Coverage Report

Created: 2025-06-13 06:56

/src/openssl/crypto/mem_sec.c
Line
Count
Source (jump to first uncovered line)
1
/*
2
 * Copyright 2015-2024 The OpenSSL Project Authors. All Rights Reserved.
3
 * Copyright 2004-2014, Akamai Technologies. All Rights Reserved.
4
 *
5
 * Licensed under the Apache License 2.0 (the "License").  You may not use
6
 * this file except in compliance with the License.  You can obtain a copy
7
 * in the file LICENSE in the source distribution or at
8
 * https://www.openssl.org/source/license.html
9
 */
10
11
/*
12
 * This file is in two halves. The first half implements the public API
13
 * to be used by external consumers, and to be used by OpenSSL to store
14
 * data in a "secure arena." The second half implements the secure arena.
15
 * For details on that implementation, see below (look for uppercase
16
 * "SECURE HEAP IMPLEMENTATION").
17
 */
18
#include "internal/e_os.h"
19
#include <openssl/crypto.h>
20
#include <openssl/err.h>
21
22
#include <string.h>
23
24
#ifndef OPENSSL_NO_SECURE_MEMORY
25
# if defined(_WIN32)
26
#  include <windows.h>
27
#  if defined(WINAPI_FAMILY_PARTITION)
28
#   if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP | WINAPI_PARTITION_SYSTEM)
29
/*
30
 * While VirtualLock is available under the app partition (e.g. UWP),
31
 * the headers do not define the API. Define it ourselves instead.
32
 */
33
WINBASEAPI
34
BOOL
35
WINAPI
36
VirtualLock(
37
    _In_ LPVOID lpAddress,
38
    _In_ SIZE_T dwSize
39
    );
40
#   endif
41
#  endif
42
# endif
43
# include <stdlib.h>
44
# include <assert.h>
45
# if defined(OPENSSL_SYS_UNIX)
46
#  include <unistd.h>
47
# endif
48
# include <sys/types.h>
49
# if defined(OPENSSL_SYS_UNIX)
50
#  include <sys/mman.h>
51
#  if defined(__FreeBSD__)
52
#    define MADV_DONTDUMP MADV_NOCORE
53
#  endif
54
#  if !defined(MAP_CONCEAL)
55
0
#    define MAP_CONCEAL 0
56
#  endif
57
# endif
58
# if defined(OPENSSL_SYS_LINUX)
59
#  include <sys/syscall.h>
60
#  if defined(SYS_mlock2)
61
#   include <linux/mman.h>
62
#   include <errno.h>
63
#  endif
64
#  include <sys/param.h>
65
# endif
66
# include <sys/stat.h>
67
# include <fcntl.h>
68
#endif
69
#ifndef HAVE_MADVISE
70
# if defined(MADV_DONTDUMP)
71
#  define HAVE_MADVISE 1
72
# else
73
#  define HAVE_MADVISE 0
74
# endif
75
#endif
76
#if HAVE_MADVISE
77
# undef NO_MADVISE
78
#else
79
# define NO_MADVISE
80
#endif
81
82
0
#define CLEAR(p, s) OPENSSL_cleanse(p, s)
83
#ifndef PAGE_SIZE
84
0
# define PAGE_SIZE    4096
85
#endif
86
#if !defined(MAP_ANON) && defined(MAP_ANONYMOUS)
87
# define MAP_ANON MAP_ANONYMOUS
88
#endif
89
90
#ifndef OPENSSL_NO_SECURE_MEMORY
91
static size_t secure_mem_used;
92
93
static int secure_mem_initialized;
94
95
static CRYPTO_RWLOCK *sec_malloc_lock = NULL;
96
97
/*
98
 * These are the functions that must be implemented by a secure heap (sh).
