Telethon/telethon/network/mtproto_plain_sender.py

64 lines
2.0 KiB
Python

import time
from ..errors import BrokenAuthKeyError
from ..extensions import BinaryReader, BinaryWriter
class MtProtoPlainSender:
"""MTProto Mobile Protocol plain sender
(https://core.telegram.org/mtproto/description#unencrypted-messages)
"""
def __init__(self, connection):
self._sequence = 0
self._time_offset = 0
self._last_msg_id = 0
self._connection = connection
def connect(self):
self._connection.connect()
def disconnect(self):
self._connection.close()
def send(self, data):
"""Sends a plain packet (auth_key_id = 0) containing the
given message body (data)
"""
with BinaryWriter(known_length=len(data) + 20) as writer:
writer.write_long(0)
writer.write_long(self._get_new_msg_id())
writer.write_int(len(data))
writer.write(data)
packet = writer.get_bytes()
self._connection.send(packet)
def receive(self):
"""Receives a plain packet, returning the body of the response"""
body = self._connection.recv()
if body == b'l\xfe\xff\xff': # -404 little endian signed
# Broken authorization, must reset the auth key
raise BrokenAuthKeyError()
with BinaryReader(body) as reader:
reader.read_long() # auth_key_id
reader.read_long() # msg_id
message_length = reader.read_int()
response = reader.read(message_length)
return response
def _get_new_msg_id(self):
"""Generates a new message ID based on the current time since epoch"""
# See core.telegram.org/mtproto/description#message-identifier-msg-id
now = time.time()
nanoseconds = int((now - int(now)) * 1e+9)
# "message identifiers are divisible by 4"
new_msg_id = (int(now) << 32) | (nanoseconds << 2)
if self._last_msg_id >= new_msg_id:
new_msg_id = self._last_msg_id + 4
self._last_msg_id = new_msg_id
return new_msg_id