xref: /freebsd/sys/crypto/libsodium/utils.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
1 /*
2  * ISC License
3  *
4  * Copyright (c) 2013-2018
5  * Frank Denis <j at pureftpd dot org>
6  *
7  * Permission to use, copy, modify, and/or distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <sys/cdefs.h>
21 #include <sys/types.h>
22 #include <sys/systm.h>
23 
24 #include <sodium/utils.h>
25 
26 void
27 sodium_memzero(void *b, size_t n)
28 {
29 	explicit_bzero(b, n);
30 }
31 
32 int
33 sodium_is_zero(const unsigned char *n, const size_t nlen)
34 {
35     size_t                 i;
36     volatile unsigned char d = 0U;
37 
38     for (i = 0U; i < nlen; i++) {
39         d |= n[i];
40     }
41     return 1 & ((d - 1) >> 8);
42 }
43