1 /*- 2 * Copyright (c) 2017 Oliver Pinter 3 * Copyright (c) 2017 W. Dean Freeman 4 * Copyright (c) 2000-2015 Mark R V Murray 5 * Copyright (c) 2013 Arthur Mesh 6 * Copyright (c) 2004 Robert N. M. Watson 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 * in this position and unchanged. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 * 30 */ 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/ck.h> 35 #include <sys/conf.h> 36 #include <sys/epoch.h> 37 #include <sys/eventhandler.h> 38 #include <sys/hash.h> 39 #include <sys/kernel.h> 40 #include <sys/kthread.h> 41 #include <sys/linker.h> 42 #include <sys/lock.h> 43 #include <sys/malloc.h> 44 #include <sys/module.h> 45 #include <sys/mutex.h> 46 #include <sys/random.h> 47 #include <sys/sbuf.h> 48 #include <sys/sysctl.h> 49 #include <sys/unistd.h> 50 51 #include <machine/atomic.h> 52 #include <machine/cpu.h> 53 54 #include <crypto/rijndael/rijndael-api-fst.h> 55 #include <crypto/sha2/sha256.h> 56 57 #include <dev/random/fortuna.h> 58 #include <dev/random/hash.h> 59 #include <dev/random/randomdev.h> 60 #include <dev/random/random_harvestq.h> 61 62 #if defined(RANDOM_ENABLE_ETHER) 63 #define _RANDOM_HARVEST_ETHER_OFF 0 64 #else 65 #define _RANDOM_HARVEST_ETHER_OFF (1u << RANDOM_NET_ETHER) 66 #endif 67 #if defined(RANDOM_ENABLE_UMA) 68 #define _RANDOM_HARVEST_UMA_OFF 0 69 #else 70 #define _RANDOM_HARVEST_UMA_OFF (1u << RANDOM_UMA) 71 #endif 72 73 /* 74 * Note that random_sources_feed() will also use this to try and split up 75 * entropy into a subset of pools per iteration with the goal of feeding 76 * HARVESTSIZE into every pool at least once per second. 77 */ 78 #define RANDOM_KTHREAD_HZ 10 79 80 static void random_kthread(void); 81 static void random_sources_feed(void); 82 83 /* 84 * Random must initialize much earlier than epoch, but we can initialize the 85 * epoch code before SMP starts. Prior to SMP, we can safely bypass 86 * concurrency primitives. 87 */ 88 static __read_mostly bool epoch_inited; 89 static __read_mostly epoch_t rs_epoch; 90 91 /* 92 * How many events to queue up. We create this many items in 93 * an 'empty' queue, then transfer them to the 'harvest' queue with 94 * supplied junk. When used, they are transferred back to the 95 * 'empty' queue. 96 */ 97 #define RANDOM_RING_MAX 1024 98 #define RANDOM_ACCUM_MAX 8 99 100 /* 1 to let the kernel thread run, 0 to terminate, -1 to mark completion */ 101 volatile int random_kthread_control; 102 103 104 /* Allow the sysadmin to select the broad category of 105 * entropy types to harvest. 106 */ 107 __read_frequently u_int hc_source_mask; 108 109 struct random_sources { 110 CK_LIST_ENTRY(random_sources) rrs_entries; 111 struct random_source *rrs_source; 112 }; 113 114 static CK_LIST_HEAD(sources_head, random_sources) source_list = 115 CK_LIST_HEAD_INITIALIZER(source_list); 116 117 SYSCTL_NODE(_kern_random, OID_AUTO, harvest, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 118 "Entropy Device Parameters"); 119 120 /* 121 * Put all the harvest queue context stuff in one place. 122 * this make is a bit easier to lock and protect. 