1 /* $FreeBSD: src/sys/dev/rndtest/rndtest.c,v 1.1.4.1 2003/06/04 17:10:30 sam Exp $ */ 2 /* $OpenBSD$ */ 3 4 /* 5 * Copyright (c) 2002 Jason L. Wright (jason@thought.net) 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by Jason L. Wright 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 24 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 25 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 26 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 27 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 28 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 30 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 31 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 * POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/bus.h> 38 #include <sys/callout.h> 39 #include <sys/kernel.h> 40 #include <sys/malloc.h> 41 #include <sys/module.h> 42 #include <sys/random.h> 43 #include <sys/sysctl.h> 44 #include <machine/stdarg.h> 45 46 #include <dev/rndtest/rndtest.h> 47 48 static void rndtest_test(struct rndtest_state *); 49 static void rndtest_timeout(void *); 50 51 /* The tests themselves */ 52 static int rndtest_monobit(struct rndtest_state *); 53 static int rndtest_runs(struct rndtest_state *); 54 static int rndtest_longruns(struct rndtest_state *); 55 static int rndtest_chi_4(struct rndtest_state *); 56 57 static int rndtest_runs_check(struct rndtest_state *, int, int *); 58 static void rndtest_runs_record(struct rndtest_state *, int, int *); 59 60 static const struct rndtest_testfunc { 61 int (*test)(struct rndtest_state *); 62 } rndtest_funcs[] = { 63 { rndtest_monobit }, 64 { rndtest_runs }, 65 { rndtest_chi_4 }, 66 { rndtest_longruns }, 67 }; 68 69 #define RNDTEST_NTESTS (sizeof(rndtest_funcs)/sizeof(rndtest_funcs[0])) 70 71 SYSCTL_NODE(_kern, OID_AUTO, rndtest, CTLFLAG_RD, 0, "RNG test parameters"); 72 73 static int rndtest_retest = 120; /* interval in seconds */ 74 SYSCTL_INT(_kern_rndtest, OID_AUTO, retest, CTLFLAG_RW, &rndtest_retest, 75 0, "retest interval (seconds)"); 76 static struct rndtest_stats rndstats; 77 SYSCTL_STRUCT(_kern_rndtest, OID_AUTO, stats, CTLFLAG_RD, &rndstats, 78 rndtest_stats, "RNG test statistics"); 79 static int rndtest_verbose = 1; /* report only failures */ 80 SYSCTL_INT(_kern_rndtest, OID_AUTO, verbose, CTLFLAG_RW, &rndtest_verbose, 81 0, "display results on console"); 82 83 struct rndtest_state * 84 rndtest_attach(device_t dev) 85 { 86 struct rndtest_state *rsp; 87 88 rsp = malloc(sizeof (*rsp), M_DEVBUF, M_NOWAIT); 89 if (rsp != NULL) { 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 #if __FreeBSD_version < 500000 97 callout_init(&rsp->rs_to); 98 #else 99 /* NB: 1 means the callout runs w/o Giant locked */ 100 callout_init(&rsp->rs_to, 1); 101 #endif 102 } else 103 device_printf(dev, "rndtest_init: no memory for state block\n"); 104 return (rsp); 105 } 106 107 void 108 rndtest_detach(struct rndtest_state *rsp) 109 { 110 callout_stop(&rsp->rs_to); 111 free(rsp, M_DEVBUF); 112 } 113 114 void 115 rndtest_harvest(struct rndtest_state *rsp, void *buf, u_int len) 116 { 117 size_t i; 118 /* 119 * If enabled, collect data and run tests when we have enough. 