package com.ruoyi.common.signature;


import com.ruoyi.common.constant.Constants;

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

public class AESUtils {

    private static final String key="Bd26jqDDJcdnBocn";
    private static final String iv ="oVKRQCjElggSbd8D";

    /**
     * @Description AES算法加密明文
     * @param data 明文
     * @param key 密钥，长度16
     * @param iv 偏移量，长度16
     * @return 密文
     */
    public static String encrypt(String data){
        try {
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            int blockSize = cipher.getBlockSize();
            byte[] dataBytes = data.getBytes(Constants.UTF8);
            int plaintextLength = dataBytes.length;

            if (plaintextLength % blockSize != 0) {
                plaintextLength = plaintextLength + (blockSize - (plaintextLength % blockSize));
            }

            byte[] plaintext = new byte[plaintextLength];
            System.arraycopy(dataBytes, 0, plaintext, 0, dataBytes.length);

            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());  // CBC模式，需要一个向量iv，可增加加密算法的强度

            cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
            byte[] encrypted = cipher.doFinal(plaintext);
            // BASE64做转码。
            String aseEncode = Base64.getEncoder().encodeToString(encrypted);
            return aseEncode.trim();

        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e.getMessage());
        }
    }

    /**
     * @Description AES算法解密密文
     * @param data 密文
     * @param key 密钥，长度16
     * @param iv 偏移量，长度16
     * @return 明文
     */
    public static String decrypt(String data){
        try
        {
            byte[] encryptCode = Base64.getDecoder().decode(data);//先用base64解密

            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);

            byte[] original = cipher.doFinal(encryptCode);
            String originalString = new String(original);
            return originalString.trim();
        }
        catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e.getMessage());
        }
    }

    public static void main(String[] args) throws Exception {

        String key="Bd26jqDDJcdnBocn";
        String iv ="oVKRQCjElggSbd8D";

       /* System.out.println("****************************************");
        String encode = AESUtils.encrypt("测试", key, iv);
        System.out.println(encode);
        System.out.println("****************************************");
        String decode = AESUtils.decrypt(encode, key, iv);
        System.out.println(decode);
        System.out.println("****************************************");*/
    }

}