2 -- Copyright (C) 2008-2010 Matthew Wild
3 -- Copyright (C) 2008-2010 Waqas Hussain
5 -- This project is MIT/X11 licensed. Please see the
6 -- COPYING file in the source package for more information.
9 local hosts = _G.hosts;
11 local log = module._log;
13 local st = require "util.stanza";
14 local sha256_hash = require "util.hashes".sha256;
15 local nameprep = require "util.encodings".stringprep.nameprep;
16 local check_cert_status = module:depends"s2s".check_cert_status;
17 local uuid_gen = require"util.uuid".generate;
19 local xmlns_stream = "http://etherx.jabber.org/streams";
21 local dialback_requests = setmetatable({}, { __mode = 'v' });
23 local dialback_secret = module.host .. module:get_option_string("dialback_secret", uuid_gen());
24 local dwd = module:get_option_boolean("dialback_without_dialback", false);
26 function module.save()
27 return { dialback_secret = dialback_secret };
30 function module.restore(state)
31 dialback_secret = state.dialback_secret;
34 function generate_dialback(id, to, from)
35 return sha256_hash(id..to..dialback_secret, true);
38 function initiate_dialback(session)
39 -- generate dialback key
40 session.dialback_key = generate_dialback(session.streamid, session.to_host, session.from_host);
41 session.sends2s(st.stanza("db:result", { from = session.from_host, to = session.to_host }):text(session.dialback_key));
42 session.log("debug", "sent dialback key on outgoing s2s stream");
45 function verify_dialback(id, to, from, key)
46 return key == generate_dialback(id, to, from);
49 module:hook("stanza/jabber:server:dialback:verify", function(event)
50 local origin, stanza = event.origin, event.stanza;
52 if origin.type == "s2sin_unauthed" or origin.type == "s2sin" then
53 -- We are being asked to verify the key, to ensure it was generated by us
54 origin.log("debug", "verifying that dialback key is ours...");
55 local attr = stanza.attr;
57 module:log("warn", "Ignoring incoming session from %s claiming a dialback key for %s is %s",
58 origin.from_host or "(unknown)", attr.from or "(unknown)", attr.type);
61 -- COMPAT: Grr, ejabberd breaks this one too?? it is black and white in XEP-220 example 34
62 --if attr.from ~= origin.to_host then error("invalid-from"); end
64 if verify_dialback(attr.id, attr.from, attr.to, stanza[1]) then
68 origin.log("warn", "Asked to verify a dialback key that was incorrect. An imposter is claiming to be %s?", attr.to);
70 origin.log("debug", "verified dialback key... it is %s", type);
71 origin.sends2s(st.stanza("db:verify", { from = attr.to, to = attr.from, id = attr.id, type = type }):text(stanza[1]));
76 module:hook("stanza/jabber:server:dialback:result", function(event)
77 local origin, stanza = event.origin, event.stanza;
79 if origin.type == "s2sin_unauthed" or origin.type == "s2sin" then
80 -- he wants to be identified through dialback
81 -- We need to check the key with the Authoritative server
82 local attr = stanza.attr;
83 local to, from = nameprep(attr.to), nameprep(attr.from);
86 -- Not a host that we serve
87 origin.log("warn", "%s tried to connect to %s, which we don't serve", from, to);
88 origin:close("host-unknown");
91 origin:close("improper-addressing");
94 if dwd and origin.secure then
95 if check_cert_status(origin, from) == false then
97 elseif origin.cert_chain_status == "valid" and origin.cert_identity_status == "valid" then
98 origin.sends2s(st.stanza("db:result", { to = from, from = to, id = attr.id, type = "valid" }));
99 module:fire_event("s2s-authenticated", { session = origin, host = from });
104 origin.hosts[from] = { dialback_key = stanza[1] };
106 dialback_requests[from.."/"..origin.streamid] = origin;
108 -- COMPAT: ejabberd, gmail and perhaps others do not always set 'to' and 'from'
109 -- on streams. We fill in the session's to/from here instead.
110 if not origin.from_host then
111 origin.from_host = from;
113 if not origin.to_host then
117 origin.log("debug", "asking %s if key %s belongs to them", from, stanza[1]);
118 module:fire_event("route/remote", {
119 from_host = to, to_host = from;
120 stanza = st.stanza("db:verify", { from = to, to = from, id = origin.streamid }):text(stanza[1]);
126 module:hook("stanza/jabber:server:dialback:verify", function(event)
127 local origin, stanza = event.origin, event.stanza;
129 if origin.type == "s2sout_unauthed" or origin.type == "s2sout" then
130 local attr = stanza.attr;
131 local dialback_verifying = dialback_requests[attr.from.."/"..(attr.id or "")];
132 if dialback_verifying and attr.from == origin.to_host then
134 if attr.type == "valid" then
135 module:fire_event("s2s-authenticated", { session = dialback_verifying, host = attr.from });
138 -- Warn the original connection that is was not verified successfully
139 log("warn", "authoritative server for %s denied the key", attr.from or "(unknown)");
142 if dialback_verifying.destroyed then
143 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+$"));
145 dialback_verifying.sends2s(
146 st.stanza("db:result", { from = attr.to, to = attr.from, id = attr.id, type = valid })
147 :text(dialback_verifying.hosts[attr.from].dialback_key));
149 dialback_requests[attr.from.."/"..(attr.id or "")] = nil;
155 module:hook("stanza/jabber:server:dialback:result", function(event)
156 local origin, stanza = event.origin, event.stanza;
158 if origin.type == "s2sout_unauthed" or origin.type == "s2sout" then
159 -- Remote server is telling us whether we passed dialback
161 local attr = stanza.attr;
162 if not hosts[attr.to] then
163 origin:close("host-unknown");
165 elseif hosts[attr.to].s2sout[attr.from] ~= origin then
167 origin:close("invalid-id");
170 if stanza.attr.type == "valid" then
171 module:fire_event("s2s-authenticated", { session = origin, host = attr.from });
173 origin:close("not-authorized", "dialback authentication failed");
179 module:hook_stanza(xmlns_stream, "features", function (origin, stanza)
180 if not origin.external_auth or origin.external_auth == "failed" then
181 module:log("debug", "Initiating dialback...");
182 initiate_dialback(origin);
187 module:hook("s2sout-authenticate-legacy", function (event)
188 module:log("debug", "Initiating dialback...");
189 initiate_dialback(event.origin);
193 -- Offer dialback to incoming hosts
194 module:hook("s2s-stream-features", function (data)
195 data.features:tag("dialback", { xmlns='urn:xmpp:features:dialback' }):up();