+ Jabber implementation using slixmpp

.gitignore

@@ -131,3 +131,4 @@ dmypy.json
 # All local-only / private files
 **/local*
 **/priv*
+**/.omemo

README.md

@@ -200,6 +200,18 @@ See also sample configurations in the `test/` directory.
 Please first review [YAML syntax](https://yaml.org/spec/1.1/#id857168) if you don't know about YAML.
 
 
+
+## Using the Jabber/XMPP backend
+
+By using `--backend jabber` you can make the bot chat with XMPP (a.k.a. Jabber) users.
+
+### Jabber-specific options
+
+- `--username` and `--password` are the JabberID (e.g. *myusername@myserver.im*) and password of the bot's account, used to send and read messages. If either parameter is missing, will try to read `jid` and `password` from `~/.xtalk` file.
+- `--recipient` is the JabberID of the person to send the message to
+
+
+
 ## Using the Signal backend
 
 By using `--backend signal` you can make the bot chat with Signal users.
@@ -230,13 +242,6 @@ Sample command line to run the bot with Signal :
 
 ## Resources
 
-### Python libraries
-
-- [xmpppy](https://github.com/xmpppy/xmpppy) : this library is very easy to use but it does allow easy access to thread or timestamp, and no OMEMO...
-- [slixmpp](https://lab.louiz.org/poezio/slixmpp) : seems like a cool library too and pretends to require minimal dependencies ; however the quick start example does not work OOTB... It supports OMEMO so it's probably going to be to winner.
-- [github.com/horazont/aioxmpp](https://github.com/horazont/aioxmpp) : officially referenced library from xmpp.org, seems the most complete but misses practical introduction and [does not provide OMEMO OOTB](https://github.com/horazont/aioxmpp/issues/338).
-
-
 ### IBM Cloud
 
 - [Language Translator service](https://cloud.ibm.com/catalog/services/language-translator)
@@ -246,3 +251,17 @@ Sample command line to run the bot with Signal :
 
 - [Signal home](https://signal.org/)
 - [signal-cli man page](https://github.com/AsamK/signal-cli/blob/master/man/signal-cli.1.adoc)
+
+### Jabber
+
+- Official XMPP libraries : https://xmpp.org/software/libraries.html
+- OMEMO compatible clients : https://omemo.top/
+- [OMEMO official Python library](https://github.com/omemo/python-omemo) : looks very immature
+- *Gaijim*, a Windows/MacOS/Linux XMPP client with OMEMO support : [gajim.org](https://gajim.org/) | [dev.gajim.org/gajim](https://dev.gajim.org/gajim)
+- *Conversations*, an Android XMPP client with OMEMO support and paid hosting : https://conversations.im
+
+Python libraries :
+
+- [xmpppy](https://github.com/xmpppy/xmpppy) : this library is very easy to use but it does allow easy access to thread or timestamp, and no OMEMO...
+- [github.com/horazont/aioxmpp](https://github.com/horazont/aioxmpp) : officially referenced library from xmpp.org, seems the most complete but misses practical introduction and [does not provide OMEMO OOTB](https://github.com/horazont/aioxmpp/issues/338).
+- [slixmpp](https://lab.louiz.org/poezio/slixmpp) : seems like a cool library too and pretends to require minimal dependencies ; plus it [supports OMEMO](https://lab.louiz.org/poezio/slixmpp-omemo/) so it's the winner. [API doc](https://slixmpp.readthedocs.io/).

