* drop old-room hack
pretty sure we don't need this any more.
* Remove incorrect comment about modifying `context`
It doesn't look like the supplied context is ever modified.
* Stop `_auth_and_persist_event` modifying its parameters
This is only called in three places. Two of them don't pass `auth_events`, and
the third doesn't use the dict after passing it in, so this should be non-functional.
* Stop `_check_event_auth` modifying its parameters
`_check_event_auth` is only called in three places. `on_send_membership_event`
doesn't pass an `auth_events`, and `prep` and `_auth_and_persist_event` do not
use the map after passing it in.
* Stop `_update_auth_events_and_context_for_auth` modifying its parameters
Return the updated auth event dict, rather than modifying the parameter.
This is only called from `_check_event_auth`.
* Improve documentation on `_auth_and_persist_event`
Rename `auth_events` parameter to better reflect what it contains.
* Improve documentation on `_NewEventInfo`
* Improve documentation on `_check_event_auth`
rename `auth_events` parameter to better describe what it contains
* changelog
This adds 'allowed_room_ids' (in addition to 'allowed_spaces', for backwards
compatibility) to the federation response of the spaces summary.
A future PR will remove the 'allowed_spaces' flag.
If there are no services providing a protocol, omit it completely
instead of returning an empty dictionary.
This fixes a long-standing spec compliance bug.
The room type is per MSC3288 to allow the identity-server to
change invitation wording based on whether the invitation is to
a room or a space.
The prefixed key will be replaced once MSC3288 is accepted
into the spec.
* Make historical messages available to federated servers
Part of MSC2716: https://github.com/matrix-org/matrix-doc/pull/2716
Follow-up to https://github.com/matrix-org/synapse/pull/9247
* Debug message not available on federation
* Add base starting insertion point when no chunk ID is provided
* Fix messages from multiple senders in historical chunk
Follow-up to https://github.com/matrix-org/synapse/pull/9247
Part of MSC2716: https://github.com/matrix-org/matrix-doc/pull/2716
---
Previously, Synapse would throw a 403,
`Cannot force another user to join.`,
because we were trying to use `?user_id` from a single virtual user
which did not match with messages from other users in the chunk.
* Remove debug lines
* Messing with selecting insertion event extremeties
* Move db schema change to new version
* Add more better comments
* Make a fake requester with just what we need
See https://github.com/matrix-org/synapse/pull/10276#discussion_r660999080
* Store insertion events in table
* Make base insertion event float off on its own
See https://github.com/matrix-org/synapse/pull/10250#issuecomment-875711889
Conflicts:
synapse/rest/client/v1/room.py
* Validate that the app service can actually control the given user
See https://github.com/matrix-org/synapse/pull/10276#issuecomment-876316455
Conflicts:
synapse/rest/client/v1/room.py
* Add some better comments on what we're trying to check for
* Continue debugging
* Share validation logic
* Add inserted historical messages to /backfill response
* Remove debug sql queries
* Some marker event implemntation trials
* Clean up PR
* Rename insertion_event_id to just event_id
* Add some better sql comments
* More accurate description
* Add changelog
* Make it clear what MSC the change is part of
* Add more detail on which insertion event came through
* Address review and improve sql queries
* Only use event_id as unique constraint
* Fix test case where insertion event is already in the normal DAG
* Remove debug changes
* Add support for MSC2716 marker events
* Process markers when we receive it over federation
* WIP: make hs2 backfill historical messages after marker event
* hs2 to better ask for insertion event extremity
But running into the `sqlite3.IntegrityError: NOT NULL constraint failed: event_to_state_groups.state_group`
error
* Add insertion_event_extremities table
* Switch to chunk events so we can auth via power_levels
Previously, we were using `content.chunk_id` to connect one
chunk to another. But these events can be from any `sender`
and we can't tell who should be able to send historical events.
We know we only want the application service to do it but these
events have the sender of a real historical message, not the
application service user ID as the sender. Other federated homeservers
also have no indicator which senders are an application service on
the originating homeserver.
So we want to auth all of the MSC2716 events via power_levels
and have them be sent by the application service with proper
PL levels in the room.
