File

plugins/mod_legacyauth.lua @ 11665:148075532021

net.server_epoll: Prevent stack overflow of opportunistic writes net.http.files serving a big enough file on a fast enough connection with opportunistic_writes enabled could trigger a stack overflow through repeatedly serving more data that immediately gets sent, draining the buffer and triggering more data to be sent. This also blocked the server on a single task until completion or an error. This change prevents nested opportunistic writes, which should prevent the stack overflow, at the cost of reduced download speed, but this is unlikely to be noticeable outside of Gbit networks. Speed at the cost of blocking other processing is not worth it, especially with the risk of stack overflow.
author Kim Alvefur <zash@zash.se>
date Sun, 11 Jul 2021 09:39:21 +0200
parent 10557:e1cb869e2f6c
child 12328:a80314101bc6
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-- 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 t_concat = table.concat;

local secure_auth_only = module:get_option("c2s_require_encryption",
	module:get_option("require_encryption"))
	or not(module:get_option("allow_unencrypted_plain_auth"));

local sessionmanager = require "core.sessionmanager";
local usermanager = require "core.usermanager";
local nodeprep = require "util.encodings".stringprep.nodeprep;
local resourceprep = require "util.encodings".stringprep.resourceprep;

module:add_feature("jabber:iq:auth");
module:hook("stream-features", function(event)
	local origin, features = event.origin, event.features;
	if secure_auth_only and not origin.secure then
		-- Sorry, not offering to insecure streams!
		return;
	elseif not origin.username then
		features:tag("auth", {xmlns='http://jabber.org/features/iq-auth'}):up();
	end
end);

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

	if session.type ~= "c2s_unauthed" then
		(session.sends2s or session.send)(st.error_reply(stanza, "cancel", "service-unavailable",
			"Legacy authentication is only allowed for unauthenticated client connections."));
		return true;
	end

	if secure_auth_only and not session.secure then
		session.send(st.error_reply(stanza, "modify", "not-acceptable", "Encryption (SSL or TLS) is required to connect to this server"));
		return true;
	end

	local query = stanza.tags[1];
	local username = query:get_child("username");
	local password = query:get_child("password");
	local resource = query:get_child("resource");
	if not (username and password and resource) then
		local reply = st.reply(stanza);
		session.send(reply:query("jabber:iq:auth")
			:tag("username"):up()
			:tag("password"):up()
			:tag("resource"):up());
	else
		username, password, resource = t_concat(username), t_concat(password), t_concat(resource);
		username = nodeprep(username);
		resource = resourceprep(resource)
		if not (username and resource) then
			session.send(st.error_reply(stanza, "modify", "bad-request"));
			return true;
		end
		if usermanager.test_password(username, session.host, password) then
			-- Authentication successful!
			local success, err = sessionmanager.make_authenticated(session, username);
			if success then
				local err_type, err_msg;
				success, err_type, err, err_msg = sessionmanager.bind_resource(session, resource);
				if not success then
					session.send(st.error_reply(stanza, err_type, err, err_msg));
					session.username, session.type = nil, "c2s_unauthed"; -- FIXME should this be placed in sessionmanager?
					return true;
				elseif resource ~= session.resource then -- server changed resource, not supported by legacy auth
					session.send(st.error_reply(stanza, "cancel", "conflict", "The requested resource could not be assigned to this session."));
					session:close(); -- FIXME undo resource bind and auth instead of closing the session?
					return true;
				end
				session.send(st.reply(stanza));
			else
				session.send(st.error_reply(stanza, "auth", "not-authorized", err));
			end
		else
			session.send(st.error_reply(stanza, "auth", "not-authorized"));
		end
	end
	return true;
end);