synapse/tests/crypto/test_keyring.py
2023-09-12 11:08:04 +01:00

719 lines
27 KiB
Python

# Copyright 2017-2021 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.
# 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 typing import Any, Dict, List, Optional, cast
from unittest.mock import Mock
import attr
import canonicaljson
import signedjson.key
import signedjson.sign
from signedjson.key import encode_verify_key_base64, get_verify_key
from signedjson.types import SigningKey, VerifyKey
from twisted.internet import defer
from twisted.internet.defer import Deferred, ensureDeferred
from twisted.test.proto_helpers import MemoryReactor
from synapse.api.errors import SynapseError
from synapse.crypto import keyring
from synapse.crypto.keyring import (
PerspectivesKeyFetcher,
ServerKeyFetcher,
StoreKeyFetcher,
)
from synapse.logging.context import (
ContextRequest,
LoggingContext,
current_context,
make_deferred_yieldable,
)
from synapse.server import HomeServer
from synapse.storage.keys import FetchKeyResult
from synapse.types import JsonDict
from synapse.util import Clock
from tests import unittest
from tests.unittest import logcontext_clean, override_config
class MockPerspectiveServer:
def __init__(self) -> None:
self.server_name = "mock_server"
self.key = signedjson.key.generate_signing_key("0")
def get_verify_keys(self) -> Dict[str, str]:
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: str, verify_key: VerifyKey) -> JsonDict:
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: JsonDict) -> None:
signedjson.sign.sign_json(res, self.server_name, self.key)
@attr.s(slots=True, auto_attribs=True)
class FakeRequest:
id: str
@logcontext_clean
class KeyringTestCase(unittest.HomeserverTestCase):
def check_context(
self, val: ContextRequest, expected: Optional[ContextRequest]
) -> ContextRequest:
self.assertEqual(getattr(current_context(), "request", None), expected)
return val
def test_verify_json_objects_for_server_awaits_previous_requests(self) -> None:
mock_fetcher = Mock()
mock_fetcher.get_keys = Mock()
kr = keyring.Keyring(self.hs, key_fetchers=(mock_fetcher,))
# a signed object that we are going to try to validate
key1 = signedjson.key.generate_signing_key("1")
json1: JsonDict = {}
signedjson.sign.sign_json(json1, "server10", key1)
# start off a first set of lookups. We make the mock fetcher block until this
# deferred completes.
first_lookup_deferred: "Deferred[None]" = Deferred()
async def first_lookup_fetch(
server_name: str, key_ids: List[str], minimum_valid_until_ts: int
) -> Dict[str, FetchKeyResult]:
# self.assertEqual(current_context().request.id, "context_11")
self.assertEqual(server_name, "server10")
self.assertEqual(key_ids, [get_key_id(key1)])
self.assertEqual(minimum_valid_until_ts, 0)
await make_deferred_yieldable(first_lookup_deferred)
return {get_key_id(key1): FetchKeyResult(get_verify_key(key1), 100)}
mock_fetcher.get_keys.side_effect = first_lookup_fetch
async def first_lookup() -> None:
with LoggingContext(
"context_11", request=cast(ContextRequest, FakeRequest("context_11"))
):
res_deferreds = kr.verify_json_objects_for_server(
[("server10", json1, 0), ("server11", {}, 0)]
)
# the unsigned json should be rejected pretty quickly
self.assertTrue(res_deferreds[1].called)
try:
await 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)
await make_deferred_yieldable(res_deferreds[0])
d0 = ensureDeferred(first_lookup())
self.pump()
mock_fetcher.get_keys.assert_called_once()
# a second request for a server with outstanding requests
# should block rather than start a second call
async def second_lookup_fetch(
server_name: str, key_ids: List[str], minimum_valid_until_ts: int
) -> Dict[str, FetchKeyResult]:
# self.assertEqual(current_context().request.id, "context_12")
return {get_key_id(key1): FetchKeyResult(get_verify_key(key1), 100)}
mock_fetcher.get_keys.reset_mock()
mock_fetcher.get_keys.side_effect = second_lookup_fetch
second_lookup_state = [0]
async def second_lookup() -> None:
with LoggingContext(
"context_12", request=cast(ContextRequest, FakeRequest("context_12"))
):
res_deferreds_2 = kr.verify_json_objects_for_server(
[
(
"server10",
json1,
0,
)
]
)
res_deferreds_2[0].addBoth(self.check_context, None)
second_lookup_state[0] = 1
await make_deferred_yieldable(res_deferreds_2[0])
second_lookup_state[0] = 2
d2 = ensureDeferred(second_lookup())
self.pump()
# the second request should be pending, but the fetcher should not yet have been
# called
self.assertEqual(second_lookup_state[0], 1)
mock_fetcher.get_keys.assert_not_called()
# complete the first request
first_lookup_deferred.callback(None)
