Merge remote-tracking branch 'origin/develop' into clokep/thread-api

.github/workflows/latest_deps.yml

@@ -135,11 +135,42 @@ jobs:
             /logs/**/*.log*
 
 
-  # TODO: run complement (as with twisted trunk, see #12473).
+  complement:
+    if: "${{ !failure() && !cancelled() }}"
+    runs-on: ubuntu-latest
 
-  # open an issue if the build fails, so we know about it.
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - arrangement: monolith
+            database: SQLite
+
+          - arrangement: monolith
+            database: Postgres
+
+          - arrangement: workers
+            database: Postgres
+
+    steps:
+      - name: Run actions/checkout@v2 for synapse
+        uses: actions/checkout@v2
+        with:
+          path: synapse
+
+      - name: Prepare Complement's Prerequisites
+        run: synapse/.ci/scripts/setup_complement_prerequisites.sh
+
+      - run: |
+          set -o pipefail
+          TEST_ONLY_IGNORE_POETRY_LOCKFILE=1 POSTGRES=${{ (matrix.database == 'Postgres') && 1 || '' }} WORKERS=${{ (matrix.arrangement == 'workers') && 1 || '' }} COMPLEMENT_DIR=`pwd`/complement synapse/scripts-dev/complement.sh -json 2>&1 | gotestfmt
+        shell: bash
+        name: Run Complement Tests
+
+  # Open an issue if the build fails, so we know about it.
+  # Only do this if we're not experimenting with this action in a PR.
   open-issue:
-    if: failure()
+    if: "failure() && github.event_name != 'push' && github.event_name != 'pull_request'"
     needs:
       # TODO: should mypy be included here? It feels more brittle than the other two.
       - mypy

.github/workflows/tests.yml

@@ -328,6 +328,9 @@ jobs:
           - arrangement: monolith
             database: Postgres
 
+          - arrangement: workers
+            database: Postgres
+
     steps:
       - name: Run actions/checkout@v2 for synapse
         uses: actions/checkout@v2
@@ -343,30 +346,6 @@ jobs:
         shell: bash
         name: Run Complement Tests
 
-  # XXX When complement with workers is stable, move this back into the standard
-  #     "complement" matrix above.
-  #
-  # See https://github.com/matrix-org/synapse/issues/13161
-  complement-workers:
-    if: "${{ !failure() && !cancelled() }}"
-    needs: linting-done
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Run actions/checkout@v2 for synapse
-        uses: actions/checkout@v2
-        with:
-          path: synapse
-
-      - name: Prepare Complement's Prerequisites
-        run: synapse/.ci/scripts/setup_complement_prerequisites.sh
-
-      - run: |
-          set -o pipefail
-          POSTGRES=1 WORKERS=1 COMPLEMENT_DIR=`pwd`/complement synapse/scripts-dev/complement.sh -json 2>&1 | gotestfmt
-        shell: bash
-        name: Run Complement Tests
-
   # a job which marks all the other jobs as complete, thus allowing PRs to be merged.
   tests-done:
     if: ${{ always() }}

CHANGES.md

@@ -1,7 +1,13 @@
+Synapse 1.64.0rc2 (2022-07-29)
+==============================
+
+This RC reintroduces support for `account_threepid_delegates.email`, which was removed in 1.64.0rc1. It remains deprecated and will be removed altogether in a future release. ([\#13406](https://github.com/matrix-org/synapse/issues/13406))
+
+
 Synapse 1.64.0rc1 (2022-07-26)
 ==============================
 
-As of this release, Synapse no longer allows the tasks of verifying email address ownership, and password reset confirmation, to be delegated to an identity server. For more information, see the [upgrade notes](https://matrix-org.github.io/synapse/v1.64/upgrade.html#upgrading-to-v1640).
+This RC removed the ability to delegate the tasks of verifying email address ownership, and password reset confirmation, to an identity server.
 
 We have also stopped building `.deb` packages for Ubuntu 21.10 as it is no longer an active version of Ubuntu.
 

changelog.d/13213.misc

@@ -0,0 +1 @@
+Enable Complement CI tests in the 'latest deps' test run.

changelog.d/13221.doc

@@ -0,0 +1 @@
+Document which HTTP resources support gzip compression.

changelog.d/13370.feature

@@ -0,0 +1 @@
+Use stable prefixes for [MSC3827](https://github.com/matrix-org/matrix-spec-proposals/pull/3827).

changelog.d/13397.misc

@@ -0,0 +1 @@
+Adding missing type hints to tests.

changelog.d/13413.bugfix

@@ -0,0 +1 @@
+Faster room joins: fix a bug which caused rejected events to become un-rejected during state syncing.

changelog.d/13420.misc

@@ -0,0 +1 @@
+Re-enable running Complement tests against Synapse with workers.

debian/changelog

@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.64.0~rc2) stable; urgency=medium
+
+  * New Synapse release 1.64.0rc2.
+
+ -- Synapse Packaging team <packages@matrix.org>  Fri, 29 Jul 2022 12:22:53 +0100
+
 matrix-synapse-py3 (1.64.0~rc1) stable; urgency=medium
 
   * New Synapse release 1.64.0rc1.

docker/Dockerfile

@@ -68,7 +68,18 @@ COPY pyproject.toml poetry.lock /synapse/
 # reason, such as when a git repository is used directly as a dependency.
 ARG TEST_ONLY_SKIP_DEP_HASH_VERIFICATION
 
-RUN /root/.local/bin/poetry export --extras all -o /synapse/requirements.txt ${TEST_ONLY_SKIP_DEP_HASH_VERIFICATION:+--without-hashes}
+# If specified, we won't use the Poetry lockfile.
+# Instead, we'll just install what a regular `pip install` would from PyPI.
+ARG TEST_ONLY_IGNORE_POETRY_LOCKFILE
+
+# Export the dependencies, but only if we're actually going to use the Poetry lockfile.
+# Otherwise, just create an empty requirements file so that the Dockerfile can
+# proceed.
+RUN if [ -z "$TEST_ONLY_IGNORE_POETRY_LOCKFILE" ]; then \
+    /root/.local/bin/poetry export --extras all -o /synapse/requirements.txt ${TEST_ONLY_SKIP_DEP_HASH_VERIFICATION:+--without-hashes}; \
+  else \
+    touch /synapse/requirements.txt; \
+  fi
 
