FreeBSD-5.3/sys/dev/rndtest/rndtest.c
/* $OpenBSD$ */
/*
* Copyright (c) 2002 Jason L. Wright (jason@thought.net)
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Jason L. Wright
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/dev/rndtest/rndtest.c,v 1.4 2003/08/24 17:54:22 obrien Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/callout.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/random.h>
#include <sys/sysctl.h>
#include <machine/stdarg.h>
#include <dev/rndtest/rndtest.h>
static void rndtest_test(struct rndtest_state *);
static void rndtest_timeout(void *);
/* The tests themselves */
static int rndtest_monobit(struct rndtest_state *);
static int rndtest_runs(struct rndtest_state *);
static int rndtest_longruns(struct rndtest_state *);
static int rndtest_chi_4(struct rndtest_state *);
static int rndtest_runs_check(struct rndtest_state *, int, int *);
static void rndtest_runs_record(struct rndtest_state *, int, int *);
static const struct rndtest_testfunc {
int (*test)(struct rndtest_state *);
} rndtest_funcs[] = {
{ rndtest_monobit },
{ rndtest_runs },
{ rndtest_chi_4 },
{ rndtest_longruns },
};
#define RNDTEST_NTESTS (sizeof(rndtest_funcs)/sizeof(rndtest_funcs[0]))
SYSCTL_NODE(_kern, OID_AUTO, rndtest, CTLFLAG_RD, 0, "RNG test parameters");
static int rndtest_retest = 120; /* interval in seconds */
SYSCTL_INT(_kern_rndtest, OID_AUTO, retest, CTLFLAG_RW, &rndtest_retest,
0, "retest interval (seconds)");
static struct rndtest_stats rndstats;
SYSCTL_STRUCT(_kern_rndtest, OID_AUTO, stats, CTLFLAG_RD, &rndstats,
rndtest_stats, "RNG test statistics");
static int rndtest_verbose = 1; /* report only failures */
SYSCTL_INT(_kern_rndtest, OID_AUTO, verbose, CTLFLAG_RW, &rndtest_verbose,
0, "display results on console");
struct rndtest_state *
rndtest_attach(device_t dev)
{
struct rndtest_state *rsp;
rsp = malloc(sizeof (*rsp), M_DEVBUF, M_NOWAIT);
if (rsp != NULL) {
rsp->rs_begin = rsp->rs_buf;
rsp->rs_end = rsp->rs_buf + sizeof(rsp->rs_buf);
rsp->rs_current = rsp->rs_begin;
rsp->rs_discard = 1;
rsp->rs_collect = 1;
rsp->rs_parent = dev;
#if __FreeBSD_version < 500000
callout_init(&rsp->rs_to);
#else
callout_init(&rsp->rs_to, CALLOUT_MPSAFE);
#endif
} else
device_printf(dev, "rndtest_init: no memory for state block\n");
return (rsp);
}
void
rndtest_detach(struct rndtest_state *rsp)
{
callout_stop(&rsp->rs_to);
free(rsp, M_DEVBUF);
}
void
rndtest_harvest(struct rndtest_state *rsp, void *buf, u_int len)
{
size_t i;
/*
* If enabled, collect data and run tests when we have enough.
*/
if (rsp->rs_collect) {
for (i = 0; i < len; i++) {
*rsp->rs_current = ((u_char *) buf)[i];
if (++rsp->rs_current == rsp->rs_end) {
rndtest_test(rsp);
rsp->rs_current = rsp->rs_begin;
/*
* If tests passed, turn off collection and
* schedule another test. Otherwise we keep
* testing until the data looks ok.
*/
if (!rsp->rs_discard && rndtest_retest != 0) {
rsp->rs_collect = 0;
callout_reset(&rsp->rs_to,
hz * rndtest_retest,
rndtest_timeout, rsp);
break;
}
}
}
}
/*
* Only stir entropy that passes muster into the pool.
