sys/dev/crypto/rndtest/rndtest.c

   1 /*      $FreeBSD: src/sys/dev/rndtest/rndtest.c,v 1.1.4.1 2003/06/04 17:10:30 sam Exp $ */
   2 /*      $DragonFly: src/sys/dev/crypto/rndtest/rndtest.c,v 1.9 2006/12/18 20:41:01 dillon Exp $ */
   3 /*      $OpenBSD$       */
   4
   5 /*
   6  * Copyright (c) 2002 Jason L. Wright (jason@thought.net)
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed by Jason L. Wright
  20  * 4. The name of the author may not be used to endorse or promote products
  21  *    derived from this software without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  25  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  26  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  27  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  28  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  29  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  31  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  32  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  33  * POSSIBILITY OF SUCH DAMAGE.
  34  */
  35
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/bus.h>
  39 #include <sys/callout.h>
  40 #include <sys/kernel.h>
  41 #include <sys/malloc.h>
  42 #include <sys/module.h>
  43 #include <sys/random.h>
  44 #include <sys/sysctl.h>
  45 #include <machine/stdarg.h>
  46
  47 #include "rndtest.h"
  48
  49 static  void rndtest_test(struct rndtest_state *);
  50 static  void rndtest_timeout(void *);
  51
  52 /* The tests themselves */
  53 static  int rndtest_monobit(struct rndtest_state *);
  54 static  int rndtest_runs(struct rndtest_state *);
  55 static  int rndtest_longruns(struct rndtest_state *);
  56 static  int rndtest_chi_4(struct rndtest_state *);
  57
  58 static  int rndtest_runs_check(struct rndtest_state *, int, int *);
  59 static  void rndtest_runs_record(struct rndtest_state *, int, int *);
  60
  61 static const struct rndtest_testfunc {
  62         int (*test)(struct rndtest_state *);
  63 } rndtest_funcs[] = {
  64         { rndtest_monobit },
  65         { rndtest_runs },
  66         { rndtest_chi_4 },
  67         { rndtest_longruns },
  68 };
  69
  70 #define RNDTEST_NTESTS  (sizeof(rndtest_funcs)/sizeof(rndtest_funcs[0]))
  71
  72 SYSCTL_NODE(_kern, OID_AUTO, rndtest, CTLFLAG_RD, 0, "RNG test parameters");
  73
  74 static  int rndtest_retest = 120;               /* interval in seconds */
  75 SYSCTL_INT(_kern_rndtest, OID_AUTO, retest, CTLFLAG_RW, &rndtest_retest,
  76             0, "retest interval (seconds)");
  77 static struct rndtest_stats rndstats;
  78 SYSCTL_STRUCT(_kern_rndtest, OID_AUTO, stats, CTLFLAG_RD, &rndstats,
  79             rndtest_stats, "RNG test statistics");
  80 static  int rndtest_verbose = 1;                /* report only failures */
  81 SYSCTL_INT(_kern_rndtest, OID_AUTO, verbose, CTLFLAG_RW, &rndtest_verbose,
  82             0, "display results on console");
  83
  84 struct rndtest_state *
  85 rndtest_attach(device_t dev)
  86 {
  87         struct rndtest_state *rsp;
  88
  89         rsp = kmalloc(sizeof (*rsp), M_DEVBUF, M_INTWAIT);
  90         rsp->rs_begin = rsp->rs_buf;
  91         rsp->rs_end = rsp->rs_buf + sizeof(rsp->rs_buf);
  92         rsp->rs_current = rsp->rs_begin;
  93         rsp->rs_discard = 1;
  94         rsp->rs_collect = 1;
  95         rsp->rs_parent = dev;
  96         /* NB: 1 means the callout runs w/o Giant locked */
  97         callout_init_mp(&rsp->rs_to);
  98         return (rsp);
  99 }
 100
 101 void
 102 rndtest_detach(struct rndtest_state *rsp)
 103 {
 104         callout_stop(&rsp->rs_to);
 105         kfree(rsp, M_DEVBUF);
 106 }
 107
 108 void
 109 rndtest_harvest(struct rndtest_state *rsp, void *buf, u_int len)
 110 {
 111         size_t i;
 112         /*
 113          * If enabled, collect data and run tests when we have enough.
