crypto/init.c

   1 /*
   2  * Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include "e_os.h"
  11 #include "internal/cryptlib_int.h"
  12 #include <openssl/err.h>
  13 #include "internal/rand_int.h"
  14 #include "internal/bio.h"
  15 #include <openssl/evp.h>
  16 #include "internal/evp_int.h"
  17 #include "internal/conf.h"
  18 #include "internal/async.h"
  19 #include "internal/engine.h"
  20 #include "internal/comp.h"
  21 #include "internal/err.h"
  22 #include "internal/err_int.h"
  23 #include "internal/objects.h"
  24 #include <stdlib.h>
  25 #include <assert.h>
  26 #include "internal/thread_once.h"
  27 #include "internal/dso_conf.h"
  28 #include "internal/dso.h"
  29 #include "internal/store.h"
  30 #include <openssl/trace.h>
  31
  32 static int stopped = 0;
  33
  34 typedef struct ossl_init_stop_st OPENSSL_INIT_STOP;
  35 struct ossl_init_stop_st {
  36     void (*handler)(void);
  37     OPENSSL_INIT_STOP *next;
  38 };
  39
  40 static OPENSSL_INIT_STOP *stop_handlers = NULL;
  41 static CRYPTO_RWLOCK *init_lock = NULL;
  42
  43 static CRYPTO_ONCE base = CRYPTO_ONCE_STATIC_INIT;
  44 static int base_inited = 0;
  45 DEFINE_RUN_ONCE_STATIC(ossl_init_base)
  46 {
  47     /* no need to init trace */
  48
  49     OSSL_TRACE(INIT, "ossl_init_base: setting up stop handlers\n");
  50 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
  51     ossl_malloc_setup_failures();
  52 #endif
  53
  54     if ((init_lock = CRYPTO_THREAD_lock_new()) == NULL)
  55         goto err;
  56     OPENSSL_cpuid_setup();
  57
  58     if (!ossl_init_thread())
  59         return 0;
  60
  61     base_inited = 1;
  62     return 1;
  63
  64 err:
  65     OSSL_TRACE(INIT, "ossl_init_base failed!\n");
  66     CRYPTO_THREAD_lock_free(init_lock);
  67     init_lock = NULL;
  68
  69     return 0;
  70 }
  71
  72 static CRYPTO_ONCE register_atexit = CRYPTO_ONCE_STATIC_INIT;
  73 #if !defined(OPENSSL_SYS_UEFI) && defined(_WIN32)
  74 static int win32atexit(void)
  75 {
  76     OPENSSL_cleanup();
  77     return 0;
  78 }
  79 #endif
  80
  81 DEFINE_RUN_ONCE_STATIC(ossl_init_register_atexit)
  82 {
  83 #ifdef OPENSSL_INIT_DEBUG
  84     fprintf(stderr, "OPENSSL_INIT: ossl_init_register_atexit()\n");
  85 #endif
  86 #ifndef OPENSSL_SYS_UEFI
  87 # ifdef _WIN32
  88     /* We use _onexit() in preference because it gets called on DLL unload */
  89     if (_onexit(win32atexit) == NULL)
  90         return 0;
  91 # else
  92     if (atexit(OPENSSL_cleanup) != 0)
  93         return 0;
  94 # endif
  95 #endif
  96
  97     return 1;
  98 }
  99
 100 DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_no_register_atexit,
 101                            ossl_init_register_atexit)
 102 {
 103 #ifdef OPENSSL_INIT_DEBUG
 104     fprintf(stderr, "OPENSSL_INIT: ossl_init_no_register_atexit ok!\n");
 105 #endif
 106     /* Do nothing in this case */
 107     return 1;
 108 }
 109
 110 static CRYPTO_ONCE load_crypto_nodelete = CRYPTO_ONCE_STATIC_INIT;
 111 DEFINE_RUN_ONCE_STATIC(ossl_init_load_crypto_nodelete)
 112 {
 113     OSSL_TRACE(INIT, "ossl_init_load_crypto_nodelete()\n");
 114
 115 #if !defined(OPENSSL_USE_NODELETE) \
 116     && !defined(OPENSSL_NO_PINSHARED)
 117 # if defined(DSO_WIN32) && !defined(_WIN32_WCE)
 118     {
 119         HMODULE handle = NULL;
 120         BOOL ret;
 121
 122         /* We don't use the DSO route for WIN32 because there is a better way */
 123         ret = GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS
 124                                 | GET_MODULE_HANDLE_EX_FLAG_PIN,
 125                                 (void *)&base_inited, &handle);
 126
 127         OSSL_TRACE1(INIT,
 128                     "ossl_init_load_crypto_nodelete: "
 129                     "obtained DSO reference? %s\n",
 130                     (ret == TRUE ? "No!" : "Yes."));
 131         return (ret == TRUE) ? 1 : 0;
 132     }
 133 # elif !defined(DSO_NONE)
 134     /*
 135      * Deliberately leak a reference to ourselves. This will force the library
 136      * to remain loaded until the atexit() handler is run at process exit.