nicobot/jabber.py

@@ -0,0 +1,333 @@
+import logging
+import time
+import os
+
+from slixmpp import ClientXMPP, JID
+from slixmpp.exceptions import IqTimeout, IqError
+from slixmpp.stanza import Message
+import slixmpp_omemo
+from slixmpp_omemo import PluginCouldNotLoad, MissingOwnKey, EncryptionPrepareException
+from slixmpp_omemo import UndecidedException, UntrustedException, NoAvailableSession
+from omemo.exceptions import MissingBundleException
+import asyncio
+
+# Own classes
+from chatter import Chatter
+from helpers import *
+
+
+""" Copy-pasted from https://github.com/xmpppy/xmpppy/blob/master/docs/examples/xtalk.py """
+def read_xtalk_file( filename=os.environ['HOME']+'/.xtalk' ):
+
+    jidparams={}
+    if os.access(filename,os.R_OK):
+        for ln in open(filename).readlines():
+            if not ln[0] in ('#',';'):
+                key,val=ln.strip().split('=',1)
+                jidparams[key.lower()]=val
+    for mandatory in ['jid','password']:
+        if mandatory not in jidparams.keys():
+            raise ValueError('Please point ~/.xtalk config file to valid JID for sending messages. It should look like:\n\n#Uncomment fields before use and type in correct credentials.\n#JID=romeo@montague.net/resource (/resource is optional)\n#PASSWORD=juliet')
+    return jidparams
+
+
+
+class SliXmppClient(ClientXMPP):
+
+    """
+        This generic XMPP client is able to send & receive plain & OMEMO-encrypted messages.
+
+        Code is mostly taken from https://lab.louiz.org/poezio/slixmpp-omemo/-/blob/master/examples/echo_client.py
+    """
+
+    eme_ns = 'eu.siacs.conversations.axolotl'
+
+    def __init__(self, jid, password, message_handler):
+
+        """
+            jid, password : valid account to send and receive messages
+            message_handler : a Callable( original_message:Message, decrypted_body )
+        """
+
+        ClientXMPP.__init__(self, jid, password)
+
+        self.add_event_handler("session_start", self.session_start)
+        self.add_event_handler("message", self.message)
+
+        self.register_plugin('xep_0030') # Service Discovery
+        self.register_plugin('xep_0199') # XMPP Ping
+        self.register_plugin('xep_0380') # Explicit Message Encryption
+
+        try:
+            self.register_plugin(
+                'xep_0384',
+                {
+                    'data_dir': '.omemo',
+                },
+                module=slixmpp_omemo,
+            ) # OMEMO
+        except (PluginCouldNotLoad,):
+            log.exception('And error occured when loading the omemo plugin.')
+            sys.exit(1)
+
+        self.message_handler = message_handler
+
+
+    def session_start(self, event):
+        self.send_presence()
+        self.get_roster()
+
+        # Most get_*/set_* methods from plugins use Iq stanzas, which
+        # can generate IqError and IqTimeout exceptions
+        #
+        # try:
+        #     self.get_roster()
+        # except IqError as err:
+        #     logging.error('There was an error getting the roster')
+        #     logging.error(err.iq['error']['condition'])
+        #     self.disconnect()
+        # except IqTimeout:
+        #     logging.error('Server is taking too long to respond')
+        #     self.disconnect()
+
+
+    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.
+        """
+
+        # Sample encrypted message :
+        #
+        # <message xml:lang="en" to="bot9cd51f1a@conversations.im/1655465886336291765177990819" from="bot649ad4ad@conversations.im/Conversations.7Z6J" type="chat" id="26a30844-37d0-4f27-8daa-fd2107f5e706"><archived xmlns="urn:xmpp:mam:tmp" by="bot9cd51f1a@conversations.im" id="1590067423912722"/><stanza-id xmlns="urn:xmpp:sid:0" by="bot9cd51f1a@conversations.im" id="1590067423912722"/>
+        #     <encrypted xmlns="eu.siacs.conversations.axolotl">
+        #         <header sid="307701646">
+        #             <key rid="45781751">MwohBadGcbUIiKsYACIw8UjlZHsOEf79+fjBM44O9bM1YatXKRKaIYuaIkajsedDkIK906Srxk2N5B7jh8EozEAFKpfeqZg//Hqrin6wOGpX+TZ5kUJziXIALUaRs59D3J0=</key>
+        #             <key rid="1929813965">MwohBWTCE+eWLNmdgTy/gyEAAYACIwzz9+B/UFiaCu+5rcHmh3tyQ/GgBhVa+mk81YkQErXpjCpAPyWbKVJn2TH1dXH4Yj7VYYis0HDQ7r28ZDcMMXoxFcp2VNO9l7S23wI=</key>
+        #             <iv>5eM9IHpWSbKfLJj6</iv>
+        #         </header>
+        #         <payload>pX7D+54c</payload>
+        #     </encrypted><request xmlns="urn:xmpp:receipts"/><markable xmlns="urn:xmpp:chat-markers:0"/><origin-id xmlns="urn:xmpp:sid:0" id="26a30844-37d0-4f27-8daa-fd2107f5e706"/><store xmlns="urn:xmpp:hints"/><encryption xmlns="urn:xmpp:eme:0" name="OMEMO" namespace="eu.siacs.conversations.axolotl"/>
