fix(tpl): ensure backward compat with authz / authn templates

This commit leans heavy into discouraging the former approach where
only part of placeholders were interpolated, depending on `placeholders`
option.

apps/emqx_auth/src/emqx_authn/emqx_authn_utils.erl

@@ -18,6 +18,7 @@
 
 -include_lib("emqx/include/emqx_placeholder.hrl").
 -include_lib("emqx_authn.hrl").
+-include_lib("snabbkaffe/include/trace.hrl").
 
 -export([
     create_resource/3,
@@ -44,13 +45,13 @@
     default_headers_no_content_type/0
 ]).
 
--define(AUTHN_PLACEHOLDERS, [
-    <<?VAR_USERNAME>>,
-    <<?VAR_CLIENTID>>,
-    <<?VAR_PASSWORD>>,
-    <<?VAR_PEERHOST>>,
-    <<?VAR_CERT_SUBJECT>>,
-    <<?VAR_CERT_CN_NAME>>
+-define(ALLOWED_VARS, [
+    ?VAR_USERNAME,
+    ?VAR_CLIENTID,
+    ?VAR_PASSWORD,
+    ?VAR_PEERHOST,
+    ?VAR_CERT_SUBJECT,
+    ?VAR_CERT_CN_NAME
 ]).
 
 -define(DEFAULT_RESOURCE_OPTS, #{
@@ -108,21 +109,55 @@ check_password_from_selected_map(Algorithm, Selected, Password) ->
 
 parse_deep(Template) ->
     Result = emqx_connector_template:parse_deep(Template),
-    ok = emqx_connector_template:validate(?AUTHN_PLACEHOLDERS, Result),
-    Result.
+    handle_disallowed_placeholders(Result, {deep, Template}).
 
 parse_str(Template) ->
     Result = emqx_connector_template:parse(Template),
-    ok = emqx_connector_template:validate(?AUTHN_PLACEHOLDERS, Result),
-    Result.
+    handle_disallowed_placeholders(Result, {string, Template}).
 
 parse_sql(Template, ReplaceWith) ->
     {Statement, Result} = emqx_connector_template_sql:parse_prepstmt(
         Template,
         #{parameters => ReplaceWith, strip_double_quote => true}
     ),
-    ok = emqx_connector_template:validate(?AUTHN_PLACEHOLDERS, Result),
-    {Statement, Result}.
+    {Statement, handle_disallowed_placeholders(Result, {string, Template})}.
+
+handle_disallowed_placeholders(Template, Source) ->
+    case emqx_connector_template:validate(?ALLOWED_VARS, Template) of
+        ok ->
+            Template;
+        {error, Disallowed} ->
+            ?tp(warning, "authn_template_invalid", #{
+                template => Source,
+                reason => Disallowed,
+                allowed => #{placeholders => ?ALLOWED_VARS},
+                notice =>
+                    "Disallowed placeholders will be rendered as is."
+                    " However, consider using `$${...}` escaping for literal `${...}` where"
+                    " needed to avoid unexpected results."
+            }),
+            Result = prerender_disallowed_placeholders(Template),
+            case Source of
+                {string, _} ->
+                    emqx_connector_template:parse(Result);
+                {deep, _} ->
+                    emqx_connector_template:parse_deep(Result)
+            end
+    end.
+
+prerender_disallowed_placeholders(Template) ->
+    {Result, _} = emqx_connector_template:render(Template, #{}, #{
+        var_trans => fun(Name, _) ->
+            % NOTE
+            % Rendering disallowed placeholders in escaped form, which will then
+            % parse as a literal string.
+            case lists:member(Name, ?ALLOWED_VARS) of
+                true -> "${" ++ Name ++ "}";
+                false -> "$${" ++ Name ++ "}"
+            end
+        end
+    }),
+    Result.
 
 render_deep(Template, Credential) ->
     % NOTE
@@ -130,7 +165,7 @@ render_deep(Template, Credential) ->
     {Term, _Errors} = emqx_connector_template:render(
         Template,
         mapping_credential(Credential),
-        #{var_trans => fun handle_var/2}
+        #{var_trans => fun to_string/2}
     ),
     Term.
 