123 */ 124 static struct harvest_context { 125 /* The harvest mutex protects all of harvest_context and 126 * the related data. 127 */ 128 struct mtx hc_mtx; 129 /* Round-robin destination cache. */ 130 u_int hc_destination[ENTROPYSOURCE]; 131 /* The context of the kernel thread processing harvested entropy */ 132 struct proc *hc_kthread_proc; 133 /* 134 * A pair of buffers for queued events. New events are added to the 135 * active queue while the kthread processes the other one in parallel. 136 */ 137 struct entropy_buffer { 138 struct harvest_event ring[RANDOM_RING_MAX]; 139 u_int pos; 140 } hc_entropy_buf[2]; 141 u_int hc_active_buf; 142 struct fast_entropy_accumulator { 143 volatile u_int pos; 144 uint32_t buf[RANDOM_ACCUM_MAX]; 145 } hc_entropy_fast_accumulator; 146 } harvest_context; 147 148 #define RANDOM_HARVEST_INIT_LOCK() mtx_init(&harvest_context.hc_mtx, \ 149 "entropy harvest mutex", NULL, MTX_SPIN) 150 #define RANDOM_HARVEST_LOCK() mtx_lock_spin(&harvest_context.hc_mtx) 151 #define RANDOM_HARVEST_UNLOCK() mtx_unlock_spin(&harvest_context.hc_mtx) 152 153 static struct kproc_desc random_proc_kp = { 154 "rand_harvestq", 155 random_kthread, 156 &harvest_context.hc_kthread_proc, 157 }; 158 159 /* Pass the given event straight through to Fortuna/Whatever. */ 160 static __inline void 161 random_harvestq_fast_process_event(struct harvest_event *event) 162 { 163 p_random_alg_context->ra_event_processor(event); 164 explicit_bzero(event, sizeof(*event)); 165 } 166 167 static void 168 random_kthread(void) 169 { 170 struct harvest_context *hc; 171 172 hc = &harvest_context; 173 for (random_kthread_control = 1; random_kthread_control;) { 174 struct entropy_buffer *buf; 175 u_int entries; 176 177 /* Deal with queued events. */ 178 RANDOM_HARVEST_LOCK(); 179 buf = &hc->hc_entropy_buf[hc->hc_active_buf]; 180 entries = buf->pos; 181 buf->pos = 0; 182 hc->hc_active_buf = (hc->hc_active_buf + 1) % 183 nitems(hc->hc_entropy_buf); 184 RANDOM_HARVEST_UNLOCK(); 185 for (u_int i = 0; i < entries; i++) 186 random_harvestq_fast_process_event(&buf->ring[i]); 187 188 /* Poll sources of noise. */ 189 random_sources_feed(); 190 191 /* XXX: FIX!! Increase the high-performance data rate? Need some measurements first. */ 192 for (u_int i = 0; i < RANDOM_ACCUM_MAX; i++) { 193 if (hc->hc_entropy_fast_accumulator.buf[i]) { 194 random_harvest_direct(&hc->hc_entropy_fast_accumulator.buf[i], 195 sizeof(hc->hc_entropy_fast_accumulator.buf[0]), RANDOM_UMA); 196 hc->hc_entropy_fast_accumulator.buf[i] = 0; 197 } 198 } 199 /* XXX: FIX!! This is a *great* place to pass hardware/live entropy to random(9) */ 200 tsleep_sbt(&hc->hc_kthread_proc, 0, "-", 201 SBT_1S/RANDOM_KTHREAD_HZ, 0, C_PREL(1)); 202 } 203 random_kthread_control = -1; 204 wakeup(&hc->hc_kthread_proc); 205 kproc_exit(0); 206 /* NOTREACHED */ 207 } 208 SYSINIT(random_device_h_proc, SI_SUB_KICK_SCHEDULER, SI_ORDER_ANY, kproc_start, 209 &random_proc_kp); 210 _Static_assert(SI_SUB_KICK_SCHEDULER > SI_SUB_RANDOM, 211 "random kthread starting before subsystem initialization"); 212 213 static void 214 rs_epoch_init(void *dummy __unused) 215 { 216 rs_epoch = epoch_alloc("Random Sources", EPOCH_PREEMPT); 217 epoch_inited = true; 218 } 219 SYSINIT(rs_epoch_init, SI_SUB_EPOCH, SI_ORDER_ANY, rs_epoch_init, NULL); 220 221 /* 222 * Run through all fast sources reading entropy for the given 223 * number of rounds, which should be a multiple of the number 224 * of entropy accumulation pools in use; it is 32 for Fortuna. 