Matrix-Mirrors/anonymousland-synapse
1
0
Fork 0
mirror of https://git.anonymousland.org/anonymousland/synapse.git synced 2025-05-02 17:54:48 -04:00
Code Issues Projects Releases Packages Wiki Activity

allow uploading keys for cross-signing

Browse source
This commit is contained in:
Hubert Chathi 2019-07-25 11:08:24 -04:00
parent d1c7c2a98a
commit c659b9f94f
11 changed files with 621 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

198
synapse/handlers/e2e_keys.py
View file

@ -1,6 +1,7 @@
# -*- coding: utf-8 -*-
# Copyright 2016 OpenMarket Ltd
# Copyright 2018 New Vector Ltd
# Copyright 2018-2019 New Vector Ltd
# Copyright 2019 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
@ -19,12 +20,17 @@ import logging
from six import iteritems
from canonicaljson import encode_canonical_json, json
from signedjson.sign import SignatureVerifyException, verify_signed_json
from twisted.internet import defer
from synapse.api.errors import CodeMessageException, SynapseError
from synapse.api.errors import CodeMessageException, Codes, SynapseError
from synapse.logging.context import make_deferred_yieldable, run_in_background
from synapse.types import UserID, get_domain_from_id
from synapse.types import (
UserID,
get_domain_from_id,
get_verify_key_from_cross_signing_key,
)
from synapse.util.retryutils import NotRetryingDestination
logger = logging.getLogger(__name__)
@ -46,7 +52,7 @@ class E2eKeysHandler(object):
)
@defer.inlineCallbacks
def query_devices(self, query_body, timeout):
def query_devices(self, query_body, timeout, from_user_id):
""" Handle a device key query from a client
{
@ -64,6 +70,11 @@ class E2eKeysHandler(object):
}
}
}
Args:
from_user_id (str): the user making the query. This is used when
adding cross-signing signatures to limit what signatures users
can see.
"""
device_keys_query = query_body.get("device_keys", {})
@ -118,6 +129,11 @@ class E2eKeysHandler(object):
r = remote_queries_not_in_cache.setdefault(domain, {})
r[user_id] = remote_queries[user_id]
# Get cached cross-signing keys
cross_signing_keys = yield self.query_cross_signing_keys(
device_keys_query, from_user_id
)
# Now fetch any devices that we don't have in our cache
@defer.inlineCallbacks
def do_remote_query(destination):
@ -131,6 +147,14 @@ class E2eKeysHandler(object):
if user_id in destination_query:
results[user_id] = keys
for user_id, key in remote_result["master_keys"].items():
if user_id in destination_query:
cross_signing_keys["master"][user_id] = key
for user_id, key in remote_result["self_signing_keys"].items():
if user_id in destination_query:
cross_signing_keys["self_signing"][user_id] = key
except Exception as e:
failures[destination] = _exception_to_failure(e)
@ -144,7 +168,73 @@ class E2eKeysHandler(object):
)
)
defer.returnValue({"device_keys": results, "failures": failures})
ret = {"device_keys": results, "failures": failures}
for key, value in iteritems(cross_signing_keys):
ret[key + "_keys"] = value
defer.returnValue(ret)
@defer.inlineCallbacks
def query_cross_signing_keys(self, query, from_user_id):
"""Get cross-signing keys for users
Args:
query (Iterable[string]) an iterable of user IDs. A dict whose keys
are user IDs satisfies this, so the query format used for
query_devices can be used here.
from_user_id (str): the user making the query. This is used when
adding cross-signing signatures to limit what signatures users
can see.
Returns:
defer.Deferred[dict[str, dict[str, dict]]]: map from
(master|self_signing|user_signing) -> user_id -> key
"""
master_keys = {}
self_signing_keys = {}
user_signing_keys = {}
for user_id in query:
# XXX: consider changing the store functions to allow querying
# multiple users simultaneously.
try:
key = yield self.store.get_e2e_cross_signing_key(
user_id, "master", from_user_id
)
if key:
master_keys[user_id] = key
except Exception as e:
logger.info("Error getting master key: %s", e)
try:
key = yield self.store.get_e2e_cross_signing_key(
user_id, "self_signing", from_user_id
)
if key:
self_signing_keys[user_id] = key
