1 /* $NetBSD: t_getentropy.c,v 1.1 2022/05/31 13:42:59 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2022 The NetBSD Foundation, Inc.
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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __RCSID("$NetBSD: t_getentropy.c,v 1.1 2022/05/31 13:42:59 riastradh Exp $");
31
32 #include <sys/mman.h>
33
34 #include <atf-c.h>
35 #include <errno.h>
36 #include <limits.h>
37 #include <stdint.h>
38 #include <string.h>
39 #include <unistd.h>
40
41 static uint8_t buf[289];
42 static uint8_t zero[sizeof(buf)];
43
44 __CTASSERT(GETENTROPY_MAX == 256);
45
46 ATF_TC(getentropy_0);
ATF_TC_HEAD(getentropy_0,tc)47 ATF_TC_HEAD(getentropy_0, tc)
48 {
49 atf_tc_set_md_var(tc, "descr", "getentropy 0 bytes");
50 atf_tc_set_md_var(tc, "timeout", "2");
51 }
ATF_TC_BODY(getentropy_0,tc)52 ATF_TC_BODY(getentropy_0, tc)
53 {
54
55 memset(buf, 0, sizeof(buf));
56 if (getentropy(buf, 0) == -1)
57 atf_tc_fail("getentropy: %d (%s)", errno, strerror(errno));
58 ATF_CHECK(memcmp(buf, zero, sizeof(buf)) == 0);
59 }
60
61 ATF_TC(getentropy_32);
ATF_TC_HEAD(getentropy_32,tc)62 ATF_TC_HEAD(getentropy_32, tc)
63 {
64 atf_tc_set_md_var(tc, "descr", "getentropy 32 bytes");
65 atf_tc_set_md_var(tc, "timeout", "2");
66 }
ATF_TC_BODY(getentropy_32,tc)67 ATF_TC_BODY(getentropy_32, tc)
68 {
69
70 memset(buf, 0, sizeof(buf));
71 if (getentropy(buf + 1, 32) == -1)
72 atf_tc_fail("getentropy: %d (%s)", errno, strerror(errno));
73 ATF_CHECK(buf[0] == 0);
74 ATF_CHECK(memcmp(buf + 1, zero, 32) != 0);
75 ATF_CHECK(memcmp(buf + 1 + 32, zero, sizeof(buf) - 1 - 32) == 0);
76 }
77
78 ATF_TC(getentropy_256);
ATF_TC_HEAD(getentropy_256,tc)79 ATF_TC_HEAD(getentropy_256, tc)
80 {
81 atf_tc_set_md_var(tc, "descr", "getentropy 256 bytes");
82 atf_tc_set_md_var(tc, "timeout", "2");
83 }
ATF_TC_BODY(getentropy_256,tc)84 ATF_TC_BODY(getentropy_256, tc)
85 {
86
87 memset(buf, 0, sizeof(buf));
88 if (getentropy(buf + 1, 256) == -1)
89 atf_tc_fail("getentropy: %d (%s)", errno, strerror(errno));
90 ATF_CHECK(buf[0] == 0);
91 ATF_CHECK(memcmp(buf + 1, zero, 256) != 0);
92 ATF_CHECK(memcmp(buf + 1 + 256, zero, sizeof(buf) - 1 - 256) == 0);
93 }
94
95 ATF_TC(getentropy_257);
ATF_TC_HEAD(getentropy_257,tc)96 ATF_TC_HEAD(getentropy_257, tc)
97 {
98 atf_tc_set_md_var(tc, "descr", "getentropy 257 bytes (beyond max)");
99 atf_tc_set_md_var(tc, "timeout", "2");
100 }
ATF_TC_BODY(getentropy_257,tc)101 ATF_TC_BODY(getentropy_257, tc)
102 {
103
104 memset(buf, 0, sizeof(buf));
105 ATF_CHECK_ERRNO(EINVAL, getentropy(buf, 257) == -1);
106 ATF_CHECK(memcmp(buf, zero, sizeof(buf)) == 0);
107 }
108
109 ATF_TC(getentropy_null);
ATF_TC_HEAD(getentropy_null,tc)110 ATF_TC_HEAD(getentropy_null, tc)
111 {
