This adds a cross-process lock for refresh to work correctly.
We want to coordinate token refresh across multiple processes. For that, we're using a cross-process lock, and a value in the database identifying the latest session tokens that are valid (a hash of the actual tokens, for security reasons).
Whenever we run into an HTTP error indicating that the tokens have been invalidated, we try to refresh the access tokens; that's already existing prior to this PR. The novelty introduced is that we take a cross-process lock before doing so, now. Taking this lock will also load a session hash from the database, and we'll compare it against the latest "known" session hash (that the current process saved into its memory).
If there's no mismatch (i.e. the database and the currently known are the same), then we're all good and can keep going with the refresh, synchronize the hashes everywhere (in-memory and database), make sure the client is notified about it (through a new user-provided callback `SaveSessionCallback`; on iOS this will save it into the device's keychain).
Otherwise, that means another process has done a refresh under our feet. In that case, we ask an authoritative source for trusted session tokens. On iOS, they're reloaded from the device keychain; that happens through a new user-provided callback `ReloadSessionCallback`. Then, we make sure that the DB and the in-memory value recall this latest value.
An embedder who would like to make use of the cross-process locking mechanism should call `client.oidc().set_session_callbacks` and `client.oidc().enable_cross_process_refresh`. If only interested with the pings for new sessions, the client may only call `client.oidc().set_session_callbacks`.
Fixes https://github.com/matrix-org/matrix-rust-sdk/issues/2418.
Fixes https://github.com/matrix-org/matrix-rust-sdk/issues/2476
## Future improvements
- More testing of the whole flow. Not sure if mocking will be quite fit for OIDC, as this may require setting up an HTTPS server for the authentication code exchange and other OIDC-specific flows.
- Get rid of `SessionChange`, which duplicates in some way how a client can be notified about session changes.
---
* chore: replace manual StateMemoryStore::new with derived Default
* feat: add store backing for cross-process locking in state store
* chore: rename CryptoStoreLock to CrossProcessStoreLock
* chore: generalize cross-process lock
* feat: move the cross-process locking mechanism to the main crate
* feat: add support for cross-process store lock in the state store 🥳
* feat: implement a cross-process lock for OIDC token refresh
* chore: tweak comment + function name
* feat: make restore_session safe wrt cross-process lock
* feat: add FFI method + add mechanism to reload from keychain
* fix rename
* feat: return early when there was another process refreshed tokens
* fix FFI compile error + tweak some comments
* fix: put the reload_session callback and cross-process locks behind Arc to share them across clients
* feat: Add session retrieval to FFI.
* HACKY; KIDS DON'T DO THIS AT HOME
* chore: log if the hash from db isn't the same from the one from the returned session
* make it simpler to test OIDC token refresh
* some work, that includes fixes and a first test
* feat: require that the reload_session_callback be set at the same time as the cross-process lock
* chore: traces, traces everywhere
* fix: inherit session_change_sender when creating the notification client
* Some FFI improvements to help with tokio problems
* feat: resilient mode when DB/callback disagree about session (callback wins!)
* chore: move sender.send to the finish_refreshing function
* feat: add a save_session callback in the FFI and use it to save the session in keychain while holding XP lock
* fix test expectation after adding the check 🤷
* feat: split the ClientDelegate into two parts, including brand new ClientSessionDelegate
* chore: get rid of lease lock impl in the state store, as it's now unused
* a mix of fmt + clippy
* feat: add ctor for the crossprocessrefreshlockctx
* Include user ID when retrieving session.
Necessary as this isn't known when creating the AuthenticationService.
* yo dawg, you can't block while you block
* share auth data between parent and child client, add lock, AAAAAA this is messy
* tweaks
* feat: make the cross-process store locks generic
And move the implementation to the common crate.
* chore: upgrade some code comments to doc comments in `OngoingMigration`
* feat: implement `CryptoStore::remove_custom_value`
As it's going to be used for the OIDC PR, so as to remove a remembered hash of session tokens.
* remove unneeded remnants
* correctly wait for current request to finish
* feat: make it possible to setup session delegates on android too(?)
* put the cross process stuff in its own file
* typos 🤷
* fix: detach before sending token refresh request, to make sure the response tokens are always properly saved
* kleepee
* First round of review, thanks jonas!
* review round 2. FIGHT
* remove useless logs + avoid using deref explicitly
* more specialized error when cross-process lock is enabled without session callbacks
* fix: avoid cyclic reference between the session callback and client
---------
Co-authored-by: Doug <douglase@element.io>
Co-authored-by: Jonas Platte <jplatte@matrix.org>
When receiving a sliding sync room response for a room that had no local events in its timeline cache,
we'd mark the room as limited before, which is incorrect. It was made worse by the fact that later in
the code, we'd clear the local cache if a room was marked as limited, so this is a problem that would
repeat itself over time (assuming empty responses for that room).
This fixes it and unifies logs so there's only one log line per room, at most.
Fixes https://github.com/vector-im/element-x-android/issues/1281
Fixes https://github.com/matrix-org/matrix-rust-sdk/issues/2540
