1/*
2 * Copyright 2015-2023 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 "e_os.h"
19#include <openssl/crypto.h>
20
21#include <string.h>
22
23#ifndef OPENSSL_NO_SECURE_MEMORY
24# if defined(_WIN32)
25#  include <windows.h>
26#  if defined(WINAPI_FAMILY_PARTITION)
27#   if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP | WINAPI_PARTITION_SYSTEM)
28/*
29 * While VirtualLock is available under the app partition (e.g. UWP),
30 * the headers do not define the API. Define it ourselves instead.
31 */
32WINBASEAPI
33BOOL
34WINAPI
35VirtualLock(
36    _In_ LPVOID lpAddress,
37    _In_ SIZE_T dwSize
38    );
39#   endif
40#  endif
41# endif
42# include <stdlib.h>
43# include <assert.h>
44# if defined(OPENSSL_SYS_UNIX)
45#  include <unistd.h>
46# endif
47# include <sys/types.h>
48# if defined(OPENSSL_SYS_UNIX)
49#  include <sys/mman.h>
50#  if defined(__FreeBSD__)
51#    define MADV_DONTDUMP MADV_NOCORE
52#  endif
53#  if !defined(MAP_CONCEAL)
54#    define MAP_CONCEAL 0
55#  endif
56# endif
57# if defined(OPENSSL_SYS_LINUX)
58#  include <sys/syscall.h>
59#  if defined(SYS_mlock2)
60#   include <linux/mman.h>
61#   include <errno.h>
62#  endif
63#  include <sys/param.h>
64# endif
65# include <sys/stat.h>
66# include <fcntl.h>
67#endif
68
69#define CLEAR(p, s) OPENSSL_cleanse(p, s)
70#ifndef PAGE_SIZE
71# define PAGE_SIZE    4096
72#endif
73#if !defined(MAP_ANON) && defined(MAP_ANONYMOUS)
74# define MAP_ANON MAP_ANONYMOUS
75#endif
76
77#ifndef OPENSSL_NO_SECURE_MEMORY
78static size_t secure_mem_used;
79
80static int secure_mem_initialized;
81
82static CRYPTO_RWLOCK *sec_malloc_lock = NULL;
83
84/*
85 * These are the functions that must be implemented by a secure heap (sh).
86 */
87static int sh_init(size_t size, size_t minsize);
88static void *sh_malloc(size_t size);
89static void sh_free(void *ptr);
90static void sh_done(void);
91static size_t sh_actual_size(char *ptr);
92static int sh_allocated(const char *ptr);
93#endif
94
95int CRYPTO_secure_malloc_init(size_t size, size_t minsize)
96{
97#ifndef OPENSSL_NO_SECURE_MEMORY
98    int ret = 0;
99
100    if (!secure_mem_initialized) {
101        sec_malloc_lock = CRYPTO_THREAD_lock_new();
102        if (sec_malloc_lock == NULL)
103            return 0;
104        if ((ret = sh_init(size, minsize)) != 0) {
105            secure_mem_initialized = 1;
106        } else {
107            CRYPTO_THREAD_lock_free(sec_malloc_lock);
108            sec_malloc_lock = NULL;
109        }
110    }
111
112    return ret;
113#else
114    return 0;
115#endif /* OPENSSL_NO_SECURE_MEMORY */
116}
117
118int CRYPTO_secure_malloc_done(void)
119{
120#ifndef OPENSSL_NO_SECURE_MEMORY
121    if (secure_mem_used == 0) {
122        sh_done();
123        secure_mem_initialized = 0;
124        CRYPTO_THREAD_lock_free(sec_malloc_lock);
125        sec_malloc_lock = NULL;
126        return 1;
127    }
128#endif /* OPENSSL_NO_SECURE_MEMORY */
129    return 0;
130}
131
132int CRYPTO_secure_malloc_initialized(void)
