_ Git - BearSSL/blob - src/ssl/ssl_client_full.c

   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 CBC.
  47          * -- AES-128 is preferred over AES-256 (AES-128 is already
  48          *    strong enough, and AES-256 is 40% more expensive).
  49          */
  50         static const uint16_t suites[] = {
  51                 BR_TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
  52                 BR_TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
  53                 BR_TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
  54                 BR_TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
  55                 BR_TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
  56                 BR_TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
  57                 BR_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,
  58                 BR_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
  59                 BR_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384,
  60                 BR_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,
  61                 BR_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
  62                 BR_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
  63                 BR_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
  64                 BR_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
  65                 BR_TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256,
  66                 BR_TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256,
  67                 BR_TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384,
  68                 BR_TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384,
  69                 BR_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256,
  70                 BR_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256,
  71                 BR_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384,
  72                 BR_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384,
  73                 BR_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA,
  74                 BR_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA,
  75                 BR_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA,
  76                 BR_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA,
  77                 BR_TLS_RSA_WITH_AES_128_GCM_SHA256,
  78                 BR_TLS_RSA_WITH_AES_256_GCM_SHA384,
  79                 BR_TLS_RSA_WITH_AES_128_CBC_SHA256,
  80                 BR_TLS_RSA_WITH_AES_256_CBC_SHA256,
  81                 BR_TLS_RSA_WITH_AES_128_CBC_SHA,
  82                 BR_TLS_RSA_WITH_AES_256_CBC_SHA,
  83                 BR_TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA,
  84                 BR_TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
  85                 BR_TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA,
  86                 BR_TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA,
  87                 BR_TLS_RSA_WITH_3DES_EDE_CBC_SHA
  88         };
  89
  90         /*
  91          * All hash functions are activated.
  92          * Note: the X.509 validation engine will nonetheless refuse to
  93          * validate signatures that use MD5 as hash function.
  94          */
  95         static const br_hash_class *hashes[] = {
  96                 &br_md5_vtable,
  97                 &br_sha1_vtable,
  98                 &br_sha224_vtable,
  99                 &br_sha256_vtable,
 100                 &br_sha384_vtable,
 101                 &br_sha512_vtable
 102         };
 103
 104         int id;
 105
 106         /*
 107          * Reset client context and set supported versions from TLS-1.0
 108          * to TLS-1.2 (inclusive).
 109          */
 110         br_ssl_client_zero(cc);
 111         br_ssl_engine_set_versions(&cc->eng, BR_TLS10, BR_TLS12);
 112
 113         /*
 114          * X.509 engine uses SHA-256 to hash certificate DN (for
 115          * comparisons).
 116          */
 117         br_x509_minimal_init(xc, &br_sha256_vtable,
 118                 trust_anchors, trust_anchors_num);
 119
 120         /*
 121          * Set suites and asymmetric crypto implementations. We use the
 122          * "i31" code for RSA (it is somewhat faster than the "i32"
 123          * implementation).
 124          * TODO: change that when better implementations are made available.
 125          */
 126         br_ssl_engine_set_suites(&cc->eng, suites,
 127                 (sizeof suites) / (sizeof suites[0]));
 128         br_ssl_client_set_default_rsapub(cc);
 129         br_ssl_engine_set_default_rsavrfy(&cc->eng);
 130         br_ssl_engine_set_default_ecdsa(&cc->eng);
 131         br_x509_minimal_set_rsa(xc, br_ssl_engine_get_rsavrfy(&cc->eng));
 132         br_x509_minimal_set_ecdsa(xc,
 133                 br_ssl_engine_get_ec(&cc->eng),
 134                 br_ssl_engine_get_ecdsa(&cc->eng));
 135
 136         /*
 137          * Set supported hash functions, for the SSL engine and for the
 138          * X.509 engine.
 139          */
 140         for (id = br_md5_ID; id <= br_sha512_ID; id ++) {
 141                 const br_hash_class *hc;
 142
 143                 hc = hashes[id - 1];
 144                 br_ssl_engine_set_hash(&cc->eng, id, hc);
 145                 br_x509_minimal_set_hash(xc, id, hc);
 146         }
 147
 148         /*
 149          * Link the X.509 engine in the SSL engine.
 150          */
 151         br_ssl_engine_set_x509(&cc->eng, &xc->vtable);
 152
 153         /*
 154          * Set the PRF implementations.
 155          */
 156         br_ssl_engine_set_prf10(&cc->eng, &br_tls10_prf);
 157         br_ssl_engine_set_prf_sha256(&cc->eng, &br_tls12_sha256_prf);
 158         br_ssl_engine_set_prf_sha384(&cc->eng, &br_tls12_sha384_prf);
 159
 160         /*
 161          * Symmetric encryption. We use the "default" implementations
 162          * (fastest among constant-time implementations).
 163          */
 164         br_ssl_engine_set_default_aes_cbc(&cc->eng);
 165         br_ssl_engine_set_default_aes_gcm(&cc->eng);
 166         br_ssl_engine_set_default_des_cbc(&cc->eng);
 167         br_ssl_engine_set_default_chapol(&cc->eng);
 168 }