 114          */
 115         if (rsp->rs_collect) {
 116                 for (i = 0; i < len; i++) {
 117                         *rsp->rs_current = ((u_char *) buf)[i];
 118                         if (++rsp->rs_current == rsp->rs_end) {
 119                                 rndtest_test(rsp);
 120                                 rsp->rs_current = rsp->rs_begin;
 121                                 /*
 122                                  * If tests passed, turn off collection and
 123                                  * schedule another test. Otherwise we keep
 124                                  * testing until the data looks ok.
 125                                  */
 126                                 if (!rsp->rs_discard && rndtest_retest != 0) {
 127                                         rsp->rs_collect = 0;
 128                                         callout_reset(&rsp->rs_to,
 129                                                 hz * rndtest_retest,
 130                                                 rndtest_timeout, rsp);
 131                                         break;
 132                                 }
 133                         }
 134                 }
 135         }
 136         /*
 137          * Only stir entropy that passes muster into the pool.
 138          */
 139         if (rsp->rs_discard)
 140                 rndstats.rst_discard += len;
 141         else {
 142 #if defined(__DragonFly__) || __FreeBSD_version < 500000
 143                 /* XXX verify buffer is word aligned */
 144                 u_int32_t *p = buf;
 145                 for (len /= sizeof (u_int32_t); len; len--)
 146                         add_true_randomness(*p++);
 147 #else
 148                 random_harvest(buf, len, len*NBBY, 0, RANDOM_PURE);
 149 #endif
 150         }
 151 }
 152
 153 static void
 154 rndtest_test(struct rndtest_state *rsp)
 155 {
 156         int i, rv = 0;
 157
 158         rndstats.rst_tests++;
 159         for (i = 0; i < RNDTEST_NTESTS; i++)
 160                 rv |= (*rndtest_funcs[i].test)(rsp);
 161         rsp->rs_discard = (rv != 0);
 162 }
 163
 164 static void
 165 rndtest_report(struct rndtest_state *rsp, int failure, const char *fmt, ...)
 166 {
 167         char buf[80];
 168         __va_list ap;
 169
 170         if (rndtest_verbose == 0)
 171                 return;
 172         if (!failure && rndtest_verbose == 1)   /* don't report successes */
 173                 return;
 174         __va_start(ap, fmt);
 175         kvsnprintf(buf, sizeof (buf), fmt, ap);
 176         __va_end(ap);
 177         device_printf(rsp->rs_parent, "rndtest: %s\n", buf);
 178 }
 179
 180 #define RNDTEST_MONOBIT_MINONES 9725
 181 #define RNDTEST_MONOBIT_MAXONES 10275
 182
 183 static int
 184 rndtest_monobit(struct rndtest_state *rsp)
 185 {
 186         int i, ones = 0, j;
 187         u_int8_t r;
 188
 189         for (i = 0; i < RNDTEST_NBYTES; i++) {
 190                 r = rsp->rs_buf[i];
 191                 for (j = 0; j < 8; j++, r <<= 1)
 192                         if (r & 0x80)
 193                                 ones++;
 194         }
 195         if (ones > RNDTEST_MONOBIT_MINONES &&
 196             ones < RNDTEST_MONOBIT_MAXONES) {
 197                 if (rndtest_verbose > 1)
 198                         rndtest_report(rsp, 0, "monobit pass (%d < %d < %d)",
 199                             RNDTEST_MONOBIT_MINONES, ones,
 200                             RNDTEST_MONOBIT_MAXONES);
 201                 return (0);
 202         } else {
