java加密解密(3-DES)

package com.xxxx.util;

import java.net.URLDecoder;
import java.net.URLEncoder;
import java.security.MessageDigest;

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

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

public class MD5 {

public static String md5(String str) {
try {
MessageDigest md = MessageDigest.getInstance("MD5");
md.update(str.getBytes());
byte b[] = md.digest();

int i;

StringBuffer buf = new StringBuffer("");
for (int offset = 0; offset < b.length; offset++) {
i = b[offset];
if (i < 0)
i += 256;
if (i < 16)
buf.append("0");
buf.append(Integer.toHexString(i));
}
str = buf.toString();
} catch (Exception e) {
e.printStackTrace();

}
return str;
}
/**
* 进行MD5加密
* @param String 原始的SPKEY
* @return byte[] 指定加密方式为md5后的byte[]
*/
private static byte[] md_5(String strSrc){
byte[] returnByte = null;
try{
MessageDigest md5 = MessageDigest.getInstance("MD5");
returnByte = md5.digest(strSrc.getBytes("GBK"));
}catch(Exception e){
e.printStackTrace();
}
return returnByte;
}
/**
* 得到3-DES的密钥匙
* 根据根据需要，如密钥匙为24个字节，md5加密出来的是16个字节，因此后面补8个字节的0
* @param String 原始的SPKEY
* @return byte[] 指定加密方式为md5后的byte[]
*/
private static byte[] getEnKey(String spKey){
byte[] desKey=null;
try{
byte[] desKey1 = md_5(spKey);
desKey = new byte[24];
int i = 0;
while (i < desKey1.length && i < 24) {
desKey[i] = desKey1[i];
i++;
}
if (i < 24) {
desKey[i] = 0;
i++;
}
}catch(Exception e){
e.printStackTrace();
}
return desKey;
}

/**
* 3-DES加密
* @param byte[] src 要进行3-DES加密的byte[]
* @param byte[] enKey 3-DES加密密钥
* @return byte[] 3-DES加密后的byte[]
*/
public static byte[] Encrypt(byte[] src,byte[] enKey){
byte[] encryptedData = null;
try{
DESedeKeySpec dks = new DESedeKeySpec(enKey);
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DESede");
SecretKey key = keyFactory.generateSecret(dks);
Cipher cipher = Cipher.getInstance("DESede");
cipher.init(Cipher.ENCRYPT_MODE, key);
encryptedData = cipher.doFinal(src);
}catch(Exception e){
e.printStackTrace();
}
return encryptedData;
}

/**
*
*进行3-DES解密（密钥匙等同于加密的密钥匙）。
* @param byte[] src 要进行3-DES解密byte[]
* @param String spkey分配的SPKEY
* @return String 3-DES解密后的String
*/
public static String deCrypt(byte[] debase64,String spKey){
String strDe = null;
Cipher cipher = null;
try{
cipher=Cipher.getInstance("DESede");
byte[] key = getEnKey(spKey);
DESedeKeySpec dks = new DESedeKeySpec(key);
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DESede");
SecretKey sKey = keyFactory.generateSecret(dks);
cipher.init(Cipher.DECRYPT_MODE, sKey);
byte ciphertext[] = cipher.doFinal(debase64);
strDe = new String(ciphertext,"UTF-16LE");
}catch(Exception ex){
strDe = "";
ex.printStackTrace();
}
return strDe;
}
/**
* 3-DES加密
* @param String src 要进行3-DES加密的String
* @param String spkey分配的SPKEY
* @return String 3-DES加密后的String
*/
public static String get3DESEncrypt(String src,String spkey){
String requestValue="";
try{
//得到3-DES的密钥匙
byte[] enKey = getEnKey(spkey);
//要进行3-DES加密的内容在进行/"UTF-16LE/"取字节
byte[] src2 = src.getBytes("UTF-16LE");
//进行3-DES加密后的内容的字节
byte[] encryptedData = Encrypt(src2,enKey);
//进行3-DES加密后的内容进行BASE64编码
String base64String = getBase64Encode(encryptedData);
//BASE64编码去除换行符后
String base64Encrypt = filter(base64String);
//对BASE64编码中的HTML控制码进行转义的过程
requestValue=getURLEncode(base64Encrypt);
}catch(Exception e){
e.printStackTrace();
}
return requestValue;
}

/**
* 对字符串进行URLDecoder.encode(strEncoding)编码
* @param String src 要进行编码的字符串
*
* @return String 进行编码后的字符串
*/
@SuppressWarnings("deprecation")
public static String getURLEncode(String src){
String requestValue="";
try{
requestValue = URLEncoder.encode(src);
}catch(Exception e){
e.printStackTrace();
}
return requestValue;
}

/**
* 去掉字符串的换行符号
* base64编码3-DES的数据时，得到的字符串有换行符号，根据需要可以去掉
*/
private static String filter(String str){
String output = null;
StringBuffer sb = new StringBuffer();
for(int i = 0; i < str.length(); i++){
int asc = str.charAt(i);
if(asc != 10 && asc != 13)
sb.append(str.subSequence(i, i + 1));
}
output = new String(sb);
return output;
}

/**
* 对字符串进行Base64编码
* @param byte[] src 要进行编码的字符
*
* @return String 进行编码后的字符串
*/
public static String getBase64Encode(byte[] src){
String requestValue="";
try{
BASE64Encoder base64en = new BASE64Encoder();
requestValue=base64en.encode(src);
}catch(Exception e){
e.printStackTrace();
}
return requestValue;
}

/**
* 3-DES解密
* @param String src 要进行3-DES解密的String
* @param String spkey分配的SPKEY
* @return String 3-DES加密后的String
*/
public static String get3DESDecrypt(String src,String spkey){
String requestValue="";
try{
//得到3-DES的密钥匙
//URLDecoder.decodeTML控制码进行转义的过程
String URLValue=getURLDecoderdecode(src);
//进行3-DES加密后的内容进行BASE64编码
BASE64Decoder base64Decode = new BASE64Decoder();
byte[] base64DValue = base64Decode.decodeBuffer(URLValue);
//要进行3-DES加密的内容在进行/"UTF-16LE/"取字节
requestValue = deCrypt(base64DValue,spkey);
}catch(Exception e){
e.printStackTrace();
}
return requestValue;
}

/**
* 对字符串进行URLDecoder.decode(strEncoding)解码
* @param String src 要进行解码的字符串
*
* @return String 进行解码后的字符串
*/
@SuppressWarnings("deprecation")
public static String getURLDecoderdecode(String src){
String requestValue="";
try{
requestValue = URLDecoder.decode(src);
}catch(Exception e){
e.printStackTrace();
}
return requestValue;
}

public static void main(String[] args) {

String oldString = "毒素发";
String SPKEY = "123456";
System.out.println("1。分配的SPKEY为: "+SPKEY);
System.out.println("2。的内容为: "+oldString);
String reValue = MD5.get3DESEncrypt(oldString,SPKEY);
reValue = reValue.trim().intern();
System.out.println("进行3-DES加密后的内容: "+reValue);
String reValue2 = MD5.get3DESDecrypt(reValue,SPKEY);
System.out.println("进行3-DES解密后的内容: "+reValue2);

System.out.println(md5("123456"));
System.out.println(md5("mj1"));
}
}