diff --git a/CHANGES b/CHANGES
index 7ab81cb908..9395529e39 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,11 @@
 
  Changes between 1.0.1 and 1.1.0  [xx XXX xxxx]
 
+  *) Extensive self tests and health checking required by SP800-90 DRBG.
+     Remove strength parameter from FIPS_drbg_instantiate and always
+     instantiate at maximum supported strength.
+     [Steve Henson]
+
   *) Add SRP support.
      [Tom Wu <tjw@cs.stanford.edu> and Ben Laurie]
 
diff --git a/crypto/fips_err.h b/crypto/fips_err.h
index 0995b35deb..4b75c2dc0b 100644
--- a/crypto/fips_err.h
+++ b/crypto/fips_err.h
@@ -84,6 +84,7 @@ static ERR_STRING_DATA FIPS_str_functs[]=
 {ERR_FUNC(FIPS_F_FIPS_CIPHERINIT),	"FIPS_CIPHERINIT"},
 {ERR_FUNC(FIPS_F_FIPS_DIGESTINIT),	"FIPS_DIGESTINIT"},
 {ERR_FUNC(FIPS_F_FIPS_DRBG_GENERATE),	"FIPS_drbg_generate"},
+{ERR_FUNC(FIPS_F_FIPS_DRBG_HEALTH_CHECK),	"FIPS_DRBG_HEALTH_CHECK"},
 {ERR_FUNC(FIPS_F_FIPS_DRBG_INIT),	"FIPS_drbg_init"},
 {ERR_FUNC(FIPS_F_FIPS_DRBG_INSTANTIATE),	"FIPS_drbg_instantiate"},
 {ERR_FUNC(FIPS_F_FIPS_DRBG_NEW),	"FIPS_drbg_new"},
@@ -117,6 +118,8 @@ static ERR_STRING_DATA FIPS_str_reasons[]=
 {ERR_REASON(FIPS_R_CANNOT_READ_EXE)      ,"cannot read exe"},
 {ERR_REASON(FIPS_R_CANNOT_READ_EXE_DIGEST),"cannot read exe digest"},
 {ERR_REASON(FIPS_R_CONTRADICTING_EVIDENCE),"contradicting evidence"},
+{ERR_REASON(FIPS_R_ENTROPY_ERROR_UNDETECTED),"entropy error undetected"},
+{ERR_REASON(FIPS_R_ENTROPY_NOT_REQUESTED_FOR_RESEED),"entropy not requested for reseed"},
 {ERR_REASON(FIPS_R_ERROR_INITIALISING_DRBG),"error initialising drbg"},
 {ERR_REASON(FIPS_R_ERROR_INSTANTIATING_DRBG),"error instantiating drbg"},
 {ERR_REASON(FIPS_R_ERROR_RETRIEVING_ENTROPY),"error retrieving entropy"},
@@ -127,7 +130,9 @@ static ERR_STRING_DATA FIPS_str_reasons[]=
 {ERR_REASON(FIPS_R_FINGERPRINT_DOES_NOT_MATCH_SEGMENT_ALIASING),"fingerprint does not match segment aliasing"},
 {ERR_REASON(FIPS_R_FIPS_MODE_ALREADY_SET),"fips mode already set"},
 {ERR_REASON(FIPS_R_FIPS_SELFTEST_FAILED) ,"fips selftest failed"},
+{ERR_REASON(FIPS_R_FUNCTION_ERROR)       ,"function error"},
 {ERR_REASON(FIPS_R_GENERATE_ERROR)       ,"generate error"},
+{ERR_REASON(FIPS_R_GENERATE_ERROR_UNDETECTED),"generate error undetected"},
 {ERR_REASON(FIPS_R_INSTANTIATE_ERROR)    ,"instantiate error"},
 {ERR_REASON(FIPS_R_INSUFFICIENT_SECURITY_STRENGTH),"insufficient security strength"},
 {ERR_REASON(FIPS_R_INVALID_KEY_LENGTH)   ,"invalid key length"},
@@ -136,13 +141,18 @@ static ERR_STRING_DATA FIPS_str_reasons[]=
 {ERR_REASON(FIPS_R_NON_FIPS_METHOD)      ,"non fips method"},
 {ERR_REASON(FIPS_R_NOT_INSTANTIATED)     ,"not instantiated"},
 {ERR_REASON(FIPS_R_PAIRWISE_TEST_FAILED) ,"pairwise test failed"},
+{ERR_REASON(FIPS_R_PERSONALISATION_ERROR_UNDETECTED),"personalisation error undetected"},
 {ERR_REASON(FIPS_R_PERSONALISATION_STRING_TOO_LONG),"personalisation string too long"},
+{ERR_REASON(FIPS_R_REQUEST_LENGTH_ERROR_UNDETECTED),"request length error undetected"},
 {ERR_REASON(FIPS_R_REQUEST_TOO_LARGE_FOR_DRBG),"request too large for drbg"},
+{ERR_REASON(FIPS_R_RESEED_COUNTER_ERROR) ,"reseed counter error"},
 {ERR_REASON(FIPS_R_RESEED_ERROR)         ,"reseed error"},
 {ERR_REASON(FIPS_R_RSA_DECRYPT_ERROR)    ,"rsa decrypt error"},
 {ERR_REASON(FIPS_R_RSA_ENCRYPT_ERROR)    ,"rsa encrypt error"},
 {ERR_REASON(FIPS_R_SELFTEST_FAILED)      ,"selftest failed"},
+{ERR_REASON(FIPS_R_STRENGTH_ERROR_UNDETECTED),"strength error undetected"},
 {ERR_REASON(FIPS_R_TEST_FAILURE)         ,"test failure"},
+{ERR_REASON(FIPS_R_UNINSTANTIATE_ZEROISE_ERROR),"uninstantiate zeroise error"},
 {ERR_REASON(FIPS_R_UNSUPPORTED_DRBG_TYPE),"unsupported drbg type"},
 {ERR_REASON(FIPS_R_UNSUPPORTED_PLATFORM) ,"unsupported platform"},
 {0,NULL}
diff --git a/fips/ecdh/fips_ecdhvs.c b/fips/ecdh/fips_ecdhvs.c
index c68daf2e94..38178f5eea 100644
--- a/fips/ecdh/fips_ecdhvs.c
+++ b/fips/ecdh/fips_ecdhvs.c
@@ -279,7 +279,7 @@ int main(int argc,char **argv)
 	int argn = argc - 1;
 	FILE *in, *out;
 	char buf[2048], lbuf[2048];
-	unsigned char *rhash;
+	unsigned char *rhash = NULL;
 	long rhashlen;
 	BIGNUM *cx = NULL, *cy = NULL;
 	BIGNUM *id = NULL, *ix = NULL, *iy = NULL;
diff --git a/fips/ecdsa/fips_ecdsavs.c b/fips/ecdsa/fips_ecdsavs.c
index 379df65501..2492ee42c0 100644
--- a/fips/ecdsa/fips_ecdsavs.c
+++ b/fips/ecdsa/fips_ecdsavs.c
@@ -460,7 +460,7 @@ static int SigVer(FILE *in, FILE *out)
 
