port.org.bouncycastle.asn1.DLSequence Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of dss-model Show documentation

DSS Model contains the data model representation for DSS

There is a newer version: 6.0.d4j.2

package port.org.bouncycastle.asn1;

import java.io.IOException;
import java.util.Enumeration;

/**
 * The DLSequence encodes a SEQUENCE using definite length form.
 */
public class DLSequence extends ASN1Sequence {

	private int bodyLength = -1;

	/**
	 * Create an empty sequence
	 */
	public DLSequence() {
	}

	/**
	 * Create a sequence containing one object
	 */
	public DLSequence(ASN1Encodable obj) {
		super(obj);
	}

	/**
	 * Create a sequence containing a vector of objects.
	 */
	public DLSequence(ASN1EncodableVector v) {
		super(v);
	}

	/**
	 * Create a sequence containing an array of objects.
	 */
	public DLSequence(ASN1Encodable[] array) {
		super(array);
	}

	private int getBodyLength() throws IOException {
		if (bodyLength < 0) {
			int length = 0;

			for (Enumeration e = this.getObjects(); e.hasMoreElements();) {
				Object obj = e.nextElement();

				length += ((ASN1Encodable) obj).toASN1Primitive().toDLObject().encodedLength();
			}

			bodyLength = length;
		}

		return bodyLength;
	}

	@Override
	int encodedLength() throws IOException {
		int length = getBodyLength();

		return 1 + StreamUtil.calculateBodyLength(length) + length;
	}

	/**
	 * A note on the implementation:
	 * 
	 * As DL requires the constructed, definite-length model to be used for structured types, this varies slightly from the ASN.1 descriptions given. Rather than just outputting SEQUENCE, we also have to specify CONSTRUCTED, and the objects length.
	 */
	@Override
	void encode(ASN1OutputStream out) throws IOException {
		ASN1OutputStream dOut = out.getDLSubStream();
		int length = getBodyLength();

		out.write(BERTags.SEQUENCE | BERTags.CONSTRUCTED);
		out.writeLength(length);

		for (Enumeration e = this.getObjects(); e.hasMoreElements();) {
			Object obj = e.nextElement();

			dOut.writeObject((ASN1Encodable) obj);
		}
	}

}