120 */ 121 if (rsp->rs_collect) { 122 for (i = 0; i < len; i++) { 123 *rsp->rs_current = ((u_char *) buf)[i]; 124 if (++rsp->rs_current == rsp->rs_end) { 125 rndtest_test(rsp); 126 rsp->rs_current = rsp->rs_begin; 127 /* 128 * If tests passed, turn off collection and 129 * schedule another test. Otherwise we keep 130 * testing until the data looks ok. 131 */ 132 if (!rsp->rs_discard && rndtest_retest != 0) { 133 rsp->rs_collect = 0; 134 callout_reset(&rsp->rs_to, 135 hz * rndtest_retest, 136 rndtest_timeout, rsp); 137 break; 138 } 139 } 140 } 141 } 142 /* 143 * Only stir entropy that passes muster into the pool. 144 */ 145 if (rsp->rs_discard) 146 rndstats.rst_discard += len; 147 else { 148 #if __FreeBSD_version < 500000 149 /* XXX verify buffer is word aligned */ 150 u_int32_t *p = buf; 151 for (len /= sizeof (u_int32_t); len; len--) 152 add_true_randomness(*p++); 153 #else 154 random_harvest(buf, len, len*NBBY, 0, RANDOM_PURE); 155 #endif 156 } 157 } 158 159 static void 160 rndtest_test(struct rndtest_state *rsp) 161 { 162 int i, rv = 0; 163 164 rndstats.rst_tests++; 165 for (i = 0; i < RNDTEST_NTESTS; i++) 166 rv |= (*rndtest_funcs[i].test)(rsp); 167 rsp->rs_discard = (rv != 0); 168 } 169 170 static void 171 rndtest_report(struct rndtest_state *rsp, int failure, const char *fmt, ...) 172 { 173 char buf[80]; 174 va_list ap; 175 176 if (rndtest_verbose == 0) 177 return; 178 if (!failure && rndtest_verbose == 1) /* don't report successes */ 179 return; 180 va_start(ap, fmt); 181 vsnprintf(buf, sizeof (buf), fmt, ap); 182 va_end(ap); 183 device_printf(rsp->rs_parent, "rndtest: %s\n", buf); 184 } 185 186 #define RNDTEST_MONOBIT_MINONES 9725 187 #define RNDTEST_MONOBIT_MAXONES 10275 188 189 static int 190 rndtest_monobit(struct rndtest_state *rsp) 191 { 192 int i, ones = 0, j; 193 u_int8_t r; 194 195 for (i = 0; i < RNDTEST_NBYTES; i++) { 196 r = rsp->rs_buf[i]; 197 for (j = 0; j < 8; j++, r <<= 1) 198 if (r & 0x80) 199 ones++; 200 } 201 if (ones > RNDTEST_MONOBIT_MINONES && 202 ones < RNDTEST_MONOBIT_MAXONES) { 203 if (rndtest_verbose > 1) 204 rndtest_report(rsp, 0, "monobit pass (%d < %d < %d)", 205 RNDTEST_MONOBIT_MINONES, ones, 206 RNDTEST_MONOBIT_MAXONES); 207 return (0); 208 } else { 209 if (rndtest_verbose) 210 rndtest_report(rsp, 1, 211 "monobit failed (%d ones)", ones); 212 rndstats.rst_monobit++; 213 return (-1); 214 } 215 } 216 217 #define RNDTEST_RUNS_NINTERVAL 6 218 219 static const struct rndtest_runs_tabs { 220 u_int16_t min, max; 221 } rndtest_runs_tab[] = { 222 { 2343, 2657 }, 223 { 1135, 1365 }, 224 { 542, 708 }, 225 { 251, 373 }, 226 { 111, 201 }, 227 { 111, 201 }, 228 }; 229 230 static int 231 rndtest_runs(struct rndtest_state *rsp) 232 { 233 int i, j, ones, zeros, rv = 0; 234 int onei[RNDTEST_RUNS_NINTERVAL], zeroi[RNDTEST_RUNS_NINTERVAL]; 235 u_int8_t c; 236 237 bzero(onei, sizeof(onei)); 238 bzero(zeroi, sizeof(zeroi)); 239 ones = zeros = 0; 240 for (i = 0; i < RNDTEST_NBYTES; i++) { 241 c = rsp->rs_buf[i]; 242 for (j = 0; j < 8; j++, c <<= 1) { 243 if (c & 0x80) { 244 ones++; 245 rndtest_runs_record(rsp, zeros, zeroi); 246 zeros = 0; 247 } else { 248 zeros++; 249 rndtest_runs_record(rsp, ones, onei); 250 ones = 0; 251 } 252 } 253 } 254 rndtest_runs_record(rsp, ones, onei); 255 rndtest_runs_record(rsp, zeros, zeroi); 256 257 rv |= rndtest_runs_check(rsp, 0, zeroi); 258 rv |= rndtest_runs_check(rsp, 1, onei); 259 260 if (rv) 261 rndstats.rst_runs++; 262 263 return (rv); 264 } 265 266 static void 267 rndtest_runs_record(struct rndtest_state *rsp, int len, int *intrv) 268 { 269 if (len == 0) 270 return; 271 if (len > RNDTEST_RUNS_NINTERVAL) 272 len = RNDTEST_RUNS_NINTERVAL; 273 len -= 1; 