 int main(int argc, char **argv)
 	{
-	FILE *in, *out;
+	FILE *in = NULL, *out = NULL;
 	const char *cmd = argv[1];
 	int rv = 0;
 	fips_set_error_print();
diff --git a/fips/fips.h b/fips/fips.h
index cd75e19562..af36f03236 100644
--- a/fips/fips.h
+++ b/fips/fips.h
@@ -194,6 +194,7 @@ void ERR_load_FIPS_strings(void);
 #define FIPS_F_FIPS_CIPHERINIT				 128
 #define FIPS_F_FIPS_DIGESTINIT				 127
 #define FIPS_F_FIPS_DRBG_GENERATE			 132
+#define FIPS_F_FIPS_DRBG_HEALTH_CHECK			 137
 #define FIPS_F_FIPS_DRBG_INIT				 136
 #define FIPS_F_FIPS_DRBG_INSTANTIATE			 133
 #define FIPS_F_FIPS_DRBG_NEW				 134
@@ -224,6 +225,8 @@ void ERR_load_FIPS_strings(void);
 #define FIPS_R_CANNOT_READ_EXE				 103
 #define FIPS_R_CANNOT_READ_EXE_DIGEST			 104
 #define FIPS_R_CONTRADICTING_EVIDENCE			 114
+#define FIPS_R_ENTROPY_ERROR_UNDETECTED			 133
+#define FIPS_R_ENTROPY_NOT_REQUESTED_FOR_RESEED		 134
 #define FIPS_R_ERROR_INITIALISING_DRBG			 120
 #define FIPS_R_ERROR_INSTANTIATING_DRBG			 121
 #define FIPS_R_ERROR_RETRIEVING_ENTROPY			 122
@@ -234,7 +237,9 @@ void ERR_load_FIPS_strings(void);
 #define FIPS_R_FINGERPRINT_DOES_NOT_MATCH_SEGMENT_ALIASING 112
 #define FIPS_R_FIPS_MODE_ALREADY_SET			 102
 #define FIPS_R_FIPS_SELFTEST_FAILED			 106
+#define FIPS_R_FUNCTION_ERROR				 135
 #define FIPS_R_GENERATE_ERROR				 124
+#define FIPS_R_GENERATE_ERROR_UNDETECTED		 136
 #define FIPS_R_INSTANTIATE_ERROR			 125
 #define FIPS_R_INSUFFICIENT_SECURITY_STRENGTH		 132
 #define FIPS_R_INVALID_KEY_LENGTH			 109
@@ -243,13 +248,18 @@ void ERR_load_FIPS_strings(void);
 #define FIPS_R_NON_FIPS_METHOD				 100
 #define FIPS_R_NOT_INSTANTIATED				 127
 #define FIPS_R_PAIRWISE_TEST_FAILED			 107
+#define FIPS_R_PERSONALISATION_ERROR_UNDETECTED		 137
 #define FIPS_R_PERSONALISATION_STRING_TOO_LONG		 128
+#define FIPS_R_REQUEST_LENGTH_ERROR_UNDETECTED		 138
 #define FIPS_R_REQUEST_TOO_LARGE_FOR_DRBG		 129
+#define FIPS_R_RESEED_COUNTER_ERROR			 139
 #define FIPS_R_RESEED_ERROR				 130
 #define FIPS_R_RSA_DECRYPT_ERROR			 115
 #define FIPS_R_RSA_ENCRYPT_ERROR			 116
 #define FIPS_R_SELFTEST_FAILED				 101
+#define FIPS_R_STRENGTH_ERROR_UNDETECTED		 140
 #define FIPS_R_TEST_FAILURE				 117
+#define FIPS_R_UNINSTANTIATE_ZEROISE_ERROR		 141
 #define FIPS_R_UNSUPPORTED_DRBG_TYPE			 131
 #define FIPS_R_UNSUPPORTED_PLATFORM			 113
 
