Send device list updates to servers (outbound only) (#1237)

* Add QueryDeviceMessages to serve up device keys and stream IDs

* Consume key change events in fedsender

Don't yet send them to destinations as we haven't worked them out yet

* Send device list updates to all required servers

* Glue it all together

build/gobind/monolith.go

@@ -131,17 +131,15 @@ func (m *DendriteMonolith) Start() {
 	)
 
 	asAPI := appservice.NewInternalAPI(base, userAPI, rsAPI)
-
+	stateAPI := currentstateserver.NewInternalAPI(base.Cfg, base.KafkaConsumer)
 	fsAPI := federationsender.NewInternalAPI(
-		base, federation, rsAPI, keyRing,
+		base, federation, rsAPI, stateAPI, keyRing,
 	)
 
 	// The underlying roomserver implementation needs to be able to call the fedsender.
 	// This is different to rsAPI which can be the http client which doesn't need this dependency
 	rsAPI.SetFederationSenderAPI(fsAPI)
 
-	stateAPI := currentstateserver.NewInternalAPI(base.Cfg, base.KafkaConsumer)
-
 	monolith := setup.Monolith{
 		Config:        base.Cfg,
 		AccountDB:     accountDB,

cmd/dendrite-demo-libp2p/main.go

@@ -153,6 +153,7 @@ func main() {
 		base, serverKeyAPI,
 	)
 
+	stateAPI := currentstateserver.NewInternalAPI(base.Base.Cfg, base.Base.KafkaConsumer)
 	rsAPI := roomserver.NewInternalAPI(
 		&base.Base, keyRing, federation,
 	)
@@ -161,10 +162,9 @@ func main() {
 	)
 	asAPI := appservice.NewInternalAPI(&base.Base, userAPI, rsAPI)
 	fsAPI := federationsender.NewInternalAPI(
-		&base.Base, federation, rsAPI, keyRing,
+		&base.Base, federation, rsAPI, stateAPI, keyRing,
 	)
 	rsAPI.SetFederationSenderAPI(fsAPI)
-	stateAPI := currentstateserver.NewInternalAPI(base.Base.Cfg, base.Base.KafkaConsumer)
 	provider := newPublicRoomsProvider(base.LibP2PPubsub, rsAPI, stateAPI)
 	err = provider.Start()
 	if err != nil {

cmd/dendrite-demo-yggdrasil/main.go

@@ -117,17 +117,15 @@ func main() {
 	)
 
 	asAPI := appservice.NewInternalAPI(base, userAPI, rsAPI)
-
+	stateAPI := currentstateserver.NewInternalAPI(base.Cfg, base.KafkaConsumer)
 	fsAPI := federationsender.NewInternalAPI(
-		base, federation, rsAPI, keyRing,
+		base, federation, rsAPI, stateAPI, keyRing,
 	)
 
 	rsComponent.SetFederationSenderAPI(fsAPI)
 
 	embed.Embed(base.BaseMux, *instancePort, "Yggdrasil Demo")
 
-	stateAPI := currentstateserver.NewInternalAPI(base.Cfg, base.KafkaConsumer)
-
 	monolith := setup.Monolith{
 		Config:        base.Cfg,
 		AccountDB:     accountDB,

cmd/dendrite-federation-sender-server/main.go

@@ -31,7 +31,7 @@ func main() {
 
 	rsAPI := base.RoomserverHTTPClient()
 	fsAPI := federationsender.NewInternalAPI(
-		base, federation, rsAPI, keyRing,
+		base, federation, rsAPI, base.CurrentStateAPIClient(), keyRing,
 	)
 	federationsender.AddInternalRoutes(base.InternalAPIMux, fsAPI)
 

cmd/dendrite-monolith-server/main.go

@@ -109,8 +109,10 @@ func main() {
 		asAPI = base.AppserviceHTTPClient()
 	}
 
+	stateAPI := currentstateserver.NewInternalAPI(base.Cfg, base.KafkaConsumer)
+
 	fsAPI := federationsender.NewInternalAPI(
-		base, federation, rsAPI, keyRing,
+		base, federation, rsAPI, stateAPI, keyRing,
 	)
 	if base.UseHTTPAPIs {
 		federationsender.AddInternalRoutes(base.InternalAPIMux, fsAPI)
@@ -120,8 +122,6 @@ func main() {
 	// This is different to rsAPI which can be the http client which doesn't need this dependency
 	rsImpl.SetFederationSenderAPI(fsAPI)
 
