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Replace the RC4 algorithm for generating in-kernel secure random

Browse Source 
numbers with Chacha20. Keep the API, though, as that is what the
other *BSD's have done.

Use the boot-time entropy stash (if present) to bootstrap the
in-kernel entropy source.

Reviewed by: delphij,rwatson
Approved by: so(delphij)
MFC after: 2 months
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D10048
This commit is contained in:
Mark Murray 2017-04-16 09:11:02 +00:00
parent c6fd01fbbb
commit 150890b0c6
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=317015
9 changed files with 405 additions and 126 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
sys/boot/forth/loader.conf
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@ -48,7 +48,7 @@ bitmap_type="splash_image_data" # and place it on the module_path
entropy_cache_load="YES" # Set this to NO to disable loading
# entropy at boot time
entropy_cache_name="/boot/entropy" # Set this to the name of the file
entropy_cache_type="/boot/entropy" # Required for the kernel to find
entropy_cache_type="boot_entropy_cache" # Required for the kernel to find
# the boot-time entropy cache. This
# must not change value even if the
# _name above does change!

1
sys/conf/files
View File

@ -3810,6 +3810,7 @@ kgssapi/gsstest.c optional kgssapi_debug
# the file should be moved to conf/files.<arch> from here.
#
libkern/arc4random.c standard
crypto/chacha20/chacha.c standard
libkern/asprintf.c standard
libkern/bcd.c standard
libkern/bsearch.c standard

