Telethon/network/tcp_transport.py
Lonami 75a648f438 Several fixes to authenticator, added more unit tests
Some fixes include, in more detail:
- Using little over big endianess in some parts
- Flagging all the constructor numbers as unsigned
- Fixed bugs with factorizer
- Implemented TLSharp's RSA
2016-09-03 10:54:58 +02:00

55 lines
1.9 KiB
Python
Executable File

# This file is based on TLSharp
# https://github.com/sochix/TLSharp/blob/master/TLSharp.Core/Network/TcpTransport.cs
from zlib import crc32
from network.tcp_message import TcpMessage
from network.tcp_client import TcpClient
class TcpTransport:
def __init__(self, ip_address, port):
self._tcp_client = TcpClient()
self._send_counter = 0
self._tcp_client.connect(ip_address, port)
def send(self, packet):
"""Sends the given packet (bytes array) to the connected peer"""
if not self._tcp_client.connected:
raise ConnectionError('Client not connected to server.')
# Get a TcpMessage which contains the given packet
tcp_message = TcpMessage(self._send_counter, packet)
# TODO In TLSharp, this is async; Should both send and receive be here too?
self._tcp_client.write(tcp_message.encode())
self._send_counter += 1
def receive(self):
"""Receives a TcpMessage from the connected peer"""
# First read everything
packet_length_bytes = self._tcp_client.read(4)
packet_length = int.from_bytes(packet_length_bytes, byteorder='little')
seq_bytes = self._tcp_client.read(4)
seq = int.from_bytes(seq_bytes, byteorder='little')
body = self._tcp_client.read(packet_length - 12)
checksum = int.from_bytes(self._tcp_client.read(4), byteorder='little')
# Then perform the checks
rv = packet_length_bytes + seq_bytes + body
# Ensure it's unsigned (http://stackoverflow.com/a/30092291/4759433)
valid_checksum = crc32(rv) & 0xFFFFFFFF
if checksum != valid_checksum:
raise ValueError('Invalid checksum, skip')
# If we passed the tests, we can then return a valid TcpMessage
return TcpMessage(seq, body)
def dispose(self):
if self._tcp_client.connected:
self._tcp_client.close()