1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2018 Conrad Meyer <cem@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/param.h>
30 #include <sys/random.h>
31 #include <errno.h>
32
33 #include <atf-c.h>
34
35 #include <zstd.h>
36
37 static const unsigned valid_flags[] = { 0, GRND_NONBLOCK, GRND_RANDOM,
38 GRND_NONBLOCK | GRND_RANDOM };
39
40 ATF_TC_WITHOUT_HEAD(getrandom_randomness);
ATF_TC_BODY(getrandom_randomness,tc)41 ATF_TC_BODY(getrandom_randomness, tc)
42 {
43 char randomb[4096], compressed[5000];
44 ssize_t ret;
45 size_t i, j, c;
46 unsigned mode;
47
48 for (i = 0; i < nitems(valid_flags); i++) {
49 mode = valid_flags[i];
50
51 /* Get new random data, filling randomb. */
52
53 memset(randomb, 0, sizeof(randomb));
54
55 for (j = 0; j < sizeof(randomb);) {
56 ret = getrandom(&randomb[j], sizeof(randomb) - j, mode);
57 if (ret < 0 && (mode & GRND_NONBLOCK) != 0 &&
58 errno == EAGAIN)
59 continue;
60
61 ATF_REQUIRE_MSG(ret >= 0, "other error: %d", errno);
62 ATF_REQUIRE_MSG(ret > 0, "bogus zero return");
63
64 j += (size_t)ret;
65 }
66
67 /* Perform compressibility test */
68 c = ZSTD_compress(compressed, sizeof(compressed), randomb,
69 sizeof(randomb), ZSTD_maxCLevel());
70 ATF_REQUIRE_MSG(!ZSTD_isError(c), "zstd compress: %s",
71 ZSTD_getErrorName(c));
72
73 /*
74 * If the output is very compressible, it's probably not random
75 */
76 ATF_REQUIRE_MSG(c > (sizeof(randomb) * 4 / 5),
77 "purportedly random data was compressible: %zu/%zu or %f%%",
78 c, sizeof(randomb), (double)c / (double)sizeof(randomb));
79 }
80 }
81
82 ATF_TC_WITHOUT_HEAD(getrandom_fault);
ATF_TC_BODY(getrandom_fault,tc)83 ATF_TC_BODY(getrandom_fault, tc)
84 {
85 ssize_t ret;
86
87 ret = getrandom(NULL, 1, 0);
88 ATF_REQUIRE_EQ(ret, -1);
89 ATF_REQUIRE_EQ(errno, EFAULT);
90 }
91
92 ATF_TC_WITHOUT_HEAD(getrandom_count);
ATF_TC_BODY(getrandom_count,tc)93 ATF_TC_BODY(getrandom_count, tc)
94 {
95 char buf[4096], reference[4096];
96 ssize_t ret;
97
98 /* getrandom(2) does not modify buf past the requested length */
99 _Static_assert(sizeof(reference) == sizeof(buf), "must match");
100 memset(reference, 0x7C, sizeof(reference));
101
102 memset(buf, 0x7C, sizeof(buf));
103 ret = getrandom(buf, 1, 0);
104 ATF_REQUIRE_EQ(ret, 1);
105 ATF_REQUIRE_EQ(memcmp(&buf[1], reference, sizeof(reference) - 1), 0);
106
107 memset(buf, 0x7C, sizeof(buf));
108 ATF_REQUIRE_EQ(getrandom(buf, 15, 0), 15);
109 ATF_REQUIRE_EQ(memcmp(&buf[15], reference, sizeof(reference) - 15), 0);
110
111 memset(buf, 0x7C, sizeof(buf));
112 ATF_REQUIRE_EQ(getrandom(buf, 255, 0), 255);
113 ATF_REQUIRE_EQ(memcmp(&buf[255], reference, sizeof(reference) - 255), 0);
114
115 memset(buf, 0x7C, sizeof(buf));
116 ATF_REQUIRE_EQ(getrandom(buf, 4095, 0), 4095);
117 ATF_REQUIRE_EQ(memcmp(&buf[4095], reference, sizeof(reference) - 4095), 0);
118 }
119
ATF_TP_ADD_TCS(tp)120 ATF_TP_ADD_TCS(tp)
121 {
122
123 ATF_TP_ADD_TC(tp, getrandom_count);
124 ATF_TP_ADD_TC(tp, getrandom_fault);
125 ATF_TP_ADD_TC(tp, getrandom_randomness);
126 return (atf_no_error());
127 }
128