Signing identity tweaks

clientapi/routing/membership.go

@@ -323,7 +323,12 @@ func buildMembershipEvent(
 		return nil, err
 	}
 
-	return eventutil.QueryAndBuildEvent(ctx, &builder, cfg.Matrix, evTime, rsAPI, nil)
+	identity, err := cfg.Matrix.SigningIdentityFor(device.UserDomain())
+	if err != nil {
+		return nil, err
+	}
+
+	return eventutil.QueryAndBuildEvent(ctx, &builder, cfg.Matrix, identity, evTime, rsAPI, nil)
 }
 
 // loadProfile lookups the profile of a given user from the database and returns

clientapi/routing/profile.go

@@ -284,7 +284,7 @@ func updateProfile(
 	}
 
 	events, err := buildMembershipEvents(
-		ctx, res.RoomIDs, *profile, userID, cfg, evTime, rsAPI,
+		ctx, device, res.RoomIDs, *profile, userID, cfg, evTime, rsAPI,
 	)
 	switch e := err.(type) {
 	case nil:
@@ -349,6 +349,7 @@ func getProfile(
 
 func buildMembershipEvents(
 	ctx context.Context,
+	device *userapi.Device,
 	roomIDs []string,
 	newProfile authtypes.Profile, userID string, cfg *config.ClientAPI,
 	evTime time.Time, rsAPI api.ClientRoomserverAPI,
@@ -380,7 +381,12 @@ func buildMembershipEvents(
 			return nil, err
 		}
 
-		event, err := eventutil.QueryAndBuildEvent(ctx, &builder, cfg.Matrix, evTime, rsAPI, nil)
+		identity, err := cfg.Matrix.SigningIdentityFor(device.UserDomain())
+		if err != nil {
+			return nil, err
+		}
+
+		event, err := eventutil.QueryAndBuildEvent(ctx, &builder, cfg.Matrix, identity, evTime, rsAPI, nil)
 		if err != nil {
 			return nil, err
 		}

clientapi/routing/redaction.go

@@ -123,8 +123,13 @@ func SendRedaction(
 		return jsonerror.InternalServerError()
 	}
 
+	identity, err := cfg.Matrix.SigningIdentityFor(device.UserDomain())
+	if err != nil {
+		return jsonerror.InternalServerError()
+	}
+
 	var queryRes roomserverAPI.QueryLatestEventsAndStateResponse
-	e, err := eventutil.QueryAndBuildEvent(req.Context(), &builder, cfg.Matrix, time.Now(), rsAPI, &queryRes)
+	e, err := eventutil.QueryAndBuildEvent(req.Context(), &builder, cfg.Matrix, identity, time.Now(), rsAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return util.JSONResponse{
 			Code: http.StatusNotFound,

clientapi/routing/sendevent.go

@@ -276,8 +276,14 @@ func generateSendEvent(
 		return nil, &resErr
 	}
 
+	identity, err := cfg.Matrix.SigningIdentityFor(device.UserDomain())
+	if err != nil {
+		resErr := jsonerror.InternalServerError()
+		return nil, &resErr
+	}
+
 	var queryRes api.QueryLatestEventsAndStateResponse
-	e, err := eventutil.QueryAndBuildEvent(ctx, &builder, cfg.Matrix, evTime, rsAPI, &queryRes)
+	e, err := eventutil.QueryAndBuildEvent(ctx, &builder, cfg.Matrix, identity, evTime, rsAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return nil, &util.JSONResponse{
 			Code: http.StatusNotFound,

clientapi/threepid/invites.go

@@ -359,8 +359,13 @@ func emit3PIDInviteEvent(
 		return err
 	}
 
+	identity, err := cfg.Matrix.SigningIdentityFor(device.UserDomain())
+	if err != nil {
+		return err
+	}
+
 	queryRes := api.QueryLatestEventsAndStateResponse{}
-	event, err := eventutil.QueryAndBuildEvent(ctx, builder, cfg.Matrix, evTime, rsAPI, &queryRes)
+	event, err := eventutil.QueryAndBuildEvent(ctx, builder, cfg.Matrix, identity, evTime, rsAPI, &queryRes)
 	if err != nil {
 		return err
 	}

federationapi/routing/join.go

@@ -131,10 +131,20 @@ func MakeJoin(
 		return jsonerror.InternalServerError()
 	}
 
