1 /* $NetBSD: test_rand.c,v 1.2 2017/01/28 21:31:47 christos Exp $ */
2
3 /*
4 * Copyright (c) 2007 Kungliga Tekniska Högskolan
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
usage(int ret)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
main(int argc,char ** argv)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