tuxbot-bot/venv/lib/python3.7/site-packages/nacl/bindings/crypto_generichash.py
2019-12-16 18:12:10 +01:00

216 lines
7.8 KiB
Python

# Copyright 2013 Donald Stufft and individual contributors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import absolute_import, division, print_function
from six import integer_types
from nacl import exceptions as exc
from nacl._sodium import ffi, lib
from nacl.exceptions import ensure
crypto_generichash_BYTES = lib.crypto_generichash_blake2b_bytes()
crypto_generichash_BYTES_MIN = lib.crypto_generichash_blake2b_bytes_min()
crypto_generichash_BYTES_MAX = lib.crypto_generichash_blake2b_bytes_max()
crypto_generichash_KEYBYTES = lib.crypto_generichash_blake2b_keybytes()
crypto_generichash_KEYBYTES_MIN = lib.crypto_generichash_blake2b_keybytes_min()
crypto_generichash_KEYBYTES_MAX = lib.crypto_generichash_blake2b_keybytes_max()
crypto_generichash_SALTBYTES = lib.crypto_generichash_blake2b_saltbytes()
crypto_generichash_PERSONALBYTES = \
lib.crypto_generichash_blake2b_personalbytes()
crypto_generichash_STATEBYTES = lib.crypto_generichash_statebytes()
_OVERLONG = '{0} length greater than {1} bytes'
_TOOBIG = '{0} greater than {1}'
def _checkparams(digest_size, key, salt, person):
"""Check hash paramters"""
ensure(isinstance(key, bytes),
'Key must be a bytes sequence',
raising=exc.TypeError)
ensure(isinstance(salt, bytes),
'Salt must be a bytes sequence',
raising=exc.TypeError)
ensure(isinstance(person, bytes),
'Person must be a bytes sequence',
raising=exc.TypeError)
ensure(isinstance(digest_size, integer_types),
'Digest size must be an integer number',
raising=exc.TypeError)
ensure(digest_size <= crypto_generichash_BYTES_MAX,
_TOOBIG.format("Digest_size", crypto_generichash_BYTES_MAX),
raising=exc.ValueError)
ensure(len(key) <= crypto_generichash_KEYBYTES_MAX,
_OVERLONG.format("Key", crypto_generichash_KEYBYTES_MAX),
raising=exc.ValueError)
ensure(len(salt) <= crypto_generichash_SALTBYTES,
_OVERLONG.format("Salt", crypto_generichash_SALTBYTES),
raising=exc.ValueError)
ensure(len(person) <= crypto_generichash_PERSONALBYTES,
_OVERLONG.format("Person", crypto_generichash_PERSONALBYTES),
raising=exc.ValueError)
def generichash_blake2b_salt_personal(data,
digest_size=crypto_generichash_BYTES,
key=b'', salt=b'', person=b''):
"""One shot hash interface
:param data: the input data to the hash function
:param digest_size: must be at most
:py:data:`.crypto_generichash_BYTES_MAX`;
the default digest size is
:py:data:`.crypto_generichash_BYTES`
:type digest_size: int
:param key: must be at most
:py:data:`.crypto_generichash_KEYBYTES_MAX` long
:type key: bytes
:param salt: must be at most
:py:data:`.crypto_generichash_SALTBYTES` long;
will be zero-padded if needed
:type salt: bytes
:param person: must be at most
:py:data:`.crypto_generichash_PERSONALBYTES` long:
will be zero-padded if needed
:type person: bytes
:return: digest_size long digest
:rtype: bytes
"""
_checkparams(digest_size, key, salt, person)
ensure(isinstance(data, bytes),
'Input data must be a bytes sequence',
raising=exc.TypeError)
digest = ffi.new("unsigned char[]", digest_size)
# both _salt and _personal must be zero-padded to the correct length
_salt = ffi.new("unsigned char []", crypto_generichash_SALTBYTES)
_person = ffi.new("unsigned char []", crypto_generichash_PERSONALBYTES)
ffi.memmove(_salt, salt, len(salt))
ffi.memmove(_person, person, len(person))
rc = lib.crypto_generichash_blake2b_salt_personal(digest, digest_size,
data, len(data),
key, len(key),
_salt, _person)
ensure(rc == 0, 'Unexpected failure',
raising=exc.RuntimeError)
return ffi.buffer(digest, digest_size)[:]
def generichash_blake2b_init(key=b'', salt=b'',
person=b'',
digest_size=crypto_generichash_BYTES):
"""
Create a new initialized blake2b hash state
:param key: must be at most
:py:data:`.crypto_generichash_KEYBYTES_MAX` long
:type key: bytes
:param salt: must be at most
:py:data:`.crypto_generichash_SALTBYTES` long;
will be zero-padded if needed
:type salt: bytes
:param person: must be at most
:py:data:`.crypto_generichash_PERSONALBYTES` long:
will be zero-padded if needed
:type person: bytes
:param digest_size: must be at most
:py:data:`.crypto_generichash_BYTES_MAX`;
the default digest size is
:py:data:`.crypto_generichash_BYTES`
:type digest_size: int
:return: an initizialized state buffer
:rtype: object
"""
_checkparams(digest_size, key, salt, person)
statebuf = ffi.new("unsigned char[]", crypto_generichash_STATEBYTES)
# both _salt and _personal must be zero-padded to the correct length
_salt = ffi.new("unsigned char []", crypto_generichash_SALTBYTES)
_person = ffi.new("unsigned char []", crypto_generichash_PERSONALBYTES)
ffi.memmove(_salt, salt, len(salt))
ffi.memmove(_person, person, len(person))
rc = lib.crypto_generichash_blake2b_init_salt_personal(statebuf,
key, len(key),
digest_size,
_salt, _person)
ensure(rc == 0, 'Unexpected failure',
raising=exc.RuntimeError)
return statebuf
def generichash_blake2b_update(statebuf, data):
"""Update the blake2b hash state
:param statebuf: an initialized blake2b state buffer as returned from
:py:func:`.crypto_generichash_blake2b_init`
:type statebuf: object
:param data:
:type data: bytes
"""
ensure(isinstance(data, bytes),
'Input data must be a bytes sequence',
raising=exc.TypeError)
rc = lib.crypto_generichash_blake2b_update(statebuf, data, len(data))
ensure(rc == 0, 'Unexpected failure',
raising=exc.RuntimeError)
def generichash_blake2b_final(statebuf, digest_size):
"""Finalize the blake2b hash state and return the digest.
:param statebuf:
:type statebuf: object
:param digest_size:
:type digest_size: int
:return: the blake2 digest of the passed-in data stream
:rtype: bytes
"""
_digest = ffi.new("unsigned char[]", crypto_generichash_BYTES_MAX)
rc = lib.crypto_generichash_blake2b_final(statebuf, _digest, digest_size)
ensure(rc == 0, 'Unexpected failure',
raising=exc.RuntimeError)
return ffi.buffer(_digest, digest_size)[:]
def generichash_blake2b_state_copy(statebuf):
"""Return a copy of the given blake2b hash state"""
newstate = ffi.new("unsigned char[]", crypto_generichash_STATEBYTES)
ffi.memmove(newstate, statebuf, crypto_generichash_STATEBYTES)
return newstate