@@ -140,7 +175,7 @@ render_str(Template, Credential) ->
     {String, _Errors} = emqx_connector_template:render(
         Template,
         mapping_credential(Credential),
-        #{var_trans => fun handle_var/2}
+        #{var_trans => fun to_string/2}
     ),
     unicode:characters_to_binary(String).
 
@@ -150,7 +185,7 @@ render_urlencoded_str(Template, Credential) ->
     {String, _Errors} = emqx_connector_template:render(
         Template,
         mapping_credential(Credential),
-        #{var_trans => fun urlencode_var/2}
+        #{var_trans => fun to_urlencoded_string/2}
     ),
     unicode:characters_to_binary(String).
 
@@ -160,7 +195,7 @@ render_sql_params(ParamList, Credential) ->
     {Row, _Errors} = emqx_connector_template:render(
         ParamList,
         mapping_credential(Credential),
-        #{var_trans => fun handle_sql_var/2}
+        #{var_trans => fun to_sql_valaue/2}
     ),
     Row.
 
@@ -283,22 +318,24 @@ without_password(Credential, [Name | Rest]) ->
             without_password(Credential, Rest)
     end.
 
-urlencode_var(Var, Value) ->
-    emqx_http_lib:uri_encode(handle_var(Var, Value)).
+to_urlencoded_string(Name, Value) ->
+    emqx_http_lib:uri_encode(to_string(Name, Value)).
 
-handle_var(_, undefined) ->
-    <<>>;
-handle_var([<<"peerhost">>], PeerHost) ->
-    emqx_connector_template:to_string(inet:ntoa(PeerHost));
-handle_var(_, Value) ->
-    emqx_connector_template:to_string(Value).
+to_string(Name, Value) ->
+    emqx_connector_template:to_string(render_var(Name, Value)).
 
-handle_sql_var(_, undefined) ->
+to_sql_valaue(Name, Value) ->
+    emqx_connector_sql:to_sql_value(render_var(Name, Value)).
+
+render_var(_, undefined) ->
+    % NOTE
+    % Any allowed but undefined binding will be replaced with empty string, even when
+    % rendering SQL values.
     <<>>;
-handle_sql_var([<<"peerhost">>], PeerHost) ->
-    emqx_connector_sql:to_sql_value(inet:ntoa(PeerHost));
-handle_sql_var(_, Value) ->
-    emqx_connector_sql:to_sql_value(Value).
+render_var(?VAR_PEERHOST, Value) ->
+    inet:ntoa(Value);
+render_var(_Name, Value) ->
+    Value.
 
 mapping_credential(C = #{cn := CN, dn := DN}) ->
     C#{cert_common_name => CN, cert_subject => DN};

apps/emqx_auth/src/emqx_authz/emqx_authz_rule.erl

@@ -183,8 +183,7 @@ compile_topic(<<"eq ", Topic/binary>>) ->
 compile_topic({eq, Topic}) ->
     {eq, emqx_topic:words(bin(Topic))};
 compile_topic(Topic) ->
-    Template = emqx_connector_template:parse(Topic),
-    ok = emqx_connector_template:validate([?VAR_USERNAME, ?VAR_CLIENTID], Template),
+    Template = emqx_authz_utils:parse_str(Topic, [?VAR_USERNAME, ?VAR_CLIENTID]),
     case emqx_connector_template:trivial(Template) of
         true -> emqx_topic:words(bin(Topic));
         false -> {pattern, Template}

apps/emqx_auth/src/emqx_authz/emqx_authz_utils.erl

@@ -16,7 +16,9 @@
 
 -module(emqx_authz_utils).
 
+-include_lib("emqx/include/emqx_placeholder.hrl").
 -include_lib("emqx_authz.hrl").
+-include_lib("snabbkaffe/include/trace.hrl").
 
