/*

 * Copyright 2016-2022 The OpenSSL Project Authors. All Rights Reserved.

 *

 * 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

 */

/* We need to use some engine deprecated APIs */

#define OPENSSL_SUPPRESS_DEPRECATED

#include "internal/e_os.h"

#include "crypto/cryptlib.h"

#include <openssl/err.h>

#include "crypto/rand.h"

#include "internal/bio.h"

#include <openssl/evp.h>

#include "crypto/evp.h"

#include "internal/conf.h"

#include "crypto/async.h"

#include "crypto/engine.h"

#include "internal/comp.h"

#include "internal/err.h"

#include "crypto/err.h"

#include "crypto/objects.h"

#include <stdlib.h>

#include <assert.h>

#include "internal/thread_once.h"

#include "crypto/dso_conf.h"

#include "internal/dso.h"

#include "crypto/store.h"

#include <openssl/cmp_util.h> /* for OSSL_CMP_log_close() */

#include <openssl/trace.h>

#include "crypto/ctype.h"

static int stopped = 0;

static uint64_t optsdone = 0;

typedef struct ossl_init_stop_st OPENSSL_INIT_STOP;

struct ossl_init_stop_st {

    void (*handler)(void);

    OPENSSL_INIT_STOP *next;

};

static OPENSSL_INIT_STOP *stop_handlers = NULL;

/* Guards access to the optsdone variable on platforms without atomics */

static CRYPTO_RWLOCK *optsdone_lock = NULL;

/* Guards simultaneous INIT_LOAD_CONFIG calls with non-NULL settings */

static CRYPTO_RWLOCK *init_lock = NULL;

static CRYPTO_THREAD_LOCAL in_init_config_local;

static CRYPTO_ONCE base = CRYPTO_ONCE_STATIC_INIT;

static int base_inited = 0;

DEFINE_RUN_ONCE_STATIC(ossl_init_base)

{

    /* no need to init trace */

    OSSL_TRACE(INIT, "ossl_init_base: setting up stop handlers\n");

#ifndef OPENSSL_NO_CRYPTO_MDEBUG

    ossl_malloc_setup_failures();

#endif

    if ((optsdone_lock = CRYPTO_THREAD_lock_new()) == NULL

        || (init_lock = CRYPTO_THREAD_lock_new()) == NULL)

        goto err;

    OPENSSL_cpuid_setup();

    if (!ossl_init_thread())

        goto err;

    if (!CRYPTO_THREAD_init_local(&in_init_config_local, NULL))

        goto err;

    base_inited = 1;

    return 1;

err:

    OSSL_TRACE(INIT, "ossl_init_base failed!\n");

    CRYPTO_THREAD_lock_free(optsdone_lock);

    optsdone_lock = NULL;

    CRYPTO_THREAD_lock_free(init_lock);

    init_lock = NULL;

    return 0;

}

static CRYPTO_ONCE register_atexit = CRYPTO_ONCE_STATIC_INIT;

#if !defined(OPENSSL_SYS_UEFI) && defined(_WIN32)

static int win32atexit(void)

{

    OPENSSL_cleanup();

    return 0;

}

#endif

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 defined(_WIN32) && !defined(__BORLANDC__)

    /* We use _onexit() in preference because it gets called on DLL unload */

    if (_onexit(win32atexit) == NULL)

        return 0;

# else

    if (atexit(OPENSSL_cleanup) != 0)

        return 0;

# endif

#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)

{

    OSSL_TRACE(INIT, "ossl_init_load_crypto_nodelete()\n");

#if !defined(OPENSSL_USE_NODELETE) \

    && !defined(OPENSSL_NO_PINSHARED)

# if defined(DSO_WIN32) && !defined(_WIN32_WCE)

    {

        HMODULE handle = NULL;

        BOOL ret;

        /* We don't use the DSO route for WIN32 because there is a better way */

        ret = GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS

                                | GET_MODULE_HANDLE_EX_FLAG_PIN,

                                (void *)&base_inited, &handle);

        OSSL_TRACE1(INIT,

                    "ossl_init_load_crypto_nodelete: "

                    "obtained DSO reference? %s\n",

                    (ret == TRUE ? "No!" : "Yes."));

        return (ret == TRUE) ? 1 : 0;

    }

# elif !defined(DSO_NONE)

    /*

     * Deliberately leak a reference to ourselves. This will force the library

     * to remain loaded until the atexit() handler is run at process exit.

