1*0957b409SSimon J. Gerraty /*
2*0957b409SSimon J. Gerraty * Copyright (c) 2017 Thomas Pornin <pornin@bolet.org>
3*0957b409SSimon J. Gerraty *
4*0957b409SSimon J. Gerraty * Permission is hereby granted, free of charge, to any person obtaining
5*0957b409SSimon J. Gerraty * a copy of this software and associated documentation files (the
6*0957b409SSimon J. Gerraty * "Software"), to deal in the Software without restriction, including
7*0957b409SSimon J. Gerraty * without limitation the rights to use, copy, modify, merge, publish,
8*0957b409SSimon J. Gerraty * distribute, sublicense, and/or sell copies of the Software, and to
9*0957b409SSimon J. Gerraty * permit persons to whom the Software is furnished to do so, subject to
10*0957b409SSimon J. Gerraty * the following conditions:
11*0957b409SSimon J. Gerraty *
12*0957b409SSimon J. Gerraty * The above copyright notice and this permission notice shall be
13*0957b409SSimon J. Gerraty * included in all copies or substantial portions of the Software.
14*0957b409SSimon J. Gerraty *
15*0957b409SSimon J. Gerraty * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16*0957b409SSimon J. Gerraty * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17*0957b409SSimon J. Gerraty * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18*0957b409SSimon J. Gerraty * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19*0957b409SSimon J. Gerraty * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20*0957b409SSimon J. Gerraty * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21*0957b409SSimon J. Gerraty * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22*0957b409SSimon J. Gerraty * SOFTWARE.
23*0957b409SSimon J. Gerraty */
24*0957b409SSimon J. Gerraty
25*0957b409SSimon J. Gerraty #include "inner.h"
26*0957b409SSimon J. Gerraty
27*0957b409SSimon J. Gerraty #define FIELD_LEN ((BR_MAX_EC_SIZE + 7) >> 3)
28*0957b409SSimon J. Gerraty
29*0957b409SSimon J. Gerraty /* see bearssl_ec.h */
30*0957b409SSimon J. Gerraty uint32_t
br_ecdsa_i15_vrfy_asn1(const br_ec_impl * impl,const void * hash,size_t hash_len,const br_ec_public_key * pk,const void * sig,size_t sig_len)31*0957b409SSimon J. Gerraty br_ecdsa_i15_vrfy_asn1(const br_ec_impl *impl,
32*0957b409SSimon J. Gerraty const void *hash, size_t hash_len,
33*0957b409SSimon J. Gerraty const br_ec_public_key *pk,
34*0957b409SSimon J. Gerraty const void *sig, size_t sig_len)
35*0957b409SSimon J. Gerraty {
36*0957b409SSimon J. Gerraty /*
37*0957b409SSimon J. Gerraty * We use a double-sized buffer because a malformed ASN.1 signature
38*0957b409SSimon J. Gerraty * may trigger a size expansion when converting to "raw" format.
39*0957b409SSimon J. Gerraty */
40*0957b409SSimon J. Gerraty unsigned char rsig[(FIELD_LEN << 2) + 24];
41*0957b409SSimon J. Gerraty
42*0957b409SSimon J. Gerraty if (sig_len > ((sizeof rsig) >> 1)) {
43*0957b409SSimon J. Gerraty return 0;
44*0957b409SSimon J. Gerraty }
45*0957b409SSimon J. Gerraty memcpy(rsig, sig, sig_len);
46*0957b409SSimon J. Gerraty sig_len = br_ecdsa_asn1_to_raw(rsig, sig_len);
47*0957b409SSimon J. Gerraty return br_ecdsa_i15_vrfy_raw(impl, hash, hash_len, pk, rsig, sig_len);
48*0957b409SSimon J. Gerraty }
49