-	stateAPI := currentstateserver.NewInternalAPI(base.Cfg, base.KafkaConsumer)
-
 	monolith := setup.Monolith{
 		Config:        base.Cfg,
 		AccountDB:     accountDB,

cmd/dendritejs/main.go

@@ -208,17 +208,16 @@ func main() {
 		KeyDatabase: fetcher,
 	}
 
+	stateAPI := currentstateserver.NewInternalAPI(base.Cfg, base.KafkaConsumer)
 	rsAPI := roomserver.NewInternalAPI(base, keyRing, federation)
 	eduInputAPI := eduserver.NewInternalAPI(base, cache.New(), userAPI)
 	asQuery := appservice.NewInternalAPI(
 		base, userAPI, rsAPI,
 	)
-	fedSenderAPI := federationsender.NewInternalAPI(base, federation, rsAPI, &keyRing)
+	fedSenderAPI := federationsender.NewInternalAPI(base, federation, rsAPI, stateAPI, &keyRing)
 	rsAPI.SetFederationSenderAPI(fedSenderAPI)
 	p2pPublicRoomProvider := NewLibP2PPublicRoomsProvider(node, fedSenderAPI, federation)
 
-	stateAPI := currentstateserver.NewInternalAPI(base.Cfg, base.KafkaConsumer)
-
 	monolith := setup.Monolith{
 		Config:        base.Cfg,
 		AccountDB:     accountDB,

federationapi/routing/devices.go

@@ -13,10 +13,11 @@
 package routing
 
 import (
+	"encoding/json"
 	"net/http"
 
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
-	userapi "github.com/matrix-org/dendrite/userapi/api"
+	keyapi "github.com/matrix-org/dendrite/keyserver/api"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
 )
@@ -24,30 +25,35 @@ import (
 // GetUserDevices for the given user id
 func GetUserDevices(
 	req *http.Request,
-	userAPI userapi.UserInternalAPI,
+	keyAPI keyapi.KeyInternalAPI,
 	userID string,
 ) util.JSONResponse {
-	response := gomatrixserverlib.RespUserDevices{
-		UserID: userID,
-		// TODO: we should return an incrementing stream ID each time the device
-		// list changes for delta changes to be recognised
-		StreamID: 0,
-	}
-
-	var res userapi.QueryDevicesResponse
-	err := userAPI.QueryDevices(req.Context(), &userapi.QueryDevicesRequest{
+	var res keyapi.QueryDeviceMessagesResponse
+	keyAPI.QueryDeviceMessages(req.Context(), &keyapi.QueryDeviceMessagesRequest{
 		UserID: userID,
 	}, &res)
-	if err != nil {
-		util.GetLogger(req.Context()).WithError(err).Error("userAPI.QueryDevices failed")
+	if res.Error != nil {
+		util.GetLogger(req.Context()).WithError(res.Error).Error("keyAPI.QueryDeviceMessages failed")
 		return jsonerror.InternalServerError()
 	}
 
+	response := gomatrixserverlib.RespUserDevices{
+		UserID:   userID,
+		StreamID: res.StreamID,
+	}
+
 	for _, dev := range res.Devices {
+		var key gomatrixserverlib.RespUserDeviceKeys
+		err := json.Unmarshal(dev.DeviceKeys.KeyJSON, &key)
+		if err != nil {
+			util.GetLogger(req.Context()).WithError(err).Warnf("malformed device key: %s", string(dev.DeviceKeys.KeyJSON))
+			continue
+		}
+
 		device := gomatrixserverlib.RespUserDevice{
-			DeviceID:    dev.ID,
+			DeviceID:    dev.DeviceID,
 			DisplayName: dev.DisplayName,
-			Keys:        []gomatrixserverlib.RespUserDeviceKeys{},
+			Keys:        []gomatrixserverlib.RespUserDeviceKeys{key},
 		}
 		response.Devices = append(response.Devices, device)
 	}

