【知识积累】DES算法之C#加密&Java解密

一、前言

　　在项目需要添加安全模块，客户端调用服务端发布的service必须要经过验证，加密算法采用DES，客户端采用C#进行加密，服务端使用Java进行解密。废话不多说，直接上代码。

二、客户端

　　客户端采用C#进行开发，C#进行DES加密解密代码清单如下：　

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
using System.IO;

namespace DESHelper
{
    public class DESHelper
    {
        private static string m_encryptkey = "ENCRYPTT";
        private static string m_str = "IAMACOEDR";

        public static string DESEncrypt()
        {
            string str = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + m_str;
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray = Encoding.GetEncoding("UTF-8").GetBytes(str);
            //建立加密对象的密钥和偏移量
            //原文使用ASCIIEncoding.ASCII方法的GetBytes方法
            //使得输入密码必须输入英文文本
            des.Key = ASCIIEncoding.ASCII.GetBytes(m_encryptkey);
            des.IV = ASCIIEncoding.ASCII.GetBytes(m_encryptkey);
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);

            cs.Write(inputByteArray, , inputByteArray.Length);
            cs.FlushFinalBlock();
            StringBuilder ret = new StringBuilder();
            foreach (byte b in ms.ToArray())
            {
                ret.AppendFormat("{0:X2}", b);
            }
            ret.ToString();
            return ret.ToString();
        }

        public static string DESDecrypt(string pToDecrypt, string sKey)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray = new byte[pToDecrypt.Length / ];
            for (int x = ; x < pToDecrypt.Length / ; x++)
            {
                int i = (Convert.ToInt32(pToDecrypt.Substring(x * , ), ));
                inputByteArray[x] = (byte)i;
            }
            des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
            des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, , inputByteArray.Length);
            cs.FlushFinalBlock();
            StringBuilder ret = new StringBuilder();
            return System.Text.Encoding.Default.GetString(ms.ToArray());
        }

        static void Main(string[] args)
        {
            string str = DESEncrypt();
            Console.WriteLine(str);
            Console.WriteLine(DESDecrypt(str, m_encryptkey));
        }
    }
}

　　运行结果：

　　34DB26C86E933FB8F9C294A563BEF742D85451292A3C40C6FC8DF5A99C56EDCC
　　2016-03-10 12:43:05IAMACOEDR

三、服务器

　　服务器采用Java进行开发，Java进行DES加密解密代码清单如下：　

import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;
import java.security.Key;
import java.security.spec.AlgorithmParameterSpec;
import javax.crypto.Cipher;

public class Des {
    //解密数据
    public static String decrypt(String message,String key) throws Exception {
        byte[] bytesrc =convertHexString(message);
        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
        DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
        IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
        cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
        byte[] retByte = cipher.doFinal(bytesrc);   

        return new String(retByte);
    }  

    // 加密数据
    public static byte[] encrypt(String message, String key)
            throws Exception {
        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
        DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
        IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
        cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);   

        return cipher.doFinal(message.getBytes("UTF-8"));
    }   

    public static byte[] convertHexString(String ss) {
        byte digest[] = new byte[ss.length() / 2];
        for(int i = 0; i < digest.length; i++) {
            String byteString = ss.substring(2 * i, 2 * i + 2);
            int byteValue = Integer.parseInt(byteString, 16);
            digest[i] = (byte)byteValue;
        }    

        return digest;
    }  

    public static String toHexString(byte b[]) {
        StringBuffer hexString = new StringBuffer();
        for (int i = 0; i < b.length; i++) {
            String plainText = Integer.toHexString(0xff & b[i]);
            if (plainText.length() < 2)
                plainText = "0" + plainText;
            hexString.append(plainText);
        }   

        return hexString.toString();
    }       

    public static void main(String[] args) throws Exception {
        String key = "ENCRYPTT";
        String value = "IAMACODER";
        String formatString = java.net.URLEncoder.encode(value, "utf-8");
        System.out.println("加密数据:"+ formatString);
        String encryptedString = toHexString(encrypt(formatString, key));
        System.out.println("加密后的数据为:" + encryptedString);
        String decryptedString = java.net.URLDecoder.decode(decrypt(encryptedString, key), "utf-8") ;
        System.out.println("解密后的数据:" + decryptedString);
    }
}

　　运行结果：

　　加密数据:IAMACODER
　　加密后的数据为:a8a3f8641ec18ddeff808105c493510e
　　解密后的数据:IAMACODER

四、测试C#加密&Java解密

　　将C#端加密的字符串传入Java端(替换decrypt中的encryptedString即可)直接进行解密，可以得到如下结果：

　　加密数据:IAMACODER
　　加密后的数据为:a8a3f8641ec18ddeff808105c493510e
　　解密后的数据:2016-03-10 12:43:05IAMACOEDR

五、总结

　　这是一个小的功能模块，有此需求的园友可以直接拿去使用，谢谢各位园友观看~