+        #     <body>I sent you an OMEMO encrypted message but your client doesn’t seem to support that. Find more information on https://conversations.im/omemo</body>
+        # </message>
+
+        # Sample plain message :
+        # <message xml:lang="en" to="bot9cd51f1a@conversations.im/11834511835037473566179797763" from="bot649ad4ad@conversations.im/Conversations.7Z6J" type="chat" id="5677cbdf-11d2-4aed-889e-0fb3e850a390"><archived xmlns="urn:xmpp:mam:tmp" by="bot9cd51f1a@conversations.im" id="1590095998371956"/><stanza-id xmlns="urn:xmpp:sid:0" by="bot9cd51f1a@conversations.im" id="1590095998371956"/><request xmlns="urn:xmpp:receipts"/><markable xmlns="urn:xmpp:chat-markers:0"/><origin-id xmlns="urn:xmpp:sid:0" id="5677cbdf-11d2-4aed-889e-0fb3e850a390"/><active xmlns="http://jabber.org/protocol/chatstates"/>
+        #     <body>My message</body>
+        # </message>
+
+        logging.debug("XMPP message received : %r",msg)
+
+        # TODO ? with xmppy I used to allow the following types : ["message","chat","normal",None]
+        if msg['type'] not in ('chat', 'normal'):
+            logging.debug("Discarding message of type %r",msg['type'])
+            return None
+
+        if not self['xep_0384'].is_encrypted(msg):
+            logging.debug('This message was not encrypted')
+            self.message_handler(msg,msg['body'])
+            return None
+
+        try:
+            mfrom = msg['from']
+            encrypted = msg['omemo_encrypted']
+            body = self['xep_0384'].decrypt_message(encrypted, mfrom, allow_untrusted)
+            # TODO Is it always UTF-8-encoded ?
+            self.message_handler(msg,body.decode("utf8"))
+            return None
+        except (MissingOwnKey,):
+            # The message is missing our own key, it was not encrypted for
+            # us, and we can't decrypt it.
+            logging.exception('I can\'t decrypt this message as it is not encrypted for me : %r',msg)
+            return None
+        except (NoAvailableSession,):
+            # 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?
+            logging.exception('I can\'t decrypt this message as it uses an encrypted session I don\'t know about : %r',msg)
+            return None
+        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.
+            logging.exception("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)
+            return None
+        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.
+            logging.exception('I was not able to decrypt the message : %r',msg)
+            return None
+        except (Exception,):
+            logging.exception('An error occured while attempting decryption')
+            raise
+
+        return None
+
+
+    async def plain_send(self, body, receiver, type='chat'):
+        """
+        Helper to send messages
+        """
+
+        msg = self.make_message(mto=receiver, mtype=type)
+        msg['body'] = body
+        return msg.send()
+
+
+    async def plain_reply(self, original_msg, body):
+        """
+        Helper to reply to messages
+        """
+
+        return self.plain_send( body, original_msg['from'], original_msg['type'] )
+
+
+    async def encrypted_send(self, body, recipient, type='chat'):
+        """Helper to send encrypted messages"""
+
+        msg = self.make_message(mto=recipient, mtype=type)
+        msg['eme']['namespace'] = self.eme_ns
+        msg['eme']['name'] = self['xep_0380'].mechanisms[self.eme_ns]
+
+        expect_problems = {}  # type: Optional[Dict[JID, List[int]]]
+
+        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.
+                #
+                # Note that this function returns an `<encrypted/>` object,
+                # and not a full Message stanza. This combined with the
+                # `recipients` parameter that requires for a list of JIDs,
+                # allows you to encrypt for 1:1 as well as groupchats (MUC).
+                #
+                # `expect_problems`: See EncryptionPrepareException handling.
+                recipients = [JID(recipient)]
+                encrypt = await self['xep_0384'].encrypt_message(body, recipients, expect_problems)
+                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. In
+                # this bot we will automatically trust undecided recipients.
+                self['xep_0384'].trust(exn.bare_jid, exn.device, exn.ik)
+            # TODO: catch NoEligibleDevicesException
+            except EncryptionPrepareException as exn:
+                # This exception is being raised when the library has tried
