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).

6 files changed, 241 insertions, 45 deletions

diff --git a/lib/asn1/test/asn1_SUITE.erl b/lib/asn1/test/asn1_SUITE.erl
index 61b360ddf2..83bd66a631 100644
--- a/lib/asn1/test/asn1_SUITE.erl
+++ b/lib/asn1/test/asn1_SUITE.erl
@@ -96,7 +96,6 @@ groups() ->
        testChoTypeRefSeq,
        testChoTypeRefSet,
        testMultipleLevels,
-       testDef,
        testOpt,
        testSeqDefault,
        % Uses 'External'
@@ -141,9 +140,9 @@ groups() ->
        testDeepTConstr,
        testExport,
        testImport,
-       % Uses 'ParamBasic'
-       {group, [], [testParamBasic,
-                    testDER]},
+       testParamBasic,
+       testDER,
+       testDEFAULT,
        testMvrasn6,
        testContextSwitchingTypes,
        testOpenTypeImplicitTag,
@@ -326,20 +325,21 @@ testCompactBitString(Config, Rule, Opts) ->
 			  [Rule, compact_bit_string|Opts]),
     testCompactBitString:otp_4869(Rule).
 
-testPrimStrings(Config) -> test(Config, fun testPrimStrings/3).
+testPrimStrings(Config) ->
+    test(Config, fun testPrimStrings/3, [ber,{ber,[der]},per,uper]).
 testPrimStrings(Config, Rule, Opts) ->
     asn1_test_lib:compile_all(["PrimStrings", "BitStr"], Config, [Rule|Opts]),
-    testPrimStrings_cases(Rule),
+    testPrimStrings_cases(Rule, Opts),
     asn1_test_lib:compile_all(["PrimStrings", "BitStr"], Config,
 			      [legacy_bit_string,Rule|Opts]),
-    testPrimStrings:bit_string(Rule),
+    testPrimStrings:bit_string(Rule, Opts),
     asn1_test_lib:compile_all(["PrimStrings", "BitStr"], Config,
 			      [compact_bit_string,Rule|Opts]),
-    testPrimStrings:bit_string(Rule),
+    testPrimStrings:bit_string(Rule, Opts),
     testPrimStrings:more_strings(Rule).
 
-testPrimStrings_cases(Rule) ->
-    testPrimStrings:bit_string(Rule),
+testPrimStrings_cases(Rule, Opts) ->
+    testPrimStrings:bit_string(Rule, Opts),
     testPrimStrings:octet_string(Rule),
     testPrimStrings:numeric_string(Rule),
     testPrimStrings:other_strings(Rule),
@@ -429,6 +429,13 @@ testDef(Config, Rule, Opts) ->
     asn1_test_lib:compile("Def", Config, [Rule|Opts]),
     testDef:main(Rule).
 
+testDEFAULT(Config) ->
+    test(Config, fun testDEFAULT/3, [ber,{ber,[der]},per,uper]).
+testDEFAULT(Config, Rule, Opts) ->
+    asn1_test_lib:compile_all(["Def","Default"], Config, [Rule|Opts]),
+    testDef:main(Rule),
+    testSeqSetDefaultVal:main(Rule, Opts).
+
 testOpt(Config) -> test(Config, fun testOpt/3).
 testOpt(Config, Rule, Opts) ->
     asn1_test_lib:compile("Opt", Config, [Rule|Opts]),
@@ -516,7 +523,8 @@ testSetDefault(Config, Rule, Opts) ->
     asn1_test_lib:compile("SetDefault", Config, [Rule|Opts]),
     testSetDefault:main(Rule).
 
-testParamBasic(Config) -> test(Config, fun testParamBasic/3).
+testParamBasic(Config) ->
+    test(Config, fun testParamBasic/3, [ber,{ber,[der]},per,uper]).
 testParamBasic(Config, Rule, Opts) ->
     asn1_test_lib:compile("ParamBasic", Config, [Rule|Opts]),
     testParamBasic:main(Rule).
@@ -873,11 +881,7 @@ testDER(Config) ->
     test(Config, fun testDER/3, [ber]).
 testDER(Config, Rule, Opts) ->
     asn1_test_lib:compile("DERSpec", Config, [Rule, der|Opts]),
-    testDER:test(),
-    asn1_test_lib:compile("ParamBasic", Config, [Rule, der|Opts]),
-    testParamBasic:main(der),
-    asn1_test_lib:compile("Default", Config, [Rule, der|Opts]),
-    testSeqSetDefaultVal:main(Rule).
+    testDER:test().
 
