Fix broken handling of default values for BIT STRINGs

For DER/PER/UPER, a value equal to the DEFAULT is not supposed to
be encoded.

BIT STRINGs values can be represented as Erlang terms in four
different ways: as an integer, as a list of zeroes and ones,
as a {Unused,Binary} tuple, or as an Erlang bitstring.

When encoding a BIT STRING, only certain representations of
BIT STRINGs values were recognized. All representations must
be recognized.

When decoding a DEFAULT value for a BIT STRING, the actual value
given in the decoding would be either an integer or a list
of zeroes and one (depending on how the literal was written in
the specification). We expect that the default value should be
in the same representation as any other BIT STRING value (i.e.
by default an Erlang bitstring, or a list if the 'legacy_bitstring'
option has been given, or as compact bitstring if 'compact_bitstring'
has been given).

7 files changed, 246 insertions, 132 deletions

diff --git a/lib/asn1/src/asn1ct_check.erl b/lib/asn1/src/asn1ct_check.erl
index eddcda0018..04227fd23b 100644
--- a/lib/asn1/src/asn1ct_check.erl
+++ b/lib/asn1/src/asn1ct_check.erl
@@ -2534,89 +2534,54 @@ normalize_integer(S,Int=#'Externalvaluereference'{value=Name},Type) ->
 normalize_integer(_,Int,_) ->
     exit({'Unknown INTEGER value',Int}).
 
-normalize_bitstring(S,Value,Type)->
-    %% There are four different Erlang formats of BIT STRING:
-    %% 1 - a list of ones and zeros.
-    %% 2 - a list of atoms.
-    %% 3 - as an integer, for instance in hexadecimal form.
-    %% 4 - as a tuple {Unused, Binary} where Unused is an integer
-    %%   and tells how many bits of Binary are unused.
-    %% 
-    %% normalize_bitstring/3 transforms Value according to:
-    %% A to 3,
-    %% B to 1,
-    %% C to 1 or 3
-    %% D to 2,
-    %% Value can be on format:
-    %% A - {hstring, String}, where String is a hexadecimal string.
-    %% B - {bstring, String}, where String is a string on bit format
-    %% C - #'Externalvaluereference'{value=V}, where V is a defined value
-    %% D - list of #'Externalvaluereference', where each value component
-    %%     is an identifier corresponing to NamedBits in Type.
-    %% E - list of ones and zeros, if Value already is normalized.
+%% normalize_bitstring(S, Value, Type) -> bitstring()
+%%  Convert a literal value for a BIT STRING to an Erlang bit string.
+%%
+normalize_bitstring(S, Value, Type)->
     case Value of
 	{hstring,String} when is_list(String) ->
-	    hstring_to_int(String);
+	    hstring_to_bitstring(String);
 	{bstring,String} when is_list(String) ->
-	    bstring_to_bitlist(String);
-	Rec when is_record(Rec,'Externalvaluereference') ->
-	    get_normalized_value(S,Value,Type,
-				 fun normalize_bitstring/3,[]);
+	    bstring_to_bitstring(String);
+	#'Externalvaluereference'{} ->
+	    get_normalized_value(S, Value, Type,
+				 fun normalize_bitstring/3, []);
 	RecList when is_list(RecList) ->
-	    case Type of
-		NBL when is_list(NBL) ->
-		    F = fun(#'Externalvaluereference'{value=Name}) ->
-				case lists:keysearch(Name,1,NBL) of
-				    {value,{Name,_}} ->
-					Name;
-				    Other ->
-					throw({error,Other})
-				end;
-			   (I) when I =:= 1; I =:= 0 ->
-				I;
-			   (Other) ->
-				throw({error,Other})
-			end,
-		    case catch lists:map(F,RecList) of
-			{error,Reason} ->
-			    asn1ct:warning("default value not "
-					   "compatible with type definition ~p~n",
-					   [Reason],S,
-					   "default value not "
-					   "compatible with type definition"),
-			    Value;
-			NewList ->
-			    NewList
-		    end;
-		_ ->
+	    F = fun(#'Externalvaluereference'{value=Name}) ->
+			case lists:keymember(Name, 1, Type) of
+			    true -> Name;
+			    false -> throw({error,false})
+			end;
+		   (Name) when is_atom(Name) ->
+			%% Already normalized.
+			Name;
+		   (Other) ->
+			throw({error,Other})
+		end,
+	    try
+		lists:map(F, RecList)
+	    catch
+		throw:{error,Reason} ->
 		    asn1ct:warning("default value not "
 				   "compatible with type definition ~p~n",
-				   [RecList],S,
+				   [Reason],S,
 				   "default value not "
 				   "compatible with type definition"),
 		    Value
 	    end;
-	{Name,String} when is_atom(Name) ->
-	    normalize_bitstring(S,String,Type);
-	Other ->
-	    asn1ct:warning("illegal default value ~p~n",[Other],S,
-			   "illegal default value"),
-	    Value
+	Bs when is_bitstring(Bs) ->
+	    %% Already normalized.
+	    Bs
     end.
 
