%% %% %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]). -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, [])). %%% %%% 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).