Coverage Report

Created: 2024-05-21 06:33

/src/openssl/crypto/initthread.c
Line
Count
Source (jump to first uncovered line)
1
/*
2
 * Copyright 2019-2023 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_provider_init).
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
3
{
60
3
    glob_tevent_reg = OPENSSL_zalloc(sizeof(*glob_tevent_reg));
61
3
    if (glob_tevent_reg == NULL)
62
0
        return 0;
63
64
3
    glob_tevent_reg->skhands = sk_THREAD_EVENT_HANDLER_PTR_new_null();
65
3
    glob_tevent_reg->lock = CRYPTO_THREAD_lock_new();
66
3
    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
3
    return 1;
75
3
}
76
77
static GLOBAL_TEVENT_REGISTER *get_global_tevent_register(void)
78
13
{
79
13
    if (!RUN_ONCE(&tevent_register_runonce, create_global_tevent_register))
80
0
        return NULL;
81
13
    return glob_tevent_reg;
82
13
}
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
9
{
96
9
    THREAD_EVENT_HANDLER **hands = CRYPTO_THREAD_get_local(local);
97
98
9
    if (alloc) {
99
3
        if (hands == NULL) {
100
101
3
            if ((hands = OPENSSL_zalloc(sizeof(*hands))) == NULL)
102
0
                return NULL;
103
104
3
            if (!CRYPTO_THREAD_set_local(local, hands)) {
105
0
                OPENSSL_free(hands);
106
0
                return NULL;
107
0
            }
108
109
3
#ifndef FIPS_MODULE
110
3
            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
3
#endif
116
3
        }
117
6
    } else if (!keep) {
118
3
        CRYPTO_THREAD_set_local(local, NULL);
119
3
    }
120
121
9
    return hands;
122
9
}
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
3
{
156
3
    int ret;
157
3
    GLOBAL_TEVENT_REGISTER *gtr;
158
159
3
    gtr = get_global_tevent_register();
160
3
    if (gtr == NULL)
161
0
        return 0;
162
163
3
    if (!CRYPTO_THREAD_write_lock(gtr->lock))
164
0
        return 0;
165
3
    ret = (sk_THREAD_EVENT_HANDLER_PTR_push(gtr->skhands, hands) != 0);
166
3
    CRYPTO_THREAD_unlock(gtr->lock);
167
168
3
    return ret;
169
3
}
170
171
static void init_thread_remove_handlers(THREAD_EVENT_HANDLER **handsin)
172
3
{
173
3
    GLOBAL_TEVENT_REGISTER *gtr;
174
3
    int i;
175
176
3
    gtr = get_global_tevent_register();
177
3
    if (gtr == NULL)
178
0
        return;
179
3
    if (!CRYPTO_THREAD_write_lock(gtr->lock))
180
0
        return;
181
3
    for (i = 0; i < sk_THREAD_EVENT_HANDLER_PTR_num(gtr->skhands); i++) {
182
3
        THREAD_EVENT_HANDLER **hands
183
3
            = sk_THREAD_EVENT_HANDLER_PTR_value(gtr->skhands, i);
184
185
3
        if (hands == handsin) {
186
3
            sk_THREAD_EVENT_HANDLER_PTR_delete(gtr->skhands, i);
187
3
            CRYPTO_THREAD_unlock(gtr->lock);
188
3
            return;
189
3
        }
190
3
    }
191
0
    CRYPTO_THREAD_unlock(gtr->lock);
192
0
    return;
193
3
}
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
3
{
204
3
    if (!CRYPTO_THREAD_init_local(&destructor_key.value,
205
3
                                  init_thread_destructor))
206
0
        return 0;
207
208
3
    return 1;
209
3
}
210
211
void ossl_cleanup_thread(void)
212
3
{
213
3
    init_thread_deregister(NULL, 1);
214
3
    CRYPTO_THREAD_cleanup_local(&destructor_key.value);
215
3
    destructor_key.sane = -1;
216
3
}
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
3
{
231
3
    if (destructor_key.sane != -1) {
232
3
        THREAD_EVENT_HANDLER **hands
233
3
            = init_get_thread_local(&destructor_key.value, 0, 0);
234
3
        init_thread_stop(NULL, hands);
235
236
3
        init_thread_remove_handlers(hands);
237
3
        OPENSSL_free(hands);
238
3
    }
239
3
}
240
241
void ossl_ctx_thread_stop(OSSL_LIB_CTX *ctx)
242
3
{
243
3
    if (destructor_key.sane != -1) {
244
3
        THREAD_EVENT_HANDLER **hands
245
3
            = init_get_thread_local(&destructor_key.value, 0, 1);
246
3
