WIP: MAS in complement

Sliding Sync: Add typing notification extension (MSC3961) (#17505 )
[MSC3961](https://github.com/matrix-org/matrix-spec-proposals/pull/3961): Sliding Sync Extension: Typing Notifications Based on [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575): Sliding Sync
2024-08-05 17:30:40 +02:00 · 2024-07-31 13:20:23 -05:00 · 2024-07-31 12:20:46 -05:00 · 2024-07-31 11:47:26 -05:00 · 2024-07-30 13:20:29 -05:00 · 2024-07-30 12:49:55 -05:00
152 changed files with 20123 additions and 2265 deletions
@@ -21,6 +21,7 @@ jobs:
      trial: ${{ !startsWith(github.ref, 'refs/pull/') || steps.filter.outputs.trial }}
      integration: ${{ !startsWith(github.ref, 'refs/pull/') || steps.filter.outputs.integration }}
      linting: ${{ !startsWith(github.ref, 'refs/pull/') || steps.filter.outputs.linting }}
+      linting_readme: ${{ !startsWith(github.ref, 'refs/pull/') || steps.filter.outputs.linting_readme }}
    steps:
    - uses: dorny/paths-filter@v3
      id: filter
@@ -73,6 +74,9 @@ jobs:
            - 'poetry.lock'
            - '.github/workflows/tests.yml'

+          linting_readme:
+            - 'README.rst'
+
  check-sampleconfig:
    runs-on: ubuntu-latest
    needs: changes
@@ -135,7 +139,7 @@ jobs:

      - name: Semantic checks (ruff)
        # --quiet suppresses the update check.
-        run: poetry run ruff --quiet .
+        run: poetry run ruff check --quiet .

  lint-mypy:
    runs-on: ubuntu-latest
@@ -269,6 +273,20 @@ jobs:

      - run: cargo fmt --check

+  # This is to detect issues with the rst file, which can otherwise cause issues
+  # when uploading packages to PyPi.
+  lint-readme:
+    runs-on: ubuntu-latest
+    needs: changes
+    if: ${{ needs.changes.outputs.linting_readme == 'true' }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.x"
+      - run: "pip install rstcheck"
+      - run: "rstcheck --report-level=WARNING README.rst"
+
  # Dummy step to gate other tests on without repeating the whole list
  linting-done:
    if: ${{ !cancelled() }} # Run this even if prior jobs were skipped
@@ -284,9 +302,10 @@ jobs:
      - lint-clippy
      - lint-clippy-nightly
      - lint-rustfmt
+      - lint-readme
    runs-on: ubuntu-latest
    steps:
-      - uses: matrix-org/done-action@v2
+      - uses: matrix-org/done-action@v3
        with:
          needs: ${{ toJSON(needs) }}

@@ -301,6 +320,7 @@ jobs:
            lint-clippy
            lint-clippy-nightly
            lint-rustfmt
+            lint-readme


  calculate-test-jobs:
@@ -717,7 +737,7 @@ jobs:
      - linting-done
    runs-on: ubuntu-latest
    steps:
-      - uses: matrix-org/done-action@v2
+      - uses: matrix-org/done-action@v3
        with:
          needs: ${{ toJSON(needs) }}

@@ -1,3 +1,184 @@
+# Synapse 1.112.0 (2024-07-30)
+
+This security release is to update our locked dependency on Twisted to 24.7.0rc1, which includes a security fix for [CVE-2024-41671 / GHSA-c8m8-j448-xjx7: Disordered HTTP pipeline response in twisted.web, again](https://github.com/twisted/twisted/security/advisories/GHSA-c8m8-j448-xjx7).
+
+Note that this security fix is also available as **Synapse 1.111.1**, which does not include the rest of the changes in Synapse 1.112.0.
+
+This issue means that, if multiple HTTP requests are pipelined in the same TCP connection, Synapse can send responses to the wrong HTTP request.
+If a reverse proxy was configured to use HTTP pipelining, this could result in responses being sent to the wrong user, severely harming confidentiality.
+
+With that said, despite being a high severity issue, **we consider it unlikely that Synapse installations will be affected**.
+The use of HTTP pipelining in this fashion would cause worse performance for clients (request-response latencies would be increased as users' responses would be artificially blocked behind other users' slow requests). Further, Nginx and Haproxy, two common reverse proxies, do not appear to support configuring their upstreams to use HTTP pipelining and thus would not be affected. For both of these reasons, we consider it unlikely that a Synapse deployment would be set up in such a configuration.
+
+Despite that, we cannot rule out that some installations may exist with this unusual setup and so we are releasing this security update today.
+
+**pip users:** Note that by default, upgrading Synapse using pip will not automatically upgrade Twisted. **Please manually install the new version of Twisted** using `pip install Twisted==24.7.0rc1`. Note also that even the `--upgrade-strategy=eager` flag to `pip install -U matrix-synapse` will not upgrade Twisted to a patched version because it is only a release candidate at this time.
+
+### Internal Changes
+
+- Upgrade locked dependency on Twisted to 24.7.0rc1. ([\#17502](https://github.com/element-hq/synapse/issues/17502))
+
+
+# Synapse 1.112.0rc1 (2024-07-23)
+
+Please note that this release candidate does not include the security dependency update
+included in version 1.111.1 as this version was released before 1.111.1.
+The same security fix can be found in the full release of 1.112.0.
+
+### Features
+
+- Add to-device extension support to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17416](https://github.com/element-hq/synapse/issues/17416))
+- Populate `name`/`avatar` fields in experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17418](https://github.com/element-hq/synapse/issues/17418))
+- Populate `heroes` and room summary fields (`joined_count`, `invited_count`) in experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17419](https://github.com/element-hq/synapse/issues/17419))
+- Populate `is_dm` room field in experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17429](https://github.com/element-hq/synapse/issues/17429))
+- Add room subscriptions to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17432](https://github.com/element-hq/synapse/issues/17432))
+- Prepare for authenticated media freeze. ([\#17433](https://github.com/element-hq/synapse/issues/17433))
+- Add E2EE extension support to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17454](https://github.com/element-hq/synapse/issues/17454))
+
+### Bugfixes
+
+- Add configurable option to always include offline users in presence sync results. Contributed by @Michael-Hollister. ([\#17231](https://github.com/element-hq/synapse/issues/17231))
+- Fix bug in experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint when using room type filters and the user has one or more remote invites. ([\#17434](https://github.com/element-hq/synapse/issues/17434))
+- Order `heroes` by `stream_ordering` as the Matrix specification states (applies to `/sync`). ([\#17435](https://github.com/element-hq/synapse/issues/17435))
+- Fix rare bug where `/sync` would break for a user when using workers with multiple stream writers. ([\#17438](https://github.com/element-hq/synapse/issues/17438))
+
+### Improved Documentation
+
+- Update the readme image to have a white background, so that it is readable in dark mode. ([\#17387](https://github.com/element-hq/synapse/issues/17387))
+- Add Red Hat Enterprise Linux and Rocky Linux 8 and 9 installation instructions. ([\#17423](https://github.com/element-hq/synapse/issues/17423))
+- Improve documentation for the [`default_power_level_content_override`](https://element-hq.github.io/synapse/latest/usage/configuration/config_documentation.html#default_power_level_content_override) config option. ([\#17451](https://github.com/element-hq/synapse/issues/17451))
+
+### Internal Changes
+
+- Make sure we always use the right logic for enabling the media repo. ([\#17424](https://github.com/element-hq/synapse/issues/17424))
+- Fix argument documentation for method `RateLimiter.record_action`. ([\#17426](https://github.com/element-hq/synapse/issues/17426))
+- Reduce volume of 'Waiting for current token' logs, which were introduced in v1.109.0. ([\#17428](https://github.com/element-hq/synapse/issues/17428))
+- Limit concurrent remote downloads to 6 per IP address, and decrement remote downloads without a content-length from the ratelimiter after the download is complete. ([\#17439](https://github.com/element-hq/synapse/issues/17439))
+- Remove unnecessary call to resume producing in fake channel. ([\#17449](https://github.com/element-hq/synapse/issues/17449))
+- Update experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint to bump room when it is created. ([\#17453](https://github.com/element-hq/synapse/issues/17453))
+- Speed up generating sliding sync responses. ([\#17458](https://github.com/element-hq/synapse/issues/17458))
+- Add cache to `get_rooms_for_local_user_where_membership_is` to speed up sliding sync. ([\#17460](https://github.com/element-hq/synapse/issues/17460))
+- Speed up fetching room keys from backup. ([\#17461](https://github.com/element-hq/synapse/issues/17461))
+- Speed up sorting of the room list in sliding sync. ([\#17468](https://github.com/element-hq/synapse/issues/17468))
+- Implement handling of `$ME` as a state key in sliding sync. ([\#17469](https://github.com/element-hq/synapse/issues/17469))
+
+
+
+### Updates to locked dependencies
+
+* Bump bytes from 1.6.0 to 1.6.1. ([\#17441](https://github.com/element-hq/synapse/issues/17441))
+* Bump hiredis from 2.3.2 to 3.0.0. ([\#17464](https://github.com/element-hq/synapse/issues/17464))
+* Bump jsonschema from 4.22.0 to 4.23.0. ([\#17444](https://github.com/element-hq/synapse/issues/17444))
+* Bump matrix-org/done-action from 2 to 3. ([\#17440](https://github.com/element-hq/synapse/issues/17440))
+* Bump mypy from 1.9.0 to 1.10.1. ([\#17445](https://github.com/element-hq/synapse/issues/17445))
+* Bump pyopenssl from 24.1.0 to 24.2.1. ([\#17465](https://github.com/element-hq/synapse/issues/17465))
+* Bump ruff from 0.5.0 to 0.5.4. ([\#17466](https://github.com/element-hq/synapse/issues/17466))
+* Bump sentry-sdk from 2.6.0 to 2.8.0. ([\#17456](https://github.com/element-hq/synapse/issues/17456))
+* Bump sentry-sdk from 2.8.0 to 2.10.0. ([\#17467](https://github.com/element-hq/synapse/issues/17467))
+* Bump setuptools from 67.6.0 to 70.0.0. ([\#17448](https://github.com/element-hq/synapse/issues/17448))
+* Bump twine from 5.1.0 to 5.1.1. ([\#17443](https://github.com/element-hq/synapse/issues/17443))
+* Bump types-jsonschema from 4.22.0.20240610 to 4.23.0.20240712. ([\#17446](https://github.com/element-hq/synapse/issues/17446))
+* Bump ulid from 1.1.2 to 1.1.3. ([\#17442](https://github.com/element-hq/synapse/issues/17442))
+* Bump zipp from 3.15.0 to 3.19.1. ([\#17427](https://github.com/element-hq/synapse/issues/17427))
+
+
+# Synapse 1.111.1 (2024-07-30)
+
+This security release is to update our locked dependency on Twisted to 24.7.0rc1, which includes a security fix for [CVE-2024-41671 / GHSA-c8m8-j448-xjx7: Disordered HTTP pipeline response in twisted.web, again](https://github.com/twisted/twisted/security/advisories/GHSA-c8m8-j448-xjx7).
+
+This issue means that, if multiple HTTP requests are pipelined in the same TCP connection, Synapse can send responses to the wrong HTTP request.
+If a reverse proxy was configured to use HTTP pipelining, this could result in responses being sent to the wrong user, severely harming confidentiality.
+
+With that said, despite being a high severity issue, **we consider it unlikely that Synapse installations will be affected**.
+The use of HTTP pipelining in this fashion would cause worse performance for clients (request-response latencies would be increased as users' responses would be artificially blocked behind other users' slow requests). Further, Nginx and Haproxy, two common reverse proxies, do not appear to support configuring their upstreams to use HTTP pipelining and thus would not be affected. For both of these reasons, we consider it unlikely that a Synapse deployment would be set up in such a configuration.
+
+Despite that, we cannot rule out that some installations may exist with this unusual setup and so we are releasing this security update today.
+
+**pip users:** Note that by default, upgrading Synapse using pip will not automatically upgrade Twisted. **Please manually install the new version of Twisted** using `pip install Twisted==24.7.0rc1`. Note also that even the `--upgrade-strategy=eager` flag to `pip install -U matrix-synapse` will not upgrade Twisted to a patched version because it is only a release candidate at this time.
+
+
+### Internal Changes
+
+- Upgrade locked dependency on Twisted to 24.7.0rc1. ([\#17502](https://github.com/element-hq/synapse/issues/17502))
+
+
+# Synapse 1.111.0 (2024-07-16)
+
+No significant changes since 1.111.0rc2.
+
+
+
+
+# Synapse 1.111.0rc2 (2024-07-10)
+
+### Bugfixes
+
+- Fix bug where using `synapse.app.media_repository` worker configuration would break the new media endpoints. ([\#17420](https://github.com/element-hq/synapse/issues/17420))
+
+### Improved Documentation
+
+- Document the new federation media worker endpoints in the [upgrade notes](https://element-hq.github.io/synapse/v1.111/upgrade.html) and [worker docs](https://element-hq.github.io/synapse/v1.111/workers.html). ([\#17421](https://github.com/element-hq/synapse/issues/17421))
+
+### Internal Changes
+
+- Route authenticated federation media requests to media repository workers in Complement tests. ([\#17422](https://github.com/element-hq/synapse/issues/17422))
+
+
+
+
+# Synapse 1.111.0rc1 (2024-07-09)
+
+### Features
+
+- Add `rooms` data to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17320](https://github.com/element-hq/synapse/issues/17320))
+- Add `room_types`/`not_room_types` filtering to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17337](https://github.com/element-hq/synapse/issues/17337))
+- Return "required state" in experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17342](https://github.com/element-hq/synapse/issues/17342))
+- Support [MSC3916](https://github.com/matrix-org/matrix-spec-proposals/blob/main/proposals/3916-authentication-for-media.md) by adding [`_matrix/client/v1/media/download`](https://spec.matrix.org/v1.11/client-server-api/#get_matrixclientv1mediadownloadservernamemediaid) endpoint. ([\#17365](https://github.com/element-hq/synapse/issues/17365))
+- Support [MSC3916](https://github.com/matrix-org/matrix-spec-proposals/blob/rav/authentication-for-media/proposals/3916-authentication-for-media.md)
+  by adding [`_matrix/client/v1/media/thumbnail`](https://spec.matrix.org/v1.11/client-server-api/#get_matrixclientv1mediathumbnailservernamemediaid), [`_matrix/federation/v1/media/thumbnail`](https://spec.matrix.org/v1.11/server-server-api/#get_matrixfederationv1mediathumbnailmediaid) endpoints and stabilizing the
+  remaining [`_matrix/client/v1/media`](https://spec.matrix.org/v1.11/client-server-api/#get_matrixclientv1mediaconfig) endpoints. ([\#17388](https://github.com/element-hq/synapse/issues/17388))
+- Add `rooms.bump_stamp` for easier client-side sorting in experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17395](https://github.com/element-hq/synapse/issues/17395))
+- Forget all of a user's rooms upon deactivation, preventing local room purges from being blocked on deactivated users. ([\#17400](https://github.com/element-hq/synapse/issues/17400))
+- Declare support for [Matrix 1.11](https://matrix.org/blog/2024/06/20/matrix-v1.11-release/). ([\#17403](https://github.com/element-hq/synapse/issues/17403))
+- [MSC3861](https://github.com/matrix-org/matrix-spec-proposals/pull/3861): allow overriding the introspection endpoint. ([\#17406](https://github.com/element-hq/synapse/issues/17406))
+
+### Bugfixes
+
+- Fix rare race which caused no new to-device messages to be received from remote server. ([\#17362](https://github.com/element-hq/synapse/issues/17362))
+- Fix bug in experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint when using an old database. ([\#17398](https://github.com/element-hq/synapse/issues/17398))
+
+### Improved Documentation
+
+- Clarify that `url_preview_url_blacklist` is a usability feature. ([\#17356](https://github.com/element-hq/synapse/issues/17356))
+- Fix broken links in README. ([\#17379](https://github.com/element-hq/synapse/issues/17379))
+- Clarify that changelog content *and file extension* need to match in order for entries to merge. ([\#17399](https://github.com/element-hq/synapse/issues/17399))
+
+### Internal Changes
+
+- Make the release script create a release branch for Complement as well. ([\#17318](https://github.com/element-hq/synapse/issues/17318))
+- Fix uploading packages to PyPi. ([\#17363](https://github.com/element-hq/synapse/issues/17363))
+- Add CI check for the README. ([\#17367](https://github.com/element-hq/synapse/issues/17367))
+- Fix linting errors from new `ruff` version. ([\#17381](https://github.com/element-hq/synapse/issues/17381), [\#17411](https://github.com/element-hq/synapse/issues/17411))
+- Fix building debian packages on non-clean checkouts. ([\#17390](https://github.com/element-hq/synapse/issues/17390))
+- Finish up work to allow per-user feature flags. ([\#17392](https://github.com/element-hq/synapse/issues/17392), [\#17410](https://github.com/element-hq/synapse/issues/17410))
+- Allow enabling sliding sync per-user. ([\#17393](https://github.com/element-hq/synapse/issues/17393))
+
+
+
+### Updates to locked dependencies
+
+* Bump certifi from 2023.7.22 to 2024.7.4. ([\#17404](https://github.com/element-hq/synapse/issues/17404))
+* Bump cryptography from 42.0.7 to 42.0.8. ([\#17382](https://github.com/element-hq/synapse/issues/17382))
+* Bump ijson from 3.2.3 to 3.3.0. ([\#17413](https://github.com/element-hq/synapse/issues/17413))
+* Bump log from 0.4.21 to 0.4.22. ([\#17384](https://github.com/element-hq/synapse/issues/17384))
+* Bump mypy-zope from 1.0.4 to 1.0.5. ([\#17414](https://github.com/element-hq/synapse/issues/17414))
+* Bump pillow from 10.3.0 to 10.4.0. ([\#17412](https://github.com/element-hq/synapse/issues/17412))
+* Bump pydantic from 2.7.1 to 2.8.2. ([\#17415](https://github.com/element-hq/synapse/issues/17415))
+* Bump ruff from 0.3.7 to 0.5.0. ([\#17381](https://github.com/element-hq/synapse/issues/17381))
+* Bump serde from 1.0.203 to 1.0.204. ([\#17409](https://github.com/element-hq/synapse/issues/17409))
+* Bump serde_json from 1.0.117 to 1.0.120. ([\#17385](https://github.com/element-hq/synapse/issues/17385), [\#17408](https://github.com/element-hq/synapse/issues/17408))
+* Bump types-setuptools from 69.5.0.20240423 to 70.1.0.20240627. ([\#17380](https://github.com/element-hq/synapse/issues/17380))
+
 # Synapse 1.110.0 (2024-07-03)

 No significant changes since 1.110.0rc3.
@@ -48,7 +229,7 @@ No significant changes since 1.110.0rc3.
  This is useful for scripts that bootstrap user accounts with initial passwords. ([\#17304](https://github.com/element-hq/synapse/issues/17304))
 - Add support for via query parameter from [MSC4156](https://github.com/matrix-org/matrix-spec-proposals/pull/4156). ([\#17322](https://github.com/element-hq/synapse/issues/17322))
 - Add `is_invite` filtering to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17335](https://github.com/element-hq/synapse/issues/17335))
- Support [MSC3916](https://github.com/matrix-org/matrix-spec-proposals/blob/rav/authentication-for-media/proposals/3916-authentication-for-media.md) by adding a federation /download endpoint. ([\#17350](https://github.com/element-hq/synapse/issues/17350))
+- Support [MSC3916](https://github.com/matrix-org/matrix-spec-proposals/blob/main/proposals/3916-authentication-for-media.md) by adding a federation /download endpoint. ([\#17350](https://github.com/element-hq/synapse/issues/17350))

 ### Bugfixes

@@ -67,9 +67,9 @@ checksum = "79296716171880943b8470b5f8d03aa55eb2e645a4874bdbb28adb49162e012c"

 [[package]]
 name = "bytes"
-version = "1.6.0"
+version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "514de17de45fdb8dc022b1a7975556c53c86f9f0aa5f534b98977b171857c2c9"
+checksum = "a12916984aab3fa6e39d655a33e09c0071eb36d6ab3aea5c2d78551f1df6d952"

 [[package]]
 name = "cfg-if"
@@ -234,9 +234,9 @@ dependencies = [

 [[package]]
 name = "log"
-version = "0.4.21"
+version = "0.4.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90ed8c1e510134f979dbc4f070f87d4313098b704861a105fe34231c70a3901c"
+checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"

 [[package]]
 name = "memchr"
@@ -485,18 +485,18 @@ checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"

 [[package]]
 name = "serde"
-version = "1.0.203"
+version = "1.0.204"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7253ab4de971e72fb7be983802300c30b5a7f0c2e56fab8abfc6a214307c0094"
+checksum = "bc76f558e0cbb2a839d37354c575f1dc3fdc6546b5be373ba43d95f231bf7c12"
 dependencies = [
 "serde_derive",
 ]

 [[package]]
 name = "serde_derive"
-version = "1.0.203"
+version = "1.0.204"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "500cbc0ebeb6f46627f50f3f5811ccf6bf00643be300b4c3eabc0ef55dc5b5ba"
+checksum = "e0cd7e117be63d3c3678776753929474f3b04a43a080c744d6b0ae2a8c28e222"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -505,11 +505,12 @@ dependencies = [

 [[package]]
 name = "serde_json"
-version = "1.0.117"
+version = "1.0.121"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "455182ea6142b14f93f4bc5320a2b31c1f266b66a4a5c858b013302a5d8cbfc3"
+checksum = "4ab380d7d9f22ef3f21ad3e6c1ebe8e4fc7a2000ccba2e4d71fc96f15b2cb609"
 dependencies = [
 "itoa",
+ "memchr",
 "ryu",
 "serde",
 ]
@@ -597,9 +598,9 @@ checksum = "42ff0bf0c66b8238c6f3b578df37d0b7848e55df8577b3f74f92a69acceeb825"

 [[package]]
 name = "ulid"
-version = "1.1.2"
+version = "1.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34778c17965aa2a08913b57e1f34db9b4a63f5de31768b55bf20d2795f921259"
+checksum = "04f903f293d11f31c0c29e4148f6dc0d033a7f80cebc0282bea147611667d289"
 dependencies = [
 "getrandom",
 "rand",
@@ -1,4 +1,4 @@
-.. image:: https://github.com/element-hq/product/assets/87339233/7abf477a-5277-47f3-be44-ea44917d8ed7
+.. image:: ./docs/element_logo_white_bg.svg
   :height: 60px

 **Element Synapse - Matrix homeserver implementation**
@@ -179,10 +179,10 @@ desired ``localpart`` in the 'User name' box.
 -----------------------

 Enterprise quality support for Synapse including SLAs is available as part of an
-`Element Server Suite (ESS) <https://element.io/pricing>` subscription.
+`Element Server Suite (ESS) <https://element.io/pricing>`_ subscription.

