Email/First Name and Last Name in ASP.Net Core Controller Side

Question

I am trying to get the E-Mail/First Name and Last Name on the Controller side of ASP.Net Web 

User Name i am getting via 

string UserName = HttpContext.User.Identity.Name;

But i am getting NULL in 

MailId = UserPrincipal.Current.EmailAddress;

FirstName = UserPrincipal.Current.GivenName;

LastName = UserPrincipal.Current.Surname;

Unfortunately our LDAP server is not providing the Mail Address