 -export([
     cleanup_resources/0,
@@ -109,21 +111,56 @@ update_config(Path, ConfigRequest) ->
 
 parse_deep(Template, PlaceHolders) ->
     Result = emqx_connector_template:parse_deep(Template),
-    ok = emqx_connector_template:validate(PlaceHolders, Result),
-    Result.
+    handle_disallowed_placeholders(Result, {deep, Template}, PlaceHolders).
 
 parse_str(Template, PlaceHolders) ->
     Result = emqx_connector_template:parse(Template),
-    ok = emqx_connector_template:validate(PlaceHolders, Result),
-    Result.
+    handle_disallowed_placeholders(Result, {string, Template}, PlaceHolders).
 
 parse_sql(Template, ReplaceWith, PlaceHolders) ->
     {Statement, Result} = emqx_connector_template_sql:parse_prepstmt(
         Template,
         #{parameters => ReplaceWith, strip_double_quote => true}
     ),
-    ok = emqx_connector_template:validate(PlaceHolders, Result),
-    {Statement, Result}.
+    FResult = handle_disallowed_placeholders(Result, {string, Template}, PlaceHolders),
+    {Statement, FResult}.
+
+handle_disallowed_placeholders(Template, Source, Allowed) ->
+    case emqx_connector_template:validate(Allowed, Template) of
+        ok ->
+            Template;
+        {error, Disallowed} ->
+            ?tp(warning, "authz_template_invalid", #{
+                template => Source,
+                reason => Disallowed,
+                allowed => #{placeholders => Allowed},
+                notice =>
+                    "Disallowed placeholders will be rendered as is."
+                    " However, consider using `$${...}` escaping for literal `${...}` where"
+                    " needed to avoid unexpected results."
+            }),
+            Result = prerender_disallowed_placeholders(Template, Allowed),
+            case Source of
+                {string, _} ->
+                    emqx_connector_template:parse(Result);
+                {deep, _} ->
+                    emqx_connector_template:parse_deep(Result)
+            end
+    end.
+
+prerender_disallowed_placeholders(Template, Allowed) ->
+    {Result, _} = emqx_connector_template:render(Template, #{}, #{
+        var_trans => fun(Name, _) ->
+            % NOTE
+            % Rendering disallowed placeholders in escaped form, which will then
+            % parse as a literal string.
+            case lists:member(Name, Allowed) of
+                true -> "${" ++ Name ++ "}";
+                false -> "$${" ++ Name ++ "}"
+            end
+        end
+    }),
+    Result.
 
 render_deep(Template, Values) ->
     % NOTE
@@ -131,7 +168,7 @@ render_deep(Template, Values) ->
     {Term, _Errors} = emqx_connector_template:render(
         Template,
         client_vars(Values),
-        #{var_trans => fun handle_var/2}
+        #{var_trans => fun to_string/2}
     ),
     Term.
 
@@ -141,7 +178,7 @@ render_str(Template, Values) ->
     {String, _Errors} = emqx_connector_template:render(
         Template,
         client_vars(Values),
-        #{var_trans => fun handle_var/2}
+        #{var_trans => fun to_string/2}
     ),
     unicode:characters_to_binary(String).
 
@@ -151,7 +188,7 @@ render_urlencoded_str(Template, Values) ->
     {String, _Errors} = emqx_connector_template:render(
         Template,
         client_vars(Values),
-        #{var_trans => fun urlencode_var/2}
+        #{var_trans => fun to_urlencoded_string/2}
     ),
     unicode:characters_to_binary(String).
 
@@ -161,7 +198,7 @@ render_sql_params(ParamList, Values) ->
     {Row, _Errors} = emqx_connector_template:render(
         ParamList,
         client_vars(Values),
-        #{var_trans => fun handle_sql_var/2}
+        #{var_trans => fun to_sql_value/2}
     ),
     Row.
 
@@ -229,22 +266,24 @@ convert_client_var({dn, DN}) -> {cert_subject, DN};
 convert_client_var({protocol, Proto}) -> {proto_name, Proto};
 convert_client_var(Other) -> Other.
 