224
sys/crypto/chacha20/chacha.c Normal file
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@ -0,0 +1,224 @@
/*
chacha-merged.c version 20080118
D. J. Bernstein
Public domain.
*/
/* $OpenBSD: chacha.c,v 1.1 2013/11/21 00:45:44 djm Exp $ */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/types.h>
#include <crypto/chacha20/chacha.h>
typedef uint8_t u8;
typedef uint32_t u32;
typedef struct chacha_ctx chacha_ctx;
#define U8C(v) (v##U)
#define U32C(v) (v##U)
#define U8V(v) ((u8)(v) & U8C(0xFF))
#define U32V(v) ((u32)(v) & U32C(0xFFFFFFFF))
#define ROTL32(v, n) \
(U32V((v) << (n)) | ((v) >> (32 - (n))))
#define U8TO32_LITTLE(p) \
(((u32)((p)[0]) ) | \
((u32)((p)[1]) << 8) | \
((u32)((p)[2]) << 16) | \
((u32)((p)[3]) << 24))
#define U32TO8_LITTLE(p, v) \
do { \
(p)[0] = U8V((v) ); \
(p)[1] = U8V((v) >> 8); \
(p)[2] = U8V((v) >> 16); \
(p)[3] = U8V((v) >> 24); \
} while (0)
#define ROTATE(v,c) (ROTL32(v,c))
#define XOR(v,w) ((v) ^ (w))
#define PLUS(v,w) (U32V((v) + (w)))
#define PLUSONE(v) (PLUS((v),1))
#define QUARTERROUND(a,b,c,d) \
a = PLUS(a,b); d = ROTATE(XOR(d,a),16); \
c = PLUS(c,d); b = ROTATE(XOR(b,c),12); \
a = PLUS(a,b); d = ROTATE(XOR(d,a), 8); \
c = PLUS(c,d); b = ROTATE(XOR(b,c), 7);
static const char sigma[16] = "expand 32-byte k";
static const char tau[16] = "expand 16-byte k";
void
chacha_keysetup(chacha_ctx *x,const u8 *k,u32 kbits)
{
const char *constants;
x->input[4] = U8TO32_LITTLE(k + 0);
x->input[5] = U8TO32_LITTLE(k + 4);
x->input[6] = U8TO32_LITTLE(k + 8);
x->input[7] = U8TO32_LITTLE(k + 12);
if (kbits == 256) { /* recommended */
k += 16;
constants = sigma;
} else { /* kbits == 128 */
constants = tau;
}
x->input[8] = U8TO32_LITTLE(k + 0);
x->input[9] = U8TO32_LITTLE(k + 4);
x->input[10] = U8TO32_LITTLE(k + 8);
x->input[11] = U8TO32_LITTLE(k + 12);
x->input[0] = U8TO32_LITTLE(constants + 0);
x->input[1] = U8TO32_LITTLE(constants + 4);
x->input[2] = U8TO32_LITTLE(constants + 8);
x->input[3] = U8TO32_LITTLE(constants + 12);
}
void
chacha_ivsetup(chacha_ctx *x, const u8 *iv, const u8 *counter)
{
x->input[12] = counter == NULL ? 0 : U8TO32_LITTLE(counter + 0);
x->input[13] = counter == NULL ? 0 : U8TO32_LITTLE(counter + 4);
x->input[14] = U8TO32_LITTLE(iv + 0);
x->input[15] = U8TO32_LITTLE(iv + 4);
}
void
chacha_encrypt_bytes(chacha_ctx *x,const u8 *m,u8 *c,u32 bytes)
{
u32 x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15;
u32 j0, j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11, j12, j13, j14, j15;
u8 *ctarget = NULL;
u8 tmp[64];
u_int i;
if (!bytes) return;
j0 = x->input[0];
j1 = x->input[1];
j2 = x->input[2];
j3 = x->input[3];
j4 = x->input[4];
j5 = x->input[5];
j6 = x->input[6];
j7 = x->input[7];
j8 = x->input[8];
j9 = x->input[9];
j10 = x->input[10];
j11 = x->input[11];
j12 = x->input[12];
j13 = x->input[13];
j14 = x->input[14];
j15 = x->input[15];
for (;;) {
if (bytes < 64) {
for (i = 0;i < bytes;++i) tmp[i] = m[i];
m = tmp;
ctarget = c;
c = tmp;
}
x0 = j0;
x1 = j1;
x2 = j2;
x3 = j3;
x4 = j4;
x5 = j5;
x6 = j6;
x7 = j7;
x8 = j8;
x9 = j9;
x10 = j10;
x11 = j11;
x12 = j12;
x13 = j13;
x14 = j14;
x15 = j15;
for (i = 20;i > 0;i -= 2) {
QUARTERROUND( x0, x4, x8,x12)
QUARTERROUND( x1, x5, x9,x13)
QUARTERROUND( x2, x6,x10,x14)
QUARTERROUND( x3, x7,x11,x15)
QUARTERROUND( x0, x5,x10,x15)
QUARTERROUND( x1, x6,x11,x12)
QUARTERROUND( x2, x7, x8,x13)
QUARTERROUND( x3, x4, x9,x14)
}
x0 = PLUS(x0,j0);
x1 = PLUS(x1,j1);
x2 = PLUS(x2,j2);
x3 = PLUS(x3,j3);
x4 = PLUS(x4,j4);
x5 = PLUS(x5,j5);
x6 = PLUS(x6,j6);
x7 = PLUS(x7,j7);
x8 = PLUS(x8,j8);
x9 = PLUS(x9,j9);
x10 = PLUS(x10,j10);
x11 = PLUS(x11,j11);
x12 = PLUS(x12,j12);
x13 = PLUS(x13,j13);
x14 = PLUS(x14,j14);
x15 = PLUS(x15,j15);
x0 = XOR(x0,U8TO32_LITTLE(m + 0));
x1 = XOR(x1,U8TO32_LITTLE(m + 4));
x2 = XOR(x2,U8TO32_LITTLE(m + 8));
x3 = XOR(x3,U8TO32_LITTLE(m + 12));
x4 = XOR(x4,U8TO32_LITTLE(m + 16));
x5 = XOR(x5,U8TO32_LITTLE(m + 20));
x6 = XOR(x6,U8TO32_LITTLE(m + 24));
x7 = XOR(x7,U8TO32_LITTLE(m + 28));
x8 = XOR(x8,U8TO32_LITTLE(m + 32));
x9 = XOR(x9,U8TO32_LITTLE(m + 36));
x10 = XOR(x10,U8TO32_LITTLE(m + 40));
x11 = XOR(x11,U8TO32_LITTLE(m + 44));
x12 = XOR(x12,U8TO32_LITTLE(m + 48));
x13 = XOR(x13,U8TO32_LITTLE(m + 52));
x14 = XOR(x14,U8TO32_LITTLE(m + 56));
x15 = XOR(x15,U8TO32_LITTLE(m + 60));
j12 = PLUSONE(j12);
if (!j12) {
j13 = PLUSONE(j13);
/* stopping at 2^70 bytes per nonce is user's responsibility */
}
U32TO8_LITTLE(c + 0,x0);
U32TO8_LITTLE(c + 4,x1);
U32TO8_LITTLE(c + 8,x2);
U32TO8_LITTLE(c + 12,x3);
U32TO8_LITTLE(c + 16,x4);
U32TO8_LITTLE(c + 20,x5);
U32TO8_LITTLE(c + 24,x6);
U32TO8_LITTLE(c + 28,x7);
U32TO8_LITTLE(c + 32,x8);
U32TO8_LITTLE(c + 36,x9);
U32TO8_LITTLE(c + 40,x10);
U32TO8_LITTLE(c + 44,x11);
U32TO8_LITTLE(c + 48,x12);
U32TO8_LITTLE(c + 52,x13);
U32TO8_LITTLE(c + 56,x14);
U32TO8_LITTLE(c + 60,x15);
if (bytes <= 64) {
if (bytes < 64) {
for (i = 0;i < bytes;++i) ctarget[i] = c[i];
}
x->input[12] = j12;
x->input[13] = j13;
return;
}
bytes -= 64;
c += 64;
m += 64;
}
}

