lib/libcrypto/ex_data.c

   1 /* $OpenBSD: ex_data.c,v 1.19 2017/01/29 17:49:22 beck Exp $ */
   2
   3 /*
   4  * Overhaul notes;
   5  *
   6  * This code is now *mostly* thread-safe. It is now easier to understand in what
   7  * ways it is safe and in what ways it is not, which is an improvement. Firstly,
   8  * all per-class stacks and index-counters for ex_data are stored in the same
   9  * global LHASH table (keyed by class). This hash table uses locking for all
  10  * access with the exception of CRYPTO_cleanup_all_ex_data(), which must only be
  11  * called when no other threads can possibly race against it (even if it was
  12  * locked, the race would mean it's possible the hash table might have been
  13  * recreated after the cleanup). As classes can only be added to the hash table,
  14  * and within each class, the stack of methods can only be incremented, the
  15  * locking mechanics are simpler than they would otherwise be. For example, the
  16  * new/dup/free ex_data functions will lock the hash table, copy the method
  17  * pointers it needs from the relevant class, then unlock the hash table before
  18  * actually applying those method pointers to the task of the new/dup/free
  19  * operations. As they can't be removed from the method-stack, only
  20  * supplemented, there's no race conditions associated with using them outside
  21  * the lock. The get/set_ex_data functions are not locked because they do not
  22  * involve this global state at all - they operate directly with a previously
  23  * obtained per-class method index and a particular "ex_data" variable. These
  24  * variables are usually instantiated per-context (eg. each RSA structure has
  25  * one) so locking on read/write access to that variable can be locked locally
  26  * if required (eg. using the "RSA" lock to synchronise access to a
  27  * per-RSA-structure ex_data variable if required).
  28  * [Geoff]
  29  */
  30
  31 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  32  * All rights reserved.
  33  *
  34  * This package is an SSL implementation written
  35  * by Eric Young (eay@cryptsoft.com).
  36  * The implementation was written so as to conform with Netscapes SSL.
  37  *
  38  * This library is free for commercial and non-commercial use as long as
  39  * the following conditions are aheared to.  The following conditions
  40  * apply to all code found in this distribution, be it the RC4, RSA,
  41  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  42  * included with this distribution is covered by the same copyright terms
  43  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  44  *
  45  * Copyright remains Eric Young's, and as such any Copyright notices in
  46  * the code are not to be removed.
  47  * If this package is used in a product, Eric Young should be given attribution
  48  * as the author of the parts of the library used.
  49  * This can be in the form of a textual message at program startup or
  50  * in documentation (online or textual) provided with the package.
  51  *
  52  * Redistribution and use in source and binary forms, with or without
  53  * modification, are permitted provided that the following conditions
  54  * are met:
  55  * 1. Redistributions of source code must retain the copyright
  56  *    notice, this list of conditions and the following disclaimer.
  57  * 2. Redistributions in binary form must reproduce the above copyright
  58  *    notice, this list of conditions and the following disclaimer in the
  59  *    documentation and/or other materials provided with the distribution.
  60  * 3. All advertising materials mentioning features or use of this software
  61  *    must display the following acknowledgement:
  62  *    "This product includes cryptographic software written by
  63  *     Eric Young (eay@cryptsoft.com)"
  64  *    The word 'cryptographic' can be left out if the rouines from the library
  65  *    being used are not cryptographic related :-).
  66  * 4. If you include any Windows specific code (or a derivative thereof) from
  67  *    the apps directory (application code) you must include an acknowledgement:
  68  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  69  *
  70  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  71  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  72  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  73  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  74  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  75  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  76  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  77  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  78  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  79  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  80  * SUCH DAMAGE.
  81  *
  82  * The licence and distribution terms for any publically available version or
  83  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  84  * copied and put under another distribution licence
  85  * [including the GNU Public Licence.]
  86  */
  87 /* ====================================================================
  88  * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
  89  *
  90  * Redistribution and use in source and binary forms, with or without
  91  * modification, are permitted provided that the following conditions
  92  * are met:
  93  *
  94  * 1. Redistributions of source code must retain the above copyright
  95  *    notice, this list of conditions and the following disclaimer.
  96  *
  97  * 2. Redistributions in binary form must reproduce the above copyright
  98  *    notice, this list of conditions and the following disclaimer in
  99  *    the documentation and/or other materials provided with the
 100  *    distribution.
 101  *
 102  * 3. All advertising materials mentioning features or use of this
 103  *    software must display the following acknowledgment:
 104  *    "This product includes software developed by the OpenSSL Project
 105  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 106  *
 107  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 108  *    endorse or promote products derived from this software without
 109  *    prior written permission. For written permission, please contact
 110  *    openssl-core@openssl.org.
