xref: /freebsd/contrib/bearssl/src/ssl/ssl_client_full.c (revision 59c8e88e72633afbc47a4ace0d2170d00d51f7dc)
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 /* see bearssl_ssl.h */
28 void
29 br_ssl_client_init_full(br_ssl_client_context *cc,
30 	br_x509_minimal_context *xc,
31 	const br_x509_trust_anchor *trust_anchors, size_t trust_anchors_num)
32 {
33 	/*
34 	 * The "full" profile supports all implemented cipher suites.
35 	 *
36 	 * Rationale for suite order, from most important to least
37 	 * important rule:
38 	 *
39 	 * -- Don't use 3DES if AES or ChaCha20 is available.
40 	 * -- Try to have Forward Secrecy (ECDHE suite) if possible.
41 	 * -- When not using Forward Secrecy, ECDH key exchange is
42 	 *    better than RSA key exchange (slightly more expensive on the
43 	 *    client, but much cheaper on the server, and it implies smaller
44 	 *    messages).
45 	 * -- ChaCha20+Poly1305 is better than AES/GCM (faster, smaller code).
46 	 * -- GCM is better than CCM and CBC. CCM is better than CBC.
47 	 * -- CCM is preferable over CCM_8 (with CCM_8, forgeries may succeed
48 	 *    with probability 2^(-64)).
49 	 * -- AES-128 is preferred over AES-256 (AES-128 is already
50 	 *    strong enough, and AES-256 is 40% more expensive).
51 	 */
52 	static const uint16_t suites[] = {
53 		BR_TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
54 		BR_TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
55 		BR_TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
56 		BR_TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
57 		BR_TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
58 		BR_TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
59 		BR_TLS_ECDHE_ECDSA_WITH_AES_128_CCM,
60 		BR_TLS_ECDHE_ECDSA_WITH_AES_256_CCM,
61 		BR_TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8,
62 		BR_TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8,
63 		BR_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,
64 		BR_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
65 		BR_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384,
66 		BR_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,
67 		BR_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
68 		BR_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
69 		BR_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
70 		BR_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
71 		BR_TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256,
72 		BR_TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256,
73 		BR_TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384,
74 		BR_TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384,
75 		BR_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256,
76 		BR_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256,
77 		BR_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384,
78 		BR_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384,
79 		BR_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA,
80 		BR_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA,
81 		BR_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA,
82 		BR_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA,
83 		BR_TLS_RSA_WITH_AES_128_GCM_SHA256,
84 		BR_TLS_RSA_WITH_AES_256_GCM_SHA384,
85 		BR_TLS_RSA_WITH_AES_128_CCM,
86 		BR_TLS_RSA_WITH_AES_256_CCM,
87 		BR_TLS_RSA_WITH_AES_128_CCM_8,
88 		BR_TLS_RSA_WITH_AES_256_CCM_8,
89 		BR_TLS_RSA_WITH_AES_128_CBC_SHA256,
90 		BR_TLS_RSA_WITH_AES_256_CBC_SHA256,
91 		BR_TLS_RSA_WITH_AES_128_CBC_SHA,
92 		BR_TLS_RSA_WITH_AES_256_CBC_SHA,
93 		BR_TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA,
94 		BR_TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
95 		BR_TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA,
96 		BR_TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA,
97 		BR_TLS_RSA_WITH_3DES_EDE_CBC_SHA
98 	};
99 
100 	/*
101 	 * All hash functions are activated.
102 	 * Note: the X.509 validation engine will nonetheless refuse to
103 	 * validate signatures that use MD5 as hash function.
104 	 */
105 	static const br_hash_class *hashes[] = {
106 		&br_md5_vtable,
107 		&br_sha1_vtable,
108 		&br_sha224_vtable,
109 		&br_sha256_vtable,
110 		&br_sha384_vtable,
111 		&br_sha512_vtable
112 	};
113 
114 	int id;
115 
116 	/*
117 	 * Reset client context and set supported versions from TLS-1.0
118 	 * to TLS-1.2 (inclusive).
119 	 */
120 	br_ssl_client_zero(cc);
121 	br_ssl_engine_set_versions(&cc->eng, BR_TLS10, BR_TLS12);
122 
123 	/*
124 	 * X.509 engine uses SHA-256 to hash certificate DN (for
125 	 * comparisons).
126 	 */
127 	br_x509_minimal_init(xc, &br_sha256_vtable,
128 		trust_anchors, trust_anchors_num);
129 
130 	/*
131 	 * Set suites and asymmetric crypto implementations. We use the
132 	 * "i31" code for RSA (it is somewhat faster than the "i32"
133 	 * implementation).
134 	 * TODO: change that when better implementations are made available.
135 	 */
136 	br_ssl_engine_set_suites(&cc->eng, suites,
137 		(sizeof suites) / (sizeof suites[0]));
138 	br_ssl_client_set_default_rsapub(cc);
139 	br_ssl_engine_set_default_rsavrfy(&cc->eng);
140 	br_ssl_engine_set_default_ecdsa(&cc->eng);
141 	br_x509_minimal_set_rsa(xc, br_ssl_engine_get_rsavrfy(&cc->eng));
142 	br_x509_minimal_set_ecdsa(xc,
143 		br_ssl_engine_get_ec(&cc->eng),
144 		br_ssl_engine_get_ecdsa(&cc->eng));
145 
146 	/*
147 	 * Set supported hash functions, for the SSL engine and for the
148 	 * X.509 engine.
149 	 */
150 	for (id = br_md5_ID; id <= br_sha512_ID; id ++) {
151 		const br_hash_class *hc;
152 
153 		hc = hashes[id - 1];
154 		br_ssl_engine_set_hash(&cc->eng, id, hc);
155 		br_x509_minimal_set_hash(xc, id, hc);
156 	}
157 
158 	/*
159 	 * Link the X.509 engine in the SSL engine.
160 	 */
161 	br_ssl_engine_set_x509(&cc->eng, &xc->vtable);
162 
163 	/*
164 	 * Set the PRF implementations.
165 	 */
166 	br_ssl_engine_set_prf10(&cc->eng, &br_tls10_prf);
167 	br_ssl_engine_set_prf_sha256(&cc->eng, &br_tls12_sha256_prf);
168 	br_ssl_engine_set_prf_sha384(&cc->eng, &br_tls12_sha384_prf);
169 
170 	/*
171 	 * Symmetric encryption. We use the "default" implementations
172 	 * (fastest among constant-time implementations).
173 	 */
174 	br_ssl_engine_set_default_aes_cbc(&cc->eng);
175 	br_ssl_engine_set_default_aes_ccm(&cc->eng);
176 	br_ssl_engine_set_default_aes_gcm(&cc->eng);
177 	br_ssl_engine_set_default_des_cbc(&cc->eng);
178 	br_ssl_engine_set_default_chapol(&cc->eng);
179 }
180