*/
if (rsp->rs_discard)
rndstats.rst_discard += len;
else {
#if __FreeBSD_version < 500000
/* XXX verify buffer is word aligned */
u_int32_t *p = buf;
for (len /= sizeof (u_int32_t); len; len--)
add_true_randomness(*p++);
#else
random_harvest(buf, len, len*NBBY, 0, RANDOM_PURE);
#endif
}
}
static void
rndtest_test(struct rndtest_state *rsp)
{
int i, rv = 0;
rndstats.rst_tests++;
for (i = 0; i < RNDTEST_NTESTS; i++)
rv |= (*rndtest_funcs[i].test)(rsp);
rsp->rs_discard = (rv != 0);
}
static void
rndtest_report(struct rndtest_state *rsp, int failure, const char *fmt, ...)
{
char buf[80];
va_list ap;
if (rndtest_verbose == 0)
return;
if (!failure && rndtest_verbose == 1) /* don't report successes */
return;
va_start(ap, fmt);
vsnprintf(buf, sizeof (buf), fmt, ap);
va_end(ap);
device_printf(rsp->rs_parent, "rndtest: %s\n", buf);
}
#define RNDTEST_MONOBIT_MINONES 9725
#define RNDTEST_MONOBIT_MAXONES 10275
static int
rndtest_monobit(struct rndtest_state *rsp)
{
int i, ones = 0, j;
u_int8_t r;
for (i = 0; i < RNDTEST_NBYTES; i++) {
r = rsp->rs_buf[i];
for (j = 0; j < 8; j++, r <<= 1)
if (r & 0x80)
ones++;
}
if (ones > RNDTEST_MONOBIT_MINONES &&
ones < RNDTEST_MONOBIT_MAXONES) {
if (rndtest_verbose > 1)
rndtest_report(rsp, 0, "monobit pass (%d < %d < %d)",
RNDTEST_MONOBIT_MINONES, ones,
RNDTEST_MONOBIT_MAXONES);
return (0);
} else {
if (rndtest_verbose)
rndtest_report(rsp, 1,
"monobit failed (%d ones)", ones);
rndstats.rst_monobit++;
return (-1);
}
}
#define RNDTEST_RUNS_NINTERVAL 6
static const struct rndtest_runs_tabs {
u_int16_t min, max;
} rndtest_runs_tab[] = {
{ 2343, 2657 },
{ 1135, 1365 },
{ 542, 708 },
{ 251, 373 },
{ 111, 201 },
{ 111, 201 },
};
static int
rndtest_runs(struct rndtest_state *rsp)
{
int i, j, ones, zeros, rv = 0;
int onei[RNDTEST_RUNS_NINTERVAL], zeroi[RNDTEST_RUNS_NINTERVAL];
u_int8_t c;
bzero(onei, sizeof(onei));
bzero(zeroi, sizeof(zeroi));
ones = zeros = 0;
for (i = 0; i < RNDTEST_NBYTES; i++) {
c = rsp->rs_buf[i];
for (j = 0; j < 8; j++, c <<= 1) {
if (c & 0x80) {
ones++;
rndtest_runs_record(rsp, zeros, zeroi);
zeros = 0;
} else {
zeros++;
rndtest_runs_record(rsp, ones, onei);
ones = 0;
}
}
}
rndtest_runs_record(rsp, ones, onei);
rndtest_runs_record(rsp, zeros, zeroi);
rv |= rndtest_runs_check(rsp, 0, zeroi);
rv |= rndtest_runs_check(rsp, 1, onei);
if (rv)
rndstats.rst_runs++;
return (rv);
}
static void
rndtest_runs_record(struct rndtest_state *rsp, int len, int *intrv)
{
if (len == 0)
return;
if (len > RNDTEST_RUNS_NINTERVAL)
len = RNDTEST_RUNS_NINTERVAL;
len -= 1;
intrv[len]++;
}
static int
rndtest_runs_check(struct rndtest_state *rsp, int val, int *src)
{
int i, rv = 0;
for (i = 0; i < RNDTEST_RUNS_NINTERVAL; i++) {
