}
    }

    /**
     * Derives an AES key using the Kerberos key derivation function.
     * This method implements the simplified key derivation for AES encryption types.
     *
     * @param key the base Kerberos key
     * @param constant the key derivation constant
     * @return the derived key bytes
     * @throws GeneralSecurityException if cryptographic operations fail
     */

 *
 * 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
 */

    /**
     * Derive a new key from an existing key
     *
     * @param baseKey the base key
     * @param label key derivation label
     * @param context key derivation context
     * @param length desired key length in bytes
     * @return derived key
     * @throws GeneralSecurityException if key derivation fails
     */

- **Encryption Context**: Per-session encryption state management
- **Key Derivation**: SMB3 KDF implementation with dialect-specific parameters
- **Pre-Authentication Integrity**: SMB 3.1.1 PAI for preventing downgrade attacks
- **Automatic Detection**: Encryption automatically enabled when servers require it
- **Secure Key Management**: Proper key derivation and nonce generation

### Core Features

        }

        // Increment rotation counter for tracking and key derivation
        rotationCount++;

        // SMB3-compliant key rotation: Use rotation counter as per SMB3 specification
        // This follows Microsoft's approach for predictable but unique key derivation
        byte[] modifiedSessionKey = new byte[sessionKey.length + 8];

 * <ul>
 *   <li>by transforming the value from a successful input step,
 *   <li>by catching the exception from a failed input step, or
 *   <li>by combining the results of several input steps.
 * </ul>
 *
 * Each derivation can capture the next value or any intermediate objects for later closing.
 *
 * <p>A step can be the input to at most one derived step. Once you transform its value, catch its

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");

import org.junit.jupiter.api.Test;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.ValueSource;

/**
 * Test class for Smb3KeyDerivation.
 * Tests the SMB3 SP800-108 Counter Mode Key Derivation implementation.
 */
@DisplayName("Smb3KeyDerivation Tests")
class Smb3KeyDerivationTest {

    private byte[] sessionKey;
    private byte[] preauthIntegrity;

    @BeforeEach
    void setUp() {

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the Derivative Works, if and wherever such third-party notices normally 

          include a readable copy of the attribution notices contained
          within such NOTICE file, excluding those notices that do not
          pertain to any part of the Derivative Works, in at least one
          of the following places: within a NOTICE text file distributed
          as part of the Derivative Works; within the Source form or