asp.net开发微信公众平台之验证消息的真实性

/// <summary>
  /// 微信推送消息模型
  /// </summary>
  public class WeChatMsgRequestModel
  {
    public string timestamp { get; set; }
    public string nonce { get; set; }

    public string msg_signature { get; set; }
  }

public class WeChatRequestValidAttribute : ActionFilterAttribute
  {
    private const string Token = "StupidMe";

    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
      //参数适配
      Model.FormatModel.WeChatMsgRequestModel model = new Model.FormatModel.WeChatMsgRequestModel() { nonce= filterContext.HttpContext.Request.QueryString["nonce"],msg_signature= filterContext.HttpContext.Request.QueryString["msg_signature"],timestamp= filterContext.HttpContext.Request.QueryString["timestamp"] };
      //验证
      if (CheckSignature(model))
      {
        base.OnActionExecuting(filterContext);
      }      
    }

    private bool CheckSignature(Model.FormatModel.WeChatMsgRequestModel model)
    {
      string signature, timestamp, nonce, tempStr;
      //获取请求来的参数
      signature = model.msg_signature;
      timestamp = model.timestamp;
      nonce = model.nonce;
      //创建数组，将 Token, timestamp, nonce 三个参数加入数组
      string[] array = { Token, timestamp, nonce };
      //进行排序
      Array.Sort(array);
      //拼接为一个字符串
      tempStr = String.Join("", array);
      //对字符串进行 SHA1加密
      tempStr = FormsAuthentication.HashPasswordForStoringInConfigFile(tempStr, "SHA1").ToLower();
      //判断signature 是否正确
      if (tempStr.Equals(signature))
      {
        return true;
      }
      else
      {
        return false;
      }
    }
  }

/// <summary>
    /// 日志助手
    /// </summary>
    private static Common.LogHelper logger = new Common.LogHelper(typeof(HomeController));

    [Filters.WeChatRequestValid]
    public void Valid(Model.FormatModel.WeChatMsgRequestModel model)
    {
      if (ModelState.IsValid)
      {
        try
        {
          //判断是否是POST请求
          if (HttpContext.Request.HttpMethod.ToUpper() == "POST")
          {
            //从请求的数据流中获取请求信息
            using (Stream stream = HttpContext.Request.InputStream)
            {
              byte[] postBytes = new byte[stream.Length];
              stream.Read(postBytes, 0, (int)stream.Length);
              string postString = System.Text.Encoding.UTF8.GetString(postBytes);
              Handle(postString,model);
            }
          }
        }
        catch (Exception ex)
        {
          logger.Error("发生异常,异常信息：" + ex.Message + ex.StackTrace);
        }
      }
    }