Introduce a no-pinshared option
[openssl.git] / crypto / init.c
index 01619bc129b9506270973e3a96e87f380c72af08..6b6bd71967534d8c67e6124f4ed4091651650fd9 100644 (file)
@@ -1,37 +1,57 @@
 /*
- * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
  *
- * Licensed under the OpenSSL license (the "License").  You may not use
+ * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
  * in the file LICENSE in the source distribution or at
  * https://www.openssl.org/source/license.html
  */
 
-#include <internal/cryptlib_int.h>
+#include "e_os.h"
+#include "internal/cryptlib_int.h"
 #include <openssl/err.h>
-#include <internal/rand.h>
-#include <internal/bio.h>
+#include "internal/rand_int.h"
+#include "internal/bio.h"
 #include <openssl/evp.h>
-#include <internal/evp_int.h>
-#include <internal/conf.h>
-#include <internal/async.h>
-#include <internal/engine.h>
-#include <internal/comp.h>
-#include <internal/err.h>
-#include <internal/err_int.h>
-#include <internal/objects.h>
+#include "internal/evp_int.h"
+#include "internal/conf.h"
+#include "internal/async.h"
+#include "internal/engine.h"
+#include "internal/comp.h"
+#include "internal/err.h"
+#include "internal/err_int.h"
+#include "internal/objects.h"
 #include <stdlib.h>
 #include <assert.h>
-#include <internal/thread_once.h>
-#include <internal/dso.h>
+#include "internal/thread_once.h"
+#include "internal/dso_conf.h"
+#include "internal/dso.h"
+#include "internal/store.h"
 
 static int stopped = 0;
 
-static void ossl_init_thread_stop(struct thread_local_inits_st *locals);
+/*
+ * Since per-thread-specific-data destructors are not universally
+ * available, i.e. not on Windows, only below CRYPTO_THREAD_LOCAL key
+ * is assumed to have destructor associated. And then an effort is made
+ * to call this single destructor on non-pthread platform[s].
+ *
+ * Initial value is "impossible". It is used as guard value to shortcut
+ * destructor for threads terminating before libcrypto is initialized or
+ * after it's de-initialized. Access to the key doesn't have to be
+ * serialized for the said threads, because they didn't use libcrypto
+ * and it doesn't matter if they pick "impossible" or derefernce real
+ * key value and pull NULL past initialization in the first thread that
+ * intends to use libcrypto.
+ */
+static union {
+    long sane;
+    CRYPTO_THREAD_LOCAL value;
+} destructor_key = { -1 };
 
-static CRYPTO_THREAD_LOCAL threadstopkey;
+static void ossl_init_thread_stop(struct thread_local_inits_st *locals);
 
-static void ossl_init_thread_stop_wrap(void *local)
+static void ossl_init_thread_destructor(void *local)
 {
     ossl_init_thread_stop((struct thread_local_inits_st *)local);
 }
@@ -39,14 +59,17 @@ static void ossl_init_thread_stop_wrap(void *local)
 static struct thread_local_inits_st *ossl_init_get_thread_local(int alloc)
 {
     struct thread_local_inits_st *local =
-        CRYPTO_THREAD_get_local(&threadstopkey);
-
-    if (local == NULL && alloc) {
-        local = OPENSSL_zalloc(sizeof *local);
-        CRYPTO_THREAD_set_local(&threadstopkey, local);
-    }
-    if (!alloc) {
-        CRYPTO_THREAD_set_local(&threadstopkey, NULL);
+        CRYPTO_THREAD_get_local(&destructor_key.value);
+
+    if (alloc) {
+        if (local == NULL
+            && (local = OPENSSL_zalloc(sizeof(*local))) != NULL
+            && !CRYPTO_THREAD_set_local(&destructor_key.value, local)) {
+            OPENSSL_free(local);
+            return NULL;
+        }
+    } else {
+        CRYPTO_THREAD_set_local(&destructor_key.value, NULL);
     }
 
