Merge from default

11 files changed, 300 insertions, 109 deletions

diff --git a/src/rabbit_access_control.erl b/src/rabbit_access_control.erl
index 2bc946db..8c550e35 100644
--- a/src/rabbit_access_control.erl
+++ b/src/rabbit_access_control.erl
@@ -33,8 +33,9 @@
 -include_lib("stdlib/include/qlc.hrl").
 -include("rabbit.hrl").
 
--export([user_pass_login/2, check_user_pass_login/2, make_salt/0,
-         check_vhost_access/2, check_resource_access/3]).
+-export([user_pass_login/2, check_user_pass_login/2, check_user_login/2,
+         make_salt/0, check_password/2, check_vhost_access/2,
+         check_resource_access/3, list_vhosts/1]).
 -export([add_user/2, delete_user/1, change_password/2, set_admin/1,
          clear_admin/1, list_users/0, lookup_user/1, clear_password/1]).
 -export([change_password_hash/2, hash_password/1]).
@@ -47,7 +48,7 @@
 
 -ifdef(use_specs).
 
--export_type([username/0, password/0, password_hash/0]).
+-export_type([username/0, password/0, password_hash/0, permission_atom/0]).
 
 -type(permission_atom() :: 'configure' | 'read' | 'write').
 -type(username() :: binary()).
@@ -61,11 +62,12 @@
         (username(), password())
         -> {'ok', rabbit_types:user()} | {'refused', string(), [any()]}).
 -spec(make_salt/0 :: () -> binary()).
+-spec(check_password/2 :: (password(), password_hash()) -> boolean()).
 -spec(check_vhost_access/2 ::
         (rabbit_types:user(), rabbit_types:vhost())
         -> 'ok' | rabbit_types:channel_exit()).
 -spec(check_resource_access/3 ::
-        (username(), rabbit_types:r(atom()), permission_atom())
+        (rabbit_types:user(), rabbit_types:r(atom()), permission_atom())
         -> 'ok' | rabbit_types:channel_exit()).
 -spec(add_user/2 :: (username(), password()) -> 'ok').
 -spec(delete_user/1 :: (username()) -> 'ok').
@@ -77,7 +79,7 @@
 -spec(clear_admin/1 :: (username()) -> 'ok').
 -spec(list_users/0 :: () -> [{username(), boolean()}]).
 -spec(lookup_user/1 ::
-        (username()) -> rabbit_types:ok(rabbit_types:user())
+        (username()) -> rabbit_types:ok(rabbit_types:internal_user())
                             | rabbit_types:error('not_found')).
 -spec(add_vhost/1 :: (rabbit_types:vhost()) -> 'ok').
 -spec(delete_vhost/1 :: (rabbit_types:vhost()) -> 'ok').
@@ -109,88 +111,94 @@ user_pass_login(User, Pass) ->
             U
     end.
 
