CVE-2016-1232: Add Dialback Key Generation and Validation support (XEP-0185)

3 files changed, 44 insertions, 55 deletions

diff --git a/src/ejabberd_s2s.erl b/src/ejabberd_s2s.erl
index 0e51ec044..24694f3f0 100644
--- a/src/ejabberd_s2s.erl
+++ b/src/ejabberd_s2s.erl
@@ -35,8 +35,8 @@
 
 %% API
 -export([start_link/0, route/3, have_connection/1,
-	 has_key/2, get_connections_pids/1, try_register/1,
-	 remove_connection/3, find_connection/2,
+	 make_key/2, get_connections_pids/1, try_register/1,
+	 remove_connection/2, find_connection/2,
 	 dirty_get_connections/0, allow_host/2,
 	 incoming_s2s_number/0, outgoing_s2s_number/0,
 	 clean_temporarily_blocked_table/0,
@@ -75,8 +75,7 @@
 %% once a server is temporarly blocked, it stay blocked for 60 seconds
 
 -record(s2s, {fromto = {<<"">>, <<"">>} :: {binary(), binary()} | '_',
-              pid = self()              :: pid() | '_' | '$1',
-              key = <<"">>              :: binary() | '_'}).
+              pid = self()              :: pid() | '_' | '$1'}).
 
 -record(state, {}).
 
@@ -134,19 +133,15 @@ is_temporarly_blocked(Host) ->
     end.
 
 -spec remove_connection({binary(), binary()},
-                        pid(), binary()) -> {atomic, ok} |
-                                            ok |
-                                            {aborted, any()}.
+                        pid()) -> {atomic, ok} | ok | {aborted, any()}.
 
-remove_connection(FromTo, Pid, Key) ->
+remove_connection(FromTo, Pid) ->
     case catch mnesia:dirty_match_object(s2s,
-					 #s2s{fromto = FromTo, pid = Pid,
-					      _ = '_'})
+					 #s2s{fromto = FromTo, pid = Pid})
 	of
-      [#s2s{pid = Pid, key = Key}] ->
+      [#s2s{pid = Pid}] ->
 	  F = fun () ->
-		      mnesia:delete_object(#s2s{fromto = FromTo, pid = Pid,
-						key = Key})
+		      mnesia:delete_object(#s2s{fromto = FromTo, pid = Pid})
 	      end,
 	  mnesia:transaction(F);
       _ -> ok
@@ -162,19 +157,6 @@ have_connection(FromTo) ->
             false
     end.
 
--spec has_key({binary(), binary()}, binary()) -> boolean().
-
-has_key(FromTo, Key) ->
-    case mnesia:dirty_select(s2s,
-			     [{#s2s{fromto = FromTo, key = Key, _ = '_'},
-			       [],
-			       ['$_']}]) of
-	[] ->
-	    false;
-	_ ->
-	    true
-    end.
-
 -spec get_connections_pids({binary(), binary()}) -> [pid()].
 
 get_connections_pids(FromTo) ->
@@ -185,10 +167,9 @@ get_connections_pids(FromTo) ->
 	    []
     end.
 
--spec try_register({binary(), binary()}) -> {key, binary()} | false.
+-spec try_register({binary(), binary()}) -> boolean().
 
 try_register(FromTo) ->
-    Key = randoms:get_string(),
     MaxS2SConnectionsNumber = max_s2s_connections_number(FromTo),
     MaxS2SConnectionsNumberPerNode =
 	max_s2s_connections_number_per_node(FromTo),
@@ -198,9 +179,8 @@ try_register(FromTo) ->
 							      MaxS2SConnectionsNumber,
 							      MaxS2SConnectionsNumberPerNode),
 		if NeededConnections > 0 ->
-		       mnesia:write(#s2s{fromto = FromTo, pid = self(),
-					 key = Key}),
-		       {key, Key};
+		       mnesia:write(#s2s{fromto = FromTo, pid = self()}),
+		       true;
 		   true -> false
 		end
 	end,
@@ -241,6 +221,12 @@ check_peer_certificate(SockMod, Sock, Peer) ->
 	    {error, <<"Cannot get peer certificate">>}
     end.
 
+make_key({From, To}, StreamID) ->
+    Secret = ejabberd_config:get_option(shared_key, fun(V) -> V end),
+    p1_sha:to_hexlist(
+      crypto:hmac(sha256, p1_sha:to_hexlist(crypto:hash(sha256, Secret)),
+		  [To, " ", From, " ", StreamID])).
+
 %%====================================================================
 %% gen_server callbacks
 %%====================================================================
@@ -407,17 +393,15 @@ open_several_connections(N, MyServer, Server, From,
 
