asp.net DES加密解密

數據加密標準DES加密算法是一種對稱加密算法，DES 使用一個 56 位的密鑰以及附加的 8 位奇偶校驗位，產生最大 64 位的分組大小。這是一個迭代的分組密碼，使用稱爲 Feistel 的技術，其中將加密的文本塊分紅兩半。使用子密鑰對其中一半應用循環功能，而後將輸出與另外一半進行「異或」運算；接着交換這兩半，這一過程會繼續下去，但最後一個循環不交換。DES 使用 16 個循環，使用異或，置換，代換，移位操做四種基本運算。

 

特色：數據加密標準，速度較快，適用於加密大量數據的場合；

 

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

namespace DBI.SaaS.Web.Common
{
    public class SecurityHelper
    {
        //默認密鑰向量
        private static byte[] Keys = { 0x13, 0x24, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
        /**//// <summary>
            /// DES加密字符串
            /// </summary>
            /// <param name="encryptString">待加密的字符串</param>
            /// <param name="encryptKey">加密密鑰,要求爲8位</param>
            /// <returns>加密成功返回加密後的字符串，失敗返回源串</returns>
        public static string EncryptDES(string encryptString, string encryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Convert.ToBase64String(mStream.ToArray());
            }
            catch
            {
                return encryptString;
            }
        }

        /**//// <summary>
            /// DES解密字符串
            /// </summary>
            /// <param name="decryptString">待解密的字符串</param>
            /// <param name="decryptKey">解密密鑰,要求爲8位,和加密密鑰相同</param>
            /// <returns>解密成功返回解密後的字符串，失敗返源串</returns>
        public static string DecryptDES(string decryptString, string decryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Convert.FromBase64String(decryptString);
                DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Encoding.UTF8.GetString(mStream.ToArray());
            }
            catch
            {
                return decryptString;
            }
        }

        /// <summary>
        /// 建立加密簽名
        /// </summary>
        /// <param name="userinfo"></param>
        /// <returns></returns>
        public static string CreateSignature(string userinfo)
        {
            var token = Guid.NewGuid().ToString("N").Substring(0,8);
            return  EncryptDES(userinfo, token);
        }

        /// <summary>
        /// 獲取當前隨機碼
        /// </summary>
        /// <returns></returns>
        public static string GetCode()
        {
            Random rd = new Random();
            int shu = rd.Next(97, 122);
            char c = (char)shu;
            Random rdnumber = new Random();
            var val= rdnumber.Next(0, 99999);
            return c + val.ToString().PadLeft(5, '0');
        }
    }
}