Commit 28b7678e authored by Niels Möller's avatar Niels Möller

New function curve25519_base.

parent 2ac6d737
2014-08-06 Niels Möller <nisse@lysator.liu.se> 2014-08-06 Niels Möller <nisse@lysator.liu.se>
* curve25519-base.c (curve25519_base): New file, new function.
Analogous to NaCl's crypto_scalarmult_base.
* curve25519.h: New file.
* Makefile.in (hogweed_SOURCES): Added curve25519-base.c.
(HEADERS): Added curve25519.h.
* gmp-glue.c (mpn_set_base256_le, mpn_get_base256_le): New functions. * gmp-glue.c (mpn_set_base256_le, mpn_get_base256_le): New functions.
* gmp-glue.h: Declare them. * gmp-glue.h: Declare them.
......
...@@ -174,12 +174,13 @@ hogweed_SOURCES = sexp.c sexp-format.c \ ...@@ -174,12 +174,13 @@ hogweed_SOURCES = sexp.c sexp-format.c \
ecc-point.c ecc-scalar.c ecc-point-mul.c ecc-point-mul-g.c \ ecc-point.c ecc-scalar.c ecc-point-mul.c ecc-point-mul-g.c \
ecc-ecdsa-sign.c ecdsa-sign.c \ ecc-ecdsa-sign.c ecdsa-sign.c \
ecc-ecdsa-verify.c ecdsa-verify.c ecdsa-keygen.c \ ecc-ecdsa-verify.c ecdsa-verify.c ecdsa-keygen.c \
curve25519-base.c \
$(OPT_HOGWEED_SOURCES) $(OPT_HOGWEED_SOURCES)
HEADERS = aes.h arcfour.h arctwo.h asn1.h blowfish.h \ HEADERS = aes.h arcfour.h arctwo.h asn1.h blowfish.h \
base16.h base64.h buffer.h camellia.h cast128.h \ base16.h base64.h buffer.h camellia.h cast128.h \
cbc.h ccm.h chacha.h chacha-poly1305.h ctr.h \ cbc.h ccm.h chacha.h chacha-poly1305.h ctr.h \
des.h des-compat.h dsa.h dsa-compat.h eax.h \ curve25519.h des.h des-compat.h dsa.h dsa-compat.h eax.h \
ecc-curve.h ecc.h ecdsa.h \ ecc-curve.h ecc.h ecdsa.h \
gcm.h gosthash94.h hmac.h \ gcm.h gosthash94.h hmac.h \
knuth-lfib.h \ knuth-lfib.h \
......
/* curve25519-base.c
Copyright (C) 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/.
*/
#if HAVE_CONFIG_H
# include "config.h"
#endif
#include <string.h>
#include "curve25519.h"
#include "ecc.h"
#include "ecc-internal.h"
/* Intended to be compatible with NaCl's crypto_scalarmult_base. */
void
curve25519_base (uint8_t *r, const uint8_t *n)
{
uint8_t t[CURVE25519_SIZE];
mp_limb_t *scratch;
mp_size_t ecc_size;
mp_size_t itch;
#define p scratch
#define x (scratch + 3*ecc_size)
#define scratch_out (scratch + 4*ecc_size)
memcpy (t, n, sizeof(t));
t[0] &= ~7;
t[CURVE25519_SIZE-1] = (t[CURVE25519_SIZE-1] & 0x3f) | 0x40;
ecc_size = nettle_curve25519.size;
itch = 4*ecc_size + ECC_MUL_G_EH_ITCH(ecc_size);
scratch = gmp_alloc_limbs (itch);
mpn_set_base256_le (x, ecc_size, t, CURVE25519_SIZE);
ecc_mul_g_eh (&nettle_curve25519, p, x, scratch_out);
ecc_eh_to_a (&nettle_curve25519, 2, x, p, scratch_out);
mpn_get_base256_le (r, CURVE25519_SIZE, x, ecc_size);
gmp_free_limbs (scratch, itch);
}
/* curve25519.h
Copyright (C) 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/.
*/
#ifndef NETTLE_CURVE25519_H
#define NETTLE_CURVE25519_H
#include "nettle-types.h"
#ifdef __cplusplus
extern "C" {
#endif
/* Name mangling */
#define curve25519_base nettle_curve25519_base
#define CURVE25519_SIZE 32
void
curve25519_base (uint8_t *q, const uint8_t *n);
#endif /* NETTLE_CURVE25519_H */
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