I wouldn't even pretend to understand the crypto laws without a good lawyer. There's a lot of detail at this site. My understanding (which may be wrong) is that DES is export controlled from the U.S. but that restriction was relaxed to allow 56-bit exports in 1998 or so. A lot of open source simply says, "I can't possibly get this right, so if you're outside the U.S. figure it out yourself." Unfortunate, but that may be the case here.