/* $NetBSD: test_rand.c,v 1.2 2017/01/28 21:31:47 christos Exp $ */
/*
* Copyright (c) 2007 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Portions Copyright (c) 2009 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <config.h>
#include <krb5/roken.h>
#include <math.h>
#include <krb5/getarg.h>
#include "rand.h"
/*
*
*/
static int version_flag;
static int help_flag;
static int len = 1024 * 1024;
static char *rand_method;
static char *filename;
static struct getargs args[] = {
{ "length", 0, arg_integer, &len,
"length", NULL },
{ "file", 0, arg_string, &filename,
"file name", NULL },
{ "method", 0, arg_string, &rand_method,
"method", NULL },
{ "version", 0, arg_flag, &version_flag,
"print version", NULL },
{ "help", 0, arg_flag, &help_flag,
NULL, NULL }
};
/*
*
*/
/*
*
*/
static void
usage (int ret)
{
arg_printusage (args,
sizeof(args)/sizeof(args[0]),
NULL,
"");
exit (ret);
}
int
main(int argc, char **argv)
{
int idx = 0;
char *buffer;
char path[MAXPATHLEN];
setprogname(argv[0]);
if(getarg(args, sizeof(args) / sizeof(args[0]), argc, argv, &idx))
usage(1);
if (help_flag)
usage(0);
if(version_flag){
print_version(NULL);
exit(0);
}
if (argc != idx)
usage(1);
buffer = emalloc(len);
if (rand_method) {
if (0) {
}
#ifndef NO_RAND_FORTUNA_METHOD
else if (strcasecmp(rand_method, "fortuna") == 0)
RAND_set_rand_method(RAND_fortuna_method());
#endif
#ifndef NO_RAND_UNIX_METHOD
else if (strcasecmp(rand_method, "unix") == 0)
RAND_set_rand_method(RAND_unix_method());
#endif
#ifdef WIN32
else if (strcasecmp(rand_method, "w32crypto") == 0)
RAND_set_rand_method(RAND_w32crypto_method());
#endif
else
errx(1, "unknown method %s", rand_method);
}
if (RAND_file_name(path, sizeof(path)) == NULL)
errx(1, "RAND_file_name failed");
if (RAND_status() != 1)
errx(1, "random not ready yet");
if (RAND_bytes(buffer, len) != 1)
errx(1, "RAND_bytes");
if (filename)
rk_dumpdata(filename, buffer, len);
/* head vs tail */
if (len >= 100000) {
unsigned bytes[256];
unsigned bits[8];
size_t bit, i;
double res;
double slen = sqrt((double)len);
memset(bits, 0, sizeof(bits));
memset(bytes, 0, sizeof(bytes));
for (i = 0; i < len; i++) {
unsigned char c = ((unsigned char *)buffer)[i];
bytes[c]++;
for (bit = 0; bit < 8 && c; bit++) {
if (c & 1)
bits[bit]++;
c = c >> 1;
}
}
/*
* The count for each bit value has a mean of n*p = len/2,
* and a standard deviation of sqrt(n*p*q) ~ sqrt(len/4).
* Normalizing by dividing by "n*p", we get a mean of 1 and
* a standard deviation of sqrt(q/n*p) = 1/sqrt(len).
*
* A 5.33-sigma event happens 1 time in 10 million.
* A 5.73-sigma event happens 1 time in 100 million.
* A 6.11-sigma event happens 1 time in 1000 million.
*
* We tolerate 5.33-sigma events (we have 8 not entirely
* independent chances of skewed results) and want to fail
* with a good RNG less often than 1 time in million.
*/
for (bit = 0; bit < 8; bit++) {
res = slen * fabs(1.0 - 2 * (double)bits[bit] / len);
if (res > 5.33)
errx(1, "head%d vs tail%d: %.1f-sigma (%d of %d)",
(int)bit, (int)bit, res, bits[bit], len);
printf("head vs tails bit%d: %f-sigma\n", (int)bit, res);
}
/*
* The count of each byte value has a mean of n*p = len/256,
* and a standard deviation of sqrt(n*p*q) ~ sqrt(len/256).
* Normalizing by dividing by "n*p", we get a mean of 1 and
* a standard deviation of sqrt(q/n*p) ~ 16/sqrt(len).
*
* We tolerate 5.73-sigma events (we have 256 not entirely
* independent chances of skewed results). Note, for example,
* a 5.2-sigma event was observed in ~5,000 runs.
*/
for (i = 0; i < 256; i++) {
res = (slen / 16) * fabs(1.0 - 256 * (double)bytes[i] / len);
if (res > 5.73)
errx(1, "byte %d: %.1f-sigma (%d of %d)",
(int) i, res, bytes[i], len);
printf("byte %d: %f-sigma\n", (int)i, res);
}
}
free(buffer);
/* test write random file */
{
static const char *file = "test.file";
if (RAND_write_file(file) != 1)
errx(1, "RAND_write_file");
if (RAND_load_file(file, 1024) != 1)
errx(1, "RAND_load_file");
unlink(file);
}
return 0;
}