per,uper: Optimize decoding of the string data types

6 files changed, 176 insertions, 263 deletions

diff --git a/lib/asn1/src/asn1ct_gen_per.erl b/lib/asn1/src/asn1ct_gen_per.erl
index b38af3306a..25b0d46295 100644
--- a/lib/asn1/src/asn1ct_gen_per.erl
+++ b/lib/asn1/src/asn1ct_gen_per.erl
@@ -1131,6 +1131,22 @@ gen_dec_imm_1({'INTEGER',NamedNumberList}, Constraint, Aligned) ->
     asn1ct_imm:per_dec_named_integer(Constraint,
 				     NamedNumberList,
 				     Aligned);
+gen_dec_imm_1('BMPString'=Type, Constraint, Aligned) ->
+    gen_dec_k_m_string(Type, Constraint, Aligned);
+gen_dec_imm_1('NumericString'=Type, Constraint, Aligned) ->
+    gen_dec_k_m_string(Type, Constraint, Aligned);
+gen_dec_imm_1('PrintableString'=Type, Constraint, Aligned) ->
+    gen_dec_k_m_string(Type, Constraint, Aligned);
+gen_dec_imm_1('VisibleString'=Type, Constraint, Aligned) ->
+    gen_dec_k_m_string(Type, Constraint, Aligned);
+gen_dec_imm_1('IA5String'=Type, Constraint, Aligned) ->
+    gen_dec_k_m_string(Type, Constraint, Aligned);
+gen_dec_imm_1('UniversalString'=Type, Constraint, Aligned) ->
+    gen_dec_k_m_string(Type, Constraint, Aligned);
+gen_dec_imm_1('UTCTime', Constraint, Aligned) ->
+    gen_dec_k_m_string('VisibleString', Constraint, Aligned);
+gen_dec_imm_1('GeneralizedTime', Constraint, Aligned) ->
+    gen_dec_k_m_string('VisibleString', Constraint, Aligned);
 gen_dec_imm_1('OCTET STRING', Constraint, Aligned) ->
     SzConstr = get_constraint(Constraint, 'SizeConstraint'),
     Imm = asn1ct_imm:per_dec_octet_string(SzConstr, Aligned),
@@ -1151,6 +1167,9 @@ gen_dec_copy_bitstring(Imm) ->
 	end,
     {call,D,Imm}.
 
+gen_dec_k_m_string(Type, Constraint, Aligned) ->
+    asn1ct_imm:per_dec_k_m_string(Type, Constraint, Aligned).
+
 gen_dec_prim(Erule, Type, BytesVar) ->
     case gen_dec_imm(Erule, Type) of
 	no ->
@@ -1171,9 +1190,6 @@ gen_dec_prim_1(Erule,
 	    call(Erule, decode_relative_oid, [BytesVar]);
 	'ObjectDescriptor' ->
 	    call(Erule, decode_ObjectDescriptor, [BytesVar]);
-	'NumericString' ->
-	    call(Erule, decode_NumericString,
-		 [BytesVar,{asis,Constraint}]);
 	TString when TString == 'TeletexString';
 		     TString == 'T61String' ->
 	    call(Erule, decode_TeletexString,
@@ -1181,27 +1197,10 @@ gen_dec_prim_1(Erule,
 	'VideotexString' ->
 	    call(Erule, decode_VideotexString,
 		 [BytesVar,{asis,Constraint}]);
-	'UTCTime' ->
-	    call(Erule, decode_VisibleString, [BytesVar,{asis,Constraint}]);
-	'GeneralizedTime' ->
-	    call(Erule, decode_VisibleString, [BytesVar,{asis,Constraint}]);
 	'GraphicString' ->
 	    call(Erule, decode_GraphicString,[BytesVar,{asis,Constraint}]);
-	'VisibleString' ->
-	    call(Erule, decode_VisibleString, [BytesVar,{asis,Constraint}]);
 	'GeneralString' ->
 	    call(Erule, decode_GeneralString, [BytesVar,{asis,Constraint}]);
-	'PrintableString' ->
-	    call(Erule, decode_PrintableString,
-		 [BytesVar,{asis,Constraint}]);
-	'IA5String' ->
-	    call(Erule, decode_IA5String, [BytesVar,{asis,Constraint}]);
-	'BMPString' ->
-	    call(Erule, decode_BMPString,
-		 [BytesVar,{asis,Constraint}]);
-	'UniversalString' ->
-	    call(Erule, decode_UniversalString,
-		 [BytesVar,{asis,Constraint}]);
 	'UTF8String' ->
 	    call(Erule, decode_UTF8String, [BytesVar]);
 	#'ObjectClassFieldType'{} ->
diff --git a/lib/asn1/src/asn1ct_gen_per_rt2ct.erl b/lib/asn1/src/asn1ct_gen_per_rt2ct.erl
index bf08494c5c..b6be3a1a8f 100644
--- a/lib/asn1/src/asn1ct_gen_per_rt2ct.erl
+++ b/lib/asn1/src/asn1ct_gen_per_rt2ct.erl
@@ -263,54 +263,26 @@ emit_enc_k_m_string(SizeC, NumBits, CharOutTab, Value) ->
     call(per, encode_known_multiplier_string,
 	 [{asis,SizeC},NumBits,{asis,CharOutTab},Value]).
 
