1 /* $OpenBSD$ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-4-Clause 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/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/bus.h> 42 #include <sys/callout.h> 43 #include <sys/kernel.h> 44 #include <sys/malloc.h> 45 #include <sys/module.h> 46 #include <sys/random.h> 47 #include <sys/sysctl.h> 48 #include <machine/stdarg.h> 49 50 #include <dev/rndtest/rndtest.h> 51 52 static void rndtest_test(struct rndtest_state *); 53 static void rndtest_timeout(void *); 54 55 /* The tests themselves */ 56 static int rndtest_monobit(struct rndtest_state *); 57 static int rndtest_runs(struct rndtest_state *); 58 static int rndtest_longruns(struct rndtest_state *); 59 static int rndtest_chi_4(struct rndtest_state *); 60 61 static int rndtest_runs_check(struct rndtest_state *, int, int *); 62 static void rndtest_runs_record(struct rndtest_state *, int, int *); 63 64 static const struct rndtest_testfunc { 65 int (*test)(struct rndtest_state *); 66 } rndtest_funcs[] = { 67 { rndtest_monobit }, 68 { rndtest_runs }, 69 { rndtest_chi_4 }, 70 { rndtest_longruns }, 71 }; 72 73 #define RNDTEST_NTESTS nitems(rndtest_funcs) 74 75 static SYSCTL_NODE(_kern, OID_AUTO, rndtest, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 76 "RNG test parameters"); 77 static int rndtest_retest = 120; /* interval in seconds */ 78 SYSCTL_INT(_kern_rndtest, OID_AUTO, retest, CTLFLAG_RW, &rndtest_retest, 79 0, "retest interval (seconds)"); 80 static struct rndtest_stats rndstats; 81 SYSCTL_STRUCT(_kern_rndtest, OID_AUTO, stats, CTLFLAG_RD, &rndstats, 82 rndtest_stats, "RNG test statistics"); 83 static int rndtest_verbose = 1; /* report only failures */ 84 SYSCTL_INT(_kern_rndtest, OID_AUTO, verbose, CTLFLAG_RW, &rndtest_verbose, 85 0, "display results on console"); 86 87 struct rndtest_state * 88 rndtest_attach(device_t dev) 89 { 90 struct rndtest_state *rsp; 91 92 rsp = malloc(sizeof (*rsp), M_DEVBUF, M_NOWAIT); 93 if (rsp != NULL) { 94 rsp->rs_begin = rsp->rs_buf; 95 rsp->rs_end = rsp->rs_buf + sizeof(rsp->rs_buf); 96 rsp->rs_current = rsp->rs_begin; 97 rsp->rs_discard = 1; 98 rsp->rs_collect = 1; 99 rsp->rs_parent = dev; 100 callout_init(&rsp->rs_to, 1); 101 } else 102 device_printf(dev, "rndtest_init: no memory for state block\n"); 103 return (rsp); 104 } 105 106 void 107 rndtest_detach(struct rndtest_state *rsp) 108 { 109 callout_stop(&rsp->rs_to); 110 free(rsp, M_DEVBUF); 111 } 112 113 void 114 rndtest_harvest(struct rndtest_state *rsp, void *buf, u_int len) 115 { 116 size_t i; 117 /* 118 * If enabled, collect data and run tests when we have enough. 119 */ 120 if (rsp->rs_collect) { 121 for (i = 0; i < len; i++) { 122 *rsp->rs_current = ((u_char *) buf)[i]; 123 if (++rsp->rs_current == rsp->rs_end) { 124 rndtest_test(rsp); 125 rsp->rs_current = rsp->rs_begin; 126 /* 127 * If tests passed, turn off collection and 128 * schedule another test. Otherwise we keep 129 * testing until the data looks ok. 130 */ 131 if (!rsp->rs_discard && rndtest_retest != 0) { 132 rsp->rs_collect = 0; 133 callout_reset(&rsp->rs_to, 134 hz * rndtest_retest, 135 rndtest_timeout, rsp); 136 break; 137 } 138 } 139 } 140 } 141 /* 142 * Only