* Switch to chunk events for federation
* Add unstable room version to support new historical PL
* Messy: Fix undefined state_group for federated historical events
```
2021-07-13 02:27:57,810 - synapse.handlers.federation - 1248 - ERROR - GET-4 - Failed to backfill from hs1 because NOT NULL constraint failed: event_to_state_groups.state_group
Traceback (most recent call last):
File "/usr/local/lib/python3.8/site-packages/synapse/handlers/federation.py", line 1216, in try_backfill
await self.backfill(
File "/usr/local/lib/python3.8/site-packages/synapse/handlers/federation.py", line 1035, in backfill
await self._auth_and_persist_event(dest, event, context, backfilled=True)
File "/usr/local/lib/python3.8/site-packages/synapse/handlers/federation.py", line 2222, in _auth_and_persist_event
await self._run_push_actions_and_persist_event(event, context, backfilled)
File "/usr/local/lib/python3.8/site-packages/synapse/handlers/federation.py", line 2244, in _run_push_actions_and_persist_event
await self.persist_events_and_notify(
File "/usr/local/lib/python3.8/site-packages/synapse/handlers/federation.py", line 3290, in persist_events_and_notify
events, max_stream_token = await self.storage.persistence.persist_events(
File "/usr/local/lib/python3.8/site-packages/synapse/logging/opentracing.py", line 774, in _trace_inner
return await func(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/synapse/storage/persist_events.py", line 320, in persist_events
ret_vals = await yieldable_gather_results(enqueue, partitioned.items())
File "/usr/local/lib/python3.8/site-packages/synapse/storage/persist_events.py", line 237, in handle_queue_loop
ret = await self._per_item_callback(
File "/usr/local/lib/python3.8/site-packages/synapse/storage/persist_events.py", line 577, in _persist_event_batch
await self.persist_events_store._persist_events_and_state_updates(
File "/usr/local/lib/python3.8/site-packages/synapse/storage/databases/main/events.py", line 176, in _persist_events_and_state_updates
await self.db_pool.runInteraction(
File "/usr/local/lib/python3.8/site-packages/synapse/storage/database.py", line 681, in runInteraction
result = await self.runWithConnection(
File "/usr/local/lib/python3.8/site-packages/synapse/storage/database.py", line 770, in runWithConnection
return await make_deferred_yieldable(
File "/usr/local/lib/python3.8/site-packages/twisted/python/threadpool.py", line 238, in inContext
result = inContext.theWork() # type: ignore[attr-defined]
File "/usr/local/lib/python3.8/site-packages/twisted/python/threadpool.py", line 254, in <lambda>
inContext.theWork = lambda: context.call( # type: ignore[attr-defined]
File "/usr/local/lib/python3.8/site-packages/twisted/python/context.py", line 118, in callWithContext
return self.currentContext().callWithContext(ctx, func, *args, **kw)
File "/usr/local/lib/python3.8/site-packages/twisted/python/context.py", line 83, in callWithContext
return func(*args, **kw)
File "/usr/local/lib/python3.8/site-packages/twisted/enterprise/adbapi.py", line 293, in _runWithConnection
compat.reraise(excValue, excTraceback)
File "/usr/local/lib/python3.8/site-packages/twisted/python/deprecate.py", line 298, in deprecatedFunction
return function(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/twisted/python/compat.py", line 403, in reraise
raise exception.with_traceback(traceback)
File "/usr/local/lib/python3.8/site-packages/twisted/enterprise/adbapi.py", line 284, in _runWithConnection
result = func(conn, *args, **kw)
File "/usr/local/lib/python3.8/site-packages/synapse/storage/database.py", line 765, in inner_func
return func(db_conn, *args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/synapse/storage/database.py", line 549, in new_transaction
r = func(cursor, *args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/synapse/logging/utils.py", line 69, in wrapped
return f(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/synapse/storage/databases/main/events.py", line 385, in _persist_events_txn
self._store_event_state_mappings_txn(txn, events_and_contexts)
File "/usr/local/lib/python3.8/site-packages/synapse/storage/databases/main/events.py", line 2065, in _store_event_state_mappings_txn
self.db_pool.simple_insert_many_txn(
File "/usr/local/lib/python3.8/site-packages/synapse/storage/database.py", line 923, in simple_insert_many_txn
txn.execute_batch(sql, vals)
File "/usr/local/lib/python3.8/site-packages/synapse/storage/database.py", line 280, in execute_batch
self.executemany(sql, args)
File "/usr/local/lib/python3.8/site-packages/synapse/storage/database.py", line 300, in executemany
self._do_execute(self.txn.executemany, sql, *args)
File "/usr/local/lib/python3.8/site-packages/synapse/storage/database.py", line 330, in _do_execute
return func(sql, *args)
sqlite3.IntegrityError: NOT NULL constraint failed: event_to_state_groups.state_group
```
* Revert "Messy: Fix undefined state_group for federated historical events"
This reverts commit 187ab28611.