federationapi/routing/routing.go

@@ -186,7 +186,7 @@ func Setup(
 		"federation_user_devices", cfg.Matrix.ServerName, keys, wakeup,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
 			return GetUserDevices(
-				httpReq, userAPI, vars["userID"],
+				httpReq, keyAPI, vars["userID"],
 			)
 		},
 	)).Methods(http.MethodGet)

federationsender/consumers/keychange.go

@@ -0,0 +1,135 @@
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package consumers
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"github.com/Shopify/sarama"
+	stateapi "github.com/matrix-org/dendrite/currentstateserver/api"
+	"github.com/matrix-org/dendrite/federationsender/queue"
+	"github.com/matrix-org/dendrite/federationsender/storage"
+	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/internal/config"
+	"github.com/matrix-org/dendrite/keyserver/api"
+	"github.com/matrix-org/gomatrixserverlib"
+	log "github.com/sirupsen/logrus"
+)
+
+// KeyChangeConsumer consumes events that originate in key server.
+type KeyChangeConsumer struct {
+	consumer   *internal.ContinualConsumer
+	db         storage.Database
+	queues     *queue.OutgoingQueues
+	serverName gomatrixserverlib.ServerName
+	stateAPI   stateapi.CurrentStateInternalAPI
+}
+
+// NewKeyChangeConsumer creates a new KeyChangeConsumer. Call Start() to begin consuming from key servers.
+func NewKeyChangeConsumer(
+	cfg *config.Dendrite,
+	kafkaConsumer sarama.Consumer,
+	queues *queue.OutgoingQueues,
+	store storage.Database,
+	stateAPI stateapi.CurrentStateInternalAPI,
+) *KeyChangeConsumer {
+	c := &KeyChangeConsumer{
+		consumer: &internal.ContinualConsumer{
+			Topic:          string(cfg.Kafka.Topics.OutputKeyChangeEvent),
+			Consumer:       kafkaConsumer,
+			PartitionStore: store,
+		},
+		queues:     queues,
+		db:         store,
+		serverName: cfg.Matrix.ServerName,
+		stateAPI:   stateAPI,
+	}
+	c.consumer.ProcessMessage = c.onMessage
+
+	return c
+}
+
+// Start consuming from key servers
+func (t *KeyChangeConsumer) Start() error {
+	if err := t.consumer.Start(); err != nil {
+		return fmt.Errorf("t.consumer.Start: %w", err)
+	}
+	return nil
+}
+
+// onMessage is called in response to a message received on the
+// key change events topic from the key server.
+func (t *KeyChangeConsumer) onMessage(msg *sarama.ConsumerMessage) error {
+	var m api.DeviceMessage
+	if err := json.Unmarshal(msg.Value, &m); err != nil {
+		log.WithError(err).Errorf("failed to read device message from key change topic")
+		return nil
+	}
+	logger := log.WithField("user_id", m.UserID)
+
+	// only send key change events which originated from us
+	_, originServerName, err := gomatrixserverlib.SplitID('@', m.UserID)
+	if err != nil {
+		logger.WithError(err).Error("Failed to extract domain from key change event")
+		return nil
+	}
+	if originServerName != t.serverName {
+		return nil
+	}
+
+	var queryRes stateapi.QueryRoomsForUserResponse
+	err = t.stateAPI.QueryRoomsForUser(context.Background(), &stateapi.QueryRoomsForUserRequest{
+		UserID:         m.UserID,
+		WantMembership: "join",
+	}, &queryRes)
+	if err != nil {
+		logger.WithError(err).Error("failed to calculate joined rooms for user")
+		return nil
+	}
+	// send this key change to all servers who share rooms with this user.
+	destinations, err := t.db.GetJoinedHostsForRooms(context.Background(), queryRes.RoomIDs)
+	if err != nil {
+		logger.WithError(err).Error("failed to calculate joined hosts for rooms user is in")
+		return nil
+	}
+
+	// Pack the EDU and marshal it
+	edu := &gomatrixserverlib.EDU{
+		Type:   gomatrixserverlib.MDeviceListUpdate,
+		Origin: string(t.serverName),
+	}
+	event := gomatrixserverlib.DeviceListUpdateEvent{
+		UserID:            m.UserID,
+		DeviceID:          m.DeviceID,
+		DeviceDisplayName: m.DisplayName,
+		StreamID:          m.StreamID,
+		PrevID:            prevID(m.StreamID),
+		Deleted:           len(m.KeyJSON) == 0,
+		Keys:              m.KeyJSON,
+	}
+	if edu.Content, err = json.Marshal(event); err != nil {
+		return err
+	}
+
+	log.Infof("Sending device list update message to %q", destinations)
+	return t.queues.SendEDU(edu, t.serverName, destinations)
+}
+
+func prevID(streamID int) []int {
+	if streamID <= 1 {
+		return nil
+	}
+	return []int{streamID - 1}
+}

