# -*- coding: utf-8 -*-
# _scrypt.py
# Copyright (C) 2017 LEAP Encryption Access Project
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

from cryptography.hazmat.backends.interfaces import ScryptBackend
from cryptography.hazmat.backends import default_backend

backend = default_backend()
OPENSSL_HAS_SCRYPT = isinstance(backend, ScryptBackend)

if OPENSSL_HAS_SCRYPT:
    from cryptography.hazmat.primitives.kdf.scrypt import Scrypt

    def hash(secret, salt, buflen=32):
        return Scrypt(salt, buflen, 16384, 8, 1, backend).derive(secret)
else:
    import scrypt

    def hash(secret, salt, buflen=32):
        return scrypt.hash(secret, salt, buflen=buflen)