Mercurial > libervia-backend
view src/plugins/plugin_sec_otr.py @ 2256:61e836cc9512
plugin invitations: name is now registered as nickname on XMPP server thanks to plugin identity
author | Goffi <goffi@goffi.org> |
---|---|
date | Sun, 21 May 2017 20:08:42 +0200 |
parents | 33c8c4973743 |
children | 8b37a62336c3 |
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#!/usr/bin/env python2 # -*- coding: utf-8 -*- # SAT plugin for OTR encryption # Copyright (C) 2009-2016 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/>. # XXX: thanks to Darrik L Mazey for his documentation (https://blog.darmasoft.net/2013/06/30/using-pure-python-otr.html) # this implentation is based on it from sat.core.i18n import _, D_ from sat.core.constants import Const as C from sat.core.log import getLogger from sat.core import exceptions log = getLogger(__name__) from sat.tools import xml_tools from twisted.words.protocols.jabber import jid from twisted.python import failure from twisted.internet import defer from sat.memory import persistent import potr import copy import time import uuid PLUGIN_INFO = { C.PI_NAME: u"OTR", C.PI_IMPORT_NAME: u"OTR", C.PI_TYPE: u"SEC", C.PI_PROTOCOLS: [u"XEP-0364"], C.PI_DEPENDENCIES: [u"XEP-0280", u"XEP-0334"], C.PI_MAIN: u"OTR", C.PI_HANDLER: u"no", C.PI_DESCRIPTION: _(u"""Implementation of OTR""") } NS_OTR = "otr_plugin" PRIVATE_KEY = "PRIVATE KEY" OTR_MENU = D_(u'OTR') AUTH_TXT = D_(u"To authenticate your correspondent, you need to give your below fingerprint *BY AN EXTERNAL CANAL* (i.e. not in this chat), and check that the one he gives you is the same as below. If there is a mismatch, there can be a spy between you!") DROP_TXT = D_(u"You private key is used to encrypt messages for your correspondent, nobody except you must know it, if you are in doubt, you should drop it!\n\nAre you sure you want to drop your private key?") # NO_LOG_AND = D_(u"/!\\Your history is not logged anymore, and") # FIXME: not used at the moment NO_ADV_FEATURES = D_(u"Some of advanced features are disabled !") DEFAULT_POLICY_FLAGS = { 'ALLOW_V1':False, 'ALLOW_V2':True, 'REQUIRE_ENCRYPTION':True, } OTR_STATE_TRUSTED = 'trusted' OTR_STATE_UNTRUSTED = 'untrusted' OTR_STATE_UNENCRYPTED = 'unencrypted' OTR_STATE_ENCRYPTED = 'encrypted' class Context(potr.context.Context): def __init__(self, host, account, other_jid): super(Context, self).__init__(account, other_jid) self.host = host def getPolicy(self, key): if key in DEFAULT_POLICY_FLAGS: return DEFAULT_POLICY_FLAGS[key] else: return False def inject(self, msg_str, appdata=None): """Inject encrypted data in the stream if appdata is not None, we are sending a message in sendMessageDataTrigger stanza will be injected directly if appdata is None, else we just update the element and follow normal workflow @param msg_str(str): encrypted message body @param appdata(None, dict): None for signal message, message data when an encrypted message is going to be sent """ assert isinstance(self.peer, jid.JID) msg = msg_str.decode('utf-8') client = self.user.client log.debug(u'injecting encrypted message to {to}'.format(to=self.peer)) if appdata is None: mess_data = { 'from': client.jid, 'to': self.peer, 'uid': unicode(uuid.uuid4()), 'message': {'': msg}, 'subject': {}, 'type': 'chat', 'extra': {}, 'timestamp': time.time(), } client.generateMessageXML(mess_data) client.send(mess_data['xml']) else: message_elt = appdata[u'xml'] assert message_elt.name == u'message' message_elt.addElement("body", content=msg) def setState(self, state): client = self.user.client old_state = self.state super(Context, self).setState(state) log.debug(u"setState: %s (old_state=%s)" % (state, old_state)) if state == potr.context.STATE_PLAINTEXT: feedback = _(u"/!