Add history visibility guards (#1470)

* Add history visibility guards

Default to 'joined' visibility to avoid leaking events, until we get
around to implementing history visibility completely. Related #617

* Don't apply his vis checks on shared rooms

* Fix order of checks

* Linting and remove another misleading check

* Update whitelist
This commit is contained in:
Kegsay 2020-10-02 17:08:13 +01:00 committed by GitHub
parent c870435c17
commit 279044cd90
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5 changed files with 124 additions and 9 deletions

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@ -26,6 +26,7 @@ import (
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/syncapi/storage"
"github.com/matrix-org/dendrite/syncapi/types"
userapi "github.com/matrix-org/dendrite/userapi/api"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/util"
"github.com/sirupsen/logrus"
@ -41,6 +42,7 @@ type messagesReq struct {
from *types.TopologyToken
to *types.TopologyToken
fromStream *types.StreamingToken
device *userapi.Device
wasToProvided bool
limit int
backwardOrdering bool
@ -58,7 +60,7 @@ const defaultMessagesLimit = 10
// client-server API.
// See: https://matrix.org/docs/spec/client_server/latest.html#get-matrix-client-r0-rooms-roomid-messages
func OnIncomingMessagesRequest(
req *http.Request, db storage.Database, roomID string,
req *http.Request, db storage.Database, roomID string, device *userapi.Device,
federation *gomatrixserverlib.FederationClient,
rsAPI api.RoomserverInternalAPI,
cfg *config.SyncAPI,
@ -151,6 +153,7 @@ func OnIncomingMessagesRequest(
wasToProvided: wasToProvided,
limit: limit,
backwardOrdering: backwardOrdering,
device: device,
}
clientEvents, start, end, err := mReq.retrieveEvents()
@ -238,6 +241,10 @@ func (r *messagesReq) retrieveEvents() (
}
events = reversed(events)
}
events = r.filterHistoryVisible(events)
if len(events) == 0 {
return []gomatrixserverlib.ClientEvent{}, *r.from, *r.to, nil
}
// Convert all of the events into client events.
clientEvents = gomatrixserverlib.HeaderedToClientEvents(events, gomatrixserverlib.FormatAll)
@ -252,6 +259,90 @@ func (r *messagesReq) retrieveEvents() (
return clientEvents, start, end, err
}
// nolint:gocyclo
func (r *messagesReq) filterHistoryVisible(events []gomatrixserverlib.HeaderedEvent) []gomatrixserverlib.HeaderedEvent {
// TODO FIXME: We don't fully implement history visibility yet. To avoid leaking events which the
// user shouldn't see, we check the recent events and remove any prior to the join event of the user
// which is equiv to history_visibility: joined
joinEventIndex := -1
for i, ev := range events {
if ev.Type() == gomatrixserverlib.MRoomMember && ev.StateKeyEquals(r.device.UserID) {
membership, _ := ev.Membership()
if membership == "join" {
joinEventIndex = i
break
}
}
}
var result []gomatrixserverlib.HeaderedEvent
var eventsToCheck []gomatrixserverlib.HeaderedEvent
if joinEventIndex != -1 {
if r.backwardOrdering {
result = events[:joinEventIndex+1]
eventsToCheck = append(eventsToCheck, result[0])
} else {
result = events[joinEventIndex:]
eventsToCheck = append(eventsToCheck, result[len(result)-1])
}
} else {
eventsToCheck = []gomatrixserverlib.HeaderedEvent{events[0], events[len(events)-1]}
result = events
}
// make sure the user was in the room for both the earliest and latest events, we need this because
// some backpagination results will not have the join event (e.g if they hit /messages at the join event itself)
wasJoined := true
for _, ev := range eventsToCheck {
var queryRes api.QueryStateAfterEventsResponse
err := r.rsAPI.QueryStateAfterEvents(r.ctx, &api.QueryStateAfterEventsRequest{
RoomID: ev.RoomID(),
PrevEventIDs: ev.PrevEventIDs(),
StateToFetch: []gomatrixserverlib.StateKeyTuple{
{EventType: gomatrixserverlib.MRoomMember, StateKey: r.device.UserID},
{EventType: gomatrixserverlib.MRoomHistoryVisibility, StateKey: ""},
},
}, &queryRes)
if err != nil {
wasJoined = false
break
}
var hisVisEvent, membershipEvent *gomatrixserverlib.HeaderedEvent
for i := range queryRes.StateEvents {
switch queryRes.StateEvents[i].Type() {
case gomatrixserverlib.MRoomMember:
membershipEvent = &queryRes.StateEvents[i]
case gomatrixserverlib.MRoomHistoryVisibility:
hisVisEvent = &queryRes.StateEvents[i]
}
}
if hisVisEvent == nil {
return events // apply no filtering as it defaults to Shared.
}
hisVis, _ := hisVisEvent.HistoryVisibility()
if hisVis == "shared" {
return events // apply no filtering
}
if membershipEvent == nil {
wasJoined = false
break
}
membership, err := membershipEvent.Membership()
if err != nil {
wasJoined = false
break
}
if membership != "join" {
wasJoined = false
break
}
}
if !wasJoined {
util.GetLogger(r.ctx).WithField("num_events", len(events)).Warnf("%s was not joined to room during these events, omitting them", r.device.UserID)
return []gomatrixserverlib.HeaderedEvent{}
}
return result
}
func (r *messagesReq) getStartEnd(events []gomatrixserverlib.HeaderedEvent) (start, end types.TopologyToken, err error) {
start, err = r.db.EventPositionInTopology(
r.ctx, events[0].EventID(),

