# Persistent Handles Feature - Detailed Design Document

## 1. Overview

Persistent handles (also known as durable handles) allow SMB3 connections to survive network disconnections, server reboots, and client reconnections. This feature is critical for enterprise reliability and seamless failover scenarios.

## 2. Protocol Specification Reference

- **MS-SMB2 Section 2.2.13.2.3**: SMB2_CREATE_DURABLE_HANDLE_REQUEST

 */
package jcifs.internal.smb2.lease;

import jcifs.internal.smb2.create.CreateContextRequest;
import jcifs.internal.util.SMBUtil;

/**
 * Directory Lease Context for SMB3 directory leasing
 *
 * This context extends standard lease context with directory-specific metadata
 * for enhanced directory caching capabilities.
 */
public class DirectoryLeaseContext implements CreateContextRequest {

import jcifs.internal.smb2.info.Smb2QueryInfoRequest;
import jcifs.internal.smb2.info.Smb2SetInfoRequest;
import jcifs.internal.smb2.io.Smb2ReadRequest;
import jcifs.internal.smb2.io.Smb2WriteRequest;

/**
 * Load balancer for SMB3 Multi-Channel connections
 */
public class ChannelLoadBalancer {

    private final ChannelManager manager;
    private LoadBalancingStrategy strategy;
    private final AtomicInteger roundRobinCounter;

    /**

import jcifs.Configuration;
import jcifs.config.PropertyConfiguration;
import jcifs.internal.smb2.ServerMessageBlock2Request;
import jcifs.smb.SmbSessionInternal;
import jcifs.smb.SmbTransportInternal;

/**
 * Unit tests for SMB3 Multi-Channel functionality
 *
 * These tests verify the multi-channel implementation without requiring a real SMB server.
 */
@ExtendWith(MockitoExtension.class)
@MockitoSettings(strictness = Strictness.LENIENT)

            cipherId = EncryptionNegotiateContext.CIPHER_AES128_CCM;
        } else {
            throw new SmbUnsupportedOperationException("SMB3 required for encryption, negotiated: " + dialect);
        }

        try {
            // Derive encryption and decryption keys using SMB3 KDF
            final int dialectInt = dialect.getDialect();

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import jcifs.internal.util.SMBUtil;
import jcifs.smb.SmbFile;

/**
 * Handles directory change notifications for SMB3 directory leasing
 */
public class DirectoryChangeNotifier {

    private static final Logger log = LoggerFactory.getLogger(DirectoryChangeNotifier.class);

    // Backoff and timing constants (in ms)

    }

    @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

                negoContexts.add(new EncryptionNegotiateContext(config, cipherArray));
            }

            // Add compression context for SMB3 compression support
            if (config.isCompressionEnabled()) {
                negoContexts.add(new CompressionNegotiateContext(config, new int[] { CompressionNegotiateContext.COMPRESSION_LZ77,

                    "Dialect ANY should be greater than lowest dialect");
            assertTrue(Smb2Constants.SMB2_DIALECT_ANY < Smb2Constants.SMB2_DIALECT_0300, "Dialect ANY should be less than SMB3 dialects");
        }

        @Test
        @DisplayName("Capability values should fit in 32-bit integer")
        void testCapabilityValueRange() {

import jcifs.internal.SMBSigningDigest;
import jcifs.internal.util.SMBUtil;
import jcifs.smb.SmbException;
import jcifs.util.Hexdump;

/**
 * Base class for SMB2/SMB3 protocol messages.
 *
 * This abstract class provides common functionality for all SMB2/SMB3
 * message types including encoding, decoding, and message handling.
 *
 * @author mbechler
 */
public abstract class ServerMessageBlock2 implements CommonServerMessageBlock {