/javaSecu/src/com/liwei/javasecu/corejava/Eryptogram.java

package com.liwei.javasecu.corejava;



/**

 * @(#)Eryptogram.java 1.00 04/03/11

 *

 * Copyright (c) 2003-2004 Abacus,Ltd.

 *

 * ?????

 *

 * 

 *

 */

import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;



/**

 * ?????

 * 

 * @author WangHu

 * @version 1.00 2004?03?18?

 */

public class Eryptogram {

	private static String Algorithm = "DES";

	// ?? ????,?? DES,DESede,Blowfish

	static boolean debug = false;



	/**

	 * ?????.

	 */

	public Eryptogram() {



	}



	/**

	 * ????

	 * 

	 * @return byte[] ???????

	 * @throws exception

	 *             ????.

	 */

	public static byte[] getSecretKey() throws Exception {

		KeyGenerator keygen = KeyGenerator.getInstance(Algorithm);

		SecretKey deskey = keygen.generateKey();

		if (debug)

			System.out.println("????:" + byte2hex(deskey.getEncoded()));

		return deskey.getEncoded();



	}



	/**

	 * ?????????????????

	 * 

	 * @param input

	 *            ???????

	 * @param key

	 *            ??

	 * @return byte[] ??????

	 * @throws Exception

	 */

	public static byte[] encryptData(byte[] input, byte[] key) throws Exception {

		SecretKey deskey = new javax.crypto.spec.SecretKeySpec(key, Algorithm);

		if (debug) {

			System.out.println("???????:" + byte2hex(input));

			System.out.println("???????:" + new String(input));



		}

		Cipher c1 = Cipher.getInstance(Algorithm);

		c1.init(Cipher.ENCRYPT_MODE, deskey);

		byte[] cipherByte = c1.doFinal(input);

		if (debug)

			System.out.println("???????:" + byte2hex(cipherByte));

		return cipherByte;



	}



	/**

	 * ?????????????????????

	 * 

	 * @param input

	 *            ??????

	 * @param key

	 *            ??

	 * @return byte[] ??????

	 * @throws Exception

	 */

	public static byte[] decryptData(byte[] input, byte[] key) throws Exception {

		SecretKey deskey = new javax.crypto.spec.SecretKeySpec(key, Algorithm);

		if (debug)

			System.out.println("??????:" + byte2hex(input));

		Cipher c1 = Cipher.getInstance(Algorithm);

		c1.init(Cipher.DECRYPT_MODE, deskey);

		byte[] clearByte = c1.doFinal(input);

		if (debug) {

			System.out.println("???????:" + byte2hex(clearByte));

			System.out.println("???????:" + (new String(clearByte)));



		}

		return clearByte;



	}



	/**

	 * ??????16?????

	 * 

	 * @param byte[] b ?????????

	 * @return String ??????16?????

	 */

	public static String byte2hex(byte[] b) {

		String hs = "";

		String stmp = "";

		for (int n = 0; n < b.length; n++) {

			stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));

			if (stmp.length() == 1)

				hs = hs + "0" + stmp;

			else

				hs = hs + stmp;

			if (n < b.length - 1)

				hs = hs + ":";



		}

		return hs.toUpperCase();



	}



	public static void main(String[] args) {

		try {

			debug = false;

			Eryptogram etg = new Eryptogram();

			byte[] key = etg.getSecretKey();

			System.out.println("key = " + key);

			String aa = "1234567";

			byte[] data = aa.getBytes();

			System.out.println(data);

			byte[] en = etg.encryptData(data, key);

			System.out.println("encryptData = " + new String(en));

			byte[] de = etg.decryptData(en, key);

			System.out.println("decryptData = " + new String(de));



		} catch (Exception e) {

			e.printStackTrace();



		}

	}

}