bugfix: ensure the SessionStore is cleared when regenerating the OlmMachine

crates/matrix-sdk-base/src/client.rs

@@ -220,7 +220,9 @@ impl BaseClient {
         tracing::debug!("regenerating OlmMachine");
         let session_meta = self.session_meta().ok_or(Error::OlmError(OlmError::MissingSession))?;
 
-        // Recreate it.
+        // Recreate the `OlmMachine` and wipe the in-memory cache in the store
+        // because we suspect it has stale data.
+        self.crypto_store.clear_caches().await;
         let olm_machine = OlmMachine::with_store(
             &session_meta.user_id,
             &session_meta.device_id,
@@ -1695,6 +1697,36 @@ mod tests {
         client.get_room(room_id).expect("Just-created room not found!")
     }
 
+    #[cfg(feature = "e2e-encryption")]
+    #[async_test]
+    async fn test_regerating_olm_clears_store_caches() {
+        // See https://github.com/matrix-org/matrix-rust-sdk/issues/3110
+        // We must clear the store cache when we regenerate the OlmMachine
+        // to ensure we really get the new state.
+
+        use ruma::{owned_device_id, owned_user_id};
+
+        use crate::store::StoreConfig;
+
+        // Given a client using a fake store
+        let user_id = owned_user_id!("@u:m.o");
+        let device_id = owned_device_id!("DEVICE");
+        let fake_store = fake_crypto_store::FakeCryptoStore::default();
+        let store_config = StoreConfig::new().crypto_store(fake_store.clone());
+        let client = BaseClient::with_store_config(store_config);
+        client.set_session_meta(SessionMeta { user_id, device_id }).await.unwrap();
+        fake_store.clear_method_calls();
+
+        // When we regenerate the OlmMachine
+        client.regenerate_olm().await.expect("Failed to regenerate olm");
+
+        // Then we cleared the store cache
+        assert!(
+            fake_store.method_calls().contains(&"clear_caches".to_owned()),
+            "No clear_caches call!"
+        );
+    }
+
     #[async_test]
     async fn test_deserialization_failure() {
         let user_id = user_id!("@alice:example.org");
@@ -1884,4 +1916,292 @@ mod tests {
         assert_eq!(member.display_name().unwrap(), "Invited Alice");
         assert_eq!(member.avatar_url().unwrap().to_string(), "mxc://localhost/fewjilfewjil42");
     }
+
+    #[cfg(feature = "e2e-encryption")]
+    mod fake_crypto_store {
+        use std::{
+            collections::HashMap,
+            convert::Infallible,
+            sync::{Arc, Mutex},
+        };
+
+        use async_trait::async_trait;
+        use matrix_sdk_crypto::{
+            olm::{InboundGroupSession, OutboundGroupSession, PrivateCrossSigningIdentity},
+            store::{
+                BackupKeys, Changes, CryptoStore, PendingChanges, RoomKeyCounts, RoomSettings,
+            },
+            types::events::room_key_withheld::RoomKeyWithheldEvent,
+            Account, GossipRequest, GossippedSecret, ReadOnlyDevice, ReadOnlyUserIdentities,
+            SecretInfo, Session, TrackedUser,
+        };
+        use ruma::{
+            events::secret::request::SecretName, DeviceId, OwnedDeviceId, RoomId, TransactionId,
+            UserId,
+        };
+
+        #[derive(Clone, Debug, Default)]
+        pub(crate) struct FakeCryptoStore {
+            pub method_calls: Arc<Mutex<Vec<String>>>,
+        }
+
+        impl FakeCryptoStore {
+            pub fn method_calls(&self) -> Vec<String> {
+                self.method_calls.lock().unwrap().clone()
+            }
+
+            pub fn clear_method_calls(&self) {
+                self.method_calls.lock().unwrap().clear();
+            }
+
+            fn call(&self, method_name: &str) {
+                self.method_calls.lock().unwrap().push(method_name.to_owned());
+            }
+        }
+
+        #[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
+        #[cfg_attr(not(target_arch = "wasm32"), async_trait)]
+        impl CryptoStore for FakeCryptoStore {
+            type Error = Infallible;
+
+            async fn clear_caches(&self) {
+                self.call("clear_caches");
+            }
+
+            async fn load_account(&self) -> Result<Option<Account>, Self::Error> {
+                self.call("load_account");
+                Ok(None)
+            }
+
+            async fn load_identity(
+                &self,
+            ) -> Result<Option<PrivateCrossSigningIdentity>, Self::Error> {
+                self.call("load_identity");
+                Ok(None)
+            }
+
+            async fn next_batch_token(&self) -> Result<Option<String>, Self::Error> {
+                self.call("next_batch_token");
+                Ok(None)
+            }
+
+            async fn save_pending_changes(
+                &self,
+                _changes: PendingChanges,
+            ) -> Result<(), Self::Error> {
+                self.call("save_pending_changes");
+                Ok(())
+            }
+
+            async fn save_changes(&self, _changes: Changes) -> Result<(), Self::Error> {
+                self.call("save_changes");
+                Ok(())
+            }
+
+            async fn get_sessions(
+                &self,
+                _sender_key: &str,
+            ) -> Result<Option<Arc<tokio::sync::Mutex<Vec<Session>>>>, Self::Error> {
+                self.call("get_sessions");
+                Ok(None)
+            }
+
+            async fn get_inbound_group_session(
+                &self,
+                _room_id: &RoomId,
+                _session_id: &str,
+            ) -> Result<Option<InboundGroupSession>, Self::Error> {
+                self.call("get_inbound_group_session");
+                Ok(None)
+            }
+
+            async fn get_withheld_info(
+                &self,
+                _room_id: &RoomId,
+                _session_id: &str,
+            ) -> Result<Option<RoomKeyWithheldEvent>, Self::Error> {
+                self.call("get_withheld_info");
+                Ok(None)
+            }
+
+            async fn get_inbound_group_sessions(
+                &self,