-urlencode_var(Var, Value) ->
-    emqx_http_lib:uri_encode(handle_var(Var, Value)).
+to_urlencoded_string(Name, Value) ->
+    emqx_http_lib:uri_encode(to_string(Name, Value)).
 
-handle_var(_, undefined) ->
-    <<>>;
-handle_var([<<"peerhost">>], IpAddr) ->
-    inet_parse:ntoa(IpAddr);
-handle_var(_Name, Value) ->
-    emqx_connector_template:to_string(Value).
+to_string(Name, Value) ->
+    emqx_connector_template:to_string(render_var(Name, Value)).
 
-handle_sql_var(_, undefined) ->
+to_sql_value(Name, Value) ->
+    emqx_connector_sql:to_sql_value(render_var(Name, Value)).
+
+render_var(_, undefined) ->
+    % NOTE
+    % Any allowed but undefined binding will be replaced with empty string, even when
+    % rendering SQL values.
     <<>>;
-handle_sql_var([<<"peerhost">>], IpAddr) ->
-    inet_parse:ntoa(IpAddr);
-handle_sql_var(_Name, Value) ->
-    emqx_connector_sql:to_sql_value(Value).
+render_var(?VAR_PEERHOST, Value) ->
+    inet:ntoa(Value);
+render_var(_Name, Value) ->
+    Value.
 
 bin(A) when is_atom(A) -> atom_to_binary(A, utf8);
 bin(L) when is_list(L) -> list_to_binary(L);

apps/emqx_auth_http/src/emqx_authz_http.erl

@@ -38,7 +38,7 @@
 -compile(nowarn_export_all).
 -endif.
 
--define(PLACEHOLDERS, [
+-define(ALLOWED_VARS, [
     ?VAR_USERNAME,
     ?VAR_CLIENTID,
     ?VAR_PEERHOST,
@@ -50,9 +50,9 @@
     ?VAR_CERT_CN_NAME
 ]).
 
--define(PLACEHOLDERS_FOR_RICH_ACTIONS, [
-    <<?VAR_QOS>>,
-    <<?VAR_RETAIN>>
+-define(ALLOWED_VARS_RICH_ACTIONS, [
+    ?VAR_QOS,
+    ?VAR_RETAIN
 ]).
 
 description() ->
@@ -157,14 +157,14 @@ parse_config(
         method => Method,
         base_url => BaseUrl,
         headers => Headers,
-        base_path_templete => emqx_authz_utils:parse_str(Path, placeholders()),
+        base_path_templete => emqx_authz_utils:parse_str(Path, allowed_vars()),
         base_query_template => emqx_authz_utils:parse_deep(
             cow_qs:parse_qs(to_bin(Query)),
-            placeholders()
+            allowed_vars()
         ),
         body_template => emqx_authz_utils:parse_deep(
             maps:to_list(maps:get(body, Conf, #{})),
-            placeholders()
+            allowed_vars()
         ),
         request_timeout => ReqTimeout,
         %% pool_type default value `random`
@@ -260,10 +260,10 @@ to_bin(B) when is_binary(B) -> B;
 to_bin(L) when is_list(L) -> list_to_binary(L);
 to_bin(X) -> X.
 
-placeholders() ->
-    placeholders(emqx_authz:feature_available(rich_actions)).
+allowed_vars() ->
+    allowed_vars(emqx_authz:feature_available(rich_actions)).
 
-placeholders(true) ->
-    ?PLACEHOLDERS ++ ?PLACEHOLDERS_FOR_RICH_ACTIONS;
-placeholders(false) ->
-    ?PLACEHOLDERS.
+allowed_vars(true) ->
+    ?ALLOWED_VARS ++ ?ALLOWED_VARS_RICH_ACTIONS;
+allowed_vars(false) ->
+    ?ALLOWED_VARS.

apps/emqx_auth_http/test/emqx_authn_http_SUITE.erl

@@ -27,7 +27,7 @@
 -define(PATH, [?CONF_NS_ATOM]).
 