+	identity, err := cfg.Matrix.SigningIdentityFor(request.Destination())
+	if err != nil {
+		return util.JSONResponse{
+			Code: http.StatusNotFound,
+			JSON: jsonerror.NotFound(
+				fmt.Sprintf("Server name %q does not exist", request.Destination()),
+			),
+		}
+	}
+
 	queryRes := api.QueryLatestEventsAndStateResponse{
 		RoomVersion: verRes.RoomVersion,
 	}
-	event, err := eventutil.QueryAndBuildEvent(httpReq.Context(), &builder, cfg.Matrix, time.Now(), rsAPI, &queryRes)
+	event, err := eventutil.QueryAndBuildEvent(httpReq.Context(), &builder, cfg.Matrix, identity, time.Now(), rsAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return util.JSONResponse{
 			Code: http.StatusNotFound,

federationapi/routing/leave.go

@@ -13,6 +13,7 @@
 package routing
 
 import (
+	"fmt"
 	"net/http"
 	"time"
 
@@ -60,8 +61,18 @@ func MakeLeave(
 		return jsonerror.InternalServerError()
 	}
 
+	identity, err := cfg.Matrix.SigningIdentityFor(request.Destination())
+	if err != nil {
+		return util.JSONResponse{
+			Code: http.StatusNotFound,
+			JSON: jsonerror.NotFound(
+				fmt.Sprintf("Server name %q does not exist", request.Destination()),
+			),
+		}
+	}
+
 	var queryRes api.QueryLatestEventsAndStateResponse
-	event, err := eventutil.QueryAndBuildEvent(httpReq.Context(), &builder, cfg.Matrix, time.Now(), rsAPI, &queryRes)
+	event, err := eventutil.QueryAndBuildEvent(httpReq.Context(), &builder, cfg.Matrix, identity, time.Now(), rsAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return util.JSONResponse{
 			Code: http.StatusNotFound,

internal/eventutil/events.go

@@ -38,7 +38,8 @@ var ErrRoomNoExists = errors.New("room does not exist")
 // Returns an error if something else went wrong
 func QueryAndBuildEvent(
 	ctx context.Context,
-	builder *gomatrixserverlib.EventBuilder, cfg *config.Global, evTime time.Time,
+	builder *gomatrixserverlib.EventBuilder, cfg *config.Global,
+	identity *gomatrixserverlib.SigningIdentity, evTime time.Time,
 	rsAPI api.QueryLatestEventsAndStateAPI, queryRes *api.QueryLatestEventsAndStateResponse,
 ) (*gomatrixserverlib.HeaderedEvent, error) {
 	if queryRes == nil {
@@ -50,30 +51,24 @@ func QueryAndBuildEvent(
 		// This can pass through a ErrRoomNoExists to the caller
 		return nil, err
 	}
-	return BuildEvent(ctx, builder, cfg, evTime, eventsNeeded, queryRes)
+	return BuildEvent(ctx, builder, cfg, identity, evTime, eventsNeeded, queryRes)
 }
 
 // BuildEvent builds a Matrix event from the builder and QueryLatestEventsAndStateResponse
 // provided.
 func BuildEvent(
 	ctx context.Context,
-	builder *gomatrixserverlib.EventBuilder, cfg *config.Global, evTime time.Time,
+	builder *gomatrixserverlib.EventBuilder, cfg *config.Global,
+	identity *gomatrixserverlib.SigningIdentity, evTime time.Time,
 	eventsNeeded *gomatrixserverlib.StateNeeded, queryRes *api.QueryLatestEventsAndStateResponse,
 ) (*gomatrixserverlib.HeaderedEvent, error) {
-	err := addPrevEventsToEvent(builder, eventsNeeded, queryRes)
+	if err := addPrevEventsToEvent(builder, eventsNeeded, queryRes); err != nil {
-	if err != nil {
 		return nil, err
 	}
 
-	_, domain, err := cfg.SplitLocalID('@', builder.Sender)
-	if err != nil {
-		return nil, err
-	}
-
-	// TODO: Fix key ID and private key here
 	event, err := builder.Build(
-		evTime, domain, cfg.KeyID,
+		evTime, identity.ServerName, identity.KeyID,
-		cfg.PrivateKey, queryRes.RoomVersion,
+		identity.PrivateKey, queryRes.RoomVersion,
 	)
 	if err != nil {
 		return nil, err

roomserver/internal/alias.go

@@ -195,6 +195,16 @@ func (r *RoomserverInternalAPI) RemoveRoomAlias(
 				sender = ev.Sender()
 			}
 
