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split signing into ecdsa_sign_digest and ecdsa_sign/ecdsa_sign_double

This commit is contained in:
Pavol Rusnak 2014-02-02 20:36:03 +01:00
parent a40a077613
commit 73489fbd33
2 changed files with 25 additions and 10 deletions

33
ecdsa.c
View File

@ -195,28 +195,41 @@ int generate_k_rfc6979(bignum256 *secret, const uint8_t *priv_key, const uint8_t
return 1;
}
// uses secp256k1 curve
// priv_key is a 32 byte big endian stored number
// msg is a data to be signed
// msg_len is the message length
// sig is 64 bytes long array for the signature
int ecdsa_sign(const uint8_t *priv_key, const uint8_t *msg, uint32_t msg_len, uint8_t *sig)
{
uint32_t i;
uint8_t hash[32];
SHA256_Raw(msg, msg_len, hash);
return ecdsa_sign_digest(priv_key, hash, sig);
}
// msg is a data to be signed
// msg_len is the message length
int ecdsa_sign_double(const uint8_t *priv_key, const uint8_t *msg, uint32_t msg_len, uint8_t *sig)
{
uint8_t hash[32];
SHA256_Raw(msg, msg_len, hash);
SHA256_Raw(hash, 32, hash);
return ecdsa_sign_digest(priv_key, hash, sig);
}
// uses secp256k1 curve
// priv_key is a 32 byte big endian stored number
// sig is 64 bytes long array for the signature
// digest is 32 bytes of digest
int ecdsa_sign_digest(const uint8_t *priv_key, const uint8_t *digest, uint8_t *sig)
{
uint32_t i;
curve_point R;
bignum256 k, z;
bignum256 *da = &R.y;
// compute hash function of message
SHA256_Raw(msg, msg_len, hash);
// if double hash is required uncomment the following line:
// SHA256_Raw(hash, 32, hash);
bn_read_be(hash, &z);
bn_read_be(digest, &z);
#if USE_RFC6979
// generate K deterministically
if (generate_k_rfc6979(&k, priv_key, hash) != 0) {
if (generate_k_rfc6979(&k, priv_key, digest) != 0) {
return 1;
}
#else

View File

@ -37,6 +37,8 @@ void point_double(curve_point *cp);
void scalar_multiply(bignum256 *k, curve_point *res);
int ecdsa_sign(const uint8_t *priv_key, const uint8_t *msg, uint32_t msg_len, uint8_t *sig);
int ecdsa_sign_double(const uint8_t *priv_key, const uint8_t *msg, uint32_t msg_len, uint8_t *sig);
int ecdsa_sign_digest(const uint8_t *priv_key, const uint8_t *digest, uint8_t *sig);
void ecdsa_get_public_key33(const uint8_t *priv_key, uint8_t *pub_key);
void ecdsa_get_public_key65(const uint8_t *priv_key, uint8_t *pub_key);
void ecdsa_get_address(const uint8_t *pub_key, uint8_t version, char *addr);