-- 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
			end
			session.send(st.reply(stanza));
		else
			session.send(st.error_reply(stanza, "auth", "not-authorized"));
		end
	end
	return true;
end);
