store an RLock instance to make this class safely multi-threaded
|
|
self._lock = RLock()
|
|
|
|
# Used when logging out, the only request that seems to use 'ack' requests
|
|
# TODO There might be a better way to handle msgs_ack requests
|
|
self.logging_out = False
|
|
|
|
def connect(self):
|
|
"""Connects to the server"""
|
|
self._transport.connect()
|
|
|
|
def disconnect(self):
|
|
"""Disconnects from the server"""
|
|
self._transport.close()
|
|
|
|
# region Send and receive
|
|
|
|
def send(self, request):
|
|
"""Sends the specified MTProtoRequest, previously sending any message
|
|
which needed confirmation."""
|
|
|
|
# Now only us can be using this method
|
|
with self._lock:
|
|
self._logger.debug('send() acquired the lock')
|
|
|
|
# If any message needs confirmation send an AckRequest first
|
|
self._send_acknowledges()
|
|
|
|
# Finally send our packed request
|
|
with BinaryWriter() as writer:
|
|
request.on_send(writer)
|
|
self._send_packet(writer.get_bytes(), request)
|
|
self._pending_receive.append(request)
|
|
|
|
# And update the saved session
|
|
self.session.save()
|
|
|
|
self._logger.debug('send() released the lock')
|
|
|
|
def _send_acknowledges(self):
|
|
"""Sends a messages acknowledge for all those who _need_confirmation"""
|
|
if self._need_confirmation:
|
|
msgs_ack = MsgsAck(self._need_confirmation)
|
|
with BinaryWriter() as writer:
|
|
msgs_ack.on_send(writer)
|
|
self._send_packet(writer.get_bytes(), msgs_ack)
|
|
|
|
del self._need_confirmation[:]
|
|
|
|
def receive(self, request=None, timeout=timedelta(seconds=5), updates=None):
|
|
"""Receives the specified MTProtoRequest ("fills in it"
|
|
the received data). This also restores the updates thread.
|
|
An optional timeout can be specified to cancel the operation
|
|
if no data has been read after its time delta.
|
|
|
|
If 'request' is None, a single item will be read into
|
|
the 'updates' list (which cannot be None).
|
|
|
|
If 'request' is not None, any update received before
|
|
reading the request's result will be put there unless
|
|
it's None, in which case updates will be ignored.
|
|
"""
|
|
if request is None and updates is None:
|
|
raise ValueError('Both the "request" and "updates"'
|
|
'parameters cannot be None at the same time.')
|
|
|
|
with self._lock:
|
|
self._logger.debug('receive() acquired the lock')
|
|
# Don't stop trying to receive until we get the request we wanted
|
|
# or, if there is no request, until we read an update
|
|
while (request and not request.confirm_received) or \
|
|
(not request and not updates):
|
|
self._logger.info('Trying to .receive() the request result...')
|
|
seq, body = self._transport.receive(timeout)
|
|
message, remote_msg_id, remote_seq = self._decode_msg(body)
|
|
|
|
with BinaryReader(message) as reader:
|
|
self._process_msg(
|
|
remote_msg_id, remote_seq, reader, updates)
|
|
|
|
# We're done receiving, remove the request from pending, if any
|
|
if request:
|
|
try:
|
|
self._pending_receive.remove(request)
|
|
except ValueError: pass
|
|
|
|
self._logger.info('Request result received')
|
|
self._logger.debug('receive() released the lock')
|
|
|
|
def receive_update(self, timeout=timedelta(seconds=5)):
|
|
"""Receives an update object and returns its result"""
|
|
updates = []
|
|
self.receive(timeout=timeout, updates=updates)
|
|
return updates[0]
|
|
|
|
def cancel_receive(self):
|
|
"""Cancels any pending receive operation
|
|
by raising a ReadCancelledError"""
|
|
self._transport.cancel_receive()
|
|
|
|
# endregion
|
|
|
|
# region Low level processing
|
|
|
|
def _send_packet(self, packet, request):
|
|
"""Sends the given packet bytes with the additional
|
|
information of the original request. This does NOT lock the threads!"""
