Make redaction check easier to read (#2995)

We need to check the redaction PL in Dendrite, if we do it in GMSL, we
end up not sending the event to the output stream because it will be
rejected.

---------

Co-authored-by: kegsay <kegan@matrix.org>
This commit is contained in:
Till 2023-03-03 14:03:17 +01:00 committed by GitHub
parent 7cde99a7a7
commit 9bcd0a2105
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 285 additions and 28 deletions

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@ -26,14 +26,14 @@ import (
"github.com/tidwall/gjson"
"github.com/matrix-org/dendrite/roomserver/internal/helpers"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/util"
"github.com/opentracing/opentracing-go"
"github.com/prometheus/client_golang/prometheus"
"github.com/sirupsen/logrus"
"github.com/matrix-org/dendrite/roomserver/internal/helpers"
userAPI "github.com/matrix-org/dendrite/userapi/api"
fedapi "github.com/matrix-org/dendrite/federationapi/api"
@ -275,10 +275,8 @@ func (r *Inputer) processRoomEvent(
// Check if the event is allowed by its auth events. If it isn't then
// we consider the event to be "rejected" — it will still be persisted.
redactAllowed := true
if err = gomatrixserverlib.Allowed(event, &authEvents); err != nil {
isRejected = true
redactAllowed = false
rejectionErr = err
logger.WithError(rejectionErr).Warnf("Event %s not allowed by auth events", event.EventID())
}
@ -358,22 +356,6 @@ func (r *Inputer) processRoomEvent(
return fmt.Errorf("updater.StoreEvent: %w", err)
}
// if storing this event results in it being redacted then do so.
var (
redactedEventID string
redactionEvent *gomatrixserverlib.Event
redactedEvent *gomatrixserverlib.Event
)
if !isRejected && !isCreateEvent {
redactionEvent, redactedEvent, err = r.DB.MaybeRedactEvent(ctx, roomInfo, eventNID, event, redactAllowed)
if err != nil {
return err
}
if redactedEvent != nil {
redactedEventID = redactedEvent.EventID()
}
}
// For outliers we can stop after we've stored the event itself as it
// doesn't have any associated state to store and we don't need to
// notify anyone about it.
@ -402,6 +384,24 @@ func (r *Inputer) processRoomEvent(
}
}
// if storing this event results in it being redacted then do so.
// we do this after calculating state for this event as we may need to get power levels
var (
redactedEventID string
redactionEvent *gomatrixserverlib.Event
redactedEvent *gomatrixserverlib.Event
)
if !isRejected && !isCreateEvent {
resolver := state.NewStateResolution(r.DB, roomInfo)
redactionEvent, redactedEvent, err = r.DB.MaybeRedactEvent(ctx, roomInfo, eventNID, event, &resolver)
if err != nil {
return err
}
if redactedEvent != nil {
redactedEventID = redactedEvent.EventID()
}
}
// We stop here if the event is rejected: We've stored it but won't update
// forward extremities or notify downstream components about it.
switch {

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@ -26,6 +26,7 @@ import (
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/roomserver/auth"
"github.com/matrix-org/dendrite/roomserver/internal/helpers"
"github.com/matrix-org/dendrite/roomserver/state"
"github.com/matrix-org/dendrite/roomserver/storage"
"github.com/matrix-org/dendrite/roomserver/types"
)
@ -629,7 +630,9 @@ func persistEvents(ctx context.Context, db storage.Database, events []*gomatrixs
continue
}
_, redactedEvent, err := db.MaybeRedactEvent(ctx, roomInfo, eventNID, ev.Unwrap(), true)
resolver := state.NewStateResolution(db, roomInfo)
_, redactedEvent, err := db.MaybeRedactEvent(ctx, roomInfo, eventNID, ev.Unwrap(), &resolver)
if err != nil {
logrus.WithError(err).WithField("event_id", ev.EventID()).Error("Failed to redact event")
continue

