diff options
Diffstat (limited to 'plugins/mod_dialback.lua')
| -rw-r--r-- | plugins/mod_dialback.lua | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/plugins/mod_dialback.lua b/plugins/mod_dialback.lua new file mode 100644 index 00000000..9dcb0ed5 --- /dev/null +++ b/plugins/mod_dialback.lua @@ -0,0 +1,181 @@ +-- Prosody IM +-- Copyright (C) 2008-2010 Matthew Wild +-- Copyright (C) 2008-2010 Waqas Hussain +-- +-- This project is MIT/X11 licensed. Please see the +-- COPYING file in the source package for more information. +-- + +local hosts = _G.hosts; + +local log = module._log; + +local st = require "util.stanza"; +local sha256_hash = require "util.hashes".sha256; +local nameprep = require "util.encodings".stringprep.nameprep; + +local xmlns_stream = "http://etherx.jabber.org/streams"; + +local dialback_requests = setmetatable({}, { __mode = 'v' }); + +function generate_dialback(id, to, from) + return sha256_hash(id..to..from..hosts[from].dialback_secret, true); +end + +function initiate_dialback(session) + -- generate dialback key + session.dialback_key = generate_dialback(session.streamid, session.to_host, session.from_host); + session.sends2s(st.stanza("db:result", { from = session.from_host, to = session.to_host }):text(session.dialback_key)); + session.log("info", "sent dialback key on outgoing s2s stream"); +end + +function verify_dialback(id, to, from, key) + return key == generate_dialback(id, to, from); +end + +module:hook("stanza/jabber:server:dialback:verify", function(event) + local origin, stanza = event.origin, event.stanza; + + if origin.type == "s2sin_unauthed" or origin.type == "s2sin" then + -- We are being asked to verify the key, to ensure it was generated by us + origin.log("debug", "verifying that dialback key is ours..."); + local attr = stanza.attr; + if attr.type then + module:log("warn", "Ignoring incoming session from %s claiming a dialback key for %s is %s", + origin.from_host or "(unknown)", attr.from or "(unknown)", attr.type); + return true; + end + -- COMPAT: Grr, ejabberd breaks this one too?? it is black and white in XEP-220 example 34 + --if attr.from ~= origin.to_host then error("invalid-from"); end + local type; + if verify_dialback(attr.id, attr.from, attr.to, stanza[1]) then + type = "valid" + else + type = "invalid" + origin.log("warn", "Asked to verify a dialback key that was incorrect. An imposter is claiming to be %s?", attr.to); + end + origin.log("debug", "verified dialback key... it is %s", type); + origin.sends2s(st.stanza("db:verify", { from = attr.to, to = attr.from, id = attr.id, type = type }):text(stanza[1])); + return true; + end +end); + +module:hook("stanza/jabber:server:dialback:result", function(event) + local origin, stanza = event.origin, event.stanza; + + if origin.type == "s2sin_unauthed" or origin.type == "s2sin" then + -- he wants to be identified through dialback + -- We need to check the key with the Authoritative server + local attr = stanza.attr; + local to, from = nameprep(attr.to), nameprep(attr.from); + + if not hosts[to] then + -- Not a host that we serve + origin.log("info", "%s tried to connect to %s, which we don't serve", from, to); + origin:close("host-unknown"); + return true; + elseif not from then + origin:close("improper-addressing"); + end + + origin.hosts[from] = { dialback_key = stanza[1] }; + + dialback_requests[from.."/"..origin.streamid] = origin; + + -- COMPAT: ejabberd, gmail and perhaps others do not always set 'to' and 'from' + -- on streams. We fill in the session's to/from here instead. + if not origin.from_host then + origin.from_host = from; + end + if not origin.to_host then + origin.to_host = to; + end + + origin.log("debug", "asking %s if key %s belongs to them", from, stanza[1]); + module:fire_event("route/remote", { + from_host = to, to_host = from; + stanza = st.stanza("db:verify", { from = to, to = from, id = origin.streamid }):text(stanza[1]); + }); + return true; + end +end); + +module:hook("stanza/jabber:server:dialback:verify", function(event) + local origin, stanza = event.origin, event.stanza; + + if origin.type == "s2sout_unauthed" or origin.type == "s2sout" then + local attr = stanza.attr; + local dialback_verifying = dialback_requests[attr.from.."/"..(attr.id or "")]; + if dialback_verifying and attr.from == origin.to_host then + local valid; + if attr.type == "valid" then + module:fire_event("s2s-authenticated", { session = dialback_verifying, host = attr.from }); + valid = "valid"; + else + -- Warn the original connection that is was not verified successfully + log("warn", "authoritative server for %s denied the key", attr.from or "(unknown)"); + valid = "invalid"; + end + if dialback_verifying.destroyed then + 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+$")); + else + dialback_verifying.sends2s( + st.stanza("db:result", { from = attr.to, to = attr.from, id = attr.id, type = valid }) + :text(dialback_verifying.hosts[attr.from].dialback_key)); + end + dialback_requests[attr.from.."/"..(attr.id or "")] = nil; + end + return true; + end +end); + +module:hook("stanza/jabber:server:dialback:result", function(event) + local origin, stanza = event.origin, event.stanza; + + if origin.type == "s2sout_unauthed" or origin.type == "s2sout" then + -- Remote server is telling us whether we passed dialback + + local attr = stanza.attr; + if not hosts[attr.to] then + origin:close("host-unknown"); + return true; + elseif hosts[attr.to].s2sout[attr.from] ~= origin then + -- This isn't right + origin:close("invalid-id"); + return true; + end + if stanza.attr.type == "valid" then + module:fire_event("s2s-authenticated", { session = origin, host = attr.from }); + else + origin:close("not-authorized", "dialback authentication failed"); + end + return true; + end +end); + +module:hook_stanza("urn:ietf:params:xml:ns:xmpp-sasl", "failure", function (origin, stanza) + if origin.external_auth == "failed" then + module:log("debug", "SASL EXTERNAL failed, falling back to dialback"); + initiate_dialback(origin); + return true; + end +end, 100); + +module:hook_stanza(xmlns_stream, "features", function (origin, stanza) + if not origin.external_auth or origin.external_auth == "failed" then + module:log("debug", "Initiating dialback..."); + initiate_dialback(origin); + return true; + end +end, 100); + +module:hook("s2sout-authenticate-legacy", function (event) + module:log("debug", "Initiating dialback..."); + initiate_dialback(event.origin); + return true; +end, 100); + +-- Offer dialback to incoming hosts +module:hook("s2s-stream-features", function (data) + data.features:tag("dialback", { xmlns='urn:xmpp:features:dialback' }):up(); +end); |