summary refs log tree commit diff
path: root/tests/crypto/test_keyring.py
blob: 7c63b2ea4c15f90cdd20593b538958e0df001aa0 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
# 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.test_utils import make_awaitable
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_json(
            "server9",
            get_key_id(key1),
            from_server="test",
            ts_now_ms=int(time.time() * 1000),
            ts_expires_ms=1000,
            # The entire response gets signed & stored, just include the bits we
            # care about.
            key_json_bytes=canonicaljson.encode_canonical_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_for_server_with_null_valid_until_ms(self) -> None:
        """Tests that we correctly handle key requests for keys we've stored
        with a null `ts_valid_until_ms`
        """
        mock_fetcher = Mock()
        mock_fetcher.get_keys = Mock(return_value=make_awaitable({}))

        key1 = signedjson.key.generate_signing_key("1")
        r = self.hs.get_datastores().main.store_server_signature_keys(
            "server9",
            int(time.time() * 1000),
            # None is not a valid value in FetchKeyResult, but we're abusing this
            # API to insert null values into the database. The nulls get converted
            # to 0 when fetched in KeyStore.get_server_signature_keys.
            {("server9", get_key_id(key1)): FetchKeyResult(get_verify_key(key1), None)},  # type: ignore[arg-type]
        )
        self.get_success(r)

        json1: JsonDict = {}
        signedjson.sign.sign_json(json1, "server9", key1)

        # should succeed on a signed object with a 0 minimum_valid_until_ms
        d = self.hs.get_datastores().main.get_server_signature_keys(
            [("server9", get_key_id(key1))]
        )
        result = self.get_success(d)
        self.assertEquals(result[("server9", get_key_id(key1))].valid_until_ts, 0)

    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
        lookup_triplet = (SERVER_NAME, testverifykey_id, None)
        key_json = self.get_success(
            self.hs.get_datastores().main.get_server_keys_json_for_remote(
                [lookup_triplet]
            )
        )
        res_keys = key_json[lookup_triplet]
        self.assertEqual(len(res_keys), 1)
        res = res_keys[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(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
        lookup_triplet = (SERVER_NAME, testverifykey_id, None)
        key_json = self.get_success(
            self.hs.get_datastores().main.get_server_keys_json_for_remote(
                [lookup_triplet]
            )
        )
        res_keys = key_json[lookup_triplet]
        self.assertEqual(len(res_keys), 1)
        res = res_keys[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_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
        lookup_triplet = (SERVER_NAME, testverifykey_id, None)
        key_json = self.get_success(
            self.hs.get_datastores().main.get_server_keys_json_for_remote(
                [lookup_triplet]
            )
        )
        res_keys = key_json[lookup_triplet]
        self.assertEqual(len(res_keys), 1)
        res = res_keys[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) -> 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)