9feff969a0
These ones were unambiguous cases where the Foundation was the only listed copyright holder (in the associated license block). Sponsored by: The FreeBSD Foundation
253 lines
6.9 KiB
C
253 lines
6.9 KiB
C
/*-
|
|
* Copyright (c) 2017 The FreeBSD Foundation
|
|
*
|
|
* 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 <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/param.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/libkern.h>
|
|
#include <sys/linker.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mutex.h>
|
|
#include <sys/random.h>
|
|
#include <sys/smp.h>
|
|
#include <sys/time.h>
|
|
|
|
#include <machine/cpu.h>
|
|
|
|
#include <crypto/chacha20/chacha.h>
|
|
#include <crypto/sha2/sha256.h>
|
|
#include <dev/random/randomdev.h>
|
|
#ifdef RANDOM_FENESTRASX
|
|
#include <dev/random/fenestrasX/fx_pub.h>
|
|
#endif
|
|
|
|
#define CHACHA20_RESEED_BYTES 65536
|
|
#define CHACHA20_RESEED_SECONDS 300
|
|
#define CHACHA20_KEYBYTES 32
|
|
#define CHACHA20_BUFFER_SIZE 64
|
|
|
|
CTASSERT(CHACHA20_KEYBYTES*8 >= CHACHA_MINKEYLEN);
|
|
|
|
#ifndef RANDOM_FENESTRASX
|
|
int arc4rand_iniseed_state = ARC4_ENTR_NONE;
|
|
#endif
|
|
|
|
MALLOC_DEFINE(M_CHACHA20RANDOM, "chacha20random", "chacha20random structures");
|
|
|
|
struct chacha20_s {
|
|
struct mtx mtx;
|
|
int numbytes;
|
|
time_t t_reseed;
|
|
u_int8_t m_buffer[CHACHA20_BUFFER_SIZE];
|
|
struct chacha_ctx ctx;
|
|
#ifdef RANDOM_FENESTRASX
|
|
uint64_t seed_version;
|
|
#endif
|
|
} __aligned(CACHE_LINE_SIZE);
|
|
|
|
static struct chacha20_s *chacha20inst = NULL;
|
|
|
|
#define CHACHA20_FOREACH(_chacha20) \
|
|
for (_chacha20 = &chacha20inst[0]; \
|
|
_chacha20 <= &chacha20inst[mp_maxid]; \
|
|
_chacha20++)
|
|
|
|
/*
|
|
* Mix up the current context.
|
|
*/
|
|
static void
|
|
chacha20_randomstir(struct chacha20_s *chacha20)
|
|
{
|
|
struct timeval tv_now;
|
|
u_int8_t key[CHACHA20_KEYBYTES];
|
|
#ifdef RANDOM_FENESTRASX
|
|
uint64_t seed_version;
|
|
|
|
#else
|
|
if (__predict_false(random_bypass_before_seeding && !is_random_seeded())) {
|
|
SHA256_CTX ctx;
|
|
uint64_t cc;
|
|
uint32_t fver;
|
|
|
|
if (!arc4random_bypassed_before_seeding) {
|
|
arc4random_bypassed_before_seeding = true;
|
|
if (!random_bypass_disable_warnings)
|
|
printf("arc4random: WARNING: initial seeding "
|
|
"bypassed the cryptographic random device "
|
|
"because it was not yet seeded and the "
|
|
"knob 'bypass_before_seeding' was "
|
|
"enabled.\n");
|
|
}
|
|
|
|
/* Last ditch effort to inject something in a bad condition. */
|
|
cc = get_cyclecount();
|
|
SHA256_Init(&ctx);
|
|
SHA256_Update(&ctx, key, sizeof(key));
|
|
SHA256_Update(&ctx, &cc, sizeof(cc));
|
|
fver = __FreeBSD_version;
|
|
SHA256_Update(&ctx, &fver, sizeof(fver));
|
|
_Static_assert(sizeof(key) == SHA256_DIGEST_LENGTH,
|
|
"make sure 256 bits is still 256 bits");
|
|
SHA256_Final(key, &ctx);
|
|
} else {
|
|
#endif
|
|
#ifdef RANDOM_FENESTRASX
|
|
read_random_key(key, CHACHA20_KEYBYTES, &seed_version);
|
|
#else
|
|
/*
|
|
* If the loader(8) did not have an entropy stash from the
|
|
* previous shutdown to load, then we will block. The answer is
|
|
* to make sure there is an entropy stash at shutdown time.
|
|
*
|
|
* On the other hand, if the random_bypass_before_seeding knob
|
|
* was set and we landed in this branch, we know this won't
|
|
* block because we know the random device is seeded.