-hstring_to_int(L) when is_list(L) ->
-    hstring_to_int(L,0).
-hstring_to_int([H|T],Acc) when H >= $A, H =< $F ->
-    hstring_to_int(T,(Acc bsl 4) + (H - $A + 10) ) ;
-hstring_to_int([H|T],Acc) when H >= $0, H =< $9 ->
-    hstring_to_int(T,(Acc bsl 4) + (H - $0));
-hstring_to_int([],Acc) ->
-    Acc.
+hstring_to_bitstring(L) ->
+    << <<(hex_to_int(D)):4>> || D <- L >>.
 
-bstring_to_bitlist([H|T]) when H == $0; H == $1 ->
-    [H - $0 | bstring_to_bitlist(T)];
-bstring_to_bitlist([]) ->
-    [].
+bstring_to_bitstring(L) ->
+    << <<(D-$0):1>> || D <- L >>.
+
+hex_to_int(D) when $0 =< D, D =< $9 -> D - $0;
+hex_to_int(D) when $A =< D, D =< $F -> D - ($A - 10).
 
 %% normalize_octetstring/1 changes representation of input Value to a 
 %% list of octets.
diff --git a/lib/asn1/src/asn1ct_constructed_ber_bin_v2.erl b/lib/asn1/src/asn1ct_constructed_ber_bin_v2.erl
index 8359b81b33..a38da8bcc2 100644
--- a/lib/asn1/src/asn1ct_constructed_ber_bin_v2.erl
+++ b/lib/asn1/src/asn1ct_constructed_ber_bin_v2.erl
@@ -1155,7 +1155,8 @@ gen_dec_line(Erules,TopType,Cname,CTags,Type,OptOrMand,DecObjInf)  ->
 		
 		emit([indent(4),"_ ->",nl]),
 		case OptOrMand of
-		    {'DEFAULT', Def} ->
+		    {'DEFAULT', Def0} ->
+			Def = asn1ct_gen:conform_value(Type, Def0),
 			emit([indent(8),"{",{asis,Def},",",{prev,tlv},"}",nl]);
 		    'OPTIONAL' ->
 			emit([indent(8),"{ asn1_NOVALUE, ",{prev,tlv},"}",nl])
diff --git a/lib/asn1/src/asn1ct_constructed_per.erl b/lib/asn1/src/asn1ct_constructed_per.erl
index 8d4afc0a0b..4672f7edd3 100644
--- a/lib/asn1/src/asn1ct_constructed_per.erl
+++ b/lib/asn1/src/asn1ct_constructed_per.erl
@@ -770,8 +770,10 @@ optionals(L) -> optionals(L,[],2).
 