+                # all it could and doesn't know what to do anymore. It
+                # contains a list of exceptions that the user must resolve, or
+                # explicitely ignore via `expect_problems`.
+                # TODO: We might need to bail out here if errors are the same?
+                for error in exn.errors:
+                    if isinstance(error, MissingBundleException):
+                        # We choose to ignore MissingBundleException. It seems
+                        # to be somewhat accepted that it's better not to
+                        # encrypt for a device if it has problems and encrypt
+                        # for the rest, rather than error out. The "faulty"
+                        # device won't be able to decrypt and should display a
+                        # generic message. The receiving end-user at this
+                        # point can bring up the issue if it happens.
+                        logging.warning('Could not find keys for device "%d" of recipient "%s". Skipping.', error.device, error.bare_jid)
+                        jid = JID(error.bare_jid)
+                        device_list = expect_problems.setdefault(jid, [])
+                        device_list.append(error.device)
+            except (IqError, IqTimeout) as exn:
+                logging.exception('An error occured while fetching information on %r', recipient)
+                return None
+            except Exception as exn:
+                logging.exception('An error occured while attempting to encrypt to %r', recipient)
+                raise
+
+        return None
+
+
+    async def encrypted_reply(self, original_msg, body):
+        """Helper to reply with encrypted messages"""
+
+        logging.debug("Replying to %r",original_msg)
+        return self.encrypted_send( body, recipient=original_msg['from'], type=original_msg['type'] )
+
+
+
+class JabberChatter(Chatter):
+
+    """
+        Sends and receives messages with XMPP (a.k.a. Jabber).
+
+        It implements nicobot.Chatter by wrapping an internal slixmpp.ClientXMPP instance.
+    """
+
+    def __init__( self, jid, password, recipient ):
+
+        self.recipient = recipient
+        self.xmpp = SliXmppClient( jid, password, message_handler=self.on_xmpp_message )
+
+    def on_xmpp_message( self, original_message, decrypted_body ):
+        """
+            Called by the internal xmpp client when a message has arrived.
+
+            original_message: The received Message instance
+            decrypted_body: either the given body if it was plain text or the OMEMO-decrypted one (always a string)
+        """
+
+        logging.log(TRACE,"<<< %r",original_message)
+        logging.debug("<<< %r",decrypted_body)
+        self.bot.onMessage(decrypted_body)
+
+    def connect(self):
+
+        logging.debug("Connecting...")
+        # Connects and waits for the connection to be established
+        # See https://slixmpp.readthedocs.io/using_asyncio.html
+        self.xmpp.connected_event = asyncio.Event()
+        callback = lambda _: self.xmpp.connected_event.set()
+        self.xmpp.add_event_handler('session_start', callback)
+        self.xmpp.connect()
+        loop = asyncio.get_event_loop()
+        loop.run_until_complete(self.xmpp.connected_event.wait())
+        logging.debug("Connected.")
+
+    def start( self, bot ):
+        """
+            Waits for messages and calls the 'onMessage' method of the given Bot
+        """
+        self.bot = bot
+        # do some other stuff before running the event loop, e.g.
+        # loop.run_until_complete(httpserver.init())
+        self.xmpp.process(forever=False)
+        # FIXME Following error when exiting :
+        # Task was destroyed but it is pending! task: <Task pending coro=<XMLStream.run_filters() running at /home/./.local/lib/python3.6/site-packages/slixmpp/xmlstream/xmlstream.py:972> wait_for=<Future pending cb=[<TaskWakeupMethWrapper object at 0x7fa91adc0fd8>()]>>
+
+    def send( self, message ):
+        """
+            Sends the given message using the underlying implemented chat protocol
+        """
+        logging.debug(">>> %s",message)
+        loop = asyncio.get_event_loop()
+        loop.run_until_complete(self.xmpp.encrypted_send( body=message, recipient=self.recipient ))
+
+    def stop( self ):
+        """
+            Stops waiting for messages and exits the engine
+        """
+        self.xmpp.disconnect()

requirements.txt

@@ -12,3 +12,6 @@ requests
 emoji-country-flag
 # https://pyyaml.org/wiki/PyYAMLDocumentation
 pyyaml
+
+##### Requirements for jabber #####
+slixmpp-omemo