 specialized_decodes(Config) ->
     test(Config, fun specialized_decodes/3, [ber]).
diff --git a/lib/asn1/test/asn1_SUITE_data/Default.asn b/lib/asn1/test/asn1_SUITE_data/Default.asn
index 6604953c1f..168ce50bb2 100644
--- a/lib/asn1/test/asn1_SUITE_data/Default.asn
+++ b/lib/asn1/test/asn1_SUITE_data/Default.asn
@@ -21,7 +21,8 @@ SeqBS ::= SEQUENCE {
   a BIT STRING DEFAULT '1010110'B,
   b BIT STRING DEFAULT 'A8A'H,
   c BIT STRING {first(0),second(1),third(2)} DEFAULT {second},
-  d BIT STRING DEFAULT onelist
+  d BIT STRING DEFAULT onelist,
+  e BIT STRING DEFAULT '01011010'B
 }
 
 SetBS ::= SET {
diff --git a/lib/asn1/test/asn1_SUITE_data/PrimStrings.asn1 b/lib/asn1/test/asn1_SUITE_data/PrimStrings.asn1
index 08e7f94ab6..a5b4c8a53d 100644
--- a/lib/asn1/test/asn1_SUITE_data/PrimStrings.asn1
+++ b/lib/asn1/test/asn1_SUITE_data/PrimStrings.asn1
@@ -46,7 +46,13 @@ BS256 ::= BIT STRING (SIZE (256))
 
 BS1024 ::= BIT STRING (SIZE (1024))
 
-  
+  BsDef1 ::= SEQUENCE {
+     s BIT STRING DEFAULT '101111'B
+  }
+
+  BsDef2 ::= SEQUENCE {
+     s BIT STRING DEFAULT 'DEADBEEF'H
+  }
 
   Os ::= OCTET STRING
   OsCon ::= [60] OCTET STRING
diff --git a/lib/asn1/test/testParamBasic.erl b/lib/asn1/test/testParamBasic.erl
index 3a55408e94..3db89ca174 100644
--- a/lib/asn1/test/testParamBasic.erl
+++ b/lib/asn1/test/testParamBasic.erl
@@ -38,7 +38,9 @@ main(Rules) ->
 	    <<48,3,128,1,11>> =
 		roundtrip_enc('T11', #'T11'{number=11,string="hej"}),
 	    <<48,3,128,1,11>> =
-		roundtrip_enc('T12', #'T12'{number=11,string=[1,0,1,0]});
+		roundtrip_enc('T12',
+			      #'T12'{number=11,string=[1,0,1,0]},
+			      #'T12'{number=11,string = <<10:4>>});
 	_ -> ok
     end,
     ok.
@@ -48,3 +50,6 @@ roundtrip(Type, Value) ->
 
 roundtrip_enc(Type, Value) ->
     asn1_test_lib:roundtrip_enc('ParamBasic', Type, Value).
+
+roundtrip_enc(Type, Value, Expected) ->
+    asn1_test_lib:roundtrip_enc('ParamBasic', Type, Value, Expected).
diff --git a/lib/asn1/test/testPrimStrings.erl b/lib/asn1/test/testPrimStrings.erl
index be5409aa92..2fe0780701 100644
--- a/lib/asn1/test/testPrimStrings.erl
+++ b/lib/asn1/test/testPrimStrings.erl
@@ -19,7 +19,7 @@
 %%
 -module(testPrimStrings).
 
--export([bit_string/1]).
+-export([bit_string/2]).
 -export([octet_string/1]).
 -export([numeric_string/1]).
 -export([other_strings/1]).
@@ -68,7 +68,7 @@ fragmented_lengths() ->
      K64-1,K64,K64+1,K64+(1 bsl 7)-1,K64+(1 bsl 7),K64+(1 bsl 7)+1,
      K64+K16-1,K64+K16,K64+K16+1].
 
