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 create_context = require "core.certmanager".create_context;
  10 local rawgetopt = require"core.configmanager".rawget;
  11 local st = require "util.stanza";
  12
  13 local c2s_require_encryption = module:get_option("c2s_require_encryption", 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_initiate= st.stanza("starttls", starttls_attr);
  26 local starttls_proceed = st.stanza("proceed", starttls_attr);
  27 local starttls_failure = st.stanza("failure", starttls_attr);
  28 local c2s_feature = st.stanza("starttls", starttls_attr);
  29 local s2s_feature = st.stanza("starttls", starttls_attr);
  30 if c2s_require_encryption then c2s_feature:tag("required"):up(); end
  31 if s2s_require_encryption then s2s_feature:tag("required"):up(); end
  32
  33 local hosts = prosody.hosts;
  34 local host = hosts[module.host];
  35
  36 local ssl_ctx_c2s, ssl_ctx_s2sout, ssl_ctx_s2sin;
  37 local ssl_cfg_c2s, ssl_cfg_s2sout, ssl_cfg_s2sin;
  38 do
  39         local NULL, err = {};
  40         local modhost = module.host;
  41         local parent = modhost:match("%.(.*)$");
  42
  43         local parent_ssl = rawgetopt(parent,  "ssl") or NULL;
  44         local host_ssl   = rawgetopt(modhost, "ssl") or parent_ssl;
  45
  46         local global_c2s = rawgetopt("*",     "c2s_ssl") or NULL;
  47         local parent_c2s = rawgetopt(parent,  "c2s_ssl") or NULL;
  48         local host_c2s   = rawgetopt(modhost, "c2s_ssl") or parent_c2s;
  49
  50         local global_s2s = rawgetopt("*",     "s2s_ssl") or NULL;
  51         local parent_s2s = rawgetopt(parent,  "s2s_ssl") or NULL;
  52         local host_s2s   = rawgetopt(modhost, "s2s_ssl") or parent_s2s;
  53
  54         ssl_ctx_c2s, err, ssl_cfg_c2s = create_context(host.host, "server", host_c2s, host_ssl, global_c2s); -- for incoming client connections
  55         if not ssl_ctx_c2s then module:log("error", "Error creating context for c2s: %s", err); end
  56
  57         ssl_ctx_s2sout, err, ssl_cfg_s2sout = create_context(host.host, "client", host_s2s, host_ssl, global_s2s); -- for outgoing server connections
  58         if not ssl_ctx_s2sout then module:log("error", "Error creating contexts for s2sout: %s", err); end
  59
  60         ssl_ctx_s2sin, err, ssl_cfg_s2sin = create_context(host.host, "server", host_s2s, host_ssl, global_s2s); -- for incoming server connections
  61         if not ssl_ctx_s2sin then module:log("error", "Error creating contexts for s2sin: %s", err); end
  62 end
  63
  64 local function can_do_tls(session)
  65         if session.ssl_ctx == false or not session.conn.starttls then
  66                 return false;
  67         elseif session.ssl_ctx then
  68                 return true;
  69         end
  70         if session.type == "c2s_unauthed" then
  71                 session.ssl_ctx = ssl_ctx_c2s;
  72                 session.ssl_cfg = ssl_cfg_c2s;
  73         elseif session.type == "s2sin_unauthed" and allow_s2s_tls then
  74                 session.ssl_ctx = ssl_ctx_s2sin;
  75                 session.ssl_cfg = ssl_cfg_s2sin;
  76         elseif session.direction == "outgoing" and allow_s2s_tls then
  77                 session.ssl_ctx = ssl_ctx_s2sout;
  78                 session.ssl_cfg = ssl_cfg_s2sout;
  79         else
  80                 return false;
  81         end
  82         return session.ssl_ctx;
  83 end
  84
  85 -- Hook <starttls/>
  86 module:hook("stanza/urn:ietf:params:xml:ns:xmpp-tls:starttls", function(event)
  87         local origin = event.origin;
  88         if can_do_tls(origin) then
  89                 (origin.sends2s or origin.send)(starttls_proceed);
  90                 origin:reset_stream();
  91                 origin.conn:starttls(origin.ssl_ctx);
  92                 origin.log("debug", "TLS negotiation started for %s...", origin.type);
  93                 origin.secure = false;
  94         else
  95                 origin.log("warn", "Attempt to start TLS, but TLS is not available on this %s connection", origin.type);
  96                 (origin.sends2s or origin.send)(starttls_failure);
  97                 origin:close();
  98         end
  99         return true;
 100 end);
 101
 102 -- Advertize stream feature
 103 module:hook("stream-features", function(event)
 104         local origin, features = event.origin, event.features;
 105         if can_do_tls(origin) then
 106                 features:add_child(c2s_feature);
 107         end
 108 end);
 109 module:hook("s2s-stream-features", function(event)
 110         local origin, features = event.origin, event.features;
 111         if can_do_tls(origin) then
 112                 features:add_child(s2s_feature);
 113         end
 114 end);
 115
 116 -- For s2sout connections, start TLS if we can
 117 module:hook_stanza("http://etherx.jabber.org/streams", "features", function (session, stanza)
 118         module:log("debug", "Received features element");
 119         if can_do_tls(session) and stanza:get_child("starttls", xmlns_starttls) then
 120                 module:log("debug", "%s is offering TLS, taking up the offer...", session.to_host);
 121                 session.sends2s(starttls_initiate);
 122                 return true;
 123         end
 124 end, 500);
 125
 126 module:hook_stanza(xmlns_starttls, "proceed", function (session, stanza)
 127         module:log("debug", "Proceeding with TLS on s2sout...");
 128         session:reset_stream();
 129         session.conn:starttls(session.ssl_ctx);
 130         session.secure = false;
 131         return true;
 132 end);