Index: head/sys/dev/random/fortuna.c =================================================================== --- head/sys/dev/random/fortuna.c (revision 348198) +++ head/sys/dev/random/fortuna.c (revision 348199) @@ -1,493 +1,492 @@ /*- * Copyright (c) 2017 W. Dean Freeman * Copyright (c) 2013-2015 Mark R V Murray * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer * in this position and unchanged. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ /* * This implementation of Fortuna is based on the descriptions found in * ISBN 978-0-470-47424-2 "Cryptography Engineering" by Ferguson, Schneier * and Kohno ("FS&K"). */ #include __FBSDID("$FreeBSD$"); #include #include #ifdef _KERNEL #include #include #include #include #include #include #include #include #include #include #else /* !_KERNEL */ #include #include #include #include #include #include #include "unit_test.h" #endif /* _KERNEL */ #include #include #include #include #ifdef _KERNEL #include #endif #include #include /* Defined in FS&K */ #define RANDOM_FORTUNA_NPOOLS 32 /* The number of accumulation pools */ #define RANDOM_FORTUNA_DEFPOOLSIZE 64 /* The default pool size/length for a (re)seed */ #define RANDOM_FORTUNA_MAX_READ (1 << 20) /* Max bytes in a single read */ /* * The allowable range of RANDOM_FORTUNA_DEFPOOLSIZE. The default value is above. * Making RANDOM_FORTUNA_DEFPOOLSIZE too large will mean a long time between reseeds, * and too small may compromise initial security but get faster reseeds. */ #define RANDOM_FORTUNA_MINPOOLSIZE 16 #define RANDOM_FORTUNA_MAXPOOLSIZE INT_MAX CTASSERT(RANDOM_FORTUNA_MINPOOLSIZE <= RANDOM_FORTUNA_DEFPOOLSIZE); CTASSERT(RANDOM_FORTUNA_DEFPOOLSIZE <= RANDOM_FORTUNA_MAXPOOLSIZE); /* This algorithm (and code) presumes that RANDOM_KEYSIZE is twice as large as RANDOM_BLOCKSIZE */ CTASSERT(RANDOM_BLOCKSIZE == sizeof(uint128_t)); CTASSERT(RANDOM_KEYSIZE == 2*RANDOM_BLOCKSIZE); /* Probes for dtrace(1) */ #ifdef _KERNEL SDT_PROVIDER_DECLARE(random); SDT_PROVIDER_DEFINE(random); SDT_PROBE_DEFINE2(random, fortuna, event_processor, debug, "u_int", "struct fs_pool *"); #endif /* _KERNEL */ /* * This is the beastie that needs protecting. It contains all of the * state that we are excited about. Exactly one is instantiated. */ static struct fortuna_state { struct fs_pool { /* P_i */ u_int fsp_length; /* Only the first one is used by Fortuna */ struct randomdev_hash fsp_hash; } fs_pool[RANDOM_FORTUNA_NPOOLS]; u_int fs_reseedcount; /* ReseedCnt */ uint128_t fs_counter; /* C */ union randomdev_key fs_key; /* K */ u_int fs_minpoolsize; /* Extras */ /* Extras for the OS */ #ifdef _KERNEL /* For use when 'pacing' the reseeds */ sbintime_t fs_lasttime; #endif /* Reseed lock */ mtx_t fs_mtx; } fortuna_state; #ifdef _KERNEL static struct sysctl_ctx_list random_clist; RANDOM_CHECK_UINT(fs_minpoolsize, RANDOM_FORTUNA_MINPOOLSIZE, RANDOM_FORTUNA_MAXPOOLSIZE); #else static uint8_t zero_region[RANDOM_ZERO_BLOCKSIZE]; #endif static void random_fortuna_pre_read(void); static void random_fortuna_read(uint8_t *, u_int); static bool random_fortuna_seeded(void); static bool random_fortuna_seeded_internal(void); static void random_fortuna_process_event(struct harvest_event *); static void random_fortuna_init_alg(void *); static void random_fortuna_deinit_alg(void *); static void random_fortuna_reseed_internal(uint32_t *entropy_data, u_int blockcount); struct random_algorithm random_alg_context = { .ra_ident = "Fortuna", .ra_init_alg = random_fortuna_init_alg, .ra_deinit_alg = random_fortuna_deinit_alg, .ra_pre_read = random_fortuna_pre_read, .ra_read = random_fortuna_read, .ra_seeded = random_fortuna_seeded, .ra_event_processor = random_fortuna_process_event, .ra_poolcount = RANDOM_FORTUNA_NPOOLS, }; /* ARGSUSED */ static void random_fortuna_init_alg(void *unused __unused) { int i; #ifdef _KERNEL struct sysctl_oid *random_fortuna_o; #endif RANDOM_RESEED_INIT_LOCK(); /* * Fortuna parameters. Do not adjust these unless you have * have a very good clue about what they do! */ fortuna_state.fs_minpoolsize = RANDOM_FORTUNA_DEFPOOLSIZE; #ifdef _KERNEL fortuna_state.fs_lasttime = 0; random_fortuna_o = SYSCTL_ADD_NODE(&random_clist, SYSCTL_STATIC_CHILDREN(_kern_random), OID_AUTO, "fortuna", CTLFLAG_RW, 0, "Fortuna Parameters"); SYSCTL_ADD_PROC(&random_clist, SYSCTL_CHILDREN(random_fortuna_o), OID_AUTO, "minpoolsize", CTLTYPE_UINT | CTLFLAG_RWTUN, &fortuna_state.fs_minpoolsize, RANDOM_FORTUNA_DEFPOOLSIZE, random_check_uint_fs_minpoolsize, "IU", "Minimum pool size necessary to cause a reseed"); KASSERT(fortuna_state.fs_minpoolsize > 0, ("random: Fortuna threshold must be > 0 at startup")); #endif /*- * FS&K - InitializePRNG() * - P_i = \epsilon * - ReseedCNT = 0 */ for (i = 0; i < RANDOM_FORTUNA_NPOOLS; i++) { randomdev_hash_init(&fortuna_state.fs_pool[i].fsp_hash); fortuna_state.fs_pool[i].fsp_length = 0; } fortuna_state.fs_reseedcount = 0; /*- * FS&K - InitializeGenerator() * - C = 0 * - K = 0 */ fortuna_state.fs_counter = UINT128_ZERO; explicit_bzero(&fortuna_state.fs_key, sizeof(fortuna_state.fs_key)); } /* ARGSUSED */ static void random_fortuna_deinit_alg(void *unused __unused) { RANDOM_RESEED_DEINIT_LOCK(); explicit_bzero(&fortuna_state, sizeof(fortuna_state)); #ifdef _KERNEL sysctl_ctx_free(&random_clist); #endif } /*- * FS&K - AddRandomEvent() * Process a single stochastic event off the harvest queue */ static void random_fortuna_process_event(struct harvest_event *event) { u_int pl; RANDOM_RESEED_LOCK(); /*- * FS&K - P_i = P_i| * Accumulate the event into the appropriate pool * where each event carries the destination information. * * The hash_init() and hash_finish() calls are done in * random_fortuna_pre_read(). * * We must be locked against pool state modification which can happen * during accumulation/reseeding and reading/regating. */ pl = event->he_destination % RANDOM_FORTUNA_NPOOLS; /* * We ignore low entropy static/counter fields towards the end of the * he_event structure in order to increase measurable entropy when * conducting SP800-90B entropy analysis measurements of seed material * fed into PRNG. * -- wdf */ KASSERT(event->he_size <= sizeof(event->he_entropy), ("%s: event->he_size: %hhu > sizeof(event->he_entropy): %zu\n", __func__, event->he_size, sizeof(event->he_entropy))); randomdev_hash_iterate(&fortuna_state.fs_pool[pl].fsp_hash, &event->he_somecounter, sizeof(event->he_somecounter)); randomdev_hash_iterate(&fortuna_state.fs_pool[pl].fsp_hash, event->he_entropy, event->he_size); /*- * Don't wrap the length. This is a "saturating" add. * XXX: FIX!!: We don't actually need lengths for anything but fs_pool[0], * but it's been useful debugging to see them all. */ fortuna_state.fs_pool[pl].fsp_length = MIN(RANDOM_FORTUNA_MAXPOOLSIZE, fortuna_state.fs_pool[pl].fsp_length + sizeof(event->he_somecounter) + event->he_size); - explicit_bzero(event, sizeof(*event)); RANDOM_RESEED_UNLOCK(); } /*- * FS&K - Reseed() * This introduces new key material into the output generator. * Additionally it increments the output generator's counter * variable C. When C > 0, the output generator is seeded and * will deliver output. * The entropy_data buffer passed is a very specific size; the * product of RANDOM_FORTUNA_NPOOLS and RANDOM_KEYSIZE. */ static void random_fortuna_reseed_internal(uint32_t *entropy_data, u_int blockcount) { struct randomdev_hash context; uint8_t hash[RANDOM_KEYSIZE]; const void *keymaterial; size_t keysz; bool seeded; RANDOM_RESEED_ASSERT_LOCK_OWNED(); seeded = random_fortuna_seeded_internal(); if (seeded) { randomdev_getkey(&fortuna_state.fs_key, &keymaterial, &keysz); KASSERT(keysz == RANDOM_KEYSIZE, ("%s: key size %zu not %u", __func__, keysz, (unsigned)RANDOM_KEYSIZE)); } /*- * FS&K - K = Hd(K|s) where Hd(m) is H(H(0^512|m)) * - C = C + 1 */ randomdev_hash_init(&context); randomdev_hash_iterate(&context, zero_region, RANDOM_ZERO_BLOCKSIZE); if (seeded) randomdev_hash_iterate(&context, keymaterial, keysz); randomdev_hash_iterate(&context, entropy_data, RANDOM_KEYSIZE*blockcount); randomdev_hash_finish(&context, hash); randomdev_hash_init(&context); randomdev_hash_iterate(&context, hash, RANDOM_KEYSIZE); randomdev_hash_finish(&context, hash); randomdev_encrypt_init(&fortuna_state.fs_key, hash); explicit_bzero(hash, sizeof(hash)); /* Unblock the device if this is the first time we are reseeding. */ if (uint128_is_zero(fortuna_state.fs_counter)) randomdev_unblock(); uint128_increment(&fortuna_state.fs_counter); } /*- * FS&K - GenerateBlocks() * Generate a number of complete blocks of random output. */ static __inline void random_fortuna_genblocks(uint8_t *buf, u_int blockcount) { RANDOM_RESEED_ASSERT_LOCK_OWNED(); KASSERT(!uint128_is_zero(fortuna_state.fs_counter), ("FS&K: C != 0")); /* * Fills buf with RANDOM_BLOCKSIZE * blockcount bytes of keystream. * Increments fs_counter as it goes. */ randomdev_keystream(&fortuna_state.fs_key, &fortuna_state.fs_counter, buf, blockcount); } /*- * FS&K - PseudoRandomData() * This generates no more than 2^20 bytes of data, and cleans up its * internal state when finished. It is assumed that a whole number of * blocks are available for writing; any excess generated will be * ignored. */ static __inline void random_fortuna_genrandom(uint8_t *buf, u_int bytecount) { uint8_t temp[RANDOM_BLOCKSIZE * RANDOM_KEYS_PER_BLOCK]; u_int blockcount; RANDOM_RESEED_ASSERT_LOCK_OWNED(); /*- * FS&K - assert(n < 2^20 (== 1 MB) * - r = first-n-bytes(GenerateBlocks(ceil(n/16))) * - K = GenerateBlocks(2) */ KASSERT((bytecount <= RANDOM_FORTUNA_MAX_READ), ("invalid single read request to Fortuna of %d bytes", bytecount)); blockcount = howmany(bytecount, RANDOM_BLOCKSIZE); random_fortuna_genblocks(buf, blockcount); random_fortuna_genblocks(temp, RANDOM_KEYS_PER_BLOCK); randomdev_encrypt_init(&fortuna_state.fs_key, temp); explicit_bzero(temp, sizeof(temp)); } /*- * FS&K - RandomData() (Part 1) * Used to return processed entropy from the PRNG. There is a pre_read * required to be present (but it can be a stub) in order to allow * specific actions at the begin of the read. */ void random_fortuna_pre_read(void) { #ifdef _KERNEL sbintime_t now; #endif struct randomdev_hash context; uint32_t s[RANDOM_FORTUNA_NPOOLS*RANDOM_KEYSIZE_WORDS]; uint8_t temp[RANDOM_KEYSIZE]; u_int