32
sys/crypto/chacha20/chacha.h Normal file
View File

@ -0,0 +1,32 @@
/* $OpenBSD: chacha.h,v 1.4 2016/08/27 04:04:56 guenther Exp $ */
/*
chacha-merged.c version 20080118
D. J. Bernstein
Public domain.
$FreeBSD$
*/
#ifndef CHACHA_H
#define CHACHA_H
#include <sys/types.h>
struct chacha_ctx {
u_int input[16];
};
#define CHACHA_MINKEYLEN 16
#define CHACHA_NONCELEN 8
#define CHACHA_CTRLEN 8
#define CHACHA_STATELEN (CHACHA_NONCELEN+CHACHA_CTRLEN)
#define CHACHA_BLOCKLEN 64
void chacha_keysetup(struct chacha_ctx *x, const u_char *k, u_int kbits);
void chacha_ivsetup(struct chacha_ctx *x, const u_char *iv, const u_char *ctr);
void chacha_encrypt_bytes(struct chacha_ctx *x, const u_char *m,
u_char *c, u_int bytes);
#endif /* CHACHA_H */

11
sys/dev/random/random_harvestq.c
View File

@ -352,10 +352,19 @@ random_harvestq_prime(void *unused __unused)
* 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_HARVESTQ_BOOT_ENTROPY_FILE);
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);
/* skip the first bit of the stash so others like arc4 can also have some. */
if (size > RANDOM_CACHED_SKIP_START) {
data += RANDOM_CACHED_SKIP_START;
size -= RANDOM_CACHED_SKIP_START;
}
/* 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) {

4
sys/dev/random/random_harvestq.h
View File

@ -1,5 +1,5 @@
/*-
* Copyright (c) 2013-2015 Mark R V Murray
* Copyright (c) 2013-2015, 2017 Mark R V Murray
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@ -45,8 +45,6 @@ struct harvest_event {
void read_rate_increment(u_int);
#define RANDOM_HARVESTQ_BOOT_ENTROPY_FILE "/boot/entropy"
#define RANDOM_HARVEST_INIT_LOCK(x) mtx_init(&harvest_context.hc_mtx, "entropy harvest mutex", NULL, MTX_SPIN)
#define RANDOM_HARVEST_LOCK(x) mtx_lock_spin(&harvest_context.hc_mtx)
#define RANDOM_HARVEST_UNLOCK(x) mtx_unlock_spin(&harvest_context.hc_mtx)

