lyggkj/gkaq/yjpt-java/trunk/java_src/com/jtgh/yjpt/common/Des.java

package com.jtgh.yjpt.common;


import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

public class Des {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		try {
			System.out.println(encrypt("123456"));
			System.out.println(decrypt(encrypt("123456")));
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	/**
	 * DES�㷨��Կ
	 */
	private static final String DES_KEY = "yjpt_gkj";

	/**
	 * ��ݼ��ܣ��㷨��DES��
	 * 
	 * @param data
	 *            Ҫ���м��ܵ����
	 * @return ���ܺ�����
	 */
	public static String encrypt(String data) {
		String encryptedData = null;
		try {
			// DES�㷨Ҫ����һ�������ε������Դ
			SecureRandom sr = new SecureRandom();
			DESKeySpec deskey = new DESKeySpec(DES_KEY.getBytes());
			// ����һ���ܳ׹�����Ȼ�������DESKeySpecת����һ��SecretKey����
			SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
			SecretKey key = keyFactory.generateSecret(deskey);
			// ���ܶ���
			Cipher cipher = Cipher.getInstance("DES");
			cipher.init(Cipher.ENCRYPT_MODE, key, sr);
			// ���ܣ������ֽ����������ַ�
			encryptedData = new sun.misc.BASE64Encoder().encode(cipher
					.doFinal(data.getBytes()));
		} catch (Exception e) {
			// log.error("���ܴ��󣬴�����Ϣ��", e);
			throw new RuntimeException("���ܴ��󣬴�����Ϣ��", e);
		}
		return encryptedData;
	}

	/**
	 * ��ݽ��ܣ��㷨��DES��
	 * 
	 * @param cryptData
	 *            �������
	 * @return ���ܺ�����
	 */
	public static String decrypt(String cryptData) {
		String decryptedData = null;
		try {
			// DES�㷨Ҫ����һ�������ε������Դ
			SecureRandom sr = new SecureRandom();
			DESKeySpec deskey = new DESKeySpec(DES_KEY.getBytes());
			// ����һ���ܳ׹�����Ȼ�������DESKeySpecת����һ��SecretKey����
			SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
			SecretKey key = keyFactory.generateSecret(deskey);
			// ���ܶ���
			Cipher cipher = Cipher.getInstance("DES");
			cipher.init(Cipher.DECRYPT_MODE, key, sr);
			// ���ַ����Ϊ�ֽ����飬������
			decryptedData = new String(
					cipher.doFinal(new sun.misc.BASE64Decoder()
							.decodeBuffer(cryptData)));
		} catch (Exception e) {
			// log.error("���ܴ��󣬴�����Ϣ��", e);
			throw new RuntimeException("���ܴ��󣬴�����Ϣ��", e);
		}
		return decryptedData;
	}
}