-check_user_pass_login(Username, Pass) ->
-    Refused = {refused, "user '~s' - invalid credentials", [Username]},
-    case lookup_user(Username) of
-        {ok, User} ->
-            case check_password(Pass, User#user.password_hash) of
-                true -> {ok, User};
-                _    -> Refused
-            end;
-        {error, not_found} ->
-            Refused
-    end.
-
-internal_lookup_vhost_access(Username, VHostPath) ->
-    %% TODO: use dirty ops instead
-    rabbit_misc:execute_mnesia_transaction(
-      fun () ->
-              case mnesia:read({rabbit_user_permission,
-                                #user_vhost{username     = Username,
-                                            virtual_host = VHostPath}}) of
-                  [] -> not_found;
-                  [R] -> {ok, R}
-              end
-      end).
-
-check_vhost_access(#user{username = Username}, VHostPath) ->
+check_user_pass_login(Username, Password) ->
+    check_user_login(Username, [{password, Password}]).
+
+check_user_login(Username, AuthProps) ->
+    {ok, Modules} = application:get_env(rabbit, auth_backends),
+    lists:foldl(
+      fun(Module, {refused, _, _}) ->
+              case Module:check_user_login(Username, AuthProps) of
+                  {error, E} ->
+                      {refused, "~s failed authenticating ~s: ~p~n",
+                       [Module, Username, E]};
+                  Else ->
+                      Else
+              end;
+         (_, {ok, User}) ->
+              {ok, User}
+      end, {refused, "No modules checked '~s'", [Username]}, Modules).
+
+check_vhost_access(User = #user{ username     = Username,
+                                 auth_backend = Module }, VHostPath) ->
     ?LOGDEBUG("Checking VHost access for ~p to ~p~n", [Username, VHostPath]),
-    case internal_lookup_vhost_access(Username, VHostPath) of
-        {ok, _R} ->
+    check_access(
+      fun() ->
+              vhost_exists(VHostPath) andalso
+                  Module:check_vhost_access(User, VHostPath, write)
+      end,
+      "~s failed checking vhost access to ~s for ~s: ~p~n",
+      [Module, VHostPath, Username],
+      "access to vhost '~s' refused for user '~s'",
+      [VHostPath, Username]).
+
+check_resource_access(User, R = #resource{kind = exchange, name = <<"">>},
+                      Permission) ->
+    check_resource_access(User, R#resource{name = <<"amq.default">>},
+                          Permission);
+check_resource_access(User = #user{username = Username, auth_backend = Module},
+                      Resource, Permission) ->
+    check_access(
+      fun() -> Module:check_resource_access(User, Resource, Permission) end,
+      "~s failed checking resource access to ~p for ~s: ~p~n",
+      [Module, Resource, Username],
+      "access to ~s refused for user '~s'",
+      [rabbit_misc:rs(Resource), Username]).
+
+check_access(Fun, ErrStr, ErrArgs, RefStr, RefArgs) ->
+    Allow = case Fun() of
+                {error, _} = E ->
+                    rabbit_log:error(ErrStr, ErrArgs ++ [E]),
+                    false;
+                Else ->
+                    Else
+            end,
+    case Allow of
+        true ->
             ok;
-        not_found ->
-            rabbit_misc:protocol_error(
-              access_refused, "access to vhost '~s' refused for user '~s'",
-              [VHostPath, Username])
+        false ->
+            rabbit_misc:protocol_error(access_refused, RefStr, RefArgs)
     end.
 
-permission_index(configure) -> #permission.configure;
-permission_index(write)     -> #permission.write;
-permission_index(read)      -> #permission.read.
+list_vhosts(User = #user{username = Username, auth_backend = Module}) ->
+    lists:filter(
+      fun(VHost) ->
+              case Module:check_vhost_access(User, VHost, read) of
+                  {error, _} = E ->
+                      rabbit_log:warning("~w failed checking vhost access "
+                                         "to ~s for ~s: ~p~n",
+                                         [Module, VHost, Username, E]),
+                      false;
+                  Else ->
+                      Else
+              end
+      end, list_vhosts()).
 
-check_resource_access(Username,
-                      R = #resource{kind = exchange, name = <<"">>},
-                      Permission) ->
-    check_resource_access(Username,
-                          R#resource{name = <<"amq.default">>},
-                          Permission);
-check_resource_access(Username,
-                      R = #resource{virtual_host = VHostPath, name = Name},
-                      Permission) ->
-    Res = case mnesia:dirty_read({rabbit_user_permission,
-                                  #user_vhost{username     = Username,
-                                              virtual_host = VHostPath}}) of
-              [] ->
-                  false;
-              [#user_permission{permission = P}] ->
-                  PermRegexp =
-                      case element(permission_index(Permission), P) of
-                          %% <<"^$">> breaks Emacs' erlang mode
-                          <<"">> -> <<$^, $$>>;
-                          RE     -> RE
-                      end,
-                  case re:run(Name, PermRegexp, [{capture, none}]) of
-                      match    -> true;
-                      nomatch  -> false
-                  end
-          end,
-    if Res  -> ok;
-       true -> rabbit_misc:protocol_error(
-                 access_refused, "access to ~s refused for user '~s'",
-                 [rabbit_misc:rs(R), Username])
-    end.
+%% TODO move almost everything below this line to rabbit_auth_backend_internal
+%%----------------------------------------------------------------------------
 
