crypto/mem_sec.c

   1 /*
   2  * Copyright 2015-2018 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 # include <stdlib.h>
  25 # include <assert.h>
  26 # include <unistd.h>
  27 # include <sys/types.h>
  28 # include <sys/mman.h>
  29 # if defined(OPENSSL_SYS_LINUX)
  30 #  include <sys/syscall.h>
  31 #  if defined(SYS_mlock2)
  32 #   include <linux/mman.h>
  33 #   include <errno.h>
  34 #  endif
  35 #  include <sys/param.h>
  36 # endif
  37 # include <sys/stat.h>
  38 # include <fcntl.h>
  39 #endif
  40
  41 #define CLEAR(p, s) OPENSSL_cleanse(p, s)
  42 #ifndef PAGE_SIZE
  43 # define PAGE_SIZE    4096
  44 #endif
  45 #if !defined(MAP_ANON) && defined(MAP_ANONYMOUS)
  46 # define MAP_ANON MAP_ANONYMOUS
  47 #endif
  48
  49 #ifndef OPENSSL_NO_SECURE_MEMORY
  50 static size_t secure_mem_used;
  51
  52 static int secure_mem_initialized;
  53
  54 static CRYPTO_RWLOCK *sec_malloc_lock = NULL;
  55
  56 /*
  57  * These are the functions that must be implemented by a secure heap (sh).
  58  */
  59 static int sh_init(size_t size, size_t minsize);
  60 static void *sh_malloc(size_t size);
  61 static void sh_free(void *ptr);
  62 static void sh_done(void);
  63 static size_t sh_actual_size(char *ptr);
  64 static int sh_allocated(const char *ptr);
  65 #endif
  66
  67 int CRYPTO_secure_malloc_init(size_t size, size_t minsize)
  68 {
  69 #ifndef OPENSSL_NO_SECURE_MEMORY
  70     int ret = 0;
  71
  72     if (!secure_mem_initialized) {
  73         sec_malloc_lock = CRYPTO_THREAD_lock_new();
  74         if (sec_malloc_lock == NULL)
  75             return 0;
  76         if ((ret = sh_init(size, minsize)) != 0) {
  77             secure_mem_initialized = 1;
  78         } else {
  79             CRYPTO_THREAD_lock_free(sec_malloc_lock);
  80             sec_malloc_lock = NULL;
  81         }
  82     }
  83
  84     return ret;
  85 #else
  86     return 0;
  87 #endif /* OPENSSL_NO_SECURE_MEMORY */
  88 }
  89
  90 int CRYPTO_secure_malloc_done(void)
  91 {
  92 #ifndef OPENSSL_NO_SECURE_MEMORY
  93     if (secure_mem_used == 0) {
  94         sh_done();
  95         secure_mem_initialized = 0;
  96         CRYPTO_THREAD_lock_free(sec_malloc_lock);
  97         sec_malloc_lock = NULL;
  98         return 1;
  99     }
 100 #endif /* OPENSSL_NO_SECURE_MEMORY */
 101     return 0;
 102 }
 103
 104 int CRYPTO_secure_malloc_initialized(void)
 105 {
 106 #ifndef OPENSSL_NO_SECURE_MEMORY
 107     return secure_mem_initialized;
 108 #else
 109     return 0;
 110 #endif /* OPENSSL_NO_SECURE_MEMORY */
 111 }
 112
 113 void *CRYPTO_secure_malloc(size_t num, const char *file, int line)
 114 {
 115 #ifndef OPENSSL_NO_SECURE_MEMORY
 116     void *ret;
 117     size_t actual_size;
 118
 119     if (!secure_mem_initialized) {
 120         return CRYPTO_malloc(num, file, line);
 121     }
 122     CRYPTO_THREAD_write_lock(sec_malloc_lock);
 123     ret = sh_malloc(num);
 124     actual_size = ret ? sh_actual_size(ret) : 0;
 125     secure_mem_used += actual_size;
