Commit daba492c authored by Bodo Möller's avatar Bodo Möller
Browse files

md_rand.c thread safety

parent 24cff6ce

CHANGES

+8 −2
Original line number Diff line number Diff line
@@ -8,8 +8,8 @@ 
     and OpenSSL 0.9.7 were developped in parallel, based on OpenSSL 0.9.6.  



     Change log entries are tagged as follows:

         -) applies to 0.9.6a/0.9.6b only

         *) applies to 0.9.6a/0.9.6b and 0.9.7

         -) applies to 0.9.6a/0.9.6b/0.9.6c only

         *) applies to 0.9.6a/0.9.6b/0.9.6c and 0.9.7

         +) applies to 0.9.7 only



  *) In
@@ -24,6 +24,12 @@ 
     always reject numbers >= n.

     [Bodo Moeller]



  *) In crypto/rand/md_rand.c, use a new short-time lock CRYPTO_LOCK_RAND2

     to synchronize access to 'locking_thread'.  This is necessary on

     systems where access to 'locking_thread' (an 'unsigned long'

     variable) is not atomic.

     [Bodo Moeller]



  *) In crypto/rand/md_rand.c, set 'locking_thread' to current thread's ID

     *before* setting the 'crypto_lock_rand' flag.  The previous code had

     a race condition if 0 is a valid thread ID.

crypto/cryptlib.c

+2 −1
Original line number Diff line number Diff line
@@ -90,6 +90,7 @@ static const char* lock_names[CRYPTO_NUM_LOCKS] = 
	"ssl_sess_cert",

	"ssl",

	"rand",

	"rand2",

	"debug_malloc",

	"BIO",

	"gethostbyname",
@@ -102,7 +103,7 @@ static const char* lock_names[CRYPTO_NUM_LOCKS] = 
	"dynlock",

	"engine",

	"ui",

#if CRYPTO_NUM_LOCKS != 30

#if CRYPTO_NUM_LOCKS != 31

# error "Inconsistency between crypto.h and cryptlib.c"

#endif

	};

crypto/crypto.h

+14 −13
Original line number Diff line number Diff line
@@ -113,19 +113,20 @@ extern "C" { 
#define	CRYPTO_LOCK_SSL_SESS_CERT	15

#define	CRYPTO_LOCK_SSL			16

#define	CRYPTO_LOCK_RAND		17

#define	CRYPTO_LOCK_MALLOC		18

#define	CRYPTO_LOCK_BIO			19

#define	CRYPTO_LOCK_GETHOSTBYNAME	20

#define	CRYPTO_LOCK_GETSERVBYNAME	21

#define	CRYPTO_LOCK_READDIR		22

#define	CRYPTO_LOCK_RSA_BLINDING	23

#define	CRYPTO_LOCK_DH			24

#define	CRYPTO_LOCK_MALLOC2		25

#define	CRYPTO_LOCK_DSO			26

#define	CRYPTO_LOCK_DYNLOCK		27

#define	CRYPTO_LOCK_ENGINE		28

#define	CRYPTO_LOCK_UI			29

#define	CRYPTO_NUM_LOCKS		30

#define	CRYPTO_LOCK_RAND2		18

#define	CRYPTO_LOCK_MALLOC		19

#define	CRYPTO_LOCK_BIO			20

#define	CRYPTO_LOCK_GETHOSTBYNAME	21

#define	CRYPTO_LOCK_GETSERVBYNAME	22

#define	CRYPTO_LOCK_READDIR		23

#define	CRYPTO_LOCK_RSA_BLINDING	24

#define	CRYPTO_LOCK_DH			25

#define	CRYPTO_LOCK_MALLOC2		26

#define	CRYPTO_LOCK_DSO			27

#define	CRYPTO_LOCK_DYNLOCK		28

#define	CRYPTO_LOCK_ENGINE		29

#define	CRYPTO_LOCK_UI			30

#define	CRYPTO_NUM_LOCKS		31



#define CRYPTO_LOCK		1

#define CRYPTO_UNLOCK		2

crypto/rand/md_rand.c

+21 −2
Original line number Diff line number Diff line
@@ -144,6 +144,7 @@ static int initialized=0; 
static unsigned int crypto_lock_rand = 0; /* may be set only when a thread

                                           * holds CRYPTO_LOCK_RAND

                                           * (to prevent double locking) */

/* access to lockin_thread is synchronized by CRYPTO_LOCK_RAND2 */

static unsigned long locking_thread = 0; /* valid iff crypto_lock_rand is set */
@@ -210,7 +211,14 @@ static void ssleay_rand_add(const void *buf, int num, double add) 
	 */



	/* check if we already have the lock */

	do_not_lock = crypto_lock_rand && (locking_thread == CRYPTO_thread_id());

	if (crypto_lock_rand)

		{

		CRYPTO_r_lock(CRYPTO_LOCK_RAND2);

		do_not_lock = (locking_thread == CRYPTO_thread_id());

		CRYPTO_r_unlock(CRYPTO_LOCK_RAND2);

		}

	else

		do_not_lock = 0;



	if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND);

	st_idx=state_index;
@@ -361,7 +369,9 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) 
	CRYPTO_w_lock(CRYPTO_LOCK_RAND);



	/* prevent ssleay_rand_bytes() from trying to obtain the lock again */

	CRYPTO_w_lock(CRYPTO_LOCK_RAND2);

	locking_thread = CRYPTO_thread_id();

	CRYPTO_w_unlock(CRYPTO_LOCK_RAND2);

	crypto_lock_rand = 1;



	if (!initialized)
@@ -520,14 +530,23 @@ static int ssleay_rand_status(void) 


	/* check if we already have the lock

	 * (could happen if a RAND_poll() implementation calls RAND_status()) */

	do_not_lock = crypto_lock_rand && (locking_thread == CRYPTO_thread_id());

	if (crypto_lock_rand)

		{

		CRYPTO_r_lock(CRYPTO_LOCK_RAND2);

		do_not_lock = (locking_thread == CRYPTO_thread_id());

		CRYPTO_r_unlock(CRYPTO_LOCK_RAND2);

		}

	else

		do_not_lock = 0;

	

	if (!do_not_lock)

		{

		CRYPTO_w_lock(CRYPTO_LOCK_RAND);

		

		/* prevent ssleay_rand_bytes() from trying to obtain the lock again */

		CRYPTO_w_lock(CRYPTO_LOCK_RAND2);

		locking_thread = CRYPTO_thread_id();

		CRYPTO_w_unlock(CRYPTO_LOCK_RAND2);

		crypto_lock_rand = 1;

		}