// Create PAC with unaligned buffer offset
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        writeLittleEndianInt(baos, 1); // bufferCount
        writeLittleEndianInt(baos, PacConstants.PAC_VERSION); // version
        writeLittleEndianInt(baos, PacConstants.LOGON_INFO); // type
        writeLittleEndianInt(baos, 10); // size
        writeLittleEndianLong(baos, 25); // Unaligned offset (not multiple of 8)

     * This prevents accidental modification of these critical constants.
     */
    @Test
    void testConstantValues() {
        // Verify the PAC version
        assertEquals(0, PacConstants.PAC_VERSION, "PAC_VERSION should be 0");

        // Verify PAC buffer types
        assertEquals(1, PacConstants.LOGON_INFO, "LOGON_INFO should be 1");
        assertEquals(2, PacConstants.CREDENTIAL_TYPE, "CREDENTIAL_TYPE should be 2");

 * Defines buffer types and other constants used in PAC parsing and validation.
 */
public interface PacConstants {

    /**
     * PAC structure version number.
     */
    int PAC_VERSION = 0;

    /**
     * Buffer type for user logon information.
     */
    int LOGON_INFO = 1;
    /**
     * Buffer type for credential information.
     */
    int CREDENTIAL_TYPE = 2;
    /**

        DataOutputStream dos = new DataOutputStream(baos);

        // Write header with no buffers
        dos.writeInt(Integer.reverseBytes(0));
        dos.writeInt(Integer.reverseBytes(PacConstants.PAC_VERSION));

        byte[] noBufPac = baos.toByteArray();

        PACDecodingException e = assertThrows(PACDecodingException.class, () -> {
            new KerberosPacAuthData(noBufPac, keys);
        });

                throw new PACDecodingException("Empty PAC");
            }

            int bufferCount = pacStream.readInt();
            int version = pacStream.readInt();

            if (version != PacConstants.PAC_VERSION) {
                throw new PACDecodingException("Unrecognized PAC version " + version);
            }

            for (int bufferIndex = 0; bufferIndex < bufferCount; bufferIndex++) {