e79a002d7067ae9c332d76998c59b627071034fe
[BearSSL] / src / rsa / rsa_i31_pkcs1_vrfy.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_rsa.h */
28 uint32_t
29 br_rsa_i31_pkcs1_vrfy(const unsigned char *x, size_t xlen,
30 const unsigned char *hash_oid, size_t hash_len,
31 const br_rsa_public_key *pk, unsigned char *hash_out)
32 {
33 unsigned char sig[BR_MAX_RSA_SIZE >> 3];
34
35 if (xlen > (sizeof sig)) {
36 return 0;
37 }
38 memcpy(sig, x, xlen);
39 if (!br_rsa_i31_public(sig, xlen, pk)) {
40 return 0;
41 }
42 return br_rsa_pkcs1_sig_unpad(sig, xlen, hash_oid, hash_len, hash_out);
43 }