 ###
 ### Stage 1: builder
@@ -108,8 +119,17 @@ COPY synapse /synapse/synapse/
 # ... and what we need to `pip install`.
 COPY pyproject.toml README.rst /synapse/
 
+# Repeat of earlier build argument declaration, as this is a new build stage.
+ARG TEST_ONLY_IGNORE_POETRY_LOCKFILE
+
 # Install the synapse package itself.
-RUN pip install --prefix="/install" --no-deps --no-warn-script-location /synapse
+# If we have populated requirements.txt, we don't install any dependencies
+# as we should already have those from the previous `pip install` step.
+RUN if [ -z "$TEST_ONLY_IGNORE_POETRY_LOCKFILE" ]; then \
+    pip install --prefix="/install" --no-deps --no-warn-script-location /synapse[all]; \
+  else \
+    pip install --prefix="/install" --no-warn-script-location /synapse[all]; \
+  fi
 
 ###
 ### Stage 2: runtime

docs/upgrade.md

@@ -91,19 +91,6 @@ process, for example:
 
 # Upgrading to v1.64.0
 
-## Delegation of email validation no longer supported
-
-As of this version, Synapse no longer allows the tasks of verifying email address
-ownership, and password reset confirmation, to be delegated to an identity server.
-
-To continue to allow users to add email addresses to their homeserver accounts,
-and perform password resets, make sure that Synapse is configured with a
-working email server in the `email` configuration section (including, at a
-minimum, a `notif_from` setting.)
-
-Specifying an `email` setting under `account_threepid_delegates` will now cause
-an error at startup.
-
 ## Changes to the event replication streams
 
 Synapse now includes a flag indicating if an event is an outlier when

pyproject.toml

@@ -54,7 +54,7 @@ skip_gitignore = true
 
 [tool.poetry]
 name = "matrix-synapse"
-version = "1.64.0rc1"
+version = "1.64.0rc2"
 description = "Homeserver for the Matrix decentralised comms protocol"
 authors = ["Matrix.org Team and Contributors <packages@matrix.org>"]
 license = "Apache-2.0"

scripts-dev/complement.sh

@@ -101,6 +101,7 @@ if [ -z "$skip_docker_build" ]; then
     echo_if_github "::group::Build Docker image: matrixdotorg/synapse"
     docker build -t matrixdotorg/synapse \
       --build-arg TEST_ONLY_SKIP_DEP_HASH_VERIFICATION \
+      --build-arg TEST_ONLY_IGNORE_POETRY_LOCKFILE \
       -f "docker/Dockerfile" .
     echo_if_github "::endgroup::"
 

synapse/api/constants.py

@@ -268,4 +268,4 @@ class PublicRoomsFilterFields:
     """
 
     GENERIC_SEARCH_TERM: Final = "generic_search_term"
-    ROOM_TYPES: Final = "org.matrix.msc3827.room_types"
+    ROOM_TYPES: Final = "room_types"

synapse/app/homeserver.py

@@ -44,6 +44,7 @@ from synapse.app._base import (
     register_start,
 )
 from synapse.config._base import ConfigError, format_config_error
+from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.config.homeserver import HomeServerConfig
 from synapse.config.server import ListenerConfig
 from synapse.federation.transport.server import TransportLayerServer
@@ -201,7 +202,7 @@ class SynapseHomeServer(HomeServer):
                 }
             )
 
-            if self.config.email.can_verify_email:
+            if self.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
                 from synapse.rest.synapse.client.password_reset import (
                     PasswordResetSubmitTokenResource,
                 )

synapse/config/emailconfig.py

@@ -18,6 +18,7 @@
 import email.utils
 import logging
 import os
+from enum import Enum
 from typing import Any
 
 import attr
@@ -135,22 +136,40 @@ class EmailConfig(Config):
 
         self.email_enable_notifs = email_config.get("enable_notifs", False)
 
+        self.threepid_behaviour_email = (
+            # Have Synapse handle the email sending if account_threepid_delegates.email
+            # is not defined
+            # msisdn is currently always remote while Synapse does not support any method of
+            # sending SMS messages
+            ThreepidBehaviour.REMOTE
+            if self.root.registration.account_threepid_delegate_email
+            else ThreepidBehaviour.LOCAL
+        )
+
         if config.get("trust_identity_server_for_password_resets"):
             raise ConfigError(
-                'The config option "trust_identity_server_for_password_resets" '
-                "is no longer supported. Please remove it from the config file."
+                'The config option "trust_identity_server_for_password_resets" has been removed.'
+                "Please consult the configuration manual at docs/usage/configuration/config_documentation.md for "
+                "details and update your config file."
             )
 
-        # If we have email config settings, assume that we can verify ownership of
-        # email addresses.
-        self.can_verify_email = email_config != {}
+        self.local_threepid_handling_disabled_due_to_email_config = False
+        if (
+            self.threepid_behaviour_email == ThreepidBehaviour.LOCAL
+            and email_config == {}
+        ):
+            # We cannot warn the user this has happened here
+            # Instead do so when a user attempts to reset their password
+            self.local_threepid_handling_disabled_due_to_email_config = True
+
+            self.threepid_behaviour_email = ThreepidBehaviour.OFF
 
         # Get lifetime of a validation token in milliseconds
         self.email_validation_token_lifetime = self.parse_duration(
             email_config.get("validation_token_lifetime", "1h")
         )
 
-        if self.can_verify_email:
+        if self.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
             missing = []
             if not self.email_notif_from:
                 missing.append("email.notif_from")
@@ -341,3 +360,18 @@ class EmailConfig(Config):
                     "Config option email.invite_client_location must be a http or https URL",
                     path=("email", "invite_client_location"),
                 )
+
+
+class ThreepidBehaviour(Enum):
+    """
+    Enum to define the behaviour of Synapse with regards to when it contacts an identity
+    server for 3pid registration and password resets
+
+    REMOTE = use an external server to send tokens
+    LOCAL = send tokens ourselves
+    OFF = disable registration via 3pid and password resets
+    """
+
+    REMOTE = "remote"
+    LOCAL = "local"
+    OFF = "off"

synapse/config/experimental.py

@@ -88,9 +88,6 @@ class ExperimentalConfig(Config):
         # MSC3715: dir param on /relations.
         self.msc3715_enabled: bool = experimental.get("msc3715_enabled", False)
 
