* @param resp The response.
     * @param challenge The domain controller challenge.
     * @throws IOException If an IO error occurs.
     * @return the authenticated NtlmPasswordAuthentication object
     * @throws IOException If an IO error occurs.
     * @throws ServletException If an error occurs.
     */
    public static NtlmPasswordAuthentication authenticate(final HttpServletRequest req, final HttpServletResponse resp,

   * close or flush either object.
   *
   * @param from the object to read from
   * @param to the object to write to
   * @return the number of characters copied
   * @throws IOException if an I/O error occurs
   */
  @CanIgnoreReturnValue
  public static long copy(Readable from, Appendable to) throws IOException {
    // The most common case is that from is a Reader (like InputStreamReader or StringReader) so

   * reader each time it is called.
   *
   * <p>The caller is responsible for ensuring that the returned reader is closed.
   *
   * @throws IOException if an I/O error occurs while opening the reader
   */
  public abstract Reader openStream() throws IOException;

  /**
   * Opens a new {@link BufferedReader} for reading from this source. This method returns a new,

   * reader each time it is called.
   *
   * <p>The caller is responsible for ensuring that the returned reader is closed.
   *
   * @throws IOException if an I/O error occurs while opening the reader
   */
  public abstract Reader openStream() throws IOException;

  /**
   * Opens a new {@link BufferedReader} for reading from this source. This method returns a new,

     * @param workstation the workstation
     * @param challenge the Type 2 challenge message
     * @return the Base64-encoded Type 3 message
     * @throws NTLMEngineException if an NTLM engine error occurs
     * @throws CrawlingAccessException if an error occurs during message generation
     */
    @Override
    public String generateType3Msg(final String username, final String password, final String domain, final String workstation,

     *
     * @throws IOException if a network error occurs
     */

    @Override
    public int read(final byte[] b) throws IOException {
        return read(b, 0, b.length);
    }

    /**
     * Reads up to len bytes of data from this input stream into an array of bytes.
     *
     * @throws IOException if a network error occurs
     */

    @Override

     * @throws IOException if an I/O error occurs
     */
    protected abstract void makeKey(Request request) throws IOException;

    /**
     * Reads and returns the key of the next message without consuming it.
     *
     * @return the request key of the next message
     * @throws IOException if an I/O error occurs
     */
    protected abstract Request peekKey() throws IOException;

    /**

/**
 * Tests for KerberosEncData.
 */
class KerberosEncDataTest {

    /**
     * Test constructor with a valid token.
     *
     * @throws IOException if an I/O error occurs
     * @throws PACDecodingException if a PAC decoding error occurs
     * @throws UnknownHostException if the IP address is not found
     */
    @Test
    void testConstructor() throws IOException, PACDecodingException, UnknownHostException {

  }

  /**
   * Reads all bytes from a URL into a byte array.
   *
   * @param url the URL to read from
   * @return a byte array containing all the bytes from the URL
   * @throws IOException if an I/O error occurs
   */
  public static byte[] toByteArray(URL url) throws IOException {
    return asByteSource(url).read();
  }

  /**
   * Reads all characters from a URL into a {@link String}, using the given character set.

   * independent stream each time it is called.
   *
   * <p>The caller is responsible for ensuring that the returned stream is closed.
   *
   * @throws IOException if an I/O error occurs while opening the stream
   */
  public abstract OutputStream openStream() throws IOException;

  /**
   * Opens a new buffered {@link OutputStream} for writing to this sink. The returned stream is not