-If you are an existing ESS subscriber then you can raise a `support request <https://ems.element.io/support>`
-and access the `knowledge base <https://ems-docs.element.io>`.
+If you are an existing ESS subscriber then you can raise a `support request <https://ems.element.io/support>`_
+and access the `knowledge base <https://ems-docs.element.io>`_.

 🤝 Community support
 --------------------
@@ -0,0 +1 @@
+Track which rooms have been sent to clients in the experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint.
@@ -0,0 +1 @@
+Update experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint to handle invite/knock rooms when filtering.
@@ -0,0 +1 @@
+Change sliding sync to use their own token format in preparation for storing per-connection state.
@@ -0,0 +1 @@
+Update the [`allowed_local_3pids`](https://element-hq.github.io/synapse/v1.112/usage/configuration/config_documentation.html#allowed_local_3pids) config option's msisdn address to a working example.
@@ -0,0 +1 @@
+Add Account Data extension support to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint.
@@ -0,0 +1 @@
+Ensure we don't send down negative `bump_stamp` in experimental sliding sync endpoint.
@@ -0,0 +1 @@
+Do not send down empty room entries down experimental sliding sync endpoint.
@@ -0,0 +1 @@
+Refactor Sliding Sync tests to better utilize the `SlidingSyncBase`.
@@ -0,0 +1 @@
+Refactor Sliding Sync tests to better utilize the `SlidingSyncBase`.
@@ -0,0 +1 @@
+Add receipts extension support to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint.
@@ -0,0 +1 @@
+Fix a bug introduced in v1.110.0 which caused `/keys/query` to return incomplete results, leading to high network activity and CPU usage on Matrix clients.
@@ -0,0 +1 @@
+Add some opentracing tags and logging to the experimental sliding sync implementation.
@@ -0,0 +1 @@
+Split and move Sliding Sync tests so we have some more sane test file sizes.
@@ -0,0 +1 @@
+Add typing notification extension support to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint.
@@ -0,0 +1 @@
+Update the `limited` field description in the Sliding Sync response to accurately describe what it actually represents.
@@ -1,3 +1,39 @@
+matrix-synapse-py3 (1.112.0) stable; urgency=medium
+
+  * New Synapse release 1.112.0.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 30 Jul 2024 17:15:48 +0100
+
+matrix-synapse-py3 (1.112.0~rc1) stable; urgency=medium
+
+  * New Synapse release 1.112.0rc1.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 23 Jul 2024 08:58:55 -0600
+
+matrix-synapse-py3 (1.111.1) stable; urgency=medium
+
+  * New Synapse release 1.111.1.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 30 Jul 2024 16:13:52 +0100
+
+matrix-synapse-py3 (1.111.0) stable; urgency=medium
+
+  * New Synapse release 1.111.0.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 16 Jul 2024 12:42:46 +0200
+
+matrix-synapse-py3 (1.111.0~rc2) stable; urgency=medium
+
+  * New synapse release 1.111.0rc2.
+
+ -- Synapse Packaging team <packages@matrix.org>  Wed, 10 Jul 2024 08:46:54 +0000
+
+matrix-synapse-py3 (1.111.0~rc1) stable; urgency=medium
+
+  * New synapse release 1.111.0rc1.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 09 Jul 2024 09:49:25 +0000
+
 matrix-synapse-py3 (1.110.0) stable; urgency=medium

  * New Synapse release 1.110.0.
@@ -5,7 +5,7 @@ _Description: Name of the server:
 servers via federation. This is normally the public hostname of the
 server running synapse, but can be different if you set up delegation.
 Please refer to the delegation documentation in this case:
- https://github.com/element-hq/synapse/blob/master/docs/delegate.md.
+ https://element-hq.github.io/synapse/latest/delegate.html.

 Template: matrix-synapse/report-stats
 Type: boolean
@@ -27,7 +27,7 @@ ARG PYTHON_VERSION=3.11
 ###
 # We hardcode the use of Debian bookworm here because this could change upstream
 # and other Dockerfiles used for testing are expecting bookworm.
-FROM docker.io/library/python:${PYTHON_VERSION}-slim-bookworm as requirements
+FROM docker.io/library/python:${PYTHON_VERSION}-slim-bookworm AS requirements

 # RUN --mount is specific to buildkit and is documented at
 # https://github.com/moby/buildkit/blob/master/frontend/dockerfile/docs/syntax.md#build-mounts-run---mount.
@@ -87,7 +87,7 @@ RUN if [ -z "$TEST_ONLY_IGNORE_POETRY_LOCKFILE" ]; then \
 ###
 ### Stage 1: builder
 ###
-FROM docker.io/library/python:${PYTHON_VERSION}-slim-bookworm as builder
+FROM docker.io/library/python:${PYTHON_VERSION}-slim-bookworm AS builder

 # install the OS build deps
 RUN \
@@ -24,7 +24,7 @@ ARG distro=""
 # https://launchpad.net/~jyrki-pulliainen/+archive/ubuntu/dh-virtualenv, but
 # it's not obviously easier to use that than to build our own.)

-FROM docker.io/library/${distro} as builder
+FROM docker.io/library/${distro} AS builder

 RUN apt-get update -qq -o Acquire::Languages=none
 RUN env DEBIAN_FRONTEND=noninteractive apt-get install \
@@ -1,67 +1,62 @@
 # syntax=docker/dockerfile:1

 ARG SYNAPSE_VERSION=latest
-ARG FROM=matrixdotorg/synapse:$SYNAPSE_VERSION
+ARG SYNAPSE_IMAGE=docker.io/matrixdotorg/synapse:$SYNAPSE_VERSION

-# first of all, we create a base image with an nginx which we can copy into the
-# target image. For repeated rebuilds, this is much faster than apt installing
-# each time.
+ARG MAS_VERSION=latest
+ARG MAS_IMAGE=ghcr.io/matrix-org/matrix-authentication-service:$MAS_VERSION

-FROM docker.io/library/debian:bookworm-slim AS deps_base
-    RUN \
-       --mount=type=cache,target=/var/cache/apt,sharing=locked \
-       --mount=type=cache,target=/var/lib/apt,sharing=locked \
-      apt-get update -qq && \
-      DEBIAN_FRONTEND=noninteractive apt-get install -yqq --no-install-recommends \
-          redis-server nginx-light
+ARG REDIS_VERSION=7.4.0
+ARG REDIS_IMAGE=docker.io/library/redis:$REDIS_VERSION-bookworm

-# Similarly, a base to copy the redis server from.
-#
-# The redis docker image has fewer dynamic libraries than the debian package,
-# which makes it much easier to copy (but we need to make sure we use an image
-# based on the same debian version as the synapse image, to make sure we get
-# the expected version of libc.
-FROM docker.io/library/redis:7-bookworm AS redis_base
+ARG NGINX_VERSION=1.26.1
+ARG NGINX_IMAGE=docker.io/library/nginx:$NGINX_VERSION-bookworm
+
+FROM $NGINX_IMAGE AS nginx
+FROM $REDIS_IMAGE AS redis
+FROM $MAS_IMAGE AS mas

 # now build the final image, based on the the regular Synapse docker image
-FROM $FROM
+FROM $SYNAPSE_IMAGE

-    # Install supervisord with pip instead of apt, to avoid installing a second
-    # copy of python.
-    RUN --mount=type=cache,target=/root/.cache/pip \
-        pip install supervisor~=4.2
-    RUN mkdir -p /etc/supervisor/conf.d
+# Install supervisord with pip instead of apt, to avoid installing a second
+# copy of python.
+RUN --mount=type=cache,target=/root/.cache/pip \
+    pip install supervisor~=4.2
+RUN mkdir -p /etc/supervisor/conf.d

-    # Copy over redis and nginx
-    COPY --from=redis_base /usr/local/bin/redis-server /usr/local/bin
+# Copy over redis, nginx and matrix-authentication-service
+COPY --from=redis /usr/local/bin/redis-server /usr/local/bin

-    COPY --from=deps_base /usr/sbin/nginx /usr/sbin
-    COPY --from=deps_base /usr/share/nginx /usr/share/nginx
-    COPY --from=deps_base /usr/lib/nginx /usr/lib/nginx
-    COPY --from=deps_base /etc/nginx /etc/nginx
-    RUN rm /etc/nginx/sites-enabled/default
-    RUN mkdir /var/log/nginx /var/lib/nginx
-    RUN chown www-data /var/lib/nginx
+COPY --from=nginx /usr/sbin/nginx /usr/sbin
+COPY --from=nginx /usr/share/nginx /usr/share/nginx
+COPY --from=nginx /usr/lib/nginx /usr/lib/nginx
+COPY --from=nginx /etc/nginx /etc/nginx
+RUN mkdir /var/log/nginx /var/lib/nginx
+RUN chown www-data /var/lib/nginx

-    # have nginx log to stderr/out
-    RUN ln -sf /dev/stdout /var/log/nginx/access.log
-    RUN ln -sf /dev/stderr /var/log/nginx/error.log
+# have nginx log to stderr/out
+RUN ln -sf /dev/stdout /var/log/nginx/access.log
+RUN ln -sf /dev/stderr /var/log/nginx/error.log

-    # Copy Synapse worker, nginx and supervisord configuration template files
-    COPY ./docker/conf-workers/* /conf/
+COPY --from=mas /usr/local/bin/mas-cli /usr/local/bin
+COPY --from=mas /usr/local/share/mas-cli /usr/local/share

-    # Copy a script to prefix log lines with the supervisor program name
-    COPY ./docker/prefix-log /usr/local/bin/
+# Copy Synapse worker, nginx and supervisord configuration template files
+COPY ./docker/conf-workers/* /conf/

-    # Expose nginx listener port
-    EXPOSE 8080/tcp
+# Copy a script to prefix log lines with the supervisor program name
+COPY ./docker/prefix-log /usr/local/bin/

-    # A script to read environment variables and create the necessary
-    # files to run the desired worker configuration. Will start supervisord.
-    COPY ./docker/configure_workers_and_start.py /configure_workers_and_start.py
-    ENTRYPOINT ["/configure_workers_and_start.py"]
+# Expose nginx listener port
+EXPOSE 8080/tcp

-    # Replace the healthcheck with one which checks *all* the workers. The script
-    # is generated by configure_workers_and_start.py.
-    HEALTHCHECK --start-period=5s --interval=15s --timeout=5s \
-        CMD /bin/sh /healthcheck.sh
+# A script to read environment variables and create the necessary
+# files to run the desired worker configuration. Will start supervisord.
+COPY ./docker/configure_workers_and_start.py /configure_workers_and_start.py
+ENTRYPOINT ["/configure_workers_and_start.py"]
+
+# Replace the healthcheck with one which checks *all* the workers. The script
+# is generated by configure_workers_and_start.py.
+HEALTHCHECK --start-period=5s --interval=15s --timeout=5s \
+    CMD /bin/sh /healthcheck.sh
@@ -11,6 +11,9 @@ DIST=$(cut -d ':' -f2 <<< "${distro:?}")
 cp -aT /synapse/source /synapse/build
 cd /synapse/build

+# Delete any existing `.so` files to ensure a clean build.
+rm -f /synapse/build/synapse/*.so
+
 # if this is a prerelease, set the Section accordingly.
 #
 # When the package is later added to the package repo, reprepro will use the
@@ -6,11 +6,17 @@
 # Instructions for building this image from those it depends on is detailed in this guide:
 # https://github.com/element-hq/synapse/blob/develop/docker/README-testing.md#testing-with-postgresql-and-single-or-multi-process-synapse

-ARG SYNAPSE_VERSION=latest
 # This is an intermediate image, to be built locally (not pulled from a registry).
-ARG FROM=matrixdotorg/synapse-workers:$SYNAPSE_VERSION
+ARG SYNAPSE_WORKERS_IMAGE=synapse-workers
+
+ARG POSTGRES_VERSION=13
+ARG POSTGRES_IMAGE=docker.io/library/postgres:$POSTGRES_VERSION-bookworm
+
+# Save the Postgres image for later
+FROM $POSTGRES_IMAGE AS postgres
+
+FROM $SYNAPSE_WORKERS_IMAGE

-FROM $FROM
 # First of all, we copy postgres server from the official postgres image,
 # since for repeated rebuilds, this is much faster than apt installing
 # postgres each time.
@@ -20,8 +26,8 @@ FROM $FROM
 # the same debian version as Synapse's docker image (so the versions of the
 # shared libraries match).
 RUN adduser --system --uid 999 postgres --home /var/lib/postgresql
-COPY --from=docker.io/library/postgres:13-bookworm /usr/lib/postgresql /usr/lib/postgresql
-COPY --from=docker.io/library/postgres:13-bookworm /usr/share/postgresql /usr/share/postgresql
+COPY --from=postgres /usr/lib/postgresql /usr/lib/postgresql
+COPY --from=postgres /usr/share/postgresql /usr/share/postgresql
 RUN mkdir /var/run/postgresql && chown postgres /var/run/postgresql
 ENV PATH="${PATH}:/usr/lib/postgresql/13/bin"
 ENV PGDATA=/var/lib/postgresql/data
@@ -29,9 +35,10 @@ ENV PGDATA=/var/lib/postgresql/data
 # We also initialize the database at build time, rather than runtime, so that it's faster to spin up the image.
 RUN gosu postgres initdb --locale=C --encoding=UTF-8 --auth-host password

-# Configure a password and create a database for Synapse
+# Configure a password and create a database for Synapse and MAS
 RUN echo "ALTER USER postgres PASSWORD 'somesecret'" | gosu postgres postgres --single
 RUN echo "CREATE DATABASE synapse" | gosu postgres postgres --single
+RUN echo "CREATE DATABASE mas" | gosu postgres postgres --single

 # Extend the shared homeserver config to disable rate-limiting,
 # set Complement's static shared secret, enable registration, amongst other
@@ -20,4 +20,15 @@ app_service_config_files:
 {%- endfor %}
 {%- endif %}

+{% if enable_mas %}
+experimental_features:
+  msc3861:
+    enabled: true
+    issuer: "http://localhost:8008/"
+    client_id: "0000000000000000000SYNAPSE"
+    client_auth_method: client_secret_basic
+    client_secret: choozia3ThiefahZaofeiveish1kahr0
+    admin_token: eeShoo4ceebae4Lo4Che1hoofoophaiz
+{% endif %}
+
 {{ shared_worker_config }}
@@ -35,3 +35,12 @@ autorestart=true
 # Redis can be disabled if the image is being used without workers
 autostart={{ enable_redis }}

+[program:mas]
+comamnd=/usr/local/bin/prefix-log /usr/local/bin/mas-cli --config /conf/mas.yaml
+stdout_logfile=/dev/stdout
+stdout_logfile_maxbytes=0
+stderr_logfile=/dev/stderr
+stderr_logfile_maxbytes=0
+autorestart=unexpected
+
+autostart={{ enable_mas }}
@@ -117,7 +117,7 @@ WORKERS_CONFIG: Dict[str, Dict[str, Any]] = {
    },
    "media_repository": {
        "app": "synapse.app.generic_worker",
-        "listener_resources": ["media"],
+        "listener_resources": ["media", "client"],
        "endpoint_patterns": [
            "^/_matrix/media/",
            "^/_synapse/admin/v1/purge_media_cache$",
@@ -125,6 +125,8 @@ WORKERS_CONFIG: Dict[str, Dict[str, Any]] = {
            "^/_synapse/admin/v1/user/.*/media.*$",
            "^/_synapse/admin/v1/media/.*$",
            "^/_synapse/admin/v1/quarantine_media/.*$",
+            "^/_matrix/client/v1/media/.*$",
+            "^/_matrix/federation/v1/media/.*$",
        ],
        # The first configured media worker will run the media background jobs
        "shared_extra_conf": {
@@ -957,6 +959,7 @@ def generate_worker_files(
        shared_worker_config=yaml.dump(shared_config),
        appservice_registrations=appservice_registrations,
        enable_redis=workers_in_use,
+        enable_mas=False,
        workers_in_use=workers_in_use,
        using_unix_sockets=using_unix_sockets,
    )
@@ -979,6 +982,7 @@ def generate_worker_files(
        "/etc/supervisor/supervisord.conf",
        main_config_path=config_path,
        enable_redis=workers_in_use,
+        enable_mas=False,
        using_unix_sockets=using_unix_sockets,
    )

@@ -1,21 +1,17 @@
 # Experimental Features API

 This API allows a server administrator to enable or disable some experimental features on a per-user
-basis. The currently supported features are: 
- [MSC3026](https://github.com/matrix-org/matrix-spec-proposals/pull/3026): busy 
-presence state enabled
- [MSC3881](https://github.com/matrix-org/matrix-spec-proposals/pull/3881): enable remotely toggling push notifications 
-for another client 
- [MSC3967](https://github.com/matrix-org/matrix-spec-proposals/pull/3967): do not require
-UIA when first uploading cross-signing keys. 
-
+basis. The currently supported features are:
+- [MSC3881](https://github.com/matrix-org/matrix-spec-proposals/pull/3881): enable remotely toggling push notifications
+for another client
+- [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575): enable experimental sliding sync support

 To use it, you will need to authenticate by providing an `access_token`
 for a server admin: see [Admin API](../usage/administration/admin_api/).

 ## Enabling/Disabling Features

-This API allows a server administrator to enable experimental features for a given user. The request must 
+This API allows a server administrator to enable experimental features for a given user. The request must
 provide a body containing the user id and listing the features to enable/disable in the following format:
 ```json
 {
@@ -35,7 +31,7 @@ PUT /_synapse/admin/v1/experimental_features/<user_id>
 ```

 ## Listing Enabled Features
- 
+
 To list which features are enabled/disabled for a given user send a request to the following API:

 ```
@@ -52,4 +48,4 @@ user like so:
      "msc3967": false
   }
 }
-```
+```
@@ -449,9 +449,9 @@ For example, a fix in PR #1234 would have its changelog entry in
 > The security levels of Florbs are now validated when received
 > via the `/federation/florb` endpoint. Contributed by Jane Matrix.

-If there are multiple pull requests involved in a single bugfix/feature/etc,
-then the content for each `changelog.d` file should be the same. Towncrier will
-merge the matching files together into a single changelog entry when we come to
+If there are multiple pull requests involved in a single bugfix/feature/etc, then the
+content for each `changelog.d` file and file extension should be the same. Towncrier
+will merge the matching files together into a single changelog entry when we come to
 release.

 ### How do I know what to call the changelog file before I create the PR?
@@ -0,0 +1,94 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   width="41.440346mm"
+   height="10.383124mm"
+   viewBox="0 0 41.440346 10.383125"
+   version="1.1"
+   id="svg1"
+   xml:space="preserve"
+   sodipodi:docname="element_logo_white_bg.svg"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg"><sodipodi:namedview
+     id="namedview1"
+     pagecolor="#ffffff"
+     bordercolor="#000000"
+     borderopacity="0.25"
+     inkscape:showpageshadow="2"
+     inkscape:pageopacity="0.0"
+     inkscape:pagecheckerboard="0"
+     inkscape:deskcolor="#d1d1d1"
+     inkscape:document-units="mm"
+     showgrid="false"
+     inkscape:export-bgcolor="#ffffffff" /><defs
+     id="defs1" /><g
+     id="layer1"
+     transform="translate(-84.803844,-143.2075)"
+     inkscape:export-filename="element_logo_white_bg.svg"
+     inkscape:export-xdpi="96"
+     inkscape:export-ydpi="96"><g
+       style="fill:none"
+       id="g1"
+       transform="matrix(0.26458333,0,0,0.26458333,85.841658,144.26667)"><rect
+         style="display:inline;fill:#ffffff;fill-opacity:1;stroke:#ffffff;stroke-width:1.31041;stroke-dasharray:none;stroke-opacity:1"
+         id="rect20"
+         width="155.31451"
+         height="37.932892"
+         x="-3.2672384"
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+         rx="3.3718522"
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@@ -67,7 +67,7 @@ in Synapse can be deactivated.
 **NOTE**: This has an impact on security and is for testing purposes only!

 To deactivate the certificate validation, the following setting must be added to
-your [homserver.yaml](../usage/configuration/homeserver_sample_config.md).
+your [homeserver.yaml](../usage/configuration/homeserver_sample_config.md).

