1 /* ecc-point-mul-g.c
2 
3    Copyright (C) 2013 Niels Möller
4 
5    This file is part of GNU Nettle.
6 
7    GNU Nettle is free software: you can redistribute it and/or
8    modify it under the terms of either:
9 
10      * the GNU Lesser General Public License as published by the Free
11        Software Foundation; either version 3 of the License, or (at your
12        option) any later version.
13 
14    or
15 
16      * the GNU General Public License as published by the Free
17        Software Foundation; either version 2 of the License, or (at your
18        option) any later version.
19 
20    or both in parallel, as here.
21 
22    GNU Nettle is distributed in the hope that it will be useful,
23    but WITHOUT ANY WARRANTY; without even the implied warranty of
24    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
25    General Public License for more details.
26 
27    You should have received copies of the GNU General Public License and
28    the GNU Lesser General Public License along with this program.  If
29    not, see http://www.gnu.org/licenses/.
30 */
31 
32 /* Development of Nettle's ECC support was funded by the .SE Internet Fund. */
33 
34 #if HAVE_CONFIG_H
35 # include "config.h"
36 #endif
37 
38 #include <assert.h>
39 
40 #include "ecc.h"
41 #include "ecc-internal.h"
42 #include "nettle-internal.h"
43 
44 void
ecc_point_mul_g(struct ecc_point * r,const struct ecc_scalar * n)45 ecc_point_mul_g (struct ecc_point *r, const struct ecc_scalar *n)
46 {
47   TMP_DECL(scratch, mp_limb_t, 3*ECC_MAX_SIZE + ECC_MUL_G_ITCH (ECC_MAX_SIZE));
48   const struct ecc_curve *ecc = r->ecc;
49   mp_limb_t size = ecc->p.size;
50   mp_size_t itch = 3*size + ecc->mul_g_itch;
51 
52   assert (n->ecc == ecc);
53 
54   TMP_ALLOC (scratch, itch);
55 
56   ecc->mul_g (ecc, scratch, n->p, scratch + 3*size);
57   ecc->h_to_a (ecc, 0, r->p, scratch, scratch + 3*size);
58 }
59