File

plugins/mod_offline.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 8030:bd3527198308
child 10242:7e5d2a6c9390
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-- Prosody IM
-- Copyright (C) 2008-2009 Matthew Wild
-- Copyright (C) 2008-2009 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--


local datetime = require "util.datetime";
local jid_split = require "util.jid".split;

local offline_messages = module:open_store("offline", "archive");

module:add_feature("msgoffline");

module:hook("message/offline/handle", function(event)
	local origin, stanza = event.origin, event.stanza;
	local to = stanza.attr.to;
	local node;
	if to then
		node = jid_split(to)
	else
		node = origin.username;
	end

	return offline_messages:append(node, nil, stanza, os.time(), "");
end, -1);

module:hook("message/offline/broadcast", function(event)
	local origin = event.origin;

	local node, host = origin.username, origin.host;

	local data = offline_messages:find(node);
	if not data then return true; end
	for _, stanza, when in data do
		stanza:tag("delay", {xmlns = "urn:xmpp:delay", from = host, stamp = datetime.datetime(when)}):up(); -- XEP-0203
		origin.send(stanza);
	end
	offline_messages:delete(node);
	return true;
end, -1);