1 /* $FreeBSD: src/sys/dev/rndtest/rndtest.c,v 1.1.4.1 2003/06/04 17:10:30 sam Exp $ */ 2 /* $DragonFly: src/sys/dev/crypto/rndtest/rndtest.c,v 1.9 2006/12/18 20:41:01 dillon Exp $ */ 3 /* $OpenBSD$ */ 4 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 "rndtest.h" 48 49 static int rndtest_modevent(module_t, int, void *); 50 static void rndtest_report(struct rndtest_state *, int, const char *, ...) 51 __printflike(3, 4); 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 (sizeof(rndtest_funcs)/sizeof(rndtest_funcs[0])) 74 75 SYSCTL_NODE(_kern, OID_AUTO, rndtest, CTLFLAG_RD, 0, "RNG test parameters"); 76 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 = kmalloc(sizeof (*rsp), M_DEVBUF, M_INTWAIT); 93 rsp->rs_begin = rsp->rs_buf; 94 rsp->rs_end = rsp->rs_buf + sizeof(rsp->rs_buf); 95 rsp->rs_current = rsp->rs_begin; 96 rsp->rs_discard = 1; 97 rsp->rs_collect = 1; 98 rsp->rs_parent = dev; 99 /* NB: 1 means the callout runs w/o Giant locked */ 100 callout_init_mp(&rsp->rs_to); 101 return (rsp); 102 } 103 104 void 105 rndtest_detach(struct rndtest_state *rsp) 106 { 107 callout_stop(&rsp->rs_to); 108 kfree(rsp, M_DEVBUF); 109 } 110 111 void 112 rndtest_harvest(struct rndtest_state *rsp, void *buf, u_int len) 113 { 114 size_t i; 115 /* 116 * If enabled, collect data and run tests when we have enough. 117 */ 118 if (rsp->rs_collect) { 119 for (i = 0; i < len; i++) { 120 *rsp->rs_current = ((u_char *) buf)[i]; 121 if (++rsp->rs_current == rsp->rs_end) { 122 rndtest_test(rsp); 123 rsp->rs_current = rsp->rs_begin; 124 /* 125 * If tests passed, turn off collection and 126 * schedule another test. Otherwise we keep 127 * testing until the data looks ok. 128 */ 129 if (!rsp->rs_discard && rndtest_retest != 0) { 130 rsp->rs_collect = 0; 131 callout_reset(&rsp->rs_to, 132 hz * rndtest_retest, 133 rndtest_timeout, rsp); 134 break; 135 } 136 } 137 } 138 } 139 /* 140 * Only stir entropy that passes muster into the pool. 141 */ 142 if (rsp->rs_discard) 143 rndstats.rst_discard += len; 144 else { 145 #if defined(__DragonFly__) || __FreeBSD_version < 500000 146 /* XXX verify buffer is word aligned */ 147 u_int32_t *p = buf; 148 for (len /= sizeof (u_int32_t); len; len--) 149 add_true_randomness(*p++); 150 #else 151 random_harvest(buf, len, len*NBBY, 0, RANDOM_PURE); 152 #endif 153 } 154 } 155 156 static void 157 rndtest_test(struct rndtest_state *rsp) 158 { 159 int i, rv = 0; 160 161 rndstats.rst_tests++; 162 for (i = 0; i < RNDTEST_NTESTS; i++) 163 rv |= (*rndtest_funcs[i].test)(rsp); 164 rsp->rs_discard = (rv != 0); 165 } 166 167 static void 168 rndtest_report(struct rndtest_state *rsp, int failure, const char *fmt, ...) 