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# -*- coding: utf-8 -*-
#
# Copyright 2015 Bahtiar `kalkin-` Gadimov <bahtiar@gadimov.de>
#
# This file is part of Gajim-OMEMO plugin.
#
# The Gajim-OMEMO plugin is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option) any
# later version.
#
# Gajim-OMEMO 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# the Gajim-OMEMO plugin. If not, see <http://www.gnu.org/licenses/>.
#
""" This module handles all the XMPP logic like creating different kind of
stanza nodes and geting data from stanzas.
"""
import logging
import random
from base64 import b64decode, b64encode
from nbxmpp.protocol import NS_PUBSUB, Iq
from nbxmpp.simplexml import Node
from common import gajim # pylint: disable=import-error
from common.pep import AbstractPEP # pylint: disable=import-error
from plugins.helpers import log_calls # pylint: disable=import-error
NS_PUBSUB_EVENT = NS_PUBSUB + '#event'
NS_EME = 'urn:xmpp:eme:0'
NS_OMEMO = 'eu.siacs.conversations.axolotl'
NS_DEVICE_LIST = NS_OMEMO + '.devicelist'
NS_NOTIFY = NS_DEVICE_LIST + '+notify'
NS_BUNDLES = NS_OMEMO + '.bundles:'
log = logging.getLogger('gajim.plugin_system.omemo')
class PublishNode(Node):
def __init__(self, node_str, data):
assert node_str is not None and isinstance(data, Node)
Node.__init__(self, tag='publish', attrs={'node': node_str})
self.addChild('item').addChild(node=data)
class PubsubNode(Node):
def __init__(self, data):
assert isinstance(data, Node)
Node.__init__(self, tag='pubsub', attrs={'xmlns': NS_PUBSUB})
self.addChild(node=data)
class DeviceListAnnouncement(Iq):
def __init__(self, device_list):
assert isinstance(device_list, list)
assert len(device_list) > 0
id_ = gajim.get_an_id()
attrs = {'id': id_}
Iq.__init__(self, typ='set', attrs=attrs)
list_node = Node('list', attrs={'xmlns': NS_OMEMO})
for device in device_list:
list_node.addChild('device').setAttr('id', device)
publish = PublishNode(NS_DEVICE_LIST, list_node)
pubsub = PubsubNode(publish)
self.addChild(node=pubsub)
class OmemoMessage(Node):
def __init__(self, msg_dict):
# , contact_jid, key, iv, payload, dev_id, my_dev_id):
Node.__init__(self, 'encrypted', attrs={'xmlns': NS_OMEMO})
header = Node('header', attrs={'sid': msg_dict['sid']})
for rid, (key, prekey) in msg_dict['keys'].items():
if prekey:
child = header.addChild('key',
attrs={'prekey': 'true', 'rid': rid})
else:
child = header.addChild('key',
attrs={'rid': rid})
child.addData(b64encode(key).decode('utf-8'))
header.addChild('iv').addData(b64encode(msg_dict['iv']).decode('utf-8'))
self.addChild(node=header)
self.addChild('payload').addData(b64encode(msg_dict['payload'])
.decode('utf-8'))
class BundleInformationQuery(Iq):
def __init__(self, contact_jid, device_id):
assert isinstance(device_id, int)
id_ = gajim.get_an_id()
attrs = {'id': id_}
Iq.__init__(self, typ='get', attrs=attrs, to=contact_jid)
items = Node('items', attrs={'node': NS_BUNDLES + str(device_id)})
pubsub = PubsubNode(items)
self.addChild(node=pubsub)
class BundleInformationAnnouncement(Iq):
def __init__(self, state_bundle, device_id):
id_ = gajim.get_an_id()
attrs = {'id': id_}
Iq.__init__(self, typ='set', attrs=attrs)
bundle_node = self.make_bundle_node(state_bundle)
publish = PublishNode(NS_BUNDLES + str(device_id), bundle_node)
pubsub = PubsubNode(publish)
self.addChild(node=pubsub)
def make_bundle_node(self, state_bundle):
result = Node('bundle', attrs={'xmlns': NS_OMEMO})
prekey_pub_node = result.addChild(
'signedPreKeyPublic',
attrs={'signedPreKeyId': state_bundle['signedPreKeyId']})
prekey_pub_node.addData(state_bundle['signedPreKeyPublic']
.decode('utf-8'))
prekey_sig_node = result.addChild('signedPreKeySignature')
prekey_sig_node.addData(state_bundle['signedPreKeySignature']
.decode('utf-8'))
identity_key_node = result.addChild('identityKey')
identity_key_node.addData(state_bundle['identityKey'].decode('utf-8'))
prekeys = result.addChild('prekeys')
for key in state_bundle['prekeys']:
prekeys.addChild('preKeyPublic',
attrs={'preKeyId': key[0]}) \
.addData(key[1].decode('utf-8'))
return result
class DevicelistQuery(Iq):
def __init__(self, contact_jid,):
id_ = gajim.get_an_id()
attrs = {'id': id_}
Iq.__init__(self, typ='get', attrs=attrs, to=contact_jid)
items = Node('items', attrs={'node': NS_DEVICE_LIST})
pubsub = PubsubNode(items)
self.addChild(node=pubsub)
class DevicelistPEP(AbstractPEP):
type_ = 'headline'
namespace = NS_DEVICE_LIST
def _extract_info(self, items):
return ({}, [])
@log_calls('OmemoPlugin')
def unpack_device_bundle(bundle, device_id):
pubsub = bundle.getTag('pubsub', namespace=NS_PUBSUB)
if not pubsub:
log.warning('OMEMO device bundle has no pubsub node')
return
items = pubsub.getTag('items', attrs={'node': NS_BUNDLES + str(device_id)})
