Merge branch 'fixrestrictedjoin' into 'next'

fix: rejoining restricted rooms over federation

See merge request famedly/conduit!431

4 files changed, 352 insertions, 94 deletions

diff --git a/src/api/client_server/membership.rs b/src/api/client_server/membership.rs
index 2267cbf..f6e94e6 100644
--- a/src/api/client_server/membership.rs
+++ b/src/api/client_server/membership.rs
@@ -12,12 +12,15 @@ use ruma::{
     },
     canonical_json::to_canonical_value,
     events::{
-        room::member::{MembershipState, RoomMemberEventContent},
+        room::{
+            join_rules::{JoinRule, RoomJoinRulesEventContent},
+            member::{MembershipState, RoomMemberEventContent},
+        },
         RoomEventType, StateEventType,
     },
     serde::Base64,
-    CanonicalJsonObject, CanonicalJsonValue, EventId, OwnedEventId, OwnedRoomId, OwnedServerName,
-    OwnedUserId, RoomId, RoomVersionId, UserId,
+    state_res, CanonicalJsonObject, CanonicalJsonValue, EventId, OwnedEventId, OwnedRoomId,
+    OwnedServerName, OwnedUserId, RoomId, RoomVersionId, UserId,
 };
 use serde_json::value::{to_raw_value, RawValue as RawJsonValue};
 use std::{
@@ -480,33 +483,10 @@ async fn join_room_by_id_helper(
         .state_cache
         .server_in_room(services().globals.server_name(), room_id)?
     {
-        let mut make_join_response_and_server = Err(Error::BadServerResponse(
-            "No server available to assist in joining.",
-        ));
-
-        for remote_server in servers {
-            let make_join_response = services()
-                .sending
-                .send_federation_request(
-                    remote_server,
-                    federation::membership::prepare_join_event::v1::Request {
-                        room_id,
-                        user_id: sender_user,
-                        ver: &services().globals.supported_room_versions(),
-                    },
-                )
-                .await;
-
-            make_join_response_and_server = make_join_response.map(|r| (r, remote_server));
-
-            if make_join_response_and_server.is_ok() {
-                break;
-            }
-        }
-
-        let (make_join_response, remote_server) = make_join_response_and_server?;
+        let (make_join_response, remote_server) =
+            make_join_request(sender_user, room_id, servers).await?;
 
-        let room_version = match make_join_response.room_version {
+        let room_version_id = match make_join_response.room_version {
             Some(room_version)
                 if services()
                     .globals
@@ -568,14 +548,14 @@ async fn join_room_by_id_helper(
             services().globals.server_name().as_str(),
             services().globals.keypair(),
             &mut join_event_stub,
-            &room_version,
+            &room_version_id,
         )
         .expect("event is valid, we just created it");
 
         // Generate event id
         let event_id = format!(
             "${}",
-            ruma::signatures::reference_hash(&join_event_stub, &room_version)
+            ruma::signatures::reference_hash(&join_event_stub, &room_version_id)
                 .expect("ruma can calculate reference hashes")
         );
         let event_id = <&EventId>::try_from(event_id.as_str())
@@ -588,12 +568,12 @@ async fn join_room_by_id_helper(
         );
 
         // It has enough fields to be called a proper event now
-        let join_event = join_event_stub;
+        let mut join_event = join_event_stub;
 
         let send_join_response = services()
             .sending
             .send_federation_request(
-                remote_server,
+                &remote_server,
                 federation::membership::create_join_event::v2::Request {
                     room_id,
                     event_id,
@@ -602,9 +582,53 @@ async fn join_room_by_id_helper(
             )
             .await?;
 
