diff options
| -rw-r--r-- | changelog.d/5392.bugfix | 1 | ||||
| -rw-r--r-- | changelog.d/5415.bugfix | 1 | ||||
| -rw-r--r-- | synapse/config/key.py | 27 | ||||
| -rw-r--r-- | synapse/crypto/keyring.py | 7 | ||||
| -rw-r--r-- | synapse/storage/keys.py | 8 | ||||
| -rw-r--r-- | tests/crypto/test_keyring.py | 50 |
6 files changed, 82 insertions, 12 deletions
diff --git a/changelog.d/5392.bugfix b/changelog.d/5392.bugfix new file mode 100644 index 0000000000..295a7cfce1 --- /dev/null +++ b/changelog.d/5392.bugfix @@ -0,0 +1 @@ +Remove redundant warning about key server response validation. diff --git a/changelog.d/5415.bugfix b/changelog.d/5415.bugfix new file mode 100644 index 0000000000..83629e193d --- /dev/null +++ b/changelog.d/5415.bugfix @@ -0,0 +1 @@ +Fix bug where old keys stored in the database with a null valid until timestamp caused all verification requests for that key to fail. diff --git a/synapse/config/key.py b/synapse/config/key.py index aba7092ccd..424875feae 100644 --- a/synapse/config/key.py +++ b/synapse/config/key.py @@ -41,6 +41,15 @@ validation or TLS certificate validation. This is likely to be very insecure. If you are *sure* you want to do this, set 'accept_keys_insecurely' on the keyserver configuration.""" +RELYING_ON_MATRIX_KEY_ERROR = """\ +Your server is configured to accept key server responses without TLS certificate +validation, and which are only signed by the old (possibly compromised) +matrix.org signing key 'ed25519:auto'. This likely isn't what you want to do, +and you should enable 'federation_verify_certificates' in your configuration. + +If you are *sure* you want to do this, set 'accept_keys_insecurely' on the +trusted_key_server configuration.""" + logger = logging.getLogger(__name__) @@ -340,10 +349,20 @@ def _parse_key_servers(key_servers, federation_verify_certificates): result.verify_keys[key_id] = verify_key if ( - not verify_keys - and not server.get("accept_keys_insecurely") - and not federation_verify_certificates + not federation_verify_certificates and + not server.get("accept_keys_insecurely") ): - raise ConfigError(INSECURE_NOTARY_ERROR) + _assert_keyserver_has_verify_keys(result) yield result + + +def _assert_keyserver_has_verify_keys(trusted_key_server): + if not trusted_key_server.verify_keys: + raise ConfigError(INSECURE_NOTARY_ERROR) + + # also check that they are not blindly checking the old matrix.org key + if trusted_key_server.server_name == "matrix.org" and any( + key_id == "ed25519:auto" for key_id in trusted_key_server.verify_keys + ): + raise ConfigError(RELYING_ON_MATRIX_KEY_ERROR) diff --git a/synapse/crypto/keyring.py b/synapse/crypto/keyring.py index 96964b0d50..6f603f1961 100644 --- a/synapse/crypto/keyring.py +++ b/synapse/crypto/keyring.py @@ -750,13 +750,6 @@ class PerspectivesKeyFetcher(BaseV2KeyFetcher): verify_signed_json(response, perspective_name, perspective_keys[key_id]) verified = True - if perspective_name == "matrix.org" and key_id == "ed25519:auto": - logger.warning( - "Trusting trusted_key_server responses signed by the " - "compromised matrix.org signing key 'ed25519:auto'. " - "This is a placebo." - ) - if not verified: raise KeyLookupError( "Response not signed with a known key: signed with: %r, known keys: %r" diff --git a/synapse/storage/keys.py b/synapse/storage/keys.py index 5300720dbb..e3655ad8d7 100644 --- a/synapse/storage/keys.py +++ b/synapse/storage/keys.py @@ -80,6 +80,14 @@ class KeyStore(SQLBaseStore): for row in txn: server_name, key_id, key_bytes, ts_valid_until_ms = row + + if ts_valid_until_ms is None: + # Old keys may be stored with a ts_valid_until_ms of null, + # in which case we treat this as if it was set to `0`, i.e. + # it won't match key requests that define a minimum + # `ts_valid_until_ms`. + ts_valid_until_ms = 0 + res = FetchKeyResult( verify_key=decode_verify_key_bytes(key_id, bytes(key_bytes)), valid_until_ts=ts_valid_until_ms, diff --git a/tests/crypto/test_keyring.py b/tests/crypto/test_keyring.py index 4b1901ce31..5a355f00cc 100644 --- a/tests/crypto/test_keyring.py +++ b/tests/crypto/test_keyring.py @@ -25,7 +25,11 @@ 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.crypto.keyring import ( + PerspectivesKeyFetcher, + ServerKeyFetcher, + StoreKeyFetcher, +) from synapse.storage.keys import FetchKeyResult from synapse.util import logcontext from synapse.util.logcontext import LoggingContext @@ -219,6 +223,50 @@ class KeyringTestCase(unittest.HomeserverTestCase): # 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) |