Merge pull request #4946 from matrix-org/rav/history_sharing/share_on_invite

sdk: share room history when we send an invite, subject to an experimental feature flag.

Author: richvdh

crates/matrix-sdk/Cargo.toml

@@ -48,6 +48,7 @@ uniffi = ["dep:uniffi", "matrix-sdk-base/uniffi", "dep:matrix-sdk-ffi-macros"]
 experimental-widgets = ["dep:uuid"]
 
 docsrs = ["e2e-encryption", "sqlite", "indexeddb", "sso-login", "qrcode"]
+experimental-share-history-on-invite = []
 
 [dependencies]
 anyhow = { workspace = true, optional = true }

crates/matrix-sdk/src/room/mod.rs

@@ -158,10 +158,7 @@ use crate::{
     BaseRoom, Client, Error, HttpResult, Result, RoomState, TransmissionProgress,
 };
 #[cfg(feature = "e2e-encryption")]
-use crate::{
-    crypto::types::events::CryptoContextInfo, encryption::backups::BackupState,
-    room::shared_room_history::share_room_history,
-};
+use crate::{crypto::types::events::CryptoContextInfo, encryption::backups::BackupState};
 
 pub mod edit;
 pub mod futures;
@@ -1480,6 +1477,11 @@ impl Room {
     /// * `user_id` - The `UserId` of the user to invite to the room.
     #[instrument(skip_all)]
     pub async fn invite_user_by_id(&self, user_id: &UserId) -> Result<()> {
+        #[cfg(all(feature = "experimental-share-history-on-invite", feature = "e2e-encryption"))]
+        {
+            shared_room_history::share_room_history(self, user_id.to_owned()).await?;
+        }
+
         let recipient = InvitationRecipient::UserId { user_id: user_id.to_owned() };
         let request = invite_user::v3::Request::new(self.room_id().to_owned(), recipient);
         self.client.send(request).await?;
@@ -1806,21 +1808,6 @@ impl Room {
         Ok(())
     }
 
-    /// Share any shareable E2EE history in this room with the given recipient,
-    /// as per [MSC4268].
-    ///
-    /// [MSC4268]: https://github.com/matrix-org/matrix-spec-proposals/pull/4268
-    ///
-    /// This is temporarily exposed for integration testing as part of
-    /// experimental work on history sharing. In future, it will be combined
-    /// with sending an invite.
-    #[cfg(feature = "e2e-encryption")]
-    #[doc(hidden)]
-    #[instrument(skip_all, fields(room_id = ?self.room_id(), ?user_id))]
-    pub async fn share_history<'a>(&'a self, user_id: &UserId) -> Result<()> {
-        share_room_history(self, user_id.to_owned()).await
-    }
-
     /// Wait for the room to be fully synced.
     ///
     /// This method makes sure the room that was returned when joining a room

crates/matrix-sdk/src/room/shared_room_history.rs

@@ -15,17 +15,30 @@
 use std::iter;
 
 use ruma::OwnedUserId;
+use tracing::{info, instrument, warn};
 
 use crate::{crypto::types::events::room_key_bundle::RoomKeyBundleContent, Error, Result, Room};
 
 /// Share any shareable E2EE history in the given room with the given recipient,
 /// as per [MSC4268].
 ///
 /// [MSC4268]: https://github.com/matrix-org/matrix-spec-proposals/pull/4268
+#[instrument(skip(room), fields(room_id = ?room.room_id()))]
 pub async fn share_room_history(room: &Room, user_id: OwnedUserId) -> Result<()> {
-    tracing::info!("Sharing message history in {} with {}", room.room_id(), user_id);
     let client = &room.client;
 
+    // 0. We can only share room history if our user has set up cross signing
+    let own_identity = match client.user_id() {
+        Some(own_user) => client.encryption().get_user_identity(own_user).await?,
+        None => None,
+    };
+    if own_identity.is_none() {
+        warn!("Not sharing message history as cross-signing is not set up");
+        return Ok(());
+    }
+
+    info!("Sharing message history");
+
     // 1. Construct the key bundle
     let bundle = {
         let olm_machine = client.olm_machine().await;
@@ -34,7 +47,7 @@ pub async fn share_room_history(room: &Room, user_id: OwnedUserId) -> Result<()>
     };
 
     if bundle.is_empty() {
-        tracing::info!("No keys to share");
+        info!("No keys to share");
         return Ok(());
     }
 
@@ -43,7 +56,7 @@ pub async fn share_room_history(room: &Room, user_id: OwnedUserId) -> Result<()>
     let upload =
         client.upload_encrypted_file(&mime::APPLICATION_JSON, &mut (json.as_slice())).await?;
 
-    tracing::info!(
+    info!(
         media_url = ?upload.url,
         shared_keys = bundle.room_keys.len(),
         withheld_keys = bundle.withheld.len(),

labs/multiverse/Cargo.toml

@@ -16,7 +16,7 @@ crossterm = "0.28.1"
 futures-util = { workspace = true }
 imbl = { workspace = true }
 itertools = { workspace = true }
-matrix-sdk = { path = "../../crates/matrix-sdk", features = ["sso-login"] }
+matrix-sdk = { path = "../../crates/matrix-sdk", features = ["sso-login", "experimental-share-history-on-invite"] }
 matrix-sdk-base = { path = "../../crates/matrix-sdk-base" }
 matrix-sdk-common = { path = "../../crates/matrix-sdk-common" }
 matrix-sdk-ui = { path = "../../crates/matrix-sdk-ui" }

testing/matrix-sdk-integration-testing/Cargo.toml

@@ -17,7 +17,7 @@ futures = { version = "0.3.29", features = ["executor"] }
 futures-core = { workspace = true }
 futures-util = { workspace = true }
 http = { workspace = true }
-matrix-sdk = {workspace = true, default-features = true, features = ["testing", "qrcode"] }
+matrix-sdk = {workspace = true, default-features = true, features = ["testing", "qrcode", "experimental-share-history-on-invite"] }
 matrix-sdk-base = { workspace = true, default-features = true, features = ["testing", "qrcode"] }
 matrix-sdk-ui = { workspace = true, default-features = true }
 matrix-sdk-test = { workspace = true }

testing/matrix-sdk-integration-testing/src/tests/e2ee.rs

@@ -1289,8 +1289,7 @@ async fn test_history_share_on_invite() -> Result<()> {
         .expect("We should be able to send a message to the room");
 
     // Alice invites Bob to the room
-    // TODO: invite Bob rather than just call `share_history`
-    alice_room.share_history(bob.user_id().unwrap()).await?;
+    alice_room.invite_user_by_id(bob.user_id().unwrap()).await?;
 
     let bob_response = bob.sync_once().instrument(bob_span.clone()).await?;