 optionals([#'ComponentType'{prop='OPTIONAL'}|Rest], Acc, Pos) ->
     optionals(Rest, [Pos|Acc], Pos+1);
-optionals([#'ComponentType'{prop={'DEFAULT',Val}}|Rest], Acc, Pos) ->
-    optionals(Rest, [{Pos,Val}|Acc], Pos+1);
+optionals([#'ComponentType'{typespec=T,prop={'DEFAULT',Val}}|Rest],
+	  Acc, Pos) ->
+    Vals = def_values(T, Val),
+    optionals(Rest, [{Pos,Vals}|Acc], Pos+1);
 optionals([#'ComponentType'{}|Rest], Acc, Pos) ->
     optionals(Rest, Acc, Pos+1);
 optionals([], Acc, _) ->
@@ -888,7 +890,8 @@ gen_enc_components_call1(Erule,TopType,
 	       optional ->
 		   asn1ct_imm:enc_absent(Element, [asn1_NOVALUE], Imm1);
 	       {default,Def} ->
-		   asn1ct_imm:enc_absent(Element, [asn1_DEFAULT,Def], Imm1)
+		   DefValues = def_values(Type, Def),
+		   asn1ct_imm:enc_absent(Element, DefValues, Imm1)
 	   end,
     Imm = case Imm2 of
 	      [] -> [];
@@ -899,6 +902,38 @@ gen_enc_components_call1(_Erule,_TopType,[],Pos,_,_, Acc) ->
     ImmList = lists:reverse(Acc),
     {ImmList,Pos}.
 
+def_values(#type{def=#'Externaltypereference'{module=Mod,type=Type}}, Def) ->
+    #typedef{typespec=T} = asn1_db:dbget(Mod, Type),
+    def_values(T, Def);
+def_values(#type{def={'BIT STRING',[]}}, Bs) when is_bitstring(Bs) ->
+    ListBs = [B || <<B:1>> <= Bs],
+    IntBs = lists:foldl(fun(B, A) ->
+				(A bsl 1) bor B
+			end, 0, lists:reverse(ListBs)),
+    Sz = bit_size(Bs),
+    Compact = case 8 - Sz rem 8 of
+		  8 ->
+		      {0,Bs};
+		  Unused ->
+		      {Unused,<<Bs:Sz/bits,0:Unused>>}
+	      end,
+    [asn1_DEFAULT,Bs,Compact,ListBs,IntBs];
+def_values(#type{def={'BIT STRING',[_|_]=Ns}}, List) when is_list(List) ->
+    Bs = asn1ct_gen:named_bitstring_value(List, Ns),
+    ListBs = [B || <<B:1>> <= Bs],
+    IntBs = lists:foldl(fun(B, A) ->
+				(A bsl 1) bor B
+			end, 0, lists:reverse(ListBs)),
+    Args = [List,Bs,ListBs,IntBs],
+    {call,per_common,is_default_bitstring,Args};
+def_values(#type{def={'INTEGER',Ns}}, Def) ->
+    [asn1_DEFAULT,Def|case lists:keyfind(Def, 2, Ns) of
+			  false -> [];
+			  {Val,Def} -> [Val]
+		      end];
+def_values(_, Def) ->
+    [asn1_DEFAULT,Def].
+
 gen_enc_line_imm(Erule, TopType, Cname, Type, Element, DynamicEnc, Ext) ->
     Imm0 = gen_enc_line_imm_1(Erule, TopType, Cname, Type,
 			      Element, DynamicEnc),
@@ -1207,7 +1242,8 @@ gen_dec_comp_call(Comp, Erule, TopType, Tpos, OptTable, DecInfObj,
 
