package com.flow.util;

import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import org.apache.commons.codec.binary.Base64;

public class DESUtil {
    public static final String KEY_ALGORITHM = "DES";
    public static final String CIPHER_ALGORITHM = "DESede/CBC/PKCS5Padding";
    public static String key = "FHGT4KHVJKVKV2KHCTBM";

    public DESUtil() {
    }

    private static SecretKey keyGenerator(String keyStr) throws Exception {
        byte[] input = HexString2Bytes(keyStr);
        DESKeySpec desKey = new DESKeySpec(input);
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey securekey = keyFactory.generateSecret(desKey);
        return securekey;
    }

    private static int parse(char c) {
        if (c >= 'a') {
            return c - 97 + 10 & 15;
        } else {
            return c >= 'A' ? c - 65 + 10 & 15 : c - 48 & 15;
        }
    }

    public static byte[] HexString2Bytes(String hexstr) {
        byte[] b = new byte[hexstr.length() / 2];
        int j = 0;

        for(int i = 0; i < b.length; ++i) {
            char c0 = hexstr.charAt(j++);
            char c1 = hexstr.charAt(j++);
            b[i] = (byte)(parse(c0) << 4 | parse(c1));
        }

        return b;
    }

    public static String encrypt(String data, String key) throws Exception {
        SecureRandom sr = new SecureRandom();
        DESKeySpec dks = new DESKeySpec(key.getBytes());
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey securekey = keyFactory.generateSecret(dks);
        Cipher cipher = Cipher.getInstance("DES");
        cipher.init(1, securekey, sr);
        byte[] results = cipher.doFinal(data.getBytes());
        return Base64.encodeBase64String(results);
    }

    public static String decrypt(String data, String key) throws Exception {
        SecureRandom sr = new SecureRandom();
        DESKeySpec dks = new DESKeySpec(key.getBytes());
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey securekey = keyFactory.generateSecret(dks);
        Cipher cipher = Cipher.getInstance("DES");
        cipher.init(2, securekey, sr);
        return new String(cipher.doFinal(Base64.decodeBase64(data)));
    }

    public static void main(String[] args) throws Exception {
        String url = "jdbc:mysql://localhost:3306/hxzkflow?useUnicode=true&characterEncoding=UTF-8&useSSL=false&autoReconnect=true";
        String username = "15210640466";
        String password = "123456";
        System.out.println("url: " + url);
        System.out.println("username: " + username);
        System.out.println("password: " + password);
        String e_url = encrypt(url, key);
        String e_username = encrypt(username, key);
        String e_password = encrypt(password, key);
        System.out.println("加密后url: " + e_url);
        System.out.println("加密后username: " + e_username);
        System.out.println("加密后password: " + e_password);
    }
}