File

plugins/muc/whois.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 9112:e66d932eeb58
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 valid_whois = {
	moderators = true;
	anyone = true;
};

local function get_whois(room)
	return room._data.whois or "moderators";
end

local function set_whois(room, whois)
	assert(valid_whois[whois], "Invalid whois value")
	if get_whois(room) == whois then return false; end
	room._data.whois = whois;
	return true;
end

module:hook("muc-disco#info", function(event)
	local whois = get_whois(event.room) ~= "anyone" and "muc_semianonymous" or "muc_nonanonymous";
	event.reply:tag("feature", { var = whois }):up();
end);

module:hook("muc-config-form", function(event)
	local whois = get_whois(event.room);
	table.insert(event.form, {
		name = 'muc#roomconfig_whois',
		type = 'list-single',
		label = 'Addresses (JIDs) of room occupants may be viewed by:',
		options = {
			{ value = 'moderators', label = 'Moderators only', default = whois == 'moderators' },
			{ value = 'anyone',     label = 'Anyone',          default = whois == 'anyone' }
		}
	});
end, 80-4);

module:hook("muc-config-submitted/muc#roomconfig_whois", function(event)
	if set_whois(event.room, event.value) then
		local code = (event.value == 'moderators') and "173" or "172";
		event.status_codes[code] = true;
	end
end);

-- Mask 'from' jid as occupant jid if room is anonymous
module:hook("muc-invite", function(event)
	local room, stanza = event.room, event.stanza;
	if get_whois(room) == "moderators" and room:get_default_role(room:get_affiliation(stanza.attr.to)) ~= "moderator" then
		local invite = stanza:get_child("x", "http://jabber.org/protocol/muc#user"):get_child("invite");
		local occupant_jid = room:get_occupant_jid(invite.attr.from);
		if occupant_jid ~= nil then -- FIXME: This will expose real jid if inviter is not in room
			invite.attr.from = occupant_jid;
		end
	end
end, 50);

return {
	get = get_whois;
	set = set_whois;
};