public async Task ValidateAsync(CookieValidatePrincipalContext context) {
string userId = context.Principal.GetUserId();
var principal = await ValidateSecurityStamp(context.Principal, userId);
if (principal != null) {
context.ReplacePrincipal(principal);
context.ShouldRenew = true;
} else {
context.RejectPrincipal();
await context.HttpContext.Authentication.LogOffAsync(Options);
}
}
