PDU Sender split (#3100)

Initial cut of splitting PDU Sender into SenderID & looking up UserID where required.

5 files changed, 55 insertions, 27 deletions

diff --git a/federationapi/federationapi_test.go b/federationapi/federationapi_test.go
index beb648a4..a97bcdea 100644
--- a/federationapi/federationapi_test.go
+++ b/federationapi/federationapi_test.go
@@ -36,6 +36,10 @@ type fedRoomserverAPI struct {
 	queryRoomsForUser func(ctx context.Context, req *rsapi.QueryRoomsForUserRequest, res *rsapi.QueryRoomsForUserResponse) error
 }
 
+func (f *fedRoomserverAPI) QueryUserIDForSender(ctx context.Context, roomID string, senderID string) (*spec.UserID, error) {
+	return spec.NewUserID(senderID, true)
+}
+
 // PerformJoin will call this function
 func (f *fedRoomserverAPI) InputRoomEvents(ctx context.Context, req *rsapi.InputRoomEventsRequest, res *rsapi.InputRoomEventsResponse) {
 	if f.inputRoomEvents == nil {
diff --git a/federationapi/internal/perform.go b/federationapi/internal/perform.go
index ed800d03..2d59d0f9 100644
--- a/federationapi/internal/perform.go
+++ b/federationapi/internal/perform.go
@@ -156,15 +156,20 @@ func (r *FederationInternalAPI) performJoinUsingServer(
 	}
 
 	joinInput := gomatrixserverlib.PerformJoinInput{
-		UserID:        user,
-		RoomID:        room,
-		ServerName:    serverName,
-		Content:       content,
-		Unsigned:      unsigned,
-		PrivateKey:    r.cfg.Matrix.PrivateKey,
-		KeyID:         r.cfg.Matrix.KeyID,
-		KeyRing:       r.keyRing,
-		EventProvider: federatedEventProvider(ctx, r.federation, r.keyRing, user.Domain(), serverName),
+		UserID:     user,
+		RoomID:     room,
+		ServerName: serverName,
+		Content:    content,
+		Unsigned:   unsigned,
+		PrivateKey: r.cfg.Matrix.PrivateKey,
+		KeyID:      r.cfg.Matrix.KeyID,
+		KeyRing:    r.keyRing,
+		EventProvider: federatedEventProvider(ctx, r.federation, r.keyRing, user.Domain(), serverName, func(roomID, senderID string) (*spec.UserID, error) {
+			return r.rsAPI.QueryUserIDForSender(ctx, roomID, senderID)
+		}),
+		UserIDQuerier: func(roomID, senderID string) (*spec.UserID, error) {
+			return r.rsAPI.QueryUserIDForSender(ctx, roomID, senderID)
+		},
 	}
 	response, joinErr := gomatrixserverlib.PerformJoin(ctx, r, joinInput)
 
@@ -358,8 +363,11 @@ func (r *FederationInternalAPI) performOutboundPeekUsingServer(
 
 	// authenticate the state returned (check its auth events etc)
 	// the equivalent of CheckSendJoinResponse()
+	userIDProvider := func(roomID, senderID string) (*spec.UserID, error) {
+		return r.rsAPI.QueryUserIDForSender(ctx, roomID, senderID)
+	}
 	authEvents, stateEvents, err := gomatrixserverlib.CheckStateResponse(
-		ctx, &respPeek, respPeek.RoomVersion, r.keyRing, federatedEventProvider(ctx, r.federation, r.keyRing, r.cfg.Matrix.ServerName, serverName),
+		ctx, &respPeek, respPeek.RoomVersion, r.keyRing, federatedEventProvider(ctx, r.federation, r.keyRing, r.cfg.Matrix.ServerName, serverName, userIDProvider), userIDProvider,
 	)
 	if err != nil {
 		return fmt.Errorf("error checking state returned from peeking: %w", err)
@@ -509,7 +517,7 @@ func (r *FederationInternalAPI) SendInvite(
 	event gomatrixserverlib.PDU,
 	strippedState []gomatrixserverlib.InviteStrippedState,
 ) (gomatrixserverlib.PDU, error) {
-	_, origin, err := r.cfg.Matrix.SplitLocalID('@', event.Sender())
+	inviter, err := r.rsAPI.QueryUserIDForSender(ctx, event.RoomID(), event.SenderID())
 	if err != nil {
 		return nil, err
 	}
@@ -542,7 +550,7 @@ func (r *FederationInternalAPI) SendInvite(
 		return nil, fmt.Errorf("gomatrixserverlib.NewInviteV2Request: %w", err)
 	}
 
