# SMB3 Lease Feature - Detailed Design Document

## 1. Overview

SMB3 leases provide a client caching mechanism that replaces the traditional oplock mechanism. Leases enable better performance through client-side caching while maintaining cache coherency across multiple clients.

## 2. Protocol Specification Reference

- **MS-SMB2 Section 2.2.13**: SMB2 CREATE Request with Lease Context
- **MS-SMB2 Section 2.2.14**: SMB2 CREATE Response with Lease State

import org.bouncycastle.crypto.generators.KDFCounterBytesGenerator;
import org.bouncycastle.crypto.macs.HMac;
import org.bouncycastle.crypto.params.KDFCounterParameters;

/**
 * SMB3 SP800-108 Counter Mode Key Derivation
 *
 * @author mbechler
 *
 */
public final class Smb3KeyDerivation {

    private static final byte[] SIGNCONTEXT_300 = toCBytes("SmbSign");

# SMB3 Advanced Features Implementation Plan

## Overview
This document outlines the implementation plan for advanced SMB3 features that are currently not implemented in JCIFS. These features are essential for enterprise-grade SMB3 support, providing enhanced performance, reliability, and scalability.

## Implementation Phases

### Phase 1: SMB3 Lease Implementation (Foundation)
**Priority: HIGH** | **Estimated Effort: 3-4 weeks**

    }

    /**
     * Test secure negotiation requirement for SMB3
     */
    @Test
    public void testSecureNegotiateRequired() throws CIFSException {
        BaseConfiguration config = new BaseConfiguration(true);

        // Verify secure negotiate is required for SMB3
        assertTrue("Secure negotiate should be required for SMB3", config.isRequireSecureNegotiate());
    }

    /**
     * AES-128-CCM cipher identifier for SMB3 encryption
     */
    public static final int CIPHER_AES_128_CCM = EncryptionNegotiateContext.CIPHER_AES128_CCM;
    /**
     * AES-128-GCM cipher identifier for SMB3.1.1 encryption
     */
    public static final int CIPHER_AES_128_GCM = EncryptionNegotiateContext.CIPHER_AES128_GCM;
    /**
     * AES-256-CCM cipher identifier for SMB3 encryption (future support)
     */

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package jcifs.internal.smb2;

/**
 * Constants for SMB2/SMB3 protocol.
 *
 * This class contains protocol-specific constants, command codes,
 * flags, and other values used in SMB2/SMB3 communication.
 *
 * @author mbechler
 */
public final class Smb2Constants {

    /**
     *
     */
    private Smb2Constants() {
    }

## Version

[Versions in Maven Repository](https://repo1.maven.org/maven2/org/codelibs/jcifs/)

## Requirements

- Java 17 or higher
- SLF4J for logging
- Bouncy Castle (for SMB3 encryption support)

## Using Maven

```xml

package jcifs.smb.compression;

import jcifs.CIFSException;

/**
 * Interface for SMB3 compression services.
 *
 * Provides compression and decompression functionality for SMB3 protocol
 * data transfers with support for multiple compression algorithms.
 */
public interface CompressionService {

    /**
     * Compression algorithm constants matching SMB3 specification.
     */
    public static final int COMPRESSION_NONE = 0x0;

 */
package jcifs.internal.smb2.lease;

/**
 * Defines directory lease state constants for SMB2/SMB3 directory leasing.
 *
 * This class provides constants and utility methods for managing directory lease states
 * in SMB2/SMB3 protocol implementations. Directory leases enable clients to cache
 * directory metadata and reduce network round-trips for directory operations.
 */

import jcifs.internal.CommonServerMessageBlockResponse;
import jcifs.internal.SMBProtocolDecodingException;
import jcifs.smb.NtStatus;

/**
 * Base class for SMB2/SMB3 response messages.
 *
 * This abstract class provides common functionality for handling
 * response messages in the SMB2/SMB3 protocol.
 *
 * @author mbechler
 */
public abstract class ServerMessageBlock2Response extends ServerMessageBlock2 implements CommonServerMessageBlockResponse {