forked-synapse/tests/crypto/test_keyring.py
Richard van der Hoff 9fbb20a531
Stop hardcoding trust of old matrix.org key (#5374)
There are a few changes going on here:

* We make checking the signature on a key server response optional: if no
  verify_keys are specified, we trust to TLS to validate the connection.

* We change the default config so that it does not require responses to be
  signed by the old key.

* We replace the old 'perspectives' config with 'trusted_key_servers', which
  is also formatted slightly differently.

* We emit a warning to the logs every time we trust a key server response
  signed by the old key.
2019-06-06 17:33:11 +01:00

549 lines
20 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2017 New Vector Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import time
from mock import Mock
import canonicaljson
import signedjson.key
import signedjson.sign
from signedjson.key import encode_verify_key_base64, get_verify_key
from twisted.internet import defer
from synapse.api.errors import SynapseError
from synapse.crypto import keyring
from synapse.crypto.keyring import PerspectivesKeyFetcher, ServerKeyFetcher
from synapse.storage.keys import FetchKeyResult
from synapse.util import logcontext
from synapse.util.logcontext import LoggingContext
from tests import unittest
class MockPerspectiveServer(object):
def __init__(self):
self.server_name = "mock_server"
self.key = signedjson.key.generate_signing_key(0)
def get_verify_keys(self):
vk = signedjson.key.get_verify_key(self.key)
return {"%s:%s" % (vk.alg, vk.version): encode_verify_key_base64(vk)}
def get_signed_key(self, server_name, verify_key):
key_id = "%s:%s" % (verify_key.alg, verify_key.version)
res = {
"server_name": server_name,
"old_verify_keys": {},
"valid_until_ts": time.time() * 1000 + 3600,
"verify_keys": {key_id: {"key": encode_verify_key_base64(verify_key)}},
}
self.sign_response(res)
return res
def sign_response(self, res):
signedjson.sign.sign_json(res, self.server_name, self.key)
class KeyringTestCase(unittest.HomeserverTestCase):
def make_homeserver(self, reactor, clock):
self.mock_perspective_server = MockPerspectiveServer()
self.http_client = Mock()
config = self.default_config()
config["trusted_key_servers"] = [
{
"server_name": self.mock_perspective_server.server_name,
"verify_keys": self.mock_perspective_server.get_verify_keys(),
}
]
return self.setup_test_homeserver(
handlers=None, http_client=self.http_client, config=config
)
def check_context(self, _, expected):
self.assertEquals(
getattr(LoggingContext.current_context(), "request", None), expected
)
def test_wait_for_previous_lookups(self):
kr = keyring.Keyring(self.hs)
lookup_1_deferred = defer.Deferred()
lookup_2_deferred = defer.Deferred()
# we run the lookup in a logcontext so that the patched inlineCallbacks can check
# it is doing the right thing with logcontexts.
wait_1_deferred = run_in_context(
kr.wait_for_previous_lookups, {"server1": lookup_1_deferred}
)
# there were no previous lookups, so the deferred should be ready
self.successResultOf(wait_1_deferred)
# set off another wait. It should block because the first lookup
# hasn't yet completed.
wait_2_deferred = run_in_context(
kr.wait_for_previous_lookups, {"server1": lookup_2_deferred}
)
self.assertFalse(wait_2_deferred.called)
# let the first lookup complete (in the sentinel context)
lookup_1_deferred.callback(None)