     return local;
@@ -65,23 +88,68 @@ static CRYPTO_ONCE base = CRYPTO_ONCE_STATIC_INIT;
 static int base_inited = 0;
 DEFINE_RUN_ONCE_STATIC(ossl_init_base)
 {
+    CRYPTO_THREAD_LOCAL key;
+
 #ifdef OPENSSL_INIT_DEBUG
     fprintf(stderr, "OPENSSL_INIT: ossl_init_base: Setting up stop handlers\n");
 #endif
-    /*
-     * We use a dummy thread local key here. We use the destructor to detect
-     * when the thread is going to stop (where that feature is available)
-     */
-    CRYPTO_THREAD_init_local(&threadstopkey, ossl_init_thread_stop_wrap);
-#ifndef OPENSSL_SYS_UEFI
-    atexit(OPENSSL_cleanup);
+#ifndef OPENSSL_NO_CRYPTO_MDEBUG
+    ossl_malloc_setup_failures();
 #endif
-    if ((init_lock = CRYPTO_THREAD_lock_new()) == NULL)
+    if (!CRYPTO_THREAD_init_local(&key, ossl_init_thread_destructor))
         return 0;
+    if ((init_lock = CRYPTO_THREAD_lock_new()) == NULL)
+        goto err;
     OPENSSL_cpuid_setup();
+
+    destructor_key.value = key;
     base_inited = 1;
+    return 1;
 
-#if !defined(OPENSSL_NO_DSO) && !defined(OPENSSL_USE_NODELETE)
+err:
+#ifdef OPENSSL_INIT_DEBUG
+    fprintf(stderr, "OPENSSL_INIT: ossl_init_base not ok!\n");
+#endif
+    CRYPTO_THREAD_lock_free(init_lock);
+    init_lock = NULL;
+
+    CRYPTO_THREAD_cleanup_local(&key);
+    return 0;
+}
+
+static CRYPTO_ONCE register_atexit = CRYPTO_ONCE_STATIC_INIT;
+DEFINE_RUN_ONCE_STATIC(ossl_init_register_atexit)
+{
+# ifdef OPENSSL_INIT_DEBUG
+    fprintf(stderr, "OPENSSL_INIT: ossl_init_register_atexit()\n");
+# endif
+#ifndef OPENSSL_SYS_UEFI
+    if (atexit(OPENSSL_cleanup) != 0)
+        return 0;
+#endif
+
+    return 1;
+}
+
+DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_no_register_atexit,
+                           ossl_init_register_atexit)
+{
+#ifdef OPENSSL_INIT_DEBUG
+    fprintf(stderr, "OPENSSL_INIT: ossl_init_no_register_atexit ok!\n");
+#endif
+    /* Do nothing in this case */
+    return 1;
+}
+
+static CRYPTO_ONCE load_crypto_nodelete = CRYPTO_ONCE_STATIC_INIT;
+DEFINE_RUN_ONCE_STATIC(ossl_init_load_crypto_nodelete)
+{
+#ifdef OPENSSL_INIT_DEBUG
+    fprintf(stderr, "OPENSSL_INIT: ossl_init_load_crypto_nodelete()\n");
+#endif
+#if !defined(OPENSSL_NO_DSO) \
+    && !defined(OPENSSL_USE_NODELETE) \
+    && !defined(OPENSSL_NO_PINSHARED)
 # ifdef DSO_WIN32
     {
         HMODULE handle = NULL;
@@ -92,18 +160,36 @@ DEFINE_RUN_ONCE_STATIC(ossl_init_base)
                                 | GET_MODULE_HANDLE_EX_FLAG_PIN,
                                 (void *)&base_inited, &handle);
 
+#  ifdef OPENSSL_INIT_DEBUG
+        fprintf(stderr, "OPENSSL_INIT: obtained DSO reference? %s\n",
+                (ret == TRUE ? "No!" : "Yes."));
+#  endif
         return (ret == TRUE) ? 1 : 0;
     }
 # else
     /*
      * Deliberately leak a reference to ourselves. This will force the library
-     * to remain loaded until the atexit() handler is run a process exit.
+     * to remain loaded until the atexit() handler is run at process exit.
      */
     {
-        DSO *dso = NULL;
+        DSO *dso;
+        void *err;
+
+        if (!err_shelve_state(&err))
+            return 0;
 
