60 lines
1.7 KiB
C
Executable File
60 lines
1.7 KiB
C
Executable File
/* $OpenBSD: getentropy_win.c,v 1.5 2016/08/07 03:27:21 tb Exp $ */
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/*
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* Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org>
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* Copyright (c) 2014, Bob Beck <beck@obtuse.com>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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* Emulation of getentropy(2) as documented at:
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* http://man.openbsd.org/getentropy.2
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*/
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#include <windows.h>
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#include <errno.h>
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#include <stdint.h>
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#include <sys/types.h>
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#include <wincrypt.h>
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#include <process.h>
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int getentropy(void *buf, size_t len);
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/*
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* On Windows, CryptGenRandom is supposed to be a well-seeded
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* cryptographically strong random number generator.
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*/
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int
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getentropy(void *buf, size_t len)
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{
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HCRYPTPROV provider;
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if (len > 256) {
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errno = EIO;
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return (-1);
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}
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if (CryptAcquireContext(&provider, NULL, NULL, PROV_RSA_FULL,
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CRYPT_VERIFYCONTEXT) == 0)
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goto fail;
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if (CryptGenRandom(provider, len, buf) == 0) {
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CryptReleaseContext(provider, 0);
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goto fail;
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}
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CryptReleaseContext(provider, 0);
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return (0);
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fail:
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errno = EIO;
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return (-1);
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}
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