|
|
*/
|
|
read_random(key, CHACHA20_KEYBYTES);
|
|
}
|
|
#endif
|
|
getmicrouptime(&tv_now);
|
|
mtx_lock(&chacha20->mtx);
|
|
chacha_keysetup(&chacha20->ctx, key, CHACHA20_KEYBYTES*8);
|
|
chacha_ivsetup(&chacha20->ctx, (u_char *)&tv_now.tv_sec, (u_char *)&tv_now.tv_usec);
|
|
/* Reset for next reseed cycle. */
|
|
chacha20->t_reseed = tv_now.tv_sec + CHACHA20_RESEED_SECONDS;
|
|
chacha20->numbytes = 0;
|
|
#ifdef RANDOM_FENESTRASX
|
|
chacha20->seed_version = seed_version;
|
|
#endif
|
|
mtx_unlock(&chacha20->mtx);
|
|
}
|
|
|
|
/*
|
|
* Initialize the contexts.
|
|
*/
|
|
static void
|
|
chacha20_init(void)
|
|
{
|
|
struct chacha20_s *chacha20;
|
|
|
|
chacha20inst = malloc((mp_maxid + 1) * sizeof(struct chacha20_s),
|
|
M_CHACHA20RANDOM, M_NOWAIT | M_ZERO);
|
|
KASSERT(chacha20inst != NULL, ("chacha20_init: memory allocation error"));
|
|
|
|
CHACHA20_FOREACH(chacha20) {
|
|
mtx_init(&chacha20->mtx, "chacha20_mtx", NULL, MTX_DEF);
|
|
chacha20->t_reseed = -1;
|
|
chacha20->numbytes = 0;
|
|
explicit_bzero(chacha20->m_buffer, CHACHA20_BUFFER_SIZE);
|
|
explicit_bzero(&chacha20->ctx, sizeof(chacha20->ctx));
|
|
}
|
|
}
|
|
SYSINIT(chacha20, SI_SUB_LOCK, SI_ORDER_ANY, chacha20_init, NULL);
|
|
|
|
|
|
static void
|
|
chacha20_uninit(void)
|
|
{
|
|
struct chacha20_s *chacha20;
|
|
|
|
CHACHA20_FOREACH(chacha20)
|
|
mtx_destroy(&chacha20->mtx);
|
|
free(chacha20inst, M_CHACHA20RANDOM);
|
|
}
|
|
SYSUNINIT(chacha20, SI_SUB_LOCK, SI_ORDER_ANY, chacha20_uninit, NULL);
|
|
|
|
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
void
|
|
arc4rand(void *ptr, u_int len, int reseed)
|
|
{
|
|
struct chacha20_s *chacha20;
|
|
struct timeval tv;
|
|
u_int length;
|
|
u_int8_t *p;
|
|
|
|
#ifdef RANDOM_FENESTRASX
|
|
if (__predict_false(reseed))
|
|
#else
|
|
if (__predict_false(reseed ||
|
|
(arc4rand_iniseed_state == ARC4_ENTR_HAVE &&
|
|
atomic_cmpset_int(&arc4rand_iniseed_state, ARC4_ENTR_HAVE, ARC4_ENTR_SEED))))
|
|
#endif
|
|
CHACHA20_FOREACH(chacha20)
|
|
chacha20_randomstir(chacha20);
|
|
|
|
getmicrouptime(&tv);
|
|
chacha20 = &chacha20inst[curcpu];
|
|
/* We may get unlucky and be migrated off this CPU, but that is expected to be infrequent */
|
|
if ((chacha20->numbytes > CHACHA20_RESEED_BYTES) || (tv.tv_sec > chacha20->t_reseed))
|
|
chacha20_randomstir(chacha20);
|
|
|
|
mtx_lock(&chacha20->mtx);
|
|
#ifdef RANDOM_FENESTRASX
|
|
if (__predict_false(
|
|
atomic_load_acq_64(&fxrng_root_generation) != chacha20->seed_version
|
|
)) {
|
|
mtx_unlock(&chacha20->mtx);
|
|
chacha20_randomstir(chacha20);
|
|
mtx_lock(&chacha20->mtx);
|
|
}
|
|
#endif
|
|
|
|
p = ptr;
|
|
while (len) {
|
|
length = MIN(CHACHA20_BUFFER_SIZE, len);
|
|
chacha_encrypt_bytes(&chacha20->ctx, chacha20->m_buffer, p, length);
|
|
p += length;
|
|
len -= length;
|
|
chacha20->numbytes += length;
|
|
if (chacha20->numbytes > CHACHA20_RESEED_BYTES) {
|
|
mtx_unlock(&chacha20->mtx);
|
|
chacha20_randomstir(chacha20);
|
|
mtx_lock(&chacha20->mtx);
|
|
}
|
|
}
|
|
mtx_unlock(&chacha20->mtx);
|
|
}
|
|
|
|
uint32_t
|
|
arc4random(void)
|
|
{
|
|
uint32_t ret;
|
|
|
|
arc4rand(&ret, sizeof(ret), 0);
|
|
return ret;
|
|
}
|
|
|
|
void
|
|
arc4random_buf(void *ptr, size_t len)
|
|
{
|
|
|
|
arc4rand(ptr, len, 0);
|
|
}
|