diff --git a/fips/rand/fips_drbg_ctr.c b/fips/rand/fips_drbg_ctr.c
index 738abdd835..7e6d497ad1 100644
--- a/fips/rand/fips_drbg_ctr.c
+++ b/fips/rand/fips_drbg_ctr.c
@@ -352,7 +352,7 @@ static int drbg_ctr_generate(DRBG_CTX *dctx,
 
 static int drbg_ctr_uninstantiate(DRBG_CTX *dctx)
 	{
-	OPENSSL_cleanse(&dctx->d.ctr, sizeof(DRBG_CTR_CTX));
+	memset(&dctx->d.ctr, 0, sizeof(DRBG_CTR_CTX));
 	return 1;
 	}
 
@@ -385,7 +385,6 @@ int fips_drbg_ctr_init(DRBG_CTX *dctx)
 	dctx->generate = drbg_ctr_generate;
 	dctx->uninstantiate = drbg_ctr_uninstantiate;
 
-
 	cctx->keylen = keylen;
 	dctx->strength = keylen * 8;
 	dctx->blocklength = 16;
@@ -423,7 +422,7 @@ int fips_drbg_ctr_init(DRBG_CTX *dctx)
 		}
 
 	dctx->max_request = 1<<19;
-	dctx->reseed_counter = DRBG_MAX_LENGTH;
+	dctx->reseed_interval = 1<<24;
 
 	return 1;
 	}
diff --git a/fips/rand/fips_drbg_hash.c b/fips/rand/fips_drbg_hash.c
index ca3bce7320..f6135c031f 100644
--- a/fips/rand/fips_drbg_hash.c
+++ b/fips/rand/fips_drbg_hash.c
@@ -377,6 +377,7 @@ int fips_drbg_hash_init(DRBG_CTX *dctx)
 	dctx->max_adin = DRBG_MAX_LENGTH;
 