 137      */
 138     {
 139         DSO *dso;
 140         void *err;
 141
 142         if (!err_shelve_state(&err))
 143             return 0;
 144
 145         dso = DSO_dsobyaddr(&base_inited, DSO_FLAG_NO_UNLOAD_ON_FREE);
 146         /*
 147          * In case of No!, it is uncertain our exit()-handlers can still be
 148          * called. After dlclose() the whole library might have been unloaded
 149          * already.
 150          */
 151         OSSL_TRACE1(INIT, "obtained DSO reference? %s\n",
 152                     (dso == NULL ? "No!" : "Yes."));
 153         DSO_free(dso);
 154         err_unshelve_state(err);
 155     }
 156 # endif
 157 #endif
 158
 159     return 1;
 160 }
 161
 162 static CRYPTO_ONCE load_crypto_strings = CRYPTO_ONCE_STATIC_INIT;
 163 static int load_crypto_strings_inited = 0;
 164 DEFINE_RUN_ONCE_STATIC(ossl_init_load_crypto_strings)
 165 {
 166     int ret = 1;
 167     /*
 168      * OPENSSL_NO_AUTOERRINIT is provided here to prevent at compile time
 169      * pulling in all the error strings during static linking
 170      */
 171 #if !defined(OPENSSL_NO_ERR) && !defined(OPENSSL_NO_AUTOERRINIT)
 172     OSSL_TRACE(INIT, "err_load_crypto_strings_int()\n");
 173     ret = err_load_crypto_strings_int();
 174     load_crypto_strings_inited = 1;
 175 #endif
 176     return ret;
 177 }
 178
 179 DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_no_load_crypto_strings,
 180                            ossl_init_load_crypto_strings)
 181 {
 182     /* Do nothing in this case */
 183     return 1;
 184 }
 185
 186 static CRYPTO_ONCE add_all_ciphers = CRYPTO_ONCE_STATIC_INIT;
 187 DEFINE_RUN_ONCE_STATIC(ossl_init_add_all_ciphers)
 188 {
 189     /*
 190      * OPENSSL_NO_AUTOALGINIT is provided here to prevent at compile time
 191      * pulling in all the ciphers during static linking
 192      */
 193 #ifndef OPENSSL_NO_AUTOALGINIT
 194     OSSL_TRACE(INIT, "openssl_add_all_ciphers_int()\n");
 195     openssl_add_all_ciphers_int();
 196 #endif
 197     return 1;
 198 }
 199
 200 DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_no_add_all_ciphers,
 201                            ossl_init_add_all_ciphers)
 202 {
 203     /* Do nothing */
 204     return 1;
 205 }
 206
 207 static CRYPTO_ONCE add_all_digests = CRYPTO_ONCE_STATIC_INIT;
 208 DEFINE_RUN_ONCE_STATIC(ossl_init_add_all_digests)
 209 {
 210     /*
 211      * OPENSSL_NO_AUTOALGINIT is provided here to prevent at compile time
 212      * pulling in all the ciphers during static linking
 213      */
 214 #ifndef OPENSSL_NO_AUTOALGINIT
 215     OSSL_TRACE(INIT, "openssl_add_all_digests()\n");
 216     openssl_add_all_digests_int();
 217 #endif
 218     return 1;
 219 }
 220
 221 DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_no_add_all_digests,
