package test;
/* @auther wjh @date 2018-08-01*/
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.lang3.StringUtils;
import org.apache.log4j.Logger;

public class AESUtil {

private static final Logger logger  =Logger.getLogger(AESUtil.class);
private static final String defaultCharset = "UTF-8";
private static final String KEY_AES = "AES";
private static final String KEY = "123456";

/**
* 加密
*
* @param data 需要加密的內容
* @param key 加密密碼
* @return
*/
public static String encrypt(String data, String key) {
return doAES(data, key, Cipher.ENCRYPT_MODE);
}

/**
* 解密
*
* @param data 待解密內容
* @param key 解密金鑰
* @return
*/
public static String decrypt(String data, String key) {
return doAES(data, key, Cipher.DECRYPT_MODE);
}

/**
* 加解密
*
* @param data 待處理資料
* @param password 金鑰
* @param mode 加解密mode
* @return
*/
private static String doAES(String data, String key, int mode) {
try {
if (StringUtils.isBlank(data) || StringUtils.isBlank(key)) {
return null;
}
//判斷是加密還是解密
boolean encrypt = mode == Cipher.ENCRYPT_MODE;
byte[] content;
//true 加密內容 false 解密內容
if (encrypt) {
content = data.getBytes(defaultCharset);
} else {
content = parseHexStr2Byte(data);
}
//1.構造金鑰生成器，指定為AES演算法,不區分大小寫
KeyGenerator kgen = KeyGenerator.getInstance(KEY_AES);
//2.根據ecnodeRules規則初始化金鑰生成器
//生成一個128位的隨機源,根據傳入的位元組陣列
kgen.init(128, new SecureRandom(key.getBytes()));
//3.產生原始對稱金鑰
SecretKey secretKey = kgen.generateKey();
//4.獲得原始對稱金鑰的位元組陣列
byte[] enCodeFormat = secretKey.getEncoded();
//5.根據位元組陣列生成AES金鑰
SecretKeySpec keySpec = new SecretKeySpec(enCodeFormat, KEY_AES);
//6.根據指定演算法AES自成密碼器
Cipher cipher = Cipher.getInstance(KEY_AES);// 建立密碼器
//7.初始化密碼器，第一個引數為加密(Encrypt_mode)或者解密解密(Decrypt_mode)操作，第二個引數為使用的KEY
cipher.init(mode, keySpec);// 初始化
byte[] result = cipher.doFinal(content);
if (encrypt) {
//將二進位制轉換成16進位制
return parseByte2HexStr(result);
} else {
return new String(result, defaultCharset);
}
} catch (Exception e) {
logger.error(“AES 密文處理異常”, e);
// System.out.print(“Exception”);
}
return null;
}
/**
* 將二進位制轉換成16進位制
*
* @param buf
* @return
*/
public static String parseByte2HexStr(byte buf[]) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < buf.length; i++) {
String hex = Integer.toHexString(buf[i] & 0xFF);
if (hex.length() == 1) {
hex = ‘0’ + hex;
}
sb.append(hex.toUpperCase());
}
return sb.toString();
}
/**
* 將16進位制轉換為二進位制
*
* @param hexStr
* @return
*/
public static byte[] parseHexStr2Byte(String hexStr) {
if (hexStr.length() < 1) {
return null;
}
byte[] result = new byte[hexStr.length() / 2];
for (int i = 0; i < hexStr.length() / 2; i++) {
int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
result[i] = (byte) (high * 16 + low);
}
return result;
}
public static void main(String[] args) throws Exception {
String content = “{‘repairPhone’:’18547854787’,’customPhone’:’12365478965’,’captchav’:’58m7’}”;
System.out.println(“加密前：” + content);
System.out.println(“加密金鑰和解密金鑰：” + KEY);
String encrypt = encrypt(content, KEY);
System.out.println(“加密後：” + encrypt);
String decrypt = decrypt(encrypt, KEY);
System.out.println(“解密後：” + decrypt);
}
}