How to set vaue of attribute samesite on the cookie __RequestVerificationToken_Lw__

Question

I have an antirforgery token(@Html.AntiForgeryToken()) on a cshtml page, which generates a cookie RequestVerificationToken_Lw. The attribute values on this cookie are HTTP and Secure. But I need the SameSite also to be set. How do I achieve this?

@Html.AntiForgeryToken()

__RequestVerificationToken_Lw__

Answer 1

Can this help?

in Global.asax.cs

 public class MvcApplication : System.Web.HttpApplication
 {

        protected void Application_PreSendRequestHeaders(object sender,EventArgs e) {
            // This code will mark the __RequestVerificationToken cookie SameSite=Strict 
            if (Request.Cookies.Count>0) {
                foreach (string s in Request.Cookies.AllKeys) {
                    if (s.ToLower() == "__requestverificationtoken") {
                        HttpCookie c = Request.Cookies[s];
                        c.SameSite = System.Web.SameSiteMode.Strict;
                        Response.Cookies.Set(c);
                    }
                }
            }           
        }
 }