if (src[i] < rndtest_runs_tab[i].min ||
src[i] > rndtest_runs_tab[i].max) {
rndtest_report(rsp, 1,
"%s interval %d failed (%d, %d-%d)",
val ? "ones" : "zeros",
i + 1, src[i], rndtest_runs_tab[i].min,
rndtest_runs_tab[i].max);
rv = -1;
} else {
rndtest_report(rsp, 0,
"runs pass %s interval %d (%d < %d < %d)",
val ? "ones" : "zeros",
i + 1, rndtest_runs_tab[i].min, src[i],
rndtest_runs_tab[i].max);
}
}
return (rv);
}
static int
rndtest_longruns(struct rndtest_state *rsp)
{
int i, j, ones = 0, zeros = 0, maxones = 0, maxzeros = 0;
u_int8_t c;
for (i = 0; i < RNDTEST_NBYTES; i++) {
c = rsp->rs_buf[i];
for (j = 0; j < 8; j++, c <<= 1) {
if (c & 0x80) {
zeros = 0;
ones++;
if (ones > maxones)
maxones = ones;
} else {
ones = 0;
zeros++;
if (zeros > maxzeros)
maxzeros = zeros;
}
}
}
if (maxones < 26 && maxzeros < 26) {
rndtest_report(rsp, 0, "longruns pass (%d ones, %d zeros)",
maxones, maxzeros);
return (0);
} else {
rndtest_report(rsp, 1, "longruns fail (%d ones, %d zeros)",
maxones, maxzeros);
rndstats.rst_longruns++;
return (-1);
}
}
/*
* chi^2 test over 4 bits: (this is called the poker test in FIPS 140-2,
* but it is really the chi^2 test over 4 bits (the poker test as described
* by Knuth vol 2 is something different, and I take him as authoritative
* on nomenclature over NIST).
*/
#define RNDTEST_CHI4_K 16
#define RNDTEST_CHI4_K_MASK (RNDTEST_CHI4_K - 1)
/*
* The unnormalized values are used so that we don't have to worry about
* fractional precision. The "real" value is found by:
* (V - 1562500) * (16 / 5000) = Vn (where V is the unnormalized value)
*/
#define RNDTEST_CHI4_VMIN 1563181 /* 2.1792 */
#define RNDTEST_CHI4_VMAX 1576929 /* 46.1728 */
static int
rndtest_chi_4(struct rndtest_state *rsp)
{
unsigned int freq[RNDTEST_CHI4_K], i, sum;
for (i = 0; i < RNDTEST_CHI4_K; i++)
freq[i] = 0;
/* Get number of occurances of each 4 bit pattern */
for (i = 0; i < RNDTEST_NBYTES; i++) {
freq[(rsp->rs_buf[i] >> 4) & RNDTEST_CHI4_K_MASK]++;
freq[(rsp->rs_buf[i] >> 0) & RNDTEST_CHI4_K_MASK]++;
}
for (i = 0, sum = 0; i < RNDTEST_CHI4_K; i++)
sum += freq[i] * freq[i];
if (sum >= 1563181 && sum <= 1576929) {
rndtest_report(rsp, 0, "chi^2(4): pass (sum %u)", sum);
return (0);
} else {
rndtest_report(rsp, 1, "chi^2(4): failed (sum %u)", sum);
rndstats.rst_chi++;
return (-1);
}
}
static void
rndtest_timeout(void *xrsp)
{
struct rndtest_state *rsp = xrsp;
rsp->rs_collect = 1;
}
static int
rndtest_modevent(module_t mod, int type, void *unused)
{
switch (type) {
case MOD_LOAD:
return 0;
case MOD_UNLOAD:
return 0;
}
return EINVAL;
}
static moduledata_t rndtest_mod = {
"rndtest",
rndtest_modevent,
0
};
DECLARE_MODULE(rndtest, rndtest_mod, SI_SUB_DRIVERS, SI_ORDER_ANY);
MODULE_VERSION(rndtest, 1);