22

✏️ Editing: cSHAKE256.py

# ===================================================================
#
# Copyright (c) 2021, Legrandin <helderijs@gmail.com>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in
#    the documentation and/or other materials provided with the
#    distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
# ===================================================================

from Crypto.Util._raw_api import c_size_t
from Crypto.Hash.cSHAKE128 import cSHAKE_XOF

def _new(data, custom, function):
    # Use Keccak[512]
    return cSHAKE_XOF(data, custom, 512, function)

def new(data=None, custom=None):
    """Return a fresh instance of a cSHAKE256 object.

Args:
       data (bytes/bytearray/memoryview):
        The very first chunk of the message to hash.
        It is equivalent to an early call to :meth:`update`.
        Optional.
       custom (bytes):
        Optional.
        A customization bytestring (``S`` in SP 800-185).

:Return: A :class:`cSHAKE_XOF` object
    """

# Use Keccak[512]
    return cSHAKE_XOF(data, custom, 512, b'')

MR SKB