     */

    {

        DSO *dso;

        void *err;

        if (!err_shelve_state(&err))

            return 0;

        dso = DSO_dsobyaddr(&base_inited, DSO_FLAG_NO_UNLOAD_ON_FREE);

        /*

         * In case of No!, it is uncertain our exit()-handlers can still be

         * called. After dlclose() the whole library might have been unloaded

         * already.

         */

        OSSL_TRACE1(INIT, "obtained DSO reference? %s\n",

                    (dso == NULL ? "No!" : "Yes."));

        DSO_free(dso);

        err_unshelve_state(err);

    }

# endif

#endif

    return 1;

}

static CRYPTO_ONCE load_crypto_strings = CRYPTO_ONCE_STATIC_INIT;

DEFINE_RUN_ONCE_STATIC(ossl_init_load_crypto_strings)

{

    int ret = 1;

    /*

     * OPENSSL_NO_AUTOERRINIT is provided here to prevent at compile time

     * pulling in all the error strings during static linking

     */

#if !defined(OPENSSL_NO_ERR) && !defined(OPENSSL_NO_AUTOERRINIT)

    OSSL_TRACE(INIT, "ossl_err_load_crypto_strings()\n");

    ret = ossl_err_load_crypto_strings();

#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)

{

    /*

     * OPENSSL_NO_AUTOALGINIT is provided here to prevent at compile time

     * pulling in all the ciphers during static linking

     */

#ifndef OPENSSL_NO_AUTOALGINIT

    OSSL_TRACE(INIT, "openssl_add_all_ciphers_int()\n");

    openssl_add_all_ciphers_int();

#endif

    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)

{

    /*

     * OPENSSL_NO_AUTOALGINIT is provided here to prevent at compile time

     * pulling in all the ciphers during static linking

     */

#ifndef OPENSSL_NO_AUTOALGINIT

    OSSL_TRACE(INIT, "openssl_add_all_digests()\n");

    openssl_add_all_digests_int();

#endif

    return 1;

}

DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_no_add_all_digests,

                           ossl_init_add_all_digests)

{

    /* Do nothing */

    return 1;

}

static CRYPTO_ONCE config = CRYPTO_ONCE_STATIC_INIT;

static int config_inited = 0;

static const OPENSSL_INIT_SETTINGS *conf_settings = NULL;

DEFINE_RUN_ONCE_STATIC(ossl_init_config)

{

    int ret = ossl_config_int(NULL);

    config_inited = 1;

    return ret;

}

DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_config_settings, ossl_init_config)

{

    int ret = ossl_config_int(conf_settings);

    config_inited = 1;

    return ret;

}

DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_no_config, ossl_init_config)

{

    OSSL_TRACE(INIT, "ossl_no_config_int()\n");

    ossl_no_config_int();

    config_inited = 1;

    return 1;

}

static CRYPTO_ONCE async = CRYPTO_ONCE_STATIC_INIT;

static int async_inited = 0;

DEFINE_RUN_ONCE_STATIC(ossl_init_async)

{

    OSSL_TRACE(INIT, "async_init()\n");

    if (!async_init())

        return 0;

    async_inited = 1;

    return 1;

}

#ifndef OPENSSL_NO_ENGINE

static CRYPTO_ONCE engine_openssl = CRYPTO_ONCE_STATIC_INIT;

DEFINE_RUN_ONCE_STATIC(ossl_init_engine_openssl)