 	dctx->max_request = 1<<19;
+	dctx->reseed_interval = 1<<24;
 
 	return 1;
 	}
diff --git a/fips/rand/fips_drbg_lib.c b/fips/rand/fips_drbg_lib.c
index 31c5a7a8b0..0e06273cef 100644
--- a/fips/rand/fips_drbg_lib.c
+++ b/fips/rand/fips_drbg_lib.c
@@ -118,7 +118,6 @@ void FIPS_drbg_free(DRBG_CTX *dctx)
 	}
 
 int FIPS_drbg_instantiate(DRBG_CTX *dctx,
-				int strength,
 				const unsigned char *pers, size_t perslen)
 	{
 	size_t entlen, noncelen;
@@ -151,12 +150,6 @@ int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 		goto end;
 		}
 
-	if (strength > dctx->strength)
-		{
-		r = FIPS_R_INSUFFICIENT_SECURITY_STRENGTH;
-		goto end;
-		}
-
 	dctx->status = DRBG_STATUS_ERROR;
 
 	entlen = dctx->get_entropy(dctx, dctx->entropy, dctx->strength,
@@ -197,8 +190,6 @@ int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 
 	dctx->status = DRBG_STATUS_READY;
 	dctx->reseed_counter = 1;
-	/* Initial test value for reseed interval */
-	dctx->reseed_interval = 1<<24;
 
 	end:
 
@@ -208,7 +199,7 @@ int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 	if (dctx->status == DRBG_STATUS_READY)
 		return 1;
 
-	if (r && !(dctx->flags & DRBG_FLAG_TEST))
+	if (r && !(dctx->flags & DRBG_FLAG_NOERR))
 		FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, r);
 
 	return 0;
@@ -265,7 +256,7 @@ int FIPS_drbg_reseed(DRBG_CTX *dctx,
 	if (dctx->status == DRBG_STATUS_READY)
 		return 1;
 
-	if (r && !(dctx->flags & DRBG_FLAG_TEST))
+	if (r && !(dctx->flags & DRBG_FLAG_NOERR))
 		FIPSerr(FIPS_F_FIPS_DRBG_RESEED, r);
 
 	return 0;
@@ -313,7 +304,7 @@ int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
 		dctx->status = DRBG_STATUS_ERROR;
 		goto end;
 		}
-	if (dctx->reseed_counter > dctx->reseed_interval)
+	if (dctx->reseed_counter >= dctx->reseed_interval)
 		dctx->status = DRBG_STATUS_RESEED;
 	else
 		dctx->reseed_counter++;
@@ -321,7 +312,7 @@ int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
 	end:
 	if (r)
 		{
-		if (!(dctx->flags & DRBG_FLAG_TEST))
+		if (!(dctx->flags & DRBG_FLAG_NOERR))
 			FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, r);
 		return 0;
 		}
@@ -331,11 +322,14 @@ int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
 
 int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
 	{
-	int save_type, save_flags, rv;
-	save_type = dctx->type;
-	save_flags = dctx->flags;
+	int rv;
+	if (!dctx->uninstantiate)
+		return 1;
 	rv = dctx->uninstantiate(dctx);
-	OPENSSL_cleanse(dctx, sizeof(DRBG_CTX));
+	/* Although we'd like to cleanse here we can't because we have to
+	 * test the uninstantiate really zeroes the data.
+	 */
+	memset(dctx, 0, sizeof(DRBG_CTX));
 	/* If method has problems uninstantiating, return error */
 	return rv;
 	}
diff --git a/fips/rand/fips_drbg_selftest.c b/fips/rand/fips_drbg_selftest.c
index e94a5d8e79..4f28d5ab15 100644
--- a/fips/rand/fips_drbg_selftest.c
+++ b/fips/rand/fips_drbg_selftest.c
@@ -726,8 +726,10 @@ typedef struct
 	{
 	const unsigned char *ent;
 	size_t entlen;
+	int entcnt;
 	const unsigned char *nonce;
 	size_t noncelen;
+	int noncecnt;
 	} TEST_ENT;
 
 static size_t test_entropy(DRBG_CTX *dctx, unsigned char *out,
@@ -735,6 +737,7 @@ static size_t test_entropy(DRBG_CTX *dctx, unsigned char *out,
 	{
 	TEST_ENT *t = FIPS_drbg_get_app_data(dctx);
 	memcpy(out, t->ent, t->entlen);
+	t->entcnt++;
 	return t->entlen;
 	}
 
