# =================================================================== # # 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)