99
 */
100
static int sh_init(size_t size, size_t minsize);
101
static void *sh_malloc(size_t size);
102
static void sh_free(void *ptr);
103
static void sh_done(void);
104
static size_t sh_actual_size(char *ptr);
105
static int sh_allocated(const char *ptr);
106
#endif
107
108
int CRYPTO_secure_malloc_init(size_t size, size_t minsize)
109
0
{
110
0
#ifndef OPENSSL_NO_SECURE_MEMORY
111
0
    int ret = 0;
112
113
0
    if (!secure_mem_initialized) {
114
0
        sec_malloc_lock = CRYPTO_THREAD_lock_new();
115
0
        if (sec_malloc_lock == NULL)
116
0
            return 0;
117
0
        if ((ret = sh_init(size, minsize)) != 0) {
118
0
            secure_mem_initialized = 1;
119
0
        } else {
120
0
            CRYPTO_THREAD_lock_free(sec_malloc_lock);
121
0
            sec_malloc_lock = NULL;
122
0
        }
123
0
    }
124
125
0
    return ret;
126
#else
127
    return 0;
128
#endif /* OPENSSL_NO_SECURE_MEMORY */
129
0
}
130
131
int CRYPTO_secure_malloc_done(void)
132
2
{
133
2
#ifndef OPENSSL_NO_SECURE_MEMORY
134
2
    if (secure_mem_used == 0) {
135
2
        sh_done();
136
2
        secure_mem_initialized = 0;
137
2
        CRYPTO_THREAD_lock_free(sec_malloc_lock);
138
2
        sec_malloc_lock = NULL;
139
2
        return 1;
140
2
    }
141
0
#endif /* OPENSSL_NO_SECURE_MEMORY */
142
0
    return 0;
143
2
}
144
145
int CRYPTO_secure_malloc_initialized(void)
146
0
{
147
0
#ifndef OPENSSL_NO_SECURE_MEMORY
148
0
    return secure_mem_initialized;
149
#else
150
    return 0;
151
#endif /* OPENSSL_NO_SECURE_MEMORY */
152
0
}
153
154
void *CRYPTO_secure_malloc(size_t num, const char *file, int line)
155
2
{
156
2
#ifndef OPENSSL_NO_SECURE_MEMORY
157
2
    void *ret = NULL;
158
2
    size_t actual_size;
159
2
    int reason = CRYPTO_R_SECURE_MALLOC_FAILURE;
160
161
2
    if (!secure_mem_initialized) {
162
2
        return CRYPTO_malloc(num, file, line);
163
2
    }
164
0
    if (!CRYPTO_THREAD_write_lock(sec_malloc_lock)) {
165
0
        reason = ERR_R_CRYPTO_LIB;
166
0
        goto err;
167
0
    }
168
0
    ret = sh_malloc(num);
169
0
    actual_size = ret ? sh_actual_size(ret) : 0;
170
0
    secure_mem_used += actual_size;
171
0
    CRYPTO_THREAD_unlock(sec_malloc_lock);
172
0
 err:
173
0
    if (ret == NULL && (file != NULL || line != 0)) {
174
0
        ERR_new();
175
0
        ERR_set_debug(file, line, NULL);
176
0
        ERR_set_error(ERR_LIB_CRYPTO, reason, NULL);
177
0
    }
178
0
    return ret;
179
#else
180
    return CRYPTO_malloc(num, file, line);
181
#endif /* OPENSSL_NO_SECURE_MEMORY */
182
0
}
183
184
void *CRYPTO_secure_zalloc(size_t num, const char *file, int line)
185
3
{
186
3
#ifndef OPENSSL_NO_SECURE_MEMORY
187
3
    if (secure_mem_initialized)
188
        /* CRYPTO_secure_malloc() zeroes allocations when it is implemented */
189
0
        return CRYPTO_secure_malloc(num, file, line);
190
3
#endif
191
3
    return CRYPTO_zalloc(num, file, line);
192
3
}
193
194
void CRYPTO_secure_free(void *ptr, const char *file, int line)
195
0
{
196
0
#ifndef OPENSSL_NO_SECURE_MEMORY
197
0
    size_t actual_size;
198
199
0
    if (ptr == NULL)
200
0
        return;
201
0
    if (!CRYPTO_secure_allocated(ptr)) {
202
0
        CRYPTO_free(ptr, file, line);
203
0
        return;
204
0
    }
205
0
