import java.io.IOException;

/**
 * Abstract base class for SPNEGO authentication tokens used in GSS-API negotiation
 */
public abstract class SpnegoToken {

    /**
     * Protected constructor for SPNEGO token implementations.
     */
    protected SpnegoToken() {
    }

    private byte[] mechanismToken;

    private byte[] mechanismListMIC;

    /**

        SpnegoToken spnegoToken = null;
        try {
            spnegoToken = switch (token[0]) {
            case (byte) 0x60 -> new NegTokenInit(token);
            case (byte) 0xa1 -> new NegTokenTarg(token);
            default -> throw new SpnegoException("Invalid token type");
            };
            return spnegoToken;
        } catch (final IOException e) {
            throw new SpnegoException("Invalid token");
        }

/**
 * Tests for SpnegoToken.
 * Uses a minimal concrete subclass to exercise abstract methods.
 */
class SpnegoTokenTest {

    /**
     * Minimal concrete implementation for testing.
     * - parse: sets mechanismToken, throws on null
     * - toByteArray: returns mechanismToken or empty array if null
     */
    static class TestSpnegoToken extends SpnegoToken {
        private boolean parsed = false;

import org.bouncycastle.asn1.DERSequence;
import org.bouncycastle.asn1.DERTaggedObject;

/**
 * SPNEGO response token (NegTokenTarg) used in SPNEGO authentication exchanges
 */
public class NegTokenTarg extends SpnegoToken {

    /**
     * Result code indicating unspecified result
     */
    public static final int UNSPECIFIED_RESULT = -1;
    /**
     * Result code indicating authentication completed successfully
     */

import org.bouncycastle.asn1.DERSequence;
import org.bouncycastle.asn1.DERTaggedObject;

import jcifs.util.Hexdump;

/**
 * SPNEGO initial token
 */
public class NegTokenInit extends SpnegoToken {

    /**
     * Context flag for delegation capability
     */
    public static final int DELEGATION = 0x80;
    /**
     * Context flag for mutual authentication requirement
     */