xref: /freebsd/contrib/bearssl/src/ec/ec_pubkey.c (revision 2aaf9152a852aba9eb2036b95f4948ee77988826)
1*0957b409SSimon J. Gerraty /*
2*0957b409SSimon J. Gerraty  * Copyright (c) 2018 Thomas Pornin <pornin@bolet.org>
3*0957b409SSimon J. Gerraty  *
4*0957b409SSimon J. Gerraty  * Permission is hereby granted, free of charge, to any person obtaining
5*0957b409SSimon J. Gerraty  * a copy of this software and associated documentation files (the
6*0957b409SSimon J. Gerraty  * "Software"), to deal in the Software without restriction, including
7*0957b409SSimon J. Gerraty  * without limitation the rights to use, copy, modify, merge, publish,
8*0957b409SSimon J. Gerraty  * distribute, sublicense, and/or sell copies of the Software, and to
9*0957b409SSimon J. Gerraty  * permit persons to whom the Software is furnished to do so, subject to
10*0957b409SSimon J. Gerraty  * the following conditions:
11*0957b409SSimon J. Gerraty  *
12*0957b409SSimon J. Gerraty  * The above copyright notice and this permission notice shall be
13*0957b409SSimon J. Gerraty  * included in all copies or substantial portions of the Software.
14*0957b409SSimon J. Gerraty  *
15*0957b409SSimon J. Gerraty  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16*0957b409SSimon J. Gerraty  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17*0957b409SSimon J. Gerraty  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18*0957b409SSimon J. Gerraty  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19*0957b409SSimon J. Gerraty  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20*0957b409SSimon J. Gerraty  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21*0957b409SSimon J. Gerraty  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22*0957b409SSimon J. Gerraty  * SOFTWARE.
23*0957b409SSimon J. Gerraty  */
24*0957b409SSimon J. Gerraty 
25*0957b409SSimon J. Gerraty #include "inner.h"
26*0957b409SSimon J. Gerraty 
27*0957b409SSimon J. Gerraty static const unsigned char POINT_LEN[] = {
28*0957b409SSimon J. Gerraty 	  0,   /* 0: not a valid curve ID */
29*0957b409SSimon J. Gerraty 	 43,   /* sect163k1 */
30*0957b409SSimon J. Gerraty 	 43,   /* sect163r1 */
31*0957b409SSimon J. Gerraty 	 43,   /* sect163r2 */
32*0957b409SSimon J. Gerraty 	 51,   /* sect193r1 */
33*0957b409SSimon J. Gerraty 	 51,   /* sect193r2 */
34*0957b409SSimon J. Gerraty 	 61,   /* sect233k1 */
35*0957b409SSimon J. Gerraty 	 61,   /* sect233r1 */
36*0957b409SSimon J. Gerraty 	 61,   /* sect239k1 */
37*0957b409SSimon J. Gerraty 	 73,   /* sect283k1 */
38*0957b409SSimon J. Gerraty 	 73,   /* sect283r1 */
39*0957b409SSimon J. Gerraty 	105,   /* sect409k1 */
40*0957b409SSimon J. Gerraty 	105,   /* sect409r1 */
41*0957b409SSimon J. Gerraty 	145,   /* sect571k1 */
42*0957b409SSimon J. Gerraty 	145,   /* sect571r1 */
43*0957b409SSimon J. Gerraty 	 41,   /* secp160k1 */
44*0957b409SSimon J. Gerraty 	 41,   /* secp160r1 */
45*0957b409SSimon J. Gerraty 	 41,   /* secp160r2 */
46*0957b409SSimon J. Gerraty 	 49,   /* secp192k1 */
47*0957b409SSimon J. Gerraty 	 49,   /* secp192r1 */
48*0957b409SSimon J. Gerraty 	 57,   /* secp224k1 */
49*0957b409SSimon J. Gerraty 	 57,   /* secp224r1 */
50*0957b409SSimon J. Gerraty 	 65,   /* secp256k1 */
51*0957b409SSimon J. Gerraty 	 65,   /* secp256r1 */
52*0957b409SSimon J. Gerraty 	 97,   /* secp384r1 */
53*0957b409SSimon J. Gerraty 	133,   /* secp521r1 */
54*0957b409SSimon J. Gerraty 	 65,   /* brainpoolP256r1 */
55*0957b409SSimon J. Gerraty 	 97,   /* brainpoolP384r1 */
56*0957b409SSimon J. Gerraty 	129,   /* brainpoolP512r1 */
57*0957b409SSimon J. Gerraty 	 32,   /* curve25519 */
58*0957b409SSimon J. Gerraty 	 56,   /* curve448 */
59*0957b409SSimon J. Gerraty };
60*0957b409SSimon J. Gerraty 
61*0957b409SSimon J. Gerraty /* see bearssl_ec.h */
62*0957b409SSimon J. Gerraty size_t
br_ec_compute_pub(const br_ec_impl * impl,br_ec_public_key * pk,void * kbuf,const br_ec_private_key * sk)63*0957b409SSimon J. Gerraty br_ec_compute_pub(const br_ec_impl *impl, br_ec_public_key *pk,
64*0957b409SSimon J. Gerraty 	void *kbuf, const br_ec_private_key *sk)
65*0957b409SSimon J. Gerraty {
66*0957b409SSimon J. Gerraty 	int curve;
67*0957b409SSimon J. Gerraty 	size_t len;
68*0957b409SSimon J. Gerraty 
69*0957b409SSimon J. Gerraty 	curve = sk->curve;
70*0957b409SSimon J. Gerraty 	if (curve < 0 || curve >= 32 || curve >= (int)(sizeof POINT_LEN)
71*0957b409SSimon J. Gerraty 		|| ((impl->supported_curves >> curve) & 1) == 0)
72*0957b409SSimon J. Gerraty 	{
73*0957b409SSimon J. Gerraty 		return 0;
74*0957b409SSimon J. Gerraty 	}
75*0957b409SSimon J. Gerraty 	if (kbuf == NULL) {
76*0957b409SSimon J. Gerraty 		return POINT_LEN[curve];
77*0957b409SSimon J. Gerraty 	}
78*0957b409SSimon J. Gerraty 	len = impl->mulgen(kbuf, sk->x, sk->xlen, curve);
79*0957b409SSimon J. Gerraty 	if (pk != NULL) {
80*0957b409SSimon J. Gerraty 		pk->curve = curve;
81*0957b409SSimon J. Gerraty 		pk->q = kbuf;
82*0957b409SSimon J. Gerraty 		pk->qlen = len;
83*0957b409SSimon J. Gerraty 	}
84*0957b409SSimon J. Gerraty 	return len;
85*0957b409SSimon J. Gerraty }
86