248
sys/libkern/arc4random.c
View File

@ -1,11 +1,28 @@
/*-
* THE BEER-WARE LICENSE
* Copyright (c) 2017 The FreeBSD Foundation
* All rights reserved.
*
* <dan@FreeBSD.ORG> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you
* think this stuff is worth it, you can buy me a beer in return.
* 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.
*
* Dan Moschuk
*/
#include <sys/cdefs.h>
@ -14,144 +31,122 @@ __FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/random.h>
#include <sys/libkern.h>
#include <sys/linker.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/time.h>
#include <sys/smp.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/random.h>
#include <sys/smp.h>
#include <sys/time.h>
#define ARC4_RESEED_BYTES 65536
#define ARC4_RESEED_SECONDS 300
#define ARC4_KEYBYTES 256
#include <crypto/chacha20/chacha.h>
#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);
int arc4rand_iniseed_state = ARC4_ENTR_NONE;
MALLOC_DEFINE(M_ARC4RANDOM, "arc4random", "arc4random structures");
MALLOC_DEFINE(M_CHACHA20RANDOM, "chacha20random", "chacha20random structures");
struct arc4_s {
struct chacha20_s {
struct mtx mtx;
u_int8_t i, j;
int numruns;
u_int8_t sbox[256];
int numbytes;
int first_time_done;
time_t t_reseed;
u_int8_t m_buffer[CHACHA20_BUFFER_SIZE];
struct chacha_ctx ctx;
} __aligned(CACHE_LINE_SIZE);
static struct arc4_s *arc4inst = NULL;
static struct chacha20_s *chacha20inst = NULL;
#define ARC4_FOREACH(_arc4) \
for (_arc4 = &arc4inst[0]; _arc4 <= &arc4inst[mp_maxid]; _arc4++)
static u_int8_t arc4_randbyte(struct arc4_s *arc4);
static __inline void
arc4_swap(u_int8_t *a, u_int8_t *b)
{
u_int8_t c;
c = *a;
*a = *b;
*b = c;
}
#define CHACHA20_FOREACH(_chacha20) \
for (_chacha20 = &chacha20inst[0]; \
_chacha20 <= &chacha20inst[mp_maxid]; \
_chacha20++)
/*
* Stir our S-box.
* Mix up the current context.
*/
static void
arc4_randomstir(struct arc4_s* arc4)
chacha20_randomstir(struct chacha20_s* chacha20)
{
u_int8_t key[ARC4_KEYBYTES];
int n;
struct timeval tv_now;
size_t n, size;
u_int8_t key[CHACHA20_KEYBYTES], *data;
caddr_t keyfile;
/*
* XXX: FIX!! This isn't brilliant. Need more confidence.
* This returns zero entropy before random(4) is seeded.
* This is making the best of what may be an insecure
* Situation. If the loader(8) did not have an entropy
* stash from the previous shutdown to load, then we will
* be improperly seeded. The answer is to make sure there
* is an entropy stash at shutdown time.
*/
(void)read_random(key, ARC4_KEYBYTES);
(void)read_random(key, CHACHA20_KEYBYTES);
if (!chacha20->first_time_done) {
keyfile = preload_search_by_type(RANDOM_CACHED_BOOT_ENTROPY_MODULE);
if (keyfile != NULL) {
data = preload_fetch_addr(keyfile);
size = MIN(preload_fetch_size(keyfile), CHACHA20_KEYBYTES);
for (n = 0; n < size; n++)
key[n] ^= data[n];
explicit_bzero(data, size);
if (bootverbose)
printf("arc4random: read %zu bytes from preloaded cache\n", size);
} else
printf("arc4random: no preloaded entropy cache\n");
chacha20->first_time_done = 1;
}
getmicrouptime(&tv_now);
mtx_lock(&arc4->mtx);
for (n = 0; n < 256; n++) {
arc4->j = (arc4->j + arc4->sbox[n] + key[n]) % 256;
arc4_swap(&arc4->sbox[n], &arc4->sbox[arc4->j]);
}
arc4->i = arc4->j = 0;
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. */
arc4->t_reseed = tv_now.tv_sec + ARC4_RESEED_SECONDS;
arc4->numruns = 0;
/*
* Throw away the first N words of output, as suggested in the
* paper "Weaknesses in the Key Scheduling Algorithm of RC4"
* by Fluher, Mantin, and Shamir. (N = 768 in our case.)
*
* http://dl.acm.org/citation.cfm?id=646557.694759
*/
for (n = 0; n < 768*4; n++)
arc4_randbyte(arc4);
mtx_unlock(&arc4->mtx);
chacha20->t_reseed = tv_now.tv_sec + CHACHA20_RESEED_SECONDS;
chacha20->numbytes = 0;
mtx_unlock(&chacha20->mtx);
}
/*
* Initialize our S-box to its beginning defaults.
* Initialize the contexts.
*/
static void
arc4_init(void)
chacha20_init(void)
{
struct arc4_s *arc4;
int n;
struct chacha20_s *chacha20;
arc4inst = malloc((mp_maxid + 1) * sizeof(struct arc4_s),
M_ARC4RANDOM, M_NOWAIT | M_ZERO);
KASSERT(arc4inst != NULL, ("arc4_init: memory allocation error"));
chacha20inst = malloc((mp_maxid + 1) * sizeof(struct chacha20_s),
M_CHACHA20RANDOM, M_NOWAIT | M_ZERO);
KASSERT(chacha20inst != NULL, ("chacha20_init: memory allocation error"));
ARC4_FOREACH(arc4) {
mtx_init(&arc4->mtx, "arc4_mtx", NULL, MTX_DEF);
arc4->i = arc4->j = 0;
for (n = 0; n < 256; n++)
arc4->sbox[n] = (u_int8_t) n;
arc4->t_reseed = -1;
arc4->numruns = 0;
CHACHA20_FOREACH(chacha20) {
mtx_init(&chacha20->mtx, "chacha20_mtx", NULL, MTX_DEF);
chacha20->t_reseed = -1;
chacha20->numbytes = 0;
chacha20->first_time_done = 0;
explicit_bzero(chacha20->m_buffer, CHACHA20_BUFFER_SIZE);
explicit_bzero(&chacha20->ctx, sizeof(chacha20->ctx));
}
}
SYSINIT(arc4, SI_SUB_LOCK, SI_ORDER_ANY, arc4_init, NULL);
SYSINIT(chacha20, SI_SUB_LOCK, SI_ORDER_ANY, chacha20_init, NULL);
static void
arc4_uninit(void)
chacha20_uninit(void)
{
struct arc4_s *arc4;
struct chacha20_s *chacha20;
ARC4_FOREACH(arc4) {
mtx_destroy(&arc4->mtx);
}
free(arc4inst, M_ARC4RANDOM);
CHACHA20_FOREACH(chacha20)
mtx_destroy(&chacha20->mtx);
free(chacha20inst, M_CHACHA20RANDOM);
}
SYSUNINIT(chacha20, SI_SUB_LOCK, SI_ORDER_ANY, chacha20_uninit, NULL);
SYSUNINIT(arc4, SI_SUB_LOCK, SI_ORDER_ANY, arc4_uninit, NULL);
/*
* Generate a random byte.
*/
static u_int8_t
arc4_randbyte(struct arc4_s *arc4)
{
u_int8_t arc4_t;
arc4->i = (arc4->i + 1) % 256;
arc4->j = (arc4->j + arc4->sbox[arc4->i]) % 256;
arc4_swap(&arc4->sbox[arc4->i], &arc4->sbox[arc4->j]);
arc4_t = (arc4->sbox[arc4->i] + arc4->sbox[arc4->j]) % 256;
return arc4->sbox[arc4_t];
}
/*
* MPSAFE
@ -159,28 +154,36 @@ arc4_randbyte(struct arc4_s *arc4)
void
arc4rand(void *ptr, u_int len, int reseed)
{
u_char *p;
struct chacha20_s *chacha20;
struct timeval tv;
struct arc4_s *arc4;
u_int length;
u_int8_t *p;
if (reseed || atomic_cmpset_int(&arc4rand_iniseed_state,
ARC4_ENTR_HAVE, ARC4_ENTR_SEED)) {
ARC4_FOREACH(arc4)
arc4_randomstir(arc4);
}
if (reseed || atomic_cmpset_int(&arc4rand_iniseed_state, ARC4_ENTR_HAVE, ARC4_ENTR_SEED))
CHACHA20_FOREACH(chacha20)
chacha20_randomstir(chacha20);
arc4 = &arc4inst[curcpu];
chacha20 = &chacha20inst[curcpu];
getmicrouptime(&tv);
if ((arc4->numruns > ARC4_RESEED_BYTES) ||
(tv.tv_sec > arc4->t_reseed))
arc4_randomstir(arc4);
/* 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(&arc4->mtx);
arc4->numruns += len;
mtx_lock(&chacha20->mtx);
p = ptr;
while (len--)
*p++ = arc4_randbyte(arc4);
mtx_unlock(&arc4->mtx);
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
@ -188,6 +191,13 @@ arc4random(void)
{
uint32_t ret;
arc4rand(&ret, sizeof ret, 0);
arc4rand(&ret, sizeof(ret), 0);
return ret;
}
void
arc4random_buf(void *ptr, size_t len)
{
arc4rand(ptr, len, 0);
}