133{
134#ifndef OPENSSL_NO_SECURE_MEMORY
135    return secure_mem_initialized;
136#else
137    return 0;
138#endif /* OPENSSL_NO_SECURE_MEMORY */
139}
140
141void *CRYPTO_secure_malloc(size_t num, const char *file, int line)
142{
143#ifndef OPENSSL_NO_SECURE_MEMORY
144    void *ret;
145    size_t actual_size;
146
147    if (!secure_mem_initialized) {
148        return CRYPTO_malloc(num, file, line);
149    }
150    if (!CRYPTO_THREAD_write_lock(sec_malloc_lock))
151        return NULL;
152    ret = sh_malloc(num);
153    actual_size = ret ? sh_actual_size(ret) : 0;
154    secure_mem_used += actual_size;
155    CRYPTO_THREAD_unlock(sec_malloc_lock);
156    return ret;
157#else
158    return CRYPTO_malloc(num, file, line);
159#endif /* OPENSSL_NO_SECURE_MEMORY */
160}
161
162void *CRYPTO_secure_zalloc(size_t num, const char *file, int line)
163{
164#ifndef OPENSSL_NO_SECURE_MEMORY
165    if (secure_mem_initialized)
166        /* CRYPTO_secure_malloc() zeroes allocations when it is implemented */
167        return CRYPTO_secure_malloc(num, file, line);
168#endif
169    return CRYPTO_zalloc(num, file, line);
170}
171
172void CRYPTO_secure_free(void *ptr, const char *file, int line)
173{
174#ifndef OPENSSL_NO_SECURE_MEMORY
175    size_t actual_size;
176
177    if (ptr == NULL)
178        return;
179    if (!CRYPTO_secure_allocated(ptr)) {
180        CRYPTO_free(ptr, file, line);
181        return;
182    }
183    if (!CRYPTO_THREAD_write_lock(sec_malloc_lock))
184        return;
185    actual_size = sh_actual_size(ptr);
186    CLEAR(ptr, actual_size);
187    secure_mem_used -= actual_size;
188    sh_free(ptr);
189    CRYPTO_THREAD_unlock(sec_malloc_lock);
190#else
191    CRYPTO_free(ptr, file, line);
192#endif /* OPENSSL_NO_SECURE_MEMORY */
193}
194
195void CRYPTO_secure_clear_free(void *ptr, size_t num,
196                              const char *file, int line)
197{
198#ifndef OPENSSL_NO_SECURE_MEMORY
199    size_t actual_size;
200
201    if (ptr == NULL)
202        return;
203    if (!CRYPTO_secure_allocated(ptr)) {
204        OPENSSL_cleanse(ptr, num);
205        CRYPTO_free(ptr, file, line);
206        return;
207    }
208    if (!CRYPTO_THREAD_write_lock(sec_malloc_lock))
209        return;
210    actual_size = sh_actual_size(ptr);
211    CLEAR(ptr, actual_size);
212    secure_mem_used -= actual_size;
213    sh_free(ptr);
214    CRYPTO_THREAD_unlock(sec_malloc_lock);
215#else
216    if (ptr == NULL)
217        return;
218    OPENSSL_cleanse(ptr, num);
219    CRYPTO_free(ptr, file, line);
220#endif /* OPENSSL_NO_SECURE_MEMORY */
221}
222
223int CRYPTO_secure_allocated(const void *ptr)
224{
225#ifndef OPENSSL_NO_SECURE_MEMORY
226    if (!secure_mem_initialized)
227        return 0;
228    /*
229     * Only read accesses to the arena take place in sh_allocated() and this
230     * is only changed by the sh_init() and sh_done() calls which are not
231     * locked.  Hence, it is safe to make this check without a lock too.
