/*
* Copyright (c) 2016 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
#include <string.h>
#include <sys/errno.h>
#include <stdint.h>
extern void *secure_memset(void *, int, size_t);
/*
* The memset_s function copies the value c into the first n bytes
* pointed by s. No more than smax bytes will be copied.
*
* In contrast to the memset function, calls to memset_s will never
* be ''optimised away'' by a compiler, ensuring the memory copy
* even if s is not accessed anymore after this call.
*/
int
memset_s(void *s, size_t smax, int c, size_t n)
{
int err = 0;
if (s == NULL) {
return EINVAL;
}
if (smax > RSIZE_MAX) {
return E2BIG;
}
if (n > smax) {
n = smax;
err = EOVERFLOW;
}
/*
* secure_memset is defined in assembly, we therefore
* expect that the compiler will not inline the call.
*/
secure_memset(s, c, n);
return err;
}
int
timingsafe_bcmp(const void *b1, const void *b2, size_t n)
{
const unsigned char *p1 = b1, *p2 = b2;
unsigned char ret = 0;
for (; n > 0; n--) {
ret |= *p1++ ^ *p2++;
}
/* map zero to zero and nonzero to one */
return (ret + 0xff) >> 8;
}