core_crypto/mls/conversation/
merge.rs

1//! A MLS group can be merged (aka committed) when it has a pending commit. The latter is a commit
2//! we created which is still waiting to be "committed". By doing so, we will apply all the
3//! modifications present in the commit to the ratchet tree and also persist the new group in the
4//! keystore. Like this, even if the application crashes we will be able to restore.
5//!
6//! This table summarizes when a MLS group can be merged:
7//!
8//! | can be merged ?   | 0 pend. Commit | 1 pend. Commit |
9//! |-------------------|----------------|----------------|
10//! | 0 pend. Proposal  | ❌              | ✅              |
11//! | 1+ pend. Proposal | ❌              | ✅              |
12//!
13
14use core_crypto_keystore::entities::MlsEncryptionKeyPair;
15use openmls_traits::OpenMlsCryptoProvider;
16
17use mls_crypto_provider::MlsCryptoProvider;
18
19use super::Result;
20use crate::{MlsError, mls::MlsConversation, prelude::Session};
21
22/// Abstraction over a MLS group capable of merging a commit
23impl MlsConversation {
24    /// see [TransactionContext::commit_accepted]
25    #[cfg_attr(test, crate::durable)]
26    pub(crate) async fn commit_accepted(&mut self, client: &Session, backend: &MlsCryptoProvider) -> Result<()> {
27        // openmls stores here all the encryption keypairs used for update proposals..
28        let previous_own_leaf_nodes = self.group.own_leaf_nodes.clone();
29
30        self.group
31            .merge_pending_commit(backend)
32            .await
33            .map_err(MlsError::wrap("merging pending commit"))?;
34        self.persist_group_when_changed(&backend.keystore(), false).await?;
35
36        // ..so if there's any, we clear them after the commit is merged
37        for oln in &previous_own_leaf_nodes {
38            let ek = oln.encryption_key().as_slice();
39            let _ = backend.key_store().remove::<MlsEncryptionKeyPair, _>(ek).await;
40        }
41
42        client
43            .notify_epoch_changed(self.id.clone(), self.group.epoch().as_u64())
44            .await;
45
46        Ok(())
47    }
48}
49
50#[cfg(test)]
51mod tests {
52    use wasm_bindgen_test::*;
53
54    use crate::test_utils::*;
55
56    wasm_bindgen_test_configure!(run_in_browser);
57
58    mod commit_accepted {
59        use super::*;
60
61        #[apply(all_cred_cipher)]
62        #[wasm_bindgen_test]
63        async fn should_apply_pending_commit(case: TestContext) {
64            run_test_with_client_ids(case.clone(), ["alice", "bob"], move |[alice_central, bob_central]| {
65                Box::pin(async move {
66                    let id = conversation_id();
67                    alice_central
68                        .transaction
69                        .new_conversation(&id, case.credential_type, case.cfg.clone())
70                        .await
71                        .unwrap();
72                    alice_central.invite_all(&case, &id, [&bob_central]).await.unwrap();
73                    assert_eq!(alice_central.get_conversation_unchecked(&id).await.members().len(), 2);
74                    alice_central
75                        .transaction
76                        .conversation(&id)
77                        .await
78                        .unwrap()
79                        .remove_members(&[bob_central.get_client_id().await])
80                        .await
81                        .unwrap();
82                    assert_eq!(alice_central.get_conversation_unchecked(&id).await.members().len(), 1);
83                })
84            })
85            .await
86        }
87
88        #[apply(all_cred_cipher)]
89        #[wasm_bindgen_test]
90        async fn should_clear_pending_commit_and_proposals(case: TestContext) {
91            run_test_with_client_ids(case.clone(), ["alice"], move |[mut alice_central]| {
92                Box::pin(async move {
93                    let id = conversation_id();
94                    alice_central
95                        .transaction
96                        .new_conversation(&id, case.credential_type, case.cfg.clone())
97                        .await
98                        .unwrap();
99                    alice_central.transaction.new_update_proposal(&id).await.unwrap();
100                    alice_central.create_unmerged_commit(&id).await;
101                    assert!(!alice_central.pending_proposals(&id).await.is_empty());
102                    assert!(alice_central.pending_commit(&id).await.is_some());
103                    alice_central
104                        .get_conversation_unchecked(&id)
105                        .await
106                        .commit_accepted(
107                            &alice_central.transaction.session().await.unwrap(),
108                            &alice_central.session.crypto_provider,
109                        )
110                        .await
111                        .unwrap();
112                    assert!(alice_central.pending_commit(&id).await.is_none());
113                    assert!(alice_central.pending_proposals(&id).await.is_empty());
114                })
115            })
116            .await
117        }
118
119        #[apply(all_cred_cipher)]
120        #[wasm_bindgen_test]
121        async fn should_clean_associated_key_material(case: TestContext) {
122            run_test_with_client_ids(case.clone(), ["alice"], move |[alice_central]| {
123                Box::pin(async move {
124                    let id = conversation_id();
125                    alice_central
126                        .transaction
127                        .new_conversation(&id, case.credential_type, case.cfg.clone())
128                        .await
129                        .unwrap();
130
131                    let initial_count = alice_central.transaction.count_entities().await;
132
133                    alice_central.transaction.new_update_proposal(&id).await.unwrap();
134                    let post_proposal_count = alice_central.transaction.count_entities().await;
135                    assert_eq!(
136                        post_proposal_count.encryption_keypair,
137                        initial_count.encryption_keypair + 1
138                    );
139
140                    alice_central
141                        .transaction
142                        .conversation(&id)
143                        .await
144                        .unwrap()
145                        .commit_pending_proposals()
146                        .await
147                        .unwrap();
148
149                    let final_count = alice_central.transaction.count_entities().await;
150                    assert_eq!(initial_count, final_count);
151                })
152            })
153            .await
154        }
155    }
156}
core_crypto/mls/conversation/merge.rs

core_crypto/mls/conversation/
merge.rs
