DES加密解密类-java

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:[email protected]" mce_href="mailto:[email protected]">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:[email protected]" mce_href="mailto:[email protected]">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:[email protected]" mce_href="mailto:[email protected]">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:[email protected]" mce_href="mailto:[email protected]">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:[email protected]" mce_href="mailto:[email protected]">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(); } } 

本文转自：http://www.blogjava.net/amigoxie/archive/2007/07/31/133544.html

 

另一个例子:

/** * @author 李国庆 * @company leemenz (C) copyright * @time Nov 1, 2006 10:18:41 AM * @version 1.0.0.0 * @package com.des */ package com.des; import java.security.*; import javax.crypto.*; public class DESPlus { private static String strDefaultKey = "national"; private Cipher encryptCipher = null; private Cipher decryptCipher = null; /** * 将byte数组转换为表示16进制值的字符串， 如：byte[]{8,18}转换为：0813， 和public static byte[] * hexStr2ByteArr(String strIn) 互为可逆的转换过程 * * @param arrB * 需要转换的byte数组 * @return 转换后的字符串 * @throws Exception * 本方法不处理任何异常，所有异常全部抛出 */ public static String byteArr2HexStr(byte[] arrB) throws Exception { int iLen = arrB.length; // 每个byte用两个字符才能表示，所以字符串的长度是数组长度的两倍 StringBuffer sb = new StringBuffer(iLen * 2); for (int i = 0; i < iLen; i++) { int intTmp = arrB<i>; // 把负数转换为正数 while (intTmp < 0) { intTmp = intTmp + 256; } // 小于0F的数需要在前面补0 if (intTmp < 16) { sb.append("0"); } sb.append(Integer.toString(intTmp, 16)); } return sb.toString(); } /** * 将表示16进制值的字符串转换为byte数组， 和public static String byteArr2HexStr(byte[] arrB) * 互为可逆的转换过程 * * @param strIn * 需要转换的字符串 * @return 转换后的byte数组 * @throws Exception * 本方法不处理任何异常，所有异常全部抛出 * @author <a href="mailto:[email protected]" mce_href="mailto:[email protected]">LiGuoQing</a> */ public static byte[] hexStr2ByteArr(String strIn) throws Exception { byte[] arrB = strIn.getBytes(); int iLen = arrB.length; // 两个字符表示一个字节，所以字节数组长度是字符串长度除以2 byte[] arrOut = new byte[iLen / 2]; for (int i = 0; i < iLen; i = i + 2) { String strTmp = new String(arrB, i, 2); arrOut[i / 2] = (byte) Integer.parseInt(strTmp, 16); } return arrOut; } /** * 默认构造方法，使用默认密钥 * * @throws Exception */ public DESPlus() throws Exception { this(strDefaultKey); } /** * 指定密钥构造方法 * * @param strKey * 指定的密钥 * @throws Exception */ public DESPlus(String strKey) throws Exception { Security.addProvider(new com.sun.crypto.provider.SunJCE()); Key key = getKey(strKey.getBytes()); encryptCipher = Cipher.getInstance("DES"); encryptCipher.init(Cipher.ENCRYPT_MODE, key); decryptCipher = Cipher.getInstance("DES"); decryptCipher.init(Cipher.DECRYPT_MODE, key); } /** * 加密字节数组 * * @param arrB * 需加密的字节数组 * @return 加密后的字节数组 * @throws Exception */ public byte[] encrypt(byte[] arrB) throws Exception { return encryptCipher.doFinal(arrB); } /** * 加密字符串 * * @param strIn * 需加密的字符串 * @return 加密后的字符串 * @throws Exception */ public String encrypt(String strIn) throws Exception { return byteArr2HexStr(encrypt(strIn.getBytes())); } /** * 解密字节数组 * * @param arrB * 需解密的字节数组 * @return 解密后的字节数组 * @throws Exception */ public byte[] decrypt(byte[] arrB) throws Exception { return decryptCipher.doFinal(arrB); } /** * 解密字符串 * * @param strIn * 需解密的字符串 * @return 解密后的字符串 * @throws Exception */ public String decrypt(String strIn) throws Exception { return new String(decrypt(hexStr2ByteArr(strIn))); } /** * 从指定字符串生成密钥，密钥所需的字节数组长度为8位 不足8位时后面补0，超出8位只取前8位 * * @param arrBTmp * 构成该字符串的字节数组 * @return 生成的密钥 * @throws java.lang.Exception */ private Key getKey(byte[] arrBTmp) throws Exception { // 创建一个空的8位字节数组（默认值为0） byte[] arrB = new byte[8]; // 将原始字节数组转换为8位 for (int i = 0; i < arrBTmp.length && i < arrB.length; i++) { arrB<i> = arrBTmp<i>; } // 生成密钥 Key key = new javax.crypto.spec.SecretKeySpec(arrB, "DES"); return key; } } 测试程序 Test.java /** * @author 李国庆 * @company leemenz (C) copyright * @time Nov 1, 2006 10:24:06 AM * @version 1.0.0.0 * @package com.des */ package com.des; /** * @author Administrator * */ public class Test { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub try { String test = "Hellow Word!"; //DESPlus des = new DESPlus();//默认密钥 DESPlus des = new DESPlus("leemenz");//自定义密钥 System.out.println("加密前的字符："+test); System.out.println("加密后的字符："+des.encrypt(test)); System.out.println("解密后的字符："+des.decrypt(des.encrypt(test))); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } } } 

此篇转载自:http://www.icnote.com/des-encrypt/