Support older Matrix rooms versions starting from version 4

include/mod_matrix_gw.hrl

@@ -21,6 +21,13 @@
 -record(room_version,
         {id :: binary(),
          %% use the same field names as in Synapse
+         enforce_key_validity :: boolean(),
+         special_case_aliases_auth :: boolean(),
+         strict_canonicaljson :: boolean(),
+         limit_notifications_power_levels :: boolean(),
+         knock_join_rule :: boolean(),
+         restricted_join_rule :: boolean(),
+         restricted_join_rule_fix :: boolean(),
          knock_restricted_join_rule :: boolean(),
          enforce_int_power_levels :: boolean(),
          implicit_room_creator :: boolean(),

src/mod_matrix_gw.erl

@@ -41,6 +41,7 @@
 	 handle_info/2, terminate/2, code_change/3,
          depends/2, mod_opt_type/1, mod_options/1, mod_doc/0]).
 -export([parse_auth/1, encode_canonical_json/1,
+         is_canonical_json/1,
          get_id_domain_exn/1,
          base64_decode/1, base64_encode/1,
          prune_event/2, get_event_id/2, content_hash/1,
@@ -155,8 +156,8 @@ process([<<"federation">>, <<"v2">>, <<"invite">>, RoomID, EventID],
                     %% TODO: check type and userid
                     Host = ejabberd_config:get_myname(),
                     PrunedEvent = prune_event(Event, RoomVersion),
-                    ?DEBUG("invite ~p~n", [{RoomID, EventID, Event, RoomVer, catch mod_matrix_gw_s2s:check_signature(Host, PrunedEvent), get_pruned_event_id(PrunedEvent)}]),
+                    %?DEBUG("invite ~p~n", [{RoomID, EventID, Event, RoomVer, catch mod_matrix_gw_s2s:check_signature(Host, PrunedEvent, RoomVersion), get_pruned_event_id(PrunedEvent)}]),
-                    case mod_matrix_gw_s2s:check_signature(Host, PrunedEvent) of
+                    case mod_matrix_gw_s2s:check_signature(Host, PrunedEvent, RoomVersion) of
                         true ->
                             case get_pruned_event_id(PrunedEvent) of
                                 EventID ->
@@ -629,9 +630,15 @@ prune_event(#{<<"type">> := Type, <<"content">> := Content} = Event,
     Content2 =
         case Type of
             <<"m.room.member">> ->
-                C3 = maps:with([<<"membership">>,
+                C3 =
-                                <<"join_authorised_via_users_server">>],
+                    case RoomVersion#room_version.restricted_join_rule_fix of
-                               Content),
+                        true ->
+                            maps:with([<<"membership">>,
+                                       <<"join_authorised_via_users_server">>],
+                                      Content);
+                        false ->
+                            maps:with([<<"membership">>], Content)
+                    end,
                 case RoomVersion#room_version.updated_redaction_rules of
                     false ->
                         C3;
@@ -653,7 +660,12 @@ prune_event(#{<<"type">> := Type, <<"content">> := Content} = Event,
                         Content
                 end;
             <<"m.room.join_rules">> ->
-                maps:with([<<"join_rule">>, <<"allow">>], Content);
+                case RoomVersion#room_version.restricted_join_rule of
+                    false ->
+                        maps:with([<<"join_rule">>], Content);
+                    true ->
+                        maps:with([<<"join_rule">>, <<"allow">>], Content)
+                end;
             <<"m.room.power_levels">> ->
                 case RoomVersion#room_version.updated_redaction_rules of
                     false ->
@@ -677,6 +689,8 @@ prune_event(#{<<"type">> := Type, <<"content">> := Content} = Event,
                     true ->
                         maps:with([<<"redacts">>], Content)
                 end;
+            <<"m.room.aliases">> when RoomVersion#room_version.special_case_aliases_auth ->
+                maps:with([<<"aliases">>], Content);
             _ -> #{}
         end,
     Event2#{<<"content">> := Content2}.
@@ -716,6 +730,27 @@ sort_json(List) when is_list(List) ->
 sort_json(JSON) ->
     JSON.
 
