做项目时用到的DES加密解密类，代码如下：
import java.security.*;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
/** *//**
* Copyright 2007 GuangZhou Cotel Co. Ltd.
* All right reserved.
* DES加密解密类.
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* @version 1.0
* Creation date: 2007-7-31 - 上午11:59:28
*/
public class Des 
{
/** *//** 加密、解密key. */
private static final String PASSWORD_CRYPT_KEY = "kEHrDooxWHCWtfeSxvDvgqZq";
/** *//** 加密算法,可用 DES,DESede,Blowfish. */
private final static String ALGORITHM = "DES";
public static void main(String[] args) throws Exception {
String md5Password = "202cb962ac59075b964b07152d234b70";
String str = Des.encrypt(md5Password);
System.out.println("str: " + str);
str = Des.decrypt(str);
System.out.println("str: " + str);
}
/** *//**
* 对数据进行DES加密.
* @param data 待进行DES加密的数据
* @return 返回经过DES加密后的数据
* @throws Exception
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* Creation date: 2007-7-31 - 下午12:06:24
*/
public final static String decrypt(String data) throws Exception {
return new String(decrypt(hex2byte(data.getBytes()),
PASSWORD_CRYPT_KEY.getBytes()));
}
/** *//**
* 对用DES加密过的数据进行解密.
* @param data DES加密数据
* @return 返回解密后的数据
* @throws Exception
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* Creation date: 2007-7-31 - 下午12:07:54
*/
public final static String encrypt(String data) throws Exception {
return byte2hex(encrypt(data.getBytes(), PASSWORD_CRYPT_KEY
.getBytes()));
}
/** *//**
* 用指定的key对数据进行DES加密.
* @param data 待加密的数据
* @param key DES加密的key
* @return 返回DES加密后的数据
* @throws Exception
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* Creation date: 2007-7-31 - 下午12:09:03
*/
private static byte[] encrypt(byte[] data, 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(ALGORITHM);
SecretKey securekey = keyFactory.generateSecret(dks);
// Cipher对象实际完成加密操作
Cipher cipher = Cipher.getInstance(ALGORITHM);
// 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(data);
}
/** *//**
* 用指定的key对数据进行DES解密.
* @param data 待解密的数据
* @param key DES解密的key
* @return 返回DES解密后的数据
* @throws Exception
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* Creation date: 2007-7-31 - 下午12:10:34
*/
private static byte[] decrypt(byte[] data, 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(ALGORITHM);
SecretKey securekey = keyFactory.generateSecret(dks);
// Cipher对象实际完成解密操作
Cipher cipher = Cipher.getInstance(ALGORITHM);
// 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(data);
}
public 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 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();
}
} 参考文章：
http://zhidao.baidu.com/question/21703942.html
posted on 2007-07-31 12:18
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