From: Dr. Stephen Henson <steve@openssl.org>
Date: Wed, 21 Sep 2011 18:24:12 +0000 (+0000)
Subject: Perform health check on all reseed operations not associated with
X-Git-Tag: OpenSSL-fips-2_0-rc1~131
X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff_plain;h=05272d4c516fb1167581d35b31a7f815eafa9c57;ds=sidebyside

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).
---

diff --git a/fips/rand/fips_drbg_lib.c b/fips/rand/fips_drbg_lib.c
index c2e42896d1..9873742c45 100644
--- a/fips/rand/fips_drbg_lib.c
+++ b/fips/rand/fips_drbg_lib.c
@@ -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;
diff --git a/fips/rand/fips_drbg_selftest.c b/fips/rand/fips_drbg_selftest.c
index 76667a0167..3bc7eab95c 100644
--- a/fips/rand/fips_drbg_selftest.c
+++ b/fips/rand/fips_drbg_selftest.c
@@ -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);
 			}
 		}