public class DESCryption
 {

 /// <summary>
 /// //注意了，是8个字符，64位
 /// </summary>
 private static string PrivateRsa = ConfigurationManager.AppSettings["PrivateRsa"];

 /// <summary>
 /// //注意了，是8个字符，64位
 /// </summary>
 private static string PublicRsa = ConfigurationManager.AppSettings["PublicRsa"];

 /// <summary>
 /// 加密
 /// </summary>
 /// <param name="data"></param>
 /// <returns></returns>
 public static string Encode(string data)
 {
 byte[] byKey = Encoding.ASCII.GetBytes(PrivateRsa);
 byte[] byIV = Encoding.ASCII.GetBytes(PublicRsa);

 DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
 int i = cryptoProvider.KeySize;
 MemoryStream ms = new MemoryStream();
 CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateEncryptor(byKey, byIV), CryptoStreamMode.Write);

 StreamWriter sw = new StreamWriter(cst);
 sw.Write(data);
 sw.Flush();
 cst.FlushFinalBlock();
 sw.Flush();
 return Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length);

 }

 /// <summary>
 /// 解密
 /// </summary>
 /// <param name="data"></param>
 /// <returns></returns>
 public static string Decode(string data)
 {
 byte[] byKey = Encoding.ASCII.GetBytes(PrivateRsa);
 byte[] byIV = Encoding.ASCII.GetBytes(PublicRsa);

 byte[] byEnc;
 try
 {
 byEnc = Convert.FromBase64String(data);
 }
 catch
 {
 return null;
 }

 DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
 MemoryStream ms = new MemoryStream(byEnc);
 CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateDecryptor(byKey, byIV), CryptoStreamMode.Read);
 StreamReader sr = new StreamReader(cst);
 return sr.ReadToEnd();
 }
 }

//请求参数
 string requestTime = httpContext.Request["rtime"]; //请求时间经过DESC签名
 if (string.IsNullOrEmpty(requestTime))
 return false;


 //请求时间DESC解密后加上时间戳的时间即该请求的有效时间
 DateTime Requestdt = DateTime.Parse(DESCryption.Decode(requestTime)).AddMinutes(int.Parse(TimeStamp));
 DateTime Newdt = DateTime.Now; //服务器接收请求的当前时间
 if (Requestdt < Newdt)
 {
 return false;
 }
 else
 {
 //进行其他操作
 var userinfo = JwtHelp.GetJwtDecode(authHeader);
 //举个例子 生成jwtToken 存入redis中 
 //这个地方用jwtToken当作key 获取实体val 然后看看jwtToken根据redis是否一样
 if (userinfo.UserName == "admin" && userinfo.Pwd == "123")
  return true;
 }