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 format = string.format;
11 local hosts = _G.hosts;
12 local s2s_make_authenticated = require "core.s2smanager".make_authenticated;
14 local log = module._log;
16 local st = require "util.stanza";
17 local sha256_hash = require "util.hashes".sha256;
19 local xmlns_stream = "http://etherx.jabber.org/streams";
20 local xmlns_dialback = "jabber:server:dialback";
22 local dialback_requests = setmetatable({}, { __mode = 'v' });
24 function generate_dialback(id, to, from)
25 return sha256_hash(id..to..from..hosts[from].dialback_secret, true);
28 function initiate_dialback(session)
29 -- generate dialback key
30 session.dialback_key = generate_dialback(session.streamid, session.to_host, session.from_host);
31 session.sends2s(format("<db:result from='%s' to='%s'>%s</db:result>", session.from_host, session.to_host, session.dialback_key));
32 session.log("info", "sent dialback key on outgoing s2s stream");
35 function verify_dialback(id, to, from, key)
36 return key == generate_dialback(id, to, from);
39 module:hook("stanza/jabber:server:dialback:verify", function(event)
40 local origin, stanza = event.origin, event.stanza;
42 if origin.type == "s2sin_unauthed" or origin.type == "s2sin" then
43 -- We are being asked to verify the key, to ensure it was generated by us
44 origin.log("debug", "verifying that dialback key is ours...");
45 local attr = stanza.attr;
46 -- COMPAT: Grr, ejabberd breaks this one too?? it is black and white in XEP-220 example 34
47 --if attr.from ~= origin.to_host then error("invalid-from"); end
49 if verify_dialback(attr.id, attr.from, attr.to, stanza[1]) then
53 origin.log("warn", "Asked to verify a dialback key that was incorrect. An imposter is claiming to be %s?", attr.to);
55 origin.log("debug", "verified dialback key... it is %s", type);
56 origin.sends2s(st.stanza("db:verify", { from = attr.to, to = attr.from, id = attr.id, type = type }):text(stanza[1]));
61 module:hook("stanza/jabber:server:dialback:result", function(event)
62 local origin, stanza = event.origin, event.stanza;
64 if origin.type == "s2sin_unauthed" or origin.type == "s2sin" then
65 -- he wants to be identified through dialback
66 -- We need to check the key with the Authoritative server
67 local attr = stanza.attr;
68 origin.hosts[attr.from] = { dialback_key = stanza[1] };
70 if not hosts[attr.to] then
71 -- Not a host that we serve
72 origin.log("info", "%s tried to connect to %s, which we don't serve", attr.from, attr.to);
73 origin:close("host-unknown");
77 dialback_requests[attr.from.."/"..origin.streamid] = origin;
79 if not origin.from_host then
80 -- Just used for friendlier logging
81 origin.from_host = attr.from;
83 if not origin.to_host then
84 -- Just used for friendlier logging
85 origin.to_host = attr.to;
88 origin.log("debug", "asking %s if key %s belongs to them", attr.from, stanza[1]);
89 origin.send(st.stanza("db:verify", { from = attr.to, to = attr.from, id = origin.streamid }):text(stanza[1]));
94 module:hook("stanza/jabber:server:dialback:verify", function(event)
95 local origin, stanza = event.origin, event.stanza;
97 if origin.type == "s2sout_unauthed" or origin.type == "s2sout" then
98 local attr = stanza.attr;
99 local dialback_verifying = dialback_requests[attr.from.."/"..(attr.id or "")];
100 module:log("debug", tostring(dialback_verifying).." "..attr.from.." "..origin.to_host);
101 if dialback_verifying and attr.from == origin.to_host then
103 if attr.type == "valid" then
104 s2s_make_authenticated(dialback_verifying, attr.from);
107 -- Warn the original connection that is was not verified successfully
108 log("warn", "authoritative server for "..(attr.from or "(unknown)").." denied the key");
111 if not dialback_verifying.sends2s then
112 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+$"));
114 dialback_verifying.sends2s(
115 st.stanza("db:result", { from = attr.to, to = attr.from, id = attr.id, type = valid })
116 :text(dialback_verifying.hosts[attr.from].dialback_key));
118 dialback_requests[attr.from.."/"..(attr.id or "")] = nil;
124 module:hook("stanza/jabber:server:dialback:result", function(event)
125 local origin, stanza = event.origin, event.stanza;
127 if origin.type == "s2sout_unauthed" or origin.type == "s2sout" then
128 -- Remote server is telling us whether we passed dialback
130 local attr = stanza.attr;
131 if not hosts[attr.to] then
132 origin:close("host-unknown");
134 elseif hosts[attr.to].s2sout[attr.from] ~= origin then
136 origin:close("invalid-id");
139 if stanza.attr.type == "valid" then
140 s2s_make_authenticated(origin, attr.from);
142 origin:close("not-authorized", "dialback authentication failed");
148 module:hook_stanza("urn:ietf:params:xml:ns:xmpp-sasl", "failure", function (origin, stanza)
149 if origin.external_auth == "failed" then
150 module:log("debug", "SASL EXTERNAL failed, falling back to dialback");
151 initiate_dialback(origin);
156 module:hook_stanza(xmlns_stream, "features", function (origin, stanza)
157 if not origin.external_auth or origin.external_auth == "failed" then
158 module:log("debug", "Initiating dialback...");
159 initiate_dialback(origin);
164 module:hook("s2s-authenticate-legacy", function (event)
165 module:log("debug", "Initiating dialback...");
166 initiate_dialback(event.origin);
170 -- Offer dialback to incoming hosts
171 module:hook("s2s-stream-features", function (data)
172 data.features:tag("dialback", { xmlns='urn:xmpp:features:dialback' }):up();