2 * Copyright (c) 2000-2013 Mark R V Murray
3 * Copyright (c) 2004 Robert N. M. Watson
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer
11 * in this position and unchanged.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #include "opt_random.h"
31 #if !defined(RANDOM_YARROW) && !defined(RANDOM_FORTUNA)
33 #elif defined(RANDOM_YARROW) && defined(RANDOM_FORTUNA)
34 #error "Must define either RANDOM_YARROW or RANDOM_FORTUNA"
36 #if defined(RANDOM_FORTUNA)
37 #error "Fortuna is not yet implemented"
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/fcntl.h>
46 #include <sys/kernel.h>
48 #include <sys/malloc.h>
49 #include <sys/module.h>
50 #include <sys/mutex.h>
52 #include <sys/random.h>
53 #include <sys/selinfo.h>
54 #include <sys/sysctl.h>
56 #include <sys/unistd.h>
58 #include <machine/bus.h>
59 #include <machine/cpu.h>
61 #include <dev/random/randomdev.h>
62 #include <dev/random/randomdev_soft.h>
63 #include <dev/random/random_harvestq.h>
64 #include <dev/random/random_adaptors.h>
65 #if defined(RANDOM_YARROW)
66 #include <dev/random/yarrow.h>
68 #if defined(RANDOM_FORTUNA)
69 #include <dev/random/fortuna.h>
73 static int randomdev_poll(int event, struct thread *td);
74 static int randomdev_block(int flag);
75 static void randomdev_flush_reseed(void);
77 #if defined(RANDOM_YARROW)
78 static struct random_adaptor random_context = {
79 .ident = "Software, Yarrow",
80 .init = randomdev_init,
81 .deinit = randomdev_deinit,
82 .block = randomdev_block,
83 .read = random_yarrow_read,
84 .poll = randomdev_poll,
85 .reseed = randomdev_flush_reseed,
86 .seeded = 0, /* This will be seeded during entropy processing */
87 .priority = 90, /* High priority, so top of the list. Fortuna may still win. */
89 #define RANDOM_MODULE_NAME yarrow
90 #define RANDOM_CSPRNG_NAME "yarrow"
93 #if defined(RANDOM_FORTUNA)
94 static struct random_adaptor random_context = {
95 .ident = "Software, Fortuna",
96 .init = randomdev_init,
97 .deinit = randomdev_deinit,
98 .block = randomdev_block,
99 .read = random_fortuna_read,
100 .poll = randomdev_poll,
101 .reseed = randomdev_flush_reseed,
102 .seeded = 0, /* This will be excplicitly seeded at startup when secured */
103 .priority = 100, /* High priority, so top of the list. Beat Yarrow. */
105 #define RANDOM_MODULE_NAME fortuna
106 #define RANDOM_CSPRNG_NAME "fortuna"
109 TUNABLE_INT("kern.random.sys.seeded", &random_context.seeded);
111 /* List for the dynamic sysctls */
112 static struct sysctl_ctx_list random_clist;
116 random_check_boolean(SYSCTL_HANDLER_ARGS)
118 if (oidp->oid_arg1 != NULL && *(u_int *)(oidp->oid_arg1) != 0)
119 *(u_int *)(oidp->oid_arg1) = 1;
120 return (sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req));
126 struct sysctl_oid *random_sys_o, *random_sys_harvest_o;
128 #if defined(RANDOM_YARROW)
129 random_yarrow_init_alg(&random_clist);
131 #if defined(RANDOM_FORTUNA)
132 random_fortuna_init_alg(&random_clist);
135 random_sys_o = SYSCTL_ADD_NODE(&random_clist,
136 SYSCTL_STATIC_CHILDREN(_kern_random),
137 OID_AUTO, "sys", CTLFLAG_RW, 0,
138 "Entropy Device Parameters");
140 SYSCTL_ADD_PROC(&random_clist,
141 SYSCTL_CHILDREN(random_sys_o),
142 OID_AUTO, "seeded", CTLTYPE_INT | CTLFLAG_RW,
143 &random_context.seeded, 0, random_check_boolean, "I",
146 random_sys_harvest_o = SYSCTL_ADD_NODE(&random_clist,
147 SYSCTL_CHILDREN(random_sys_o),
148 OID_AUTO, "harvest", CTLFLAG_RW, 0,
151 SYSCTL_ADD_PROC(&random_clist,
