A local copy of OpenSSL from GitHub
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/*
* Copyright 2019-2020 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
*/
#include <openssl/crypto.h>
#include <openssl/core_dispatch.h>
#include "crypto/cryptlib.h"
#include "prov/providercommon.h"
#include "internal/thread_once.h"
#ifdef FIPS_MODULE
#include "prov/provider_ctx.h"
/*
* Thread aware code may want to be told about thread stop events. We register
* to hear about those thread stop events when we see a new thread has started.
* We call the ossl_init_thread_start function to do that. In the FIPS provider
* we have our own copy of ossl_init_thread_start, which cascades notifications
* about threads stopping from libcrypto to all the code in the FIPS provider
* that needs to know about it.
*
* The FIPS provider tells libcrypto about which threads it is interested in
* by calling "c_thread_start" which is a function pointer created during
* provider initialisation (i.e. OSSL_init_provider).
*/
extern OSSL_FUNC_core_thread_start_fn *c_thread_start;
#endif
typedef struct thread_event_handler_st THREAD_EVENT_HANDLER;
struct thread_event_handler_st {
const void *index;
void *arg;
OSSL_thread_stop_handler_fn handfn;
THREAD_EVENT_HANDLER *next;
};
#ifndef FIPS_MODULE
DEFINE_SPECIAL_STACK_OF(THREAD_EVENT_HANDLER_PTR, THREAD_EVENT_HANDLER *)
typedef struct global_tevent_register_st GLOBAL_TEVENT_REGISTER;
struct global_tevent_register_st {
STACK_OF(THREAD_EVENT_HANDLER_PTR) *skhands;
CRYPTO_RWLOCK *lock;
};
static GLOBAL_TEVENT_REGISTER *glob_tevent_reg = NULL;
static CRYPTO_ONCE tevent_register_runonce = CRYPTO_ONCE_STATIC_INIT;
DEFINE_RUN_ONCE_STATIC(create_global_tevent_register)
{
glob_tevent_reg = OPENSSL_zalloc(sizeof(*glob_tevent_reg));
if (glob_tevent_reg == NULL)
return 0;
glob_tevent_reg->skhands = sk_THREAD_EVENT_HANDLER_PTR_new_null();
glob_tevent_reg->lock = CRYPTO_THREAD_lock_new();
if (glob_tevent_reg->skhands == NULL || glob_tevent_reg->lock == NULL) {
sk_THREAD_EVENT_HANDLER_PTR_free(glob_tevent_reg->skhands);
CRYPTO_THREAD_lock_free(glob_tevent_reg->lock);
OPENSSL_free(glob_tevent_reg);
glob_tevent_reg = NULL;
return 0;
}
return 1;
}
static GLOBAL_TEVENT_REGISTER *get_global_tevent_register(void)
{
if (!RUN_ONCE(&tevent_register_runonce, create_global_tevent_register))
return NULL;
return glob_tevent_reg;
}
#endif
#ifndef FIPS_MODULE
static int init_thread_push_handlers(THREAD_EVENT_HANDLER **hands);
static void init_thread_remove_handlers(THREAD_EVENT_HANDLER **handsin);
static void init_thread_destructor(void *hands);
static int init_thread_deregister(void *arg, int all);
#endif
static void init_thread_stop(void *arg, THREAD_EVENT_HANDLER **hands);
static THREAD_EVENT_HANDLER **
init_get_thread_local(CRYPTO_THREAD_LOCAL *local, int alloc, int keep)
{
THREAD_EVENT_HANDLER **hands = CRYPTO_THREAD_get_local(local);
if (alloc) {
if (hands == NULL) {
if ((hands = OPENSSL_zalloc(sizeof(*hands))) == NULL)
return NULL;
if (!CRYPTO_THREAD_set_local(local, hands)) {
OPENSSL_free(hands);
return NULL;
}
#ifndef FIPS_MODULE
if (!init_thread_push_handlers(hands)) {
CRYPTO_THREAD_set_local(local, NULL);
OPENSSL_free(hands);
return NULL;
}
#endif
}
} else if (!keep) {
CRYPTO_THREAD_set_local(local, NULL);
}
return hands;
}
#ifndef FIPS_MODULE
/*
* 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 dereference 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 };
/*
* The thread event handler list is a thread specific linked list
* of callback functions which are invoked in list order by the
* current thread in case of certain events. (Currently, there is
* only one type of event, the 'thread stop' event.)
