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.


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:

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 =
str ='abc')
sequence = [ int, str ] )

Example - constructing a SET

int =
str ='abc')
set = [ int, str ] )
Read & Write

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.

Class Methods

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.


int =
zero_tagged_int =, 0, :IMPLICIT)
private_explicit_zero_tagged_int =, 0, :EXPLICIT, :PRIVATE)
Instance Methods

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.


asn1_ary.each do |asn1|
  puts asn1

See ASN1Data#to_der for details.