dendrite/clientapi/routing/redaction.go
2023-09-27 08:27:08 +02:00

208 lines
6.2 KiB
Go

// Copyright 2020 The Matrix.org Foundation C.I.C.
//
// 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 routing
import (
"context"
"errors"
"net/http"
"time"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/gomatrixserverlib/spec"
"github.com/matrix-org/util"
"github.com/matrix-org/dendrite/clientapi/httputil"
"github.com/matrix-org/dendrite/internal/eventutil"
"github.com/matrix-org/dendrite/internal/transactions"
roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/roomserver/types"
"github.com/matrix-org/dendrite/setup/config"
userapi "github.com/matrix-org/dendrite/userapi/api"
)
type redactionContent struct {
Reason string `json:"reason"`
Redacts string `json:"redacts"`
}
type redactionResponse struct {
EventID string `json:"event_id"`
}
func SendRedaction(
req *http.Request, device *userapi.Device, roomID, eventID string, cfg *config.ClientAPI,
rsAPI roomserverAPI.ClientRoomserverAPI,
txnID *string,
txnCache *transactions.Cache,
) util.JSONResponse {
deviceUserID, userIDErr := spec.NewUserID(device.UserID, true)
if userIDErr != nil {
return util.JSONResponse{
Code: http.StatusForbidden,
JSON: spec.Forbidden("userID doesn't have power level to redact"),
}
}
validRoomID, err := spec.NewRoomID(roomID)
if err != nil {
return util.JSONResponse{
Code: http.StatusBadRequest,
JSON: spec.BadJSON("RoomID is invalid"),
}
}
senderID, queryErr := rsAPI.QuerySenderIDForUser(req.Context(), *validRoomID, *deviceUserID)
if queryErr != nil {
return util.JSONResponse{
Code: http.StatusForbidden,
JSON: spec.Forbidden("userID doesn't have power level to redact"),
}
}
resErr := checkMemberInRoom(req.Context(), rsAPI, *deviceUserID, roomID)
if resErr != nil {
return *resErr
}
// if user is member of room, and sender ID is nil, then this user doesn't have a pseudo ID for some reason,
// which is unexpected.
if senderID == nil {
util.GetLogger(req.Context()).WithField("userID", *deviceUserID).WithField("roomID", roomID).Error("missing sender ID for user, despite having membership")
return util.JSONResponse{
Code: http.StatusInternalServerError,
JSON: spec.Unknown("internal server error"),
}
}
if txnID != nil {
// Try to fetch response from transactionsCache
if res, ok := txnCache.FetchTransaction(device.AccessToken, *txnID, req.URL); ok {
return *res
}
}
ev := roomserverAPI.GetEvent(req.Context(), rsAPI, roomID, eventID)
if ev == nil {
return util.JSONResponse{
Code: 400,
JSON: spec.NotFound("unknown event ID"), // TODO: is it ok to leak existence?
}
}
if ev.RoomID().String() != roomID {
return util.JSONResponse{
Code: 400,
JSON: spec.NotFound("cannot redact event in another room"),
}
}
// "Users may redact their own events, and any user with a power level greater than or equal
// to the redact power level of the room may redact events there"
// https://matrix.org/docs/spec/client_server/r0.6.1#put-matrix-client-r0-rooms-roomid-redact-eventid-txnid
allowedToRedact := ev.SenderID() == *senderID
if !allowedToRedact {
plEvent := roomserverAPI.GetStateEvent(req.Context(), rsAPI, roomID, gomatrixserverlib.StateKeyTuple{
EventType: spec.MRoomPowerLevels,
StateKey: "",
})
if plEvent == nil {
return util.JSONResponse{
Code: 403,
JSON: spec.Forbidden("You don't have permission to redact this event, no power_levels event in this room."),
}
}
pl, plErr := plEvent.PowerLevels()
if plErr != nil {
return util.JSONResponse{
Code: 403,
JSON: spec.Forbidden(
"You don't have permission to redact this event, the power_levels event for this room is malformed so auth checks cannot be performed.",
),
}
}
allowedToRedact = pl.UserLevel(*senderID) >= pl.Redact
}
if !allowedToRedact {
return util.JSONResponse{
Code: 403,
JSON: spec.Forbidden("You don't have permission to redact this event, power level too low."),
}
}
var r redactionContent
resErr = httputil.UnmarshalJSONRequest(req, &r)
if resErr != nil {
return *resErr
}
// create the new event and set all the fields we can
proto := gomatrixserverlib.ProtoEvent{
SenderID: string(*senderID),
RoomID: roomID,
Type: spec.MRoomRedaction,
Redacts: eventID,
}
// Room version 11 expects the "redacts" field on the
// content field, so add it here as well
r.Redacts = eventID
err = proto.SetContent(r)
if err != nil {
util.GetLogger(req.Context()).WithError(err).Error("proto.SetContent failed")
return util.JSONResponse{
Code: http.StatusInternalServerError,
JSON: spec.InternalServerError{},
}
}
identity, err := rsAPI.SigningIdentityFor(req.Context(), *validRoomID, *deviceUserID)
if err != nil {
return util.JSONResponse{
Code: http.StatusInternalServerError,
JSON: spec.InternalServerError{},
}
}
var queryRes roomserverAPI.QueryLatestEventsAndStateResponse
e, err := eventutil.QueryAndBuildEvent(req.Context(), &proto, &identity, time.Now(), rsAPI, &queryRes)
if errors.Is(err, eventutil.ErrRoomNoExists{}) {
return util.JSONResponse{
Code: http.StatusNotFound,
JSON: spec.NotFound("Room does not exist"),
}
}
domain := device.UserDomain()
if err = roomserverAPI.SendEvents(context.Background(), rsAPI, roomserverAPI.KindNew, []*types.HeaderedEvent{e}, device.UserDomain(), domain, domain, nil, false); err != nil {
util.GetLogger(req.Context()).WithError(err).Errorf("failed to SendEvents")
return util.JSONResponse{
Code: http.StatusInternalServerError,
JSON: spec.InternalServerError{},
}
}
res := util.JSONResponse{
Code: 200,
JSON: redactionResponse{
EventID: e.EventID(),
},
}
// Add response to transactionsCache
if txnID != nil {
txnCache.AddTransaction(device.AccessToken, *txnID, req.URL, &res)
}
return res
}