Trouble retaining CustomPrincipal type in HttpContext - asp.net-mvc

Question

I have an MVC app which I'm having trouble ex[posing a custom principal to my views. It has the following classes that help me manage auth cookies.
public class AuthenticationManager
{
public void SetAuthCookie(UserViewModel user)
{
var serializeModel = new CustomPrincipalSerializeModel
{
Id = user.UserId,
Email = user.Email,
Name = user.Name
};
var serializer = new JavaScriptSerializer();
var customPrincipal = customPrincipalMapper.Convert(serializeModel);
var httpContext = ContextHelper.GetHttpContextBase();
httpContext.User = customPrincipal;
var userData = serializer.Serialize(serializeModel);
var authTicket = new FormsAuthenticationTicket(1, serializeModel.Email, DateTime.Now, DateTime.Now.AddYears(5), false, userData);
var encTicket = FormsAuthentication.Encrypt(authTicket);
var authCookie = new HttpCookie(FormsAuthentication.FormsCookieName, encTicket);
httpContext.Response.Cookies.Add(authCookie);
}
}
public static class ContextHelper
{
public static HttpContextBase GetHttpContextBase()
{
return new HttpContextWrapper(HttpContext.Current);
}
}
I also have the following BaseViewPage classes which allow me to expose the current user to my views:
public abstract class BaseViewPage : WebViewPage
{
public virtual new CustomPrincipal User
{
get { return base.User as CustomPrincipal; }
}
}
public abstract class BaseViewPage<TModel> : WebViewPage<TModel>
{
public virtual new CustomPrincipal User
{
get { return base.User as CustomPrincipal; }
}
}
FWIW, this requires <pages pageBaseType="Giftster.Web.Views.BaseViewPage"> to be in my View's Web.config file.
Immediately, after the httpContext.User = customPrincipal; line runs in AuthenticationManager.SetAuthCookie(), the type of object which ContextHelper.GetHttpContextBase().User returns is a CustomPrincipal. If I refresh the page, however, and put a break point in BaseViewPage, base.User as CustomPrincipal (and ContextHelper.GetHttpContextBase().User as CustomPrincipal for that matter) equals null. base.User is not null, though: It is of type GenericPrincipal, so there is either a casting issue or a problem with storing/retrieving the correct type.
Why is base.User in my BaseViewPage not of type CustomPrincipal?
Thanks in advance.

Answer 1

You need to create your CustomPrincipal from the cookie in each request and add it to the current context. Add the following to the Global.asax.cs file
protected void Application_PostAuthenticateRequest(object sender, EventArgs e)
{
// Get the authentication cookie
HttpCookie authCookie = Request.Cookies[FormsAuthentication.FormsCookieName];
// If the cookie can't be found, don't issue the ticket
if (authCookie == null)
{
return;
}
// Extract the forms authentication cookie
FormsAuthenticationTicket authTicket = FormsAuthentication.Decrypt(authCookie.Value);
// Deserialise user data
JavaScriptSerializer serializer = new JavaScriptSerializer();
CustomPrincipalSerializeModel data = serializer.Deserialize<CustomPrincipalSerializeModel>(authTicket.UserData);
// Create principal
CustomPrincipal principal = new CustomPrincipal(authTicket.Name);
// Set the properties of CustomPrincipal
principal.Email = data.Email;
.... // etc
// Assign to current context
HttpContext.Current.User = principal;
}
Note also the following line is not required in you SetAuthCookie() method
httpContext.User = customPrincipal;
You might also consider adding the following to a BaseController (from which all other controllers derive) so the CustomPrincipal properties can be accessed easily in each controller method
public new CustomPrincipalSerializeModel User
{
get { return (CustomPrincipal)HttpContext.User; }
}