* Fix federated events being rejected for no state_groups
Add fix from https://github.com/matrix-org/synapse/pull/10439
until it merges.
* Adapting to experimental room version
* Some log cleanup
* Add better comments around extremity fetching code and why
* Rename to be more accurate to what the function returns
* Add changelog
* Ignore rejected events
* Use simplified upsert
* Add Erik's explanation of extra event checks
See https://github.com/matrix-org/synapse/pull/10498#discussion_r680880332
* Clarify that the depth is not directly correlated to the backwards extremity that we return
See https://github.com/matrix-org/synapse/pull/10498#discussion_r681725404
* lock only matters for sqlite
See https://github.com/matrix-org/synapse/pull/10498#discussion_r681728061
* Move new SQL changes to its own delta file
* Clean up upsert docstring
* Bump database schema version (62)
* Make historical messages available to federated servers
Part of MSC2716: https://github.com/matrix-org/matrix-doc/pull/2716
Follow-up to https://github.com/matrix-org/synapse/pull/9247
* Debug message not available on federation
* Add base starting insertion point when no chunk ID is provided
* Fix messages from multiple senders in historical chunk
Follow-up to https://github.com/matrix-org/synapse/pull/9247
Part of MSC2716: https://github.com/matrix-org/matrix-doc/pull/2716
---
Previously, Synapse would throw a 403,
`Cannot force another user to join.`,
because we were trying to use `?user_id` from a single virtual user
which did not match with messages from other users in the chunk.
* Remove debug lines
* Messing with selecting insertion event extremeties
* Move db schema change to new version
* Add more better comments
* Make a fake requester with just what we need
See https://github.com/matrix-org/synapse/pull/10276#discussion_r660999080
* Store insertion events in table
* Make base insertion event float off on its own
See https://github.com/matrix-org/synapse/pull/10250#issuecomment-875711889
Conflicts:
synapse/rest/client/v1/room.py
* Validate that the app service can actually control the given user
See https://github.com/matrix-org/synapse/pull/10276#issuecomment-876316455
Conflicts:
synapse/rest/client/v1/room.py
* Add some better comments on what we're trying to check for
* Continue debugging
* Share validation logic
* Add inserted historical messages to /backfill response
* Remove debug sql queries
* Some marker event implemntation trials
* Clean up PR
* Rename insertion_event_id to just event_id
* Add some better sql comments
* More accurate description
* Add changelog
* Make it clear what MSC the change is part of
* Add more detail on which insertion event came through
* Address review and improve sql queries
* Only use event_id as unique constraint
* Fix test case where insertion event is already in the normal DAG
* Remove debug changes
* Switch to chunk events so we can auth via power_levels
Previously, we were using `content.chunk_id` to connect one
chunk to another. But these events can be from any `sender`
and we can't tell who should be able to send historical events.
We know we only want the application service to do it but these
events have the sender of a real historical message, not the
application service user ID as the sender. Other federated homeservers
also have no indicator which senders are an application service on
the originating homeserver.
So we want to auth all of the MSC2716 events via power_levels
and have them be sent by the application service with proper
PL levels in the room.
* Switch to chunk events for federation
* Add unstable room version to support new historical PL
* Fix federated events being rejected for no state_groups
Add fix from https://github.com/matrix-org/synapse/pull/10439
until it merges.
* Only connect base insertion event to prev_event_ids
Per discussion with @erikjohnston,
https://matrix.to/#/!UytJQHLQYfvYWsGrGY:jki.re/$12bTUiObDFdHLAYtT7E-BvYRp3k_xv8w0dUQHibasJk?via=jki.re&via=matrix.org
* Make it possible to get the room_version with txn
* Allow but ignore historical events in unsupported room version
See https://github.com/matrix-org/synapse/pull/10245#discussion_r675592489
We can't reject historical events on unsupported room versions because homeservers without knowledge of MSC2716 or the new room version don't reject historical events either.