# and now both verifications should succeed.
self.get_success(d0)
self.get_success(d2)
def test_verify_json_for_server(self) -> None:
kr = keyring.Keyring(self.hs)
key1 = signedjson.key.generate_signing_key("1")
r = self.hs.get_datastores().main.store_server_keys_response(
"server9",
from_server="test",
ts_added_ms=int(time.time() * 1000),
verify_keys={
get_key_id(key1): FetchKeyResult(
verify_key=get_verify_key(key1), valid_until_ts=1000
)
},
# The entire response gets signed & stored, just include the bits we
# care about.
response_json={
"verify_keys": {
get_key_id(key1): {
"key": encode_verify_key_base64(get_verify_key(key1))
}
}
},
)
self.get_success(r)
json1: JsonDict = {}
signedjson.sign.sign_json(json1, "server9", key1)
# should fail immediately on an unsigned object
d = kr.verify_json_for_server("server9", {}, 0)
self.get_failure(d, SynapseError)
# should succeed on a signed object
d = kr.verify_json_for_server("server9", json1, 500)
# self.assertFalse(d.called)
self.get_success(d)
def test_verify_for_local_server(self) -> None:
"""Ensure that locally signed JSON can be verified without fetching keys
over federation
"""
kr = keyring.Keyring(self.hs)
json1: JsonDict = {}
signedjson.sign.sign_json(json1, self.hs.hostname, self.hs.signing_key)
# Test that verify_json_for_server succeeds on a object signed by ourselves
d = kr.verify_json_for_server(self.hs.hostname, json1, 0)
self.get_success(d)
OLD_KEY = signedjson.key.generate_signing_key("old")
@override_config(
{
"old_signing_keys": {
f"{OLD_KEY.alg}:{OLD_KEY.version}": {
"key": encode_verify_key_base64(
signedjson.key.get_verify_key(OLD_KEY)
),
"expired_ts": 1000,
}
}
}
)
def test_verify_for_local_server_old_key(self) -> None:
"""Can also use keys in old_signing_keys for verification"""
json1: JsonDict = {}
signedjson.sign.sign_json(json1, self.hs.hostname, self.OLD_KEY)
kr = keyring.Keyring(self.hs)
d = kr.verify_json_for_server(self.hs.hostname, json1, 0)
self.get_success(d)
def test_verify_for_local_server_unknown_key(self) -> None:
"""Local keys that we no longer have should be fetched via the fetcher"""
# the key we'll sign things with (nb, not known to the Keyring)
key2 = signedjson.key.generate_signing_key("2")
# set up a mock fetcher which will return the key
async def get_keys(
server_name: str, key_ids: List[str], minimum_valid_until_ts: int
) -> Dict[str, FetchKeyResult]:
self.assertEqual(server_name, self.hs.hostname)
self.assertEqual(key_ids, [get_key_id(key2)])
return {get_key_id(key2): FetchKeyResult(get_verify_key(key2), 1200)}
mock_fetcher = Mock()
mock_fetcher.get_keys = Mock(side_effect=get_keys)
kr = keyring.Keyring(
self.hs, key_fetchers=(StoreKeyFetcher(self.hs), mock_fetcher)
)
# sign the json
json1: JsonDict = {}
signedjson.sign.sign_json(json1, self.hs.hostname, key2)
# ... and check we can verify it.
d = kr.verify_json_for_server(self.hs.hostname, json1, 0)
self.get_success(d)
def test_verify_json_dedupes_key_requests(self) -> None:
"""Two requests for the same key should be deduped."""
