gajim-plural/gajim/common/modules/bits_of_binary.py

175 lines
5.3 KiB
Python

# Copyright (C) 2018 Emmanuel Gil Peyrot <linkmauve AT linkmauve.fr>
#
# This file is part of Gajim.
#
# Gajim 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; version 3 only.
#
# Gajim 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 Gajim. If not, see <http://www.gnu.org/licenses/>.
import logging
import hashlib
from base64 import b64decode
from pathlib import Path
import nbxmpp
from gajim.common import app
from gajim.common import configpaths
log = logging.getLogger('gajim.c.m.bob')
class BitsOfBinary:
def __init__(self, con):
self._con = con
self._account = con.name
self.handlers = [
('iq', self._answer_bob_request, 'get', nbxmpp.NS_BOB)
]
# Used to track which cids are in-flight.
self.awaiting_cids = {}
def _answer_bob_request(self, _con, stanza):
log.info('Request from %s for BoB data', stanza.getFrom())
iq = stanza.buildReply('error')
err = nbxmpp.ErrorNode(nbxmpp.ERR_ITEM_NOT_FOUND)
iq.addChild(node=err)
log.info('Sending item-not-found')
self._con.connection.send(iq)
raise nbxmpp.NodeProcessed
def _on_bob_received(self, _con, result, cid):
"""
Called when we receive BoB data
"""
if cid not in self.awaiting_cids:
return
if result.getType() == 'result':
data = result.getTags('data', namespace=nbxmpp.NS_BOB)
if data.getAttr('cid') == cid:
for func in self.awaiting_cids[cid]:
cb = func[0]
args = func[1]
pos = func[2]
bob_data = data.getData()
def recurs(node, cid, data):
if node.getData() == 'cid:' + cid:
node.setData(data)
else:
for child in node.getChildren():
recurs(child, cid, data)
recurs(args[pos], cid, bob_data)
cb(*args)
del self.awaiting_cids[cid]
return
# An error occured, call callback without modifying data.
for func in self.awaiting_cids[cid]:
cb = func[0]
args = func[1]
cb(*args)
del self.awaiting_cids[cid]
def get_bob_data(self, cid, to, callback, args, position):
"""
Request for BoB (XEP-0231) and when data will arrive, call callback
with given args, after having replaced cid by it's data in
args[position]
"""
if cid in self.awaiting_cids:
self.awaiting_cids[cid].appends((callback, args, position))
else:
self.awaiting_cids[cid] = [(callback, args, position)]
iq = nbxmpp.Iq(to=to, typ='get')
iq.addChild(name='data', attrs={'cid': cid}, namespace=nbxmpp.NS_BOB)
self._con.connection.SendAndCallForResponse(
iq, self._on_bob_received, {'cid': cid})
def parse_bob_data(stanza):
data_node = stanza.getTag('data', namespace=nbxmpp.NS_BOB)
if data_node is None:
return
cid = data_node.getAttr('cid')
type_ = data_node.getAttr('type')
max_age = data_node.getAttr('max-age')
if max_age is not None:
try:
max_age = int(max_age)
except Exception:
log.exception(stanza)
return
if cid is None or type_ is None:
log.warning('Invalid data node (no cid or type attr): %s', stanza)
return
try:
algo_hash = cid.split('@')[0]
algo, hash_ = algo_hash.split('+')
except Exception:
log.exception('Invalid cid: %s', stanza)
return
bob_data = data_node.getData()
if not bob_data:
log.warning('No data found: %s', stanza)
return
filepath = Path(configpaths.get('BOB')) / algo_hash
if algo_hash in app.bob_cache or filepath.exists():
log.info('BoB data already cached')
return
try:
bob_data = b64decode(bob_data)
except Exception:
log.warning('Unable to decode data')
log.exception(stanza)
return
if len(bob_data) > 10000:
log.warning('%s: data > 10000 bytes', stanza.getFrom())
return
try:
sha = hashlib.new(algo)
except ValueError as error:
log.warning(stanza)
log.warning(error)
return
sha.update(bob_data)
if sha.hexdigest() != hash_:
log.warning('Invalid hash: %s', stanza)
return
if max_age == 0:
app.bob_cache[algo_hash] = bob_data
else:
try:
with open(str(filepath), 'w+b') as file:
file.write(bob_data)
except Exception:
log.warning('Unable to save data')
log.exception(stanza)
return
log.info('BoB data stored: %s', algo_hash)
return filepath
def get_instance(*args, **kwargs):
return BitsOfBinary(*args, **kwargs), 'BitsOfBinary'