diff options
Diffstat (limited to 'frozen_deps/Cryptodome/Hash/keccak.py')
| -rw-r--r-- | frozen_deps/Cryptodome/Hash/keccak.py | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/frozen_deps/Cryptodome/Hash/keccak.py b/frozen_deps/Cryptodome/Hash/keccak.py new file mode 100644 index 0000000..9ae8ec5 --- /dev/null +++ b/frozen_deps/Cryptodome/Hash/keccak.py @@ -0,0 +1,173 @@ +# =================================================================== +# +# 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 Cryptodome.Util.py3compat import bord + +from Cryptodome.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("Cryptodome.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) |