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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 tls.Crypto.Util.py3compat import bord
- from tls.Crypto.Util._raw_api import (load_pycryptodome_raw_lib,
- VoidPointer, SmartPointer,
- create_string_buffer,
- get_raw_buffer, c_size_t,
- c_uint8_ptr)
- _raw_keccak_lib = load_pycryptodome_raw_lib("Crypto.Hash._keccak",
- """
- int keccak_init(void **state,
- size_t capacity_bytes,
- uint8_t padding_byte);
- int keccak_destroy(void *state);
- int keccak_absorb(void *state,
- const uint8_t *in,
- size_t len);
- int keccak_squeeze(const void *state,
- uint8_t *out,
- size_t len);
- int keccak_digest(void *state, uint8_t *digest, size_t len);
- """)
- class Keccak_Hash(object):
- """A Keccak hash object.
- Do not instantiate directly.
- Use the :func:`new` function.
- :ivar digest_size: the size in bytes of the resulting hash
- :vartype digest_size: integer
- """
- def __init__(self, data, digest_bytes, update_after_digest):
- # The size of the resulting hash in bytes.
- self.digest_size = digest_bytes
- self._update_after_digest = update_after_digest
- self._digest_done = False
- state = VoidPointer()
- result = _raw_keccak_lib.keccak_init(state.address_of(),
- c_size_t(self.digest_size * 2),
- 0x01)
- if result:
- raise ValueError("Error %d while instantiating keccak" % result)
- self._state = SmartPointer(state.get(),
- _raw_keccak_lib.keccak_destroy)
- 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._digest_done and not self._update_after_digest:
- raise TypeError("You can only call 'digest' or 'hexdigest' on this object")
- 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 keccak" % result)
- return self
- def digest(self):
- """Return the **binary** (non-printable) digest of the message that has been hashed so far.
- :return: The hash digest, computed over the data processed so far.
- Binary form.
- :rtype: byte string
- """
- self._digest_done = True
- bfr = create_string_buffer(self.digest_size)
- result = _raw_keccak_lib.keccak_digest(self._state.get(),
- bfr,
- c_size_t(self.digest_size))
- if result:
- raise ValueError("Error %d while squeezing keccak" % result)
- return get_raw_buffer(bfr)
- def hexdigest(self):
- """Return the **printable** digest of the message that has been hashed so far.
- :return: The hash digest, computed over the data processed so far.
- Hexadecimal encoded.
- :rtype: string
- """
- return "".join(["%02x" % bord(x) for x in self.digest()])
- def new(self, **kwargs):
- """Create a fresh Keccak hash object."""
- if "digest_bytes" not in kwargs and "digest_bits" not in kwargs:
- kwargs["digest_bytes"] = self.digest_size
- return new(**kwargs)
- def new(**kwargs):
- """Create a new hash object.
- Args:
- data (bytes/bytearray/memoryview):
- The very first chunk of the message to hash.
- It is equivalent to an early call to :meth:`Keccak_Hash.update`.
- digest_bytes (integer):
- The size of the digest, in bytes (28, 32, 48, 64).
- digest_bits (integer):
- The size of the digest, in bits (224, 256, 384, 512).
- update_after_digest (boolean):
- Whether :meth:`Keccak.digest` can be followed by another
- :meth:`Keccak.update` (default: ``False``).
- :Return: A :class:`Keccak_Hash` hash object
- """
- data = kwargs.pop("data", None)
- update_after_digest = kwargs.pop("update_after_digest", False)
- digest_bytes = kwargs.pop("digest_bytes", None)
- digest_bits = kwargs.pop("digest_bits", None)
- if None not in (digest_bytes, digest_bits):
- raise TypeError("Only one digest parameter must be provided")
- if (None, None) == (digest_bytes, digest_bits):
- raise TypeError("Digest size (bits, bytes) not provided")
- if digest_bytes is not None:
- if digest_bytes not in (28, 32, 48, 64):
- raise ValueError("'digest_bytes' must be: 28, 32, 48 or 64")
- else:
- if digest_bits not in (224, 256, 384, 512):
- raise ValueError("'digest_bytes' must be: 224, 256, 384 or 512")
- digest_bytes = digest_bits // 8
- if kwargs:
- raise TypeError("Unknown parameters: " + str(kwargs))
- return Keccak_Hash(data, digest_bytes, update_after_digest)
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