java安全2

package com.ngsn.security;


import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;

/**
 * 对称加密（加密解密的密钥一样）
 * @author John.Yao
 *
 */
public class SecretKeyTest1 {
	
	public static void main(String[] args) throws Exception{
	//	SecretEncrypt();
		
		SecretDecrypt();
		
	}
	/**
	 * 加密方法
	 * 将加密的密钥保存在zxx_secret.key文件中
	 * 将加密的数据保存在zxx.data文件中
	 * @throws Exception
	 */
	private static void SecretEncrypt() throws Exception{
		//Cipher  此类为加密和解密提供密码功能
		Cipher cipher = Cipher.getInstance("AES");
		//根据AES的加密方法生成一个密钥
		SecretKey key = KeyGenerator.getInstance("AES").generateKey();
		
		FileOutputStream fosKey = new FileOutputStream("zxx_secret.key");
		ObjectOutputStream oosSecretKey = new ObjectOutputStream(fosKey);
		//将密钥保存到zxx_secret.key文件中
		oosSecretKey.writeObject(key);
		oosSecretKey.close();
		fosKey.close();
		
		
		//初始化
		//Cipher.ENCRYPT_MODE 为加密模式
		//key 为加密的密钥
		cipher.init(Cipher.ENCRYPT_MODE,key);
		//对byte[] 进行加密，返回一个加密后的byte[]
		byte[] result = cipher.doFinal("abc".getBytes());
		System.out.println("result----->"+new String(result));
		
		FileOutputStream fosData = new FileOutputStream("zxx.data");
		fosData.write(result);
		fosData.close();
	}
	/**
	 * 解密方法
	 * @throws Exception
	 */
	private static void SecretDecrypt()throws Exception{
		//Cipher  此类为加密和解密提供密码功能
		Cipher cipher = Cipher.getInstance("AES");
		//从zxx_secret.key文件中得到key
		FileInputStream fisKey = new FileInputStream("zxx_secret.key");
		ObjectInputStream ois = new ObjectInputStream(fisKey);
		Key key = (Key)ois.readObject();
		ois.close();
		fisKey.close();
		//解密
		//初始化
		cipher.init(Cipher.DECRYPT_MODE, key);
		//从zxx.data文件中得到加密的数据
		FileInputStream fis = new FileInputStream("zxx.data");
		byte[] buffer = new byte[1024];
		int len = 0;
		ByteArrayOutputStream bos = new ByteArrayOutputStream();
		while((len = fis.read(buffer)) != -1){
			bos.write(buffer, 0, len);
		}
		//从输出流中得到byte[]的加密数据
		byte[] result = bos.toByteArray();
		fis.close();
		bos.close();
		//对加密的数据进行解密
		byte[] b = cipher.doFinal(result);
		System.out.println("b------>"+new String(b));
		

	}
}