Please see my comment to the question, where I explain why it is not valid. If your files are already served up by some HTTP server, you need to access to the file using some client side. Generally, you can only download files. Uploading is only possible if the server supports it; usually it provides some HTML page with a Web form or a special control where the HTTP requests are done using Ajax.
Practically, the difference between HTTP and HTTPS is that you need to pass authentication in the same client's session.
Now, it's not clear if you need some code on server side or on client side; in principle, you can do both. Most usual questions are about the client side. Basically, you can do everything using the class
System.Net.HttpWebRequest
(for both HTTP and HTTPS). Please see:
http://msdn.microsoft.com/en-us/library/system.net.webrequest.aspx[
^],
http://msdn.microsoft.com/en-us/library/system.net.httpwebrequest.aspx[
^].
—SA