169 { 170 char buf[80]; 171 __va_list ap; 172 173 if (rndtest_verbose == 0) 174 return; 175 if (!failure && rndtest_verbose == 1) /* don't report successes */ 176 return; 177 __va_start(ap, fmt); 178 kvsnprintf(buf, sizeof (buf), fmt, ap); 179 __va_end(ap); 180 device_printf(rsp->rs_parent, "rndtest: %s\n", buf); 181 } 182 183 #define RNDTEST_MONOBIT_MINONES 9725 184 #define RNDTEST_MONOBIT_MAXONES 10275 185 186 static int 187 rndtest_monobit(struct rndtest_state *rsp) 188 { 189 int i, ones = 0, j; 190 u_int8_t r; 191 192 for (i = 0; i < RNDTEST_NBYTES; i++) { 193 r = rsp->rs_buf[i]; 194 for (j = 0; j < 8; j++, r <<= 1) 195 if (r & 0x80) 196 ones++; 197 } 198 if (ones > RNDTEST_MONOBIT_MINONES && 199 ones < RNDTEST_MONOBIT_MAXONES) { 200 if (rndtest_verbose > 1) 201 rndtest_report(rsp, 0, "monobit pass (%d < %d < %d)", 202 RNDTEST_MONOBIT_MINONES, ones, 203 RNDTEST_MONOBIT_MAXONES); 204 return (0); 205 } else { 206 if (rndtest_verbose) 207 rndtest_report(rsp, 1, 208 "monobit failed (%d ones)", ones); 209 rndstats.rst_monobit++; 210 return (-1); 211 } 212 } 213 214 #define RNDTEST_RUNS_NINTERVAL 6 215 216 static const struct rndtest_runs_tabs { 217 u_int16_t min, max; 218 } rndtest_runs_tab[] = { 219 { 2343, 2657 }, 220 { 1135, 1365 }, 221 { 542, 708 }, 222 { 251, 373 }, 223 { 111, 201 }, 224 { 111, 201 }, 225 }; 226 227 static int 228 rndtest_runs(struct rndtest_state *rsp) 229 { 230 int i, j, ones, zeros, rv = 0; 231 int onei[RNDTEST_RUNS_NINTERVAL], zeroi[RNDTEST_RUNS_NINTERVAL]; 232 u_int8_t c; 233 234 bzero(onei, sizeof(onei)); 235 bzero(zeroi, sizeof(zeroi)); 236 ones = zeros = 0; 237 for (i = 0; i < RNDTEST_NBYTES; i++) { 238 c = rsp->rs_buf[i]; 239 for (j = 0; j < 8; j++, c <<= 1) { 240 if (c & 0x80) { 241 ones++; 242 rndtest_runs_record(rsp, zeros, zeroi); 243 zeros = 0; 244 } else { 245 zeros++; 246 rndtest_runs_record(rsp, ones, onei); 247 ones = 0; 248 } 249 } 250 } 251 rndtest_runs_record(rsp, ones, onei); 252 rndtest_runs_record(rsp, zeros, zeroi); 253 254 rv |= rndtest_runs_check(rsp, 0, zeroi); 255 rv |= rndtest_runs_check(rsp, 1, onei); 256 257 if (rv) 258 rndstats.rst_runs++; 259 260 return (rv); 261 } 262 263 static void 264 rndtest_runs_record(struct rndtest_state *rsp, int len, int *intrv) 265 { 266 if (len == 0) 267 return; 268 if (len > RNDTEST_RUNS_NINTERVAL) 269 len = RNDTEST_RUNS_NINTERVAL; 270 len -= 1; 271 intrv[len]++; 272 } 273 274 static int 275 rndtest_runs_check(struct rndtest_state *rsp, int val, int *src) 276 { 277 int i, rv = 0; 278 279 for (i = 0; i < RNDTEST_RUNS_NINTERVAL; i++) { 280 if (src[i] < rndtest_runs_tab[i].min || 281 src[i] > rndtest_runs_tab[i].max) { 282 rndtest_report(rsp, 1, 283 "%s interval %d failed (%d, %d-%d)", 284 val ? "ones" : "zeros", 285 i + 1, src[i], rndtest_runs_tab[i].min, 286 rndtest_runs_tab[i].max); 287 rv = -1; 288 } else { 289 rndtest_report(rsp, 0, 290 "runs pass %s interval %d (%d < %d < %d)", 291 val ? "ones" : "zeros", 292 i + 1, rndtest_runs_tab[i].min, src[i], 