+        if let Some(signed_raw) = &send_join_response.room_state.event {
+            let (signed_event_id, signed_value) =
+                match gen_event_id_canonical_json(&signed_raw, &room_version_id) {
+                    Ok(t) => t,
+                    Err(_) => {
+                        // Event could not be converted to canonical json
+                        return Err(Error::BadRequest(
+                            ErrorKind::InvalidParam,
+                            "Could not convert event to canonical json.",
+                        ));
+                    }
+                };
+
+            if &signed_event_id != event_id {
+                return Err(Error::BadRequest(
+                    ErrorKind::InvalidParam,
+                    "Server sent event with wrong event id",
+                ));
+            }
+
+            if let Ok(signature) = signed_value["signatures"]
+                .as_object()
+                .ok_or(Error::BadRequest(
+                    ErrorKind::InvalidParam,
+                    "Server sent invalid signatures type",
+                ))
+                .and_then(|e| {
+                    e.get(remote_server.as_str()).ok_or(Error::BadRequest(
+                        ErrorKind::InvalidParam,
+                        "Server did not send its signature",
+                    ))
+                })
+            {
+                join_event
+                    .get_mut("signatures")
+                    .expect("we created a valid pdu")
+                    .as_object_mut()
+                    .expect("we created a valid pdu")
+                    .insert(remote_server.to_string(), signature.clone());
+            } else {
+                warn!("Server {} sent invalid sendjoin event", remote_server);
+            }
+        }
+
         services().rooms.short.get_or_create_shortroomid(room_id)?;
 
-        let parsed_pdu = PduEvent::from_id_val(event_id, join_event.clone())
+        let parsed_join_pdu = PduEvent::from_id_val(event_id, join_event.clone())
             .map_err(|_| Error::BadServerResponse("Invalid join event PDU."))?;
 
         let mut state = HashMap::new();
@@ -613,14 +637,14 @@ async fn join_room_by_id_helper(
         services()
             .rooms
             .event_handler
-            .fetch_join_signing_keys(&send_join_response, &room_version, &pub_key_map)
+            .fetch_join_signing_keys(&send_join_response, &room_version_id, &pub_key_map)
             .await?;
 
         for result in send_join_response
             .room_state
             .state
             .iter()
-            .map(|pdu| validate_and_add_event_id(pdu, &room_version, &pub_key_map))
+            .map(|pdu| validate_and_add_event_id(pdu, &room_version_id, &pub_key_map))
         {
             let (event_id, value) = match result {
                 Ok(t) => t,
@@ -645,31 +669,11 @@ async fn join_room_by_id_helper(
             }
         }
 
-        let incoming_shortstatekey = services().rooms.short.get_or_create_shortstatekey(
-            &parsed_pdu.kind.to_string().into(),
-            parsed_pdu
-                .state_key
-                .as_ref()
-                .expect("Pdu is a membership state event"),
-        )?;
-
-        state.insert(incoming_shortstatekey, parsed_pdu.event_id.clone());
-
-        let create_shortstatekey = services()
-            .rooms
-            .short
-            .get_shortstatekey(&StateEventType::RoomCreate, "")?
-            .expect("Room exists");
-
-        if state.get(&create_shortstatekey).is_none() {
-            return Err(Error::BadServerResponse("State contained no create event."));
-        }
-
         for result in send_join_response
             .room_state
             .auth_chain
             .iter()
-            .map(|pdu| validate_and_add_event_id(pdu, &room_version, &pub_key_map))
+            .map(|pdu| validate_and_add_event_id(pdu, &room_version_id, &pub_key_map))
         {
             let (event_id, value) = match result {
                 Ok(t) => t,
@@ -682,6 +686,34 @@ async fn join_room_by_id_helper(
                 .add_pdu_outlier(&event_id, &value)?;
         }
 
