File

plugins/muc/lock.lib.lua @ 12181:783056b4e448 0.11 0.11.12

util.xml: Do not allow doctypes, comments or processing instructions Yes. This is as bad as it sounds. CVE pending. In Prosody itself, this only affects mod_websocket, which uses util.xml to parse the <open/> frame, thus allowing unauthenticated remote DoS using Billion Laughs. However, third-party modules using util.xml may also be affected by this. This commit installs handlers which disallow the use of doctype declarations and processing instructions without any escape hatch. It, by default, also introduces such a handler for comments, however, there is a way to enable comments nontheless. This is because util.xml is used to parse human-facing data, where comments are generally a desirable feature, and also because comments are generally harmless.
author Jonas Schäfer <jonas@wielicki.name>
date Mon, 10 Jan 2022 18:23:54 +0100
parent 8866:2c60ae791bdc
child 10450:c1edeb9fe337
line wrap: on
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-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
-- Copyright (C) 2014 Daurnimator
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

local st = require "util.stanza";

local lock_rooms = module:get_option_boolean("muc_room_locking", true);
local lock_room_timeout = module:get_option_number("muc_room_lock_timeout", 300);

local function lock(room)
	module:fire_event("muc-room-locked", {room = room;});
	room._data.locked = os.time() + lock_room_timeout;
end
local function unlock(room)
	module:fire_event("muc-room-unlocked", {room = room;});
	room._data.locked = nil;
end
local function is_locked(room)
	local ts = room._data.locked;
	if ts then
		if os.time() < ts then return true; end
		unlock(room);
	end
	return false;
end

if lock_rooms then
	module:hook("muc-room-pre-create", function(event)
		-- Older groupchat protocol doesn't lock
		if not event.stanza:get_child("x", "http://jabber.org/protocol/muc") then return end
		-- Lock room at creation
		local room = event.room;
		lock(room);
	end, 10);
end

-- Don't let users into room while it is locked
module:hook("muc-occupant-pre-join", function(event)
	if not event.is_new_room and is_locked(event.room) then -- Deny entry
		module:log("debug", "Room is locked, denying entry");
		event.origin.send(st.error_reply(event.stanza, "cancel", "item-not-found"));
		return true;
	end
end, -30);

-- When config is submitted; unlock the room
module:hook("muc-config-submitted", function(event)
	if is_locked(event.room) then
		unlock(event.room);
	end
end, -1);

return {
	lock = lock;
	unlock = unlock;
	is_locked = is_locked;
};