         dso = DSO_dsobyaddr(&base_inited, DSO_FLAG_NO_UNLOAD_ON_FREE);
+#  ifdef OPENSSL_INIT_DEBUG
+        fprintf(stderr, "OPENSSL_INIT: obtained DSO reference? %s\n",
+                (dso == NULL ? "No!" : "Yes."));
+        /*
+         * In case of No!, it is uncertain our exit()-handlers can still be
+         * called. After dlclose() the whole library might have been unloaded
+         * already.
+         */
+#  endif
         DSO_free(dso);
+        err_unshelve_state(err);
     }
 # endif
 #endif
@@ -113,12 +199,6 @@ DEFINE_RUN_ONCE_STATIC(ossl_init_base)
 
 static CRYPTO_ONCE load_crypto_strings = CRYPTO_ONCE_STATIC_INIT;
 static int load_crypto_strings_inited = 0;
-DEFINE_RUN_ONCE_STATIC(ossl_init_no_load_crypto_strings)
-{
-    /* Do nothing in this case */
-    return 1;
-}
-
 DEFINE_RUN_ONCE_STATIC(ossl_init_load_crypto_strings)
 {
     int ret = 1;
@@ -133,10 +213,17 @@ DEFINE_RUN_ONCE_STATIC(ossl_init_load_crypto_strings)
 # endif
     ret = err_load_crypto_strings_int();
     load_crypto_strings_inited = 1;
-#endif    
+#endif
     return ret;
 }
 
+DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_no_load_crypto_strings,
+                           ossl_init_load_crypto_strings)
+{
+    /* Do nothing in this case */
+    return 1;
+}
+
 static CRYPTO_ONCE add_all_ciphers = CRYPTO_ONCE_STATIC_INIT;
 DEFINE_RUN_ONCE_STATIC(ossl_init_add_all_ciphers)
 {
@@ -154,6 +241,13 @@ DEFINE_RUN_ONCE_STATIC(ossl_init_add_all_ciphers)
     return 1;
 }
 
+DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_no_add_all_ciphers,
+                           ossl_init_add_all_ciphers)
+{
+    /* Do nothing */
+    return 1;
+}
+
 static CRYPTO_ONCE add_all_digests = CRYPTO_ONCE_STATIC_INIT;
 DEFINE_RUN_ONCE_STATIC(ossl_init_add_all_digests)
 {
@@ -171,7 +265,31 @@ DEFINE_RUN_ONCE_STATIC(ossl_init_add_all_digests)
     return 1;
 }
 
-DEFINE_RUN_ONCE_STATIC(ossl_init_no_add_algs)
+DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_no_add_all_digests,
+                           ossl_init_add_all_digests)
+{
+    /* Do nothing */
+    return 1;
+}
+
+static CRYPTO_ONCE add_all_macs = CRYPTO_ONCE_STATIC_INIT;
+DEFINE_RUN_ONCE_STATIC(ossl_init_add_all_macs)
+{
+    /*
+     * OPENSSL_NO_AUTOALGINIT is provided here to prevent at compile time
+     * pulling in all the macs during static linking
+     */
+#ifndef OPENSSL_NO_AUTOALGINIT
+# ifdef OPENSSL_INIT_DEBUG
+    fprintf(stderr, "OPENSSL_INIT: ossl_init_add_all_macs: "
+                    "openssl_add_all_macs_int()\n");
+# endif
+    openssl_add_all_macs_int();
+#endif
+    return 1;
+}
+
+DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_no_add_all_macs, ossl_init_add_all_macs)
 {
     /* Do nothing */
     return 1;
@@ -191,7 +309,7 @@ DEFINE_RUN_ONCE_STATIC(ossl_init_config)
     config_inited = 1;
     return 1;
 }
-DEFINE_RUN_ONCE_STATIC(ossl_init_no_config)
+DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_no_config, ossl_init_config)
 {
 #ifdef OPENSSL_INIT_DEBUG
     fprintf(stderr,
@@ -226,16 +344,15 @@ DEFINE_RUN_ONCE_STATIC(ossl_init_engine_openssl)
     engine_load_openssl_int();
     return 1;
 }
-# if !defined(OPENSSL_NO_HW) && \
-    (defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__DragonFly__) || defined(HAVE_CRYPTODEV))
-static CRYPTO_ONCE engine_cryptodev = CRYPTO_ONCE_STATIC_INIT;
-DEFINE_RUN_ONCE_STATIC(ossl_init_engine_cryptodev)
+# ifndef OPENSSL_NO_DEVCRYPTOENG
+static CRYPTO_ONCE engine_devcrypto = CRYPTO_ONCE_STATIC_INIT;
+DEFINE_RUN_ONCE_STATIC(ossl_init_engine_devcrypto)
 {
 #  ifdef OPENSSL_INIT_DEBUG
-    fprintf(stderr, "OPENSSL_INIT: ossl_init_engine_cryptodev: "
-                    "engine_load_cryptodev_int()\n");
+    fprintf(stderr, "OPENSSL_INIT: ossl_init_engine_devcrypto: "
+                    "engine_load_devcrypto_int()\n");
 #  endif
-    engine_load_cryptodev_int();
+    engine_load_devcrypto_int();
     return 1;
 }
 # endif
@@ -323,9 +440,9 @@ static void ossl_init_thread_stop(struct thread_local_inits_st *locals)
     if (locals->async) {
 #ifdef OPENSSL_INIT_DEBUG
         fprintf(stderr, "OPENSSL_INIT: ossl_init_thread_stop: "
-                        "ASYNC_cleanup_thread()\n");
+                        "async_delete_thread_state()\n");
 #endif
-        ASYNC_cleanup_thread();
+        async_delete_thread_state();
     }
 
