Base64

package com.kma.ctf2;
import java.security.MessageDigest;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import sun.misc.BASE64Decoder;
public class Decode1 {
    public String returnFlag() {
        try {
            MessageDigest localMessageDigest = MessageDigest.getInstance("SHA");
            localMessageDigest.update("KMA_fag_not_here".getBytes());
            SecretKeySpec localSecretKeySpec = new SecretKeySpec(localMessageDigest.digest(), 0, 16, "AES");
            Cipher localCipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
//            byte[] arrayOfByte = Base64.decode("rMto79APL5CFQ9PU6iSP6e2tbxRJ6Xv0s5znSnYneog=", 0);
            BASE64Decoder decoder = new BASE64Decoder();
            byte[] arrayOfByte = decoder.decodeBuffer("rMto79APL5CFQ9PU6iSP6e2tbxRJ6Xv0s5znSnYneog=");
            //
            localCipher.init(2, localSecretKeySpec);
            String str = new String(localCipher.doFinal(arrayOfByte));
            return str;
        } catch (Exception localException) {
            localException.printStackTrace();
        }
        return null;
    }
    public static void main(String[] args) {
        Decode1 dc = new Decode1();
        System.out.println("" + dc.returnFlag());
    }
}