{

    OSSL_TRACE(INIT, "engine_load_openssl_int()\n");

    engine_load_openssl_int();

    return 1;

}

# ifndef OPENSSL_NO_RDRAND

static CRYPTO_ONCE engine_rdrand = CRYPTO_ONCE_STATIC_INIT;

DEFINE_RUN_ONCE_STATIC(ossl_init_engine_rdrand)

{

    OSSL_TRACE(INIT, "engine_load_rdrand_int()\n");

    engine_load_rdrand_int();

    return 1;

}

# endif

static CRYPTO_ONCE engine_dynamic = CRYPTO_ONCE_STATIC_INIT;

DEFINE_RUN_ONCE_STATIC(ossl_init_engine_dynamic)

{

    OSSL_TRACE(INIT, "engine_load_dynamic_int()\n");

    engine_load_dynamic_int();

    return 1;

}

# ifndef OPENSSL_NO_STATIC_ENGINE

#  ifndef OPENSSL_NO_DEVCRYPTOENG

static CRYPTO_ONCE engine_devcrypto = CRYPTO_ONCE_STATIC_INIT;

DEFINE_RUN_ONCE_STATIC(ossl_init_engine_devcrypto)

{

    OSSL_TRACE(INIT, "engine_load_devcrypto_int()\n");

    engine_load_devcrypto_int();

    return 1;

}

#  endif

#  if !defined(OPENSSL_NO_PADLOCKENG)

static CRYPTO_ONCE engine_padlock = CRYPTO_ONCE_STATIC_INIT;

DEFINE_RUN_ONCE_STATIC(ossl_init_engine_padlock)

{

    OSSL_TRACE(INIT, "engine_load_padlock_int()\n");

    engine_load_padlock_int();

    return 1;

}

#  endif

#  if defined(OPENSSL_SYS_WIN32) && !defined(OPENSSL_NO_CAPIENG)

static CRYPTO_ONCE engine_capi = CRYPTO_ONCE_STATIC_INIT;

DEFINE_RUN_ONCE_STATIC(ossl_init_engine_capi)

{

    OSSL_TRACE(INIT, "engine_load_capi_int()\n");

    engine_load_capi_int();

    return 1;

}

#  endif

#  if !defined(OPENSSL_NO_AFALGENG)

static CRYPTO_ONCE engine_afalg = CRYPTO_ONCE_STATIC_INIT;

DEFINE_RUN_ONCE_STATIC(ossl_init_engine_afalg)

{

    OSSL_TRACE(INIT, "engine_load_afalg_int()\n");

    engine_load_afalg_int();

    return 1;

}

#  endif

# endif

#endif

void OPENSSL_cleanup(void)

{

    OPENSSL_INIT_STOP *currhandler, *lasthandler;

    /*

     * At some point we should consider looking at this function with a view to

     * moving most/all of this into onfree handlers in OSSL_LIB_CTX.

     */

    /* If we've not been inited then no need to deinit */

    if (!base_inited)

        return;

    /* Might be explicitly called and also by atexit */

    if (stopped)

        return;

    stopped = 1;

    /*

     * Thread stop may not get automatically called by the thread library for

     * the very last thread in some situations, so call it directly.

     */

    OPENSSL_thread_stop();

    currhandler = stop_handlers;

    while (currhandler != NULL) {

        currhandler->handler();

        lasthandler = currhandler;

        currhandler = currhandler->next;

        OPENSSL_free(lasthandler);

    }

    stop_handlers = NULL;

    CRYPTO_THREAD_lock_free(optsdone_lock);

    optsdone_lock = NULL;

    CRYPTO_THREAD_lock_free(init_lock);

    init_lock = NULL;

    CRYPTO_THREAD_cleanup_local(&in_init_config_local);

    /*

     * We assume we are single-threaded for this function, i.e. no race

     * conditions for the various "*_inited" vars below.

