Stronger checks for /send_join (#2604)

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Neil Alexander 2022-08-02 10:22:17 +01:00 committed by GitHub
parent 6b6b420b9f
commit eab87ef07d
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@ -202,6 +202,14 @@ func SendJoin(
}
}
// Check that the event is from the server sending the request.
if event.Origin() != request.Origin() {
return util.JSONResponse{
Code: http.StatusForbidden,
JSON: jsonerror.Forbidden("The join must be sent by the server it originated on"),
}
}
// Check that a state key is provided.
if event.StateKey() == nil || event.StateKeyEquals("") {
return util.JSONResponse{
@ -216,6 +224,22 @@ func SendJoin(
}
}
// 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 domain gomatrixserverlib.ServerName
if _, domain, err = gomatrixserverlib.SplitID('@', event.Sender()); err != nil {
return util.JSONResponse{
Code: http.StatusForbidden,
JSON: jsonerror.Forbidden("The sender of the join is invalid"),
}
} else if domain != request.Origin() {
return util.JSONResponse{
Code: http.StatusForbidden,
JSON: jsonerror.Forbidden("The sender of the join must belong to the origin server"),
}
}
// Check that the room ID is correct.
if event.RoomID() != roomID {
return util.JSONResponse{
@ -242,14 +266,6 @@ func SendJoin(
}
}
// Check that the event is from the server sending the request.
if event.Origin() != request.Origin() {
return util.JSONResponse{
Code: http.StatusForbidden,
JSON: jsonerror.Forbidden("The join must be sent by the server it originated on"),
}
}
// Check that this is in fact a join event
membership, err := event.Membership()
if err != nil {