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@ -51,7 +51,7 @@ func Setup(
if err != nil {
return util.ErrorResponse(err)
}
return OnIncomingMessagesRequest(req, syncDB, vars["roomID"], federation, rsAPI, cfg)
return OnIncomingMessagesRequest(req, syncDB, vars["roomID"], device, federation, rsAPI, cfg)
})).Methods(http.MethodGet, http.MethodOptions)
r0mux.Handle("/user/{userId}/filter",

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@ -769,6 +769,33 @@ func (d *Database) getJoinResponseForCompleteSync(
return
}
// TODO FIXME: We don't fully implement history visibility yet. To avoid leaking events which the
// user shouldn't see, we check the recent events and remove any prior to the join event of the user
// which is equiv to history_visibility: joined
joinEventIndex := -1
for i := len(recentStreamEvents) - 1; i >= 0; i-- {
ev := recentStreamEvents[i]
if ev.Type() == gomatrixserverlib.MRoomMember && ev.StateKeyEquals(device.UserID) {
membership, _ := ev.Membership()
if membership == "join" {
joinEventIndex = i
if i > 0 {
// the create event happens before the first join, so we should cut it at that point instead
if recentStreamEvents[i-1].Type() == gomatrixserverlib.MRoomCreate && recentStreamEvents[i-1].StateKeyEquals("") {
joinEventIndex = i - 1
break
}
}
break
}
}
}
if joinEventIndex != -1 {
// cut all events earlier than the join (but not the join itself)
recentStreamEvents = recentStreamEvents[joinEventIndex:]
limited = false // so clients know not to try to backpaginate
}
// Retrieve the backward topology position, i.e. the position of the
// oldest event in the room's topology.
var prevBatchStr string

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@ -689,6 +689,7 @@ func assertInvitedToRooms(t *testing.T, res *types.Response, roomIDs []string) {
}
func assertEventsEqual(t *testing.T, msg string, checkRoomID bool, gots []gomatrixserverlib.ClientEvent, wants []gomatrixserverlib.HeaderedEvent) {
t.Helper()
if len(gots) != len(wants) {
t.Fatalf("%s response returned %d events, want %d", msg, len(gots), len(wants))
}

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@ -90,8 +90,6 @@ Real non-joined users can get state for world_readable rooms
Real non-joined users can get individual state for world_readable rooms
#Real non-joined users can get individual state for world_readable rooms after leaving
Real non-joined users cannot send messages to guest_access rooms if not joined
Real users can sync from world_readable guest_access rooms if joined
Real users can sync from default guest_access rooms if joined
Can't forget room you're still in
Can get rooms/{roomId}/members
Can create filter
@ -236,13 +234,11 @@ Outbound federation can query v2 /send_join
Inbound federation can receive v2 /send_join
Message history can be paginated
Getting messages going forward is limited for a departed room (SPEC-216)
m.room.history_visibility == "world_readable" allows/forbids appropriately for Real users
Backfill works correctly with history visibility set to joined
Guest user cannot call /events globally
Guest users can join guest_access rooms
Guest user can set display names
Guest user cannot upgrade other users
m.room.history_visibility == "world_readable" allows/forbids appropriately for Guest users
Guest non-joined user cannot call /events on shared room
Guest non-joined user cannot call /events on invited room
Guest non-joined user cannot call /events on joined room
@ -252,8 +248,6 @@ Guest non-joined users can get individual state for world_readable rooms
Guest non-joined users cannot room initalSync for non-world_readable rooms
Guest non-joined users can get individual state for world_readable rooms after leaving
Guest non-joined users cannot send messages to guest_access rooms if not joined
Guest users can sync from world_readable guest_access rooms if joined
Guest users can sync from default guest_access rooms if joined
Real non-joined users cannot room initalSync for non-world_readable rooms
Push rules come down in an initial /sync
Regular users can add and delete aliases in the default room configuration
@ -479,3 +473,5 @@ Inbound /make_join rejects attempts to join rooms where all users have left
Inbound federation rejects invites which include invalid JSON for room version 6
Inbound federation rejects invite rejections which include invalid JSON for room version 6
GET /capabilities is present and well formed for registered user
m.room.history_visibility == "joined" allows/forbids appropriately for Guest users
m.room.history_visibility == "joined" allows/forbids appropriately for Real users