52 lines
1.5 KiB
Python
52 lines
1.5 KiB
Python
# Copyright 2013 Donald Stufft and individual contributors
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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from nacl import exceptions as exc
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from nacl._sodium import ffi, lib
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randombytes_SEEDBYTES: int = lib.randombytes_seedbytes()
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def randombytes(size: int) -> bytes:
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"""
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Returns ``size`` number of random bytes from a cryptographically secure
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random source.
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:param size: int
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:rtype: bytes
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"""
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buf = ffi.new("unsigned char[]", size)
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lib.randombytes(buf, size)
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return ffi.buffer(buf, size)[:]
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def randombytes_buf_deterministic(size: int, seed: bytes) -> bytes:
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"""
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Returns ``size`` number of deterministically generated pseudorandom bytes
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from a seed
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:param size: int
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:param seed: bytes
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:rtype: bytes
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"""
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if len(seed) != randombytes_SEEDBYTES:
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raise exc.TypeError(
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"Deterministic random bytes must be generated from 32 bytes"
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)
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buf = ffi.new("unsigned char[]", size)
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lib.randombytes_buf_deterministic(buf, size, seed)
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return ffi.buffer(buf, size)[:]
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