    if (!CRYPTO_THREAD_write_lock(sec_malloc_lock))
206
0
        return;
207
0
    actual_size = sh_actual_size(ptr);
208
0
    CLEAR(ptr, actual_size);
209
0
    secure_mem_used -= actual_size;
210
0
    sh_free(ptr);
211
0
    CRYPTO_THREAD_unlock(sec_malloc_lock);
212
#else
213
    CRYPTO_free(ptr, file, line);
214
#endif /* OPENSSL_NO_SECURE_MEMORY */
215
0
}
216
217
void CRYPTO_secure_clear_free(void *ptr, size_t num,
218
                              const char *file, int line)
219
6
{
220
6
#ifndef OPENSSL_NO_SECURE_MEMORY
221
6
    size_t actual_size;
222
223
6
    if (ptr == NULL)
224
1
        return;
225
5
    if (!CRYPTO_secure_allocated(ptr)) {
226
5
        OPENSSL_cleanse(ptr, num);
227
5
        CRYPTO_free(ptr, file, line);
228
5
        return;
229
5
    }
230
0
    if (!CRYPTO_THREAD_write_lock(sec_malloc_lock))
231
0
        return;
232
0
    actual_size = sh_actual_size(ptr);
233
0
    CLEAR(ptr, actual_size);
234
0
    secure_mem_used -= actual_size;
235
0
    sh_free(ptr);
236
0
    CRYPTO_THREAD_unlock(sec_malloc_lock);
237
#else
238
    if (ptr == NULL)
239
        return;
240
    OPENSSL_cleanse(ptr, num);
241
    CRYPTO_free(ptr, file, line);
242
#endif /* OPENSSL_NO_SECURE_MEMORY */
243
0
}
244
245
int CRYPTO_secure_allocated(const void *ptr)
246
5
{
247
5
#ifndef OPENSSL_NO_SECURE_MEMORY
248
5
    if (!secure_mem_initialized)
249
5
        return 0;
250
    /*
251
     * Only read accesses to the arena take place in sh_allocated() and this
252
     * is only changed by the sh_init() and sh_done() calls which are not
253
     * locked.  Hence, it is safe to make this check without a lock too.
254
     */
255
0
    return sh_allocated(ptr);
256
#else
257
    return 0;
258
#endif /* OPENSSL_NO_SECURE_MEMORY */
259
5
}
260
261
size_t CRYPTO_secure_used(void)
262
0
{
263
0
    size_t ret = 0;
264
265
0
#ifndef OPENSSL_NO_SECURE_MEMORY
266
0
    if (!CRYPTO_THREAD_read_lock(sec_malloc_lock))
267
0
        return 0;
268
269
0
    ret = secure_mem_used;
270
271
0
    CRYPTO_THREAD_unlock(sec_malloc_lock);
272
0
#endif /* OPENSSL_NO_SECURE_MEMORY */
273
0
    return ret;
274
0
}
275
276
size_t CRYPTO_secure_actual_size(void *ptr)
277
0
{
278
0
#ifndef OPENSSL_NO_SECURE_MEMORY
279
0
    size_t actual_size;
280
281
0
    if (!CRYPTO_THREAD_write_lock(sec_malloc_lock))
282
0
        return 0;
283
0
    actual_size = sh_actual_size(ptr);
284
0
    CRYPTO_THREAD_unlock(sec_malloc_lock);
285
0
    return actual_size;
286
#else
287
    return 0;
288
#endif
289
0
}
290
291
/*
292
 * SECURE HEAP IMPLEMENTATION
293
 */
294
#ifndef OPENSSL_NO_SECURE_MEMORY
295
296
297
/*
298
 * The implementation provided here uses a fixed-sized mmap() heap,
299
 * which is locked into memory, not written to core files, and protected
300
 * on either side by an unmapped page, which will catch pointer overruns
301
 * (or underruns) and an attempt to read data out of the secure heap.
302
 * Free'd memory is zero'd or otherwise cleansed.
303
 *
304
 * This is a pretty standard buddy allocator.  We keep areas in a multiple
305
 * of "sh.minsize" units.  The freelist and bitmaps are kept separately,
306
 * so all (and only) data is kept in the mmap'd heap.
307
 *
308
 * This code assumes eight-bit bytes.  The numbers 3 and 7 are all over the
309
 * place.
