自动生成AES密钥，并使用生成的进行加密解密2

package com.digican.books.a0102.b0101;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.security.InvalidKeyException;
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;
import javax.crypto.spec.SecretKeySpec;

/**
 * 2010年9月1日
 * @author 姚大庆
 */
public class DigicanAES {
	
	public static void main(String[] args) throws Exception {
		//加密
		/*byte[] text = "hello world".getBytes();
		byte[] b = getAESEncode("d:\\testAES",text);
		FileOutputStream fos = new FileOutputStream("d:\\testAESjiamji");
		fos.write(b);
		fos.flush();
		fos.close();*/
		
		//解密
		/*File file = new File("d:\\testAESjiamji");
		byte[] bm = new byte[(int) file.length()];
		FileInputStream fis = new FileInputStream(file);
		fis.read(bm);
		byte[] b = getAESDecode("d:\\testAES", bm);
		System.out.println(new String(b));*/
	}

	/**
	 * 生成密钥
	 * 自动生成AES128位密钥
	 * 传入保存密钥文件路径
	 * filePath 表示文件存储路径加文件名；例如d:\aes.txt
	 * @throws NoSuchAlgorithmException 
	 * @throws IOException 
	 */
	public static void getAutoCreateAESKey(String filePath) throws NoSuchAlgorithmException, IOException{
		KeyGenerator kg = KeyGenerator.getInstance("AES");
		kg.init(128);//要生成多少位，只需要修改这里即可128, 192或256
		SecretKey sk = kg.generateKey();
		byte[] b = sk.getEncoded();
		FileOutputStream fos = new FileOutputStream(filePath);
		fos.write(b);
		fos.flush();
		fos.close();
	}
	
	/**
	 * 加密
	 * 使用对称密钥进行加密
	 * keyFilePath 密钥存放路径
	 * text 要加密的字节数组
	 * 加密后返回一个字节数组
	 * @throws IOException 
	 * @throws NoSuchPaddingException 
	 * @throws NoSuchAlgorithmException 
	 * @throws InvalidKeyException 
	 * @throws BadPaddingException 
	 * @throws IllegalBlockSizeException 
	 */
	public static byte[] getAESEncode(String keyFilePath,byte[] text) throws IOException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException{
		File file = new File(keyFilePath);
		byte[] key = new byte[(int) file.length()];
		FileInputStream fis = new FileInputStream(file);
		fis.read(key);
		SecretKeySpec sKeySpec = new SecretKeySpec(key, "AES");
		Cipher cipher = Cipher.getInstance("AES");
		cipher.init(Cipher.ENCRYPT_MODE, sKeySpec);
		byte[] bjiamihou = cipher.doFinal(text);
		return bjiamihou;
	}
	
	/**
	 * 解密
	 * 使用对称密钥进行解密
	 * keyFilePath 密钥存放路径
	 * text 要解密的字节数组
	 * 解密后返回一个字节数组
	 * @throws IOException 
	 * @throws NoSuchPaddingException 
	 * @throws NoSuchAlgorithmException 
	 * @throws InvalidKeyException 
	 * @throws BadPaddingException 
	 * @throws IllegalBlockSizeException 
	 */
	public static byte[] getAESDecode(String keyFilePath,byte[] text) throws IOException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException{
		File file = new File(keyFilePath);
		byte[] key = new byte[(int) file.length()];
		FileInputStream fis = new FileInputStream(file);
		fis.read(key);
		SecretKeySpec sKeySpec = new SecretKeySpec(key, "AES");
		Cipher cipher = Cipher.getInstance("AES");
		cipher.init(Cipher.DECRYPT_MODE, sKeySpec);
		byte[] bjiemihou = cipher.doFinal(text);
		return bjiemihou;
	}
}


//解密C语言的AES加密后数据，要把JAVA中的AES改成AES/ECB/NoPadding