-	inviteRes, err := r.federation.SendInviteV2(ctx, origin, destination, inviteReq)
+	inviteRes, err := r.federation.SendInviteV2(ctx, inviter.Domain(), destination, inviteReq)
 	if err != nil {
 		return nil, fmt.Errorf("r.federation.SendInviteV2: failed to send invite: %w", err)
 	}
@@ -635,6 +643,7 @@ func checkEventsContainCreateEvent(events []gomatrixserverlib.PDU) error {
 func federatedEventProvider(
 	ctx context.Context, federation fclient.FederationClient,
 	keyRing gomatrixserverlib.JSONVerifier, origin, server spec.ServerName,
+	userIDForSender spec.UserIDForSender,
 ) gomatrixserverlib.EventProvider {
 	// A list of events that we have retried, if they were not included in
 	// the auth events supplied in the send_join.
@@ -684,7 +693,7 @@ func federatedEventProvider(
 				}
 
 				// Check the signatures of the event.
-				if err := gomatrixserverlib.VerifyEventSignatures(ctx, ev, keyRing); err != nil {
+				if err := gomatrixserverlib.VerifyEventSignatures(ctx, ev, keyRing, userIDForSender); err != nil {
 					return nil, fmt.Errorf("missingAuth VerifyEventSignatures: %w", err)
 				}
 
diff --git a/federationapi/routing/invite.go b/federationapi/routing/invite.go
index 78a09d94..d792335b 100644
--- a/federationapi/routing/invite.go
+++ b/federationapi/routing/invite.go
@@ -95,6 +95,9 @@ func InviteV2(
 			StateQuerier:      rsAPI.StateQuerier(),
 			InviteEvent:       inviteReq.Event(),
 			StrippedState:     inviteReq.InviteRoomState(),
+			UserIDQuerier: func(roomID, senderID string) (*spec.UserID, error) {
+				return rsAPI.QueryUserIDForSender(httpReq.Context(), roomID, senderID)
+			},
 		}
 		event, jsonErr := handleInvite(httpReq.Context(), input, rsAPI)
 		if jsonErr != nil {
@@ -185,6 +188,9 @@ func InviteV1(
 		StateQuerier:      rsAPI.StateQuerier(),
 		InviteEvent:       event,
 		StrippedState:     strippedState,
+		UserIDQuerier: func(roomID, senderID string) (*spec.UserID, error) {
+			return rsAPI.QueryUserIDForSender(httpReq.Context(), roomID, senderID)
+		},
 	}
 	event, jsonErr := handleInvite(httpReq.Context(), input, rsAPI)
 	if jsonErr != nil {
diff --git a/federationapi/routing/join.go b/federationapi/routing/join.go
index 2980c2af..9da05918 100644
--- a/federationapi/routing/join.go
+++ b/federationapi/routing/join.go
@@ -99,15 +99,18 @@ func MakeJoin(
 	}
 