except Exception as e:
logger.info("Error getting self-signing key: %s", e)
# users can see other users' master and self-signing keys, but can
# only see their own user-signing keys
if from_user_id == user_id:
try:
key = yield self.store.get_e2e_cross_signing_key(
user_id, "user_signing", from_user_id
)
if key:
user_signing_keys[user_id] = key
except Exception as e:
logger.info("Error getting user-signing key: %s", e)
defer.returnValue(
{
"master": master_keys,
"self_signing": self_signing_keys,
"user_signing": user_signing_keys,
}
)
@defer.inlineCallbacks
def query_local_devices(self, query):
@ -342,6 +432,104 @@ class E2eKeysHandler(object):
yield self.store.add_e2e_one_time_keys(user_id, device_id, time_now, new_keys)
@defer.inlineCallbacks
def upload_signing_keys_for_user(self, user_id, keys):
"""Upload signing keys for cross-signing
Args:
user_id (string): the user uploading the keys
keys (dict[string, dict]): the signing keys
"""
# if a master key is uploaded, then check it. Otherwise, load the
# stored master key, to check signatures on other keys
if "master_key" in keys:
master_key = keys["master_key"]
_check_cross_signing_key(master_key, user_id, "master")
else:
master_key = yield self.store.get_e2e_cross_signing_key(user_id, "master")
# if there is no master key, then we can't do anything, because all the
# other cross-signing keys need to be signed by the master key
if not master_key:
raise SynapseError(400, "No master key available", Codes.MISSING_PARAM)
master_key_id, master_verify_key = get_verify_key_from_cross_signing_key(
master_key
)
# for the other cross-signing keys, make sure that they have valid
# signatures from the master key
if "self_signing_key" in keys:
self_signing_key = keys["self_signing_key"]
_check_cross_signing_key(
self_signing_key, user_id, "self_signing", master_verify_key
)
if "user_signing_key" in keys:
user_signing_key = keys["user_signing_key"]
_check_cross_signing_key(
user_signing_key, user_id, "user_signing", master_verify_key
)
# if everything checks out, then store the keys and send notifications
deviceids = []
if "master_key" in keys:
yield self.store.set_e2e_cross_signing_key(user_id, "master", master_key)
deviceids.append(master_verify_key.version)
if "self_signing_key" in keys:
yield self.store.set_e2e_cross_signing_key(
user_id, "self_signing", self_signing_key
)
deviceids.append(
get_verify_key_from_cross_signing_key(self_signing_key)[1].version
)
if "user_signing_key" in keys:
yield self.store.set_e2e_cross_signing_key(
user_id, "user_signing", user_signing_key
)
# the signature stream matches the semantics that we want for
# user-signing key updates: only the user themselves is notified of
# their own user-signing key updates
yield self.device_handler.notify_user_signature_update(user_id, [user_id])
# master key and self-signing key updates match the semantics of device
# list updates: all users who share an encrypted room are notified
if len(deviceids):
yield self.device_handler.notify_device_update(user_id, deviceids)
defer.returnValue({})
def _check_cross_signing_key(key, user_id, key_type, signing_key=None):
"""Check a cross-signing key uploaded by a user. Performs some basic sanity
checking, and ensures that it is signed, if a signature is required.
Args:
key (dict): the key data to verify
user_id (str): the user whose key is being checked
key_type (str): the type of key that the key should be
signing_key (VerifyKey): (optional) the signing key that the key should
be signed with. If omitted, signatures will not be checked.
"""
if (
key.get("user_id") != user_id
or key_type not in key.get("usage", [])
or len(key.get("keys", {})) != 1
):
raise SynapseError(400, ("Invalid %s key" % (key_type,)), Codes.INVALID_PARAM)
if signing_key:
try:
verify_signed_json(key, user_id, signing_key)
except SignatureVerifyException:
raise SynapseError(
400, ("Invalid signature on %s key" % key_type), Codes.INVALID_SIGNATURE
)
def _exception_to_failure(e):
if isinstance(e, CodeMessageException):