/src/openssl/crypto/initthread.c

Source (jump to first uncovered line)
/*
 * Copyright 2019-2022 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
 */

#include <openssl/crypto.h>
#include <openssl/core_dispatch.h>
#include "crypto/cryptlib.h"
#include "prov/providercommon.h"
#include "internal/thread_once.h"
#include "crypto/context.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 {
#ifndef FIPS_MODULE
    const void *index;
#endif
    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;

    if (!CRYPTO_THREAD_write_lock(gtr->lock))
        return 0;
    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;
    if (!CRYPTO_THREAD_write_lock(gtr->lock))
        return;
    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);
    /*
     * 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(OSSL_LIB_CTX *ctx)
{
    if (destructor_key.sane != -1) {
        THREAD_EVENT_HANDLER **hands
            = init_get_thread_local(&destructor_key.value, 0, 1);
        init_thread_stop(ctx, hands);
    }
}

#else

void *ossl_thread_event_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;
}

void ossl_thread_event_ctx_free(void *tlocal)
{
    OPENSSL_free(tlocal);
}

static void ossl_arg_thread_stop(void *arg)
{
    ossl_ctx_thread_stop((OSSL_LIB_CTX *)arg);
}

void ossl_ctx_thread_stop(OSSL_LIB_CTX *ctx)
{
    THREAD_EVENT_HANDLER **hands;
    CRYPTO_THREAD_LOCAL *local
        = ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_THREAD_EVENT_HANDLER_INDEX);

    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;
#ifndef FIPS_MODULE
    GLOBAL_TEVENT_REGISTER *gtr;
#endif

    /* Can't do much about this */
    if (hands == NULL)
        return;

#ifndef FIPS_MODULE
    gtr = get_global_tevent_register();
    if (gtr == NULL)
        return;

    if (!CRYPTO_THREAD_write_lock(gtr->lock))
        return;
#endif

    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);
    }
#ifndef FIPS_MODULE
    CRYPTO_THREAD_unlock(gtr->lock);
#endif
}

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);
#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_arg_thread_stop,
                            ctx))
            return 0;
    }
#endif

    hand = OPENSSL_malloc(sizeof(*hand));
    if (hand == NULL)
        return 0;

    hand->handfn = handfn;
    hand->arg = arg;
#ifndef FIPS_MODULE
    hand->index = index;
#endif
    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) {
        if (!CRYPTO_THREAD_write_lock(gtr->lock))
            return 0;
    } 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

