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