openssl/crypto/init.c
Randall S. Becker 99fb31c167 Add atexit configuration option to using atexit() in libcrypto at build-time.
This fixes an issue with a mix of atexit() usage in DLL and statically linked
libcrypto that came out in the test suite on NonStop, which has slightly
different DLL unload processing semantics compared to Linux. The change
allows a build configuration to select whether to register OPENSSL_cleanup()
with atexit() or not, so avoid situations where atexit() registration causes
SIGSEGV.

INSTALL.md and CHANGES.md have been modified to include and describe this
option.

The no-atexit option has been added to .github/workflows/run-checker-daily.yml.

Fixes: #23135

Signed-of-by: Randall S. Becker <randall.becker@nexbridge.ca>

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Todd Short <todd.short@me.com>
(Merged from https://github.com/openssl/openssl/pull/23394)
2024-02-01 20:26:42 -05:00

732 lines
21 KiB
C

/*
* Copyright 2016-2023 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)
{
#ifndef OPENSSL_NO_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
#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)
void *err;
if (!err_shelve_state(&err))
return 0;
OSSL_TRACE(INIT, "ossl_err_load_crypto_strings()\n");
ret = ossl_err_load_crypto_strings();
err_unshelve_state(err);
#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;
}