Coverage Report

Created: 2023-09-25 06:41

Line	Count	Source (jump to first uncovered line)
1		/*
2		* Copyright 2019-2022 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 <openssl/crypto.h>
11		#include <openssl/core_dispatch.h>
12		#include "crypto/cryptlib.h"
13		#include "prov/providercommon.h"
14		#include "internal/thread_once.h"
15		#include "crypto/context.h"
16
17		#ifdef FIPS_MODULE
18		#include "prov/provider_ctx.h"
19
20		/*
21		* Thread aware code may want to be told about thread stop events. We register
22		* to hear about those thread stop events when we see a new thread has started.
23		* We call the ossl_init_thread_start function to do that. In the FIPS provider
24		* we have our own copy of ossl_init_thread_start, which cascades notifications
25		* about threads stopping from libcrypto to all the code in the FIPS provider
26		* that needs to know about it.
27		*
28		* The FIPS provider tells libcrypto about which threads it is interested in
29		* by calling "c_thread_start" which is a function pointer created during
30		* provider initialisation (i.e. OSSL_init_provider).
31		*/
32		extern OSSL_FUNC_core_thread_start_fn *c_thread_start;
33		#endif
34
35		typedef struct thread_event_handler_st THREAD_EVENT_HANDLER;
36		struct thread_event_handler_st {
37		#ifndef FIPS_MODULE
38		const void *index;
39		#endif
40		void *arg;
41		OSSL_thread_stop_handler_fn handfn;
42		THREAD_EVENT_HANDLER *next;
43		};
44
45		#ifndef FIPS_MODULE
46		DEFINE_SPECIAL_STACK_OF(THREAD_EVENT_HANDLER_PTR, THREAD_EVENT_HANDLER *)
47
48		typedef struct global_tevent_register_st GLOBAL_TEVENT_REGISTER;
49		struct global_tevent_register_st {
50		STACK_OF(THREAD_EVENT_HANDLER_PTR) *skhands;
51		CRYPTO_RWLOCK *lock;
52		};
53
54		static GLOBAL_TEVENT_REGISTER *glob_tevent_reg = NULL;
55
56		static CRYPTO_ONCE tevent_register_runonce = CRYPTO_ONCE_STATIC_INIT;
57
58		DEFINE_RUN_ONCE_STATIC(create_global_tevent_register)
59	2	{
60	2	glob_tevent_reg = OPENSSL_zalloc(sizeof(*glob_tevent_reg));
61	2	if (glob_tevent_reg == NULL)
62	0	return 0;
63
64	2	glob_tevent_reg->skhands = sk_THREAD_EVENT_HANDLER_PTR_new_null();
65	2	glob_tevent_reg->lock = CRYPTO_THREAD_lock_new();
66	2	if (glob_tevent_reg->skhands == NULL \|\| glob_tevent_reg->lock == NULL) {
67	0	sk_THREAD_EVENT_HANDLER_PTR_free(glob_tevent_reg->skhands);
68	0	CRYPTO_THREAD_lock_free(glob_tevent_reg->lock);
69	0	OPENSSL_free(glob_tevent_reg);
70	0	glob_tevent_reg = NULL;
71	0	return 0;
72	0	}
73
74	2	return 1;
75	2	}
76
77		static GLOBAL_TEVENT_REGISTER *get_global_tevent_register(void)
78	9	{
79	9	if (!RUN_ONCE(&tevent_register_runonce, create_global_tevent_register))
80	0	return NULL;
81	9	return glob_tevent_reg;
82	9	}
83		#endif
84
85		#ifndef FIPS_MODULE
86		static int init_thread_push_handlers(THREAD_EVENT_HANDLER **hands);
87		static void init_thread_remove_handlers(THREAD_EVENT_HANDLER **handsin);
88		static void init_thread_destructor(void *hands);
89		static int init_thread_deregister(void *arg, int all);
90		#endif
91		static void init_thread_stop(void arg, THREAD_EVENT_HANDLER *hands);
92
93		static THREAD_EVENT_HANDLER **
94		init_get_thread_local(CRYPTO_THREAD_LOCAL *local, int alloc, int keep)
95	7	{
96	7	THREAD_EVENT_HANDLER **hands = CRYPTO_THREAD_get_local(local);