225 */ 226 static void 227 random_sources_feed(void) 228 { 229 uint32_t entropy[HARVESTSIZE]; 230 struct epoch_tracker et; 231 struct random_sources *rrs; 232 u_int i, n, npools; 233 bool rse_warm; 234 235 rse_warm = epoch_inited; 236 237 /* 238 * Evenly-ish distribute pool population across the second based on how 239 * frequently random_kthread iterates. 240 * 241 * For Fortuna, the math currently works out as such: 242 * 243 * 64 bits * 4 pools = 256 bits per iteration 244 * 256 bits * 10 Hz = 2560 bits per second, 320 B/s 245 * 246 */ 247 npools = howmany(p_random_alg_context->ra_poolcount, RANDOM_KTHREAD_HZ); 248 249 /*- 250 * If we're not seeded yet, attempt to perform a "full seed", filling 251 * all of the PRNG's pools with entropy; if there is enough entropy 252 * available from "fast" entropy sources this will allow us to finish 253 * seeding and unblock the boot process immediately rather than being 254 * stuck for a few seconds with random_kthread gradually collecting a 255 * small chunk of entropy every 1 / RANDOM_KTHREAD_HZ seconds. 256 * 257 * We collect RANDOM_FORTUNA_DEFPOOLSIZE bytes per pool, i.e. enough 258 * to fill Fortuna's pools in the default configuration. With another 259 * PRNG or smaller pools for Fortuna, we might collect more entropy 260 * than needed to fill the pools, but this is harmless; alternatively, 261 * a different PRNG, larger pools, or fast entropy sources which are 262 * not able to provide as much entropy as we request may result in the 263 * not being fully seeded (and thus remaining blocked) but in that 264 * case we will return here after 1 / RANDOM_KTHREAD_HZ seconds and 265 * try again for a large amount of entropy. 266 */ 267 if (!p_random_alg_context->ra_seeded()) 268 npools = howmany(p_random_alg_context->ra_poolcount * 269 RANDOM_FORTUNA_DEFPOOLSIZE, sizeof(entropy)); 270 271 /* 272 * Step over all of live entropy sources, and feed their output 273 * to the system-wide RNG. 274 */ 275 if (rse_warm) 276 epoch_enter_preempt(rs_epoch, &et); 277 CK_LIST_FOREACH(rrs, &source_list, rrs_entries) { 278 for (i = 0; i < npools; i++) { 279 n = rrs->rrs_source->rs_read(entropy, sizeof(entropy)); 280 KASSERT((n <= sizeof(entropy)), ("%s: rs_read returned too much data (%u > %zu)", __func__, n, sizeof(entropy))); 281 /* 282 * Sometimes the HW entropy source doesn't have anything 283 * ready for us. This isn't necessarily untrustworthy. 284 * We don't perform any other verification of an entropy 285 * source (i.e., length is allowed to be anywhere from 1 286 * to sizeof(entropy), quality is unchecked, etc), so 287 * don't balk verbosely at slow random sources either. 288 * There are reports that RDSEED on x86 metal falls 289 * behind the rate at which we query it, for example. 