95 lines
3.2 KiB
Python
95 lines
3.2 KiB
Python
# random.py
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#
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# Copyright (C) 2006-2026 wolfSSL Inc.
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#
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# This file is part of wolfSSL.
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#
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# wolfSSL is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 3 of the License, or
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# (at your option) any later version.
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#
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# wolfSSL is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
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# pylint: disable=no-member,no-name-in-module
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from __future__ import annotations
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from wolfcrypt._ffi import ffi as _ffi
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from wolfcrypt._ffi import lib as _lib
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from wolfcrypt.exceptions import WolfCryptApiError, WolfCryptError
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class Random:
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"""
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A Cryptographically Secure Pseudo Random Number Generator - CSPRNG
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"""
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def __init__(self, nonce: __builtins__.bytes = b"", device_id: int = -2) -> None:
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self._native_object: _lib.RNG | None = None
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self._native_object = _ffi.new("WC_RNG *")
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ret = _lib.wc_InitRngNonce_ex(self._native_object, nonce, len(nonce), _ffi.NULL, device_id)
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if ret < 0: # pragma: no cover
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self._native_object = None
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raise WolfCryptApiError("RNG init error", ret)
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# making sure _lib.wc_FreeRng outlives WC_RNG instances
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_delete = staticmethod(_lib.wc_FreeRng)
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def __del__(self) -> None:
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if self._native_object is not None:
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try:
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self._delete(self._native_object)
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except AttributeError:
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# Can occur during interpreter shutdown
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pass
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@property
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def native_object(self) -> _lib.RNG:
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if self._native_object is None:
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raise WolfCryptError("RNG not initialized")
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return self._native_object
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def byte(self) -> __builtins__.bytes:
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"""
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Generate and return a random byte.
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"""
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result = _ffi.new("byte[1]")
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ret = _lib.wc_RNG_GenerateByte(self.native_object, result)
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if ret < 0: # pragma: no cover
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raise WolfCryptApiError("RNG generate byte error", ret)
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return _ffi.buffer(result, 1)[:]
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def bytes(self, length: int) -> __builtins__.bytes:
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"""
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Generate and return a random sequence of length bytes.
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"""
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result = _ffi.new(f"byte[{length}]")
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ret = _lib.wc_RNG_GenerateBlock(self.native_object, result, length)
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if ret < 0: # pragma: no cover
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raise WolfCryptApiError("RNG generate block error", ret)
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return _ffi.buffer(result, length)[:]
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if _lib.HASHDRBG_ENABLED:
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def reseed(self, seed: __builtins__.bytes) -> None:
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"""
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Reseed the DRBG with the provided seed material.
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"""
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assert self.native_object is not None
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ret = _lib.wc_RNG_DRBG_Reseed(self.native_object, seed, len(seed))
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if ret < 0: # pragma: no cover
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raise WolfCryptApiError("RNG reseed error", ret)
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