works

crypto/src/mls/conversation/merge.rs

@@ -11,6 +11,7 @@
 //! | 1+ pend. Proposal | ❌              | ✅              |
 //!
 
+use core_crypto_keystore::entities::MlsEncryptionKeyPair;
 use openmls::prelude::MlsGroupStateError;
 use openmls_traits::OpenMlsCryptoProvider;
 
@@ -27,8 +28,19 @@ impl MlsConversation {
     /// see [MlsCentral::commit_accepted]
     #[cfg_attr(test, crate::durable)]
     pub async fn commit_accepted(&mut self, backend: &MlsCryptoProvider) -> CryptoResult<()> {
+        // openmls stores here all the encryption keypairs used for update proposals..
+        let previous_own_leaf_nodes = self.group.own_leaf_nodes.clone();
+
         self.group.merge_pending_commit(backend).await.map_err(MlsError::from)?;
-        self.persist_group_when_changed(backend, false).await
+        self.persist_group_when_changed(backend, false).await?;
+
+        // ..so if there's any, we clear them after the commit is merged
+        for oln in &previous_own_leaf_nodes {
+            let ek = oln.encryption_key().as_slice();
+            let _ = backend.key_store().remove::<MlsEncryptionKeyPair, _>(ek).await;
+        }
+
+        Ok(())
     }
 
     /// see [MlsCentral::clear_pending_proposal]
@@ -79,7 +91,6 @@ impl MlsCentral {
     /// to be used for the new epoch.
     /// We can now safely "merge" it (effectively apply the commit to the group) and update it
     /// in the keystore. The previous can be discarded to respect Forward Secrecy.
-    #[cfg_attr(test, crate::idempotent)]
     pub async fn commit_accepted(&mut self, conversation_id: &ConversationId) -> CryptoResult<()> {
         self.get_conversation(conversation_id)
             .await?
@@ -210,6 +221,38 @@ pub mod tests {
             )
             .await
         }
+
+        // #[apply(all_cred_cipher)]
+        // #[wasm_bindgen_test]
+        #[async_std::test]
+        pub async fn should_clean_associated_key_material(/*case: TestCase*/) {
+            let case = TestCase::default();
+            run_test_with_client_ids(case.clone(), ["alice"], move |[mut alice_central]| {
+                Box::pin(async move {
+                    let id = conversation_id();
+                    alice_central
+                        .new_conversation(id.clone(), case.credential_type, case.cfg.clone())
+                        .await
+                        .unwrap();
+
+                    let initial_count = alice_central.count_entities().await;
+
+                    alice_central.new_update_proposal(&id).await.unwrap();
+                    let post_proposal_count = alice_central.count_entities().await;
+                    assert_eq!(
+                        post_proposal_count.encryption_keypair,
+                        initial_count.encryption_keypair + 1
+                    );
+
+                    alice_central.commit_pending_proposals(&id).await.unwrap();
+                    alice_central.commit_accepted(&id).await.unwrap();
+
+                    let final_count = alice_central.count_entities().await;
+                    assert_eq!(initial_count, final_count);
+                })
+            })
+            .await
+        }
     }
 
     pub mod clear_pending_proposal {