290 * But it's still a better entropy source than RDRAND. 291 */ 292 if (n == 0) 293 continue; 294 random_harvest_direct(entropy, n, rrs->rrs_source->rs_source); 295 } 296 } 297 if (rse_warm) 298 epoch_exit_preempt(rs_epoch, &et); 299 explicit_bzero(entropy, sizeof(entropy)); 300 } 301 302 static int 303 random_check_uint_harvestmask(SYSCTL_HANDLER_ARGS) 304 { 305 static const u_int user_immutable_mask = 306 (((1 << ENTROPYSOURCE) - 1) & (-1UL << RANDOM_PURE_START)) | 307 _RANDOM_HARVEST_ETHER_OFF | _RANDOM_HARVEST_UMA_OFF; 308 309 int error; 310 u_int value, orig_value; 311 312 orig_value = value = hc_source_mask; 313 error = sysctl_handle_int(oidp, &value, 0, req); 314 if (error != 0 || req->newptr == NULL) 315 return (error); 316 317 if (flsl(value) > ENTROPYSOURCE) 318 return (EINVAL); 319 320 /* 321 * Disallow userspace modification of pure entropy sources. 322 */ 323 hc_source_mask = (value & ~user_immutable_mask) | 324 (orig_value & user_immutable_mask); 325 return (0); 326 } 327 SYSCTL_PROC(_kern_random_harvest, OID_AUTO, mask, 328 CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0, 329 random_check_uint_harvestmask, "IU", 330 "Entropy harvesting mask"); 331 332 static int 333 random_print_harvestmask(SYSCTL_HANDLER_ARGS) 334 { 335 struct sbuf sbuf; 336 int error, i; 337 338 error = sysctl_wire_old_buffer(req, 0); 339 if (error == 0) { 340 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 341 for (i = ENTROPYSOURCE - 1; i >= 0; i--) 342 sbuf_cat(&sbuf, (hc_source_mask & (1 << i)) ? "1" : "0"); 343 error = sbuf_finish(&sbuf); 344 sbuf_delete(&sbuf); 345 } 346 return (error); 347 } 348 SYSCTL_PROC(_kern_random_harvest, OID_AUTO, mask_bin, 349 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, 350 random_print_harvestmask, "A", 351 "Entropy harvesting mask (printable)"); 352 353 static const char *random_source_descr[ENTROPYSOURCE] = { 354 [RANDOM_CACHED] = "CACHED", 355 [RANDOM_ATTACH] = "ATTACH", 356 [RANDOM_KEYBOARD] = "KEYBOARD", 357 [RANDOM_MOUSE] = "MOUSE", 358 [RANDOM_NET_TUN] = "NET_TUN", 359 [RANDOM_NET_ETHER] = "NET_ETHER", 360 [RANDOM_NET_NG] = "NET_NG", 361 [RANDOM_INTERRUPT] = "INTERRUPT", 362 [RANDOM_SWI] = "SWI", 363 [RANDOM_FS_ATIME] = "FS_ATIME", 364 [RANDOM_UMA] = "UMA", 365 [RANDOM_CALLOUT] = "CALLOUT", /* ENVIRONMENTAL_END */ 366 [RANDOM_PURE_OCTEON] = "PURE_OCTEON", /* PURE_START */ 367 [RANDOM_PURE_SAFE] = "PURE_SAFE", 368 [RANDOM_PURE_GLXSB] = "PURE_GLXSB", 369 [RANDOM_PURE_HIFN] = "PURE_HIFN", 370 [RANDOM_PURE_RDRAND] = "PURE_RDRAND", 371 [RANDOM_PURE_NEHEMIAH] = "PURE_NEHEMIAH", 372 [RANDOM_PURE_RNDTEST] = "PURE_RNDTEST", 373 [RANDOM_PURE_VIRTIO] = "PURE_VIRTIO", 374 [RANDOM_PURE_BROADCOM] = "PURE_BROADCOM", 375 [RANDOM_PURE_CCP] = "PURE_CCP", 376 [RANDOM_PURE_DARN] = "PURE_DARN", 377 [RANDOM_PURE_TPM] = "PURE_TPM", 378 [RANDOM_PURE_VMGENID] = "PURE_VMGENID", 379 [RANDOM_PURE_QUALCOMM] = "PURE_QUALCOMM", 380 [RANDOM_PURE_ARMV8] = "PURE_ARMV8", 381 [RANDOM_PURE_ARM_TRNG] = "PURE_ARM_TRNG", 382 /* "ENTROPYSOURCE" */ 383 }; 384 385 static int 386 random_print_harvestmask_symbolic(SYSCTL_HANDLER_ARGS) 387 { 388 struct sbuf sbuf; 389 int error, i; 390 bool first; 391 392 first = true; 393 error = sysctl_wire_old_buffer(req, 0); 394 if (error == 0) { 395 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 396 for (i = ENTROPYSOURCE - 1; i >= 0; i--) { 397 if (i >= RANDOM_PURE_START && 398 (hc_source_mask & (1 << i)) == 0) 399 continue; 400 if (!first) 401 sbuf_cat(&sbuf, ","); 402 sbuf_cat(&sbuf, !