# now the second wait should complete.
self.successResultOf(wait_2_deferred)
def test_verify_json_objects_for_server_awaits_previous_requests(self):
key1 = signedjson.key.generate_signing_key(1)
kr = keyring.Keyring(self.hs)
json1 = {}
signedjson.sign.sign_json(json1, "server10", key1)
persp_resp = {
"server_keys": [
self.mock_perspective_server.get_signed_key(
"server10", signedjson.key.get_verify_key(key1)
)
]
}
persp_deferred = defer.Deferred()
@defer.inlineCallbacks
def get_perspectives(**kwargs):
self.assertEquals(LoggingContext.current_context().request, "11")
with logcontext.PreserveLoggingContext():
yield persp_deferred
defer.returnValue(persp_resp)
self.http_client.post_json.side_effect = get_perspectives
# start off a first set of lookups
@defer.inlineCallbacks
def first_lookup():
with LoggingContext("11") as context_11:
context_11.request = "11"
res_deferreds = kr.verify_json_objects_for_server(
[("server10", json1, 0, "test10"), ("server11", {}, 0, "test11")]
)
# the unsigned json should be rejected pretty quickly
self.assertTrue(res_deferreds[1].called)
try:
yield res_deferreds[1]
self.assertFalse("unsigned json didn't cause a failure")
except SynapseError:
pass
self.assertFalse(res_deferreds[0].called)
res_deferreds[0].addBoth(self.check_context, None)
yield logcontext.make_deferred_yieldable(res_deferreds[0])
# let verify_json_objects_for_server finish its work before we kill the
# logcontext
yield self.clock.sleep(0)
d0 = first_lookup()
# wait a tick for it to send the request to the perspectives server
# (it first tries the datastore)
self.pump()
self.http_client.post_json.assert_called_once()
# a second request for a server with outstanding requests
# should block rather than start a second call
@defer.inlineCallbacks
def second_lookup():
with LoggingContext("12") as context_12:
context_12.request = "12"
self.http_client.post_json.reset_mock()
self.http_client.post_json.return_value = defer.Deferred()
res_deferreds_2 = kr.verify_json_objects_for_server(
[("server10", json1, 0, "test")]
)
res_deferreds_2[0].addBoth(self.check_context, None)
yield logcontext.make_deferred_yieldable(res_deferreds_2[0])
# let verify_json_objects_for_server finish its work before we kill the
# logcontext
yield self.clock.sleep(0)
d2 = second_lookup()
self.pump()
self.http_client.post_json.assert_not_called()
# complete the first request
persp_deferred.callback(persp_resp)
self.get_success(d0)
self.get_success(d2)
def test_verify_json_for_server(self):
kr = keyring.Keyring(self.hs)
key1 = signedjson.key.generate_signing_key(1)
r = self.hs.datastore.store_server_verify_keys(
"server9",
time.time() * 1000,
[("server9", get_key_id(key1), FetchKeyResult(get_verify_key(key1), 1000))],
)
self.get_success(r)
json1 = {}
signedjson.sign.sign_json(json1, "server9", key1)
# should fail immediately on an unsigned object
d = _verify_json_for_server(kr, "server9", {}, 0, "test unsigned")
self.failureResultOf(d, SynapseError)
# should suceed on a signed object
d = _verify_json_for_server(kr, "server9", json1, 500, "test signed")
# self.assertFalse(d.called)
self.get_success(d)
def test_verify_json_dedupes_key_requests(self):
"""Two requests for the same key should be deduped."""
key1 = signedjson.key.generate_signing_key(1)
def get_keys(keys_to_fetch):
# there should only be one request object (with the max validity)
self.assertEqual(keys_to_fetch, {"server1": {get_key_id(key1): 1500}})
return defer.succeed(
{
"server1": {
get_key_id(key1): FetchKeyResult(get_verify_key(key1), 1200)
}
}
)
mock_fetcher = keyring.KeyFetcher()
mock_fetcher.get_keys = Mock(side_effect=get_keys)
kr = keyring.Keyring(self.hs, key_fetchers=(mock_fetcher,))
json1 = {}
signedjson.sign.sign_json(json1, "server1", key1)
# the first request should succeed; the second should fail because the key
# has expired
results = kr.verify_json_objects_for_server(
[("server1", json1, 500, "test1"), ("server1", json1, 1500, "test2")]
)
self.assertEqual(len(results), 2)
self.get_success(results[0])
e = self.get_failure(results[1], SynapseError).value
self.assertEqual(e.errcode, "M_UNAUTHORIZED")
self.assertEqual(e.code, 401)
# there should have been a single call to the fetcher
mock_fetcher.get_keys.assert_called_once()
def test_verify_json_falls_back_to_other_fetchers(self):
"""If the first fetcher cannot provide a recent enough key, we fall back"""
key1 = signedjson.key.generate_signing_key(1)