 ```yaml
 use_insecure_ssl_client_just_for_testing_do_not_use: true
@@ -309,7 +309,62 @@ sudo dnf install libtiff-devel libjpeg-devel libzip-devel freetype-devel \
                 libwebp-devel libxml2-devel libxslt-devel libpq-devel \
                 python3-virtualenv libffi-devel openssl-devel python3-devel \
                 libicu-devel
-sudo dnf groupinstall "Development Tools"
+sudo dnf group install "Development Tools"
+```
+
+##### Red Hat Enterprise Linux / Rocky Linux
+
+*Note: The term "RHEL" below refers to both Red Hat Enterprise Linux and Rocky Linux. The distributions are 1:1 binary compatible.*
+
+It's recommended to use the latest Python versions. 
+
+RHEL 8 in particular ships with Python 3.6 by default which is EOL and therefore no longer supported by Synapse. RHEL 9 ship with Python 3.9 which is still supported by the Python core team as of this writing. However, newer Python versions provide significant performance improvements and they're available in official distributions' repositories. Therefore it's recommended to use them.
+
+Python 3.11 and 3.12 are available for both RHEL 8 and 9.
+
+These commands should be run as root user.
+
+RHEL 8
+```bash
+# Enable PowerTools repository
+dnf config-manager --set-enabled powertools
+```
+RHEL 9
+```bash
+# Enable CodeReady Linux Builder repository
+crb enable
+```
+
+Install new version of Python. You only need one of these:
+```bash
+# Python 3.11
+dnf install python3.11 python3.11-devel
+```
+```bash
+# Python 3.12
+dnf install python3.12 python3.12-devel
+```
+Finally, install common prerequisites
+```bash
+dnf install libicu libicu-devel libpq5 libpq5-devel lz4 pkgconf 
+dnf group install "Development Tools"
+```
+###### Using venv module instead of virtualenv command
+
+It's recommended to use Python venv module directly rather than the virtualenv command.
+* On RHEL 9, virtualenv is only available on [EPEL](https://docs.fedoraproject.org/en-US/epel/).
+* On RHEL 8, virtualenv is based on Python 3.6. It does not support creating 3.11/3.12 virtual environments.
+
+Here's an example of creating Python 3.12 virtual environment and installing Synapse from PyPI. 
+
+```bash
+mkdir -p ~/synapse
+# To use Python 3.11, simply use the command "python3.11" instead.
+python3.12 -m venv ~/synapse/env
+source ~/synapse/env/bin/activate
+pip install --upgrade pip
+pip install --upgrade setuptools
+pip install matrix-synapse
 ```

 ##### macOS
@@ -117,6 +117,20 @@ each upgrade are complete before moving on to the next upgrade, to avoid
 stacking them up. You can monitor the currently running background updates with
 [the Admin API](usage/administration/admin_api/background_updates.html#status).

+# Upgrading to v1.111.0
+
+## New worker endpoints for authenticated client and federation media
+
+[Media repository workers](./workers.md#synapseappmedia_repository) handling
+Media APIs can now handle the following endpoint patterns:
+
+```
+^/_matrix/client/v1/media/.*$
+^/_matrix/federation/v1/media/.*$
+```
+
+Please update your reverse proxy configuration.
+
 # Upgrading to v1.106.0

 ## Minimum supported Rust version
@@ -246,6 +246,7 @@ Example configuration:
 ```yaml
 presence:
  enabled: false
+  include_offline_users_on_sync: false
 ```

 `enabled` can also be set to a special value of "untracked" which ignores updates
@@ -254,6 +255,10 @@ received via clients and federation, while still accepting updates from the

 *The "untracked" option was added in Synapse 1.96.0.*

+When clients perform an initial or `full_state` sync, presence results for offline users are
+not included by default. Setting `include_offline_users_on_sync` to `true` will always include
+offline users in the results. Defaults to false.
+
 ---
 ### `require_auth_for_profile_requests`

@@ -1863,6 +1868,18 @@ federation_rr_transactions_per_room_per_second: 40
 ## Media Store
 Config options related to Synapse's media store.

+---
+### `enable_authenticated_media`
+
+When set to true, all subsequent media uploads will be marked as authenticated, and will not be available over legacy
+unauthenticated media endpoints (`/_matrix/media/(r0|v3|v1)/download` and `/_matrix/media/(r0|v3|v1)/thumbnail`) - requests for authenticated media over these endpoints will result in a 404. All media, including authenticated media, will be available over the authenticated media endpoints `_matrix/client/v1/media/download` and `_matrix/client/v1/media/thumbnail`. Media uploaded prior to setting this option to true will still be available over the legacy endpoints. Note if the setting is switched to false
+after enabling, media marked as authenticated will be available over legacy endpoints. Defaults to false, but
+this will change to true in a future Synapse release.
+
+Example configuration:
+```yaml
+enable_authenticated_media: true
+```
 ---
 ### `enable_media_repo`

@@ -1976,9 +1993,10 @@ This will not prevent the listed domains from accessing media themselves.
 It simply prevents users on this server from downloading media originating
 from the listed servers.

-This will have no effect on media originating from the local server.
-This only affects media downloaded from other Matrix servers, to
-block domains from URL previews see [`url_preview_url_blacklist`](#url_preview_url_blacklist).
+This will have no effect on media originating from the local server. This only
+affects media downloaded from other Matrix servers, to control URL previews see
+[`url_preview_ip_range_blacklist`](#url_preview_ip_range_blacklist) or
+[`url_preview_url_blacklist`](#url_preview_url_blacklist).

 Defaults to an empty list (nothing blocked).

@@ -2130,12 +2148,14 @@ url_preview_ip_range_whitelist:
 ---
 ### `url_preview_url_blacklist`

-Optional list of URL matches that the URL preview spider is
-denied from accessing.  You should use `url_preview_ip_range_blacklist`
-in preference to this, otherwise someone could define a public DNS
-entry that points to a private IP address and circumvent the blacklist.
-This is more useful if you know there is an entire shape of URL that
-you know that will never want synapse to try to spider.
+Optional list of URL matches that the URL preview spider is denied from
+accessing.  This is a usability feature, not a security one. You should use
+`url_preview_ip_range_blacklist` in preference to this, otherwise someone could
+define a public DNS entry that points to a private IP address and circumvent
+the blacklist. Applications that perform redirects or serve different content
+when detecting that Synapse is accessing them can also bypass the blacklist.
+This is more useful if you know there is an entire shape of URL that you know
+that you do not want Synapse to preview.

 Each list entry is a dictionary of url component attributes as returned
 by urlparse.urlsplit as applied to the absolute form of the URL.  See
@@ -2366,7 +2386,7 @@ enable_registration_without_verification: true
 ---
 ### `registrations_require_3pid`

-If this is set, users must provide all of the specified types of 3PID when registering an account.
+If this is set, users must provide all of the specified types of [3PID](https://spec.matrix.org/latest/appendices/#3pid-types) when registering an account.

 Note that [`enable_registration`](#enable_registration) must also be set to allow account registration.

@@ -2391,6 +2411,9 @@ disable_msisdn_registration: true

 Mandate that users are only allowed to associate certain formats of
 3PIDs with accounts on this server, as specified by the `medium` and `pattern` sub-options.
+`pattern` is a [Perl-like regular expression](https://docs.python.org/3/library/re.html#module-re).
+
+More information about 3PIDs, allowed `medium` types and their `address` syntax can be found [in the Matrix spec](https://spec.matrix.org/latest/appendices/#3pid-types).

 Example configuration:
 ```yaml
@@ -2400,7 +2423,7 @@ allowed_local_3pids:
  - medium: email
    pattern: '^[^@]+@vector\.im$'
  - medium: msisdn
-    pattern: '\+44'
+    pattern: '^44\d{10}$'
 ```
 ---
 ### `enable_3pid_lookup`
@@ -4131,6 +4154,38 @@ default_power_level_content_override:
   trusted_private_chat: null
   public_chat: null
 ```
+
+The default power levels for each preset are:
+```yaml
+"m.room.name": 50
+"m.room.power_levels": 100
+"m.room.history_visibility": 100
+"m.room.canonical_alias": 50
+"m.room.avatar": 50
+"m.room.tombstone": 100
+"m.room.server_acl": 100
+"m.room.encryption": 100
+```
+
+So a complete example where the default power-levels for a preset are maintained
+but the power level for a new key is set is:
+```yaml
+default_power_level_content_override:
+   private_chat:
+    events:
+      "com.example.foo": 0
+      "m.room.name": 50
+      "m.room.power_levels": 100
+      "m.room.history_visibility": 100
+      "m.room.canonical_alias": 50
+      "m.room.avatar": 50
+      "m.room.tombstone": 100
+      "m.room.server_acl": 100
+      "m.room.encryption": 100
+   trusted_private_chat: null
+   public_chat: null
+```
+
 ---
 ### `forget_rooms_on_leave`

@@ -739,6 +739,8 @@ An example for a federation sender instance:
 Handles the media repository. It can handle all endpoints starting with:

    /_matrix/media/
+    /_matrix/client/v1/media/
+    /_matrix/federation/v1/media/

 ... and the following regular expressions matching media-specific administration APIs:

@@ -96,3 +96,6 @@ ignore_missing_imports = True
 # https://github.com/twisted/treq/pull/366
 [mypy-treq.*]
 ignore_missing_imports = True
+
+[mypy-multipart.*]
+ignore_missing_imports = True
@@ -43,6 +43,7 @@ target-version = ['py38', 'py39', 'py310', 'py311']
 [tool.ruff]
 line-length = 88

+[tool.ruff.lint]
 # See https://beta.ruff.rs/docs/rules/#error-e
 # for error codes. The ones we ignore are:
 #  E501: Line too long (black enforces this for us)
@@ -96,7 +97,7 @@ module-name = "synapse.synapse_rust"

 [tool.poetry]
 name = "matrix-synapse"
-version = "1.110.0"
+version = "1.112.0"
 description = "Homeserver for the Matrix decentralised comms protocol"
 authors = ["Matrix.org Team and Contributors <packages@matrix.org>"]
 license = "AGPL-3.0-or-later"
@@ -200,8 +201,8 @@ netaddr = ">=0.7.18"
 # add a lower bound to the Jinja2 dependency.
 Jinja2 = ">=3.0"
 bleach = ">=1.4.3"
-# We use `Self`, which were added in `typing-extensions` 4.0.
-typing-extensions = ">=4.0"
+# We use `assert_never`, which were added in `typing-extensions` 4.1.
+typing-extensions = ">=4.1"
 # We enforce that we have a `cryptography` version that bundles an `openssl`
 # with the latest security patches.
 cryptography = ">=3.4.7"
@@ -224,6 +225,8 @@ pydantic = ">=1.7.4, <3"
 # needed.
 setuptools_rust = ">=1.3"

+# This is used for parsing multipart responses
+python-multipart = ">=0.0.9"

 # Optional Dependencies
 # ---------------------
@@ -319,7 +322,7 @@ all = [
 # This helps prevents merge conflicts when running a batch of dependabot updates.
 isort = ">=5.10.1"
 black = ">=22.7.0"
-ruff = "0.3.7"
+ruff = "0.5.5"
 # Type checking only works with the pydantic.v1 compat module from pydantic v2
 pydantic = "^2"

@@ -167,11 +167,11 @@ if [ -z "$skip_docker_build" ]; then
            -f "docker/editable.Dockerfile" .

        $CONTAINER_RUNTIME build -t synapse-workers-editable \
-            --build-arg FROM=synapse-editable \
+            --build-arg SYNAPSE_IMAGE=synapse-editable \
            -f "docker/Dockerfile-workers" .

        $CONTAINER_RUNTIME build -t complement-synapse-editable \
-            --build-arg FROM=synapse-workers-editable \
+            --build-arg SUNAPSE_WORKERS_IMAGE=synapse-workers-editable \
            -f "docker/complement/Dockerfile" "docker/complement"

        # Prepare the Rust module
@@ -180,21 +180,24 @@ if [ -z "$skip_docker_build" ]; then
    else

        # Build the base Synapse image from the local checkout
-        echo_if_github "::group::Build Docker image: matrixdotorg/synapse"
-        $CONTAINER_RUNTIME 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 "::group::Build Docker image: synapse"
+        $CONTAINER_RUNTIME build -t synapse \
+            --build-arg TEST_ONLY_SKIP_DEP_HASH_VERIFICATION \
+            --build-arg TEST_ONLY_IGNORE_POETRY_LOCKFILE \
+            -f "docker/Dockerfile" .
        echo_if_github "::endgroup::"

        # Build the workers docker image (from the base Synapse image we just built).
-        echo_if_github "::group::Build Docker image: matrixdotorg/synapse-workers"
-        $CONTAINER_RUNTIME build -t matrixdotorg/synapse-workers -f "docker/Dockerfile-workers" .
+        echo_if_github "::group::Build Docker image: synapse-workers"
+        $CONTAINER_RUNTIME build -t synapse-workers \
+            --build-arg SYNAPSE_IMAGE=synapse \
+            -f "docker/Dockerfile-workers" .
        echo_if_github "::endgroup::"

        # Build the unified Complement image (from the worker Synapse image we just built).
-        echo_if_github "::group::Build Docker image: complement/Dockerfile"
+        echo_if_github "::group::Build Docker image: complement-synapse"
        $CONTAINER_RUNTIME build -t complement-synapse \
+            --build-arg SYNAPSE_WORKERS_IMAGE=synapse-workers \
            -f "docker/complement/Dockerfile" "docker/complement"
        echo_if_github "::endgroup::"

@@ -112,7 +112,7 @@ python3 -m black "${files[@]}"

 # Catch any common programming mistakes in Python code.
 # --quiet suppresses the update check.
-ruff --quiet --fix "${files[@]}"
+ruff check --quiet --fix "${files[@]}"

 # Catch any common programming mistakes in Rust code.
 #
@@ -70,6 +70,7 @@ def cli() -> None:
            pip install -e .[dev]

      - A checkout of the sytest repository at ../sytest
+      - A checkout of the complement repository at ../complement

    Then to use:

@@ -112,10 +113,12 @@ def _prepare() -> None:
    # Make sure we're in a git repo.
    synapse_repo = get_repo_and_check_clean_checkout()
    sytest_repo = get_repo_and_check_clean_checkout("../sytest", "sytest")
+    complement_repo = get_repo_and_check_clean_checkout("../complement", "complement")

    click.secho("Updating Synapse and Sytest git repos...")
    synapse_repo.remote().fetch()
    sytest_repo.remote().fetch()
+    complement_repo.remote().fetch()

    # Get the current version and AST from root Synapse module.
    current_version = get_package_version()
@@ -208,7 +211,15 @@ def _prepare() -> None:
            "Which branch should the release be based on?", default=default
        )

-        for repo_name, repo in {"synapse": synapse_repo, "sytest": sytest_repo}.items():
+        for repo_name, repo in {
+            "synapse": synapse_repo,
+            "sytest": sytest_repo,
+            "complement": complement_repo,
+        }.items():
+            # Special case for Complement: `develop` maps to `main`
+            if repo_name == "complement" and branch_name == "develop":
+                branch_name = "main"
+
            base_branch = find_ref(repo, branch_name)
            if not base_branch:
                print(f"Could not find base branch {branch_name} for {repo_name}!")
@@ -231,6 +242,12 @@ def _prepare() -> None:
        if click.confirm("Push new SyTest branch?", default=True):
            sytest_repo.git.push("-u", sytest_repo.remote().name, release_branch_name)

+        # Same for Complement
+        if click.confirm("Push new Complement branch?", default=True):
+            complement_repo.git.push(
+                "-u", complement_repo.remote().name, release_branch_name
+            )
+
    # Switch to the release branch and ensure it's up to date.
    synapse_repo.git.checkout(release_branch_name)
    update_branch(synapse_repo)
@@ -630,6 +647,9 @@ def _merge_back() -> None:
    else:
        # Full release
        sytest_repo = get_repo_and_check_clean_checkout("../sytest", "sytest")
+        complement_repo = get_repo_and_check_clean_checkout(
+            "../complement", "complement"
+        )

        if click.confirm(f"Merge {branch_name} → master?", default=True):
            _merge_into(synapse_repo, branch_name, "master")
@@ -643,6 +663,9 @@ def _merge_back() -> None:
        if click.confirm("On SyTest, merge master → develop?", default=True):
            _merge_into(sytest_repo, "master", "develop")

+        if click.confirm(f"On Complement, merge {branch_name} → main?", default=True):
+            _merge_into(complement_repo, branch_name, "main")
+

@cli.command()
 def announce() -> None:
@@ -44,7 +44,7 @@ logger = logging.getLogger("generate_workers_map")


 class MockHomeserver(HomeServer):
-    DATASTORE_CLASS = DataStore  # type: ignore
+    DATASTORE_CLASS = DataStore

    def __init__(self, config: HomeServerConfig, worker_app: Optional[str]) -> None:
        super().__init__(config.server.server_name, config=config)
@@ -119,18 +119,19 @@ BOOLEAN_COLUMNS = {
    "e2e_room_keys": ["is_verified"],
    "event_edges": ["is_state"],
    "events": ["processed", "outlier", "contains_url"],
-    "local_media_repository": ["safe_from_quarantine"],
+    "local_media_repository": ["safe_from_quarantine", "authenticated"],
+    "per_user_experimental_features": ["enabled"],
    "presence_list": ["accepted"],
    "presence_stream": ["currently_active"],
    "public_room_list_stream": ["visibility"],
    "pushers": ["enabled"],
    "redactions": ["have_censored"],
+    "remote_media_cache": ["authenticated"],
    "room_stats_state": ["is_federatable"],
    "rooms": ["is_public", "has_auth_chain_index"],
    "users": ["shadow_banned", "approved", "locked", "suspended"],
    "un_partial_stated_event_stream": ["rejection_status_changed"],
    "users_who_share_rooms": ["share_private"],
-    "per_user_experimental_features": ["enabled"],
 }


@@ -41,7 +41,7 @@ logger = logging.getLogger("update_database")


 class MockHomeserver(HomeServer):
-    DATASTORE_CLASS = DataStore  # type: ignore [assignment]
+    DATASTORE_CLASS = DataStore

    def __init__(self, config: HomeServerConfig):
        super().__init__(
@@ -18,7 +18,7 @@
 # [This file includes modifications made by New Vector Limited]
 #
 #
-from typing import Optional, Tuple
+from typing import TYPE_CHECKING, Optional, Tuple

 from typing_extensions import Protocol

@@ -28,6 +28,9 @@ from synapse.appservice import ApplicationService
 from synapse.http.site import SynapseRequest
 from synapse.types import Requester

+if TYPE_CHECKING:
+    from synapse.rest.admin.experimental_features import ExperimentalFeature
+
 # guests always get this device id.
 GUEST_DEVICE_ID = "guest_device"

@@ -87,6 +90,19 @@ class Auth(Protocol):
            AuthError if access is denied for the user in the access token
        """

+    async def get_user_by_req_experimental_feature(
+        self,
+        request: SynapseRequest,
+        feature: "ExperimentalFeature",
+        allow_guest: bool = False,
+        allow_expired: bool = False,
+        allow_locked: bool = False,
+    ) -> Requester:
+        """Like `get_user_by_req`, except also checks if the user has access to
+        the experimental feature. If they don't returns a 404 unrecognized
+        request.
+        """
+
    async def validate_appservice_can_control_user_id(
        self, app_service: ApplicationService, user_id: str
    ) -> None:
@@ -28,6 +28,7 @@ from synapse.api.errors import (
    Codes,
    InvalidClientTokenError,
    MissingClientTokenError,
+    UnrecognizedRequestError,
 )
 from synapse.http.site import SynapseRequest
 from synapse.logging.opentracing import active_span, force_tracing, start_active_span
@@ -38,8 +39,10 @@ from . import GUEST_DEVICE_ID
 from .base import BaseAuth

 if TYPE_CHECKING:
+    from synapse.rest.admin.experimental_features import ExperimentalFeature
    from synapse.server import HomeServer

+
 logger = logging.getLogger(__name__)


@@ -106,6 +109,32 @@ class InternalAuth(BaseAuth):
                    parent_span.set_tag("appservice_id", requester.app_service.id)
            return requester

+    async def get_user_by_req_experimental_feature(
+        self,
+        request: SynapseRequest,
+        feature: "ExperimentalFeature",
+        allow_guest: bool = False,
+        allow_expired: bool = False,
+        allow_locked: bool = False,
+    ) -> Requester:
+        try:
+            requester = await self.get_user_by_req(
+                request,
+                allow_guest=allow_guest,
+                allow_expired=allow_expired,
+                allow_locked=allow_locked,
+            )
+            if await self.store.is_feature_enabled(requester.user.to_string(), feature):
+                return requester
+
+            raise UnrecognizedRequestError(code=404)
+        except (AuthError, InvalidClientTokenError):
+            if feature.is_globally_enabled(self.hs.config):
+                # If its globally enabled then return the auth error
+                raise
+
+            raise UnrecognizedRequestError(code=404)
+
    @cancellable
    async def _wrapped_get_user_by_req(
        self,
@@ -40,6 +40,7 @@ from synapse.api.errors import (
    OAuthInsufficientScopeError,
    StoreError,
    SynapseError,
+    UnrecognizedRequestError,
 )
 from synapse.http.site import SynapseRequest
 from synapse.logging.context import make_deferred_yieldable
@@ -48,6 +49,7 @@ from synapse.util import json_decoder
 from synapse.util.caches.cached_call import RetryOnExceptionCachedCall

 if TYPE_CHECKING:
+    from synapse.rest.admin.experimental_features import ExperimentalFeature
    from synapse.server import HomeServer

 logger = logging.getLogger(__name__)
@@ -143,6 +145,18 @@ class MSC3861DelegatedAuth(BaseAuth):
        # metadata.validate_introspection_endpoint()
        return metadata

+    async def _introspection_endpoint(self) -> str:
+        """
+        Returns the introspection endpoint of the issuer
+
+        It uses the config option if set, otherwise it will use OIDC discovery to get it
+        """
+        if self._config.introspection_endpoint is not None:
+            return self._config.introspection_endpoint
+
+        metadata = await self._load_metadata()
+        return metadata.get("introspection_endpoint")
+
    async def _introspect_token(self, token: str) -> IntrospectionToken:
        """
        Send a token to the introspection endpoint and returns the introspection response
@@ -159,8 +173,7 @@ class MSC3861DelegatedAuth(BaseAuth):
        Returns:
            The introspection response
        """
-        metadata = await self._issuer_metadata.get()
-        introspection_endpoint = metadata.get("introspection_endpoint")
+        introspection_endpoint = await self._introspection_endpoint()
        raw_headers: Dict[str, str] = {
            "Content-Type": "application/x-www-form-urlencoded",
            "User-Agent": str(self._http_client.user_agent, "utf-8"),
@@ -245,6 +258,32 @@ class MSC3861DelegatedAuth(BaseAuth):

        return requester

+    async def get_user_by_req_experimental_feature(
+        self,
+        request: SynapseRequest,
+        feature: "ExperimentalFeature",
+        allow_guest: bool = False,
+        allow_expired: bool = False,
+        allow_locked: bool = False,
+    ) -> Requester:
+        try:
+            requester = await self.get_user_by_req(
+                request,
+                allow_guest=allow_guest,
+                allow_expired=allow_expired,
+                allow_locked=allow_locked,
+            )
+            if await self.store.is_feature_enabled(requester.user.to_string(), feature):
+                return requester
+
+            raise UnrecognizedRequestError(code=404)
+        except (AuthError, InvalidClientTokenError):
+            if feature.is_globally_enabled(self.hs.config):
+                # If its globally enabled then return the auth error
+                raise
+
+            raise UnrecognizedRequestError(code=404)
+
    async def get_user_by_access_token(
        self,
        token: str,
@@ -50,7 +50,7 @@ class Membership:
    KNOCK: Final = "knock"
    LEAVE: Final = "leave"
    BAN: Final = "ban"
-    LIST: Final = {INVITE, JOIN, KNOCK, LEAVE, BAN}
+    LIST: Final = frozenset((INVITE, JOIN, KNOCK, LEAVE, BAN))


 class PresenceState:
@@ -128,9 +128,13 @@ class EventTypes:
    SpaceParent: Final = "m.space.parent"

    Reaction: Final = "m.reaction"
+    Sticker: Final = "m.sticker"
+    LiveLocationShareStart: Final = "m.beacon_info"

    CallInvite: Final = "m.call.invite"

+    PollStart: Final = "m.poll.start"
+

 class ToDeviceEventTypes:
    RoomKeyRequest: Final = "m.room_key_request"
@@ -221,6 +225,11 @@ class EventContentFields:
    # This is deprecated in MSC2175.
    ROOM_CREATOR: Final = "creator"

+    # The version of the room for `m.room.create` events.
+    ROOM_VERSION: Final = "room_version"
+
+    ROOM_NAME: Final = "name"
+
    # Used in m.room.guest_access events.
    GUEST_ACCESS: Final = "guest_access"

@@ -233,6 +242,9 @@ class EventContentFields:
    # an unspecced field added to to-device messages to identify them uniquely-ish
    TO_DEVICE_MSGID: Final = "org.matrix.msgid"

