2 * Copyright (c) 2011 David Schultz
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
31 #include <sys/types.h>
39 * BUFSIZE is the number of bytes of rc4 output to compare. The probability
40 * that this test fails spuriously is 2**(-BUFSIZE * 8).
45 * Test whether arc4random_buf() returns the same sequence of bytes in both
46 * parent and child processes. (Hint: It shouldn't.)
48 int main(int argc, char *argv[]) {
50 char parentbuf[BUFSIZE];
51 char childbuf[BUFSIZE];
58 page = mmap(NULL, sizeof(struct shared_page), PROT_READ | PROT_WRITE,
59 MAP_ANON | MAP_SHARED, -1, 0);
60 if (page == MAP_FAILED) {
61 printf("fail 1 - mmap\n");
65 arc4random_buf(&c, 1);
69 printf("fail 1 - fork\n");
74 arc4random_buf(page->childbuf, BUFSIZE);
79 arc4random_buf(page->parentbuf, BUFSIZE);
82 if (memcmp(page->parentbuf, page->childbuf, BUFSIZE) == 0) {
83 printf("fail 1 - sequences are the same\n");
87 printf("ok 1 - sequences are different\n");