federationsender/federationsender.go

@@ -16,6 +16,7 @@ package federationsender
 
 import (
 	"github.com/gorilla/mux"
+	stateapi "github.com/matrix-org/dendrite/currentstateserver/api"
 	"github.com/matrix-org/dendrite/federationsender/api"
 	"github.com/matrix-org/dendrite/federationsender/consumers"
 	"github.com/matrix-org/dendrite/federationsender/internal"
@@ -41,6 +42,7 @@ func NewInternalAPI(
 	base *setup.BaseDendrite,
 	federation *gomatrixserverlib.FederationClient,
 	rsAPI roomserverAPI.RoomserverInternalAPI,
+	stateAPI stateapi.CurrentStateInternalAPI,
 	keyRing *gomatrixserverlib.KeyRing,
 ) api.FederationSenderInternalAPI {
 	federationSenderDB, err := storage.NewDatabase(string(base.Cfg.Database.FederationSender), base.Cfg.DbProperties())
@@ -76,6 +78,12 @@ func NewInternalAPI(
 	if err := tsConsumer.Start(); err != nil {
 		logrus.WithError(err).Panic("failed to start typing server consumer")
 	}
+	keyConsumer := consumers.NewKeyChangeConsumer(
+		base.Cfg, base.KafkaConsumer, queues, federationSenderDB, stateAPI,
+	)
+	if err := keyConsumer.Start(); err != nil {
+		logrus.WithError(err).Panic("failed to start key server consumer")
+	}
 
 	return internal.NewFederationSenderInternalAPI(federationSenderDB, base.Cfg, rsAPI, federation, keyRing, stats, queues)
 }

federationsender/storage/interface.go

@@ -30,6 +30,8 @@ type Database interface {
 
 	GetJoinedHosts(ctx context.Context, roomID string) ([]types.JoinedHost, error)
 	GetAllJoinedHosts(ctx context.Context) ([]gomatrixserverlib.ServerName, error)
+	// GetJoinedHostsForRooms returns the complete set of servers in the rooms given.
+	GetJoinedHostsForRooms(ctx context.Context, roomIDs []string) ([]gomatrixserverlib.ServerName, error)
 
 	StoreJSON(ctx context.Context, js string) (*shared.Receipt, error)
 

federationsender/storage/postgres/joined_hosts_table.go

@@ -60,12 +60,16 @@ const selectJoinedHostsSQL = "" +
 const selectAllJoinedHostsSQL = "" +
 	"SELECT DISTINCT server_name FROM federationsender_joined_hosts"
 
+const selectJoinedHostsForRoomsSQL = "" +
+	"SELECT DISTINCT server_name FROM federationsender_joined_hosts WHERE room_id = ANY($1)"
+
 type joinedHostsStatements struct {
 	db                            *sql.DB
 	insertJoinedHostsStmt         *sql.Stmt
 	deleteJoinedHostsStmt         *sql.Stmt
 	selectJoinedHostsStmt         *sql.Stmt
 	selectAllJoinedHostsStmt      *sql.Stmt
+	selectJoinedHostsForRoomsStmt *sql.Stmt
 }
 
 func NewPostgresJoinedHostsTable(db *sql.DB) (s *joinedHostsStatements, err error) {
@@ -88,6 +92,9 @@ func NewPostgresJoinedHostsTable(db *sql.DB) (s *joinedHostsStatements, err erro
 	if s.selectAllJoinedHostsStmt, err = s.db.Prepare(selectAllJoinedHostsSQL); err != nil {
 		return
 	}
+	if s.selectJoinedHostsForRoomsStmt, err = s.db.Prepare(selectJoinedHostsForRoomsSQL); err != nil {
+		return
+	}
 	return
 }
 