232     */
233    return sh_allocated(ptr);
234#else
235    return 0;
236#endif /* OPENSSL_NO_SECURE_MEMORY */
237}
238
239size_t CRYPTO_secure_used(void)
240{
241    size_t ret = 0;
242
243#ifndef OPENSSL_NO_SECURE_MEMORY
244    if (!CRYPTO_THREAD_read_lock(sec_malloc_lock))
245        return 0;
246
247    ret = secure_mem_used;
248
249    CRYPTO_THREAD_unlock(sec_malloc_lock);
250#endif /* OPENSSL_NO_SECURE_MEMORY */
251    return ret;
252}
253
254size_t CRYPTO_secure_actual_size(void *ptr)
255{
256#ifndef OPENSSL_NO_SECURE_MEMORY
257    size_t actual_size;
258
259    if (!CRYPTO_THREAD_write_lock(sec_malloc_lock))
260        return 0;
261    actual_size = sh_actual_size(ptr);
262    CRYPTO_THREAD_unlock(sec_malloc_lock);
263    return actual_size;
264#else
265    return 0;
266#endif
267}
268
269/*
270 * SECURE HEAP IMPLEMENTATION
271 */
272#ifndef OPENSSL_NO_SECURE_MEMORY
273
274
275/*
276 * The implementation provided here uses a fixed-sized mmap() heap,
277 * which is locked into memory, not written to core files, and protected
278 * on either side by an unmapped page, which will catch pointer overruns
279 * (or underruns) and an attempt to read data out of the secure heap.
280 * Free'd memory is zero'd or otherwise cleansed.
281 *
282 * This is a pretty standard buddy allocator.  We keep areas in a multiple
283 * of "sh.minsize" units.  The freelist and bitmaps are kept separately,
284 * so all (and only) data is kept in the mmap'd heap.
285 *
286 * This code assumes eight-bit bytes.  The numbers 3 and 7 are all over the
287 * place.
288 */
289
290#define ONE ((size_t)1)
291
292# define TESTBIT(t, b)  (t[(b) >> 3] &  (ONE << ((b) & 7)))
293# define SETBIT(t, b)   (t[(b) >> 3] |= (ONE << ((b) & 7)))
294# define CLEARBIT(t, b) (t[(b) >> 3] &= (0xFF & ~(ONE << ((b) & 7))))
295
296#define WITHIN_ARENA(p) \
297    ((char*)(p) >= sh.arena && (char*)(p) < &sh.arena[sh.arena_size])
298#define WITHIN_FREELIST(p) \
299    ((char*)(p) >= (char*)sh.freelist && (char*)(p) < (char*)&sh.freelist[sh.freelist_size])
300
301
302typedef struct sh_list_st
303{
304    struct sh_list_st *next;
305    struct sh_list_st **p_next;
306} SH_LIST;
307
308typedef struct sh_st
309{
310    char* map_result;
311    size_t map_size;
312    char *arena;
313    size_t arena_size;
314    char **freelist;
315    ossl_ssize_t freelist_size;
316    size_t minsize;
317    unsigned char *bittable;
318    unsigned char *bitmalloc;
319    size_t bittable_size; /* size in bits */
320} SH;
321
322static SH sh;
323
324static size_t sh_getlist(char *ptr)
325{
326    ossl_ssize_t list = sh.freelist_size - 1;
327    size_t bit = (sh.arena_size + ptr - sh.arena) / sh.minsize;
328
329    for (; bit; bit >>= 1, list--) {
330        if (TESTBIT(sh.bittable, bit))
331            break;
332        OPENSSL_assert((bit & 1) == 0);
333    }
334
335    return list;
336}
337
338
339static int sh_testbit(char *ptr, int list, unsigned char *table)
340{
341    size_t bit;
342
343    OPENSSL_assert(list >= 0 && list < sh.freelist_size);
344    OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
345    bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
346    OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
347    return TESTBIT(table, bit);
348}
349
350static void sh_clearbit(char *ptr, int list, unsigned char *table)
351{
352    size_t bit;
353
354    OPENSSL_assert(list >= 0 && list < sh.freelist_size);
355    OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
356    bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
357    OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
358    OPENSSL_assert(TESTBIT(table, bit));
359    CLEARBIT(table, bit);
360}
361
362static void sh_setbit(char *ptr, int list, unsigned char *table)
