# 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

public static final String USE_RDMA = "jcifs.smb.client.useRDMA";
public static final String RDMA_PROVIDER = "jcifs.smb.client.rdmaProvider";
public static final String RDMA_READ_WRITE_THRESHOLD = "jcifs.smb.client.rdmaReadWriteThreshold";
public static final String RDMA_MAX_SEND_SIZE = "jcifs.smb.client.rdmaMaxSendSize";
public static final String RDMA_MAX_RECEIVE_SIZE = "jcifs.smb.client.rdmaMaxReceiveSize";

 */
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() {
    }

    /**
     * SMB2 header length in bytes
     */

import jcifs.internal.smb2.info.Smb2QueryDirectoryResponse;

/**
 * SMB2/SMB3 implementation of directory entry enumeration iterator.
 * Provides efficient directory listing capabilities for SMB2/SMB3 protocol versions.
 *
 * @author mbechler
 *
 */
public class DirFileEntryEnumIterator2 extends DirFileEntryEnumIteratorBase {

    private static final Logger log = LoggerFactory.getLogger(DirFileEntryEnumIterator2.class);

import jcifs.CIFSException;
import jcifs.DialectVersion;
import jcifs.internal.smb2.nego.EncryptionNegotiateContext;
import jcifs.util.SecureKeyManager;

/**
 * SMB2/SMB3 Encryption Context
 *
 * Manages encryption and decryption operations for SMB2/SMB3 sessions.
 * Handles both AES-CCM (SMB 3.0/3.0.2) and AES-GCM (SMB 3.1.1) cipher suites.
 *
 * @author mbechler
 */

    /**
     * Gets the flags field which contains flags in SMB 3.1.1 or encryption algorithm ID in SMB 3.0/3.0.2
     *
     * @return the flags (SMB 3.1.1) or encryption algorithm (SMB 3.0/3.0.2)
     */
    public int getFlags() {
        return this.flags;
    }

    /**
     * Sets the flags field which contains flags in SMB 3.1.1 or encryption algorithm ID in SMB 3.0/3.0.2
     *
     * @param flags

import jcifs.internal.SMBSigningDigest;
import jcifs.internal.util.SMBUtil;
import jcifs.util.Crypto;

/**
 * SMB2/SMB3 message signing digest implementation.
 *
 * This class handles cryptographic signing of SMB2/SMB3 messages to ensure
 * message integrity and authenticity. It supports different signing algorithms
 * used in various SMB2/SMB3 dialect versions.
 *
 * @author mbechler
 */

- **MS-SMB2 Section 2.2.35**: SMB2 Change Notify Request
- **MS-SMB2 Section 2.2.36**: SMB2 Change Notify Response
- **MS-SMB2 Section 3.3.5.9.11**: Directory Leasing and Caching

## 3. Directory Lease Types

### 3.1 Directory-Specific Lease States
```java
public class DirectoryLeaseState extends Smb2LeaseState {
    // Standard lease states apply, plus directory-specific semantics:
    
    // READ_CACHING for directories means:

    /**
     * Test pre-auth integrity with non-SMB3.1.1 should throw exception
     */
    @Test
    @DisplayName("Pre-auth integrity should fail with non-SMB3.1.1")
    void testPreauthWithNonSmb311() throws Exception {
        // Setup SMB3.0
        when(negotiateResponse.getSelectedDialect()).thenReturn(DialectVersion.SMB300);
        setPrivateField(transport, "smb2", true);

     *
     */
    private Smb3KeyDerivation() {
    }

    /**
     * Derives the SMB3 signing key from the session key using the appropriate KDF for the dialect.
     *
     * @param dialect the SMB dialect version
     * @param sessionKey the base session key
     * @param preauthIntegrity the pre-authentication integrity hash (for SMB 3.1.1) or null
     * @return derived signing key
     */