v0.1.7

author: Determinant <[email protected]> 2022-11-17 18:08:59 -0800
committer: Determinant <[email protected]> 2022-11-17 18:08:59 -0800
commit: 8154806fe2fccacdc3dafaa68181a07bcf8d6c4c (patch)
tree: f477e6a005599bb88c18db142c267b9297c6060b /frozen_deps/Cryptodome/Hash/cSHAKE128.py
parent: be4dc086591c9bced04a507d127c83811c5700c4 (diff)
1 files changed, 187 insertions, 0 deletions
diff --git a/frozen_deps/Cryptodome/Hash/cSHAKE128.py b/frozen_deps/Cryptodome/Hash/cSHAKE128.py
new file mode 100644
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+++ b/frozen_deps/Cryptodome/Hash/cSHAKE128.py
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+# ===================================================================
+#
+# Copyright (c) 2021, Legrandin <[email protected]>
+# 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 Cryptodome.Util.py3compat import bchr
+
+from Cryptodome.Util._raw_api import (VoidPointer, SmartPointer,
+ create_string_buffer,
+ get_raw_buffer, c_size_t,
+ c_uint8_ptr, c_ubyte)
+
+from Cryptodome.Util.number import long_to_bytes
+
+from Cryptodome.Hash.keccak import _raw_keccak_lib
+
+
+def _left_encode(x):
+ """Left encode function as defined in NIST SP 800-185"""
+
+ assert (x < (1 << 2040) and x >= 0)
+
+ # Get number of bytes needed to represent this integer.
+ num = 1 if x == 0 else (x.bit_length() + 7) // 8
+
+ return bchr(num) + long_to_bytes(x)
+
+
+def _right_encode(x):
+ """Right encode function as defined in NIST SP 800-185"""
+
+ assert (x < (1 << 2040) and x >= 0)
+
+ # Get number of bytes needed to represent this integer.
+ num = 1 if x == 0 else (x.bit_length() + 7) // 8
+
+ return long_to_bytes(x) + bchr(num)
+
+
+def _encode_str(x):
+ """Encode string function as defined in NIST SP 800-185"""
+
+ bitlen = len(x) * 8
+ if bitlen >= (1 << 2040):
+ raise ValueError("String too large to encode in cSHAKE")
+
+ return _left_encode(bitlen) + x
+
+
+def _bytepad(x, length):
+ """Zero pad byte string as defined in NIST SP 800-185"""
+
+ to_pad = _left_encode(length) + x
+
+ # Note: this implementation works with byte aligned strings,
+ # hence no additional bit padding is needed at this point.
+ npad = (length - len(to_pad) % length) % length
+
+ return to_pad + b'\x00' * npad
+
+
+class cSHAKE_XOF(object):
+ """A cSHAKE hash object.
+ Do not instantiate directly.
+ Use the :func:`new` function.
+ """
+
+ def __init__(self, data, custom, capacity, function):
+ state = VoidPointer()
+
+ if custom or function:
+ prefix_unpad = _encode_str(function) + _encode_str(custom)
+ prefix = _bytepad(prefix_unpad, (1600 - capacity)//8)
+ self._padding = 0x04
+ else:
+ prefix = None
+ self._padding = 0x1F # for SHAKE
+
+ result = _raw_keccak_lib.keccak_init(state.address_of(),
+ c_size_t(capacity//8),
+ c_ubyte(24))
+ if result:
+ raise ValueError("Error %d while instantiating cSHAKE"
+ % result)
+ self._state = SmartPointer(state.get(),
+ _raw_keccak_lib.keccak_destroy)
+ self._is_squeezing = False
+
+ if prefix:
+ self.update(prefix)
+
+ if data:
+ self.update(data)
+
+ def update(self, data):
+ """Continue hashing of a message by consuming the next chunk of data.
+
+ Args:
+ data (byte string/byte array/memoryview): The next chunk of the message being hashed.
+ """
+
+ if self._is_squeezing:
+ raise TypeError("You cannot call 'update' after the first 'read'")
+
+ result = _raw_keccak_lib.keccak_absorb(self._state.get(),
+ c_uint8_ptr(data),
+ c_size_t(len(data)))
+ if result:
+ raise ValueError("Error %d while updating %s state"
+ % (result, self.name))
+ return self
+
+ def read(self, length):
+ """
+ Compute the next piece of XOF output.
+
+ .. note::
+ You cannot use :meth:`update` anymore after the first call to
+ :meth:`read`.
+
+ Args:
+ length (integer): the amount of bytes this method must return
+
+ :return: the next piece of XOF output (of the given length)
+ :rtype: byte string
+ """
+
+ self._is_squeezing = True
+ bfr = create_string_buffer(length)
+ result = _raw_keccak_lib.keccak_squeeze(self._state.get(),
+ bfr,
+ c_size_t(length),
+ c_ubyte(self._padding))
+ if result:
+ raise ValueError("Error %d while extracting from %s"
+ % (result, self.name))
+
+ return get_raw_buffer(bfr)
+
+
+def _new(data, custom, function):
+ # Use Keccak[256]
+ return cSHAKE_XOF(data, custom, 256, function)
+
+
+def new(data=None, custom=None):
+ """Return a fresh instance of a cSHAKE128 object.
+
+ Args:
+ data (bytes/bytearray/memoryview):
+ Optional.
+ The very first chunk of the message to hash.
+ It is equivalent to an early call to :meth:`update`.
+ custom (bytes):
+ Optional.
+ A customization bytestring (``S`` in SP 800-185).
+
+ :Return: A :class:`cSHAKE_XOF` object
+ """
+
+ # Use Keccak[256]
+ return cSHAKE_XOF(data, custom, 256, b'')
author	Determinant <[email protected]>	2022-11-17 18:08:59 -0800
committer	Determinant <[email protected]>	2022-11-17 18:08:59 -0800
commit	8154806fe2fccacdc3dafaa68181a07bcf8d6c4c (patch)
tree	f477e6a005599bb88c18db142c267b9297c6060b /frozen_deps/Cryptodome/Hash/cSHAKE128.py
parent	be4dc086591c9bced04a507d127c83811c5700c4 (diff)