core_crypto/mls/conversation/
welcome.rs

1use core_crypto_keystore::{Database, entities::PersistedMlsPendingGroup, traits::FetchFromDatabase};
2use openmls::prelude::{MlsGroup, Welcome};
3use openmls_traits::OpenMlsCryptoProvider;
4
5use super::{Error, Result};
6use crate::{
7    ConversationId, LeafError, MlsConversation, MlsConversationConfiguration, MlsError,
8    e2e_identity::NewCrlDistributionPoints, group_store::GroupStore, mls_provider::MlsCryptoProvider,
9};
10
11/// Contains everything client needs to know after decrypting an (encrypted) Welcome message
12#[derive(Debug)]
13pub struct WelcomeBundle {
14    /// MLS Group Id
15    pub id: ConversationId,
16    /// New CRL distribution points that appeared by the introduction of a new credential
17    pub crl_new_distribution_points: NewCrlDistributionPoints,
18}
19
20impl MlsConversation {
21    // ? Do we need to provide the ratchet_tree to the MlsGroup? Does everything crumble down if we can't actually get
22    // it?
23    /// Create the MLS conversation from an MLS Welcome message
24    pub(crate) async fn from_welcome_message(
25        welcome: Welcome,
26        configuration: MlsConversationConfiguration,
27        provider: &MlsCryptoProvider,
28        database: &Database,
29        mls_groups: &mut GroupStore<MlsConversation>,
30    ) -> Result<Self> {
31        let mls_group_config = configuration.as_openmls_default_configuration()?;
32
33        let group = MlsGroup::new_from_welcome(provider, &mls_group_config, welcome, None)
34            .await
35            .map_err(|err| {
36                use openmls::prelude::WelcomeError;
37                match err {
38                    WelcomeError::NoMatchingKeyPackage | WelcomeError::NoMatchingEncryptionKey => Error::OrphanWelcome,
39                    _ => MlsError::wrap("group could not be created from welcome")(err).into(),
40                }
41            })?;
42
43        let id = ConversationId::from(group.group_id().as_slice());
44        let existing_conversation = mls_groups.get_fetch(&id, database, None).await;
45        let conversation_exists = existing_conversation.ok().flatten().is_some();
46
47        let pending_group = provider
48            .key_store()
49            .get_borrowed::<PersistedMlsPendingGroup>(id.as_ref())
50            .await;
51        let pending_group_exists = pending_group.ok().flatten().is_some();
52
53        if conversation_exists || pending_group_exists {
54            return Err(LeafError::ConversationAlreadyExists(id).into());
55        }
56
57        Self::from_mls_group(group, configuration, database).await
58    }
59}
core_crypto/mls/conversation/welcome.rs

core_crypto/mls/conversation/
welcome.rs
