java生成秘钥key,并保存秘钥到文件中

本例子采用的是Java的对称加密其中的一种方式（3DES），其他的加密方式也类似。生成一个key秘钥，发送方使用生成的key秘钥进行加密操作，然后把生成的key秘钥保存到文件中，提供给需要解密的一方使用key秘钥进行解密操作。（期间一定要保存key秘钥不被泄露）

package com.bobo.encryption.asymmetric;import java.io.BufferedReader;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.security.Key;import java.security.SecureRandom;import javax.crypto.Cipher;import javax.crypto.KeyGenerator;import javax.crypto.SecretKey;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.DESedeKeySpec;import com.sun.org.apache.xerces.internal.impl.dv.util.HexBin;/** * 把生成的密钥key保存到文件 和  读取文件中保存的密钥key * (发送方进行加密，接收方进行解密) * @author win7 * */public class SaveKeyTest {    //要加密的数据public static String bobo="http://blog.csdn.net/bobo0915";//加密后的密文数据public static byte[] result;  //需要传输给 接收方 接收方进行解密public static void main(String[] args) {// TODO Auto-generated method stubsendSecret();receiveSecret();}/** * 模拟发送方 生成秘钥，并保存秘钥  * (通过其他方式把秘钥提供给接收方，邮件，网络，U盘...) */public static void sendSecret(){try {//1.初始化key秘钥KeyGenerator keyGenerator = KeyGenerator.getInstance("DESede");keyGenerator.init(new SecureRandom());SecretKey secretKey= keyGenerator.generateKey();//转换key秘钥DESedeKeySpec deSedeKeySpec=new DESedeKeySpec(secretKey.getEncoded());SecretKeyFactory secretKeyFactory=SecretKeyFactory.getInstance("DESede");Key  key= secretKeyFactory.generateSecret(deSedeKeySpec);//2.对生成的密钥key进行编码保存String keyencode= HexBin.encode(key.getEncoded());//写入文件保存File file=new File("F:\\keyencode.txt");OutputStream outputStream=new FileOutputStream(file);outputStream.write(keyencode.getBytes());outputStream.close();System.out.println(keyencode+" -----> key保存成功");//3.进行加密Cipher cipher=Cipher.getInstance("DESede/ECB/PKCS5Padding");cipher.init(Cipher.ENCRYPT_MODE, key);result= cipher.doFinal(bobo.getBytes());System.out.println("发送方进行加密："+HexBin.encode(result));} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}}/** * 模拟接收方 读取文件中的秘钥，进行加解密 */public static void receiveSecret(){try {//1.读取文件中的密钥File file = new File("F:\\keyencode.txt");InputStream inputStream = new FileInputStream(file);//文件内容的字节流InputStreamReader inputStreamReader= new InputStreamReader(inputStream); //得到文件的字符流BufferedReader bufferedReader=new BufferedReader(inputStreamReader); //放入读取缓冲区String readd="";StringBuffer stringBuffer=new StringBuffer();while ((readd=bufferedReader.readLine())!=null) {stringBuffer.append(readd);}inputStream.close();String keystr=stringBuffer.toString();System.out.println(keystr+" -----> key读取成功");  //读取出来的key是编码之后的 要进行转码 //2.通过读取到的key获取到key秘钥对象byte[] keybyte= HexBin.decode(keystr);DESedeKeySpec deSedeKeySpec=new DESedeKeySpec(keybyte);SecretKeyFactory secretKeyFactory=SecretKeyFactory.getInstance("DESede");Key  key= secretKeyFactory.generateSecret(deSedeKeySpec); //获取到key秘钥//3.进行解密Cipher cipher=Cipher.getInstance("DESede/ECB/PKCS5Padding");cipher.init(Cipher.DECRYPT_MODE, key);result= cipher.doFinal(result);System.out.println("接收方进行解密："+new String(result));} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}}}