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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.io.OutputStream;

/**
 * Stream that produces output based on the default encoding for the passed in objects.
 */
public class ASN1OutputStream {

	private OutputStream os;

	public ASN1OutputStream(OutputStream os) {
		this.os = os;
	}

	void writeLength(int length) throws IOException {
		if (length > 127) {
			int size = 1;
			int val = length;

			while ((val >>>= 8) != 0) {
				size++;
			}

			write((byte) (size | 0x80));

			for (int i = (size - 1) * 8; i >= 0; i -= 8) {
				write((byte) (length >> i));
			}
		} else {
			write((byte) length);
		}
	}

	void write(int b) throws IOException {
		os.write(b);
	}

	void write(byte[] bytes) throws IOException {
		os.write(bytes);
	}

	void write(byte[] bytes, int off, int len) throws IOException {
		os.write(bytes, off, len);
	}

	void writeEncoded(int tag, byte[] bytes) throws IOException {
		write(tag);
		writeLength(bytes.length);
		write(bytes);
	}

	void writeTag(int flags, int tagNo) throws IOException {
		if (tagNo < 31) {
			write(flags | tagNo);
		} else {
			write(flags | 0x1f);
			if (tagNo < 128) {
				write(tagNo);
			} else {
				byte[] stack = new byte[5];
				int pos = stack.length;

				stack[--pos] = (byte) (tagNo & 0x7F);

				do {
					tagNo >>= 7;
			stack[--pos] = (byte) ((tagNo & 0x7F) | 0x80);
				} while (tagNo > 127);

				write(stack, pos, stack.length - pos);
			}
		}
	}

	void writeEncoded(int flags, int tagNo, byte[] bytes) throws IOException {
		writeTag(flags, tagNo);
		writeLength(bytes.length);
		write(bytes);
	}

	protected void writeNull() throws IOException {
		os.write(BERTags.NULL);
		os.write(0x00);
	}

	public void writeObject(ASN1Encodable obj) throws IOException {
		if (obj != null) {
			obj.toASN1Primitive().encode(this);
		} else {
			throw new IOException("null object detected");
		}
	}

	void writeImplicitObject(ASN1Primitive obj) throws IOException {
		if (obj != null) {
			obj.encode(new ImplicitOutputStream(os));
		} else {
			throw new IOException("null object detected");
		}
	}

	public void close() throws IOException {
		os.close();
	}

	public void flush() throws IOException {
		os.flush();
	}

	ASN1OutputStream getDERSubStream() {
		return new DEROutputStream(os);
	}

	ASN1OutputStream getDLSubStream() {
		return new DLOutputStream(os);
	}

	private class ImplicitOutputStream extends ASN1OutputStream {
		private boolean first = true;

		public ImplicitOutputStream(OutputStream os) {
			super(os);
		}

		@Override
		public void write(int b) throws IOException {
			if (first) {
				first = false;
			} else {
				super.write(b);
			}
		}
	}
}