Telethon/telethon/telegram_bare_client.py
2017-08-24 19:09:37 +02:00

568 lines
21 KiB
Python

import logging
import pyaes
from datetime import timedelta
from hashlib import md5
from os import path
from io import BytesIO
# Import some externalized utilities to work with the Telegram types and more
from . import helpers as utils
from .errors import (
RPCError, FloodWaitError, FileMigrateError, TypeNotFoundError
)
from .network import authenticator, MtProtoSender, TcpTransport
from .utils import get_appropriated_part_size
from .crypto import AES
from .crypto import rsa
# For sending and receiving requests
from .tl import TLObject, JsonSession
from .tl.all_tlobjects import layer
from .tl.functions import (
InitConnectionRequest, InvokeWithLayerRequest, PingRequest
)
# Initial request
from .tl.functions.help import GetConfigRequest
from .tl.functions.auth import (
ImportAuthorizationRequest, ExportAuthorizationRequest
)
# Easier access for working with media
from .tl.functions.upload import (
GetFileRequest, GetCdnFileRequest, ReuploadCdnFileRequest,
SaveBigFilePartRequest, SaveFilePartRequest
)
from .tl.functions.help import GetCdnConfigRequest
# All the types we need to work with
from .tl.types import InputFile, InputFileBig
from .tl.types.upload import FileCdnRedirect, CdnFileReuploadNeeded
class TelegramBareClient:
"""Bare Telegram Client with just the minimum -
The reason to distinguish between a MtProtoSender and a
TelegramClient itself is because the sender is just that,
a sender, which should know nothing about Telegram but
rather how to handle this specific connection.
The TelegramClient itself should know how to initialize
a proper connection to the servers, as well as other basic
methods such as disconnection and reconnection.
This distinction between a bare client and a full client
makes it possible to create clones of the bare version
(by using the same session, IP address and port) to be
able to execute queries on either, without the additional
cost that would involve having the methods for signing in,
logging out, and such.
"""
# Current TelegramClient version
__version__ = '0.12.1'
# region Initialization
def __init__(self, session, api_id, api_hash,
proxy=None, timeout=timedelta(seconds=5)):
"""Initializes the Telegram client with the specified API ID and Hash.
Session must always be a Session instance, and an optional proxy
can also be specified to be used on the connection.
"""
self.session = session
self.api_id = int(api_id)
self.api_hash = api_hash
self.proxy = proxy
self._timeout = timeout
self._logger = logging.getLogger(__name__)
# Cache "exported" senders 'dc_id: TelegramBareClient' and
# their corresponding sessions not to recreate them all
# the time since it's a (somewhat expensive) process.
self._cached_clients = {}
# These will be set later
self.dc_options = None
self._sender = None
# endregion
# region Connecting
def connect(self, exported_auth=None, initial_query=None):
"""Connects to the Telegram servers, executing authentication if
required. Note that authenticating to the Telegram servers is
not the same as authenticating the desired user itself, which
may require a call (or several) to 'sign_in' for the first time.
If 'exported_auth' is not None, it will be used instead to
determine the authorization key for the current session.
If 'initial_query' is not None, it will override the default
'GetConfigRequest()', and its result will be returned ONLY
if the client wasn't connected already.