152 SYSCTL_CHILDREN(random_sys_harvest_o),
153 OID_AUTO, "ethernet", CTLTYPE_INT | CTLFLAG_RW,
154 &harvest.ethernet, 1, random_check_boolean, "I",
155 "Harvest NIC entropy");
156 SYSCTL_ADD_PROC(&random_clist,
157 SYSCTL_CHILDREN(random_sys_harvest_o),
158 OID_AUTO, "point_to_point", CTLTYPE_INT | CTLFLAG_RW,
159 &harvest.point_to_point, 1, random_check_boolean, "I",
160 "Harvest serial net entropy");
161 SYSCTL_ADD_PROC(&random_clist,
162 SYSCTL_CHILDREN(random_sys_harvest_o),
163 OID_AUTO, "interrupt", CTLTYPE_INT | CTLFLAG_RW,
164 &harvest.interrupt, 1, random_check_boolean, "I",
165 "Harvest IRQ entropy");
166 SYSCTL_ADD_PROC(&random_clist,
167 SYSCTL_CHILDREN(random_sys_harvest_o),
168 OID_AUTO, "swi", CTLTYPE_INT | CTLFLAG_RW,
169 &harvest.swi, 1, random_check_boolean, "I",
170 "Harvest SWI entropy");
172 random_harvestq_init(random_process_event);
174 /* Register the randomness harvesting routine */
175 randomdev_init_harvester(random_harvestq_internal,
176 random_context.read);
180 randomdev_deinit(void)
182 /* Deregister the randomness harvesting routine */
183 randomdev_deinit_harvester();
185 #if defined(RANDOM_YARROW)
186 random_yarrow_deinit_alg();
188 #if defined(RANDOM_FORTUNA)
189 random_fortuna_deinit_alg();
192 sysctl_ctx_free(&random_clist);
196 randomdev_unblock(void)
198 if (!random_context.seeded) {
199 selwakeuppri(&random_context.rsel, PUSER);
200 wakeup(&random_context);
201 printf("random: unblocking device.\n");
202 random_context.seeded = 1;
204 /* Do arc4random(9) a favour while we are about it. */
205 (void)atomic_cmpset_int(&arc4rand_iniseed_state, ARC4_ENTR_NONE,
210 randomdev_poll(int events, struct thread *td)
214 mtx_lock(&random_reseed_mtx);
216 if (random_context.seeded)
217 revents = events & (POLLIN | POLLRDNORM);
219 selrecord(td, &random_context.rsel);
221 mtx_unlock(&random_reseed_mtx);
226 randomdev_block(int flag)
230 mtx_lock(&random_reseed_mtx);
233 while (!random_context.seeded && !error) {
234 if (flag & O_NONBLOCK)
237 printf("random: blocking on read.\n");
238 error = msleep(&random_context,
240 PUSER | PCATCH, "block", 0);
243 mtx_unlock(&random_reseed_mtx);
248 /* Helper routine to perform explicit reseeds */
250 randomdev_flush_reseed(void)
252 /* Command a entropy queue flush and wait for it to finish */
253 random_kthread_control = 1;
254 while (random_kthread_control)
257 #if defined(RANDOM_YARROW)
258 /* This ultimately calls randomdev_unblock() */
259 random_yarrow_reseed();
261 #if defined(RANDOM_FORTUNA)
262 /* This ultimately calls randomdev_unblock() */
263 random_fortuna_reseed();
268 randomdev_modevent(module_t mod __unused, int type, void *unused __unused)
273 random_adaptor_register(RANDOM_CSPRNG_NAME, &random_context);
275 * For statically built kernels that contain both device
276 * random and options PADLOCK_RNG/RDRAND_RNG/etc..,
277 * this event handler will do nothing, since the random
278 * driver-specific handlers are loaded after these HW
279 * consumers, and hence hasn't yet registered for this event.
281 * In case where both the random driver and RNG's are built
282 * as seperate modules, random.ko is loaded prior to *_rng.ko's
283 * (by dependency). This event handler is there to delay
284 * creation of /dev/{u,}random and attachment of this *_rng.ko.
286 EVENTHANDLER_INVOKE(random_adaptor_attach, &random_context);
293 RANDOM_ADAPTOR_MODULE(RANDOM_MODULE_NAME, randomdev_modevent, 1);