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-rw-r--r--lib/asn1/src/asn1rtt_per_common.erl126
1 files changed, 126 insertions, 0 deletions
diff --git a/lib/asn1/src/asn1rtt_per_common.erl b/lib/asn1/src/asn1rtt_per_common.erl
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+++ b/lib/asn1/src/asn1rtt_per_common.erl
@@ -0,0 +1,126 @@
+%%
+%% %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).