/*
* Copyright 2008 biaoping.yin
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.frameworkset.common.poolman.security;
import java.security.Key;
import java.security.Security;
import javax.crypto.Cipher;
/**
*
* <p>Title: DESCipher.java</p>
*
* <p>Description: 一个采用DES算法的加密解密类,可以通过设置密钥或使用默认密钥，对字符串和字节数组进行加密和解密运算。</p>
*
* <p>Copyright: Copyright (c) 2007</p>
* @Date 2012-3-14 下午3:23:03
* @author biaoping.yin
* @version 1.0
*/
public class DESCipher {
private static final String DEFAULTKEY = "BBOSSGRP";
private Cipher encryptCipher = null;
private Cipher decryptCipher = null;
/**
* 将参数字节数组转换为16进制值表示组合而成的字符串。
*
* @param byte[] 需要转换的byte数组
* @return String 转换后的字符串
* @throws Exception
* JAVA异常
*/
public static String byteGrpToHexStr(byte[] arrB) throws Exception {
int iLen = arrB.length;
StringBuffer tempSB = new StringBuffer(iLen * 2);
for (int i = 0; i < iLen; i++) {
int intTmp = arrB[i];
while (intTmp < 0) {
intTmp = intTmp + 256;
}
if (intTmp < 16) {
tempSB.append("0");
}
tempSB.append(Integer.toString(intTmp, 16));
}
return tempSB.toString();
}
/**
* 将参数16进制值表示组合而成的字符串转换为字节数组。
*
* @param String
* 需要转换的字符串
* @return byte[] 转换后的byte数组
* @throws Exception
* JAVA异常
*/
public static byte[] hexStrToByteGrp(String strIn) throws Exception {
byte[] arrB = strIn.getBytes();
int iLen = arrB.length;
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 DESCipher() throws Exception {
this(DEFAULTKEY);
}
/**
* 指定密钥构造方法
*
* @param String
* 指定的密钥
* @throws Exception
* JAVA异常
*/
public DESCipher(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 byte[] 需加密的字节数组
* @return byte[] 加密后的字节数组
* @throws Exception
* JAVA异常
*/
public byte[] encrypt(byte[] arrB) throws Exception {
return encryptCipher.doFinal(arrB);
}
/**
* 加密字符串
* 将字符串转换为字节数组后重用encrypt(byte[])方法进行加密，并将得到字节数组转换为字符串返回
*
* @param String
* 需加密的字符串
* @return String 加密后的字符串
* @throws Exception
* JAVA异常
*/
public String encrypt(String strIn) throws Exception {
return byteGrpToHexStr(encrypt(strIn.getBytes()));
}
/**
* 解密字节数组
*
* @param byte[] 需解密的字节数组
* @return byte[] 解密后的字节数组
* @throws Exception
* JAVA异常
*/
public byte[] decrypt(byte[] arrB) throws Exception {
return decryptCipher.doFinal(arrB);
}
/**
* 解密字符串
* 将参数字符串转换为字节数组后重用decrypt(String)方法进行解密，并将得到的解密字符数组转换为字符串后返回。
*
* @param String
* 需解密的字符串
* @return String 解密后的字符串
* @throws Exception
* JAVA异常
*/
public String decrypt(String strIn) throws Exception {
return new String(decrypt(hexStrToByteGrp(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 byte[] 构成该字符串的字节数组
* @return Key 生成的密钥
* @throws Exception
* JAVA异常
*/
private Key getKey(byte[] arrBTmp) throws Exception {
byte[] arrB = new byte[8];
for (int i = 0; i < arrBTmp.length && i < arrB.length; i++) {
arrB[i] = arrBTmp[i];
}
Key key = new javax.crypto.spec.SecretKeySpec(arrB, "DES");
return key;
}
public static void main(String[] args){
System.out.println(DEFAULTKEY.getBytes().length);
}
}