     if (locals->err_state) {
@@ -336,18 +453,31 @@ static void ossl_init_thread_stop(struct thread_local_inits_st *locals)
         err_delete_thread_state();
     }
 
+    if (locals->rand) {
+#ifdef OPENSSL_INIT_DEBUG
+        fprintf(stderr, "OPENSSL_INIT: ossl_init_thread_stop: "
+                        "drbg_delete_thread_state()\n");
+#endif
+        drbg_delete_thread_state();
+    }
+
     OPENSSL_free(locals);
 }
 
 void OPENSSL_thread_stop(void)
 {
-    ossl_init_thread_stop(
-        (struct thread_local_inits_st *)ossl_init_get_thread_local(0));
+    if (destructor_key.sane != -1)
+        ossl_init_thread_stop(ossl_init_get_thread_local(0));
 }
 
 int ossl_init_thread_start(uint64_t opts)
 {
-    struct thread_local_inits_st *locals = ossl_init_get_thread_local(1);
+    struct thread_local_inits_st *locals;
+
+    if (!OPENSSL_init_crypto(0, NULL))
+        return 0;
+
+    locals = ossl_init_get_thread_local(1);
 
     if (locals == NULL)
         return 0;
@@ -368,12 +498,21 @@ int ossl_init_thread_start(uint64_t opts)
         locals->err_state = 1;
     }
 
+    if (opts & OPENSSL_INIT_THREAD_RAND) {
+#ifdef OPENSSL_INIT_DEBUG
+        fprintf(stderr, "OPENSSL_INIT: ossl_init_thread_start: "
+                        "marking thread for rand\n");
+#endif
+        locals->rand = 1;
+    }
+
     return 1;
 }
 
 void OPENSSL_cleanup(void)
 {
     OPENSSL_INIT_STOP *currhandler, *lasthandler;
+    CRYPTO_THREAD_LOCAL key;
 
     /* If we've not been inited then no need to deinit */
     if (!base_inited)
@@ -400,6 +539,7 @@ void OPENSSL_cleanup(void)
     stop_handlers = NULL;
 
     CRYPTO_THREAD_lock_free(init_lock);
+    init_lock = NULL;
 
     /*
      * We assume we are single-threaded for this function, i.e. no race
@@ -432,7 +572,9 @@ void OPENSSL_cleanup(void)
         err_free_strings_int();
     }
 
-    CRYPTO_THREAD_cleanup_local(&threadstopkey);
+    key = destructor_key.value;
+    destructor_key.sane = -1;
+    CRYPTO_THREAD_cleanup_local(&key);
 