-emit_dec_known_multiplier_string(StringType,C,BytesVar) ->
-    SizeC = get_constraint(C,'SizeConstraint'),
-    PAlphabC = get_constraint(C,'PermittedAlphabet'),
-    case {StringType,PAlphabC} of
-	{'BMPString',{_,_}} ->
-	    exit({error,{asn1,
-			 {'not implemented',
-			  "BMPString with PermittedAlphabet "
-			  "constraint"}}});
-	_ ->
-	    ok
-    end,
-    NumBits = get_NumBits(C,StringType),
-    CharInTab = get_CharInTab(C,StringType),
-    case SizeC of
-	0 ->
-	    emit({"{[],",BytesVar,"}"});
-	_ ->
-	    call(per, decode_known_multiplier_string,
-		 [{asis,StringType},{asis,SizeC},NumBits,
-		  {asis,CharInTab},BytesVar])
-    end.
-
 
 %% copied from run time module
 
-get_CharOutTab(C,StringType) ->
-    get_CharTab(C,StringType,out).
-
-get_CharInTab(C,StringType) ->
-    get_CharTab(C,StringType,in).
-
-get_CharTab(C,StringType,InOut) ->
+get_CharOutTab(C, StringType) ->
     case get_constraint(C,'PermittedAlphabet') of
 	{'SingleValue',Sv} ->
-	    get_CharTab2(C,StringType,hd(Sv),lists:max(Sv),Sv,InOut);
+	    get_CharTab2(C, StringType, hd(Sv), lists:max(Sv), Sv);
 	no ->
 	    case StringType of
 		'IA5String' ->
 		    {0,16#7F,notab};
 		'VisibleString' ->
-		    get_CharTab2(C,StringType,16#20,16#7F,notab,InOut);
+		    get_CharTab2(C, StringType, 16#20, 16#7F, notab);
 		'PrintableString' ->
 		    Chars = lists:sort(
 			      " '()+,-./0123456789:=?ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"),
-		    get_CharTab2(C,StringType,hd(Chars),lists:max(Chars),Chars,InOut);
+		    get_CharTab2(C, StringType, hd(Chars),
+				 lists:max(Chars), Chars);
 		'NumericString' ->
-		    get_CharTab2(C,StringType,16#20,$9," 0123456789",InOut);
+		    get_CharTab2(C, StringType, 16#20, $9, " 0123456789");
 		'UniversalString' ->
 		    {0,16#FFFFFFFF,notab};
 		'BMPString' ->
@@ -318,18 +290,13 @@ get_CharTab(C,StringType,InOut) ->
 	    end
     end.
 
