plugins/mod_tls.lua

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-- Prosody IM
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-- Copyright (C) 2008-2010 Matthew Wild
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-- Copyright (C) 2008-2010 Waqas Hussain
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-- 
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-- This project is MIT/X11 licensed. Please see the
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-- COPYING file in the source package for more information.
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--
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local config = require "core.configmanager";
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local create_context = require "core.certmanager".create_context;
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local st = require "util.stanza";
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local secure_auth_only = module:get_option("c2s_require_encryption") or module:get_option("require_encryption");
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local secure_s2s_only = module:get_option("s2s_require_encryption");
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local allow_s2s_tls = module:get_option("s2s_allow_encryption") ~= false;
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local xmlns_starttls = 'urn:ietf:params:xml:ns:xmpp-tls';
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local starttls_attr = { xmlns = xmlns_starttls };
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local starttls_proceed = st.stanza("proceed", starttls_attr);
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local starttls_failure = st.stanza("failure", starttls_attr);
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local c2s_feature = st.stanza("starttls", starttls_attr);
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local s2s_feature = st.stanza("starttls", starttls_attr);
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if secure_auth_only then c2s_feature:tag("required"):up(); end
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if secure_s2s_only then s2s_feature:tag("required"):up(); end
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local global_ssl_ctx = prosody.global_ssl_ctx;
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local host = hosts[module.host];
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local function can_do_tls(session)
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	if session.type == "c2s_unauthed" then
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		return session.conn.starttls and host.ssl_ctx_in;
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	elseif session.type == "s2sin_unauthed" and allow_s2s_tls then
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		return session.conn.starttls and host.ssl_ctx_in;
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	elseif session.direction == "outgoing" and allow_s2s_tls then
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		return session.conn.starttls and host.ssl_ctx;
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	end
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	return false;
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end
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-- Hook <starttls/>
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module:hook("stanza/urn:ietf:params:xml:ns:xmpp-tls:starttls", function(event)
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	local origin = event.origin;
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	if can_do_tls(origin) then
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		(origin.sends2s or origin.send)(starttls_proceed);
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		origin:reset_stream();
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		local host = origin.to_host or origin.host;
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		local ssl_ctx = host and hosts[host].ssl_ctx_in or global_ssl_ctx;
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		origin.conn:starttls(ssl_ctx);
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		origin.log("info", "TLS negotiation started for %s...", origin.type);
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		origin.secure = false;
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	else
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		origin.log("warn", "Attempt to start TLS, but TLS is not available on this %s connection", origin.type);
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		(origin.sends2s or origin.send)(starttls_failure);
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		origin:close();
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	end
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	return true;
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end);
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-- Advertize stream feature
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module:hook("stream-features", function(event)
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	local origin, features = event.origin, event.features;
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	if can_do_tls(origin) then
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		features:add_child(c2s_feature);
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	end
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end);
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module:hook("s2s-stream-features", function(event)
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	local origin, features = event.origin, event.features;
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	if can_do_tls(origin) then
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		features:add_child(s2s_feature);
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	end
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end);
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-- For s2sout connections, start TLS if we can
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module:hook_stanza("http://etherx.jabber.org/streams", "features", function (session, stanza)
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	module:log("debug", "Received features element");
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	if can_do_tls(session) and stanza:child_with_ns(xmlns_starttls) then
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		module:log("%s is offering TLS, taking up the offer...", session.to_host);
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		session.sends2s("<starttls xmlns='"..xmlns_starttls.."'/>");
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		return true;
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	end
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end, 500);
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module:hook_stanza(xmlns_starttls, "proceed", function (session, stanza)
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	module:log("debug", "Proceeding with TLS on s2sout...");
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	session:reset_stream();
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	local ssl_ctx = session.from_host and hosts[session.from_host].ssl_ctx or global_ssl_ctx;
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	session.conn:starttls(ssl_ctx);
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	session.secure = false;
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	return true;
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end);
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function module.load()
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	local global_ssl_config = config.get("*", "core", "ssl");
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	local ssl_config = config.get(module.host, "core", "ssl");
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	local base_host = module.host:match("%.(.*)");
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	if ssl_config == global_ssl_config and hosts[base_host] then
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		ssl_config = config.get(base_host, "core", "ssl");
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	end
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	host.ssl_ctx = create_context(host.host, "client", ssl_config); -- for outgoing connections
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	host.ssl_ctx_in = create_context(host.host, "server", ssl_config); -- for incoming connections
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end
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function module.unload()
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	host.ssl_ctx = nil;
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	host.ssl_ctx_in = nil;
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end