+			_, senderDomain, err := r.Cfg.Matrix.SplitLocalID('@', sender)
+			if err != nil {
+				return err
+			}
+
+			identity, err := r.Cfg.Matrix.SigningIdentityFor(senderDomain)
+			if err != nil {
+				return err
+			}
+
 			builder := &gomatrixserverlib.EventBuilder{
 				Sender:   sender,
 				RoomID:   ev.RoomID(),
@@ -216,7 +226,7 @@ func (r *RoomserverInternalAPI) RemoveRoomAlias(
 				return err
 			}
 
-			newEvent, err := eventutil.BuildEvent(ctx, builder, r.Cfg.Matrix, time.Now(), &eventsNeeded, stateRes)
+			newEvent, err := eventutil.BuildEvent(ctx, builder, r.Cfg.Matrix, identity, time.Now(), &eventsNeeded, stateRes)
 			if err != nil {
 				return err
 			}

roomserver/internal/perform/perform_admin.go

@@ -139,7 +139,12 @@ func (r *Admin) PerformAdminEvacuateRoom(
 			return nil
 		}
 
-		event, err := eventutil.BuildEvent(ctx, fledglingEvent, r.Cfg.Matrix, time.Now(), &eventsNeeded, latestRes)
+		identity, err := r.Cfg.Matrix.SigningIdentityFor(senderDomain)
+		if err != nil {
+			continue
+		}
+
+		event, err := eventutil.BuildEvent(ctx, fledglingEvent, r.Cfg.Matrix, identity, time.Now(), &eventsNeeded, latestRes)
 		if err != nil {
 			res.Error = &api.PerformError{
 				Code: api.PerformErrorBadRequest,
@@ -242,6 +247,15 @@ func (r *Admin) PerformAdminDownloadState(
 	req *api.PerformAdminDownloadStateRequest,
 	res *api.PerformAdminDownloadStateResponse,
 ) error {
+	_, senderDomain, err := r.Cfg.Matrix.SplitLocalID('@', req.UserID)
+	if err != nil {
+		res.Error = &api.PerformError{
+			Code: api.PerformErrorBadRequest,
+			Msg:  fmt.Sprintf("r.Cfg.Matrix.SplitLocalID: %s", err),
+		}
+		return nil
+	}
+
 	roomInfo, err := r.DB.RoomInfo(ctx, req.RoomID)
 	if err != nil {
 		res.Error = &api.PerformError{
@@ -331,7 +345,12 @@ func (r *Admin) PerformAdminDownloadState(
 		Depth:        depth,
 	}
 
-	ev, err := eventutil.BuildEvent(ctx, builder, r.Cfg.Matrix, time.Now(), &eventsNeeded, queryRes)
+	identity, err := r.Cfg.Matrix.SigningIdentityFor(senderDomain)
+	if err != nil {
+		return err
+	}
+
+	ev, err := eventutil.BuildEvent(ctx, builder, r.Cfg.Matrix, identity, time.Now(), &eventsNeeded, queryRes)
 	if err != nil {
 		res.Error = &api.PerformError{
 			Code: api.PerformErrorBadRequest,

roomserver/internal/perform/perform_join.go

@@ -196,7 +196,7 @@ func (r *Joiner) performJoinRoomByID(
 
 	// Prepare the template for the join event.
 	userID := req.UserID
-	_, userDomain, err := gomatrixserverlib.SplitID('@', userID)
+	_, userDomain, err := r.Cfg.Matrix.SplitLocalID('@', userID)
 	if err != nil {
 		return "", "", &rsAPI.PerformError{
 			Code: rsAPI.PerformErrorBadRequest,
@@ -282,7 +282,7 @@ func (r *Joiner) performJoinRoomByID(
 	// locally on the homeserver.
 	// TODO: Check what happens if the room exists on the server
 	// but everyone has since left. I suspect it does the wrong thing.
-	event, buildRes, err := buildEvent(ctx, r.DB, r.Cfg.Matrix, &eb)
+	event, buildRes, err := buildEvent(ctx, r.DB, r.Cfg.Matrix, userDomain, &eb)
 
 	switch err {
 	case nil:
@@ -409,7 +409,9 @@ func (r *Joiner) populateAuthorisedViaUserForRestrictedJoin(
 }
 
 func buildEvent(
-	ctx context.Context, db storage.Database, cfg *config.Global, builder *gomatrixserverlib.EventBuilder,
+	ctx context.Context, db storage.Database, cfg *config.Global,
+	senderDomain gomatrixserverlib.ServerName,
+	builder *gomatrixserverlib.EventBuilder,
 ) (*gomatrixserverlib.HeaderedEvent, *rsAPI.QueryLatestEventsAndStateResponse, error) {
 	eventsNeeded, err := gomatrixserverlib.StateNeededForEventBuilder(builder)
 	if err != nil {
@@ -437,7 +439,12 @@ func buildEvent(
 		}
 	}
 
