Commit 05272d4c authored by Dr. Stephen Henson's avatar Dr. Stephen Henson
Browse files

Perform health check on all reseed operations not associated with 

prediction resistance requests. Although SP 800-90 is arguably unclear
on whether this is necessary adding an additional check has minimal
penalty (very few applications will make an explicit reseed request).
parent 4420b3b1

fips/rand/fips_drbg_lib.c

+24 −4
Original line number Diff line number Diff line
@@ -273,8 +273,8 @@ int FIPS_drbg_instantiate(DRBG_CTX *dctx, 


	}



int FIPS_drbg_reseed(DRBG_CTX *dctx,

			const unsigned char *adin, size_t adinlen)

static int drbg_reseed(DRBG_CTX *dctx,

			const unsigned char *adin, size_t adinlen, int hcheck)

	{

	unsigned char *entropy = NULL;

	size_t entlen;
@@ -303,6 +303,17 @@ int FIPS_drbg_reseed(DRBG_CTX *dctx, 
		}



	dctx->status = DRBG_STATUS_ERROR;

	/* Peform health check on all reseed operations if not a prediction

	 * resistance request and not in test mode.

	 */

	if (hcheck && !(dctx->xflags & DRBG_FLAG_TEST))

		{

		if (!FIPS_drbg_test(dctx))

			{

			r = FIPS_R_SELFTEST_FAILURE;

			goto end;

			}

		}



	entlen = fips_get_entropy(dctx, &entropy, dctx->strength,

				dctx->min_entropy, dctx->max_entropy);
@@ -333,6 +344,12 @@ int FIPS_drbg_reseed(DRBG_CTX *dctx, 
	return 0;

	}



int FIPS_drbg_reseed(DRBG_CTX *dctx,

			const unsigned char *adin, size_t adinlen)

	{

	return drbg_reseed(dctx, adin, adinlen, 1);

	}



static int fips_drbg_check(DRBG_CTX *dctx)

	{

	if (dctx->xflags & DRBG_FLAG_TEST)
@@ -340,7 +357,7 @@ static int fips_drbg_check(DRBG_CTX *dctx) 
	dctx->health_check_cnt++;

	if (dctx->health_check_cnt >= dctx->health_check_interval)

		{

		if (FIPS_drbg_test(dctx) <= 0)

		if (!FIPS_drbg_test(dctx))

			{

			FIPSerr(FIPS_F_FIPS_DRBG_CHECK, FIPS_R_SELFTEST_FAILURE);

			dctx->status = DRBG_STATUS_ERROR;
@@ -389,7 +406,10 @@ int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen, 


	if (dctx->status == DRBG_STATUS_RESEED || prediction_resistance)

		{

		if (!FIPS_drbg_reseed(dctx, adin, adinlen))

		/* If prediction resistance request don't do health check */

		int hcheck = prediction_resistance ? 0 : 1;

		

		if (!drbg_reseed(dctx, adin, adinlen, hcheck))

			{

			r = FIPS_R_RESEED_ERROR;

			goto end;

fips/rand/fips_drbg_selftest.c

+2 −3
Original line number Diff line number Diff line
@@ -772,9 +772,8 @@ int fips_drbg_kat(DRBG_CTX *dctx, int nid, unsigned int flags) 
		{

		if (td->nid == nid && td->flags == flags)

			{

			rv = fips_drbg_single_kat(dctx, td, 0);

			if (rv <= 0)

				return rv;

			if (!fips_drbg_single_kat(dctx, td, 0))

				return 0;

			return fips_drbg_health_check(dctx, td);

			}

		}