```javaimport java.util.Base64;import java.util.Scanner;
public class mysteryMethods{    public static void main(String[] args) {        Scanner scanner = new Scanner(System.in);        System.out.print("Flag: ");        String userInput = scanner.nextLine();        String encryptedInput = encryptInput(userInput);
        if (checkFlag(encryptedInput)) {            System.out.println("Correct flag! Congratulations!");        } else {            System.out.println("Incorrect flag! Please try again.");        }    }
    public static String encryptInput(String input) {        String flag = input;        flag = unknown2(flag, 345345345);        flag = unknown1(flag);        flag = unknown2(flag, 00000);        flag = unknown(flag, 25);        return flag;    }
    public static boolean checkFlag(String encryptedInput) {        return encryptedInput.equals("OS1QYj9VaEolaDgTSTXxSWj5Uj5JNVwRUT4vX290L1ondF1z");    }
    public static String unknown(String input, int something) {        StringBuilder result = new StringBuilder();        for (char c : input.toCharArray()) {            if (Character.isLetter(c)) {                char base = Character.isUpperCase(c) ? 'A' : 'a';                int offset = (c - base + something) % 26;                if (offset < 0) {                    offset += 26;                }                c = (char) (base + offset);            }            result.append(c);        }        return result.toString();    }
    public static String unknown1(String xyz) {        return new StringBuilder(xyz).reverse().toString();    }
    public static String unknown2(String xyz, int integer) {        return Base64.getEncoder().encodeToString(xyz.getBytes());    }}```
![image](https://github.com/jeromepalayoor/ctf-archive-hub/assets/63996033/6234214b-bfb4-447d-9679-1802138b66bb)
`unknown` looks like caesar cipher shift.
![image](https://github.com/jeromepalayoor/ctf-archive-hub/assets/63996033/fb7f5521-6354-4536-89dd-7c2f5f51ff29)
`unknown1` looks like it reverses the string
![image](https://github.com/jeromepalayoor/ctf-archive-hub/assets/63996033/bd278258-59cc-41a9-aaaa-03bd5aff8a7a)
`unknown2` looks like a base64 encoder
![image](https://github.com/jeromepalayoor/ctf-archive-hub/assets/63996033/6d821d2e-7c9b-47d9-b646-45a34c20b4d0)
Reverse the encoded string using [cyberchef](https://gchq.github.io/CyberChef/#recipe=ROT13(true,true,false,27)From_Base64('A-Za-z0-9%2B/%3D',true,false)Reverse('Character')From_Base64('A-Za-z0-9%2B/%3D',true,false)&input=T1MxUVlqOVZhRW9sYURnVFNUWHhTV2o1VWo1Sk5Wd1JVVDR2WDI5MEwxb25kRjF6)
![image](https://github.com/jeromepalayoor/ctf-archive-hub/assets/63996033/1c002b36-f732-470a-91ef-bef87f6ce42f)
Flag: `flag{hsCTF_I5_r3aLLy_fUN}`