*
     * @see jcifs.internal.SMBSigningDigest#sign(byte[], int, int, jcifs.internal.CommonServerMessageBlock,
     *      jcifs.internal.CommonServerMessageBlock)
     */
    @Override
    public void sign ( byte[] data, int offset, int length, CommonServerMessageBlock request, CommonServerMessageBlock response ) {
        if ( log.isTraceEnabled() ) {
            log.trace("Signing with seq " + this.signSequence);
        }

package jcifs.internal;


/**
 * @author mbechler
 *
 */
public interface SMBSigningDigest {

    /**
     * Performs MAC signing of the SMB. This is done as follows.
     * The signature field of the SMB is overwritten with the sequence number;
     * The MD5 digest of the MAC signing key + the entire SMB is taken;
     * The first 8 bytes of this are placed in the signature field.
     *
     * @param data

     * @param address
     * @param port
     * @param exclusive
     *            whether to acquire an unshared connection
     * @param forceSigning
     *            whether to enforce SMB signing on this connection
     * @return a transport connection to the target
     */
    SmbTransport getSmbTransport ( CIFSContext tc, Address address, int port, boolean exclusive, boolean forceSigning );


    /**

                 * junk. We need to bump up the wordCount here so that this method returns
                 * the correct number of bytes for signing purposes. Otherwise we get a
                 * signing verification failure.
                 */
                if ( this.getCommand() == SMB_COM_NT_CREATE_ANDX && ( (SmbComNTCreateAndXResponse) this ).isExtended()

            if (SmbTransport.log.level >= 3)
                SmbTransport.log.println(
                    "Default credentials (jcifs.smb1.smb1.client.username/password)" +
                    " not specified. SMB signing may not work propertly." +
                    "  Skipping DC interrogation." );
        } else {
            SmbSession ssn = trans.getSmbSession( NtlmPasswordAuthentication.DEFAULT );

            log.flush();
        }
        updates = 0;

        return b;
    }

    /**
     * Performs MAC signing of the SMB.  This is done as follows.
     * The signature field of the SMB is overwritted with the sequence number;
     * The MD5 digest of the MAC signing key + the entire SMB is taken;
     * The first 8 bytes of this are placed in the signature field.
     *
     * @param data The data.

    /**
     * Indicates datagram authentication.
     */
    public static final int NTLMSSP_NEGOTIATE_DATAGRAM_STYLE = 0x00000040;

    /**
     * Indicates that the LAN Manager session key should be used for
     * signing and sealing authenticated communication.
     */
    public static final int NTLMSSP_NEGOTIATE_LM_KEY = 0x00000080;

    /**
     * ??? According to spec this is a reserved bit and must be set to zero
     */

     * @return the maximum buffer size reported by the server
     * @throws CIFSException
     */
    int getMaximumBufferSize () throws CIFSException;


    /**
     * @return whether the session uses SMB signing
     * @throws CIFSException
     * @throws SmbException
     */
    boolean areSignaturesActive () throws CIFSException;


    /**
     * Internal/testing use only
     * 
     * @return attached session

    public int getSecurityMode () {
        return this.securityMode;
    }


    @Override
    public boolean isSigningEnforced () {
        return ( getSecurityMode() & Smb2Constants.SMB2_NEGOTIATE_SIGNING_REQUIRED ) != 0;
    }


    /**
     * @return the capabilities
     */
    public int getCapabilities () {
        return this.capabilities;
    }


    /**

     */
    @Override
    public final boolean isError () {
        return this.error;
    }


    /**
     * @return whether the packet has been signed.
     */
    public boolean isSigned () {
        return ( getFlags() & SMB2_FLAGS_SIGNED ) != 0;
    }


    /**
     * {@inheritDoc}
     *
     * @see jcifs.util.transport.Response#getExpiration()
     */
    @Override