(hc_source_mask & (1 << i)) ? "[" : ""); 403 sbuf_cat(&sbuf, random_source_descr[i]); 404 sbuf_cat(&sbuf, !(hc_source_mask & (1 << i)) ? "]" : ""); 405 first = false; 406 } 407 error = sbuf_finish(&sbuf); 408 sbuf_delete(&sbuf); 409 } 410 return (error); 411 } 412 SYSCTL_PROC(_kern_random_harvest, OID_AUTO, mask_symbolic, 413 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, 414 random_print_harvestmask_symbolic, "A", 415 "Entropy harvesting mask (symbolic)"); 416 417 static void 418 random_harvestq_init(void *unused __unused) 419 { 420 static const u_int almost_everything_mask = 421 (((1 << (RANDOM_ENVIRONMENTAL_END + 1)) - 1) & 422 ~_RANDOM_HARVEST_ETHER_OFF & ~_RANDOM_HARVEST_UMA_OFF); 423 424 hc_source_mask = almost_everything_mask; 425 RANDOM_HARVEST_INIT_LOCK(); 426 harvest_context.hc_active_buf = 0; 427 } 428 SYSINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_THIRD, random_harvestq_init, NULL); 429 430 /* 431 * Subroutine to slice up a contiguous chunk of 'entropy' and feed it into the 432 * underlying algorithm. Returns number of bytes actually fed into underlying 433 * algorithm. 434 */ 435 static size_t 436 random_early_prime(char *entropy, size_t len) 437 { 438 struct harvest_event event; 439 size_t i; 440 441 len = rounddown(len, sizeof(event.he_entropy)); 442 if (len == 0) 443 return (0); 444 445 for (i = 0; i < len; i += sizeof(event.he_entropy)) { 446 event.he_somecounter = random_get_cyclecount(); 447 event.he_size = sizeof(event.he_entropy); 448 event.he_source = RANDOM_CACHED; 449 event.he_destination = 450 harvest_context.hc_destination[RANDOM_CACHED]++; 451 memcpy(event.he_entropy, entropy + i, sizeof(event.he_entropy)); 452 random_harvestq_fast_process_event(&event); 453 } 454 explicit_bzero(entropy, len); 455 return (len); 456 } 457 458 /* 459 * Subroutine to search for known loader-loaded files in memory and feed them 460 * into the underlying algorithm early in boot. Returns the number of bytes 461 * loaded (zero if none were loaded). 462 */ 463 static size_t 464 random_prime_loader_file(const char *type) 465 { 466 uint8_t *keyfile, *data; 467 size_t size; 468 469 keyfile = preload_search_by_type(type); 470 if (keyfile == NULL) 471 return (0); 472 473 data = preload_fetch_addr(keyfile); 474 size = preload_fetch_size(keyfile); 475 if (data == NULL) 476 return (0); 477 478 return (random_early_prime(data, size)); 479 } 480 481 /* 482 * This is used to prime the RNG by grabbing any early random stuff 483 * known to the kernel, and inserting it directly into the hashing 484 * module, currently Fortuna. 485 */ 486 static void 487 random_harvestq_prime(void *unused __unused) 488 { 489 size_t size; 490 491 /* 492 * Get entropy that may have been preloaded by loader(8) 493 * and use it to pre-charge the entropy harvest queue. 