+is_canonical_json(N) when is_integer(N),
+                          -16#1FFFFFFFFFFFFF =< N,
+                          N =< 16#1FFFFFFFFFFFFF ->
+    true;
+is_canonical_json(B) when is_binary(B) ->
+    true;
+is_canonical_json(B) when is_boolean(B) ->
+    true;
+is_canonical_json(Map) when is_map(Map) ->
+    maps:fold(
+      fun(_K, V, true) ->
+              is_canonical_json(V);
+         (_K, _V, false) ->
+              false
+      end, true, Map);
+is_canonical_json(List) when is_list(List) ->
+    lists:all(fun is_canonical_json/1, List);
+is_canonical_json(_) ->
+    false.
+
+
 base64_decode(B) ->
     Fixed =
         case size(B) rem 4 of

src/mod_matrix_gw_room.erl

@@ -103,6 +103,7 @@
 -define(ROOM_MESSAGE, <<"m.room.message">>).
 -define(ROOM_HISTORY_VISIBILITY, <<"m.room.history_visibility">>).
 -define(ROOM_TOPIC, <<"m.room.topic">>).
+-define(ROOM_ALIASES, <<"m.room.aliases">>).
 
 -define(MAX_DEPTH, 16#7FFFFFFFFFFFFFFF).
 -define(MAX_TXN_RETRIES, 5).
@@ -650,9 +651,7 @@ handle_event(cast, {join_direct, MatrixServer, RoomID, Sender, UserID}, State, D
                   Host, get, MatrixServer,
                   [<<"_matrix">>, <<"federation">>, <<"v1">>, <<"make_join">>,
                    RoomID, UserID],
-                  [{<<"ver">>, <<"9">>},
+                  [{<<"ver">>, V} || V <- supported_versions()],
-                   {<<"ver">>, <<"10">>},
-                   {<<"ver">>, <<"11">>}],
                   none,
                   [{timeout, 5000}],
                   [{sync, true},
@@ -770,9 +769,7 @@ handle_event(cast, {join, UserJID, Packet}, _State, Data) ->
                           Host, get, MatrixServer,
                           [<<"_matrix">>, <<"federation">>, <<"v1">>, <<"make_join">>,
                            RoomID, UserID],
-                          [{<<"ver">>, <<"9">>},
+                          [{<<"ver">>, V} || V <- supported_versions()],
-                           {<<"ver">>, <<"10">>},
-                           {<<"ver">>, <<"11">>}],
                           none,
                           [{timeout, 5000}],
                           [{sync, true},
@@ -1280,7 +1277,7 @@ check_event_auth(Event, StateMap, Data) ->
                                         <<"ban">> ->
                                             check_event_auth_ban(
                                               Event, StateMap, Data);
-                                        <<"knock">> ->
+                                        <<"knock">> when (Data#data.room_version)#room_version.knock_join_rule ->
                                             check_event_auth_knock(
                                               Event, StateMap, Data);
                                         _ ->
@@ -1289,6 +1286,18 @@ check_event_auth(Event, StateMap, Data) ->
                                 _ ->
                                     false
                             end;
+                        ?ROOM_ALIASES when (Data#data.room_version)#room_version.special_case_aliases_auth ->
+                            case Event#event.state_key of
+                                undefined ->
+                                    false;
+                                StateKey ->
+                                    case mod_matrix_gw:get_id_domain_exn(Event#event.sender) of
+                                        StateKey ->
+                                            true;
+                                        _ ->
+                                            false
+                                    end
+                            end;
                         _ ->
                             Sender = Event#event.sender,
                             case maps:find({?ROOM_MEMBER, Sender}, StateMap) of
