hi nettle folks--
The list of language bindings at:
http://www.lysator.liu.se/~nisse/nettle/
doesn't mention haskell yet, but Clint Adams' nettle bindings for that language are available here:
http://hackage.haskell.org/package/bindings-nettle
They're not exhaustive, but probably worth pointing to.
Thanks for nettle!
--dkg