 comp_call_pre_post(noext, mandatory, _, _, _, _, _, _) ->
     {[],[]};
-comp_call_pre_post(noext, Prop, _, _, TextPos, OptTable, NumOptionals, Ext) ->
+comp_call_pre_post(noext, Prop, _, Type, TextPos,
+		   OptTable, NumOptionals, Ext) ->
     %% OPTIONAL or DEFAULT
     OptPos = get_optionality_pos(TextPos, OptTable),
     Element = case NumOptionals - OptPos of
@@ -1225,7 +1261,7 @@ comp_call_pre_post(noext, Prop, _, _, TextPos, OptTable, NumOptionals, Ext) ->
 	      emit([";",nl,
 		    "0 ->",nl,
 		    "{"]),
-	      gen_dec_component_no_val(Ext, Prop),
+	      gen_dec_component_no_val(Ext, Type, Prop),
 	      emit([",",{curr,bytes},"}",nl,
 		    "end"]),
 	      St
@@ -1247,10 +1283,10 @@ comp_call_pre_post({ext,_,_}, Prop, Pos, Type, _, _, _, Ext) ->
 			       components=ExtGroupCompList2}}
 		    when is_integer(Number2)->
 		      emit("{extAddGroup,"),
-		      gen_dec_extaddGroup_no_val(Ext, ExtGroupCompList2),
+		      gen_dec_extaddGroup_no_val(Ext, Type, ExtGroupCompList2),
 		      emit("}");
 		  _ ->
-		      gen_dec_component_no_val(Ext, Prop)
+		      gen_dec_component_no_val(Ext, Type, Prop)
 	      end,
 	      emit([",",{curr,bytes},"}",nl,
 		    "end"]),
@@ -1265,21 +1301,22 @@ is_mandatory_predef_tab_c(_, _, {"got objfun through args","ObjFun"}) ->
 is_mandatory_predef_tab_c(_,_,_) ->
     true.
 
-gen_dec_extaddGroup_no_val(Ext,[#'ComponentType'{prop=Prop}])->
-    gen_dec_component_no_val(Ext,Prop),
+gen_dec_extaddGroup_no_val(Ext, Type, [#'ComponentType'{prop=Prop}])->
+    gen_dec_component_no_val(Ext, Type, Prop),
     ok;
-gen_dec_extaddGroup_no_val(Ext,[#'ComponentType'{prop=Prop}|Rest])->
-    gen_dec_component_no_val(Ext,Prop),
-    emit({","}),
-    gen_dec_extaddGroup_no_val(Ext,Rest);
-gen_dec_extaddGroup_no_val(_, []) ->
+gen_dec_extaddGroup_no_val(Ext, Type, [#'ComponentType'{prop=Prop}|Rest])->
+    gen_dec_component_no_val(Ext, Type, Prop),
+    emit(","),
+    gen_dec_extaddGroup_no_val(Ext, Type, Rest);
+gen_dec_extaddGroup_no_val(_, _, []) ->
     ok.
 
-gen_dec_component_no_val(_,{'DEFAULT',DefVal}) ->
+gen_dec_component_no_val(_, Type, {'DEFAULT',DefVal0}) ->
+    DefVal = asn1ct_gen:conform_value(Type, DefVal0),
     emit([{asis,DefVal}]);
-gen_dec_component_no_val(_,'OPTIONAL') ->
+gen_dec_component_no_val(_, _, 'OPTIONAL') ->
     emit({"asn1_NOVALUE"});
-gen_dec_component_no_val({ext,_,_},mandatory) ->
+gen_dec_component_no_val({ext,_,_}, _, mandatory) ->
     emit({"asn1_NOVALUE"}).
     