i; KASSERT(fortuna_state.fs_minpoolsize > 0, ("random: Fortuna threshold must be > 0")); RANDOM_RESEED_LOCK(); #ifdef _KERNEL /* FS&K - Use 'getsbinuptime()' to prevent reseed-spamming. */ now = getsbinuptime(); #endif if (fortuna_state.fs_pool[0].fsp_length < fortuna_state.fs_minpoolsize #ifdef _KERNEL /* * FS&K - Use 'getsbinuptime()' to prevent reseed-spamming, but do * not block initial seeding (fs_lasttime == 0). */ || (__predict_true(fortuna_state.fs_lasttime != 0) && now - fortuna_state.fs_lasttime <= SBT_1S/10) #endif ) { RANDOM_RESEED_UNLOCK(); return; } #ifdef _KERNEL /* * When set, pretend we do not have enough entropy to reseed yet. */ KFAIL_POINT_CODE(DEBUG_FP, random_fortuna_pre_read, { if (RETURN_VALUE != 0) { RANDOM_RESEED_UNLOCK(); return; } }); #endif #ifdef _KERNEL fortuna_state.fs_lasttime = now; #endif /* FS&K - ReseedCNT = ReseedCNT + 1 */ fortuna_state.fs_reseedcount++; /* s = \epsilon at start */ for (i = 0; i < RANDOM_FORTUNA_NPOOLS; i++) { /* FS&K - if Divides(ReseedCnt, 2^i) ... */ if ((fortuna_state.fs_reseedcount % (1 << i)) == 0) { /*- * FS&K - temp = (P_i) * - P_i = \epsilon * - s = s|H(temp) */ randomdev_hash_finish(&fortuna_state.fs_pool[i].fsp_hash, temp); randomdev_hash_init(&fortuna_state.fs_pool[i].fsp_hash); fortuna_state.fs_pool[i].fsp_length = 0; randomdev_hash_init(&context); randomdev_hash_iterate(&context, temp, RANDOM_KEYSIZE); randomdev_hash_finish(&context, s + i*RANDOM_KEYSIZE_WORDS); } else break; } #ifdef _KERNEL SDT_PROBE2(random, fortuna, event_processor, debug, fortuna_state.fs_reseedcount, fortuna_state.fs_pool); #endif /* FS&K */ random_fortuna_reseed_internal(s, i); RANDOM_RESEED_UNLOCK(); /* Clean up and secure */ explicit_bzero(s, sizeof(s)); explicit_bzero(temp, sizeof(temp)); } /*- * FS&K - RandomData() (Part 2) * Main read from Fortuna, continued. May be called multiple times after * the random_fortuna_pre_read() above. * The supplied buf MUST be a multiple of RANDOM_BLOCKSIZE in size. * Lots of code presumes this for efficiency, both here and in other * routines. You are NOT allowed to break this! */ void random_fortuna_read(uint8_t *buf, u_int bytecount) { KASSERT((bytecount % RANDOM_BLOCKSIZE) == 0, ("%s(): bytecount (= %d) must be a multiple of %d", __func__, bytecount, RANDOM_BLOCKSIZE )); RANDOM_RESEED_LOCK(); random_fortuna_genrandom(buf, bytecount); RANDOM_RESEED_UNLOCK(); } #ifdef _KERNEL static bool block_seeded_status = false; SYSCTL_BOOL(_kern_random, OID_AUTO, block_seeded_status, CTLFLAG_RWTUN, &block_seeded_status, 0, "If non-zero, pretend Fortuna is in an unseeded state. By setting " "this as a tunable, boot can be tested as if the random device is " "unavailable."); #endif static bool random_fortuna_seeded_internal(void) { return (!uint128_is_zero(fortuna_state.fs_counter)); } static bool random_fortuna_seeded(void) { #ifdef _KERNEL if (block_seeded_status) return (false); #endif if (__predict_true(random_fortuna_seeded_internal())) return (true); /* * Maybe we have enough entropy in the zeroth pool but just haven't * kicked the initial seed step. Do so now. */ random_fortuna_pre_read(); return (random_fortuna_seeded_internal()); } Index: head/sys/dev/random/random_harvestq.c =================================================================== --- head/sys/dev/random/random_harvestq.c (revision 348198) +++ head/sys/dev/random/random_harvestq.c (revision 348199) @@ -1,560 +1,559 @@ /*- * Copyright (c) 2017 Oliver Pinter * Copyright (c) 2017 W. Dean Freeman * Copyright (c) 2000-2015 Mark R V Murray * Copyright (c) 2013 Arthur Mesh * Copyright (c) 2004 Robert N. M. Watson * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer * in this position and unchanged. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(RANDOM_LOADABLE) #include #include #endif #include #include #include #include #include #include #include #if defined(RANDOM_ENABLE_ETHER) #define _RANDOM_HARVEST_ETHER_OFF 0 #else #define _RANDOM_HARVEST_ETHER_OFF (1u << RANDOM_NET_ETHER) #endif #if defined(RANDOM_ENABLE_UMA) #define _RANDOM_HARVEST_UMA_OFF 0 #else #define _RANDOM_HARVEST_UMA_OFF (1u << RANDOM_UMA) #endif static void random_kthread(void); static void random_sources_feed(void); static u_int read_rate; /* List for the dynamic sysctls */ static struct sysctl_ctx_list random_clist; /* * How many events to queue up. We create this many items in * an 'empty' queue, then transfer them to the 'harvest' queue with * supplied junk. When used, they are transferred back to the * 'empty' queue. */ #define RANDOM_RING_MAX 1024 #define RANDOM_ACCUM_MAX 8 /* 1 to let the kernel thread run, 0 to terminate, -1 to mark completion */ volatile int random_kthread_control; /* Allow the sysadmin to select the broad category of * entropy types to harvest. */ __read_frequently u_int hc_source_mask; /* * Put all the harvest queue context stuff in one place. * this make is a bit easier to lock and protect. */ static struct harvest_context { /* The harvest mutex protects all of harvest_context and * the related data. */ struct mtx hc_mtx; /* Round-robin destination cache. */ u_int hc_destination[ENTROPYSOURCE]; /* The