 222                            ossl_init_add_all_digests)
 223 {
 224     /* Do nothing */
 225     return 1;
 226 }
 227
 228 static CRYPTO_ONCE config = CRYPTO_ONCE_STATIC_INIT;
 229 static int config_inited = 0;
 230 static const OPENSSL_INIT_SETTINGS *conf_settings = NULL;
 231 DEFINE_RUN_ONCE_STATIC(ossl_init_config)
 232 {
 233     int ret = openssl_config_int(conf_settings);
 234     config_inited = 1;
 235     return ret;
 236 }
 237 DEFINE_RUN_ONCE_STATIC_ALT(ossl_init_no_config, ossl_init_config)
 238 {
 239     OSSL_TRACE(INIT, "openssl_no_config_int()\n");
 240     openssl_no_config_int();
 241     config_inited = 1;
 242     return 1;
 243 }
 244
 245 static CRYPTO_ONCE async = CRYPTO_ONCE_STATIC_INIT;
 246 static int async_inited = 0;
 247 DEFINE_RUN_ONCE_STATIC(ossl_init_async)
 248 {
 249     OSSL_TRACE(INIT, "async_init()\n");
 250     if (!async_init())
 251         return 0;
 252     async_inited = 1;
 253     return 1;
 254 }
 255
 256 #ifndef OPENSSL_NO_ENGINE
 257 static CRYPTO_ONCE engine_openssl = CRYPTO_ONCE_STATIC_INIT;
 258 DEFINE_RUN_ONCE_STATIC(ossl_init_engine_openssl)
 259 {
 260     OSSL_TRACE(INIT, "engine_load_openssl_int()\n");
 261     engine_load_openssl_int();
 262     return 1;
 263 }
 264 # ifndef OPENSSL_NO_RDRAND
 265 static CRYPTO_ONCE engine_rdrand = CRYPTO_ONCE_STATIC_INIT;
 266 DEFINE_RUN_ONCE_STATIC(ossl_init_engine_rdrand)
 267 {
 268     OSSL_TRACE(INIT, "engine_load_rdrand_int()\n");
 269     engine_load_rdrand_int();
 270     return 1;
 271 }
 272 # endif
 273 static CRYPTO_ONCE engine_dynamic = CRYPTO_ONCE_STATIC_INIT;
 274 DEFINE_RUN_ONCE_STATIC(ossl_init_engine_dynamic)
 275 {
 276     OSSL_TRACE(INIT, "engine_load_dynamic_int()\n");
 277     engine_load_dynamic_int();
 278     return 1;
 279 }
 280 # ifndef OPENSSL_NO_STATIC_ENGINE
 281 #  ifndef OPENSSL_NO_DEVCRYPTOENG
 282 static CRYPTO_ONCE engine_devcrypto = CRYPTO_ONCE_STATIC_INIT;
 283 DEFINE_RUN_ONCE_STATIC(ossl_init_engine_devcrypto)
 284 {
 285     OSSL_TRACE(INIT, "engine_load_devcrypto_int()\n");
 286     engine_load_devcrypto_int();
 287     return 1;
 288 }
 289 #  endif
 290 #  if !defined(OPENSSL_NO_PADLOCKENG)
 291 static CRYPTO_ONCE engine_padlock = CRYPTO_ONCE_STATIC_INIT;
 292 DEFINE_RUN_ONCE_STATIC(ossl_init_engine_padlock)
 293 {
 294     OSSL_TRACE(INIT, "engine_load_padlock_int()\n");
 295     engine_load_padlock_int();
 296     return 1;
 297 }
 298 #  endif
 299 #  if defined(OPENSSL_SYS_WIN32) && !defined(OPENSSL_NO_CAPIENG)
 300 static CRYPTO_ONCE engine_capi = CRYPTO_ONCE_STATIC_INIT;
 301 DEFINE_RUN_ONCE_STATIC(ossl_init_engine_capi)
 302 {
 303     OSSL_TRACE(INIT, "engine_load_capi_int()\n");
 304     engine_load_capi_int();
 305     return 1;
 306 }
 307 #  endif
