To my knowledge, the core in no way supports SSL. There are two 3rd party solutions for SSL you can buy that I know about:
SSL Module 3.2 from Thomas Thorpe (http://www.snowcovered.com/snowcovered2/Default.aspx?tabid=166&CatalogItemID=1505&CatalogID=7&search=SSL&pagenumber=0&sortby=&tagid=-1)
SSL Redirect 1.0 from Sanibel Logic LLC (http://www.snowcovered.com/snowcovered2/Default.aspx?tabid=166&CatalogItemID=3155&CatalogID=7&search=SSL&pagenumber=0&sortby=&tagid=-1)
I currently use the first one and it does the job. I am using version 3.1 of it, and I have experienced some issues with it around the setting of the redirects it lets you configure. But, if you don't touch that, and just use a basic configuration, it works. Also be cautious that it says it supports a shared SSL certificate environment (like a common SSL cert you get in a basic shared hosting account), which it does, but it will only support this for a single portal because it forces you to add that shared SSL domain in as a portal alias. Because portal aliases are unique, you can only set it up for a single portal, not all portals on your host. It looks like he is up to version 3.2 now, so these things may have changed.
I have not used the second module. It looks like it takes a little different approach from the first and allows you to setup general SSL rules for all portals on a host, instead of configuring each portal specifically.
Both I believe require you to make a change to your web.config to add an additional httpModule. They do this to intercept web requests to pages, and if it decides it is a page you have said you want to be secure, it then redirects to the same page with the https prefix and vice versa before any content is sent to the user . I don't think this is the ideal solution because of the multiple server hits involved, but it works.