# Copyright 2016 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
import binascii
import nacl.bindings
from nacl.utils import bytes_as_string
BYTES = nacl.bindings.crypto_generichash_BYTES
BYTES_MIN = nacl.bindings.crypto_generichash_BYTES_MIN
BYTES_MAX = nacl.bindings.crypto_generichash_BYTES_MAX
KEYBYTES = nacl.bindings.crypto_generichash_KEYBYTES
KEYBYTES_MIN = nacl.bindings.crypto_generichash_KEYBYTES_MIN
KEYBYTES_MAX = nacl.bindings.crypto_generichash_KEYBYTES_MAX
SALTBYTES = nacl.bindings.crypto_generichash_SALTBYTES
PERSONALBYTES = nacl.bindings.crypto_generichash_PERSONALBYTES
_b2b_init = nacl.bindings.crypto_generichash_blake2b_init
_b2b_final = nacl.bindings.crypto_generichash_blake2b_final
_b2b_copy = nacl.bindings.crypto_generichash_blake2b_state_copy
_b2b_update = nacl.bindings.crypto_generichash_blake2b_update
[docs]class blake2b(object):
"""
:py:mod:`hashlib` API compatible blake2b algorithm implementation
"""
MAX_DIGEST_SIZE = BYTES
MAX_KEY_SIZE = KEYBYTES_MAX
PERSON_SIZE = PERSONALBYTES
SALT_SIZE = SALTBYTES
def __init__(self, data=b'', digest_size=BYTES, key=b'',
salt=b'', person=b''):
"""
:py:class:`.blake2b` algorithm initializer
:param data:
:type data: bytes
:param int digest_size: the requested digest size; must be
at most :py:attr:`.MAX_DIGEST_SIZE`;
the default digest size is :py:data:`.BYTES`
:param key: the key to be set for keyed MAC/PRF usage; if set,
the key must be at most :py:data:`.KEYBYTES_MAX` long
:type key: bytes
:param salt: an initialization salt at most
:py:attr:`.SALT_SIZE` long; it will be zero-padded
if needed
:type salt: bytes
:param person: a personalization string at most
:py:attr:`.PERSONAL_SIZE` long; it will be zero-padded
if needed
:type person: bytes
"""
self._state = _b2b_init(key=key, salt=salt, person=person,
digest_size=digest_size)
self._digest_size = digest_size
if data:
self.update(data)
@property
def digest_size(self):
return self._digest_size
@property
def block_size(self):
return 128
@property
def name(self):
return 'blake2b'
def update(self, data):
_b2b_update(self._state, data)
def digest(self):
_st = nacl.bindings.crypto_generichash_blake2b_state_copy(self._state)
return _b2b_final(_st, self.digest_size)
def hexdigest(self):
return bytes_as_string(binascii.hexlify(self.digest()))
def copy(self):
_cp = type(self)(digest_size=self.digest_size)
_st = _b2b_copy(self._state)
_cp._state = _st
return _cp
[docs]def scrypt(password, salt='', n=2**20, r=8, p=1,
maxmem=2**25, dklen=64):
"""
Derive a cryptographic key using the scrypt KDF.
Implements the same signature as the ``hashlib.scrypt`` implemented
in cpython version 3.6
"""
return nacl.bindings.crypto_pwhash_scryptsalsa208sha256_ll(
password, salt, n, r, p, maxmem=maxmem, dklen=dklen)