     */

#ifndef OPENSSL_NO_COMP

    OSSL_TRACE(INIT, "OPENSSL_cleanup: ossl_comp_zlib_cleanup()\n");

    ossl_comp_zlib_cleanup();

    OSSL_TRACE(INIT, "OPENSSL_cleanup: ossl_comp_brotli_cleanup()\n");

    ossl_comp_brotli_cleanup();

    OSSL_TRACE(INIT, "OPENSSL_cleanup: ossl_comp_zstd_cleanup()\n");

    ossl_comp_zstd_cleanup();

#endif

    if (async_inited) {

        OSSL_TRACE(INIT, "OPENSSL_cleanup: async_deinit()\n");

        async_deinit();

    }

    /*

     * Note that cleanup order is important:

     * - ossl_rand_cleanup_int could call an ENGINE's RAND cleanup function so

     * must be called before engine_cleanup_int()

     * - ENGINEs use CRYPTO_EX_DATA and therefore, must be cleaned up

     * before the ex data handlers are wiped during default ossl_lib_ctx deinit.

     * - ossl_config_modules_free() can end up in ENGINE code so must be called

     * before engine_cleanup_int()

     * - ENGINEs and additional EVP algorithms might use added OIDs names so

     * ossl_obj_cleanup_int() must be called last

     */

    OSSL_TRACE(INIT, "OPENSSL_cleanup: ossl_rand_cleanup_int()\n");

    ossl_rand_cleanup_int();

    OSSL_TRACE(INIT, "OPENSSL_cleanup: ossl_config_modules_free()\n");

    ossl_config_modules_free();

#ifndef OPENSSL_NO_ENGINE

    OSSL_TRACE(INIT, "OPENSSL_cleanup: engine_cleanup_int()\n");

    engine_cleanup_int();

#endif

#ifndef OPENSSL_NO_DEPRECATED_3_0

    OSSL_TRACE(INIT, "OPENSSL_cleanup: ossl_store_cleanup_int()\n");

    ossl_store_cleanup_int();

#endif

    OSSL_TRACE(INIT, "OPENSSL_cleanup: ossl_lib_ctx_default_deinit()\n");

    ossl_lib_ctx_default_deinit();

    ossl_cleanup_thread();

    OSSL_TRACE(INIT, "OPENSSL_cleanup: bio_cleanup()\n");

    bio_cleanup();

    OSSL_TRACE(INIT, "OPENSSL_cleanup: evp_cleanup_int()\n");

    evp_cleanup_int();

    OSSL_TRACE(INIT, "OPENSSL_cleanup: ossl_obj_cleanup_int()\n");

    ossl_obj_cleanup_int();

    OSSL_TRACE(INIT, "OPENSSL_cleanup: err_int()\n");

    err_cleanup();

    OSSL_TRACE(INIT, "OPENSSL_cleanup: CRYPTO_secure_malloc_done()\n");

    CRYPTO_secure_malloc_done();

#ifndef OPENSSL_NO_CMP

    OSSL_TRACE(INIT, "OPENSSL_cleanup: OSSL_CMP_log_close()\n");

    OSSL_CMP_log_close();

#endif

    OSSL_TRACE(INIT, "OPENSSL_cleanup: ossl_trace_cleanup()\n");

    ossl_trace_cleanup();

    base_inited = 0;

}

/*

 * If this function is called with a non NULL settings value then it must be

 * called prior to any threads making calls to any OpenSSL functions,

 * i.e. passing a non-null settings value is assumed to be single-threaded.

 */

int OPENSSL_init_crypto(uint64_t opts, const OPENSSL_INIT_SETTINGS *settings)

{

    uint64_t tmp;

    int aloaddone = 0;

   /* Applications depend on 0 being returned when cleanup was already done */

    if (stopped) {

        if (!(opts & OPENSSL_INIT_BASE_ONLY))

            ERR_raise(ERR_LIB_CRYPTO, ERR_R_INIT_FAIL);

        return 0;

    }

    /*

     * We ignore failures from this function. It is probably because we are

     * on a platform that doesn't support lockless atomic loads (we may not

     * have created optsdone_lock yet so we can't use it). This is just an

     * optimisation to skip the full checks in this function if we don't need

     * to, so we carry on regardless in the event of failure.

