Rating:
```java
import 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());
}
}
```
`unknown` looks like caesar cipher shift.
`unknown1` looks like it reverses the string
`unknown2` looks like a base64 encoder
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)
Flag: `flag{hsCTF_I5_r3aLLy_fUN}`
