From: Dr. Stephen Henson <steve@openssl.org>
Date: Wed, 4 Dec 2013 13:39:04 +0000 (+0000)
Subject: Avoid multiple locks in FIPS mode.
X-Git-Tag: OpenSSL_1_0_2-beta1~140
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=c43dc3dd77c48898104dfca06793f6836805e7eb;p=oweals%2Fopenssl.git

Avoid multiple locks in FIPS mode.

PR: 3176.

In FIPS mode ssleay_rand_bytes is only used for PRNG seeding and is
performed in either a single threaded context (when the PRNG is first
initialised) or under a lock (reseeding). To avoid multiple locks disable
use of CRYPTO_LOCK_RAND in FIPS mode in ssleay_rand_bytes.
---

diff --git a/crypto/rand/md_rand.c b/crypto/rand/md_rand.c
index 1e3bcb9bc4..2dd22d2beb 100644
--- a/crypto/rand/md_rand.c
+++ b/crypto/rand/md_rand.c
@@ -380,8 +380,11 @@ static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo)
 	 * are fed into the hash function and the results are kept in the
 	 * global 'md'.
 	 */
-
-	CRYPTO_w_lock(CRYPTO_LOCK_RAND);
+#ifdef OPENSSL_FIPS
+	/* NB: in FIPS mode we are already under a lock */
+	if (FIPS_mode())
+#endif
+		CRYPTO_w_lock(CRYPTO_LOCK_RAND);
 
 	/* prevent ssleay_rand_bytes() from trying to obtain the lock again */
 	CRYPTO_w_lock(CRYPTO_LOCK_RAND2);
@@ -460,7 +463,10 @@ static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo)
 
 	/* before unlocking, we must clear 'crypto_lock_rand' */
 	crypto_lock_rand = 0;
-	CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
+#ifdef OPENSSL_FIPS
+	if (FIPS_mode())
+#endif
+		CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
 
 	while (num > 0)
 		{
@@ -512,10 +518,16 @@ static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo)
 	MD_Init(&m);
 	MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));
 	MD_Update(&m,local_md,MD_DIGEST_LENGTH);
-	CRYPTO_w_lock(CRYPTO_LOCK_RAND);
+#ifdef OPENSSL_FIPS
+	if (FIPS_mode())
+#endif
+		CRYPTO_w_lock(CRYPTO_LOCK_RAND);
 	MD_Update(&m,md,MD_DIGEST_LENGTH);
 	MD_Final(&m,md);
-	CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
+#ifdef OPENSSL_FIPS
+	if (FIPS_mode())
+#endif
+		CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
 
 	EVP_MD_CTX_cleanup(&m);
 	if (ok)