@@ -144,6 +151,27 @@ func (s *joinedHostsStatements) SelectAllJoinedHosts(
 	return result, rows.Err()
 }
 
+func (s *joinedHostsStatements) SelectJoinedHostsForRooms(
+	ctx context.Context, roomIDs []string,
+) ([]gomatrixserverlib.ServerName, error) {
+	rows, err := s.selectJoinedHostsForRoomsStmt.QueryContext(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "selectJoinedHostsForRoomsStmt: rows.close() failed")
+
+	var result []gomatrixserverlib.ServerName
+	for rows.Next() {
+		var serverName string
+		if err = rows.Scan(&serverName); err != nil {
+			return nil, err
+		}
+		result = append(result, gomatrixserverlib.ServerName(serverName))
+	}
+
+	return result, rows.Err()
+}
+
 func joinedHostsFromStmt(
 	ctx context.Context, stmt *sql.Stmt, roomID string,
 ) ([]types.JoinedHost, error) {

federationsender/storage/shared/storage.go

@@ -123,6 +123,10 @@ func (d *Database) GetAllJoinedHosts(ctx context.Context) ([]gomatrixserverlib.S
 	return d.FederationSenderJoinedHosts.SelectAllJoinedHosts(ctx)
 }
 
+func (d *Database) GetJoinedHostsForRooms(ctx context.Context, roomIDs []string) ([]gomatrixserverlib.ServerName, error) {
+	return d.FederationSenderJoinedHosts.SelectJoinedHostsForRooms(ctx, roomIDs)
+}
+
 // StoreJSON adds a JSON blob into the queue JSON table and returns
 // a NID. The NID will then be used when inserting the per-destination
 // metadata entries.

federationsender/storage/sqlite3/joined_hosts_table.go

@@ -59,6 +59,9 @@ const selectJoinedHostsSQL = "" +
 const selectAllJoinedHostsSQL = "" +
 	"SELECT DISTINCT server_name FROM federationsender_joined_hosts"
 
+const selectJoinedHostsForRoomsSQL = "" +
+	"SELECT DISTINCT server_name FROM federationsender_joined_hosts WHERE room_id IN ($1)"
+
 type joinedHostsStatements struct {
 	db                            *sql.DB
 	writer                        *sqlutil.TransactionWriter
@@ -66,6 +69,7 @@ type joinedHostsStatements struct {
 	deleteJoinedHostsStmt         *sql.Stmt
 	selectJoinedHostsStmt         *sql.Stmt
 	selectAllJoinedHostsStmt      *sql.Stmt
+	selectJoinedHostsForRoomsStmt *sql.Stmt
 }
 
 func NewSQLiteJoinedHostsTable(db *sql.DB) (s *joinedHostsStatements, err error) {
@@ -89,6 +93,9 @@ func NewSQLiteJoinedHostsTable(db *sql.DB) (s *joinedHostsStatements, err error)
 	if s.selectAllJoinedHostsStmt, err = db.Prepare(selectAllJoinedHostsSQL); err != nil {
 		return
 	}
+	if s.selectJoinedHostsForRoomsStmt, err = db.Prepare(selectJoinedHostsForRoomsSQL); err != nil {
+		return
+	}
 	return
 }
 
@@ -153,6 +160,32 @@ func (s *joinedHostsStatements) SelectAllJoinedHosts(
 	return result, rows.Err()
 }
 
+func (s *joinedHostsStatements) SelectJoinedHostsForRooms(
+	ctx context.Context, roomIDs []string,
+) ([]gomatrixserverlib.ServerName, error) {
+	iRoomIDs := make([]interface{}, len(roomIDs))
+	for i := range roomIDs {
+		iRoomIDs[i] = roomIDs[i]
+	}
+
+	rows, err := s.selectJoinedHostsForRoomsStmt.QueryContext(ctx, iRoomIDs...)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "selectJoinedHostsForRoomsStmt: rows.close() failed")
+
+	var result []gomatrixserverlib.ServerName
+	for rows.Next() {
+		var serverName string
+		if err = rows.Scan(&serverName); err != nil {
+			return nil, err
+		}
+		result = append(result, gomatrixserverlib.ServerName(serverName))
+	}
+
+	return result, rows.Err()
+}
+
 func joinedHostsFromStmt(
 	ctx context.Context, stmt *sql.Stmt, roomID string,
 ) ([]types.JoinedHost, error) {

