%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2012-2013. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
%%
-module(asn1rtt_per_common).
-include("asn1_records.hrl").
-export([decode_fragmented/3,
decode_compact_bit_string/1,
decode_legacy_bit_string/1,
decode_named_bit_string/2,
decode_chars/2,decode_chars/3,
decode_chars_16bit/1,
decode_big_chars/2,
decode_oid/1,decode_relative_oid/1,
encode_chars/2,encode_chars/3,
encode_chars_compact_map/3,
encode_chars_16bit/1,encode_big_chars/1,
encode_fragmented/2,
encode_oid/1,encode_relative_oid/1,
encode_unconstrained_number/1,
bitstring_from_positions/1,bitstring_from_positions/2,
to_bitstring/1,to_bitstring/2,
to_named_bitstring/1,to_named_bitstring/2,
bs_drop_trailing_zeroes/1,adjust_trailing_zeroes/2,
is_default_bitstring/3,is_default_bitstring/5,
extension_bitmap/3,
open_type_to_binary/1,legacy_open_type_to_binary/1]).
-define('16K',16384).
decode_fragmented(SegSz0, Buf0, Unit) ->
SegSz = SegSz0 * Unit * ?'16K',
<<Res:SegSz/bitstring,Buf/bitstring>> = Buf0,
decode_fragmented_1(Buf, Unit, Res).
decode_fragmented_1(<<0:1,N:7,Buf0/bitstring>>, Unit, Res) ->
Sz = N*Unit,
<<S:Sz/bitstring,Buf/bitstring>> = Buf0,
{<<Res/bitstring,S/bitstring>>,Buf};
decode_fragmented_1(<<1:1,0:1,N:14,Buf0/bitstring>>, Unit, Res) ->
Sz = N*Unit,
<<S:Sz/bitstring,Buf/bitstring>> = Buf0,
{<<Res/bitstring,S/bitstring>>,Buf};
decode_fragmented_1(<<1:1,1:1,SegSz0:6,Buf0/bitstring>>, Unit, Res0) ->
SegSz = SegSz0 * Unit * ?'16K',
<<Frag:SegSz/bitstring,Buf/bitstring>> = Buf0,
Res = <<Res0/bitstring,Frag/bitstring>>,
decode_fragmented_1(Buf, Unit, Res).
decode_named_bit_string(Val, NNL) ->
Bits = [B || <<B:1>> <= Val],
decode_named_bit_string_1(0, Bits, NNL, []).
decode_legacy_bit_string(Val) ->
[B || <<B:1>> <= Val].
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)).
decode_oid(Octets) ->
[First|Rest] = dec_subidentifiers(Octets, 0, []),
Idlist = if
First < 40 ->
[0,First|Rest];
First < 80 ->
[1,First - 40|Rest];
true ->
[2,First - 80|Rest]
end,
list_to_tuple(Idlist).
decode_relative_oid(Octets) ->
list_to_tuple(dec_subidentifiers(Octets, 0, [])).
encode_chars(Val, NumBits) ->
<< <<C:NumBits>> || C <- Val >>.
encode_chars(Val, NumBits, {Lb,Tab}) ->
<< <<(enc_char(C, Lb, Tab)):NumBits>> || C <- Val >>.
encode_chars_compact_map(Val, NumBits, {Lb,Limit}) ->
<< <<(enc_char_cm(C, Lb, Limit)):NumBits>> || C <- Val >>.
encode_chars_16bit(Val) ->
L = [case C of
{0,0,A,B} -> [A,B];
C when is_integer(C) -> [0,C]
end || C <- Val],
iolist_to_binary(L).
encode_big_chars(Val) ->
L = [case C of
{_,_,_,_} -> tuple_to_list(C);
C when is_integer(C) -> [<<0,0,0>>,C]
end || C <- Val],
iolist_to_binary(L).
encode_fragmented(Bin, Unit) ->
encode_fragmented_1(Bin, Unit, 4).
encode_oid(Val) when is_tuple(Val) ->
encode_oid(tuple_to_list(Val));
encode_oid(Val) ->
iolist_to_binary(e_object_identifier(Val)).