-get_CharTab2(C,StringType,Min,Max,Chars,InOut) ->
+get_CharTab2(C, StringType, Min, Max, Chars) ->
     BitValMax = (1 bsl get_NumBits(C,StringType))-1,
     if
 	Max =< BitValMax ->
 	    {0,Max,notab};
 	true ->
-	    case InOut of
-		out ->
-		    {Min,Max,create_char_tab(Min,Chars)};
-		in  ->
-		    {Min,Max,list_to_tuple(Chars)}
-	    end
+	    {Min,Max,create_char_tab(Min,Chars)}
     end.
 
 create_char_tab(Min,L) ->
@@ -1401,7 +1368,6 @@ gen_decode_user(Erules,D) when is_record(D,typedef) ->
 
 gen_dec_prim(Erules,Att,BytesVar) ->
     Typename = Att#type.def,
-    Constraint = Att#type.constraint,
     case Typename of
 	'INTEGER' ->
 	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
@@ -1429,8 +1395,7 @@ gen_dec_prim(Erules,Att,BytesVar) ->
 	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
 
 	'NumericString' ->
-	    emit_dec_known_multiplier_string('NumericString',
-					     Constraint,BytesVar);
+	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
 	TString when TString == 'TeletexString';
 		     TString == 'T61String' ->
 	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
@@ -1439,32 +1404,30 @@ gen_dec_prim(Erules,Att,BytesVar) ->
 	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
 
 	'UTCTime' ->
-	    emit_dec_known_multiplier_string('VisibleString',
-					     Constraint,BytesVar);
+	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
+
 	'GeneralizedTime' ->
-	    emit_dec_known_multiplier_string('VisibleString',
-					     Constraint,BytesVar);
+	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
+
 	'GraphicString' ->
 	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
 
 	'VisibleString' ->
-	    emit_dec_known_multiplier_string('VisibleString',
-					     Constraint,BytesVar);
+	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
+
 	'GeneralString' ->
 	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
 
 	'PrintableString' ->
-	    emit_dec_known_multiplier_string('PrintableString',
-					     Constraint,BytesVar);
+	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
 	'IA5String' ->
-	    emit_dec_known_multiplier_string('IA5String',Constraint,BytesVar);
+	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
 
 	'BMPString' ->
-	    emit_dec_known_multiplier_string('BMPString',Constraint,BytesVar);
+	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
 
 	'UniversalString' ->
-	    emit_dec_known_multiplier_string('UniversalString',
-					     Constraint,BytesVar);
+	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
 
 	'UTF8String' ->
 	    asn1ct_gen_per:gen_dec_prim(Erules, Att, BytesVar);
diff --git a/lib/asn1/src/asn1ct_imm.erl b/lib/asn1/src/asn1ct_imm.erl
index d0459ae60b..fca85fd778 100644
--- a/lib/asn1/src/asn1ct_imm.erl
+++ b/lib/asn1/src/asn1ct_imm.erl
@@ -21,7 +21,8 @@
 -export([per_dec_raw_bitstring/2,
 	 per_dec_boolean/0,per_dec_enumerated/2,per_dec_enumerated/3,
 	 per_dec_extension_map/1,
-	 per_dec_integer/2,per_dec_length/3,per_dec_named_integer/3,
+	 per_dec_integer/2,per_dec_k_m_string/3,
+	 per_dec_length/3,per_dec_named_integer/3,
 	 per_dec_octet_string/2,per_dec_open_type/1,per_dec_real/1]).
 -export([optimize_alignment/1,optimize_alignment/2,
 	 dec_slim_cg/2,dec_code_gen/2]).
@@ -109,6 +110,13 @@ per_dec_named_integer(Constraint, NamedList0, Aligned) ->
     NamedList = [{K,V} || {V,K} <- NamedList0] ++ [integer_default],
     {map,Int,NamedList}.
 
+per_dec_k_m_string(StringType, Constraint, Aligned) ->
+    SzConstr = get_constraint(Constraint, 'SizeConstraint'),
+    N = string_num_bits(StringType, Constraint, Aligned),
+    Imm = dec_string(SzConstr, N, Aligned),
+    Chars = char_tab(Constraint, StringType, N),
+    convert_string(N, Chars, Imm).
+
 per_dec_octet_string(Constraint, Aligned) ->
     dec_string(Constraint, 8, Aligned).
 
@@ -259,6 +267,93 @@ matched_range({get_bits,Bits0,[U|Flags]}) when is_integer(U) ->
     end;
 matched_range(_Op) -> unknown.
 