key1 = signedjson.key.generate_signing_key("1")
async def get_keys(
server_name: str, key_ids: List[str], minimum_valid_until_ts: int
) -> Dict[str, FetchKeyResult]:
# there should only be one request object (with the max validity)
self.assertEqual(server_name, "server1")
self.assertEqual(key_ids, [get_key_id(key1)])
self.assertEqual(minimum_valid_until_ts, 1500)
return {get_key_id(key1): FetchKeyResult(get_verify_key(key1), 1200)}
mock_fetcher = Mock()
mock_fetcher.get_keys = Mock(side_effect=get_keys)
kr = keyring.Keyring(self.hs, key_fetchers=(mock_fetcher,))
json1: JsonDict = {}
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,
),
("server1", json1, 1500),
]
)
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) -> None:
"""If the first fetcher cannot provide a recent enough key, we fall back"""
key1 = signedjson.key.generate_signing_key("1")
async def get_keys1(
server_name: str, key_ids: List[str], minimum_valid_until_ts: int
) -> Dict[str, FetchKeyResult]:
self.assertEqual(server_name, "server1")
self.assertEqual(key_ids, [get_key_id(key1)])
self.assertEqual(minimum_valid_until_ts, 1500)
return {get_key_id(key1): FetchKeyResult(get_verify_key(key1), 800)}
async def get_keys2(
server_name: str, key_ids: List[str], minimum_valid_until_ts: int
) -> Dict[str, FetchKeyResult]:
self.assertEqual(server_name, "server1")
self.assertEqual(key_ids, [get_key_id(key1)])
self.assertEqual(minimum_valid_until_ts, 1500)
return {get_key_id(key1): FetchKeyResult(get_verify_key(key1), 1200)}
mock_fetcher1 = Mock()
mock_fetcher1.get_keys = Mock(side_effect=get_keys1)
mock_fetcher2 = Mock()
mock_fetcher2.get_keys = Mock(side_effect=get_keys2)
kr = keyring.Keyring(self.hs, key_fetchers=(mock_fetcher1, mock_fetcher2))
json1: JsonDict = {}
signedjson.sign.sign_json(json1, "server1", key1)
results = kr.verify_json_objects_for_server(
[
(
"server1",
json1,
1200,
),
(
"server1",
json1,
1500,
),
]
)
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()
@logcontext_clean
class ServerKeyFetcherTestCase(unittest.HomeserverTestCase):
def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:
self.http_client = Mock()
hs = self.setup_test_homeserver(federation_http_client=self.http_client)
return hs
def test_get_keys_from_server(self) -> None:
# 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)
async def get_json(destination: str, path: str, **kwargs: Any) -> JsonDict:
self.assertEqual(destination, SERVER_NAME)
self.assertEqual(path, "/_matrix/key/v2/server")
return response
self.http_client.get_json.side_effect = get_json
keys = self.get_success(fetcher.get_keys(SERVER_NAME, ["key1"], 0))
k = keys[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
key_json = self.get_success(
self.hs.get_datastores().main.get_server_keys_json_for_remote(
SERVER_NAME, [testverifykey_id]
)
)
res = key_json[testverifykey_id]
self.assertIsNotNone(res)
assert res is not None
self.assertEqual(res.added_ts, self.reactor.seconds() * 1000)
self.assertEqual(res.valid_until_ts, VALID_UNTIL_TS)
# we expect it to be encoded as canonical json *before* it hits the db
self.assertEqual(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(SERVER_NAME, ["key1"], 0))
self.assertEqual(keys, {})
class PerspectivesKeyFetcherTestCase(unittest.HomeserverTestCase):
def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:
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(
federation_http_client=self.http_client, config=config
)
def build_perspectives_response(
self,
server_name: str,
signing_key: SigningKey,
valid_until_ts: int,
) -> dict:
"""
Build a valid perspectives server response to a request for the given key
"""
verify_key = signedjson.key.get_verify_key(signing_key)
verifykey_id = "%s:%s" % (verify_key.alg, verify_key.version)
response = {
"server_name": server_name,
"old_verify_keys": {},
"valid_until_ts": valid_until_ts,
"verify_keys": {
verifykey_id: {
"key": signedjson.key.encode_verify_key_base64(verify_key)
}
},
}
# the response must be signed by both the origin server and the perspectives
# server.
signedjson.sign.sign_json(response, server_name, signing_key)
self.mock_perspective_server.sign_response(response)
return response
def expect_outgoing_key_query(
self, expected_server_name: str, expected_key_id: str, response: dict
) -> None:
"""
Tell the mock http client to expect a perspectives-server key query
"""
async def post_json(
destination: str, path: str, data: JsonDict, **kwargs: Any
) -> JsonDict:
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[expected_server_name].keys()), [expected_key_id])
return {"server_keys": [response]}
self.http_client.post_json.side_effect = post_json
def test_get_keys_from_perspectives(self) -> None:
# 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
response = self.build_perspectives_response(
SERVER_NAME,
testkey,
VALID_UNTIL_TS,
)
self.expect_outgoing_key_query(SERVER_NAME, "key1", response)
keys = self.get_success(fetcher.get_keys(SERVER_NAME, ["key1"], 0))
self.assertIn(testverifykey_id, keys)
k = keys[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
key_json = self.get_success(
self.hs.get_datastores().main.get_server_keys_json_for_remote(
SERVER_NAME, [testverifykey_id]
)
)
res = key_json[testverifykey_id]
self.assertIsNotNone(res)
assert res is not None
self.assertEqual(res.added_ts, self.reactor.seconds() * 1000)
self.assertEqual(res.valid_until_ts, VALID_UNTIL_TS)
self.assertEqual(res.key_json, canonicaljson.encode_canonical_json(response))
def test_get_multiple_keys_from_perspectives(self) -> None:
"""Check that we can correctly request multiple keys for the same server"""
fetcher = PerspectivesKeyFetcher(self.hs)
SERVER_NAME = "server2"
testkey1 = signedjson.key.generate_signing_key("ver1")
testverifykey1 = signedjson.key.get_verify_key(testkey1)
testverifykey1_id = "ed25519:ver1"
testkey2 = signedjson.key.generate_signing_key("ver2")
testverifykey2 = signedjson.key.get_verify_key(testkey2)
testverifykey2_id = "ed25519:ver2"
VALID_UNTIL_TS = 200 * 1000
response1 = self.build_perspectives_response(
SERVER_NAME,
testkey1,
VALID_UNTIL_TS,
)
response2 = self.build_perspectives_response(
SERVER_NAME,
testkey2,
VALID_UNTIL_TS,
)
async def post_json(
destination: str, path: str, data: JsonDict, **kwargs: str
) -> JsonDict:
self.assertEqual(destination, self.mock_perspective_server.server_name)
self.assertEqual(path, "/_matrix/key/v2/query")
# check that the request is for the expected keys
q = data["server_keys"]
self.assertEqual(
list(q[SERVER_NAME].keys()), [testverifykey1_id, testverifykey2_id]
)
