core_crypto/mls/conversation/
welcome.rs

1use core_crypto_keystore::{Database, entities::PersistedMlsPendingGroup, traits::FetchFromDatabase};
2use openmls::prelude::{MlsGroup, Welcome};
3use openmls_traits::OpenMlsCryptoProvider;
4use wire_e2e_identity::NewCrlDistributionPoints;
5
6use super::{Error, Result};
7use crate::{
8    ConversationId, LeafError, MlsConversation, MlsConversationConfiguration, MlsError, group_store::GroupStore,
9    mls_provider::MlsCryptoProvider,
10};
11
12/// Contains everything client needs to know after decrypting an (encrypted) Welcome message
13#[derive(Debug)]
14pub struct WelcomeBundle {
15    /// MLS Group Id
16    pub id: ConversationId,
17    /// New CRL distribution points that appeared by the introduction of a new credential
18    pub crl_new_distribution_points: NewCrlDistributionPoints,
19}
20
21impl MlsConversation {
22    // ? Do we need to provide the ratchet_tree to the MlsGroup? Does everything crumble down if we can't actually get
23    // it?
24    /// Create the MLS conversation from an MLS Welcome message
25    pub(crate) async fn from_welcome_message(
26        welcome: Welcome,
27        configuration: MlsConversationConfiguration,
28        provider: &MlsCryptoProvider,
29        database: &Database,
30        mls_groups: &mut GroupStore<MlsConversation>,
31    ) -> Result<Self> {
32        let mls_group_config = configuration.as_openmls_default_configuration()?;
33
34        let group = MlsGroup::new_from_welcome(provider, &mls_group_config, welcome, None)
35            .await
36            .map_err(|err| {
37                use openmls::prelude::WelcomeError;
38                match err {
39                    WelcomeError::NoMatchingKeyPackage | WelcomeError::NoMatchingEncryptionKey => Error::OrphanWelcome,
40                    _ => MlsError::wrap("group could not be created from welcome")(err).into(),
41                }
42            })?;
43
44        let id = ConversationId::from(group.group_id().as_slice());
45        let existing_conversation = mls_groups.get_fetch(&id, database, None).await;
46        let conversation_exists = existing_conversation.ok().flatten().is_some();
47
48        let pending_group = provider
49            .key_store()
50            .get_borrowed::<PersistedMlsPendingGroup>(id.as_ref())
51            .await;
52        let pending_group_exists = pending_group.ok().flatten().is_some();
53
54        if conversation_exists || pending_group_exists {
55            return Err(LeafError::ConversationAlreadyExists(id).into());
56        }
57
58        Self::from_mls_group(group, configuration, database).await
59    }
60}
core_crypto/mls/conversation/welcome.rs

core_crypto/mls/conversation/
welcome.rs