*
* We also keep a global reference to that linked list, so that we
* can deregister handlers if necessary before all the threads are
* stopped.
*/
static int init_thread_push_handlers(THREAD_EVENT_HANDLER **hands)
{
int ret;
GLOBAL_TEVENT_REGISTER *gtr;
gtr = get_global_tevent_register();
if (gtr == NULL)
return 0;
CRYPTO_THREAD_write_lock(gtr->lock);
ret = (sk_THREAD_EVENT_HANDLER_PTR_push(gtr->skhands, hands) != 0);
CRYPTO_THREAD_unlock(gtr->lock);
return ret;
}
static void init_thread_remove_handlers(THREAD_EVENT_HANDLER **handsin)
{
GLOBAL_TEVENT_REGISTER *gtr;
int i;
gtr = get_global_tevent_register();
if (gtr == NULL)
return;
CRYPTO_THREAD_write_lock(gtr->lock);
for (i = 0; i < sk_THREAD_EVENT_HANDLER_PTR_num(gtr->skhands); i++) {
THREAD_EVENT_HANDLER **hands
= sk_THREAD_EVENT_HANDLER_PTR_value(gtr->skhands, i);
if (hands == handsin) {
sk_THREAD_EVENT_HANDLER_PTR_delete(gtr->skhands, i);
CRYPTO_THREAD_unlock(gtr->lock);
return;
}
}
CRYPTO_THREAD_unlock(gtr->lock);
return;
}
static void init_thread_destructor(void *hands)
{
init_thread_stop(NULL, (THREAD_EVENT_HANDLER **)hands);
init_thread_remove_handlers(hands);
OPENSSL_free(hands);
}
int ossl_init_thread(void)
{
if (!CRYPTO_THREAD_init_local(&destructor_key.value,
init_thread_destructor))
return 0;
return 1;
}
void ossl_cleanup_thread(void)
{
init_thread_deregister(NULL, 1);
CRYPTO_THREAD_cleanup_local(&destructor_key.value);
destructor_key.sane = -1;
}
void OPENSSL_thread_stop_ex(OSSL_LIB_CTX *ctx)
{
ctx = ossl_lib_ctx_get_concrete(ctx);
/*
* TODO(3.0). It would be nice if we could figure out a way to do this on
* all threads that have used the OSSL_LIB_CTX when the context is freed.
* This is currently not possible due to the use of thread local variables.
*/
ossl_ctx_thread_stop(ctx);
}
void OPENSSL_thread_stop(void)
{
if (destructor_key.sane != -1) {
THREAD_EVENT_HANDLER **hands
= init_get_thread_local(&destructor_key.value, 0, 0);
init_thread_stop(NULL, hands);
init_thread_remove_handlers(hands);
OPENSSL_free(hands);
}
}
void ossl_ctx_thread_stop(void *arg)
{
if (destructor_key.sane != -1) {
THREAD_EVENT_HANDLER **hands
= init_get_thread_local(&destructor_key.value, 0, 1);
init_thread_stop(arg, hands);
}
}
#else
static void *thread_event_ossl_ctx_new(OSSL_LIB_CTX *libctx)
{
THREAD_EVENT_HANDLER **hands = NULL;
CRYPTO_THREAD_LOCAL *tlocal = OPENSSL_zalloc(sizeof(*tlocal));
if (tlocal == NULL)
return NULL;
if (!CRYPTO_THREAD_init_local(tlocal, NULL)) {
goto err;
}
hands = OPENSSL_zalloc(sizeof(*hands));
if (hands == NULL)
goto err;
if (!CRYPTO_THREAD_set_local(tlocal, hands))
goto err;
return tlocal;
err:
OPENSSL_free(hands);
OPENSSL_free(tlocal);
return NULL;
}
static void thread_event_ossl_ctx_free(void *tlocal)
{
OPENSSL_free(tlocal);
}
static const OSSL_LIB_CTX_METHOD thread_event_ossl_ctx_method = {
thread_event_ossl_ctx_new,
thread_event_ossl_ctx_free,
};
void ossl_ctx_thread_stop(void *arg)
{
THREAD_EVENT_HANDLER **hands;
OSSL_LIB_CTX *ctx = PROV_LIBCTX_OF(arg);
CRYPTO_THREAD_LOCAL *local
= ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_THREAD_EVENT_HANDLER_INDEX,
&thread_event_ossl_ctx_method);