310
 */
311
312
0
#define ONE ((size_t)1)
313
314
0
# define TESTBIT(t, b)  (t[(b) >> 3] &  (ONE << ((b) & 7)))
315
0
# define SETBIT(t, b)   (t[(b) >> 3] |= (ONE << ((b) & 7)))
316
0
# define CLEARBIT(t, b) (t[(b) >> 3] &= (0xFF & ~(ONE << ((b) & 7))))
317
318
#define WITHIN_ARENA(p) \
319
0
    ((char*)(p) >= sh.arena && (char*)(p) < &sh.arena[sh.arena_size])
320
#define WITHIN_FREELIST(p) \
321
    ((char*)(p) >= (char*)sh.freelist && (char*)(p) < (char*)&sh.freelist[sh.freelist_size])
322
323
324
typedef struct sh_list_st {
325
    struct sh_list_st *next;
326
    struct sh_list_st **p_next;
327
} SH_LIST;
328
329
typedef struct sh_st {
330
    char* map_result;
331
    size_t map_size;
332
    char *arena;
333
    size_t arena_size;
334
    char **freelist;
335
    ossl_ssize_t freelist_size;
336
    size_t minsize;
337
    unsigned char *bittable;
338
    unsigned char *bitmalloc;
339
    size_t bittable_size; /* size in bits */
340
} SH;
341
342
static SH sh;
343
344
static size_t sh_getlist(char *ptr)
345
0
{
346
0
    ossl_ssize_t list = sh.freelist_size - 1;
347
0
    size_t bit = (sh.arena_size + ptr - sh.arena) / sh.minsize;
348
349
0
    for (; bit; bit >>= 1, list--) {
350
0
        if (TESTBIT(sh.bittable, bit))
351
0
            break;
352
0
        OPENSSL_assert((bit & 1) == 0);
353
0
    }
354
355
0
    return list;
356
0
}
357
358
359
static int sh_testbit(char *ptr, int list, unsigned char *table)
360
0
{
361
0
    size_t bit;
362
363
0
    OPENSSL_assert(list >= 0 && list < sh.freelist_size);
364
0
    OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
365
0
    bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
366
0
    OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
367
0
    return TESTBIT(table, bit);
368
0
}
369
370
static void sh_clearbit(char *ptr, int list, unsigned char *table)
371
0
{
372
0
    size_t bit;
373
374
0
    OPENSSL_assert(list >= 0 && list < sh.freelist_size);
375
0
    OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
376
0
    bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
377
0
    OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
378
0
    OPENSSL_assert(TESTBIT(table, bit));
379
0
    CLEARBIT(table, bit);
380
0
}
381
382
static void sh_setbit(char *ptr, int list, unsigned char *table)
383
0
{
384
0
    size_t bit;
385
386
0
    OPENSSL_assert(list >= 0 && list < sh.freelist_size);
387
0
    OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
388
0
    bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
389
0
    OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
390
0
    OPENSSL_assert(!TESTBIT(table, bit));
391
0
    SETBIT(table, bit);
392
0
}
393
394
static void sh_add_to_list(char **list, char *ptr)
395
0
{
396
0
    SH_LIST *temp;
397
398
0
    OPENSSL_assert(WITHIN_FREELIST(list));
399
0
    OPENSSL_assert(WITHIN_ARENA(ptr));
400
401
0
    temp = (SH_LIST *)ptr;
402
0
    temp->next = *(SH_LIST **)list;
403
0
    OPENSSL_assert(temp->next == NULL || WITHIN_ARENA(temp->next));
404
0
    temp->p_next = (SH_LIST **)list;
405
406
0
    if (temp->next != NULL) {
407
0
        OPENSSL_assert((char **)temp->next->p_next == list);
408
0
        temp->next->p_next = &(temp->next);
409
0
    }
410
411
0
    *list = ptr;
412
0
}
413
414
static void sh_remove_from_list(char *ptr)
415
0
{
416
0
    SH_LIST *temp, *temp2;
417
418
0
    temp = (SH_LIST *)ptr;
419
0
    if (temp->next != NULL)
420
0
        temp->next->p_next = temp->p_next;
421
0
    *temp->p_next = temp->next;
422
0
    if (temp->next == NULL)
423
0
        return;
424
425
0
    temp2 = temp->next;
426
0
    OPENSSL_assert(WITHIN_FREELIST(temp2->p_next) || WITHIN_ARENA(temp2->p_next));
427
0
}
428
429
430
static int sh_init(size_t size, size_t minsize)
431
0
{
432
0
    int ret;
433
0
    size_t i;
434
0
    size_t pgsize;
435
0
    size_t aligned;
436
#if defined(_WIN32)
437
    DWORD flOldProtect;
438
    SYSTEM_INFO systemInfo;
439
#endif
440
441
0
    memset(&sh, 0, sizeof(sh));
442
443
    /* make sure size is a powers of 2 */
444
0
    OPENSSL_assert(size > 0);
445
0
    OPENSSL_assert((size & (size - 1)) == 0);
446
0
    if (size == 0 || (size & (size - 1)) != 0)
447
0
        goto err;
448
449
0
    if (minsize <= sizeof(SH_LIST)) {
450
0
        OPENSSL_assert(sizeof(SH_LIST) <= 65536);
451
        /*
452
         * Compute the minimum possible allocation size.