 new_connection(MyServer, Server, From, FromTo,
 	       MaxS2SConnectionsNumber, MaxS2SConnectionsNumberPerNode) ->
-    Key = randoms:get_string(),
     {ok, Pid} = ejabberd_s2s_out:start(
-		  MyServer, Server, {new, Key}),
+		  MyServer, Server, new),
     F = fun() ->
 		L = mnesia:read({s2s, FromTo}),
 		NeededConnections = needed_connections_number(L,
 							      MaxS2SConnectionsNumber,
 							      MaxS2SConnectionsNumberPerNode),
 		if NeededConnections > 0 ->
-		       mnesia:write(#s2s{fromto = FromTo, pid = Pid,
-					 key = Key}),
+		       mnesia:write(#s2s{fromto = FromTo, pid = Pid}),
 		       ?INFO_MSG("New s2s connection started ~p", [Pid]),
 		       Pid;
 		   true -> choose_connection(From, L)
@@ -520,9 +504,12 @@ update_tables() ->
     end,
     case catch mnesia:table_info(s2s, attributes) of
       [fromto, node, key] ->
-	  mnesia:transform_table(s2s, ignore, [fromto, pid, key]),
+	  mnesia:transform_table(s2s, ignore, [fromto, pid]),
+	  mnesia:clear_table(s2s);
+      [fromto, pid, key] ->
+	  mnesia:transform_table(s2s, ignore, [fromto, pid]),
 	  mnesia:clear_table(s2s);
-      [fromto, pid, key] -> ok;
+      [fromto, pid] -> ok;
       {'EXIT', _} -> ok
     end,
     case lists:member(local_s2s, mnesia:system_info(tables)) of
diff --git a/src/ejabberd_s2s_in.erl b/src/ejabberd_s2s_in.erl
index 1b184a274..4159dee4a 100644
--- a/src/ejabberd_s2s_in.erl
+++ b/src/ejabberd_s2s_in.erl
@@ -432,9 +432,9 @@ stream_established({xmlstreamelement, El}, StateData) ->
 	  ?DEBUG("VERIFY KEY: ~p", [{To, From, Id, Key}]),
 	  LTo = jid:nameprep(To),
 	  LFrom = jid:nameprep(From),
-	  Type = case ejabberd_s2s:has_key({LTo, LFrom}, Key) of
-		   true -> <<"valid">>;
-		   _ -> <<"invalid">>
+	  Type = case ejabberd_s2s:make_key({LTo, LFrom}, Id) of
+		     Key -> <<"valid">>;
+		     _ -> <<"invalid">>
 		 end,
 	  send_element(StateData,
 		       #xmlel{name = <<"db:verify">>,
diff --git a/src/ejabberd_s2s_out.erl b/src/ejabberd_s2s_out.erl
index a5f728055..331f54436 100644
--- a/src/ejabberd_s2s_out.erl
+++ b/src/ejabberd_s2s_out.erl
@@ -56,6 +56,7 @@
 -record(state,
 	{socket                           :: ejabberd_socket:socket_state(),
          streamid = <<"">>                :: binary(),
+	 remote_streamid = <<"">>         :: binary(),
          use_v10 = true                   :: boolean(),
          tls = false                      :: boolean(),
 	 tls_required = false             :: boolean(),
@@ -69,7 +70,7 @@
          server = <<"">>                  :: binary(),
 	 queue = queue:new()              :: ?TQUEUE,
          delay_to_retry = undefined_delay :: undefined_delay | non_neg_integer(),
-         new = false                      :: false | binary(),
+         new = false                      :: boolean(),
 	 verify = false                   :: false | {pid(), binary(), binary()},
          bridge                           :: {atom(), atom()},
          timer = make_ref()               :: reference()}).
@@ -196,7 +197,7 @@ init([From, Server, Type]) ->
                   true -> TLSOpts4
               end,
     {New, Verify} = case Type of
-		      {new, Key} -> {Key, false};
+		      new -> {true, false};
 		      {verify, Pid, Key, SID} ->
 			  start_connection(self()), {false, {Pid, Key, SID}}
 		    end,
@@ -310,7 +311,7 @@ open_socket2(Type, Addr, Port) ->
 
 wait_for_stream({xmlstreamstart, _Name, Attrs},
 		StateData) ->
-    {CertCheckRes, CertCheckMsg, NewStateData} =
+    {CertCheckRes, CertCheckMsg, StateData0} =
 	if StateData#state.tls_certverify, StateData#state.tls_enabled ->
 	       {Res, Msg} =
 		   ejabberd_s2s:check_peer_certificate(ejabberd_socket,
@@ -322,6 +323,8 @@ wait_for_stream({xmlstreamstart, _Name, Attrs},
 	   true ->
 	       {no_verify, <<"Not verified">>, StateData}
 	end,
+    RemoteStreamID = xml:get_attr_s(<<"id">>, Attrs),
+    NewStateData = StateData0#state{remote_streamid = RemoteStreamID},
     case {xml:get_attr_s(<<"xmlns">>, Attrs),
 	  xml:get_attr_s(<<"xmlns:db">>, Attrs),
 	  xml:get_attr_s(<<"version">>, Attrs) == <<"1.0">>}
@@ -958,10 +961,10 @@ terminate(Reason, StateName, StateData) ->
     ?DEBUG("terminated: ~p", [{Reason, StateName}]),
     case StateData#state.new of
       false -> ok;
-      Key ->
+      true ->
 	  ejabberd_s2s:remove_connection({StateData#state.myname,
 					  StateData#state.server},
-					 self(), Key)
+					 self())
     end,
     bounce_queue(StateData#state.queue,
 		 ?ERR_REMOTE_SERVER_NOT_FOUND),
@@ -1029,19 +1032,18 @@ bounce_messages(Error) ->
 send_db_request(StateData) ->
     Server = StateData#state.server,
     New = case StateData#state.new of
-	    false ->
-		case ejabberd_s2s:try_register({StateData#state.myname,
-						Server})
-		    of
-		  {key, Key} -> Key;
-		  false -> false
-		end;
-	    Key -> Key
+	      false ->
+		  ejabberd_s2s:try_register({StateData#state.myname, Server});
+	      true ->
+		  true
 	  end,
     NewStateData = StateData#state{new = New},
     try case New of
-	  false -> ok;
-	  Key1 ->
+	    false -> ok;
+	    true ->
+	      Key1 = ejabberd_s2s:make_key(
+		       {StateData#state.myname, Server},
+		       StateData#state.remote_streamid),
 	      send_element(StateData,
 			   #xmlel{name = <<"db:result">>,
 				  attrs =