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); 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 } 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); 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 } 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); 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 } 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); 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 } 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); 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 } 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); 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 } 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); 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 } 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 } 176 177 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