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 #define FIELD_LEN ((BR_MAX_EC_SIZE + 7) >> 3) 28 29 /* see bearssl_ec.h */ 30 uint32_t 31 br_ecdsa_i31_vrfy_asn1(const br_ec_impl *impl, 32 const void *hash, size_t hash_len, 33 const br_ec_public_key *pk, 34 const void *sig, size_t sig_len) 35 { 36 /* 37 * We use a double-sized buffer because a malformed ASN.1 signature 38 * may trigger a size expansion when converting to "raw" format. 39 */ 40 unsigned char rsig[(FIELD_LEN << 2) + 24]; 41 42 if (sig_len > ((sizeof rsig) >> 1)) { 43 return 0; 44 } 45 memcpy(rsig, sig, sig_len); 46 sig_len = br_ecdsa_asn1_to_raw(rsig, sig_len); 47 return br_ecdsa_i31_vrfy_raw(impl, hash, hash_len, pk, rsig, sig_len); 48 } 49