def get_keys1(keys_to_fetch):
self.assertEqual(keys_to_fetch, {"server1": {get_key_id(key1): 1500}})
return defer.succeed(
{
"server1": {
get_key_id(key1): FetchKeyResult(get_verify_key(key1), 800)
}
}
)
def get_keys2(keys_to_fetch):
self.assertEqual(keys_to_fetch, {"server1": {get_key_id(key1): 1500}})
return defer.succeed(
{
"server1": {
get_key_id(key1): FetchKeyResult(get_verify_key(key1), 1200)
}
}
)
mock_fetcher1 = keyring.KeyFetcher()
mock_fetcher1.get_keys = Mock(side_effect=get_keys1)
mock_fetcher2 = keyring.KeyFetcher()
mock_fetcher2.get_keys = Mock(side_effect=get_keys2)
kr = keyring.Keyring(self.hs, key_fetchers=(mock_fetcher1, mock_fetcher2))
json1 = {}
signedjson.sign.sign_json(json1, "server1", key1)
results = kr.verify_json_objects_for_server(
[("server1", json1, 1200, "test1"), ("server1", json1, 1500, "test2")]
)
self.assertEqual(len(results), 2)
self.get_success(results[0])
e = self.get_failure(results[1], SynapseError).value
self.assertEqual(e.errcode, "M_UNAUTHORIZED")
self.assertEqual(e.code, 401)
# there should have been a single call to each fetcher
mock_fetcher1.get_keys.assert_called_once()
mock_fetcher2.get_keys.assert_called_once()
class ServerKeyFetcherTestCase(unittest.HomeserverTestCase):
def make_homeserver(self, reactor, clock):
self.http_client = Mock()
hs = self.setup_test_homeserver(handlers=None, http_client=self.http_client)
return hs
def test_get_keys_from_server(self):
# arbitrarily advance the clock a bit
self.reactor.advance(100)
SERVER_NAME = "server2"
fetcher = ServerKeyFetcher(self.hs)
testkey = signedjson.key.generate_signing_key("ver1")
testverifykey = signedjson.key.get_verify_key(testkey)
testverifykey_id = "ed25519:ver1"
VALID_UNTIL_TS = 200 * 1000
# valid response
response = {
"server_name": SERVER_NAME,
"old_verify_keys": {},
"valid_until_ts": VALID_UNTIL_TS,
"verify_keys": {
testverifykey_id: {
"key": signedjson.key.encode_verify_key_base64(testverifykey)
}
},
}
signedjson.sign.sign_json(response, SERVER_NAME, testkey)
def get_json(destination, path, **kwargs):
self.assertEqual(destination, SERVER_NAME)
self.assertEqual(path, "/_matrix/key/v2/server/key1")
return response
self.http_client.get_json.side_effect = get_json
keys_to_fetch = {SERVER_NAME: {"key1": 0}}
keys = self.get_success(fetcher.get_keys(keys_to_fetch))
k = keys[SERVER_NAME][testverifykey_id]
self.assertEqual(k.valid_until_ts, VALID_UNTIL_TS)
self.assertEqual(k.verify_key, testverifykey)
self.assertEqual(k.verify_key.alg, "ed25519")
self.assertEqual(k.verify_key.version, "ver1")
# check that the perspectives store is correctly updated
lookup_triplet = (SERVER_NAME, testverifykey_id, None)
key_json = self.get_success(
self.hs.get_datastore().get_server_keys_json([lookup_triplet])
)
res = key_json[lookup_triplet]
self.assertEqual(len(res), 1)
res = res[0]
self.assertEqual(res["key_id"], testverifykey_id)
self.assertEqual(res["from_server"], SERVER_NAME)
self.assertEqual(res["ts_added_ms"], self.reactor.seconds() * 1000)
self.assertEqual(res["ts_valid_until_ms"], VALID_UNTIL_TS)
# we expect it to be encoded as canonical json *before* it hits the db
self.assertEqual(
bytes(res["key_json"]), canonicaljson.encode_canonical_json(response)
)
# change the server name: the result should be ignored
response["server_name"] = "OTHER_SERVER"
keys = self.get_success(fetcher.get_keys(keys_to_fetch))
self.assertEqual(keys, {})
class PerspectivesKeyFetcherTestCase(unittest.HomeserverTestCase):
def make_homeserver(self, reactor, clock):
self.mock_perspective_server = MockPerspectiveServer()
self.http_client = Mock()
config = self.default_config()
config["trusted_key_servers"] = [
{
"server_name": self.mock_perspective_server.server_name,
"verify_keys": self.mock_perspective_server.get_verify_keys(),
}
]
return self.setup_test_homeserver(
handlers=None, http_client=self.http_client, config=config
)
def test_get_keys_from_perspectives(self):
# arbitrarily advance the clock a bit
self.reactor.advance(100)
fetcher = PerspectivesKeyFetcher(self.hs)
SERVER_NAME = "server2"
testkey = signedjson.key.generate_signing_key("ver1")
testverifykey = signedjson.key.get_verify_key(testkey)
testverifykey_id = "ed25519:ver1"
VALID_UNTIL_TS = 200 * 1000
# valid response
response = {
"server_name": SERVER_NAME,
"old_verify_keys": {},
"valid_until_ts": VALID_UNTIL_TS,
"verify_keys": {
testverifykey_id: {
"key": signedjson.key.encode_verify_key_base64(testverifykey)