 -define(HTTP_PORT, 32333).
--define(HTTP_PATH, "/auth").
+-define(HTTP_PATH, "/auth/[...]").
 -define(CREDENTIALS, #{
     clientid => <<"clienta">>,
     username => <<"plain">>,
@@ -146,8 +146,12 @@ t_authenticate(_Config) ->
 test_user_auth(#{
     handler := Handler,
     config_params := SpecificConfgParams,
-    result := Result
+    result := Expect
 }) ->
+    Result = perform_user_auth(SpecificConfgParams, Handler, ?CREDENTIALS),
+    ?assertEqual(Expect, Result).
+
+perform_user_auth(SpecificConfgParams, Handler, Credentials) ->
     AuthConfig = maps:merge(raw_http_auth_config(), SpecificConfgParams),
 
     {ok, _} = emqx:update_config(
@@ -157,21 +161,21 @@ test_user_auth(#{
 
     ok = emqx_authn_http_test_server:set_handler(Handler),
 
-    ?assertEqual(Result, emqx_access_control:authenticate(?CREDENTIALS)),
+    Result = emqx_access_control:authenticate(Credentials),
 
     emqx_authn_test_lib:delete_authenticators(
         [authentication],
         ?GLOBAL
-    ).
+    ),
+
+    Result.
 
 t_authenticate_path_placeholders(_Config) ->
-    ok = emqx_authn_http_test_server:stop(),
-    {ok, _} = emqx_authn_http_test_server:start_link(?HTTP_PORT, <<"/[...]">>),
     ok = emqx_authn_http_test_server:set_handler(
         fun(Req0, State) ->
             Req =
                 case cowboy_req:path(Req0) of
-                    <<"/my/p%20ath//us%20er/auth//">> ->
+                    <<"/auth/p%20ath//us%20er/auth//">> ->
                         cowboy_req:reply(
                             200,
                             #{<<"content-type">> => <<"application/json">>},
@@ -193,7 +197,7 @@ t_authenticate_path_placeholders(_Config) ->
     AuthConfig = maps:merge(
         raw_http_auth_config(),
         #{
-            <<"url">> => <<"http://127.0.0.1:32333/my/p%20ath//${username}/auth//">>,
+            <<"url">> => <<"http://127.0.0.1:32333/auth/p%20ath//${username}/auth//">>,
             <<"body">> => #{}
         }
     ),
@@ -255,6 +259,39 @@ t_no_value_for_placeholder(_Config) ->
         ?GLOBAL
     ).
 
+t_disallowed_placeholders_preserved(_Config) ->
+    Config = #{
+        <<"method">> => <<"post">>,
+        <<"headers">> => #{<<"content-type">> => <<"application/json">>},
+        <<"body">> => #{
+            <<"username">> => ?PH_USERNAME,
+            <<"password">> => ?PH_PASSWORD,
+            <<"this">> => <<"${whatisthis}">>
+        }
+    },
+    Handler = fun(Req0, State) ->
+        {ok, Body, Req1} = cowboy_req:read_body(Req0),
+        #{
+            <<"username">> := <<"plain">>,
+            <<"password">> := <<"plain">>,
+            <<"this">> := <<"${whatisthis}">>
+        } = emqx_utils_json:decode(Body),
+        Req = cowboy_req:reply(
+            200,
+            #{<<"content-type">> => <<"application/json">>},
+            emqx_utils_json:encode(#{result => allow, is_superuser => false}),
+            Req1
+        ),
+        {ok, Req, State}
+    end,
+    ?assertMatch({ok, _}, perform_user_auth(Config, Handler, ?CREDENTIALS)),
+
+    % NOTE: disallowed placeholder left intact, which makes the URL invalid
+    ConfigUrl = Config#{
+        <<"url">> => <<"http://127.0.0.1:32333/auth/${whatisthis}">>
+    },
+    ?assertMatch({error, _}, perform_user_auth(ConfigUrl, Handler, ?CREDENTIALS)).
+
 t_destroy(_Config) ->
     AuthConfig = raw_http_auth_config(),
 

apps/emqx_auth_http/test/emqx_authz_http_SUITE.erl

@@ -494,6 +494,67 @@ t_no_value_for_placeholder(_Config) ->
         emqx_access_control:authorize(ClientInfo, ?AUTHZ_PUBLISH, <<"t">>)
     ).
 
