package com.nationalelectric.greenH5.utils;

import java.nio.charset.Charset;

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

import Decoder.BASE64Decoder;
import Decoder.BASE64Encoder;

public class DesUtil {

	private static Charset CS = Charset.forName("utf8");

	public static String encrypt(String srcStr, String sKey, String sIV) throws Exception {
		return encrypt(srcStr, CS, sKey, sIV);
	}

	public static String decrypt(String base64Str, String sKey, String sIV) throws Exception {
		return decrypt(base64Str, CS, sKey, sIV);
	}

	/**
	 * 对给定的字符串以指定的编码方式和密钥进行加密
	 * 
	 * @param srcStr
	 *            待加密的字符串
	 * @param sKey
	 *            密钥
	 */
	public static String encrypt(String srcStr, Charset charset, String sKey, String sIV) throws Exception {
		byte[] src = srcStr.getBytes();
		byte[] buf = encrypt(src, sKey, sIV);
		BASE64Encoder encoder = new BASE64Encoder();
		return encoder.encode(buf);
	}

	/**
	 * 对给定的密文以指定的编码方式和密钥进行解密
	 * 
	 * @param hexStr
	 *            需要解密的密文
	 * @param charset
	 *            字符集
	 * @param sKey
	 *            密钥
	 * @return 解密后的原文
	 * @throws Exception
	 */
	public static String decrypt(String base64Str, Charset charset, String sKey, String sIV) throws Exception {
		BASE64Decoder decoder = new BASE64Decoder();
		byte[] src = decoder.decodeBuffer(base64Str);
		byte[] buf = decrypt(src, sKey, sIV);
		return new String(buf, charset);

	}

	public static byte[] encrypt(byte[] data, String sKey, String sIV) {
		try {
			byte[] key = sKey.getBytes();
			byte[] bIV = sIV.getBytes();

			IvParameterSpec iv = new IvParameterSpec(bIV);
			DESKeySpec desKey = new DESKeySpec(key);

			SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
			SecretKey securekey = keyFactory.generateSecret(desKey);

			Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");

			cipher.init(Cipher.ENCRYPT_MODE, securekey, iv);

			return cipher.doFinal(data);
		} catch (Throwable e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * 解密
	 * 
	 * @param src
	 * @param sKey
	 * @return
	 * @throws Exception
	 */
	public static byte[] decrypt(byte[] src, String sKey, String sIV) throws Exception {
		byte[] key = sKey.getBytes();
		byte[] bIV = sIV.getBytes();
		// 初始化向量
		IvParameterSpec iv = new IvParameterSpec(bIV);
		// 创建一个DESKeySpec对象
		DESKeySpec desKey = new DESKeySpec(key);
		// 创建一个密匙工厂
		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
		// 将DESKeySpec对象转换成SecretKey对象
		SecretKey securekey = keyFactory.generateSecret(desKey);
		// Cipher对象实际完成解密操作
		Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
		// 用密匙初始化Cipher对象
		cipher.init(Cipher.DECRYPT_MODE, securekey, iv);
		// 真正开始解密操作
		return cipher.doFinal(src);
	}

	public static void main(String[] args) throws Exception {
		String data = "0004774159";
		String skey = "YWtoaWw6";
		String iv = "L+toj8%]";
		Charset cs = Charset.forName("utf8");
		String ss = encrypt(data, cs, skey, iv);
		System.out.println("===明文:" + data);
		System.out.println("===密钥:" + skey);
		System.out.println("===向量:" + iv);
		System.out.println("===密文:" + ss);
		String kk = decrypt(ss, cs, skey, iv);
		System.out.println("===解密:" + kk);
	}
}