+        if !state_res::event_auth::auth_check(
+            &state_res::RoomVersion::new(&room_version_id).expect("room version is supported"),
+            &parsed_join_pdu,
+            None::<PduEvent>, // TODO: third party invite
+            |k, s| {
+                services()
+                    .rooms
+                    .timeline
+                    .get_pdu(
+                        state.get(
+                            &services()
+                                .rooms
+                                .short
+                                .get_or_create_shortstatekey(&k.to_string().into(), s)
+                                .ok()?,
+                        )?,
+                    )
+                    .ok()?
+            },
+        )
+        .map_err(|_e| Error::BadRequest(ErrorKind::InvalidParam, "Auth check failed"))?
+        {
+            return Err(Error::BadRequest(
+                ErrorKind::InvalidParam,
+                "Auth check failed",
+            ));
+        }
+
         let (statehash_before_join, new, removed) = services().rooms.state_compressor.save_state(
             room_id,
             state
@@ -705,12 +737,12 @@ async fn join_room_by_id_helper(
 
         // We append to state before appending the pdu, so we don't have a moment in time with the
         // pdu without it's state. This is okay because append_pdu can't fail.
-        let statehash_after_join = services().rooms.state.append_to_state(&parsed_pdu)?;
+        let statehash_after_join = services().rooms.state.append_to_state(&parsed_join_pdu)?;
 
         services().rooms.timeline.append_pdu(
-            &parsed_pdu,
+            &parsed_join_pdu,
             join_event,
-            vec![(*parsed_pdu.event_id).to_owned()],
+            vec![(*parsed_join_pdu.event_id).to_owned()],
             &state_lock,
         )?;
 
@@ -732,7 +764,8 @@ async fn join_room_by_id_helper(
             join_authorized_via_users_server: None,
         };
 
-        services().rooms.timeline.build_and_append_pdu(
+        // Try normal join first
+        let error = match services().rooms.timeline.build_and_append_pdu(
             PduBuilder {
                 event_type: RoomEventType::RoomMember,
                 content: to_raw_value(&event).expect("event is valid, we just created it"),
@@ -743,14 +776,216 @@ async fn join_room_by_id_helper(
             sender_user,
             room_id,
             &state_lock,
+        ) {
+            Ok(_event_id) => return Ok(join_room_by_id::v3::Response::new(room_id.to_owned())),
+            Err(e) => e,
+        };
+
+        // TODO: Conduit does not implement restricted join rules yet, we always ask over
+        // federation
+        let join_rules_event = services().rooms.state_accessor.room_state_get(
+            &room_id,
+            &StateEventType::RoomJoinRules,
+            "",
         )?;
-    }
 
