openssl/crypto/init.c

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/*
* Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (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 "e_os.h"
#include "internal/cryptlib_int.h"
#include <openssl/err.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 <stdlib.h>
#include <assert.h>
#include "internal/thread_once.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);
static CRYPTO_THREAD_LOCAL threadstopkey;
static void ossl_init_thread_stop_wrap(void *local)
{
ossl_init_thread_stop((struct thread_local_inits_st *)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));
if (local != NULL && !CRYPTO_THREAD_set_local(&threadstopkey, local)) {
OPENSSL_free(local);
return NULL;
}
}
if (!alloc) {
CRYPTO_THREAD_set_local(&threadstopkey, NULL);
}
return local;
}
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;
static CRYPTO_RWLOCK *init_lock = NULL;
static CRYPTO_ONCE base = CRYPTO_ONCE_STATIC_INIT;
static int base_inited = 0;
DEFINE_RUN_ONCE_STATIC(ossl_init_base)
{
#ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_base: Setting up stop handlers\n");
#endif
#ifndef OPENSSL_NO_CRYPTO_MDEBUG
ossl_malloc_setup_failures();
#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);
#endif
if ((init_lock = CRYPTO_THREAD_lock_new()) == NULL)
return 0;
OPENSSL_cpuid_setup();
/*
* BIG FAT WARNING!
* Everything needed to be initialized in this function before threads
* come along MUST happen before base_inited is set to 1, or we will
* see race conditions.
*/
base_inited = 1;
#if !defined(OPENSSL_NO_DSO) && !defined(OPENSSL_USE_NODELETE)
# ifdef DSO_WIN32
{
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);
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 at process exit.
*/
{
DSO *dso = NULL;
ERR_set_mark();
dso = DSO_dsobyaddr(&base_inited, DSO_FLAG_NO_UNLOAD_ON_FREE);
DSO_free(dso);
ERR_pop_to_mark();
}
# endif
#endif
return 1;
}
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;
/*
* 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)
# ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_load_crypto_strings: "
"err_load_crypto_strings_int()\n");
# endif
ret = err_load_crypto_strings_int();
load_crypto_strings_inited = 1;
#endif
return ret;
}
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
# ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_add_all_ciphers: "
"openssl_add_all_ciphers_int()\n");
# endif
openssl_add_all_ciphers_int();
#endif
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
# ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_add_all_digests: "
"openssl_add_all_digests()\n");
# endif
openssl_add_all_digests_int();
#endif
return 1;
}
DEFINE_RUN_ONCE_STATIC(ossl_init_no_add_algs)
{
/* Do nothing */
return 1;
}
static CRYPTO_ONCE config = CRYPTO_ONCE_STATIC_INIT;
static int config_inited = 0;
static const char *appname;
DEFINE_RUN_ONCE_STATIC(ossl_init_config)
{
#ifdef OPENSSL_INIT_DEBUG
fprintf(stderr,
"OPENSSL_INIT: ossl_init_config: openssl_config(%s)\n",
appname == NULL ? "NULL" : appname);
#endif
openssl_config_int(appname);
config_inited = 1;
return 1;
}
DEFINE_RUN_ONCE_STATIC(ossl_init_no_config)
{
#ifdef OPENSSL_INIT_DEBUG
fprintf(stderr,
"OPENSSL_INIT: ossl_init_config: openssl_no_config_int()\n");
#endif
openssl_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)
{
#ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_async: async_init()\n");
#endif
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)
{
# ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_engine_openssl: "
"engine_load_openssl_int()\n");
# endif
engine_load_openssl_int();
return 1;
}
# 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_devcrypto: "
"engine_load_devcrypto_int()\n");
# endif
engine_load_devcrypto_int();
return 1;
}
# endif
# ifndef OPENSSL_NO_RDRAND
static CRYPTO_ONCE engine_rdrand = CRYPTO_ONCE_STATIC_INIT;
DEFINE_RUN_ONCE_STATIC(ossl_init_engine_rdrand)
{
# ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_engine_rdrand: "
"engine_load_rdrand_int()\n");
# endif
engine_load_rdrand_int();
return 1;
}
