freebsd-skq/sys/opencrypto/gfmult.c
John-Mark Gurney 08fca7a56b Add some new modes to OpenCrypto. These modes are AES-ICM (can be used
for counter mode), and AES-GCM.  Both of these modes have been added to
the aesni module.

Included is a set of tests to validate that the software and aesni
module calculate the correct values.  These use the NIST KAT test
vectors.  To run the test, you will need to install a soon to be
committed port, nist-kat that will install the vectors.  Using a port
is necessary as the test vectors are around 25MB.

All the man pages were updated.  I have added a new man page, crypto.7,
which includes a description of how to use each mode.  All the new modes
and some other AES modes are present.  It would be good for someone
else to go through and document the other modes.

A new ioctl was added to support AEAD modes which AES-GCM is one of them.
Without this ioctl, it is not possible to test AEAD modes from userland.

Add a timing safe bcmp for use to compare MACs.  Previously we were using
bcmp which could leak timing info and result in the ability to forge
messages.

Add a minor optimization to the aesni module so that single segment
mbufs don't get copied and instead are updated in place.  The aesni
module needs to be updated to support blocked IO so segmented mbufs
don't have to be copied.

We require that the IV be specified for all calls for both GCM and ICM.
This is to ensure proper use of these functions.

Obtained from:	p4: //depot/projects/opencrypto
Relnotes:	yes
Sponsored by:	FreeBSD Foundation
Sponsored by:	NetGate
2014-12-12 19:56:36 +00:00

