The parent class for all constructed encodings. The value attribute of a Constructive
is always an Array
. Attributes are the same as for ASN1Data
, with the addition of tagging.
SET and SEQUENCE
Most constructed encodings come in the form of a SET or a SEQUENCE. These encodings are represented by one of the two sub-classes of Constructive:
-
OpenSSL::ASN1::Sequence
Please note that tagged sequences and sets are still parsed as instances of ASN1Data
. Find
further details on tagged values there.
Example - constructing a SEQUENCE
int = OpenSSL::ASN1::Integer.new(1) str = OpenSSL::ASN1::PrintableString.new('abc') sequence = OpenSSL::ASN1::Sequence.new( [ int, str ] )
Example - constructing a SET
int = OpenSSL::ASN1::Integer.new(1) str = OpenSSL::ASN1::PrintableString.new('abc') set = OpenSSL::ASN1::Set.new( [ int, str ] )
May be used as a hint for encoding a value either implicitly or explicitly by setting it either to :IMPLICIT
or to :EXPLICIT
. tagging is not set when a ASN.1 structure is parsed using OpenSSL::ASN1.decode
.
static VALUE
ossl_asn1_initialize(int argc, VALUE *argv, VALUE self)
{
VALUE value, tag, tagging, tag_class;
int default_tag;
rb_scan_args(argc, argv, "13", &value, &tag, &tagging, &tag_class);
default_tag = ossl_asn1_default_tag(self);
if (default_tag == -1 || argc > 1) {
if(NIL_P(tag))
ossl_raise(eASN1Error, "must specify tag number");
if(!NIL_P(tagging) && !SYMBOL_P(tagging))
ossl_raise(eASN1Error, "invalid tagging method");
if(NIL_P(tag_class)) {
if (NIL_P(tagging))
tag_class = sym_UNIVERSAL;
else
tag_class = sym_CONTEXT_SPECIFIC;
}
if(!SYMBOL_P(tag_class))
ossl_raise(eASN1Error, "invalid tag class");
}
else{
tag = INT2NUM(default_tag);
tagging = Qnil;
tag_class = sym_UNIVERSAL;
}
ossl_asn1_set_tag(self, tag);
ossl_asn1_set_value(self, value);
ossl_asn1_set_tagging(self, tagging);
ossl_asn1_set_tag_class(self, tag_class);
ossl_asn1_set_indefinite_length(self, Qfalse);
if (default_tag == V_ASN1_BIT_STRING)
rb_ivar_set(self, sivUNUSED_BITS, INT2FIX(0));
return self;
}
value: is mandatory.
tag: optional, may be specified for tagged values. If no tag is specified, the UNIVERSAL tag corresponding to the Primitive
sub-class is used by default.
tagging: may be used as an encoding hint to encode a value either explicitly or implicitly, see ASN1
for possible values.
tag_class: if tag and tagging are nil
then this is set to :UNIVERSAL
by default. If either tag or tagging are set then :CONTEXT_SPECIFIC
is used as the default. For possible values please cf. ASN1
.
Example
int = OpenSSL::ASN1::Integer.new(42) zero_tagged_int = OpenSSL::ASN1::Integer.new(42, 0, :IMPLICIT) private_explicit_zero_tagged_int = OpenSSL::ASN1::Integer.new(42, 0, :EXPLICIT, :PRIVATE)
static VALUE
ossl_asn1cons_each(VALUE self)
{
rb_block_call(ossl_asn1_get_value(self), id_each, 0, 0, 0, 0);
return self;
}
Calls the given block once for each element in self, passing that element as parameter asn1. If no block is given, an enumerator is returned instead.
Example
asn1_ary.each do |asn1| puts asn1 end
static VALUE
ossl_asn1cons_to_der(VALUE self)
{
VALUE ary, str;
long i;
int indef_len;
indef_len = RTEST(ossl_asn1_get_indefinite_length(self));
ary = rb_convert_type(ossl_asn1_get_value(self), T_ARRAY, "Array", "to_a");
str = rb_str_new(NULL, 0);
for (i = 0; i < RARRAY_LEN(ary); i++) {
VALUE item = RARRAY_AREF(ary, i);
if (indef_len && rb_obj_is_kind_of(item, cASN1EndOfContent)) {
if (i != RARRAY_LEN(ary) - 1)
ossl_raise(eASN1Error, "illegal EOC octets in value");
/*
* EOC is not really part of the content, but we required to add one
* at the end in the past.
*/
break;
}
item = ossl_to_der_if_possible(item);
StringValue(item);
rb_str_append(str, item);
}
return to_der_internal(self, 1, indef_len, str);
}
See ASN1Data#to_der
for details.