1 /*-
2 * Copyright (c) 2011 David Schultz
3 * Copyright (c) 2024 Robert Clausecker <fuz@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/types.h>
29 #include <sys/mman.h>
30 #include <sys/wait.h>
31 #include <errno.h>
32 #include <stdio.h>
33 #include <stdint.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <unistd.h>
37
38 #include <atf-c.h>
39
40 /*
41 * BUFSIZE is the number of bytes of rc4 output to compare. The probability
42 * that this test fails spuriously is 2**(-BUFSIZE * 8).
43 */
44 #define BUFSIZE 8
45
46 /*
47 * Test whether arc4random_buf() returns the same sequence of bytes in both
48 * parent and child processes. (Hint: It shouldn't.)
49 */
50 ATF_TC_WITHOUT_HEAD(test_arc4random);
ATF_TC_BODY(test_arc4random,tc)51 ATF_TC_BODY(test_arc4random, tc)
52 {
53 struct shared_page {
54 char parentbuf[BUFSIZE];
55 char childbuf[BUFSIZE];
56 } *page;
57 pid_t pid;
58 char c;
59
60 page = mmap(NULL, sizeof(struct shared_page), PROT_READ | PROT_WRITE,
61 MAP_ANON | MAP_SHARED, -1, 0);
62 ATF_REQUIRE_MSG(page != MAP_FAILED, "mmap failed; errno=%d", errno);
63
64 arc4random_buf(&c, 1);
65
66 pid = fork();
67 ATF_REQUIRE(0 <= pid);
68 if (pid == 0) {
69 /* child */
70 arc4random_buf(page->childbuf, BUFSIZE);
71 exit(0);
72 } else {
73 /* parent */
74 int status;
75 arc4random_buf(page->parentbuf, BUFSIZE);
76 wait(&status);
77 }
78 ATF_CHECK_MSG(memcmp(page->parentbuf, page->childbuf, BUFSIZE) != 0,
79 "sequences are the same");
80 }
81
82 /*
83 * Test whether arc4random_uniform() returns a number below the given threshold.
84 * Test with various thresholds.
85 */
86 ATF_TC_WITHOUT_HEAD(test_arc4random_uniform);
ATF_TC_BODY(test_arc4random_uniform,tc)87 ATF_TC_BODY(test_arc4random_uniform, tc)
88 {
89 size_t i, j;
90 static const uint32_t thresholds[] = {
91 1, 2, 3, 4, 5, 10, 100, 1000,
92 INT32_MAX, (uint32_t)INT32_MAX + 1,
93 UINT32_MAX - 1000000000, UINT32_MAX - 1000000, UINT32_MAX - 1, 0
94 };
95
96 for (i = 0; thresholds[i] != 0; i++)
97 for (j = 0; j < 10000; j++)
98 ATF_CHECK(arc4random_uniform(thresholds[i]) < thresholds[i]);
99
100 /* for a threshold of zero, just check that we get zero every time */
101 for (j = 0; j < 1000; j++)
102 ATF_CHECK_EQ(0, arc4random_uniform(0));
103 }
104
ATF_TP_ADD_TCS(tp)105 ATF_TP_ADD_TCS(tp)
106 {
107
108 ATF_TP_ADD_TC(tp, test_arc4random);
109 ATF_TP_ADD_TC(tp, test_arc4random_uniform);
110
111 return (atf_no_error());
112 }
113