encode_relative_oid(Val) when is_tuple(Val) ->
encode_relative_oid(tuple_to_list(Val));
encode_relative_oid(Val) when is_list(Val) ->
list_to_binary([e_object_element(X)||X <- Val]).
encode_unconstrained_number(Val) when Val >= 0 ->
if
Val < 16#80 ->
[1,Val];
Val < 16#100 ->
[<<2,0>>,Val];
true ->
case binary:encode_unsigned(Val) of
<<0:1,_/bitstring>>=Bin ->
case byte_size(Bin) of
Sz when Sz < 128 ->
[Sz,Bin];
Sz when Sz < 16384 ->
[<<2:2,Sz:14>>,Bin]
end;
<<1:1,_/bitstring>>=Bin ->
case byte_size(Bin)+1 of
Sz when Sz < 128 ->
[Sz,0,Bin];
Sz when Sz < 16384 ->
[<<2:2,Sz:14,0:8>>,Bin]
end
end
end;
encode_unconstrained_number(Val) ->
Oct = enint(Val, []),
Len = length(Oct),
if
Len < 128 ->
[Len|Oct];
Len < 16384 ->
[<<2:2,Len:14>>|Oct]
end.
%% bitstring_from_positions([Position]) -> BitString
%% Given an unsorted list of bit positions (0..MAX), construct
%% a BIT STRING. The rightmost bit will always be a one.
bitstring_from_positions([]) -> <<>>;
bitstring_from_positions([_|_]=L0) ->
L1 = lists:sort(L0),
L = diff(L1, -1),
<< <<1:(N+0)>> || N <- L >>.
%% bitstring_from_positions([Position], Lb) -> BitString
%% Given an unsorted list of bit positions (0..MAX) and a lower bound
%% for the number of bits, construct BIT STRING (zero-padded on the
%% right side if needed).
bitstring_from_positions(L0, Lb) ->
L1 = lists:sort(L0),
L = diff(L1, -1, Lb-1),
<< <<B:(N+0)>> || {B,N} <- L >>.
%% to_bitstring(Val) -> BitString
%% Val = BitString | {Unused,Binary} | [OneOrZero] | Integer
%% Given one of the possible representations for a BIT STRING,
%% return a bitstring (without adding or removing any zero bits
%% at the right end).
to_bitstring({0,Bs}) when is_binary(Bs) ->
Bs;
to_bitstring({Unused,Bs0}) when is_binary(Bs0) ->
Sz = bit_size(Bs0) - Unused,
<<Bs:Sz/bits,_/bits>> = Bs0,
Bs;
to_bitstring(Bs) when is_bitstring(Bs) ->
Bs;
to_bitstring(Int) when is_integer(Int), Int >= 0 ->
L = int_to_bitlist(Int),
<< <<B:1>> || B <- L >>;
to_bitstring(L) when is_list(L) ->
<< <<B:1>> || B <- L >>.
%% to_bitstring(Val, Lb) -> BitString
%% Val = BitString | {Unused,Binary} | [OneOrZero] | Integer
%% Lb = Integer
%% Given one of the possible representations for a BIT STRING
%% and the lower bound for the number of bits,
%% return a bitstring at least Lb bits long (padded with zeroes
%% if needed).
to_bitstring({0,Bs}, Lb) when is_binary(Bs) ->
case bit_size(Bs) of
Sz when Sz < Lb ->
<<Bs/bits,0:(Lb-Sz)>>;
_ ->
Bs
end;
to_bitstring({Unused,Bs0}, Lb) when is_binary(Bs0) ->
Sz = bit_size(Bs0) - Unused,
if
Sz < Lb ->
<<Bs0:Sz/bits,0:(Lb-Sz)>>;
true ->
<<Bs:Sz/bits,_/bits>> = Bs0,
Bs
end;
to_bitstring(Bs, Lb) when is_bitstring(Bs) ->
adjust_size(Bs, Lb);
to_bitstring(Int, Lb) when is_integer(Int), Int >= 0 ->
L = int_to_bitlist(Int),
Bs = << <<B:1>> || B <- L >>,
adjust_size(Bs, Lb);
to_bitstring(L, Lb) when is_list(L) ->
Bs = << <<B:1>> || B <- L >>,
adjust_size(Bs, Lb).
