sudo/lib/util/explicit_bzero.c

78 lines
2.1 KiB
C

/*
* SPDX-License-Identifier: ISC
*
* Copyright (c) 2020 Todd C. Miller <Todd.Miller@sudo.ws>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* This is an open source non-commercial project. Dear PVS-Studio, please check it.
* PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
*/
#include <config.h>
#define __STDC_WANT_LIB_EXT1__ 1 /* for memset_s() */
#include <string.h>
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#include <sudo_compat.h>
#ifndef HAVE_EXPLICIT_BZERO
# if defined(HAVE_EXPLICIT_MEMSET)
void
sudo_explicit_bzero(void *s, size_t n)
{
explicit_memset(s, 0, n);
}
# elif defined(HAVE_MEMSET_EXPLICIT)
void
sudo_explicit_bzero(void *s, size_t n)
{
memset_explicit(s, 0, n);
}
# elif defined(HAVE_MEMSET_S)
void
sudo_explicit_bzero(void *s, size_t n)
{
(void)memset_s(s, n, 0, n);
}
# elif defined(HAVE_BZERO)
/* Jumping through a volatile function pointer should not be optimized away. */
void (* volatile sudo_explicit_bzero_impl)(void *, size_t) =
(void (*)(void *, size_t))bzero;
void
sudo_explicit_bzero(void *s, size_t n)
{
sudo_explicit_bzero_impl(s, n);
}
# else
void
sudo_explicit_bzero(void *v, size_t n)
{
volatile unsigned char *s = v;
/* Updating through a volatile pointer should not be optimized away. */
while (n--)
*s++ = 0;
}
# endif /* HAVE_BZERO */
#endif /* HAVE_EXPLICIT_BZERO */