Commit a3efe1b6 authored by Dr. Stephen Henson's avatar Dr. Stephen Henson
Browse files

Avoid multiple lock using FIPS DRBG. 



Don't use multiple locks when SP800-90 DRBG is used outside FIPS mode.

PR#3176
Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
parent 789b1259

crypto/rand/md_rand.c

+9 −13
Original line number Diff line number Diff line
@@ -335,6 +335,11 @@ static void ssleay_rand_seed(const void *buf, int num) 
	}



static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo)

	{

	return md_rand_bytes_lock(buf, num, pseudo, 1);

	}



int md_rand_bytes_lock(unsigned char *buf, int num, int pseudo, int lock)

	{

	static volatile int stirred_pool = 0;

	int i,j,k,st_num,st_idx;
@@ -383,10 +388,7 @@ 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'.

	 */

#ifdef OPENSSL_FIPS

	/* NB: in FIPS mode we are already under a lock */

	if (!FIPS_mode())

#endif

	if (lock)

		CRYPTO_w_lock(CRYPTO_LOCK_RAND);



	/* prevent ssleay_rand_bytes() from trying to obtain the lock again */
@@ -466,9 +468,7 @@ static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo) 


	/* before unlocking, we must clear 'crypto_lock_rand' */

	crypto_lock_rand = 0;

#ifdef OPENSSL_FIPS

	if (!FIPS_mode())

#endif

	if (lock)

		CRYPTO_w_unlock(CRYPTO_LOCK_RAND);



	while (num > 0)
@@ -521,15 +521,11 @@ 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);

#ifdef OPENSSL_FIPS

	if (!FIPS_mode())

#endif

	if (lock)

		CRYPTO_w_lock(CRYPTO_LOCK_RAND);

	MD_Update(&m,md,MD_DIGEST_LENGTH);

	MD_Final(&m,md);

#ifdef OPENSSL_FIPS

	if (!FIPS_mode())

#endif

	if (lock)

		CRYPTO_w_unlock(CRYPTO_LOCK_RAND);



	EVP_MD_CTX_cleanup(&m);

crypto/rand/rand_lcl.h

+1 −0
Original line number Diff line number Diff line
@@ -154,5 +154,6 @@ 
#define	MD(a,b,c)		EVP_Digest(a,b,c,NULL,EVP_md2(), NULL)

#endif



int md_rand_bytes_lock(unsigned char *buf, int num, int pseudo, int lock);



#endif

crypto/rand/rand_lib.c

+2 −1
Original line number Diff line number Diff line
@@ -68,6 +68,7 @@ 
#ifdef OPENSSL_FIPS

#include <openssl/fips.h>

#include <openssl/fips_rand.h>

#include "rand_lcl.h"

#endif



#ifndef OPENSSL_NO_ENGINE
@@ -199,7 +200,7 @@ static size_t drbg_get_entropy(DRBG_CTX *ctx, unsigned char **pout, 
	*pout = OPENSSL_malloc(min_len);

	if (!*pout)

		return 0;

	if (RAND_SSLeay()->bytes(*pout, min_len) <= 0)

	if (md_rand_bytes_lock(*pout, min_len, 0, 0) <= 0)

		{

		OPENSSL_free(*pout);

		*pout = NULL;