_ Git - BearSSL/blob - src/ssl/ssl_scert_single_ec.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 static int
  28 se_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
  80 static uint32_t
  81 se_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
  96 static size_t
  97 se_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
 117 static 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 */
 125 void
 126 br_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 }