return {"server_keys": [response1, response2]}
self.http_client.post_json.side_effect = post_json
# fire off two separate requests; they should get merged together into a
# single HTTP hit.
request1_d = defer.ensureDeferred(
fetcher.get_keys(SERVER_NAME, [testverifykey1_id], 0)
)
request2_d = defer.ensureDeferred(
fetcher.get_keys(SERVER_NAME, [testverifykey2_id], 0)
)
keys1 = self.get_success(request1_d)
self.assertIn(testverifykey1_id, keys1)
k = keys1[testverifykey1_id]
self.assertEqual(k.valid_until_ts, VALID_UNTIL_TS)
self.assertEqual(k.verify_key, testverifykey1)
self.assertEqual(k.verify_key.alg, "ed25519")
self.assertEqual(k.verify_key.version, "ver1")
keys2 = self.get_success(request2_d)
self.assertIn(testverifykey2_id, keys2)
k = keys2[testverifykey2_id]
self.assertEqual(k.valid_until_ts, VALID_UNTIL_TS)
self.assertEqual(k.verify_key, testverifykey2)
self.assertEqual(k.verify_key.alg, "ed25519")
self.assertEqual(k.verify_key.version, "ver2")
# finally, ensure that only one request was sent
self.assertEqual(self.http_client.post_json.call_count, 1)
def test_get_perspectives_own_key(self) -> None:
"""Check that we can get the perspectives server's own keys
This is slightly complicated by the fact that the perspectives server may
use different keys for signing notary responses.
"""
# arbitrarily advance the clock a bit
self.reactor.advance(100)
fetcher = PerspectivesKeyFetcher(self.hs)
SERVER_NAME = self.mock_perspective_server.server_name
testkey = signedjson.key.generate_signing_key("ver1")
testverifykey = signedjson.key.get_verify_key(testkey)
testverifykey_id = "ed25519:ver1"
VALID_UNTIL_TS = 200 * 1000
response = self.build_perspectives_response(
SERVER_NAME, testkey, VALID_UNTIL_TS
)
self.expect_outgoing_key_query(SERVER_NAME, "key1", response)
keys = self.get_success(fetcher.get_keys(SERVER_NAME, ["key1"], 0))
self.assertIn(testverifykey_id, keys)
k = keys[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
key_json = self.get_success(
self.hs.get_datastores().main.get_server_keys_json_for_remote(
SERVER_NAME, [testverifykey_id]
)
)
res = key_json[testverifykey_id]
self.assertIsNotNone(res)
assert res is not None
self.assertEqual(res.added_ts, self.reactor.seconds() * 1000)
self.assertEqual(res.valid_until_ts, VALID_UNTIL_TS)
self.assertEqual(res.key_json, canonicaljson.encode_canonical_json(response))
def test_invalid_perspectives_responses(self) -> None:
"""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() -> dict:
return self.build_perspectives_response(
SERVER_NAME, testkey, VALID_UNTIL_TS
)
def get_key_from_perspectives(response: JsonDict) -> Dict[str, FetchKeyResult]:
fetcher = PerspectivesKeyFetcher(self.hs)
self.expect_outgoing_key_query(SERVER_NAME, "key1", response)
return self.get_success(fetcher.get_keys(SERVER_NAME, ["key1"], 0))
# 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[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]
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]
keys = get_key_from_perspectives(response)
self.assertEqual(keys, {}, "Expected empty dict with missing origin server sig")
def get_key_id(key: SigningKey) -> str:
"""Get the matrix ID tag for a given SigningKey or VerifyKey"""
return "%s:%s" % (key.alg, key.version)