|
|
request.msg_id = self.session.get_new_msg_id()
|
|
|
|
# First calculate plain_text to encrypt it
|
|
with BinaryWriter() as plain_writer:
|
|
plain_writer.write_long(self.session.salt, signed=False)
|
|
plain_writer.write_long(self.session.id, signed=False)
|
|
plain_writer.write_long(request.msg_id)
|
|
plain_writer.write_int(
|
|
self.session.generate_sequence(request.confirmed))
|
|
|
|
plain_writer.write_int(len(packet))
|
|
plain_writer.write(packet)
|
|
|
|
msg_key = utils.calc_msg_key(plain_writer.get_bytes())
|
|
|
|
key, iv = utils.calc_key(self.session.auth_key.key, msg_key, True)
|
|
cipher_text = AES.encrypt_ige(plain_writer.get_bytes(), key, iv)
|
|
|
|
# And then finally send the encrypted packet
|
|
with BinaryWriter() as cipher_writer:
|
|
cipher_writer.write_long(
|
|
self.session.auth_key.key_id, signed=False)
|
|
cipher_writer.write(msg_key)
|
|
cipher_writer.write(cipher_text)
|
|
self._transport.send(cipher_writer.get_bytes())
|
|
|
|
def _decode_msg(self, body):
|
|
"""Decodes an received encrypted message body bytes"""
|
|
message = None
|
|
remote_msg_id = None
|
|
remote_sequence = None
|
|
|
|
with BinaryReader(body) as reader:
|
|
if len(body) < 8:
|
|
raise BufferError("Can't decode packet ({})".format(body))
|
|
|
|
# TODO Check for both auth key ID and msg_key correctness
|
|
reader.read_long() # remote_auth_key_id
|
|
msg_key = reader.read(16)
|
|
|
|
key, iv = utils.calc_key(self.session.auth_key.key, msg_key, False)
|
|
plain_text = AES.decrypt_ige(
|
|
reader.read(len(body) - reader.tell_position()), key, iv)
|
|
|
|
with BinaryReader(plain_text) as plain_text_reader:
|
|
plain_text_reader.read_long() # remote_salt
|
|
plain_text_reader.read_long() # remote_session_id
|
|
remote_msg_id = plain_text_reader.read_long()
|
|
remote_sequence = plain_text_reader.read_int()
|
|
msg_len = plain_text_reader.read_int()
|
|
message = plain_text_reader.read(msg_len)
|
|
|
|
return message, remote_msg_id, remote_sequence
|
|
|
|
def _process_msg(self, msg_id, sequence, reader, updates):
|
|
"""Processes and handles a Telegram message.
|
|
|
|
Returns True if the message was handled correctly and doesn't
|
|
need to be skipped. Returns False otherwise.
|
|
"""
|
|
|
|
# TODO Check salt, session_id and sequence_number
|
|
self._need_confirmation.append(msg_id)
|
|
|
|
code = reader.read_int(signed=False)
|
|
reader.seek(-4)
|
|
|
|
# The following codes are "parsed manually"
|
|
if code == 0xf35c6d01: # rpc_result, (response of an RPC call, i.e., we sent a request)
|
|
return self._handle_rpc_result(msg_id, sequence, reader)
|
|
|
|
if code == 0x347773c5: # pong
|
|
return self._handle_pong(msg_id, sequence, reader)
|
|
|
|
if code == 0x73f1f8dc: # msg_container
|
|
return self._handle_container(msg_id, sequence, reader, updates)
|
|
|
|
if code == 0x3072cfa1: # gzip_packed
|
|
return self._handle_gzip_packed(msg_id, sequence, reader, updates)
|
|
|
|
if code == 0xedab447b: # bad_server_salt
|
|
return self._handle_bad_server_salt(msg_id, sequence, reader)
|
|
|
|
if code == 0xa7eff811: # bad_msg_notification
|
|
return self._handle_bad_msg_notification(msg_id, sequence, reader)
|
|
|
|
# msgs_ack, it may handle the request we wanted
|
|
if code == 0x62d6b459:
|
|
ack = reader.tgread_object()
|
|
for r in self._pending_receive:
|
|
if r.msg_id in ack.msg_ids:
|
|
self._logger.warning('Ack found for the a request')
|
|
|
|
if self.logging_out:
|
|
self._logger.info('Message ack confirmed a request')
