plugins/mod_tls.lua

-- Prosody IM
-- Copyright (C) 2008-2009 Matthew Wild
-- Copyright (C) 2008-2009 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 xmlns_stream = 'http://etherx.jabber.org/streams';
local xmlns_starttls = 'urn:ietf:params:xml:ns:xmpp-tls';

local secure_auth_only = module:get_option("c2s_require_encryption") or module:get_option("require_encryption");
local secure_s2s_only = module:get_option("s2s_require_encryption");

local global_ssl_ctx = prosody.global_ssl_ctx;

module:hook("stanza/urn:ietf:params:xml:ns:xmpp-tls:starttls", function(event)
	local origin = event.origin;
	if origin.conn.starttls and origin.type == "c2s_unauthed" or origin.type == "s2sin_unauthed" then
		(origin.sends2s or origin.send)(st.stanza("proceed", { xmlns = xmlns_starttls }));
		origin:reset_stream();
		local host = origin.to_host or origin.host;
		local ssl_ctx = host and hosts[host].ssl_ctx_in or global_ssl_ctx;
		origin.conn:starttls(ssl_ctx);
		origin.log("info", "TLS negotiation started for %s...", origin.type);
		origin.secure = false;
	else
		-- FIXME: What reply?
		origin.log("warn", "Attempt to start TLS, but TLS is not available on this %s connection", origin.type);
	end
	return true;
end);


local starttls_attr = { xmlns = xmlns_starttls };
module:add_event_hook("stream-features", 
		function (session, features)
			if not session.username and session.conn.starttls then
				features:tag("starttls", starttls_attr);
				if secure_auth_only then
					features:tag("required"):up():up();
				else
					features:up();
				end
			end
		end);

module:hook("s2s-stream-features", 
		function (data)
			local session, features = data.session, data.features;
			if session.to_host and session.type ~= "s2sin" and session.conn.starttls then
				features:tag("starttls", starttls_attr):up();
				if secure_s2s_only then
					features:tag("required"):up():up();
				else
					features:up();
				end
			end
		end);

-- For s2sout connections, start TLS if we can
module:hook_stanza(xmlns_stream, "features",
		function (session, stanza)
			module:log("debug", "Received features element");
			if session.conn.starttls and stanza:child_with_ns(xmlns_starttls) then
				module:log("%s is offering TLS, taking up the offer...", session.to_host);
				session.sends2s("<starttls xmlns='"..xmlns_starttls.."'/>");
				return true;
			end
		end, 500);

module:hook_stanza(xmlns_starttls, "proceed",
		function (session, stanza)
			module:log("debug", "Proceeding with TLS on s2sout...");
			session:reset_stream();
			local ssl_ctx = session.from_host and hosts[session.from_host].ssl_ctx or global_ssl_ctx;
			session.conn:starttls(ssl_ctx, true);
			session.secure = false;
			return true;
		end);