View File

@ -2,19 +2,25 @@ package roomserver_test
import (
"context"
"crypto/ed25519"
"reflect"
"testing"
"time"
"github.com/stretchr/testify/assert"
"github.com/matrix-org/dendrite/roomserver/state"
"github.com/matrix-org/dendrite/roomserver/types"
"github.com/matrix-org/dendrite/setup/base"
"github.com/matrix-org/dendrite/userapi"
userAPI "github.com/matrix-org/dendrite/userapi/api"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/dendrite/federationapi"
"github.com/matrix-org/dendrite/setup/jetstream"
"github.com/matrix-org/dendrite/syncapi"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/dendrite/roomserver"
"github.com/matrix-org/dendrite/roomserver/api"
@ -379,3 +385,189 @@ func TestPurgeRoom(t *testing.T) {
}
})
}
type fledglingEvent struct {
Type string
StateKey *string
Sender string
RoomID string
Redacts string
Depth int64
PrevEvents []interface{}
}
func mustCreateEvent(t *testing.T, ev fledglingEvent) (result *gomatrixserverlib.HeaderedEvent) {
t.Helper()
roomVer := gomatrixserverlib.RoomVersionV9
seed := make([]byte, ed25519.SeedSize) // zero seed
key := ed25519.NewKeyFromSeed(seed)
eb := gomatrixserverlib.EventBuilder{
Sender: ev.Sender,
Type: ev.Type,
StateKey: ev.StateKey,
RoomID: ev.RoomID,
Redacts: ev.Redacts,
Depth: ev.Depth,
PrevEvents: ev.PrevEvents,
}
err := eb.SetContent(map[string]interface{}{})
if err != nil {
t.Fatalf("mustCreateEvent: failed to marshal event content %v", err)
}
signedEvent, err := eb.Build(time.Now(), "localhost", "ed25519:test", key, roomVer)
if err != nil {
t.Fatalf("mustCreateEvent: failed to sign event: %s", err)
}
h := signedEvent.Headered(roomVer)
return h
}
func TestRedaction(t *testing.T) {
alice := test.NewUser(t)
bob := test.NewUser(t)
charlie := test.NewUser(t, test.WithSigningServer("notlocalhost", "abc", test.PrivateKeyB))
testCases := []struct {
name string
additionalEvents func(t *testing.T, room *test.Room)
wantRedacted bool
}{
{
name: "can redact own message",
wantRedacted: true,
additionalEvents: func(t *testing.T, room *test.Room) {
redactedEvent := room.CreateAndInsert(t, alice, "m.room.message", map[string]interface{}{"body": "hello world"})
builderEv := mustCreateEvent(t, fledglingEvent{
Type: gomatrixserverlib.MRoomRedaction,
Sender: alice.ID,
RoomID: room.ID,
Redacts: redactedEvent.EventID(),
Depth: redactedEvent.Depth() + 1,
PrevEvents: []interface{}{redactedEvent.EventID()},
})
room.InsertEvent(t, builderEv.Headered(gomatrixserverlib.RoomVersionV9))
},
},
{
name: "can redact others message, allowed by PL",
wantRedacted: true,
additionalEvents: func(t *testing.T, room *test.Room) {
redactedEvent := room.CreateAndInsert(t, bob, "m.room.message", map[string]interface{}{"body": "hello world"})
builderEv := mustCreateEvent(t, fledglingEvent{
Type: gomatrixserverlib.MRoomRedaction,
Sender: alice.ID,
RoomID: room.ID,
Redacts: redactedEvent.EventID(),
Depth: redactedEvent.Depth() + 1,
PrevEvents: []interface{}{redactedEvent.EventID()},
})
room.InsertEvent(t, builderEv.Headered(gomatrixserverlib.RoomVersionV9))
},
},
{
name: "can redact others message, same server",
wantRedacted: true,
additionalEvents: func(t *testing.T, room *test.Room) {
redactedEvent := room.CreateAndInsert(t, alice, "m.room.message", map[string]interface{}{"body": "hello world"})
builderEv := mustCreateEvent(t, fledglingEvent{
Type: gomatrixserverlib.MRoomRedaction,
Sender: bob.ID,
RoomID: room.ID,
Redacts: redactedEvent.EventID(),
Depth: redactedEvent.Depth() + 1,
PrevEvents: []interface{}{redactedEvent.EventID()},
})
room.InsertEvent(t, builderEv.Headered(gomatrixserverlib.RoomVersionV9))
},
},
{
name: "can not redact others message, missing PL",
additionalEvents: func(t *testing.T, room *test.Room) {
redactedEvent := room.CreateAndInsert(t, bob, "m.room.message", map[string]interface{}{"body": "hello world"})
builderEv := mustCreateEvent(t, fledglingEvent{
Type: gomatrixserverlib.MRoomRedaction,
Sender: charlie.ID,
RoomID: room.ID,
Redacts: redactedEvent.EventID(),
Depth: redactedEvent.Depth() + 1,
PrevEvents: []interface{}{redactedEvent.EventID()},
})
room.InsertEvent(t, builderEv.Headered(gomatrixserverlib.RoomVersionV9))
},
},
}
ctx := context.Background()
test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
_, db, close := mustCreateDatabase(t, dbType)
defer close()
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
authEvents := []types.EventNID{}
var roomInfo *types.RoomInfo
var err error
room := test.NewRoom(t, alice, test.RoomPreset(test.PresetPublicChat))
room.CreateAndInsert(t, bob, gomatrixserverlib.MRoomMember, map[string]interface{}{
"membership": "join",
}, test.WithStateKey(bob.ID))
room.CreateAndInsert(t, charlie, gomatrixserverlib.MRoomMember, map[string]interface{}{
"membership": "join",
}, test.WithStateKey(charlie.ID))
if tc.additionalEvents != nil {
tc.additionalEvents(t, room)
}
for _, ev := range room.Events() {
roomInfo, err = db.GetOrCreateRoomInfo(ctx, ev.Event)
assert.NoError(t, err)
assert.NotNil(t, roomInfo)
evTypeNID, err := db.GetOrCreateEventTypeNID(ctx, ev.Type())
assert.NoError(t, err)
stateKeyNID, err := db.GetOrCreateEventStateKeyNID(ctx, ev.StateKey())
assert.NoError(t, err)
eventNID, stateAtEvent, err := db.StoreEvent(ctx, ev.Event, roomInfo, evTypeNID, stateKeyNID, authEvents, false)
assert.NoError(t, err)
if ev.StateKey() != nil {
authEvents = append(authEvents, eventNID)
}
// Calculate the snapshotNID etc.
plResolver := state.NewStateResolution(db, roomInfo)
stateAtEvent.BeforeStateSnapshotNID, err = plResolver.CalculateAndStoreStateBeforeEvent(ctx, ev.Event, false)
assert.NoError(t, err)
// Update the room
updater, err := db.GetRoomUpdater(ctx, roomInfo)
assert.NoError(t, err)
err = updater.SetState(ctx, eventNID, stateAtEvent.BeforeStateSnapshotNID)
assert.NoError(t, err)
err = updater.Commit()
assert.NoError(t, err)
_, redactedEvent, err := db.MaybeRedactEvent(ctx, roomInfo, eventNID, ev.Event, &plResolver)
assert.NoError(t, err)
if redactedEvent != nil {
assert.Equal(t, ev.Redacts(), redactedEvent.EventID())
}
if ev.Type() == gomatrixserverlib.MRoomRedaction {
nids, err := db.EventNIDs(ctx, []string{ev.Redacts()})
assert.NoError(t, err)
evs, err := db.Events(ctx, roomInfo, []types.EventNID{nids[ev.Redacts()].EventNID})
assert.NoError(t, err)
assert.Equal(t, 1, len(evs))
assert.Equal(t, tc.wantRedacted, evs[0].Redacted())
}
}
})
}
})
}