%% to_named_bitstring(Val) -> BitString
%% Val = BitString | {Unused,Binary} | [OneOrZero] | Integer
%% Given one of the possible representations for a BIT STRING,
%% return a bitstring where any trailing zeroes have been stripped.
to_named_bitstring(Val) ->
Bs = to_bitstring(Val),
bs_drop_trailing_zeroes(Bs).
%% to_named_bitstring(Val, Lb) -> BitString
%% Val = BitString | {Unused,Binary} | [OneOrZero] | Integer
%% Lb = Integer
%% Given one of the possible representations for a BIT STRING
%% and the lower bound for the number of bits,
%% return a bitstring that is at least Lb bits long. There will
%% be zeroes at the right only if needed to reach the lower bound
%% for the number of bits.
to_named_bitstring({0,Bs}, Lb) when is_binary(Bs) ->
adjust_trailing_zeroes(Bs, Lb);
to_named_bitstring({Unused,Bs0}, Lb) when is_binary(Bs0) ->
Sz = bit_size(Bs0) - Unused,
<<Bs:Sz/bits,_/bits>> = Bs0,
adjust_trailing_zeroes(Bs, Lb);
to_named_bitstring(Bs, Lb) when is_bitstring(Bs) ->
adjust_trailing_zeroes(Bs, Lb);
to_named_bitstring(Val, Lb) ->
%% Obsolete representations: list or integer. Optimize
%% for correctness, not speed.
adjust_trailing_zeroes(to_bitstring(Val), Lb).
is_default_bitstring(asn1_DEFAULT, _, _) ->
true;
is_default_bitstring(Named, Named, _) ->
true;
is_default_bitstring(Bs, _, Bs) ->
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(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).
open_type_to_binary({asn1_OPENTYPE,Bin}) when is_binary(Bin) ->
Bin.
legacy_open_type_to_binary({asn1_OPENTYPE,Bin}) when is_binary(Bin) ->
Bin;
legacy_open_type_to_binary(Bin) when is_binary(Bin) ->
Bin;
legacy_open_type_to_binary(List) when is_list(List) ->
List.
%%%
%%% Internal functions.
%%%
decode_named_bit_string_1(Pos, [0|Bt], Names, Acc) ->
decode_named_bit_string_1(Pos+1, Bt, Names, Acc);
decode_named_bit_string_1(Pos, [1|Bt], Names, Acc) ->
case lists:keyfind(Pos, 2, Names) of
{Name,_} ->
decode_named_bit_string_1(Pos+1, Bt, Names, [Name|Acc]);
false ->
decode_named_bit_string_1(Pos+1, Bt, Names, [{bit,Pos}|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([]) -> [].
dec_subidentifiers([H|T], Av, Al) when H >=16#80 ->
dec_subidentifiers(T, (Av bsl 7) bor (H band 16#7F), Al);
dec_subidentifiers([H|T], Av, Al) ->
dec_subidentifiers(T, 0, [(Av bsl 7) bor H|Al]);
dec_subidentifiers([], _Av, Al) ->
lists:reverse(Al).
enc_char(C0, Lb, Tab) ->
try element(C0-Lb, Tab) of
ill ->
illegal_char_error();
C ->
C
catch
error:badarg ->
illegal_char_error()
end.
enc_char_cm(C0, Lb, Limit) ->
C = C0 - Lb,
if
0 =< C, C < Limit ->
C;
true ->
illegal_char_error()
end.
illegal_char_error() ->
error({error,{asn1,"value forbidden by FROM constraint"}}).
encode_fragmented_1(Bin, Unit, N) ->
SegSz = Unit * N * ?'16K',
case Bin of
<<B:SegSz/bitstring,T/bitstring>> ->
[<<3:2,N:6>>,B|encode_fragmented_1(T, Unit, N)];
_ when N > 1 ->
encode_fragmented_1(Bin, Unit, N-1);
_ ->
case bit_size(Bin) div Unit of
Len when Len < 128 ->
[Len,Bin];
Len when Len < 16384 ->
[<<2:2,Len:14>>,Bin]
end
end.