     *

     * There could be a race here with other threads, so that optsdone has not

     * been updated yet, even though the options have in fact been initialised.

     * This doesn't matter - it just means we will run the full function

     * unnecessarily - but all the critical code is contained in RUN_ONCE

     * functions anyway so we are safe.

     */

    if (CRYPTO_atomic_load(&optsdone, &tmp, NULL)) {

        if ((tmp & opts) == opts)

            return 1;

        aloaddone = 1;

    }

    /*

     * At some point we should look at this function with a view to moving

     * most/all of this into OSSL_LIB_CTX.

     *

     * When the caller specifies OPENSSL_INIT_BASE_ONLY, that should be the

     * *only* option specified.  With that option we return immediately after

     * doing the requested limited initialization.  Note that

     * err_shelve_state() called by us via ossl_init_load_crypto_nodelete()

     * re-enters OPENSSL_init_crypto() with OPENSSL_INIT_BASE_ONLY, but with

     * base already initialized this is a harmless NOOP.

     *

     * If we remain the only caller of err_shelve_state() the recursion should

     * perhaps be removed, but if in doubt, it can be left in place.

     */

    if (!RUN_ONCE(&base, ossl_init_base))

        return 0;

    if (opts & OPENSSL_INIT_BASE_ONLY)

        return 1;

    /*

     * optsdone_lock should definitely be set up now, so we can now repeat the

     * same check from above but be sure that it will work even on platforms

     * without lockless CRYPTO_atomic_load

     */

    if (!aloaddone) {

        if (!CRYPTO_atomic_load(&optsdone, &tmp, optsdone_lock))

            return 0;

        if ((tmp & opts) == opts)

            return 1;

    }

    /*

     * Now we don't always set up exit handlers, the INIT_BASE_ONLY calls

     * should not have the side-effect of setting up exit handlers, and

     * therefore, this code block is below the INIT_BASE_ONLY-conditioned early

     * return above.

     */

    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 (!RUN_ONCE(&load_crypto_nodelete, ossl_init_load_crypto_nodelete))

        return 0;

    if ((opts & OPENSSL_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)

            && !RUN_ONCE(&load_crypto_strings, ossl_init_load_crypto_strings))

        return 0;

    if ((opts & OPENSSL_INIT_NO_ADD_ALL_CIPHERS)

            && !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)

            && !RUN_ONCE(&add_all_ciphers, ossl_init_add_all_ciphers))

        return 0;

    if ((opts & OPENSSL_INIT_NO_ADD_ALL_DIGESTS)

            && !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_ATFORK)

            && !openssl_init_fork_handlers())

        return 0;

    if ((opts & OPENSSL_INIT_NO_LOAD_CONFIG)

            && !RUN_ONCE_ALT(&config, ossl_init_no_config, ossl_init_config))

        return 0;

    if (opts & OPENSSL_INIT_LOAD_CONFIG) {

        int loading = CRYPTO_THREAD_get_local(&in_init_config_local) != NULL;

        /* If called recursively from OBJ_ calls, just skip it. */

        if (!loading) {

            int ret;

            if (!CRYPTO_THREAD_set_local(&in_init_config_local, (void *)-1))

                return 0;

            if (settings == NULL) {

                ret = RUN_ONCE(&config, ossl_init_config);

            } else {

                if (!CRYPTO_THREAD_write_lock(init_lock))

                    return 0;

                conf_settings = settings;

                ret = RUN_ONCE_ALT(&config, ossl_init_config_settings,

                                   ossl_init_config);

                conf_settings = NULL;

                CRYPTO_THREAD_unlock(init_lock);

            }

            if (ret <= 0)

                return 0;

        }

    }

    if ((opts & OPENSSL_INIT_ASYNC)