 308 #  if !defined(OPENSSL_NO_AFALGENG)
 309 static CRYPTO_ONCE engine_afalg = CRYPTO_ONCE_STATIC_INIT;
 310 DEFINE_RUN_ONCE_STATIC(ossl_init_engine_afalg)
 311 {
 312     OSSL_TRACE(INIT, "engine_load_afalg_int()\n");
 313     engine_load_afalg_int();
 314     return 1;
 315 }
 316 #  endif
 317 # endif
 318 #endif
 319
 320 #ifndef OPENSSL_NO_COMP
 321 static CRYPTO_ONCE zlib = CRYPTO_ONCE_STATIC_INIT;
 322
 323 static int zlib_inited = 0;
 324 DEFINE_RUN_ONCE_STATIC(ossl_init_zlib)
 325 {
 326     /* Do nothing - we need to know about this for the later cleanup */
 327     zlib_inited = 1;
 328     return 1;
 329 }
 330 #endif
 331
 332 void OPENSSL_cleanup(void)
 333 {
 334     OPENSSL_INIT_STOP *currhandler, *lasthandler;
 335
 336     /*
 337      * TODO(3.0): This function needs looking at with a view to moving most/all
 338      * of this into onfree handlers in OPENSSL_CTX.
 339      */
 340
 341     /* If we've not been inited then no need to deinit */
 342     if (!base_inited)
 343         return;
 344
 345     /* Might be explicitly called and also by atexit */
 346     if (stopped)
 347         return;
 348     stopped = 1;
 349
 350     /*
 351      * Thread stop may not get automatically called by the thread library for
 352      * the very last thread in some situations, so call it directly.
 353      */
 354     OPENSSL_thread_stop();
 355
 356     currhandler = stop_handlers;
 357     while (currhandler != NULL) {
 358         currhandler->handler();
 359         lasthandler = currhandler;
 360         currhandler = currhandler->next;
 361         OPENSSL_free(lasthandler);
 362     }
 363     stop_handlers = NULL;
 364
 365     CRYPTO_THREAD_lock_free(init_lock);
 366     init_lock = NULL;
 367
 368     /*
 369      * We assume we are single-threaded for this function, i.e. no race
 370      * conditions for the various "*_inited" vars below.
 371      */
 372
 373 #ifndef OPENSSL_NO_COMP
 374     if (zlib_inited) {
 375         OSSL_TRACE(INIT, "OPENSSL_cleanup: comp_zlib_cleanup_int()\n");
 376         comp_zlib_cleanup_int();
 377     }
 378 #endif
 379
 380     if (async_inited) {
 381         OSSL_TRACE(INIT, "OPENSSL_cleanup: async_deinit()\n");
 382         async_deinit();
 383     }
 384
 385     if (load_crypto_strings_inited) {
 386         OSSL_TRACE(INIT, "OPENSSL_cleanup: err_free_strings_int()\n");
 387         err_free_strings_int();
 388     }
 389
 390     /*
 391      * Note that cleanup order is important:
 392      * - rand_cleanup_int could call an ENGINE's RAND cleanup function so
 393      * must be called before engine_cleanup_int()
 394      * - ENGINEs use CRYPTO_EX_DATA and therefore, must be cleaned up
 395      * before the ex data handlers are wiped during default openssl_ctx deinit.