        init_thread_stop(ctx, hands);
247
3
    }
248
3
}
249
250
#else
251
252
static void ossl_arg_thread_stop(void *arg);
253
254
/* Register the current thread so that we are informed if it gets stopped */
255
int ossl_thread_register_fips(OSSL_LIB_CTX *libctx)
256
{
257
    return c_thread_start(FIPS_get_core_handle(libctx), ossl_arg_thread_stop,
258
                          libctx);
259
}
260
261
void *ossl_thread_event_ctx_new(OSSL_LIB_CTX *libctx)
262
{
263
    THREAD_EVENT_HANDLER **hands = NULL;
264
    CRYPTO_THREAD_LOCAL *tlocal = OPENSSL_zalloc(sizeof(*tlocal));
265
266
    if (tlocal == NULL)
267
        return NULL;
268
269
    if (!CRYPTO_THREAD_init_local(tlocal, NULL)) {
270
        goto err;
271
    }
272
273
    hands = OPENSSL_zalloc(sizeof(*hands));
274
    if (hands == NULL)
275
        goto err;
276
277
    if (!CRYPTO_THREAD_set_local(tlocal, hands))
278
        goto err;
279
280
    /*
281
     * We should ideally call ossl_thread_register_fips() here. This function
282
     * is called during the startup of the FIPS provider and we need to ensure
283
     * that the main thread is registered to receive thread callbacks in order
284
     * to free |hands| that we allocated above. However we are too early in
285
     * the FIPS provider initialisation that FIPS_get_core_handle() doesn't work
286
     * yet. So we defer this to the main provider OSSL_provider_init_int()
287
     * function.
288
     */
289
290
    return tlocal;
291
 err:
292
    OPENSSL_free(hands);
293
    OPENSSL_free(tlocal);
294
    return NULL;
295
}
296
297
void ossl_thread_event_ctx_free(void *tlocal)
298
{
299
    OPENSSL_free(tlocal);
300
}
301
302
static void ossl_arg_thread_stop(void *arg)
303
{
304
    ossl_ctx_thread_stop((OSSL_LIB_CTX *)arg);
305
}
306
307
void ossl_ctx_thread_stop(OSSL_LIB_CTX *ctx)
308
{
309
    THREAD_EVENT_HANDLER **hands;
310
    CRYPTO_THREAD_LOCAL *local
311
        = ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_THREAD_EVENT_HANDLER_INDEX);
312
313
    if (local == NULL)
314
        return;
315
    hands = init_get_thread_local(local, 0, 0);
316
    init_thread_stop(ctx, hands);
317
    OPENSSL_free(hands);
318
}
319
#endif /* FIPS_MODULE */
320
321
322
static void init_thread_stop(void *arg, THREAD_EVENT_HANDLER **hands)
323
6
{
324
6
    THREAD_EVENT_HANDLER *curr, *prev = NULL, *tmp;
325
6
#ifndef FIPS_MODULE
326
6
    GLOBAL_TEVENT_REGISTER *gtr;
327
6
#endif
328
329
    /* Can't do much about this */
330
6
    if (hands == NULL)
331
3
        return;
332
333
3
#ifndef FIPS_MODULE
334
3
    gtr = get_global_tevent_register();
335
3
    if (gtr == NULL)
336
0
        return;
337
338
3
    if (!CRYPTO_THREAD_write_lock(gtr->lock))
339
0
        return;
340
3
#endif
341
342
3
    curr = *hands;
343
6
    while (curr != NULL) {
344
3
        if (arg != NULL && curr->arg != arg) {
345
0
            prev = curr;
346
0
            curr = curr->next;
347
0
            continue;
348
0
        }
349
3
        curr->handfn(curr->arg);
350
3
        if (prev == NULL)
351
3
            *hands = curr->next;
352
0
        else
353
0
            prev->next = curr->next;
354
355
3
        tmp = curr;
356
3
        curr = curr->next;
357
358
3
        OPENSSL_free(tmp);
359
3
    }
360
3
#ifndef FIPS_MODULE
361
3
    CRYPTO_THREAD_unlock(gtr->lock);
362
3
#endif
363
3
}
364
365
int ossl_init_thread_start(const void *index, void *arg,
366
                           OSSL_thread_stop_handler_fn handfn)
367
3
{
368
3
    THREAD_EVENT_HANDLER **hands;
369
3
    THREAD_EVENT_HANDLER *hand;
370
#ifdef FIPS_MODULE
371
    OSSL_LIB_CTX *ctx = arg;
372
373
    /*
374
     * In FIPS mode the list of THREAD_EVENT_HANDLERs is unique per combination
375
     * of OSSL_LIB_CTX and thread. This is because in FIPS mode each
376
     * OSSL_LIB_CTX gets informed about thread stop events individually.
