Fix issue 9059 (backport #9149)

deps/rabbitmq_auth_backend_ldap/src/rabbit_auth_backend_ldap.erl

@@ -17,7 +17,7 @@
 
 -export([user_login_authentication/2, user_login_authorization/2,
          check_vhost_access/3, check_resource_access/4, check_topic_access/4,
-         state_can_expire/0]).
+         state_can_expire/0, format_multi_attr/1, format_multi_attr/2]).
 
 -export([get_connections/0]).
 
@@ -699,14 +699,32 @@ get_attributes(AttrName, [#eldap_entry{attributes = A}|Rem]) ->
 get_attributes(AttrName, [_|Rem])    -> get_attributes(AttrName, Rem).
 
 %% Format multiple attribute values for logging
-format_multi_attr(Attrs) ->
-    format_multi_attr(io_lib:printable_list(Attrs), Attrs).
-
+%% The attribute can be:
+%%  - an ascii string (Erlang recognizes it as a printable_list)
+%%  - an non-ascii string (Erlang does not recognize it as a printable_list)
+%%  - a list/array of strings, which may contain ascii only or non-ascii and ascii characters
+utf8_list_to_string(List) -> unicode:characters_to_list(list_to_binary(List)).
+join_utf8_list(Acc, Sep, List) -> Acc ++ utf8_list_to_string(List) ++ Sep.
+
+format_multi_attr_value(Acc, _Sep, []) -> Acc;
+format_multi_attr_value(Acc, Sep, [H|T]) when is_list(H) ->
+  [H1|_T1] = H,
+  case H1 of
+    V when is_list(V) -> format_multi_attr_value(join_utf8_list(Acc, Sep, V), Sep, T);
+    _ -> format_multi_attr_value(join_utf8_list(Acc, Sep, H), Sep, T)
+  end;
+format_multi_attr_value(Acc, Sep, List) -> join_utf8_list(Acc, Sep, List).
+
+format_multi_attr(Attrs) -> format_multi_attr(io_lib:printable_list(Attrs), Attrs).
 format_multi_attr(true, Attrs)                     -> Attrs;
-format_multi_attr(_,    Attrs) when is_list(Attrs) -> string:join(Attrs, "; ");
+format_multi_attr(_,    Attrs) when is_list(Attrs) ->
+  [H|_T] = Attrs,
+  case H of
+    V when is_list(V) -> format_multi_attr_value("", "; ", Attrs);
+    _ -> utf8_list_to_string(Attrs)
+  end;
 format_multi_attr(_,    Error)                     -> Error.
 
-
 %% In case of multiple attributes, check for equality bi-directionally
 is_multi_attr_member(Str1, Str2) ->
     lists:member(Str1, Str2) orelse lists:member(Str2, Str1).

deps/rabbitmq_auth_backend_ldap/test/unit_SUITE.erl

@@ -16,7 +16,8 @@ all() ->
     [
      fill,
      ad_fill,
-     user_dn_pattern_gh_7161
+     user_dn_pattern_gh_7161,
+     format_different_types_of_ldap_attribute_values
     ].
 
 fill(_Config) ->
@@ -51,3 +52,25 @@ user_dn_pattern_gh_7161(_Config) ->
     ok = application:load(rabbitmq_auth_backend_ldap),
     {ok, UserDnPattern} = application:get_env(rabbitmq_auth_backend_ldap, user_dn_pattern),
     ?assertEqual("${username}", UserDnPattern).
+
+utf8_list_to_string(StrangeList) ->
+  unicode:characters_to_list(list_to_binary(StrangeList)).
+
+heuristic_encoding_bin(Bin) when is_binary(Bin) ->
+    case unicode:characters_to_binary(Bin,utf8,utf8) of
+	Bin ->
+	    utf8;
+	_ ->
+	    latin1
+    end.
+
+format_different_types_of_ldap_attribute_values(_Config) ->
+    AsciiOnlyAttr = [50,56,48,48,48,45],
+    ?assertEqual("28000-", rabbit_auth_backend_ldap:format_multi_attr("28000-")),
+    ?assertEqual("28000-", rabbit_auth_backend_ldap:format_multi_attr(AsciiOnlyAttr)),
+
+    NonAsciiAttr = [50,56,48,48,48,45,195,159],
+    ?assertEqual("28000-ß", rabbit_auth_backend_ldap:format_multi_attr(NonAsciiAttr)),
+
+    ?assertEqual("one; 28000-ß; two; ", rabbit_auth_backend_ldap:format_multi_attr(["one", NonAsciiAttr, "two"])),
+    ok.