Fixed tiny bugs with authentication, added more unit tests

This commit is contained in:
Lonami 2016-09-04 21:07:09 +02:00
parent 7c8c65560e
commit b027dd2c8f
11 changed files with 98 additions and 32 deletions

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@ -36,6 +36,7 @@ class AES:
def encrypt_ige(plain_text, key, iv):
"""Encrypts the given text in 16-bytes blocks by using the given key and 32-bytes initialization vector"""
# TODO: Random padding
if len(plain_text) % 16 != 0: # Add padding if and only if it's not evenly divisible by 16 already
padding = bytes(16 - len(plain_text) % 16)
plain_text += padding

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@ -1,6 +1,7 @@
# This file is based on TLSharp
# https://github.com/sochix/TLSharp/blob/master/TLSharp.Core/Network/MtProtoPlainSender.cs
import time
import random
from utils import BinaryWriter, BinaryReader
@ -36,7 +37,11 @@ class MtProtoPlainSender:
def get_new_msg_id(self):
"""Generates a new message ID based on the current time (in ms) since epoch"""
new_msg_id = int(self._time_offset + time.time() * 1000) # Multiply by 1000 to get milliseconds
# See https://core.telegram.org/mtproto/description#message-identifier-msg-id
ms_time = int(time.time() * 1000)
new_msg_id = (((ms_time // 1000) << 32) | # "must approximately equal unixtime*2^32"
((ms_time % 1000) << 22) | # "approximate moment in time the message was created"
random.randint(0, 524288) << 2) # "message identifiers are divisible by 4"
# Ensure that we always return a message ID which is higher than the previous one
if self._last_msg_id >= new_msg_id:

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@ -100,7 +100,7 @@ class MtProtoSender:
remote_auth_key_id = reader.read_long()
msg_key = reader.read(16)
key, iv = utils.calc_key(self.session.auth_key.data, msg_key, False)
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:
@ -262,6 +262,8 @@ class MtProtoSender:
if request_id == mtproto_request.msg_id:
mtproto_request.confirm_received = True
else:
print('We did not get the ID we expected. Got {}, but it should have been {}'.format(request_id, mtproto_request.msg_id))
inner_code = reader.read_int(signed=False)
if inner_code == 0x2144ca19: # RPC Error

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@ -1,8 +1,7 @@
# This file is based on TLSharp
# https://github.com/sochix/TLSharp/blob/master/TLSharp.Core/Network/TcpMessage.cs
from zlib import crc32
from utils import BinaryWriter, BinaryReader
from binascii import crc32
class TcpMessage:
@ -31,10 +30,8 @@ class TcpMessage:
writer.write_int(len(self.body) + 12)
writer.write_int(self.sequence_number)
writer.write(self.body)
writer.flush() # Flush so we can get the buffer in the CRC
# Ensure it's unsigned (see http://stackoverflow.com/a/30092291/4759433)
crc = crc32(writer.get_bytes()[0:8 + len(self.body)]) & 0xFFFFFFFF
crc = crc32(writer.get_bytes())
writer.write_int(crc, signed=False)
return writer.get_bytes()
@ -55,10 +52,9 @@ class TcpMessage:
seq = reader.read_int()
packet = reader.read(packet_len - 12)
checksum = reader.read_int()
checksum = reader.read_int(signed=False)
# Ensure it's unsigned (see http://stackoverflow.com/a/30092291/4759433)
valid_checksum = crc32(body[:packet_len - 4]) & 0xFFFFFFFF
valid_checksum = crc32(body[:packet_len - 4])
if checksum != valid_checksum:
raise ValueError('Invalid checksum, skip')

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@ -1,7 +1,7 @@
# This file is based on TLSharp
# https://github.com/sochix/TLSharp/blob/master/TLSharp.Core/Network/TcpTransport.cs
from zlib import crc32
from network import TcpMessage, TcpClient
from binascii import crc32
class TcpTransport:
@ -35,12 +35,11 @@ class TcpTransport:
body = self._tcp_client.read(packet_length - 12)
checksum = int.from_bytes(self._tcp_client.read(4), byteorder='little')
checksum = int.from_bytes(self._tcp_client.read(4), byteorder='little', signed=False)
# 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
valid_checksum = crc32(rv)
if checksum != valid_checksum:
raise ValueError('Invalid checksum, skip')

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@ -1,5 +1,9 @@
import os
# Only import most stuff if the TLObjects were generated
if os.path.isfile('tl/all_tlobjects.py'):
from .all_tlobjects import tlobjects
from .session import Session
from .mtproto_request import MTProtoRequest
from .telegram_client import TelegramClient
del os
from .tlobject import TLObject, TLArg

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@ -4,6 +4,7 @@ from os.path import isfile as file_exists
import time
import pickle
import utils
import random
class Session:
@ -38,9 +39,13 @@ class Session:
def get_new_msg_id(self):
"""Generates a new message ID based on the current time (in ms) since epoch"""
# Refer to mtproto_plain_sender.py for the original method, this is a simple copy
new_msg_id = int(self.time_offset + time.time() * 1000)
if self.last_message_id >= new_msg_id:
new_msg_id = self._last_msg_id + 4
ms_time = int(time.time() * 1000)
new_msg_id = (((ms_time // 1000 + self.time_offset) << 32) | # "must approximately equal unixtime*2^32"
((ms_time % 1000) << 22) | # "approximate moment in time the message was created"
random.randint(0, 524288) << 2) # "message identifiers are divisible by 4"
self._last_msg_id = new_msg_id
if self.last_message_id >= new_msg_id:
new_msg_id = self.last_message_id + 4
self.last_message_id = new_msg_id
return new_msg_id