+t_disallowed_placeholders_preserved(_Config) ->
+    ok = setup_handler_and_config(
+        fun(Req0, State) ->
+            {ok, Body, Req1} = cowboy_req:read_body(Req0),
+            ?assertMatch(
+                #{
+                    <<"cname">> := <<>>,
+                    <<"usertypo">> := <<"${usertypo}">>
+                },
+                emqx_utils_json:decode(Body)
+            ),
+            {ok, ?AUTHZ_HTTP_RESP(allow, Req1), State}
+        end,
+        #{
+            <<"method">> => <<"post">>,
+            <<"body">> => #{
+                <<"cname">> => ?PH_CERT_CN_NAME,
+                <<"usertypo">> => <<"${usertypo}">>
+            }
+        }
+    ),
+
+    ClientInfo = #{
+        clientid => <<"client id">>,
+        username => <<"user name">>,
+        peerhost => {127, 0, 0, 1},
+        protocol => <<"MQTT">>,
+        zone => default,
+        listener => {tcp, default}
+    },
+
+    ?assertEqual(
+        allow,
+        emqx_access_control:authorize(ClientInfo, ?AUTHZ_PUBLISH, <<"t">>)
+    ).
+
+t_disallowed_placeholders_path(_Config) ->
+    ok = setup_handler_and_config(
+        fun(Req, State) ->
+            {ok, ?AUTHZ_HTTP_RESP(allow, Req), State}
+        end,
+        #{
+            <<"url">> => <<"http://127.0.0.1:33333/authz/use%20rs/${typo}">>
+        }
+    ),
+
+    ClientInfo = #{
+        clientid => <<"client id">>,
+        username => <<"user name">>,
+        peerhost => {127, 0, 0, 1},
+        protocol => <<"MQTT">>,
+        zone => default,
+        listener => {tcp, default}
+    },
+
+    % % NOTE: disallowed placeholder left intact, which makes the URL invalid
+    ?assertEqual(
+        deny,
+        emqx_access_control:authorize(ClientInfo, ?AUTHZ_PUBLISH, <<"t">>)
+    ).
+
 t_create_replace(_Config) ->
     ClientInfo = #{
         clientid => <<"clientid">>,

apps/emqx_auth_mongodb/src/emqx_authz_mongodb.erl

@@ -35,7 +35,7 @@
 -compile(nowarn_export_all).
 -endif.
 
--define(PLACEHOLDERS, [
+-define(ALLOWED_VARS, [
     ?VAR_USERNAME,
     ?VAR_CLIENTID,
     ?VAR_PEERHOST,
@@ -49,11 +49,11 @@ description() ->
 create(#{filter := Filter} = Source) ->
     ResourceId = emqx_authz_utils:make_resource_id(?MODULE),
     {ok, _Data} = emqx_authz_utils:create_resource(ResourceId, emqx_mongodb, Source),
-    FilterTemp = emqx_authz_utils:parse_deep(Filter, ?PLACEHOLDERS),
+    FilterTemp = emqx_authz_utils:parse_deep(Filter, ?ALLOWED_VARS),
     Source#{annotations => #{id => ResourceId}, filter_template => FilterTemp}.
 
 update(#{filter := Filter} = Source) ->
-    FilterTemp = emqx_authz_utils:parse_deep(Filter, ?PLACEHOLDERS),
+    FilterTemp = emqx_authz_utils:parse_deep(Filter, ?ALLOWED_VARS),
     case emqx_authz_utils:update_resource(emqx_mongodb, Source) of
         {error, Reason} ->
             error({load_config_error, Reason});

apps/emqx_auth_mysql/src/emqx_authz_mysql.erl

@@ -37,7 +37,7 @@
 -compile(nowarn_export_all).
 -endif.
 
