view libervia/backend/plugins/plugin_xep_0320.py @ 4219:1b5cf2ee1d86

plugin XEP-0384, XEP-0391: download missing devices list: when a peer jid was not in our roster, devices list was not retrieved, resulting in failed en/decryption. This patch does check it and download missing devices list in necessary. There is no subscription managed yet, so the list won't be updated in case of new devices, this should be addressed at some point.
author Goffi <goffi@goffi.org>
date Tue, 05 Mar 2024 17:31:36 +0100
parents 4b842c1fb686
children
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#!/usr/bin/env python3

# Libervia plugin
# Copyright (C) 2009-2023 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from twisted.words.protocols.jabber.xmlstream import XMPPHandler
from twisted.words.xish import domish
from wokkel import disco, iwokkel
from zope.interface import implementer

from libervia.backend.core.constants import Const as C
from libervia.backend.core.i18n import _
from libervia.backend.core.log import getLogger


log = getLogger(__name__)

NS_JINGLE_DTLS = "urn:xmpp:jingle:apps:dtls:0"

PLUGIN_INFO = {
    C.PI_NAME: "Use of DTLS-SRTP in Jingle Sessions",
    C.PI_IMPORT_NAME: "XEP-0320",
    C.PI_TYPE: "XEP",
    C.PI_MODES: C.PLUG_MODE_BOTH,
    C.PI_PROTOCOLS: ["XEP-0320"],
    C.PI_DEPENDENCIES: ["XEP-0176"],
    C.PI_RECOMMENDATIONS: [],
    C.PI_MAIN: "XEP_0320",
    C.PI_HANDLER: "yes",
    C.PI_DESCRIPTION: _("""Use of DTLS-SRTP with RTP (for e2ee of A/V calls)"""),
}


class XEP_0320:
    def __init__(self, host):
        log.info(f"plugin {PLUGIN_INFO[C.PI_NAME]!r} initialization")
        host.trigger.add("XEP-0176_parse_transport", self._parse_transport_trigger)
        host.trigger.add("XEP-0176_build_transport", self._build_transport_trigger)

    def get_handler(self, client):
        return XEP_0320_handler()

    def _parse_transport_trigger(
        self, transport_elt: domish.Element, ice_data: dict
    ) -> bool:
        """Parse the <fingerprint> element"""
        fingerprint_elt = next(
            transport_elt.elements(NS_JINGLE_DTLS, "fingerprint"), None
        )
        if fingerprint_elt is not None:
            try:
                ice_data["fingerprint"] = {
                    "hash": fingerprint_elt["hash"],
                    "setup": fingerprint_elt["setup"],
                    "fingerprint": str(fingerprint_elt),
                }
            except KeyError as e:
                log.warning(
                    f"invalid <fingerprint> (attribue {e} is missing): "
                    f"{fingerprint_elt.toXml()})"
                )

        return True

    def _build_transport_trigger(
        self, tranport_elt: domish.Element, ice_data: dict
    ) -> bool:
        """Build the <fingerprint> element if possible"""
        try:
            fingerprint_data = ice_data["fingerprint"]
            hash_ = fingerprint_data["hash"]
            setup = fingerprint_data["setup"]
            fingerprint = fingerprint_data["fingerprint"]
        except KeyError:
            pass
        else:
            fingerprint_elt = tranport_elt.addElement(
                (NS_JINGLE_DTLS, "fingerprint"), content=fingerprint
            )
            fingerprint_elt["hash"] = hash_
            fingerprint_elt["setup"] = setup

        return True


@implementer(iwokkel.IDisco)
class XEP_0320_handler(XMPPHandler):
    def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
        return [disco.DiscoFeature(NS_JINGLE_DTLS)]

    def getDiscoItems(self, requestor, target, nodeIdentifier=""):
        return []