xref: /freebsd/contrib/bearssl/src/ssl/ssl_ccert_single_ec.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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 
27 static void
28 cc_none0(const br_ssl_client_certificate_class **pctx)
29 {
30 	(void)pctx;
31 }
32 
33 static void
34 cc_none1(const br_ssl_client_certificate_class **pctx, size_t len)
35 {
36 	(void)pctx;
37 	(void)len;
38 }
39 
40 static void
41 cc_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 
49 static void
50 cc_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 
90 static uint32_t
91 cc_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 
106 static size_t
107 cc_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 
126 static 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 */
139 void
140 br_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