97
98	7	if (alloc) {
99	3	if (hands == NULL) {
100
101	2	if ((hands = OPENSSL_zalloc(sizeof(*hands))) == NULL)
102	0	return NULL;
103
104	2	if (!CRYPTO_THREAD_set_local(local, hands)) {
105	0	OPENSSL_free(hands);
106	0	return NULL;
107	0	}
108
109	2	#ifndef FIPS_MODULE
110	2	if (!init_thread_push_handlers(hands)) {
111	0	CRYPTO_THREAD_set_local(local, NULL);
112	0	OPENSSL_free(hands);
113	0	return NULL;
114	0	}
115	2	#endif
116	2	}
117	4	} else if (!keep) {
118	2	CRYPTO_THREAD_set_local(local, NULL);
119	2	}
120
121	7	return hands;
122	7	}
123
124		#ifndef FIPS_MODULE
125		/*
126		* Since per-thread-specific-data destructors are not universally
127		* available, i.e. not on Windows, only below CRYPTO_THREAD_LOCAL key
128		* is assumed to have destructor associated. And then an effort is made
129		* to call this single destructor on non-pthread platform[s].
130		*
131		* Initial value is "impossible". It is used as guard value to shortcut
132		* destructor for threads terminating before libcrypto is initialized or
133		* after it's de-initialized. Access to the key doesn't have to be
134		* serialized for the said threads, because they didn't use libcrypto
135		* and it doesn't matter if they pick "impossible" or dereference real
136		* key value and pull NULL past initialization in the first thread that
137		* intends to use libcrypto.
138		*/
139		static union {
140		long sane;
141		CRYPTO_THREAD_LOCAL value;
142		} destructor_key = { -1 };
143
144		/*
145		* The thread event handler list is a thread specific linked list
146		* of callback functions which are invoked in list order by the
147		* current thread in case of certain events. (Currently, there is
148		* only one type of event, the 'thread stop' event.)
149		*
150		* We also keep a global reference to that linked list, so that we
151		* can deregister handlers if necessary before all the threads are
152		* stopped.
153		*/
154		static int init_thread_push_handlers(THREAD_EVENT_HANDLER **hands)
155	2	{
156	2	int ret;
157	2	GLOBAL_TEVENT_REGISTER *gtr;
158
159	2	gtr = get_global_tevent_register();
160	2	if (gtr == NULL)
161	0	return 0;
162
163	2	if (!CRYPTO_THREAD_write_lock(gtr->lock))
164	0	return 0;
165	2	ret = (sk_THREAD_EVENT_HANDLER_PTR_push(gtr->skhands, hands) != 0);
166	2	CRYPTO_THREAD_unlock(gtr->lock);
167
168	2	return ret;
169	2	}
170
171		static void init_thread_remove_handlers(THREAD_EVENT_HANDLER **handsin)
172	2	{
173	2	GLOBAL_TEVENT_REGISTER *gtr;
174	2	int i;
175
176	2	gtr = get_global_tevent_register();
177	2	if (gtr == NULL)
178	0	return;
179	2	if (!CRYPTO_THREAD_write_lock(gtr->lock))
180	0	return;
181	2	for (i = 0; i < sk_THREAD_EVENT_HANDLER_PTR_num(gtr->skhands); i++) {
182	2	THREAD_EVENT_HANDLER **hands
183	2	= sk_THREAD_EVENT_HANDLER_PTR_value(gtr->skhands, i);
184
185	2	if (hands == handsin) {
186	2	sk_THREAD_EVENT_HANDLER_PTR_delete(gtr->skhands, i);
187	2	CRYPTO_THREAD_unlock(gtr->lock);
188	2	return;
189	2	}
190	2	}
191	0	CRYPTO_THREAD_unlock(gtr->lock);
192	0	return;
193	2	}
194
195		static void init_thread_destructor(void *hands)
196	0	{
197	0	init_thread_stop(NULL, (THREAD_EVENT_HANDLER **)hands);
198	0	init_thread_remove_handlers(hands);
199	0	OPENSSL_free(hands);
200	0	}
201
202		int ossl_init_thread(void)
203	2	{