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@ -59,6 +59,47 @@ func NewStateResolution(db StateResolutionStorage, roomInfo *types.RoomInfo) Sta
}
}
type PowerLevelResolver interface {
Resolve(ctx context.Context, eventID string) (*gomatrixserverlib.PowerLevelContent, error)
}
func (p *StateResolution) Resolve(ctx context.Context, eventID string) (*gomatrixserverlib.PowerLevelContent, error) {
stateEntries, err := p.LoadStateAtEvent(ctx, eventID)
if err != nil {
return nil, err
}
wantTuple := types.StateKeyTuple{
EventTypeNID: types.MRoomPowerLevelsNID,
EventStateKeyNID: types.EmptyStateKeyNID,
}
var plNID types.EventNID
for _, entry := range stateEntries {
if entry.StateKeyTuple == wantTuple {
plNID = entry.EventNID
break
}
}
if plNID == 0 {
return nil, fmt.Errorf("unable to find power level event")
}
events, err := p.db.Events(ctx, p.roomInfo, []types.EventNID{plNID})
if err != nil {
return nil, err
}
if len(events) == 0 {
return nil, fmt.Errorf("unable to find power level event")
}
powerlevels, err := events[0].PowerLevels()
if err != nil {
return nil, err
}
return powerlevels, nil
}
// LoadStateAtSnapshot loads the full state of a room at a particular snapshot.
// This is typically the state before an event or the current state of a room.
// Returns a sorted list of state entries or an error if there was a problem talking to the database.