+string_num_bits(StringType, Constraint, Aligned) ->
+    case get_constraint(Constraint, 'PermittedAlphabet') of
+	{'SingleValue',Sv} ->
+	    charbits(length(Sv), Aligned);
+	no ->
+	    case StringType of
+		'IA5String' ->
+		    charbits(128, Aligned);
+		'VisibleString' ->
+		    charbits(95, Aligned);
+		'PrintableString' ->
+		    charbits(74, Aligned);
+		'NumericString' ->
+		    charbits(11, Aligned);
+		'UniversalString' ->
+		    32;
+		'BMPString' ->
+		    16
+	    end
+    end.
+
+charbits(NumChars, false) ->
+    uper_num_bits(NumChars);
+charbits(NumChars, true) ->
+    1 bsl uper_num_bits(uper_num_bits(NumChars)).
+
+convert_string(8, notab, Imm) ->
+    {convert,binary_to_list,Imm};
+convert_string(NumBits, notab, Imm) when NumBits < 8 ->
+    Dec = fun(V, Buf) ->
+		  emit(["{",{call,per_common,decode_chars,
+			     [V,NumBits]},com,Buf,"}"])
+	  end,
+    {call,Dec,Imm};
+convert_string(NumBits, notab, Imm) when NumBits =:= 16 ->
+    Dec = fun(V, Buf) ->
+		  emit(["{",{call,per_common,decode_chars_16bit,
+			     [V]},com,Buf,"}"])
+	  end,
+    {call,Dec,Imm};
+convert_string(NumBits, notab, Imm) ->
+    Dec = fun(V, Buf) ->
+		  emit(["{",{call,per_common,decode_big_chars,
+			     [V,NumBits]},com,Buf,"}"])
+	  end,
+    {call,Dec,Imm};
+convert_string(NumBits, Chars, Imm) ->
+    Dec = fun(V, Buf) ->
+		  emit(["{",{call,per_common,decode_chars,
+			     [V,NumBits,{asis,Chars}]},com,Buf,"}"])
+	  end,
+    {call,Dec,Imm}.
+
+char_tab(C, StringType, NumBits) ->
+    case get_constraint(C, 'PermittedAlphabet') of
+	{'SingleValue',Sv} ->
+	    char_tab_1(Sv, NumBits);
+	no ->
+	    case StringType of
+		'IA5String' ->
+		    notab;
+		'VisibleString' ->
+		    notab;
+		'PrintableString' ->
+		    Chars = " '()+,-./0123456789:=?"
+			"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+			"abcdefghijklmnopqrstuvwxyz",
+		    char_tab_1(Chars, NumBits);
+		'NumericString' ->
+		    char_tab_1(" 0123456789", NumBits);
+		'UniversalString' ->
+		    notab;
+		'BMPString' ->
+		    notab
+	    end
+    end.
+
+char_tab_1(Chars, NumBits) ->
+    Max = lists:max(Chars),
+    BitValMax = (1 bsl NumBits) - 1,
+    if
+	Max =< BitValMax ->
+	    notab;
+	true ->
+	    list_to_tuple(lists:sort(Chars))
+    end.
+
 %%%
 %%% Remove unnecessary aligning to octet boundaries.
 %%%
diff --git a/lib/asn1/src/asn1rtt_per.erl b/lib/asn1/src/asn1rtt_per.erl
index 7903dcf9e9..bcd74d9da7 100644
--- a/lib/asn1/src/asn1rtt_per.erl
+++ b/lib/asn1/src/asn1rtt_per.erl
@@ -38,7 +38,6 @@
 	 encode_UTF8String/1,decode_UTF8String/1,
 	 encode_octet_string/3,
 	 encode_known_multiplier_string/4,
-	 decode_known_multiplier_string/5,
 	 octets_to_complete/2]).
 
 -define('16K',16384).
@@ -871,27 +870,6 @@ decode_restricted_string(Bytes,aligned) ->
     {Len,Bytes2} = decode_length(Bytes,undefined),
     getoctets_as_list(Bytes2,Len).
 