Since we can't rely on the auth check here to stop historical events on unsupported room versions, I've added some additional checks in the processing/persisting code (`synapse/storage/databases/main/events.py` -> `_handle_insertion_event` and `_handle_chunk_event`). I've had to do some refactoring so there is method to fetch the room version by `txn`.
* Move to unique index syntax
See https://github.com/matrix-org/synapse/pull/10245#discussion_r675638509
* High-level document how the insertion->chunk lookup works
* Remove create_event fallback for room_versions
See https://github.com/matrix-org/synapse/pull/10245/files#r677641879
* Use updated method name
==============================
Bugfixes
--------
- Fix a bug introduced in Synapse 1.38 which caused an exception at startup when SAML authentication was enabled. ([\#10477](https://github.com/matrix-org/synapse/issues/10477))
- Fix a long-standing bug where Synapse would not inform clients that a device had exhausted its one-time-key pool, potentially causing problems decrypting events. ([\#10485](https://github.com/matrix-org/synapse/issues/10485))
- Fix reporting old R30 stats as R30v2 stats. Introduced in v1.39.0rc1. ([\#10486](https://github.com/matrix-org/synapse/issues/10486))
Internal Changes
----------------
- Fix an error which prevented the Github Actions workflow to build the docker images from running. ([\#10461](https://github.com/matrix-org/synapse/issues/10461))
- Fix release script to correctly version debian changelog when doing RCs. ([\#10465](https://github.com/matrix-org/synapse/issues/10465))
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Merge tag 'v1.39.0rc3' into develop
Synapse 1.39.0rc3 (2021-07-28)
==============================
Bugfixes
--------
- Fix a bug introduced in Synapse 1.38 which caused an exception at startup when SAML authentication was enabled. ([\#10477](https://github.com/matrix-org/synapse/issues/10477))
- Fix a long-standing bug where Synapse would not inform clients that a device had exhausted its one-time-key pool, potentially causing problems decrypting events. ([\#10485](https://github.com/matrix-org/synapse/issues/10485))
- Fix reporting old R30 stats as R30v2 stats. Introduced in v1.39.0rc1. ([\#10486](https://github.com/matrix-org/synapse/issues/10486))
Internal Changes
----------------
- Fix an error which prevented the Github Actions workflow to build the docker images from running. ([\#10461](https://github.com/matrix-org/synapse/issues/10461))
- Fix release script to correctly version debian changelog when doing RCs. ([\#10465](https://github.com/matrix-org/synapse/issues/10465))
This adds an API for third-party plugin modules to implement account validity, so they can provide this feature instead of Synapse. The module implementing the current behaviour for this feature can be found at https://github.com/matrix-org/synapse-email-account-validity.
To allow for a smooth transition between the current feature and the new module, hooks have been added to the existing account validity endpoints to allow their behaviours to be overridden by a module.
Previously only world-readable rooms were shown. This means that
rooms which are public, knockable, or invite-only with a pending invitation,
are included in a space summary. It also applies the same logic to
the experimental room version from MSC3083 -- if a user has access
to the proper allowed rooms then it is shown in the spaces summary.
This change is made per MSC3173 allowing stripped state of a room to
be shown to any potential room joiner.
* Add base starting insertion point when no chunk ID is provided
This is so we can have the marker event point to this initial
insertion event and be able to traverse the events in the first chunk.
Because modules might send extra state events when processing an event (e.g. matrix-org/synapse-dinsic#100), and in some cases these extra events might get dropped if we don't recalculate the initial event's auth.
The idea here is to stop people sending things that aren't joins/leaves/knocks through these endpoints: previously you could send anything you liked through them. I wasn't able to find any security holes from doing so, but it doesn't sound like a good thing.
This implements refresh tokens, as defined by MSC2918
This MSC has been implemented client side in Hydrogen Web: vector-im/hydrogen-web#235
The basics of the MSC works: requesting refresh tokens on login, having the access tokens expire, and using the refresh token to get a new one.
Signed-off-by: Quentin Gliech <quentingliech@gmail.com>
If a room is remote and we don't have a user in it, always try to join it. It might fail if the room is invite-only, but we don't have a user to invite with, so at this point it's the best we can do.
Fixes#10233 (at least to some extent)
Implemented config option sso.update_profile_information to keep user's display name in sync with the SSO displayname.
Signed-off-by: Johannes Kanefendt <johannes.kanefendt@krzn.de>
An accidental mis-ordering of operations during #6739 technically allowed an incoming knock event over federation in before checking it against any configured Third Party Access Rules modules.