 126     CRYPTO_THREAD_unlock(sec_malloc_lock);
 127     return ret;
 128 #else
 129     return CRYPTO_malloc(num, file, line);
 130 #endif /* OPENSSL_NO_SECURE_MEMORY */
 131 }
 132
 133 void *CRYPTO_secure_zalloc(size_t num, const char *file, int line)
 134 {
 135 #ifndef OPENSSL_NO_SECURE_MEMORY
 136     if (secure_mem_initialized)
 137         /* CRYPTO_secure_malloc() zeroes allocations when it is implemented */
 138         return CRYPTO_secure_malloc(num, file, line);
 139 #endif
 140     return CRYPTO_zalloc(num, file, line);
 141 }
 142
 143 void CRYPTO_secure_free(void *ptr, const char *file, int line)
 144 {
 145 #ifndef OPENSSL_NO_SECURE_MEMORY
 146     size_t actual_size;
 147
 148     if (ptr == NULL)
 149         return;
 150     if (!CRYPTO_secure_allocated(ptr)) {
 151         CRYPTO_free(ptr, file, line);
 152         return;
 153     }
 154     CRYPTO_THREAD_write_lock(sec_malloc_lock);
 155     actual_size = sh_actual_size(ptr);
 156     CLEAR(ptr, actual_size);
 157     secure_mem_used -= actual_size;
 158     sh_free(ptr);
 159     CRYPTO_THREAD_unlock(sec_malloc_lock);
 160 #else
 161     CRYPTO_free(ptr, file, line);
 162 #endif /* OPENSSL_NO_SECURE_MEMORY */
 163 }
 164
 165 void CRYPTO_secure_clear_free(void *ptr, size_t num,
 166                               const char *file, int line)
 167 {
 168 #ifndef OPENSSL_NO_SECURE_MEMORY
 169     size_t actual_size;
 170
 171     if (ptr == NULL)
 172         return;
 173     if (!CRYPTO_secure_allocated(ptr)) {
 174         OPENSSL_cleanse(ptr, num);
 175         CRYPTO_free(ptr, file, line);
 176         return;
 177     }
 178     CRYPTO_THREAD_write_lock(sec_malloc_lock);
 179     actual_size = sh_actual_size(ptr);
 180     CLEAR(ptr, actual_size);
 181     secure_mem_used -= actual_size;
 182     sh_free(ptr);
 183     CRYPTO_THREAD_unlock(sec_malloc_lock);
 184 #else
 185     if (ptr == NULL)
 186         return;
 187     OPENSSL_cleanse(ptr, num);
 188     CRYPTO_free(ptr, file, line);
 189 #endif /* OPENSSL_NO_SECURE_MEMORY */
 190 }
 191
 192 int CRYPTO_secure_allocated(const void *ptr)
 193 {
 194 #ifndef OPENSSL_NO_SECURE_MEMORY
 195     int ret;
 196
 197     if (!secure_mem_initialized)
 198         return 0;
 199     CRYPTO_THREAD_write_lock(sec_malloc_lock);
 200     ret = sh_allocated(ptr);
 201     CRYPTO_THREAD_unlock(sec_malloc_lock);
 202     return ret;
 203 #else
 204     return 0;
 205 #endif /* OPENSSL_NO_SECURE_MEMORY */
 206 }
 207
 208 size_t CRYPTO_secure_used(void)
 209 {
 210 #ifndef OPENSSL_NO_SECURE_MEMORY
 211     return secure_mem_used;
 212 #else
 213     return 0;
 214 #endif /* OPENSSL_NO_SECURE_MEMORY */
 215 }
 216
 217 size_t CRYPTO_secure_actual_size(void *ptr)
 218 {
 219 #ifndef OPENSSL_NO_SECURE_MEMORY
 220     size_t actual_size;
 221
 222     CRYPTO_THREAD_write_lock(sec_malloc_lock);
 223     actual_size = sh_actual_size(ptr);
 224     CRYPTO_THREAD_unlock(sec_malloc_lock);
 225     return actual_size;
 226 #else
 227     return 0;
 228 #endif
 229 }
 230 /* END OF PAGE ...