112 atf_tc_set_md_var(tc, "descr", "getentropy with null buffer");
113 atf_tc_set_md_var(tc, "timeout", "2");
114 }
ATF_TC_BODY(getentropy_null,tc)115 ATF_TC_BODY(getentropy_null, tc)
116 {
117
118 ATF_CHECK_ERRNO(EFAULT, getentropy(NULL, 32) == -1);
119 }
120
121 ATF_TC(getentropy_nearnull);
ATF_TC_HEAD(getentropy_nearnull,tc)122 ATF_TC_HEAD(getentropy_nearnull, tc)
123 {
124 atf_tc_set_md_var(tc, "descr", "getentropy with nearly null buffer");
125 atf_tc_set_md_var(tc, "timeout", "2");
126 }
ATF_TC_BODY(getentropy_nearnull,tc)127 ATF_TC_BODY(getentropy_nearnull, tc)
128 {
129
130 ATF_CHECK_ERRNO(EFAULT, getentropy((char *)(uintptr_t)1, 32) == -1);
131 }
132
133 ATF_TC(getentropy_badaddr);
ATF_TC_HEAD(getentropy_badaddr,tc)134 ATF_TC_HEAD(getentropy_badaddr, tc)
135 {
136 atf_tc_set_md_var(tc, "descr", "getentropy with bad address");
137 atf_tc_set_md_var(tc, "timeout", "2");
138 }
ATF_TC_BODY(getentropy_badaddr,tc)139 ATF_TC_BODY(getentropy_badaddr, tc)
140 {
141 size_t pagesize = sysconf(_SC_PAGESIZE);
142 char *p;
143
144 /*
145 * Allocate three consecutive pages and make the middle one
146 * nonwritable.
147 */
148 p = mmap(NULL, 3*pagesize, PROT_READ|PROT_WRITE,
149 MAP_ANON|MAP_PRIVATE, -1, 0);
150 if (p == MAP_FAILED)
151 atf_tc_fail("mmap: %d (%s)", errno, strerror(errno));
152 if (mprotect(p + pagesize, pagesize, PROT_READ) == -1)
153 atf_tc_fail("mprotect: %d (%s)", errno, strerror(errno));
154
155 /* Verify that writing to the end of the first page works. */
156 if (getentropy(p + pagesize - 25, 25) == -1)
157 atf_tc_fail("getentropy 1: %d (%s)", errno, strerror(errno));
158 ATF_CHECK(memcmp(p + pagesize - 25, zero, 25) != 0);
159
160 /*
161 * Verify that writes into the middle page, whether straddling
162 * the surrounding pages or not, fail with EFAULT.
163 */
164 ATF_CHECK_ERRNO(EFAULT, getentropy(p + pagesize - 1, 2) == -1);
165 ATF_CHECK_ERRNO(EFAULT, getentropy(p + pagesize, 32) == -1);
166 ATF_CHECK_ERRNO(EFAULT, getentropy(p + 2*pagesize - 1, 2) == -1);
167
168 /* Verify that writing to the start of the last page works. */
169 if (getentropy(p + 2*pagesize, 25) == -1)
170 atf_tc_fail("getentropy 2: %d (%s)", errno, strerror(errno));
171 ATF_CHECK(memcmp(p + pagesize - 25, zero, 25) != 0);
172
173 if (munmap(p, 3*pagesize) == -1)
174 atf_tc_fail("munmap: %d (%s)", errno, strerror(errno));
175 }
176
ATF_TP_ADD_TCS(tp)177 ATF_TP_ADD_TCS(tp)
178 {
179
180 ATF_TP_ADD_TC(tp, getentropy_0);
181 ATF_TP_ADD_TC(tp, getentropy_256);
182 ATF_TP_ADD_TC(tp, getentropy_257);
183 ATF_TP_ADD_TC(tp, getentropy_32);
184 ATF_TP_ADD_TC(tp, getentropy_badaddr);
185 ATF_TP_ADD_TC(tp, getentropy_nearnull);
186 ATF_TP_ADD_TC(tp, getentropy_null);
187
188 return atf_no_error();
189 }
190