453
         * This must be a power of 2 and at least as large as the SH_LIST
454
         * structure.
455
         */
456
0
        minsize = sizeof(SH_LIST) - 1;
457
0
        minsize |= minsize >> 1;
458
0
        minsize |= minsize >> 2;
459
0
        if (sizeof(SH_LIST) > 16)
460
0
            minsize |= minsize >> 4;
461
0
        if (sizeof(SH_LIST) > 256)
462
0
            minsize |= minsize >> 8;
463
0
        minsize++;
464
0
    } else {
465
        /* make sure minsize is a powers of 2 */
466
0
          OPENSSL_assert((minsize & (minsize - 1)) == 0);
467
0
          if ((minsize & (minsize - 1)) != 0)
468
0
              goto err;
469
0
    }
470
471
0
    sh.arena_size = size;
472
0
    sh.minsize = minsize;
473
0
    sh.bittable_size = (sh.arena_size / sh.minsize) * 2;
474
475
    /* Prevent allocations of size 0 later on */
476
0
    if (sh.bittable_size >> 3 == 0)
477
0
        goto err;
478
479
0
    sh.freelist_size = -1;
480
0
    for (i = sh.bittable_size; i; i >>= 1)
481
0
        sh.freelist_size++;
482
483
0
    sh.freelist = OPENSSL_zalloc(sh.freelist_size * sizeof(char *));
484
0
    OPENSSL_assert(sh.freelist != NULL);
485
0
    if (sh.freelist == NULL)
486
0
        goto err;
487
488
0
    sh.bittable = OPENSSL_zalloc(sh.bittable_size >> 3);
489
0
    OPENSSL_assert(sh.bittable != NULL);
490
0
    if (sh.bittable == NULL)
491
0
        goto err;
492
493
0
    sh.bitmalloc = OPENSSL_zalloc(sh.bittable_size >> 3);
494
0
    OPENSSL_assert(sh.bitmalloc != NULL);
495
0
    if (sh.bitmalloc == NULL)
496
0
        goto err;
497
498
    /* Allocate space for heap, and two extra pages as guards */
499
0
#if defined(_SC_PAGE_SIZE) || defined (_SC_PAGESIZE)
500
0
    {
501
0
# if defined(_SC_PAGE_SIZE)
502
0
        long tmppgsize = sysconf(_SC_PAGE_SIZE);
503
# else
504
        long tmppgsize = sysconf(_SC_PAGESIZE);
505
# endif
506
0
        if (tmppgsize < 1)
507
0
            pgsize = PAGE_SIZE;
508
0
        else
509
0
            pgsize = (size_t)tmppgsize;
510
0
    }
511
#elif defined(_WIN32)
512
    GetSystemInfo(&systemInfo);
513
    pgsize = (size_t)systemInfo.dwPageSize;
514
#else
515
    pgsize = PAGE_SIZE;
516
#endif
517
0
    sh.map_size = pgsize + sh.arena_size + pgsize;
518
519
0
#if !defined(_WIN32)
520
0
# ifdef MAP_ANON
521
0
    sh.map_result = mmap(NULL, sh.map_size,
522
0
                         PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE|MAP_CONCEAL, -1, 0);
523
# else
524
    {
525
        int fd;
526
527
        sh.map_result = MAP_FAILED;
528
        if ((fd = open("/dev/zero", O_RDWR)) >= 0) {
529
            sh.map_result = mmap(NULL, sh.map_size,
530
                                 PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
531
            close(fd);
532
        }
533
    }
534
# endif
535
0
    if (sh.map_result == MAP_FAILED)
536
0
        goto err;
537
#else
538
    sh.map_result = VirtualAlloc(NULL, sh.map_size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
539
540
    if (sh.map_result == NULL)
541
            goto err;
542
#endif
543
544
0
    sh.arena = (char *)(sh.map_result + pgsize);
545
0
    sh_setbit(sh.arena, 0, sh.bittable);
546
0
    sh_add_to_list(&sh.freelist[0], sh.arena);
547
548
    /* Now try to add guard pages and lock into memory. */
