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;
18 local nameprep = require "util.encodings".stringprep.nameprep;
20 local xmlns_stream = "http://etherx.jabber.org/streams";
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;
80 if not origin.from_host then
81 -- Just used for friendlier logging
82 origin.from_host = nameprep(attr.from);
83 -- COMPAT: Fix server's chopness by not including from
86 if not origin.to_host then
87 -- Just used for friendlier logging
88 origin.to_host = nameprep(attr.to);
89 -- COMPAT: Fix server's chopness by not including to
93 if not origin.from_host and not origin.to_host then
94 origin.log("debug", "Improper addressing supplied, no to or from?");
95 origin:close("improper-addressing");
97 -- COMPAT: reset session.send
99 origin.send = function(stanza) hosts[attr.to].events.fire_event("route/remote", { from_host = origin.to_host, to_host = origin.from_host, stanza = stanza}); end
102 origin.log("debug", "asking %s if key %s belongs to them", attr.from, stanza[1]);
103 origin.send(st.stanza("db:verify", { from = attr.to, to = attr.from, id = origin.streamid }):text(stanza[1]));
108 module:hook("stanza/jabber:server:dialback:verify", function(event)
109 local origin, stanza = event.origin, event.stanza;
111 if origin.type == "s2sout_unauthed" or origin.type == "s2sout" then
112 local attr = stanza.attr;
113 local dialback_verifying = dialback_requests[attr.from.."/"..(attr.id or "")];
114 module:log("debug", tostring(dialback_verifying).." "..attr.from.." "..origin.to_host);
115 if dialback_verifying and attr.from == origin.to_host then
117 if attr.type == "valid" then
118 s2s_make_authenticated(dialback_verifying, attr.from);
121 -- Warn the original connection that is was not verified successfully
122 log("warn", "authoritative server for "..(attr.from or "(unknown)").." denied the key");
125 if not dialback_verifying.sends2s then
126 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+$"));
128 dialback_verifying.sends2s(
129 st.stanza("db:result", { from = attr.to, to = attr.from, id = attr.id, type = valid })
130 :text(dialback_verifying.hosts[attr.from].dialback_key));
132 dialback_requests[attr.from.."/"..(attr.id or "")] = nil;
138 module:hook("stanza/jabber:server:dialback:result", function(event)
139 local origin, stanza = event.origin, event.stanza;
141 if origin.type == "s2sout_unauthed" or origin.type == "s2sout" then
142 -- Remote server is telling us whether we passed dialback
144 local attr = stanza.attr;
145 if not hosts[attr.to] then
146 origin:close("host-unknown");
148 elseif hosts[attr.to].s2sout[attr.from] ~= origin then
150 origin:close("invalid-id");
153 if stanza.attr.type == "valid" then
154 s2s_make_authenticated(origin, attr.from);
156 origin:close("not-authorized", "dialback authentication failed");
162 module:hook_stanza("urn:ietf:params:xml:ns:xmpp-sasl", "failure", function (origin, stanza)
163 if origin.external_auth == "failed" then
164 module:log("debug", "SASL EXTERNAL failed, falling back to dialback");
165 initiate_dialback(origin);
170 module:hook_stanza(xmlns_stream, "features", function (origin, stanza)
171 if not origin.external_auth or origin.external_auth == "failed" then
172 module:log("debug", "Initiating dialback...");
173 initiate_dialback(origin);
178 module:hook("s2s-authenticate-legacy", function (event)
179 module:log("debug", "Initiating dialback...");
180 initiate_dialback(event.origin);
184 -- Offer dialback to incoming hosts
185 module:hook("s2s-stream-features", function (data)
186 data.features:tag("dialback", { xmlns='urn:xmpp:features:dialback' }):up();