-bit_string(Rules) ->
+bit_string(Rules, Opts) ->
     
     %%==========================================================
     %% Bs1 ::= BIT STRING
@@ -90,9 +90,10 @@ bit_string(Rules) ->
     bs_roundtrip('Bs1', [0,1,0,0,1,0]),
     bs_roundtrip('Bs1', [1,0,0,0,0,0,0,0,0]),
     bs_roundtrip('Bs1', [0,1,0,0,1,0,1,1,1,1,1,0,0,0,1,0,0,1,1]),
-    
-    case Rules of
-	ber ->
+
+
+    case {Rules,Opts} of
+	{ber,[]} ->
 	    bs_decode('Bs1', <<35,8,3,2,0,73,3,2,4,32>>,
 		      [0,1,0,0,1,0,0,1,0,0,1,0]),
 	    bs_decode('Bs1', <<35,9,3,2,0,234,3,3,7,156,0>>,
@@ -100,7 +101,17 @@ bit_string(Rules) ->
 	    bs_decode('Bs1', <<35,128,3,2,0,234,3,3,7,156,0,0,0>>,
 		      [1,1,1,0,1,0,1,0,1,0,0,1,1,1,0,0,0]);
 	_ ->
-	    ok
+	    %% DER, PER, UPER
+	    consistent_def_enc('BsDef1',
+			       [2#111101,
+				[1,0,1,1,1,1],
+				{2,<<2#101111:6,0:2>>},
+				<<2#101111:6>>]),
+	    consistent_def_enc('BsDef2',
+			       [[1,1,0,1, 1,1,1,0, 1,0,1,0, 1,1,0,1,
+				 1,0,1,1, 1,1,1,0, 1,1,1,0, 1,1,1,1],
+				{0,<<16#DEADBEEF:4/unit:8>>},
+				<<16#DEADBEEF:4/unit:8>>])
     end,
 
     
@@ -217,6 +228,24 @@ bit_string(Rules) ->
 	_ -> per_bs_strings()
     end.
 
+consistent_def_enc(Type, Vs) ->
+    M = 'PrimStrings',
+    {ok,Enc} = M:encode(Type, {Type,asn1_DEFAULT}),
+    {ok,Val} = M:decode(Type, Enc),
+
+    %% Ensure that the value has the correct format.
+    case {M:bit_string_format(),Val} of
+	{bitstring,{_,Bs}} when is_bitstring(Bs) -> ok;
+	{compact,{_,{Unused,Bin}}} when is_integer(Unused),
+					is_binary(Bin) -> ok;
+	{legacy,{_,Bs}} when is_list(Bs) -> ok
+    end,
+
+    %% All values should be recognized and encoded as the
+    %% the default value (i.e. not encoded at all).
+    _ = [{ok,Enc} = M:encode(Type, {Type,V}) || V <- Vs],
+    ok.
+
 %% The PER encoding rules requires that a BIT STRING with
 %% named positions should never have any trailing zeroes
 %% (except to reach the minimum number of bits as given by
diff --git a/lib/asn1/test/testSeqSetDefaultVal.erl b/lib/asn1/test/testSeqSetDefaultVal.erl
index fb61bf1647..044099199f 100644
--- a/lib/asn1/test/testSeqSetDefaultVal.erl
+++ b/lib/asn1/test/testSeqSetDefaultVal.erl
@@ -18,7 +18,7 @@
 %%
 %%
 -module(testSeqSetDefaultVal).
--export([main/1]).
+-export([main/2]).
 
 -include("External.hrl").
 -include_lib("test_server/include/test_server.hrl").
@@ -34,7 +34,8 @@
 -record('SeqBS',{a = asn1_DEFAULT, 
 		 b = asn1_DEFAULT, 
 		 c = asn1_DEFAULT,
-		 d = asn1_DEFAULT}).
+		 d = asn1_DEFAULT,
+		 e = asn1_DEFAULT}).
 -record('SetBS',{a = asn1_DEFAULT, 
 		 b = asn1_DEFAULT, 
 		 c = asn1_DEFAULT,
@@ -93,7 +94,119 @@
 -record('S4_b',{ba = asn1_DEFAULT, 
 		bb = asn1_DEFAULT}).
 