@@ -743,6 +746,7 @@ static size_t test_nonce(DRBG_CTX *dctx, unsigned char *out,
 	{
 	TEST_ENT *t = FIPS_drbg_get_app_data(dctx);
 	memcpy(out, t->nonce, t->noncelen);
+	t->noncecnt++;
 	return t->noncelen;
 	}
 
@@ -767,8 +771,10 @@ static int fips_drbg_single_kat(DRBG_CTX *dctx, DRBG_SELFTEST_DATA *td)
 	t.entlen = td->entlen;
 	t.nonce = td->nonce;
 	t.noncelen = td->noncelen;
+	t.entcnt = 0;
+	t.noncecnt = 0;
 
-	if (!FIPS_drbg_instantiate(dctx, 0, td->pers, td->perslen))
+	if (!FIPS_drbg_instantiate(dctx, td->pers, td->perslen))
 		goto err;
 
 	t.ent = td->entpr;
@@ -796,13 +802,197 @@ static int fips_drbg_single_kat(DRBG_CTX *dctx, DRBG_SELFTEST_DATA *td)
 	return rv;
 	}
 
+/* This is the "health check" function required by SP800-90. Induce several
+ * failure modes and check an error condition is set.
+ */
+
+static int fips_drbg_health_check(DRBG_CTX *dctx, DRBG_SELFTEST_DATA *td)
+	{
+	unsigned char randout[1024];
+	TEST_ENT t;
+	size_t i;
+	unsigned char *p = (unsigned char *)dctx;
+
+	/* Initialise DRBG */
+
+	if (!FIPS_drbg_init(dctx, td->nid, td->flags))
+		goto err;
+
+	if (!FIPS_drbg_set_test_mode(dctx, test_entropy, test_nonce))
+		goto err;
+
+	FIPS_drbg_set_app_data(dctx, &t);
+
+	t.ent = td->ent;
+	t.entlen = td->entlen;
+	t.nonce = td->nonce;
+	t.noncelen = td->noncelen;
+	t.entcnt = 0;
+	t.noncecnt = 0;
+
+	/* Don't report induced errors */
+	dctx->flags |= DRBG_FLAG_NOERR;
+
+	/* Try too large a personalisation length */
+	if (FIPS_drbg_instantiate(dctx, td->pers, dctx->max_pers + 1) > 0)
+		{
+		FIPSerr(FIPS_F_FIPS_DRBG_HEALTH_CHECK, FIPS_R_PERSONALISATION_ERROR_UNDETECTED);
+		goto err;
+		}
+
+	/* Test entropy source failure detection */
+
+	t.entlen = 0;
+	if (FIPS_drbg_instantiate(dctx, td->pers, td->perslen) > 0)
+		{
+		FIPSerr(FIPS_F_FIPS_DRBG_HEALTH_CHECK, FIPS_R_ENTROPY_ERROR_UNDETECTED);
+		goto err;
+		}
+
+	/* Try to generate output from uninstantiated DRBG */
+	if (FIPS_drbg_generate(dctx, randout, td->katlen, 0, 0,
+				td->adin, td->adinlen))
+		{
+		FIPSerr(FIPS_F_FIPS_DRBG_HEALTH_CHECK, FIPS_R_GENERATE_ERROR_UNDETECTED);
+		goto err;
+		}
+
+	/* Instantiate with valid data. NB: errors now reported again */
+	if (!FIPS_drbg_init(dctx, td->nid, td->flags))
+		goto err;
+	if (!FIPS_drbg_set_test_mode(dctx, test_entropy, test_nonce))
+		goto err;
+	FIPS_drbg_set_app_data(dctx, &t);
+
+	t.entlen = td->entlen;
+	if (!FIPS_drbg_instantiate(dctx, td->pers, td->perslen))
+		goto err;
+
+	/* Check generation is now OK */
+	if (!FIPS_drbg_generate(dctx, randout, td->katlen, 0, 0,
+				td->adin, td->adinlen))
+		goto err;
+
+	/* Try to generate with too high a strength.
+	 */
+
+	dctx->flags |= DRBG_FLAG_NOERR;
+	if (dctx->strength != 256)
+		{
+		if (FIPS_drbg_generate(dctx, randout, td->katlen, 256, 0,
+					td->adin, td->adinlen))
+			{
+			FIPSerr(FIPS_F_FIPS_DRBG_HEALTH_CHECK, FIPS_R_STRENGTH_ERROR_UNDETECTED);
+
+			goto err;
+			}
+		}
+
+	/* Request too much data for one request */
+	if (FIPS_drbg_generate(dctx, randout, dctx->max_request + 1, 0, 0,
+				td->adin, td->adinlen))
+		{
+		FIPSerr(FIPS_F_FIPS_DRBG_HEALTH_CHECK, FIPS_R_REQUEST_LENGTH_ERROR_UNDETECTED);
+		goto err;
+		}
+
