The main drawback of this ( and it's a minor drawback in the larger scheme of things ) is that this isn't a portable interface and isn't available on other POSI

The main drawback of this ( and it's a minor drawback in the larger scheme of things ) is that this isn't a portable interface and isn't available on other POSIX-ish OS's. It looks like there are key agents available for Freebsd, OS X and Illumos though. Thanks for pointing this out.