context of the kernel thread processing harvested entropy */ struct proc *hc_kthread_proc; /* * Lockless ring buffer holding entropy events * If ring.in == ring.out, * the buffer is empty. * If ring.in != ring.out, * the buffer contains harvested entropy. * If (ring.in + 1) == ring.out (mod RANDOM_RING_MAX), * the buffer is full. * * NOTE: ring.in points to the last added element, * and ring.out points to the last consumed element. * * The ring.in variable needs locking as there are multiple * sources to the ring. Only the sources may change ring.in, * but the consumer may examine it. * * The ring.out variable does not need locking as there is * only one consumer. Only the consumer may change ring.out, * but the sources may examine it. */ struct entropy_ring { struct harvest_event ring[RANDOM_RING_MAX]; volatile u_int in; volatile u_int out; } hc_entropy_ring; struct fast_entropy_accumulator { volatile u_int pos; uint32_t buf[RANDOM_ACCUM_MAX]; } hc_entropy_fast_accumulator; } harvest_context; static struct kproc_desc random_proc_kp = { "rand_harvestq", random_kthread, &harvest_context.hc_kthread_proc, }; /* Pass the given event straight through to Fortuna/Whatever. */ static __inline void random_harvestq_fast_process_event(struct harvest_event *event) { #if defined(RANDOM_LOADABLE) RANDOM_CONFIG_S_LOCK(); if (p_random_alg_context) #endif p_random_alg_context->ra_event_processor(event); #if defined(RANDOM_LOADABLE) RANDOM_CONFIG_S_UNLOCK(); #endif + explicit_bzero(event, sizeof(*event)); } static void random_kthread(void) { u_int maxloop, ring_out, i; /* * Locking is not needed as this is the only place we modify ring.out, and * we only examine ring.in without changing it. Both of these are volatile, * and this is a unique thread. */ for (random_kthread_control = 1; random_kthread_control;) { /* Deal with events, if any. Restrict the number we do in one go. */ maxloop = RANDOM_RING_MAX; while (harvest_context.hc_entropy_ring.out != harvest_context.hc_entropy_ring.in) { ring_out = (harvest_context.hc_entropy_ring.out + 1)%RANDOM_RING_MAX; random_harvestq_fast_process_event(harvest_context.hc_entropy_ring.ring + ring_out); harvest_context.hc_entropy_ring.out = ring_out; if (!--maxloop) break; } random_sources_feed(); /* XXX: FIX!! Increase the high-performance data rate? Need some measurements first. */ for (i = 0; i < RANDOM_ACCUM_MAX; i++) { if (harvest_context.hc_entropy_fast_accumulator.buf[i]) { random_harvest_direct(harvest_context.hc_entropy_fast_accumulator.buf + i, sizeof(harvest_context.hc_entropy_fast_accumulator.buf[0]), RANDOM_UMA); harvest_context.hc_entropy_fast_accumulator.buf[i] = 0; } } /* XXX: FIX!! This is a *great* place to pass hardware/live entropy to random(9) */ tsleep_sbt(&harvest_context.hc_kthread_proc, 0, "-", SBT_1S/10, 0, C_PREL(1)); } random_kthread_control = -1; wakeup(&harvest_context.hc_kthread_proc); kproc_exit(0); /* NOTREACHED */ } /* This happens well after SI_SUB_RANDOM */ SYSINIT(random_device_h_proc, SI_SUB_KICK_SCHEDULER, SI_ORDER_ANY, kproc_start, &random_proc_kp); /* * Run through all fast sources reading entropy for the given * number of rounds, which should be a multiple of the number * of entropy accumulation pools in use; it is 32 for Fortuna. */ static void random_sources_feed(void) { uint32_t entropy[HARVESTSIZE]; struct random_sources *rrs; u_int i, n, local_read_rate; /* * Step over all of live entropy sources, and feed their output * to the system-wide RNG. */ #if defined(RANDOM_LOADABLE) RANDOM_CONFIG_S_LOCK(); if (p_random_alg_context) { /* It's an indenting error. Yeah, Yeah. */ #endif local_read_rate = atomic_readandclear_32(&read_rate); /* Perform at least one read per round */ local_read_rate = MAX(local_read_rate, 1); /* But not exceeding RANDOM_KEYSIZE_WORDS */ local_read_rate = MIN(local_read_rate, RANDOM_KEYSIZE_WORDS); LIST_FOREACH(rrs, &source_list, rrs_entries) { for (i = 0; i < p_random_alg_context->ra_poolcount*local_read_rate; i++) { n = rrs->rrs_source->rs_read(entropy, sizeof(entropy)); KASSERT((n <= sizeof(entropy)), ("%s: rs_read returned too much data (%u > %zu)", __func__, n, sizeof(entropy))); /* * Sometimes the HW entropy source doesn't have anything * ready for us. This isn't necessarily untrustworthy. * We don't perform any other verification of an entropy * source (i.e., length is allowed to be anywhere from 1 * to sizeof(entropy), quality is unchecked, etc), so * don't balk verbosely at slow random sources either. * There are reports that RDSEED on x86 metal falls * behind the rate at which we query it, for example. * But it's still a better entropy source than RDRAND. */ if (n == 0) continue; random_harvest_direct(entropy, n, rrs->rrs_source->rs_source); } } explicit_bzero(entropy, sizeof(entropy)); #if defined(RANDOM_LOADABLE) } RANDOM_CONFIG_S_UNLOCK(); #endif } void read_rate_increment(u_int chunk) { atomic_add_32(&read_rate, chunk); } /* ARGSUSED */ static int random_check_uint_harvestmask(SYSCTL_HANDLER_ARGS) { static const u_int user_immutable_mask = (((1 << ENTROPYSOURCE) - 1) & (-1UL << RANDOM_PURE_START)) | _RANDOM_HARVEST_ETHER_OFF | _RANDOM_HARVEST_UMA_OFF; int error; u_int value, orig_value; orig_value = value = hc_source_mask; error = sysctl_handle_int(oidp, &value, 0, req); if (error != 0 || req->newptr == NULL) return (error); if (flsl(value) > ENTROPYSOURCE) return (EINVAL); /* * Disallow userspace modification of pure entropy sources. */ hc_source_mask = (value & ~user_immutable_mask) | (orig_value & user_immutable_mask); return (0); } /* ARGSUSED */ static int random_print_harvestmask(SYSCTL_HANDLER_ARGS) { struct sbuf sbuf; int error, i; error = sysctl_wire_old_buffer(req, 0); if (error == 0) { sbuf_new_for_sysctl(&sbuf, NULL, 128, req); for (i = ENTROPYSOURCE - 1; i >= 0; i--) sbuf_cat(&sbuf, (hc_source_mask & (1 << i)) ? "1" : "0"); error = sbuf_finish(&sbuf); sbuf_delete(&sbuf); } return (error); } static const char *random_source_descr[ENTROPYSOURCE] = { [RANDOM_CACHED] = "CACHED", [RANDOM_ATTACH] = "ATTACH", [RANDOM_KEYBOARD] = "KEYBOARD", [RANDOM_MOUSE] = "MOUSE", [RANDOM_NET_TUN] = "NET_TUN", [RANDOM_NET_ETHER] = "NET_ETHER", [RANDOM_NET_NG] = "NET_NG", [RANDOM_INTERRUPT] = "INTERRUPT", [RANDOM_SWI] = "SWI", [RANDOM_FS_ATIME] = "FS_ATIME", [RANDOM_UMA] = "UMA", /* ENVIRONMENTAL_END */ [RANDOM_PURE_OCTEON] = "PURE_OCTEON", /* PURE_START */ [RANDOM_PURE_SAFE] = "PURE_SAFE", [RANDOM_PURE_GLXSB] = "PURE_GLXSB", [RANDOM_PURE_UBSEC] = "PURE_UBSEC", [RANDOM_PURE_HIFN] = "PURE_HIFN", [RANDOM_PURE_RDRAND] = "PURE_RDRAND", [RANDOM_PURE_NEHEMIAH] = "PURE_NEHEMIAH", [RANDOM_PURE_RNDTEST] = "PURE_RNDTEST", [RANDOM_PURE_VIRTIO] = "PURE_VIRTIO", [RANDOM_PURE_BROADCOM] = "PURE_BROADCOM", [RANDOM_PURE_CCP] = "PURE_CCP", [RANDOM_PURE_DARN] = "PURE_DARN", [RANDOM_PURE_TPM] = "PURE_TPM", /* "ENTROPYSOURCE" */ }; /* ARGSUSED */ static int random_print_harvestmask_symbolic(SYSCTL_HANDLER_ARGS) { struct sbuf sbuf; int error, i; bool first; first = true; error = sysctl_wire_old_buffer(req, 0); if (error == 0) { sbuf_new_for_sysctl(&sbuf, NULL, 128, req); for (i = ENTROPYSOURCE - 1; i >= 0; i--) { if (i >= RANDOM_PURE_START && (hc_source_mask & (1 << i)) == 0) continue; if (!first) sbuf_cat(&sbuf, ","); sbuf_cat(&sbuf, !(hc_source_mask & (1 << i)) ? "[" : ""); sbuf_cat(&sbuf, random_source_descr[i]); sbuf_cat(&sbuf, !(hc_source_mask & (1 << i)) ? "]" : ""); first = false; } error = sbuf_finish(&sbuf); sbuf_delete(&sbuf); } return (error); } /* ARGSUSED */ static void random_harvestq_init(void *unused __unused) { static const u_int almost_everything_mask = (((1 << (RANDOM_ENVIRONMENTAL_END + 1)) - 1) & ~_RANDOM_HARVEST_ETHER_OFF & ~_RANDOM_HARVEST_UMA_OFF); struct sysctl_oid *random_sys_o; random_sys_o = SYSCTL_ADD_NODE(&random_clist, SYSCTL_STATIC_CHILDREN(_kern_random), OID_AUTO, "harvest", CTLFLAG_RW, 0, "Entropy Device Parameters"); hc_source_mask = almost_everything_mask; SYSCTL_ADD_PROC(&random_clist, SYSCTL_CHILDREN(random_sys_o), OID_AUTO, "mask", CTLTYPE_UINT | CTLFLAG_RW, NULL, 0, random_check_uint_harvestmask, "IU", "Entropy harvesting mask"); SYSCTL_ADD_PROC(&random_clist, SYSCTL_CHILDREN(random_sys_o), OID_AUTO, "mask_bin", CTLTYPE_STRING | CTLFLAG_RD, NULL, 0, random_print_harvestmask, "A", "Entropy harvesting mask (printable)"); SYSCTL_ADD_PROC(&random_clist, SYSCTL_CHILDREN(random_sys_o), OID_AUTO, "mask_symbolic", CTLTYPE_STRING | CTLFLAG_RD, NULL, 0, random_print_harvestmask_symbolic, "A", "Entropy harvesting mask (symbolic)"); RANDOM_HARVEST_INIT_LOCK(); harvest_context.hc_entropy_ring.in = harvest_context.hc_entropy_ring.out = 0; } SYSINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_SECOND, random_harvestq_init, NULL); /* * This is used to prime the RNG by grabbing any early random stuff * known to the kernel, and inserting it directly into the hashing * module, currently Fortuna. */ /* ARGSUSED */ static void random_harvestq_prime(void *unused __unused) { struct harvest_event event; size_t count, size, i; uint8_t *keyfile, *data; /* * Get entropy that may have been preloaded by loader(8) * and use it to pre-charge the entropy harvest queue. */ keyfile = preload_search_by_type(RANDOM_CACHED_BOOT_ENTROPY_MODULE); #ifndef NO_BACKWARD_COMPATIBILITY if (keyfile == NULL) keyfile = preload_search_by_type(RANDOM_LEGACY_BOOT_ENTROPY_MODULE); #endif if (keyfile != NULL) { data = preload_fetch_addr(keyfile); size = preload_fetch_size(keyfile); /* Trim the size. If the admin has a file with a funny size, we lose some. Tough. */ size -= (size % sizeof(event.he_entropy)); if (data != NULL && size != 0) { for (i = 0; i < size; i += sizeof(event.he_entropy)) { count = sizeof(event.he_entropy); event.he_somecounter = (uint32_t)get_cyclecount(); event.he_size = count; event.he_source = RANDOM_CACHED; event.he_destination = harvest_context.hc_destination[RANDOM_CACHED]++; memcpy(event.he_entropy, data + i, sizeof(event.he_entropy)); random_harvestq_fast_process_event(&event); - explicit_bzero(&event, sizeof(event)); } explicit_bzero(data, size); if (bootverbose) printf("random: read %zu bytes from preloaded cache\n", size); } else if (bootverbose) printf("random: no preloaded entropy cache\n"); } } SYSINIT(random_device_prime, SI_SUB_RANDOM, SI_ORDER_FOURTH, random_harvestq_prime, NULL); /* ARGSUSED */ static void random_harvestq_deinit(void *unused __unused) { /* Command the hash/reseed thread to end and wait for it to finish */ random_kthread_control = 0; while (random_kthread_control >= 0) tsleep(&harvest_context.hc_kthread_proc, 0, "harvqterm", hz/5); sysctl_ctx_free(&random_clist); } SYSUNINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_SECOND, random_harvestq_deinit, NULL); /*- * Entropy harvesting queue routine. * * This is supposed to be fast; do not do anything slow in here! * It is also illegal (and morally reprehensible) to insert any * high-rate data here. "High-rate" is defined as a data source * that will usually cause lots of failures of the "Lockless read" * check a few lines below. This includes the "always-on" sources * like the Intel "rdrand" or the VIA Nehamiah "xstore" sources. */ /* XXXRW: get_cyclecount() is cheap on most modern hardware, where cycle * counters are built in, but on older hardware it will do a real time clock * read which can be quite expensive. */ void random_harvest_queue_(const void *entropy, u_int size, enum random_entropy_source origin) { struct harvest_event *event; u_int ring_in; KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin)); RANDOM_HARVEST_LOCK(); ring_in = (harvest_context.hc_entropy_ring.in + 1)%RANDOM_RING_MAX; if (ring_in != harvest_context.hc_entropy_ring.out) { /* The ring is not full */ event = harvest_context.hc_entropy_ring.ring + ring_in; event->he_somecounter = (uint32_t)get_cyclecount(); event->he_source = origin; event->he_destination = harvest_context.hc_destination[origin]++; if (size <= sizeof(event->he_entropy)) { event->he_size = size; memcpy(event->he_entropy, entropy, size); } else { /* Big event, so squash it */ event->he_size = sizeof(event->he_entropy[0]); event->he_entropy[0] = jenkins_hash(entropy, size, (uint32_t)(uintptr_t)event); } harvest_context.hc_entropy_ring.in = ring_in; } RANDOM_HARVEST_UNLOCK(); } /*- * Entropy harvesting fast routine. * * This is supposed to be very fast; do not do anything slow in here! * This is the right place for high-rate harvested data. */ void random_harvest_fast_(const void *entropy, u_int size) { u_int pos; pos = harvest_context.hc_entropy_fast_accumulator.pos; harvest_context.hc_entropy_fast_accumulator.buf[pos] ^= jenkins_hash(entropy, size, (uint32_t)get_cyclecount()); harvest_context.hc_entropy_fast_accumulator.pos = (pos + 1)%RANDOM_ACCUM_MAX; } /*- * Entropy harvesting direct routine. * * This is not supposed to be fast, but will only be used during * (e.g.) booting when initial entropy is being gathered. */ void random_harvest_direct_(const void *entropy, u_int size, enum random_entropy_source origin) { struct harvest_event event; KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin)); size = MIN(size, sizeof(event.he_entropy)); event.he_somecounter = (uint32_t)get_cyclecount(); event.he_size = size; event.he_source = origin; event.he_destination = harvest_context.hc_destination[origin]++; memcpy(event.he_entropy, entropy, size); random_harvestq_fast_process_event(&event); - explicit_bzero(&event, sizeof(event)); } void random_harvest_register_source(enum random_entropy_source source) { hc_source_mask |= (1 << source); } void random_harvest_deregister_source(enum random_entropy_source source) { hc_source_mask &= ~(1 << source); } MODULE_VERSION(random_harvestq, 1); Index: head/sys/dev/random/randomdev.c =================================================================== --- head/sys/dev/random/randomdev.c (revision 348198) +++ head/sys/dev/random/randomdev.c (revision 348199) @@ -1,496 +1,496 @@ /*- * Copyright (c) 2017 Oliver Pinter * Copyright (c) 2000-2015 Mark R V Murray * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer * in this position and unchanged. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define RANDOM_UNIT 0 #if defined(RANDOM_LOADABLE) #define READ_RANDOM_UIO _read_random_uio #define READ_RANDOM _read_random #define IS_RANDOM_SEEDED _is_random_seeded static int READ_RANDOM_UIO(struct uio *, bool); static void READ_RANDOM(void *, u_int); static bool IS_RANDOM_SEEDED(void); #else #define READ_RANDOM_UIO read_random_uio #define READ_RANDOM read_random #define IS_RANDOM_SEEDED is_random_seeded #endif static d_read_t randomdev_read; static d_write_t randomdev_write; static d_poll_t randomdev_poll; static d_ioctl_t randomdev_ioctl; static struct cdevsw random_cdevsw = { .d_name = "random", .d_version = D_VERSION, .d_read = randomdev_read, .d_write = randomdev_write, .d_poll = randomdev_poll, .d_ioctl = randomdev_ioctl, }; /* For use with make_dev(9)/destroy_dev(9). */ static struct cdev *random_dev; static void random_alg_context_ra_init_alg(void *data) { p_random_alg_context = &random_alg_context; p_random_alg_context->ra_init_alg(data); #if defined(RANDOM_LOADABLE) random_infra_init(READ_RANDOM_UIO, READ_RANDOM, IS_RANDOM_SEEDED); #endif } static void random_alg_context_ra_deinit_alg(void *data) { #if defined(RANDOM_LOADABLE) random_infra_uninit(); #endif p_random_alg_context->ra_deinit_alg(data); p_random_alg_context = NULL; } SYSINIT(random_device, SI_SUB_RANDOM, SI_ORDER_THIRD, random_alg_context_ra_init_alg, NULL); SYSUNINIT(random_device, SI_SUB_RANDOM, SI_ORDER_THIRD, random_alg_context_ra_deinit_alg, NULL); static struct selinfo rsel; /* * This is the read uio(9) interface for random(4). */ /* ARGSUSED */ static int randomdev_read(struct cdev *dev __unused, struct uio *uio, int flags) { return (READ_RANDOM_UIO(uio, (flags & O_NONBLOCK) != 0)); } /* * If the random device is not seeded, blocks until it is seeded. * * Returns zero when the random device is seeded. * * If the 'interruptible' parameter is true, and the device is unseeded, this * routine may be interrupted. If interrupted, it will return either ERESTART * or EINTR. */ #define SEEDWAIT_INTERRUPTIBLE true #define SEEDWAIT_UNINTERRUPTIBLE false static int randomdev_wait_until_seeded(bool interruptible) { int error, spamcount, slpflags; slpflags = interruptible ? PCATCH : 0; error = 0; spamcount = 0; while (!p_random_alg_context->ra_seeded()) { /* keep tapping away at the pre-read until we seed/unblock. */ p_random_alg_context->ra_pre_read(); /* Only bother the console every 10 seconds or so */ if (spamcount == 0) printf("random: %s unblock wait\n", __func__); spamcount = (spamcount + 1) % 100; error = tsleep(&random_alg_context, slpflags, "randseed", hz / 10); if (error == ERESTART || error == EINTR) { KASSERT(interruptible, ("unexpected wake of non-interruptible sleep")); break; } /* Squash tsleep timeout condition */ if (error == EWOULDBLOCK) error = 0; KASSERT(error == 0, ("unexpected tsleep error %d", error)); } return (error); } int READ_RANDOM_UIO(struct uio *uio, bool nonblock) { uint8_t *random_buf; int error; ssize_t read_len, total_read, c; /* 16 MiB takes about 0.08 s CPU time on my 2017 AMD Zen CPU */ #define SIGCHK_PERIOD (16 * 1024 * 1024) const size_t sigchk_period = SIGCHK_PERIOD; CTASSERT(SIGCHK_PERIOD % PAGE_SIZE == 0); #undef SIGCHK_PERIOD random_buf = malloc(PAGE_SIZE, M_ENTROPY, M_WAITOK); p_random_alg_context->ra_pre_read(); error = 0; /* (Un)Blocking logic */ if (!p_random_alg_context->ra_seeded()) { if (nonblock) error = EWOULDBLOCK; else error = randomdev_wait_until_seeded( SEEDWAIT_INTERRUPTIBLE); } if (error == 0) { read_rate_increment((uio->uio_resid + sizeof(uint32_t))/sizeof(uint32_t)); total_read = 0; while (uio->uio_resid && !error) { read_len = uio->uio_resid; /* * Belt-and-braces. * Round up the read length to a crypto block size multiple, * which is what the underlying generator is expecting. * See the random_buf size requirements in the Fortuna code. */ read_len = roundup(read_len, RANDOM_BLOCKSIZE); /* Work in chunks page-sized or less */ read_len = MIN(read_len, PAGE_SIZE); p_random_alg_context->ra_read(random_buf, read_len); c = MIN(uio->uio_resid, read_len); /* * uiomove() may yield the CPU before each 'c' bytes * (up to PAGE_SIZE) are copied out. */ error = uiomove(random_buf, c, uio); total_read += c; /* * Poll for signals every few MBs to avoid very long * uninterruptible syscalls. */ if (error == 0 && uio->uio_resid != 0 && total_read % sigchk_period == 0) { error = tsleep_sbt(&random_alg_context, PCATCH, "randrd", SBT_1NS, 0, C_HARDCLOCK); /* Squash tsleep timeout condition */ if (error == EWOULDBLOCK) error = 0; } } if (error == ERESTART || error == EINTR) error = 0; } free(random_buf, M_ENTROPY); return (error); } /*- * Kernel API version of read_random(). This is similar to read_random_uio(), * except it doesn't interface with uio(9). It cannot assumed that random_buf * is a multiple of RANDOM_BLOCKSIZE bytes. * * If the tunable 'kern.random.initial_seeding.bypass_before_seeding' is set * non-zero, silently fail to emit random data (matching the pre-r346250 * behavior). If read_random is called prior to seeding and bypassed because * of this tunable, the condition is reported in the read-only sysctl * 'kern.random.initial_seeding.read_random_bypassed_before_seeding'. */ void READ_RANDOM(void *random_buf, u_int len) { u_int read_directly_len; KASSERT(random_buf != NULL, ("No suitable random buffer in %s", __func__)); p_random_alg_context->ra_pre_read(); if (len == 0) return; /* (Un)Blocking logic */ if (__predict_false(!p_random_alg_context->ra_seeded())) { if (random_bypass_before_seeding) { if (!read_random_bypassed_before_seeding) { if (!random_bypass_disable_warnings) printf("read_random: WARNING: bypassing" " request for random data because " "the random device is not yet " "seeded and the knob " "'bypass_before_seeding' was " "enabled.