1/*
2 * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files (the
6 * "Software"), to deal in the Software without restriction, including
7 * without limitation the rights to use, copy, modify, merge, publish,
8 * distribute, sublicense, and/or sell copies of the Software, and to
9 * permit persons to whom the Software is furnished to do so, subject to
10 * the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22 * SOFTWARE.
23 */
24
25#include "inner.h"
26
27static void
28cc_none0(const br_ssl_client_certificate_class **pctx)
29{
30	(void)pctx;
31}
32
33static void
34cc_none1(const br_ssl_client_certificate_class **pctx, size_t len)
35{
36	(void)pctx;
37	(void)len;
38}
39
40static void
41cc_none2(const br_ssl_client_certificate_class **pctx,
42	const unsigned char *data, size_t len)
43{
44	(void)pctx;
45	(void)data;
46	(void)len;
47}
48
49static void
50cc_choose(const br_ssl_client_certificate_class **pctx,
51	const br_ssl_client_context *cc, uint32_t auth_types,
52	br_ssl_client_certificate *choices)
53{
54	br_ssl_client_certificate_ec_context *zc;
55	int x;
56	int scurve;
57
58	zc = (br_ssl_client_certificate_ec_context *)pctx;
59	scurve = br_ssl_client_get_server_curve(cc);
60
61	if ((zc->allowed_usages & BR_KEYTYPE_KEYX) != 0
62		&& scurve == zc->sk->curve)
63	{
64		int x;
65
66		x = (zc->issuer_key_type == BR_KEYTYPE_RSA) ? 16 : 17;
67		if (((auth_types >> x) & 1) != 0) {
68			choices->auth_type = BR_AUTH_ECDH;
69			choices->hash_id = -1;
70			choices->chain = zc->chain;
71			choices->chain_len = zc->chain_len;
72		}
73	}
74
75	/*
76	 * For ECDSA authentication, we must choose an appropriate
77	 * hash function.
78	 */
79	x = br_ssl_choose_hash((unsigned)(auth_types >> 8));
80	if (x == 0 || (zc->allowed_usages & BR_KEYTYPE_SIGN) == 0) {
81		memset(choices, 0, sizeof *choices);
82		return;
83	}
84	choices->auth_type = BR_AUTH_ECDSA;
85	choices->hash_id = x;
86	choices->chain = zc->chain;
87	choices->chain_len = zc->chain_len;
88}
89
90static uint32_t
91cc_do_keyx(const br_ssl_client_certificate_class **pctx,
92	unsigned char *data, size_t *len)
93{
94	br_ssl_client_certificate_ec_context *zc;
95	uint32_t r;
96	size_t xoff, xlen;
97
98	zc = (br_ssl_client_certificate_ec_context *)pctx;
99	r = zc->iec->mul(data, *len, zc->sk->x, zc->sk->xlen, zc->sk->curve);
100	xoff = zc->iec->xoff(zc->sk->curve, &xlen);
101	memmove(data, data + xoff, xlen);
102	*len = xlen;
103	return r;
104}
105
106static size_t
107cc_do_sign(const br_ssl_client_certificate_class **pctx,
108	int hash_id, size_t hv_len, unsigned char *data, size_t len)
109{
110	br_ssl_client_certificate_ec_context *zc;
111	unsigned char hv[64];
112	const br_hash_class *hc;
113
114	zc = (br_ssl_client_certificate_ec_context *)pctx;
115	memcpy(hv, data, hv_len);
116	hc = br_multihash_getimpl(zc->mhash, hash_id);
117	if (hc == NULL) {
118		return 0;
119	}
120	if (len < 139) {
121		return 0;
122	}
123	return zc->iecdsa(zc->iec, hc, hv, zc->sk, data);
124}
125
126static const br_ssl_client_certificate_class ccert_vtable = {
127	sizeof(br_ssl_client_certificate_ec_context),
128	cc_none0, /* start_name_list */
129	cc_none1, /* start_name */
130	cc_none2, /* append_name */
131	cc_none0, /* end_name */
132	cc_none0, /* end_name_list */
133	cc_choose,
134	cc_do_keyx,
135	cc_do_sign
136};
137
138/* see bearssl_ssl.h */
139void
140br_ssl_client_set_single_ec(br_ssl_client_context *cc,
141	const br_x509_certificate *chain, size_t chain_len,
142	const br_ec_private_key *sk, unsigned allowed_usages,
143	unsigned cert_issuer_key_type,
144	const br_ec_impl *iec, br_ecdsa_sign iecdsa)
145{
146	cc->client_auth.single_ec.vtable = &ccert_vtable;
147	cc->client_auth.single_ec.chain = chain;
148	cc->client_auth.single_ec.chain_len = chain_len;
149	cc->client_auth.single_ec.sk = sk;
150	cc->client_auth.single_ec.allowed_usages = allowed_usages;
151	cc->client_auth.single_ec.issuer_key_type = cert_issuer_key_type;
152	cc->client_auth.single_ec.mhash = &cc->eng.mhash;
153	cc->client_auth.single_ec.iec = iec;
154	cc->client_auth.single_ec.iecdsa = iecdsa;
155	cc->client_auth_vtable = &cc->client_auth.single_ec.vtable;
156}
157