rsa_i32_pkcs1_vrfy.c

/*
 * Copyright (c) 2016 Thomas Pornin <[email protected]>
 *
 * 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"

/* see bearssl_rsa.h */
uint32_t
br_rsa_i32_pkcs1_vrfy(const unsigned char *x, size_t xlen,
	const unsigned char *hash_oid, size_t hash_len,
	const br_rsa_public_key *pk, unsigned char *hash_out)
{
	unsigned char sig[BR_MAX_RSA_SIZE >> 3];

	if (xlen > (sizeof sig)) {
		return 0;
	}
	memcpy(sig, x, xlen);
	if (!br_rsa_i32_public(sig, xlen, pk)) {
		return 0;
	}
	return br_rsa_pkcs1_sig_unpad(sig, xlen, hash_oid, hash_len, hash_out);
}