+            ) -> Result<Vec<InboundGroupSession>, Self::Error> {
+                self.call("get_inbound_group_sessions");
+                Ok(vec![])
+            }
+
+            async fn inbound_group_session_counts(
+                &self,
+                _backup_version: Option<&str>,
+            ) -> Result<RoomKeyCounts, Self::Error> {
+                self.call("inbound_group_session_counts");
+                Ok(RoomKeyCounts { total: 0, backed_up: 0 })
+            }
+
+            async fn inbound_group_sessions_for_backup(
+                &self,
+                _backup_version: &str,
+                _limit: usize,
+            ) -> Result<Vec<InboundGroupSession>, Self::Error> {
+                self.call("inbound_group_sessions_for_backup");
+                Ok(vec![])
+            }
+
+            async fn mark_inbound_group_sessions_as_backed_up(
+                &self,
+                _backup_version: &str,
+                _room_and_session_ids: &[(&RoomId, &str)],
+            ) -> Result<(), Self::Error> {
+                self.call("mark_inbound_group_sessions_as_backed_up");
+                Ok(())
+            }
+
+            async fn reset_backup_state(&self) -> Result<(), Self::Error> {
+                self.call("reset_backup_state");
+                Ok(())
+            }
+
+            async fn load_backup_keys(&self) -> Result<BackupKeys, Self::Error> {
+                self.call("load_backup_keys");
+                Ok(BackupKeys::default())
+            }
+
+            async fn get_outbound_group_session(
+                &self,
+                _room_id: &RoomId,
+            ) -> Result<Option<OutboundGroupSession>, Self::Error> {
+                self.call("get_outbound_group_session");
+                Ok(None)
+            }
+
+            async fn load_tracked_users(&self) -> Result<Vec<TrackedUser>, Self::Error> {
+                self.call("load_tracked_users");
+                Ok(vec![])
+            }
+
+            async fn save_tracked_users(
+                &self,
+                _tracked_users: &[(&UserId, bool)],
+            ) -> Result<(), Self::Error> {
+                self.call("save_tracked_users");
+                Ok(())
+            }
+
+            async fn get_device(
+                &self,
+                _user_id: &UserId,
+                _device_id: &DeviceId,
+            ) -> Result<Option<ReadOnlyDevice>, Self::Error> {
+                self.call("get_device");
+                Ok(None)
+            }
+
+            async fn get_user_devices(
+                &self,
+                _user_id: &UserId,
+            ) -> Result<HashMap<OwnedDeviceId, ReadOnlyDevice>, Self::Error> {
+                self.call("get_user_devices");
+                Ok(HashMap::default())
+            }
+
+            async fn get_user_identity(
+                &self,
+                _user_id: &UserId,
+            ) -> Result<Option<ReadOnlyUserIdentities>, Self::Error> {
+                self.call("get_user_identity");
+                Ok(None)
+            }
+
+            async fn is_message_known(
+                &self,
+                _message_hash: &matrix_sdk_crypto::olm::OlmMessageHash,
+            ) -> Result<bool, Self::Error> {
+                self.call("is_message_known");
+                Ok(false)
+            }
+
+            async fn get_outgoing_secret_requests(
+                &self,
+                _request_id: &TransactionId,
+            ) -> Result<Option<GossipRequest>, Self::Error> {
+                self.call("get_outgoing_secret_requests");
+                Ok(None)
+            }
+
+            async fn get_secret_request_by_info(
+                &self,
+                _key_info: &SecretInfo,
+            ) -> Result<Option<GossipRequest>, Self::Error> {
+                self.call("get_secret_request_by_info");
+                Ok(None)
+            }
+
+            async fn get_unsent_secret_requests(&self) -> Result<Vec<GossipRequest>, Self::Error> {
+                self.call("get_unsent_secret_requests");
+                Ok(vec![])
+            }
+
+            async fn delete_outgoing_secret_requests(
+                &self,
+                _request_id: &TransactionId,
+            ) -> Result<(), Self::Error> {
+                self.call("delete_outgoing_secret_requests");
+                Ok(())
+            }
+
+            async fn get_secrets_from_inbox(
+                &self,
+                _secret_name: &SecretName,
+            ) -> Result<Vec<GossippedSecret>, Self::Error> {
+                self.call("get_secrets_from_inbox");
+                Ok(vec![])
+            }
+
+            async fn delete_secrets_from_inbox(
+                &self,
+                _secret_name: &SecretName,
+            ) -> Result<(), Self::Error> {
+                self.call("delete_secrets_from_inbox");
+                Ok(())
+            }
+
+            async fn get_room_settings(
+                &self,
+                _room_id: &RoomId,
+            ) -> Result<Option<RoomSettings>, Self::Error> {
+                self.call("get_room_settings");
+                Ok(None)
+            }
+
+            async fn get_custom_value(&self, _key: &str) -> Result<Option<Vec<u8>>, Self::Error> {
+                self.call("get_custom_value");
+                Ok(None)
+            }
+
+            async fn set_custom_value(
+                &self,
+                _key: &str,
+                _value: Vec<u8>,
+            ) -> Result<(), Self::Error> {
+                self.call("set_custom_value");
+                Ok(())
+            }
+
+            async fn remove_custom_value(&self, _key: &str) -> Result<(), Self::Error> {
+                self.call("remove_custom_value");
+                Ok(())
+            }
+
+            async fn try_take_leased_lock(
+                &self,
+                _lease_duration_ms: u32,
+                _key: &str,
+                _holder: &str,
+            ) -> Result<bool, Self::Error> {
+                self.call("try_take_leased_lock");
+                Ok(true)
+            }
+        }
+    }
 }