stir entropy that passes muster into the pool. 143 */ 144 if (rsp->rs_discard) 145 rndstats.rst_discard += len; 146 else 147 /* MarkM: FIX!! Check that this does not swamp the harvester! */ 148 random_harvest_queue(buf, len, RANDOM_PURE_RNDTEST); 149 } 150 151 static void 152 rndtest_test(struct rndtest_state *rsp) 153 { 154 int i, rv = 0; 155 156 rndstats.rst_tests++; 157 for (i = 0; i < RNDTEST_NTESTS; i++) 158 rv |= (*rndtest_funcs[i].test)(rsp); 159 rsp->rs_discard = (rv != 0); 160 } 161 162 static void 163 rndtest_report(struct rndtest_state *rsp, int failure, const char *fmt, ...) 164 { 165 char buf[80]; 166 va_list ap; 167 168 if (rndtest_verbose == 0) 169 return; 170 if (!failure && rndtest_verbose == 1) /* don't report successes */ 171 return; 172 va_start(ap, fmt); 173 vsnprintf(buf, sizeof (buf), fmt, ap); 174 va_end(ap); 175 device_printf(rsp->rs_parent, "rndtest: %s\n", buf); 176 } 177 178 #define RNDTEST_MONOBIT_MINONES 9725 179 #define RNDTEST_MONOBIT_MAXONES 10275 180 181 static int 182 rndtest_monobit(struct rndtest_state *rsp) 183 { 184 int i, ones = 0, j; 185 u_int8_t r; 186 187 for (i = 0; i < RNDTEST_NBYTES; i++) { 188 r = rsp->rs_buf[i]; 189 for (j = 0; j < 8; j++, r <<= 1) 190 if (r & 0x80) 191 ones++; 192 } 193 if (ones > RNDTEST_MONOBIT_MINONES && 194 ones < RNDTEST_MONOBIT_MAXONES) { 195 if (rndtest_verbose > 1) 196 rndtest_report(rsp, 0, "monobit pass (%d < %d < %d)", 197 RNDTEST_MONOBIT_MINONES, ones, 198 RNDTEST_MONOBIT_MAXONES); 199 return (0); 200 } else { 201 if (rndtest_verbose) 202 rndtest_report(rsp, 1, 203 "monobit failed (%d ones)", ones); 204 rndstats.rst_monobit++; 205 return (-1); 206 } 207 } 208 209 #define RNDTEST_RUNS_NINTERVAL 6 210 211 static const struct rndtest_runs_tabs { 212 u_int16_t min, max; 213 } rndtest_runs_tab[] = { 214 { 2343, 2657 }, 215 { 1135, 1365 }, 216 { 542, 708 }, 217 { 251, 373 }, 218 { 111, 201 }, 219 { 111, 201 }, 220 }; 221 222 static int 223 rndtest_runs(struct rndtest_state *rsp) 224 { 225 int i, j, ones, zeros, rv = 0; 226 int onei[RNDTEST_RUNS_NINTERVAL], zeroi[RNDTEST_RUNS_NINTERVAL]; 227 u_int8_t c; 228 229 bzero(onei, sizeof(onei)); 230 bzero(zeroi, sizeof(zeroi)); 231 ones = zeros = 0; 232 for (i = 0; i < RNDTEST_NBYTES; i++) { 233 c = rsp->rs_buf[i]; 234 for (j = 0; j < 8; j++, c <<= 1) { 235 if (c & 0x80) { 236 ones++; 237 rndtest_runs_record(rsp, zeros, zeroi); 238 zeros = 0; 239 } else { 240 zeros++; 241 rndtest_runs_record(rsp, ones, onei); 242 ones = 0; 243 } 244 } 245 } 246 rndtest_runs_record(rsp, ones, onei); 247 rndtest_runs_record(rsp, zeros, zeroi); 248 249 rv |= rndtest_runs_check(rsp, 0, zeroi); 250 rv |= rndtest_runs_check(rsp, 1, onei); 251 252 if (rv) 253 rndstats.rst_runs++; 254 255 return (rv); 256 } 257 258 static void 259 rndtest_runs_record(struct rndtest_state *rsp, int len, int *intrv) 260 { 261 if (len == 0) 262 return; 263 if (len > RNDTEST_RUNS_NINTERVAL) 264 len = RNDTEST_RUNS_NINTERVAL; 265 len -= 1; 266 intrv[len]++; 267 } 268 269 static int 270 rndtest_runs_check(struct rndtest_state *rsp, int val, int *src) 271 { 272 int i, rv = 0; 273 274 for (i = 0; i < RNDTEST_RUNS_NINTERVAL; i++) { 275 if (src[i] < rndtest_runs_tab[i].min || 276 src[i] > rndtest_runs_tab[i].max) { 277 rndtest_report(rsp, 1, 278 "%s interval %d failed (%d, %d-%d)", 279 val ? "ones" : "zeros", 280 i + 1, src[i], rndtest_runs_tab[i].min, 281 rndtest_runs_tab[i].max); 282 rv = -1; 283 } else { 284 rndtest_report(rsp, 0, 285 "runs pass %s interval %d (%d < %d < %d)", 286 val ? "ones" : "zeros", 287 i + 1, rndtest_runs_tab[i].min, src[i], 288 rndtest_runs_tab[i].max); 289 } 290 } 291 return (rv); 292 } 293 294 static int 295 rndtest_longruns(struct rndtest_state *rsp) 296 { 297 int i, j, ones = 0, zeros = 0, maxones = 0, maxzeros = 0; 298 u_int8_t c; 299 300 for (i = 0; i < RNDTEST_NBYTES; i++) { 301 c = rsp->rs_buf[i]; 302 for (j = 0; j < 8; j++, c <<= 1) { 303 if (c & 0x80) { 304 zeros = 0; 305 ones++; 306 if (ones > maxones) 307 maxones = ones; 308 } else { 309 ones = 0; 310 zeros++; 311 if (zeros > maxzeros) 312 maxzeros = zeros; 313 } 314 } 315 } 316 317 if (maxones < 26 && maxzeros < 26) { 318 rndtest_report(rsp, 0, "longruns pass (%d ones, %d zeros)", 319 maxones, maxzeros); 320 return (0); 321 } else { 322 rndtest_report(rsp, 1, "longruns fail (%d ones, %d zeros)", 323 maxones, maxzeros); 324 rndstats.rst_longruns++; 325 return (-1); 326 } 327 } 328 329 /* 330 * chi^2 test over 4 bits: (this is called the poker test in FIPS 140-2, 331 * but it is really the chi^2 test over 4 bits (the poker test as described 332 * by Knuth vol 2 is something different, and I take him as authoritative 333 * on nomenclature over NIST). 334 */ 335 #define RNDTEST_CHI4_K 16 336 #define RNDTEST_CHI4_K_MASK (RNDTEST_CHI4_K - 1) 337 338 /* 339 * The unnormalized values are used so that we don't have to worry about 340 * fractional precision. The "real" value is found by: 341 * (V - 1562500) * (16 / 5000) = Vn (where V is the unnormalized value) 342 */ 343 #define RNDTEST_CHI4_VMIN 1563181 /* 2.1792 */ 344 #define RNDTEST_CHI4_VMAX 1576929 /* 46.1728 */ 345 346 static int 347 rndtest_chi_4(struct rndtest_state *rsp) 348 { 349 unsigned int freq[RNDTEST_CHI4_K], i, sum; 350 351 for (i = 0; i < RNDTEST_CHI4_K; i++) 352 freq[i] = 0; 353 354 /* Get number of occurrences of each 4 bit pattern */ 355 for (i = 0; i < RNDTEST_NBYTES; i++) { 356 freq[(rsp->rs_buf[i] >> 4) & RNDTEST_CHI4_K_MASK]++; 357 freq[(rsp->rs_buf[i] >> 0) & RNDTEST_CHI4_K_MASK]++; 358 } 359 360 for (i = 0, sum = 0; i < RNDTEST_CHI4_K; i++) 361 sum += freq[i] * freq[i]; 362 363 if (sum >= 1563181 && sum <= 1576929) { 364 rndtest_report(rsp, 0, "chi^2(4): pass (sum %u)", sum); 365 return (0); 366 } else { 367 rndtest_report(rsp, 1, "chi^2(4): failed (sum %u)", sum); 368 rndstats.rst_chi++; 369 return (-1); 370 } 371 } 372 373 static void 374 rndtest_timeout(void *xrsp) 375 { 376 struct rndtest_state *rsp = xrsp; 377 378 rsp->rs_collect = 1; 379 } 380 381 static int 382 rndtest_modevent(module_t mod, int type, void *unused) 383 { 384 switch (type) { 385 case MOD_LOAD: 386 return 0; 387 case MOD_UNLOAD: 388 return 0; 389 } 390 return EINVAL; 391 } 392 393 static moduledata_t rndtest_mod = { 394 "rndtest", 395 rndtest_modevent, 396 0 397 }; 398 DECLARE_MODULE(rndtest, rndtest_mod, SI_SUB_DRIVERS, SI_ORDER_ANY); 399 MODULE_VERSION(rndtest, 1); 400