/**
     * {@inheritDoc}
     *
     * @see jcifs.smb.NtlmPasswordAuthenticator#getUserSessionKey(jcifs.CIFSContext, byte[])
     */
    @Override
    public byte[] getUserSessionKey(final CIFSContext tc, final byte[] chlng) {
        if (this.hashesExternal) {
            return null;
        }
        return super.getUserSessionKey(tc, chlng);
    }

    /**
     * {@inheritDoc}
     *

                auth.getUserSessionKey(transport.server.encryptionKey, macSigningKey, 0);
                System.arraycopy(auth.getUnicodeHash(transport.server.encryptionKey), 0, macSigningKey, 16, 24);
                break;
            case 3:
            case 4:
            case 5:
                macSigningKey = new byte[16];
                auth.getUserSessionKey(transport.server.encryptionKey, macSigningKey, 0);

            case 4:
            case 5:
                this.macSigningKey = new byte[16];
                auth.getUserSessionKey(transport.getContext(), serverEncryptionKey, this.macSigningKey, 0);
                break;
            default:
                this.macSigningKey = new byte[40];
                auth.getUserSessionKey(transport.getContext(), serverEncryptionKey, this.macSigningKey, 0);

     *         used in SMB MAC signing and NTLMSSP signing and sealing.
     */
    public byte[] getUserSessionKey(CIFSContext tc, byte[] chlng) {
        byte[] key = new byte[16];
        try {
            getUserSessionKey(tc, chlng, key, 0);
        } catch (Exception ex) {
            log.error("Failed to get session key", ex);
        }
        return key;
    }

     * used in SMB MAC signing and NTLMSSP signing and sealing.
     */
    public byte[] getUserSessionKey(final byte[] challenge) {
        if (hashesExternal) {
            return null;
        }
        final byte[] key = new byte[16];
        try {
            getUserSessionKey(challenge, key, 0);
        } catch (final Exception ex) {
            if (LogStream.level > 0) {

                int offset = invocation.getArgument(3);
                System.arraycopy(new byte[16], 0, dest, offset, 16);
                return null;
            }).when(mockAuth).getUserSessionKey(eq(mockContext), eq(serverEncryptionKey), any(byte[].class), eq(0));
        } else {
            // For LM compatibility 0-2, 40 bytes are used
            doAnswer(invocation -> {