Files
data-lite-c/Sources/DataLiteC/libtomcrypt/pk/ecc/ecc_verify_hash.c

48 lines
1.6 KiB
C

/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
#include "tomcrypt_private.h"
#if defined(LTC_MECC) && defined(LTC_DER)
/**
@file ecc_verify_hash.c
ECC Crypto, Tom St Denis
*/
/**
Verify an ECC signature (ANSI X9.62 format)
@param sig The signature to verify
@param siglen The length of the signature (octets)
@param hash The hash (message digest) that was signed
@param hashlen The length of the hash (octets)
@param stat [out] Result of signature, 1==valid, 0==invalid
@param key The corresponding public ECC key
@return CRYPT_OK if successful (even if the signature is not valid)
*/
int ecc_verify_hash(const unsigned char *sig, unsigned long siglen,
const unsigned char *hash, unsigned long hashlen,
int *stat, const ecc_key *key)
{
void *r, *s;
int err;
LTC_ARGCHK(sig != NULL);
if ((err = ltc_mp_init_multi(&r, &s, NULL)) != CRYPT_OK) return err;
/* ANSI X9.62 format - ASN.1 encoded SEQUENCE{ INTEGER(r), INTEGER(s) } */
if ((err = der_decode_sequence_multi_ex(sig, siglen, LTC_DER_SEQ_SEQUENCE | LTC_DER_SEQ_STRICT,
LTC_ASN1_INTEGER, 1UL, r,
LTC_ASN1_INTEGER, 1UL, s,
LTC_ASN1_EOL, 0UL, LTC_NULL)) != CRYPT_OK) { goto error; }
err = ecc_verify_hash_internal(r, s, hash, hashlen, stat, key);
error:
ltc_mp_deinit_multi(r, s, LTC_NULL);
return err;
}
#endif