+    # `m.room.encryption`` algorithm field
+    ENCRYPTION_ALGORITHM: Final = "algorithm"
+

 class EventUnsignedContentFields:
    """Fields found inside the 'unsigned' data on events"""
@@ -130,7 +130,8 @@ class Ratelimiter:
                Overrides the value set during instantiation if set.
            burst_count: How many actions that can be performed before being limited.
                Overrides the value set during instantiation if set.
-            update: Whether to count this check as performing the action
+            update: Whether to count this check as performing the action. If the action
+                cannot be performed, the user's action count is not incremented at all.
            n_actions: The number of times the user wants to do this action. If the user
                cannot do all of the actions, the user's action count is not incremented
                at all.
@@ -235,9 +236,8 @@ class Ratelimiter:
            requester: The requester that is doing the action, if any.
            key: An arbitrary key used to classify an action. Defaults to the
                requester's user ID.
-            n_actions: The number of times the user wants to do this action. If the user
-                cannot do all of the actions, the user's action count is not incremented
-                at all.
+            n_actions: The number of times the user performed the action. May be negative
+                to "refund" the rate limit.
            _time_now_s: The current time. Optional, defaults to the current time according
                to self.clock. Only used by tests.
        """
@@ -110,7 +110,7 @@ class AdminCmdStore(


 class AdminCmdServer(HomeServer):
-    DATASTORE_CLASS = AdminCmdStore  # type: ignore
+    DATASTORE_CLASS = AdminCmdStore


 async def export_data_command(hs: HomeServer, args: argparse.Namespace) -> None:
@@ -74,6 +74,9 @@ from synapse.storage.databases.main.event_push_actions import (
    EventPushActionsWorkerStore,
 )
 from synapse.storage.databases.main.events_worker import EventsWorkerStore
+from synapse.storage.databases.main.experimental_features import (
+    ExperimentalFeaturesStore,
+)
 from synapse.storage.databases.main.filtering import FilteringWorkerStore
 from synapse.storage.databases.main.keys import KeyStore
 from synapse.storage.databases.main.lock import LockStore
@@ -155,6 +158,7 @@ class GenericWorkerStore(
    LockStore,
    SessionStore,
    TaskSchedulerWorkerStore,
+    ExperimentalFeaturesStore,
 ):
    # Properties that multiple storage classes define. Tell mypy what the
    # expected type is.
@@ -163,7 +167,7 @@ class GenericWorkerStore(


 class GenericWorkerServer(HomeServer):
-    DATASTORE_CLASS = GenericWorkerStore  # type: ignore
+    DATASTORE_CLASS = GenericWorkerStore

    def _listen_http(self, listener_config: ListenerConfig) -> None:
        assert listener_config.http_options is not None
@@ -81,7 +81,7 @@ def gz_wrap(r: Resource) -> Resource:


 class SynapseHomeServer(HomeServer):
-    DATASTORE_CLASS = DataStore  # type: ignore
+    DATASTORE_CLASS = DataStore

    def _listener_http(
        self,
@@ -217,7 +217,7 @@ class SynapseHomeServer(HomeServer):
            )

        if name in ["media", "federation", "client"]:
-            if self.config.server.enable_media_repo:
+            if self.config.media.can_load_media_repo:
                media_repo = self.get_media_repository_resource()
                resources.update(
                    {
@@ -140,6 +140,12 @@ class MSC3861:
                ("experimental", "msc3861", "client_auth_method"),
            )

+    introspection_endpoint: Optional[str] = attr.ib(
+        default=None,
+        validator=attr.validators.optional(attr.validators.instance_of(str)),
+    )
+    """The URL of the introspection endpoint used to validate access tokens."""
+
    account_management_url: Optional[str] = attr.ib(
        default=None,
        validator=attr.validators.optional(attr.validators.instance_of(str)),
@@ -437,10 +443,6 @@ class ExperimentalConfig(Config):
            "msc3823_account_suspension", False
        )

-        self.msc3916_authenticated_media_enabled = experimental.get(
-            "msc3916_authenticated_media_enabled", False
-        )
-
        # MSC4151: Report room API (Client-Server API)
        self.msc4151_enabled: bool = experimental.get("msc4151_enabled", False)

@@ -126,7 +126,7 @@ class ContentRepositoryConfig(Config):
        # Only enable the media repo if either the media repo is enabled or the
        # current worker app is the media repo.
        if (
-            self.root.server.enable_media_repo is False
+            config.get("enable_media_repo", True) is False
            and config.get("worker_app") != "synapse.app.media_repository"
        ):
            self.can_load_media_repo = False
@@ -272,6 +272,10 @@ class ContentRepositoryConfig(Config):
                remote_media_lifetime
            )

+        self.enable_authenticated_media = config.get(
+            "enable_authenticated_media", False
+        )
+
    def generate_config_section(self, data_dir_path: str, **kwargs: Any) -> str:
        assert data_dir_path is not None
        media_store = os.path.join(data_dir_path, "media_store")
@@ -384,6 +384,11 @@ class ServerConfig(Config):
        # Whether to internally track presence, requires that presence is enabled,
        self.track_presence = self.presence_enabled and presence_enabled != "untracked"

+        # Determines if presence results for offline users are included on initial/full sync
+        self.presence_include_offline_users_on_sync = presence_config.get(
+            "include_offline_users_on_sync", False
+        )
+
        # Custom presence router module
        # This is the legacy way of configuring it (the config should now be put in the modules section)
        self.presence_router_module_class = None
@@ -395,12 +400,6 @@ class ServerConfig(Config):
                self.presence_router_config,
            ) = load_module(presence_router_config, ("presence", "presence_router"))

-        # whether to enable the media repository endpoints. This should be set
-        # to false if the media repository is running as a separate endpoint;
-        # doing so ensures that we will not run cache cleanup jobs on the
-        # master, potentially causing inconsistency.
-        self.enable_media_repo = config.get("enable_media_repo", True)
-
        # Whether to require authentication to retrieve profile data (avatars,
        # display names) of other users through the client API.
        self.require_auth_for_profile_requests = config.get(
@@ -554,3 +554,22 @@ def relation_from_event(event: EventBase) -> Optional[_EventRelation]:
            aggregation_key = None

    return _EventRelation(parent_id, rel_type, aggregation_key)
+
+
+@attr.s(slots=True, frozen=True, auto_attribs=True)
+class StrippedStateEvent:
+    """
+    A stripped down state event. Usually used for remote invite/knocks so the user can
+    make an informed decision on whether they want to join.
+
+    Attributes:
+        type: Event `type`
+        state_key: Event `state_key`
+        sender: Event `sender`
+        content: Event `content`
+    """
+
+    type: str
+    state_key: str
+    sender: str
+    content: Dict[str, Any]
@@ -49,7 +49,7 @@ from synapse.api.errors import Codes, SynapseError
 from synapse.api.room_versions import RoomVersion
 from synapse.types import JsonDict, Requester

-from . import EventBase, make_event_from_dict
+from . import EventBase, StrippedStateEvent, make_event_from_dict

 if TYPE_CHECKING:
    from synapse.handlers.relations import BundledAggregations
@@ -836,3 +836,48 @@ def maybe_upsert_event_field(
            del container[key]

    return upsert_okay
+
+
+def strip_event(event: EventBase) -> JsonDict:
+    """
+    Used for "stripped state" events which provide a simplified view of the state of a
+    room intended to help a potential joiner identify the room (relevant when the user
+    is invited or knocked).
+
+    Stripped state events can only have the `sender`, `type`, `state_key` and `content`
+    properties present.
+    """
+
+    return {
+        "type": event.type,
+        "state_key": event.state_key,
+        "content": event.content,
+        "sender": event.sender,
+    }
+
+
+def parse_stripped_state_event(raw_stripped_event: Any) -> Optional[StrippedStateEvent]:
+    """
+    Given a raw value from an event's `unsigned` field, attempt to parse it into a
+    `StrippedStateEvent`.
+    """
+    if isinstance(raw_stripped_event, dict):
+        # All of these fields are required
+        type = raw_stripped_event.get("type")
+        state_key = raw_stripped_event.get("state_key")
+        sender = raw_stripped_event.get("sender")
+        content = raw_stripped_event.get("content")
+        if (
+            isinstance(type, str)
+            and isinstance(state_key, str)
+            and isinstance(sender, str)
+            and isinstance(content, dict)
+        ):
+            return StrippedStateEvent(
+                type=type,
+                state_key=state_key,
+                sender=sender,
+                content=content,
+            )
+
+    return None
@@ -1871,6 +1871,52 @@ class FederationClient(FederationBase):

        return filtered_statuses, filtered_failures

+    async def federation_download_media(
+        self,
+        destination: str,
+        media_id: str,
+        output_stream: BinaryIO,
+        max_size: int,
+        max_timeout_ms: int,
+        download_ratelimiter: Ratelimiter,
+        ip_address: str,
+    ) -> Union[
+        Tuple[int, Dict[bytes, List[bytes]], bytes],
+        Tuple[int, Dict[bytes, List[bytes]]],
+    ]:
+        try:
+            return await self.transport_layer.federation_download_media(
+                destination,
+                media_id,
+                output_stream=output_stream,
+                max_size=max_size,
+                max_timeout_ms=max_timeout_ms,
+                download_ratelimiter=download_ratelimiter,
+                ip_address=ip_address,
+            )
+        except HttpResponseException as e:
+            # If an error is received that is due to an unrecognised endpoint,
+            # fallback to the _matrix/media/v3/download endpoint. Otherwise, consider it a legitimate error
+            # and raise.
+            if not is_unknown_endpoint(e):
+                raise
+
+        logger.debug(
+            "Couldn't download media %s/%s over _matrix/federation/v1/media/download, falling back to _matrix/media/v3/download path",
+            destination,
+            media_id,
+        )
+
+        return await self.transport_layer.download_media_v3(
+            destination,
+            media_id,
+            output_stream=output_stream,
+            max_size=max_size,
+            max_timeout_ms=max_timeout_ms,
+            download_ratelimiter=download_ratelimiter,
+            ip_address=ip_address,
+        )
+
    async def download_media(
        self,
        destination: str,
@@ -338,12 +338,11 @@ class PerDestinationQueue:
                    # not caught up yet
                    return

-            pending_pdus = []
            while True:
                self._new_data_to_send = False

                async with _TransactionQueueManager(self) as (
-                    pending_pdus,
+                    pending_pdus,  # noqa: F811
                    pending_edus,
                ):
                    if not pending_pdus and not pending_edus:
@@ -824,7 +824,6 @@ class TransportLayerClient:
        ip_address: str,
    ) -> Tuple[int, Dict[bytes, List[bytes]]]:
        path = f"/_matrix/media/r0/download/{destination}/{media_id}"
-
        return await self.client.get_file(
            destination,
            path,
@@ -852,7 +851,6 @@ class TransportLayerClient:
        ip_address: str,
    ) -> Tuple[int, Dict[bytes, List[bytes]]]:
        path = f"/_matrix/media/v3/download/{destination}/{media_id}"
-
        return await self.client.get_file(
            destination,
            path,
@@ -873,6 +871,29 @@ class TransportLayerClient:
            ip_address=ip_address,
        )

+    async def federation_download_media(
+        self,
+        destination: str,
+        media_id: str,
+        output_stream: BinaryIO,
+        max_size: int,
+        max_timeout_ms: int,
+        download_ratelimiter: Ratelimiter,
+        ip_address: str,
+    ) -> Tuple[int, Dict[bytes, List[bytes]], bytes]:
+        path = f"/_matrix/federation/v1/media/download/{media_id}"
+        return await self.client.federation_get_file(
+            destination,
+            path,
+            output_stream=output_stream,
+            max_size=max_size,
+            args={
+                "timeout_ms": str(max_timeout_ms),
+            },
+            download_ratelimiter=download_ratelimiter,
+            ip_address=ip_address,
+        )
+

 def _create_path(federation_prefix: str, path: str, *args: str) -> str:
    """
@@ -32,8 +32,9 @@ from synapse.federation.transport.server._base import (
 from synapse.federation.transport.server.federation import (
    FEDERATION_SERVLET_CLASSES,
    FederationAccountStatusServlet,
+    FederationMediaDownloadServlet,
+    FederationMediaThumbnailServlet,
    FederationUnstableClientKeysClaimServlet,
-    FederationUnstableMediaDownloadServlet,
 )
 from synapse.http.server import HttpServer, JsonResource
 from synapse.http.servlet import (
@@ -316,11 +317,11 @@ def register_servlets(
            ):
                continue

-            if servletclass == FederationUnstableMediaDownloadServlet:
-                if (
-                    not hs.config.server.enable_media_repo
-                    or not hs.config.experimental.msc3916_authenticated_media_enabled
-                ):
+            if (
+                servletclass == FederationMediaDownloadServlet
+                or servletclass == FederationMediaThumbnailServlet
+            ):
+                if not hs.config.media.can_load_media_repo:
                    continue

            servletclass(
@@ -362,7 +362,9 @@ class BaseFederationServlet:
                                return None
                            if (
                                func.__self__.__class__.__name__  # type: ignore
-                                == "FederationUnstableMediaDownloadServlet"
+                                == "FederationMediaDownloadServlet"
+                                or func.__self__.__class__.__name__  # type: ignore
+                                == "FederationMediaThumbnailServlet"
                            ):
                                response = await func(
                                    origin, content, request, *args, **kwargs
@@ -374,7 +376,9 @@ class BaseFederationServlet:
                    else:
                        if (
                            func.__self__.__class__.__name__  # type: ignore
-                            == "FederationUnstableMediaDownloadServlet"
+                            == "FederationMediaDownloadServlet"
+                            or func.__self__.__class__.__name__  # type: ignore
+                            == "FederationMediaThumbnailServlet"
                        ):
                            response = await func(
                                origin, content, request, *args, **kwargs
@@ -46,11 +46,13 @@ from synapse.http.servlet import (
    parse_boolean_from_args,
    parse_integer,
    parse_integer_from_args,
+    parse_string,
    parse_string_from_args,
    parse_strings_from_args,
 )
 from synapse.http.site import SynapseRequest
 from synapse.media._base import DEFAULT_MAX_TIMEOUT_MS, MAXIMUM_ALLOWED_MAX_TIMEOUT_MS
+from synapse.media.thumbnailer import ThumbnailProvider
 from synapse.types import JsonDict
 from synapse.util import SYNAPSE_VERSION
 from synapse.util.ratelimitutils import FederationRateLimiter
@@ -790,7 +792,7 @@ class FederationAccountStatusServlet(BaseFederationServerServlet):
        return 200, {"account_statuses": statuses, "failures": failures}


-class FederationUnstableMediaDownloadServlet(BaseFederationServerServlet):
+class FederationMediaDownloadServlet(BaseFederationServerServlet):
    """
    Implementation of new federation media `/download` endpoint outlined in MSC3916. Returns
    a multipart/mixed response consisting of a JSON object and the requested media
@@ -798,7 +800,6 @@ class FederationUnstableMediaDownloadServlet(BaseFederationServerServlet):
    """

    PATH = "/media/download/(?P<media_id>[^/]*)"
-    PREFIX = FEDERATION_UNSTABLE_PREFIX + "/org.matrix.msc3916"
    RATELIMIT = True

    def __init__(
@@ -827,6 +828,59 @@ class FederationUnstableMediaDownloadServlet(BaseFederationServerServlet):
        )


+class FederationMediaThumbnailServlet(BaseFederationServerServlet):
+    """
+    Implementation of new federation media `/thumbnail` endpoint outlined in MSC3916. Returns
+    a multipart/mixed response consisting of a JSON object and the requested media
+    item. This endpoint only returns local media.
+    """
+
+    PATH = "/media/thumbnail/(?P<media_id>[^/]*)"
+    RATELIMIT = True
+
+    def __init__(
+        self,
+        hs: "HomeServer",
+        ratelimiter: FederationRateLimiter,
+        authenticator: Authenticator,
+        server_name: str,
+    ):
+        super().__init__(hs, authenticator, ratelimiter, server_name)
+        self.media_repo = self.hs.get_media_repository()
+        self.dynamic_thumbnails = hs.config.media.dynamic_thumbnails
+        self.thumbnail_provider = ThumbnailProvider(
+            hs, self.media_repo, self.media_repo.media_storage
+        )
+
+    async def on_GET(
+        self,
+        origin: Optional[str],
+        content: Literal[None],
+        request: SynapseRequest,
+        media_id: str,
+    ) -> None:
+
+        width = parse_integer(request, "width", required=True)
+        height = parse_integer(request, "height", required=True)
+        method = parse_string(request, "method", "scale")
+        # TODO Parse the Accept header to get an prioritised list of thumbnail types.
+        m_type = "image/png"
+        max_timeout_ms = parse_integer(
+            request, "timeout_ms", default=DEFAULT_MAX_TIMEOUT_MS
+        )
+        max_timeout_ms = min(max_timeout_ms, MAXIMUM_ALLOWED_MAX_TIMEOUT_MS)
+
+        if self.dynamic_thumbnails:
+            await self.thumbnail_provider.select_or_generate_local_thumbnail(
+                request, media_id, width, height, method, m_type, max_timeout_ms, True
+            )
+        else:
+            await self.thumbnail_provider.respond_local_thumbnail(
+                request, media_id, width, height, method, m_type, max_timeout_ms, True
+            )
+        self.media_repo.mark_recently_accessed(None, media_id)
+
+
 FEDERATION_SERVLET_CLASSES: Tuple[Type[BaseFederationServlet], ...] = (
    FederationSendServlet,
    FederationEventServlet,
@@ -858,5 +912,6 @@ FEDERATION_SERVLET_CLASSES: Tuple[Type[BaseFederationServlet], ...] = (
    FederationV1SendKnockServlet,
    FederationMakeKnockServlet,
    FederationAccountStatusServlet,
-    FederationUnstableMediaDownloadServlet,
+    FederationMediaDownloadServlet,
+    FederationMediaThumbnailServlet,
 )
@@ -283,6 +283,10 @@ class DeactivateAccountHandler:
                    ratelimit=False,
                    require_consent=False,
                )
+
+                # Mark the room forgotten too, because they won't be able to do this
+                # for us. This may lead to the room being purged eventually.
+                await self._room_member_handler.forget(user, room_id)
            except Exception:
                logger.exception(
                    "Failed to part user %r from room %r: ignoring and continuing",
@@ -39,6 +39,7 @@ from synapse.metrics.background_process_metrics import (
 )
 from synapse.storage.databases.main.client_ips import DeviceLastConnectionInfo
 from synapse.types import (
+    DeviceListUpdates,
    JsonDict,
    JsonMapping,
    ScheduledTask,
@@ -214,7 +215,7 @@ class DeviceWorkerHandler:
    @cancellable
    async def get_user_ids_changed(
        self, user_id: str, from_token: StreamToken
-    ) -> JsonDict:
+    ) -> DeviceListUpdates:
        """Get list of users that have had the devices updated, or have newly
        joined a room, that `user_id` may be interested in.
        """
@@ -341,11 +342,19 @@ class DeviceWorkerHandler:
            possibly_joined = set()
            possibly_left = set()

-        result = {"changed": list(possibly_joined), "left": list(possibly_left)}
+        device_list_updates = DeviceListUpdates(
+            changed=possibly_joined,
+            left=possibly_left,
+        )

-        log_kv(result)
+        log_kv(
+            {
+                "changed": device_list_updates.changed,
+                "left": device_list_updates.left,
+            }
+        )

-        return result
+        return device_list_updates

    async def on_federation_query_user_devices(self, user_id: str) -> JsonDict:
        if not self.hs.is_mine(UserID.from_string(user_id)):
@@ -291,13 +291,20 @@ class E2eKeysHandler:

            # Only try and fetch keys for destinations that are not marked as
            # down.
-            filtered_destinations = await filter_destinations_by_retry_limiter(
-                remote_queries_not_in_cache.keys(),
-                self.clock,
-                self.store,
-                # Let's give an arbitrary grace period for those hosts that are
-                # only recently down
-                retry_due_within_ms=60 * 1000,
+            unfiltered_destinations = remote_queries_not_in_cache.keys()
+            filtered_destinations = set(
+                await filter_destinations_by_retry_limiter(
+                    unfiltered_destinations,
+                    self.clock,
+                    self.store,
+                    # Let's give an arbitrary grace period for those hosts that are
+                    # only recently down
+                    retry_due_within_ms=60 * 1000,
+                )
+            )
+            failures.update(
+                (dest, _NOT_READY_FOR_RETRY_FAILURE)
+                for dest in (unfiltered_destinations - filtered_destinations)
            )

            await concurrently_execute(
@@ -1641,6 +1648,9 @@ def _check_device_signature(
        raise SynapseError(400, "Invalid signature", Codes.INVALID_SIGNATURE)


+_NOT_READY_FOR_RETRY_FAILURE = {"status": 503, "message": "Not ready for retry"}
+
+
 def _exception_to_failure(e: Exception) -> JsonDict:
    if isinstance(e, SynapseError):
        return {"status": e.code, "errcode": e.errcode, "message": str(e)}
@@ -1649,7 +1659,7 @@ def _exception_to_failure(e: Exception) -> JsonDict:
        return {"status": e.code, "message": str(e)}

    if isinstance(e, NotRetryingDestination):
-        return {"status": 503, "message": "Not ready for retry"}
+        return _NOT_READY_FOR_RETRY_FAILURE

    # include ConnectionRefused and other errors
    #
@@ -34,7 +34,7 @@ from synapse.api.errors import (
 from synapse.logging.opentracing import log_kv, trace
 from synapse.storage.databases.main.e2e_room_keys import RoomKey
 from synapse.types import JsonDict
-from synapse.util.async_helpers import Linearizer
+from synapse.util.async_helpers import ReadWriteLock

 if TYPE_CHECKING:
    from synapse.server import HomeServer
@@ -58,7 +58,7 @@ class E2eRoomKeysHandler:
        # clients belonging to a user will receive and try to upload a new session at
        # roughly the same time.  Also used to lock out uploads when the key is being
        # changed.
-        self._upload_linearizer = Linearizer("upload_room_keys_lock")
+        self._upload_lock = ReadWriteLock()

    @trace
    async def get_room_keys(
@@ -89,7 +89,7 @@ class E2eRoomKeysHandler:

        # we deliberately take the lock to get keys so that changing the version
        # works atomically
-        async with self._upload_linearizer.queue(user_id):
+        async with self._upload_lock.read(user_id):
            # make sure the backup version exists
            try:
                await self.store.get_e2e_room_keys_version_info(user_id, version)
@@ -132,7 +132,7 @@ class E2eRoomKeysHandler:
        """

        # lock for consistency with uploading
-        async with self._upload_linearizer.queue(user_id):
+        async with self._upload_lock.write(user_id):
            # make sure the backup version exists
            try:
                version_info = await self.store.get_e2e_room_keys_version_info(
@@ -193,7 +193,7 @@ class E2eRoomKeysHandler:
        # TODO: Validate the JSON to make sure it has the right keys.