-decode_known_multiplier_string(StringType,SizeC,NumBits,CharInTab,Bytes) ->
-    case SizeC of
-	Ub when is_integer(Ub), Ub*NumBits =< 16  ->
-	    chars_decode(Bytes,NumBits,StringType,CharInTab,Ub);
-	Ub when is_integer(Ub),Ub =<65535 -> % fixed length
-	    Bytes1 = align(Bytes),
-	    chars_decode(Bytes1,NumBits,StringType,CharInTab,Ub);
-	Vl when is_list(Vl) ->
-	    {Len,Bytes1} = decode_length(Bytes,{hd(Vl),lists:max(Vl)}),
-	    Bytes2 = align(Bytes1),
-	    chars_decode(Bytes2,NumBits,StringType,CharInTab,Len);
-	no  ->
-	    {Len,Bytes1} = decode_length(Bytes,undefined),
-	    Bytes2 = align(Bytes1),
-	    chars_decode(Bytes2,NumBits,StringType,CharInTab,Len);
-	{Lb,Ub}->
-	    {Len,Bytes1} = decode_length(Bytes,{Lb,Ub}),
-	    Bytes2 = align(Bytes1),
-	    chars_decode(Bytes2,NumBits,StringType,CharInTab,Len)
-    end.
-
 encode_GeneralString(_C,Val) ->
     encode_restricted_string(Val).
 decode_GeneralString(Bytes,_C) ->
@@ -918,18 +896,6 @@ decode_VideotexString(Bytes,_C) ->
     decode_restricted_string(Bytes,aligned).
 
 
-
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%% getBMPChars(Bytes,Len) ->{BMPcharList,RemainingBytes}
-%%
-getBMPChars(<<T/binary>>, 0, Acc) ->
-    {lists:reverse(Acc),T};
-getBMPChars(<<0,O2,Bytes1/bitstring>>, Len, Acc) ->
-    getBMPChars(Bytes1,Len-1,[O2|Acc]);
-getBMPChars(<<O1,O2,Bytes1/bitstring>>, Len, Acc) ->
-    getBMPChars(Bytes1,Len-1,[{0,0,O1,O2}|Acc]).
-
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% chars_encode(C,StringType,Value) -> ValueList
 %%
@@ -970,36 +936,6 @@ pre_complete_bits(NumBits,Val) when NumBits =< 2040 -> % 255 * 8
     [30,Unused,Len div 8,<<(Val bsl Unused):Len>>].
 
 
-chars_decode(Bytes,_,'BMPString',_,Len) ->
-    getBMPChars(Bytes,Len,[]);
-chars_decode(Bytes,NumBits,_StringType,CharInTab,Len) ->
-    chars_decode2(Bytes,CharInTab,NumBits,Len).
-
-
-chars_decode2(Bytes,CharInTab,NumBits,Len) ->
-    chars_decode2(Bytes,CharInTab,NumBits,Len,[]).
-
-chars_decode2(Bytes,_CharInTab,_NumBits,0,Acc) ->
-    {lists:reverse(Acc),Bytes};
-chars_decode2(Bytes,{Min,Max,notab},NumBits,Len,Acc) when NumBits > 8 ->
-    {Char,Bytes2} = getbits(Bytes,NumBits),
-    Result =
-	if
-	    Char < 256 -> Char;
-	    true ->
-		list_to_tuple(binary_to_list(<<Char:32>>))
-	end,
-    chars_decode2(Bytes2,{Min,Max,notab},NumBits,Len -1,[Result|Acc]);
-chars_decode2(Bytes,{Min,Max,notab},NumBits,Len,Acc) ->
-    {Char,Bytes2} = getbits(Bytes,NumBits),
-    chars_decode2(Bytes2,{Min,Max,notab},NumBits,Len -1,[Char+Min|Acc]);
-
-%% BMPString and UniversalString with PermittedAlphabet is currently not supported
-chars_decode2(Bytes,{Min,Max,CharInTab},NumBits,Len,Acc) ->
-    {Char,Bytes2} = getbits(Bytes,NumBits),
-    chars_decode2(Bytes2,{Min,Max,CharInTab},NumBits,Len -1,[element(Char+1,CharInTab)|Acc]).
-
-
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% encode_UTF8String(Val) -> CompleteList
 %% Val -> <<utf8encoded binary>>
diff --git a/lib/asn1/src/asn1rtt_per_common.erl b/lib/asn1/src/asn1rtt_per_common.erl
index 2edd240baf..cd6e9e2c99 100644
--- a/lib/asn1/src/asn1rtt_per_common.erl
+++ b/lib/asn1/src/asn1rtt_per_common.erl
@@ -24,7 +24,10 @@
 -export([decode_fragmented/3,
 	 decode_compact_bit_string/1,
 	 decode_legacy_bit_string/1,
-	 decode_named_bit_string/2]).
+	 decode_named_bit_string/2,
+	 decode_chars/2,decode_chars/3,
+	 decode_chars_16bit/1,
+	 decode_big_chars/2]).
 