 add_user(Username, Password) ->
     R = rabbit_misc:execute_mnesia_transaction(
           fun () ->
                   case mnesia:wread({rabbit_user, Username}) of
                       [] ->
-                          ok = mnesia:write(rabbit_user,
-                                            #user{username = Username,
-                                                  password_hash =
-                                                      hash_password(Password),
-                                                  is_admin = false},
-                                            write);
+                          ok = mnesia:write(
+                                 rabbit_user,
+                                 #internal_user{username = Username,
+                                                password_hash =
+                                                    hash_password(Password),
+                                                is_admin = false},
+                                 write);
                       _ ->
                           mnesia:abort({user_already_exists, Username})
                   end
@@ -226,7 +234,8 @@ clear_password(Username) ->
 
 change_password_hash(Username, PasswordHash) ->
     R = update_user(Username, fun(User) ->
-                                      User#user{ password_hash = PasswordHash }
+                                      User#internal_user{
+                                        password_hash = PasswordHash }
                               end),
     rabbit_log:info("Changed password for user ~p~n", [Username]),
     R.
@@ -257,7 +266,7 @@ clear_admin(Username) ->
 
 set_admin(Username, IsAdmin) ->
     R = update_user(Username, fun(User) ->
-                                      User#user{is_admin = IsAdmin}
+                                      User#internal_user{is_admin = IsAdmin}
                               end),
     rabbit_log:info("Set user admin flag for user ~p to ~p~n",
                     [Username, IsAdmin]),
@@ -274,8 +283,8 @@ update_user(Username, Fun) ->
 
 list_users() ->
     [{Username, IsAdmin} ||
-        #user{username = Username, is_admin = IsAdmin} <-
-            mnesia:dirty_match_object(rabbit_user, #user{_ = '_'})].
+        #internal_user{username = Username, is_admin = IsAdmin} <-
+            mnesia:dirty_match_object(rabbit_user, #internal_user{_ = '_'})].
 