 231
 232    ... START OF PAGE */
 233
 234 /*
 235  * SECURE HEAP IMPLEMENTATION
 236  */
 237 #ifndef OPENSSL_NO_SECURE_MEMORY
 238
 239
 240 /*
 241  * The implementation provided here uses a fixed-sized mmap() heap,
 242  * which is locked into memory, not written to core files, and protected
 243  * on either side by an unmapped page, which will catch pointer overruns
 244  * (or underruns) and an attempt to read data out of the secure heap.
 245  * Free'd memory is zero'd or otherwise cleansed.
 246  *
 247  * This is a pretty standard buddy allocator.  We keep areas in a multiple
 248  * of "sh.minsize" units.  The freelist and bitmaps are kept separately,
 249  * so all (and only) data is kept in the mmap'd heap.
 250  *
 251  * This code assumes eight-bit bytes.  The numbers 3 and 7 are all over the
 252  * place.
 253  */
 254
 255 #define ONE ((size_t)1)
 256
 257 # define TESTBIT(t, b)  (t[(b) >> 3] &  (ONE << ((b) & 7)))
 258 # define SETBIT(t, b)   (t[(b) >> 3] |= (ONE << ((b) & 7)))
 259 # define CLEARBIT(t, b) (t[(b) >> 3] &= (0xFF & ~(ONE << ((b) & 7))))
 260
 261 #define WITHIN_ARENA(p) \
 262     ((char*)(p) >= sh.arena && (char*)(p) < &sh.arena[sh.arena_size])
 263 #define WITHIN_FREELIST(p) \
 264     ((char*)(p) >= (char*)sh.freelist && (char*)(p) < (char*)&sh.freelist[sh.freelist_size])
 265
 266
 267 typedef struct sh_list_st
 268 {
 269     struct sh_list_st *next;
 270     struct sh_list_st **p_next;
 271 } SH_LIST;
 272
 273 typedef struct sh_st
 274 {
 275     char* map_result;
 276     size_t map_size;
 277     char *arena;
 278     size_t arena_size;
 279     char **freelist;
 280     ossl_ssize_t freelist_size;
 281     size_t minsize;
 282     unsigned char *bittable;
 283     unsigned char *bitmalloc;
 284     size_t bittable_size; /* size in bits */
 285 } SH;
 286
 287 static SH sh;
 288
 289 static size_t sh_getlist(char *ptr)
 290 {
 291     ossl_ssize_t list = sh.freelist_size - 1;
 292     size_t bit = (sh.arena_size + ptr - sh.arena) / sh.minsize;
 293
 294     for (; bit; bit >>= 1, list--) {
 295         if (TESTBIT(sh.bittable, bit))
 296             break;
 297         OPENSSL_assert((bit & 1) == 0);
 298     }
 299
 300     return list;
 301 }
 302
 303
 304 static int sh_testbit(char *ptr, int list, unsigned char *table)
 305 {
 306     size_t bit;
 307
 308     OPENSSL_assert(list >= 0 && list < sh.freelist_size);
 309     OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
 310     bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
 311     OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
 312     return TESTBIT(table, bit);
 313 }
 314
 315 static void sh_clearbit(char *ptr, int list, unsigned char *table)
 316 {
 317     size_t bit;
 318
 319     OPENSSL_assert(list >= 0 && list < sh.freelist_size);
 320     OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
 321     bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
 322     OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
 323     OPENSSL_assert(TESTBIT(table, bit));
 324     CLEARBIT(table, bit);
 325 }
 326
 327 static void sh_setbit(char *ptr, int list, unsigned char *table)
 328 {
 329     size_t bit;
 330
 331     OPENSSL_assert(list >= 0 && list < sh.freelist_size);
 332     OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