274 intrv[len]++; 275 } 276 277 static int 278 rndtest_runs_check(struct rndtest_state *rsp, int val, int *src) 279 { 280 int i, rv = 0; 281 282 for (i = 0; i < RNDTEST_RUNS_NINTERVAL; i++) { 283 if (src[i] < rndtest_runs_tab[i].min || 284 src[i] > rndtest_runs_tab[i].max) { 285 rndtest_report(rsp, 1, 286 "%s interval %d failed (%d, %d-%d)", 287 val ? "ones" : "zeros", 288 i + 1, src[i], rndtest_runs_tab[i].min, 289 rndtest_runs_tab[i].max); 290 rv = -1; 291 } else { 292 rndtest_report(rsp, 0, 293 "runs pass %s interval %d (%d < %d < %d)", 294 val ? "ones" : "zeros", 295 i + 1, rndtest_runs_tab[i].min, src[i], 296 rndtest_runs_tab[i].max); 297 } 298 } 299 return (rv); 300 } 301 302 static int 303 rndtest_longruns(struct rndtest_state *rsp) 304 { 305 int i, j, ones = 0, zeros = 0, maxones = 0, maxzeros = 0; 306 u_int8_t c; 307 308 for (i = 0; i < RNDTEST_NBYTES; i++) { 309 c = rsp->rs_buf[i]; 310 for (j = 0; j < 8; j++, c <<= 1) { 311 if (c & 0x80) { 312 zeros = 0; 313 ones++; 314 if (ones > maxones) 315 maxones = ones; 316 } else { 317 ones = 0; 318 zeros++; 319 if (zeros > maxzeros) 320 maxzeros = zeros; 321 } 322 } 323 } 324 325 if (maxones < 26 && maxzeros < 26) { 326 rndtest_report(rsp, 0, "longruns pass (%d ones, %d zeros)", 327 maxones, maxzeros); 328 return (0); 329 } else { 330 rndtest_report(rsp, 1, "longruns fail (%d ones, %d zeros)", 331 maxones, maxzeros); 332 rndstats.rst_longruns++; 333 return (-1); 334 } 335 } 336 337 /* 338 * chi^2 test over 4 bits: (this is called the poker test in FIPS 140-2, 339 * but it is really the chi^2 test over 4 bits (the poker test as described 340 * by Knuth vol 2 is something different, and I take him as authoritative 341 * on nomenclature over NIST). 342 */ 343 #define RNDTEST_CHI4_K 16 344 #define RNDTEST_CHI4_K_MASK (RNDTEST_CHI4_K - 1) 345 346 /* 347 * The unnormalized values are used so that we don't have to worry about 348 * fractional precision. The "real" value is found by: 349 * (V - 1562500) * (16 / 5000) = Vn (where V is the unnormalized value) 350 */ 351 #define RNDTEST_CHI4_VMIN 1563181 /* 2.1792 */ 352 #define RNDTEST_CHI4_VMAX 1576929 /* 46.1728 */ 353 354 static int 355 rndtest_chi_4(struct rndtest_state *rsp) 356 { 357 unsigned int freq[RNDTEST_CHI4_K], i, sum; 358 359 for (i = 0; i < RNDTEST_CHI4_K; i++) 360 freq[i] = 0; 361 362 /* Get number of occurances of each 4 bit pattern */ 363 for (i = 0; i < RNDTEST_NBYTES; i++) { 364 freq[(rsp->rs_buf[i] >> 4) & RNDTEST_CHI4_K_MASK]++; 365 freq[(rsp->rs_buf[i] >> 0) & RNDTEST_CHI4_K_MASK]++; 366 } 367 368 for (i = 0, sum = 0; i < RNDTEST_CHI4_K; i++) 369 sum += freq[i] * freq[i]; 370 371 if (sum >= 1563181 && sum <= 1576929) { 372 rndtest_report(rsp, 0, "chi^2(4): pass (sum %u)", sum); 373 return (0); 374 } else { 375 rndtest_report(rsp, 1, "chi^2(4): failed (sum %u)", sum); 376 rndstats.rst_chi++; 377 return (-1); 378 } 379 } 380 381 static void 382 rndtest_timeout(void *xrsp) 383 { 384 struct rndtest_state *rsp = xrsp; 385 386 rsp->rs_collect = 1; 387 } 388 389 static int 390 rndtest_modevent(module_t mod, int type, void *unused) 391 { 392 switch (type) { 393 case MOD_LOAD: 394 return 0; 395 case MOD_UNLOAD: 396 return 0; 397 } 398 return EINVAL; 399 } 400 401 static moduledata_t rndtest_mod = { 402 "rndtest", 403 rndtest_modevent, 404 0 405 }; 406 DECLARE_MODULE(rndtest, rndtest_mod, SI_SUB_DRIVERS, SI_ORDER_ANY); 407 MODULE_VERSION(rndtest, 1); 408