package edu.nju.util;


import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.net.URLEncoder;
import java.util.Base64;

public class AESUtil {

    //偏移量
    private static String IV ="mooctestmooctest";
    //钥匙
    private static String KEY = "TESTMOOCTESTMOOC";

    //加密
    public static String encrypt(String str) {
        try {
            byte[] bytes = str.getBytes();
            IvParameterSpec ivParameterSpec = new IvParameterSpec(IV.getBytes());
            SecretKeySpec secretKeySpec = new SecretKeySpec(KEY.getBytes(), "AES");
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivParameterSpec);
            bytes = cipher.doFinal(bytes);
            bytes = Base64.getEncoder().encode(bytes);
            String res  = new String(bytes);
            return URLEncoder.encode(res);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    //解密
    public static String decrypt(String str) {
        try {
            byte[] bytes = Base64.getDecoder().decode(str);
            IvParameterSpec ivParameterSpec = new IvParameterSpec(IV.getBytes());
            SecretKeySpec secretKeySpec = new SecretKeySpec(KEY.getBytes(), "AES");
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, ivParameterSpec);
            bytes = cipher.doFinal(bytes);
            return new String(bytes);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

}