 333     bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
 334     OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
 335     OPENSSL_assert(!TESTBIT(table, bit));
 336     SETBIT(table, bit);
 337 }
 338
 339 static void sh_add_to_list(char **list, char *ptr)
 340 {
 341     SH_LIST *temp;
 342
 343     OPENSSL_assert(WITHIN_FREELIST(list));
 344     OPENSSL_assert(WITHIN_ARENA(ptr));
 345
 346     temp = (SH_LIST *)ptr;
 347     temp->next = *(SH_LIST **)list;
 348     OPENSSL_assert(temp->next == NULL || WITHIN_ARENA(temp->next));
 349     temp->p_next = (SH_LIST **)list;
 350
 351     if (temp->next != NULL) {
 352         OPENSSL_assert((char **)temp->next->p_next == list);
 353         temp->next->p_next = &(temp->next);
 354     }
 355
 356     *list = ptr;
 357 }
 358
 359 static void sh_remove_from_list(char *ptr)
 360 {
 361     SH_LIST *temp, *temp2;
 362
 363     temp = (SH_LIST *)ptr;
 364     if (temp->next != NULL)
 365         temp->next->p_next = temp->p_next;
 366     *temp->p_next = temp->next;
 367     if (temp->next == NULL)
 368         return;
 369
 370     temp2 = temp->next;
 371     OPENSSL_assert(WITHIN_FREELIST(temp2->p_next) || WITHIN_ARENA(temp2->p_next));
 372 }
 373
 374
 375 static int sh_init(size_t size, size_t minsize)
 376 {
 377     int ret;
 378     size_t i;
 379     size_t pgsize;
 380     size_t aligned;
 381
 382     memset(&sh, 0, sizeof(sh));
 383
 384     /* make sure size and minsize are powers of 2 */
 385     OPENSSL_assert(size > 0);
 386     OPENSSL_assert((size & (size - 1)) == 0);
 387     OPENSSL_assert((minsize & (minsize - 1)) == 0);
 388     if (size <= 0 || (size & (size - 1)) != 0)
 389         goto err;
 390     if (minsize == 0 || (minsize & (minsize - 1)) != 0)
 391         goto err;
 392
 393     while (minsize < (int)sizeof(SH_LIST))
 394         minsize *= 2;
 395
 396     sh.arena_size = size;
 397     sh.minsize = minsize;
 398     sh.bittable_size = (sh.arena_size / sh.minsize) * 2;
 399
 400     /* Prevent allocations of size 0 later on */
 401     if (sh.bittable_size >> 3 == 0)
 402         goto err;
 403
 404     sh.freelist_size = -1;
 405     for (i = sh.bittable_size; i; i >>= 1)
 406         sh.freelist_size++;
 407
 408     sh.freelist = OPENSSL_zalloc(sh.freelist_size * sizeof(char *));
 409     OPENSSL_assert(sh.freelist != NULL);
 410     if (sh.freelist == NULL)
 411         goto err;
 412
 413     sh.bittable = OPENSSL_zalloc(sh.bittable_size >> 3);
 414     OPENSSL_assert(sh.bittable != NULL);
 415     if (sh.bittable == NULL)
 416         goto err;
 417
 418     sh.bitmalloc = OPENSSL_zalloc(sh.bittable_size >> 3);
 419     OPENSSL_assert(sh.bitmalloc != NULL);
 420     if (sh.bitmalloc == NULL)
 421         goto err;
 422
 423     /* Allocate space for heap, and two extra pages as guards */
 424 #if defined(_SC_PAGE_SIZE) || defined (_SC_PAGESIZE)
 425     {
 426 # if defined(_SC_PAGE_SIZE)
 427         long tmppgsize = sysconf(_SC_PAGE_SIZE);
 428 # else
 429         long tmppgsize = sysconf(_SC_PAGESIZE);
 430 # endif
 431         if (tmppgsize < 1)
 432             pgsize = PAGE_SIZE;
 433         else
 434             pgsize = (size_t)tmppgsize;
 435     }
 436 #else
 437     pgsize = PAGE_SIZE;
 438 #endif
 439     sh.map_size = pgsize + sh.arena_size + pgsize;
 440     if (1) {
 441 #ifdef MAP_ANON
