Files
data-lite-c/Sources/DataLiteC/libtomcrypt/pk/ecc/ecc_sign_hash_eth27.c

58 lines
1.8 KiB
C

/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
#include "tomcrypt_private.h"
#ifdef LTC_MECC
/**
Sign a message digest (Ethereum format with recovery_id+27)
@param in The message digest to sign
@param inlen The length of the digest
@param out [out] The destination for the signature
@param outlen [in/out] The max size and resulting size of the signature
@param prng An active PRNG state
@param wprng The index of the PRNG you wish to use
@param key A private ECC key
@return CRYPT_OK if successful
*/
int ecc_sign_hash_eth27(const unsigned char *in, unsigned long inlen,
unsigned char *out, unsigned long *outlen,
prng_state *prng, int wprng, const ecc_key *key)
{
int err, recid;
void *r, *s;
unsigned long i;
LTC_ARGCHK(out != NULL);
LTC_ARGCHK(outlen != NULL);
LTC_ARGCHK(key != NULL);
/* Only valid for secp256k1 - OID 1.3.132.0.10 */
if (pk_oid_cmp_with_ulong("1.3.132.0.10", key->dp.oid, key->dp.oidlen) != CRYPT_OK) {
return CRYPT_ERROR;
}
if (*outlen < 65) {
*outlen = 65;
return CRYPT_BUFFER_OVERFLOW;
}
if ((err = ltc_mp_init_multi(&r, &s, LTC_NULL)) != CRYPT_OK) return err;
if ((err = ecc_sign_hash_internal(in, inlen, r, s, prng, wprng, &recid, key)) != CRYPT_OK) goto error;
zeromem(out, 65);
*outlen = 65;
i = ltc_mp_unsigned_bin_size(r);
if ((err = ltc_mp_to_unsigned_bin(r, out + 32 - i)) != CRYPT_OK) goto error;
i = ltc_mp_unsigned_bin_size(s);
if ((err = ltc_mp_to_unsigned_bin(s, out + 64 - i)) != CRYPT_OK) goto error;
out[64] = (unsigned char)(recid + 27); /* Recovery ID is 27/28 for Ethereum */
err = CRYPT_OK;
error:
ltc_mp_deinit_multi(r, s, LTC_NULL);
return err;
}
#endif