plugins/mod_dialback.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2008-2009 Matthew Wild
   3 -- Copyright (C) 2008-2009 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
  10 local hosts = _G.hosts;
  11 local send_s2s = require "core.s2smanager".send_to_host;
  12 local s2s_make_authenticated = require "core.s2smanager".make_authenticated;
  13 local s2s_initiate_dialback = require "core.s2smanager".initiate_dialback;
  14 local s2s_verify_dialback = require "core.s2smanager".verify_dialback;
  15 local s2s_destroy_session = require "core.s2smanager".destroy_session;
  16
  17 local log = module._log;
  18
  19 local st = require "util.stanza";
  20
  21 local xmlns_stream = "http://etherx.jabber.org/streams";
  22 local xmlns_dialback = "jabber:server:dialback";
  23
  24 local dialback_requests = setmetatable({}, { __mode = 'v' });
  25
  26 module:add_handler({"s2sin_unauthed", "s2sin"}, "verify", xmlns_dialback,
  27         function (origin, stanza)
  28                 -- We are being asked to verify the key, to ensure it was generated by us
  29                 origin.log("debug", "verifying that dialback key is ours...");
  30                 local attr = stanza.attr;
  31                 -- COMPAT: Grr, ejabberd breaks this one too?? it is black and white in XEP-220 example 34
  32                 --if attr.from ~= origin.to_host then error("invalid-from"); end
  33                 local type;
  34                 if s2s_verify_dialback(attr.id, attr.from, attr.to, stanza[1]) then
  35                         type = "valid"
  36                 else
  37                         type = "invalid"
  38                         origin.log("warn", "Asked to verify a dialback key that was incorrect. An imposter is claiming to be %s?", attr.to);
  39                 end
  40                 origin.log("debug", "verified dialback key... it is %s", type);
  41                 origin.sends2s(st.stanza("db:verify", { from = attr.to, to = attr.from, id = attr.id, type = type }):text(stanza[1]));
  42         end);
  43
  44 module:add_handler({ "s2sin_unauthed", "s2sin" }, "result", xmlns_dialback,
  45         function (origin, stanza)
  46                 -- he wants to be identified through dialback
  47                 -- We need to check the key with the Authoritative server
  48                 local attr = stanza.attr;
  49                 origin.hosts[attr.from] = { dialback_key = stanza[1] };
  50
  51                 if not hosts[attr.to] then
  52                         -- Not a host that we serve
  53                         origin.log("info", "%s tried to connect to %s, which we don't serve", attr.from, attr.to);
  54                         origin:close("host-unknown");
  55                         return;
  56                 end
  57
  58                 dialback_requests[attr.from] = origin;
  59
  60                 if not origin.from_host then
  61                         -- Just used for friendlier logging
  62                         origin.from_host = attr.from;
  63                 end
  64                 if not origin.to_host then
  65                         -- Just used for friendlier logging
  66                         origin.to_host = attr.to;
  67                 end
  68
  69                 origin.log("debug", "asking %s if key %s belongs to them", attr.from, stanza[1]);
  70                 send_s2s(attr.to, attr.from,
  71                         st.stanza("db:verify", { from = attr.to, to = attr.from, id = origin.streamid }):text(stanza[1]));
  72         end);
  73
  74 module:add_handler({ "s2sout_unauthed", "s2sout" }, "verify", xmlns_dialback,
  75         function (origin, stanza)
  76                 local attr = stanza.attr;
  77                 local dialback_verifying = dialback_requests[attr.from];
  78                 if dialback_verifying then
  79                         local valid;
  80                         if attr.type == "valid" then
  81                                 s2s_make_authenticated(dialback_verifying, attr.from);
  82                                 valid = "valid";
  83                         else
  84                                 -- Warn the original connection that is was not verified successfully
  85                                 log("warn", "authoritative server for "..(attr.from or "(unknown)").." denied the key");
  86                                 valid = "invalid";
  87                         end
  88                         if not dialback_verifying.sends2s then
  89                                 log("warn", "Incoming s2s session %s was closed in the meantime, so we can't notify it of the db result", tostring(dialback_verifying):match("%w+$"));
  90                         else
  91                                 dialback_verifying.sends2s(
  92                                                 st.stanza("db:result", { from = attr.to, to = attr.from, id = attr.id, type = valid })
  93                                                                 :text(dialback_verifying.hosts[attr.from].dialback_key));
  94                         end
  95                         dialback_requests[attr.from] = nil;
  96                 end
  97         end);
  98
  99 module:add_handler({ "s2sout_unauthed", "s2sout" }, "result", xmlns_dialback,
 100         function (origin, stanza)
 101                 -- Remote server is telling us whether we passed dialback
 102
 103                 local attr = stanza.attr;
 104                 if not hosts[attr.to] then
 105                         origin:close("host-unknown");
 106                         return;
 107                 elseif hosts[attr.to].s2sout[attr.from] ~= origin then
 108                         -- This isn't right
 109                         origin:close("invalid-id");
 110                         return;
 111                 end
 112                 if stanza.attr.type == "valid" then
 113                         s2s_make_authenticated(origin, attr.from);
 114                 else
 115                         s2s_destroy_session(origin)
 116                 end
 117         end);
 118
 119 module:hook_stanza(xmlns_stream, "features", function (origin, stanza)
 120                 s2s_initiate_dialback(origin);
 121                 return true;
 122         end, 100);
 123
 124 -- Offer dialback to incoming hosts
 125 module:hook("s2s-stream-features", function (data)
 126                 data.features:tag("dialback", { xmlns='urn:xmpp:features:dialback' }):tag("optional"):up():up();
 127         end);