- /* $OpenBSD: getentropy_netbsd.c,v 1.3 2016/08/07 03:27:21 tb Exp $ */
-
- /*
- * Copyright (c) 2014 Pawel Jakub Dawidek <pjd@FreeBSD.org>
- * Copyright (c) 2014 Brent Cook <bcook@openbsd.org>
- *
- * 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.
- *
- * Emulation of getentropy(2) as documented at:
- * http://man.openbsd.org/getentropy.2
- */
-
- #include <sys/types.h>
- #include <sys/sysctl.h>
-
- #include <errno.h>
- #include <stddef.h>
-
- /*
- * Derived from lib/libc/gen/arc4random.c from FreeBSD.
- */
- static size_t
- getentropy_sysctl(u_char *buf, size_t size)
- {
- int mib[2];
- size_t len, done;
-
- mib[0] = CTL_KERN;
- mib[1] = KERN_ARND;
- done = 0;
-
- do {
- len = size;
- if (sysctl(mib, 2, buf, &len, NULL, 0) == -1)
- return (done);
- done += len;
- buf += len;
- size -= len;
- } while (size > 0);
-
- return (done);
- }
-
- int
- getentropy(void *buf, size_t len)
- {
- if (len <= 256 &&
- getentropy_sysctl(buf, len) == len) {
- return (0);
- }
-
- errno = EIO;
- return (-1);
- }
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