mod_dialback: COMPAT reset session.send function for servers (e.g. ejabberd) which...
[prosody.git] / plugins / mod_dialback.lua
index 59fc4332c3511586a7654939ce6a5aee25a21c96..cc076db5ad87a141fd5f76a5b1cc0cdf5df0e4ab 100644 (file)
--- Prosody IM v0.2
--- Copyright (C) 2008 Matthew Wild
--- Copyright (C) 2008 Waqas Hussain
+-- Prosody IM
+-- Copyright (C) 2008-2010 Matthew Wild
+-- Copyright (C) 2008-2010 Waqas Hussain
 -- 
--- This program is free software; you can redistribute it and/or
--- modify it under the terms of the GNU General Public License
--- as published by the Free Software Foundation; either version 2
--- of the License, or (at your option) any later version.
--- 
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
--- 
--- You should have received a copy of the GNU General Public License
--- along with this program; if not, write to the Free Software
--- Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
 --
 
+local format = string.format;
 
-
-local send_s2s = require "core.s2smanager".send_to_host;
+local hosts = _G.hosts;
 local s2s_make_authenticated = require "core.s2smanager".make_authenticated;
-local s2s_verify_dialback = require "core.s2smanager".verify_dialback;
+
+local log = module._log;
 
 local st = require "util.stanza";
+local sha256_hash = require "util.hashes".sha256;
+
+local xmlns_stream = "http://etherx.jabber.org/streams";
 
-local log = require "util.logger".init("mod_dialback");
+local dialback_requests = setmetatable({}, { __mode = 'v' });
 
-local xmlns_dialback = "jabber:server:dialback";
+function generate_dialback(id, to, from)
+       return sha256_hash(id..to..from..hosts[from].dialback_secret, true);
+end
 
-module:add_handler({"s2sin_unauthed", "s2sin"}, "verify", xmlns_dialback,
-       function (origin, stanza)
+function initiate_dialback(session)
+       -- generate dialback key
+       session.dialback_key = generate_dialback(session.streamid, session.to_host, session.from_host);
+       session.sends2s(format("<db:result from='%s' to='%s'>%s</db:result>", session.from_host, session.to_host, 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
-               log("debug", "verifying dialback key...");
+               origin.log("debug", "verifying that dialback key is ours...");
                local attr = stanza.attr;
-               -- FIXME: Grr, ejabberd breaks this one too?? it is black and white in XEP-220 example 34
+               -- 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 s2s_verify_dialback(attr.id, attr.from, attr.to, stanza[1]) then
+               if verify_dialback(attr.id, attr.from, attr.to, stanza[1]) then
                        type = "valid"
                else
                        type = "invalid"
-                       log("warn", "Asked to verify a dialback key that was incorrect. An imposter is claiming to be %s?", attr.to);
+                       origin.log("warn", "Asked to verify a dialback key that was incorrect. An imposter is claiming to be %s?", attr.to);
                end
-               log("debug", "verified dialback key... it is %s", type);
+               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]));
-       end);
+               return true;
+       end
+end);
 
-module:add_handler("s2sin_unauthed", "result", xmlns_dialback,
-       function (origin, stanza)
+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;
+               origin.hosts[attr.from] = { dialback_key = stanza[1] };
+               
+               if not hosts[attr.to] then
+                       -- Not a host that we serve
+                       origin.log("info", "%s tried to connect to %s, which we don't serve", attr.from, attr.to);
+                       origin:close("host-unknown");
+                       return true;
+               end
+               
+               dialback_requests[attr.from.."/"..origin.streamid] = origin;
+               
+               if not origin.from_host then
+                       -- Just used for friendlier logging
+                       origin.from_host = attr.from;
+                       -- COMPAT: Fix ejabberd chopness by resetting the send function
+                       origin.log("debug", "Remote server didn't specify a from attr, resetting session.send now that we know where to knock to.");
+                       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
+               end
+               if not origin.to_host then
+                       -- Just used for friendlier logging
+                       origin.to_host = attr.to;
+               end
+               
+               origin.log("debug", "asking %s if key %s belongs to them", attr.from, stanza[1]);
+               origin.send(st.stanza("db:verify", { from = attr.to, to = attr.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;
-               origin.from_host = attr.from;
-               origin.to_host = attr.to;
-               origin.dialback_key = stanza[1];
-               log("debug", "asking %s if key %s belongs to them", origin.from_host, origin.dialback_key);
-               send_s2s(origin.to_host, origin.from_host,
-                       st.stanza("db:verify", { from = origin.to_host, to = origin.from_host, id = origin.streamid }):text(origin.dialback_key));
-               hosts[origin.to_host].s2sout[origin.from_host].dialback_verifying = origin;
-       end);
-
-module:add_handler({ "s2sout_unauthed", "s2sout" }, "verify", xmlns_dialback,
-       function (origin, stanza)
-               if origin.dialback_verifying then
+               local dialback_verifying = dialback_requests[attr.from.."/"..(attr.id or "")];
+               module:log("debug", tostring(dialback_verifying).." "..attr.from.." "..origin.to_host);
+               if dialback_verifying and attr.from == origin.to_host then
                        local valid;
-                       local attr = stanza.attr;
                        if attr.type == "valid" then
-                               s2s_make_authenticated(origin.dialback_verifying);
+                               s2s_make_authenticated(dialback_verifying, attr.from);
                                valid = "valid";
                        else
                                -- Warn the original connection that is was not verified successfully
-                               log("warn", "dialback for "..(origin.dialback_verifying.from_host or "(unknown)").." failed");
+                               log("warn", "authoritative server for "..(attr.from or "(unknown)").." denied the key");
                                valid = "invalid";
                        end
-                       if not origin.dialback_verifying.sends2s then
-                               log("warn", "Incoming s2s session %s was closed in the meantime, so we can't notify it of the db result", tostring(origin.dialback_verifying):match("%w+$"));
+                       if not dialback_verifying.sends2s then
+                               log("warn", "Incoming s2s session %s was closed in the meantime, so we can't notify it of the db result", tostring(dialback_verifying):match("%w+$"));
                        else
-                               origin.dialback_verifying.sends2s(
+                               dialback_verifying.sends2s(
                                                st.stanza("db:result", { from = attr.to, to = attr.from, id = attr.id, type = valid })
-                                                               :text(origin.dialback_verifying.dialback_key));
+                                                               :text(dialback_verifying.hosts[attr.from].dialback_key));
                        end
+                       dialback_requests[attr.from.."/"..(attr.id or "")] = nil;
                end
-       end);
+               return true;
+       end
+end);
 
-module:add_handler({ "s2sout_unauthed", "s2sout" }, "result", xmlns_dialback,
-       function (origin, stanza)
+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
-                       s2s_make_authenticated(origin);
+                       s2s_make_authenticated(origin, attr.from);
                else
-                       -- FIXME
-                       error("dialback failed!");
+                       origin:close("not-authorized", "dialback authentication failed");
                end
-       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("s2s-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);