--define(PLACEHOLDERS, [
+-define(ALLOWED_VARS, [
     ?VAR_USERNAME,
     ?VAR_CLIENTID,
     ?VAR_PEERHOST,
@@ -49,14 +49,14 @@ description() ->
     "AuthZ with Mysql".
 
 create(#{query := SQL} = Source0) ->
-    {PrepareSQL, TmplToken} = emqx_authz_utils:parse_sql(SQL, '?', ?PLACEHOLDERS),
+    {PrepareSQL, TmplToken} = emqx_authz_utils:parse_sql(SQL, '?', ?ALLOWED_VARS),
     ResourceId = emqx_authz_utils:make_resource_id(?MODULE),
     Source = Source0#{prepare_statement => #{?PREPARE_KEY => PrepareSQL}},
     {ok, _Data} = emqx_authz_utils:create_resource(ResourceId, emqx_mysql, Source),
     Source#{annotations => #{id => ResourceId, tmpl_token => TmplToken}}.
 
 update(#{query := SQL} = Source0) ->
-    {PrepareSQL, TmplToken} = emqx_authz_utils:parse_sql(SQL, '?', ?PLACEHOLDERS),
+    {PrepareSQL, TmplToken} = emqx_authz_utils:parse_sql(SQL, '?', ?ALLOWED_VARS),
     Source = Source0#{prepare_statement => #{?PREPARE_KEY => PrepareSQL}},
     case emqx_authz_utils:update_resource(emqx_mysql, Source) of
         {error, Reason} ->

apps/emqx_auth_postgresql/src/emqx_authz_postgresql.erl

@@ -37,7 +37,7 @@
 -compile(nowarn_export_all).
 -endif.
 
--define(PLACEHOLDERS, [
+-define(ALLOWED_VARS, [
     ?VAR_USERNAME,
     ?VAR_CLIENTID,
     ?VAR_PEERHOST,
@@ -49,7 +49,7 @@ description() ->
     "AuthZ with PostgreSQL".
 
 create(#{query := SQL0} = Source) ->
-    {SQL, PlaceHolders} = emqx_authz_utils:parse_sql(SQL0, '$n', ?PLACEHOLDERS),
+    {SQL, PlaceHolders} = emqx_authz_utils:parse_sql(SQL0, '$n', ?ALLOWED_VARS),
     ResourceID = emqx_authz_utils:make_resource_id(emqx_postgresql),
     {ok, _Data} = emqx_authz_utils:create_resource(
         ResourceID,
@@ -59,7 +59,7 @@ create(#{query := SQL0} = Source) ->
     Source#{annotations => #{id => ResourceID, placeholders => PlaceHolders}}.
 
 update(#{query := SQL0, annotations := #{id := ResourceID}} = Source) ->
-    {SQL, PlaceHolders} = emqx_authz_utils:parse_sql(SQL0, '$n', ?PLACEHOLDERS),
+    {SQL, PlaceHolders} = emqx_authz_utils:parse_sql(SQL0, '$n', ?ALLOWED_VARS),
     case
         emqx_authz_utils:update_resource(
             emqx_postgresql,

apps/emqx_auth_redis/src/emqx_authz_redis.erl

@@ -35,7 +35,7 @@
 -compile(nowarn_export_all).
 -endif.
 
--define(PLACEHOLDERS, [
+-define(ALLOWED_VARS, [
     ?VAR_CERT_CN_NAME,
     ?VAR_CERT_SUBJECT,
     ?VAR_PEERHOST,
@@ -133,7 +133,7 @@ parse_cmd(Query) ->
     case emqx_redis_command:split(Query) of
         {ok, Cmd} ->
             ok = validate_cmd(Cmd),
-            emqx_authz_utils:parse_deep(Cmd, ?PLACEHOLDERS);
+            emqx_authz_utils:parse_deep(Cmd, ?ALLOWED_VARS);
         {error, Reason} ->
             error({invalid_redis_cmd, Reason, Query})
     end.