 #ifdef OPENSSL_INIT_DEBUG
     fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: "
@@ -468,16 +610,20 @@ void OPENSSL_cleanup(void)
      * obj_cleanup_int() must be called last
      */
     rand_cleanup_int();
+    rand_drbg_cleanup_int();
     conf_modules_free_int();
 #ifndef OPENSSL_NO_ENGINE
     engine_cleanup_int();
 #endif
+    ossl_store_cleanup_int();
     crypto_cleanup_all_ex_data_int();
     bio_cleanup();
     evp_cleanup_int();
     obj_cleanup_int();
     err_cleanup();
 
+    CRYPTO_secure_malloc_done();
+
     base_inited = 0;
 }
 
@@ -488,27 +634,32 @@ void OPENSSL_cleanup(void)
  */
 int OPENSSL_init_crypto(uint64_t opts, const OPENSSL_INIT_SETTINGS *settings)
 {
-    static int stoperrset = 0;
-
     if (stopped) {
-        if (!stoperrset) {
-            /*
-             * We only ever set this once to avoid getting into an infinite
-             * loop where the error system keeps trying to init and fails so
-             * sets an error etc
-             */
-            stoperrset = 1;
+        if (!(opts & OPENSSL_INIT_BASE_ONLY))
             CRYPTOerr(CRYPTO_F_OPENSSL_INIT_CRYPTO, ERR_R_INIT_FAIL);
-        }
         return 0;
     }
 
-    if (!base_inited && !RUN_ONCE(&base, ossl_init_base))
+    if (!RUN_ONCE(&base, ossl_init_base))
+        return 0;
+
+    if ((opts & OPENSSL_INIT_NO_ATEXIT) != 0) {
+        if (!RUN_ONCE_ALT(&register_atexit, ossl_init_no_register_atexit,
+                          ossl_init_register_atexit))
+            return 0;
+    } else if (!RUN_ONCE(&register_atexit, ossl_init_register_atexit)) {
+        return 0;
+    }
+
+    if (!(opts & OPENSSL_INIT_BASE_ONLY)
+            && !RUN_ONCE(&load_crypto_nodelete,
+                         ossl_init_load_crypto_nodelete))
         return 0;
 
     if ((opts & OPENSSL_INIT_NO_LOAD_CRYPTO_STRINGS)
-            && !RUN_ONCE(&load_crypto_strings,
-                         ossl_init_no_load_crypto_strings))
+            && !RUN_ONCE_ALT(&load_crypto_strings,
+                             ossl_init_no_load_crypto_strings,
+                             ossl_init_load_crypto_strings))
         return 0;
 
     if ((opts & OPENSSL_INIT_LOAD_CRYPTO_STRINGS)
@@ -516,7 +667,8 @@ int OPENSSL_init_crypto(uint64_t opts, const OPENSSL_INIT_SETTINGS *settings)
         return 0;
 
     if ((opts & OPENSSL_INIT_NO_ADD_ALL_CIPHERS)
-            && !RUN_ONCE(&add_all_ciphers, ossl_init_no_add_algs))
+            && !RUN_ONCE_ALT(&add_all_ciphers, ossl_init_no_add_all_ciphers,
+                             ossl_init_add_all_ciphers))
         return 0;
 
     if ((opts & OPENSSL_INIT_ADD_ALL_CIPHERS)
@@ -524,15 +676,29 @@ int OPENSSL_init_crypto(uint64_t opts, const OPENSSL_INIT_SETTINGS *settings)
         return 0;
 
     if ((opts & OPENSSL_INIT_NO_ADD_ALL_DIGESTS)
-            && !RUN_ONCE(&add_all_digests, ossl_init_no_add_algs))
+            && !RUN_ONCE_ALT(&add_all_digests, ossl_init_no_add_all_digests,
+                             ossl_init_add_all_digests))
         return 0;
 
     if ((opts & OPENSSL_INIT_ADD_ALL_DIGESTS)
             && !RUN_ONCE(&add_all_digests, ossl_init_add_all_digests))
         return 0;
 
