| # 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 nacl import exceptions as exc | |
| from nacl._sodium import ffi, lib | |
| randombytes_SEEDBYTES: int = lib.randombytes_seedbytes() | |
| def randombytes(size: int) -> bytes: | |
| """ | |
| 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: int, seed: bytes) -> bytes: | |
| """ | |
| 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)[:] | |