 396      * - conf_modules_free_int() can end up in ENGINE code so must be called
 397      * before engine_cleanup_int()
 398      * - ENGINEs and additional EVP algorithms might use added OIDs names so
 399      * obj_cleanup_int() must be called last
 400      */
 401     OSSL_TRACE(INIT, "OPENSSL_cleanup: rand_cleanup_int()\n");
 402     rand_cleanup_int();
 403
 404     OSSL_TRACE(INIT, "OPENSSL_cleanup: conf_modules_free_int()\n");
 405     conf_modules_free_int();
 406
 407 #ifndef OPENSSL_NO_ENGINE
 408     OSSL_TRACE(INIT, "OPENSSL_cleanup: engine_cleanup_int()\n");
 409     engine_cleanup_int();
 410 #endif
 411     OSSL_TRACE(INIT, "OPENSSL_cleanup: ossl_store_cleanup_int()\n");
 412     ossl_store_cleanup_int();
 413
 414     OSSL_TRACE(INIT, "OPENSSL_cleanup: openssl_ctx_default_deinit()\n");
 415     openssl_ctx_default_deinit();
 416
 417     ossl_cleanup_thread();
 418
 419     OSSL_TRACE(INIT, "OPENSSL_cleanup: bio_cleanup()\n");
 420     bio_cleanup();
 421
 422     OSSL_TRACE(INIT, "OPENSSL_cleanup: evp_cleanup_int()\n");
 423     evp_cleanup_int();
 424
 425     OSSL_TRACE(INIT, "OPENSSL_cleanup: obj_cleanup_int()\n");
 426     obj_cleanup_int();
 427
 428     OSSL_TRACE(INIT, "OPENSSL_cleanup: err_int()\n");
 429     err_cleanup();
 430
 431     OSSL_TRACE(INIT, "OPENSSL_cleanup: CRYPTO_secure_malloc_done()\n");
 432     CRYPTO_secure_malloc_done();
 433
 434     OSSL_TRACE(INIT, "OPENSSL_cleanup: ossl_trace_cleanup()\n");
 435     ossl_trace_cleanup();
 436
 437     base_inited = 0;
 438 }
 439
 440 /*
 441  * If this function is called with a non NULL settings value then it must be
 442  * called prior to any threads making calls to any OpenSSL functions,
 443  * i.e. passing a non-null settings value is assumed to be single-threaded.
 444  */
 445 int OPENSSL_init_crypto(uint64_t opts, const OPENSSL_INIT_SETTINGS *settings)
 446 {
 447     /*
 448      * TODO(3.0): This function needs looking at with a view to moving most/all
 449      * of this into OPENSSL_CTX.
 450      */
 451
 452     if (stopped) {
 453         if (!(opts & OPENSSL_INIT_BASE_ONLY))
 454             CRYPTOerr(CRYPTO_F_OPENSSL_INIT_CRYPTO, ERR_R_INIT_FAIL);
 455         return 0;
 456     }
 457
 458     /*
 459      * When the caller specifies OPENSSL_INIT_BASE_ONLY, that should be the
 460      * *only* option specified.  With that option we return immediately after
 461      * doing the requested limited initialization.  Note that
 462      * err_shelve_state() called by us via ossl_init_load_crypto_nodelete()
 463      * re-enters OPENSSL_init_crypto() with OPENSSL_INIT_BASE_ONLY, but with
 464      * base already initialized this is a harmless NOOP.
 465      *
 466      * If we remain the only caller of err_shelve_state() the recursion should
 467      * perhaps be removed, but if in doubt, it can be left in place.
 468      */
 469     if (!RUN_ONCE(&base, ossl_init_base))
 470         return 0;
 471
 472     if (opts & OPENSSL_INIT_BASE_ONLY)
 473         return 1;
 474
 475     /*
 476      * Now we don't always set up exit handlers, the INIT_BASE_ONLY calls
 477      * should not have the side-effect of setting up exit handlers, and
 478      * therefore, this code block is below the INIT_BASE_ONLY-conditioned early
 479      * return above.
