NullReferenceException in Microsoft.Web.Administration when adding https binding

Question

I\'m trying to programmatically add a binding to my default website however I am consistently getting a null reference exception within the Microsoft.Web.Administration dll.

Answer 1

So I found the answer by decompiling the Microsoft.Web.Administration dll and poking through the stack. It turns out that if you get a Site with a helper function it doesn't set the internal ServerManager property on the site.

The function the dll that caused the issue was this in Microsoft.Web.Administration::Configuration

internal void SetDirty()
{
  if (this._hasBeenCommitted || this._configurationManager.Owner.ReadOnly)
    throw new InvalidOperationException(Resources.ObjectHasBeenCommited);
  this._isDirty = true;
}

The only thing that could have been null here was either _configurationManager or _configurationManager.Owner. I checked what Owner was and it was a ServerManager which tipped me off that I should probably query the Site from within a using block of server manager. Once I did that the null ref went away and everything worked. It's unfortunate that they aren't checking for null's but maybe the assumption is nobody would ever act on a site object without the server manager context.

Anyways, here is the updated code:

class Program
{
    static void Main(string[] args)
    {

        using (var serverManager = new ServerManager())
        {
            var selfSignedCnName = "TEST_SELF_SIGNED";
            var websiteName = "Default Web Site";

            var site = serverManager.Sites.Where(p => p.Name.ToLower() == websiteName.ToLower()).FirstOrDefault(); 
            var store = new X509Store(StoreName.Root, StoreLocation.LocalMachine);
            store.Open(OpenFlags.OpenExistingOnly | OpenFlags.ReadWrite);

            var certificate = store.Certificates.Find(X509FindType.FindByIssuerName, selfSignedCnName, true).OfType().FirstOrDefault();

            site.Bindings.Add("*:443:", certificate.GetCertHash(), store.Name);

            store.Close();

            serverManager.CommitChanges();
        }
    }

}

It's also clear from my initial post that wrapping the entire code block in a server manager doesn't mean anything, they aren't cascaded. You have to act on the site from the server manager it came from.