1 /* $FreeBSD$ */ 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, reset, 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 /* NB: 1 means the callout runs w/o Giant locked */ 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 /* 114 * If enabled, collect data and run tests when we have enough. 115 */ 116 if (rsp->rs_collect) { 117 size_t i; 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 random_harvest(buf, len, len*NBBY, 0, RANDOM_PURE); 145 } 146 147 static void 148 rndtest_test(struct rndtest_state *rsp) 149 { 150 int i, rv = 0; 151 152 rndstats.rst_tests++; 153 for (i = 0; i < RNDTEST_NTESTS; i++) 154 rv |= (*rndtest_funcs[i].test)(rsp); 155 rsp->rs_discard = (rv != 0); 156 } 157 158 static void 159 rndtest_report(struct rndtest_state *rsp, int failure, const char *fmt, ...) 160 { 161 char buf[80]; 162 va_list ap; 163 164 if (rndtest_verbose == 0) 165 return; 166 if (!failure && rndtest_verbose == 1) /* don't report successes */ 167 return; 168 va_start(ap, fmt); 169 vsnprintf(buf, sizeof (buf), fmt, ap); 170 va_end(ap); 171 device_printf(rsp->rs_parent, "rndtest: %s\n", buf); 172 } 173 174 #define RNDTEST_MONOBIT_MINONES 9725 175 #define RNDTEST_MONOBIT_MAXONES 10275 176 177 static int 178 rndtest_monobit(struct rndtest_state *rsp) 179 { 180 int i, ones = 0, j; 181 u_int8_t r; 182 183 for (i = 0; i < RNDTEST_NBYTES; i++) { 184 r = rsp->rs_buf[i]; 185 for (j = 0; j < 8; j++, r <<= 1) 186 if (r & 0x80) 187 ones++; 188 } 189 if (ones > RNDTEST_MONOBIT_MINONES && 190 ones < RNDTEST_MONOBIT_MAXONES) { 191 if (rndtest_verbose > 1) 192 rndtest_report(rsp, 0, "monobit pass (%d < %d < %d)", 193 RNDTEST_MONOBIT_MINONES, ones, 194 RNDTEST_MONOBIT_MAXONES); 195 return (0); 196 } else { 197 if (rndtest_verbose) 198 rndtest_report(rsp, 1, 199 "monobit failed (%d ones)", ones); 200 rndstats.rst_monobit++; 201 return (-1); 202 } 203 } 204 205 #define RNDTEST_RUNS_NINTERVAL 6 206 207 static const struct rndtest_runs_tabs { 208 u_int16_t min, max; 209 } rndtest_runs_tab[] = { 210 { 2343, 2657 }, 211 { 1135, 1365 }, 212 { 542, 708 }, 213 { 251, 373 }, 214 { 111, 201 }, 215 { 111, 201 }, 216 }; 217 218 static int 219 rndtest_runs(struct rndtest_state *rsp) 220 { 221 int i, j, ones, zeros, rv = 0; 222 int onei[RNDTEST_RUNS_NINTERVAL], zeroi[RNDTEST_RUNS_NINTERVAL]; 223 u_int8_t c; 224 225 bzero(onei, sizeof(onei)); 226 bzero(zeroi, sizeof(zeroi)); 227 ones = zeros = 0; 228 for (i = 0; i < RNDTEST_NBYTES; i++) { 229 c = rsp->rs_buf[i]; 230 for (j = 0; j < 8; j++, c <<= 1) { 231 if (c & 0x80) { 232 ones++; 233 rndtest_runs_record(rsp, zeros, zeroi); 234 zeros = 0; 235 } else { 236 zeros++; 237 rndtest_runs_record(rsp, ones, onei); 238 ones = 0; 239 } 240 } 241 } 242 rndtest_runs_record(rsp, ones, onei); 243 rndtest_runs_record(rsp, zeros, zeroi); 244 245 rv |= rndtest_runs_check(rsp, 0, zeroi); 246 rv |= rndtest_runs_check(rsp, 1, onei); 247 248 if (rv) 249 rndstats.rst_runs++; 250 251 return (rv); 252 } 253 254 static void 255 rndtest_runs_record(struct rndtest_state *rsp, int len, int *intrv) 256 { 257 if (len == 0) 258 return; 259 if (len > RNDTEST_RUNS_NINTERVAL) 260 len = RNDTEST_RUNS_NINTERVAL; 261 len -= 1; 262 intrv[len]++; 263 } 264 265 static int 266 rndtest_runs_check(struct rndtest_state *rsp, int val, int *src) 267 { 268 