crates/matrix-sdk-crypto/CHANGELOG.md

@@ -25,6 +25,9 @@ Breaking changes:
 
 Additions:
 
+- Expose new method `CryptoStore::clear_caches`.
+  ([#3338](https://github.com/matrix-org/matrix-rust-sdk/pull/3338))
+
 - Expose new method `OlmMachine::device_creation_time`.
   ([#3275](https://github.com/matrix-org/matrix-rust-sdk/pull/3275))
 

crates/matrix-sdk-crypto/src/store/caches.rs

@@ -48,6 +48,13 @@ impl SessionStore {
         Self::default()
     }
 
+    /// Clear all entries in the session store.
+    ///
+    /// This is intended to be used when regenerating olm machines.
+    pub fn clear(&self) {
+        self.entries.write().unwrap().clear()
+    }
+
     /// Add a session to the store.
     ///
     /// Returns true if the session was added, false if the session was

crates/matrix-sdk-crypto/src/store/integration_tests.rs

@@ -71,7 +71,7 @@ macro_rules! cryptostore_integration_tests {
                 Account::with_device_id(alice_id(), alice_device_id())
             }
 
-            async fn get_account_and_session() -> (Account, Session) {
+            pub(crate) async fn get_account_and_session() -> (Account, Session) {
                 let alice = Account::with_device_id(alice_id(), alice_device_id());
                 let mut bob = Account::with_device_id(bob_id(), bob_device_id());
 

crates/matrix-sdk-crypto/src/store/memorystore.rs

@@ -145,6 +145,14 @@ type Result<T> = std::result::Result<T, Infallible>;
 impl CryptoStore for MemoryStore {
     type Error = Infallible;
 
+    async fn clear_caches(&self) {
+        // no-op: it makes no sense to delete fields here as we would forget our
+        // identity, etc Effectively we have no caches as the fields
+        // *are* the underlying store. Calling this method only makes
+        // sense if there is some other layer (e.g disk) persistence
+        // happening.
+    }
+
     async fn load_account(&self) -> Result<Option<Account>> {
         Ok(self.account.read().unwrap().as_ref().map(|acc| acc.deep_clone()))
     }
@@ -718,6 +726,10 @@ mod integration_tests {
     impl CryptoStore for PersistentMemoryStore {
         type Error = <MemoryStore as CryptoStore>::Error;
 
+        async fn clear_caches(&self) {
+            self.0.clear_caches().await
+        }
+
         async fn load_account(&self) -> Result<Option<Account>, Self::Error> {
             self.0.load_account().await
         }