// Last 4 bytes remain zero-initialized
        } else if (nonce.length == 16) {
            // For GCM cipher, use full 16-byte nonce
            System.arraycopy(nonce, 0, this.nonce, 0, 16);
        } else {
            throw new IllegalArgumentException("Nonce must be 12 bytes (CCM) or 16 bytes (GCM)");
        }
        this.originalMessageSize = originalMessageSize;
        this.flags = flags;

        if (keyLength == 32) {
            // AES-256 support
            transformation = "AES/GCM/NoPadding";
        } else if (keyLength == 16) {
            // AES-128 (existing)
            transformation = "AES/GCM/NoPadding";
        } else {
            throw new IllegalArgumentException("Unsupported key length for GCM: " + keyLength);
        }

        byte[] key = null;
        byte[] keyCopy = null;

**Protocol Selection:**
- Default Range: SMB1 to SMB 3.1.1
- Automatic Negotiation: Client offers all supported dialects, server selects highest common version
- Configurable: Min/max versions can be set via configuration properties

### SMB3 Encryption Support
- **SMB2 Transform Header**: Encrypted message wrapping

        // Nonces should have proper size
        assertEquals(16, nonce1.length, "GCM nonce should be 16 bytes");
        assertEquals(16, nonce2.length, "GCM nonce should be 16 bytes");
        assertEquals(16, nonce3.length, "GCM nonce should be 16 bytes");

        // For GCM, last 4 bytes should contain incrementing counter

    /**
     * AES 128 CCM
     */
    public static final int CIPHER_AES128_CCM = 0x1;

    /**
     * AES 128 GCM
     */
    public static final int CIPHER_AES128_GCM = 0x2;

    /**
     * AES 256 CCM
     */
    public static final int CIPHER_AES256_CCM = 0x3;

    /**
     * AES 256 GCM
     */
    public static final int CIPHER_AES256_GCM = 0x4;

    private int[] ciphers;

    /**

/**
 * Secure credential storage with encryption at rest.
 *
 * Provides secure storage of passwords and other sensitive credentials
 * using AES-GCM encryption with PBKDF2 key derivation.
 *
 * Features:
 * - Encrypts credentials at rest using AES-256-GCM
 * - Uses PBKDF2 for key derivation from master password
 * - Secure wiping of sensitive data
 * - Thread-safe operations
 * - Protection against timing attacks
 */

	"aes128-ctr", "aes192-ctr", "aes256-ctr",
	"aes128-gcm@openssh.com", gcm256CipherID,
	chacha20Poly1305ID,
	"arcfour256", "arcfour128", "arcfour",
	aes128cbcID,
	tripledescbcID,
}

// preferredCiphers specifies the default preference for ciphers.
// https://cs.opensource.google/go/x/crypto/+/refs/tags/v0.22.0:ssh/common.go;l=37
var preferredCiphers = []string{
	"aes128-gcm@openssh.com", gcm256CipherID,
	chacha20Poly1305ID,

 * </ul>
 * <p>
 * <strong>Security Considerations:</strong>
 * </p>
 * <ul>
 * <li>Default Blowfish algorithm is suitable for general-purpose encryption</li>
 * <li>For high-security applications, consider using AES with GCM mode via {@link #setAlgorithm(String)} and {@link #setTransformation(String)}</li>
 * <li>Ensure keys are securely generated and stored</li>

            if (config.isEncryptionEnabled()) {
                // Build cipher list based on AES-256 support
                List<Integer> ciphers = new ArrayList<>();

                // Prefer GCM over CCM for better performance
                if (config.isAES256Enabled()) {
                    ciphers.add(EncryptionNegotiateContext.CIPHER_AES256_GCM);

    }

    @Test
    @DisplayName("Test log encryption")
    void testLogEncryption() {
        logger.logEncryption(true, "AES-128-GCM", "SMB3.1.1");

        Map<EventType, Long> stats = logger.getStatistics();
        assertEquals(Long.valueOf(1), stats.get(EventType.ENCRYPTION_ENABLED), "Should have 1 encryption event");
    }

    @Test