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 sha256_hmac = require "util.hashes".hmac_sha256;
16 local nameprep = require "util.encodings".stringprep.nameprep;
17 local check_cert_status = module:depends"s2s".check_cert_status;
18 local uuid_gen = require"util.uuid".generate;
20 local xmlns_stream = "http://etherx.jabber.org/streams";
22 local dialback_requests = setmetatable({}, { __mode = 'v' });
24 local dialback_secret = sha256_hash(module:get_option_string("dialback_secret", uuid_gen()), true);
25 local dwd = module:get_option_boolean("dialback_without_dialback", false);
27 function module.save()
28 return { dialback_secret = dialback_secret };
31 function module.restore(state)
32 dialback_secret = state.dialback_secret;
35 function generate_dialback(id, to, from)
36 return sha256_hmac(dialback_secret, to .. ' ' .. from .. ' ' .. id, true);
39 function initiate_dialback(session)
40 -- generate dialback key
41 session.dialback_key = generate_dialback(session.streamid, session.to_host, session.from_host);
42 session.sends2s(st.stanza("db:result", { from = session.from_host, to = session.to_host }):text(session.dialback_key));
43 session.log("debug", "sent dialback key on outgoing s2s stream");
46 function verify_dialback(id, to, from, key)
47 return key == generate_dialback(id, to, from);
50 module:hook("stanza/jabber:server:dialback:verify", function(event)
51 local origin, stanza = event.origin, event.stanza;
53 if origin.type == "s2sin_unauthed" or origin.type == "s2sin" then
54 -- We are being asked to verify the key, to ensure it was generated by us
55 origin.log("debug", "verifying that dialback key is ours...");
56 local attr = stanza.attr;
58 module:log("warn", "Ignoring incoming session from %s claiming a dialback key for %s is %s",
59 origin.from_host or "(unknown)", attr.from or "(unknown)", attr.type);
62 -- COMPAT: Grr, ejabberd breaks this one too?? it is black and white in XEP-220 example 34
63 --if attr.from ~= origin.to_host then error("invalid-from"); end
65 if verify_dialback(attr.id, attr.from, attr.to, stanza[1]) then
69 origin.log("warn", "Asked to verify a dialback key that was incorrect. An imposter is claiming to be %s?", attr.to);
71 origin.log("debug", "verified dialback key... it is %s", type);
72 origin.sends2s(st.stanza("db:verify", { from = attr.to, to = attr.from, id = attr.id, type = type }):text(stanza[1]));
77 module:hook("stanza/jabber:server:dialback:result", function(event)
78 local origin, stanza = event.origin, event.stanza;
80 if origin.type == "s2sin_unauthed" or origin.type == "s2sin" then
81 -- he wants to be identified through dialback
82 -- We need to check the key with the Authoritative server
83 local attr = stanza.attr;
84 local to, from = nameprep(attr.to), nameprep(attr.from);
87 -- Not a host that we serve
88 origin.log("warn", "%s tried to connect to %s, which we don't serve", from, to);
89 origin:close("host-unknown");
92 origin:close("improper-addressing");
95 if dwd and origin.secure then
96 if check_cert_status(origin, from) == false then
98 elseif origin.cert_chain_status == "valid" and origin.cert_identity_status == "valid" then
99 origin.sends2s(st.stanza("db:result", { to = from, from = to, id = attr.id, type = "valid" }));
100 module:fire_event("s2s-authenticated", { session = origin, host = from });
105 origin.hosts[from] = { dialback_key = stanza[1] };
107 dialback_requests[from.."/"..origin.streamid] = origin;
109 -- COMPAT: ejabberd, gmail and perhaps others do not always set 'to' and 'from'
110 -- on streams. We fill in the session's to/from here instead.
111 if not origin.from_host then
112 origin.from_host = from;
114 if not origin.to_host then
118 origin.log("debug", "asking %s if key %s belongs to them", from, stanza[1]);
119 module:fire_event("route/remote", {
120 from_host = to, to_host = from;
121 stanza = st.stanza("db:verify", { from = to, to = from, id = origin.streamid }):text(stanza[1]);
127 module:hook("stanza/jabber:server:dialback:verify", function(event)
128 local origin, stanza = event.origin, event.stanza;
130 if origin.type == "s2sout_unauthed" or origin.type == "s2sout" then
131 local attr = stanza.attr;
132 local dialback_verifying = dialback_requests[attr.from.."/"..(attr.id or "")];
133 if dialback_verifying and attr.from == origin.to_host then
135 if attr.type == "valid" then
136 module:fire_event("s2s-authenticated", { session = dialback_verifying, host = attr.from });
139 -- Warn the original connection that is was not verified successfully
140 log("warn", "authoritative server for %s denied the key", attr.from or "(unknown)");
143 if dialback_verifying.destroyed then
144 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+$"));
146 dialback_verifying.sends2s(
147 st.stanza("db:result", { from = attr.to, to = attr.from, id = attr.id, type = valid })
148 :text(dialback_verifying.hosts[attr.from].dialback_key));
150 dialback_requests[attr.from.."/"..(attr.id or "")] = nil;
156 module:hook("stanza/jabber:server:dialback:result", function(event)
157 local origin, stanza = event.origin, event.stanza;
159 if origin.type == "s2sout_unauthed" or origin.type == "s2sout" then
160 -- Remote server is telling us whether we passed dialback
162 local attr = stanza.attr;
163 if not hosts[attr.to] then
164 origin:close("host-unknown");
166 elseif hosts[attr.to].s2sout[attr.from] ~= origin then
168 origin:close("invalid-id");
171 if stanza.attr.type == "valid" then
172 module:fire_event("s2s-authenticated", { session = origin, host = attr.from });
174 origin:close("not-authorized", "dialback authentication failed");
180 module:hook_stanza(xmlns_stream, "features", function (origin, stanza)
181 if not origin.external_auth or origin.external_auth == "failed" then
182 module:log("debug", "Initiating dialback...");
183 initiate_dialback(origin);
188 module:hook("s2sout-authenticate-legacy", function (event)
189 module:log("debug", "Initiating dialback...");
190 initiate_dialback(event.origin);
194 -- Offer dialback to incoming hosts
195 module:hook("s2s-stream-features", function (data)
196 data.features:tag("dialback", { xmlns='urn:xmpp:features:dialback' }):up();