"""
if self._sender and self._sender.is_connected():
# Try sending a ping to make sure we're connected already
# TODO Maybe there's a better way to check this
try:
if initial_query is None:
self(PingRequest(utils.generate_random_long()))
return True
else:
return self(initial_query)
except:
# If ping failed, ensure we're disconnected first
self.disconnect()
transport = TcpTransport(self.session.server_address,
self.session.port,
proxy=self.proxy,
timeout=self._timeout)
try:
if not self.session.auth_key:
self.session.auth_key, self.session.time_offset = \
authenticator.do_authentication(transport)
self.session.save()
self._sender = MtProtoSender(transport, self.session)
self._sender.connect()
# Now it's time to send an InitConnectionRequest
# This must always be invoked with the layer we'll be using
if exported_auth is None:
query = initial_query if initial_query else GetConfigRequest()
else:
query = ImportAuthorizationRequest(
exported_auth.id, exported_auth.bytes)
request = InitConnectionRequest(
api_id=self.api_id,
device_model=self.session.device_model,
system_version=self.session.system_version,
app_version=self.session.app_version,
lang_code=self.session.lang_code,
system_lang_code=self.session.system_lang_code,
lang_pack='', # "langPacks are for official apps only"
query=query)
result = self(InvokeWithLayerRequest(
layer=layer, query=request
))
if initial_query is None:
if exported_auth is not None:
result = self(GetConfigRequest())
# We're only interested in the DC options,
# although many other options are available!
self.dc_options = result.dc_options
return True
else:
return result
except TypeNotFoundError as e:
# This is fine, probably layer migration
self._logger.debug('Found invalid item, probably migrating', e)
self.disconnect()
return self.connect(exported_auth=exported_auth,
initial_query=initial_query)
except (RPCError, ConnectionError) as error:
# Probably errors from the previous session, ignore them
self.disconnect()
self._logger.debug('Could not stabilise initial connection: {}'
.format(error))
return None if initial_query else False
def disconnect(self):
"""Disconnects from the Telegram server"""
if self._sender:
self._sender.disconnect()
self._sender = None
def reconnect(self, new_dc=None):
"""Disconnects and connects again (effectively reconnecting).
If 'new_dc' is not None, the current authorization key is
removed, the DC used is switched, and a new connection is made.
"""
self.disconnect()
if new_dc is not None:
self.session.auth_key = None # Force creating new auth_key
dc = self._get_dc(new_dc)
self.session.server_address = dc.ip_address
self.session.port = dc.port
self.session.save()
self.connect()
# endregion
# region Properties
def set_timeout(self, timeout):
if timeout is None:
self._timeout = None
elif isinstance(timeout, int) or isinstance(timeout, float):
self._timeout = timedelta(seconds=timeout)
elif isinstance(timeout, timedelta):
self._timeout = timeout
else:
raise ValueError(
'{} is not a valid type for a timeout'.format(type(timeout))
)
if self._sender:
self._sender.transport.timeout = self._timeout
def get_timeout(self):
return self._timeout
timeout = property(get_timeout, set_timeout)
# endregion
# region Working with different Data Centers
def _get_dc(self, dc_id, cdn=False):
"""Gets the Data Center (DC) associated to 'dc_id'"""
if not self.dc_options:
raise ConnectionError(
'Cannot determine the required data center IP address. '
'Stabilise a successful initial connection first.')
try:
return next(dc for dc in self.dc_options
if dc.id == dc_id and bool(dc.cdn) == cdn)
except StopIteration:
if not cdn:
raise
for pk in self(GetCdnConfigRequest()).public_keys:
rsa.add_key(pk.public_key)
self.dc_options = self(GetConfigRequest()).dc_options
return self._get_dc(dc_id, cdn=cdn)
def _get_exported_client(self, dc_id,
init_connection=False,
bypass_cache=False):
"""Gets a cached exported TelegramBareClient for the desired DC.
If it's the first time retrieving the TelegramBareClient, the
current authorization is exported to the new DC so that
it can be used there, and the connection is initialized.
If after using the sender a ConnectionResetError is raised,
this method should be called again with init_connection=True
in order to perform the reconnection.
If bypass_cache is True, a new client will be exported and
it will not be cached.