This PR corrects that by performing the TPAR check *before* persisting the event.
This could cause a minor data leak if someone defined a non-restricted join rule
with an allow key or used a restricted join rule in an older room version, but this is
unlikely.
Additionally this starts adding unit tests to the spaces summary handler.
This PR adds a common configuration section for all modules (see docs). These modules are then loaded at startup by the homeserver. Modules register their hooks and web resources using the new `register_[...]_callbacks` and `register_web_resource` methods of the module API.
Dangerous actions means deactivating an account, modifying an account
password, or adding a 3PID.
Other actions (deleting devices, uploading keys) can re-use the same UI
auth session if ui_auth.session_timeout is configured.
* Room version 7 for knocking.
* Stable prefixes and endpoints (both client and federation) for knocking.
* Removes the experimental configuration flag.
Spawned from missing messages we were seeing on `matrix.org` from a
federated Gtiter bridged room, https://gitlab.com/gitterHQ/webapp/-/issues/2770.
The underlying issue in Synapse is tracked by https://github.com/matrix-org/synapse/issues/10066
where the message and join event race and the message is `soft_failed` before the
`join` event reaches the remote federated server.
Less soft_failed events = better and usually this should only trigger for events
where people are doing bad things and trying to fuzz and fake everything.
Fixes#1834.
`get_new_events_for_appservice` internally calls `get_events_as_list`, which will filter out any rejected events. If all returned events are filtered out, `_notify_interested_services` will return without updating the last handled stream position. If there are 100 consecutive such events, processing will halt altogether.
Breaking the loop is now done by checking whether we're up-to-date with `current_max` in the loop condition, instead of relying on an empty `events` list.
Signed-off-by: Willem Mulder <14mRh4X0r@gmail.com>
If backfilling is slow then the client may time out and retry, causing
Synapse to start a new `/backfill` before the existing backfill has
finished, duplicating work.
Empirically, this helped my server considerably when handling gaps in Matrix HQ. The problem was that we would repeatedly call have_seen_events for the same set of (50K or so) auth_events, each of which would take many minutes to complete, even though it's only an index scan.
To be more consistent with similar code. The check now automatically
raises an AuthError instead of passing back a boolean. It also absorbs
some shared logic between callers.
This should help ensure that equivalent results are achieved between
homeservers querying for the summary of a space.
This implements modified MSC1772 rules, according to MSC2946.
The different is that the origin_server_ts of the m.room.create event
is not used as a tie-breaker since this might not be known if the
homeserver is not part of the room.
We were pulling the full auth chain for the room out of the DB each time
we backfilled, which can be *huge* for large rooms and is totally
unnecessary.
This is an update based on changes to MSC2946. The origin_server_ts
of the m.room.create event is copied into the creation_ts field for each
room returned from the spaces summary.
Applied a (slightly modified) patch from https://github.com/matrix-org/synapse/issues/9574.
As far as I understand this would allow the cookie set during the OIDC flow to work on deployments using public baseurls that do not sit at the URL path root.
When receiving a /send_join request for a room with join rules set to 'restricted',
check if the user is a member of the spaces defined in the 'allow' key of the join rules.
This only applies to an experimental room version, as defined in MSC3083.
This attempts to be a direct port of https://github.com/matrix-org/synapse-dinsic/pull/74 to mainline. There was some fiddling required to deal with the changes that have been made to mainline since (mainly dealing with the split of `RegistrationWorkerStore` from `RegistrationStore`, and the changes made to `self.make_request` in test code).
When receiving a /send_join request for a room with join rules set to 'restricted',
check if the user is a member of the spaces defined in the 'allow' key of the join
rules.
This only applies to an experimental room version, as defined in MSC3083.
Part of #9744
Removes all redundant `# -*- coding: utf-8 -*-` lines from files, as python 3 automatically reads source code as utf-8 now.
`Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>`
When joining a room with join rules set to 'restricted', check if the
user is a member of the spaces defined in the 'allow' key of the join rules.
This only applies to an experimental room version, as defined in MSC3083.
At the moment, if you'd like to share presence between local or remote users, those users must be sharing a room together. This isn't always the most convenient or useful situation though.
