Asp.net core 2.0 - cookie authentication

var identity = (ClaimsPrincipal)Thread.CurrentPrincipal;

services.AddAuthentication("TalesSecurityScheme")
                   .AddCookie("TalesSecurityScheme", options =>
                   {
                       options.AccessDeniedPath = new PathString("/Security/Access");
                       options.Cookie = new CookieBuilder
                       {
                           //Domain = "",
                           HttpOnly = true,
                           Name = ".Tales.Security.Cookie",
                           Path = "/",
                           SameSite = SameSiteMode.Lax,
                           SecurePolicy = CookieSecurePolicy.SameAsRequest
                       };

options.LoginPath = new PathString("/Login/StartPage");
                      options.ReturnUrlParameter = "RequestPath";
                      options.SlidingExpiration = true;
                  });

// create claims
          List<Claim> claims = new List<Claim>
          {
              new Claim(ClaimTypes.Name, EncrypterDecrypter.Encrypt(loginEntity.UserName)),
              new Claim(ClaimTypes.Email, EncrypterDecrypter.Encrypt(loginEntity.Email)),
              new Claim(ClaimTypes.Role, loginEntity.Role),
              new Claim(ClaimTypes.Gender, EncrypterDecrypter.Encrypt(loginEntity.Gender)),                 new Claim(ClaimTypes.Sid, EncrypterDecrypter.Encrypt(loginEntity.UserId))
          };

          // create identity
          ClaimsIdentity identity = new ClaimsIdentity(claims, "cookie");


          // create principal
          ClaimsPrincipal principal = new ClaimsPrincipal(identity);

          // Set current principal
          Thread.CurrentPrincipal = principal;
          HttpContext.User = principal;

          // sign-in
          await HttpContext.SignInAsync(
                  scheme: "TalesSecurityScheme",
                  principal: principal,
                  properties: new AuthenticationProperties
                  {
                      //IsPersistent = true,
                      ExpiresUtc = DateTime.UtcNow.AddMinutes(_config.Value.CookieTimeout)
                  });

var identity = (ClaimsPrincipal)Thread.CurrentPrincipal;

          if (identity != null)
          {
              // Get the claims values
              result = identity.Claims.Where(c => c.Type == ClaimTypes.Email)
                             .Select(c => c.Value).SingleOrDefault();
          }

identity