1 /* $OpenBSD$ */ 2 3 /*- 4 * Copyright (c) 2002 Jason L. Wright (jason@thought.net) 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Jason L. Wright 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 23 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 24 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 25 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 26 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 27 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 29 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 30 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 * POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/bus.h> 40 #include <sys/callout.h> 41 #include <sys/kernel.h> 42 #include <sys/malloc.h> 43 #include <sys/module.h> 44 #include <sys/random.h> 45 #include <sys/sysctl.h> 46 #include <machine/stdarg.h> 47 48 #include <dev/rndtest/rndtest.h> 49 50 static void rndtest_test(struct rndtest_state *); 51 static void rndtest_timeout(void *); 52 53 /* The tests themselves */ 54 static int rndtest_monobit(struct rndtest_state *); 55 static int rndtest_runs(struct rndtest_state *); 56 static int rndtest_longruns(struct rndtest_state *); 57 static int rndtest_chi_4(struct rndtest_state *); 58 59 static int rndtest_runs_check(struct rndtest_state *, int, int *); 60 static void rndtest_runs_record(struct rndtest_state *, int, int *); 61 62 static const struct rndtest_testfunc { 63 int (*test)(struct rndtest_state *); 64 } rndtest_funcs[] = { 65 { rndtest_monobit }, 66 { rndtest_runs }, 67 { rndtest_chi_4 }, 68 { rndtest_longruns }, 69 }; 70 71 #define RNDTEST_NTESTS nitems(rndtest_funcs) 72 73 static SYSCTL_NODE(_kern, OID_AUTO, rndtest, CTLFLAG_RD, 0, 74 "RNG test parameters"); 75 static int rndtest_retest = 120; /* interval in seconds */ 76 SYSCTL_INT(_kern_rndtest, OID_AUTO, retest, CTLFLAG_RW, &rndtest_retest, 77 0, "retest interval (seconds)"); 78 static struct rndtest_stats rndstats; 79 SYSCTL_STRUCT(_kern_rndtest, OID_AUTO, stats, CTLFLAG_RD, &rndstats, 80 rndtest_stats, "RNG test statistics"); 81 static int rndtest_verbose = 1; /* report only failures */ 82 SYSCTL_INT(_kern_rndtest, OID_AUTO, verbose, CTLFLAG_RW, &rndtest_verbose, 83 0, "display results on console"); 84 85 struct rndtest_state * 86 rndtest_attach(device_t dev) 87 { 88 struct rndtest_state *rsp; 89 90 rsp = malloc(sizeof (*rsp), M_DEVBUF, M_NOWAIT); 91 if (rsp != NULL) { 92 rsp->rs_begin = rsp->rs_buf; 93 rsp->rs_end = rsp->rs_buf + sizeof(rsp->rs_buf); 94 rsp->rs_current = rsp->rs_begin; 95 rsp->rs_discard = 1; 96 rsp->rs_collect = 1; 97 rsp->rs_parent = dev; 98 #if __FreeBSD_version < 500000 99 callout_init(&rsp->rs_to); 100 #else 101 callout_init(&rsp->rs_to, 1); 102 #endif 103 } else 104 device_printf(dev, "rndtest_init: no memory for state block\n"); 105 return (rsp); 106 } 107 108 void 109 rndtest_detach(struct rndtest_state *rsp) 110 { 111 callout_stop(&rsp->rs_to); 112 free(rsp, M_DEVBUF); 113 } 114 115 void 116 rndtest_harvest(struct rndtest_state *rsp, void *buf, u_int len) 117 { 118 size_t i; 119 /* 120 * If enabled, collect data and run tests when we have enough. 121 */ 122 if (rsp->rs_collect) { 123 for (i = 0; i < len; i++) { 124 *rsp->rs_current = ((u_char *) buf)[i]; 125 if (++rsp->rs_current == rsp->rs_end) { 126 rndtest_test(rsp); 127 rsp->rs_current = rsp->rs_begin; 128 /* 129 * If tests passed, turn off collection and 130 * schedule another test. Otherwise we keep 131 * testing until the data looks ok. 132 */ 133 if (!rsp->rs_discard && rndtest_retest != 0) { 134 rsp->rs_collect = 0; 135 callout_reset(&rsp->rs_to, 136 hz * rndtest_retest, 137 rndtest_timeout, rsp); 138 break; 139 } 140 } 141 } 142 } 143 /* 144 * Only stir entropy that passes muster into the pool. 145 */ 146 if (rsp->rs_discard) 147 rndstats.rst_discard += len; 148 else 149 /* MarkM: FIX!! Check that this does not swamp the harvester! */ 150 random_harvest_queue(buf, len, len*NBBY/2, RANDOM_PURE_RNDTEST); 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 vsnprintf(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 occurrences 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); 402