Commit 3ca631498500bce15930d2abfe22eb4e437adc8a - libcryptx-perl

DSA: properly handle FIPS 186-4 (4.6 + 4.7) Karel Miko 7 years ago

2 changed file(s) with 7 addition(s) and 1 deletion(s). Raw diff Collapse all Expand all

-0

src/ltc/pk/dsa/dsa_sign_hash.c less more

83	83
84	84	if (mp_iszero(r) == LTC_MP_YES) { goto retry; }
85	85
	86	/* FIPS 186-4 4.6: use leftmost min(bitlen(q), bitlen(hash)) */
	87	if (inlen > key->qord) inlen = key->qord;
	88
86	89	/* now find s = (in + xr)/k mod q */
87	90	if ((err = mp_read_unsigned_bin(tmp, (unsigned char *)in, inlen)) != CRYPT_OK) { goto error; }
88	91	if ((err = mp_mul(key->x, r, s)) != CRYPT_OK) { goto error; }

-1

src/ltc/pk/dsa/dsa_verify_hash.c less more

52	52	err = CRYPT_INVALID_PACKET;
53	53	goto error;
54	54	}
55
	55
	56	/* FIPS 186-4 4.7: use leftmost min(bitlen(q), bitlen(hash)) bits of 'hash' */
	57	if (hashlen > key->qord) hashlen = key->qord;
	58
56	59	/* w = 1/s mod q */
57	60	if ((err = mp_invmod(s, key->q, w)) != CRYPT_OK) { goto error; }
58	61