 lookup_user(Username) ->
     rabbit_misc:dirty_read({rabbit_user, Username}).
diff --git a/src/rabbit_auth_backend.erl b/src/rabbit_auth_backend.erl
new file mode 100644
index 00000000..18f32873
--- /dev/null
+++ b/src/rabbit_auth_backend.erl
@@ -0,0 +1,48 @@
+%%   The contents of this file are subject to the Mozilla Public License
+%%   Version 1.1 (the "License"); you may not use this file except in
+%%   compliance with the License. You may obtain a copy of the License at
+%%   http://www.mozilla.org/MPL/
+%%
+%%   Software distributed under the License is distributed on an "AS IS"
+%%   basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
+%%   License for the specific language governing rights and limitations
+%%   under the License.
+%%
+%%   The Original Code is RabbitMQ.
+%%
+%%   The Initial Developers of the Original Code are LShift Ltd,
+%%   Cohesive Financial Technologies LLC, and Rabbit Technologies Ltd.
+%%
+%%   Portions created before 22-Nov-2008 00:00:00 GMT by LShift Ltd,
+%%   Cohesive Financial Technologies LLC, or Rabbit Technologies Ltd
+%%   are Copyright (C) 2007-2008 LShift Ltd, Cohesive Financial
+%%   Technologies LLC, and Rabbit Technologies Ltd.
+%%
+%%   Portions created by LShift Ltd are Copyright (C) 2007-2010 LShift
+%%   Ltd. Portions created by Cohesive Financial Technologies LLC are
+%%   Copyright (C) 2007-2010 Cohesive Financial Technologies
+%%   LLC. Portions created by Rabbit Technologies Ltd are Copyright
+%%   (C) 2007-2010 Rabbit Technologies Ltd.
+%%
+%%   All Rights Reserved.
+%%
+%%   Contributor(s): ______________________________________.
+%%
+
+-module(rabbit_auth_backend).
+
+-export([behaviour_info/1]).
+
+behaviour_info(callbacks) ->
+    [
+     %% A description (TODO should this be here if we're not using registry?).
+     {description, 0},
+
+     {check_user_login, 2},
+
+     {check_vhost_access, 3},
+
+     {check_resource_access, 3}
+    ];
+behaviour_info(_Other) ->
+    undefined.
diff --git a/src/rabbit_auth_backend_internal.erl b/src/rabbit_auth_backend_internal.erl
new file mode 100644
index 00000000..df5a0ace
--- /dev/null
+++ b/src/rabbit_auth_backend_internal.erl
@@ -0,0 +1,112 @@
+%%   The contents of this file are subject to the Mozilla Public License
+%%   Version 1.1 (the "License"); you may not use this file except in
+%%   compliance with the License. You may obtain a copy of the License at
+%%   http://www.mozilla.org/MPL/
+%%
+%%   Software distributed under the License is distributed on an "AS IS"
+%%   basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
+%%   License for the specific language governing rights and limitations
+%%   under the License.
+%%
+%%   The Original Code is RabbitMQ.
+%%
+%%   The Initial Developers of the Original Code are LShift Ltd,
+%%   Cohesive Financial Technologies LLC, and Rabbit Technologies Ltd.
+%%
+%%   Portions created before 22-Nov-2008 00:00:00 GMT by LShift Ltd,
+%%   Cohesive Financial Technologies LLC, or Rabbit Technologies Ltd
+%%   are Copyright (C) 2007-2008 LShift Ltd, Cohesive Financial
+%%   Technologies LLC, and Rabbit Technologies Ltd.
+%%
+%%   Portions created by LShift Ltd are Copyright (C) 2007-2010 LShift
+%%   Ltd. Portions created by Cohesive Financial Technologies LLC are
+%%   Copyright (C) 2007-2010 Cohesive Financial Technologies
+%%   LLC. Portions created by Rabbit Technologies Ltd are Copyright
+%%   (C) 2007-2010 Rabbit Technologies Ltd.
+%%
+%%   All Rights Reserved.
+%%
+%%   Contributor(s): ______________________________________.
+%%
+
+-module(rabbit_auth_backend_internal).
+-include("rabbit.hrl").
+
+-behaviour(rabbit_auth_backend).
+
+-export([description/0]).
+-export([check_user_login/2, check_vhost_access/3, check_resource_access/3]).
+
+-include("rabbit_auth_backend_spec.hrl").
+
+%% Our internal user database
+
+description() ->
+    [{name, <<"Internal">>},
+     {description, <<"Internal user / password database">>}].
+
+check_user_login(Username, []) ->
+    internal_check_user_login(Username, fun() -> true end);
+check_user_login(Username, [{password, Password}]) ->
+    internal_check_user_login(
+      Username,
+      fun(#internal_user{password_hash = Hash}) ->
+              rabbit_access_control:check_password(Password, Hash)
+      end);
+check_user_login(Username, AuthProps) ->
+    exit({unknown_auth_props, Username, AuthProps}).
+
+internal_check_user_login(Username, Fun) ->
+    Refused = {refused, "user '~s' - invalid credentials", [Username]},
+    case rabbit_access_control:lookup_user(Username) of
+        {ok, User = #internal_user{is_admin = IsAdmin}} ->
+            case Fun(User) of
+                true -> {ok, #user{username     = Username,
+                                   is_admin     = IsAdmin,
+                                   auth_backend = ?MODULE,
+                                   impl         = User}};
+                _    -> Refused
+            end;
+        {error, not_found} ->
+            Refused
+    end.
+
+check_vhost_access(#user{is_admin = true},    _VHostPath, read) ->
+    true;
+
+check_vhost_access(#user{username = Username}, VHostPath, write) ->
+    %% TODO: use dirty ops instead
+    rabbit_misc:execute_mnesia_transaction(
+      fun () ->
+              case mnesia:read({rabbit_user_permission,
+                                #user_vhost{username     = Username,
+                                            virtual_host = VHostPath}}) of
+                  []   -> false;
+                  [_R] -> true
+              end
+      end).
+
+check_resource_access(#user{username = Username},
+                      #resource{virtual_host = VHostPath, name = Name},
+                      Permission) ->
+    case mnesia:dirty_read({rabbit_user_permission,
+                            #user_vhost{username     = Username,
+                                        virtual_host = VHostPath}}) of
+        [] ->
+            false;
+        [#user_permission{permission = P}] ->
+            PermRegexp =
+                case element(permission_index(Permission), P) of
+                    %% <<"^$">> breaks Emacs' erlang mode
+                    <<"">> -> <<$^, $$>>;
+                    RE     -> RE
+                end,
+            case re:run(Name, PermRegexp, [{capture, none}]) of
+                match    -> true;
+                nomatch  -> false
+            end
+    end.
+
+permission_index(configure) -> #permission.configure;
+permission_index(write)     -> #permission.write;
+permission_index(read)      -> #permission.read.
diff --git a/src/rabbit_auth_mechanism_external.erl b/src/rabbit_auth_mechanism_external.erl
index 6572f786..1c4e5c15 100644
--- a/src/rabbit_auth_mechanism_external.erl
+++ b/src/rabbit_auth_mechanism_external.erl
@@ -81,7 +81,7 @@ handle_response(_Response, #state{username = Username}) ->
         {refused, _, _} = E ->
             E;
         _ ->
-            case rabbit_access_control:lookup_user(Username) of
+            case rabbit_access_control:check_user_login(Username, []) of
                 {ok, User} ->
                     {ok, User};
                 {error, not_found} ->
diff --git a/src/rabbit_channel.erl b/src/rabbit_channel.erl
index 4e9bd4b1..d50599c1 100644
--- a/src/rabbit_channel.erl
+++ b/src/rabbit_channel.erl
@@ -47,7 +47,7 @@
 -record(ch, {state, channel, reader_pid, writer_pid, limiter_pid,
              start_limiter_fun, transaction_id, tx_participants, next_tag,
              uncommitted_ack_q, unacked_message_q,
-             username, virtual_host, most_recently_declared_queue,
+             user, virtual_host, most_recently_declared_queue,
              consumer_mapping, blocking, queue_collector_pid, stats_timer,
              confirm_enabled, publish_seqno, confirm_multiple, confirm_tref,
              held_confirms, unconfirmed, queues_for_msg}).
@@ -83,7 +83,7 @@
 -type(channel_number() :: non_neg_integer()).
 