\\ conversation with %(other_jid)s is now UNENCRYPTED") % {'other_jid': self.peer.full()} self.host.bridge.otrState(OTR_STATE_UNENCRYPTED, self.peer.full(), client.profile) elif state == potr.context.STATE_ENCRYPTED: try: trusted = self.getCurrentTrust() except TypeError: trusted = False trusted_str = _(u"trusted") if trusted else _(u"untrusted") if old_state == potr.context.STATE_ENCRYPTED: feedback = D_(u"{trusted} OTR conversation with {other_jid} REFRESHED").format( trusted = trusted_str, other_jid = self.peer.full()) else: feedback = D_(u"{trusted} encrypted OTR conversation started with {other_jid}\n{extra_info}").format( trusted = trusted_str, other_jid = self.peer.full(), extra_info = NO_ADV_FEATURES) self.host.bridge.otrState(OTR_STATE_ENCRYPTED, self.peer.full(), client.profile) elif state == potr.context.STATE_FINISHED: feedback = D_(u"OTR conversation with {other_jid} is FINISHED").format(other_jid = self.peer.full()) self.host.bridge.otrState(OTR_STATE_UNENCRYPTED, self.peer.full(), client.profile) else: log.error(D_(u"Unknown OTR state")) return client.feedback(self.peer, feedback) def disconnect(self): """Disconnect the session.""" if self.state != potr.context.STATE_PLAINTEXT: super(Context, self).disconnect() def finish(self): """Finish the session - avoid to send any message but the user still has to end the session himself.""" if self.state == potr.context.STATE_ENCRYPTED: self.processTLVs([potr.proto.DisconnectTLV()]) class Account(potr.context.Account): # TODO: manage trusted keys: if a fingerprint is not used anymore, we have no way to remove it from database yet (same thing for a correspondent jid) # TODO: manage explicit message encryption def __init__(self, host, client): log.debug(u"new account: %s" % client.jid) if not client.jid.resource: log.warning("Account created without resource") super(Account, self).__init__(unicode(client.jid), "xmpp", 1024) self.host = host self.client = client def loadPrivkey(self): log.debug(u"loadPrivkey") return self.privkey def savePrivkey(self): log.debug(u"savePrivkey") if self.privkey is None: raise exceptions.InternalError(_(u"Save is called but privkey is None !")) priv_key = self.privkey.serializePrivateKey().encode('hex') d = self.host.memory.encryptValue(priv_key, self.client.profile) def save_encrypted_key(encrypted_priv_key): self.client._otr_data[PRIVATE_KEY] = encrypted_priv_key d.addCallback(save_encrypted_key) def loadTrusts(self): trust_data = self.client._otr_data.get('trust', {}) for jid_, jid_data in trust_data.iteritems(): for fingerprint, trust_level in jid_data.iteritems(): log.debug(u'setting trust for {jid}: [{fingerprint}] = "{trust_level}"'.format(jid=jid_, fingerprint=fingerprint, trust_level=trust_level)) self.trusts.setdefault(jid.JID(jid_), {})[fingerprint] = trust_level def saveTrusts(self): log.debug(u"saving trusts for {profile}".format(profile=self.client.profile)) log.debug(u"trusts = {}".format(self.client._otr_data['trust'])) self.client._otr_data.force('trust') def setTrust(self, other_jid, fingerprint, trustLevel): try: trust_data = self.client._otr_data['trust'] except KeyError: trust_data = {} self.client._otr_data['trust'] = trust_data jid_data = trust_data.setdefault(other_jid.full(), {}) jid_data[fingerprint] = trustLevel super(Account, self).setTrust(other_jid, fingerprint, trustLevel) class ContextManager(object): def __init__(self, host, client): self.host = host self.account = Account(host, client) self.contexts = {} def startContext(self, other_jid): assert isinstance(other_jid, jid.JID) context = self.contexts.setdefault(other_jid, Context(self.host, self.account, other_jid)) return context def getContextForUser(self, other): log.debug(u"getContextForUser [%s]" % other) if not other.resource: log.warning(u"getContextForUser called with a bare jid: %s" % other.full()) return self.startContext(other) class OTR(object): def __init__(self, host): log.info(_(u"OTR plugin initialization")) self.host = host self.context_managers = {} self.skipped_profiles = set() # FIXME: OTR should not be skipped per profile, this need to be refactored self._p_hints = host.plugins[u'XEP-0334'] self._p_carbons = host.plugins[u'XEP-0280'] host.trigger.add("MessageReceived", self.MessageReceivedTrigger, priority=100000) host.trigger.add("sendMessage", self.sendMessageTrigger, priority=100000) host.trigger.add("sendMessageData", self._sendMessageDataTrigger) host.bridge.addMethod("skipOTR", ".plugin", in_sign='s', out_sign='', method=self._skipOTR) # FIXME: must be removed, must be done on per-message basis host.bridge.addSignal("otrState", ".plugin", signature='sss') # args: state, destinee_jid, profile host.importMenu((OTR_MENU, D_(u"Start/Refresh")), self._otrStartRefresh, security_limit=0, help_string=D_(u"Start or refresh an OTR