 
diff --git a/lib/asn1/src/asn1ct_gen.erl b/lib/asn1/src/asn1ct_gen.erl
index 3452d29085..30d337635b 100644
--- a/lib/asn1/src/asn1ct_gen.erl
+++ b/lib/asn1/src/asn1ct_gen.erl
@@ -33,7 +33,9 @@
 	 insert_once/2,
 	 ct_gen_module/1,
 	 index2suffix/1,
-	 get_record_name_prefix/0]).
+	 get_record_name_prefix/0,
+	 conform_value/2,
+	 named_bitstring_value/2]).
 -export([pgen/5,
 	 mk_var/1, 
 	 un_hyphen_var/1]).
@@ -1485,8 +1487,14 @@ gen_prim_check_call(PrimType, Default, Element, Type) ->
 		  end,
 	    check_call(check_int, [Default,Element,{asis,NNL}]);
 	'BIT STRING' ->
-	    {_,NBL} = Type#type.def,
-	    check_call(check_bitstring, [Default,Element,{asis,NBL}]);
+	    case Type#type.def of
+		{_,[]} ->
+		    check_call(check_bitstring,
+			       [Default,Element]);
+		{_,[_|_]=NBL} ->
+		    check_call(check_named_bitstring,
+			       [Default,Element,{asis,NBL}])
+	    end;
 	'OCTET STRING' ->
 	    check_call(check_octetstring, [Default,Element]);
 	'NULL' ->
@@ -1640,9 +1648,33 @@ unify_if_string(PrimType) ->
 	Other -> Other
     end.
 
-
-	
-	
+conform_value(#type{def={'BIT STRING',[]}}, Bs) ->
+    case asn1ct:get_bit_string_format() of
+	compact when is_binary(Bs) ->
+	    {0,Bs};
+	compact when is_bitstring(Bs) ->
+	    Sz = bit_size(Bs),
+	    Unused = 8 - bit_size(Bs),
+	    {Unused,<<Bs:Sz/bits,0:Unused>>};
+	legacy ->
+	    [B || <<B:1>> <= Bs];
+	bitstring when is_bitstring(Bs) ->
+	    Bs
+    end;
+conform_value(_, Value) -> Value.
+
+named_bitstring_value(List, Names) ->
+    Int = lists:foldl(fun(N, A) ->
+			      {N,Pos} = lists:keyfind(N, 1, Names),
+			      A bor (1 bsl Pos)
+		      end, 0, List),
+    named_bitstring_value_1(<<>>, Int).
+
+named_bitstring_value_1(Bs, 0) ->
+    Bs;
+named_bitstring_value_1(Bs, Int) ->
+    B = Int band 1,
+    named_bitstring_value_1(<<Bs/bitstring,B:1>>, Int bsr 1).
 
 get_inner(A) when is_atom(A) -> A;    
 get_inner(Ext) when is_record(Ext,'Externaltypereference') -> Ext;    
diff --git a/lib/asn1/src/asn1ct_imm.erl b/lib/asn1/src/asn1ct_imm.erl
index 892178f61b..dfa4ce0d6b 100644
--- a/lib/asn1/src/asn1ct_imm.erl
+++ b/lib/asn1/src/asn1ct_imm.erl
@@ -319,14 +319,22 @@ per_enc_extensions(Val0, Pos0, NumBits, Aligned) when NumBits > 0 ->
 	{'cond',[[{eq,Bitmap,0}],
 		 ['_'|Length ++ PutBits]],{var,"Extensions"}}].
 