This PR adds a module to Synapse that will allow deployments to set up extra logic on where presence updates should be routed. The module must implement two methods, `get_users_for_states` and `get_interested_users`. These methods are given presence updates or user IDs and must return information that Synapse will use to grant passing presence updates around.
A method is additionally added to `ModuleApi` which allows triggering a set of users to receive the current, online presence information for all users they are considered interested in. This is the equivalent of that user receiving presence information during an initial sync.
The goal of this module is to be fairly generic and useful for a variety of applications, with hard requirements being:
* Sending state for a specific set or all known users to a defined set of local and remote users.
* The ability to trigger an initial sync for specific users, so they receive all current state.
`room_invite_state_types` was inconvenient as a configuration setting, because
anyone that ever set it would not receive any new types that were added to the
defaults. Here, we deprecate the old setting, and replace it with a couple of
new settings under `room_prejoin_state`.
This should fix a class of bug where we forget to check if e.g. the appservice shouldn't be ratelimited.
We also check the `ratelimit_override` table to check if the user has ratelimiting disabled. That table is really only meant to override the event sender ratelimiting, so we don't use any values from it (as they might not make sense for different rate limits), but we do infer that if ratelimiting is disabled for the user we should disabled all ratelimits.
Fixes#9663
Running `dmypy run` will do a `mypy` check while spinning up a daemon
that makes rerunning `dmypy run` a lot faster.
`dmypy` doesn't support `follow_imports = silent` and has
`local_partial_types` enabled, so this PR enables those options and
fixes the issues that were newly raised. Note that `local_partial_types`
will be enabled by default in upcoming mypy releases.
Builds on the work done in #9643 to add a federation API for space summaries.
There's a bit of refactoring of the existing client-server code first, to avoid too much duplication.
We had two functions named `get_forward_extremities_for_room` and
`get_forward_extremeties_for_room` that took different paramters. We
rename one of them to avoid confusion.
Instead of if the user does not have a password hash. This allows a SSO
user to add a password to their account, but only if the local password
database is configured.
Fixes https://github.com/matrix-org/synapse/issues/9572
When a SSO user logs in for the first time, we create a local Matrix user for them. This goes through the register_user flow, which ends up triggering the spam checker. Spam checker modules don't currently have any way to differentiate between a user trying to sign up initially, versus an SSO user (whom has presumably already been approved elsewhere) trying to log in for the first time.
This PR passes `auth_provider_id` as an argument to the `check_registration_for_spam` function. This argument will contain an ID of an SSO provider (`"saml"`, `"cas"`, etc.) if one was used, else `None`.
Background: When we receive incoming federation traffic, and notice that we are missing prev_events from
the incoming traffic, first we do a `/get_missing_events` request, and then if we still have missing prev_events,
we set up new backwards-extremities. To do that, we need to make a `/state_ids` request to ask the remote
server for the state at those prev_events, and then we may need to then ask the remote server for any events
in that state which we don't already have, as well as the auth events for those missing state events, so that we
can auth them.
This PR attempts to optimise the processing of that state request. The `state_ids` API returns a list of the state
events, as well as a list of all the auth events for *all* of those state events. The optimisation comes from the
observation that we are currently loading all of those auth events into memory at the start of the operation, but
we almost certainly aren't going to need *all* of the auth events. Rather, we can check that we have them, and
leave the actual load into memory for later. (Ideally the federation API would tell us which auth events we're
actually going to need, but it doesn't.)
The effect of this is to reduce the number of events that I need to load for an event in Matrix HQ from about
60000 to about 22000, which means it can stay in my in-memory cache, whereas previously the sheer number
of events meant that all 60K events had to be loaded from db for each request, due to the amount of cache
churn. (NB I've already tripled the size of the cache from its default of 10K).
Unfortunately I've ended up basically C&Ping `_get_state_for_room` and `_get_events_from_store_or_dest` into
a new method, because `_get_state_for_room` is also called during backfill, which expects the auth events to be
returned, so the same tricks don't work. That said, I don't really know why that codepath is completely different
(ultimately we're doing the same thing in setting up a new backwards extremity) so I've left a TODO suggesting
that we clean it up.
We either need to pass the auth provider over the replication api, or make sure
we report the auth provider on the worker that received the request. I've gone
with the latter.
This great big stack of commits is a a whole load of hoop-jumping to make it easier to store additional values in login tokens, and then to actually store the SSO Identity Provider in the login token. (Making use of that data will follow in a subsequent PR.)