private static final byte[] SIGNCONTEXT_300 = toCBytes("SmbSign");
    private static final byte[] SIGNLABEL_300 = toCBytes("SMB2AESCMAC");
    private static final byte[] SIGNLABEL_311 = toCBytes("SMBSigningKey");

    private static final byte[] APPCONTEXT_300 = toCBytes("SmbRpc");
    private static final byte[] APPLABEL_300 = toCBytes("SMB2APP");
    private static final byte[] APPLABEL_311 = toCBytes("SMBAppKey");