@@ -1372,8 +1381,11 @@ check_event_auth_join(Event, StateMap, Data) ->
                             case {JoinRule, SenderMembership} of
                                 {<<"public">>, _} -> true;
                                 {<<"invite">>, <<"invite">>} -> true;
-                                {<<"knock">>, <<"invite">>} -> true;
+                                {<<"knock">>, <<"invite">>}
-                                {<<"restricted">>, <<"invite">>} ->
+                                  when (Data#data.room_version)#room_version.knock_join_rule ->
+                                    true;
+                                {<<"restricted">>, <<"invite">>}
+                                  when (Data#data.room_version)#room_version.restricted_join_rule ->
                                     %% TODO
                                     true;
                                 {<<"knock_restricted">>, <<"invite">>}
@@ -1442,7 +1454,7 @@ check_event_auth_leave(Event, StateMap, Data) ->
                     case SenderMembership of
                         <<"invite">> -> true;
                         <<"join">> -> true;
-                        <<"knock">> -> true;
+                        <<"knock">> when (Data#data.room_version)#room_version.knock_join_rule -> true;
                         _ -> false
                     end;
                 _ ->
@@ -1609,6 +1621,13 @@ check_event_auth_power_levels(Event, StateMap, Data) ->
     try
         case Event#event.json of
             #{<<"content">> := NewPL = #{<<"users">> := Users}} when is_map(Users) ->
+                CheckKeys =
+                    case (Data#data.room_version)#room_version.limit_notifications_power_levels of
+                        false ->
+                            [<<"events">>, <<"users">>];
+                        true ->
+                            [<<"events">>, <<"users">>, <<"notifications">>]
+                    end,
                 case (Data#data.room_version)#room_version.enforce_int_power_levels of
                     true ->
                         lists:foreach(
@@ -1632,7 +1651,7 @@ check_event_auth_power_levels(Event, StateMap, Data) ->
                                             end
                                     end, [], NewMap)
                           end,
-                          [<<"events">>, <<"users">>, <<"notifications">>]);
+                          CheckKeys);
                     false ->
                         ok
                 end,
@@ -1677,7 +1696,7 @@ check_event_auth_power_levels(Event, StateMap, Data) ->
                                             end
                                     end, [], maps:merge(OldMap, NewMap))
                           end,
-                          [<<"events">>, <<"users">>, <<"notifications">>]),
+                          CheckKeys),
                         true;
                     _ ->
                         true
@@ -1772,7 +1791,7 @@ fill_event(JSON, Data) ->
                         _ -> []
                     end
             end,
-            compute_event_auth_keys(JSON))),
+            compute_event_auth_keys(JSON, Data#data.room_version))),
     {JSON#{<<"auth_events">> => AuthEvents,
            <<"depth">> => Depth2,
            <<"origin">> => MatrixServer,
@@ -1923,7 +1942,8 @@ get_latest_events(Pid) ->
 check_event_signature(Host, Event) ->
     PrunedEvent = mod_matrix_gw:prune_event(Event#event.json,
                                             Event#event.room_version),
-    mod_matrix_gw_s2s:check_signature(Host, PrunedEvent).
+    mod_matrix_gw_s2s:check_signature(Host, PrunedEvent,
+                                      Event#event.room_version).
 
