diff options
Diffstat (limited to 'src/secp256k1.c')
| -rw-r--r-- | src/secp256k1.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/src/secp256k1.c b/src/secp256k1.c index 36fde24c3d..8f34c35283 100644 --- a/src/secp256k1.c +++ b/src/secp256k1.c @@ -423,8 +423,12 @@ static int nonce_function_rfc6979(unsigned char *nonce32, const unsigned char *m unsigned int offset = 0; secp256k1_rfc6979_hmac_sha256 rng; unsigned int i; + secp256k1_scalar msg; + unsigned char msgmod32[32]; + secp256k1_scalar_set_b32(&msg, msg32, NULL); + secp256k1_scalar_get_b32(msgmod32, &msg); /* We feed a byte array to the PRNG as input, consisting of: - * - the private key (32 bytes) and message (32 bytes), see RFC 6979 3.2d. + * - the private key (32 bytes) and reduced message (32 bytes), see RFC 6979 3.2d. * - optionally 32 extra bytes of data, see RFC 6979 3.6 Additional Data. * - optionally 16 extra bytes with the algorithm name. * Because the arguments have distinct fixed lengths it is not possible for @@ -432,7 +436,7 @@ static int nonce_function_rfc6979(unsigned char *nonce32, const unsigned char *m * nonces. */ buffer_append(keydata, &offset, key32, 32); - buffer_append(keydata, &offset, msg32, 32); + buffer_append(keydata, &offset, msgmod32, 32); if (data != NULL) { buffer_append(keydata, &offset, data, 32); } |