-    drop(state_lock);
+        let join_rules_event_content: Option<RoomJoinRulesEventContent> = join_rules_event
+            .as_ref()
+            .map(|join_rules_event| {
+                serde_json::from_str(join_rules_event.content.get()).map_err(|e| {
+                    warn!("Invalid join rules event: {}", e);
+                    Error::bad_database("Invalid join rules event in db.")
+                })
+            })
+            .transpose()?;
+
+        if matches!(
+            join_rules_event_content,
+            Some(RoomJoinRulesEventContent {
+                join_rule: JoinRule::Restricted { .. }
+            }) | Some(RoomJoinRulesEventContent {
+                join_rule: JoinRule::KnockRestricted { .. }
+            })
+        ) {
+            let (make_join_response, remote_server) =
+                make_join_request(sender_user, room_id, servers).await?;
+
+            let room_version_id = match make_join_response.room_version {
+                Some(room_version_id)
+                    if services()
+                        .globals
+                        .supported_room_versions()
+                        .contains(&room_version_id) =>
+                {
+                    room_version_id
+                }
+                _ => return Err(Error::BadServerResponse("Room version is not supported")),
+            };
+            let mut join_event_stub: CanonicalJsonObject =
+                serde_json::from_str(make_join_response.event.get()).map_err(|_| {
+                    Error::BadServerResponse("Invalid make_join event json received from server.")
+                })?;
+            let join_authorized_via_users_server = join_event_stub
+                .get("content")
+                .map(|s| {
+                    s.as_object()?
+                        .get("join_authorised_via_users_server")?
+                        .as_str()
+                })
+                .and_then(|s| OwnedUserId::try_from(s.unwrap_or_default()).ok());
+            // TODO: Is origin needed?
+            join_event_stub.insert(
+                "origin".to_owned(),
+                CanonicalJsonValue::String(services().globals.server_name().as_str().to_owned()),
+            );
+            join_event_stub.insert(
+                "origin_server_ts".to_owned(),
+                CanonicalJsonValue::Integer(
+                    utils::millis_since_unix_epoch()
+                        .try_into()
+                        .expect("Timestamp is valid js_int value"),
+                ),
+            );
+            join_event_stub.insert(
+                "content".to_owned(),
+                to_canonical_value(RoomMemberEventContent {
+                    membership: MembershipState::Join,
+                    displayname: services().users.displayname(sender_user)?,
+                    avatar_url: services().users.avatar_url(sender_user)?,
+                    is_direct: None,
+                    third_party_invite: None,
+                    blurhash: services().users.blurhash(sender_user)?,
+                    reason: None,
+                    join_authorized_via_users_server,
+                })
+                .expect("event is valid, we just created it"),
+            );
+
+            // We don't leave the event id in the pdu because that's only allowed in v1 or v2 rooms
+            join_event_stub.remove("event_id");
+
+            // In order to create a compatible ref hash (EventID) the `hashes` field needs to be present
+            ruma::signatures::hash_and_sign_event(
+                services().globals.server_name().as_str(),
+                services().globals.keypair(),
+                &mut join_event_stub,
+                &room_version_id,
+            )
+            .expect("event is valid, we just created it");
+
+            // Generate event id
+            let event_id = format!(
+                "${}",
+                ruma::signatures::reference_hash(&join_event_stub, &room_version_id)
+                    .expect("ruma can calculate reference hashes")
+            );
+            let event_id = <&EventId>::try_from(event_id.as_str())
+                .expect("ruma's reference hashes are valid event ids");
+
+            // Add event_id back
+            join_event_stub.insert(
+                "event_id".to_owned(),
+                CanonicalJsonValue::String(event_id.as_str().to_owned()),
+            );
+
+            // It has enough fields to be called a proper event now
+            let join_event = join_event_stub;
+
+            let send_join_response = services()
+                .sending
+                .send_federation_request(
+                    &remote_server,
+                    federation::membership::create_join_event::v2::Request {
+                        room_id,
+                        event_id,
+                        pdu: &PduEvent::convert_to_outgoing_federation_event(join_event.clone()),
+                    },
+                )
+                .await?;
+
+            if let Some(signed_raw) = send_join_response.room_state.event {
+                let (signed_event_id, signed_value) =
+                    match gen_event_id_canonical_json(&signed_raw, &room_version_id) {
+                        Ok(t) => t,
+                        Err(_) => {
+                            // Event could not be converted to canonical json
+                            return Err(Error::BadRequest(
+                                ErrorKind::InvalidParam,
+                                "Could not convert event to canonical json.",
+                            ));
+                        }
+                    };
+
+                if &signed_event_id != event_id {
+                    return Err(Error::BadRequest(
+                        ErrorKind::InvalidParam,
+                        "Server sent event with wrong event id",
+                    ));
+                }
+
+                drop(state_lock);
+                let pub_key_map = RwLock::new(BTreeMap::new());
+                services()
+                    .rooms
+                    .event_handler
+                    .handle_incoming_pdu(
+                        &remote_server,
+                        &signed_event_id,
+                        room_id,
+                        signed_value,
+                        true,
+                        &pub_key_map,
+                    )
+                    .await?;
+            } else {
+                return Err(error);
+            }
+        } else {
+            return Err(error);
+        }
+    }
 
