Class: OpenSSL::ASN1::Constructive
 Inherits:

Object
 Object
 OpenSSL::ASN1::Constructive
 Defined in:
 ossl_asn1.c
Overview
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 subclasses of Constructive:

OpenSSL::ASN1::Set

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 ] )
Infinite length primitive values
The only case where Constructive is used directly is for infinite length
encodings of primitive values. These encodings are always constructed, with
the contents of the value
Array
being either
UNIVERSAL noninfinite length partial encodings of the actual value or
again constructive encodings with infinite length (i.e. infinite length
primitive encodings may be constructed recursively with another infinite
length value within an already infinite length value). Each partial
encoding must be of the same UNIVERSAL type as the overall encoding. The
value of the overall encoding consists of the concatenation of each partial
encoding taken in sequence. The value
array of the outer
infinite length value must end with a OpenSSL::ASN1::EndOfContent instance.
Please note that it is not possible to encode Constructive without the
infinite_length
attribute being set to true
, use
OpenSSL::ASN1::Sequence or OpenSSL::ASN1::Set in these cases instead.
Example  Infinite length OCTET STRING
partial1 = OpenSSL::ASN1::OctetString.new("\x01")
partial2 = OpenSSL::ASN1::OctetString.new("\x02")
inf_octets = OpenSSL::ASN1::Constructive.new( [ partial1,
partial2,
OpenSSL::ASN1::EndOfContent.new ],
OpenSSL::ASN1::OCTET_STRING,
nil,
:UNIVERSAL )
# The real value of inf_octets is "\x01\x02", i.e. the concatenation
# of partial1 and partial2
inf_octets.infinite_length = true
der = inf_octets.to_der
asn1 = OpenSSL::ASN1.decode(der)
puts asn1.infinite_length # => true