        # XXX: perhaps we should use a finer grained lock here?
-        async with self._upload_linearizer.queue(user_id):
+        async with self._upload_lock.write(user_id):
            # Check that the version we're trying to upload is the current version
            try:
                version_info = await self.store.get_e2e_room_keys_version_info(user_id)
@@ -355,7 +355,7 @@ class E2eRoomKeysHandler:
        # TODO: Validate the JSON to make sure it has the right keys.

        # lock everyone out until we've switched version
-        async with self._upload_linearizer.queue(user_id):
+        async with self._upload_lock.write(user_id):
            new_version = await self.store.create_e2e_room_keys_version(
                user_id, version_info
            )
@@ -382,7 +382,7 @@ class E2eRoomKeysHandler:
        }
        """

-        async with self._upload_linearizer.queue(user_id):
+        async with self._upload_lock.read(user_id):
            try:
                res = await self.store.get_e2e_room_keys_version_info(user_id, version)
            except StoreError as e:
@@ -407,7 +407,7 @@ class E2eRoomKeysHandler:
            NotFoundError: if this backup version doesn't exist
        """

-        async with self._upload_linearizer.queue(user_id):
+        async with self._upload_lock.write(user_id):
            try:
                await self.store.delete_e2e_room_keys_version(user_id, version)
            except StoreError as e:
@@ -437,7 +437,7 @@ class E2eRoomKeysHandler:
            raise SynapseError(
                400, "Version in body does not match", Codes.INVALID_PARAM
            )
-        async with self._upload_linearizer.queue(user_id):
+        async with self._upload_lock.write(user_id):
            try:
                old_info = await self.store.get_e2e_room_keys_version_info(
                    user_id, version
@@ -286,8 +286,14 @@ class ReceiptEventSource(EventSource[MultiWriterStreamToken, JsonMapping]):
        room_ids: Iterable[str],
        is_guest: bool,
        explicit_room_id: Optional[str] = None,
+        to_key: Optional[MultiWriterStreamToken] = None,
    ) -> Tuple[List[JsonMapping], MultiWriterStreamToken]:
-        to_key = self.get_current_key()
+        """
+        Find read receipts for given rooms (> `from_token` and <= `to_token`)
+        """
+
+        if to_key is None:
+            to_key = self.get_current_key()

        if from_key == to_key:
            return [], to_key
@@ -1188,6 +1188,8 @@ class RoomCreationHandler:
            )
            events_to_send.append((power_event, power_context))
        else:
+            # Please update the docs for `default_power_level_content_override` when
+            # updating the `events` dict below
            power_level_content: JsonDict = {
                "users": {creator_id: 100},
                "users_default": 0,
@@ -293,7 +293,9 @@ class StatsHandler:
                    "history_visibility"
                )
            elif delta.event_type == EventTypes.RoomEncryption:
-                room_state["encryption"] = event_content.get("algorithm")
+                room_state["encryption"] = event_content.get(
+                    EventContentFields.ENCRYPTION_ALGORITHM
+                )
            elif delta.event_type == EventTypes.Name:
                room_state["name"] = event_content.get("name")
            elif delta.event_type == EventTypes.Topic:
@@ -1352,7 +1352,7 @@ class SyncHandler:
            await_full_state = True
            lazy_load_members = False

-        state_at_timeline_end = await self._state_storage_controller.get_state_at(
+        state_at_timeline_end = await self._state_storage_controller.get_state_ids_at(
            room_id,
            stream_position=end_token,
            state_filter=state_filter,
@@ -1480,11 +1480,13 @@ class SyncHandler:
        else:
            # We can get here if the user has ignored the senders of all
            # the recent events.
-            state_at_timeline_start = await self._state_storage_controller.get_state_at(
-                room_id,
-                stream_position=end_token,
-                state_filter=state_filter,
-                await_full_state=await_full_state,
+            state_at_timeline_start = (
+                await self._state_storage_controller.get_state_ids_at(
+                    room_id,
+                    stream_position=end_token,
+                    state_filter=state_filter,
+                    await_full_state=await_full_state,
+                )
            )

        if batch.limited:
@@ -1502,14 +1504,14 @@ class SyncHandler:
            # about them).
            state_filter = StateFilter.all()

-        state_at_previous_sync = await self._state_storage_controller.get_state_at(
+        state_at_previous_sync = await self._state_storage_controller.get_state_ids_at(
            room_id,
            stream_position=since_token,
            state_filter=state_filter,
            await_full_state=await_full_state,
        )

-        state_at_timeline_end = await self._state_storage_controller.get_state_at(
+        state_at_timeline_end = await self._state_storage_controller.get_state_ids_at(
            room_id,
            stream_position=end_token,
            state_filter=state_filter,
@@ -2268,7 +2270,11 @@ class SyncHandler:
            user=user,
            from_key=presence_key,
            is_guest=sync_config.is_guest,
-            include_offline=include_offline,
+            include_offline=(
+                True
+                if self.hs_config.server.presence_include_offline_users_on_sync
+                else include_offline
+            ),
        )
        assert presence_key
        sync_result_builder.now_token = now_token.copy_and_replace(
@@ -2508,7 +2514,7 @@ class SyncHandler:
                continue

            if room_id in sync_result_builder.joined_room_ids or has_join:
-                old_state_ids = await self._state_storage_controller.get_state_at(
+                old_state_ids = await self._state_storage_controller.get_state_ids_at(
                    room_id,
                    since_token,
                    state_filter=StateFilter.from_types([(EventTypes.Member, user_id)]),
@@ -2539,7 +2545,7 @@ class SyncHandler:
                else:
                    if not old_state_ids:
                        old_state_ids = (
-                            await self._state_storage_controller.get_state_at(
+                            await self._state_storage_controller.get_state_ids_at(
                                room_id,
                                since_token,
                                state_filter=StateFilter.from_types(
@@ -565,7 +565,12 @@ class TypingNotificationEventSource(EventSource[int, JsonMapping]):
        room_ids: Iterable[str],
        is_guest: bool,
        explicit_room_id: Optional[str] = None,
+        to_key: Optional[int] = None,
    ) -> Tuple[List[JsonMapping], int]:
+        """
+        Find typing notifications for given rooms (> `from_token` and <= `to_token`)
+        """
+
        with Measure(self.clock, "typing.get_new_events"):
            from_key = int(from_key)
            handler = self.get_typing_handler()
@@ -574,7 +579,9 @@ class TypingNotificationEventSource(EventSource[int, JsonMapping]):
            for room_id in room_ids:
                if room_id not in handler._room_serials:
                    continue
-                if handler._room_serials[room_id] <= from_key:
+                if handler._room_serials[room_id] <= from_key or (
+                    to_key is not None and handler._room_serials[room_id] > to_key
+                ):
                    continue

                events.append(self._make_event_for(room_id))
@@ -35,6 +35,8 @@ from typing import (
    Union,
 )

+import attr
+import multipart
 import treq
 from canonicaljson import encode_canonical_json
 from netaddr import AddrFormatError, IPAddress, IPSet
@@ -1006,6 +1008,130 @@ class _DiscardBodyWithMaxSizeProtocol(protocol.Protocol):
        self._maybe_fail()


+@attr.s(auto_attribs=True, slots=True)
+class MultipartResponse:
+    """
+    A small class to hold parsed values of a multipart response.
+    """
+
+    json: bytes = b"{}"
+    length: Optional[int] = None
+    content_type: Optional[bytes] = None
+    disposition: Optional[bytes] = None
+    url: Optional[bytes] = None
+
+
+class _MultipartParserProtocol(protocol.Protocol):
+    """
+    Protocol to read and parse a MSC3916 multipart/mixed response
+    """
+
+    transport: Optional[ITCPTransport] = None
+
+    def __init__(
+        self,
+        stream: ByteWriteable,
+        deferred: defer.Deferred,
+        boundary: str,
+        max_length: Optional[int],
+    ) -> None:
+        self.stream = stream
+        self.deferred = deferred
+        self.boundary = boundary
+        self.max_length = max_length
+        self.parser = None
+        self.multipart_response = MultipartResponse()
+        self.has_redirect = False
+        self.in_json = False
+        self.json_done = False
+        self.file_length = 0
+        self.total_length = 0
+        self.in_disposition = False
+        self.in_content_type = False
+
+    def dataReceived(self, incoming_data: bytes) -> None:
+        if self.deferred.called:
+            return
+
+        # we don't have a parser yet, instantiate it
+        if not self.parser:
+
+            def on_header_field(data: bytes, start: int, end: int) -> None:
+                if data[start:end] == b"Location":
+                    self.has_redirect = True
+                if data[start:end] == b"Content-Disposition":
+                    self.in_disposition = True
+                if data[start:end] == b"Content-Type":
+                    self.in_content_type = True
+
+            def on_header_value(data: bytes, start: int, end: int) -> None:
+                # the first header should be content-type for application/json
+                if not self.in_json and not self.json_done:
+                    assert data[start:end] == b"application/json"
+                    self.in_json = True
+                elif self.has_redirect:
+                    self.multipart_response.url = data[start:end]
+                elif self.in_content_type:
+                    self.multipart_response.content_type = data[start:end]
+                    self.in_content_type = False
+                elif self.in_disposition:
+                    self.multipart_response.disposition = data[start:end]
+                    self.in_disposition = False
+
+            def on_part_data(data: bytes, start: int, end: int) -> None:
+                # we've seen json header but haven't written the json data
+                if self.in_json and not self.json_done:
+                    self.multipart_response.json = data[start:end]
+                    self.json_done = True
+                # we have a redirect header rather than a file, and have already captured it
+                elif self.has_redirect:
+                    return
+                # otherwise we are in the file part
+                else:
+                    logger.info("Writing multipart file data to stream")
+                    try:
+                        self.stream.write(data[start:end])
+                    except Exception as e:
+                        logger.warning(
+                            f"Exception encountered writing file data to stream: {e}"
+                        )
+                        self.deferred.errback()
+                    self.file_length += end - start
+
+            callbacks = {
+                "on_header_field": on_header_field,
+                "on_header_value": on_header_value,
+                "on_part_data": on_part_data,
+            }
+            self.parser = multipart.MultipartParser(self.boundary, callbacks)
+
+        self.total_length += len(incoming_data)
+        if self.max_length is not None and self.total_length >= self.max_length:
+            self.deferred.errback(BodyExceededMaxSize())
+            # Close the connection (forcefully) since all the data will get
+            # discarded anyway.
+            assert self.transport is not None
+            self.transport.abortConnection()
+
+        try:
+            self.parser.write(incoming_data)  # type: ignore[attr-defined]
+        except Exception as e:
+            logger.warning(f"Exception writing to multipart parser: {e}")
+            self.deferred.errback()
+            return
+
+    def connectionLost(self, reason: Failure = connectionDone) -> None:
+        # If the maximum size was already exceeded, there's nothing to do.
+        if self.deferred.called:
+            return
+
+        if reason.check(ResponseDone):
+            self.multipart_response.length = self.file_length
+            self.deferred.callback(self.multipart_response)
+        else:
+            self.deferred.errback(reason)
+
+
 class _ReadBodyWithMaxSizeProtocol(protocol.Protocol):
    """A protocol which reads body to a stream, erroring if the body exceeds a maximum size."""

@@ -1091,6 +1217,32 @@ def read_body_with_max_size(
    return d


+def read_multipart_response(
+    response: IResponse, stream: ByteWriteable, boundary: str, max_length: Optional[int]
+) -> "defer.Deferred[MultipartResponse]":
+    """
+    Reads a MSC3916 multipart/mixed response and parses it, reading the file part (if it contains one) into
+    the stream passed in and returning a deferred resolving to a MultipartResponse
+
+    Args:
+        response: The HTTP response to read from.
+        stream: The file-object to write to.
+        boundary: the multipart/mixed boundary string
+        max_length: maximum allowable length of the response
+    """
+    d: defer.Deferred[MultipartResponse] = defer.Deferred()
+
+    # If the Content-Length header gives a size larger than the maximum allowed
+    # size, do not bother downloading the body.
+    if max_length is not None and response.length != UNKNOWN_LENGTH:
+        if response.length > max_length:
+            response.deliverBody(_DiscardBodyWithMaxSizeProtocol(d))
+            return d
+
+    response.deliverBody(_MultipartParserProtocol(stream, d, boundary, max_length))
+    return d
+
+
 def encode_query_args(args: Optional[QueryParams]) -> bytes:
    """
    Encodes a map of query arguments to bytes which can be appended to a URL.
@@ -75,9 +75,11 @@ from synapse.http.client import (
    BlocklistingAgentWrapper,
    BodyExceededMaxSize,
    ByteWriteable,
+    SimpleHttpClient,
    _make_scheduler,
    encode_query_args,
    read_body_with_max_size,
+    read_multipart_response,
 )
 from synapse.http.connectproxyclient import BearerProxyCredentials
 from synapse.http.federation.matrix_federation_agent import MatrixFederationAgent
@@ -88,7 +90,7 @@ from synapse.logging.context import make_deferred_yieldable, run_in_background
 from synapse.logging.opentracing import set_tag, start_active_span, tags
 from synapse.types import JsonDict
 from synapse.util import json_decoder
-from synapse.util.async_helpers import AwakenableSleeper, timeout_deferred
+from synapse.util.async_helpers import AwakenableSleeper, Linearizer, timeout_deferred
 from synapse.util.metrics import Measure
 from synapse.util.stringutils import parse_and_validate_server_name

@@ -466,6 +468,15 @@ class MatrixFederationHttpClient:

        self._sleeper = AwakenableSleeper(self.reactor)

+        self._simple_http_client = SimpleHttpClient(
+            hs,
+            ip_blocklist=hs.config.server.federation_ip_range_blocklist,
+            ip_allowlist=hs.config.server.federation_ip_range_allowlist,
+            use_proxy=True,
+        )
+
+        self.remote_download_linearizer = Linearizer("remote_download_linearizer", 6)
+
    def wake_destination(self, destination: str) -> None:
        """Called when the remote server may have come back online."""

@@ -1477,35 +1488,44 @@ class MatrixFederationHttpClient:
        )

        headers = dict(response.headers.getAllRawHeaders())
-
        expected_size = response.length
-        # if we don't get an expected length then use the max length
+
        if expected_size == UNKNOWN_LENGTH:
            expected_size = max_size
-            logger.debug(
-                f"File size unknown, assuming file is max allowable size: {max_size}"
-            )
+        else:
+            if int(expected_size) > max_size:
+                msg = "Requested file is too large > %r bytes" % (max_size,)
+                logger.warning(
+                    "{%s} [%s] %s",
+                    request.txn_id,
+                    request.destination,
+                    msg,
+                )
+                raise SynapseError(HTTPStatus.BAD_GATEWAY, msg, Codes.TOO_LARGE)

-        read_body, _ = await download_ratelimiter.can_do_action(
-            requester=None,
-            key=ip_address,
-            n_actions=expected_size,
-        )
-        if not read_body:
-            msg = "Requested file size exceeds ratelimits"
-            logger.warning(
-                "{%s} [%s] %s",
-                request.txn_id,
-                request.destination,
-                msg,
+            read_body, _ = await download_ratelimiter.can_do_action(
+                requester=None,
+                key=ip_address,
+                n_actions=expected_size,
            )
-            raise SynapseError(HTTPStatus.TOO_MANY_REQUESTS, msg, Codes.LIMIT_EXCEEDED)
+            if not read_body:
+                msg = "Requested file size exceeds ratelimits"
+                logger.warning(
+                    "{%s} [%s] %s",
+                    request.txn_id,
+                    request.destination,
+                    msg,
+                )
+                raise SynapseError(
+                    HTTPStatus.TOO_MANY_REQUESTS, msg, Codes.LIMIT_EXCEEDED
+                )

        try:
-            # add a byte of headroom to max size as function errs at >=
-            d = read_body_with_max_size(response, output_stream, expected_size + 1)
-            d.addTimeout(self.default_timeout_seconds, self.reactor)
-            length = await make_deferred_yieldable(d)
+            async with self.remote_download_linearizer.queue(ip_address):
+                # add a byte of headroom to max size as function errs at >=
+                d = read_body_with_max_size(response, output_stream, expected_size + 1)
+                d.addTimeout(self.default_timeout_seconds, self.reactor)
+                length = await make_deferred_yieldable(d)
        except BodyExceededMaxSize:
            msg = "Requested file is too large > %r bytes" % (expected_size,)
            logger.warning(
@@ -1551,8 +1571,214 @@ class MatrixFederationHttpClient:
            request.method,
            request.uri.decode("ascii"),
        )
+
+        # if we didn't know the length upfront, decrement the actual size from ratelimiter
+        if response.length == UNKNOWN_LENGTH:
+            download_ratelimiter.record_action(
+                requester=None, key=ip_address, n_actions=length
+            )
+
        return length, headers

+    async def federation_get_file(
+        self,
+        destination: str,
+        path: str,
+        output_stream: BinaryIO,
+        download_ratelimiter: Ratelimiter,
+        ip_address: str,
+        max_size: int,
+        args: Optional[QueryParams] = None,
+        retry_on_dns_fail: bool = True,
+        ignore_backoff: bool = False,
+    ) -> Tuple[int, Dict[bytes, List[bytes]], bytes]:
+        """GETs a file from a given homeserver over the federation /download endpoint
+        Args:
+            destination: The remote server to send the HTTP request to.
+            path: The HTTP path to GET.
+            output_stream: File to write the response body to.
+            download_ratelimiter: a ratelimiter to limit remote media downloads, keyed to
+                requester IP
+            ip_address: IP address of the requester
+            max_size: maximum allowable size in bytes of the file
+            args: Optional dictionary used to create the query string.
+            ignore_backoff: true to ignore the historical backoff data
+                and try the request anyway.
+
+        Returns:
+            Resolves to an (int, dict, bytes) tuple of
+            the file length, a dict of the response headers, and the file json
+
+        Raises:
+            HttpResponseException: If we get an HTTP response code >= 300
+                (except 429).
+            NotRetryingDestination: If we are not yet ready to retry this
+                server.
+            FederationDeniedError: If this destination is not on our
+                federation whitelist
+            RequestSendFailed: If there were problems connecting to the
+                remote, due to e.g. DNS failures, connection timeouts etc.
+            SynapseError: If the requested file exceeds ratelimits or the response from the
+            remote server is not a multipart response
+            AssertionError: if the resolved multipart response's length is None
+        """
+        request = MatrixFederationRequest(
+            method="GET", destination=destination, path=path, query=args
+        )
+
+        # check for a minimum balance of 1MiB in ratelimiter before initiating request
+        send_req, _ = await download_ratelimiter.can_do_action(
+            requester=None, key=ip_address, n_actions=1048576, update=False
+        )
+
+        if not send_req:
+            msg = "Requested file size exceeds ratelimits"
+            logger.warning(
+                "{%s} [%s] %s",
+                request.txn_id,
+                request.destination,
+                msg,
+            )
+            raise SynapseError(HTTPStatus.TOO_MANY_REQUESTS, msg, Codes.LIMIT_EXCEEDED)
+
+        response = await self._send_request(
+            request,
+            retry_on_dns_fail=retry_on_dns_fail,
+            ignore_backoff=ignore_backoff,
+        )
+
+        headers = dict(response.headers.getAllRawHeaders())
+        expected_size = response.length
+
+        if expected_size == UNKNOWN_LENGTH:
+            expected_size = max_size
+        else:
+            if int(expected_size) > max_size:
+                msg = "Requested file is too large > %r bytes" % (max_size,)
+                logger.warning(
+                    "{%s} [%s] %s",
+                    request.txn_id,
+                    request.destination,
+                    msg,
+                )
+                raise SynapseError(HTTPStatus.BAD_GATEWAY, msg, Codes.TOO_LARGE)
+
+            read_body, _ = await download_ratelimiter.can_do_action(
+                requester=None,
+                key=ip_address,
+                n_actions=expected_size,
+            )
+            if not read_body:
+                msg = "Requested file size exceeds ratelimits"
+                logger.warning(
+                    "{%s} [%s] %s",
+                    request.txn_id,
+                    request.destination,
+                    msg,
+                )
+                raise SynapseError(
+                    HTTPStatus.TOO_MANY_REQUESTS, msg, Codes.LIMIT_EXCEEDED
+                )
+
+        # this should be a multipart/mixed response with the boundary string in the header
+        try:
+            raw_content_type = headers.get(b"Content-Type")
+            assert raw_content_type is not None
+            content_type = raw_content_type[0].decode("UTF-8")
+            content_type_parts = content_type.split("boundary=")
+            boundary = content_type_parts[1]
+        except Exception:
+            msg = "Remote response is malformed: expected Content-Type of multipart/mixed with a boundary present."
+            logger.warning(
+                "{%s} [%s] %s",
+                request.txn_id,
+                request.destination,
+                msg,
+            )
+            raise SynapseError(HTTPStatus.BAD_GATEWAY, msg)
+
+        try:
+            async with self.remote_download_linearizer.queue(ip_address):
+                # add a byte of headroom to max size as `_MultipartParserProtocol.dataReceived` errs at >=
+                deferred = read_multipart_response(
+                    response, output_stream, boundary, expected_size + 1
+                )
+                deferred.addTimeout(self.default_timeout_seconds, self.reactor)
+        except BodyExceededMaxSize:
+            msg = "Requested file is too large > %r bytes" % (expected_size,)
+            logger.warning(
+                "{%s} [%s] %s",
+                request.txn_id,
+                request.destination,
+                msg,
+            )
+            raise SynapseError(HTTPStatus.BAD_GATEWAY, msg, Codes.TOO_LARGE)
+        except defer.TimeoutError as e:
+            logger.warning(
+                "{%s} [%s] Timed out reading response - %s %s",
+                request.txn_id,
+                request.destination,
+                request.method,
+                request.uri.decode("ascii"),
+            )
+            raise RequestSendFailed(e, can_retry=True) from e
+        except ResponseFailed as e:
+            logger.warning(
+                "{%s} [%s] Failed to read response - %s %s",
+                request.txn_id,
+                request.destination,
+                request.method,
+                request.uri.decode("ascii"),
+            )
+            raise RequestSendFailed(e, can_retry=True) from e
+        except Exception as e:
+            logger.warning(
+                "{%s} [%s] Error reading response: %s",
+                request.txn_id,
+                request.destination,
+                e,
+            )
+            raise
+
+        multipart_response = await make_deferred_yieldable(deferred)
+        if not multipart_response.url:
+            assert multipart_response.length is not None
+            length = multipart_response.length
+            headers[b"Content-Type"] = [multipart_response.content_type]
+            headers[b"Content-Disposition"] = [multipart_response.disposition]
+
+        # the response contained a redirect url to download the file from
+        else:
+            str_url = multipart_response.url.decode("utf-8")
+            logger.info(
+                "{%s} [%s] File download redirected, now downloading from: %s",
+                request.txn_id,
+                request.destination,
+                str_url,
+            )
+            length, headers, _, _ = await self._simple_http_client.get_file(
+                str_url, output_stream, expected_size
+            )
+
+        logger.info(
+            "{%s} [%s] Completed: %d %s [%d bytes] %s %s",
+            request.txn_id,
+            request.destination,
+            response.code,
+            response.phrase.decode("ascii", errors="replace"),
+            length,
+            request.method,
+            request.uri.decode("ascii"),
+        )
+
+        # if we didn't know the length upfront, decrement the actual size from ratelimiter
+        if response.length == UNKNOWN_LENGTH:
+            download_ratelimiter.record_action(
+                requester=None, key=ip_address, n_actions=length
+            )
+
+        return length, headers, multipart_response.json
+

 def _flatten_response_never_received(e: BaseException) -> str:
    if hasattr(e, "reasons"):
@@ -62,6 +62,15 @@ HOP_BY_HOP_HEADERS = {
    "Upgrade",
 }

