104 lines
3.3 KiB
Go
104 lines
3.3 KiB
Go
// 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 auth
|
|
|
|
import (
|
|
"encoding/json"
|
|
|
|
"github.com/matrix-org/gomatrixserverlib"
|
|
)
|
|
|
|
// TODO: This logic should live in gomatrixserverlib
|
|
|
|
// IsServerAllowed returns true if the server is allowed to see events in the room
|
|
// at this particular state. This function implements https://matrix.org/docs/spec/client_server/r0.6.0#id87
|
|
func IsServerAllowed(
|
|
serverName gomatrixserverlib.ServerName,
|
|
serverCurrentlyInRoom bool,
|
|
authEvents []*gomatrixserverlib.Event,
|
|
) bool {
|
|
historyVisibility := HistoryVisibilityForRoom(authEvents)
|
|
|
|
// 1. If the history_visibility was set to world_readable, allow.
|
|
if historyVisibility == "world_readable" {
|
|
return true
|
|
}
|
|
// 2. If the user's membership was join, allow.
|
|
joinedUserExists := IsAnyUserOnServerWithMembership(serverName, authEvents, gomatrixserverlib.Join)
|
|
if joinedUserExists {
|
|
return true
|
|
}
|
|
// 3. If history_visibility was set to shared, and the user joined the room at any point after the event was sent, allow.
|
|
if historyVisibility == "shared" && serverCurrentlyInRoom {
|
|
return true
|
|
}
|
|
// 4. If the user's membership was invite, and the history_visibility was set to invited, allow.
|
|
invitedUserExists := IsAnyUserOnServerWithMembership(serverName, authEvents, gomatrixserverlib.Invite)
|
|
if invitedUserExists && historyVisibility == "invited" {
|
|
return true
|
|
}
|
|
|
|
// 5. Otherwise, deny.
|
|
return false
|
|
}
|
|
|
|
func HistoryVisibilityForRoom(authEvents []*gomatrixserverlib.Event) string {
|
|
// https://matrix.org/docs/spec/client_server/r0.6.0#id87
|
|
// By default if no history_visibility is set, or if the value is not understood, the visibility is assumed to be shared.
|
|
visibility := "shared"
|
|
knownStates := []string{"invited", "joined", "shared", "world_readable"}
|
|
for _, ev := range authEvents {
|
|
if ev.Type() != gomatrixserverlib.MRoomHistoryVisibility {
|
|
continue
|
|
}
|
|
// TODO: This should be HistoryVisibilityContent to match things like 'MemberContent'. Do this when moving to GMSL
|
|
content := struct {
|
|
HistoryVisibility string `json:"history_visibility"`
|
|
}{}
|
|
if err := json.Unmarshal(ev.Content(), &content); err != nil {
|
|
break // value is not understood
|
|
}
|
|
for _, s := range knownStates {
|
|
if s == content.HistoryVisibility {
|
|
visibility = s
|
|
break
|
|
}
|
|
}
|
|
}
|
|
return visibility
|
|
}
|
|
|
|
func IsAnyUserOnServerWithMembership(serverName gomatrixserverlib.ServerName, authEvents []*gomatrixserverlib.Event, wantMembership string) bool {
|
|
for _, ev := range authEvents {
|
|
membership, err := ev.Membership()
|
|
if err != nil || membership != wantMembership {
|
|
continue
|
|
}
|
|
|
|
stateKey := ev.StateKey()
|
|
if stateKey == nil {
|
|
continue
|
|
}
|
|
|
|
_, domain, err := gomatrixserverlib.SplitID('@', *stateKey)
|
|
if err != nil {
|
|
continue
|
|
}
|
|
|
|
if domain == serverName {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|