-per_enc_optional(Val0, {Pos,Def}, _Aligned) when is_integer(Pos) ->
+per_enc_optional(Val0, {Pos,DefVals}, _Aligned) when is_integer(Pos),
+						     is_list(DefVals) ->
     Val1 = lists:concat(["element(",Pos,", ",Val0,")"]),
     {B,[Val]} = mk_vars(Val1, []),
     Zero = {put_bits,0,1,[1]},
     One = {put_bits,1,1,[1]},
-    B++[{'cond',[[{eq,Val,asn1_DEFAULT},Zero],
-		 [{eq,Val,Def},Zero],
-		 ['_',One]]}];
+    B++[{'cond',
+	 [[{eq,Val,DefVal},Zero] || DefVal <- DefVals] ++ [['_',One]]}];
+per_enc_optional(Val0, {Pos,{call,M,F,A}}, _Aligned) when is_integer(Pos) ->
+    Val1 = lists:concat(["element(",Pos,", ",Val0,")"]),
+    {B,[Val,Tmp]} = mk_vars(Val1, [tmp]),
+    Zero = {put_bits,0,1,[1]},
+    One = {put_bits,1,1,[1]},
+    B++[{call,M,F,[Val|A],Tmp},
+	{'cond',
+	 [[{eq,Tmp,true},Zero],['_',One]]}];
 per_enc_optional(Val0, Pos, _Aligned) when is_integer(Pos) ->
     Val1 = lists:concat(["element(",Pos,", ",Val0,")"]),
     {B,[Val]} = mk_vars(Val1, []),
@@ -352,7 +360,12 @@ per_enc_sof(Val0, Constraint, ElementVar, ElementImm, Aligned) ->
 	    PreBlock ++ EncLen ++ Lc
     end.
 
-enc_absent(Val0, AbsVals, Body) ->
+enc_absent(Val0, {call,M,F,A}, Body) ->
+    {B,[Var,Tmp]} = mk_vars(Val0, [tmp]),
+    B++[{call,M,F,[Var|A],Tmp},
+	{'cond',
+	 [[{eq,Tmp,true}],['_'|Body]]}];
+enc_absent(Val0, AbsVals, Body) when is_list(AbsVals) ->
     {B,[Var]} = mk_vars(Val0, []),
     Cs = [[{eq,Var,Aval}] || Aval <- AbsVals] ++ [['_'|Body]],
     B++build_cond(Cs).
diff --git a/lib/asn1/src/asn1rtt_check.erl b/lib/asn1/src/asn1rtt_check.erl
index e78b65a8fb..be4f9c8bff 100644
--- a/lib/asn1/src/asn1rtt_check.erl
+++ b/lib/asn1/src/asn1rtt_check.erl
@@ -20,7 +20,7 @@
 
 -export([check_bool/2,
 	 check_int/3,
-	 check_bitstring/3,
+	 check_bitstring/2,check_named_bitstring/3,
 	 check_octetstring/2,
 	 check_null/2,
 	 check_objectidentifier/2,
@@ -50,31 +50,54 @@ check_int(DefValue, Value, NNL) when is_atom(Value) ->
 check_int(DefaultValue, _Value, _) ->
     throw({error,DefaultValue}).
 