-        # MSC3827: Filtering of /publicRooms by room type
-        self.msc3827_enabled: bool = experimental.get("msc3827_enabled", False)
-
         # MSC3848: Introduce errcodes for specific event sending failures
         self.msc3848_enabled: bool = experimental.get("msc3848_enabled", False)
 

synapse/config/registration.py

@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import argparse
+import logging
 from typing import Any, Optional
 
 from synapse.api.constants import RoomCreationPreset
@@ -20,11 +21,15 @@ from synapse.config._base import Config, ConfigError
 from synapse.types import JsonDict, RoomAlias, UserID
 from synapse.util.stringutils import random_string_with_symbols, strtobool
 
-NO_EMAIL_DELEGATE_ERROR = """\
-Delegation of email verification to an identity server is no longer supported. To
+logger = logging.getLogger(__name__)
+
+LEGACY_EMAIL_DELEGATE_WARNING = """\
+Delegation of email verification to an identity server is now deprecated. To
 continue to allow users to add email addresses to their accounts, and use them for
 password resets, configure Synapse with an SMTP server via the `email` setting, and
 remove `account_threepid_delegates.email`.
+
+This will be an error in a future version.
 """
 
 
@@ -59,8 +64,9 @@ class RegistrationConfig(Config):
 
         account_threepid_delegates = config.get("account_threepid_delegates") or {}
         if "email" in account_threepid_delegates:
-            raise ConfigError(NO_EMAIL_DELEGATE_ERROR)
-        # self.account_threepid_delegate_email = account_threepid_delegates.get("email")
+            logger.warning(LEGACY_EMAIL_DELEGATE_WARNING)
+
+        self.account_threepid_delegate_email = account_threepid_delegates.get("email")
         self.account_threepid_delegate_msisdn = account_threepid_delegates.get("msisdn")
         self.default_identity_server = config.get("default_identity_server")
         self.allow_guest_access = config.get("allow_guest_access", False)

synapse/handlers/federation_event.py

@@ -581,6 +581,13 @@ class FederationEventHandler:
                     event.event_id,
                 )
                 return
+
+            # since the state at this event has changed, we should now re-evaluate
+            # whether it should have been rejected. We must already have all of the
+            # auth events (from last time we went round this path), so there is no
+            # need to pass the origin.
+            await self._check_event_auth(None, event, context)
+
             await self._store.update_state_for_partial_state_event(event, context)
             self._state_storage_controller.notify_event_un_partial_stated(
                 event.event_id
@@ -1624,13 +1631,15 @@ class FederationEventHandler:
         )
 
     async def _check_event_auth(
-        self, origin: str, event: EventBase, context: EventContext
+        self, origin: Optional[str], event: EventBase, context: EventContext
     ) -> None:
         """
         Checks whether an event should be rejected (for failing auth checks).
 
         Args:
-            origin: The host the event originates from.
+            origin: The host the event originates from. This is used to fetch
+               any missing auth events. It can be set to None, but only if we are
+               sure that we already have all the auth events.
             event: The event itself.
             context:
                 The event context.
@@ -1876,7 +1885,7 @@ class FederationEventHandler:
             event.internal_metadata.soft_failed = True
 
     async def _load_or_fetch_auth_events_for_event(
-        self, destination: str, event: EventBase
+        self, destination: Optional[str], event: EventBase
     ) -> Collection[EventBase]:
         """Fetch this event's auth_events, from database or remote
 
@@ -1892,12 +1901,19 @@ class FederationEventHandler:
         Args:
             destination: where to send the /event_auth request. Typically the server
                that sent us `event` in the first place.
+
+               If this is None, no attempt is made to load any missing auth events:
+               rather, an AssertionError is raised if there are any missing events.
+
             event: the event whose auth_events we want
 
         Returns:
             all of the events listed in `event.auth_events_ids`, after deduplication
 
         Raises:
+            AssertionError if some auth events were missing and no `destination` was
+            supplied.
+
             AuthError if we were unable to fetch the auth_events for any reason.
         """
         event_auth_event_ids = set(event.auth_event_ids())
@@ -1909,6 +1925,13 @@ class FederationEventHandler:
         )
         if not missing_auth_event_ids:
             return event_auth_events.values()
+        if destination is None:
+            # this shouldn't happen: destination must be set unless we know we have already
+            # persisted the auth events.
+            raise AssertionError(
+                "_load_or_fetch_auth_events_for_event() called with no destination for "
+                "an event with missing auth_events"
+            )
 
         logger.info(
             "Event %s refers to unknown auth events %s: fetching auth chain",

synapse/handlers/identity.py

@@ -26,6 +26,7 @@ from synapse.api.errors import (
     SynapseError,
 )
 from synapse.api.ratelimiting import Ratelimiter
+from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.http import RequestTimedOutError
 from synapse.http.client import SimpleHttpClient
 from synapse.http.site import SynapseRequest
@@ -415,6 +416,48 @@ class IdentityHandler:
 
         return session_id
 
+    async def request_email_token(
+        self,
+        id_server: str,
+        email: str,
+        client_secret: str,
+        send_attempt: int,
+        next_link: Optional[str] = None,
+    ) -> JsonDict:
+        """
+        Request an external server send an email on our behalf for the purposes of threepid
+        validation.
+
+        Args:
+            id_server: The identity server to proxy to
+            email: The email to send the message to
+            client_secret: The unique client_secret sends by the user
+            send_attempt: Which attempt this is
+            next_link: A link to redirect the user to once they submit the token
+
+        Returns:
+            The json response body from the server
+        """
+        params = {
+            "email": email,
+            "client_secret": client_secret,
+            "send_attempt": send_attempt,
+        }
+        if next_link:
+            params["next_link"] = next_link
+
+        try:
+            data = await self.http_client.post_json_get_json(
+                id_server + "/_matrix/identity/api/v1/validate/email/requestToken",
+                params,
+            )
+            return data
+        except HttpResponseException as e:
+            logger.info("Proxied requestToken failed: %r", e)
+            raise e.to_synapse_error()
+        except RequestTimedOutError:
+            raise SynapseError(500, "Timed out contacting identity server")
+
     async def requestMsisdnToken(
         self,
         id_server: str,
@@ -488,7 +531,18 @@ class IdentityHandler:
         validation_session = None
 
