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synapse/tests/crypto/test_keyring.py
Erik Johnston 43badd2cd4 Fix key verification when key stored with null valid_until_ms
Some keys are stored in the synapse database with a null valid_until_ms
which caused an exception to be thrown when using that key. We fix this
by treating nulls as zeroes, i.e. they keys will match verification
requests with a minimum_valid_until_ms of zero (i.e. don't validate ts)
but will not match requests with a non-zero minimum_valid_until_ms.

Fixes #5391.
2019-06-10 15:37:10 +01:00

596 lines
22 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,
StoreKeyFetcher,
)
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_for_server_with_null_valid_until_ms(self):
"""Tests that we correctly handle key requests for keys we've stored
with a null `ts_valid_until_ms`
"""
mock_fetcher = keyring.KeyFetcher()
mock_fetcher.get_keys = Mock(return_value=defer.succeed({}))
kr = keyring.Keyring(
self.hs, key_fetchers=(StoreKeyFetcher(self.hs), mock_fetcher)
)
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), None))],
)
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 fail on a signed object with a non-zero minimum_valid_until_ms,
# as it tries to refetch the keys and fails.
d = _verify_json_for_server(
kr, "server9", json1, 500, "test signed non-zero min"
)
self.get_failure(d, SynapseError)
# We expect the keyring tried to refetch the key once.
mock_fetcher.get_keys.assert_called_once_with(
{"server9": {get_key_id(key1): 500}}
)
# should succeed on a signed object with a 0 minimum_valid_until_ms
d = _verify_json_for_server(
kr, "server9", json1, 0, "test signed with zero min"
)
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)