+if hasattr(Headers, "_canonicalNameCaps"):
+    # Twisted < 24.7.0rc1
+    _canonicalHeaderName = Headers()._canonicalNameCaps  # type: ignore[attr-defined]
+else:
+    # Twisted >= 24.7.0rc1
+    # But note that `_encodeName` still exists on prior versions,
+    # it just encodes differently
+    _canonicalHeaderName = Headers()._encodeName
+

 def parse_connection_header_value(
    connection_header_value: Optional[bytes],
@@ -85,11 +94,10 @@ def parse_connection_header_value(
        The set of header names that should not be copied over from the remote response.
        The keys are capitalized in canonical capitalization.
    """
-    headers = Headers()
    extra_headers_to_remove: Set[str] = set()
    if connection_header_value:
        extra_headers_to_remove = {
-            headers._canonicalNameCaps(connection_option.strip()).decode("ascii")
+            _canonicalHeaderName(connection_option.strip()).decode("ascii")
            for connection_option in connection_header_value.split(b",")
        }

@@ -74,6 +74,7 @@ from synapse.api.errors import (
 from synapse.config.homeserver import HomeServerConfig
 from synapse.logging.context import defer_to_thread, preserve_fn, run_in_background
 from synapse.logging.opentracing import active_span, start_active_span, trace_servlet
+from synapse.types import ISynapseReactor
 from synapse.util import json_encoder
 from synapse.util.caches import intern_dict
 from synapse.util.cancellation import is_function_cancellable
@@ -868,7 +869,8 @@ async def _async_write_json_to_request_in_thread(

    with start_active_span("encode_json_response"):
        span = active_span()
-        json_str = await defer_to_thread(request.reactor, encode, span)
+        reactor: ISynapseReactor = request.reactor  # type: ignore
+        json_str = await defer_to_thread(reactor, encode, span)

    _write_bytes_to_request(request, json_str)

@@ -683,7 +683,7 @@ class SynapseSite(ProxySite):
        self.access_logger = logging.getLogger(logger_name)
        self.server_version_string = server_version_string.encode("ascii")

-    def log(self, request: SynapseRequest) -> None:
+    def log(self, request: SynapseRequest) -> None:  # type: ignore[override]
        pass


@@ -221,6 +221,7 @@ def add_file_headers(
    # select private. don't bother setting Expires as all our
    # clients are smart enough to be happy with Cache-Control
    request.setHeader(b"Cache-Control", b"public,max-age=86400,s-maxage=86400")
+
    if file_size is not None:
        request.setHeader(b"Content-Length", b"%d" % (file_size,))

@@ -302,12 +303,37 @@ async def respond_with_multipart_responder(
            )
            return

+        if media_info.media_type.lower().split(";", 1)[0] in INLINE_CONTENT_TYPES:
+            disposition = "inline"
+        else:
+            disposition = "attachment"
+
+        def _quote(x: str) -> str:
+            return urllib.parse.quote(x.encode("utf-8"))
+
+        if media_info.upload_name:
+            if _can_encode_filename_as_token(media_info.upload_name):
+                disposition = "%s; filename=%s" % (
+                    disposition,
+                    media_info.upload_name,
+                )
+            else:
+                disposition = "%s; filename*=utf-8''%s" % (
+                    disposition,
+                    _quote(media_info.upload_name),
+                )
+
        from synapse.media.media_storage import MultipartFileConsumer

        # note that currently the json_object is just {}, this will change when linked media
        # is implemented
        multipart_consumer = MultipartFileConsumer(
-            clock, request, media_info.media_type, {}, media_info.media_length
+            clock,
+            request,
+            media_info.media_type,
+            {},
+            disposition,
+            media_info.media_length,
        )

        logger.debug("Responding to media request with responder %s", responder)
@@ -430,6 +430,7 @@ class MediaRepository:
        media_id: str,
        name: Optional[str],
        max_timeout_ms: int,
+        allow_authenticated: bool = True,
        federation: bool = False,
    ) -> None:
        """Responds to requests for local media, if exists, or returns 404.
@@ -442,6 +443,7 @@ class MediaRepository:
                the filename in the Content-Disposition header of the response.
            max_timeout_ms: the maximum number of milliseconds to wait for the
                media to be uploaded.
+            allow_authenticated: whether media marked as authenticated may be served to this request
            federation: whether the local media being fetched is for a federation request

        Returns:
@@ -451,6 +453,10 @@ class MediaRepository:
        if not media_info:
            return

+        if self.hs.config.media.enable_authenticated_media and not allow_authenticated:
+            if media_info.authenticated:
+                raise NotFoundError()
+
        self.mark_recently_accessed(None, media_id)

        media_type = media_info.media_type
@@ -480,6 +486,8 @@ class MediaRepository:
        name: Optional[str],
        max_timeout_ms: int,
        ip_address: str,
+        use_federation_endpoint: bool,
+        allow_authenticated: bool = True,
    ) -> None:
        """Respond to requests for remote media.

@@ -492,6 +500,10 @@ class MediaRepository:
            max_timeout_ms: the maximum number of milliseconds to wait for the
                media to be uploaded.
            ip_address: the IP address of the requester
+            use_federation_endpoint: whether to request the remote media over the new
+                federation `/download` endpoint
+            allow_authenticated: whether media marked as authenticated may be served to this
+                request

        Returns:
            Resolves once a response has successfully been written to request
@@ -522,6 +534,8 @@ class MediaRepository:
                max_timeout_ms,
                self.download_ratelimiter,
                ip_address,
+                use_federation_endpoint,
+                allow_authenticated,
            )

        # We deliberately stream the file outside the lock
@@ -538,7 +552,13 @@ class MediaRepository:
            respond_404(request)

    async def get_remote_media_info(
-        self, server_name: str, media_id: str, max_timeout_ms: int, ip_address: str
+        self,
+        server_name: str,
+        media_id: str,
+        max_timeout_ms: int,
+        ip_address: str,
+        use_federation: bool,
+        allow_authenticated: bool,
    ) -> RemoteMedia:
        """Gets the media info associated with the remote file, downloading
        if necessary.
@@ -549,6 +569,10 @@ class MediaRepository:
            max_timeout_ms: the maximum number of milliseconds to wait for the
                media to be uploaded.
            ip_address: IP address of the requester
+            use_federation: if a download is necessary, whether to request the remote file
+                over the federation `/download` endpoint
+            allow_authenticated: whether media marked as authenticated may be served to this
+                request

        Returns:
            The media info of the file
@@ -569,6 +593,8 @@ class MediaRepository:
                max_timeout_ms,
                self.download_ratelimiter,
                ip_address,
+                use_federation,
+                allow_authenticated,
            )

        # Ensure we actually use the responder so that it releases resources
@@ -585,6 +611,8 @@ class MediaRepository:
        max_timeout_ms: int,
        download_ratelimiter: Ratelimiter,
        ip_address: str,
+        use_federation_endpoint: bool,
+        allow_authenticated: bool,
    ) -> Tuple[Optional[Responder], RemoteMedia]:
        """Looks for media in local cache, if not there then attempt to
        download from remote server.
@@ -598,12 +626,19 @@ class MediaRepository:
            download_ratelimiter: a ratelimiter limiting remote media downloads, keyed to
                requester IP.
            ip_address: the IP address of the requester
+            use_federation_endpoint: whether to request the remote media over the new federation
+            /download endpoint

        Returns:
            A tuple of responder and the media info of the file.
        """
        media_info = await self.store.get_cached_remote_media(server_name, media_id)

+        if self.hs.config.media.enable_authenticated_media and not allow_authenticated:
+            # if it isn't cached then don't fetch it or if it's authenticated then don't serve it
+            if not media_info or media_info.authenticated:
+                raise NotFoundError()
+
        # file_id is the ID we use to track the file locally. If we've already
        # seen the file then reuse the existing ID, otherwise generate a new
        # one.
@@ -629,9 +664,23 @@ class MediaRepository:
        # Failed to find the file anywhere, lets download it.

        try:
-            media_info = await self._download_remote_file(
-                server_name, media_id, max_timeout_ms, download_ratelimiter, ip_address
-            )
+            if not use_federation_endpoint:
+                media_info = await self._download_remote_file(
+                    server_name,
+                    media_id,
+                    max_timeout_ms,
+                    download_ratelimiter,
+                    ip_address,
+                )
+            else:
+                media_info = await self._federation_download_remote_file(
+                    server_name,
+                    media_id,
+                    max_timeout_ms,
+                    download_ratelimiter,
+                    ip_address,
+                )
+
        except SynapseError:
            raise
        except Exception as e:
@@ -763,6 +812,11 @@ class MediaRepository:

        logger.info("Stored remote media in file %r", fname)

+        if self.hs.config.media.enable_authenticated_media:
+            authenticated = True
+        else:
+            authenticated = False
+
        return RemoteMedia(
            media_origin=server_name,
            media_id=media_id,
@@ -773,6 +827,136 @@ class MediaRepository:
            filesystem_id=file_id,
            last_access_ts=time_now_ms,
            quarantined_by=None,
+            authenticated=authenticated,
+        )
+
+    async def _federation_download_remote_file(
+        self,
+        server_name: str,
+        media_id: str,
+        max_timeout_ms: int,
+        download_ratelimiter: Ratelimiter,
+        ip_address: str,
+    ) -> RemoteMedia:
+        """Attempt to download the remote file from the given server name.
+        Uses the given file_id as the local id and downloads the file over the federation
+        v1 download endpoint
+
+        Args:
+            server_name: Originating server
+            media_id: The media ID of the content (as defined by the
+                remote server). This is different than the file_id, which is
+                locally generated.
+            max_timeout_ms: the maximum number of milliseconds to wait for the
+                media to be uploaded.
+            download_ratelimiter: a ratelimiter limiting remote media downloads, keyed to
+                requester IP
+            ip_address: the IP address of the requester
+
+        Returns:
+            The media info of the file.
+        """
+
+        file_id = random_string(24)
+
+        file_info = FileInfo(server_name=server_name, file_id=file_id)
+
+        async with self.media_storage.store_into_file(file_info) as (f, fname):
+            try:
+                res = await self.client.federation_download_media(
+                    server_name,
+                    media_id,
+                    output_stream=f,
+                    max_size=self.max_upload_size,
+                    max_timeout_ms=max_timeout_ms,
+                    download_ratelimiter=download_ratelimiter,
+                    ip_address=ip_address,
+                )
+                # if we had to fall back to the _matrix/media endpoint it will only return
+                # the headers and length, check the length of the tuple before unpacking
+                if len(res) == 3:
+                    length, headers, json = res
+                else:
+                    length, headers = res
+            except RequestSendFailed as e:
+                logger.warning(
+                    "Request failed fetching remote media %s/%s: %r",
+                    server_name,
+                    media_id,
+                    e,
+                )
+                raise SynapseError(502, "Failed to fetch remote media")
+
+            except HttpResponseException as e:
+                logger.warning(
+                    "HTTP error fetching remote media %s/%s: %s",
+                    server_name,
+                    media_id,
+                    e.response,
+                )
+                if e.code == twisted.web.http.NOT_FOUND:
+                    raise e.to_synapse_error()
+                raise SynapseError(502, "Failed to fetch remote media")
+
+            except SynapseError:
+                logger.warning(
+                    "Failed to fetch remote media %s/%s", server_name, media_id
+                )
+                raise
+            except NotRetryingDestination:
+                logger.warning("Not retrying destination %r", server_name)
+                raise SynapseError(502, "Failed to fetch remote media")
+            except Exception:
+                logger.exception(
+                    "Failed to fetch remote media %s/%s", server_name, media_id
+                )
+                raise SynapseError(502, "Failed to fetch remote media")
+
+            if b"Content-Type" in headers:
+                media_type = headers[b"Content-Type"][0].decode("ascii")
+            else:
+                media_type = "application/octet-stream"
+            upload_name = get_filename_from_headers(headers)
+            time_now_ms = self.clock.time_msec()
+
+            # Multiple remote media download requests can race (when using
+            # multiple media repos), so this may throw a violation constraint
+            # exception. If it does we'll delete the newly downloaded file from
+            # disk (as we're in the ctx manager).
+            #
+            # However: we've already called `finish()` so we may have also
+            # written to the storage providers. This is preferable to the
+            # alternative where we call `finish()` *after* this, where we could
+            # end up having an entry in the DB but fail to write the files to
+            # the storage providers.
+            await self.store.store_cached_remote_media(
+                origin=server_name,
+                media_id=media_id,
+                media_type=media_type,
+                time_now_ms=time_now_ms,
+                upload_name=upload_name,
+                media_length=length,
+                filesystem_id=file_id,
+            )
+
+        logger.debug("Stored remote media in file %r", fname)
+
+        if self.hs.config.media.enable_authenticated_media:
+            authenticated = True
+        else:
+            authenticated = False
+
+        return RemoteMedia(
+            media_origin=server_name,
+            media_id=media_id,
+            media_type=media_type,
+            media_length=length,
+            upload_name=upload_name,
+            created_ts=time_now_ms,
+            filesystem_id=file_id,
+            last_access_ts=time_now_ms,
+            quarantined_by=None,
+            authenticated=authenticated,
        )

    def _get_thumbnail_requirements(
@@ -878,7 +1062,12 @@ class MediaRepository:
            t_len = os.path.getsize(output_path)

            await self.store.store_local_thumbnail(
-                media_id, t_width, t_height, t_type, t_method, t_len
+                media_id,
+                t_width,
+                t_height,
+                t_type,
+                t_method,
+                t_len,
            )

            return output_path
@@ -401,13 +401,14 @@ class MultipartFileConsumer:
        wrapped_consumer: interfaces.IConsumer,
        file_content_type: str,
        json_object: JsonDict,
-        content_length: Optional[int] = None,
+        disposition: str,
+        content_length: Optional[int],
    ) -> None:
        self.clock = clock
        self.wrapped_consumer = wrapped_consumer
        self.json_field = json_object
        self.json_field_written = False
-        self.content_type_written = False
+        self.file_headers_written = False
        self.file_content_type = file_content_type
        self.boundary = uuid4().hex.encode("ascii")

@@ -420,6 +421,7 @@ class MultipartFileConsumer:
        self.paused = False

        self.length = content_length
+        self.disposition = disposition

    ### IConsumer APIs ###

@@ -488,11 +490,13 @@ class MultipartFileConsumer:
            self.json_field_written = True

        # if we haven't written the content type yet, do so
-        if not self.content_type_written:
+        if not self.file_headers_written:
            type = self.file_content_type.encode("utf-8")
            content_type = Header(b"Content-Type", type)
-            self.wrapped_consumer.write(bytes(content_type) + CRLF + CRLF)
-            self.content_type_written = True
+            self.wrapped_consumer.write(bytes(content_type) + CRLF)
+            disp_header = Header(b"Content-Disposition", self.disposition)
+            self.wrapped_consumer.write(bytes(disp_header) + CRLF + CRLF)
+            self.file_headers_written = True

        self.wrapped_consumer.write(data)

@@ -506,7 +510,6 @@ class MultipartFileConsumer:
        producing data for good.
        """
        assert self.producer is not None
-
        self.paused = True
        self.producer.stopProducing()

@@ -518,7 +521,6 @@ class MultipartFileConsumer:
        the time being, and to stop until C{resumeProducing()} is called.
        """
        assert self.producer is not None
-
        self.paused = True

        if self.streaming:
@@ -549,7 +551,7 @@ class MultipartFileConsumer:
        """
        if not self.length:
            return None
-        # calculate length of json field and content-type header
+        # calculate length of json field and content-type, disposition headers
        json_field = json.dumps(self.json_field)
        json_bytes = json_field.encode("utf-8")
        json_length = len(json_bytes)
@@ -558,9 +560,13 @@ class MultipartFileConsumer:
        content_type = Header(b"Content-Type", type)
        type_length = len(bytes(content_type))

-        # 154 is the length of the elements that aren't variable, ie
+        disp = self.disposition.encode("utf-8")
+        disp_header = Header(b"Content-Disposition", disp)
+        disp_length = len(bytes(disp_header))
+
+        # 156 is the length of the elements that aren't variable, ie
        # CRLFs and boundary strings, etc
-        self.length += json_length + type_length + 154
+        self.length += json_length + type_length + disp_length + 156

        return self.length

@@ -569,7 +575,6 @@ class MultipartFileConsumer:
    async def _resumeProducingRepeatedly(self) -> None:
        assert self.producer is not None
        assert not self.streaming
-
        producer = cast("interfaces.IPullProducer", self.producer)

        self.paused = False
@@ -26,7 +26,7 @@ from typing import TYPE_CHECKING, List, Optional, Tuple, Type

 from PIL import Image

-from synapse.api.errors import Codes, SynapseError, cs_error
+from synapse.api.errors import Codes, NotFoundError, SynapseError, cs_error
 from synapse.config.repository import THUMBNAIL_SUPPORTED_MEDIA_FORMAT_MAP
 from synapse.http.server import respond_with_json
 from synapse.http.site import SynapseRequest
@@ -36,9 +36,11 @@ from synapse.media._base import (
    ThumbnailInfo,
    respond_404,
    respond_with_file,
+    respond_with_multipart_responder,
    respond_with_responder,
 )
-from synapse.media.media_storage import MediaStorage
+from synapse.media.media_storage import FileResponder, MediaStorage
+from synapse.storage.databases.main.media_repository import LocalMedia

 if TYPE_CHECKING:
    from synapse.media.media_repository import MediaRepository
@@ -271,6 +273,8 @@ class ThumbnailProvider:
        method: str,
        m_type: str,
        max_timeout_ms: int,
+        for_federation: bool,
+        allow_authenticated: bool = True,
    ) -> None:
        media_info = await self.media_repo.get_local_media_info(
            request, media_id, max_timeout_ms
@@ -278,6 +282,12 @@ class ThumbnailProvider:
        if not media_info:
            return

+        # if the media the thumbnail is generated from is authenticated, don't serve the
+        # thumbnail over an unauthenticated endpoint
+        if self.hs.config.media.enable_authenticated_media and not allow_authenticated:
+            if media_info.authenticated:
+                raise NotFoundError()
+
        thumbnail_infos = await self.store.get_local_media_thumbnails(media_id)
        await self._select_and_respond_with_thumbnail(
            request,
@@ -290,6 +300,8 @@ class ThumbnailProvider:
            media_id,
            url_cache=bool(media_info.url_cache),
            server_name=None,
+            for_federation=for_federation,
+            media_info=media_info,
        )

    async def select_or_generate_local_thumbnail(
@@ -301,14 +313,21 @@ class ThumbnailProvider:
        desired_method: str,
        desired_type: str,
        max_timeout_ms: int,
+        for_federation: bool,
+        allow_authenticated: bool = True,
    ) -> None:
        media_info = await self.media_repo.get_local_media_info(
            request, media_id, max_timeout_ms
        )
-
        if not media_info:
            return

+        # if the media the thumbnail is generated from is authenticated, don't serve the
+        # thumbnail over an unauthenticated endpoint
+        if self.hs.config.media.enable_authenticated_media and not allow_authenticated:
+            if media_info.authenticated:
+                raise NotFoundError()
+
        thumbnail_infos = await self.store.get_local_media_thumbnails(media_id)
        for info in thumbnail_infos:
            t_w = info.width == desired_width
@@ -326,10 +345,16 @@ class ThumbnailProvider:

                responder = await self.media_storage.fetch_media(file_info)
                if responder:
-                    await respond_with_responder(
-                        request, responder, info.type, info.length
-                    )
-                    return
+                    if for_federation:
+                        await respond_with_multipart_responder(
+                            self.hs.get_clock(), request, responder, media_info
+                        )
+                        return
+                    else:
+                        await respond_with_responder(
+                            request, responder, info.type, info.length
+                        )
+                        return

        logger.debug("We don't have a thumbnail of that size. Generating")

@@ -344,7 +369,15 @@ class ThumbnailProvider:
        )

        if file_path:
-            await respond_with_file(request, desired_type, file_path)
+            if for_federation:
+                await respond_with_multipart_responder(
+                    self.hs.get_clock(),
+                    request,
+                    FileResponder(open(file_path, "rb")),
+                    media_info,
+                )
+            else:
+                await respond_with_file(request, desired_type, file_path)
        else:
            logger.warning("Failed to generate thumbnail")
            raise SynapseError(400, "Failed to generate thumbnail.")
@@ -360,14 +393,28 @@ class ThumbnailProvider:
        desired_type: str,
        max_timeout_ms: int,
        ip_address: str,
+        use_federation: bool,
+        allow_authenticated: bool = True,
    ) -> None:
        media_info = await self.media_repo.get_remote_media_info(
-            server_name, media_id, max_timeout_ms, ip_address
+            server_name,
+            media_id,
+            max_timeout_ms,
+            ip_address,
+            use_federation,
+            allow_authenticated,
        )
        if not media_info:
            respond_404(request)
            return

+        # if the media the thumbnail is generated from is authenticated, don't serve the
+        # thumbnail over an unauthenticated endpoint
+        if self.hs.config.media.enable_authenticated_media and not allow_authenticated:
+            if media_info.authenticated:
+                respond_404(request)
+                return
+
        thumbnail_infos = await self.store.get_remote_media_thumbnails(
            server_name, media_id
        )
@@ -424,16 +471,29 @@ class ThumbnailProvider:
        m_type: str,
        max_timeout_ms: int,
        ip_address: str,
+        use_federation: bool,
+        allow_authenticated: bool = True,
    ) -> None:
        # TODO: Don't download the whole remote file
        # We should proxy the thumbnail from the remote server instead of
        # downloading the remote file and generating our own thumbnails.
        media_info = await self.media_repo.get_remote_media_info(
-            server_name, media_id, max_timeout_ms, ip_address
+            server_name,
+            media_id,
+            max_timeout_ms,
+            ip_address,
+            use_federation,
+            allow_authenticated,
        )
        if not media_info:
            return

