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-rw-r--r--lib/asn1/src/asn1ct_imm.erl57
1 files changed, 33 insertions, 24 deletions
diff --git a/lib/asn1/src/asn1ct_imm.erl b/lib/asn1/src/asn1ct_imm.erl
index bf362db843..a7e62e061b 100644
--- a/lib/asn1/src/asn1ct_imm.erl
+++ b/lib/asn1/src/asn1ct_imm.erl
@@ -115,25 +115,15 @@ per_dec_named_integer(Constraint, NamedList0, Aligned) ->
per_dec_k_m_string(StringType, Constraint, Aligned) ->
SzConstr = effective_constraint(bitstring, Constraint),
N = string_num_bits(StringType, Constraint, Aligned),
- %% X.691 (07/2002) 27.5.7 says if the upper bound times the number
- %% of bits is greater than or equal to 16, then the bit field should
- %% be aligned.
- Imm = dec_string(SzConstr, N, Aligned, fun(_, Ub) -> Ub >= 16 end),
+ Imm = dec_string(SzConstr, N, Aligned, k_m_string),
Chars = char_tab(Constraint, StringType, N),
convert_string(N, Chars, Imm).
per_dec_octet_string(Constraint, Aligned) ->
- dec_string(Constraint, 8, Aligned,
- %% Aligned unless the size is fixed and =< 16.
- fun(Sv, Sv) -> Sv > 16;
- (_, _) -> true
- end).
+ dec_string(Constraint, 8, Aligned, 'OCTET STRING').
per_dec_raw_bitstring(Constraint, Aligned) ->
- dec_string(Constraint, 1, Aligned,
- fun(Sv, Sv) -> Sv > 16;
- (_, _) -> true
- end).
+ dec_string(Constraint, 1, Aligned, 'BIT STRING').
per_dec_open_type(Aligned) ->
{get_bits,decode_unconstrained_length(true, Aligned),
@@ -157,21 +147,40 @@ per_dec_restricted_string(Aligned) ->
%%% Local functions.
%%%
-dec_string(Sv, U, Aligned0, AF) when is_integer(Sv) ->
+%% is_aligned(StringType, LowerBound, UpperBound) -> boolean()
+%% StringType = 'OCTET STRING' | 'BIT STRING' | k_m_string
+%% LowerBound = UpperBound = number of bits
+%% Determine whether a string should be aligned in PER.
+
+is_aligned(T, Lb, Ub) when T =:= 'OCTET STRING'; T =:= 'BIT STRING' ->
+ %% OCTET STRINGs and BIT STRINGs are aligned to a byte boundary
+ %% unless the size is fixed and less than or equal to 16 bits.
+ Lb =/= Ub orelse Lb > 16;
+is_aligned(k_m_string, _Lb, Ub) ->
+ %% X.691 (07/2002) 27.5.7 says if the upper bound times the number
+ %% of bits is greater than or equal to 16, then the bit field should
+ %% be aligned.
+ Ub >= 16.
+
+%%%
+%%% Generating the intermediate format format for decoding.
+%%%
+
+dec_string(Sv, U, Aligned0, T) when is_integer(Sv) ->
Bits = U*Sv,
- Aligned = Aligned0 andalso AF(Bits, Bits),
+ Aligned = Aligned0 andalso is_aligned(T, Bits, Bits),
{get_bits,Sv,[U,binary,{align,Aligned}]};
-dec_string({{Sv,Sv},[]}, U, Aligned, AF) ->
- bit_case(dec_string(Sv, U, Aligned, AF),
- dec_string(no, U, Aligned, AF));
-dec_string({{_,_}=C,[]}, U, Aligned, AF) ->
- bit_case(dec_string(C, U, Aligned, AF),
- dec_string(no, U, Aligned, AF));
-dec_string({Lb,Ub}, U, Aligned0, AF) ->
+dec_string({{Sv,Sv},[]}, U, Aligned, T) ->
+ bit_case(dec_string(Sv, U, Aligned, T),
+ dec_string(no, U, Aligned, T));
+dec_string({{_,_}=C,[]}, U, Aligned, T) ->
+ bit_case(dec_string(C, U, Aligned, T),
+ dec_string(no, U, Aligned, T));
+dec_string({Lb,Ub}, U, Aligned0, T) ->
Len = per_dec_constrained(Lb, Ub, Aligned0),
- Aligned = Aligned0 andalso AF(Lb*U, Ub*U),
+ Aligned = Aligned0 andalso is_aligned(T, Lb*U, Ub*U),
{get_bits,Len,[U,binary,{align,Aligned}]};
-dec_string(_, U, Aligned, _AF) ->
+dec_string(_, U, Aligned, _T) ->
Al = [{align,Aligned}],
DecRest = fun(V, Buf) ->
asn1ct_func:call(per_common,