# endif
static CRYPTO_ONCE engine_dynamic = CRYPTO_ONCE_STATIC_INIT;
DEFINE_RUN_ONCE_STATIC(ossl_init_engine_dynamic)
{
# ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_engine_dynamic: "
"engine_load_dynamic_int()\n");
# endif
engine_load_dynamic_int();
return 1;
}
# ifndef OPENSSL_NO_STATIC_ENGINE
# if !defined(OPENSSL_NO_HW) && !defined(OPENSSL_NO_HW_PADLOCK)
static CRYPTO_ONCE engine_padlock = CRYPTO_ONCE_STATIC_INIT;
DEFINE_RUN_ONCE_STATIC(ossl_init_engine_padlock)
{
# ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_engine_padlock: "
"engine_load_padlock_int()\n");
# endif
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)
{
# ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_engine_capi: "
"engine_load_capi_int()\n");
# endif
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)
{
# ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_engine_afalg: "
"engine_load_afalg_int()\n");
# endif
engine_load_afalg_int();
return 1;
}
# endif
# endif
#endif
#ifndef OPENSSL_NO_COMP
static CRYPTO_ONCE zlib = CRYPTO_ONCE_STATIC_INIT;
static int zlib_inited = 0;
DEFINE_RUN_ONCE_STATIC(ossl_init_zlib)
{
/* Do nothing - we need to know about this for the later cleanup */
zlib_inited = 1;
return 1;
}
#endif
static void ossl_init_thread_stop(struct thread_local_inits_st *locals)
{
/* Can't do much about this */
if (locals == NULL)
return;
if (locals->async) {
#ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_thread_stop: "
"ASYNC_cleanup_thread()\n");
#endif
ASYNC_cleanup_thread();
}
if (locals->err_state) {
#ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_thread_stop: "
"err_delete_thread_state()\n");
#endif
err_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));
}
int ossl_init_thread_start(uint64_t opts)
{
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;
if (opts & OPENSSL_INIT_THREAD_ASYNC) {
#ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_thread_start: "
"marking thread for async\n");
#endif
locals->async = 1;
}
if (opts & OPENSSL_INIT_THREAD_ERR_STATE) {
#ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: ossl_init_thread_start: "
"marking thread for err_state\n");
#endif
locals->err_state = 1;
}
return 1;
}
void OPENSSL_cleanup(void)
{
OPENSSL_INIT_STOP *currhandler, *lasthandler;
/* 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.
*/
ossl_init_thread_stop(ossl_init_get_thread_local(0));
currhandler = stop_handlers;
while (currhandler != NULL) {
currhandler->handler();
lasthandler = currhandler;
currhandler = currhandler->next;
OPENSSL_free(lasthandler);
}
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
* conditions for the various "*_inited" vars below.
*/
#ifndef OPENSSL_NO_COMP
if (zlib_inited) {
#ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: "
"comp_zlib_cleanup_int()\n");
#endif
comp_zlib_cleanup_int();
}
#endif
if (async_inited) {
# ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: "
"async_deinit()\n");
# endif
async_deinit();
}
if (load_crypto_strings_inited) {
#ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: "
"err_free_strings_int()\n");
#endif
err_free_strings_int();
}
CRYPTO_THREAD_cleanup_local(&threadstopkey);
#ifdef OPENSSL_INIT_DEBUG
fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: "
"rand_cleanup_int()\n");
fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: "
"conf_modules_free_int()\n");
#ifndef OPENSSL_NO_ENGINE
fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: "
"engine_cleanup_int()\n");
#endif
fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: "
"crypto_cleanup_all_ex_data_int()\n");
fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: "
"bio_sock_cleanup_int()\n");
fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: "
"bio_cleanup()\n");
fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: "
"evp_cleanup_int()\n");
fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: "
"obj_cleanup_int()\n");
fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: "
"err_cleanup()\n");
#endif
/*
* Note that cleanup order is important:
* - 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 in CRYPTO_cleanup_all_ex_data().