+    if ((opts & OPENSSL_INIT_NO_ADD_ALL_MACS)
+            && !RUN_ONCE_ALT(&add_all_macs, ossl_init_no_add_all_macs,
+                             ossl_init_add_all_macs))
+        return 0;
+
+    if ((opts & OPENSSL_INIT_ADD_ALL_MACS)
+            && !RUN_ONCE(&add_all_macs, ossl_init_add_all_macs))
+        return 0;
+
+    if ((opts & OPENSSL_INIT_ATFORK)
+            && !openssl_init_fork_handlers())
+        return 0;
+
     if ((opts & OPENSSL_INIT_NO_LOAD_CONFIG)
-            && !RUN_ONCE(&config, ossl_init_no_config))
+            && !RUN_ONCE_ALT(&config, ossl_init_no_config, ossl_init_config))
         return 0;
 
     if (opts & OPENSSL_INIT_LOAD_CONFIG) {
@@ -553,10 +719,9 @@ int OPENSSL_init_crypto(uint64_t opts, const OPENSSL_INIT_SETTINGS *settings)
     if ((opts & OPENSSL_INIT_ENGINE_OPENSSL)
             && !RUN_ONCE(&engine_openssl, ossl_init_engine_openssl))
         return 0;
-# if !defined(OPENSSL_NO_HW) && \
-    (defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__DragonFly__) || defined(HAVE_CRYPTODEV))
+# if !defined(OPENSSL_NO_HW) && !defined(OPENSSL_NO_DEVCRYPTOENG)
     if ((opts & OPENSSL_INIT_ENGINE_CRYPTODEV)
-            && !RUN_ONCE(&engine_cryptodev, ossl_init_engine_cryptodev))
+            && !RUN_ONCE(&engine_devcrypto, ossl_init_engine_devcrypto))
         return 0;
 # endif
 # ifndef OPENSSL_NO_RDRAND
@@ -604,7 +769,9 @@ int OPENSSL_atexit(void (*handler)(void))
 {
     OPENSSL_INIT_STOP *newhand;
 
-#if !defined(OPENSSL_NO_DSO) && !defined(OPENSSL_USE_NODELETE)
+#if !defined(OPENSSL_NO_DSO) \
+    && !defined(OPENSSL_USE_NODELETE)\
+    && !defined(OPENSSL_NO_PINSHARED)
     {
         union {
             void *sym;
@@ -633,21 +800,30 @@ int OPENSSL_atexit(void (*handler)(void))
          * Deliberately leak a reference to the handler. This will force the
          * library/code containing the handler to remain loaded until we run the
          * atexit handler. If -znodelete has been used then this is
-         * unneccessary.
+         * unnecessary.
          */
         {
             DSO *dso = NULL;
 
+            ERR_set_mark();
             dso = DSO_dsobyaddr(handlersym.sym, DSO_FLAG_NO_UNLOAD_ON_FREE);
+#  ifdef OPENSSL_INIT_DEBUG
+            fprintf(stderr,
+                    "OPENSSL_INIT: OPENSSL_atexit: obtained DSO reference? %s\n",
+                    (dso == NULL ? "No!" : "Yes."));
+            /* See same code above in ossl_init_base() for an explanation. */
+#  endif
             DSO_free(dso);
+            ERR_pop_to_mark();
         }
 # endif
     }
 #endif
 
-    newhand = OPENSSL_malloc(sizeof(*newhand));
-    if (newhand == NULL)
+    if ((newhand = OPENSSL_malloc(sizeof(*newhand))) == NULL) {
+        CRYPTOerr(CRYPTO_F_OPENSSL_ATEXIT, ERR_R_MALLOC_FAILURE);
         return 0;
+    }
 
     newhand->handler = handler;
     newhand->next = stop_handlers;
@@ -655,3 +831,29 @@ int OPENSSL_atexit(void (*handler)(void))
 
     return 1;
 }
+
+#ifdef OPENSSL_SYS_UNIX
+/*
+ * The following three functions are for OpenSSL developers.  This is
+ * where we set/reset state across fork (called via pthread_atfork when
+ * it exists, or manually by the application when it doesn't).
+ *
+ * WARNING!  If you put code in either OPENSSL_fork_parent or
+ * OPENSSL_fork_child, you MUST MAKE SURE that they are async-signal-
+ * safe.  See this link, for example:
+ *      http://man7.org/linux/man-pages/man7/signal-safety.7.html
+ */
+
+void OPENSSL_fork_prepare(void)
+{
+}
+
+void OPENSSL_fork_parent(void)
+{
+}
+
+void OPENSSL_fork_child(void)
+{
+    rand_fork();
+}
+#endif