 -define('16K',16384).
 
@@ -58,6 +61,20 @@ decode_compact_bit_string(Val) ->
     PadLen = (8 - (bit_size(Val) band 7)) band 7,
     {PadLen,<<Val/bitstring,0:PadLen>>}.
 
+decode_chars(Val, N) ->
+    [C || <<C:N>> <= Val].
+
+decode_chars(Val, N, Chars) ->
+    [element(C+1, Chars) || <<C:N>> <= Val].
+
+decode_chars_16bit(Val) ->
+    Cs = [C || <<C:16>> <= Val],
+    decode_chars_16bit_1(Cs).
+
+decode_big_chars(Val, N) ->
+    decode_big_chars_1(decode_chars(Val, N)).
+
+
 %%%
 %%% Internal functions.
 %%%
@@ -73,3 +90,15 @@ decode_named_bit_string_1(Pos, [1|Bt], Names, Acc) ->
     end;
 decode_named_bit_string_1(_Pos, [], _Names, Acc) ->
     lists:reverse(Acc).
+
+decode_chars_16bit_1([H|T]) when H < 256 ->
+    [H|decode_chars_16bit_1(T)];
+decode_chars_16bit_1([H|T]) ->
+    [{0,0,H bsr 8,H band 255}|decode_chars_16bit_1(T)];
+decode_chars_16bit_1([]) -> [].
+
+decode_big_chars_1([H|T]) when H < 256 ->
+    [H|decode_big_chars_1(T)];
+decode_big_chars_1([H|T]) ->
+    [list_to_tuple(binary_to_list(<<H:32>>))|decode_big_chars_1(T)];
+decode_big_chars_1([]) -> [].
diff --git a/lib/asn1/src/asn1rtt_uper.erl b/lib/asn1/src/asn1rtt_uper.erl
index 2d91e0df24..92c8d44402 100644
--- a/lib/asn1/src/asn1rtt_uper.erl
+++ b/lib/asn1/src/asn1rtt_uper.erl
@@ -34,17 +34,17 @@
 
  -export([encode_open_type/1]).
 
- -export([encode_UniversalString/2, decode_UniversalString/2,
-	 encode_PrintableString/2, decode_PrintableString/2,
+ -export([encode_UniversalString/2,
+	 encode_PrintableString/2,
 	 encode_GeneralString/2, decode_GeneralString/2,
 	 encode_GraphicString/2, decode_GraphicString/2,
 	 encode_TeletexString/2, decode_TeletexString/2,
 	 encode_VideotexString/2, decode_VideotexString/2,
-	 encode_VisibleString/2, decode_VisibleString/2,
+	 encode_VisibleString/2,
 	 encode_UTF8String/1, decode_UTF8String/1,
-	 encode_BMPString/2, decode_BMPString/2,
-	 encode_IA5String/2, decode_IA5String/2,
-	 encode_NumericString/2, decode_NumericString/2,
+	 encode_BMPString/2,
+	 encode_IA5String/2,
+	 encode_NumericString/2,
 	 encode_ObjectDescriptor/2, decode_ObjectDescriptor/1
 	]).
 
@@ -799,56 +799,23 @@ decode_restricted_string(Bytes) ->
     {Len,Bytes2} = decode_length(Bytes, undefined),
     getoctets_as_list(Bytes2,Len).
 