549
0
    ret = 1;
550
551
0
#if !defined(_WIN32)
552
    /* Starting guard is already aligned from mmap. */
553
0
    if (mprotect(sh.map_result, pgsize, PROT_NONE) < 0)
554
0
        ret = 2;
555
#else
556
    if (VirtualProtect(sh.map_result, pgsize, PAGE_NOACCESS, &flOldProtect) == FALSE)
557
        ret = 2;
558
#endif
559
560
    /* Ending guard page - need to round up to page boundary */
561
0
    aligned = (pgsize + sh.arena_size + (pgsize - 1)) & ~(pgsize - 1);
562
0
#if !defined(_WIN32)
563
0
    if (mprotect(sh.map_result + aligned, pgsize, PROT_NONE) < 0)
564
0
        ret = 2;
565
#else
566
    if (VirtualProtect(sh.map_result + aligned, pgsize, PAGE_NOACCESS, &flOldProtect) == FALSE)
567
        ret = 2;
568
#endif
569
570
0
#if defined(OPENSSL_SYS_LINUX) && defined(MLOCK_ONFAULT) && defined(SYS_mlock2)
571
0
    if (syscall(SYS_mlock2, sh.arena, sh.arena_size, MLOCK_ONFAULT) < 0) {
572
0
        if (errno == ENOSYS) {
573
0
            if (mlock(sh.arena, sh.arena_size) < 0)
574
0
                ret = 2;
575
0
        } else {
576
0
            ret = 2;
577
0
        }
578
0
    }
579
#elif defined(_WIN32)
580
    if (VirtualLock(sh.arena, sh.arena_size) == FALSE)
581
        ret = 2;
582
#else
583
    if (mlock(sh.arena, sh.arena_size) < 0)
584
        ret = 2;
585
#endif
586
0
#ifndef NO_MADVISE
587
0
    if (madvise(sh.arena, sh.arena_size, MADV_DONTDUMP) < 0)
588
0
        ret = 2;
589
0
#endif
590
591
0
    return ret;
592
593
0
 err:
594
0
    sh_done();
595
0
    return 0;
596
0
}
597
598
static void sh_done(void)
599
2
{
600
2
    OPENSSL_free(sh.freelist);
601
2
    OPENSSL_free(sh.bittable);
602
2
    OPENSSL_free(sh.bitmalloc);
603
2
#if !defined(_WIN32)
604
2
    if (sh.map_result != MAP_FAILED && sh.map_size)
605
0
        munmap(sh.map_result, sh.map_size);
606
#else
607
    if (sh.map_result != NULL && sh.map_size)
608
        VirtualFree(sh.map_result, 0, MEM_RELEASE);
609
#endif
610
2
    memset(&sh, 0, sizeof(sh));
611
2
}
612
613
static int sh_allocated(const char *ptr)
614
0
{
615
0
    return WITHIN_ARENA(ptr) ? 1 : 0;
616
0
}
617
618
static char *sh_find_my_buddy(char *ptr, int list)
619
0
{
620
0
    size_t bit;
621
0
    char *chunk = NULL;
622
623
0
    bit = (ONE << list) + (ptr - sh.arena) / (sh.arena_size >> list);
624
0
    bit ^= 1;
625
626
0
    if (TESTBIT(sh.bittable, bit) && !TESTBIT(sh.bitmalloc, bit))
627
0
        chunk = sh.arena + ((bit & ((ONE << list) - 1)) * (sh.arena_size >> list));
628
629
0
    return chunk;
630
0
}
631
632
static void *sh_malloc(size_t size)
633
0
{
634
0
    ossl_ssize_t list, slist;
635
0
    size_t i;
636
0
    char *chunk;
637
638
0
    if (size > sh.arena_size)
639
0
        return NULL;
640
641
0
    list = sh.freelist_size - 1;
642
0
    for (i = sh.minsize; i < size; i <<= 1)
643
0
        list--;
644
0
    if (list < 0)
645
0
        return NULL;
646
647
    /* try to find a larger entry to split */
648
0
    for (slist = list; slist >= 0; slist--)
649
0
        if (sh.freelist[slist] != NULL)
650
0
            break;
651
0
    if (slist < 0)
652
0
        return NULL;
653
654
    /* split larger entry */
655
0
    while (slist != list) {
656
0
        char *temp = sh.freelist[slist];
657
658
        /* remove from bigger list */
659
0
        OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
660
0
        sh_clearbit(temp, slist, sh.bittable);
661
0
        sh_remove_from_list(temp);
662
0
        OPENSSL_assert(temp != sh.freelist[slist]);
663
664
        /* done with bigger list */
665
0
        slist++;
666
667
        /* add to smaller list */
668
0
        OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
669
0
        sh_setbit(temp, slist, sh.bittable);
670
0
        sh_add_to_list(&sh.freelist[slist], temp);
671
0
        OPENSSL_assert(sh.freelist[slist] == temp);
672
673
        /* split in 2 */
674
0
        temp += sh.arena_size >> slist;
675
0
        OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
676
0
        sh_setbit(temp, slist, sh.bittable);
677
0
        sh_add_to_list(&sh.freelist[slist], temp);
678
0
        OPENSSL_assert(sh.freelist[slist] == temp);
679
680
0
        OPENSSL_assert(temp-(sh.arena_size >> slist) == sh_find_my_buddy(temp, slist));
681
0
    }
682
683
    /* peel off memory to hand back */
684
0
    chunk = sh.freelist[list];
685
0
    OPENSSL_assert(sh_testbit(chunk, list, sh.bittable));
686
0
    sh_setbit(chunk, list, sh.bitmalloc);
687
0
    sh_remove_from_list(chunk);
688
689
0
    OPENSSL_assert(WITHIN_ARENA(chunk));
690
691
    /* zero the free list header as a precaution against information leakage */
692
0
    memset(chunk, 0, sizeof(SH_LIST));
693
694
0
    return chunk;
695
0
}
696
697
static void sh_free(void *ptr)
698
0
{
699
0
    size_t list;
700
0
    void *buddy;
701
702
0
    if (ptr == NULL)
703
0
        return;
704
0
    OPENSSL_assert(WITHIN_ARENA(ptr));
705
0
    if (!WITHIN_ARENA(ptr))
706
0
        return;
707
708
0
    list = sh_getlist(ptr);
709
0
    OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
710
0
    sh_clearbit(ptr, list, sh.bitmalloc);
711
0
    sh_add_to_list(&sh.freelist[list], ptr);
712
713
    /* Try to coalesce two adjacent free areas. */
714
0
    while ((buddy = sh_find_my_buddy(ptr, list)) != NULL) {
715
0
        OPENSSL_assert(ptr == sh_find_my_buddy(buddy, list));
716
0
        OPENSSL_assert(ptr != NULL);
717
0
        OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
718
0
        sh_clearbit(ptr, list, sh.bittable);
719
0
        sh_remove_from_list(ptr);
720
0
        OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
721
0
        sh_clearbit(buddy, list, sh.bittable);
722
0
        sh_remove_from_list(buddy);
723
724
0
        list--;
725
726
        /* Zero the higher addressed block's free list pointers */
727
0
        memset(ptr > buddy ? ptr : buddy, 0, sizeof(SH_LIST));
728
0
        if (ptr > buddy)
729
0
            ptr = buddy;
730
731
0
        OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
732
0
        sh_setbit(ptr, list, sh.bittable);
733
0
        sh_add_to_list(&sh.freelist[list], ptr);
734
0
        OPENSSL_assert(sh.freelist[list] == ptr);
735
0
    }
736
0
}
737
738
static size_t sh_actual_size(char *ptr)
739
0
{
740
0
    int list;
741
742
0
    OPENSSL_assert(WITHIN_ARENA(ptr));
743
0
    if (!WITHIN_ARENA(ptr))
744
0
        return 0;
745
0
    list = sh_getlist(ptr);
746
0
    OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
747
0
    return sh.arena_size / (ONE << list);
748
0
}
749
#endif /* OPENSSL_NO_SECURE_MEMORY */