arc4random_test.c revision 277441 
1/*-
2 * Copyright (c) 2011 David Schultz
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 *
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
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/10/lib/libc/tests/gen/arc4random_test.c 277441 2015-01-20 21:42:40Z ngie $");
29
30#include <sys/types.h>
31#include <sys/mman.h>
32#include <sys/wait.h>
33#include <stdio.h>
34#include <stdlib.h>
35#include <string.h>
36#include <unistd.h>
37#include <atf-c.h>
38
39/*
40 * BUFSIZE is the number of bytes of rc4 output to compare.  The probability
41 * that this test fails spuriously is 2**(-BUFSIZE * 8).
42 */
43#define	BUFSIZE		8
44
45/*
46 * Test whether arc4random_buf() returns the same sequence of bytes in both
47 * parent and child processes.  (Hint: It shouldn't.)
48 */
49ATF_TC_WITHOUT_HEAD(test_arc4random);
50ATF_TC_BODY(test_arc4random, tc)
51{
52	struct shared_page {
53		char parentbuf[BUFSIZE];
54		char childbuf[BUFSIZE];
55	} *page;
56	pid_t pid;
57	char c;
58
59	printf("1..1\n");
60
61	page = mmap(NULL, sizeof(struct shared_page), PROT_READ | PROT_WRITE,
62		    MAP_ANON | MAP_SHARED, -1, 0);
63	if (page == MAP_FAILED) {
64		printf("fail 1 - mmap\n");
65		exit(1);
66	}
67
68	arc4random_buf(&c, 1);
69
70	pid = fork();
71	ATF_REQUIRE(0 <= pid);
72	if (pid == 0) {
73		/* child */
74		arc4random_buf(page->childbuf, BUFSIZE);
75		exit(0);
76	} else {
77		/* parent */
78		int status;
79		arc4random_buf(page->parentbuf, BUFSIZE);
80		wait(&status);
81	}
82	ATF_CHECK_MSG(memcmp(page->parentbuf, page->childbuf, BUFSIZE) != 0,
83	    "sequences are the same");
84}
85
86ATF_TP_ADD_TCS(tp)
87{
88
89	ATF_TP_ADD_TC(tp, test_arc4random);
90
91	return (atf_no_error());
92}
93