         # Try to validate as email
-        if self.hs.config.email.can_verify_email:
+        if self.hs.config.email.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
+            # Remote emails will only be used if a valid identity server is provided.
+            assert (
+                self.hs.config.registration.account_threepid_delegate_email is not None
+            )
+
+            # Ask our delegated email identity server
+            validation_session = await self.threepid_from_creds(
+                self.hs.config.registration.account_threepid_delegate_email,
+                threepid_creds,
+            )
+        elif self.hs.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
             # Get a validated session matching these details
             validation_session = await self.store.get_threepid_validation_session(
                 "email", client_secret, sid=sid, validated=True

synapse/handlers/room_list.py

@@ -182,7 +182,7 @@ class RoomListHandler:
                 == HistoryVisibility.WORLD_READABLE,
                 "guest_can_join": room["guest_access"] == "can_join",
                 "join_rule": room["join_rules"],
-                "org.matrix.msc3827.room_type": room["room_type"],
+                "room_type": room["room_type"],
             }
 
             # Filter out Nones – rather omit the field altogether

synapse/handlers/ui_auth/checkers.py

@@ -19,6 +19,7 @@ from twisted.web.client import PartialDownloadError
 
 from synapse.api.constants import LoginType
 from synapse.api.errors import Codes, LoginError, SynapseError
+from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.util import json_decoder
 
 if TYPE_CHECKING:
@@ -152,7 +153,7 @@ class _BaseThreepidAuthChecker:
 
         logger.info("Getting validated threepid. threepidcreds: %r", (threepid_creds,))
 
-        # msisdns are currently always verified via the IS
+        # msisdns are currently always ThreepidBehaviour.REMOTE
         if medium == "msisdn":
             if not self.hs.config.registration.account_threepid_delegate_msisdn:
                 raise SynapseError(
@@ -163,7 +164,18 @@ class _BaseThreepidAuthChecker:
                 threepid_creds,
             )
         elif medium == "email":
-            if self.hs.config.email.can_verify_email:
+            if (
+                self.hs.config.email.threepid_behaviour_email
+                == ThreepidBehaviour.REMOTE
+            ):
+                assert self.hs.config.registration.account_threepid_delegate_email
+                threepid = await identity_handler.threepid_from_creds(
+                    self.hs.config.registration.account_threepid_delegate_email,
+                    threepid_creds,
+                )
+            elif (
+                self.hs.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL
+            ):
                 threepid = None
                 row = await self.store.get_threepid_validation_session(
                     medium,
@@ -215,7 +227,10 @@ class EmailIdentityAuthChecker(UserInteractiveAuthChecker, _BaseThreepidAuthChec
         _BaseThreepidAuthChecker.__init__(self, hs)
 
     def is_enabled(self) -> bool:
-        return self.hs.config.email.can_verify_email
+        return self.hs.config.email.threepid_behaviour_email in (
+            ThreepidBehaviour.REMOTE,
+            ThreepidBehaviour.LOCAL,
+        )
 
     async def check_auth(self, authdict: dict, clientip: str) -> Any:
         return await self._check_threepid("email", authdict)

synapse/rest/client/account.py

@@ -28,6 +28,7 @@ from synapse.api.errors import (
     SynapseError,
     ThreepidValidationError,
 )
+from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.handlers.ui_auth import UIAuthSessionDataConstants
 from synapse.http.server import HttpServer, finish_request, respond_with_html
 from synapse.http.servlet import (
@@ -63,7 +64,7 @@ class EmailPasswordRequestTokenRestServlet(RestServlet):
         self.config = hs.config
         self.identity_handler = hs.get_identity_handler()
 
-        if self.config.email.can_verify_email:
+        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
             self.mailer = Mailer(
                 hs=self.hs,
                 app_name=self.config.email.email_app_name,
@@ -72,10 +73,11 @@ class EmailPasswordRequestTokenRestServlet(RestServlet):
             )
 
     async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
-        if not self.config.email.can_verify_email:
-            logger.warning(
-                "User password resets have been disabled due to lack of email config"
-            )
+        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.OFF:
+            if self.config.email.local_threepid_handling_disabled_due_to_email_config:
+                logger.warning(
+                    "User password resets have been disabled due to lack of email config"
+                )
             raise SynapseError(
                 400, "Email-based password resets have been disabled on this server"
             )
@@ -127,21 +129,35 @@ class EmailPasswordRequestTokenRestServlet(RestServlet):
 
             raise SynapseError(400, "Email not found", Codes.THREEPID_NOT_FOUND)
 
-        # Send password reset emails from Synapse
-        sid = await self.identity_handler.send_threepid_validation(
-            email,
-            client_secret,
-            send_attempt,
-            self.mailer.send_password_reset_mail,
-            next_link,
-        )
+        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
+            assert self.hs.config.registration.account_threepid_delegate_email
+
+            # Have the configured identity server handle the request
+            ret = await self.identity_handler.request_email_token(
+                self.hs.config.registration.account_threepid_delegate_email,
+                email,
+                client_secret,
+                send_attempt,
+                next_link,
+            )
+        else:
+            # Send password reset emails from Synapse
+            sid = await self.identity_handler.send_threepid_validation(
+                email,
+                client_secret,
+                send_attempt,
+                self.mailer.send_password_reset_mail,
+                next_link,
+            )
+
+            # Wrap the session id in a JSON object
+            ret = {"sid": sid}
 
         threepid_send_requests.labels(type="email", reason="password_reset").observe(
             send_attempt
         )
 
-        # Wrap the session id in a JSON object
-        return 200, {"sid": sid}
+        return 200, ret
 
 
 class PasswordRestServlet(RestServlet):
@@ -333,7 +349,7 @@ class EmailThreepidRequestTokenRestServlet(RestServlet):
         self.identity_handler = hs.get_identity_handler()
         self.store = self.hs.get_datastores().main
 
-        if self.config.email.can_verify_email:
+        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
             self.mailer = Mailer(
                 hs=self.hs,
                 app_name=self.config.email.email_app_name,
@@ -342,10 +358,11 @@ class EmailThreepidRequestTokenRestServlet(RestServlet):
             )
 
     async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
-        if not self.config.email.can_verify_email:
-            logger.warning(
-                "Adding emails have been disabled due to lack of an email config"
-            )
+        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.OFF:
+            if self.config.email.local_threepid_handling_disabled_due_to_email_config:
+                logger.warning(
+                    "Adding emails have been disabled due to lack of an email config"
+                )
             raise SynapseError(
                 400, "Adding an email to your account is disabled on this server"
             )
@@ -396,20 +413,35 @@ class EmailThreepidRequestTokenRestServlet(RestServlet):
 
             raise SynapseError(400, "Email is already in use", Codes.THREEPID_IN_USE)
 