if not items:
log.warning('OMEMO device bundle has no items node')
return
item = items.getTag('item', namespace=NS_PUBSUB)
if not item:
log.warning('OMEMO device bundle has no item node')
return
bundle = item.getTag('bundle', namespace=NS_OMEMO)
if not bundle:
log.warning('OMEMO device bundle has no bundle node')
return
signed_prekey_node = bundle.getTag('signedPreKeyPublic',
namespace=NS_OMEMO)
if not signed_prekey_node:
log.warning('OMEMO device bundle has no signedPreKeyPublic node')
return
result = {}
result['signedPreKeyPublic'] = decode_data(signed_prekey_node)
if not result['signedPreKeyPublic']:
log.warning('OMEMO device bundle has no signedPreKeyPublic data')
return
if not signed_prekey_node.getAttr('signedPreKeyId'):
log.warning('OMEMO device bundle has no signedPreKeyId')
return
result['signedPreKeyId'] = int(signed_prekey_node.getAttr(
'signedPreKeyId'))
signed_signature_node = bundle.getTag('signedPreKeySignature',
namespace=NS_OMEMO)
if not signed_signature_node:
log.warning('OMEMO device bundle has no signedPreKeySignature node')
return
result['signedPreKeySignature'] = decode_data(signed_signature_node)
if not result['signedPreKeySignature']:
log.warning('OMEMO device bundle has no signedPreKeySignature data')
return
identity_key_node = bundle.getTag('identityKey', namespace=NS_OMEMO)
if not identity_key_node:
log.warning('OMEMO device bundle has no identityKey node')
return
result['identityKey'] = decode_data(identity_key_node)
if not result['identityKey']:
log.warning('OMEMO device bundle has no identityKey data')
return
prekeys = bundle.getTag('prekeys', namespace=NS_OMEMO)
if not prekeys or len(prekeys.getChildren()) == 0:
log.warning('OMEMO device bundle has no prekys')
return
picked_key_node = random.SystemRandom().choice(prekeys.getChildren())
if not picked_key_node.getAttr('preKeyId'):
log.warning('OMEMO PreKey has no id set')
return
result['preKeyId'] = int(picked_key_node.getAttr('preKeyId'))
result['preKeyPublic'] = decode_data(picked_key_node)
if not result['preKeyPublic']:
return
return result
@log_calls('OmemoPlugin')
def unpack_encrypted(encrypted_node):
""" Unpacks the encrypted node, decodes the data and returns a msg_dict.
"""
if not encrypted_node.getNamespace() == NS_OMEMO:
log.warning("Encrypted node with wrong NS")
return
header_node = encrypted_node.getTag('header', namespace=NS_OMEMO)
if not header_node:
log.warning("OMEMO message without header")
return
if not header_node.getAttr('sid'):
log.warning("OMEMO message without sid in header")
return
sid = int(header_node.getAttr('sid'))
iv_node = header_node.getTag('iv', namespace=NS_OMEMO)
if not iv_node:
log.warning("OMEMO message without iv")
return
iv = decode_data(iv_node)
if not iv:
log.warning("OMEMO message without iv data")
payload_node = encrypted_node.getTag('payload', namespace=NS_OMEMO)
payload = None
if payload_node:
payload = decode_data(payload_node)
key_nodes = header_node.getTags('key')
if len(key_nodes) < 1:
log.warning("OMEMO message without keys")
return
keys = {}
for kn in key_nodes:
rid = kn.getAttr('rid')
if not rid:
log.warning('Omemo key without rid')
continue
if not kn.getData():
log.warning('Omemo key without data')
continue
keys[int(rid)] = decode_data(kn)
result = {'sid': sid, 'iv': iv, 'keys': keys, 'payload': payload}
return result
def unpack_device_list_update(stanza, account):
""" Unpacks the device list from a stanza
Parameters
----------
stanza
Returns
-------
[int]
List of device ids or empty list if nothing found
"""
event_node = stanza.getTag('event', namespace=NS_PUBSUB_EVENT)
if not event_node:
event_node = stanza.getTag('pubsub', namespace=NS_PUBSUB)
result = []
if not event_node:
log.warning(account + ' => Device list update event node empty!')
return result
items = event_node.getTag('items', {'node': NS_DEVICE_LIST})
if not items or len(items.getChildren()) != 1:
log.debug(
account +
' => Device list update items node empty or not omemo device update')
return result
list_node = items.getChildren()[0].getTag('list')
if not list_node or len(list_node.getChildren()) == 0:
log.warning(account + ' => Device list update list node empty!')
return result
devices_nodes = list_node.getChildren()
for dn in devices_nodes:
_id = dn.getAttr('id')
if _id:
result.append(int(_id))
return result
def decode_data(node):
""" Fetch the data from specified node and b64decode it. """
data = node.getData()
if not data:
log.warning("No node data")
return
try:
return b64decode(data)
except:
log.warning('b64decode broken')
return
def successful(stanza):
""" Check if stanza type is result. """
return stanza.getAttr('type') == 'result'
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