 find_event(Pid, EventID) ->
     gen_statem:call(Pid, {find_event, EventID}).
@@ -2526,8 +2546,85 @@ find_power_level_event(EventID, Data) ->
       end, undefined, Event#event.auth_events).
 
 
+binary_to_room_version(<<"4">>) ->
+    #room_version{id = <<"4">>,
+                  enforce_key_validity = false,
+                  special_case_aliases_auth = true,
+                  strict_canonicaljson = false,
+                  limit_notifications_power_levels = false,
+                  knock_join_rule = false,
+                  restricted_join_rule = false,
+                  restricted_join_rule_fix = false,
+                  knock_restricted_join_rule = false,
+                  enforce_int_power_levels = false,
+                  implicit_room_creator = false,
+                  updated_redaction_rules = false
+                 };
+binary_to_room_version(<<"5">>) ->
+    #room_version{id = <<"5">>,
+                  enforce_key_validity = true,
+                  special_case_aliases_auth = true,
+                  strict_canonicaljson = false,
+                  limit_notifications_power_levels = false,
+                  knock_join_rule = false,
+                  restricted_join_rule = false,
+                  restricted_join_rule_fix = false,
+                  knock_restricted_join_rule = false,
+                  enforce_int_power_levels = false,
+                  implicit_room_creator = false,
+                  updated_redaction_rules = false
+                 };
+binary_to_room_version(<<"6">>) ->
+    #room_version{id = <<"6">>,
+                  enforce_key_validity = true,
+                  special_case_aliases_auth = false,
+                  strict_canonicaljson = true,
+                  limit_notifications_power_levels = true,
+                  knock_join_rule = false,
+                  restricted_join_rule = false,
+                  restricted_join_rule_fix = false,
+                  knock_restricted_join_rule = false,
+                  enforce_int_power_levels = false,
+                  implicit_room_creator = false,
+                  updated_redaction_rules = false
+                 };
+binary_to_room_version(<<"7">>) ->
+    #room_version{id = <<"7">>,
+                  enforce_key_validity = true,
+                  special_case_aliases_auth = false,
+                  strict_canonicaljson = true,
+                  limit_notifications_power_levels = true,
+                  knock_join_rule = true,
+                  restricted_join_rule = false,
+                  restricted_join_rule_fix = false,
+                  knock_restricted_join_rule = false,
+                  enforce_int_power_levels = false,
+                  implicit_room_creator = false,
+                  updated_redaction_rules = false
+                 };
+binary_to_room_version(<<"8">>) ->
+    #room_version{id = <<"8">>,
+                  enforce_key_validity = true,
+                  special_case_aliases_auth = false,
+                  strict_canonicaljson = true,
+                  limit_notifications_power_levels = true,
+                  knock_join_rule = true,
+                  restricted_join_rule = true,
+                  restricted_join_rule_fix = false,
+                  knock_restricted_join_rule = false,
+                  enforce_int_power_levels = false,
+                  implicit_room_creator = false,
+                  updated_redaction_rules = false
+                 };
 binary_to_room_version(<<"9">>) ->
     #room_version{id = <<"9">>,
+                  enforce_key_validity = true,
+                  special_case_aliases_auth = false,
+                  strict_canonicaljson = true,
+                  limit_notifications_power_levels = true,
+                  knock_join_rule = true,
+                  restricted_join_rule = true,
+                  restricted_join_rule_fix = true,
                   knock_restricted_join_rule = false,
                   enforce_int_power_levels = false,
                   implicit_room_creator = false,
@@ -2535,6 +2632,13 @@ binary_to_room_version(<<"9">>) ->
                  };
 binary_to_room_version(<<"10">>) ->
     #room_version{id = <<"10">>,
+                  enforce_key_validity = true,
+                  special_case_aliases_auth = false,
+                  strict_canonicaljson = true,
+                  limit_notifications_power_levels = true,
+                  knock_join_rule = true,
+                  restricted_join_rule = true,
+                  restricted_join_rule_fix = true,
                   knock_restricted_join_rule = true,
                   enforce_int_power_levels = true,
                   implicit_room_creator = false,
@@ -2542,6 +2646,13 @@ binary_to_room_version(<<"10">>) ->
                  };
 binary_to_room_version(<<"11">>) ->
     #room_version{id = <<"11">>,
+                  enforce_key_validity = true,
+                  special_case_aliases_auth = false,
+                  strict_canonicaljson = true,
+                  limit_notifications_power_levels = true,
+                  knock_join_rule = true,
+                  restricted_join_rule = true,
+                  restricted_join_rule_fix = true,
                   knock_restricted_join_rule = true,
                   enforce_int_power_levels = true,
                   implicit_room_creator = true,
@@ -2550,6 +2661,10 @@ binary_to_room_version(<<"11">>) ->
 binary_to_room_version(_) ->
     false.
 
+supported_versions() ->
+    [<<"4">>, <<"5">>, <<"6">>, <<"7">>, <<"8">>, <<"9">>,
+     <<"10">>, <<"11">>].
+
 json_to_event(#{<<"type">> := Type,
                 <<"room_id">> := RoomID,
                 <<"depth">> := Depth,
@@ -2562,6 +2677,17 @@ json_to_event(#{<<"type">> := Type,
        is_list(AuthEvents) ->
     StateKey = maps:get(<<"state_key">>, JSON, undefined),
     EventID = mod_matrix_gw:get_event_id(JSON, RoomVersion),
+    case RoomVersion#room_version.strict_canonicaljson of
+        true ->
+            case mod_matrix_gw:is_canonical_json(JSON) of
+                true ->
+                    ok;
+                false ->
+                    throw(non_canonical_json)
+            end;
+        false ->
+            ok
+    end,
     #event{id = EventID,
            room_version = RoomVersion,
            room_id = RoomID,
@@ -3162,12 +3288,13 @@ new_room_id() ->
     MatrixServer = mod_matrix_gw_opt:matrix_domain(Host),
     <<$!, S/binary, $:, MatrixServer/binary>>.
 
