52 lines
1.6 KiB
Python
52 lines
1.6 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 nacl import exceptions as exc
|
|
from nacl._sodium import ffi, lib
|
|
|
|
randombytes_SEEDBYTES = lib.randombytes_seedbytes()
|
|
|
|
|
|
def randombytes(size):
|
|
"""
|
|
Returns ``size`` number of random bytes from a cryptographically secure
|
|
random source.
|
|
|
|
:param size: int
|
|
:rtype: bytes
|
|
"""
|
|
buf = ffi.new("unsigned char[]", size)
|
|
lib.randombytes(buf, size)
|
|
return ffi.buffer(buf, size)[:]
|
|
|
|
|
|
def randombytes_buf_deterministic(size, seed):
|
|
"""
|
|
Returns ``size`` number of deterministically generated pseudorandom bytes
|
|
from a seed
|
|
|
|
:param size: int
|
|
:param seed: bytes
|
|
:rtype: bytes
|
|
"""
|
|
if len(seed) != randombytes_SEEDBYTES:
|
|
raise exc.TypeError("Deterministic random bytes must be generated "
|
|
"from 32 bytes")
|
|
|
|
buf = ffi.new("unsigned char[]", size)
|
|
lib.randombytes_buf_deterministic(buf, size, seed)
|
|
return ffi.buffer(buf, size)[:]
|