 442         sh.map_result = mmap(NULL, sh.map_size,
 443                              PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
 444     } else {
 445 #endif
 446         int fd;
 447
 448         sh.map_result = MAP_FAILED;
 449         if ((fd = open("/dev/zero", O_RDWR)) >= 0) {
 450             sh.map_result = mmap(NULL, sh.map_size,
 451                                  PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
 452             close(fd);
 453         }
 454     }
 455     if (sh.map_result == MAP_FAILED)
 456         goto err;
 457     sh.arena = (char *)(sh.map_result + pgsize);
 458     sh_setbit(sh.arena, 0, sh.bittable);
 459     sh_add_to_list(&sh.freelist[0], sh.arena);
 460
 461     /* Now try to add guard pages and lock into memory. */
 462     ret = 1;
 463
 464     /* Starting guard is already aligned from mmap. */
 465     if (mprotect(sh.map_result, pgsize, PROT_NONE) < 0)
 466         ret = 2;
 467
 468     /* Ending guard page - need to round up to page boundary */
 469     aligned = (pgsize + sh.arena_size + (pgsize - 1)) & ~(pgsize - 1);
 470     if (mprotect(sh.map_result + aligned, pgsize, PROT_NONE) < 0)
 471         ret = 2;
 472
 473 #if defined(OPENSSL_SYS_LINUX) && defined(MLOCK_ONFAULT) && defined(SYS_mlock2)
 474     if (syscall(SYS_mlock2, sh.arena, sh.arena_size, MLOCK_ONFAULT) < 0) {
 475         if (errno == ENOSYS) {
 476             if (mlock(sh.arena, sh.arena_size) < 0)
 477                 ret = 2;
 478         } else {
 479             ret = 2;
 480         }
 481     }
 482 #else
 483     if (mlock(sh.arena, sh.arena_size) < 0)
 484         ret = 2;
 485 #endif
 486 #ifdef MADV_DONTDUMP
 487     if (madvise(sh.arena, sh.arena_size, MADV_DONTDUMP) < 0)
 488         ret = 2;
 489 #endif
 490
 491     return ret;
 492
 493  err:
 494     sh_done();
 495     return 0;
 496 }
 497
 498 static void sh_done(void)
 499 {
 500     OPENSSL_free(sh.freelist);
 501     OPENSSL_free(sh.bittable);
 502     OPENSSL_free(sh.bitmalloc);
 503     if (sh.map_result != NULL && sh.map_size)
 504         munmap(sh.map_result, sh.map_size);
 505     memset(&sh, 0, sizeof(sh));
 506 }
 507
 508 static int sh_allocated(const char *ptr)
 509 {
 510     return WITHIN_ARENA(ptr) ? 1 : 0;
 511 }
 512
 513 static char *sh_find_my_buddy(char *ptr, int list)
 514 {
 515     size_t bit;
 516     char *chunk = NULL;
 517
 518     bit = (ONE << list) + (ptr - sh.arena) / (sh.arena_size >> list);
 519     bit ^= 1;
 520
 521     if (TESTBIT(sh.bittable, bit) && !TESTBIT(sh.bitmalloc, bit))
 522         chunk = sh.arena + ((bit & ((ONE << list) - 1)) * (sh.arena_size >> list));
 523
 524     return chunk;
 525 }
 526
 527 static void *sh_malloc(size_t size)
 528 {
 529     ossl_ssize_t list, slist;
 530     size_t i;
 531     char *chunk;
 532
 533     if (size > sh.arena_size)
 534         return NULL;
 535
 536     list = sh.freelist_size - 1;
 537     for (i = sh.minsize; i < size; i <<= 1)
 538         list--;
 539     if (list < 0)
 540         return NULL;
 541
 542     /* try to find a larger entry to split */
 543     for (slist = list; slist >= 0; slist--)
 544         if (sh.freelist[slist] != NULL)
 545             break;
 546     if (slist < 0)
 547         return NULL;
 548
 549     /* split larger entry */
 550     while (slist != list) {