 -spec(start_link/7 ::
-      (channel_number(), pid(), pid(), rabbit_access_control:username(),
+      (channel_number(), pid(), pid(), rabbit_types:user(),
        rabbit_types:vhost(), pid(),
        fun ((non_neg_integer()) -> rabbit_types:ok(pid()))) ->
                            rabbit_types:ok_pid_or_error()).
@@ -111,9 +111,9 @@
 
 %%----------------------------------------------------------------------------
 
-start_link(Channel, ReaderPid, WriterPid, Username, VHost, CollectorPid,
+start_link(Channel, ReaderPid, WriterPid, User, VHost, CollectorPid,
            StartLimiterFun) ->
-    gen_server2:start_link(?MODULE, [Channel, ReaderPid, WriterPid, Username,
+    gen_server2:start_link(?MODULE, [Channel, ReaderPid, WriterPid, User,
                                      VHost, CollectorPid, StartLimiterFun], []).
 
 do(Pid, Method) ->
@@ -168,7 +168,7 @@ emit_stats(Pid) ->
 
 %%---------------------------------------------------------------------------
 
-init([Channel, ReaderPid, WriterPid, Username, VHost, CollectorPid,
+init([Channel, ReaderPid, WriterPid, User, VHost, CollectorPid,
       StartLimiterFun]) ->
     process_flag(trap_exit, true),
     ok = pg_local:join(rabbit_channels, self()),
@@ -184,7 +184,7 @@ init([Channel, ReaderPid, WriterPid, Username, VHost, CollectorPid,
                 next_tag                = 1,
                 uncommitted_ack_q       = queue:new(),
                 unacked_message_q       = queue:new(),
-                username                = Username,
+                user                    = User,
                 virtual_host            = VHost,
                 most_recently_declared_queue = <<>>,
                 consumer_mapping        = dict:new(),
@@ -371,7 +371,7 @@ return_queue_declare_ok(#resource{name = ActualName},
                                   message_count  = MessageCount,
                                   consumer_count = ConsumerCount}).
 
-check_resource_access(Username, Resource, Perm) ->
+check_resource_access(User, Resource, Perm) ->
     V = {Resource, Perm},
     Cache = case get(permission_cache) of
                 undefined -> [];
@@ -381,7 +381,7 @@ check_resource_access(Username, Resource, Perm) ->
         case lists:member(V, Cache) of
             true  -> lists:delete(V, Cache);
             false -> ok = rabbit_access_control:check_resource_access(
-                            Username, Resource, Perm),
+                            User, Resource, Perm),
                      lists:sublist(Cache, ?MAX_PERMISSION_CACHE_SIZE - 1)
         end,
     put(permission_cache, [V | CacheTail]),
@@ -391,14 +391,14 @@ clear_permission_cache() ->
     erase(permission_cache),
     ok.
 