-	ev, err := eventutil.BuildEvent(ctx, builder, cfg, time.Now(), &eventsNeeded, &queryRes)
+	identity, err := cfg.SigningIdentityFor(senderDomain)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	ev, err := eventutil.BuildEvent(ctx, builder, cfg, identity, time.Now(), &eventsNeeded, &queryRes)
 	if err != nil {
 		return nil, nil, err
 	}

roomserver/internal/perform/perform_leave.go

@@ -162,21 +162,21 @@ func (r *Leaver) performLeaveRoomByID(
 		return nil, fmt.Errorf("eb.SetUnsigned: %w", err)
 	}
 
+	// Get the sender domain.
+	_, senderDomain, serr := r.Cfg.Matrix.SplitLocalID('@', eb.Sender)
+	if serr != nil {
+		return nil, fmt.Errorf("sender %q is invalid", eb.Sender)
+	}
+
 	// We know that the user is in the room at this point so let's build
 	// a leave event.
 	// TODO: Check what happens if the room exists on the server
 	// but everyone has since left. I suspect it does the wrong thing.
-	event, buildRes, err := buildEvent(ctx, r.DB, r.Cfg.Matrix, &eb)
+	event, buildRes, err := buildEvent(ctx, r.DB, r.Cfg.Matrix, senderDomain, &eb)
 	if err != nil {
 		return nil, fmt.Errorf("eventutil.BuildEvent: %w", err)
 	}
 
-	// Get the sender domain.
-	_, senderDomain, serr := gomatrixserverlib.SplitID('@', event.Sender())
-	if serr != nil {
-		return nil, fmt.Errorf("sender %q is invalid", event.Sender())
-	}
-
 	// Give our leave event to the roomserver input stream. The
 	// roomserver will process the membership change and notify
 	// downstream automatically.

roomserver/internal/perform/perform_upgrade.go

@@ -595,8 +595,21 @@ func (r *Upgrader) makeHeaderedEvent(ctx context.Context, evTime time.Time, user
 			Msg: fmt.Sprintf("Failed to set new %q event content: %s", builder.Type, err),
 		}
 	}
+	// Get the sender domain.
+	_, senderDomain, serr := r.Cfg.Matrix.SplitLocalID('@', builder.Sender)
+	if serr != nil {
+		return nil, &api.PerformError{
+			Msg: fmt.Sprintf("Failed to split user ID %q: %s", builder.Sender, err),
+		}
+	}
+	identity, err := r.Cfg.Matrix.SigningIdentityFor(senderDomain)
+	if err != nil {
+		return nil, &api.PerformError{
+			Msg: fmt.Sprintf("Failed to get signing identity for %q: %s", senderDomain, err),
+		}
+	}
 	var queryRes api.QueryLatestEventsAndStateResponse
-	headeredEvent, err := eventutil.QueryAndBuildEvent(ctx, &builder, r.Cfg.Matrix, evTime, r.URSAPI, &queryRes)
+	headeredEvent, err := eventutil.QueryAndBuildEvent(ctx, &builder, r.Cfg.Matrix, identity, evTime, r.URSAPI, &queryRes)
 	if err == eventutil.ErrRoomNoExists {
 		return nil, &api.PerformError{
 			Code: api.PerformErrorNoRoom,

setup/config/config_global.go

@@ -146,11 +146,20 @@ func (c *Global) SplitLocalID(sigil byte, id string) (string, gomatrixserverlib.
 		return u, s, err
 	}
 	if !c.IsLocalServerName(s) {
-		return u, s, fmt.Errorf("server name not locally configured")
+		return u, s, fmt.Errorf("server name %q not known", s)
 	}
 	return u, s, nil
 }
 
+func (c *Global) SigningIdentityFor(serverName gomatrixserverlib.ServerName) (*gomatrixserverlib.SigningIdentity, error) {
+	for _, id := range c.SigningIdentities() {
+		if id.ServerName == serverName {
+			return id, nil
+		}
+	}
+	return nil, fmt.Errorf("no signing identity %q", serverName)
+}
+
 func (c *Global) SigningIdentities() []*gomatrixserverlib.SigningIdentity {
 	identities := make([]*gomatrixserverlib.SigningIdentity, 0, len(c.VirtualHosts)+1)
 	identities = append(identities, &gomatrixserverlib.SigningIdentity{