-        sid = await self.identity_handler.send_threepid_validation(
-            email,
-            client_secret,
-            send_attempt,
-            self.mailer.send_add_threepid_mail,
-            next_link,
-        )
+        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
+            assert self.hs.config.registration.account_threepid_delegate_email
+
+            # Have the configured identity server handle the request
+            ret = await self.identity_handler.request_email_token(
+                self.hs.config.registration.account_threepid_delegate_email,
+                email,
+                client_secret,
+                send_attempt,
+                next_link,
+            )
+        else:
+            # Send threepid validation emails from Synapse
+            sid = await self.identity_handler.send_threepid_validation(
+                email,
+                client_secret,
+                send_attempt,
+                self.mailer.send_add_threepid_mail,
+                next_link,
+            )
+
+            # Wrap the session id in a JSON object
+            ret = {"sid": sid}
 
         threepid_send_requests.labels(type="email", reason="add_threepid").observe(
             send_attempt
         )
 
-        # Wrap the session id in a JSON object
-        return 200, {"sid": sid}
+        return 200, ret
 
 
 class MsisdnThreepidRequestTokenRestServlet(RestServlet):
@@ -502,19 +534,25 @@ class AddThreepidEmailSubmitTokenServlet(RestServlet):
         self.config = hs.config
         self.clock = hs.get_clock()
         self.store = hs.get_datastores().main
-        if self.config.email.can_verify_email:
+        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
             self._failure_email_template = (
                 self.config.email.email_add_threepid_template_failure_html
             )
 
     async def on_GET(self, request: Request) -> None:
-        if not self.config.email.can_verify_email:
-            logger.warning(
-                "Adding emails have been disabled due to lack of an email config"
-            )
+        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.OFF:
+            if self.config.email.local_threepid_handling_disabled_due_to_email_config:
+                logger.warning(
+                    "Adding emails have been disabled due to lack of an email config"
+                )
             raise SynapseError(
                 400, "Adding an email to your account is disabled on this server"
             )
+        elif self.config.email.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
+            raise SynapseError(
+                400,
+                "This homeserver is not validating threepids.",
+            )
 
         sid = parse_string(request, "sid", required=True)
         token = parse_string(request, "token", required=True)

synapse/rest/client/register.py

@@ -31,6 +31,7 @@ from synapse.api.errors import (
 )
 from synapse.api.ratelimiting import Ratelimiter
 from synapse.config import ConfigError
+from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.config.homeserver import HomeServerConfig
 from synapse.config.ratelimiting import FederationRateLimitConfig
 from synapse.config.server import is_threepid_reserved
@@ -73,7 +74,7 @@ class EmailRegisterRequestTokenRestServlet(RestServlet):
         self.identity_handler = hs.get_identity_handler()
         self.config = hs.config
 
-        if self.hs.config.email.can_verify_email:
+        if self.hs.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
             self.mailer = Mailer(
                 hs=self.hs,
                 app_name=self.config.email.email_app_name,
@@ -82,10 +83,13 @@ class EmailRegisterRequestTokenRestServlet(RestServlet):
             )
 
     async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
-        if not self.hs.config.email.can_verify_email:
-            logger.warning(
-                "Email registration has been disabled due to lack of email config"
-            )
+        if self.hs.config.email.threepid_behaviour_email == ThreepidBehaviour.OFF:
+            if (
+                self.hs.config.email.local_threepid_handling_disabled_due_to_email_config
+            ):
+                logger.warning(
+                    "Email registration has been disabled due to lack of email config"
+                )
             raise SynapseError(
                 400, "Email-based registration has been disabled on this server"
             )
@@ -134,21 +138,35 @@ class EmailRegisterRequestTokenRestServlet(RestServlet):
 
             raise SynapseError(400, "Email is already in use", Codes.THREEPID_IN_USE)
 
-        # Send registration emails from Synapse
-        sid = await self.identity_handler.send_threepid_validation(
-            email,
-            client_secret,
-            send_attempt,
-            self.mailer.send_registration_mail,
-            next_link,
-        )
+        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
+            assert self.hs.config.registration.account_threepid_delegate_email
+
+            # Have the configured identity server handle the request
+            ret = await self.identity_handler.request_email_token(
+                self.hs.config.registration.account_threepid_delegate_email,
+                email,
+                client_secret,
+                send_attempt,
+                next_link,
+            )
+        else:
+            # Send registration emails from Synapse,
+            # wrapping the session id in a JSON object.
+            ret = {
+                "sid": await self.identity_handler.send_threepid_validation(
+                    email,
+                    client_secret,
+                    send_attempt,
+                    self.mailer.send_registration_mail,
+                    next_link,
+                )
+            }
 
         threepid_send_requests.labels(type="email", reason="register").observe(
             send_attempt
         )
 
-        # Wrap the session id in a JSON object
-        return 200, {"sid": sid}
+        return 200, ret
 
 
 class MsisdnRegisterRequestTokenRestServlet(RestServlet):
@@ -242,7 +260,7 @@ class RegistrationSubmitTokenServlet(RestServlet):
         self.clock = hs.get_clock()
         self.store = hs.get_datastores().main
 
-        if self.config.email.can_verify_email:
+        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
             self._failure_email_template = (
                 self.config.email.email_registration_template_failure_html
             )
@@ -252,10 +270,11 @@ class RegistrationSubmitTokenServlet(RestServlet):
             raise SynapseError(
                 400, "This medium is currently not supported for registration"
             )
-        if not self.config.email.can_verify_email:
-            logger.warning(
-                "User registration via email has been disabled due to lack of email config"
-            )
+        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.OFF:
+            if self.config.email.local_threepid_handling_disabled_due_to_email_config:
+                logger.warning(
+                    "User registration via email has been disabled due to lack of email config"
+                )
             raise SynapseError(
                 400, "Email-based registration is disabled on this server"
             )

synapse/rest/client/versions.py

@@ -95,8 +95,8 @@ class VersionsRestServlet(RestServlet):
                     "org.matrix.msc3026.busy_presence": self.config.experimental.msc3026_enabled,
                     # Supports receiving private read receipts as per MSC2285
                     "org.matrix.msc2285": self.config.experimental.msc2285_enabled,
-                    # Supports filtering of /publicRooms by room type MSC3827
-                    "org.matrix.msc3827": self.config.experimental.msc3827_enabled,
+                    # Supports filtering of /publicRooms by room type as per MSC3827
+                    "org.matrix.msc3827.stable": True,
                     # Adds support for importing historical messages as per MSC2716
                     "org.matrix.msc2716": self.config.experimental.msc2716_enabled,
                     # Adds support for jump to date endpoints (/timestamp_to_event) as per MSC3030

synapse/rest/synapse/client/password_reset.py

@@ -17,6 +17,7 @@ from typing import TYPE_CHECKING, Tuple
 from twisted.web.server import Request
 
 from synapse.api.errors import ThreepidValidationError
+from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.http.server import DirectServeHtmlResource
 from synapse.http.servlet import parse_string
 from synapse.util.stringutils import assert_valid_client_secret
@@ -45,6 +46,9 @@ class PasswordResetSubmitTokenResource(DirectServeHtmlResource):
         self.clock = hs.get_clock()
         self.store = hs.get_datastores().main
 
