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- # ===================================================================
- #
- # 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.py3compat import is_bytes
- from .KMAC128 import KMAC_Hash
- from . import cSHAKE256
- def new(**kwargs):
- """Create a new KMAC256 object.
- Args:
- key (bytes/bytearray/memoryview):
- The key to use to compute the MAC.
- It must be at least 256 bits long (32 bytes).
- data (bytes/bytearray/memoryview):
- Optional. The very first chunk of the message to authenticate.
- It is equivalent to an early call to :meth:`KMAC_Hash.update`.
- mac_len (integer):
- Optional. The size of the authentication tag, in bytes.
- Default is 64. Minimum is 8.
- custom (bytes/bytearray/memoryview):
- Optional. A customization byte string (``S`` in SP 800-185).
- Returns:
- A :class:`KMAC_Hash` hash object
- """
- key = kwargs.pop("key", None)
- if not is_bytes(key):
- raise TypeError("You must pass a key to KMAC256")
- if len(key) < 32:
- raise ValueError("The key must be at least 256 bits long (32 bytes)")
- data = kwargs.pop("data", None)
- mac_len = kwargs.pop("mac_len", 64)
- if mac_len < 8:
- raise ValueError("'mac_len' must be 8 bytes or more")
- custom = kwargs.pop("custom", b"")
- if kwargs:
- raise TypeError("Unknown parameters: " + str(kwargs))
- return KMAC_Hash(data, key, mac_len, custom, "20", cSHAKE256, 136)
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