204	2	if (!CRYPTO_THREAD_init_local(&destructor_key.value,
205	2	init_thread_destructor))
206	0	return 0;
207
208	2	return 1;
209	2	}
210
211		void ossl_cleanup_thread(void)
212	2	{
213	2	init_thread_deregister(NULL, 1);
214	2	CRYPTO_THREAD_cleanup_local(&destructor_key.value);
215	2	destructor_key.sane = -1;
216	2	}
217
218		void OPENSSL_thread_stop_ex(OSSL_LIB_CTX *ctx)
219	0	{
220	0	ctx = ossl_lib_ctx_get_concrete(ctx);
221		/*
222		* It would be nice if we could figure out a way to do this on all threads
223		* that have used the OSSL_LIB_CTX when the context is freed. This is
224		* currently not possible due to the use of thread local variables.
225		*/
226	0	ossl_ctx_thread_stop(ctx);
227	0	}
228
229		void OPENSSL_thread_stop(void)
230	2	{
231	2	if (destructor_key.sane != -1) {
232	2	THREAD_EVENT_HANDLER **hands
233	2	= init_get_thread_local(&destructor_key.value, 0, 0);
234	2	init_thread_stop(NULL, hands);
235
236	2	init_thread_remove_handlers(hands);
237	2	OPENSSL_free(hands);
238	2	}
239	2	}
240
241		void ossl_ctx_thread_stop(OSSL_LIB_CTX *ctx)
242	2	{
243	2	if (destructor_key.sane != -1) {
244	2	THREAD_EVENT_HANDLER **hands
245	2	= init_get_thread_local(&destructor_key.value, 0, 1);
246	2	init_thread_stop(ctx, hands);
247	2	}
248	2	}
249
250		#else
251
252		void ossl_thread_event_ctx_new(OSSL_LIB_CTX libctx)
253		{
254		THREAD_EVENT_HANDLER **hands = NULL;
255		CRYPTO_THREAD_LOCAL tlocal = OPENSSL_zalloc(sizeof(tlocal));
256
257		if (tlocal == NULL)
258		return NULL;
259
260		if (!CRYPTO_THREAD_init_local(tlocal, NULL)) {
261		goto err;
262		}
263
264		hands = OPENSSL_zalloc(sizeof(*hands));
265		if (hands == NULL)
266		goto err;
267
268		if (!CRYPTO_THREAD_set_local(tlocal, hands))
269		goto err;
270
271		return tlocal;
272		err:
273		OPENSSL_free(hands);
274		OPENSSL_free(tlocal);
275		return NULL;
276		}
277
278		void ossl_thread_event_ctx_free(void *tlocal)
279		{
280		OPENSSL_free(tlocal);
281		}
282
283		static void ossl_arg_thread_stop(void *arg)
284		{
285		ossl_ctx_thread_stop((OSSL_LIB_CTX *)arg);
286		}
287
288		void ossl_ctx_thread_stop(OSSL_LIB_CTX *ctx)
289		{
290		THREAD_EVENT_HANDLER **hands;
291		CRYPTO_THREAD_LOCAL *local
292		= ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_THREAD_EVENT_HANDLER_INDEX);
293
294		if (local == NULL)
295		return;
296		hands = init_get_thread_local(local, 0, 0);
297		init_thread_stop(ctx, hands);
298		OPENSSL_free(hands);
299		}
300		#endif /* FIPS_MODULE */
301
302
303		static void init_thread_stop(void arg, THREAD_EVENT_HANDLER *hands)
304	4	{
305	4	THREAD_EVENT_HANDLER curr, prev = NULL, *tmp;
306	4	#ifndef FIPS_MODULE
307	4	GLOBAL_TEVENT_REGISTER *gtr;
308	4	#endif
309
310		/* Can't do much about this */
311	4	if (hands == NULL)
312	2	return;
313
314	2	#ifndef FIPS_MODULE
315	2	gtr = get_global_tevent_register();
316	2	if (gtr == NULL)
317	0	return;
318
319	2	if (!CRYPTO_THREAD_write_lock(gtr->lock))
320	0	return;
321	2	#endif
322
323	2	curr = *hands;
324	5	while (curr != NULL) {
325	3	if (arg != NULL && curr->arg != arg) {
326	0	prev = curr;
327	0	curr = curr->next;
328	0	continue;
329	0	}
330	3	curr->handfn(curr->arg);
331	3	if (prev == NULL)
332	3	*hands = curr->next;
333	0	else
334	0	prev->next = curr->next;
335
336	3	tmp = curr;
337	3	curr = curr->next;
338
