102 lines
3.8 KiB
Python
102 lines
3.8 KiB
Python
#!/usr/bin/env python3
|
|
|
|
|
|
# SAT plugin for Explicit Message Encryption
|
|
# Copyright (C) 2009-2020 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 sat.core.i18n import _, D_
|
|
from sat.core.constants import Const as C
|
|
from sat.core.log import getLogger
|
|
from twisted.words.protocols.jabber import jid
|
|
|
|
log = getLogger(__name__)
|
|
|
|
PLUGIN_INFO = {
|
|
C.PI_NAME: "Explicit Message Encryption",
|
|
C.PI_IMPORT_NAME: "XEP-0380",
|
|
C.PI_TYPE: "SEC",
|
|
C.PI_PROTOCOLS: ["XEP-0380"],
|
|
C.PI_DEPENDENCIES: [],
|
|
C.PI_MAIN: "XEP_0380",
|
|
C.PI_HANDLER: "no",
|
|
C.PI_DESCRIPTION: _("""Implementation of Explicit Message Encryption"""),
|
|
}
|
|
|
|
NS_EME = "urn:xmpp:eme:0"
|
|
KNOWN_NAMESPACES = {
|
|
"urn:xmpp:otr:0": "OTR",
|
|
"jabber:x:encrypted": "Legacy OpenPGP",
|
|
"urn:xmpp:openpgp:0": "OpenPGP for XMPP",
|
|
}
|
|
|
|
|
|
class XEP_0380(object):
|
|
|
|
def __init__(self, host):
|
|
self.host = host
|
|
host.trigger.add("sendMessage", self._sendMessageTrigger)
|
|
host.trigger.add("messageReceived", self._messageReceivedTrigger, priority=100)
|
|
host.registerNamespace("eme", NS_EME)
|
|
|
|
def _addEMEElement(self, mess_data, namespace, name):
|
|
message_elt = mess_data['xml']
|
|
encryption_elt = message_elt.addElement((NS_EME, 'encryption'))
|
|
encryption_elt['namespace'] = namespace
|
|
if name is not None:
|
|
encryption_elt['name'] = name
|
|
return mess_data
|
|
|
|
def _sendMessageTrigger(self, client, mess_data, __, post_xml_treatments):
|
|
encryption = mess_data.get(C.MESS_KEY_ENCRYPTION)
|
|
if encryption is not None:
|
|
namespace = encryption['plugin'].namespace
|
|
if namespace not in KNOWN_NAMESPACES:
|
|
name = encryption['plugin'].name
|
|
else:
|
|
name = None
|
|
post_xml_treatments.addCallback(
|
|
self._addEMEElement, namespace=namespace, name=name)
|
|
return True
|
|
|
|
def _messageReceivedTrigger(self, client, message_elt, post_treat):
|
|
try:
|
|
encryption_elt = next(message_elt.elements(NS_EME, 'encryption'))
|
|
except StopIteration:
|
|
return True
|
|
|
|
namespace = encryption_elt['namespace']
|
|
if namespace in client.encryption.getNamespaces():
|
|
# message is encrypted and we can decrypt it
|
|
return True
|
|
|
|
name = KNOWN_NAMESPACES.get(namespace, encryption_elt.getAttribute("name"))
|
|
|
|
# at this point, message is encrypted but we know that we can't decrypt it,
|
|
# we need to notify the user
|
|
sender_s = message_elt['from']
|
|
to_jid = jid.JID(message_elt['from'])
|
|
algorithm = "{} [{}]".format(name, namespace) if name else namespace
|
|
log.warning(
|
|
_("Message from {sender} is encrypted with {algorithm} and we can't "
|
|
"decrypt it.".format(sender=message_elt['from'], algorithm=algorithm)))
|
|
|
|
user_msg = D_(
|
|
"User {sender} sent you an encrypted message (encrypted with {algorithm}), "
|
|
"and we can't decrypt it.").format(sender=sender_s, algorithm=algorithm)
|
|
|
|
extra = {C.MESS_EXTRA_INFO: C.EXTRA_INFO_DECR_ERR}
|
|
client.feedback(to_jid, user_msg, extra)
|
|
return False
|