Add a couple comments pointing to particular sections of RFC6979.

This commit is contained in:
Gregory Maxwell 2015-03-28 00:43:15 +00:00
parent 2632019713
commit 33270bff87
1 changed files with 7 additions and 2 deletions

View File

@ -207,15 +207,17 @@ static void secp256k1_rfc6979_hmac_sha256_initialize(secp256k1_rfc6979_hmac_sha2
static const unsigned char zero[1] = {0x00};
static const unsigned char one[1] = {0x01};
memset(rng->v, 0x01, 32);
memset(rng->k, 0x00, 32);
memset(rng->v, 0x01, 32); /* RFC6979 3.2.b. */
memset(rng->k, 0x00, 32); /* RFC6979 3.2.c. */
/* RFC6979 3.2.d. */
secp256k1_hmac_sha256_initialize(&hmac, rng->k, 32);
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);
secp256k1_hmac_sha256_write(&hmac, zero, 1);
secp256k1_hmac_sha256_write(&hmac, key, keylen);
secp256k1_hmac_sha256_write(&hmac, msg, msglen);
if (rnd && rndlen) {
/* RFC6979 3.6 "Additional data". */
secp256k1_hmac_sha256_write(&hmac, rnd, rndlen);
}
secp256k1_hmac_sha256_finalize(&hmac, rng->k);
@ -223,12 +225,14 @@ static void secp256k1_rfc6979_hmac_sha256_initialize(secp256k1_rfc6979_hmac_sha2
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);
secp256k1_hmac_sha256_finalize(&hmac, rng->v);
/* RFC6979 3.2.f. */
secp256k1_hmac_sha256_initialize(&hmac, rng->k, 32);
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);
secp256k1_hmac_sha256_write(&hmac, one, 1);
secp256k1_hmac_sha256_write(&hmac, key, keylen);
secp256k1_hmac_sha256_write(&hmac, msg, msglen);
if (rnd && rndlen) {
/* RFC6979 3.6 "Additional data". */
secp256k1_hmac_sha256_write(&hmac, rnd, rndlen);
}
secp256k1_hmac_sha256_finalize(&hmac, rng->k);
@ -239,6 +243,7 @@ static void secp256k1_rfc6979_hmac_sha256_initialize(secp256k1_rfc6979_hmac_sha2
}
static void secp256k1_rfc6979_hmac_sha256_generate(secp256k1_rfc6979_hmac_sha256_t *rng, unsigned char *out, size_t outlen) {
/* RFC6979 3.2.h. */
static const unsigned char zero[1] = {0x00};
if (rng->retry) {
secp256k1_hmac_sha256_t hmac;