}
},
}
# the response must be signed by both the origin server and the perspectives
# server.
signedjson.sign.sign_json(response, SERVER_NAME, testkey)
self.mock_perspective_server.sign_response(response)
def post_json(destination, path, data, **kwargs):
self.assertEqual(destination, self.mock_perspective_server.server_name)
self.assertEqual(path, "/_matrix/key/v2/query")
# check that the request is for the expected key
q = data["server_keys"]
self.assertEqual(list(q[SERVER_NAME].keys()), ["key1"])
return {"server_keys": [response]}
self.http_client.post_json.side_effect = post_json
keys_to_fetch = {SERVER_NAME: {"key1": 0}}
keys = self.get_success(fetcher.get_keys(keys_to_fetch))
self.assertIn(SERVER_NAME, keys)
k = keys[SERVER_NAME][testverifykey_id]
self.assertEqual(k.valid_until_ts, VALID_UNTIL_TS)
self.assertEqual(k.verify_key, testverifykey)
self.assertEqual(k.verify_key.alg, "ed25519")
self.assertEqual(k.verify_key.version, "ver1")
# check that the perspectives store is correctly updated
lookup_triplet = (SERVER_NAME, testverifykey_id, None)
key_json = self.get_success(
self.hs.get_datastore().get_server_keys_json([lookup_triplet])
)
res = key_json[lookup_triplet]
self.assertEqual(len(res), 1)
res = res[0]
self.assertEqual(res["key_id"], testverifykey_id)
self.assertEqual(res["from_server"], self.mock_perspective_server.server_name)
self.assertEqual(res["ts_added_ms"], self.reactor.seconds() * 1000)
self.assertEqual(res["ts_valid_until_ms"], VALID_UNTIL_TS)
self.assertEqual(
bytes(res["key_json"]), canonicaljson.encode_canonical_json(response)
)
def test_invalid_perspectives_responses(self):
"""Check that invalid responses from the perspectives server are rejected"""
# arbitrarily advance the clock a bit
self.reactor.advance(100)
SERVER_NAME = "server2"
testkey = signedjson.key.generate_signing_key("ver1")
testverifykey = signedjson.key.get_verify_key(testkey)
testverifykey_id = "ed25519:ver1"
VALID_UNTIL_TS = 200 * 1000
def build_response():
# valid response
response = {
"server_name": SERVER_NAME,
"old_verify_keys": {},
"valid_until_ts": VALID_UNTIL_TS,
"verify_keys": {
testverifykey_id: {
"key": signedjson.key.encode_verify_key_base64(testverifykey)
}
},
}
# the response must be signed by both the origin server and the perspectives
# server.
signedjson.sign.sign_json(response, SERVER_NAME, testkey)
self.mock_perspective_server.sign_response(response)
return response
def get_key_from_perspectives(response):
fetcher = PerspectivesKeyFetcher(self.hs)
keys_to_fetch = {SERVER_NAME: {"key1": 0}}
def post_json(destination, path, data, **kwargs):
self.assertEqual(destination, self.mock_perspective_server.server_name)
self.assertEqual(path, "/_matrix/key/v2/query")
return {"server_keys": [response]}
self.http_client.post_json.side_effect = post_json
return self.get_success(fetcher.get_keys(keys_to_fetch))
# start with a valid response so we can check we are testing the right thing
response = build_response()
keys = get_key_from_perspectives(response)
k = keys[SERVER_NAME][testverifykey_id]
self.assertEqual(k.verify_key, testverifykey)
# remove the perspectives server's signature
response = build_response()
del response["signatures"][self.mock_perspective_server.server_name]
self.http_client.post_json.return_value = {"server_keys": [response]}
keys = get_key_from_perspectives(response)
self.assertEqual(keys, {}, "Expected empty dict with missing persp server sig")
# remove the origin server's signature
response = build_response()
del response["signatures"][SERVER_NAME]
self.http_client.post_json.return_value = {"server_keys": [response]}
keys = get_key_from_perspectives(response)
self.assertEqual(keys, {}, "Expected empty dict with missing origin server sig")
def get_key_id(key):
"""Get the matrix ID tag for a given SigningKey or VerifyKey"""
return "%s:%s" % (key.alg, key.version)
@defer.inlineCallbacks
def run_in_context(f, *args, **kwargs):
with LoggingContext("testctx") as ctx:
# we set the "request" prop to make it easier to follow what's going on in the
# logs.
ctx.request = "testctx"
rv = yield f(*args, **kwargs)
defer.returnValue(rv)
def _verify_json_for_server(kr, *args):
"""thin wrapper around verify_json_for_server which makes sure it is wrapped
with the patched defer.inlineCallbacks.
"""
@defer.inlineCallbacks
def v():
rv1 = yield kr.verify_json_for_server(*args)
defer.returnValue(rv1)
return run_in_context(v)