Commit c68cc1f0 authored by Niels Möller's avatar Niels Möller

Implemented ecc_mul_g_eh. Untested.

parent ed3377db
2014-07-18 Niels Möller <nisse@lysator.liu.se>
* ecc-mul-g-eh.c (ecc_mul_g_eh, ecc_mul_g_eh_itch): New file and
functions. Untested.
* ecc.h (ecc_mul_g_eh_itch): Declare new functions.
* ecc-internal.h (ECC_MUL_G_EH_ITCH): New macro.
* Makefile.in (hogweed_SOURCES): Added ecc-mul-g-eh.c.
2014-07-17 Niels Möller <nisse@lysator.liu.se>
* ecc-add-eh.c (ecc_add_eh): Reduce scratch need.
......
......@@ -168,6 +168,7 @@ hogweed_SOURCES = sexp.c sexp-format.c \
ecc-size.c ecc-j-to-a.c ecc-a-to-j.c \
ecc-dup-jj.c ecc-add-jja.c ecc-add-jjj.c \
ecc-dup-eh.c ecc-add-eh.c ecc-add-ehh.c ecc-eh-to-a.c \
ecc-mul-g-eh.c \
ecc-mul-g.c ecc-mul-a.c ecc-hash.c ecc-random.c \
ecc-point.c ecc-scalar.c ecc-point-mul.c ecc-point-mul-g.c \
ecc-ecdsa-sign.c ecdsa-sign.c \
......
......@@ -245,6 +245,7 @@ sec_modinv (mp_limb_t *vp, mp_limb_t *ap, mp_size_t n,
#define ECC_ADD_EH_ITCH(size) (6*(size))
#define ECC_ADD_EHH_ITCH(size) (9*(size))
#define ECC_MUL_G_ITCH(size) (9*(size))
#define ECC_MUL_G_EH_ITCH(size) (9*(size))
#if ECC_MUL_A_WBITS == 0
#define ECC_MUL_A_ITCH(size) (12*(size))
#else
......
/* ecc-mul-g-eh.c
Copyright (C) 2013, 2014 Niels Möller
This file is part of GNU Nettle.
GNU Nettle is free software: you can redistribute it and/or
modify it under the terms of either:
* the GNU Lesser General Public License as published by the Free
Software Foundation; either version 3 of the License, or (at your
option) any later version.
or
* the GNU General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your
option) any later version.
or both in parallel, as here.
GNU Nettle is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received copies of the GNU General Public License and
the GNU Lesser General Public License along with this program. If
not, see http://www.gnu.org/licenses/.
*/
/* Development of Nettle's ECC support was funded by the .SE Internet Fund. */
#if HAVE_CONFIG_H
# include "config.h"
#endif
#include <assert.h>
#include "ecc.h"
#include "ecc-internal.h"
mp_size_t
ecc_mul_g_eh_itch (const struct ecc_curve *ecc)
{
/* Needs 3*ecc->size + scratch for ecc_add_jja. */
return ECC_MUL_G_EH_ITCH (ecc->size);
}
void
ecc_mul_g_eh (const struct ecc_curve *ecc, mp_limb_t *r,
const mp_limb_t *np, mp_limb_t *scratch)
{
/* Scratch need determined by the ecc_add_eh call. Current total is
9 * ecc->size, at most 648 bytes. */
#define tp scratch
#define scratch_out (scratch + 3*ecc->size)
unsigned k, c;
unsigned i, j;
unsigned bit_rows;
k = ecc->pippenger_k;
c = ecc->pippenger_c;
bit_rows = (ecc->bit_size + k - 1) / k;
/* x = 0, y = 1, z = 1 */
mpn_zero (r, 3*ecc->size);
r[ecc->size] = r[2*ecc->size] = 1;
for (i = k; i-- > 0; )
{
ecc_dup_eh (ecc, r, r, scratch);
for (j = 0; j * c < bit_rows; j++)
{
unsigned bits;
/* Avoid the mp_bitcnt_t type for compatibility with older GMP
versions. */
unsigned bit_index;
/* Extract c bits from n, stride k, starting at i + kcj,
ending at i + k (cj + c - 1)*/
for (bits = 0, bit_index = i + k*(c*j+c); bit_index > i + k*c*j; )
{
mp_size_t limb_index;
unsigned shift;
bit_index -= k;
limb_index = bit_index / GMP_NUMB_BITS;
if (limb_index >= ecc->size)
continue;
shift = bit_index % GMP_NUMB_BITS;
bits = (bits << 1) | ((np[limb_index] >> shift) & 1);
}
sec_tabselect (tp, 2*ecc->size,
(ecc->pippenger_table
+ (2*ecc->size * (mp_size_t) j << c)),
1<<c, bits);
ecc_add_eh (ecc, r, r, tp, scratch_out);
}
}
#undef tp
#undef scratch_out
}
......@@ -79,6 +79,8 @@ extern "C" {
#define ecc_mul_g nettle_ecc_mul_g
#define ecc_mul_a_itch nettle_ecc_mul_a_itch
#define ecc_mul_a nettle_ecc_mul_a
#define ecc_mul_g_eh_itch nettle_ecc_mul_g_eh_itch
#define ecc_mul_g_eh nettle_ecc_mul_g_eh
struct ecc_curve;
......@@ -284,6 +286,12 @@ ecc_mul_a (const struct ecc_curve *ecc,
const mp_limb_t *np, const mp_limb_t *p,
mp_limb_t *scratch);
mp_size_t
ecc_mul_g_eh_itch (const struct ecc_curve *ecc);
void
ecc_mul_g_eh (const struct ecc_curve *ecc, mp_limb_t *r,
const mp_limb_t *np, mp_limb_t *scratch);
#ifdef __cplusplus
}
#endif
......
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