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 st = require "util.stanza";
  11
  12 local c2s_require_encryption = module:get_option("c2s_require_encryption", module:get_option("require_encryption"));
  13 local s2s_require_encryption = module:get_option("s2s_require_encryption");
  14 local allow_s2s_tls = module:get_option("s2s_allow_encryption") ~= false;
  15 local s2s_secure_auth = module:get_option("s2s_secure_auth");
  16
  17 if s2s_secure_auth and s2s_require_encryption == false then
  18         module:log("warn", "s2s_secure_auth implies s2s_require_encryption, but s2s_require_encryption is set to false");
  19         s2s_require_encryption = true;
  20 end
  21
  22 local xmlns_starttls = 'urn:ietf:params:xml:ns:xmpp-tls';
  23 local starttls_attr = { xmlns = xmlns_starttls };
  24 local starttls_proceed = st.stanza("proceed", starttls_attr);
  25 local starttls_failure = st.stanza("failure", starttls_attr);
  26 local c2s_feature = st.stanza("starttls", starttls_attr);
  27 local s2s_feature = st.stanza("starttls", starttls_attr);
  28 if c2s_require_encryption then c2s_feature:tag("required"):up(); end
  29 if s2s_require_encryption then s2s_feature:tag("required"):up(); end
  30
  31 local hosts = prosody.hosts;
  32 local host = hosts[module.host];
  33
  34 local ssl_ctx_c2s, ssl_ctx_s2sout, ssl_ctx_s2sin;
  35 do
  36         local NULL, err = {};
  37         local global = module:context("*");
  38         local parent = module:context(module.host:match("%.(.*)$"));
  39
  40         local parent_ssl = parent:get_option("ssl");
  41         local host_ssl   = module:get_option("ssl", parent_ssl);
  42
  43         local global_c2s = global:get_option("c2s_ssl", NULL);
  44         local parent_c2s = parent:get_option("c2s_ssl", NULL);
  45         local host_c2s   = module:get_option("c2s_ssl", parent_c2s);
  46
  47         local global_s2s = global:get_option("s2s_ssl", NULL);
  48         local parent_s2s = parent:get_option("s2s_ssl", NULL);
  49         local host_s2s   = module:get_option("s2s_ssl", parent_s2s);
  50
  51         ssl_ctx_c2s, err = create_context(host.host, "server", host_c2s, host_ssl, global_c2s); -- for incoming client connections
  52         if err then module:log("error", "Error creating context for c2s: %s", err); end
  53
  54         ssl_ctx_s2sin, err = create_context(host.host, "server", host_s2s, host_ssl, global_s2s); -- for incoming server connections
  55         ssl_ctx_s2sout = create_context(host.host, "client", host_s2s, host_ssl, global_s2s); -- for outgoing server connections
  56         if err then module:log("error", "Error creating context for s2s: %s", err); end -- Both would have the same issue
  57 end
  58
  59 local function can_do_tls(session)
  60         if not session.conn.starttls then
  61                 return false;
  62         elseif session.ssl_ctx then
  63                 return true;
  64         end
  65         if session.type == "c2s_unauthed" then
  66                 session.ssl_ctx = ssl_ctx_c2s;
  67         elseif session.type == "s2sin_unauthed" and allow_s2s_tls then
  68                 session.ssl_ctx = ssl_ctx_s2sin;
  69         elseif session.direction == "outgoing" and allow_s2s_tls then
  70                 session.ssl_ctx = ssl_ctx_s2sout;
  71         else
  72                 return false;
  73         end
  74         return session.ssl_ctx;
  75 end
  76
  77 -- Hook <starttls/>
  78 module:hook("stanza/urn:ietf:params:xml:ns:xmpp-tls:starttls", function(event)
  79         local origin = event.origin;
  80         if can_do_tls(origin) then
  81                 (origin.sends2s or origin.send)(starttls_proceed);
  82                 origin:reset_stream();
  83                 origin.conn:starttls(origin.ssl_ctx);
  84                 origin.log("debug", "TLS negotiation started for %s...", origin.type);
  85                 origin.secure = false;
  86         else
  87                 origin.log("warn", "Attempt to start TLS, but TLS is not available on this %s connection", origin.type);
  88                 (origin.sends2s or origin.send)(starttls_failure);
  89                 origin:close();
  90         end
  91         return true;
  92 end);
  93
  94 -- Advertize stream feature
  95 module:hook("stream-features", function(event)
  96         local origin, features = event.origin, event.features;
  97         if can_do_tls(origin) then
  98                 features:add_child(c2s_feature);
  99         end
 100 end);
 101 module:hook("s2s-stream-features", function(event)
 102         local origin, features = event.origin, event.features;
 103         if can_do_tls(origin) then
 104                 features:add_child(s2s_feature);
 105         end
 106 end);
 107
 108 -- For s2sout connections, start TLS if we can
 109 module:hook_stanza("http://etherx.jabber.org/streams", "features", function (session, stanza)
 110         module:log("debug", "Received features element");
 111         if can_do_tls(session) and stanza:get_child("starttls", xmlns_starttls) then
 112                 module:log("debug", "%s is offering TLS, taking up the offer...", session.to_host);
 113                 session.sends2s("<starttls xmlns='"..xmlns_starttls.."'/>");
 114                 return true;
 115         end
 116 end, 500);
 117
 118 module:hook_stanza(xmlns_starttls, "proceed", function (session, stanza)
 119         module:log("debug", "Proceeding with TLS on s2sout...");
 120         session:reset_stream();
 121         session.conn:starttls(session.ssl_ctx);
 122         session.secure = false;
 123         return true;
 124 end);