339	3	OPENSSL_free(tmp);
340	3	}
341	2	#ifndef FIPS_MODULE
342	2	CRYPTO_THREAD_unlock(gtr->lock);
343	2	#endif
344	2	}
345
346		int ossl_init_thread_start(const void index, void arg,
347		OSSL_thread_stop_handler_fn handfn)
348	3	{
349	3	THREAD_EVENT_HANDLER **hands;
350	3	THREAD_EVENT_HANDLER *hand;
351		#ifdef FIPS_MODULE
352		OSSL_LIB_CTX *ctx = arg;
353
354		/*
355		* In FIPS mode the list of THREAD_EVENT_HANDLERs is unique per combination
356		* of OSSL_LIB_CTX and thread. This is because in FIPS mode each
357		* OSSL_LIB_CTX gets informed about thread stop events individually.
358		*/
359		CRYPTO_THREAD_LOCAL *local
360		= ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_THREAD_EVENT_HANDLER_INDEX);
361		#else
362		/*
363		* Outside of FIPS mode the list of THREAD_EVENT_HANDLERs is unique per
364		* thread, but may hold multiple OSSL_LIB_CTXs. We only get told about
365		* thread stop events globally, so we have to ensure all affected
366		* OSSL_LIB_CTXs are informed.
367		*/
368	3	CRYPTO_THREAD_LOCAL *local = &destructor_key.value;
369	3	#endif
370
371	3	hands = init_get_thread_local(local, 1, 0);
372	3	if (hands == NULL)
373	0	return 0;
374
375		#ifdef FIPS_MODULE
376		if (*hands == NULL) {
377		/*
378		* We've not yet registered any handlers for this thread. We need to get
379		* libcrypto to tell us about later thread stop events. c_thread_start
380		* is a callback to libcrypto defined in fipsprov.c
381		*/
382		if (!c_thread_start(FIPS_get_core_handle(ctx), ossl_arg_thread_stop,
383		ctx))
384		return 0;
385		}
386		#endif
387
388	3	hand = OPENSSL_malloc(sizeof(*hand));
389	3	if (hand == NULL)
390	0	return 0;
391
392	3	hand->handfn = handfn;
393	3	hand->arg = arg;
394	3	#ifndef FIPS_MODULE
395	3	hand->index = index;
396	3	#endif
397	3	hand->next = *hands;
398	3	*hands = hand;
399
400	3	return 1;
401	3	}
402
403		#ifndef FIPS_MODULE
404		static int init_thread_deregister(void *index, int all)
405	3	{
406	3	GLOBAL_TEVENT_REGISTER *gtr;
407	3	int i;
408
409	3	gtr = get_global_tevent_register();
410	3	if (gtr == NULL)
411	0	return 0;
412	3	if (!all) {
413	1	if (!CRYPTO_THREAD_write_lock(gtr->lock))
414	0	return 0;
415	2	} else {
416	2	glob_tevent_reg = NULL;
417	2	}
418	3	for (i = 0; i < sk_THREAD_EVENT_HANDLER_PTR_num(gtr->skhands); i++) {
419	0	THREAD_EVENT_HANDLER **hands
420	0	= sk_THREAD_EVENT_HANDLER_PTR_value(gtr->skhands, i);
421	0	THREAD_EVENT_HANDLER curr = NULL, prev = NULL, *tmp;
422
423	0	if (hands == NULL) {
424	0	if (!all)
425	0	CRYPTO_THREAD_unlock(gtr->lock);
426	0	return 0;
427	0	}
428	0	curr = *hands;
429	0	while (curr != NULL) {
430	0	if (all \|\| curr->index == index) {
431	0	if (prev != NULL)
432	0	prev->next = curr->next;
433	0	else
434	0	*hands = curr->next;
435	0	tmp = curr;
436	0	curr = curr->next;
437	0	OPENSSL_free(tmp);
438	0	continue;
439	0	}
440	0	prev = curr;
441	0	curr = curr->next;
442	0	}
443	0	if (all)
444	0	OPENSSL_free(hands);
445	0	}
446	3	if (all) {
447	2	CRYPTO_THREAD_lock_free(gtr->lock);
448	2	sk_THREAD_EVENT_HANDLER_PTR_free(gtr->skhands);
449	2	OPENSSL_free(gtr);
450	2	} else {
451	1	CRYPTO_THREAD_unlock(gtr->lock);
452	1	}
453	3	return 1;
454	3	}
455
456		int ossl_init_thread_deregister(void *index)
457	1	{
458	1	return init_thread_deregister(index, 0);
459	1	}
460		#endif