494 */ 495 size = random_prime_loader_file(RANDOM_CACHED_BOOT_ENTROPY_MODULE); 496 if (bootverbose) { 497 if (size > 0) 498 printf("random: read %zu bytes from preloaded cache\n", 499 size); 500 else 501 printf("random: no preloaded entropy cache\n"); 502 } 503 size = random_prime_loader_file(RANDOM_PLATFORM_BOOT_ENTROPY_MODULE); 504 if (bootverbose) { 505 if (size > 0) 506 printf("random: read %zu bytes from platform bootloader\n", 507 size); 508 else 509 printf("random: no platform bootloader entropy\n"); 510 } 511 } 512 SYSINIT(random_device_prime, SI_SUB_RANDOM, SI_ORDER_MIDDLE, random_harvestq_prime, NULL); 513 514 static void 515 random_harvestq_deinit(void *unused __unused) 516 { 517 518 /* Command the hash/reseed thread to end and wait for it to finish */ 519 random_kthread_control = 0; 520 while (random_kthread_control >= 0) 521 tsleep(&harvest_context.hc_kthread_proc, 0, "harvqterm", hz/5); 522 } 523 SYSUNINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_THIRD, random_harvestq_deinit, NULL); 524 525 /*- 526 * Entropy harvesting queue routine. 527 * 528 * This is supposed to be fast; do not do anything slow in here! 529 * It is also illegal (and morally reprehensible) to insert any 530 * high-rate data here. "High-rate" is defined as a data source 531 * that is likely to fill up the buffer in much less than 100ms. 532 * This includes the "always-on" sources like the Intel "rdrand" 533 * or the VIA Nehamiah "xstore" sources. 534 */ 535 /* XXXRW: get_cyclecount() is cheap on most modern hardware, where cycle 536 * counters are built in, but on older hardware it will do a real time clock 537 * read which can be quite expensive. 538 */ 539 void 540 random_harvest_queue_(const void *entropy, u_int size, enum random_entropy_source origin) 541 { 542 struct harvest_context *hc; 543 struct entropy_buffer *buf; 544 struct harvest_event *event; 545 546 KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, 547 ("%s: origin %d invalid", __func__, origin)); 548 549 hc = &harvest_context; 550 RANDOM_HARVEST_LOCK(); 551 buf = &hc->hc_entropy_buf[hc->hc_active_buf]; 552 if (buf->pos < RANDOM_RING_MAX) { 553 event = &buf->ring[buf->pos++]; 554 event->he_somecounter = random_get_cyclecount(); 555 event->he_source = origin; 556 event->he_destination = hc->hc_destination[origin]++; 557 if (size <= sizeof(event->he_entropy)) { 558 event->he_size = size; 559 memcpy(event->he_entropy, entropy, size); 560 } else { 561 /* Big event, so squash it */ 562 event->he_size = sizeof(event->he_entropy[0]); 563 event->he_entropy[0] = jenkins_hash(entropy, size, (uint32_t)(uintptr_t)event); 564 } 565 } 566 RANDOM_HARVEST_UNLOCK(); 567 } 568 569 /*- 570 * Entropy harvesting fast routine. 571 * 572 * This is supposed to be very fast; do not do anything slow in here! 573 * This is the right place for high-rate harvested data. 574 */ 575 void 576 random_harvest_fast_(const void *entropy, u_int size) 577 { 578 u_int pos; 579 580 pos = harvest_context.hc_entropy_fast_accumulator.pos; 581 harvest_context.hc_entropy_fast_accumulator.buf[pos] ^= 582 jenkins_hash(entropy, size, random_get_cyclecount()); 583 harvest_context.hc_entropy_fast_accumulator.pos = (pos + 1)%RANDOM_ACCUM_MAX; 584 } 585 586 /*- 587 * Entropy harvesting direct routine. 