svn commit: r317015 - in head/sys: boot/forth conf crypto/chacha20 dev/random libkern sys
Rodney W. Grimes
freebsd at pdx.rh.CN85.dnsmgr.net
Sun Apr 16 11:50:54 UTC 2017
> This does not use DES' Chacha20 commit, as I had already completed the
> testing for it, and received SO@ approval.
>
> DES's commit made Chaha20 a module. This is of no use to arc4random(9),
> which needs the code to be standard. Also his API is different.
>
> I have no objection to reworking the arc4random/Chacha below to use DES'
> version of Chacha, but his code needs to be standard library code,
> not an optional module.
>
> Any objections to me doing this?
Yes
We need to move towards more modules, not less. Having this standard
does not even allow one to compile a kernel without it. I should be
able to compile a kernel without arc4random(9) and without chacha if
I so desire. And I should be able to load and unload these if I so
desire. This later feature is VERY usefull for developement and
debug cycles.
I am sure with careful though we can find a way to allow arc4random
to use a pointer that knows if the chacha code is avaliable, and use
it if so, and if not fall back to something else, or punt with an
error return.
I have done this with minidumps, if my module is not loaded and the
kernel panics, and is set to attempt a minidump it just logs another
error when it finds the NULL pointer and continues on its way to
panic.
> M
>
> > On 16 Apr 2017, at 10:11, Mark Murray <markm at FreeBSD.org> wrote:
> >
> > Author: markm
> > Date: Sun Apr 16 09:11:02 2017
> > New Revision: 317015
> > URL: https://svnweb.freebsd.org/changeset/base/317015
> >
> > Log:
> > Replace the RC4 algorithm for generating in-kernel secure random
> > 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 line, and those below, will be ignored--
> >> Description of fields to fill in above: 76 columns --|
> >> PR: If and which Problem Report is related.
> >> Submitted by: If someone else sent in the change.
> >> Reported by: If someone else reported the issue.
> >> Reviewed by: If someone else reviewed your modification.
> >> Approved by: If you needed approval for this commit.
> >> Obtained from: If the change is from a third party.
> >> MFC after: N [day[s]|week[s]|month[s]]. Request a reminder email.
> >> MFH: Ports tree branch name. Request approval for merge.
> >> Relnotes: Set to 'yes' for mention in release notes.
> >> Security: Vulnerability reference (one per line) or description.
> >> Sponsored by: If the change was sponsored by an organization.
> >> Differential Revision: https://reviews.freebsd.org/D### (*full* phabric URL needed).
> >> Empty fields above will be automatically removed.
> >
> > Added:
> > head/sys/crypto/chacha20/chacha.c (contents, props changed)
> > head/sys/crypto/chacha20/chacha.h (contents, props changed)
> > Modified:
> > head/sys/boot/forth/loader.conf
> > head/sys/conf/files
> > head/sys/dev/random/random_harvestq.c
> > head/sys/dev/random/random_harvestq.h
> > head/sys/libkern/arc4random.c
> > head/sys/sys/libkern.h
> > head/sys/sys/random.h
> >
> > Modified: head/sys/boot/forth/loader.conf
> > ==============================================================================
> > --- head/sys/boot/forth/loader.conf Sun Apr 16 09:00:10 2017 (r317014)
> > +++ head/sys/boot/forth/loader.conf Sun Apr 16 09:11:02 2017 (r317015)
> > @@ -48,7 +48,7 @@ bitmap_type="splash_image_data" # and pl
> > 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!
> >
> > Modified: head/sys/conf/files
> > ==============================================================================
> > --- head/sys/conf/files Sun Apr 16 09:00:10 2017 (r317014)
> > +++ head/sys/conf/files Sun Apr 16 09:11:02 2017 (r317015)
> > @@ -3810,6 +3810,7 @@ kgssapi/gsstest.c optional kgssapi_debu
> > # 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
> >
> > Added: head/sys/crypto/chacha20/chacha.c
> > ==============================================================================
> > --- /dev/null 00:00:00 1970 (empty, because file is newly added)
> > +++ head/sys/crypto/chacha20/chacha.c Sun Apr 16 09:11:02 2017 (r317015)
> > @@ -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;
> > + }
> > +}
> >
> > Added: head/sys/crypto/chacha20/chacha.h
> > ==============================================================================
> > --- /dev/null 00:00:00 1970 (empty, because file is newly added)
> > +++ head/sys/crypto/chacha20/chacha.h Sun Apr 16 09:11:02 2017 (r317015)
> > @@ -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 */
> > +
> >
> > Modified: head/sys/dev/random/random_harvestq.c
> > ==============================================================================
> > --- head/sys/dev/random/random_harvestq.c Sun Apr 16 09:00:10 2017 (r317014)
> > +++ head/sys/dev/random/random_harvestq.c Sun Apr 16 09:11:02 2017 (r317015)
> > @@ -352,10 +352,19 @@ random_harvestq_prime(void *unused __unu
> > * 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) {
> >
> > Modified: head/sys/dev/random/random_harvestq.h
> > ==============================================================================
> > --- head/sys/dev/random/random_harvestq.h Sun Apr 16 09:00:10 2017 (r317014)
> > +++ head/sys/dev/random/random_harvestq.h Sun Apr 16 09:11:02 2017 (r317015)
> > @@ -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)
> >
> > Modified: head/sys/libkern/arc4random.c
> > ==============================================================================
> > --- head/sys/libkern/arc4random.c Sun Apr 16 09:00:10 2017 (r317014)
> > +++ head/sys/libkern/arc4random.c Sun Apr 16 09:11:02 2017 (r317015)
> > @@ -1,11 +1,28 @@
> > /*-
> > - * THE BEER-WARE LICENSE
> > + * Copyright (c) 2017 The FreeBSD Foundation
> > + * All rights reserved.
> > *
> > - * <dan at 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/malloc.h>
> > #include <sys/mutex.h>
> > -#include <sys/time.h>
> > +#include <sys/random.h>
> > #include <sys/smp.h>
> > -#include <sys/malloc.h>
> > +#include <sys/time.h>
> > +
> > +#include <crypto/chacha20/chacha.h>
> >
> > -#define ARC4_RESEED_BYTES 65536
> > -#define ARC4_RESEED_SECONDS 300
> > -#define ARC4_KEYBYTES 256
> > +#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);
> > - 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]);
> > + (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;
> > }
> > - arc4->i = arc4->j = 0;
> > + 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. */
> > - 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;
> > -
> > - arc4inst = malloc((mp_maxid + 1) * sizeof(struct arc4_s),
> > - M_ARC4RANDOM, M_NOWAIT | M_ZERO);
> > - KASSERT(arc4inst != NULL, ("arc4_init: memory allocation error"));
> > + struct chacha20_s *chacha20;
> >
> > - 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;
> > + 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;
> > + 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);
> > +}
> >
> > Modified: head/sys/sys/libkern.h
> > ==============================================================================
> > --- head/sys/sys/libkern.h Sun Apr 16 09:00:10 2017 (r317014)
> > +++ head/sys/sys/libkern.h Sun Apr 16 09:11:02 2017 (r317015)
> > @@ -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,
> >
> > Modified: head/sys/sys/random.h
> > ==============================================================================
> > --- head/sys/sys/random.h Sun Apr 16 09:00:10 2017 (r317014)
> > +++ head/sys/sys/random.h Sun Apr 16 09:11:02 2017 (r317015)
> > @@ -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);
> >
>
> --
> Mark R V Murray
>
>
>
>
--
Rod Grimes rgrimes at freebsd.org
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