diff --git a/cipher/ecc-ecdh.c b/cipher/ecc-ecdh.c
index d3a5c7a1..388cf13e 100644
--- a/cipher/ecc-ecdh.c
+++ b/cipher/ecc-ecdh.c
@@ -1,134 +1,134 @@
/* ecc-ecdh.c - Elliptic Curve Diffie-Hellman key agreement
* Copyright (C) 2019 g10 Code GmbH
*
* This file is part of Libgcrypt.
*
* Libgcrypt is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* Libgcrypt 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, see .
* SPDX-License-Identifier: LGPL-2.1+
*/
#include
#include
#include
#include
#include
#include "g10lib.h"
#include "mpi.h"
#include "cipher.h"
#include "context.h"
#include "ec-context.h"
#include "ecc-common.h"
#define ECC_CURVE25519_BYTES 32
#define ECC_CURVE448_BYTES 56
static gpg_err_code_t
prepare_ec (mpi_ec_t *r_ec, const char *name)
{
int flags = PUBKEY_FLAG_DJB_TWEAK;
return _gcry_mpi_ec_internal_new (r_ec, &flags, "ecc_mul_point", NULL, name);
}
unsigned int
_gcry_ecc_get_algo_keylen (int algo)
{
unsigned int len = 0;
if (algo == GCRY_ECC_CURVE25519)
len = ECC_CURVE25519_BYTES;
else if (algo == GCRY_ECC_CURVE448)
len = ECC_CURVE448_BYTES;
return len;
}
gpg_error_t
_gcry_ecc_mul_point (int algo, unsigned char *result,
const unsigned char *scalar, const unsigned char *point)
{
unsigned int nbits;
unsigned int nbytes;
const char *curve;
gpg_err_code_t err;
unsigned char buffer[ECC_CURVE448_BYTES];
gcry_mpi_t mpi_k;
mpi_ec_t ec;
mpi_point_t Q;
gcry_mpi_t x;
unsigned int len;
int i;
unsigned char *buf;
if (algo == GCRY_ECC_CURVE25519)
curve = "Curve25519";
else if (algo == GCRY_ECC_CURVE448)
{
curve = "X448";
return gpg_error (GPG_ERR_UNSUPPORTED_ALGORITHM);
}
else
return gpg_error (GPG_ERR_UNKNOWN_ALGORITHM);
err = prepare_ec (&ec, curve);
if (err)
return err;
nbits = ec->nbits;
nbytes = (nbits + 7)/8;
mpi_k = mpi_new (nbits);
Q = mpi_point_new (nbits);
x = mpi_new (nbits);
memcpy (buffer, scalar, nbytes);
reverse_buffer (buffer, nbytes);
_gcry_mpi_set_buffer (mpi_k, buffer, nbytes, 0);
for (i = 0; (ec->h & (1 << i)) == 0; i++)
mpi_clear_bit (mpi_k, i);
mpi_set_highbit (mpi_k, nbits - 1);
if (point)
{
mpi_point_t P = mpi_point_new (nbits);
gcry_mpi_t mpi_u = mpi_new (nbits);
- _gcry_mpi_set_buffer (mpi_u, point, nbytes, 0);
+ _gcry_mpi_set_opaque_copy (mpi_u, point, nbytes*8);
err = _gcry_ecc_mont_decodepoint (mpi_u, ec, P);
_gcry_mpi_release (mpi_u);
if (err)
goto leave;
_gcry_mpi_ec_mul_point (Q, mpi_k, P, ec);
_gcry_mpi_point_release (P);
}
else
_gcry_mpi_ec_mul_point (Q, mpi_k, ec->G, ec);
_gcry_mpi_ec_get_affine (x, NULL, Q, ec);
buf = _gcry_mpi_get_buffer (x, nbytes, &len, NULL);
if (!buf)
err = gpg_error_from_syserror ();
memcpy (result, buf, nbytes);
xfree (buf);
leave:
_gcry_mpi_release (x);
_gcry_mpi_point_release (Q);
_gcry_mpi_release (mpi_k);
return err;
}