Not an easy answer to find, however, AutoIT is capable of allowing secure HTTP, FTP, or HTTPS downloads using a script. The following script worked for me.

#include

;Sample script to download registered files from HTTP source.
;Internet Explorer used to offer the ability via http://username:password@www.myfavoratewebsite.com
InetGet("http://username:password@www.myfavoratewebsite.com/downloadme.exe", "downloadme.exe", 1)

;note: That there is no progressbar to indicate download.
;note: This script will download the executable to the same folder as the script.