"""
# Thanks badoualy/kotlogram on /telegram/api/DefaultTelegramClient.kt
# for clearly showing how to export the authorization! ^^
client = self._cached_clients.get(dc_id)
if client and not bypass_cache:
if init_connection:
client.reconnect()
return client
else:
dc = self._get_dc(dc_id)
# Export the current authorization to the new DC.
export_auth = self(ExportAuthorizationRequest(dc_id))
# Create a temporary session for this IP address, which needs
# to be different because each auth_key is unique per DC.
#
# Construct this session with the connection parameters
# (system version, device model...) from the current one.
session = JsonSession(self.session)
session.server_address = dc.ip_address
session.port = dc.port
client = TelegramBareClient(
session, self.api_id, self.api_hash,
timeout=self._timeout
)
client.connect(exported_auth=export_auth)
if not bypass_cache:
# Don't go through this expensive process every time.
self._cached_clients[dc_id] = client
return client
def _get_cdn_client(self, dc_id, query):
"""_get_exported_client counterpart for CDNs.
Returns a tuple of (client, query result)
"""
dc = self._get_dc(dc_id, cdn=True)
session = JsonSession(self.session)
session.server_address = dc.ip_address
session.port = dc.port
client = TelegramBareClient(
session, self.api_id, self.api_hash,
timeout=self._timeout
)
# This will make use of the new RSA keys for this specific CDN
return client, client.connect(initial_query=query)
# endregion
# region Invoking Telegram requests
def invoke(self, request, updates=None):
"""Invokes (sends) a MTProtoRequest and returns (receives) its result.
If 'updates' is not None, all read update object will be put
in such list. Otherwise, update objects will be ignored.
"""
if not isinstance(request, TLObject) and not request.content_related:
raise ValueError('You can only invoke requests, not types!')
if not self._sender:
raise ValueError('You must be connected to invoke requests!')
try:
self._sender.send(request)
self._sender.receive(request, updates=updates)
return request.result
except ConnectionResetError:
self._logger.debug('Server disconnected us. Reconnecting and '
'resending request...')
self.reconnect()
return self.invoke(request)
except FloodWaitError:
self.disconnect()
raise
# Let people use client(SomeRequest()) instead client.invoke(...)
__call__ = invoke
# endregion
# region Uploading media
def upload_file(self,
file,
part_size_kb=None,
file_name=None,
progress_callback=None):
"""Uploads the specified file and returns a handle (an instance
of InputFile or InputFileBig, as required) which can be later used.
Uploading a file will simply return a "handle" to the file stored
remotely in the Telegram servers, which can be later used on. This
will NOT upload the file to your own chat.
'file' may be either a file path, a byte array, or a stream.
Note that if the file is a stream it will need to be read
entirely into memory to tell its size first.
If 'progress_callback' is not None, it should be a function that
takes two parameters, (bytes_uploaded, total_bytes).
Default values for the optional parameters if left as None are:
part_size_kb = get_appropriated_part_size(file_size)
file_name = path.basename(file_path)
"""
if isinstance(file, str):
file_size = path.getsize(file)
elif isinstance(file, bytes):
file_size = len(file)
else:
file = file.read()
file_size = len(file)
if not part_size_kb:
part_size_kb = get_appropriated_part_size(file_size)
if part_size_kb > 512:
raise ValueError('The part size must be less or equal to 512KB')
part_size = int(part_size_kb * 1024)
if part_size % 1024 != 0:
raise ValueError('The part size must be evenly divisible by 1024')
# Determine whether the file is too big (over 10MB) or not
# Telegram does make a distinction between smaller or larger files
is_large = file_size > 10 * 1024 * 1024
part_count = (file_size + part_size - 1) // part_size
file_id = utils.generate_random_long()
hash_md5 = md5()
stream = open(file, 'rb') if isinstance(file, str) else BytesIO(file)
try:
for part_index in range(part_count):
# Read the file by in chunks of size part_size
part = stream.read(part_size)
# The SavePartRequest is different depending on whether
# the file is too large or not (over or less than 10MB)
if is_large:
request = SaveBigFilePartRequest(file_id, part_index,
part_count, part)
else:
request = SaveFilePartRequest(file_id, part_index, part)
result = self(request)
if result:
if not is_large:
# No need to update the hash if it's a large file
hash_md5.update(part)
if progress_callback:
progress_callback(stream.tell(), file_size)
else:
raise ValueError('Failed to upload file part {}.'
