序列化与反序列化中的AES加密

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.security.AlgorithmParameters;
import java.security.MessageDigest;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.KeySpec;
import java.util.Date;

import javax.crypto.Cipher;
import javax.crypto.SealedObject;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;

import com.yoursite.bean.UserInfo;

public class SerializationUtil {
	static String algorithm = "AES"; 
	static Cipher encrypter = null, decrypter = null;
	static { 
		setupCrypt();
	}

	/**
	 * @param args
	 */
	public static void main(String[] args) throws Exception {
		UserInfo customer = new UserInfo("河蟹", "xxx@gmail", new Date(0));
		File file = new File("D:\\instance.obj");
		serialization(file,customer);
		customer = (UserInfo)deserialization(file);
		System.out.println(customer);
	}

	// 反序列化对象
	public static Object deserialization(File file) throws Exception {

		ObjectInputStream in = null;
		SealedObject sealed = null;
		Object object = null;
		try {
			in = new ObjectInputStream(new FileInputStream(file));
			sealed = (SealedObject) in.readObject();
			object = sealed.getObject(decrypter); 
		} catch (Exception e) {
			throw e;
		} finally {
			if (in != null)
				in.close();
		}
		return object;
	}

	// 序列化对象
	@SuppressWarnings("unused")
	public static void serialization(File file,Object object) throws Exception {
		ObjectOutputStream out = null;
		SealedObject sealed = null;
		try {
			out = new ObjectOutputStream(new FileOutputStream(file)); 
			sealed = new SealedObject((Serializable) object, encrypter);
			out.writeObject(sealed);
		} catch (Exception e) {
			throw e;
		} finally {
			if (out != null)
				out.close();
		}
	}

	private static byte[] getMD5(String input) {
		try {
			byte[] bytesOfMessage = input.getBytes("UTF-8");
			MessageDigest md = MessageDigest.getInstance("MD5");
			return md.digest(bytesOfMessage);
		} catch (Exception e) {
			return null;
		}
	} 
	@SuppressWarnings("unused")
	private static void setupCrypt() {
		String key ="helloworld";
		SecretKeySpec skey = new SecretKeySpec(getMD5(key), algorithm);
		// Create an 8-byte initialization vector
		byte[] iv = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
				0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f };

		AlgorithmParameterSpec paramSpec = new IvParameterSpec(iv);
		try {
			encrypter = Cipher.getInstance("AES/CBC/PKCS5Padding");
			decrypter = Cipher.getInstance("AES/CBC/PKCS5Padding");
			// CBC requires an initialization vector
			encrypter.init(Cipher.ENCRYPT_MODE, skey, paramSpec);
			decrypter.init(Cipher.DECRYPT_MODE, skey, paramSpec);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	@SuppressWarnings("unused")
	private static void setupCrypt2() { 
		//key需要128
		String key = "81865011520190145659841015258206940634698416000116687963543955828649380740817034326700266554532335762191268533799481074944660845";
		char[] password = key.toCharArray();
		byte[] salt = "123456".getBytes();
		SecretKeyFactory factory = null;
		SecretKey tmp = null;
		KeySpec spec = new PBEKeySpec(password, salt, 1024, 128);
		try {
			factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
			tmp = factory.generateSecret(spec);
		} catch (Exception e) {
			e.printStackTrace();
		}
		SecretKey secret = new SecretKeySpec(tmp.getEncoded(), algorithm);
		try {
			encrypter = Cipher.getInstance("AES/CBC/PKCS5Padding");
			encrypter.init(Cipher.ENCRYPT_MODE, secret);
			AlgorithmParameters params = encrypter.getParameters();
			byte[] iv = params.getParameterSpec(IvParameterSpec.class).getIV();
			decrypter = Cipher.getInstance("AES/CBC/PKCS5Padding");
			decrypter.init(Cipher.DECRYPT_MODE, secret, new IvParameterSpec(iv));
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} 
	}
@SuppressWarnings("unused")
	private static void setupCrypt3() { 
		//16位
		String key = "0123456789123456";
 		SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes(), algorithm);
 		try {
 			encrypter = Cipher.getInstance(algorithm);
 	 		encrypter.init(Cipher.ENCRYPT_MODE, skeySpec);
 	 		decrypter = Cipher.getInstance(algorithm);
 	 		decrypter.init(Cipher.DECRYPT_MODE, skeySpec);
 		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} 
	}
}

一些有用链接
http://stackoverflow.com/questions/992019/java-256bit-aes-encryption/992413#992413
http://www.ibm.com/developerworks/cn/java/j-5things1/?ca=drs-cn-0504