 480      */
 481     if ((opts & OPENSSL_INIT_NO_ATEXIT) != 0) {
 482         if (!RUN_ONCE_ALT(&register_atexit, ossl_init_no_register_atexit,
 483                           ossl_init_register_atexit))
 484             return 0;
 485     } else if (!RUN_ONCE(&register_atexit, ossl_init_register_atexit)) {
 486         return 0;
 487     }
 488
 489     if (!RUN_ONCE(&load_crypto_nodelete, ossl_init_load_crypto_nodelete))
 490         return 0;
 491
 492     if ((opts & OPENSSL_INIT_NO_LOAD_CRYPTO_STRINGS)
 493             && !RUN_ONCE_ALT(&load_crypto_strings,
 494                              ossl_init_no_load_crypto_strings,
 495                              ossl_init_load_crypto_strings))
 496         return 0;
 497
 498     if ((opts & OPENSSL_INIT_LOAD_CRYPTO_STRINGS)
 499             && !RUN_ONCE(&load_crypto_strings, ossl_init_load_crypto_strings))
 500         return 0;
 501
 502     if ((opts & OPENSSL_INIT_NO_ADD_ALL_CIPHERS)
 503             && !RUN_ONCE_ALT(&add_all_ciphers, ossl_init_no_add_all_ciphers,
 504                              ossl_init_add_all_ciphers))
 505         return 0;
 506
 507     if ((opts & OPENSSL_INIT_ADD_ALL_CIPHERS)
 508             && !RUN_ONCE(&add_all_ciphers, ossl_init_add_all_ciphers))
 509         return 0;
 510
 511     if ((opts & OPENSSL_INIT_NO_ADD_ALL_DIGESTS)
 512             && !RUN_ONCE_ALT(&add_all_digests, ossl_init_no_add_all_digests,
 513                              ossl_init_add_all_digests))
 514         return 0;
 515
 516     if ((opts & OPENSSL_INIT_ADD_ALL_DIGESTS)
 517             && !RUN_ONCE(&add_all_digests, ossl_init_add_all_digests))
 518         return 0;
 519
 520     if ((opts & OPENSSL_INIT_ATFORK)
 521             && !openssl_init_fork_handlers())
 522         return 0;
 523
 524     if ((opts & OPENSSL_INIT_NO_LOAD_CONFIG)
 525             && !RUN_ONCE_ALT(&config, ossl_init_no_config, ossl_init_config))
 526         return 0;
 527
 528     if (opts & OPENSSL_INIT_LOAD_CONFIG) {
 529         int ret;
 530         CRYPTO_THREAD_write_lock(init_lock);
 531         conf_settings = settings;
 532         ret = RUN_ONCE(&config, ossl_init_config);
 533         conf_settings = NULL;
 534         CRYPTO_THREAD_unlock(init_lock);
 535         if (ret <= 0)
 536             return 0;
 537     }
 538
 539     if ((opts & OPENSSL_INIT_ASYNC)
 540             && !RUN_ONCE(&async, ossl_init_async))
 541         return 0;
 542
 543 #ifndef OPENSSL_NO_ENGINE
 544     if ((opts & OPENSSL_INIT_ENGINE_OPENSSL)
 545             && !RUN_ONCE(&engine_openssl, ossl_init_engine_openssl))
 546         return 0;
 547 # ifndef OPENSSL_NO_RDRAND
 548     if ((opts & OPENSSL_INIT_ENGINE_RDRAND)
 549             && !RUN_ONCE(&engine_rdrand, ossl_init_engine_rdrand))
 550         return 0;
 551 # endif
 552     if ((opts & OPENSSL_INIT_ENGINE_DYNAMIC)
 553             && !RUN_ONCE(&engine_dynamic, ossl_init_engine_dynamic))
 554         return 0;
 555 # ifndef OPENSSL_NO_STATIC_ENGINE
 556 #  ifndef OPENSSL_NO_DEVCRYPTOENG
 557     if ((opts & OPENSSL_INIT_ENGINE_CRYPTODEV)
 558             && !RUN_ONCE(&engine_devcrypto, ossl_init_engine_devcrypto))
 559         return 0;
 560 #  endif
 561 #  if !defined(OPENSSL_NO_PADLOCKENG)
 562     if ((opts & OPENSSL_INIT_ENGINE_PADLOCK)
 563             && !RUN_ONCE(&engine_padlock, ossl_init_engine_padlock))
 564         return 0;
 565 #  endif
 566 #  if defined(OPENSSL_SYS_WIN32) && !defined(OPENSSL_NO_CAPIENG)
 567     if ((opts & OPENSSL_INIT_ENGINE_CAPI)
 568             && !RUN_ONCE(&engine_capi, ossl_init_engine_capi))
