Before this change:

* `PerspectivesKeyFetcher` and `ServerKeyFetcher` write to `server_keys_json`.
* `PerspectivesKeyFetcher` also writes to `server_signature_keys`.
* `StoreKeyFetcher` reads from `server_signature_keys`.

After this change:

* `PerspectivesKeyFetcher` and `ServerKeyFetcher` write to `server_keys_json`.
* `PerspectivesKeyFetcher` also writes to `server_signature_keys`.
* `StoreKeyFetcher` reads from `server_keys_json`.

This results in `StoreKeyFetcher` now using the results from `ServerKeyFetcher`
in addition to those from `PerspectivesKeyFetcher`, i.e. keys which are directly
fetched from a server will now be pulled from the database instead of refetched.

An additional minor change is included to avoid creating a `PerspectivesKeyFetcher`
(and checking it) if no `trusted_key_servers` are configured.

The overall impact of this should be better usage of cached results:

* If a server has no trusted key servers configured then it should reduce how often keys
  are fetched.
* if a server's trusted key server does not have a requested server's keys cached then it
  should reduce how often keys are directly fetched.

These two lines:

```
config_obj = HomeServerConfig()
config_obj.parse_config_dict(config, "", "")
```

are called many times with the exact same value for `config`.

As the test suite is CPU-bound and non-negligeably time is spent in
`parse_config_dict`, this saves ~5% on the overall runtime of the Trial
test suite (tested with both `-j2` and `-j12` on a 12t CPU).

This is sadly rather limited, as the cache cannot be shared between
processes (it contains at least jinja2.Template and RLock objects which
aren't pickleable), and Trial tends to run close tests in different
processes.

* Convert async to normal tests in `TestSSOHandler`

* newsfile

Improve robustness when handling a perspective key response by deduplicating received server keys. (#15423)

* Change `store_server_verify_keys` to take a `Mapping[(str, str), FKR]`

This is because we already can't handle duplicate keys — leads to cardinality violation

* Newsfile

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>

---------

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>

This moves `redacts` from being a top-level property to
a `content` property in a new room version.

MSC2176 (which was previously implemented) states to not
`redact` this property.

* raise a ConfigError on an invalid app_service_config_files

* changelog

* Move config check to read_config

* Add test

* Ensure list also contains strings

This will be done in a future room version, for now an unstable
room version is added which redacts the origin field.

This uses the specced /_matrix/app/v1/... paths instead of the
"legacy" paths. If the homeserver receives an error it will retry
using the legacy path.

* Revert "Fix registering a device on an account with lots of devices (#15348)"

This reverts commit f0d8f66e.

* Revert "Delete stale non-e2e devices for users, take 3 (#15183)"

This reverts commit 78cdb72c.

Co-authored-by: reivilibre <oliverw@matrix.org>

Tests now take 40% of the time.

If enabled, for users which are exclusively owned by an application
service then the appservice will be queried for devices in addition
to any information stored in the Synapse database.

Previously, we would spin in a tight loop until
`update_state_for_partial_state_event` stopped raising
`FederationPullAttemptBackoffError`s. Replace the spinloop with a wait
until the backoff period has expired.

Signed-off-by: Sean Quah <seanq@matrix.org>

Signed-off-by: Warren Bailey <warren@warrenbailey.net>

Fixes up #15183

This should help reduce the number of devices e.g. simple bots the repeatedly login rack up.

We only delete non-e2e devices as they should be safe to delete, whereas if we delete e2e devices for a user we may accidentally break their ability to receive e2e keys for a message.

Experimental support for MSC3983 is behind a configuration flag.
If enabled, for users which are exclusively owned by an application
service then the appservice will be queried for one-time keys *if*
there are none uploaded to Synapse.

* Bump ruff from 0.0.252 to 0.0.259

Bumps [ruff](https://github.com/charliermarsh/ruff) from 0.0.252 to 0.0.259.
- [Release notes](https://github.com/charliermarsh/ruff/releases)
- [Changelog](https://github.com/charliermarsh/ruff/blob/main/BREAKING_CHANGES.md)
- [Commits](https://github.com/charliermarsh/ruff/compare/v0.0.252...v0.0.259

)

---
updated-dependencies:
- dependency-name: ruff
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

* Fix new warnings

* Mypy

* Newsfile

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Erik Johnston <erik@matrix.org>

This makes it so that we rely on the `device_id` to delete pushers on logout,
instead of relying on the `access_token_id`. This ensures we're not removing
pushers on token refresh, and prepares for a world without access token IDs
(also known as the OIDC).

This actually runs the `set_device_id_for_pushers` background update, which
was forgotten in #13831.

Note that for backwards compatibility it still deletes pushers based on the
`access_token` until the background update finishes.

Invalid mentions data received over the Client-Server API should
be rejected with a 400 error. This will hopefully stop clients from
sending invalid data, although does not help with data received
over federation.

Additionally:

* Consistently use `freeze()` in test

---------

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>
Co-authored-by: 6543 <6543@obermui.de>

Make `POST /_matrix/client/v3/rooms/{roomId}/report/{eventId}` endpoint return 404 if event exists, but the user lacks access (#15300)

When a room is deleted in Synapse we remove the event forward
extremities in the room, so if (say a bot) tries to send a message into
the room we error out due to not being able to calculate prev events for
the new event *before* we check if the sender is in the room.

Fixes #8094

Separates REST layer code from the actual URL previewing.

With Redis commands do not need to be re-issued by the main
process (they fan-out to all processes at once) and thus it is no
longer necessary to worry about them reflecting recursively forever.

Refresh remote profiles that have been marked as stale, in order to fill the user directory. [rei:userdirpriv] (#14756)

* Scaffolding for background process to refresh profiles

* Add scaffolding for background process to refresh profiles for a given server

* Implement the code to select servers to refresh from

* Ensure we don't build up multiple looping calls

* Make `get_profile` able to respect backoffs

* Add logic for refreshing users

* When backing off, schedule a refresh when the backoff is over

* Wake up the background processes when we receive an interesting state event

* Add tests

* Newsfile

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>

* Add comment about 1<<62

---------

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>

* Reproduce bad scenario in test
* Avoid catchup optimisation for partial state rooms

* Tweak docstring and type hint

* Flip logic and provide better name

* Separate decision from action

* Track a set of strings, not EventBases

* Require explicit boolean options from callers

* Add explicit option for partial state rooms

* Changelog

* Rename param

Fix missing conditional for registering `on_remove_user_third_party_identifier` module api callbacks (#15227

And fix any issues from having those type hints.

This removes the experimental configuration option and
always escapes the push rule condition keys.

Also escapes any (experimental) push rule condition keys
in the base rules which contain dot in a field name.

This removes the configuration flag & updates the identifiers to
use the stable version.

Enables MSC3925 support by default, which:

* Includes the full edit event in the bundled aggregations of an
  edited event.
* Stops modifying the original event's content to return the new
  content from the edit event.

This is a backwards-incompatible change that is considered to be
"correct" by the spec.