Go to your city or county website and find the municipal code. It should be available online and easily searchable. There will also be a state code somewhere concerning wildlife and exotic animals. These two documents exist for your local area and state and will tell you exactly what you need to know. If you are still concerned, print out the applicable sections of each and keep them with your ASFs, assuming they are not listed as banned animals on either. There is nobody that can tell you yes or no on the legality and this includes any government official... you need to have it in writing directly from the source.
This is the same thing I would do to learn the legal status of anything, including ASFs and other exotic animals, if I was in doubt and wanted to know.
*and of course the sadly necessary disclaimer for something so small... I am not lawyer and am not offering any sort of legal advice.