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