Actually it's perfectly legal in Cuba itself, but it's other countries that do not allow such cryptographic code to be released to "these" countries.

The Netherlands is not one of "these" though, so I don't think you can get into legal problems here. Since your website is one on a American server it would be wise to be cautious with it (or host these files on a Dutch server).

If you want to be on the safe side legally, just make sure people visiting your site must sign an extra license which states that people from countries in which it's not legal to download these cryptography related codes are not allowed to download this from your site.

It's a bit odd though, because anyone can download that open source project... not just from your site if you choose to use it, it's all over the net,

Cheers