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 c2s_require_encryption = module:get_option("c2s_require_encryption") or module:get_option("require_encryption");
  14 local s2s_require_encryption = module:get_option("s2s_require_encryption");
  15 local allow_s2s_tls = module:get_option("s2s_allow_encryption") ~= false;
  16 local s2s_secure_auth = module:get_option("s2s_secure_auth");
  17
  18 if s2s_secure_auth and s2s_require_encryption == false then
  19         module:log("warn", "s2s_secure_auth implies s2s_require_encryption, but s2s_require_encryption is set to false");
  20         s2s_require_encryption = true;
  21 end
  22
  23 local xmlns_starttls = 'urn:ietf:params:xml:ns:xmpp-tls';
  24 local starttls_attr = { xmlns = xmlns_starttls };
  25 local starttls_proceed = st.stanza("proceed", starttls_attr);
  26 local starttls_failure = st.stanza("failure", starttls_attr);
  27 local c2s_feature = st.stanza("starttls", starttls_attr);
  28 local s2s_feature = st.stanza("starttls", starttls_attr);
  29 if c2s_require_encryption then c2s_feature:tag("required"):up(); end
  30 if s2s_require_encryption then s2s_feature:tag("required"):up(); end
  31
  32 local hosts = prosody.hosts;
  33 local host = hosts[module.host];
  34
  35 local ssl_ctx_c2s, ssl_ctx_s2sout, ssl_ctx_s2sin;
  36 do
  37         local function get_ssl_cfg(typ)
  38                 local cfg_key = (typ and typ.."_" or "").."ssl";
  39                 local ssl_config = config.rawget(module.host, cfg_key);
  40                 if not ssl_config then
  41                         local base_host = module.host:match("%.(.*)");
  42                         ssl_config = config.get(base_host, cfg_key);
  43                 end
  44                 return ssl_config or typ and get_ssl_cfg();
  45         end
  46
  47         local ssl_config, err = get_ssl_cfg("c2s");
  48         ssl_ctx_c2s, err = create_context(host.host, "server", ssl_config); -- for incoming client connections
  49         if err then module:log("error", "Error creating context for c2s: %s", err); end
  50
  51         ssl_config = get_ssl_cfg("s2s");
  52         ssl_ctx_s2sin, err = create_context(host.host, "server", ssl_config); -- for incoming server connections
  53         ssl_ctx_s2sout = create_context(host.host, "client", ssl_config); -- for outgoing server connections
  54         if err then module:log("error", "Error creating context for s2s: %s", err); end -- Both would have the same issue
  55 end
  56
  57 local function can_do_tls(session)
  58         if not session.conn.starttls then
  59                 return false;
  60         elseif session.ssl_ctx then
  61                 return true;
  62         end
  63         if session.type == "c2s_unauthed" then
  64                 session.ssl_ctx = ssl_ctx_c2s;
  65         elseif session.type == "s2sin_unauthed" and allow_s2s_tls then
  66                 session.ssl_ctx = ssl_ctx_s2sin;
  67         elseif session.direction == "outgoing" and allow_s2s_tls then
  68                 session.ssl_ctx = ssl_ctx_s2sout;
  69         else
  70                 return false;
  71         end
  72         return session.ssl_ctx;
  73 end
  74
  75 -- Hook <starttls/>
  76 module:hook("stanza/urn:ietf:params:xml:ns:xmpp-tls:starttls", function(event)
  77         local origin = event.origin;
  78         if can_do_tls(origin) then
  79                 (origin.sends2s or origin.send)(starttls_proceed);
  80                 origin:reset_stream();
  81                 origin.conn:starttls(origin.ssl_ctx);
  82                 origin.log("debug", "TLS negotiation started for %s...", origin.type);
  83                 origin.secure = false;
  84         else
  85                 origin.log("warn", "Attempt to start TLS, but TLS is not available on this %s connection", origin.type);
  86                 (origin.sends2s or origin.send)(starttls_failure);
  87                 origin:close();
  88         end
  89         return true;
  90 end);
  91
  92 -- Advertize stream feature
  93 module:hook("stream-features", function(event)
  94         local origin, features = event.origin, event.features;
  95         if can_do_tls(origin) then
  96                 features:add_child(c2s_feature);
  97         end
  98 end);
  99 module:hook("s2s-stream-features", function(event)
 100         local origin, features = event.origin, event.features;
 101         if can_do_tls(origin) then
 102                 features:add_child(s2s_feature);
 103         end
 104 end);
 105
 106 -- For s2sout connections, start TLS if we can
 107 module:hook_stanza("http://etherx.jabber.org/streams", "features", function (session, stanza)
 108         module:log("debug", "Received features element");
 109         if can_do_tls(session) and stanza:child_with_ns(xmlns_starttls) then
 110                 module:log("debug", "%s is offering TLS, taking up the offer...", session.to_host);
 111                 session.sends2s("<starttls xmlns='"..xmlns_starttls.."'/>");
 112                 return true;
 113         end
 114 end, 500);
 115
 116 module:hook_stanza(xmlns_starttls, "proceed", function (session, stanza)
 117         module:log("debug", "Proceeding with TLS on s2sout...");
 118         session:reset_stream();
 119         session.conn:starttls(session.ssl_ctx);
 120         session.secure = false;
 121         return true;
 122 end);