\n"); read_random_bypassed_before_seeding = true; } /* Avoid potentially leaking stack garbage */ memset(random_buf, 0, len); return; } (void)randomdev_wait_until_seeded(SEEDWAIT_UNINTERRUPTIBLE); } read_rate_increment(roundup2(len, sizeof(uint32_t))); /* * The underlying generator expects multiples of * RANDOM_BLOCKSIZE. */ read_directly_len = rounddown(len, RANDOM_BLOCKSIZE); if (read_directly_len > 0) p_random_alg_context->ra_read(random_buf, read_directly_len); if (read_directly_len < len) { uint8_t remainder_buf[RANDOM_BLOCKSIZE]; p_random_alg_context->ra_read(remainder_buf, sizeof(remainder_buf)); memcpy((char *)random_buf + read_directly_len, remainder_buf, len - read_directly_len); explicit_bzero(remainder_buf, sizeof(remainder_buf)); } } bool IS_RANDOM_SEEDED(void) { return (p_random_alg_context->ra_seeded()); } static __inline void randomdev_accumulate(uint8_t *buf, u_int count) { static u_int destination = 0; static struct harvest_event event; static struct randomdev_hash hash; static uint32_t entropy_data[RANDOM_KEYSIZE_WORDS]; uint32_t timestamp; int i; /* Extra timing here is helpful to scrape scheduler jitter entropy */ randomdev_hash_init(&hash); timestamp = (uint32_t)get_cyclecount(); randomdev_hash_iterate(&hash, ×tamp, sizeof(timestamp)); randomdev_hash_iterate(&hash, buf, count); timestamp = (uint32_t)get_cyclecount(); randomdev_hash_iterate(&hash, ×tamp, sizeof(timestamp)); randomdev_hash_finish(&hash, entropy_data); - explicit_bzero(&hash, sizeof(hash)); for (i = 0; i < RANDOM_KEYSIZE_WORDS; i += sizeof(event.he_entropy)/sizeof(event.he_entropy[0])) { event.he_somecounter = (uint32_t)get_cyclecount(); event.he_size = sizeof(event.he_entropy); event.he_source = RANDOM_CACHED; event.he_destination = destination++; /* Harmless cheating */ memcpy(event.he_entropy, entropy_data + i, sizeof(event.he_entropy)); p_random_alg_context->ra_event_processor(&event); } + explicit_bzero(&event, sizeof(event)); explicit_bzero(entropy_data, sizeof(entropy_data)); } /* ARGSUSED */ static int randomdev_write(struct cdev *dev __unused, struct uio *uio, int flags __unused) { uint8_t *random_buf; int c, error = 0; ssize_t nbytes; random_buf = malloc(PAGE_SIZE, M_ENTROPY, M_WAITOK); nbytes = uio->uio_resid; while (uio->uio_resid > 0 && error == 0) { c = MIN(uio->uio_resid, PAGE_SIZE); error = uiomove(random_buf, c, uio); if (error) break; randomdev_accumulate(random_buf, c); tsleep(&random_alg_context, 0, "randwr", hz/10); } if (nbytes != uio->uio_resid && (error == ERESTART || error == EINTR)) /* Partial write, not error. */ error = 0; free(random_buf, M_ENTROPY); return (error); } /* ARGSUSED */ static int randomdev_poll(struct cdev *dev __unused, int events, struct thread *td __unused) { if (events & (POLLIN | POLLRDNORM)) { if (p_random_alg_context->ra_seeded()) events &= (POLLIN | POLLRDNORM); else selrecord(td, &rsel); } return (events); } /* This will be called by the entropy processor when it seeds itself and becomes secure */ void randomdev_unblock(void) { selwakeuppri(&rsel, PUSER); wakeup(&random_alg_context); printf("random: unblocking device.\n"); /* Do random(9) a favour while we are about it. */ (void)atomic_cmpset_int(&arc4rand_iniseed_state, ARC4_ENTR_NONE, ARC4_ENTR_HAVE); } /* ARGSUSED */ static int randomdev_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t addr __unused, int flags __unused, struct thread *td __unused) { int error = 0; switch (cmd) { /* Really handled in upper layer */ case FIOASYNC: case FIONBIO: break; default: error = ENOTTY; } return (error); } void random_source_register(struct random_source *rsource) { struct random_sources *rrs; KASSERT(rsource != NULL, ("invalid input to %s", __func__)); rrs = malloc(sizeof(*rrs), M_ENTROPY, M_WAITOK); rrs->rrs_source = rsource; random_harvest_register_source(rsource->rs_source); printf("random: registering fast source %s\n", rsource->rs_ident); LIST_INSERT_HEAD(&source_list, rrs, rrs_entries); } void random_source_deregister(struct random_source *rsource) { struct random_sources *rrs = NULL; KASSERT(rsource != NULL, ("invalid input to %s", __func__)); random_harvest_deregister_source(rsource->rs_source); LIST_FOREACH(rrs, &source_list, rrs_entries) if (rrs->rrs_source == rsource) { LIST_REMOVE(rrs, rrs_entries); break; } if (rrs != NULL) free(rrs, M_ENTROPY); } static int random_source_handler(SYSCTL_HANDLER_ARGS) { struct random_sources *rrs; struct sbuf sbuf; int error, count; sbuf_new_for_sysctl(&sbuf, NULL, 64, req); count = 0; LIST_FOREACH(rrs, &source_list, rrs_entries) { sbuf_cat(&sbuf, (count++ ? ",'" : "'")); sbuf_cat(&sbuf, rrs->rrs_source->rs_ident); sbuf_cat(&sbuf, "'"); } error = sbuf_finish(&sbuf); sbuf_delete(&sbuf); return (error); } SYSCTL_PROC(_kern_random, OID_AUTO, random_sources, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, random_source_handler, "A", "List of active fast entropy sources."); /* ARGSUSED */ static int randomdev_modevent(module_t mod __unused, int type, void *data __unused) { int error = 0; switch (type) { case MOD_LOAD: printf("random: entropy device external interface\n"); random_dev = make_dev_credf(MAKEDEV_ETERNAL_KLD, &random_cdevsw, RANDOM_UNIT, NULL, UID_ROOT, GID_WHEEL, 0644, "random"); make_dev_alias(random_dev, "urandom"); /* compatibility */ break; case MOD_UNLOAD: destroy_dev(random_dev); break; case MOD_SHUTDOWN: break; default: error = EOPNOTSUPP; break; } return (error); } static moduledata_t randomdev_mod = { "random_device", randomdev_modevent, 0 }; DECLARE_MODULE(random_device, randomdev_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); MODULE_VERSION(random_device, 1); MODULE_DEPEND(random_device, crypto, 1, 1, 1); MODULE_DEPEND(random_device, random_harvestq, 1, 1, 1);