-compute_event_auth_keys(#{<<"type">> := ?ROOM_CREATE}) ->
+compute_event_auth_keys(#{<<"type">> := ?ROOM_CREATE}, _RoomVersion) ->
     [];
 compute_event_auth_keys(#{<<"type">> := ?ROOM_MEMBER,
                           <<"sender">> := Sender,
                           <<"content">> := #{<<"membership">> := Membership} = Content,
-                          <<"state_key">> := StateKey}) ->
+                          <<"state_key">> := StateKey},
+                        RoomVersion) ->
     Common = [{?ROOM_CREATE, <<"">>},
               {?ROOM_POWER_LEVELS, <<"">>},
               {?ROOM_MEMBER, Sender},
@@ -3175,7 +3302,8 @@ compute_event_auth_keys(#{<<"type">> := ?ROOM_MEMBER,
     case Membership of
         <<"join">> ->
             case Content of
-                #{<<"join_authorised_via_users_server">> := AuthUser} ->
+                #{<<"join_authorised_via_users_server">> := AuthUser}
+                  when RoomVersion#room_version.restricted_join_rule ->
                     [{?ROOM_MEMBER, AuthUser}, {?ROOM_JOIN_RULES, <<"">>} | Common];
                 _ ->
                     [{?ROOM_JOIN_RULES, <<"">>} | Common]
@@ -3192,7 +3320,7 @@ compute_event_auth_keys(#{<<"type">> := ?ROOM_MEMBER,
         _ ->
             Common
     end;
-compute_event_auth_keys(#{<<"type">> := _, <<"sender">> := Sender}) ->
+compute_event_auth_keys(#{<<"type">> := _, <<"sender">> := Sender}, _RoomVersion) ->
     [{?ROOM_CREATE, <<"">>},
      {?ROOM_POWER_LEVELS, <<"">>},
      {?ROOM_MEMBER, Sender}].

src/mod_matrix_gw_s2s.erl

@@ -28,7 +28,7 @@
 
 %% API
 -export([start_link/2, supervisor/1, create_db/0,
-         get_connection/2, check_auth/5, check_signature/2,
+         get_connection/2, check_auth/5, check_signature/3,
          get_matrix_host_port/2]).
 
 %% gen_statem callbacks
@@ -38,6 +38,7 @@
 -include("logger.hrl").
 -include("ejabberd_http.hrl").
 -include_lib("kernel/include/inet.hrl").
+-include("mod_matrix_gw.hrl").
 
 -record(matrix_s2s,
         {to  :: binary(),
@@ -169,23 +170,29 @@ check_auth(Host, MatrixServer, AuthParams, Content, Request) ->
             false
     end.
 
-check_signature(Host, JSON) ->
+check_signature(Host, JSON, RoomVersion) ->
     case JSON of
         #{<<"sender">> := Sender,
-          <<"signatures">> := Sigs} ->
+          <<"signatures">> := Sigs,
+          <<"origin_server_ts">> := OriginServerTS} ->
             MatrixServer = mod_matrix_gw:get_id_domain_exn(Sender),
             case Sigs of
                 #{MatrixServer := #{} = KeySig} ->
                     case maps:next(maps:iterator(KeySig)) of
                         {KeyID, _Sig, _} ->
                             case catch get_key(Host, MatrixServer, KeyID) of
-                                {ok, VerifyKey, _ValidUntil} ->
+                                {ok, VerifyKey, ValidUntil} ->
-                                    %% TODO: check ValidUntil
+                                    if
-                                    case check_signature(JSON, MatrixServer, KeyID, VerifyKey) of
+                                        not RoomVersion#room_version.enforce_key_validity or
+                                        OriginServerTS =< ValidUntil ->
+                                            case check_signature(JSON, MatrixServer, KeyID, VerifyKey) of
+                                                true ->
+                                                    true;
+                                                false ->
+                                                    ?WARNING_MSG("Failed authentication: ~p", [JSON]),
+                                                    false
+                                            end;
                                         true ->
-                                            true;
-                                        false ->
-                                            ?WARNING_MSG("Failed authentication: ~p", [JSON]),
                                             false
                                     end;
                                 _ ->