006.DES加密工具类(方便、快速的加密方案)

package DESEncode;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

/**
* DES加密 解密算法
* @author zhangdi
*
*/
public class DesUtil {

private final static String DES = "DES";
private final static String ENCODE = "GBK";
private final static String defaultKey = "netwxactive";

/**
* 使用 默认key 加密
* @param data 待加密数据
* @return
* @throws Exception
*/
public static String encrypt(String data) throws Exception {
byte[] bt = encrypt(data.getBytes(ENCODE), defaultKey.getBytes(ENCODE));
String strs = new BASE64Encoder().encode(bt);
return strs;
}

/**
* 使用 默认key 解密
* @param data 待解密数据
* @return
* @throws IOException
* @throws Exception
*/
public static String decrypt(String data) throws Exception, Exception {
if (data == null)
return null;
BASE64Decoder decoder = new BASE64Decoder();
byte[] buf = decoder.decodeBuffer(data);
byte[] bt = decrypt(buf, defaultKey.getBytes(ENCODE));
return new String(bt, ENCODE);
}

/**
* Description 根据键值进行加密
* @param data 待加密数据
* @param key 密钥
* @return
* @throws Exception
*/
public static String encrypt(String data, String key) throws Exception {
byte[] bt = encrypt(data.getBytes(ENCODE), key.getBytes(ENCODE));
String strs = new BASE64Encoder().encode(bt);
return strs;
}

/**
* 根据键值进行解密
* @param data 待解密数据
* @param key 密钥
* @return
* @throws IOException
* @throws Exception
*/
public static String decrypt(String data, String key) throws Exception,
Exception {
if (data == null)
return null;
BASE64Decoder decoder = new BASE64Decoder();
byte[] buf = decoder.decodeBuffer(data);
byte[] bt = decrypt(buf, key.getBytes(ENCODE));
return new String(bt, ENCODE);
}

/**
* Description 根据键值进行加密
*
* @param data
* @param key
* 加密键byte数组
* @return
* @throws Exception
*/
private static byte[] encrypt(byte[] data, byte[] key) throws Exception {
// 生成一个可信任的随机数源
SecureRandom sr = new SecureRandom();

// 从原始密钥数据创建DESKeySpec对象
DESKeySpec dks = new DESKeySpec(key);

// 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
SecretKey securekey = keyFactory.generateSecret(dks);

// Cipher对象实际完成加密操作
Cipher cipher = Cipher.getInstance(DES);

// 用密钥初始化Cipher对象
cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);

return cipher.doFinal(data);
}

/**
* Description 根据键值进行解密
*
* @param data
* @param key 加密键byte数组
* @return
* @throws Exception
*/
private static byte[] decrypt(byte[] data, byte[] key) throws Exception {
// 生成一个可信任的随机数源
SecureRandom sr = new SecureRandom();

// 从原始密钥数据创建DESKeySpec对象
DESKeySpec dks = new DESKeySpec(key);

// 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
SecretKey securekey = keyFactory.generateSecret(dks);

// Cipher对象实际完成解密操作
Cipher cipher = Cipher.getInstance(DES);

// 用密钥初始化Cipher对象
cipher.init(Cipher.DECRYPT_MODE, securekey, sr);

return cipher.doFinal(data);
}

// public static void main(String[] args){
// String data = "12AUism810jsqASI08";
// String key ="qwerrewq";
// System.out.println("加密前===>"+data);
// try {
// System.err.println(encrypt(data, key));
// System.err.println(decrypt(encrypt(data, key), key));
//// String jiamihou = encrypt(data);
//// System.out.println("加密后===>"+jiamihou);
//// System.out.println("解密后===>"+decrypt(jiamihou));
// } catch (Exception e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
// }

}