%% E1 = 0|1|2 and (E2 < 40 when E1 = 0|1)
e_object_identifier([E1,E2|Tail]) when E1 >= 0, E1 < 2, E2 < 40; E1 =:= 2 ->
Head = 40*E1 + E2,
e_object_elements([Head|Tail], []);
e_object_identifier([_,_|_Tail]=Oid) ->
exit({error,{asn1,{'illegal_value',Oid}}}).
e_object_elements([], Acc) ->
lists:reverse(Acc);
e_object_elements([H|T], Acc) ->
e_object_elements(T, [e_object_element(H)|Acc]).
e_object_element(Num) when Num < 128 ->
[Num];
e_object_element(Num) ->
[e_o_e(Num bsr 7)|[Num band 2#1111111]].
e_o_e(Num) when Num < 128 ->
Num bor 2#10000000;
e_o_e(Num) ->
[e_o_e(Num bsr 7)|[(Num band 2#1111111) bor 2#10000000]].
enint(-1, [B1|T]) when B1 > 127 ->
[B1|T];
enint(N, Acc) ->
enint(N bsr 8, [N band 16#ff|Acc]).
diff([H|T], Prev) ->
[H-Prev|diff(T, H)];
diff([], _) -> [].
diff([H|T], Prev, Last) ->
[{1,H-Prev}|diff(T, H, Last)];
diff([], Prev, Last) when Last >= Prev ->
[{0,Last-Prev}];
diff([], _, _) -> [].
int_to_bitlist(0) -> [];
int_to_bitlist(Int) -> [Int band 1|int_to_bitlist(Int bsr 1)].
adjust_size(Bs, Lb) ->
case bit_size(Bs) of
Sz when Sz < Lb ->
<<Bs:Sz/bits,0:(Lb-Sz)>>;
_ ->
Bs
end.
adjust_trailing_zeroes(Bs0, Lb) ->
case bit_size(Bs0) of
Sz when Sz < Lb ->
%% Too short - pad with zeroes.
<<Bs0:Sz/bits,0:(Lb-Sz)>>;
Lb ->
%% Exactly the right size - nothing to do.
Bs0;
_ ->
%% Longer than the lower bound - drop trailing zeroes.
<<_:Lb/bits,Tail/bits>> = Bs0,
Sz = Lb + bit_size(bs_drop_trailing_zeroes(Tail)),
<<Bs:Sz/bits,_/bits>> = Bs0,
Bs
end.
bs_drop_trailing_zeroes(Bs) ->
bs_drop_trailing_zeroes(Bs, bit_size(Bs)).
bs_drop_trailing_zeroes(Bs, 0) ->
Bs;
bs_drop_trailing_zeroes(Bs0, Sz0) when Sz0 < 8 ->
<<Byte:Sz0>> = Bs0,
Sz = Sz0 - ntz(Byte),
<<Bs:Sz/bits,_/bits>> = Bs0,
Bs;
bs_drop_trailing_zeroes(Bs0, Sz0) ->
Sz1 = Sz0 - 8,
<<Bs1:Sz1/bits,Byte:8>> = Bs0,
case ntz(Byte) of
8 ->
bs_drop_trailing_zeroes(Bs1, Sz1);
Ntz ->
Sz = Sz0 - Ntz,
<<Bs:Sz/bits,_:Ntz/bits>> = Bs0,
Bs
end.
%% ntz(Byte) -> Number of trailing zeroes.
ntz(Byte) ->
%% The table was calculated like this:
%% NTZ = fun (B, N, NTZ) when B band 1 =:= 0 -> NTZ(B bsr 1, N+1, NTZ); (_, N, _) -> N end.
%% io:format("~w\n", [list_to_tuple([NTZ(B+256, 0, NTZ) || B <- lists:seq(0, 255)])]).
T = {8,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
7,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
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) ->
Bit = case element(Pos, Val) of
asn1_NOVALUE -> 0;
_ -> 1
end,
extension_bitmap(Val, Pos+1, Limit, (Acc bsl 1) bor Bit).