* - conf_modules_free_int() 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
* obj_cleanup_int() must be called last
*/
rand_cleanup_int();
Fix reseeding issues of the public RAND_DRBG Reseeding is handled very differently by the classic RAND_METHOD API and the new RAND_DRBG api. These differences led to some problems when the new RAND_DRBG was made the default OpenSSL RNG. In particular, RAND_add() did not work as expected anymore. These issues are discussed on the thread '[openssl-dev] Plea for a new public OpenSSL RNG API' and in Pull Request #4328. This commit fixes the mentioned issues, introducing the following changes: - Replace the fixed size RAND_BYTES_BUFFER by a new RAND_POOL API which facilitates collecting entropy by the get_entropy() callback. - Don't use RAND_poll()/RAND_add() for collecting entropy from the get_entropy() callback anymore. Instead, replace RAND_poll() by RAND_POOL_acquire_entropy(). - Add a new function rand_drbg_restart() which tries to get the DRBG in an instantiated state by all means, regardless of the current state (uninstantiated, error, ...) the DRBG is in. If the caller provides entropy or additional input, it will be used for reseeding. - Restore the original documented behaviour of RAND_add() and RAND_poll() (namely to reseed the DRBG immediately) by a new implementation based on rand_drbg_restart(). - Add automatic error recovery from temporary failures of the entropy source to RAND_DRBG_generate() using the rand_drbg_restart() function. Reviewed-by: Paul Dale <paul.dale@oracle.com> Reviewed-by: Kurt Roeckx <kurt@roeckx.be> Reviewed-by: Rich Salz <rsalz@openssl.org> Reviewed-by: Ben Kaduk <kaduk@mit.edu> (Merged from https://github.com/openssl/openssl/pull/4328)
2017-08-31 21:16:22 +00:00
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;
}
/*
* 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)
{
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;
CRYPTOerr(CRYPTO_F_OPENSSL_INIT_CRYPTO, ERR_R_INIT_FAIL);
}
return 0;
}
if (!base_inited && !RUN_ONCE(&base, ossl_init_base))
return 0;
if ((opts & OPENSSL_INIT_NO_LOAD_CRYPTO_STRINGS)
&& !RUN_ONCE(&load_crypto_strings,
ossl_init_no_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(&add_all_ciphers, ossl_init_no_add_algs))
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(&add_all_digests, ossl_init_no_add_algs))
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(&config, ossl_init_no_config))
return 0;
if (opts & OPENSSL_INIT_LOAD_CONFIG) {
int ret;
CRYPTO_THREAD_write_lock(init_lock);
appname = (settings == NULL) ? NULL : settings->appname;
ret = RUN_ONCE(&config, ossl_init_config);
CRYPTO_THREAD_unlock(init_lock);
if (!ret)
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;
# if !defined(OPENSSL_NO_HW) && !defined(OPENSSL_NO_DEVCRYPTOENG)
if ((opts & OPENSSL_INIT_ENGINE_CRYPTODEV)
&& !RUN_ONCE(&engine_devcrypto, ossl_init_engine_devcrypto))
return 0;
# endif
# 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
# if !defined(OPENSSL_NO_HW) && !defined(OPENSSL_NO_HW_PADLOCK)
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
#ifndef OPENSSL_NO_COMP
if ((opts & OPENSSL_INIT_ZLIB)
&& !RUN_ONCE(&zlib, ossl_init_zlib))
return 0;
#endif
return 1;
}
int OPENSSL_atexit(void (*handler)(void))
{
OPENSSL_INIT_STOP *newhand;
#if !defined(OPENSSL_NO_DSO) && !defined(OPENSSL_USE_NODELETE)
{
union {
void *sym;
void (*func)(void);
} handlersym;
handlersym.func = handler;
# ifdef DSO_WIN32
{
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,
handlersym.sym, &handle);
if (!ret)
return 0;
}
# else
/*
* 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;
ERR_set_mark();
dso = DSO_dsobyaddr(handlersym.sym, DSO_FLAG_NO_UNLOAD_ON_FREE);
DSO_free(dso);
ERR_pop_to_mark();
}
# endif
}
#endif
newhand = OPENSSL_malloc(sizeof(*newhand));
if (newhand == NULL)
return 0;
newhand->handler = handler;
newhand->next = stop_handlers;