if (local == NULL)
return;
hands = init_get_thread_local(local, 0, 0);
init_thread_stop(ctx, hands);
OPENSSL_free(hands);
}
#endif /* FIPS_MODULE */
static void init_thread_stop(void *arg, THREAD_EVENT_HANDLER **hands)
{
THREAD_EVENT_HANDLER *curr, *prev = NULL, *tmp;
/* Can't do much about this */
if (hands == NULL)
return;
curr = *hands;
while (curr != NULL) {
if (arg != NULL && curr->arg != arg) {
prev = curr;
curr = curr->next;
continue;
}
curr->handfn(curr->arg);
if (prev == NULL)
*hands = curr->next;
else
prev->next = curr->next;
tmp = curr;
curr = curr->next;
OPENSSL_free(tmp);
}
}
int ossl_init_thread_start(const void *index, void *arg,
OSSL_thread_stop_handler_fn handfn)
{
THREAD_EVENT_HANDLER **hands;
THREAD_EVENT_HANDLER *hand;
#ifdef FIPS_MODULE
OSSL_LIB_CTX *ctx = arg;
/*
* In FIPS mode the list of THREAD_EVENT_HANDLERs is unique per combination
* of OSSL_LIB_CTX and thread. This is because in FIPS mode each
* OSSL_LIB_CTX gets informed about thread stop events individually.
*/
CRYPTO_THREAD_LOCAL *local
= ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_THREAD_EVENT_HANDLER_INDEX,
&thread_event_ossl_ctx_method);
#else
/*
* Outside of FIPS mode the list of THREAD_EVENT_HANDLERs is unique per
* thread, but may hold multiple OSSL_LIB_CTXs. We only get told about
* thread stop events globally, so we have to ensure all affected
* OSSL_LIB_CTXs are informed.
*/
CRYPTO_THREAD_LOCAL *local = &destructor_key.value;
#endif
hands = init_get_thread_local(local, 1, 0);
if (hands == NULL)
return 0;
#ifdef FIPS_MODULE
if (*hands == NULL) {
/*
* We've not yet registered any handlers for this thread. We need to get
* libcrypto to tell us about later thread stop events. c_thread_start
* is a callback to libcrypto defined in fipsprov.c
*/
if (!c_thread_start(FIPS_get_core_handle(ctx), ossl_ctx_thread_stop))
return 0;
}
#endif
hand = OPENSSL_malloc(sizeof(*hand));
if (hand == NULL)
return 0;
hand->handfn = handfn;
hand->arg = arg;
hand->index = index;
hand->next = *hands;
*hands = hand;
return 1;
}
#ifndef FIPS_MODULE
static int init_thread_deregister(void *index, int all)
{
GLOBAL_TEVENT_REGISTER *gtr;
int i;
gtr = get_global_tevent_register();
if (gtr == NULL)
return 0;
if (!all)
CRYPTO_THREAD_write_lock(gtr->lock);
else
glob_tevent_reg = NULL;
for (i = 0; i < sk_THREAD_EVENT_HANDLER_PTR_num(gtr->skhands); i++) {
THREAD_EVENT_HANDLER **hands
= sk_THREAD_EVENT_HANDLER_PTR_value(gtr->skhands, i);
THREAD_EVENT_HANDLER *curr = NULL, *prev = NULL, *tmp;
if (hands == NULL) {
if (!all)
CRYPTO_THREAD_unlock(gtr->lock);
return 0;
}
curr = *hands;
while (curr != NULL) {
if (all || curr->index == index) {
if (prev != NULL)
prev->next = curr->next;
else
*hands = curr->next;
tmp = curr;
curr = curr->next;
OPENSSL_free(tmp);
continue;
}
prev = curr;
curr = curr->next;
}
if (all)
OPENSSL_free(hands);
}
if (all) {
CRYPTO_THREAD_lock_free(gtr->lock);
sk_THREAD_EVENT_HANDLER_PTR_free(gtr->skhands);
OPENSSL_free(gtr);
} else {
CRYPTO_THREAD_unlock(gtr->lock);
}
return 1;
}
int ossl_init_thread_deregister(void *index)
{
return init_thread_deregister(index, 0);
}
#endif