363{
364    size_t bit;
365
366    OPENSSL_assert(list >= 0 && list < sh.freelist_size);
367    OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
368    bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
369    OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
370    OPENSSL_assert(!TESTBIT(table, bit));
371    SETBIT(table, bit);
372}
373
374static void sh_add_to_list(char **list, char *ptr)
375{
376    SH_LIST *temp;
377
378    OPENSSL_assert(WITHIN_FREELIST(list));
379    OPENSSL_assert(WITHIN_ARENA(ptr));
380
381    temp = (SH_LIST *)ptr;
382    temp->next = *(SH_LIST **)list;
383    OPENSSL_assert(temp->next == NULL || WITHIN_ARENA(temp->next));
384    temp->p_next = (SH_LIST **)list;
385
386    if (temp->next != NULL) {
387        OPENSSL_assert((char **)temp->next->p_next == list);
388        temp->next->p_next = &(temp->next);
389    }
390
391    *list = ptr;
392}
393
394static void sh_remove_from_list(char *ptr)
395{
396    SH_LIST *temp, *temp2;
397
398    temp = (SH_LIST *)ptr;
399    if (temp->next != NULL)
400        temp->next->p_next = temp->p_next;
401    *temp->p_next = temp->next;
402    if (temp->next == NULL)
403        return;
404
405    temp2 = temp->next;
406    OPENSSL_assert(WITHIN_FREELIST(temp2->p_next) || WITHIN_ARENA(temp2->p_next));
407}
408
409
410static int sh_init(size_t size, size_t minsize)
411{
412    int ret;
413    size_t i;
414    size_t pgsize;
415    size_t aligned;
416#if defined(_WIN32)
417    DWORD flOldProtect;
418    SYSTEM_INFO systemInfo;
419#endif
420
421    memset(&sh, 0, sizeof(sh));
422
423    /* make sure size is a powers of 2 */
424    OPENSSL_assert(size > 0);
425    OPENSSL_assert((size & (size - 1)) == 0);
426    if (size == 0 || (size & (size - 1)) != 0)
427        goto err;
428
429    if (minsize <= sizeof(SH_LIST)) {
430        OPENSSL_assert(sizeof(SH_LIST) <= 65536);
431        /*
432         * Compute the minimum possible allocation size.
433         * This must be a power of 2 and at least as large as the SH_LIST
434         * structure.
435         */
436        minsize = sizeof(SH_LIST) - 1;
437        minsize |= minsize >> 1;
438        minsize |= minsize >> 2;
439        if (sizeof(SH_LIST) > 16)
440            minsize |= minsize >> 4;
441        if (sizeof(SH_LIST) > 256)
442            minsize |= minsize >> 8;
443        minsize++;
444    } else {
445        /* make sure minsize is a powers of 2 */
446          OPENSSL_assert((minsize & (minsize - 1)) == 0);
447          if ((minsize & (minsize - 1)) != 0)
448              goto err;
449    }
450
451    sh.arena_size = size;
452    sh.minsize = minsize;
453    sh.bittable_size = (sh.arena_size / sh.minsize) * 2;
454
455    /* Prevent allocations of size 0 later on */
456    if (sh.bittable_size >> 3 == 0)
457        goto err;
458
459    sh.freelist_size = -1;
460    for (i = sh.bittable_size; i; i >>= 1)
461        sh.freelist_size++;
462
463    sh.freelist = OPENSSL_zalloc(sh.freelist_size * sizeof(char *));
464    OPENSSL_assert(sh.freelist != NULL);
465    if (sh.freelist == NULL)
466        goto err;
467
468    sh.bittable = OPENSSL_zalloc(sh.bittable_size >> 3);
469    OPENSSL_assert(sh.bittable != NULL);
470    if (sh.bittable == NULL)
471        goto err;
472
473    sh.bitmalloc = OPENSSL_zalloc(sh.bittable_size >> 3);
474    OPENSSL_assert(sh.bitmalloc != NULL);
475    if (sh.bitmalloc == NULL)
476        goto err;
477
478    /* Allocate space for heap, and two extra pages as guards */
479#if defined(_SC_PAGE_SIZE) || defined (_SC_PAGESIZE)
480    {
481# if defined(_SC_PAGE_SIZE)
482        long tmppgsize = sysconf(_SC_PAGE_SIZE);
483# else
484        long tmppgsize = sysconf(_SC_PAGESIZE);
485# endif
486        if (tmppgsize < 1)
