+
−--
+
−-- mod_saslauth_muc
+
−--   This module implements http://xmpp.org/extensions/inbox/remote-auth.html for Prosody's MUC component
+
−--
+
−-- In your config:
+
−--   Component "conference.example.com" "muc"
+
−--       modules_enabled = { "saslauth_muc" };
+
−--
+
−--
+
−
+
−local timeout = 60; -- SASL timeout in seconds
+
−
+
−-- various imports
+
−local new_sasl = require "util.sasl".new;
+
−local st = require "util.stanza";
+
−local timer = require "util.timer";
+
−
+
−local jid_bare = require "util.jid".bare;
+
−local jid_prep = require "util.jid".prep;
+
−local base64 = require "util.encodings".base64;
+
−
+
−local hosts = hosts;
+
−local module = module;
+
−local pairs, next = pairs, next;
+
−local os_time = os.time;
+
−
+
−local muc_password = module:require("muc/password");
+
−
+
−-- SASL sessions management
+
−local _rooms = {}; -- SASL data
+
−local function get_handler_for(room, jid) return _rooms[room] and _rooms[room][jid]; end
+
−local function remove_handler_for(room, jid) if _rooms[room] then _rooms[room][jid] = nil; end end
+
−local function create_handler_for(room_jid, jid)
+
−	_rooms[room_jid] = _rooms[room_jid] or {};
+
−	_rooms[room_jid][jid] = new_sasl(module.host, { plain = function(sasl, username, realm)
+
−		local muc = hosts[module.host].modules.muc;
+
−		local room = muc and muc.get_room_from_jid(room_jid);
+
−		local password = room and muc_password.get(room);
+
−		local ret = password and true or nil;
+
−		return password or "", ret;
+
−	end });
+
−	_rooms[room_jid][jid].timeout = os_time() + timeout;
+
−	return _rooms[room_jid][jid];
+
−end
+
−
+
−-- Timer to clear SASL sessions
+
−timer.add_task(timeout, function(now)
+
−	for room, handlers in pairs(_rooms) do
+
−		for jid, handler in pairs(handlers) do
+
−			if handler.timeout <= now then handlers[jid] = nil; end
+
−		end
+
−		if next(handlers) == nil then _rooms[room] = nil; end
+
−	end
+
−	return timeout;
+
−end);
+
−function module.unload()
+
−	timeout = nil; -- stop timer on unload
+
−end
+
−
+
−-- Stanza handlers
+
−-- Don't allow anyone to join room unless they provide the password
+
−module:hook("muc-occupant-pre-join", function(event)
+
−	local room, stanza = event.room, event.stanza;
+
−	local room_password = muc_password.get(room);
+
−	if room_password then -- room has a password
+
−		local x = stanza:get_child("x", "http://jabber.org/protocol/muc");
+
−		local password = x and x:get_child_text("password", "http://jabber.org/protocol/muc");
+
−		if not password then -- no password sent
+
−			local sasl_handler = get_handler_for(jid_bare(stanza.attr.to), stanza.attr.from);
+
−			if x and sasl_handler and sasl_handler.authorized then -- if already passed SASL
+
−				x:reset():tag("password", { xmlns = "http://jabber.org/protocol/muc" }):text(room_password);
+
−			else
+
−				event.origin.send(st.error_reply(stanza, "auth", "not-authorized")
+
−					:tag("sasl-required", { xmlns = "urn:xmpp:errors" }));
+
−				return true;
+
−			end
+
−		end
+
−	end
+
−end, -18);
+
−
+
−module:hook("iq-get/bare/urn:ietf:params:xml:ns:xmpp-sasl:mechanisms", function(event)
+
−	local origin, stanza = event.origin, event.stanza;
+
−
+
−	local reply = st.reply(stanza):tag("mechanisms", { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' });
+
−	for mechanism in pairs(create_handler_for(stanza.attr.to, true):mechanisms()) do
+
−		reply:tag("mechanism"):text(mechanism):up();
+
−	end
+
−	origin.send(reply:up());
+
−	return true;
+
−end);
+
−
+
−local function build_reply(stanza, status, ret, err_msg)
+
−	local reply = st.stanza(status, {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"});
+
−	if status == "challenge" then
+
−		reply:text(base64.encode(ret or ""));
+
−	elseif status == "failure" then
+
−		reply:tag(ret):up();
+
−		if err_msg then reply:tag("text"):text(err_msg); end
+
−	elseif status == "success" then
+
−		reply:text(base64.encode(ret or ""));
+
−	else
+
−		module:log("error", "Unknown sasl status: %s", status);
+
−	end
+
−	return st.reply(stanza):add_child(reply);
+
−end
+
−local function handle_status(stanza, status)
+
−	if status == "failure" then
+
−		remove_handler_for(stanza.attr.to, stanza.attr.from);
+
−	elseif status == "success" then
+
−		get_handler_for(stanza.attr.to, stanza.attr.from).authorized = true;
+
−	end
+
−end
+
−local function sasl_process_cdata(session, stanza)
+
−	local text = stanza.tags[1][1];
+
−	if text then
+
−		text = base64.decode(text);
+
−		if not text then
+
−			remove_handler_for(stanza.attr.to, stanza.attr.from);
+
−			session.send(build_reply(stanza, "failure", "incorrect-encoding"));
+
−			return true;
+
−		end
+
−	end
+
−	local status, ret, err_msg = get_handler_for(stanza.attr.to, stanza.attr.from):process(text);
+
−	handle_status(stanza, status);
+
−	local s = build_reply(stanza, status, ret, err_msg);
+
−	session.send(s);
+
−	return true;
+
−end
+
−
+
−module:hook("iq-set/bare/urn:ietf:params:xml:ns:xmpp-sasl:auth", function(event)
+
−	local session, stanza = event.origin, event.stanza;
+
−
+
−	if not create_handler_for(stanza.attr.to, stanza.attr.from):select(stanza.tags[1].attr.mechanism) then
+
−		remove_handler_for(stanza.attr.to, stanza.attr.from);
+
−		session.send(build_reply(stanza, "failure", "invalid-mechanism"));
+
−		return true;
+
−	end
+
−	return sasl_process_cdata(session, stanza);
+
−end);
+
−module:hook("iq-set/bare/urn:ietf:params:xml:ns:xmpp-sasl:response", function(event)
+
−	local session, stanza = event.origin, event.stanza;
+
−	if not get_handler_for(stanza.attr.to, stanza.attr.from) then
+
−		session.send(build_reply(stanza, "failure", "not-authorized", "Out of order SASL element"));
+
−		return true;
+
−	end
+
−	return sasl_process_cdata(session, event.stanza);
+
−end);
+
−module:hook("iq-set/bare/urn:ietf:params:xml:ns:xmpp-sasl:abort", function(event)
+
−	local session, stanza = event.origin, event.stanza;
+
−	remove_handler_for(stanza.attr.to, stanza.attr.from);
+
−	session.send(build_reply(stanza, "failure", "aborted"));
+
−	return true;
+
−end);