refactor(emqx_license): simplify parser errors

prior to this change, badmatch exception may cause the license key
to be dumped in logs

lib-ee/emqx_license/src/emqx_license.erl

@@ -129,6 +129,7 @@ do_update({key, Content}, _Conf) when is_binary(Content); is_list(Content) ->
         {ok, _License} ->
             #{<<"key">> => Content};
         {error, Reason} ->
+            ?SLOG(error, #{msg => "failed_to_parse_license", reason => Reason}),
             error(Reason)
     end.
 

lib-ee/emqx_license/src/emqx_license_parser.erl

@@ -98,7 +98,7 @@ max_connections(#{module := Module, data := LicenseData}) ->
 %%--------------------------------------------------------------------
 
 do_parse(_Content, _Key, [], Errors) ->
-    {error, {unknown_format, lists:reverse(Errors)}};
+    {error, lists:reverse(Errors)};
 
 do_parse(Content, Key, [Module | Modules], Errors) ->
     try Module:parse(Content, Key) of
@@ -107,7 +107,7 @@ do_parse(Content, Key, [Module | Modules], Errors) ->
         {error, Error} ->
             do_parse(Content, Key, Modules, [{Module, Error} | Errors])
     catch
-        _Class:Error:_Stk ->
+        _Class : Error ->
             do_parse(Content, Key, Modules, [{Module, Error} | Errors])
     end.
 

lib-ee/emqx_license/src/emqx_license_parser_v20220101.erl

@@ -24,12 +24,14 @@
 %%------------------------------------------------------------------------------
 
 parse(Content, Key) ->
-    [EncodedPayload, EncodedSignature] = binary:split(Content, <<".">>),
-    Payload = base64:decode(EncodedPayload),
-    Signature = base64:decode(EncodedSignature),
-    case verify_signature(Payload, Signature, Key) of
-        true -> parse_payload(Payload);
-        false -> {error, invalid_signature}
+    case do_parse(Content) of
+        {ok, {Payload, Signature}} ->
+            case verify_signature(Payload, Signature, Key) of
+                true -> parse_payload(Payload);
+                false -> {error, invalid_signature}
+            end;
+        {error, Reason} ->
+            {error, Reason}
     end.
 
 dump(#{type := Type,
@@ -67,6 +69,17 @@ max_connections(#{max_connections := MaxConns}) ->
 %% Private functions
 %%------------------------------------------------------------------------------
 
+do_parse(Content) ->
+    try
+        [EncodedPayload, EncodedSignature] = binary:split(Content, <<".">>),
+        Payload = base64:decode(EncodedPayload),
+        Signature = base64:decode(EncodedSignature),
+        {ok, {Payload, Signature}}
+    catch
+        _ : _ ->
+            {error, bad_license_format}
+    end.
+
 verify_signature(Payload, Signature, Key) ->
     RSAPublicKey = public_key:der_decode('RSAPublicKey', Key),
     public_key:verify(Payload, ?DIGEST_TYPE, Signature, RSAPublicKey).

lib-ee/emqx_license/test/emqx_license_SUITE.erl

@@ -68,7 +68,7 @@ t_update_file(_Config) ->
 
     ok = file:write_file("license_with_invalid_content.lic", <<"bad license">>),
     ?assertMatch(
-       {error, {unknown_format, _}},
+       {error, [_ | _]},
        emqx_license:update_file("license_with_invalid_content.lic")),
 
     ?assertMatch(
@@ -77,7 +77,7 @@ t_update_file(_Config) ->
 
 t_update_value(_Config) ->
     ?assertMatch(
-       {error, {unknown_format, _}},
+       {error, [_ | _]},
        emqx_license:update_key("invalid.license")),
 
     {ok, LicenseValue} = file:read_file(emqx_license_test_lib:default_license()),

lib-ee/emqx_license/test/emqx_license_parser_SUITE.erl

@@ -45,8 +45,7 @@ t_parse(_Config) ->
     %% invalid version
     ?assertMatch(
        {error,
-        {unknown_format,
-         [{emqx_license_parser_v20220101,invalid_version}]}},
+        [{emqx_license_parser_v20220101,invalid_version}]},
        emqx_license_parser:parse(
          emqx_license_test_lib:make_license(
            ["220101",
@@ -63,8 +62,7 @@ t_parse(_Config) ->
     %% invalid field number
     ?assertMatch(
        {error,
-        {unknown_format,
-         [{emqx_license_parser_v20220101,invalid_field_number}]}},
+        [{emqx_license_parser_v20220101,invalid_field_number}]},
        emqx_license_parser:parse(
          emqx_license_test_lib:make_license(
            ["220111",
@@ -80,12 +78,11 @@ t_parse(_Config) ->
 
     ?assertMatch(
        {error,
-        {unknown_format,
          [{emqx_license_parser_v20220101,
            [{type,invalid_license_type},
             {customer_type,invalid_customer_type},
             {date_start,invalid_date},
-            {days,invalid_int_value}]}]}},
+            {days,invalid_int_value}]}]},
        emqx_license_parser:parse(
          emqx_license_test_lib:make_license(
            ["220111",
@@ -125,21 +122,20 @@ t_parse(_Config) ->
 
     ?assertMatch(
        {error,
-        {unknown_format,
-         [{emqx_license_parser_v20220101,invalid_signature}]}},
+         [{emqx_license_parser_v20220101,invalid_signature}]},
        emqx_license_parser:parse(
          iolist_to_binary([LicensePart, <<".">>, SignaturePart]),
          public_key_encoded())),
 
     %% totally invalid strings as license
     ?assertMatch(
-       {error, {unknown_format, _}},
+       {error, [_ | _]},
        emqx_license_parser:parse(
          <<"badlicense">>,
          public_key_encoded())),
 
     ?assertMatch(
-       {error, {unknown_format, _}},
+       {error, [_ | _]},
        emqx_license_parser:parse(
          <<"bad.license">>,
          public_key_encoded())).