487            pgsize = PAGE_SIZE;
488        else
489            pgsize = (size_t)tmppgsize;
490    }
491#elif defined(_WIN32)
492    GetSystemInfo(&systemInfo);
493    pgsize = (size_t)systemInfo.dwPageSize;
494#else
495    pgsize = PAGE_SIZE;
496#endif
497    sh.map_size = pgsize + sh.arena_size + pgsize;
498
499#if !defined(_WIN32)
500# ifdef MAP_ANON
501    sh.map_result = mmap(NULL, sh.map_size,
502                         PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE|MAP_CONCEAL, -1, 0);
503# else
504    {
505        int fd;
506
507        sh.map_result = MAP_FAILED;
508        if ((fd = open("/dev/zero", O_RDWR)) >= 0) {
509            sh.map_result = mmap(NULL, sh.map_size,
510                                 PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
511            close(fd);
512        }
513    }
514# endif
515    if (sh.map_result == MAP_FAILED)
516        goto err;
517#else
518    sh.map_result = VirtualAlloc(NULL, sh.map_size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
519
520    if (sh.map_result == NULL)
521            goto err;
522#endif
523
524    sh.arena = (char *)(sh.map_result + pgsize);
525    sh_setbit(sh.arena, 0, sh.bittable);
526    sh_add_to_list(&sh.freelist[0], sh.arena);
527
528    /* Now try to add guard pages and lock into memory. */
529    ret = 1;
530
531#if !defined(_WIN32)
532    /* Starting guard is already aligned from mmap. */
533    if (mprotect(sh.map_result, pgsize, PROT_NONE) < 0)
534        ret = 2;
535#else
536    if (VirtualProtect(sh.map_result, pgsize, PAGE_NOACCESS, &flOldProtect) == FALSE)
537        ret = 2;
538#endif
539
540    /* Ending guard page - need to round up to page boundary */
541    aligned = (pgsize + sh.arena_size + (pgsize - 1)) & ~(pgsize - 1);
542#if !defined(_WIN32)
543    if (mprotect(sh.map_result + aligned, pgsize, PROT_NONE) < 0)
544        ret = 2;
545#else
546    if (VirtualProtect(sh.map_result + aligned, pgsize, PAGE_NOACCESS, &flOldProtect) == FALSE)
547        ret = 2;
548#endif
549
550#if defined(OPENSSL_SYS_LINUX) && defined(MLOCK_ONFAULT) && defined(SYS_mlock2)
551    if (syscall(SYS_mlock2, sh.arena, sh.arena_size, MLOCK_ONFAULT) < 0) {
552        if (errno == ENOSYS) {
553            if (mlock(sh.arena, sh.arena_size) < 0)
554                ret = 2;
555        } else {
556            ret = 2;
557        }
558    }
559#elif defined(_WIN32)
560    if (VirtualLock(sh.arena, sh.arena_size) == FALSE)
561        ret = 2;
562#else
563    if (mlock(sh.arena, sh.arena_size) < 0)
564        ret = 2;
565#endif
566#ifdef MADV_DONTDUMP
567    if (madvise(sh.arena, sh.arena_size, MADV_DONTDUMP) < 0)
568        ret = 2;
569#endif
570
571    return ret;
572
573 err:
574    sh_done();
575    return 0;
576}
577
578static void sh_done(void)
579{
580    OPENSSL_free(sh.freelist);
581    OPENSSL_free(sh.bittable);
582    OPENSSL_free(sh.bitmalloc);
583#if !defined(_WIN32)
584    if (sh.map_result != MAP_FAILED && sh.map_size)
585        munmap(sh.map_result, sh.map_size);
586#else
587    if (sh.map_result != NULL && sh.map_size)
588        VirtualFree(sh.map_result, 0, MEM_RELEASE);
589#endif
590    memset(&sh, 0, sizeof(sh));
591}
592
593static int sh_allocated(const char *ptr)
594{
595    return WITHIN_ARENA(ptr) ? 1 : 0;
596}
597
598static char *sh_find_my_buddy(char *ptr, int list)
599{
600    size_t bit;
601    char *chunk = NULL;
602
603    bit = (ONE << list) + (ptr - sh.arena) / (sh.arena_size >> list);
604    bit ^= 1;
605
606    if (TESTBIT(sh.bittable, bit) && !TESTBIT(sh.bitmalloc, bit))
607        chunk = sh.arena + ((bit & ((ONE << list) - 1)) * (sh.arena_size >> list));
608
609    return chunk;
610}
611
612static void *sh_malloc(size_t size)
613{
614    ossl_ssize_t list, slist;
