clevis/COPYING.openssl

In addition, as a special exception, the copyright holders give
permission to link the code of portions of this program with the
OpenSSL library under certain conditions as described in each
individual source file, and distribute linked combinations
including the two.

You must obey the GNU General Public License in all respects
for all of the code used other than OpenSSL.  If you modify
file(s) with this exception, you may extend this exception to your
version of the file(s), but you are not obligated to do so.  If you
do not wish to do so, delete this exception statement from your
version.  If you delete this exception statement from all source
files in the program, then also delete it here.