+        self._local_threepid_handling_disabled_due_to_email_config = (
+            hs.config.email.local_threepid_handling_disabled_due_to_email_config
+        )
         self._confirmation_email_template = (
             hs.config.email.email_password_reset_template_confirmation_html
         )
@@ -55,8 +59,8 @@ class PasswordResetSubmitTokenResource(DirectServeHtmlResource):
             hs.config.email.email_password_reset_template_failure_html
         )
 
-        # This resource should only be mounted if email validation is enabled
-        assert hs.config.email.can_verify_email
+        # This resource should not be mounted if threepid behaviour is not LOCAL
+        assert hs.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL
 
     async def _async_render_GET(self, request: Request) -> Tuple[int, bytes]:
         sid = parse_string(request, "sid", required=True)

synapse/storage/databases/main/room.py

@@ -207,7 +207,7 @@ class RoomWorkerStore(CacheInvalidationWorkerStore):
     def _construct_room_type_where_clause(
         self, room_types: Union[List[Union[str, None]], None]
     ) -> Tuple[Union[str, None], List[str]]:
-        if not room_types or not self.config.experimental.msc3827_enabled:
+        if not room_types:
             return None, []
         else:
             # We use None when we want get rooms without a type

synapse/storage/databases/main/state.py

@@ -419,13 +419,15 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
         # anything that was rejected should have the same state as its
         # predecessor.
         if context.rejected:
-            assert context.state_group == context.state_group_before_event
+            state_group = context.state_group_before_event
+        else:
+            state_group = context.state_group
 
         self.db_pool.simple_update_txn(
             txn,
             table="event_to_state_groups",
             keyvalues={"event_id": event.event_id},
-            updatevalues={"state_group": context.state_group},
+            updatevalues={"state_group": state_group},
         )
 
         self.db_pool.simple_delete_one_txn(
@@ -440,7 +442,7 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
         txn.call_after(
             self._get_state_group_for_event.prefill,
             (event.event_id,),
-            context.state_group,
+            state_group,
         )
 
 

tests/handlers/test_directory.py

@@ -481,17 +481,13 @@ class TestCreatePublishedRoomACL(unittest.HomeserverTestCase):
 
         return config
 
-    def prepare(
-        self, reactor: MemoryReactor, clock: Clock, hs: HomeServer
-    ) -> HomeServer:
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         self.allowed_user_id = self.register_user(self.allowed_localpart, "pass")
         self.allowed_access_token = self.login(self.allowed_localpart, "pass")
 
         self.denied_user_id = self.register_user("denied", "pass")
         self.denied_access_token = self.login("denied", "pass")
 
-        return hs
-
     def test_denied_without_publication_permission(self) -> None:
         """
         Try to create a room, register an alias for it, and publish it,
@@ -575,9 +571,7 @@ class TestRoomListSearchDisabled(unittest.HomeserverTestCase):
 
     servlets = [directory.register_servlets, room.register_servlets]
 
-    def prepare(
-        self, reactor: MemoryReactor, clock: Clock, hs: HomeServer
-    ) -> HomeServer:
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         room_id = self.helper.create_room_as(self.user_id)
 
         channel = self.make_request(
@@ -588,8 +582,6 @@ class TestRoomListSearchDisabled(unittest.HomeserverTestCase):
         self.room_list_handler = hs.get_room_list_handler()
         self.directory_handler = hs.get_directory_handler()
 
-        return hs
-
     def test_disabling_room_list(self) -> None:
         self.room_list_handler.enable_room_list_search = True
         self.directory_handler.enable_room_list_search = True

tests/rest/client/test_register.py

@@ -586,9 +586,9 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
                 "require_at_registration": True,
             },
             "account_threepid_delegates": {
+                "email": "https://id_server",
                 "msisdn": "https://id_server",
             },
-            "email": {"notif_from": "Synapse <synapse@example.com>"},
         }
     )
     def test_advertised_flows_captcha_and_terms_and_3pids(self) -> None:

tests/rest/client/test_relations.py

@@ -1060,6 +1060,7 @@ class BundledAggregationsTestCase(BaseRelationsTestCase):
                     participated, bundled_aggregations.get("current_user_participated")
                 )
                 # The latest thread event has some fields that don't matter.
+                self.assertIn("latest_event", bundled_aggregations)
                 self.assert_dict(
                     {
                         "content": {
@@ -1072,7 +1073,7 @@ class BundledAggregationsTestCase(BaseRelationsTestCase):
                         "sender": self.user2_id,
                         "type": "m.room.test",
                     },
-                    bundled_aggregations.get("latest_event"),
+                    bundled_aggregations["latest_event"],
                 )
 
             return assert_thread
@@ -1112,6 +1113,7 @@ class BundledAggregationsTestCase(BaseRelationsTestCase):
             self.assertEqual(2, bundled_aggregations.get("count"))
             self.assertTrue(bundled_aggregations.get("current_user_participated"))
             # The latest thread event has some fields that don't matter.
+            self.assertIn("latest_event", bundled_aggregations)
             self.assert_dict(
                 {
                     "content": {
@@ -1124,7 +1126,7 @@ class BundledAggregationsTestCase(BaseRelationsTestCase):
                     "sender": self.user_id,
                     "type": "m.room.test",
                 },
-                bundled_aggregations.get("latest_event"),
+                bundled_aggregations["latest_event"],
             )
             # Check the unsigned field on the latest event.
             self.assert_dict(

tests/rest/client/test_rooms.py

@@ -496,7 +496,7 @@ class RoomStateTestCase(RoomBase):
 
         self.assertEqual(HTTPStatus.OK, channel.code, msg=channel.result["body"])
         self.assertCountEqual(
-            [state_event["type"] for state_event in channel.json_body],
+            [state_event["type"] for state_event in channel.json_list],
             {
                 "m.room.create",
                 "m.room.power_levels",
@@ -2070,7 +2070,6 @@ class PublicRoomsRoomTypeFilterTestCase(unittest.HomeserverTestCase):
 
         config = self.default_config()
         config["allow_public_rooms_without_auth"] = True
-        config["experimental_features"] = {"msc3827_enabled": True}
         self.hs = self.setup_test_homeserver(config=config)
         self.url = b"/_matrix/client/r0/publicRooms"
 
