DES算法加密解密--封装类

来源：互联网发布：配电箱尺寸计算软件编辑：程序博客网时间：2024/04/28 06:48

package com.gzdec.common.util;

import java.security.*;

import javax.crypto.Cipher;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESKeySpec;

/**

* 加密方法

* Title: lcms

* Description:

* Create DateTime: Jun 12, 2010 1:37:32 PM

* CVS last modify person: Administrator

* CVS last modify DateTime: Jun 12, 2010 1:37:32 PM

* CVS last version:

* @author */

public class EncryptUtils {

private static final String PASSWORD_CRYPT_KEY = "%^&*RG*D";

private final static String DES = "DES";

/**

* 加密

* @param src

* 数据源

* @param key

* 密钥，长度必须是8的倍数

* @return 返回加密后的数据

* @throws Exception

public static byte[] encrypt(byte[] src, byte[] key) throws Exception {

// DES算法要求有一个可信任的随机数源

SecureRandom sr = new SecureRandom();

// 从原始密匙数据创建DESKeySpec对象

DESKeySpec dks = new DESKeySpec(key);

// 创建一个密匙工厂，然后用它把DESKeySpec转换成

// 一个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);

// 用密匙初始化Cipher对象

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

// 现在，获取数据并加密

// 正式执行加密操作

return cipher.doFinal(src);

}

/**

* 解密

* @param src

* 数据源

* @param key

* 密钥，长度必须是8的倍数

* @return 返回解密后的原始数据

* @throws Exception

public static byte[] decrypt(byte[] src, byte[] key) throws Exception {

// DES算法要求有一个可信任的随机数源

SecureRandom sr = new SecureRandom();

// 从原始密匙数据创建一个DESKeySpec对象

DESKeySpec dks = new DESKeySpec(key);

// 创建一个密匙工厂，然后用它把DESKeySpec对象转换成

// 一个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);

// 用密匙初始化Cipher对象

cipher.init(Cipher.DECRYPT_MODE, securekey, sr);

// 现在，获取数据并解密

// 正式执行解密操作

return cipher.doFinal(src);

}

/**

* 密码解密

* @param data

* @return

* @throws Exception

public final static String decrypt(String data) {

try {

return new String(decrypt(hex2byte(data.getBytes()),

PASSWORD_CRYPT_KEY.getBytes()));

} catch (Exception e) {

}

return null;

}

/**

* 密码加密

* @param password

* @return

* @throws Exception

public final static String encrypt(String password) {

try {

return byte2hex(encrypt(password.getBytes(), PASSWORD_CRYPT_KEY

.getBytes()));

} catch (Exception e) {

}

return null;

}

/**

* 二行制转字符串

* @param b

* @return

private static String byte2hex(byte[] b) {

String hs = "";

String stmp = "";

for (int n = 0; n < b.length; n++) {

stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));

if (stmp.length() == 1)

hs = hs + "0" + stmp;

else

hs = hs + stmp;

}

return hs.toUpperCase();

}

private static byte[] hex2byte(byte[] b) {

if ((b.length % 2) != 0)

throw new IllegalArgumentException("长度不是偶数");

byte[] b2 = new byte[b.length / 2];

for (int n = 0; n < b.length; n += 2) {

String item = new String(b, n, 2);

b2[n / 2] = (byte) Integer.parseInt(item, 16);

}

return b2;

}

public static void main(String[] args) {

System.out.println("加密的字符串是 "

+ new EncryptUtils().encrypt("studTest"));

System.out.println("解密后的字符串是 "

+ new EncryptUtils().decrypt("3E7FB009E7C5B8CF6FFF9EA2784E2CEF"));

}