plugins/mod_roster.lua
author Jonas Schäfer <jonas@wielicki.name>
Mon, 10 Jan 2022 18:23:54 +0100
branch0.11
changeset 12185 783056b4e448
parent 8649 a267dfa9d81d
child 12104 0b14b541fd27
permissions -rw-r--r--
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.

-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--


local st = require "util.stanza"

local jid_split = require "util.jid".split;
local jid_prep = require "util.jid".prep;
local tonumber = tonumber;
local pairs = pairs;

local rm_load_roster = require "core.rostermanager".load_roster;
local rm_remove_from_roster = require "core.rostermanager".remove_from_roster;
local rm_add_to_roster = require "core.rostermanager".add_to_roster;
local rm_roster_push = require "core.rostermanager".roster_push;

module:add_feature("jabber:iq:roster");

local rosterver_stream_feature = st.stanza("ver", {xmlns="urn:xmpp:features:rosterver"});
module:hook("stream-features", function(event)
	local origin, features = event.origin, event.features;
	if origin.username then
		features:add_child(rosterver_stream_feature);
	end
end);

module:hook("iq/self/jabber:iq:roster:query", function(event)
	local session, stanza = event.origin, event.stanza;

	if stanza.attr.type == "get" then
		local roster = st.reply(stanza);

		local client_ver = tonumber(stanza.tags[1].attr.ver);
		local server_ver = tonumber(session.roster[false].version or 1);

		if not (client_ver and server_ver) or client_ver ~= server_ver then
			roster:query("jabber:iq:roster");
			-- Client does not support versioning, or has stale roster
			for jid, item in pairs(session.roster) do
				if jid then
					roster:tag("item", {
						jid = jid,
						subscription = item.subscription,
						ask = item.ask,
						name = item.name,
					});
					for group in pairs(item.groups) do
						roster:text_tag("group", group);
					end
					roster:up(); -- move out from item
				end
			end
			roster.tags[1].attr.ver = server_ver;
		end
		session.send(roster);
		session.interested = true; -- resource is interested in roster updates
	else -- stanza.attr.type == "set"
		local query = stanza.tags[1];
		if #query.tags == 1 and query.tags[1].name == "item"
				and query.tags[1].attr.xmlns == "jabber:iq:roster" and query.tags[1].attr.jid then
			local item = query.tags[1];
			local from_node, from_host = jid_split(stanza.attr.from);
			local jid = jid_prep(item.attr.jid);
			local node, host, resource = jid_split(jid);
			if not resource and host then
				if jid ~= from_node.."@"..from_host then
					if item.attr.subscription == "remove" then
						local roster = session.roster;
						local r_item = roster[jid];
						if r_item then
							module:fire_event("roster-item-removed", {
								username = node, jid = jid, item = r_item, origin = session, roster = roster,
							});
							local success, err_type, err_cond, err_msg = rm_remove_from_roster(session, jid);
							if success then
								session.send(st.reply(stanza));
								rm_roster_push(from_node, from_host, jid);
							else
								session.send(st.error_reply(stanza, err_type, err_cond, err_msg));
							end
						else
							session.send(st.error_reply(stanza, "modify", "item-not-found"));
						end
					else
						local r_item = {name = item.attr.name, groups = {}};
						if r_item.name == "" then r_item.name = nil; end
						if session.roster[jid] then
							r_item.subscription = session.roster[jid].subscription;
							r_item.ask = session.roster[jid].ask;
						else
							r_item.subscription = "none";
						end
						for group in item:childtags("group") do
							local text = group:get_text();
							if text then
								r_item.groups[text] = true;
							end
						end
						local success, err_type, err_cond, err_msg = rm_add_to_roster(session, jid, r_item);
						if success then
							-- Ok, send success
							session.send(st.reply(stanza));
							-- and push change to all resources
							rm_roster_push(from_node, from_host, jid);
						else
							-- Adding to roster failed
							session.send(st.error_reply(stanza, err_type, err_cond, err_msg));
						end
					end
				else
					-- Trying to add self to roster
					session.send(st.error_reply(stanza, "cancel", "not-allowed"));
				end
			else
				-- Invalid JID added to roster
				session.send(st.error_reply(stanza, "modify", "bad-request")); -- FIXME what's the correct error?
			end
		else
			-- Roster set didn't include a single item, or its name wasn't  'item'
			session.send(st.error_reply(stanza, "modify", "bad-request"));
		end
	end
	return true;
end);

module:hook_global("user-deleted", function(event)
	local username, host = event.username, event.host;
	local origin = event.origin or prosody.hosts[host];
	if host ~= module.host then return end
	local roster = rm_load_roster(username, host);
	for jid, item in pairs(roster) do
		if jid then
			module:fire_event("roster-item-removed", {
				username = username, jid = jid, item = item, roster = roster, origin = origin,
			});
		else
			for pending_jid in pairs(item.pending) do
				module:fire_event("roster-item-removed", {
					username = username, jid = pending_jid, roster = roster, origin = origin,
				});
			end
		end
	end
end, 300);