# class OpenSSL::ASN1::Constructive

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::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 ] )

### Public Instance Methods

each { |asn1| block } → asn1_ary
Source

    # File ext/openssl/lib/openssl/asn1.rb, line 148
    def each(&blk)
      @value.each(&blk)

      self
    end

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

to_der → DER-encoded String
Source

    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.