 203                 if (rndtest_verbose)
 204                         rndtest_report(rsp, 1,
 205                             "monobit failed (%d ones)", ones);
 206                 rndstats.rst_monobit++;
 207                 return (-1);
 208         }
 209 }
 210
 211 #define RNDTEST_RUNS_NINTERVAL  6
 212
 213 static const struct rndtest_runs_tabs {
 214         u_int16_t min, max;
 215 } rndtest_runs_tab[] = {
 216         { 2343, 2657 },
 217         { 1135, 1365 },
 218         { 542, 708 },
 219         { 251, 373 },
 220         { 111, 201 },
 221         { 111, 201 },
 222 };
 223
 224 static int
 225 rndtest_runs(struct rndtest_state *rsp)
 226 {
 227         int i, j, ones, zeros, rv = 0;
 228         int onei[RNDTEST_RUNS_NINTERVAL], zeroi[RNDTEST_RUNS_NINTERVAL];
 229         u_int8_t c;
 230
 231         bzero(onei, sizeof(onei));
 232         bzero(zeroi, sizeof(zeroi));
 233         ones = zeros = 0;
 234         for (i = 0; i < RNDTEST_NBYTES; i++) {
 235                 c = rsp->rs_buf[i];
 236                 for (j = 0; j < 8; j++, c <<= 1) {
 237                         if (c & 0x80) {
 238                                 ones++;
 239                                 rndtest_runs_record(rsp, zeros, zeroi);
 240                                 zeros = 0;
 241                         } else {
 242                                 zeros++;
 243                                 rndtest_runs_record(rsp, ones, onei);
 244                                 ones = 0;
 245                         }
 246                 }
 247         }
 248         rndtest_runs_record(rsp, ones, onei);
 249         rndtest_runs_record(rsp, zeros, zeroi);
 250
 251         rv |= rndtest_runs_check(rsp, 0, zeroi);
 252         rv |= rndtest_runs_check(rsp, 1, onei);
 253
 254         if (rv)
 255                 rndstats.rst_runs++;
 256
 257         return (rv);
 258 }
 259
 260 static void
 261 rndtest_runs_record(struct rndtest_state *rsp, int len, int *intrv)
 262 {
 263         if (len == 0)
 264                 return;
 265         if (len > RNDTEST_RUNS_NINTERVAL)
 266                 len = RNDTEST_RUNS_NINTERVAL;
 267         len -= 1;
 268         intrv[len]++;
 269 }
 270
 271 static int
 272 rndtest_runs_check(struct rndtest_state *rsp, int val, int *src)
 273 {
 274         int i, rv = 0;
 275
 276         for (i = 0; i < RNDTEST_RUNS_NINTERVAL; i++) {
 277                 if (src[i] < rndtest_runs_tab[i].min ||
 278                     src[i] > rndtest_runs_tab[i].max) {
 279                         rndtest_report(rsp, 1,
 280                             "%s interval %d failed (%d, %d-%d)",
 281                             val ? "ones" : "zeros",
 282                             i + 1, src[i], rndtest_runs_tab[i].min,
 283                             rndtest_runs_tab[i].max);
 284                         rv = -1;
 285                 } else {
 286                         rndtest_report(rsp, 0,
 287                             "runs pass %s interval %d (%d < %d < %d)",
 288                             val ? "ones" : "zeros",
 289                             i + 1, rndtest_runs_tab[i].min, src[i],
 290                             rndtest_runs_tab[i].max);
 291                 }
 292         }
 293         return (rv);
 294 }
 295
 296 static int
 297 rndtest_longruns(struct rndtest_state *rsp)
 298 {
 299         int i, j, ones = 0, zeros = 0, maxones = 0, maxzeros = 0;
 300         u_int8_t c;
 301
 302         for (i = 0; i < RNDTEST_NBYTES; i++) {
 303                 c = rsp->rs_buf[i];