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@ -19,6 +19,7 @@ import (
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/dendrite/roomserver/state"
"github.com/matrix-org/dendrite/roomserver/storage/shared"
"github.com/matrix-org/dendrite/roomserver/storage/tables"
"github.com/matrix-org/dendrite/roomserver/types"
@ -184,7 +185,7 @@ type Database interface {
GetOrCreateEventTypeNID(ctx context.Context, eventType string) (eventTypeNID types.EventTypeNID, err error)
GetOrCreateEventStateKeyNID(ctx context.Context, eventStateKey *string) (types.EventStateKeyNID, error)
MaybeRedactEvent(
ctx context.Context, roomInfo *types.RoomInfo, eventNID types.EventNID, event *gomatrixserverlib.Event, redactAllowed bool,
ctx context.Context, roomInfo *types.RoomInfo, eventNID types.EventNID, event *gomatrixserverlib.Event, plResolver state.PowerLevelResolver,
) (*gomatrixserverlib.Event, *gomatrixserverlib.Event, error)
}
@ -226,7 +227,7 @@ type EventDatabase interface {
// MaybeRedactEvent returns the redaction event and the redacted event if this call resulted in a redaction, else an error
// (nil if there was nothing to do)
MaybeRedactEvent(
ctx context.Context, roomInfo *types.RoomInfo, eventNID types.EventNID, event *gomatrixserverlib.Event, redactAllowed bool,
ctx context.Context, roomInfo *types.RoomInfo, eventNID types.EventNID, event *gomatrixserverlib.Event, plResolver state.PowerLevelResolver,
) (*gomatrixserverlib.Event, *gomatrixserverlib.Event, error)
StoreEvent(ctx context.Context, event *gomatrixserverlib.Event, roomInfo *types.RoomInfo, eventTypeNID types.EventTypeNID, eventStateKeyNID types.EventStateKeyNID, authEventNIDs []types.EventNID, isRejected bool) (types.EventNID, types.StateAtEvent, error)
}

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@ -13,6 +13,7 @@ import (
"github.com/matrix-org/dendrite/internal/caching"
"github.com/matrix-org/dendrite/internal/sqlutil"
"github.com/matrix-org/dendrite/roomserver/state"
"github.com/matrix-org/dendrite/roomserver/storage/tables"
"github.com/matrix-org/dendrite/roomserver/types"
)
@ -660,6 +661,12 @@ func (d *Database) GetOrCreateRoomInfo(ctx context.Context, event *gomatrixserve
if roomVersion, err = extractRoomVersionFromCreateEvent(event); err != nil {
return nil, fmt.Errorf("extractRoomVersionFromCreateEvent: %w", err)
}
if roomVersion == "" {
rv, ok := d.Cache.GetRoomVersion(event.RoomID())
if ok {
roomVersion = rv
}
}
var roomNID types.RoomNID
err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
roomNID, err = d.assignRoomNID(ctx, txn, event.RoomID(), roomVersion)
@ -668,6 +675,9 @@ func (d *Database) GetOrCreateRoomInfo(ctx context.Context, event *gomatrixserve
}
return nil
})
if roomVersion != "" {
d.Cache.StoreRoomVersion(event.RoomID(), roomVersion)
}
return &types.RoomInfo{
RoomVersion: roomVersion,
RoomNID: roomNID,
@ -838,6 +848,7 @@ func (d *Database) assignRoomNID(
return 0, err
}
d.Cache.StoreRoomServerRoomID(roomNID, roomID)
d.Cache.StoreRoomVersion(roomID, roomVersion)
return roomNID, nil
}
@ -926,7 +937,7 @@ func extractRoomVersionFromCreateEvent(event *gomatrixserverlib.Event) (
//
// Returns the redaction event and the redacted event if this call resulted in a redaction.
func (d *EventDatabase) MaybeRedactEvent(
ctx context.Context, roomInfo *types.RoomInfo, eventNID types.EventNID, event *gomatrixserverlib.Event, redactAllowed bool,
ctx context.Context, roomInfo *types.RoomInfo, eventNID types.EventNID, event *gomatrixserverlib.Event, plResolver state.PowerLevelResolver,
) (*gomatrixserverlib.Event, *gomatrixserverlib.Event, error) {
var (
redactionEvent, redactedEvent *types.Event
@ -966,11 +977,20 @@ func (d *EventDatabase) MaybeRedactEvent(
return nil
}
// 1. The power level of the redaction events sender is greater than or equal to the redact level. (redactAllowed)
// 2. The domain of the redaction events sender matches that of the original events sender.
_, sender1, _ := gomatrixserverlib.SplitID('@', redactedEvent.Sender())
_, sender2, _ := gomatrixserverlib.SplitID('@', redactionEvent.Sender())
if !redactAllowed || sender1 != sender2 {
var powerlevels *gomatrixserverlib.PowerLevelContent
powerlevels, err = plResolver.Resolve(ctx, redactionEvent.EventID())
if err != nil {
return err
}
switch {
case powerlevels.UserLevel(redactionEvent.Sender()) >= powerlevels.Redact:
// 1. The power level of the redaction events sender is greater than or equal to the redact level.
case sender1 == sender2:
// 2. The domain of the redaction events sender matches that of the original events sender.
default:
ignoreRedaction = true
return nil
}