session"), type_=C.MENU_SINGLE) host.importMenu((OTR_MENU, D_(u"End session")), self._otrSessionEnd, security_limit=0, help_string=D_(u"Finish an OTR session"), type_=C.MENU_SINGLE) host.importMenu((OTR_MENU, D_(u"Authenticate")), self._otrAuthenticate, security_limit=0, help_string=D_(u"Authenticate user/see your fingerprint"), type_=C.MENU_SINGLE) host.importMenu((OTR_MENU, D_(u"Drop private key")), self._dropPrivKey, security_limit=0, type_=C.MENU_SINGLE) host.trigger.add("presenceReceived", self._presenceReceivedTrigger) def _skipOTR(self, profile): """Tell the backend to not handle OTR for this profile. @param profile (str): %(doc_profile)s """ # FIXME: should not be done per profile but per message, using extra data # for message received, profile wide hook may be need, but client # should be used anyway instead of a class attribute self.skipped_profiles.add(profile) @defer.inlineCallbacks def profileConnected(self, client): if client.profile in self.skipped_profiles: return ctxMng = client._otr_context_manager = ContextManager(self.host, client) client._otr_data = persistent.PersistentBinaryDict(NS_OTR, client.profile) yield client._otr_data.load() encrypted_priv_key = client._otr_data.get(PRIVATE_KEY, None) if encrypted_priv_key is not None: priv_key = yield self.host.memory.decryptValue(encrypted_priv_key, client.profile) ctxMng.account.privkey = potr.crypt.PK.parsePrivateKey(priv_key.decode('hex'))[0] else: ctxMng.account.privkey = None ctxMng.account.loadTrusts() def profileDisconnected(self, client): if client.profile in self.skipped_profiles: self.skipped_profiles.remove(client.profile) return for context in client._otr_context_manager.contexts.values(): context.disconnect() del client._otr_context_manager def _otrStartRefresh(self, menu_data, profile): """Start or refresh an OTR session @param menu_data: %(menu_data)s @param profile: %(doc_profile)s """ client = self.host.getClient(profile) try: to_jid = jid.JID(menu_data['jid']) except KeyError: log.error(_(u"jid key is not present !")) return defer.fail(exceptions.DataError) self.startRefresh(client, to_jid) return {} def startRefresh(self, client, to_jid): """Start or refresh an OTR session @param to_jid(jid.JID): jid to start encrypted session with """ if not to_jid.resource: to_jid.resource = self.host.memory.getMainResource(client, to_jid) # FIXME: temporary and unsecure, must be changed when frontends are refactored otrctx = client._otr_context_manager.getContextForUser(to_jid) query = otrctx.sendMessage(0, '?OTRv?') otrctx.inject(query) def _otrSessionEnd(self, menu_data, profile): """End an OTR session @param menu_data: %(menu_data)s @param profile: %(doc_profile)s """ client = self.host.getClient(profile) try: to_jid = jid.JID(menu_data['jid']) except KeyError: log.error(_(u"jid key is not present !")) return defer.fail(exceptions.DataError) self.endSession(client, to_jid) return {} def endSession(self, client, to_jid): """End an OTR session""" if not to_jid.resource: to_jid.resource = self.host.memory.getMainResource(client, to_jid) # FIXME: temporary and unsecure, must be changed when frontends are refactored otrctx = client._otr_context_manager.getContextForUser(to_jid) otrctx.disconnect() return {} def _otrAuthenticate(self, menu_data, profile): """End an OTR session @param menu_data: %(menu_data)s @param profile: %(doc_profile)s """ client = self.host.getClient(profile) try: to_jid = jid.JID(menu_data['jid']) except KeyError: log.error(_(u"jid key is not present !")) return defer.fail(exceptions.DataError) return self.authenticate(client, to_jid) def authenticate(self, client, to_jid): """Authenticate other user and see our own fingerprint""" if not to_jid.resource: to_jid.resource = self.host.memory.getMainResource(client, to_jid) # FIXME: temporary and unsecure, must be changed when frontends are refactored ctxMng = client._otr_context_manager otrctx = ctxMng.getContextForUser(to_jid) priv_key = ctxMng.account.privkey if priv_key is None: # we have no private key yet dialog = xml_tools.XMLUI(C.XMLUI_DIALOG, dialog_opt = {C.XMLUI_DATA_TYPE: C.XMLUI_DIALOG_MESSAGE, C.XMLUI_DATA_MESS: _(u"You have no private key yet, start an OTR conversation to have one"), C.XMLUI_DATA_LVL: C.XMLUI_DATA_LVL_WARNING }, title = _(u"No private