Commit 87975cfa authored by Richard Levitte's avatar Richard Levitte
Browse files

Make getting and setting the RAND default method thread safe 



Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3137)
parent 005f6766

crypto/rand/rand_lib.c

+35 −2
Original line number Diff line number Diff line
@@ -12,27 +12,50 @@ 
#include "internal/cryptlib.h"

#include <openssl/opensslconf.h>

#include "internal/rand.h"



#include <openssl/engine.h>

#include "internal/thread_once.h"



#ifndef OPENSSL_NO_ENGINE

/* non-NULL if default_RAND_meth is ENGINE-provided */

static ENGINE *funct_ref = NULL;

static CRYPTO_RWLOCK *rand_engine_lock = NULL;

#endif

static const RAND_METHOD *default_RAND_meth = NULL;

static CRYPTO_RWLOCK *rand_meth_lock = NULL;

static CRYPTO_ONCE rand_lock_init = CRYPTO_ONCE_STATIC_INIT;



DEFINE_RUN_ONCE_STATIC(do_rand_lock_init)

{

#ifndef OPENSSL_NO_ENGINE

    rand_engine_lock = CRYPTO_THREAD_lock_new();

#endif

    rand_meth_lock = CRYPTO_THREAD_lock_new();

    return rand_engine_lock != NULL && rand_meth_lock != NULL;

}



int RAND_set_rand_method(const RAND_METHOD *meth)

{

    if (!RUN_ONCE(&rand_lock_init, do_rand_lock_init))

        return 0;



    CRYPTO_THREAD_write_lock(rand_meth_lock);

#ifndef OPENSSL_NO_ENGINE

    ENGINE_finish(funct_ref);

    funct_ref = NULL;

#endif

    default_RAND_meth = meth;

    CRYPTO_THREAD_unlock(rand_meth_lock);

    return 1;

}



const RAND_METHOD *RAND_get_rand_method(void)

{

    const RAND_METHOD *tmp_meth = NULL;



    if (!RUN_ONCE(&rand_lock_init, do_rand_lock_init))

        return NULL;



    CRYPTO_THREAD_write_lock(rand_meth_lock);

    if (!default_RAND_meth) {

#ifndef OPENSSL_NO_ENGINE

        ENGINE *e = ENGINE_get_default_RAND();
@@ -49,13 +72,19 @@ const RAND_METHOD *RAND_get_rand_method(void) 
#endif

            default_RAND_meth = RAND_OpenSSL();

    }

    return default_RAND_meth;

    tmp_meth = default_RAND_meth;

    CRYPTO_THREAD_unlock(rand_meth_lock);

    return tmp_meth;

}



#ifndef OPENSSL_NO_ENGINE

int RAND_set_rand_engine(ENGINE *engine)

{

    const RAND_METHOD *tmp_meth = NULL;



    if (!RUN_ONCE(&rand_lock_init, do_rand_lock_init))

        return 0;



    if (engine) {

        if (!ENGINE_init(engine))

            return 0;
@@ -65,9 +94,11 @@ int RAND_set_rand_engine(ENGINE *engine) 
            return 0;

        }

    }

    CRYPTO_THREAD_write_lock(rand_engine_lock);

    /* This function releases any prior ENGINE so call it first */

    RAND_set_rand_method(tmp_meth);

    funct_ref = engine;

    CRYPTO_THREAD_unlock(rand_engine_lock);

    return 1;

}

#endif
@@ -78,6 +109,8 @@ void rand_cleanup_int(void) 
    if (meth && meth->cleanup)

        meth->cleanup();

    RAND_set_rand_method(NULL);

    CRYPTO_THREAD_lock_free(rand_meth_lock);

    CRYPTO_THREAD_lock_free(rand_engine_lock);

}



void RAND_seed(const void *buf, int num)