GMV bus app "Permission" keygen

SaePermission.java

import java.util.Random;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

public final class SaePermission {
    public static final long MILLIS_MARGIN = 300000;
    public static final int m_iMultiplier = 131;
    private static String date;
    private static String key;

    public static final String FORMAT_PUBLIC_DATE = "yyyyMMddHHmmssSSSSS";
    private static final SimpleDateFormat formatPublicDate = new SimpleDateFormat(FORMAT_PUBLIC_DATE);
    public static final String FORMAT_DATE = "yyssSSSSSMMHHddmm";
    private static final SimpleDateFormat formatDate = new SimpleDateFormat(FORMAT_DATE);

    public static void main(String[] args) {
        Date date = new Date(System.currentTimeMillis() + MILLIS_MARGIN);
        formatPublicDate.setTimeZone(TimeZone.getTimeZone("UTC"));
        String k1 = formatPublicDate.format(date);

        formatDate.setTimeZone(TimeZone.getTimeZone("UTC"));
        String sKeyAux2 = Long.toString(Long.parseLong(formatDate.format(date)) * m_iMultiplier);
        String k2 = encrypt(sKeyAux2);

        System.out.print("k1: ");
        System.out.println(k1);
        System.out.print("k2: ");
        System.out.println(k2);
    }

    public static final char maskChar(char input) {
        char mask = 0b1010101;
        // Random random = new Random();
        // char fill = random.nextInt() & 0b0101010;
        char fill = 0b0101010;

        return (char) ((input & mask) | fill);
    }

    public static final String encrypt(String sInput) {
        if (sInput.length() == 0) {
            return "";
        }
        char[] charArray = sInput.toCharArray();
        String key = "";

        char mask = 0b1010101;
        char fill = 0b0101010;

        for (char c : charArray) {
            char c1 = (char) ((c & 170) >> 1);
            key += Character.valueOf(maskChar(c1));
            key += Character.valueOf(maskChar(c));
        }
        return key;
    }
}