-main(_Rules) ->
+main(ber, []) ->
+    %% Nothing to test because plain BER will only use
+    %% default values when explicitly told to do so by
+    %% asn1_DEFAULT.
+    ok;
+main(Rule, Opts) ->
+    %% DER, PER, UPER. These encodings should not encode
+    %% values that are equal to the default value.
+
+    case {Rule,Opts} of
+	{ber,[der]} ->
+	    der();
+	{_,_} ->
+	    ok
+    end,
+
+    Ts = [{#'SeqInts'{},
+	   [{#'SeqInts'.c,
+	     [asn1_DEFAULT,
+	      three,
+	      3]}]},
+
+	  {#'SeqBS'{},
+	   [{#'SeqBS'.a,
+	     [asn1_DEFAULT,
+	      2#0110101,
+	      [1,0,1,0,1,1,0],
+	      {1,<<16#AC>>},
+	      <<1:1,0:1,1:1,0:1,1:1,1:1,0:1>>]},
+	    {#'SeqBS'.b,
+	     [asn1_DEFAULT,
+	      2#10100010101,
+	      [1,0,1,0,1,0,0,0,1,0,1,0],
+	      {4,<<16#A8,16#A0>>},
+	      <<16#A8:8,16#A:4>>]},
+	    {#'SeqBS'.c,
+	     [asn1_DEFAULT,
+	      [second],
+	      [0,1],
+	      {6,<<0:1,1:1,0:6>>},
+	      <<1:2>>]},
+	    {#'SeqBS'.c,			%Zeroes on the right
+	     [asn1_DEFAULT,
+	      [second],
+	      [0,1,0,0,0],
+	      {4,<<0:1,1:1,0:6>>},
+	      <<1:2,0:17>>]},
+	    {#'SeqBS'.d,
+	     [asn1_DEFAULT,
+	      2#1001,
+	      [1,0,0,1],
+	      {4,<<2#1001:4,0:4>>},
+	      <<2#1001:4>>]},
+	    {#'SeqBS'.e,
+	     [asn1_DEFAULT,
+	      [0,1,0,1,1,0,1,0],
+	      {0,<<2#01011010:8>>},
+	      <<2#01011010:8>>]},
+	    %% Not EQUAL to DEFAULT.
+	    {#'SeqBS'.b,
+	     [[1,1,0],				%Not equal to DEFAULT
+	      {5,<<6:3,0:5>>},
+	      <<6:3>>]}
+	   ]},
+
+	  {#'SeqOS'{},
+	   [{#'SeqOS'.a,
+	     [asn1_DEFAULT,
+	      [172]]}]},
+
+	  {#'SeqOI'{},
+	   [{#'SeqOI'.a,
+	     [asn1_DEFAULT,
+	      {1,2,14,15}]},
+	    {#'SeqOI'.b,
+	     [asn1_DEFAULT,
+%%	      {iso,'member-body',250,3,4},
+	      {1,2,250,3,4}]},
+	    {#'SeqOI'.c,
+	     [asn1_DEFAULT,
+%%	      {iso,standard,8571,2,250,4},
+	      {1,0,8571,2,250,4}]}]}
+	 ],
+    io:format("~p\n", [Ts]),
+    R0 = [[consistency(Rec, Pos, Vs) || {Pos,Vs} <- Fs] || {Rec,Fs} <- Ts],
+    case lists:flatten(R0) of
+	[] ->
+	    ok;
+	[_|_]=R ->
+	    io:format("~p\n", [R]),
+	    ?t:fail()
+    end.
+
+consistency(Rec0, Pos, [V|Vs]) ->
+    T = element(1, Rec0),
+    Rec = setelement(Pos, Rec0, V),
+    {ok,Enc} = 'Default':encode(T, Rec),
+    {ok,_SmokeTest} = 'Default':decode(T, Enc),
+    consistency_1(Vs, Rec0, Pos, Enc).
+
+consistency_1([V|Vs], Rec0, Pos, Enc) ->
+    Rec = setelement(Pos, Rec0, V),
+    case 'Default':encode(element(1, Rec), Rec) of
+	{ok,Enc} ->
+	    consistency_1(Vs, Rec0, Pos, Enc);
+	{ok,WrongEnc} ->
+	    [{Rec,{wrong,WrongEnc},{should_be,Enc}}|
+	     consistency_1(Vs, Rec0, Pos, Enc)]
+    end;
+consistency_1([], _, _, _) -> [].
+
+der() ->
+    io:put_chars("Peforming DER-specific tests..."),
     roundtrip(<<48,0>>,
 	      'SeqInts',
 	      #'SeqInts'{a=asn1_DEFAULT,b=asn1_DEFAULT,
@@ -117,50 +230,88 @@ main(_Rules) ->
 
