/*- * Copyright (c) 2000-2013 Mark R V Murray * 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 "opt_random.h" #if !defined(RANDOM_YARROW) && !defined(RANDOM_FORTUNA) #define RANDOM_YARROW #elif defined(RANDOM_YARROW) && defined(RANDOM_FORTUNA) #error "Must define either RANDOM_YARROW or RANDOM_FORTUNA" #endif #if defined(RANDOM_FORTUNA) #error "Fortuna is not yet implemented" #endif #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(RANDOM_YARROW) #include #endif #if defined(RANDOM_FORTUNA) #include #endif static int randomdev_poll(int event, struct thread *td); static int randomdev_block(int flag); static void randomdev_flush_reseed(void); #if defined(RANDOM_YARROW) static struct random_adaptor random_context = { .ident = "Software, Yarrow", .init = randomdev_init, .deinit = randomdev_deinit, .block = randomdev_block, .read = random_yarrow_read, .poll = randomdev_poll, .reseed = randomdev_flush_reseed, .seeded = 0, /* This will be seeded during entropy processing */ .priority = 90, /* High priority, so top of the list. Fortuna may still win. */ }; #define RANDOM_MODULE_NAME yarrow #define RANDOM_CSPRNG_NAME "yarrow" #endif #if defined(RANDOM_FORTUNA) static struct random_adaptor random_context = { .ident = "Software, Fortuna", .init = randomdev_init, .deinit = randomdev_deinit, .block = randomdev_block, .read = random_fortuna_read, .poll = randomdev_poll, .reseed = randomdev_flush_reseed, .seeded = 0, /* This will be excplicitly seeded at startup when secured */ .priority = 100, /* High priority, so top of the list. Beat Yarrow. */ }; #define RANDOM_MODULE_NAME fortuna #define RANDOM_CSPRNG_NAME "fortuna" #endif TUNABLE_INT("kern.random.sys.seeded", &random_context.seeded); /* List for the dynamic sysctls */ static struct sysctl_ctx_list random_clist; /* ARGSUSED */ static int random_check_boolean(SYSCTL_HANDLER_ARGS) { if (oidp->oid_arg1 != NULL && *(u_int *)(oidp->oid_arg1) != 0) *(u_int *)(oidp->oid_arg1) = 1; return (sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req)); } void randomdev_init(void) { struct sysctl_oid *random_sys_o, *random_sys_harvest_o; #if defined(RANDOM_YARROW) random_yarrow_init_alg(&random_clist); #endif #if defined(RANDOM_FORTUNA) random_fortuna_init_alg(&random_clist); #endif random_sys_o = SYSCTL_ADD_NODE(&random_clist, SYSCTL_STATIC_CHILDREN(_kern_random), OID_AUTO, "sys", CTLFLAG_RW, 0, "Entropy Device Parameters"); SYSCTL_ADD_PROC(&random_clist, SYSCTL_CHILDREN(random_sys_o), OID_AUTO, "seeded", CTLTYPE_INT | CTLFLAG_RW, &random_context.seeded, 0, random_check_boolean, "I", "Seeded State"); random_sys_harvest_o = SYSCTL_ADD_NODE(&random_clist, SYSCTL_CHILDREN(random_sys_o), OID_AUTO, "harvest", CTLFLAG_RW, 0, "Entropy Sources"); SYSCTL_ADD_PROC(&random_clist, SYSCTL_CHILDREN(random_sys_harvest_o), OID_AUTO, "ethernet", CTLTYPE_INT | CTLFLAG_RW, &harvest.ethernet, 1, random_check_boolean, "I", "Harvest NIC entropy"); SYSCTL_ADD_PROC(&random_clist, SYSCTL_CHILDREN(random_sys_harvest_o), OID_AUTO, "point_to_point", CTLTYPE_INT | CTLFLAG_RW, &harvest.point_to_point, 1, random_check_boolean, "I", "Harvest serial net entropy"); SYSCTL_ADD_PROC(&random_clist, SYSCTL_CHILDREN(random_sys_harvest_o), OID_AUTO, "interrupt", CTLTYPE_INT | CTLFLAG_RW, &harvest.interrupt, 1, random_check_boolean, "I", "Harvest IRQ entropy"); SYSCTL_ADD_PROC(&random_clist, SYSCTL_CHILDREN(random_sys_harvest_o), OID_AUTO, "swi", CTLTYPE_INT | CTLFLAG_RW, &harvest.swi, 1, random_check_boolean, "I", "Harvest SWI entropy"); random_harvestq_init(random_process_event); /* Register the randomness harvesting routine */ randomdev_init_harvester(random_harvestq_internal, random_context.read); } void randomdev_deinit(void) { /* Deregister the randomness harvesting routine */ randomdev_deinit_harvester(); #if defined(RANDOM_YARROW) random_yarrow_deinit_alg(); #endif #if defined(RANDOM_FORTUNA) random_fortuna_deinit_alg(); #endif sysctl_ctx_free(&random_clist); } void randomdev_unblock(void) { if (!random_context.seeded) { selwakeuppri(&random_context.rsel, PUSER); wakeup(&random_context); printf("random: unblocking device.\n"); random_context.seeded = 1; } /* Do arc4random(9) a favour while we are about it. */ (void)atomic_cmpset_int(&arc4rand_iniseed_state, ARC4_ENTR_NONE, ARC4_ENTR_HAVE); } static int randomdev_poll(int events, struct thread *td) { int revents = 0; mtx_lock(&random_reseed_mtx); if (random_context.seeded) revents = events & (POLLIN | POLLRDNORM); else selrecord(td, &random_context.rsel); mtx_unlock(&random_reseed_mtx); return (revents); } static int randomdev_block(int flag) { int error = 0; mtx_lock(&random_reseed_mtx); /* Blocking logic */ while (!random_context.seeded && !error) { if (flag & O_NONBLOCK) error = EWOULDBLOCK; else { printf("random: blocking on read.\n"); error = msleep(&random_context, &random_reseed_mtx, PUSER | PCATCH, "block", 0); } } mtx_unlock(&random_reseed_mtx); return (error); } /* Helper routine to perform explicit reseeds */ static void randomdev_flush_reseed(void) { /* Command a entropy queue flush and wait for it to finish */ random_kthread_control = 1; while (random_kthread_control) pause("-", hz / 10); #if defined(RANDOM_YARROW) /* This ultimately calls randomdev_unblock() */ random_yarrow_reseed(); #endif #if defined(RANDOM_FORTUNA) /* This ultimately calls randomdev_unblock() */ random_fortuna_reseed(); #endif } static int randomdev_modevent(module_t mod __unused, int type, void *unused __unused) { switch (type) { case MOD_LOAD: random_adaptor_register(RANDOM_CSPRNG_NAME, &random_context); /* * For statically built kernels that contain both device * random and options PADLOCK_RNG/RDRAND_RNG/etc.., * this event handler will do nothing, since the random * driver-specific handlers are loaded after these HW * consumers, and hence hasn't yet registered for this event. * * In case where both the random driver and RNG's are built * as seperate modules, random.ko is loaded prior to *_rng.ko's * (by dependency). This event handler is there to delay * creation of /dev/{u,}random and attachment of this *_rng.ko. */ EVENTHANDLER_INVOKE(random_adaptor_attach, &random_context); return (0); } return (EINVAL); } RANDOM_ADAPTOR_MODULE(RANDOM_MODULE_NAME, randomdev_modevent, 1);