1 /* $NetBSD: test_rand.c,v 1.2 2017/01/28 21:31:47 christos Exp $ */ 2 3 /* 4 * Copyright (c) 2007 Kungliga Tekniska Hgskolan 5 * (Royal Institute of Technology, Stockholm, Sweden). 6 * All rights reserved. 7 * 8 * Portions Copyright (c) 2009 Apple Inc. All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 21 * 3. Neither the name of the Institute nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 */ 37 38 #include <config.h> 39 #include <krb5/roken.h> 40 #include <math.h> 41 42 #include <krb5/getarg.h> 43 44 #include "rand.h" 45 46 47 /* 48 * 49 */ 50 51 static int version_flag; 52 static int help_flag; 53 static int len = 1024 * 1024; 54 static char *rand_method; 55 static char *filename; 56 57 static struct getargs args[] = { 58 { "length", 0, arg_integer, &len, 59 "length", NULL }, 60 { "file", 0, arg_string, &filename, 61 "file name", NULL }, 62 { "method", 0, arg_string, &rand_method, 63 "method", NULL }, 64 { "version", 0, arg_flag, &version_flag, 65 "print version", NULL }, 66 { "help", 0, arg_flag, &help_flag, 67 NULL, NULL } 68 }; 69 70 /* 71 * 72 */ 73 74 /* 75 * 76 */ 77 78 static void 79 usage (int ret) 80 { 81 arg_printusage (args, 82 sizeof(args)/sizeof(args[0]), 83 NULL, 84 ""); 85 exit (ret); 86 } 87 88 int 89 main(int argc, char **argv) 90 { 91 int idx = 0; 92 char *buffer; 93 char path[MAXPATHLEN]; 94 95 setprogname(argv[0]); 96 97 if(getarg(args, sizeof(args) / sizeof(args[0]), argc, argv, &idx)) 98 usage(1); 99 100 if (help_flag) 101 usage(0); 102 103 if(version_flag){ 104 print_version(NULL); 105 exit(0); 106 } 107 108 if (argc != idx) 109 usage(1); 110 111 buffer = emalloc(len); 112 113 if (rand_method) { 114 if (0) { 115 } 116 #ifndef NO_RAND_FORTUNA_METHOD 117 else if (strcasecmp(rand_method, "fortuna") == 0) 118 RAND_set_rand_method(RAND_fortuna_method()); 119 #endif 120 #ifndef NO_RAND_UNIX_METHOD 121 else if (strcasecmp(rand_method, "unix") == 0) 122 RAND_set_rand_method(RAND_unix_method()); 123 #endif 124 #ifdef WIN32 125 else if (strcasecmp(rand_method, "w32crypto") == 0) 126 RAND_set_rand_method(RAND_w32crypto_method()); 127 #endif 128 else 129 errx(1, "unknown method %s", rand_method); 130 } 131 132 if (RAND_file_name(path, sizeof(path)) == NULL) 133 errx(1, "RAND_file_name failed"); 134 135 if (RAND_status() != 1) 136 errx(1, "random not ready yet"); 137 138 if (RAND_bytes(buffer, len) != 1) 139 errx(1, "RAND_bytes"); 140 141 if (filename) 142 rk_dumpdata(filename, buffer, len); 143 144 /* head vs tail */ 145 if (len >= 100000) { 146 unsigned bytes[256]; 147 unsigned bits[8]; 148 size_t bit, i; 149 double res; 150 double slen = sqrt((double)len); 151 152 memset(bits, 0, sizeof(bits)); 153 memset(bytes, 0, sizeof(bytes)); 154 155 for (i = 0; i < len; i++) { 156 unsigned char c = ((unsigned char *)buffer)[i]; 157 158 bytes[c]++; 159 160 for (bit = 0; bit < 8 && c; bit++) { 161 if (c & 1) 162 bits[bit]++; 163 c = c >> 1; 164 } 165 } 166 167 /* 168 * The count for each bit value has a mean of n*p = len/2, 169 * and a standard deviation of sqrt(n*p*q) ~ sqrt(len/4). 170 * Normalizing by dividing by "n*p", we get a mean of 1 and 171 * a standard deviation of sqrt(q/n*p) = 1/sqrt(len). 172 * 173 * A 5.33-sigma event happens 1 time in 10 million. 174 * A 5.73-sigma event happens 1 time in 100 million. 175 * A 6.11-sigma event happens 1 time in 1000 million. 176 * 177 * We tolerate 5.33-sigma events (we have 8 not entirely 178 * independent chances of skewed results) and want to fail 179 * with a good RNG less often than 1 time in million. 180 */ 181 for (bit = 0; bit < 8; bit++) { 182 res = slen * fabs(1.0 - 2 * (double)bits[bit] / len); 183 if (res > 5.33) 184 errx(1, "head%d vs tail%d: %.1f-sigma (%d of %d)", 185 (int)bit, (int)bit, res, bits[bit], len); 186 printf("head vs tails bit%d: %f-sigma\n", (int)bit, res); 187 } 188 189 /* 190 * The count of each byte value has a mean of n*p = len/256, 191 * and a standard deviation of sqrt(n*p*q) ~ sqrt(len/256). 192 * Normalizing by dividing by "n*p", we get a mean of 1 and 193 * a standard deviation of sqrt(q/n*p) ~ 16/sqrt(len). 194 * 195 * We tolerate 5.73-sigma events (we have 256 not entirely 196 * independent chances of skewed results). Note, for example, 197 * a 5.2-sigma event was observed in ~5,000 runs. 198 */ 199 for (i = 0; i < 256; i++) { 200 res = (slen / 16) * fabs(1.0 - 256 * (double)bytes[i] / len); 201 if (res > 5.73) 202 errx(1, "byte %d: %.1f-sigma (%d of %d)", 203 (int) i, res, bytes[i], len); 204 printf("byte %d: %f-sigma\n", (int)i, res); 205 } 206 } 207 208 free(buffer); 209 210 /* test write random file */ 211 { 212 static const char *file = "test.file"; 213 if (RAND_write_file(file) != 1) 214 errx(1, "RAND_write_file"); 215 if (RAND_load_file(file, 1024) != 1) 216 errx(1, "RAND_load_file"); 217 unlink(file); 218 } 219 220 return 0; 221 } 222
Indexes created Sun Mar 01 05:31:48 UTC 2026