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@ -2,8 +2,8 @@ import os
import re
import shutil
from parser import TLParser
from parser import SourceBuilder
from parser.tl_parser import TLParser
from parser.source_builder import SourceBuilder
def tlobjects_exist():

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@ -5,16 +5,16 @@ import unittest
import os
import platform
import utils
import network.authenticator
from tl import Session
from tl.functions import InvokeWithLayerRequest, InitConnectionRequest
from tl.functions.help import GetConfigRequest
from crypto import AES, Factorizator
from network import TcpTransport, TcpClient, MtProtoSender
from utils import BinaryWriter, BinaryReader
from tl import Session
from tl.functions import InvokeWithLayerRequest, InitConnectionRequest
from tl.functions.help import GetConfigRequest
import utils
import network.authenticator
host = 'localhost'
port = random.randint(50000, 60000) # Arbitrary non-privileged port
@ -219,6 +219,50 @@ class UnitTest(unittest.TestCase):
assert cipher_text == real, 'Decrypted text does not equal the real value (expected "{}", got "{}")'\
.format(get_representation(real), get_representation(cipher_text))
@staticmethod
def test_calc_key():
shared_key = get_bytes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
msg_keys = [
'BA-1A-CF-DA-A8-5E-43-62-6C-FA-B6-0C-3A-9B-B0-FC',
'86-6D-92-69-CF-8B-93-AA-86-4B-1F-69-D0-34-83-5D',
'A1-2F-C0-61-6F-60-1A-B0-33-8F-7D-27-08-C8-EA-15',
'3A-56-52-0F-B7-89-D7-80-F6-18-72-CD-09-B5-A8-8A',
'06-F7-84-F3-91-CC-8D-DC-7D-92-41-7A-7E-84-25-E4',
'78-4D-FC-AE-F4-C4-55-81-6D-DD-99-A7-DB-B8-A3-88'
]
are_client = [
True,
False,
True,
True,
False,
False
]
valid_keys = [
'AF-E3-84-51-6D-E0-21-0C-D9-31-E4-9A-A0-76-5F-67-63-78-A1-B0-C9-BC-16-27-76-CF-2C-9D-4D-AE-C6-A5',
'DD-30-58-B6-93-8E-C9-79-EF-83-F8-8C-6A-A7-68-03-E2-C6-B1-36-C5-BB-FC-E7-DF-D6-B1-67-F7-75-CF-6B',
'70-3F-66-AF-FE-0A-F3-1E-95-C3-25-48-8D-0F-A7-95-59-53-BF-DD-35-97-6E-7A-C0-5E-79-9C-9D-09-3B-7B',
'20-9F-82-E3-95-3F-9D-1E-EE-3E-F3-82-B0-8D-6E-76-26-5B-94-27-DD-7D-61-C3-AC-EB-FA-71-FF-0D-8F-08',
'AE-06-BF-F1-89-88-22-66-98-48-76-E6-BD-D9-39-36-2D-36-4E-CF-FD-47-D2-87-D7-49-F8-93-22-2E-66-02',
'D9-6B-43-D0-89-F7-C5-75-A2-4A-F2-2F-F0-17-5C-95-AE-FA-46-A5-95-AA-C3-B9-76-B0-3A-A8-0E-7B-EA-5D'
]
valid_ivs = [
'B8-51-F3-C5-A3-5D-C6-DF-9E-E0-51-BD-22-8D-13-09-0E-9A-9D-5E-38-A2-F8-E7-00-77-D9-C1-A7-A0-F7-0F',
'DC-4C-C2-18-01-4A-22-58-86-6C-62-B6-B5-34-37-FD-E2-61-34-B6-AF-7D-46-53-D7-5B-E0-4E-0D-19-FB-BC',
'68-BB-BA-7F-55-B9-EF-86-EE-20-5A-1A-45-4E-70-C3-48-56-A2-E9-2F-91-AD-74-23-FE-54-06-E5-68-04-E9',
'79-31-8D-F0-DC-31-60-D7-09-BC-66-F1-AB-0D-7C-CB-2A-AF-74-32-64-C5-B3-18-C4-ED-55-D9-F6-39-DD-F3',
'1F-51-66-06-05-54-B9-E0-52-6A-88-6A-70-0C-DA-8D-2B-CD-BF-8A-67-5E-1A-A7-DD-EA-1C-CE-4C-D4-34-3D',
'8E-00-97-5E-B7-A1-F7-3D-1C-16-03-CA-B3-ED-EA-80-64-8F-77-A6-C4-34-5B-B5-DC-5D-C9-EC-B7-F8-F4-76'
]
for msg_key, is_client, valid_key, valid_iv in zip(msg_keys, are_client, valid_keys, valid_ivs):
msg_key = get_bytes(msg_key)
key, iv = utils.calc_key(shared_key, msg_key, is_client)
assert get_representation(key) == valid_key
assert get_representation(iv) == valid_iv
@staticmethod
def test_authenticator():
transport = TcpTransport('149.154.167.91', 443)

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@ -1,3 +1,3 @@
from .binary_writer import BinaryWriter
from .binary_reader import BinaryReader
from .binary_writer import BinaryWriter
from .helpers import *

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@ -84,6 +84,16 @@ class BinaryReader:
"""Reads a Telegram-encoded string"""
return str(self.tgread_bytes(), encoding='utf-8')
def tgread_bool(self):
"""Reads a Telegram boolean value"""
value = self.read_int(signed=False)
if value == 0x997275b5: # boolTrue
return True
elif value == 0xbc799737: # boolFalse
return False
else:
raise ValueError('Invalid boolean code {}'.format(hex(value)))
def tgread_object(self):
"""Reads a Telegram object"""
constructor_id = self.read_int()