@@ -2123,13 +2122,13 @@ class PublicRoomsRoomTypeFilterTestCase(unittest.HomeserverTestCase):
         chunk, count = self.make_public_rooms_request([None])
 
         self.assertEqual(count, 1)
-        self.assertEqual(chunk[0].get("org.matrix.msc3827.room_type", None), None)
+        self.assertEqual(chunk[0].get("room_type", None), None)
 
     def test_returns_only_space_based_on_filter(self) -> None:
         chunk, count = self.make_public_rooms_request(["m.space"])
 
         self.assertEqual(count, 1)
-        self.assertEqual(chunk[0].get("org.matrix.msc3827.room_type", None), "m.space")
+        self.assertEqual(chunk[0].get("room_type", None), "m.space")
 
     def test_returns_both_rooms_and_space_based_on_filter(self) -> None:
         chunk, count = self.make_public_rooms_request(["m.space", None])

tests/server.py

@@ -25,6 +25,7 @@ from typing import (
     Callable,
     Dict,
     Iterable,
+    List,
     MutableMapping,
     Optional,
     Tuple,
@@ -121,7 +122,15 @@ class FakeChannel:
 
     @property
     def json_body(self) -> JsonDict:
-        return json.loads(self.text_body)
+        body = json.loads(self.text_body)
+        assert isinstance(body, dict)
+        return body
+
+    @property
+    def json_list(self) -> List[JsonDict]:
+        body = json.loads(self.text_body)
+        assert isinstance(body, list)
+        return body
 
     @property
     def text_body(self) -> str:

tests/unittest.py

@@ -28,6 +28,7 @@ from typing import (
     Generic,
     Iterable,
     List,
+    NoReturn,
     Optional,
     Tuple,
     Type,
@@ -39,7 +40,7 @@ from unittest.mock import Mock, patch
 import canonicaljson
 import signedjson.key
 import unpaddedbase64
-from typing_extensions import Protocol
+from typing_extensions import Concatenate, ParamSpec, Protocol
 
 from twisted.internet.defer import Deferred, ensureDeferred
 from twisted.python.failure import Failure
@@ -67,7 +68,7 @@ from synapse.logging.context import (
 from synapse.rest import RegisterServletsFunc
 from synapse.server import HomeServer
 from synapse.storage.keys import FetchKeyResult
-from synapse.types import JsonDict, UserID, create_requester
+from synapse.types import JsonDict, Requester, UserID, create_requester
 from synapse.util import Clock
 from synapse.util.httpresourcetree import create_resource_tree
 
@@ -88,6 +89,10 @@ setup_logging()
 TV = TypeVar("TV")
 _ExcType = TypeVar("_ExcType", bound=BaseException, covariant=True)
 
+P = ParamSpec("P")
+R = TypeVar("R")
+S = TypeVar("S")
+
 
 class _TypedFailure(Generic[_ExcType], Protocol):
     """Extension to twisted.Failure, where the 'value' has a certain type."""
@@ -97,7 +102,7 @@ class _TypedFailure(Generic[_ExcType], Protocol):
         ...
 
 
-def around(target):
+def around(target: TV) -> Callable[[Callable[Concatenate[S, P], R]], None]:
     """A CLOS-style 'around' modifier, which wraps the original method of the
     given instance with another piece of code.
 
@@ -106,11 +111,11 @@ def around(target):
         return orig(*args, **kwargs)
     """
 
-    def _around(code):
+    def _around(code: Callable[Concatenate[S, P], R]) -> None:
         name = code.__name__
         orig = getattr(target, name)
 
-        def new(*args, **kwargs):
+        def new(*args: P.args, **kwargs: P.kwargs) -> R:
             return code(orig, *args, **kwargs)
 
         setattr(target, name, new)
@@ -131,7 +136,7 @@ class TestCase(unittest.TestCase):
         level = getattr(method, "loglevel", getattr(self, "loglevel", None))
 
         @around(self)
-        def setUp(orig):
+        def setUp(orig: Callable[[], R]) -> R:
             # if we're not starting in the sentinel logcontext, then to be honest
             # all future bets are off.
             if current_context():
@@ -144,7 +149,7 @@ class TestCase(unittest.TestCase):
             if level is not None and old_level != level:
 
                 @around(self)
-                def tearDown(orig):
+                def tearDown(orig: Callable[[], R]) -> R:
                     ret = orig()
                     logging.getLogger().setLevel(old_level)
                     return ret
@@ -158,7 +163,7 @@ class TestCase(unittest.TestCase):
             return orig()
 
         @around(self)
-        def tearDown(orig):
+        def tearDown(orig: Callable[[], R]) -> R:
             ret = orig()
             # force a GC to workaround problems with deferreds leaking logcontexts when
             # they are GCed (see the logcontext docs)
@@ -167,7 +172,7 @@ class TestCase(unittest.TestCase):
 
             return ret
 
-    def assertObjectHasAttributes(self, attrs, obj):
+    def assertObjectHasAttributes(self, attrs: Dict[str, object], obj: object) -> None:
         """Asserts that the given object has each of the attributes given, and
         that the value of each matches according to assertEqual."""
         for key in attrs.keys():
@@ -178,12 +183,12 @@ class TestCase(unittest.TestCase):
             except AssertionError as e:
                 raise (type(e))(f"Assert error for '.{key}':") from e
 
-    def assert_dict(self, required, actual):
+    def assert_dict(self, required: dict, actual: dict) -> None:
         """Does a partial assert of a dict.
 
