Commit 9cbfb689841a491ecd11c668d9cbe9b7ba3e8b47 - libcryptx-perl

tuning DSA key generation Karel Miko 10 years ago

1 changed file(s) with 5 addition(s) and 8 deletion(s). Raw diff Collapse all Expand all

-8

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

28	28	int dsa_make_key(prng_state prng, int wprng, int group_size, int modulus_size, dsa_key key)
29	29	{
30	30	void tmp, tmp2;
31		int err, res, q_size;
	31	int err, res, qbits;
32	32	unsigned char *buf;
33	33
34	34	LTC_ARGCHK(key != NULL);

103	103	/* so now we have our DH structure, generator g, order q, modulus p
104	104	Now we need a random exponent [mod q] and it's power g^x mod p
105	105	*/
106		q_size = mp_unsigned_bin_size(key->q);
	106	qbits = mp_count_bits(key->q);
107	107	do {
108		if (prng_descriptor[wprng].read(buf, q_size, prng) != (unsigned long)q_size) {
109		err = CRYPT_ERROR_READPRNG;
110		goto error;
111		}
112		if ((err = mp_read_unsigned_bin(key->x, buf, q_size)) != CRYPT_OK) { goto error; }
113		} while (mp_cmp_d(key->x, 1) != LTC_MP_GT \|\| mp_cmp(key->x, key->q) != LTC_MP_LT);
	108	if ((err = rand_bn_bits(key->x, qbits, prng, wprng)) != CRYPT_OK) { goto error; }
	109	/* private key x should be from range: 1 <= x <= q-1 */
	110	} while (mp_cmp_d(key->x, 0) != LTC_MP_GT \|\| mp_cmp(key->x, key->q) != LTC_MP_LT);
114	111	if ((err = mp_exptmod(key->g, key->x, key->p, key->y)) != CRYPT_OK) { goto error; }
115	112
116	113	key->type = PK_PRIVATE;