stop_handlers = newhand;
return 1;
}
Revert the crypto "global lock" implementation Conceptually, this is a squashed version of: Revert "Address feedback" This reverts commit 75551e07bd2339dfea06ef1d31d69929e13a4495. and Revert "Add CRYPTO_thread_glock_new" This reverts commit ed6b2c7938ec6f07b15745d4183afc276e74c6dd. But there were some intervening commits that made neither revert apply cleanly, so instead do it all as one shot. The crypto global locks were an attempt to cope with the awkward POSIX semantics for pthread_atfork(); its documentation (the "RATIONALE" section) indicates that the expected usage is to have the prefork handler lock all "global" locks, and the parent and child handlers release those locks, to ensure that forking happens with a consistent (lock) state. However, the set of functions available in the child process is limited to async-signal-safe functions, and pthread_mutex_unlock() is not on the list of async-signal-safe functions! The only synchronization primitives that are async-signal-safe are the semaphore primitives, which are not really appropriate for general-purpose usage. However, the state consistency problem that the global locks were attempting to solve is not actually a serious problem, particularly for OpenSSL. That is, we can consider four cases of forking application that might use OpenSSL: (1) Single-threaded, does not call into OpenSSL in the child (e.g., the child calls exec() immediately) For this class of process, no locking is needed at all, since there is only ever a single thread of execution and the only reentrancy is due to signal handlers (which are themselves limited to async-signal-safe operation and should not be doing much work at all). (2) Single-threaded, calls into OpenSSL after fork() The application must ensure that it does not fork() with an unexpected lock held (that is, one that would get unlocked in the parent but accidentally remain locked in the child and cause deadlock). Since OpenSSL does not expose any of its internal locks to the application and the application is single-threaded, the OpenSSL internal locks will be unlocked for the fork(), and the state will be consistent. (OpenSSL will need to reseed its PRNG in the child, but that is an orthogonal issue.) If the application makes use of locks from libcrypto, proper handling for those locks is the responsibility of the application, as for any other locking primitive that is available for application programming. (3) Multi-threaded, does not call into OpenSSL after fork() As for (1), the OpenSSL state is only relevant in the parent, so no particular fork()-related handling is needed. The internal locks are relevant, but there is no interaction with the child to consider. (4) Multi-threaded, calls into OpenSSL after fork() This is the case where the pthread_atfork() hooks to ensure that all global locks are in a known state across fork() would come into play, per the above discussion. However, these "calls into OpenSSL after fork()" are still subject to the restriction to async-signal-safe functions. Since OpenSSL uses all sorts of locking and libc functions that are not on the list of safe functions (e.g., malloc()), this case is not currently usable and is unlikely to ever be usable, independently of the locking situation. So, there is no need to go through contortions to attempt to support this case in the one small area of locking interaction with fork(). In light of the above analysis (thanks @davidben and @achernya), go back to the simpler implementation that does not need to distinguish "library-global" locks or to have complicated atfork handling for locks. Reviewed-by: Kurt Roeckx <kurt@roeckx.be> Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com> (Merged from https://github.com/openssl/openssl/pull/5089)
2018-01-16 15:49:54 +00:00
#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