615    size_t i;
616    char *chunk;
617
618    if (size > sh.arena_size)
619        return NULL;
620
621    list = sh.freelist_size - 1;
622    for (i = sh.minsize; i < size; i <<= 1)
623        list--;
624    if (list < 0)
625        return NULL;
626
627    /* try to find a larger entry to split */
628    for (slist = list; slist >= 0; slist--)
629        if (sh.freelist[slist] != NULL)
630            break;
631    if (slist < 0)
632        return NULL;
633
634    /* split larger entry */
635    while (slist != list) {
636        char *temp = sh.freelist[slist];
637
638        /* remove from bigger list */
639        OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
640        sh_clearbit(temp, slist, sh.bittable);
641        sh_remove_from_list(temp);
642        OPENSSL_assert(temp != sh.freelist[slist]);
643
644        /* done with bigger list */
645        slist++;
646
647        /* add to smaller list */
648        OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
649        sh_setbit(temp, slist, sh.bittable);
650        sh_add_to_list(&sh.freelist[slist], temp);
651        OPENSSL_assert(sh.freelist[slist] == temp);
652
653        /* split in 2 */
654        temp += sh.arena_size >> slist;
655        OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
656        sh_setbit(temp, slist, sh.bittable);
657        sh_add_to_list(&sh.freelist[slist], temp);
658        OPENSSL_assert(sh.freelist[slist] == temp);
659
660        OPENSSL_assert(temp-(sh.arena_size >> slist) == sh_find_my_buddy(temp, slist));
661    }
662
663    /* peel off memory to hand back */
664    chunk = sh.freelist[list];
665    OPENSSL_assert(sh_testbit(chunk, list, sh.bittable));
666    sh_setbit(chunk, list, sh.bitmalloc);
667    sh_remove_from_list(chunk);
668
669    OPENSSL_assert(WITHIN_ARENA(chunk));
670
671    /* zero the free list header as a precaution against information leakage */
672    memset(chunk, 0, sizeof(SH_LIST));
673
674    return chunk;
675}
676
677static void sh_free(void *ptr)
678{
679    size_t list;
680    void *buddy;
681
682    if (ptr == NULL)
683        return;
684    OPENSSL_assert(WITHIN_ARENA(ptr));
685    if (!WITHIN_ARENA(ptr))
686        return;
687
688    list = sh_getlist(ptr);
689    OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
690    sh_clearbit(ptr, list, sh.bitmalloc);
691    sh_add_to_list(&sh.freelist[list], ptr);
692
693    /* Try to coalesce two adjacent free areas. */
694    while ((buddy = sh_find_my_buddy(ptr, list)) != NULL) {
695        OPENSSL_assert(ptr == sh_find_my_buddy(buddy, list));
696        OPENSSL_assert(ptr != NULL);
697        OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
698        sh_clearbit(ptr, list, sh.bittable);
699        sh_remove_from_list(ptr);
700        OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
701        sh_clearbit(buddy, list, sh.bittable);
702        sh_remove_from_list(buddy);
703
704        list--;
705
706        /* Zero the higher addressed block's free list pointers */
707        memset(ptr > buddy ? ptr : buddy, 0, sizeof(SH_LIST));
708        if (ptr > buddy)
709            ptr = buddy;
710
711        OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
712        sh_setbit(ptr, list, sh.bittable);
713        sh_add_to_list(&sh.freelist[list], ptr);
714        OPENSSL_assert(sh.freelist[list] == ptr);
715    }
716}
717
718static size_t sh_actual_size(char *ptr)
719{
720    int list;
721
722    OPENSSL_assert(WITHIN_ARENA(ptr));
723    if (!WITHIN_ARENA(ptr))
724        return 0;
725    list = sh_getlist(ptr);
726    OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
727    return sh.arena_size / (ONE << list);
728}
729#endif /* OPENSSL_NO_SECURE_MEMORY */
730