.format(part_index))
finally:
stream.close()
# Set a default file name if None was specified
if not file_name:
if isinstance(file, str):
file_name = path.basename(file)
else:
file_name = str(file_id)
if is_large:
return InputFileBig(file_id, part_count, file_name)
else:
return InputFile(file_id, part_count, file_name,
md5_checksum=hash_md5.hexdigest())
# endregion
# region Downloading media
def download_file(self,
input_location,
file,
part_size_kb=None,
file_size=None,
progress_callback=None):
"""Downloads the given InputFileLocation to file (a stream or str).
If 'progress_callback' is not None, it should be a function that
takes two parameters, (bytes_downloaded, total_bytes). Note that
'total_bytes' simply equals 'file_size', and may be None.
"""
if not part_size_kb:
if not file_size:
part_size_kb = 64 # Reasonable default
else:
part_size_kb = get_appropriated_part_size(file_size)
part_size = int(part_size_kb * 1024)
# https://core.telegram.org/api/files says:
# > part_size % 1024 = 0 (divisible by 1KB)
#
# But https://core.telegram.org/cdn (more recent) says:
# > limit must be divisible by 4096 bytes
# So we just stick to the 4096 limit.
if part_size % 4096 != 0:
raise ValueError('The part size must be evenly divisible by 4096.')
if isinstance(file, str):
# Ensure that we'll be able to download the media
utils.ensure_parent_dir_exists(file)
f = open(file, 'wb')
else:
f = file
# The used client will change if FileMigrateError occurs
client = self
try:
offset_index = 0
cdn_file_token = None
def encrypt_method(x):
return x # Defaults to no-op
while True:
offset = offset_index * part_size
try:
if cdn_file_token:
result = client(GetCdnFileRequest(
cdn_file_token, offset, part_size
))
else:
result = client(GetFileRequest(
input_location, offset, part_size
))
if isinstance(result, FileCdnRedirect):
client, cdn_file_token, encrypt_method, result = \
self._prepare_cdn_redirect(
result, offset, part_size
)
if result is None:
# File was not ready on the CDN yet
continue
except FileMigrateError as e:
client = self._get_exported_client(e.new_dc)
continue
offset_index += 1
# If we have received no data (0 bytes), the file is over
# So there is nothing left to download and write
if not result.bytes:
# Return some extra information, unless it's a cdn file
return getattr(result, 'type', '')
f.write(encrypt_method(result.bytes))
if progress_callback:
progress_callback(f.tell(), file_size)
finally:
if isinstance(file, str):
f.close()
def _prepare_cdn_redirect(self, cdn_redirect, offset, part_size):
"""Returns (client, cdn_file_token, encrypt_method, result)"""
# https://core.telegram.org/cdn
# TODO Use libssl if available
cdn_aes = pyaes.AESModeOfOperationCTR(
cdn_redirect.encryption_key
)
# The returned IV is the counter used on CTR
cdn_aes._counter._counter = list(
cdn_redirect.encryption_iv[:12] +
(offset >> 4).to_bytes(4, 'big')
)
client, cdn_file = self._get_cdn_client(
cdn_redirect.dc_id,
GetCdnFileRequest(
cdn_redirect.file_token, offset, part_size
)
)
if isinstance(cdn_file, CdnFileReuploadNeeded):
# We need to use the original client here
self(ReuploadCdnFileRequest(
file_token=cdn_redirect.file_token,
request_token=cdn_file.request_token
))
return client, cdn_redirect.file_token, cdn_aes.encrypt, None
else:
# We have the first bytes for the file
return client, cdn_redirect.file_token, cdn_aes.encrypt, cdn_file
# endregion