-%% Two equal lists or integers
-check_bitstring(_, asn1_DEFAULT, _) ->
+%% check_bitstring(Default, UserBitstring) -> true|false
+%%  Default = bitstring()
+%%  UserBitstring = integeger() | list(0|1) | {Unused,binary()} | bitstring()
+check_bitstring(_, asn1_DEFAULT) ->
     true;
-check_bitstring(V, V, _) ->
-    true;
-%% Default value as a list of 1 and 0 and user value as an integer
-check_bitstring(L=[H|T], Int, _) when is_integer(Int), is_integer(H) ->
-    case bit_list_to_int(L, length(T)) of
-	Int -> true;
-	_ -> throw({error,L,Int})
+check_bitstring(DefVal, {Unused,Binary}) ->
+    %% User value in compact format.
+    Sz = bit_size(Binary) - Unused,
+    <<Val:Sz/bitstring,_:Unused>> = Binary,
+    check_bitstring(DefVal, Val);
+check_bitstring(DefVal, Val) when is_bitstring(Val) ->
+    case Val =:= DefVal of
+	false -> throw(error);
+	true -> true
     end;
-%% Default value as an integer, val as list
-check_bitstring(Int, Val, NBL) when is_integer(Int), is_list(Val) ->
-    BL = int_to_bit_list(Int, [], length(Val)),
-    check_bitstring(BL, Val, NBL);
+check_bitstring(Def, Val) when is_list(Val) ->
+    check_bitstring_list(Def, Val);
+check_bitstring(Def, Val) when is_integer(Val) ->
+    check_bitstring_integer(Def, Val).
+
+check_bitstring_list(<<H:1,T1/bitstring>>, [H|T2]) ->
+    check_bitstring_list(T1, T2);
+check_bitstring_list(<<>>, []) ->
+    true;
+check_bitstring_list(_, _) ->
+    throw(error).
+
+check_bitstring_integer(<<H:1,T1/bitstring>>, Int) when H =:= Int band 1 ->
+    check_bitstring_integer(T1, Int bsr 1);
+check_bitstring_integer(<<>>, 0) ->
+    true;
+check_bitstring_integer(_, _) ->
+    throw(error).
+
+check_named_bitstring(_, asn1_DEFAULT, _) ->
+    true;
+check_named_bitstring(V, V, _) ->
+    true;
 %% Default value and user value as lists of ones and zeros
-check_bitstring(L1=[H1|_T1], L2=[H2|_T2], NBL=[_H|_T]) when is_integer(H1), is_integer(H2) ->
+check_named_bitstring(L1=[H1|_T1], L2=[H2|_T2], NBL=[_H|_T]) when is_integer(H1), is_integer(H2) ->
     L2new = remove_trailing_zeros(L2),
-    check_bitstring(L1, L2new, NBL);
+    check_named_bitstring(L1, L2new, NBL);
 %% Default value as a list of 1 and 0 and user value as a list of atoms
-check_bitstring(L1=[H1|_T1], L2=[H2|_T2], NBL) when is_integer(H1), is_atom(H2) ->
+check_named_bitstring(L1=[H1|_T1], L2=[H2|_T2], NBL) when is_integer(H1), is_atom(H2) ->
     L3 = bit_list_to_nbl(L1, NBL, 0, []),
-    check_bitstring(L3, L2, NBL);
+    check_named_bitstring(L3, L2, NBL);
 %% Both default value and user value as a list of atoms
-check_bitstring(L1=[H1|T1], L2=[H2|_T2], _)
+check_named_bitstring(L1=[H1|T1], L2=[H2|_T2], _)
   when is_atom(H1), is_atom(H2), length(L1) =:= length(L2) ->
     case lists:member(H1, L2) of
 	true ->
@@ -82,27 +105,29 @@ check_bitstring(L1=[H1|T1], L2=[H2|_T2], _)
 	false -> throw({error,L2})
     end;
 %% Default value as a list of atoms and user value as a list of 1 and 0
-check_bitstring(L1=[H1|_T1], L2=[H2|_T2], NBL) when is_atom(H1), is_integer(H2) ->
+check_named_bitstring(L1=[H1|_T1], L2=[H2|_T2], NBL) when is_atom(H1), is_integer(H2) ->
     L3 = bit_list_to_nbl(L2, NBL, 0, []),
-    check_bitstring(L1, L3, NBL);
+    check_named_bitstring(L1, L3, NBL);
 %% User value in compact format
-check_bitstring(DefVal,CBS={_,_}, NBL) ->
+check_named_bitstring(DefVal,CBS={_,_}, NBL) ->
     NewVal = cbs_to_bit_list(CBS),
-    check_bitstring(DefVal, NewVal, NBL);
-check_bitstring(DV, V, _) ->
+    check_named_bitstring(DefVal, NewVal, NBL);
+%% User value as a binary
+check_named_bitstring(DefVal, CBS, NBL) when is_binary(CBS) ->
+    NewVal = cbs_to_bit_list({0,CBS}),
+    check_named_bitstring(DefVal, NewVal, NBL);
+%% User value as a bitstring
+check_named_bitstring(DefVal, CBS, NBL) when is_bitstring(CBS) ->
+    BitSize = bit_size(CBS),
+    Unused = 8 - (BitSize band 7),
+    NewVal = cbs_to_bit_list({Unused,<<CBS:BitSize/bits,0:Unused>>}),
+    check_named_bitstring(DefVal, NewVal, NBL);
+check_named_bitstring(DV, V, _) ->
     throw({error,DV,V}).
 
