_ Git - BearSSL/blob - src/ssl/ssl_ccert_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 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 }