slight update

env/lib/python3.12/site-packages/Crypto/Hash/SHAKE128.py

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+# ===================================================================
+#
+# Copyright (c) 2015, 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 bord
+
+from Crypto.Util._raw_api import (load_pycryptodome_raw_lib,
+                                  VoidPointer, SmartPointer,
+                                  create_string_buffer,
+                                  get_raw_buffer, c_size_t,
+                                  c_uint8_ptr, c_ubyte)
+
+from Crypto.Hash.keccak import _raw_keccak_lib
+
+class SHAKE128_XOF(object):
+    """A SHAKE128 hash object.
+    Do not instantiate directly.
+    Use the :func:`new` function.
+
+    :ivar oid: ASN.1 Object ID
+    :vartype oid: string
+    """
+
+    # ASN.1 Object ID
+    oid = "2.16.840.1.101.3.4.2.11"
+
+    def __init__(self, data=None):
+        state = VoidPointer()
+        result = _raw_keccak_lib.keccak_init(state.address_of(),
+                                             c_size_t(32),
+                                             c_ubyte(24))
+        if result:
+            raise ValueError("Error %d while instantiating SHAKE128"
+                             % result)
+        self._state = SmartPointer(state.get(),
+                                   _raw_keccak_lib.keccak_destroy)
+        self._is_squeezing = False
+        self._padding = 0x1F
+        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 SHAKE128 state"
+                             % result)
+        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 SHAKE128"
+                             % result)
+
+        return get_raw_buffer(bfr)
+
+    def new(self, data=None):
+        return type(self)(data=data)
+
+
+def new(data=None):
+    """Return a fresh instance of a SHAKE128 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.
+
+    :Return: A :class:`SHAKE128_XOF` object
+    """
+
+    return SHAKE128_XOF(data=data)