federationsender/storage/tables/interface.go

@@ -53,6 +53,7 @@ type FederationSenderJoinedHosts interface {
 	SelectJoinedHostsWithTx(ctx context.Context, txn *sql.Tx, roomID string) ([]types.JoinedHost, error)
 	SelectJoinedHosts(ctx context.Context, roomID string) ([]types.JoinedHost, error)
 	SelectAllJoinedHosts(ctx context.Context) ([]gomatrixserverlib.ServerName, error)
+	SelectJoinedHostsForRooms(ctx context.Context, roomIDs []string) ([]gomatrixserverlib.ServerName, error)
 }
 
 type FederationSenderRooms interface {

go.mod

@@ -21,7 +21,7 @@ require (
 	github.com/matrix-org/go-http-js-libp2p v0.0.0-20200518170932-783164aeeda4
 	github.com/matrix-org/go-sqlite3-js v0.0.0-20200522092705-bc8506ccbcf3
 	github.com/matrix-org/gomatrix v0.0.0-20190528120928-7df988a63f26
-	github.com/matrix-org/gomatrixserverlib v0.0.0-20200722124340-16fba816840d
+	github.com/matrix-org/gomatrixserverlib v0.0.0-20200803165739-3bd1ef0f0852
 	github.com/matrix-org/naffka v0.0.0-20200422140631-181f1ee7401f
 	github.com/matrix-org/util v0.0.0-20190711121626-527ce5ddefc7
 	github.com/mattn/go-sqlite3 v2.0.2+incompatible

go.sum

@@ -425,6 +425,10 @@ github.com/matrix-org/gomatrixserverlib v0.0.0-20200721145051-cea6eafced2b h1:ul
 github.com/matrix-org/gomatrixserverlib v0.0.0-20200721145051-cea6eafced2b/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
 github.com/matrix-org/gomatrixserverlib v0.0.0-20200722124340-16fba816840d h1:WZXyd8YI+PQIDYjN8HxtqNRJ1DCckt9wPTi2P8cdnKM=
 github.com/matrix-org/gomatrixserverlib v0.0.0-20200722124340-16fba816840d/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20200803165250-352235625587 h1:n2IZkm5LI4lACulOa5WU6QwWUhHUtBZez7YIFr1fCOs=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20200803165250-352235625587/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20200803165739-3bd1ef0f0852 h1:OBvHjLWaT2KS9kGarX2ES0yKBL/wMxAeQB39tRrAAls=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20200803165739-3bd1ef0f0852/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
 github.com/matrix-org/naffka v0.0.0-20200422140631-181f1ee7401f h1:pRz4VTiRCO4zPlEMc3ESdUOcW4PXHH4Kj+YDz1XyE+Y=
 github.com/matrix-org/naffka v0.0.0-20200422140631-181f1ee7401f/go.mod h1:y0oDTjZDv5SM9a2rp3bl+CU+bvTRINQsdb7YlDql5Go=
 github.com/matrix-org/util v0.0.0-20190711121626-527ce5ddefc7 h1:ntrLa/8xVzeSs8vHFHK25k0C+NV74sYMJnNSg5NoSRo=

keyserver/api/api.go

@@ -32,6 +32,7 @@ type KeyInternalAPI interface {
 	QueryKeys(ctx context.Context, req *QueryKeysRequest, res *QueryKeysResponse)
 	QueryKeyChanges(ctx context.Context, req *QueryKeyChangesRequest, res *QueryKeyChangesResponse)
 	QueryOneTimeKeys(ctx context.Context, req *QueryOneTimeKeysRequest, res *QueryOneTimeKeysResponse)
+	QueryDeviceMessages(ctx context.Context, req *QueryDeviceMessagesRequest, res *QueryDeviceMessagesResponse)
 }
 