588 * 589 * This is not supposed to be fast, but will only be used during 590 * (e.g.) booting when initial entropy is being gathered. 591 */ 592 void 593 random_harvest_direct_(const void *entropy, u_int size, enum random_entropy_source origin) 594 { 595 struct harvest_event event; 596 597 KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin)); 598 size = MIN(size, sizeof(event.he_entropy)); 599 event.he_somecounter = random_get_cyclecount(); 600 event.he_size = size; 601 event.he_source = origin; 602 event.he_destination = harvest_context.hc_destination[origin]++; 603 memcpy(event.he_entropy, entropy, size); 604 random_harvestq_fast_process_event(&event); 605 } 606 607 void 608 random_harvest_register_source(enum random_entropy_source source) 609 { 610 611 hc_source_mask |= (1 << source); 612 } 613 614 void 615 random_harvest_deregister_source(enum random_entropy_source source) 616 { 617 618 hc_source_mask &= ~(1 << source); 619 } 620 621 void 622 random_source_register(struct random_source *rsource) 623 { 624 struct random_sources *rrs; 625 626 KASSERT(rsource != NULL, ("invalid input to %s", __func__)); 627 628 rrs = malloc(sizeof(*rrs), M_ENTROPY, M_WAITOK); 629 rrs->rrs_source = rsource; 630 631 random_harvest_register_source(rsource->rs_source); 632 633 printf("random: registering fast source %s\n", rsource->rs_ident); 634 635 RANDOM_HARVEST_LOCK(); 636 CK_LIST_INSERT_HEAD(&source_list, rrs, rrs_entries); 637 RANDOM_HARVEST_UNLOCK(); 638 } 639 640 void 641 random_source_deregister(struct random_source *rsource) 642 { 643 struct random_sources *rrs = NULL; 644 645 KASSERT(rsource != NULL, ("invalid input to %s", __func__)); 646 647 random_harvest_deregister_source(rsource->rs_source); 648 649 RANDOM_HARVEST_LOCK(); 650 CK_LIST_FOREACH(rrs, &source_list, rrs_entries) 651 if (rrs->rrs_source == rsource) { 652 CK_LIST_REMOVE(rrs, rrs_entries); 653 break; 654 } 655 RANDOM_HARVEST_UNLOCK(); 656 657 if (rrs != NULL && epoch_inited) 658 epoch_wait_preempt(rs_epoch); 659 free(rrs, M_ENTROPY); 660 } 661 662 static int 663 random_source_handler(SYSCTL_HANDLER_ARGS) 664 { 665 struct epoch_tracker et; 666 struct random_sources *rrs; 667 struct sbuf sbuf; 668 int error, count; 669 670 error = sysctl_wire_old_buffer(req, 0); 671 if (error != 0) 672 return (error); 673 674 sbuf_new_for_sysctl(&sbuf, NULL, 64, req); 675 count = 0; 676 epoch_enter_preempt(rs_epoch, &et); 677 CK_LIST_FOREACH(rrs, &source_list, rrs_entries) { 678 sbuf_cat(&sbuf, (count++ ? ",'" : "'")); 679 sbuf_cat(&sbuf, rrs->rrs_source->rs_ident); 680 sbuf_cat(&sbuf, "'"); 681 } 682 epoch_exit_preempt(rs_epoch, &et); 683 error = sbuf_finish(&sbuf); 684 sbuf_delete(&sbuf); 685 return (error); 686 } 687 SYSCTL_PROC(_kern_random, OID_AUTO, random_sources, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 688 NULL, 0, random_source_handler, "A", 689 "List of active fast entropy sources."); 690 691 MODULE_VERSION(random_harvestq, 1); 692