Quick Link Provider I wrote to deliver HTTPS links. Sample code for my comment on [SSL Link Provider](http://marketplace.sitecore.net/en/Modules/SSL_Link_Provider.aspx) on the Sitecore Marketplace. Running Sitecore version 6.5.

SecureLinkProvider.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Change.This.To.Suit.Your.Application
{
    class SecureLinkProvider : Sitecore.Links.LinkProvider
    {

        public string SSLRequiredValue { get; set; }
        public string AgnosticValue { get; set; }
        public string SSLRequiredValue { get; set; }

        public override string GetItemUrl(Sitecore.Data.Items.Item item, Sitecore.Links.UrlOptions options)
        {
            string requireSSL  = item.Fields["Require SSL"];
            if (!requireSSL.IsNullOrEmpty() && requireSSL == "Require SSL")
            {
                options.AlwaysIncludeServerUrl = true;
                string baseUrl = base.GetItemUrl(item, options);
                UriBuilder urlBuilder = new UriBuilder(baseUrl);
                urlBuilder.Scheme = "https";
                urlBuilder.Port = -1; // removes port from the URL so the default for the scheme is used
                return urlBuilder.ToString();
            }
            else
            {
                return base.GetItemUrl(item, options);
            }

        }
    }
}

If you're using something like this let me also recommend that you use the Robots element to tell search engines to INDEX but NO FOLLOW the links on your HTTPS pages if your main site is in HTTP. This will help avoid duplicate content issues.