 	input := gomatrixserverlib.HandleMakeJoinInput{
-		Context:            httpReq.Context(),
-		UserID:             userID,
-		RoomID:             roomID,
-		RoomVersion:        roomVersion,
-		RemoteVersions:     remoteVersions,
-		RequestOrigin:      request.Origin(),
-		LocalServerName:    cfg.Matrix.ServerName,
-		LocalServerInRoom:  res.RoomExists && res.IsInRoom,
-		RoomQuerier:        &roomQuerier,
+		Context:           httpReq.Context(),
+		UserID:            userID,
+		RoomID:            roomID,
+		RoomVersion:       roomVersion,
+		RemoteVersions:    remoteVersions,
+		RequestOrigin:     request.Origin(),
+		LocalServerName:   cfg.Matrix.ServerName,
+		LocalServerInRoom: res.RoomExists && res.IsInRoom,
+		RoomQuerier:       &roomQuerier,
+		UserIDQuerier: func(roomID, senderID string) (*spec.UserID, error) {
+			return rsAPI.QueryUserIDForSender(httpReq.Context(), roomID, senderID)
+		},
 		BuildEventTemplate: createJoinTemplate,
 	}
 	response, internalErr := gomatrixserverlib.HandleMakeJoin(input)
@@ -202,6 +205,9 @@ func SendJoin(
 		PrivateKey:        cfg.Matrix.PrivateKey,
 		Verifier:          keys,
 		MembershipQuerier: &api.MembershipQuerier{Roomserver: rsAPI},
+		UserIDQuerier: func(roomID, senderID string) (*spec.UserID, error) {
+			return rsAPI.QueryUserIDForSender(httpReq.Context(), roomID, senderID)
+		},
 	}
 	response, joinErr := gomatrixserverlib.HandleSendJoin(input)
 	switch e := joinErr.(type) {
diff --git a/federationapi/routing/leave.go b/federationapi/routing/leave.go
index d7d5b599..30e99c4f 100644
--- a/federationapi/routing/leave.go
+++ b/federationapi/routing/leave.go
@@ -95,6 +95,9 @@ func MakeLeave(
 		LocalServerName:    cfg.Matrix.ServerName,
 		LocalServerInRoom:  res.RoomExists && res.IsInRoom,
 		BuildEventTemplate: createLeaveTemplate,
+		UserIDQuerier: func(roomID, senderID string) (*spec.UserID, error) {
+			return rsAPI.QueryUserIDForSender(httpReq.Context(), roomID, senderID)
+		},
 	}
 
 	response, internalErr := gomatrixserverlib.HandleMakeLeave(input)
@@ -213,7 +216,7 @@ func SendLeave(
 			JSON: spec.BadJSON("No state key was provided in the leave event."),
 		}
 	}
-	if !event.StateKeyEquals(event.Sender()) {
+	if !event.StateKeyEquals(event.SenderID()) {
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: spec.BadJSON("Event state key must match the event sender."),
@@ -223,13 +226,13 @@ func SendLeave(
 	// Check that the sender belongs to the server that is sending us
 	// the request. By this point we've already asserted that the sender
 	// and the state key are equal so we don't need to check both.
-	var serverName spec.ServerName
-	if _, serverName, err = gomatrixserverlib.SplitID('@', event.Sender()); err != nil {
+	sender, err := rsAPI.QueryUserIDForSender(httpReq.Context(), event.RoomID(), event.SenderID())
+	if err != nil {
 		return util.JSONResponse{
 			Code: http.StatusForbidden,
 			JSON: spec.Forbidden("The sender of the join is invalid"),
 		}
-	} else if serverName != request.Origin() {
+	} else if sender.Domain() != request.Origin() {
 		return util.JSONResponse{
 			Code: http.StatusForbidden,
 			JSON: spec.Forbidden("The sender does not match the server that originated the request"),
@@ -291,7 +294,7 @@ func SendLeave(
 		}
 	}
 	verifyRequests := []gomatrixserverlib.VerifyJSONRequest{{
-		ServerName:           serverName,
+		ServerName:           sender.Domain(),
 		Message:              redacted,
 		AtTS:                 event.OriginServerTS(),
 		ValidityCheckingFunc: gomatrixserverlib.StrictValiditySignatureCheck,