-decode_known_multiplier_string(Bytes, StringType, C, _Ext) ->
-    NumBits = get_NumBits(C, StringType),
-    case get_constraint(C, 'SizeConstraint') of
-	Ub when is_integer(Ub), Ub*NumBits =< 16  ->
-	    chars_decode(Bytes, NumBits, StringType, C, Ub);
-	Ub when is_integer(Ub), Ub =<65535 -> % fixed length
-	    chars_decode(Bytes,NumBits,StringType,C,Ub);
-	0 ->
-	    {[],Bytes};
-	Vl when is_list(Vl) ->
-	    {Len,Bytes1} = decode_length(Bytes,{hd(Vl),lists:max(Vl)}),
-	    chars_decode(Bytes1,NumBits,StringType,C,Len);
-	no  ->
-	    {Len,Bytes1} = decode_length(Bytes,undefined),
-	    chars_decode(Bytes1,NumBits,StringType,C,Len);
-	{Lb,Ub}->
-	    {Len,Bytes1} = decode_length(Bytes,{Lb,Ub}),
-	    chars_decode(Bytes1,NumBits,StringType,C,Len)
-    end.
-
-
 encode_NumericString(C,Val) ->
     encode_known_multiplier_string('NumericString',C,Val).
-decode_NumericString(Bytes,C) ->
-    decode_known_multiplier_string(Bytes,'NumericString',C,false).
 
 encode_PrintableString(C,Val) ->
     encode_known_multiplier_string('PrintableString',C,Val).
-decode_PrintableString(Bytes,C) ->
-    decode_known_multiplier_string(Bytes,'PrintableString',C,false).
 
 encode_VisibleString(C,Val) -> % equivalent with ISO646String
     encode_known_multiplier_string('VisibleString',C,Val).
-decode_VisibleString(Bytes,C) ->
-    decode_known_multiplier_string(Bytes,'VisibleString',C,false).
 
 encode_IA5String(C,Val) ->
     encode_known_multiplier_string('IA5String',C,Val).
-decode_IA5String(Bytes,C) ->
-    decode_known_multiplier_string(Bytes,'IA5String',C,false).
 
 encode_BMPString(C,Val) ->
     encode_known_multiplier_string('BMPString',C,Val).
-decode_BMPString(Bytes,C) ->
-    decode_known_multiplier_string(Bytes,'BMPString',C,false).
 
 encode_UniversalString(C,Val) ->
     encode_known_multiplier_string('UniversalString',C,Val).
-decode_UniversalString(Bytes,C) ->
-    decode_known_multiplier_string(Bytes,'UniversalString',C,false).
 
 
 %% end of known-multiplier strings for which PER visible constraints are
@@ -880,33 +847,6 @@ decode_VideotexString(Bytes,_C) ->
     decode_restricted_string(Bytes).
 
 
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%% getBMPChars(Bytes, Len) -> {BMPcharList,RemainingBytes}
-%%
-getBMPChars(Bytes, 1) ->
-    {O1,Bytes2} = getbits(Bytes, 8),
-    {O2,Bytes3} = getbits(Bytes2, 8),
-    if
-	O1 == 0 ->
-	    {[O2],Bytes3};
-	true ->
-	    {[{0,0,O1,O2}],Bytes3}
-    end;
-getBMPChars(Bytes, Len) ->
-    getBMPChars(Bytes, Len, []).
-
-getBMPChars(Bytes, 0, Acc) ->
-    {lists:reverse(Acc),Bytes};
-getBMPChars(Bytes, Len, Acc) ->
-    {Octs,Bytes1} = getoctets_as_list(Bytes,2),
-    case Octs of
-	[0,O2] ->
-	    getBMPChars(Bytes1, Len-1, [O2|Acc]);
-	[O1,O2]->
-	    getBMPChars(Bytes1, Len-1, [{0,0,O1,O2}|Acc])
-    end.
-
-
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% chars_encode(C,StringType,Value) -> ValueList
 %%
@@ -970,27 +910,21 @@ get_NumBits(C,StringType) ->
     end.
 