3
sys/sys/libkern.h
View File

@ -117,7 +117,8 @@ extern int arc4rand_iniseed_state;
/* Prototypes for non-quad routines. */
struct malloc_type;
uint32_t arc4random(void);
void arc4rand(void *ptr, u_int len, int reseed);
void arc4random_buf(void *, size_t);
void arc4rand(void *, u_int, int);
int bcmp(const void *, const void *, size_t);
int timingsafe_bcmp(const void *, const void *, size_t);
void *bsearch(const void *, const void *, size_t,

6
sys/sys/random.h
View File

@ -1,5 +1,5 @@
/*-
* Copyright (c) 2000-2015 Mark R. V. Murray
* Copyright (c) 2000-2015, 2017 Mark R. V. Murray
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@ -96,6 +96,10 @@ enum random_entropy_source {
#define RANDOM_HARVEST_EVERYTHING_MASK ((1 << (RANDOM_ENVIRONMENTAL_END + 1)) - 1)
#define RANDOM_LEGACY_BOOT_ENTROPY_MODULE "/boot/entropy"
#define RANDOM_CACHED_BOOT_ENTROPY_MODULE "boot_entropy_cache"
#define RANDOM_CACHED_SKIP_START 256
#if defined(DEV_RANDOM)
void random_harvest_queue(const void *, u_int, u_int, enum random_entropy_source);
void random_harvest_fast(const void *, u_int, u_int, enum random_entropy_source);