package com.zhongzheng.common.utils;

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.*;


public class AES {
    public static boolean initialized = false;

    /**
     * AES解密
     * @param content 密文
     * @return
     * @throws InvalidAlgorithmParameterException
     * @throws NoSuchProviderException
     */
    public static byte[] decrypt(byte[] content, byte[] keyByte, byte[] ivByte) throws InvalidAlgorithmParameterException {
        initialize();
        try {
//            Cipher cipher = Cipher.getInstance("DES/ECB/NoPadding");
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
            Key sKeySpec = new SecretKeySpec(keyByte, "AES");

            cipher.init(Cipher.DECRYPT_MODE, sKeySpec, generateIV(ivByte));// 初始化
            byte[] result = cipher.doFinal(content);
            return result;
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        } catch (NoSuchProviderException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }

    public static void initialize(){
        if (initialized) return;
        Security.addProvider(new BouncyCastleProvider());
        initialized = true;
    }
    //生成iv
    public static AlgorithmParameters generateIV(byte[] iv) throws Exception{
        AlgorithmParameters params = AlgorithmParameters.getInstance("AES");
        params.init(new IvParameterSpec(iv));
        return params;
    }

    public static String SHA1(String decript) {
        try {
            MessageDigest digest = java.security.MessageDigest.getInstance("SHA-1");
            digest.update(decript.getBytes());
            byte messageDigest[] = digest.digest();
            // Create Hex String
            StringBuffer hexString = new StringBuffer();
            // 字节数组转换为 十六进制 数
            for (int i = 0; i < messageDigest.length; i++) {
                String shaHex = Integer.toHexString(messageDigest[i] & 0xFF);
                if (shaHex.length() < 2) {
                    hexString.append(0);
                }
                hexString.append(shaHex);
            }
            return hexString.toString();

        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return "";
    }
}