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 int
28se_choose(const br_ssl_server_policy_class **pctx,
29	const br_ssl_server_context *cc,
30	br_ssl_server_choices *choices)
31{
32	br_ssl_server_policy_ec_context *pc;
33	const br_suite_translated *st;
34	size_t u, st_num;
35	unsigned hash_id;
36
37	pc = (br_ssl_server_policy_ec_context *)pctx;
38	st = br_ssl_server_get_client_suites(cc, &st_num);
39	hash_id = br_ssl_choose_hash(br_ssl_server_get_client_hashes(cc) >> 8);
40	if (cc->eng.session.version < BR_TLS12) {
41		hash_id = br_sha1_ID;
42	}
43	choices->chain = pc->chain;
44	choices->chain_len = pc->chain_len;
45	for (u = 0; u < st_num; u ++) {
46		unsigned tt;
47
48		tt = st[u][1];
49		switch (tt >> 12) {
50		case BR_SSLKEYX_ECDH_RSA:
51			if ((pc->allowed_usages & BR_KEYTYPE_KEYX) != 0
52				&& pc->cert_issuer_key_type == BR_KEYTYPE_RSA)
53			{
54				choices->cipher_suite = st[u][0];
55				return 1;
56			}
57			break;
58		case BR_SSLKEYX_ECDH_ECDSA:
59			if ((pc->allowed_usages & BR_KEYTYPE_KEYX) != 0
60				&& pc->cert_issuer_key_type == BR_KEYTYPE_EC)
61			{
62				choices->cipher_suite = st[u][0];
63				return 1;
64			}
65			break;
66		case BR_SSLKEYX_ECDHE_ECDSA:
67			if ((pc->allowed_usages & BR_KEYTYPE_SIGN) != 0
68				&& hash_id != 0)
69			{
70				choices->cipher_suite = st[u][0];
71				choices->algo_id = hash_id + 0xFF00;
72				return 1;
73			}
74			break;
75		}
76	}
77	return 0;
78}
79
80static uint32_t
81se_do_keyx(const br_ssl_server_policy_class **pctx,
82	unsigned char *data, size_t *len)
83{
84	br_ssl_server_policy_ec_context *pc;
85	uint32_t r;
86	size_t xoff, xlen;
87
88	pc = (br_ssl_server_policy_ec_context *)pctx;
89	r = pc->iec->mul(data, *len, pc->sk->x, pc->sk->xlen, pc->sk->curve);
90	xoff = pc->iec->xoff(pc->sk->curve, &xlen);
91	memmove(data, data + xoff, xlen);
92	*len = xlen;
93	return r;
94}
95
96static size_t
97se_do_sign(const br_ssl_server_policy_class **pctx,
98	unsigned algo_id, unsigned char *data, size_t hv_len, size_t len)
99{
100	br_ssl_server_policy_ec_context *pc;
101	unsigned char hv[64];
102	const br_hash_class *hc;
103
104	algo_id &= 0xFF;
105	pc = (br_ssl_server_policy_ec_context *)pctx;
106	hc = br_multihash_getimpl(pc->mhash, algo_id);
107	if (hc == NULL) {
108		return 0;
109	}
110	memcpy(hv, data, hv_len);
111	if (len < 139) {
112		return 0;
113	}
114	return pc->iecdsa(pc->iec, hc, hv, pc->sk, data);
115}
116
117static const br_ssl_server_policy_class se_policy_vtable = {
118	sizeof(br_ssl_server_policy_ec_context),
119	se_choose,
120	se_do_keyx,
121	se_do_sign
122};
123
124/* see bearssl_ssl.h */
125void
126br_ssl_server_set_single_ec(br_ssl_server_context *cc,
127	const br_x509_certificate *chain, size_t chain_len,
128	const br_ec_private_key *sk, unsigned allowed_usages,
129	unsigned cert_issuer_key_type,
130	const br_ec_impl *iec, br_ecdsa_sign iecdsa)
131{
132	cc->chain_handler.single_ec.vtable = &se_policy_vtable;
133	cc->chain_handler.single_ec.chain = chain;
134	cc->chain_handler.single_ec.chain_len = chain_len;
135	cc->chain_handler.single_ec.sk = sk;
136	cc->chain_handler.single_ec.allowed_usages = allowed_usages;
137	cc->chain_handler.single_ec.cert_issuer_key_type = cert_issuer_key_type;
138	cc->chain_handler.single_ec.mhash = &cc->eng.mhash;
139	cc->chain_handler.single_ec.iec = iec;
140	cc->chain_handler.single_ec.iecdsa = iecdsa;
141	cc->policy_vtable = &cc->chain_handler.single_ec.vtable;
142}
143