377
     */
378
    CRYPTO_THREAD_LOCAL *local
379
        = ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_THREAD_EVENT_HANDLER_INDEX);
380
#else
381
    /*
382
     * Outside of FIPS mode the list of THREAD_EVENT_HANDLERs is unique per
383
     * thread, but may hold multiple OSSL_LIB_CTXs. We only get told about
384
     * thread stop events globally, so we have to ensure all affected
385
     * OSSL_LIB_CTXs are informed.
386
     */
387
3
    CRYPTO_THREAD_LOCAL *local = &destructor_key.value;
388
3
#endif
389
390
3
    hands = init_get_thread_local(local, 1, 0);
391
3
    if (hands == NULL)
392
0
        return 0;
393
394
#ifdef FIPS_MODULE
395
    if (*hands == NULL) {
396
        /*
397
         * We've not yet registered any handlers for this thread. We need to get
398
         * libcrypto to tell us about later thread stop events. c_thread_start
399
         * is a callback to libcrypto defined in fipsprov.c
400
         */
401
        if (!ossl_thread_register_fips(ctx))
402
            return 0;
403
    }
404
#endif
405
406
3
    hand = OPENSSL_malloc(sizeof(*hand));
407
3
    if (hand == NULL)
408
0
        return 0;
409
410
3
    hand->handfn = handfn;
411
3
    hand->arg = arg;
412
3
#ifndef FIPS_MODULE
413
3
    hand->index = index;
414
3
#endif
415
3
    hand->next = *hands;
416
3
    *hands = hand;
417
418
3
    return 1;
419
3
}
420
421
#ifndef FIPS_MODULE
422
static int init_thread_deregister(void *index, int all)
423
4
{
424
4
    GLOBAL_TEVENT_REGISTER *gtr;
425
4
    int i;
426
427
4
    gtr = get_global_tevent_register();
428
4
    if (gtr == NULL)
429
0
        return 0;
430
4
    if (!all) {
431
1
        if (!CRYPTO_THREAD_write_lock(gtr->lock))
432
0
            return 0;
433
3
    } else {
434
3
        glob_tevent_reg = NULL;
435
3
    }
436
4
    for (i = 0; i < sk_THREAD_EVENT_HANDLER_PTR_num(gtr->skhands); i++) {
437
0
        THREAD_EVENT_HANDLER **hands
438
0
            = sk_THREAD_EVENT_HANDLER_PTR_value(gtr->skhands, i);
439
0
        THREAD_EVENT_HANDLER *curr = NULL, *prev = NULL, *tmp;
440
441
0
        if (hands == NULL) {
442
0
            if (!all)
443
0
                CRYPTO_THREAD_unlock(gtr->lock);
444
0
            return 0;
445
0
        }
446
0
        curr = *hands;
447
0
        while (curr != NULL) {
448
0
            if (all || curr->index == index) {
449
0
                if (prev != NULL)
450
0
                    prev->next = curr->next;
451
0
                else
452
0
                    *hands = curr->next;
453
0
                tmp = curr;
454
0
                curr = curr->next;
455
0
                OPENSSL_free(tmp);
456
0
                continue;
457
0
            }
458
0
            prev = curr;
459
0
            curr = curr->next;
460
0
        }
461
0
        if (all)
462
0
            OPENSSL_free(hands);
463
0
    }
464
4
    if (all) {
465
3
        CRYPTO_THREAD_lock_free(gtr->lock);
466
3
        sk_THREAD_EVENT_HANDLER_PTR_free(gtr->skhands);
467
3
        OPENSSL_free(gtr);
468
3
    } else {
469
1
        CRYPTO_THREAD_unlock(gtr->lock);
470
1
    }
471
4
    return 1;
472
4
}
473
474
int ossl_init_thread_deregister(void *index)
475
1
{
476
1
    return init_thread_deregister(index, 0);
477
1
}
478
#endif