         Args:
-            required (dict): The keys and value which MUST be in 'actual'.
-            actual (dict): The test result. Extra keys will not be checked.
+            required: The keys and value which MUST be in 'actual'.
+            actual: The test result. Extra keys will not be checked.
         """
         for key in required:
             self.assertEqual(
@@ -191,31 +196,31 @@ class TestCase(unittest.TestCase):
             )
 
 
-def DEBUG(target):
+def DEBUG(target: TV) -> TV:
     """A decorator to set the .loglevel attribute to logging.DEBUG.
     Can apply to either a TestCase or an individual test method."""
-    target.loglevel = logging.DEBUG
+    target.loglevel = logging.DEBUG  # type: ignore[attr-defined]
     return target
 
 
-def INFO(target):
+def INFO(target: TV) -> TV:
     """A decorator to set the .loglevel attribute to logging.INFO.
     Can apply to either a TestCase or an individual test method."""
-    target.loglevel = logging.INFO
+    target.loglevel = logging.INFO  # type: ignore[attr-defined]
     return target
 
 
-def logcontext_clean(target):
+def logcontext_clean(target: TV) -> TV:
     """A decorator which marks the TestCase or method as 'logcontext_clean'
 
     ... ie, any logcontext errors should cause a test failure
     """
 
-    def logcontext_error(msg):
+    def logcontext_error(msg: str) -> NoReturn:
         raise AssertionError("logcontext error: %s" % (msg))
 
     patcher = patch("synapse.logging.context.logcontext_error", new=logcontext_error)
-    return patcher(target)
+    return patcher(target)  # type: ignore[call-overload]
 
 
 class HomeserverTestCase(TestCase):
@@ -255,7 +260,7 @@ class HomeserverTestCase(TestCase):
         method = getattr(self, methodName)
         self._extra_config = getattr(method, "_extra_config", None)
 
-    def setUp(self):
+    def setUp(self) -> None:
         """
         Set up the TestCase by calling the homeserver constructor, optionally
         hijacking the authentication system to return a fixed user, and then
@@ -306,7 +311,9 @@ class HomeserverTestCase(TestCase):
                     )
                 )
 
-                async def get_user_by_access_token(token=None, allow_guest=False):
+                async def get_user_by_access_token(
+                    token: Optional[str] = None, allow_guest: bool = False
+                ) -> JsonDict:
                     assert self.helper.auth_user_id is not None
                     return {
                         "user": UserID.from_string(self.helper.auth_user_id),
@@ -314,7 +321,11 @@ class HomeserverTestCase(TestCase):
                         "is_guest": False,
                     }
 
-                async def get_user_by_req(request, allow_guest=False):
+                async def get_user_by_req(
+                    request: SynapseRequest,
+                    allow_guest: bool = False,
+                    allow_expired: bool = False,
+                ) -> Requester:
                     assert self.helper.auth_user_id is not None
                     return create_requester(
                         UserID.from_string(self.helper.auth_user_id),
@@ -339,11 +350,11 @@ class HomeserverTestCase(TestCase):
         if hasattr(self, "prepare"):
             self.prepare(self.reactor, self.clock, self.hs)
 
-    def tearDown(self):
+    def tearDown(self) -> None:
         # Reset to not use frozen dicts.
         events.USE_FROZEN_DICTS = False
 
-    def wait_on_thread(self, deferred, timeout=10):
+    def wait_on_thread(self, deferred: Deferred, timeout: int = 10) -> None:
         """
         Wait until a Deferred is done, where it's waiting on a real thread.
         """
@@ -374,7 +385,7 @@ class HomeserverTestCase(TestCase):
             clock (synapse.util.Clock): The Clock, associated with the reactor.
 
         Returns:
-            A homeserver (synapse.server.HomeServer) suitable for testing.
+            A homeserver suitable for testing.
 
         Function to be overridden in subclasses.
         """
@@ -408,7 +419,7 @@ class HomeserverTestCase(TestCase):
             "/_synapse/admin": servlet_resource,
         }
 
-    def default_config(self):
+    def default_config(self) -> JsonDict:
         """
         Get a default HomeServer config dict.
         """
@@ -421,7 +432,9 @@ class HomeserverTestCase(TestCase):
 
         return config
 
-    def prepare(self, reactor: MemoryReactor, clock: Clock, homeserver: HomeServer):
+    def prepare(
+        self, reactor: MemoryReactor, clock: Clock, homeserver: HomeServer
+    ) -> None:
         """
         Prepare for the test.  This involves things like mocking out parts of
         the homeserver, or building test data common across the whole test
@@ -519,7 +532,7 @@ class HomeserverTestCase(TestCase):
         config_obj.parse_config_dict(config, "", "")
         kwargs["config"] = config_obj
 
-        async def run_bg_updates():
+        async def run_bg_updates() -> None:
             with LoggingContext("run_bg_updates"):
                 self.get_success(stor.db_pool.updates.run_background_updates(False))
 
@@ -538,11 +551,7 @@ class HomeserverTestCase(TestCase):
         """
         self.reactor.pump([by] * 100)
 
-    def get_success(
-        self,
-        d: Awaitable[TV],
-        by: float = 0.0,
-    ) -> TV:
+    def get_success(self, d: Awaitable[TV], by: float = 0.0) -> TV:
         deferred: Deferred[TV] = ensureDeferred(d)  # type: ignore[arg-type]
         self.pump(by=by)
         return self.successResultOf(deferred)
@@ -755,7 +764,7 @@ class FederatingHomeserverTestCase(HomeserverTestCase):
     OTHER_SERVER_NAME = "other.example.com"
     OTHER_SERVER_SIGNATURE_KEY = signedjson.key.generate_signing_key("test")
 
-    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer):
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
         super().prepare(reactor, clock, hs)
 
         # poke the other server's signing key into the key store, so that we don't
@@ -879,7 +888,7 @@ def _auth_header_for_request(
     )
 
 
-def override_config(extra_config):
+def override_config(extra_config: JsonDict) -> Callable[[TV], TV]:
     """A decorator which can be applied to test functions to give additional HS config
 
     For use
@@ -892,12 +901,13 @@ def override_config(extra_config):
                 ...
 
     Args:
-        extra_config(dict): Additional config settings to be merged into the default
+        extra_config: Additional config settings to be merged into the default
             config dict before instantiating the test homeserver.
     """
 
-    def decorator(func):
-        func._extra_config = extra_config
+    def decorator(func: TV) -> TV:
+        # This attribute is being defined.
+        func._extra_config = extra_config  # type: ignore[attr-defined]
         return func
 
     return decorator