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 (sizeof(rndtest_funcs)/sizeof(rndtest_funcs[0])) 72 73 SYSCTL_NODE(_kern, OID_AUTO, rndtest, CTLFLAG_RD, 0, "RNG test parameters"); 74 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, CALLOUT_MPSAFE); 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 #if __FreeBSD_version < 500000 150 /* XXX verify buffer is word aligned */ 151 u_int32_t *p = buf; 152 for (len /= sizeof (u_int32_t); len; len--) 153 add_true_randomness(*p++); 154 #else 155 random_harvest(buf, len, len*NBBY, 0, RANDOM_PURE); 156 #endif 157 } 158 } 159 160 static void 161 rndtest_test(struct rndtest_state *rsp) 162 { 163 int i, rv = 0; 164 165 rndstats.rst_tests++; 166 for (i = 0; i < RNDTEST_NTESTS; i++) 167 rv |= (*rndtest_funcs[i].test)(rsp); 168 rsp->rs_discard = (rv != 0); 169 } 170 171 static void 172 rndtest_report(struct rndtest_state *rsp, int failure, const char *fmt, ...) 173 { 174 char buf[80]; 175 va_list ap; 176 177 if (rndtest_verbose == 0) 178 return; 179 if (!failure && rndtest_verbose == 1) /* don't report successes */ 180 return; 181 va_start(ap, fmt); 182 vsnprintf(buf, sizeof (buf), fmt, ap); 183 va_end(ap); 184 device_printf(rsp->rs_parent, "rndtest: %s\n", buf); 185 } 186 187 #define RNDTEST_MONOBIT_MINONES 9725 188 #define RNDTEST_MONOBIT_MAXONES 10275 189 190 static int 191 rndtest_monobit(struct rndtest_state *rsp) 192 { 193 int i, ones = 0, j; 194 u_int8_t r; 195 196 for (i = 0; i < RNDTEST_NBYTES; i++) { 197 r = rsp->rs_buf[i]; 198 for (j = 0; j < 8; j++, r <<= 1) 199 if (r & 0x80) 200 ones++; 201 } 202 if (ones > RNDTEST_MONOBIT_MINONES && 203 ones < RNDTEST_MONOBIT_MAXONES) { 204 if (rndtest_verbose > 1) 205 rndtest_report(rsp, 0, "monobit pass (%d < %d < %d)", 206 RNDTEST_MONOBIT_MINONES, ones, 207 RNDTEST_MONOBIT_MAXONES); 208 return (0); 209 } else { 210 if (rndtest_verbose) 211 rndtest_report(rsp, 1, 212 "monobit failed (%d ones)", ones); 213 rndstats.rst_monobit++; 214 return (-1); 215 } 216 } 217 218 #define RNDTEST_RUNS_NINTERVAL 6 219 220 static const struct rndtest_runs_tabs { 221 u_int16_t min, max; 222 } rndtest_runs_tab[] = { 223 { 2343, 2657 }, 224 { 1135, 1365 }, 225 { 542, 708 }, 226 { 251, 373 }, 227 { 111, 201 }, 228 { 111, 201 }, 229 }; 230 231 static int 232 rndtest_runs(struct rndtest_state *rsp) 233 { 234 int i, j, ones, zeros, rv = 0; 235 int onei[RNDTEST_RUNS_NINTERVAL], zeroi[RNDTEST_RUNS_NINTERVAL]; 236 u_int8_t c; 237 238 bzero(onei, sizeof(onei)); 239 bzero(zeroi, sizeof(zeroi)); 240 ones = zeros = 0; 241 for (i = 0; i < RNDTEST_NBYTES; i++) { 242 c = rsp->rs_buf[i]; 243 for (j = 0; j < 8; j++, c <<= 1) { 244 if (c & 0x80) { 245 ones++; 246 rndtest_runs_record(rsp, zeros, zeroi); 247 zeros = 0; 248 } else { 249 zeros++; 250 rndtest_runs_record(rsp, ones, onei); 251 ones = 0; 252 } 253 } 254 } 255 rndtest_runs_record(rsp, ones, onei); 256 rndtest_runs_record(rsp, zeros, zeroi); 257 258 rv |= rndtest_runs_check(rsp, 0, zeroi); 259 rv |= rndtest_runs_check(rsp, 1, onei); 260 261 if (rv) 262 rndstats.rst_runs++; 263 264 return (rv); 265 } 266 267 static void 268 rndtest_runs_record(struct rndtest_state *rsp, int len, int *intrv) 269 { 270 if (len == 0) 271 return; 272 if (len > RNDTEST_RUNS_NINTERVAL) 273 len = RNDTEST_RUNS_NINTERVAL; 274 len -= 1; 275 intrv[len]++; 276 } 277 278 static int 279 rndtest_runs_check(struct