     Ok(join_room_by_id::v3::Response::new(room_id.to_owned()))
 }
 
+async fn make_join_request(
+    sender_user: &UserId,
+    room_id: &RoomId,
+    servers: &[OwnedServerName],
+) -> Result<(
+    federation::membership::prepare_join_event::v1::Response,
+    OwnedServerName,
+)> {
+    let mut make_join_response_and_server = Err(Error::BadServerResponse(
+        "No server available to assist in joining.",
+    ));
+
+    for remote_server in servers {
+        if remote_server == services().globals.server_name() {
+            continue;
+        }
+        let make_join_response = services()
+            .sending
+            .send_federation_request(
+                remote_server,
+                federation::membership::prepare_join_event::v1::Request {
+                    room_id,
+                    user_id: sender_user,
+                    ver: &services().globals.supported_room_versions(),
+                },
+            )
+            .await;
+
+        make_join_response_and_server = make_join_response.map(|r| (r, remote_server.clone()));
+
+        if make_join_response_and_server.is_ok() {
+            break;
+        }
+    }
+
+    make_join_response_and_server
+}
+
 fn validate_and_add_event_id(
     pdu: &RawJsonValue,
     room_version: &RoomVersionId,
@@ -870,6 +1105,8 @@ pub(crate) async fn invite_helper<'a>(
             (pdu, pdu_json, invite_room_state)
         };
 
+        let room_version_id = &services().rooms.state.get_room_version(room_id)?;
+
         let response = services()
             .sending
             .send_federation_request(
@@ -877,7 +1114,7 @@ pub(crate) async fn invite_helper<'a>(
                 create_invite::v2::Request {
                     room_id,
                     event_id: &pdu.event_id,
-                    room_version: &services().rooms.state.get_room_version(room_id)?,
+                    room_version: &room_version_id,
                     event: &PduEvent::convert_to_outgoing_federation_event(pdu_json.clone()),
                     invite_room_state: &invite_room_state,
                 },
@@ -887,7 +1124,8 @@ pub(crate) async fn invite_helper<'a>(
         let pub_key_map = RwLock::new(BTreeMap::new());
 
         // We do not add the event_id field to the pdu here because of signature and hashes checks
-        let (event_id, value) = match gen_event_id_canonical_json(&response.event) {
+        let (event_id, value) = match gen_event_id_canonical_json(&response.event, room_version_id)
+        {
             Ok(t) => t,
             Err(_) => {
                 // Event could not be converted to canonical json
diff --git a/src/api/server_server.rs b/src/api/server_server.rs
index b7f8807..12b255b 100644
--- a/src/api/server_server.rs
+++ b/src/api/server_server.rs
@@ -42,8 +42,8 @@ use ruma::{
     },
     serde::{Base64, JsonObject, Raw},
     to_device::DeviceIdOrAllDevices,
-    CanonicalJsonValue, EventId, MilliSecondsSinceUnixEpoch, OwnedEventId, OwnedRoomId,
-    OwnedServerName, OwnedServerSigningKeyId, OwnedUserId, RoomId, ServerName,
+    CanonicalJsonObject, CanonicalJsonValue, EventId, MilliSecondsSinceUnixEpoch, OwnedEventId,
+    OwnedRoomId, OwnedServerName, OwnedServerSigningKeyId, OwnedUserId, RoomId, ServerName,
 };
 use serde_json::value::{to_raw_value, RawValue as RawJsonValue};
 use std::{
@@ -664,16 +664,11 @@ pub async fn send_transaction_message_route(
     // let mut auth_cache = EventMap::new();
 
     for pdu in &body.pdus {
-        // We do not add the event_id field to the pdu here because of signature and hashes checks
-        let (event_id, value) = match gen_event_id_canonical_json(pdu) {
-            Ok(t) => t,
-            Err(_) => {
-                // Event could not be converted to canonical json
-                continue;
-            }
-        };
+        let value: CanonicalJsonObject = serde_json::from_str(pdu.get()).map_err(|e| {
+            warn!("Error parsing incoming event {:?}: {:?}", pdu, e);
+            Error::BadServerResponse("Invalid PDU in server response")
+        })?;
 
