slixmpp-omemo/examples/echo_client.py
Maxime “pep” Buquet 9e70954a0e example-bot: attempt at returning encrypted messages
Signed-off-by: Maxime “pep” Buquet <pep@bouah.net>
2019-02-24 12:28:06 +00:00

233 lines
8.5 KiB
Python

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Slixmpp OMEMO plugin
Copyright (C) 2010 Nathanael C. Fritz
Copyright (C) 2019 Maxime “pep” Buquet <pep@bouah.net>
This file is part of slixmpp-omemo.
See the file LICENSE for copying permission.
"""
import os
import sys
import asyncio
import logging
from getpass import getpass
from argparse import ArgumentParser
from slixmpp import ClientXMPP, JID
from slixmpp.stanza import Message
from slixmpp_omemo import PluginCouldNotLoad, MissingOwnKey, EncryptionPrepareException
from slixmpp_omemo import UndecidedException, UntrustedException, NoAvailableSession
import slixmpp_omemo
log = logging.getLogger(__name__)
class EchoBot(ClientXMPP):
"""
A simple Slixmpp bot that will echo encrypted messages it receives, along
with a short thank you message.
For details on how to build a client with slixmpp, look at exemples in the
slixmpp repository.
"""
eme_ns = 'eu.siacs.conversations.axolotl'
def __init__(self, jid, password):
ClientXMPP.__init__(self, jid, password)
self.add_event_handler("session_start", self.start)
self.add_event_handler("message", self.message_handler)
def start(self, _event) -> None:
"""
Process the session_start event.
Typical actions for the session_start event are
requesting the roster and broadcasting an initial
presence stanza.
Arguments:
event -- An empty dictionary. The session_start
event does not provide any additional
data.
"""
self.send_presence()
self.get_roster()
def message_handler(self, msg: Message) -> None:
asyncio.ensure_future(self.message(msg))
async def message(self, msg: Message, allow_untrusted: bool = False) -> None:
"""
Process incoming message stanzas. Be aware that this also
includes MUC messages and error messages. It is usually
a good idea to check the messages's type before processing
or sending replies.
Arguments:
msg -- The received message stanza. See the documentation
for stanza objects and the Message stanza to see
how it may be used.
"""
if msg['type'] not in ('chat', 'normal'):
return None
if not self['xep_0384'].is_encrypted(msg):
await self.plain_reply(msg, 'This message was not encrypted.\n%(body)s' % msg)
return None
try:
body = self['xep_0384'].decrypt_message(msg, allow_untrusted)
await self.encrypted_reply(msg, 'Thanks for sending\n%s' % body.decode("utf8"))
except (MissingOwnKey,):
# The message is missing our own key, it was not encrypted for
# us, and we can't decrypt it.
await self.plain_reply(
msg,
'I can\'t decrypt this message as it is not encrypted for me.',
)
except (NoAvailableSession,) as exn:
# We received a message from that contained a session that we
# don't know about (deleted session storage, etc.). We can't
# decrypt the message, and it's going to be lost.
# Here, as we need to initiate a new encrypted session, it is
# best if we send an encrypted message directly. XXX: Is it
# where we talk about self-healing messages?
await self.encrypted_reply(
msg,
'I can\'t decrypt this message as it uses an encrypted '
'session I don\'t know about.',
)
except (UndecidedException, UntrustedException) as exn:
# We received a message from an untrusted device. We can
# choose to decrypt the message nonetheless, with the
# `allow_untrusted` flag on the `decrypt_message` call, which
# we will do here. This is only possible for decryption,
# encryption will require us to decide if we trust the device
# or not. Clients _should_ indicate that the message was not
# trusted, or in undecided state, if they decide to decrypt it
# anyway.
await self.plain_reply(
msg,
"Your device '%s' is not in my trusted devices." % exn.device,
)
# We resend, setting the `allow_untrusted` parameter to True.
await self.message(msg, allow_untrusted=True)
except (EncryptionPrepareException,):
# Slixmpp tried its best, but there were errors it couldn't
# resolve. At this point you should have seen other exceptions
# and given a chance to resolve them already.
await self.plain_reply(msg, 'I was not able to decrypt the message.')
return None
async def plain_reply(self, original_msg, body) -> None:
"""
Helper to reply to messages
"""
mto = original_msg['from']
mtype = original_msg['type']
msg = self.make_message(mto=mto, mtype=mtype)
msg['body'] = body
return msg.send()
async def encrypted_reply(self, original_msg, body) -> None:
"""Helper to reply with encrypted messages"""
mto = original_msg['from']
mtype = original_msg['type']
msg = self.make_message(mto=mto, mtype=mtype)
msg['eme']['namespace'] = self.eme_ns
msg['eme']['name'] = self['xep_0380'].mechanisms[self.eme_ns]
while True:
try:
# `encrypt_message` excepts the plaintext to be sent, a list of
# bare JIDs to encrypt to, and optionally a dict of problems to
# expect per bare JID.
recipients = [mto]
encrypt = await self['xep_0384'].encrypt_message(body, recipients)
msg.append(encrypt)
return msg.send()
except UndecidedException as exn:
# The library prevents us from sending a message to an
# untrusted/undecided barejid, so we need to make a decision here.
# This is where you prompt your user to ask what to do.
self['xep_0384'].trust(exn.bare_jid, exn.device, exn.ik)
except Exception as exn:
break
return None
if __name__ == '__main__':
# Setup the command line arguments.
parser = ArgumentParser(description=EchoBot.__doc__)
# Output verbosity options.
parser.add_argument("-q", "--quiet", help="set logging to ERROR",
action="store_const", dest="loglevel",
const=logging.ERROR, default=logging.INFO)
parser.add_argument("-d", "--debug", help="set logging to DEBUG",
action="store_const", dest="loglevel",
const=logging.DEBUG, default=logging.INFO)
# JID and password options.
parser.add_argument("-j", "--jid", dest="jid",
help="JID to use")
parser.add_argument("-p", "--password", dest="password",
help="password to use")
# Data dir for omemo plugin
DATA_DIR = os.path.join(
os.path.dirname(os.path.abspath(__file__)),
'omemo',
)
parser.add_argument("--data-dir", dest="data_dir",
help="data directory", default=DATA_DIR)
args = parser.parse_args()
# Setup logging.
logging.basicConfig(level=args.loglevel,
format='%(levelname)-8s %(message)s')
if args.jid is None:
args.jid = input("Username: ")
if args.password is None:
args.password = getpass("Password: ")
# Setup the EchoBot and register plugins. Note that while plugins may
# have interdependencies, the order in which you register them does
# not matter.
# Ensure OMEMO data dir is created
os.makedirs(args.data_dir, exist_ok=True)
xmpp = EchoBot(args.jid, args.password)
xmpp.register_plugin('xep_0030') # Service Discovery
xmpp.register_plugin('xep_0199') # XMPP Ping
xmpp.register_plugin('xep_0380') # Explicit Message Encryption
try:
xmpp.register_plugin(
'xep_0384',
{
'data_dir': args.data_dir,
},
module=slixmpp_omemo,
) # OMEMO
except (PluginCouldNotLoad,):
log.exception('And error occured when loading the omemo plugin.')
sys.exit(1)
# Connect to the XMPP server and start processing XMPP stanzas.
xmpp.connect()
xmpp.process()