/// <summary>
    /// 生成秘钥
    /// </summary>
    /// <param name="timestamp"></param>
    /// <returns></returns>
    public static string CreateToken(DateTime timestamp)
    {
      StringBuilder securityKey = new StringBuilder(MD5Encypt(timestamp.ToString("yyyy")));
      securityKey.Append(MD5Encypt(timestamp.ToString("MM")));
      securityKey.Append(MD5Encypt(timestamp.ToString("dd")));
      securityKey.Append(MD5Encypt(timestamp.ToString("HH")));
      securityKey.Append(MD5Encypt(timestamp.ToString("mm")));
      securityKey.Append(MD5Encypt(timestamp.ToString("ss")));
      return MD5Encypt(securityKey.ToString());
    }

/// <summary>
  /// 授权枚举
  /// </summary>
  public enum AuthCodeEnum
  {
    Public = 1,
    Login = 2
  }

  /// <summary>
  /// 授权过滤器
  /// </summary>
  public class AuthAttribute : ActionFilterAttribute
  {
    /// <summary> 
    /// 权限代码 
    /// </summary> 
    public AuthCodeEnum Code { get; set; }

    /// <summary> 
    /// 验证权限
    /// </summary> 
    /// <param name="filterContext"></param> 
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
      var request = filterContext.HttpContext.Request;
      var session = filterContext.HttpContext.Session;
      //如果存在身份信息 
      if (Common.CurrentUser == null)
      {
        if (Code == AuthCodeEnum.Public)
        {
          return;
        }
        string reqToken = request["Token"];
        string ticket = request["Ticket"];
        Cache cache = HttpContext.Current.Cache;
        //没有获取到Token或者Token验证不通过或者没有取到从P回调的ticket 都进行再次请求P
        TokenModel tokenModel= cache.Get(ConstantHelper.TOKEN_KEY)==null?null:(TokenModel)cache.Get(ConstantHelper.TOKEN_KEY);
        if (string.IsNullOrEmpty(reqToken) || tokenModel == null || tokenModel.Token!= reqToken ||
          string.IsNullOrEmpty(ticket))
        {
          DateTime timestamp = DateTime.Now;
          string returnUrl = request.Url.AbsoluteUri;
          tokenModel = new TokenModel
          {
            TimeStamp = timestamp,
            Token = AuthernUtil.CreateToken(timestamp)
          };
          //Token加入缓存中，设计过期时间为20分钟
          cache.Add(ConstantHelper.TOKEN_KEY, tokenModel, null, DateTime.Now.AddMinutes(20),Cache.NoSlidingExpiration,CacheItemPriority.Default, null);
          filterContext.Result = new ContentResult
          {
            Content = GetAuthernScript(AuthernUtil.GetAutherUrl(tokenModel.Token, timestamp), returnUrl)
          };
          return;
        }
        LoginService service = new LoginService();
        var userinfo = service.GetUserInfo(ticket);
        session[ConstantHelper.USER_SESSION_KEY] = userinfo;
        //验证通过,cache中去掉Token,保证每个token只能使用一次
        cache.Remove(ConstantHelper.TOKEN_KEY);
      }
    }

    /// <summary>
    /// 生成跳转脚本
    /// </summary>
    /// <param name="authernUrl">统一授权地址</param>
    /// <param name="returnUrl">回调地址</param>
    /// <returns></returns>
    private string GetAuthernScript(string authernUrl, string returnUrl)
    {
      StringBuilder sbScript = new StringBuilder();
      sbScript.Append("<script type='text/javascript'>");
      sbScript.AppendFormat("window.location.href='{0}&returnUrl=' + encodeURIComponent('{1}');", authernUrl, returnUrl);
      sbScript.Append("</script>");
      return sbScript.ToString();
    }
  }

[Auth(Code = AuthCodeEnum.Login)]
     public ActionResult Index()
     {
       return View();
    }

/// <summary>
    /// 授权登陆验证
    /// </summary>
    /// <returns></returns>
    [HttpPost]
    public ActionResult PassportVertify()
    {
      var cookie=Request.Cookies[ConstantHelper.USER_COOKIE_KEY];
      if (cookie == null ||string.IsNullOrEmpty(cookie.ToString()))
      {
        return RedirectToAction("Login", new { ReturnUrl = Request["ReturnUrl"] ,Token= Request["Token"] });
      }
      string userinfo = cookie.ToString();
      var success= passportservice.AuthernVertify(Request["Token"], Convert.ToDateTime(Request["TimeStamp"]));
      if (!success)
      {
        return RedirectToAction("Login", new { ReturnUrl = Request["ReturnUrl"], Token = Request["Token"] });
      }
      return Redirect(passportservice.GetReturnUrl(userinfo, Request["Token"],Request["ReturnUrl"]));
    }

/// <summary>
    /// 验证令牌
    /// </summary>
    /// <param name="token">令牌</param>
    /// <param name="timestamp">时间戳</param>
    /// <returns></returns>
    public bool AuthernVertify(string token,DateTime timestamp)
    {
      return AuthernUtil.CreateToken(timestamp) == token;
    }