+	/* Check prediction resistance request fails if entropy source
+	 * failure.
+	 */
+
+	t.entlen = 0;
+
+	if (FIPS_drbg_generate(dctx, randout, td->katlen, 0, 1,
+				td->adin, td->adinlen))
+		{
+		FIPSerr(FIPS_F_FIPS_DRBG_HEALTH_CHECK, FIPS_R_ENTROPY_ERROR_UNDETECTED);
+		goto err;
+		}
+		
+
+	/* Instantiate again with valid data */
+
+	if (!FIPS_drbg_init(dctx, td->nid, td->flags))
+		goto err;
+	if (!FIPS_drbg_set_test_mode(dctx, test_entropy, test_nonce))
+		goto err;
+	FIPS_drbg_set_app_data(dctx, &t);
+
+	t.entlen = td->entlen;
+	/* Test reseeding works */
+	dctx->reseed_interval = 2;
+	if (!FIPS_drbg_instantiate(dctx, td->pers, td->perslen))
+		goto err;
+
+	/* Check generation is now OK */
+	if (!FIPS_drbg_generate(dctx, randout, td->katlen, 0, 0,
+				td->adin, td->adinlen))
+		goto err;
+	if (!FIPS_drbg_generate(dctx, randout, td->katlen, 0, 0,
+				td->adin, td->adinlen))
+		goto err;
+
+	/* DRBG should now require a reseed */
+	if (dctx->status != DRBG_STATUS_RESEED)
+		{
+		FIPSerr(FIPS_F_FIPS_DRBG_HEALTH_CHECK, FIPS_R_RESEED_COUNTER_ERROR);
+		goto err;
+		}
+
+
+	/* Generate again and check entropy has been requested for reseed */
+	t.entcnt = 0;
+	if (!FIPS_drbg_generate(dctx, randout, td->katlen, 0, 0,
+				td->adin, td->adinlen))
+		goto err;
+	if (t.entcnt != 1)
+		{
+		FIPSerr(FIPS_F_FIPS_DRBG_HEALTH_CHECK, FIPS_R_ENTROPY_NOT_REQUESTED_FOR_RESEED);
+		goto err;
+		}
+
+	FIPS_drbg_uninstantiate(dctx);
+	p = (unsigned char *)dctx;
+	/* Standard says we have to check uninstantiate really zeroes
+	 * the data...
+	 */
+	for (i = 0; i < sizeof(DRBG_CTX); i++)
+		{
+		if (*p != 0)
+			{
+			FIPSerr(FIPS_F_FIPS_DRBG_HEALTH_CHECK, FIPS_R_UNINSTANTIATE_ZEROISE_ERROR);
+			goto err;
+			}
+		p++;
+		}
+
+	return 1;
+
+	err:
+	/* A real error as opposed to an induced one: underlying function will
+	 * indicate the error.
+	 */
+	if (!(dctx->flags & DRBG_FLAG_NOERR))
+		FIPSerr(FIPS_F_FIPS_DRBG_HEALTH_CHECK, FIPS_R_FUNCTION_ERROR);
+	FIPS_drbg_uninstantiate(dctx);
+	return 0;
+
+	}
+		
+
 int fips_drbg_kat(DRBG_CTX *dctx, int nid, unsigned int flags)
 	{
+	int rv;
 	DRBG_SELFTEST_DATA *td;
 	for (td = drbg_test; td->nid != 0; td++)
 		{
 		if (td->nid == nid && td->flags == flags)
-			return fips_drbg_single_kat(dctx, td);
+			{
+			rv = fips_drbg_single_kat(dctx, td);
+			if (rv <= 0)
+				return rv;
+			return fips_drbg_health_check(dctx, td);
+			}
 		}
 	return 0;
 	}
@@ -815,8 +1005,12 @@ int FIPS_selftest_drbg(void)
 	if (!dctx)
 		return 0;
 	for (td = drbg_test; td->nid != 0; td++)
+		{
 		if (!fips_drbg_single_kat(dctx, td))
 			break;
+		if (!fips_drbg_health_check(dctx, td))
+			break;
+		}
 	if (td->nid == 0)
 		return 1;
 	return 0;
diff --git a/fips/rand/fips_drbgvs.c b/fips/rand/fips_drbgvs.c
index c60b80bf2f..0c5839e553 100644
--- a/fips/rand/fips_drbgvs.c
+++ b/fips/rand/fips_drbgvs.c
@@ -156,9 +156,9 @@ static size_t test_nonce(DRBG_CTX *dctx, unsigned char *out,
 int main(int argc,char **argv)
 	{
 	FILE *in, *out;
-	DRBG_CTX *dctx;
+	DRBG_CTX *dctx = NULL;
 	TEST_ENT t;
-	int r, nid;
+	int r, nid = 0;
 	int pr = 0;
 	char buf[2048], lbuf[2048];
 	unsigned char randout[2048];
@@ -166,7 +166,7 @@ int main(int argc,char **argv)
 