 304                 for (j = 0; j < 8; j++, c <<= 1) {
 305                         if (c & 0x80) {
 306                                 zeros = 0;
 307                                 ones++;
 308                                 if (ones > maxones)
 309                                         maxones = ones;
 310                         } else {
 311                                 ones = 0;
 312                                 zeros++;
 313                                 if (zeros > maxzeros)
 314                                         maxzeros = zeros;
 315                         }
 316                 }
 317         }
 318
 319         if (maxones < 26 && maxzeros < 26) {
 320                 rndtest_report(rsp, 0, "longruns pass (%d ones, %d zeros)",
 321                         maxones, maxzeros);
 322                 return (0);
 323         } else {
 324                 rndtest_report(rsp, 1, "longruns fail (%d ones, %d zeros)",
 325                         maxones, maxzeros);
 326                 rndstats.rst_longruns++;
 327                 return (-1);
 328         }
 329 }
 330
 331 /*
 332  * chi^2 test over 4 bits: (this is called the poker test in FIPS 140-2,
 333  * but it is really the chi^2 test over 4 bits (the poker test as described
 334  * by Knuth vol 2 is something different, and I take him as authoritative
 335  * on nomenclature over NIST).
 336  */
 337 #define RNDTEST_CHI4_K  16
 338 #define RNDTEST_CHI4_K_MASK     (RNDTEST_CHI4_K - 1)
 339
 340 /*
 341  * The unnormalized values are used so that we don't have to worry about
 342  * fractional precision.  The "real" value is found by:
 343  *      (V - 1562500) * (16 / 5000) = Vn   (where V is the unnormalized value)
 344  */
 345 #define RNDTEST_CHI4_VMIN       1563181         /* 2.1792 */
 346 #define RNDTEST_CHI4_VMAX       1576929         /* 46.1728 */
 347
 348 static int
 349 rndtest_chi_4(struct rndtest_state *rsp)
 350 {
 351         unsigned int freq[RNDTEST_CHI4_K], i, sum;
 352
 353         for (i = 0; i < RNDTEST_CHI4_K; i++)
 354                 freq[i] = 0;
 355
 356         /* Get number of occurances of each 4 bit pattern */
 357         for (i = 0; i < RNDTEST_NBYTES; i++) {
 358                 freq[(rsp->rs_buf[i] >> 4) & RNDTEST_CHI4_K_MASK]++;
 359                 freq[(rsp->rs_buf[i] >> 0) & RNDTEST_CHI4_K_MASK]++;
 360         }
 361
 362         for (i = 0, sum = 0; i < RNDTEST_CHI4_K; i++)
 363                 sum += freq[i] * freq[i];
 364
 365         if (sum >= 1563181 && sum <= 1576929) {
 366                 rndtest_report(rsp, 0, "chi^2(4): pass (sum %u)", sum);
 367                 return (0);
 368         } else {
 369                 rndtest_report(rsp, 1, "chi^2(4): failed (sum %u)", sum);
 370                 rndstats.rst_chi++;
 371                 return (-1);
 372         }
 373 }
 374
 375 static void
 376 rndtest_timeout(void *xrsp)
 377 {
 378         struct rndtest_state *rsp = xrsp;
 379
 380         rsp->rs_collect = 1;
 381 }
 382
 383 static int
 384 rndtest_modevent(module_t mod, int type, void *unused)
 385 {
 386         switch (type) {
 387         case MOD_LOAD:
 388                 return 0;
 389         case MOD_UNLOAD:
 390                 return 0;
 391         }
 392         return EINVAL;
 393 }
 394
 395 static moduledata_t rndtest_mod = {
 396         "rndtest",
 397         rndtest_modevent,
 398         0
 399 };
 400 DECLARE_MODULE(rndtest, rndtest_mod, SI_SUB_DRIVERS, SI_ORDER_ANY);
 401 MODULE_VERSION(rndtest, 1);