 569         return 0;
 570 #  endif
 571 #  if !defined(OPENSSL_NO_AFALGENG)
 572     if ((opts & OPENSSL_INIT_ENGINE_AFALG)
 573             && !RUN_ONCE(&engine_afalg, ossl_init_engine_afalg))
 574         return 0;
 575 #  endif
 576 # endif
 577     if (opts & (OPENSSL_INIT_ENGINE_ALL_BUILTIN
 578                 | OPENSSL_INIT_ENGINE_OPENSSL
 579                 | OPENSSL_INIT_ENGINE_AFALG)) {
 580         ENGINE_register_all_complete();
 581     }
 582 #endif
 583
 584 #ifndef OPENSSL_NO_COMP
 585     if ((opts & OPENSSL_INIT_ZLIB)
 586             && !RUN_ONCE(&zlib, ossl_init_zlib))
 587         return 0;
 588 #endif
 589
 590     return 1;
 591 }
 592
 593 int OPENSSL_atexit(void (*handler)(void))
 594 {
 595     OPENSSL_INIT_STOP *newhand;
 596
 597 #if !defined(OPENSSL_USE_NODELETE)\
 598     && !defined(OPENSSL_NO_PINSHARED)
 599     {
 600         union {
 601             void *sym;
 602             void (*func)(void);
 603         } handlersym;
 604
 605         handlersym.func = handler;
 606 # if defined(DSO_WIN32) && !defined(_WIN32_WCE)
 607         {
 608             HMODULE handle = NULL;
 609             BOOL ret;
 610
 611             /*
 612              * We don't use the DSO route for WIN32 because there is a better
 613              * way
 614              */
 615             ret = GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS
 616                                     | GET_MODULE_HANDLE_EX_FLAG_PIN,
 617                                     handlersym.sym, &handle);
 618
 619             if (!ret)
 620                 return 0;
 621         }
 622 # elif !defined(DSO_NONE)
 623         /*
 624          * Deliberately leak a reference to the handler. This will force the
 625          * library/code containing the handler to remain loaded until we run the
 626          * atexit handler. If -znodelete has been used then this is
 627          * unnecessary.
 628          */
 629         {
 630             DSO *dso = NULL;
 631
 632             ERR_set_mark();
 633             dso = DSO_dsobyaddr(handlersym.sym, DSO_FLAG_NO_UNLOAD_ON_FREE);
 634             /* See same code above in ossl_init_base() for an explanation. */
 635             OSSL_TRACE1(INIT,
 636                        "atexit: obtained DSO reference? %s\n",
 637                        (dso == NULL ? "No!" : "Yes."));
 638             DSO_free(dso);
 639             ERR_pop_to_mark();
 640         }
 641 # endif
 642     }
 643 #endif
 644
 645     if ((newhand = OPENSSL_malloc(sizeof(*newhand))) == NULL) {
 646         CRYPTOerr(CRYPTO_F_OPENSSL_ATEXIT, ERR_R_MALLOC_FAILURE);
 647         return 0;
 648     }
 649
 650     newhand->handler = handler;
 651     newhand->next = stop_handlers;
 652     stop_handlers = newhand;
 653
 654     return 1;
 655 }
 656
 657 #ifdef OPENSSL_SYS_UNIX
 658 /*
 659  * The following three functions are for OpenSSL developers.  This is
 660  * where we set/reset state across fork (called via pthread_atfork when
 661  * it exists, or manually by the application when it doesn't).
 662  *
 663  * WARNING!  If you put code in either OPENSSL_fork_parent or
 664  * OPENSSL_fork_child, you MUST MAKE SURE that they are async-signal-
 665  * safe.  See this link, for example:
 666  *      http://man7.org/linux/man-pages/man7/signal-safety.7.html
 667  */
 668
 669 void OPENSSL_fork_prepare(void)
 670 {
 671 }
 672
 673 void OPENSSL_fork_parent(void)
 674 {
 675 }
 676
 677 void OPENSSL_fork_child(void)
 678 {
 679     rand_fork();
 680     /* TODO(3.0): Inform all providers about a fork event */
 681 }
 682 #endif