Sam Hassani over at Brightstarr put together a couple of great articles on Exposing SharePoint over the internet through Web Access proxy (WAP) , a feature of Windows Server 2012R2.
These articles talk about WAP as a nice alternative to UAG and TMG (two security products Microsoft used to sell, but has since retired) I haven’t followed the steps yet, but it looks like it might be a suitable fill in for CA Siteminder in some cases as well.
The best part of the above articles, in my opinion, is that they really make this stuff look easy and accessible – I can’t wait to try this out!