From e45c6c4e2537434f087793e5c51a5cb70af9d82e Mon Sep 17 00:00:00 2001
From: "Dr. Stephen Henson" <steve@openssl.org>
Date: Mon, 7 Mar 2011 16:51:17 +0000
Subject: [PATCH] Uninstantiate and free functions for DRBG.

---
 fips/rand/fips_drbg_ctr.c  |  7 ++++++
 fips/rand/fips_drbg_hash.c |  8 +++++++
 fips/rand/fips_drbg_lib.c  | 45 ++++++++++++++++++++++++++++----------
 fips/rand/fips_drbgvs.c    |  2 ++
 fips/rand/fips_rand.h      |  3 +++
 5 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/fips/rand/fips_drbg_ctr.c b/fips/rand/fips_drbg_ctr.c
index 2b2d226c53..738abdd835 100644
--- a/fips/rand/fips_drbg_ctr.c
+++ b/fips/rand/fips_drbg_ctr.c
@@ -350,6 +350,12 @@ 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));
+	return 1;
+	}
+
 int fips_drbg_ctr_init(DRBG_CTX *dctx)
 	{
 	DRBG_CTR_CTX *cctx = &dctx->d.ctr;
@@ -377,6 +383,7 @@ int fips_drbg_ctr_init(DRBG_CTX *dctx)
 	dctx->instantiate = drbg_ctr_instantiate;
 	dctx->reseed = drbg_ctr_reseed;
 	dctx->generate = drbg_ctr_generate;
+	dctx->uninstantiate = drbg_ctr_uninstantiate;
 
 
 	cctx->keylen = keylen;
diff --git a/fips/rand/fips_drbg_hash.c b/fips/rand/fips_drbg_hash.c
index 4dbcdb6a7b..ca3bce7320 100644
--- a/fips/rand/fips_drbg_hash.c
+++ b/fips/rand/fips_drbg_hash.c
@@ -306,6 +306,13 @@ static int drbg_hash_generate(DRBG_CTX *dctx,
 	return 1;
 	}
 
+static int drbg_hash_uninstantiate(DRBG_CTX *dctx)
+	{
+	EVP_MD_CTX_cleanup(&dctx->d.hash.mctx);
+	OPENSSL_cleanse(&dctx->d.hash, sizeof(DRBG_HASH_CTX));
+	return 1;
+	}
+
 int fips_drbg_hash_init(DRBG_CTX *dctx)
 	{
 	const EVP_MD *md;
@@ -346,6 +353,7 @@ int fips_drbg_hash_init(DRBG_CTX *dctx)
 	dctx->instantiate = drbg_hash_instantiate;
 	dctx->reseed = drbg_hash_reseed;
 	dctx->generate = drbg_hash_generate;
+	dctx->uninstantiate = drbg_hash_uninstantiate;
 
 	dctx->d.hash.md = md;
 	EVP_MD_CTX_init(&hctx->mctx);
diff --git a/fips/rand/fips_drbg_lib.c b/fips/rand/fips_drbg_lib.c
index 9b497b54cc..0bf30f0314 100644
--- a/fips/rand/fips_drbg_lib.c
+++ b/fips/rand/fips_drbg_lib.c
@@ -62,30 +62,41 @@
 
 /* Support framework for SP800-90 DRBGs */
 
-DRBG_CTX *FIPS_drbg_new(int type, unsigned int flags)
+static int fips_drbg_init(DRBG_CTX *dctx, int type, unsigned int flags)
 	{
 	int rv;
-	DRBG_CTX *dctx;
-	dctx = OPENSSL_malloc(sizeof(DRBG_CTX));
 	memset(dctx, 0, sizeof(DRBG_CTX));
 	dctx->status = DRBG_STATUS_UNINITIALISED;
 	dctx->flags = flags;
 	dctx->type = type;
+
 	rv = fips_drbg_hash_init(dctx);
+
 	if (rv == -2)
 		rv = fips_drbg_ctr_init(dctx);
-	if (rv <= 0)
+
+	return rv;
+	}
+
+DRBG_CTX *FIPS_drbg_new(int type, unsigned int flags)
+	{
+	DRBG_CTX *dctx;
+	dctx = OPENSSL_malloc(sizeof(DRBG_CTX));
+	if (!dctx)
+		return NULL;
+	if (fips_drbg_init(dctx, type, flags) <= 0)
 		{
-		/* Fatal: cannot initialiase DRBG */
-		goto err;
+		OPENSSL_free(dctx);
+		return NULL;
 		}
-
 	return dctx;
+	}
 
-	err:
-	if (dctx)
-		OPENSSL_free(dctx);
-	return NULL;
+void FIPS_drbg_free(DRBG_CTX *dctx)
+	{
+	dctx->uninstantiate(dctx);
+	OPENSSL_cleanse(dctx, sizeof(DRBG_CTX));
+	OPENSSL_free(dctx);
 	}
 
 int FIPS_drbg_instantiate(DRBG_CTX *dctx,
@@ -224,6 +235,18 @@ int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
 	return 1;
 	}
 
+int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
+	{
+	int save_type, save_flags, rv;
+	save_type = dctx->type;
+	save_flags = dctx->flags;
+	rv = dctx->uninstantiate(dctx);
+	OPENSSL_cleanse(dctx, sizeof(DRBG_CTX));
+	/* If method has problems uninstantiating, return error */
+	if (rv <= 0)
+		return rv;
+	return fips_drbg_init(dctx, save_type, save_flags);
+	}
 
 int FIPS_drbg_set_test_mode(DRBG_CTX *dctx,
 	size_t (*get_entropy)(DRBG_CTX *ctx, unsigned char *out,
diff --git a/fips/rand/fips_drbgvs.c b/fips/rand/fips_drbgvs.c
index a599233908..325925072e 100644
--- a/fips/rand/fips_drbgvs.c
+++ b/fips/rand/fips_drbgvs.c
@@ -294,6 +294,8 @@ int main(int argc,char **argv)
 		if (gen == 2)
 			{
 			OutputValue("ReturnedBits", out, outlen, stdout, 0);
+			FIPS_drbg_free(dctx);
+			dctx = NULL;
 			gen = 0;
 			}
 
diff --git a/fips/rand/fips_rand.h b/fips/rand/fips_rand.h
index e0cc8c9da5..e9e2afbbaa 100644
--- a/fips/rand/fips_rand.h
+++ b/fips/rand/fips_rand.h
@@ -83,6 +83,9 @@ int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
 			int prediction_resistance,
 			const unsigned char *adin, size_t adinlen);
 
+int FIPS_drbg_uninstantiate(DRBG_CTX *dctx);
+void FIPS_drbg_free(DRBG_CTX *dctx);
+
 int FIPS_drbg_set_test_mode(DRBG_CTX *dctx,
 	size_t (*get_entropy)(DRBG_CTX *ctx, unsigned char *out,
 				int entropy, size_t min_len, size_t max_len),
-- 
2.25.1