Prevent multiple logins

Question

I am trying to block multiple logins with the same user in my application.
My idea is to update the security stamp when user signin and add that as a Claim, then in eve

Answer 1

In the past I've used IAuthorizationFilter and static logged-in user collection to achieve this:

public static class WebAppData
{
     public static ConcurrentDictionary Users = new ConcurrentDictionary();
}

public class AuthorisationAttribute : FilterAttribute, IAuthorizationFilter {

    public void OnAuthorization(AuthorizationContext filterContext){

            ...
            Handle claims authentication
            ...

            AppUser id = WebAppData.Users.Where(u=>u.Key ==userName).Select(u=>u.Value).FirstOrDefault();
            if (id == null){
                id = new AppUser {...} ;
                id.SessionId = filterContext.HttpContext.Session.SessionID;
                WebAppData.Users.TryAdd(userName, id);
            }
            else
            {
                if (id.SessionId != filterContext.HttpContext.Session.SessionID)
                {
                        FormsAuthentication.SignOut();
                        ...
                        return appropriate error response depending is it ajax request or not
                        ...


                }
            } 
     }
}

On logout:

WebAppData.Users.TryRemove(userName, out user)