            && !RUN_ONCE(&async, ossl_init_async))

        return 0;

#ifndef OPENSSL_NO_ENGINE

    if ((opts & OPENSSL_INIT_ENGINE_OPENSSL)

            && !RUN_ONCE(&engine_openssl, ossl_init_engine_openssl))

        return 0;

# ifndef OPENSSL_NO_RDRAND

    if ((opts & OPENSSL_INIT_ENGINE_RDRAND)

            && !RUN_ONCE(&engine_rdrand, ossl_init_engine_rdrand))

        return 0;

# endif

    if ((opts & OPENSSL_INIT_ENGINE_DYNAMIC)

            && !RUN_ONCE(&engine_dynamic, ossl_init_engine_dynamic))

        return 0;

# ifndef OPENSSL_NO_STATIC_ENGINE

#  ifndef OPENSSL_NO_DEVCRYPTOENG

    if ((opts & OPENSSL_INIT_ENGINE_CRYPTODEV)

            && !RUN_ONCE(&engine_devcrypto, ossl_init_engine_devcrypto))

        return 0;

#  endif

#  if !defined(OPENSSL_NO_PADLOCKENG)

    if ((opts & OPENSSL_INIT_ENGINE_PADLOCK)

            && !RUN_ONCE(&engine_padlock, ossl_init_engine_padlock))

        return 0;

#  endif

#  if defined(OPENSSL_SYS_WIN32) && !defined(OPENSSL_NO_CAPIENG)

    if ((opts & OPENSSL_INIT_ENGINE_CAPI)

            && !RUN_ONCE(&engine_capi, ossl_init_engine_capi))

        return 0;

#  endif

#  if !defined(OPENSSL_NO_AFALGENG)

    if ((opts & OPENSSL_INIT_ENGINE_AFALG)

            && !RUN_ONCE(&engine_afalg, ossl_init_engine_afalg))

        return 0;

#  endif

# endif

    if (opts & (OPENSSL_INIT_ENGINE_ALL_BUILTIN

                | OPENSSL_INIT_ENGINE_OPENSSL

                | OPENSSL_INIT_ENGINE_AFALG)) {

        ENGINE_register_all_complete();

    }

#endif

    if (!CRYPTO_atomic_or(&optsdone, opts, &tmp, optsdone_lock))

        return 0;

    return 1;

}

int OPENSSL_atexit(void (*handler)(void))

{

    OPENSSL_INIT_STOP *newhand;

#if !defined(OPENSSL_USE_NODELETE)\

    && !defined(OPENSSL_NO_PINSHARED)

    {

# if defined(DSO_WIN32) && !defined(_WIN32_WCE)

        HMODULE handle = NULL;

        BOOL ret;

        union {

            void *sym;

            void (*func)(void);

        } handlersym;

        handlersym.func = handler;

        /*

         * We don't use the DSO route for WIN32 because there is a better

         * way

         */

        ret = GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS

                                | GET_MODULE_HANDLE_EX_FLAG_PIN,

                                handlersym.sym, &handle);

        if (!ret)

            return 0;

# elif !defined(DSO_NONE)

        /*

         * 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

         * unnecessary.

         */

        DSO *dso = NULL;

        union {

            void *sym;

            void (*func)(void);

        } handlersym;

        handlersym.func = handler;

        ERR_set_mark();

        dso = DSO_dsobyaddr(handlersym.sym, DSO_FLAG_NO_UNLOAD_ON_FREE);

        /* See same code above in ossl_init_base() for an explanation. */

        OSSL_TRACE1(INIT,

                   "atexit: obtained DSO reference? %s\n",

                   (dso == NULL ? "No!" : "Yes."));

        DSO_free(dso);

        ERR_pop_to_mark();

# endif

    }

#endif

    if ((newhand = OPENSSL_malloc(sizeof(*newhand))) == NULL)

        return 0;

    newhand->handler = handler;

    newhand->next = stop_handlers;

    stop_handlers = newhand;

    return 1;

}