// 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;

**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

@DisplayName("CIFSUnsupportedCryptoException Tests")
class CIFSUnsupportedCryptoExceptionTest extends BaseTest {

    private static final String CRYPTO_ERROR_MESSAGE = "Unsupported cryptographic algorithm: AES-256-GCM";
    private static final String ALGORITHM_NAME = "AES-256-GCM";

    @Test
    @DisplayName("Default constructor should create exception with null message and cause")
    void testDefaultConstructor() {
        // Given & When

    /**
     * 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;

    /**

```

`--sftp=cipher-algos=...` specifies the allowed cipher algorithms. 
If unspecified then a sensible default is used.

Valid values: 
```
aes128-ctr
aes192-ctr
aes256-ctr
aes128-gcm@openssh.com
aes256-gcm@openssh.com
******@****.***
arcfour256
arcfour128
arcfour
aes128-cbc
3des-cbc
```

`--sftp=mac-algos=...` specifies a default set of MAC algorithms in preference order.

            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