|
|
r.confirm_received = True
|
|
|
|
return True
|
|
|
|
# If the code is not parsed manually, then it was parsed by the code generator!
|
|
# In this case, we will simply treat the incoming TLObject as an Update,
|
|
# if we can first find a matching TLObject
|
|
if code in tlobjects:
|
|
result = reader.tgread_object()
|
|
if updates is None:
|
|
self._logger.debug('Ignored update for %s', repr(result))
|
|
else:
|
|
self._logger.debug('Read update for %s', repr(result))
|
|
updates.append(result)
|
|
|
|
return True
|
|
|
|
self._logger.warning('Unknown message: {}'.format(hex(code)))
|
|
return False
|
|
|
|
# endregion
|
|
|
|
# region Message handling
|
|
|
|
def _handle_pong(self, msg_id, sequence, reader):
|
|
self._logger.debug('Handling pong')
|
|
reader.read_int(signed=False) # code
|
|
received_msg_id = reader.read_long(signed=False)
|
|
|
|
try:
|
|
request = next(r for r in self._pending_receive
|
|
if r.msg_id == received_msg_id)
|
|
|
|
self._logger.warning('Pong confirmed a request')
|
|
request.confirm_received = True
|
|
except StopIteration: pass
|
|
|
|
return True
|
|
|
|
def _handle_container(self, msg_id, sequence, reader, updates):
|
|
self._logger.debug('Handling container')
|
|
reader.read_int(signed=False) # code
|
|
size = reader.read_int()
|
|
for _ in range(size):
|
|
inner_msg_id = reader.read_long(signed=False)
|
|
reader.read_int() # inner_sequence
|
|
inner_length = reader.read_int()
|
|
begin_position = reader.tell_position()
|
|
|
|
# Note that this code is IMPORTANT for skipping RPC results of
|
|
# lost requests (i.e., ones from the previous connection session)
|
|
if not self._process_msg(
|
|
inner_msg_id, sequence, reader, updates):
|
|
reader.set_position(begin_position + inner_length)
|
|
|
|
return True
|
|
|
|
def _handle_bad_server_salt(self, msg_id, sequence, reader):
|
|
self._logger.debug('Handling bad server salt')
|
|
reader.read_int(signed=False) # code
|
|
bad_msg_id = reader.read_long(signed=False)
|
|
reader.read_int() # bad_msg_seq_no
|
|
reader.read_int() # error_code
|
|
new_salt = reader.read_long(signed=False)
|
|
self.session.salt = new_salt
|
|
|
|
try:
|
|
request = next(r for r in self._pending_receive
|
|
if r.msg_id == bad_msg_id)
|
|
|
|
self.send(request)
|
|
except StopIteration: pass
|
|
|
|
return True
|
|
|
|
def _handle_bad_msg_notification(self, msg_id, sequence, reader):
|
|
self._logger.debug('Handling bad message notification')
|
|
reader.read_int(signed=False) # code
|
|
reader.read_long(signed=False) # request_id
|
|
reader.read_int() # request_sequence
|
|
|
|
error_code = reader.read_int()
|
|
error = BadMessageError(error_code)
|
|
if 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.
|
|
self.session.update_time_offset(correct_msg_id=msg_id)
|
|
self.session.save()
|
|
self._logger.warning('Read Bad Message error: ' + str(error))
|
|
self._logger.info('Attempting to use the correct time offset.')
|
|
return True
|
|
else:
|
|
raise error
|
|
|
|
def _handle_rpc_result(self, msg_id, sequence, reader):
|
|
self._logger.debug('Handling RPC result')
|
|
reader.read_int(signed=False) # code
|
|
request_id = reader.read_long(signed=False)
|
|
inner_code = reader.read_int(signed=False)
|
|
|
|
try:
|
|
request = next(r for r in self._pending_receive
|
|
if r.msg_id == request_id)
|
|
|
|
request.confirm_received = True
|
|
except StopIteration:
|
|
request = None
|
|
|
|
if inner_code == 0x2144ca19: # RPC Error
|
|
error = rpc_message_to_error(
|
|
reader.read_int(), reader.tgread_string())
|
|
|
|
# Acknowledge that we received the error
|
|
self._need_confirmation.append(request_id)
|
|
self._send_acknowledges()
|
|
|
|
self._logger.warning('Read RPC error: %s', str(error))
|
|
if isinstance(error, InvalidDCError):
|
|
# Must resend this request, if any
|
|
if request:
|
|
request.confirm_received = False
|
|
|
|
raise error
|
|
else:
|
|
if request:
|
|
self._logger.debug('Reading request response')
|
|
if inner_code == 0x3072cfa1: # GZip packed
|
|
unpacked_data = gzip.decompress(reader.tgread_bytes())
|
|
with BinaryReader(unpacked_data) as compressed_reader:
|
|
request.on_response(compressed_reader)
|
|
else:
|
|
reader.seek(-4)
|
|
request.on_response(reader)
|
|
|
|
return True
|
|
else:
|
|
# If it's really a result for RPC from previous connection
|
|
# session, it will be skipped by the handle_container()
|
|
self._logger.warning('Lost request will be skipped.')
|
|
return False
|
|
|
|
def _handle_gzip_packed(self, msg_id, sequence, reader, updates):
|
|
self._logger.debug('Handling gzip packed data')
|
|
reader.read_int(signed=False) # code
|
|
packed_data = reader.tgread_bytes()
|
|
unpacked_data = gzip.decompress(packed_data)
|
|
|
|
with BinaryReader(unpacked_data) as compressed_reader:
|
|
return self._process_msg(
|
|
msg_id, sequence, compressed_reader, updates)
|
|
|
|
# endregion
|