+        # if the media the thumbnail is generated from is authenticated, don't serve the
+        # thumbnail over an unauthenticated endpoint
+        if self.hs.config.media.enable_authenticated_media and not allow_authenticated:
+            if media_info.authenticated:
+                raise NotFoundError()
+
        thumbnail_infos = await self.store.get_remote_media_thumbnails(
            server_name, media_id
        )
@@ -448,6 +508,7 @@ class ThumbnailProvider:
            media_info.filesystem_id,
            url_cache=False,
            server_name=server_name,
+            for_federation=False,
        )

    async def _select_and_respond_with_thumbnail(
@@ -461,6 +522,8 @@ class ThumbnailProvider:
        media_id: str,
        file_id: str,
        url_cache: bool,
+        for_federation: bool,
+        media_info: Optional[LocalMedia] = None,
        server_name: Optional[str] = None,
    ) -> None:
        """
@@ -476,6 +539,8 @@ class ThumbnailProvider:
            file_id: The ID of the media that a thumbnail is being requested for.
            url_cache: True if this is from a URL cache.
            server_name: The server name, if this is a remote thumbnail.
+            for_federation: whether the request is from the federation /thumbnail request
+            media_info: metadata about the media being requested.
        """
        logger.debug(
            "_select_and_respond_with_thumbnail: media_id=%s desired=%sx%s (%s) thumbnail_infos=%s",
@@ -511,13 +576,20 @@ class ThumbnailProvider:

            responder = await self.media_storage.fetch_media(file_info)
            if responder:
-                await respond_with_responder(
-                    request,
-                    responder,
-                    file_info.thumbnail.type,
-                    file_info.thumbnail.length,
-                )
-                return
+                if for_federation:
+                    assert media_info is not None
+                    await respond_with_multipart_responder(
+                        self.hs.get_clock(), request, responder, media_info
+                    )
+                    return
+                else:
+                    await respond_with_responder(
+                        request,
+                        responder,
+                        file_info.thumbnail.type,
+                        file_info.thumbnail.length,
+                    )
+                    return

            # If we can't find the thumbnail we regenerate it. This can happen
            # if e.g. we've deleted the thumbnails but still have the original
@@ -558,12 +630,18 @@ class ThumbnailProvider:
                )

            responder = await self.media_storage.fetch_media(file_info)
-            await respond_with_responder(
-                request,
-                responder,
-                file_info.thumbnail.type,
-                file_info.thumbnail.length,
-            )
+            if for_federation:
+                assert media_info is not None
+                await respond_with_multipart_responder(
+                    self.hs.get_clock(), request, responder, media_info
+                )
+            else:
+                await respond_with_responder(
+                    request,
+                    responder,
+                    file_info.thumbnail.type,
+                    file_info.thumbnail.length,
+                )
        else:
            # This might be because:
            # 1. We can't create thumbnails for the given media (corrupted or
@@ -773,6 +773,7 @@ class Notifier:
        stream_token = await self.event_sources.bound_future_token(stream_token)

        start = self.clock.time_msec()
+        logged = False
        while True:
            current_token = self.event_sources.get_current_token()
            if stream_token.is_before_or_eq(current_token):
@@ -783,11 +784,13 @@ class Notifier:
            if now - start > 10_000:
                return False

-            logger.info(
-                "Waiting for current token to reach %s; currently at %s",
-                stream_token,
-                current_token,
-            )
+            if not logged:
+                logger.info(
+                    "Waiting for current token to reach %s; currently at %s",
+                    stream_token,
+                    current_token,
+                )
+                logged = True

            # TODO: be better
            await self.clock.sleep(0.5)
@@ -145,6 +145,10 @@ class ClientRestResource(JsonResource):
        password_policy.register_servlets(hs, client_resource)
        knock.register_servlets(hs, client_resource)
        appservice_ping.register_servlets(hs, client_resource)
+        if hs.config.media.can_load_media_repo:
+            from synapse.rest.client import media
+
+            media.register_servlets(hs, client_resource)

        # moving to /_synapse/admin
        if is_main_process:
@@ -31,7 +31,9 @@ from synapse.rest.admin import admin_patterns, assert_requester_is_admin
 from synapse.types import JsonDict, UserID

 if TYPE_CHECKING:
-    from synapse.server import HomeServer
+    from typing_extensions import assert_never
+
+    from synapse.server import HomeServer, HomeServerConfig


 class ExperimentalFeature(str, Enum):
@@ -39,8 +41,16 @@ class ExperimentalFeature(str, Enum):
    Currently supported per-user features
    """

-    MSC3026 = "msc3026"
    MSC3881 = "msc3881"
+    MSC3575 = "msc3575"
+
+    def is_globally_enabled(self, config: "HomeServerConfig") -> bool:
+        if self is ExperimentalFeature.MSC3881:
+            return config.experimental.msc3881_enabled
+        if self is ExperimentalFeature.MSC3575:
+            return config.experimental.msc3575_enabled
+
+        assert_never(self)


 class ExperimentalFeaturesRestServlet(RestServlet):
@@ -256,9 +256,15 @@ class KeyChangesServlet(RestServlet):

        user_id = requester.user.to_string()

-        results = await self.device_handler.get_user_ids_changed(user_id, from_token)
+        device_list_updates = await self.device_handler.get_user_ids_changed(
+            user_id, from_token
+        )

-        return 200, results
+        response: JsonDict = {}
+        response["changed"] = list(device_list_updates.changed)
+        response["left"] = list(device_list_updates.left)
+
+        return 200, response


 class OneTimeKeyServlet(RestServlet):
@@ -22,6 +22,7 @@

 import logging
 import re
+from typing import Optional

 from synapse.http.server import (
    HttpServer,
@@ -46,7 +47,7 @@ from synapse.util.stringutils import parse_and_validate_server_name
 logger = logging.getLogger(__name__)


-class UnstablePreviewURLServlet(RestServlet):
+class PreviewURLServlet(RestServlet):
    """
    Same as `GET /_matrix/media/r0/preview_url`, this endpoint provides a generic preview API
    for URLs which outputs Open Graph (https://ogp.me/) responses (with some Matrix
@@ -64,9 +65,7 @@ class UnstablePreviewURLServlet(RestServlet):
      * Matrix cannot be used to distribute the metadata between homeservers.
    """

-    PATTERNS = [
-        re.compile(r"^/_matrix/client/unstable/org.matrix.msc3916/media/preview_url$")
-    ]
+    PATTERNS = [re.compile(r"^/_matrix/client/v1/media/preview_url$")]

    def __init__(
        self,
@@ -94,10 +93,8 @@ class UnstablePreviewURLServlet(RestServlet):
        respond_with_json_bytes(request, 200, og, send_cors=True)


-class UnstableMediaConfigResource(RestServlet):
-    PATTERNS = [
-        re.compile(r"^/_matrix/client/unstable/org.matrix.msc3916/media/config$")
-    ]
+class MediaConfigResource(RestServlet):
+    PATTERNS = [re.compile(r"^/_matrix/client/v1/media/config$")]

    def __init__(self, hs: "HomeServer"):
        super().__init__()
@@ -111,10 +108,10 @@ class UnstableMediaConfigResource(RestServlet):
        respond_with_json(request, 200, self.limits_dict, send_cors=True)


-class UnstableThumbnailResource(RestServlet):
+class ThumbnailResource(RestServlet):
    PATTERNS = [
        re.compile(
-            "/_matrix/client/unstable/org.matrix.msc3916/media/thumbnail/(?P<server_name>[^/]*)/(?P<media_id>[^/]*)$"
+            "/_matrix/client/v1/media/thumbnail/(?P<server_name>[^/]*)/(?P<media_id>[^/]*)$"
        )
    ]

@@ -158,11 +155,25 @@ class UnstableThumbnailResource(RestServlet):
        if self._is_mine_server_name(server_name):
            if self.dynamic_thumbnails:
                await self.thumbnailer.select_or_generate_local_thumbnail(
-                    request, media_id, width, height, method, m_type, max_timeout_ms
+                    request,
+                    media_id,
+                    width,
+                    height,
+                    method,
+                    m_type,
+                    max_timeout_ms,
+                    False,
                )
            else:
                await self.thumbnailer.respond_local_thumbnail(
-                    request, media_id, width, height, method, m_type, max_timeout_ms
+                    request,
+                    media_id,
+                    width,
+                    height,
+                    method,
+                    m_type,
+                    max_timeout_ms,
+                    False,
                )
            self.media_repo.mark_recently_accessed(None, media_id)
        else:
@@ -190,18 +201,79 @@ class UnstableThumbnailResource(RestServlet):
                m_type,
                max_timeout_ms,
                ip_address,
+                True,
            )
            self.media_repo.mark_recently_accessed(server_name, media_id)


+class DownloadResource(RestServlet):
+    PATTERNS = [
+        re.compile(
+            "/_matrix/client/v1/media/download/(?P<server_name>[^/]*)/(?P<media_id>[^/]*)(/(?P<file_name>[^/]*))?$"
+        )
+    ]
+
+    def __init__(self, hs: "HomeServer", media_repo: "MediaRepository"):
+        super().__init__()
+        self.media_repo = media_repo
+        self._is_mine_server_name = hs.is_mine_server_name
+        self.auth = hs.get_auth()
+
+    async def on_GET(
+        self,
+        request: SynapseRequest,
+        server_name: str,
+        media_id: str,
+        file_name: Optional[str] = None,
+    ) -> None:
+        # Validate the server name, raising if invalid
+        parse_and_validate_server_name(server_name)
+
+        await self.auth.get_user_by_req(request)
+
+        set_cors_headers(request)
+        set_corp_headers(request)
+        request.setHeader(
+            b"Content-Security-Policy",
+            b"sandbox;"
+            b" default-src 'none';"
+            b" script-src 'none';"
+            b" plugin-types application/pdf;"
+            b" style-src 'unsafe-inline';"
+            b" media-src 'self';"
+            b" object-src 'self';",
+        )
+        # Limited non-standard form of CSP for IE11
+        request.setHeader(b"X-Content-Security-Policy", b"sandbox;")
+        request.setHeader(b"Referrer-Policy", b"no-referrer")
+        max_timeout_ms = parse_integer(
+            request, "timeout_ms", default=DEFAULT_MAX_TIMEOUT_MS
+        )
+        max_timeout_ms = min(max_timeout_ms, MAXIMUM_ALLOWED_MAX_TIMEOUT_MS)
+
+        if self._is_mine_server_name(server_name):
+            await self.media_repo.get_local_media(
+                request, media_id, file_name, max_timeout_ms
+            )
+        else:
+            ip_address = request.getClientAddress().host
+            await self.media_repo.get_remote_media(
+                request,
+                server_name,
+                media_id,
+                file_name,
+                max_timeout_ms,
+                ip_address,
+                True,
+            )
+
+
 def register_servlets(hs: "HomeServer", http_server: HttpServer) -> None:
-    if hs.config.experimental.msc3916_authenticated_media_enabled:
-        media_repo = hs.get_media_repository()
-        if hs.config.media.url_preview_enabled:
-            UnstablePreviewURLServlet(
-                hs, media_repo, media_repo.media_storage
-            ).register(http_server)
-        UnstableMediaConfigResource(hs).register(http_server)
-        UnstableThumbnailResource(hs, media_repo, media_repo.media_storage).register(
+    media_repo = hs.get_media_repository()
+    if hs.config.media.url_preview_enabled:
+        PreviewURLServlet(hs, media_repo, media_repo.media_storage).register(
            http_server
        )
+    MediaConfigResource(hs).register(http_server)
+    ThumbnailResource(hs, media_repo, media_repo.media_storage).register(http_server)
+    DownloadResource(hs, media_repo).register(http_server)
@@ -32,6 +32,7 @@ from synapse.http.servlet import (
 )
 from synapse.http.site import SynapseRequest
 from synapse.push import PusherConfigException
+from synapse.rest.admin.experimental_features import ExperimentalFeature
 from synapse.rest.client._base import client_patterns
 from synapse.rest.synapse.client.unsubscribe import UnsubscribeResource
 from synapse.types import JsonDict
@@ -49,20 +50,22 @@ class PushersRestServlet(RestServlet):
        super().__init__()
        self.hs = hs
        self.auth = hs.get_auth()
-        self._msc3881_enabled = self.hs.config.experimental.msc3881_enabled
+        self._store = hs.get_datastores().main

    async def on_GET(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
        requester = await self.auth.get_user_by_req(request)
-        user = requester.user
+        user_id = requester.user.to_string()

-        pushers = await self.hs.get_datastores().main.get_pushers_by_user_id(
-            user.to_string()
+        msc3881_enabled = await self._store.is_feature_enabled(
+            user_id, ExperimentalFeature.MSC3881
        )

+        pushers = await self.hs.get_datastores().main.get_pushers_by_user_id(user_id)
+
        pusher_dicts = [p.as_dict() for p in pushers]

        for pusher in pusher_dicts:
-            if self._msc3881_enabled:
+            if msc3881_enabled:
                pusher["org.matrix.msc3881.enabled"] = pusher["enabled"]
                pusher["org.matrix.msc3881.device_id"] = pusher["device_id"]
            del pusher["enabled"]
@@ -80,11 +83,15 @@ class PushersSetRestServlet(RestServlet):
        self.auth = hs.get_auth()
        self.notifier = hs.get_notifier()
        self.pusher_pool = self.hs.get_pusherpool()
-        self._msc3881_enabled = self.hs.config.experimental.msc3881_enabled
+        self._store = hs.get_datastores().main

    async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
        requester = await self.auth.get_user_by_req(request)
-        user = requester.user
+        user_id = requester.user.to_string()
+
+        msc3881_enabled = await self._store.is_feature_enabled(
+            user_id, ExperimentalFeature.MSC3881
+        )

        content = parse_json_object_from_request(request)

@@ -95,7 +102,7 @@ class PushersSetRestServlet(RestServlet):
            and content["kind"] is None
        ):
            await self.pusher_pool.remove_pusher(
-                content["app_id"], content["pushkey"], user_id=user.to_string()
+                content["app_id"], content["pushkey"], user_id=user_id
            )
            return 200, {}

@@ -120,19 +127,19 @@ class PushersSetRestServlet(RestServlet):
            append = content["append"]

        enabled = True
-        if self._msc3881_enabled and "org.matrix.msc3881.enabled" in content:
+        if msc3881_enabled and "org.matrix.msc3881.enabled" in content:
            enabled = content["org.matrix.msc3881.enabled"]

        if not append:
            await self.pusher_pool.remove_pushers_by_app_id_and_pushkey_not_user(
                app_id=content["app_id"],
                pushkey=content["pushkey"],
-                not_user_id=user.to_string(),
+                not_user_id=user_id,
            )

        try:
            await self.pusher_pool.add_or_update_pusher(
-                user_id=user.to_string(),
+                user_id=user_id,
                kind=content["kind"],
                app_id=content["app_id"],
                app_display_name=content["app_display_name"],
@@ -52,8 +52,9 @@ from synapse.http.servlet import (
    parse_string,
 )
 from synapse.http.site import SynapseRequest
-from synapse.logging.opentracing import trace_with_opname
-from synapse.types import JsonDict, Requester, StreamToken
+from synapse.logging.opentracing import log_kv, set_tag, trace_with_opname
+from synapse.rest.admin.experimental_features import ExperimentalFeature
+from synapse.types import JsonDict, Requester, SlidingSyncStreamToken, StreamToken
 from synapse.types.rest.client import SlidingSyncBody
 from synapse.util import json_decoder
 from synapse.util.caches.lrucache import LruCache
@@ -673,7 +674,9 @@ class SlidingSyncE2eeRestServlet(RestServlet):
        )

    async def on_GET(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
-        requester = await self.auth.get_user_by_req(request, allow_guest=True)
+        requester = await self.auth.get_user_by_req_experimental_feature(
+            request, allow_guest=True, feature=ExperimentalFeature.MSC3575
+        )
        user = requester.user
        device_id = requester.device_id

@@ -761,7 +764,6 @@ class SlidingSyncRestServlet(RestServlet):
            "lists": {
                "foo-list": {
                    "ranges": [ [0, 99] ],
-                    "sort": [ "by_notification_level", "by_recency", "by_name" ],
                    "required_state": [
                        ["m.room.join_rules", ""],
                        ["m.room.history_visibility", ""],
@@ -771,7 +773,6 @@ class SlidingSyncRestServlet(RestServlet):
                    "filters": {
                        "is_dm": true
                    },
-                    "bump_event_types": [ "m.room.message", "m.room.encrypted" ],
                }
            },
            // Room Subscriptions API
@@ -779,10 +780,6 @@ class SlidingSyncRestServlet(RestServlet):
                "!sub1:bar": {
                    "required_state": [ ["*","*"] ],
                    "timeline_limit": 10,
-                    "include_old_rooms": {
-                        "timeline_limit": 1,
-                        "required_state": [ ["m.room.tombstone", ""], ["m.room.create", ""] ],
-                    }
                }
            },
            // Extensions API
@@ -791,7 +788,7 @@ class SlidingSyncRestServlet(RestServlet):

    Response JSON::
        {
-            "next_pos": "s58_224_0_13_10_1_1_16_0_1",
+            "pos": "s58_224_0_13_10_1_1_16_0_1",
            "lists": {
                "foo-list": {
                    "count": 1337,
@@ -830,7 +827,8 @@ class SlidingSyncRestServlet(RestServlet):
                    "joined_count": 41,
                    "invited_count": 1,
                    "notification_count": 1,
-                    "highlight_count": 0
+                    "highlight_count": 0,
+                    "num_live": 2"
                },
                // rooms from list
                "!foo:bar": {
@@ -855,7 +853,8 @@ class SlidingSyncRestServlet(RestServlet):
                    "joined_count": 4,
                    "invited_count": 0,
                    "notification_count": 54,
-                    "highlight_count": 3
+                    "highlight_count": 3,
+                    "num_live": 1,
                },
                 // ... 99 more items
            },
@@ -871,14 +870,17 @@ class SlidingSyncRestServlet(RestServlet):
        super().__init__()
        self.auth = hs.get_auth()
        self.store = hs.get_datastores().main
+        self.clock = hs.get_clock()
        self.filtering = hs.get_filtering()
        self.sliding_sync_handler = hs.get_sliding_sync_handler()
+        self.event_serializer = hs.get_event_client_serializer()

-    # TODO: Update this to `on_GET` once we figure out how we want to handle params
    async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
-        requester = await self.auth.get_user_by_req(request, allow_guest=True)
+        requester = await self.auth.get_user_by_req_experimental_feature(
+            request, allow_guest=True, feature=ExperimentalFeature.MSC3575
+        )
+
        user = requester.user
-        device_id = requester.device_id

        timeout = parse_integer(request, "timeout", default=0)
        # Position in the stream
@@ -886,22 +888,41 @@ class SlidingSyncRestServlet(RestServlet):

        from_token = None
        if from_token_string is not None:
-            from_token = await StreamToken.from_string(self.store, from_token_string)
+            from_token = await SlidingSyncStreamToken.from_string(
+                self.store, from_token_string
+            )

        # TODO: We currently don't know whether we're going to use sticky params or
        # maybe some filters like sync v2  where they are built up once and referenced
        # by filter ID. For now, we will just prototype with always passing everything
        # in.
        body = parse_and_validate_json_object_from_request(request, SlidingSyncBody)
-        logger.info("Sliding sync request: %r", body)
+
+        # Tag and log useful data to differentiate requests.
+        set_tag("sliding_sync.conn_id", body.conn_id or "")
+        log_kv(
+            {
+                "sliding_sync.lists": {
+                    list_name: {
+                        "ranges": list_config.ranges,
+                        "timeline_limit": list_config.timeline_limit,
+                    }
+                    for list_name, list_config in (body.lists or {}).items()
+                },
+                "sliding_sync.room_subscriptions": list(
+                    (body.room_subscriptions or {}).keys()
+                ),
+            }
+        )

        sync_config = SlidingSyncConfig(
            user=user,
-            device_id=device_id,
+            requester=requester,
            # FIXME: Currently, we're just manually copying the fields from the
-            # `SlidingSyncBody` into the config. How can we gurantee into the future
+            # `SlidingSyncBody` into the config. How can we guarantee into the future
            # that we don't forget any? I would like something more structured like
            # `copy_attributes(from=body, to=config)`
+            conn_id=body.conn_id,
            lists=body.lists,
            room_subscriptions=body.room_subscriptions,
            extensions=body.extensions,
@@ -920,23 +941,27 @@ class SlidingSyncRestServlet(RestServlet):
            logger.info("Client has disconnected; not serializing response.")
            return 200, {}

-        response_content = await self.encode_response(sliding_sync_results)
+        response_content = await self.encode_response(requester, sliding_sync_results)

        return 200, response_content

-    # TODO: Is there a better way to encode things?
    async def encode_response(
        self,
+        requester: Requester,
        sliding_sync_result: SlidingSyncResult,
    ) -> JsonDict:
        response: JsonDict = defaultdict(dict)