-
-bit_list_to_int([0|Bs], ShL)->
-    bit_list_to_int(Bs, ShL-1) + 0;
-bit_list_to_int([1|Bs], ShL) ->
-    bit_list_to_int(Bs, ShL-1) + (1 bsl ShL);
-bit_list_to_int([], _) ->
-    0.
-
 int_to_bit_list(0, Acc, 0) ->
     Acc;
-int_to_bit_list(Int, Acc, Len) ->
+int_to_bit_list(Int, Acc, Len) when Len > 0 ->
     int_to_bit_list(Int bsr 1, [Int band 1|Acc], Len - 1).
 
 bit_list_to_nbl([0|T], NBL, Pos, Acc) ->
diff --git a/lib/asn1/src/asn1rtt_per_common.erl b/lib/asn1/src/asn1rtt_per_common.erl
index 9e9fd87ec3..3309e6a4ca 100644
--- a/lib/asn1/src/asn1rtt_per_common.erl
+++ b/lib/asn1/src/asn1rtt_per_common.erl
@@ -37,6 +37,7 @@
 	 bitstring_from_positions/1,bitstring_from_positions/2,
 	 to_bitstring/1,to_bitstring/2,
 	 to_named_bitstring/1,to_named_bitstring/2,
+	 is_default_bitstring/5,
 	 extension_bitmap/3]).
 
 -define('16K',16384).
@@ -271,6 +272,36 @@ to_named_bitstring(Val, Lb) ->
     %% for correctness, not speed.
     adjust_trailing_zeroes(to_bitstring(Val), Lb).
 
+is_default_bitstring(asn1_DEFAULT, _, _, _, _) ->
+    true;
+is_default_bitstring({Unused,Bin}, V0, V1, V2, V3) when is_integer(Unused) ->
+    %% Convert compact bitstring to a bitstring.
+    Sz = bit_size(Bin) - Unused,
+    <<Bs:Sz/bitstring,_:Unused>> = Bin,
+    is_default_bitstring(Bs, V0, V1, V2, V3);
+is_default_bitstring(Named, Named, _, _, _) ->
+    true;
+is_default_bitstring(Bs, _, Bs, _, _) ->
+    true;
+is_default_bitstring(List, _, _, List, _) ->
+    true;
+is_default_bitstring(Int, _, _, _, Int) ->
+    true;
+is_default_bitstring(Val, _, Def, _, _) when is_bitstring(Val) ->
+    Sz = bit_size(Def),
+    case Val of
+	<<Def:Sz/bitstring,T/bitstring>> ->
+	    NumZeroes = bit_size(T),
+	    case T of
+		<<0:NumZeroes>> -> true;
+		_ -> false
+	    end;
+	_ ->
+	    false
+    end;
+is_default_bitstring(Val, _, _, List, _) when is_list(Val) ->
+    is_default_bitstring_list(List, Val);
+is_default_bitstring(_, _, _, _, _) -> false.
 
 extension_bitmap(Val, Pos, Limit) ->
     extension_bitmap(Val, Pos, Limit, 0).
@@ -447,6 +478,16 @@ ntz(Byte) ->
 	 4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0},
     element(Byte+1, T).
 
+is_default_bitstring_list([H|Def], [H|Val]) ->
+    is_default_bitstring_list(Def, Val);
+is_default_bitstring_list([], []) ->
+    true;
+is_default_bitstring_list([], [_|_]=Val) ->
+    lists:all(fun(0) -> true;
+		 (_) -> false
+	      end, Val);
+is_default_bitstring_list(_, _) -> false.
+
 extension_bitmap(_Val, Pos, Limit, Acc) when Pos >= Limit ->
     Acc;
 extension_bitmap(Val, Pos, Limit, Acc) ->