In IIS SSL sites have seemed to be limited to only one site per network interface, since you (from IIS Manager) cannot specify a host header binding on the HTTPS protocol.

It turns out, that it is only a limitation in the UI. So to have e.g. two sites with their own dedicated SSL certificate we need to add a host header binding on port 443 from either appcmd, managed code or by editing the applicationHosts.config file.

I like managed code the most, so I’ve written a small method in C# that does the trick. You need to have two SSL certificates named www.ssl1.com and www.ssl2.com installed on the machine. I just created a self signed certificate for both of them using the IIS Manager.

using System.Security.Cryptography.X509Certificates;
using Microsoft.Web.Administration;

namespace IisSsl
{
    class Program
    {
        static void Main(string[] args)
        {
            using (ServerManager _serverManager = new ServerManager())
            {
                string siteName = "SSL2";
                string certName = "www.ssl2.com";

                X509Store store = new X509Store(StoreName.My, StoreLocation.LocalMachine);
                store.Open(OpenFlags.ReadOnly);

                X509Certificate2 certificate = store.Certificates[0];

                Site site = _serverManager.Sites[siteName];

                if (site != null)
                {
                    site.Bindings.Add("*:443:" + certName,
                        certificate.GetCertHash(), store.Name);
                }
                store.Close();

                _serverManager.CommitChanges();
            }
        }
    }
}

Remember to add a reference to C:\Windows\System32\inetsrv\Microsoft.Web.Administration.dll in order to use the ServerManager class.