-        response["next_pos"] = await sliding_sync_result.next_pos.to_string(self.store)
+        response["pos"] = await sliding_sync_result.next_pos.to_string(self.store)
        serialized_lists = self.encode_lists(sliding_sync_result.lists)
        if serialized_lists:
            response["lists"] = serialized_lists
-        response["rooms"] = {}  # TODO: sliding_sync_result.rooms
-        response["extensions"] = {}  # TODO: sliding_sync_result.extensions
+        response["rooms"] = await self.encode_rooms(
+            requester, sliding_sync_result.rooms
+        )
+        response["extensions"] = await self.encode_extensions(
+            requester, sliding_sync_result.extensions
+        )

        return response

@@ -961,10 +986,185 @@ class SlidingSyncRestServlet(RestServlet):

        return serialized_lists

+    async def encode_rooms(
+        self,
+        requester: Requester,
+        rooms: Dict[str, SlidingSyncResult.RoomResult],
+    ) -> JsonDict:
+        time_now = self.clock.time_msec()
+
+        serialize_options = SerializeEventConfig(
+            event_format=format_event_for_client_v2_without_room_id,
+            requester=requester,
+        )
+
+        serialized_rooms: Dict[str, JsonDict] = {}
+        for room_id, room_result in rooms.items():
+            serialized_rooms[room_id] = {
+                "bump_stamp": room_result.bump_stamp,
+                "joined_count": room_result.joined_count,
+                "invited_count": room_result.invited_count,
+                "notification_count": room_result.notification_count,
+                "highlight_count": room_result.highlight_count,
+            }
+
+            if room_result.name:
+                serialized_rooms[room_id]["name"] = room_result.name
+
+            if room_result.avatar:
+                serialized_rooms[room_id]["avatar"] = room_result.avatar
+
+            if room_result.heroes is not None and len(room_result.heroes) > 0:
+                serialized_heroes = []
+                for hero in room_result.heroes:
+                    serialized_hero = {
+                        "user_id": hero.user_id,
+                    }
+                    if hero.display_name is not None:
+                        # Not a typo, just how "displayname" is spelled in the spec
+                        serialized_hero["displayname"] = hero.display_name
+
+                    if hero.avatar_url is not None:
+                        serialized_hero["avatar_url"] = hero.avatar_url
+
+                    serialized_heroes.append(serialized_hero)
+                serialized_rooms[room_id]["heroes"] = serialized_heroes
+
+            # We should only include the `initial` key if it's `True` to save bandwidth.
+            # The absense of this flag means `False`.
+            if room_result.initial:
+                serialized_rooms[room_id]["initial"] = room_result.initial
+
+            # This will be omitted for invite/knock rooms with `stripped_state`
+            if (
+                room_result.required_state is not None
+                and len(room_result.required_state) > 0
+            ):
+                serialized_required_state = (
+                    await self.event_serializer.serialize_events(
+                        room_result.required_state,
+                        time_now,
+                        config=serialize_options,
+                    )
+                )
+                serialized_rooms[room_id]["required_state"] = serialized_required_state
+
+            # This will be omitted for invite/knock rooms with `stripped_state`
+            if (
+                room_result.timeline_events is not None
+                and len(room_result.timeline_events) > 0
+            ):
+                serialized_timeline = await self.event_serializer.serialize_events(
+                    room_result.timeline_events,
+                    time_now,
+                    config=serialize_options,
+                    bundle_aggregations=room_result.bundled_aggregations,
+                )
+                serialized_rooms[room_id]["timeline"] = serialized_timeline
+
+            # This will be omitted for invite/knock rooms with `stripped_state`
+            if room_result.limited is not None:
+                serialized_rooms[room_id]["limited"] = room_result.limited
+
+            # This will be omitted for invite/knock rooms with `stripped_state`
+            if room_result.prev_batch is not None:
+                serialized_rooms[room_id]["prev_batch"] = (
+                    await room_result.prev_batch.to_string(self.store)
+                )
+
+            # This will be omitted for invite/knock rooms with `stripped_state`
+            if room_result.num_live is not None:
+                serialized_rooms[room_id]["num_live"] = room_result.num_live
+
+            # Field should be absent on non-DM rooms
+            if room_result.is_dm:
+                serialized_rooms[room_id]["is_dm"] = room_result.is_dm
+
+            # Stripped state only applies to invite/knock rooms
+            if (
+                room_result.stripped_state is not None
+                and len(room_result.stripped_state) > 0
+            ):
+                # TODO: `knocked_state` but that isn't specced yet.
+                #
+                # TODO: Instead of adding `knocked_state`, it would be good to rename
+                # this to `stripped_state` so it can be shared between invite and knock
+                # rooms, see
+                # https://github.com/matrix-org/matrix-spec-proposals/pull/3575#discussion_r1117629919
+                serialized_rooms[room_id]["invite_state"] = room_result.stripped_state
+
+        return serialized_rooms
+
+    async def encode_extensions(
+        self, requester: Requester, extensions: SlidingSyncResult.Extensions
+    ) -> JsonDict:
+        serialized_extensions: JsonDict = {}
+
+        if extensions.to_device is not None:
+            serialized_extensions["to_device"] = {
+                "next_batch": extensions.to_device.next_batch,
+                "events": extensions.to_device.events,
+            }
+
+        if extensions.e2ee is not None:
+            serialized_extensions["e2ee"] = {
+                # We always include this because
+                # https://github.com/vector-im/element-android/issues/3725. The spec
+                # isn't terribly clear on when this can be omitted and how a client
+                # would tell the difference between "no keys present" and "nothing
+                # changed" in terms of whole field absent / individual key type entry
+                # absent Corresponding synapse issue:
+                # https://github.com/matrix-org/synapse/issues/10456
+                "device_one_time_keys_count": extensions.e2ee.device_one_time_keys_count,
+                # https://github.com/matrix-org/matrix-doc/blob/54255851f642f84a4f1aaf7bc063eebe3d76752b/proposals/2732-olm-fallback-keys.md
+                # states that this field should always be included, as long as the
+                # server supports the feature.
+                "device_unused_fallback_key_types": extensions.e2ee.device_unused_fallback_key_types,
+            }
+
+            if extensions.e2ee.device_list_updates is not None:
+                serialized_extensions["e2ee"]["device_lists"] = {}
+
+                serialized_extensions["e2ee"]["device_lists"]["changed"] = list(
+                    extensions.e2ee.device_list_updates.changed
+                )
+                serialized_extensions["e2ee"]["device_lists"]["left"] = list(
+                    extensions.e2ee.device_list_updates.left
+                )
+
+        if extensions.account_data is not None:
+            serialized_extensions["account_data"] = {
+                # Same as the the top-level `account_data.events` field in Sync v2.
+                "global": [
+                    {"type": account_data_type, "content": content}
+                    for account_data_type, content in extensions.account_data.global_account_data_map.items()
+                ],
+                # Same as the joined room's account_data field in Sync v2, e.g the path
+                # `rooms.join["!foo:bar"].account_data.events`.
+                "rooms": {
+                    room_id: [
+                        {"type": account_data_type, "content": content}
+                        for account_data_type, content in event_map.items()
+                    ]
+                    for room_id, event_map in extensions.account_data.account_data_by_room_map.items()
+                },
+            }
+
+        if extensions.receipts is not None:
+            serialized_extensions["receipts"] = {
+                "rooms": extensions.receipts.room_id_to_receipt_map,
+            }
+
+        if extensions.typing is not None:
+            serialized_extensions["typing"] = {
+                "rooms": extensions.typing.room_id_to_typing_map,
+            }
+
+        return serialized_extensions
+

 def register_servlets(hs: "HomeServer", http_server: HttpServer) -> None:
    SyncRestServlet(hs).register(http_server)

-    if hs.config.experimental.msc3575_enabled:
-        SlidingSyncRestServlet(hs).register(http_server)
-        SlidingSyncE2eeRestServlet(hs).register(http_server)
+    SlidingSyncRestServlet(hs).register(http_server)
+    SlidingSyncE2eeRestServlet(hs).register(http_server)
@@ -25,11 +25,11 @@ import logging
 import re
 from typing import TYPE_CHECKING, Tuple

-from twisted.web.server import Request
-
 from synapse.api.constants import RoomCreationPreset
 from synapse.http.server import HttpServer
 from synapse.http.servlet import RestServlet
+from synapse.http.site import SynapseRequest
+from synapse.rest.admin.experimental_features import ExperimentalFeature
 from synapse.types import JsonDict

 if TYPE_CHECKING:
@@ -45,6 +45,8 @@ class VersionsRestServlet(RestServlet):
    def __init__(self, hs: "HomeServer"):
        super().__init__()
        self.config = hs.config
+        self.auth = hs.get_auth()
+        self.store = hs.get_datastores().main

        # Calculate these once since they shouldn't change after start-up.
        self.e2ee_forced_public = (
@@ -60,7 +62,22 @@ class VersionsRestServlet(RestServlet):
            in self.config.room.encryption_enabled_by_default_for_room_presets
        )

-    def on_GET(self, request: Request) -> Tuple[int, JsonDict]:
+    async def on_GET(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
+        msc3881_enabled = self.config.experimental.msc3881_enabled
+
+        if self.auth.has_access_token(request):
+            requester = await self.auth.get_user_by_req(
+                request,
+                allow_guest=True,
+                allow_locked=True,
+                allow_expired=True,
+            )
+            user_id = requester.user.to_string()
+
+            msc3881_enabled = await self.store.is_feature_enabled(
+                user_id, ExperimentalFeature.MSC3881
+            )
+
        return (
            200,
            {
@@ -90,6 +107,7 @@ class VersionsRestServlet(RestServlet):
                    "v1.8",
                    "v1.9",
                    "v1.10",
+                    "v1.11",
                ],
                # as per MSC1497:
                "unstable_features": {
@@ -124,7 +142,7 @@ class VersionsRestServlet(RestServlet):
                    # TODO: this is no longer needed once unstable MSC3882 does not need to be supported:
                    "org.matrix.msc3882": self.config.auth.login_via_existing_enabled,
                    # Adds support for remotely enabling/disabling pushers, as per MSC3881
-                    "org.matrix.msc3881": self.config.experimental.msc3881_enabled,
+                    "org.matrix.msc3881": msc3881_enabled,
                    # Adds support for filtering /messages by event relation.
                    "org.matrix.msc3874": self.config.experimental.msc3874_enabled,
                    # Adds support for simple HTTP rendezvous as per MSC3886
@@ -84,7 +84,7 @@ class DownloadResource(RestServlet):

        if self._is_mine_server_name(server_name):
            await self.media_repo.get_local_media(
-                request, media_id, file_name, max_timeout_ms
+                request, media_id, file_name, max_timeout_ms, allow_authenticated=False
            )
        else:
            allow_remote = parse_boolean(request, "allow_remote", default=True)
@@ -105,4 +105,6 @@ class DownloadResource(RestServlet):
                file_name,
                max_timeout_ms,
                ip_address,
+                False,
+                allow_authenticated=False,
            )
@@ -88,11 +88,27 @@ class ThumbnailResource(RestServlet):
        if self._is_mine_server_name(server_name):
            if self.dynamic_thumbnails:
                await self.thumbnail_provider.select_or_generate_local_thumbnail(
-                    request, media_id, width, height, method, m_type, max_timeout_ms
+                    request,
+                    media_id,
+                    width,
+                    height,
+                    method,
+                    m_type,
+                    max_timeout_ms,
+                    False,
+                    allow_authenticated=False,
                )
            else:
                await self.thumbnail_provider.respond_local_thumbnail(
-                    request, media_id, width, height, method, m_type, max_timeout_ms
+                    request,
+                    media_id,
+                    width,
+                    height,
+                    method,
+                    m_type,
+                    max_timeout_ms,
+                    False,
+                    allow_authenticated=False,
                )
            self.media_repo.mark_recently_accessed(None, media_id)
        else:
@@ -120,5 +136,7 @@ class ThumbnailResource(RestServlet):
                m_type,
                max_timeout_ms,
                ip_address,
+                use_federation=False,
+                allow_authenticated=False,
            )
            self.media_repo.mark_recently_accessed(server_name, media_id)
@@ -28,7 +28,7 @@
 import abc
 import functools
 import logging
-from typing import TYPE_CHECKING, Callable, Dict, List, Optional, TypeVar, cast
+from typing import TYPE_CHECKING, Callable, Dict, List, Optional, Type, TypeVar, cast

 from typing_extensions import TypeAlias

@@ -161,6 +161,7 @@ if TYPE_CHECKING:
    from synapse.handlers.jwt import JwtHandler
    from synapse.handlers.oidc import OidcHandler
    from synapse.handlers.saml import SamlHandler
+    from synapse.storage._base import SQLBaseStore


 # The annotation for `cache_in_self` used to be
@@ -255,10 +256,13 @@ class HomeServer(metaclass=abc.ABCMeta):
        "stats",
    ]

-    # This is overridden in derived application classes
-    # (such as synapse.app.homeserver.SynapseHomeServer) and gives the class to be
-    # instantiated during setup() for future return by get_datastores()
-    DATASTORE_CLASS = abc.abstractproperty()
+    @property
+    @abc.abstractmethod
+    def DATASTORE_CLASS(self) -> Type["SQLBaseStore"]:
+        # This is overridden in derived application classes
+        # (such as synapse.app.homeserver.SynapseHomeServer) and gives the class to be
+        # instantiated during setup() for future return by get_datastores()
+        pass

    def __init__(
        self,
@@ -555,6 +559,7 @@ class HomeServer(metaclass=abc.ABCMeta):
    def get_sync_handler(self) -> SyncHandler:
        return SyncHandler(self)

+    @cache_in_self
    def get_sliding_sync_handler(self) -> SlidingSyncHandler:
        return SlidingSyncHandler(self)

@@ -119,14 +119,16 @@ class SQLBaseStore(metaclass=ABCMeta):
            self._attempt_to_invalidate_cache(
                "get_user_in_room_with_profile", (room_id, user_id)
            )
-            self._attempt_to_invalidate_cache(
-                "get_rooms_for_user_with_stream_ordering", (user_id,)
-            )
            self._attempt_to_invalidate_cache("get_rooms_for_user", (user_id,))
+            self._attempt_to_invalidate_cache(
+                "_get_rooms_for_local_user_where_membership_is_inner", (user_id,)
+            )

        # Purge other caches based on room state.
        self._attempt_to_invalidate_cache("get_room_summary", (room_id,))
        self._attempt_to_invalidate_cache("get_partial_current_state_ids", (room_id,))
+        self._attempt_to_invalidate_cache("get_room_type", (room_id,))
+        self._attempt_to_invalidate_cache("get_room_encryption", (room_id,))

    def _invalidate_state_caches_all(self, room_id: str) -> None:
        """Invalidates caches that are based on the current state, but does
@@ -148,11 +150,13 @@ class SQLBaseStore(metaclass=ABCMeta):
        self._attempt_to_invalidate_cache("get_local_users_in_room", (room_id,))
        self._attempt_to_invalidate_cache("does_pair_of_users_share_a_room", None)
        self._attempt_to_invalidate_cache("get_user_in_room_with_profile", None)
-        self._attempt_to_invalidate_cache(
-            "get_rooms_for_user_with_stream_ordering", None
-        )
        self._attempt_to_invalidate_cache("get_rooms_for_user", None)
+        self._attempt_to_invalidate_cache(
+            "_get_rooms_for_local_user_where_membership_is_inner", None
+        )
        self._attempt_to_invalidate_cache("get_room_summary", (room_id,))
+        self._attempt_to_invalidate_cache("get_room_type", (room_id,))
+        self._attempt_to_invalidate_cache("get_room_encryption", (room_id,))

    def _attempt_to_invalidate_cache(
        self, cache_name: str, key: Optional[Collection[Any]]
@@ -409,7 +409,7 @@ class StateStorageController:

        return state_ids

-    async def get_state_at(
+    async def get_state_ids_at(
        self,
        room_id: str,
        stream_position: StreamToken,
@@ -436,6 +436,9 @@ class StateStorageController:
            )
        )

+        # FIXME: This will return incorrect results when there are timeline gaps. For
+        # example, when you try to get a point in the room we haven't backfilled before.
+
        if last_event_id:
            state = await self.get_state_after_event(
                last_event_id,
@@ -457,6 +460,30 @@ class StateStorageController:
            )
        return state

+    @trace
+    @tag_args
+    async def get_state_at(
+        self,
+        room_id: str,
+        stream_position: StreamToken,
+        state_filter: Optional[StateFilter] = None,
+        await_full_state: bool = True,
+    ) -> StateMap[EventBase]:
+        """Same as `get_state_ids_at` but also fetches the events"""
+        state_map_ids = await self.get_state_ids_at(
+            room_id, stream_position, state_filter, await_full_state
+        )
+
+        event_map = await self.stores.main.get_events(list(state_map_ids.values()))
+
+        state_map = {}
+        for key, event_id in state_map_ids.items():
+            event = event_map.get(event_id)
+            if event:
+                state_map[key] = event
+
+        return state_map
+
    @trace
    @tag_args
    async def get_state_for_groups(
@@ -268,17 +268,23 @@ class CacheInvalidationWorkerStore(SQLBaseStore):
            self._curr_state_delta_stream_cache.entity_has_changed(data.room_id, token)  # type: ignore[attr-defined]

            if data.type == EventTypes.Member:
-                self.get_rooms_for_user_with_stream_ordering.invalidate(  # type: ignore[attr-defined]
-                    (data.state_key,)
+                self._attempt_to_invalidate_cache(
+                    "get_rooms_for_user", (data.state_key,)
                )
-                self.get_rooms_for_user.invalidate((data.state_key,))  # type: ignore[attr-defined]
+            elif data.type == EventTypes.RoomEncryption:
+                self._attempt_to_invalidate_cache(
+                    "get_room_encryption", (data.room_id,)
+                )
+            elif data.type == EventTypes.Create:
+                self._attempt_to_invalidate_cache("get_room_type", (data.room_id,))
        elif row.type == EventsStreamAllStateRow.TypeId:
            assert isinstance(data, EventsStreamAllStateRow)
            # Similar to the above, but the entire caches are invalidated. This is
            # unfortunate for the membership caches, but should recover quickly.
            self._curr_state_delta_stream_cache.entity_has_changed(data.room_id, token)  # type: ignore[attr-defined]
-            self.get_rooms_for_user_with_stream_ordering.invalidate_all()  # type: ignore[attr-defined]
-            self.get_rooms_for_user.invalidate_all()  # type: ignore[attr-defined]
+            self._attempt_to_invalidate_cache("get_rooms_for_user", None)
+            self._attempt_to_invalidate_cache("get_room_type", (data.room_id,))
+            self._attempt_to_invalidate_cache("get_room_encryption", (data.room_id,))
        else:
            raise Exception("Unknown events stream row type %s" % (row.type,))

@@ -334,10 +340,10 @@ class CacheInvalidationWorkerStore(SQLBaseStore):
            self._attempt_to_invalidate_cache(
                "get_invited_rooms_for_local_user", (state_key,)
            )
-            self._attempt_to_invalidate_cache(
-                "get_rooms_for_user_with_stream_ordering", (state_key,)
-            )
            self._attempt_to_invalidate_cache("get_rooms_for_user", (state_key,))
+            self._attempt_to_invalidate_cache(
+                "_get_rooms_for_local_user_where_membership_is_inner", (state_key,)
+            )

            self._attempt_to_invalidate_cache(
                "did_forget",
@@ -349,6 +355,10 @@ class CacheInvalidationWorkerStore(SQLBaseStore):
            self._attempt_to_invalidate_cache(
                "get_forgotten_rooms_for_user", (state_key,)
            )
+        elif etype == EventTypes.Create:
+            self._attempt_to_invalidate_cache("get_room_type", (room_id,))
+        elif etype == EventTypes.RoomEncryption:
+            self._attempt_to_invalidate_cache("get_room_encryption", (room_id,))

        if relates_to:
            self._attempt_to_invalidate_cache(
@@ -399,16 +409,18 @@ class CacheInvalidationWorkerStore(SQLBaseStore):
        self._attempt_to_invalidate_cache("get_thread_id", None)
        self._attempt_to_invalidate_cache("get_thread_id_for_receipts", None)
        self._attempt_to_invalidate_cache("get_invited_rooms_for_local_user", None)
-        self._attempt_to_invalidate_cache(
-            "get_rooms_for_user_with_stream_ordering", None
-        )
        self._attempt_to_invalidate_cache("get_rooms_for_user", None)
+        self._attempt_to_invalidate_cache(
+            "_get_rooms_for_local_user_where_membership_is_inner", None
+        )
        self._attempt_to_invalidate_cache("did_forget", None)
        self._attempt_to_invalidate_cache("get_forgotten_rooms_for_user", None)
        self._attempt_to_invalidate_cache("get_references_for_event", None)
        self._attempt_to_invalidate_cache("get_thread_summary", None)
        self._attempt_to_invalidate_cache("get_thread_participated", None)
        self._attempt_to_invalidate_cache("get_threads", (room_id,))
+        self._attempt_to_invalidate_cache("get_room_type", (room_id,))
+        self._attempt_to_invalidate_cache("get_room_encryption", (room_id,))

        self._attempt_to_invalidate_cache("_get_state_group_for_event", None)

@@ -461,6 +473,8 @@ class CacheInvalidationWorkerStore(SQLBaseStore):
        self._attempt_to_invalidate_cache("get_forgotten_rooms_for_user", None)
        self._attempt_to_invalidate_cache("_get_membership_from_event_id", None)
        self._attempt_to_invalidate_cache("get_room_version_id", (room_id,))
+        self._attempt_to_invalidate_cache("get_room_type", (room_id,))
+        self._attempt_to_invalidate_cache("get_room_encryption", (room_id,))

        # And delete state caches.

@@ -825,14 +825,13 @@ class DeviceInboxWorkerStore(SQLBaseStore):
            # Check if we've already inserted a matching message_id for that
            # origin. This can happen if the origin doesn't receive our
            # acknowledgement from the first time we received the message.
-            already_inserted = self.db_pool.simple_select_one_txn(
+            already_inserted = self.db_pool.simple_select_list_txn(
                txn,
                table="device_federation_inbox",
                keyvalues={"origin": origin, "message_id": message_id},
                retcols=("message_id",),
-                allow_none=True,
            )
-            if already_inserted is not None:
+            if already_inserted:
                return

            # Add an entry for this message_id so that we know we've processed
@@ -1313,6 +1313,11 @@ class EventFederationWorkerStore(SignatureWorkerStore, EventsWorkerStore, SQLBas
        # We want to make the cache more effective, so we clamp to the last
        # change before the given ordering.
        last_change = self._events_stream_cache.get_max_pos_of_last_change(room_id)  # type: ignore[attr-defined]
+        if last_change is None:
+            # If the room isn't in the cache we know that the last change was
+            # somewhere before the earliest known position of the cache, so we
+            # can clamp to that.
+            last_change = self._events_stream_cache.get_earliest_known_position()  # type: ignore[attr-defined]

        # We don't always have a full stream_to_exterm_id table, e.g. after
        # the upgrade that introduced it, so we make sure we never ask for a
--- a/Show More
+++ b/Show More
				`@@ -0,0 +1 @@`
				Track which rooms have been sent to clients in the experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint.
				`@@ -0,0 +1 @@`
				Update experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint to handle invite/knock rooms when filtering.
				`@@ -0,0 +1 @@`
				`Change sliding sync to use their own token format in preparation for storing per-connection state.`
				`@@ -0,0 +1 @@`
				Update the [`allowed_local_3pids`](https://element-hq.github.io/synapse/v1.112/usage/configuration/config_documentation.html#allowed_local_3pids) config option's msisdn address to a working example.
				`@@ -0,0 +1 @@`
				Add Account Data extension support to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint.
				`@@ -0,0 +1 @@`
				Ensure we don't send down negative `bump_stamp` in experimental sliding sync endpoint.
				`@@ -0,0 +1 @@`
				`Do not send down empty room entries down experimental sliding sync endpoint.`
				`@@ -0,0 +1 @@`
				Refactor Sliding Sync tests to better utilize the `SlidingSyncBase`.
				`@@ -0,0 +1 @@`
				Add receipts extension support to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint.
				`@@ -0,0 +1 @@`
				Fix a bug introduced in v1.110.0 which caused `/keys/query` to return incomplete results, leading to high network activity and CPU usage on Matrix clients.