293 rndtest_runs_tab[i].max); 294 } 295 } 296 return (rv); 297 } 298 299 static int 300 rndtest_longruns(struct rndtest_state *rsp) 301 { 302 int i, j, ones = 0, zeros = 0, maxones = 0, maxzeros = 0; 303 u_int8_t c; 304 305 for (i = 0; i < RNDTEST_NBYTES; i++) { 306 c = rsp->rs_buf[i]; 307 for (j = 0; j < 8; j++, c <<= 1) { 308 if (c & 0x80) { 309 zeros = 0; 310 ones++; 311 if (ones > maxones) 312 maxones = ones; 313 } else { 314 ones = 0; 315 zeros++; 316 if (zeros > maxzeros) 317 maxzeros = zeros; 318 } 319 } 320 } 321 322 if (maxones < 26 && maxzeros < 26) { 323 rndtest_report(rsp, 0, "longruns pass (%d ones, %d zeros)", 324 maxones, maxzeros); 325 return (0); 326 } else { 327 rndtest_report(rsp, 1, "longruns fail (%d ones, %d zeros)", 328 maxones, maxzeros); 329 rndstats.rst_longruns++; 330 return (-1); 331 } 332 } 333 334 /* 335 * chi^2 test over 4 bits: (this is called the poker test in FIPS 140-2, 336 * but it is really the chi^2 test over 4 bits (the poker test as described 337 * by Knuth vol 2 is something different, and I take him as authoritative 338 * on nomenclature over NIST). 339 */ 340 #define RNDTEST_CHI4_K 16 341 #define RNDTEST_CHI4_K_MASK (RNDTEST_CHI4_K - 1) 342 343 /* 344 * The unnormalized values are used so that we don't have to worry about 345 * fractional precision. The "real" value is found by: 346 * (V - 1562500) * (16 / 5000) = Vn (where V is the unnormalized value) 347 */ 348 #define RNDTEST_CHI4_VMIN 1563181 /* 2.1792 */ 349 #define RNDTEST_CHI4_VMAX 1576929 /* 46.1728 */ 350 351 static int 352 rndtest_chi_4(struct rndtest_state *rsp) 353 { 354 unsigned int freq[RNDTEST_CHI4_K], i, sum; 355 356 for (i = 0; i < RNDTEST_CHI4_K; i++) 357 freq[i] = 0; 358 359 /* Get number of occurances of each 4 bit pattern */ 360 for (i = 0; i < RNDTEST_NBYTES; i++) { 361 freq[(rsp->rs_buf[i] >> 4) & RNDTEST_CHI4_K_MASK]++; 362 freq[(rsp->rs_buf[i] >> 0) & RNDTEST_CHI4_K_MASK]++; 363 } 364 365 for (i = 0, sum = 0; i < RNDTEST_CHI4_K; i++) 366 sum += freq[i] * freq[i]; 367 368 if (sum >= 1563181 && sum <= 1576929) { 369 rndtest_report(rsp, 0, "chi^2(4): pass (sum %u)", sum); 370 return (0); 371 } else { 372 rndtest_report(rsp, 1, "chi^2(4): failed (sum %u)", sum); 373 rndstats.rst_chi++; 374 return (-1); 375 } 376 } 377 378 static void 379 rndtest_timeout(void *xrsp) 380 { 381 struct rndtest_state *rsp = xrsp; 382 383 rsp->rs_collect = 1; 384 } 385 386 static int 387 rndtest_modevent(module_t mod, int type, void *unused) 388 { 389 switch (type) { 390 case MOD_LOAD: 391 return 0; 392 case MOD_UNLOAD: 393 return 0; 394 } 395 return EINVAL; 396 } 397 398 static moduledata_t rndtest_mod = { 399 "rndtest", 400 rndtest_modevent, 401 0 402 }; 403 DECLARE_MODULE(rndtest, rndtest_mod, SI_SUB_DRIVERS, SI_ORDER_ANY); 404 MODULE_VERSION(rndtest, 1); 405