key"), ) return {'xmlui': dialog.toXml()} other_fingerprint = otrctx.getCurrentKey() if other_fingerprint is None: # we have a private key, but not the fingerprint of our correspondent dialog = xml_tools.XMLUI(C.XMLUI_DIALOG, dialog_opt = {C.XMLUI_DATA_TYPE: C.XMLUI_DIALOG_MESSAGE, C.XMLUI_DATA_MESS: _(u"Your fingerprint is:\n{fingerprint}\n\nStart an OTR conversation to have your correspondent one.").format(fingerprint=priv_key), C.XMLUI_DATA_LVL: C.XMLUI_DATA_LVL_INFO }, title = _(u"Fingerprint"), ) return {'xmlui': dialog.toXml()} def setTrust(raw_data, profile): # This method is called when authentication form is submited data = xml_tools.XMLUIResult2DataFormResult(raw_data) if data['match'] == 'yes': otrctx.setCurrentTrust(OTR_STATE_TRUSTED) note_msg = _(u"Your correspondent {correspondent} is now TRUSTED") self.host.bridge.otrState(OTR_STATE_TRUSTED, to_jid.full(), client.profile) else: otrctx.setCurrentTrust('') note_msg = _(u"Your correspondent {correspondent} is now UNTRUSTED") self.host.bridge.otrState(OTR_STATE_UNTRUSTED, to_jid.full(), client.profile) note = xml_tools.XMLUI(C.XMLUI_DIALOG, dialog_opt = { C.XMLUI_DATA_TYPE: C.XMLUI_DIALOG_NOTE, C.XMLUI_DATA_MESS: note_msg.format(correspondent=otrctx.peer)} ) return {'xmlui': note.toXml()} submit_id = self.host.registerCallback(setTrust, with_data=True, one_shot=True) trusted = bool(otrctx.getCurrentTrust()) xmlui = xml_tools.XMLUI(C.XMLUI_FORM, title=_('Authentication (%s)') % to_jid.full(), submit_id=submit_id) xmlui.addText(_(AUTH_TXT)) xmlui.addDivider() xmlui.addText(D_(u"Your own fingerprint is:\n{fingerprint}").format(fingerprint=priv_key)) xmlui.addText(D_(u"Your correspondent fingerprint should be:\n{fingerprint}").format(fingerprint=other_fingerprint)) xmlui.addDivider('blank') xmlui.changeContainer('pairs') xmlui.addLabel(D_(u'Is your correspondent fingerprint the same as here ?')) xmlui.addList("match", [('yes', _('yes')),('no', _('no'))], ['yes' if trusted else 'no']) return {'xmlui': xmlui.toXml()} def _dropPrivKey(self, menu_data, profile): """Drop our private Key @param menu_data: %(menu_data)s @param profile: %(doc_profile)s """ client = self.host.getClient(profile) try: to_jid = jid.JID(menu_data['jid']) if not to_jid.resource: to_jid.resource = self.host.memory.getMainResource(client, to_jid) # FIXME: temporary and unsecure, must be changed when frontends are refactored except KeyError: log.error(_(u"jid key is not present !")) return defer.fail(exceptions.DataError) ctxMng = client._otr_context_manager if ctxMng.account.privkey is None: return {'xmlui': xml_tools.note(_(u"You don't have a private key yet !")).toXml()} def dropKey(data, profile): if C.bool(data['answer']): # we end all sessions for context in ctxMng.contexts.values(): context.disconnect() ctxMng.account.privkey = None ctxMng.account.getPrivkey() # as account.privkey is None, getPrivkey will generate a new key, and save it return {'xmlui': xml_tools.note(D_(u"Your private key has been dropped")).toXml()} return {} submit_id = self.host.registerCallback(dropKey, with_data=True, one_shot=True) confirm = xml_tools.XMLUI(C.XMLUI_DIALOG, title=_(u'Confirm private key drop'), dialog_opt = {'type': C.XMLUI_DIALOG_CONFIRM, 'message': _(DROP_TXT)}, submit_id = submit_id) return {'xmlui': confirm.toXml()} def _receivedTreatment(self, data, client): from_jid = data['from'] log.debug(u"_receivedTreatment [from_jid = %s]" % from_jid) otrctx = client._otr_context_manager.getContextForUser(from_jid) try: message = data['message'].itervalues().next() # FIXME: Q&D fix for message refactoring, message is now a dict res = otrctx.receiveMessage(message.encode('utf-8')) except potr.context.UnencryptedMessage: encrypted = False if otrctx.state == potr.context.STATE_ENCRYPTED: log.warning(u"Received unencrypted message in an encrypted context (from {jid})".format( jid = from_jid.full())) feedback=D_(u"WARNING: received unencrypted data in a supposedly encrypted context"), client.feedback(from_jid, feedback) except StopIteration: return data else: encrypted = True if encrypted: if res[0] != None: # decrypted messages handling. # receiveMessage() will return a tuple, the first part of which will be the decrypted message data['message'] = {'':res[0].decode('utf-8')} # FIXME: Q&D fix for message refactoring, message is now a dict try: # we want to keep message in history, even if no store is requested in message hints del data[u'history'] except KeyError: pass # TODO: add skip history as an option, but by default we don't skip it # data[u'history'] = C.HISTORY_SKIP # we send the decrypted message to frontends, but we don't want it in history else: log.warning(u"An encrypted message was expected, but got {}".format(data['message'])) raise failure.Failure(exceptions.CancelError('Cancelled by OTR')) # no message at all (no history, no signal) return data def _receivedTreatmentForSkippedProfiles(self, data): """This profile must be skipped because the frontend manages OTR itself, but we still need to check if the message must be stored in history or not """ # XXX: FIXME: this should not be done on a per-profile basis, but per-message try: message = data['message'].itervalues().next().encode('utf-8') # FIXME: Q&D fix for message refactoring, message is now a dict except StopIteration: return data if message.startswith(potr.proto.OTRTAG): # FIXME: it may be better to cancel the message and send it direclty to bridge # this is used by Libervia, but this may send garbage message to other frontends # if they are used at the same time as Libervia. # Hard to avoid with decryption on Libervia though. data[u'history'] = C.HISTORY_SKIP return data def MessageReceivedTrigger(self, client, message_elt, post_treat): if message_elt.getAttribute('type') == C.MESS_TYPE_GROUPCHAT: # OTR is not possible in group chats return True if client.profile in self.skipped_profiles: post_treat.addCallback(self._receivedTreatmentForSkippedProfiles) else: post_treat.addCallback(self._receivedTreatment, client) return True def _sendMessageDataTrigger(self, client, mess_data): if not 'OTR' in mess_data: return otrctx = mess_data['OTR'] message_elt = mess_data['xml'] to_jid = mess_data['to'] if otrctx.state == potr.context.STATE_ENCRYPTED: log.debug(u"encrypting message") body = None for child in list(message_elt.children): if child.name == 'body': # we remove all unencrypted body, # and will only encrypt the first one if body is None: body = child message_elt.children.remove(child) elif child.name == 'html': # we don't want any XHTML-IM element message_elt.children.remove(child) if body is None: log.warning(u"No message found") else: self._p_carbons.setPrivate(message_elt) otrctx.sendMessage(0, unicode(body).encode('utf-8'), appdata=mess_data) else: feedback = D_(u"Your message was not sent because your correspondent closed the encrypted conversation on his/her side. " u"Either close your own side, or refresh the session.") log.warning(_(u"Message discarded because closed encryption channel")) client.feedback(to_jid, feedback) raise failure.Failure(exceptions.CancelError(u'Cancelled by OTR plugin')) def sendMessageTrigger(self, client, mess_data, pre_xml_treatments, post_xml_treatments): if mess_data['type'] == 'groupchat': return True if client.profile in self.skipped_profiles: # FIXME: should not be done on a per-profile basis return True to_jid = copy.copy(mess_data['to']) if not to_jid.resource: to_jid.resource = self.host.memory.getMainResource(client, to_jid) # FIXME: full jid may not be known otrctx = client._otr_context_manager.getContextForUser(to_jid) if otrctx.state != potr.context.STATE_PLAINTEXT: self._p_hints.addHint(mess_data, self._p_hints.HINT_NO_COPY) self._p_hints.addHint(mess_data, self._p_hints.HINT_NO_PERMANENT_STORE) mess_data['OTR'] = otrctx # this indicate that encryption is needed in sendMessageData trigger if not mess_data['to'].resource: # if not resource was given, we force it here mess_data['to'] = to_jid return True def _presenceReceivedTrigger(self, entity, show, priority, statuses, profile): if show != C.PRESENCE_UNAVAILABLE: return True client = self.host.getClient(profile) if not entity.resource: try: entity.resource = self.host.memory.getMainResource(client, entity) # FIXME: temporary and unsecure, must be changed when frontends are refactored except exceptions.UnknownEntityError: return True # entity was not connected if entity in client._otr_context_manager.contexts: otrctx = client._otr_context_manager.getContextForUser(entity) otrctx.disconnect() return True