     roundtrip(<<48,0>>,
 	      'SeqBS',
-	      #'SeqBS'{a=2#1010110,b=16#A8A,c=[second],d=[1,0,0,1]},
-	      #'SeqBS'{a=[1,0,1,0,1,1,0],b=16#A8A,c=[second],d=[1,0,0,1]}),
+	      #'SeqBS'{a=2#0110101,
+		       b=2#010100010101,
+		       c=[second],
+		       d=[1,0,0,1]},
+	      #'SeqBS'{a = <<2#1010110:7>>, b = <<16#A8A:12>>,
+		       c=[second], d = <<2#1001:4>>,
+		       e = <<2#01011010:8>>}),
     roundtrip(<<48,0>>,
 	      'SeqBS',
 	      #'SeqBS'{a=[1,0,1,0,1,1,0],
 		       b=[1,0,1,0,1,0,0,0,1,0,1,0],
 		       c={5,<<64>>},
 		       d=2#1001},
-	      #'SeqBS'{a=[1,0,1,0,1,1,0],b=16#A8A,c=[second],d=[1,0,0,1]}),
+	      #'SeqBS'{a = <<2#1010110:7>>, b = <<16#A8A:12>>,
+		       c=[second], d = <<2#1001:4>>,
+		       e = <<2#01011010:8>>}),
     roundtrip(<<48,3,131,1,0>>,
 	      'SeqBS',
 	      #'SeqBS'{a=[1,0,1,0,1,1,0],
 		       b=[1,0,1,0,1,0,0,0,1,0,1,0],
 		       c={5,<<64>>},
 		       d=0},
-	      #'SeqBS'{a=[1,0,1,0,1,1,0],
-		       b=16#A8A,
-		       c=[second],
-		       d = <<>>}),
+	      #'SeqBS'{a = <<2#1010110:7>>, b = <<16#A8A:12>>,
+		       c=[second], d = <<>>,
+		       e = <<2#01011010:8>>}),
+    roundtrip(<<48,3,131,1,0>>,
+	      'SeqBS',
+	      #'SeqBS'{a = <<1:1,0:1,1:1,0:1,1:1,1:1,0:1>>,
+		       b = <<1:1,0:1,1:1,0:1,1:1,0:1,0:1,0:1,1:1,0:1,1:1,0:1>>,
+		       c = <<2:3>>,
+		       d=0,
+		       e = <<16#5A:8>>},
+	      #'SeqBS'{a = <<2#1010110:7>>, b = <<16#A8A:12>>,
+		       c=[second], d = <<>>,
+		       e = <<2#01011010:8>>}),
+
+    %% None of the default values are used.
+    roundtrip(<<48,19,128,2,7,128,129,2,5,64,130,2,5,32,131,1,0,132,2,5,224>>,
+	      'SeqBS',
+	      #'SeqBS'{a = <<1:1>>,
+		       b = {5,<<64>>},
+		       c = [third],
+		       d = 0,
+		       e = <<7:3>>},
+	      #'SeqBS'{a = <<1:1>>,
+		       b = <<2:3>>,
+		       c = [third],
+		       d = <<>>,
+		       e = <<7:3>>}),
 
     roundtrip(<<49,0>>,
 	      'SetBS',
-	      #'SetBS'{a=2#1010110,b=16#A8A,c=[second],d=[1,0,0,1]},
-	      #'SetBS'{a=[1,0,1,0,1,1,0],b=16#A8A,c=[second],d=[1,0,0,1]}),
+	      #'SetBS'{a=2#0110101,
+		       b=2#010100010101,
+		       c=[second],
+		       d=[1,0,0,1]},
+	      #'SetBS'{a = <<2#1010110:7>>, b = <<16#A8A:12>>,
+		       c=[second], d = <<2#1001:4>>}),
     roundtrip(<<49,0>>,
 	      'SetBS',
 	      #'SetBS'{a=[1,0,1,0,1,1,0],
 		       b=[1,0,1,0,1,0,0,0,1,0,1,0],
 		       c={5,<<64>>},
 		       d=9},
-	      #'SetBS'{a=[1,0,1,0,1,1,0],
-		       b=16#A8A,
-		       c=[second],
-		       d=[1,0,0,1]}),
+	      #'SetBS'{a = <<2#1010110:7>>, b = <<16#A8A:12>>,
+		       c=[second], d = <<2#1001:4>>}),
     roundtrip(<<49,3,131,1,0>>,
 	      'SetBS',
 	      #'SetBS'{a=[1,0,1,0,1,1,0],
 		       b=[1,0,1,0,1,0,0,0,1,0,1,0],
 		       c={5,<<64>>},
 		       d=0},
-	      #'SetBS'{a=[1,0,1,0,1,1,0],
-		       b=16#A8A,
-		       c=[second],
-		       d = <<>>}),
+	      #'SetBS'{a = <<2#1010110:7>>, b = <<16#A8A:12>>,
+		       c=[second], d = <<>>}),
+    roundtrip(<<49,3,131,1,0>>,
+	      'SetBS',
+	      #'SetBS'{a = <<1:1,0:1,1:1,0:1,1:1,1:1,0:1>>,
+		       b = <<1:1,0:1,1:1,0:1,1:1,0:1,0:1,0:1,1:1,0:1,1:1,0:1>>,
+		       c = <<2:3>>,
+		       d=0},
+	      #'SetBS'{a = <<2#1010110:7>>, b = <<16#A8A:12>>,
+		       c=[second], d = <<>>}),
 
     roundtrip(<<48,0>>, 'SeqOS',
 	      #'SeqOS'{a=[172],b=[16#A8,16#A0],c='NULL'}),