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Diffstat (limited to 'frozen_deps/Cryptodome/Hash/KangarooTwelve.py')
| -rw-r--r-- | frozen_deps/Cryptodome/Hash/KangarooTwelve.py | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/frozen_deps/Cryptodome/Hash/KangarooTwelve.py b/frozen_deps/Cryptodome/Hash/KangarooTwelve.py new file mode 100644 index 0000000..60ced57 --- /dev/null +++ b/frozen_deps/Cryptodome/Hash/KangarooTwelve.py @@ -0,0 +1,222 @@ +# =================================================================== +# +# 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 Cryptodome.Util.number import long_to_bytes +from Cryptodome.Util.py3compat import bchr + +from . import TurboSHAKE128 + +def _length_encode(x): + if x == 0: + return b'\x00' + + S = long_to_bytes(x) + return S + bchr(len(S)) + + +# Possible states for a KangarooTwelve instance, which depend on the amount of data processed so far. +SHORT_MSG = 1 # Still within the first 8192 bytes, but it is not certain we will exceed them. +LONG_MSG_S0 = 2 # Still within the first 8192 bytes, and it is certain we will exceed them. +LONG_MSG_SX = 3 # Beyond the first 8192 bytes. +SQUEEZING = 4 # No more data to process. + + +class K12_XOF(object): + """A KangarooTwelve hash object. + Do not instantiate directly. + Use the :func:`new` function. + """ + + def __init__(self, data, custom): + + if custom == None: + custom = b'' + + self._custom = custom + _length_encode(len(custom)) + self._state = SHORT_MSG + self._padding = None # Final padding is only decided in read() + + # Internal hash that consumes FinalNode + # The real domain separation byte will be known before squeezing + self._hash1 = TurboSHAKE128.new(domain=1) + self._length1 = 0 + + # Internal hash that produces CV_i (reset each time) + self._hash2 = None + self._length2 = 0 + + # Incremented by one for each 8192-byte block + self._ctr = 0 + + if data: + self.update(data) + + def update(self, data): + """Hash the next piece of data. + + .. note:: + For better performance, submit chunks with a length multiple of 8192 bytes. + + Args: + data (byte string/byte array/memoryview): The next chunk of the + message to hash. + """ + + if self._state == SQUEEZING: + raise TypeError("You cannot call 'update' after the first 'read'") + + if self._state == SHORT_MSG: + next_length = self._length1 + len(data) + + if next_length + len(self._custom) <= 8192: + self._length1 = next_length + self._hash1.update(data) + return self + + # Switch to tree hashing + self._state = LONG_MSG_S0 + + if self._state == LONG_MSG_S0: + data_mem = memoryview(data) + assert(self._length1 < 8192) + dtc = min(len(data), 8192 - self._length1) + self._hash1.update(data_mem[:dtc]) + self._length1 += dtc + + if self._length1 < 8192: + return self + + # Finish hashing S_0 and start S_1 + assert(self._length1 == 8192) + + divider = b'\x03' + b'\x00' * 7 + self._hash1.update(divider) + self._length1 += 8 + + self._hash2 = TurboSHAKE128.new(domain=0x0B) + self._length2 = 0 + self._ctr = 1 + + self._state = LONG_MSG_SX + return self.update(data_mem[dtc:]) + + # LONG_MSG_SX + assert(self._state == LONG_MSG_SX) + index = 0 + len_data = len(data) + + # All iteractions could actually run in parallel + data_mem = memoryview(data) + while index < len_data: + + new_index = min(index + 8192 - self._length2, len_data) + self._hash2.update(data_mem[index:new_index]) + self._length2 += new_index - index + index = new_index + + if self._length2 == 8192: + cv_i = self._hash2.read(32) + self._hash1.update(cv_i) + self._length1 += 32 + self._hash2._reset() + self._length2 = 0 + self._ctr += 1 + + return self + + def read(self, length): + """ + Produce more bytes of the digest. + + .. 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 + """ + + custom_was_consumed = False + + if self._state == SHORT_MSG: + self._hash1.update(self._custom) + self._padding = 0x07 + self._state = SQUEEZING + + if self._state == LONG_MSG_S0: + self.update(self._custom) + custom_was_consumed = True + assert(self._state == LONG_MSG_SX) + + if self._state == LONG_MSG_SX: + if not custom_was_consumed: + self.update(self._custom) + + # Is there still some leftover data in hash2? + if self._length2 > 0: + cv_i = self._hash2.read(32) + self._hash1.update(cv_i) + self._length1 += 32 + self._hash2._reset() + self._length2 = 0 + self._ctr += 1 + + trailer = _length_encode(self._ctr - 1) + b'\xFF\xFF' + self._hash1.update(trailer) + + self._padding = 0x06 + self._state = SQUEEZING + + self._hash1._domain = self._padding + return self._hash1.read(length) + + def new(self, data=None, custom=b''): + return type(self)(data, custom) + + +def new(data=None, custom=None): + """Return a fresh instance of a KangarooTwelve 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 byte string. + + :Return: A :class:`K12_XOF` object + """ + + return K12_XOF(data, custom) |