 551         char *temp = sh.freelist[slist];
 552
 553         /* remove from bigger list */
 554         OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
 555         sh_clearbit(temp, slist, sh.bittable);
 556         sh_remove_from_list(temp);
 557         OPENSSL_assert(temp != sh.freelist[slist]);
 558
 559         /* done with bigger list */
 560         slist++;
 561
 562         /* add to smaller list */
 563         OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
 564         sh_setbit(temp, slist, sh.bittable);
 565         sh_add_to_list(&sh.freelist[slist], temp);
 566         OPENSSL_assert(sh.freelist[slist] == temp);
 567
 568         /* split in 2 */
 569         temp += sh.arena_size >> slist;
 570         OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
 571         sh_setbit(temp, slist, sh.bittable);
 572         sh_add_to_list(&sh.freelist[slist], temp);
 573         OPENSSL_assert(sh.freelist[slist] == temp);
 574
 575         OPENSSL_assert(temp-(sh.arena_size >> slist) == sh_find_my_buddy(temp, slist));
 576     }
 577
 578     /* peel off memory to hand back */
 579     chunk = sh.freelist[list];
 580     OPENSSL_assert(sh_testbit(chunk, list, sh.bittable));
 581     sh_setbit(chunk, list, sh.bitmalloc);
 582     sh_remove_from_list(chunk);
 583
 584     OPENSSL_assert(WITHIN_ARENA(chunk));
 585
 586     /* zero the free list header as a precaution against information leakage */
 587     memset(chunk, 0, sizeof(SH_LIST));
 588
 589     return chunk;
 590 }
 591
 592 static void sh_free(void *ptr)
 593 {
 594     size_t list;
 595     void *buddy;
 596
 597     if (ptr == NULL)
 598         return;
 599     OPENSSL_assert(WITHIN_ARENA(ptr));
 600     if (!WITHIN_ARENA(ptr))
 601         return;
 602
 603     list = sh_getlist(ptr);
 604     OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
 605     sh_clearbit(ptr, list, sh.bitmalloc);
 606     sh_add_to_list(&sh.freelist[list], ptr);
 607
 608     /* Try to coalesce two adjacent free areas. */
 609     while ((buddy = sh_find_my_buddy(ptr, list)) != NULL) {
 610         OPENSSL_assert(ptr == sh_find_my_buddy(buddy, list));
 611         OPENSSL_assert(ptr != NULL);
 612         OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
 613         sh_clearbit(ptr, list, sh.bittable);
 614         sh_remove_from_list(ptr);
 615         OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
 616         sh_clearbit(buddy, list, sh.bittable);
 617         sh_remove_from_list(buddy);
 618
 619         list--;
 620
 621         /* Zero the higher addressed block's free list pointers */
 622         memset(ptr > buddy ? ptr : buddy, 0, sizeof(SH_LIST));
 623         if (ptr > buddy)
 624             ptr = buddy;
 625
 626         OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
 627         sh_setbit(ptr, list, sh.bittable);
 628         sh_add_to_list(&sh.freelist[list], ptr);
 629         OPENSSL_assert(sh.freelist[list] == ptr);
 630     }
 631 }
 632
 633 static size_t sh_actual_size(char *ptr)
 634 {
 635     int list;
 636
 637     OPENSSL_assert(WITHIN_ARENA(ptr));
 638     if (!WITHIN_ARENA(ptr))
 639         return 0;
 640     list = sh_getlist(ptr);
 641     OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
 642     return sh.arena_size / (ONE << list);
 643 }
 644 #endif /* OPENSSL_NO_SECURE_MEMORY */