 get_CharOutTab(C,StringType) ->
-    get_CharTab(C,StringType,out).
-
-get_CharInTab(C,StringType) ->
-    get_CharTab(C,StringType,in).
-
-get_CharTab(C,StringType,InOut) ->
     case get_constraint(C,'PermittedAlphabet') of
 	{'SingleValue',Sv} ->
-	    get_CharTab2(C,StringType,hd(Sv),lists:max(Sv),Sv,InOut);
+	    get_CharTab2(C,StringType,hd(Sv),lists:max(Sv),Sv);
 	no ->
 	    case StringType of
 		'IA5String' ->
 		    {0,16#7F,notab};
 		'VisibleString' ->
-		    get_CharTab2(C,StringType,16#20,16#7F,notab,InOut);
+		    get_CharTab2(C,StringType,16#20,16#7F,notab);
 		'PrintableString' ->
 		    Chars = lists:sort(
 			      " '()+,-./0123456789:=?ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"),
-		    get_CharTab2(C,StringType,hd(Chars),lists:max(Chars),Chars,InOut);
+		    get_CharTab2(C,StringType,hd(Chars),lists:max(Chars),Chars);
 		'NumericString' ->
-		    get_CharTab2(C,StringType,16#20,$9," 0123456789",InOut);
+		    get_CharTab2(C,StringType,16#20,$9," 0123456789");
 		'UniversalString' ->
 		    {0,16#FFFFFFFF,notab};
 		'BMPString' ->
@@ -998,18 +932,13 @@ get_CharTab(C,StringType,InOut) ->
 	    end
     end.
 
-get_CharTab2(C,StringType,Min,Max,Chars,InOut) ->
+get_CharTab2(C,StringType,Min,Max,Chars) ->
     BitValMax = (1 bsl get_NumBits(C,StringType))-1,
     if
 	Max =< BitValMax ->
 	    {0,Max,notab};
 	true ->
-	    case InOut of
-		out ->
-		    {Min,Max,create_char_tab(Min,Chars)};
-		in  ->
-		    {Min,Max,list_to_tuple(Chars)}
-	    end
+	    {Min,Max,create_char_tab(Min,Chars)}
     end.
 
 create_char_tab(Min,L) ->
@@ -1047,44 +976,6 @@ charbits1(NumOfChars) ->
     1 + charbits1(NumOfChars bsr 1).
 
 
-chars_decode(Bytes,_,'BMPString',C,Len) ->
-    case get_constraint(C,'PermittedAlphabet') of
-	no ->
-	    getBMPChars(Bytes,Len);
-	_ ->
-	    exit({error,{asn1,
-			 {'not implemented',
-			  "BMPString with PermittedAlphabet constraint"}}})
-    end;
-chars_decode(Bytes,NumBits,StringType,C,Len) ->
-    CharInTab = get_CharInTab(C,StringType),
-    chars_decode2(Bytes,CharInTab,NumBits,Len).
-
-
-chars_decode2(Bytes,CharInTab,NumBits,Len) ->
-    chars_decode2(Bytes,CharInTab,NumBits,Len,[]).
-
-chars_decode2(Bytes,_CharInTab,_NumBits,0,Acc) ->
-    {lists:reverse(Acc),Bytes};
-chars_decode2(Bytes,{Min,Max,notab},NumBits,Len,Acc) when NumBits > 8 ->
-    {Char,Bytes2} = getbits(Bytes,NumBits),
-    Result =
-	if
-	    Char < 256 -> Char;
-	    true ->
-		list_to_tuple(binary_to_list(<<Char:32>>))
-	end,
-    chars_decode2(Bytes2,{Min,Max,notab},NumBits,Len -1,[Result|Acc]);
-chars_decode2(Bytes,{Min,Max,notab},NumBits,Len,Acc) ->
-    {Char,Bytes2} = getbits(Bytes,NumBits),
-    chars_decode2(Bytes2,{Min,Max,notab},NumBits,Len -1,[Char+Min|Acc]);
-
-%% BMPString and UniversalString with PermittedAlphabet is currently not supported
-chars_decode2(Bytes,{Min,Max,CharInTab},NumBits,Len,Acc) ->
-    {Char,Bytes2} = getbits(Bytes,NumBits),
-    chars_decode2(Bytes2,{Min,Max,CharInTab},NumBits,Len -1,[element(Char+1,CharInTab)|Acc]).
-
-
 %% UTF8String
 encode_UTF8String(Val) when is_binary(Val) ->
     [encode_length(byte_size(Val)),Val];