-check_configure_permitted(Resource, #ch{username = Username}) ->
-    check_resource_access(Username, Resource, configure).
+check_configure_permitted(Resource, #ch{user = User}) ->
+    check_resource_access(User, Resource, configure).
 
-check_write_permitted(Resource, #ch{username = Username}) ->
-    check_resource_access(Username, Resource, write).
+check_write_permitted(Resource, #ch{user = User}) ->
+    check_resource_access(User, Resource, write).
 
-check_read_permitted(Resource, #ch{username = Username}) ->
-    check_resource_access(Username, Resource, read).
+check_read_permitted(Resource, #ch{user = User}) ->
+    check_resource_access(User, Resource, read).
 
 expand_queue_name_shortcut(<<>>, #ch{most_recently_declared_queue = <<>>}) ->
     rabbit_misc:protocol_error(
@@ -1300,7 +1300,7 @@ infos(Items, State) -> [{Item, i(Item, State)} || Item <- Items].
 i(pid,            _)                                 -> self();
 i(connection,     #ch{reader_pid       = ReaderPid}) -> ReaderPid;
 i(number,         #ch{channel          = Channel})   -> Channel;
-i(user,           #ch{username         = Username})  -> Username;
+i(user,           #ch{user             = User})      -> User#user.username;
 i(vhost,          #ch{virtual_host     = VHost})     -> VHost;
 i(transactional,  #ch{transaction_id   = TxnKey})    -> TxnKey =/= none;
 i(consumer_count, #ch{consumer_mapping = ConsumerMapping}) ->
diff --git a/src/rabbit_channel_sup.erl b/src/rabbit_channel_sup.erl
index 02199a65..e11f8a3e 100644
--- a/src/rabbit_channel_sup.erl
+++ b/src/rabbit_channel_sup.erl
@@ -56,7 +56,7 @@
 
 %%----------------------------------------------------------------------------
 
-start_link({Protocol, Sock, Channel, FrameMax, ReaderPid, Username, VHost,
+start_link({Protocol, Sock, Channel, FrameMax, ReaderPid, User, VHost,
             Collector}) ->
     {ok, SupPid} = supervisor2:start_link(?MODULE, []),
     {ok, WriterPid} =
@@ -69,7 +69,7 @@ start_link({Protocol, Sock, Channel, FrameMax, ReaderPid, Username, VHost,
         supervisor2:start_child(
           SupPid,
           {channel, {rabbit_channel, start_link,
-                     [Channel, ReaderPid, WriterPid, Username, VHost,
+                     [Channel, ReaderPid, WriterPid, User, VHost,
                       Collector, start_limiter_fun(SupPid)]},
            intrinsic, ?MAX_WAIT, worker, [rabbit_channel]}),
     {ok, FramingChannelPid} =
diff --git a/src/rabbit_mnesia.erl b/src/rabbit_mnesia.erl
index dadfc16e..1f2d4d7d 100644
--- a/src/rabbit_mnesia.erl
+++ b/src/rabbit_mnesia.erl
@@ -154,10 +154,10 @@ nodes_of_type(Type) ->
 
 table_definitions() ->
     [{rabbit_user,
-      [{record_name, user},
-       {attributes, record_info(fields, user)},
+      [{record_name, internal_user},
+       {attributes, record_info(fields, internal_user)},
        {disc_copies, [node()]},
-       {match, #user{_='_'}}]},
+       {match, #internal_user{_='_'}}]},
      {rabbit_user_permission,
       [{record_name, user_permission},
        {attributes, record_info(fields, user_permission)},
diff --git a/src/rabbit_reader.erl b/src/rabbit_reader.erl
index 41b14771..c542ea66 100644
--- a/src/rabbit_reader.erl
+++ b/src/rabbit_reader.erl
@@ -969,12 +969,12 @@ send_to_new_channel(Channel, AnalyzedFrame, State) ->
         channel_sup_sup_pid = ChanSupSup,
         connection = #connection{protocol  = Protocol,
                                  frame_max = FrameMax,
-                                 user      = #user{username = Username},
+                                 user      = User,
                                  vhost     = VHost}} = State,
     {ok, ChSupPid, ChFrPid} =
         rabbit_channel_sup_sup:start_channel(
           ChanSupSup, {Protocol, Sock, Channel, FrameMax,
-                       self(), Username, VHost, Collector}),
+                       self(), User, VHost, Collector}),
     erlang:monitor(process, ChSupPid),
     put({channel, Channel}, {ch_fr_pid, ChFrPid}),
     put({ch_sup_pid, ChSupPid}, {{channel, Channel}, {ch_fr_pid, ChFrPid}}),
diff --git a/src/rabbit_registry.erl b/src/rabbit_registry.erl
index 7a3fcb51..ca300e72 100644
--- a/src/rabbit_registry.erl
+++ b/src/rabbit_registry.erl
@@ -111,7 +111,8 @@ sanity_check_module(ClassModule, Module) ->
     end.
 
