package com.fr.plugin.cmd.utils;

import com.fanruan.api.log.LogKit;
import com.fr.third.org.apache.commons.codec.binary.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.Security;

public class AESUtil {
    /**
     * 密钥算法
     */
    private static final String KEY_ALGORITHM = "AES";

    /**
     * 加密/解密算法 / 工作模式 / 填充方式
     * Java 6支持PKCS5Padding填充方式
     * Bouncy Castle支持PKCS7Padding填充方式
     */
    private static final String CIPHER_ALGORITHM = "AES/CBC/PKCS7Padding";

    /**
     * 偏移量，只有CBC模式才需要
     */
    private final static String ivParameter = "xxx";

    /**
     * AES要求密钥长度为128位或192位或256位，java默认限制AES密钥长度最多128位
     */
    public static String sKey = "xxx";

    /**
     * 编码格式
     */
    public static final String ENCODING = "utf-8";


    static {
        //如果是PKCS7Padding填充方式，则必须加上下面这行
        Security.addProvider(new BouncyCastleProvider());
    }

    /**
     * AES加密
     *
     * @param source 源字符串
     * @param key    密钥
     * @return 加密后的密文
     * @throws Exception
     */
    public static String encrypt(String source, String key) {
        try {
            byte[] sourceBytes = source.getBytes(ENCODING);
            byte[] keyBytes = key.getBytes(ENCODING);
            Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM, "BC");
            IvParameterSpec iv = new IvParameterSpec(ivParameter.getBytes(ENCODING));
            cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(keyBytes, KEY_ALGORITHM), iv);
            byte[] decrypted = cipher.doFinal(sourceBytes);
            return Base64.encodeBase64String(decrypted);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * AES解密
     *
     * @param encryptStr 加密后的密文
     * @param key        密钥
     * @return 源字符串
     * @throws Exception
     */
    public static String decrypt(String encryptStr, String key) {
        try {
            byte[] sourceBytes = Base64.decodeBase64(encryptStr);
            byte[] keyBytes = key.getBytes(ENCODING);
            Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM, "BC");
            IvParameterSpec iv = new IvParameterSpec(ivParameter.getBytes(ENCODING));
            cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(keyBytes, KEY_ALGORITHM), iv);
            byte[] decoded = cipher.doFinal(sourceBytes);
            return new String(decoded, ENCODING);
        } catch (Exception e) {
            LogKit.error(e.getMessage(), e);
        }
        return null;
    }


}