-        // 0. Check the server is in the room
         let room_id: OwnedRoomId = match value
             .get("room_id")
             .and_then(|id| RoomId::parse(id.as_str()?).ok())
@@ -681,14 +676,26 @@ pub async fn send_transaction_message_route(
             Some(id) => id,
             None => {
                 // Event is invalid
-                resolved_map.insert(
-                    event_id,
-                    Err(Error::bad_database("Event needs a valid RoomId.")),
-                );
                 continue;
             }
         };
 
+        let room_version_id = match services().rooms.state.get_room_version(&room_id) {
+            Ok(v) => v,
+            Err(_) => {
+                continue;
+            }
+        };
+
+        let (event_id, value) = match gen_event_id_canonical_json(pdu, &room_version_id) {
+            Ok(t) => t,
+            Err(_) => {
+                // Event could not be converted to canonical json
+                continue;
+            }
+        };
+        // We do not add the event_id field to the pdu here because of signature and hashes checks
+
         services()
             .rooms
             .event_handler
@@ -1407,7 +1414,8 @@ async fn create_join_event(
     // let mut auth_cache = EventMap::new();
 
     // We do not add the event_id field to the pdu here because of signature and hashes checks
-    let (event_id, value) = match gen_event_id_canonical_json(pdu) {
+    let room_version_id = services().rooms.state.get_room_version(room_id)?;
+    let (event_id, value) = match gen_event_id_canonical_json(pdu, &room_version_id) {
         Ok(t) => t,
         Err(_) => {
             // Event could not be converted to canonical json
@@ -1610,8 +1618,12 @@ pub async fn create_invite_route(
 
     invite_state.push(pdu.to_stripped_state_event());
 
-    // If the room already exists, the remote server will notify us about the join via /send
-    if !services().rooms.metadata.exists(&pdu.room_id)? {
+    // If we are active in the room, the remote server will notify us about the join via /send
+    if !services()
+        .rooms
+        .state_cache
+        .server_in_room(services().globals.server_name(), &body.room_id)?
+    {
         services().rooms.state_cache.update_membership(
             &body.room_id,
             &invited_user,
diff --git a/src/service/pdu.rs b/src/service/pdu.rs
index 593a687..554f3be 100644
--- a/src/service/pdu.rs
+++ b/src/service/pdu.rs
@@ -1,4 +1,4 @@
-use crate::{services, Error};
+use crate::Error;
 use ruma::{
     events::{
         room::member::RoomMemberEventContent, AnyEphemeralRoomEvent, AnyStateEvent,
@@ -7,7 +7,7 @@ use ruma::{
     },
     serde::Raw,
     state_res, CanonicalJsonObject, CanonicalJsonValue, EventId, MilliSecondsSinceUnixEpoch,
-    OwnedEventId, OwnedRoomId, OwnedUserId, RoomId, UInt, UserId,
+    OwnedEventId, OwnedRoomId, OwnedUserId, RoomId, RoomVersionId, UInt, UserId,
 };
 use serde::{Deserialize, Serialize};
 use serde_json::{
@@ -334,23 +334,17 @@ impl Ord for PduEvent {
 /// Returns a tuple of the new `EventId` and the PDU as a `BTreeMap<String, CanonicalJsonValue>`.
 pub(crate) fn gen_event_id_canonical_json(
     pdu: &RawJsonValue,
+    room_version_id: &RoomVersionId,
 ) -> crate::Result<(OwnedEventId, CanonicalJsonObject)> {
     let value: CanonicalJsonObject = serde_json::from_str(pdu.get()).map_err(|e| {
         warn!("Error parsing incoming event {:?}: {:?}", pdu, e);
         Error::BadServerResponse("Invalid PDU in server response")
     })?;
 