 // KeyError is returned if there was a problem performing/querying the server
@@ -188,3 +189,14 @@ type QueryOneTimeKeysResponse struct {
 	Count OneTimeKeysCount
 	Error *KeyError
 }
+
+type QueryDeviceMessagesRequest struct {
+	UserID string
+}
+
+type QueryDeviceMessagesResponse struct {
+	// The latest stream ID
+	StreamID int
+	Devices  []DeviceMessage
+	Error    *KeyError
+}

keyserver/internal/internal.go

@@ -179,6 +179,24 @@ func (a *KeyInternalAPI) QueryOneTimeKeys(ctx context.Context, req *api.QueryOne
 	res.Count = *count
 }
 
+func (a *KeyInternalAPI) QueryDeviceMessages(ctx context.Context, req *api.QueryDeviceMessagesRequest, res *api.QueryDeviceMessagesResponse) {
+	msgs, err := a.DB.DeviceKeysForUser(ctx, req.UserID, nil)
+	if err != nil {
+		res.Error = &api.KeyError{
+			Err: fmt.Sprintf("failed to query DB for device keys: %s", err),
+		}
+		return
+	}
+	maxStreamID := 0
+	for _, m := range msgs {
+		if m.StreamID > maxStreamID {
+			maxStreamID = m.StreamID
+		}
+	}
+	res.Devices = msgs
+	res.StreamID = maxStreamID
+}
+
 func (a *KeyInternalAPI) QueryKeys(ctx context.Context, req *api.QueryKeysRequest, res *api.QueryKeysResponse) {
 	res.DeviceKeys = make(map[string]map[string]json.RawMessage)
 	res.Failures = make(map[string]interface{})

keyserver/inthttp/client.go

@@ -32,6 +32,7 @@ const (
 	QueryKeysPath           = "/keyserver/queryKeys"
 	QueryKeyChangesPath     = "/keyserver/queryKeyChanges"
 	QueryOneTimeKeysPath    = "/keyserver/queryOneTimeKeys"
+	QueryDeviceMessagesPath = "/keyserver/queryDeviceMessages"
 )
 
 // NewKeyServerClient creates a KeyInternalAPI implemented by talking to a HTTP POST API.
@@ -126,6 +127,23 @@ func (h *httpKeyInternalAPI) QueryOneTimeKeys(
 	}
 }
 
+func (h *httpKeyInternalAPI) QueryDeviceMessages(
+	ctx context.Context,
+	request *api.QueryDeviceMessagesRequest,
+	response *api.QueryDeviceMessagesResponse,
+) {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryDeviceMessages")
+	defer span.Finish()
+
+	apiURL := h.apiURL + QueryDeviceMessagesPath
+	err := httputil.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
+	if err != nil {
+		response.Error = &api.KeyError{
+			Err: err.Error(),
+		}
+	}
+}
+
 func (h *httpKeyInternalAPI) QueryKeyChanges(
 	ctx context.Context,
 	request *api.QueryKeyChangesRequest,

keyserver/inthttp/server.go

@@ -69,6 +69,17 @@ func AddRoutes(internalAPIMux *mux.Router, s api.KeyInternalAPI) {
 			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
 		}),
 	)
+	internalAPIMux.Handle(QueryDeviceMessagesPath,
+		httputil.MakeInternalAPI("queryDeviceMessages", func(req *http.Request) util.JSONResponse {
+			request := api.QueryDeviceMessagesRequest{}
+			response := api.QueryDeviceMessagesResponse{}
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			s.QueryDeviceMessages(req.Context(), &request, &response)
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
 	internalAPIMux.Handle(QueryKeyChangesPath,
 		httputil.MakeInternalAPI("queryKeyChanges", func(req *http.Request) util.JSONResponse {
 			request := api.QueryKeyChangesRequest{}

syncapi/internal/keychange_test.go

@@ -41,6 +41,9 @@ func (k *mockKeyAPI) QueryKeyChanges(ctx context.Context, req *keyapi.QueryKeyCh
 }
 func (k *mockKeyAPI) QueryOneTimeKeys(ctx context.Context, req *keyapi.QueryOneTimeKeysRequest, res *keyapi.QueryOneTimeKeysResponse) {
 
+}
+func (k *mockKeyAPI) QueryDeviceMessages(ctx context.Context, req *keyapi.QueryDeviceMessagesRequest, res *keyapi.QueryDeviceMessagesResponse) {
+
 }
 
 type mockCurrentStateAPI struct {