It's legal to use Brazilian rosewood that was purchased and imported before the 1990 CITES listing.
Brazil put an embargo on the export of rosewood logs in 1969 and later in the early 1990s, Brazilian Rosewood was added to the list of endangered species under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). To obtain Brazilian Rosewood today, it needs to be wood that was both harvested and exported before the ban, or harvested from natural fallen trees. Both require documentation of its provenance to permit exporting today.
The only legal source of new Brazilian Rosewood consists of the pre-convention stumps of trees cut before 1991, widely scattered over the Brazilian countryside in the Dalbergia Nigra eco-zone.
The USDA inspects and certifies all shipments of Brazilian rosewood upon entry into the U.S.A.
more info at
http://www.acousticmusic.org/CITES-and-ESA-sp-78.html and
http://www.hanoverbrazil.com/rosewood-guitars.shtml