逆向攻防世界CTF系列22-Guess-the-Number

jadx打开

import java.math.BigInteger;

public class Test05 {
    static String XOR(String _str_one, String _str_two) {
        BigInteger i1 = new BigInteger(_str_one, 16);
        BigInteger i2 = new BigInteger(_str_two, 16);
        BigInteger res = i1.xor(i2);
        String result = res.toString(16);
        return result;
    }

    public static void main(String[] args) {
        String answer = XOR("4b64ca12ace755516c178f72d05d7061", "ecd44646cfe5994ebeb35bf922e25dba");
        System.out.println("your flag is: " + 1545686892 / 5);

    }
}

得

a7b08c546302cc1fd2a4d48bf2bf2ddb

或