bearssl-rs/bearssl-sys/bundled/src/ecdsa_i15_vrfy_asn1.c

49 lines
1.7 KiB
C

/*
* Copyright (c) 2017 Thomas Pornin <pornin@bolet.org>
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "inner.h"
#define FIELD_LEN ((BR_MAX_EC_SIZE + 7) >> 3)
/* see bearssl_ec.h */
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)
{
/*
* We use a double-sized buffer because a malformed ASN.1 signature
* may trigger a size expansion when converting to "raw" format.
*/
unsigned char rsig[(FIELD_LEN << 2) + 24];
if (sig_len > ((sizeof rsig) >> 1)) {
return 0;
}
memcpy(rsig, sig, sig_len);
sig_len = br_ecdsa_asn1_to_raw(rsig, sig_len);
return br_ecdsa_i15_vrfy_raw(impl, hash, hash_len, pk, rsig, sig_len);
}