throw new CIFSUnsupportedCryptoException(e);
        }
    }


    /**
     * @param key
     *            7 or 8 byte DES key
     * @return DES cipher in encryption mode
     */
    public static Cipher getDES ( byte[] key ) {
        if ( key.length == 7 ) {
            return getDES(des7to8(key));
        }

        try {

    /**
     * Indicates that 128-bit encryption is supported.
     */
    public static final int NTLMSSP_NEGOTIATE_128 = 0x20000000;

    /**
     * Request explicit key exchange
     */
    public static final int NTLMSSP_NEGOTIATE_KEY_EXCH = 0x40000000;

    /**
     * Indicates that 56-bit encryption is supported.
     */

            break;
        case KerberosConstants.RC4_ENC_TYPE:
            decrypt = decryptRC4(data, key);
            break;
        default:
            throw new GeneralSecurityException("Unsupported encryption type " + type);
        }
        return decrypt;
    }


    /**
     * @param data
     * @param key
     * @return
     * @throws GeneralSecurityException

                && this.server.encryptionKeyLength != 8 && ctx.getConfig().getLanManCompatibility() == 0 ) {
            log.warn("Unexpected encryption key length: " + this.server.encryptionKeyLength);
            return false;
        }

        }

        if ( config.isEncryptionEnabled() && config.getMaximumVersion() != null && config.getMaximumVersion().atLeast(DialectVersion.SMB300) ) {
            this.capabilities |= Smb2Constants.SMB2_GLOBAL_CAP_ENCRYPTION;
        }

        Set<DialectVersion> dvs = DialectVersion
                .range(DialectVersion.max(DialectVersion.SMB202, config.getMinimumVersion()), config.getMaximumVersion());

    /**
     * @return whether signatures are enforced from either side
     * @throws SmbException
     */
    boolean isSigningEnforced () throws SmbException;


    /**
     * @return the encryption key used by the server
     */
    byte[] getServerEncryptionKey ();


    /**
     * @param ctx
     * @return session
     */
    SmbSession getSmbSession ( CIFSContext ctx );

    /**
     * 
     */
    public static final int SMB2_GLOBAL_CAP_DIRECTORY_LEASING = 0x20;

    /**
     * 
     */
    public static final int SMB2_GLOBAL_CAP_ENCRYPTION = 0x40;

    /**
     * 
     */
    public static final byte SMB2_0_INFO_FILE = 1;

    /**
     * 
     */
    public static final byte SMB2_0_INFO_FILESYSTEM = 2;

    /**

    }


    /**
     * 
     * @param dialect
     * @param sessionKey
     * @param preauthIntegrity
     * @return derived encryption key
     */
    public static byte[] deriveEncryptionKey ( int dialect, byte[] sessionKey, byte[] preauthIntegrity ) {
        return derive(
            sessionKey,

            return false;
        }
        if ( !foundEnc && ( caps & Smb2Constants.SMB2_GLOBAL_CAP_ENCRYPTION ) != 0 ) {
            log.error("Missing encryption negotiate context");
            return false;
        }
        else if ( !foundEnc ) {
            log.debug("No encryption support");
        }
        return true;
    }

     * 
     * This is an experimental option allowing to indicate support during protocol
     * negotiation, SMB encryption is not implemented yet.
     * 
     * @return whether SMB encryption is enabled
     * @since 2.1
     */
    boolean isEncryptionEnabled ();


    /**
     *