package com.space.utils.encrypt;

import javax.crypto.Cipher;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESKeySpec;

import javax.crypto.spec.IvParameterSpec;

import java.nio.charset.Charset;

/**

* DES加密解密工具类

* @author zhuzhe

* @date 2018/4/24 15:05

*/

public class DesUtils {

private static final String DEFAULT_CHARSET = "UTF-8";

/**

* 加密

* @param source 需要加密的明文

* @param sKey 密钥

* @return 加密后的字符串

*/

public static String encrypt(String source,String sKey) {

if (source == null) {

return null;

}

byte[] src = source.getBytes(Charset.forName(DEFAULT_CHARSET));

byte[] buf = encrypt(src, sKey);

return parseByte2HexStr(buf);

}

/**

* 解密

*

* @param cipherText 密文

* @param sKey 密钥

* @return 解密后的字符串

* @throws Exception

*/

public static String decrypt(String cipherText,String sKey) throws Exception {

if (cipherText == null) {

return null;

}

byte[] src = parseHexStr2Byte(cipherText);

byte[] buf = decrypt(src, sKey);

return new String(buf, Charset.forName(DEFAULT_CHARSET));

}

/**

* 加密

* @param data

* @param sKey

* @return

*/

private static byte[] encrypt(byte[] data, String sKey) {

try {

byte[] key = sKey.getBytes();

// 初始化向量

IvParameterSpec iv = new IvParameterSpec(key);

DESKeySpec desKey = new DESKeySpec(key);

// 创建一个密匙工厂，然后用它把DESKeySpec转换成securekey

SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");

SecretKey securekey = keyFactory.generateSecret(desKey);

// Cipher对象实际完成加密操作

Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");

// 用密匙初始化Cipher对象

cipher.init(Cipher.ENCRYPT_MODE, securekey, iv);

// 现在，获取数据并加密

// 正式执行加密操作

return cipher.doFinal(data);

} catch (Throwable e) {

e.printStackTrace();

}

return null;

}

/**

* 解密

* @param src

* @param sKey

* @return

* @throws Exception

*/

private static byte[] decrypt(byte[] src, String sKey) throws Exception {

byte[] key = sKey.getBytes();

// 初始化向量

IvParameterSpec iv = new IvParameterSpec(key);

// 创建一个DESKeySpec对象

DESKeySpec desKey = new DESKeySpec(key);

// 创建一个密匙工厂

SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");

// 将DESKeySpec对象转换成SecretKey对象

SecretKey secretKey = keyFactory.generateSecret(desKey);

// Cipher对象实际完成解密操作

Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");

// 用密匙初始化Cipher对象

cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);

// 真正开始解密操作

return cipher.doFinal(src);

}

/**

* 将二进制转换成16进制

*

* @param buf

* @return

*/

private static String parseByte2HexStr(byte buf[]) {

StringBuffer sb = new StringBuffer();

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();

}

/**

* 将16进制转换为二进制

*

* @param hexStr

* @return

*/

private 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;

}

}