Question

I’m trying to build a web application that uses an SSL connection. So I did some research and found out that I could use the RequireHttpsAttribute class to achieve what I needed. Thing is that when I use it, the execution of the application results in an 310 error(too many redirections). I even built a custom class to handle the switch from http to https. But that too results in an error.

My Class to handle te protocol switch:

Public Class RequireSSLAttribute
    Inherits ActionFilterAttribute

    Public Property IsRequired() As Boolean

    Public Overrides Sub OnActionExecuting(filterContext As ActionExecutingContext)
        If Me.IsRequired AndAlso filterContext.HttpContext.Request.Url.Scheme <> "https" Then
            filterContext.HttpContext.Response.Redirect(filterContext.HttpContext.Request.Url.OriginalString.Replace("http:", "https:").Remove(filterContext.HttpContext.Request.Url.OriginalString.LastIndexOf(":") + 1), True)
            filterContext.Result = New HttpUnauthorizedResult
        End If
    End Sub

    Public Sub New()
        IsRequired = True
    End Sub
End Class

Answer 1

I don’t know who your host is, but I just ran into a similar problem on AppHarbor and discovered this in their knowledge base:

If you’re using the built-in RequireHttpsAttribute to ensure that a
controller action always uses HTTPS you will experience a redirect
loop. The reason is that SSL is terminated at the load balancer level
and RequireHttps doesn’t recognize the X-Forwarded-Proto header it
uses to indicate that the request was made using HTTPS. You should
therefore use a custom RequireHttps attribute for this purpose.

They have also provided an example solution on Github here, which I will copy below for convenience:

using System;
using System.Web.Mvc;
using RequireHttpsAttributeBase = System.Web.Mvc.RequireHttpsAttribute;

namespace AppHarbor.Web
{
    [AttributeUsage(
        AttributeTargets.Class | AttributeTargets.Method,
        Inherited = true,
        AllowMultiple = false)]
    public class RequireHttpsAttribute : RequireHttpsAttributeBase
    {
        public override void OnAuthorization(AuthorizationContext filterContext)
        {
            if (filterContext == null)
            {
                throw new ArgumentNullException("filterContext");
            }

            if (filterContext.HttpContext.Request.IsSecureConnection)
            {
                return;
            }

            if (string.Equals(filterContext.HttpContext.Request.Headers["X-Forwarded-Proto"],
                "https",
                StringComparison.InvariantCultureIgnoreCase))
            {
                return;
            }

            if (filterContext.HttpContext.Request.IsLocal)
            {
                return;
            }

            HandleNonHttpsRequest(filterContext);
        }
    }
}

I’m not sure if this will solve your problem; but perhaps even if you aren’t using AppHarbor the root cause may be the same for you, in which case the above seems worth a shot.