int i, rv = 0; 269 270 for (i = 0; i < RNDTEST_RUNS_NINTERVAL; i++) { 271 if (src[i] < rndtest_runs_tab[i].min || 272 src[i] > rndtest_runs_tab[i].max) { 273 rndtest_report(rsp, 1, 274 "%s interval %d failed (%d, %d-%d)", 275 val ? "ones" : "zeros", 276 i + 1, src[i], rndtest_runs_tab[i].min, 277 rndtest_runs_tab[i].max); 278 rv = -1; 279 } else { 280 rndtest_report(rsp, 0, 281 "runs pass %s interval %d (%d < %d < %d)", 282 val ? "ones" : "zeros", 283 i + 1, rndtest_runs_tab[i].min, src[i], 284 rndtest_runs_tab[i].max); 285 } 286 } 287 return (rv); 288 } 289 290 static int 291 rndtest_longruns(struct rndtest_state *rsp) 292 { 293 int i, j, ones = 0, zeros = 0, maxones = 0, maxzeros = 0; 294 u_int8_t c; 295 296 for (i = 0; i < RNDTEST_NBYTES; i++) { 297 c = rsp->rs_buf[i]; 298 for (j = 0; j < 8; j++, c <<= 1) { 299 if (c & 0x80) { 300 zeros = 0; 301 ones++; 302 if (ones > maxones) 303 maxones = ones; 304 } else { 305 ones = 0; 306 zeros++; 307 if (zeros > maxzeros) 308 maxzeros = zeros; 309 } 310 } 311 } 312 313 if (maxones < 26 && maxzeros < 26) { 314 rndtest_report(rsp, 0, "longruns pass (%d ones, %d zeros)", 315 maxones, maxzeros); 316 return (0); 317 } else { 318 rndtest_report(rsp, 1, "longruns fail (%d ones, %d zeros)", 319 maxones, maxzeros); 320 rndstats.rst_longruns++; 321 return (-1); 322 } 323 } 324 325 /* 326 * chi^2 test over 4 bits: (this is called the poker test in FIPS 140-2, 327 * but it is really the chi^2 test over 4 bits (the poker test as described 328 * by Knuth vol 2 is something different, and I take him as authoritative 329 * on nomenclature over NIST). 330 */ 331 #define RNDTEST_CHI4_K 16 332 #define RNDTEST_CHI4_K_MASK (RNDTEST_CHI4_K - 1) 333 334 /* 335 * The unnormalized values are used so that we don't have to worry about 336 * fractional precision. The "real" value is found by: 337 * (V - 1562500) * (16 / 5000) = Vn (where V is the unnormalized value) 338 */ 339 #define RNDTEST_CHI4_VMIN 1563181 /* 2.1792 */ 340 #define RNDTEST_CHI4_VMAX 1576929 /* 46.1728 */ 341 342 static int 343 rndtest_chi_4(struct rndtest_state *rsp) 344 { 345 unsigned int freq[RNDTEST_CHI4_K], i, sum; 346 347 for (i = 0; i < RNDTEST_CHI4_K; i++) 348 freq[i] = 0; 349 350 /* Get number of occurances of each 4 bit pattern */ 351 for (i = 0; i < RNDTEST_NBYTES; i++) { 352 freq[(rsp->rs_buf[i] >> 4) & RNDTEST_CHI4_K_MASK]++; 353 freq[(rsp->rs_buf[i] >> 0) & RNDTEST_CHI4_K_MASK]++; 354 } 355 356 for (i = 0, sum = 0; i < RNDTEST_CHI4_K; i++) 357 sum += freq[i] * freq[i]; 358 359 if (sum >= 1563181 && sum <= 1576929) { 360 rndtest_report(rsp, 0, "chi^2(4): pass (sum %u)", sum); 361 return (0); 362 } else { 363 rndtest_report(rsp, 1, "chi^2(4): failed (sum %u)", sum); 364 rndstats.rst_chi++; 365 return (-1); 366 } 367 } 368 369 static void 370 rndtest_timeout(void *xrsp) 371 { 372 struct rndtest_state *rsp = xrsp; 373 374 rsp->rs_collect = 1; 375 } 376 377 static int 378 rndtest_modevent(module_t mod, int type, void *unused) 379 { 380 switch (type) { 381 case MOD_LOAD: 382 return 0; 383 case MOD_UNLOAD: 384 return 0; 385 } 386 return EINVAL; 387 } 388 389 static moduledata_t rndtest_mod = { 390 "rndtest", 391 rndtest_modevent, 392 0 393 }; 394 DECLARE_MODULE(rndtest, rndtest_mod, SI_SUB_DRIVERS, SI_ORDER_ANY); 395 MODULE_VERSION(rndtest, 1); 396