rndtest_state *rsp, int val, int *src) 280 { 281 int i, rv = 0; 282 283 for (i = 0; i < RNDTEST_RUNS_NINTERVAL; i++) { 284 if (src[i] < rndtest_runs_tab[i].min || 285 src[i] > rndtest_runs_tab[i].max) { 286 rndtest_report(rsp, 1, 287 "%s interval %d failed (%d, %d-%d)", 288 val ? "ones" : "zeros", 289 i + 1, src[i], rndtest_runs_tab[i].min, 290 rndtest_runs_tab[i].max); 291 rv = -1; 292 } else { 293 rndtest_report(rsp, 0, 294 "runs pass %s interval %d (%d < %d < %d)", 295 val ? "ones" : "zeros", 296 i + 1, rndtest_runs_tab[i].min, src[i], 297 rndtest_runs_tab[i].max); 298 } 299 } 300 return (rv); 301 } 302 303 static int 304 rndtest_longruns(struct rndtest_state *rsp) 305 { 306 int i, j, ones = 0, zeros = 0, maxones = 0, maxzeros = 0; 307 u_int8_t c; 308 309 for (i = 0; i < RNDTEST_NBYTES; i++) { 310 c = rsp->rs_buf[i]; 311 for (j = 0; j < 8; j++, c <<= 1) { 312 if (c & 0x80) { 313 zeros = 0; 314 ones++; 315 if (ones > maxones) 316 maxones = ones; 317 } else { 318 ones = 0; 319 zeros++; 320 if (zeros > maxzeros) 321 maxzeros = zeros; 322 } 323 } 324 } 325 326 if (maxones < 26 && maxzeros < 26) { 327 rndtest_report(rsp, 0, "longruns pass (%d ones, %d zeros)", 328 maxones, maxzeros); 329 return (0); 330 } else { 331 rndtest_report(rsp, 1, "longruns fail (%d ones, %d zeros)", 332 maxones, maxzeros); 333 rndstats.rst_longruns++; 334 return (-1); 335 } 336 } 337 338 /* 339 * chi^2 test over 4 bits: (this is called the poker test in FIPS 140-2, 340 * but it is really the chi^2 test over 4 bits (the poker test as described 341 * by Knuth vol 2 is something different, and I take him as authoritative 342 * on nomenclature over NIST). 343 */ 344 #define RNDTEST_CHI4_K 16 345 #define RNDTEST_CHI4_K_MASK (RNDTEST_CHI4_K - 1) 346 347 /* 348 * The unnormalized values are used so that we don't have to worry about 349 * fractional precision. The "real" value is found by: 350 * (V - 1562500) * (16 / 5000) = Vn (where V is the unnormalized value) 351 */ 352 #define RNDTEST_CHI4_VMIN 1563181 /* 2.1792 */ 353 #define RNDTEST_CHI4_VMAX 1576929 /* 46.1728 */ 354 355 static int 356 rndtest_chi_4(struct rndtest_state *rsp) 357 { 358 unsigned int freq[RNDTEST_CHI4_K], i, sum; 359 360 for (i = 0; i < RNDTEST_CHI4_K; i++) 361 freq[i] = 0; 362 363 /* Get number of occurances of each 4 bit pattern */ 364 for (i = 0; i < RNDTEST_NBYTES; i++) { 365 freq[(rsp->rs_buf[i] >> 4) & RNDTEST_CHI4_K_MASK]++; 366 freq[(rsp->rs_buf[i] >> 0) & RNDTEST_CHI4_K_MASK]++; 367 } 368 369 for (i = 0, sum = 0; i < RNDTEST_CHI4_K; i++) 370 sum += freq[i] * freq[i]; 371 372 if (sum >= 1563181 && sum <= 1576929) { 373 rndtest_report(rsp, 0, "chi^2(4): pass (sum %u)", sum); 374 return (0); 375 } else { 376 rndtest_report(rsp, 1, "chi^2(4): failed (sum %u)", sum); 377 rndstats.rst_chi++; 378 return (-1); 379 } 380 } 381 382 static void 383 rndtest_timeout(void *xrsp) 384 { 385 struct rndtest_state *rsp = xrsp; 386 387 rsp->rs_collect = 1; 388 } 389 390 static int 391 rndtest_modevent(module_t mod, int type, void *unused) 392 { 393 switch (type) { 394 case MOD_LOAD: 395 return 0; 396 case MOD_UNLOAD: 397 return 0; 398 } 399 return EINVAL; 400 } 401 402 static moduledata_t rndtest_mod = { 403 "rndtest", 404 rndtest_modevent, 405 0 406 }; 407 DECLARE_MODULE(rndtest, rndtest_mod, SI_SUB_DRIVERS, SI_ORDER_ANY); 408 MODULE_VERSION(rndtest, 1); 409