-    let room_id = value
-        .get("room_id")
-        .and_then(|id| RoomId::parse(id.as_str()?).ok())
-        .ok_or_else(|| Error::bad_database("PDU in db has invalid room_id."))?;
-
-    let room_version_id = services().rooms.state.get_room_version(&room_id);
-
     let event_id = format!(
         "${}",
         // Anything higher than version3 behaves the same
-        ruma::signatures::reference_hash(&value, &room_version_id?)
+        ruma::signatures::reference_hash(&value, room_version_id)
             .expect("ruma can calculate reference hashes")
     )
     .try_into()
diff --git a/src/service/rooms/event_handler/mod.rs b/src/service/rooms/event_handler/mod.rs
index 03f1f93..b352647 100644
--- a/src/service/rooms/event_handler/mod.rs
+++ b/src/service/rooms/event_handler/mod.rs
@@ -76,6 +76,7 @@ impl Service {
         is_timeline_event: bool,
         pub_key_map: &'a RwLock<BTreeMap<String, BTreeMap<String, Base64>>>,
     ) -> Result<Option<Vec<u8>>> {
+        // 0. Check the server is in the room
         if !services().rooms.metadata.exists(room_id)? {
             return Err(Error::BadRequest(
                 ErrorKind::NotFound,
@@ -101,6 +102,13 @@ impl Service {
             .room_state_get(room_id, &StateEventType::RoomCreate, "")?
             .ok_or_else(|| Error::bad_database("Failed to find create event in db."))?;
 
+        let create_event_content: RoomCreateEventContent =
+            serde_json::from_str(create_event.content.get()).map_err(|e| {
+                error!("Invalid create event: {}", e);
+                Error::BadDatabase("Invalid create event in db")
+            })?;
+        let room_version_id = &create_event_content.room_version;
+
         let first_pdu_in_room = services()
             .rooms
             .timeline
@@ -127,6 +135,7 @@ impl Service {
                 origin,
                 &create_event,
                 room_id,
+                room_version_id,
                 pub_key_map,
                 incoming_pdu.prev_events.clone(),
             )
@@ -341,6 +350,7 @@ impl Service {
                     .collect::<Vec<_>>(),
                 create_event,
                 room_id,
+                room_version_id,
                 pub_key_map,
             )
             .await;
@@ -645,6 +655,7 @@ impl Service {
                                 .collect::<Vec<_>>(),
                             create_event,
                             room_id,
+                            room_version_id,
                             pub_key_map,
                         )
                         .await;
@@ -1025,6 +1036,7 @@ impl Service {
         events: &'a [Arc<EventId>],
         create_event: &'a PduEvent,
         room_id: &'a RoomId,
+        room_version_id: &'a RoomVersionId,
         pub_key_map: &'a RwLock<BTreeMap<String, BTreeMap<String, Base64>>>,
     ) -> AsyncRecursiveType<'a, Vec<(Arc<PduEvent>, Option<BTreeMap<String, CanonicalJsonValue>>)>>
     {
@@ -1107,7 +1119,7 @@ impl Service {
                         Ok(res) => {
                             info!("Got {} over federation", next_id);
                             let (calculated_event_id, value) =
-                                match pdu::gen_event_id_canonical_json(&res.pdu) {
+                                match pdu::gen_event_id_canonical_json(&res.pdu, room_version_id) {
                                     Ok(t) => t,
                                     Err(_) => {
                                         back_off((*next_id).to_owned());
@@ -1180,6 +1192,7 @@ impl Service {
         origin: &ServerName,
         create_event: &PduEvent,
         room_id: &RoomId,
+        room_version_id: &RoomVersionId,
         pub_key_map: &RwLock<BTreeMap<String, BTreeMap<String, Base64>>>,
         initial_set: Vec<Arc<EventId>>,
     ) -> Result<(
@@ -1205,6 +1218,7 @@ impl Service {
                     &[prev_event_id.clone()],
                     create_event,
                     room_id,
+                    room_version_id,
                     pub_key_map,
                 )
                 .await