276 lines
6.5 KiB
C

/*-
* Copyright (c) 2014 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by John-Mark Gurney under
* the sponsorship of the FreeBSD Foundation and
* Rubicon Communications, LLC (Netgate).
* 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.
* 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
*
* $FreeBSD$
*
*/
#include "gfmult.h"
#define REV_POLY_REDUCT 0xe1 /* 0x87 bit reversed */
/* reverse the bits of a nibble */
static const uint8_t nib_rev[] = {
0x0, 0x8, 0x4, 0xc, 0x2, 0xa, 0x6, 0xe,
0x1, 0x9, 0x5, 0xd, 0x3, 0xb, 0x7, 0xf,
};
/* calulate v * 2 */
static inline struct gf128
gf128_mulalpha(struct gf128 v)
{
uint64_t mask;
mask = !!(v.v[1] & 1);
mask = ~(mask - 1);
v.v[1] = (v.v[1] >> 1) | ((v.v[0] & 1) << 63);
v.v[0] = (v.v[0] >> 1) ^ ((mask & REV_POLY_REDUCT) << 56);
return v;
}
/*
* Generate a table for 0-16 * h. Store the results in the table w/ indexes
* bit reversed, and the words striped across the values.
*/
void
gf128_genmultable(struct gf128 h, struct gf128table *t)
{
struct gf128 tbl[16];
int i;
tbl[0] = MAKE_GF128(0, 0);
tbl[1] = h;
for (i = 2; i < 16; i += 2) {
tbl[i] = gf128_mulalpha(tbl[i / 2]);
tbl[i + 1] = gf128_add(tbl[i], h);
}
for (i = 0; i < 16; i++) {
t->a[nib_rev[i]] = tbl[i].v[0] >> 32;
t->b[nib_rev[i]] = tbl[i].v[0];
t->c[nib_rev[i]] = tbl[i].v[1] >> 32;
t->d[nib_rev[i]] = tbl[i].v[1];
}
}
/*
* Generate tables containing h, h^2, h^3 and h^4, starting at 0.
*/
void
gf128_genmultable4(struct gf128 h, struct gf128table4 *t)
{
struct gf128 h2, h3, h4;
gf128_genmultable(h, &t->tbls[0]);
h2 = gf128_mul(h, &t->tbls[0]);
gf128_genmultable(h2, &t->tbls[1]);
h3 = gf128_mul(h, &t->tbls[1]);
gf128_genmultable(h3, &t->tbls[2]);
h4 = gf128_mul(h2, &t->tbls[1]);
gf128_genmultable(h4, &t->tbls[3]);
}
/*
* Read a row from the table.
*/
static inline struct gf128
readrow(struct gf128table *tbl, unsigned bits)
{
struct gf128 r;
bits = bits % 16;
r.v[0] = ((uint64_t)tbl->a[bits] << 32) | tbl->b[bits];
r.v[1] = ((uint64_t)tbl->c[bits] << 32) | tbl->d[bits];
return r;
}
/*
* These are the reduction values. Since we are dealing with bit reversed
* version, the values need to be bit reversed, AND the indexes are also
* bit reversed to make lookups quicker.
*/
static uint16_t reduction[] = {
0x0000, 0x1c20, 0x3840, 0x2460, 0x7080, 0x6ca0, 0x48c0, 0x54e0,
0xe100, 0xfd20, 0xd940, 0xc560, 0x9180, 0x8da0, 0xa9c0, 0xb5e0,
};
/*
* Calculate:
* (x*2^4 + word[3,0]*h) *
* 2^4 + word[7,4]*h) *
* ...
* 2^4 + word[63,60]*h
*/
static struct gf128
gfmultword(uint64_t word, struct gf128 x, struct gf128table *tbl)
{
struct gf128 row;
unsigned bits;
unsigned redbits;
int i;
for (i = 0; i < 64; i += 4) {
bits = word % 16;
/* fetch row */
row = readrow(tbl, bits);
/* x * 2^4 */
redbits = x.v[1] % 16;
x.v[1] = (x.v[1] >> 4) | (x.v[0] % 16) << 60;
x.v[0] >>= 4;
x.v[0] ^= (uint64_t)reduction[redbits] << (64 - 16);
word >>= 4;
x = gf128_add(x, row);
}
return x;
}
/*
* Calculate
* (x*2^4 + worda[3,0]*h^4+wordb[3,0]*h^3+...+wordd[3,0]*h) *
* ...
* 2^4 + worda[63,60]*h^4+ ... + wordd[63,60]*h
*
* Passing/returning struct is .5% faster than passing in via pointer on
* amd64.
*/
static struct gf128
gfmultword4(uint64_t worda, uint64_t wordb, uint64_t wordc, uint64_t wordd,
struct gf128 x, struct gf128table4 *tbl)
{
struct gf128 rowa, rowb, rowc, rowd;
unsigned bitsa, bitsb, bitsc, bitsd;
unsigned redbits;
int i;
/*
* XXX - nibble reverse words to save a shift? probably not as
* nibble reverse would take 20 ops (5 * 4) verse 16
*/
for (i = 0; i < 64; i += 4) {
bitsa = worda % 16;
bitsb = wordb % 16;
bitsc = wordc % 16;
bitsd = wordd % 16;
/* fetch row */
rowa = readrow(&tbl->tbls[3], bitsa);
rowb = readrow(&tbl->tbls[2], bitsb);
rowc = readrow(&tbl->tbls[1], bitsc);
rowd = readrow(&tbl->tbls[0], bitsd);
/* x * 2^4 */
redbits = x.v[1] % 16;
x.v[1] = (x.v[1] >> 4) | (x.v[0] % 16) << 60;
x.v[0] >>= 4;
x.v[0] ^= (uint64_t)reduction[redbits] << (64 - 16);
worda >>= 4;
wordb >>= 4;
wordc >>= 4;
wordd >>= 4;
x = gf128_add(x, gf128_add(rowa, gf128_add(rowb,
gf128_add(rowc, rowd))));
}
return x;
}
struct gf128
gf128_mul(struct gf128 v, struct gf128table *tbl)
{
struct gf128 ret;
ret = MAKE_GF128(0, 0);
ret = gfmultword(v.v[1], ret, tbl);
ret = gfmultword(v.v[0], ret, tbl);
return ret;
}
/*
* Calculate a*h^4 + b*h^3 + c*h^2 + d*h, or:
* (((a*h+b)*h+c)*h+d)*h
*/
struct gf128
gf128_mul4(struct gf128 a, struct gf128 b, struct gf128 c, struct gf128 d,
struct gf128table4 *tbl)
{
struct gf128 tmp;
tmp = MAKE_GF128(0, 0);
tmp = gfmultword4(a.v[1], b.v[1], c.v[1], d.v[1], tmp, tbl);
tmp = gfmultword4(a.v[0], b.v[0], c.v[0], d.v[0], tmp, tbl);
return tmp;
}
/*
* a = data[0..15] + r
* b = data[16..31]
* c = data[32..47]
* d = data[48..63]
*
* Calculate a*h^4 + b*h^3 + c*h^2 + d*h, or:
* (((a*h+b)*h+c)*h+d)*h
*/
struct gf128
gf128_mul4b(struct gf128 r, const uint8_t *v, struct gf128table4 *tbl)
{
struct gf128 a, b, c, d;
struct gf128 tmp;
tmp = MAKE_GF128(0, 0);
a = gf128_add(r, gf128_read(&v[0*16]));
b = gf128_read(&v[1*16]);
c = gf128_read(&v[2*16]);
d = gf128_read(&v[3*16]);
tmp = gfmultword4(a.v[1], b.v[1], c.v[1], d.v[1], tmp, tbl);
tmp = gfmultword4(a.v[0], b.v[0], c.v[0], d.v[0], tmp, tbl);
return tmp;
}