Commit e248740d authored by Dr. Stephen Henson's avatar Dr. Stephen Henson
Browse files

Minor code tidy and bug fix: need to set t = s after first pass and 

t and s do not need to have independent values after the first pass
so set t = s.
parent b63698b7

fips/rand/fips_drbg_ec.c

+12 −6
Original line number Diff line number Diff line
@@ -287,17 +287,19 @@ static int drbg_ec_generate(DRBG_CTX *dctx, 
		}



	BN_CTX_start(ectx->bctx);

	t = BN_CTX_get(ectx->bctx);

	r = BN_CTX_get(ectx->bctx);

	if (!r)

		goto err;

	if (adin && adin_len)

		{

		size_t i;

		t = BN_CTX_get(ectx->bctx);

		if (!t)

			goto err;

		/* Convert s to buffer */

		if (ectx->exbits)

			BN_lshift(ectx->s, ectx->s, ectx->exbits);

		bn2binpad(ectx->sbuf, dctx->seedlen, ectx->s);

			BN_lshift(s, s, ectx->exbits);

		bn2binpad(ectx->sbuf, dctx->seedlen, s);

		/* Step 2 */

		if (!hash_df(dctx, ectx->tbuf, adin, adin_len,

				NULL, 0, NULL, 0))
@@ -309,11 +311,13 @@ static int drbg_ec_generate(DRBG_CTX *dctx, 
			return 0;

		}

	else

		if (!BN_copy(t, ectx->s))

			goto err;

		/* Note if no additional input t and s the algorithm never

		 * needs separate values for t and s.

		 */

		t = s;



#ifdef EC_DRBG_TRACE

	bnprint(stderr, "s at start of generate: ", ectx->s);

	bnprint(stderr, "s at start of generate: ", s);

#endif



	for (;;)
@@ -360,6 +364,8 @@ static int drbg_ec_generate(DRBG_CTX *dctx, 
		if (!outlen)

			break;

		out += dctx->blocklength;

		/* Step #5 after first pass */

		t = s;

#ifdef EC_DRBG_TRACE

		fprintf(stderr, "Random bits written:\n");

		hexprint(stderr, out, dctx->blocklength);