 class_module(exchange)       -> rabbit_exchange_type;
-class_module(auth_mechanism) -> rabbit_auth_mechanism.
+class_module(auth_mechanism) -> rabbit_auth_mechanism;
+class_module(auth_backend)   -> rabbit_auth_backend.
 
 %%---------------------------------------------------------------------------
 
diff --git a/src/rabbit_types.erl b/src/rabbit_types.erl
index 548014be..15e71ee4 100644
--- a/src/rabbit_types.erl
+++ b/src/rabbit_types.erl
@@ -42,8 +42,8 @@
               vhost/0, ctag/0, amqp_error/0, r/1, r2/2, r3/3, listener/0,
               binding/0, binding_source/0, binding_destination/0,
               amqqueue/0, exchange/0,
-              connection/0, protocol/0, user/0, ok/1, error/1, ok_or_error/1,
-              ok_or_error2/2, ok_pid_or_error/0, channel_exit/0,
+              connection/0, protocol/0, user/0, internal_user/0, ok/1, error/1,
+              ok_or_error/1, ok_or_error2/2, ok_pid_or_error/0, channel_exit/0,
               connection_exit/0]).
 
 -type(channel_exit() :: no_return()).
@@ -151,9 +151,15 @@
 -type(protocol() :: rabbit_framing:protocol()).
 
 -type(user() ::
-      #user{username      :: rabbit_access_control:username(),
-            password_hash :: rabbit_access_control:password_hash(),
-            is_admin      :: boolean()}).
+        #user{username     :: rabbit_access_control:username(),
+              is_admin     :: boolean(),
+              auth_backend :: atom(),
+              impl         :: any()}).
+
+-type(internal_user() ::
+        #internal_user{username      :: rabbit_access_control:username(),
+                       password_hash :: rabbit_access_control:password_hash(),
+                       is_admin      :: boolean()}).
 
 -type(ok(A) :: {'ok', A}).
 -type(error(A) :: {'error', A}).
diff --git a/src/rabbit_upgrade_functions.erl b/src/rabbit_upgrade_functions.erl
index 1c56d51d..5dd4c558 100644
--- a/src/rabbit_upgrade_functions.erl
+++ b/src/rabbit_upgrade_functions.erl
@@ -27,6 +27,7 @@
 -rabbit_upgrade({remove_user_scope,  []}).
 -rabbit_upgrade({hash_passwords,     []}).
 -rabbit_upgrade({add_ip_to_listener, []}).
+-rabbit_upgrade({user_to_internal_user, []}).
 
 %% -------------------------------------------------------------------
 
@@ -35,6 +36,7 @@
 -spec(remove_user_scope/0  :: () -> 'ok').
 -spec(hash_passwords/0     :: () -> 'ok').
 -spec(add_ip_to_listener/0 :: () -> 'ok').
+-spec(user_to_internal_user/0 :: () -> 'ok').
 
 -endif.
 
@@ -71,8 +73,21 @@ add_ip_to_listener() ->
       end,
       [node, protocol, host, ip_address, port]).
 
+user_to_internal_user() ->
+    mnesia(
+      rabbit_user,
+      fun({user, Username, PasswordHash, IsAdmin}) ->
+              {internal_user, Username, PasswordHash, IsAdmin}
+      end,
+      [username, password_hash, is_admin], internal_user).
+
 %%--------------------------------------------------------------------
 
 mnesia(TableName, Fun, FieldList) ->
     {atomic, ok} = mnesia:transform_table(TableName, Fun, FieldList),
     ok.
+
+mnesia(TableName, Fun, FieldList, NewRecordName) ->
+    {atomic, ok} = mnesia:transform_table(TableName, Fun, FieldList,
+                                          NewRecordName),
+    ok.