plugins/mod_tls.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2008-2010 Matthew Wild
   3 -- Copyright (C) 2008-2010 Waqas Hussain
   4 --
   5 -- This project is MIT/X11 licensed. Please see the
   6 -- COPYING file in the source package for more information.
   7 --
   8
   9 local config = require "core.configmanager";
  10 local create_context = require "core.certmanager".create_context;
  11 local st = require "util.stanza";
  12
  13 local secure_auth_only = module:get_option("c2s_require_encryption") or module:get_option("require_encryption");
  14 local secure_s2s_only = module:get_option("s2s_require_encryption");
  15 local allow_s2s_tls = module:get_option("s2s_allow_encryption") ~= false;
  16
  17 local xmlns_starttls = 'urn:ietf:params:xml:ns:xmpp-tls';
  18 local starttls_attr = { xmlns = xmlns_starttls };
  19 local starttls_proceed = st.stanza("proceed", starttls_attr);
  20 local starttls_failure = st.stanza("failure", starttls_attr);
  21 local c2s_feature = st.stanza("starttls", starttls_attr);
  22 local s2s_feature = st.stanza("starttls", starttls_attr);
  23 if secure_auth_only then c2s_feature:tag("required"):up(); end
  24 if secure_s2s_only then s2s_feature:tag("required"):up(); end
  25
  26 local hosts = prosody.hosts;
  27 local host = hosts[module.host];
  28
  29 local ssl_ctx_c2s, ssl_ctx_s2sout, ssl_ctx_s2sin;
  30 do
  31         local function get_ssl_cfg(typ)
  32                 local cfg_key = (typ and typ.."_" or "").."ssl";
  33                 local ssl_config = config.rawget(module.host, cfg_key);
  34                 if not ssl_config then
  35                         local base_host = module.host:match("%.(.*)");
  36                         ssl_config = config.get(base_host, cfg_key);
  37                 end
  38                 return ssl_config or typ and get_ssl_cfg();
  39         end
  40
  41         local ssl_config, err = get_ssl_cfg("c2s");
  42         ssl_ctx_c2s, err = create_context(host.host, "server", ssl_config); -- for incoming client connections
  43         if err then module:log("error", "Error creating context for c2s: %s", err); end
  44
  45         ssl_config = get_ssl_cfg("s2s");
  46         ssl_ctx_s2sin, err = create_context(host.host, "server", ssl_config); -- for incoming server connections
  47         ssl_ctx_s2sout = create_context(host.host, "client", ssl_config); -- for outgoing server connections
  48         if err then module:log("error", "Error creating context for s2s: %s", err); end -- Both would have the same issue
  49 end
  50
  51 local function can_do_tls(session)
  52         if not session.conn.starttls then
  53                 return false;
  54         elseif session.ssl_ctx then
  55                 return true;
  56         end
  57         if session.type == "c2s_unauthed" then
  58                 module:log("debug", "session.ssl_ctx = ssl_ctx_c2s;")
  59                 session.ssl_ctx = ssl_ctx_c2s;
  60         elseif session.type == "s2sin_unauthed" and allow_s2s_tls then
  61                 session.ssl_ctx = ssl_ctx_s2sin;
  62         elseif session.direction == "outgoing" and allow_s2s_tls then
  63                 session.ssl_ctx = ssl_ctx_s2sout;
  64         else
  65                 return false;
  66         end
  67         return session.ssl_ctx;
  68 end
  69
  70 -- Hook <starttls/>
  71 module:hook("stanza/urn:ietf:params:xml:ns:xmpp-tls:starttls", function(event)
  72         local origin = event.origin;
  73         if can_do_tls(origin) then
  74                 (origin.sends2s or origin.send)(starttls_proceed);
  75                 origin:reset_stream();
  76                 origin.conn:starttls(origin.ssl_ctx);
  77                 origin.log("debug", "TLS negotiation started for %s...", origin.type);
  78                 origin.secure = false;
  79         else
  80                 origin.log("warn", "Attempt to start TLS, but TLS is not available on this %s connection", origin.type);
  81                 (origin.sends2s or origin.send)(starttls_failure);
  82                 origin:close();
  83         end
  84         return true;
  85 end);
  86
  87 -- Advertize stream feature
  88 module:hook("stream-features", function(event)
  89         local origin, features = event.origin, event.features;
  90         if can_do_tls(origin) then
  91                 features:add_child(c2s_feature);
  92         end
  93 end);
  94 module:hook("s2s-stream-features", function(event)
  95         local origin, features = event.origin, event.features;
  96         if can_do_tls(origin) then
  97                 features:add_child(s2s_feature);
  98         end
  99 end);
 100
 101 -- For s2sout connections, start TLS if we can
 102 module:hook_stanza("http://etherx.jabber.org/streams", "features", function (session, stanza)
 103         module:log("debug", "Received features element");
 104         if can_do_tls(session) and stanza:child_with_ns(xmlns_starttls) then
 105                 module:log("debug", "%s is offering TLS, taking up the offer...", session.to_host);
 106                 session.sends2s("<starttls xmlns='"..xmlns_starttls.."'/>");
 107                 return true;
 108         end
 109 end, 500);
 110
 111 module:hook_stanza(xmlns_starttls, "proceed", function (session, stanza)
 112         module:log("debug", "Proceeding with TLS on s2sout...");
 113         session:reset_stream();
 114         session.conn:starttls(session.ssl_ctx);
 115         session.secure = false;
 116         return true;
 117 end);