 	unsigned char *ent = NULL, *nonce = NULL, *pers = NULL, *adin = NULL;
 	long entlen, noncelen, perslen, adinlen;
-	int df;
+	int df = 0;
 
 	int randoutlen = 0;
 
@@ -251,7 +251,7 @@ int main(int argc,char **argv)
 			FIPS_drbg_set_test_mode(dctx, test_entropy, test_nonce);
 			FIPS_drbg_set_app_data(dctx, &t);
 			randoutlen = (int)FIPS_drbg_get_blocklength(dctx);
-			r = FIPS_drbg_instantiate(dctx, 0, pers, perslen);
+			r = FIPS_drbg_instantiate(dctx, pers, perslen);
 			if (!r)
 				{
 				fprintf(stderr, "Error instantiating DRBG\n");
diff --git a/fips/rand/fips_rand.h b/fips/rand/fips_rand.h
index 829a0e12a4..c4d1d910ba 100644
--- a/fips/rand/fips_rand.h
+++ b/fips/rand/fips_rand.h
@@ -77,7 +77,7 @@ typedef struct drbg_ctx_st DRBG_CTX;
 
 DRBG_CTX *FIPS_drbg_new(int type, unsigned int flags);
 int FIPS_drbg_init(DRBG_CTX *dctx, int type, unsigned int flags);
-int FIPS_drbg_instantiate(DRBG_CTX *dctx, int strength,
+int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 				const unsigned char *pers, size_t perslen);
 int FIPS_drbg_reseed(DRBG_CTX *dctx, const unsigned char *adin, size_t adinlen);
 int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
diff --git a/fips/rand/fips_rand_lcl.h b/fips/rand/fips_rand_lcl.h
index 2f0dfac95c..7e64bb491f 100644
--- a/fips/rand/fips_rand_lcl.h
+++ b/fips/rand/fips_rand_lcl.h
@@ -86,6 +86,8 @@ struct drbg_ctr_ctx_st
 
 /* PRNG is in test state */
 #define	DRBG_FLAG_TEST			0x2
+/* Functions shouldn't call err library */
+#define	DRBG_FLAG_NOERR			0x4
 
 /* DRBG status values */
 /* not initialised */
@@ -103,7 +105,7 @@ struct drbg_ctr_ctx_st
 
 /* A default maximum length: larger than any reasonable value used in pratice */
 
-#define DRBG_MAX_LENGTH			0x7fffffff
+#define DRBG_MAX_LENGTH			0x7ffffff0
 
 /* DRBG context structure */