 111  *
 112  * 5. Products derived from this software may not be called "OpenSSL"
 113  *    nor may "OpenSSL" appear in their names without prior written
 114  *    permission of the OpenSSL Project.
 115  *
 116  * 6. Redistributions of any form whatsoever must retain the following
 117  *    acknowledgment:
 118  *    "This product includes software developed by the OpenSSL Project
 119  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 120  *
 121  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 122  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 123  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 124  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 125  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 126  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 127  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 128  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 129  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 130  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 131  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 132  * OF THE POSSIBILITY OF SUCH DAMAGE.
 133  * ====================================================================
 134  *
 135  * This product includes cryptographic software written by Eric Young
 136  * (eay@cryptsoft.com).  This product includes software written by Tim
 137  * Hudson (tjh@cryptsoft.com).
 138  *
 139  */
 140
 141 #include <openssl/err.h>
 142 #include <openssl/lhash.h>
 143
 144 /* What an "implementation of ex_data functionality" looks like */
 145 struct st_CRYPTO_EX_DATA_IMPL {
 146         /*********************/
 147         /* GLOBAL OPERATIONS */
 148         /* Return a new class index */
 149         int (*cb_new_class)(void);
 150         /* Cleanup all state used by the implementation */
 151         void (*cb_cleanup)(void);
 152         /************************/
 153         /* PER-CLASS OPERATIONS */
 154         /* Get a new method index within a class */
 155         int (*cb_get_new_index)(int class_index, long argl, void *argp,
 156             CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
 157             CRYPTO_EX_free *free_func);
 158         /* Initialise a new CRYPTO_EX_DATA of a given class */
 159         int (*cb_new_ex_data)(int class_index, void *obj,
 160             CRYPTO_EX_DATA *ad);
 161         /* Duplicate a CRYPTO_EX_DATA of a given class onto a copy */
 162         int (*cb_dup_ex_data)(int class_index, CRYPTO_EX_DATA *to,
 163             CRYPTO_EX_DATA *from);
 164         /* Cleanup a CRYPTO_EX_DATA of a given class */
 165         void (*cb_free_ex_data)(int class_index, void *obj,
 166             CRYPTO_EX_DATA *ad);
 167 };
 168
 169 /* The implementation we use at run-time */
 170 static const CRYPTO_EX_DATA_IMPL *impl = NULL;
 171
 172 /* To call "impl" functions, use this macro rather than referring to 'impl' directly, eg.
 173  * EX_IMPL(get_new_index)(...);
 174 */
 175 #define EX_IMPL(a) impl->cb_##a
 176
 177 /* Predeclare the "default" ex_data implementation */
 178 static int int_new_class(void);
 179 static void int_cleanup(void);
 180 static int int_get_new_index(int class_index, long argl, void *argp,
 181     CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
 182     CRYPTO_EX_free *free_func);
 183 static int int_new_ex_data(int class_index, void *obj,
 184     CRYPTO_EX_DATA *ad);
 185 static int int_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
 186     CRYPTO_EX_DATA *from);
 187 static void int_free_ex_data(int class_index, void *obj,
 188     CRYPTO_EX_DATA *ad);
 189
 190 static CRYPTO_EX_DATA_IMPL impl_default = {
 191         int_new_class,
 192         int_cleanup,
 193         int_get_new_index,
 194         int_new_ex_data,
 195         int_dup_ex_data,
 196         int_free_ex_data
 197 };
 198
 199 /* Internal function that checks whether "impl" is set and if not, sets it to
 200  * the default. */
 201 static void
 202 impl_check(void)
 203 {
 204         CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
 205         if (!impl)
 206                 impl = &impl_default;
 207         CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
 208 }
 209 /* A macro wrapper for impl_check that first uses a non-locked test before
 210  * invoking the function (which checks again inside a lock). */
 211 #define IMPL_CHECK if(!impl) impl_check();
 212
 213 /* API functions to get/set the "ex_data" implementation */
 214 const CRYPTO_EX_DATA_IMPL *
 215 CRYPTO_get_ex_data_implementation(void)
 216 {
 217         IMPL_CHECK
 218         return impl;
 219 }
 220
 221 int
 222 CRYPTO_set_ex_data_implementation(const CRYPTO_EX_DATA_IMPL *i)
 223 {
 224         int toret = 0;
 225         CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
 226         if (!impl) {
 227                 impl = i;
 228                 toret = 1;
 229         }
 230         CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
 231         return toret;
 232 }
 233
 234 /****************************************************************************/
 235 /* Interal (default) implementation of "ex_data" support. API functions are
 236  * further down. */
 237
 238 /* The type that represents what each "class" used to implement locally. A STACK
 239  * of CRYPTO_EX_DATA_FUNCS plus a index-counter. The 'class_index' is the global
 240  * value representing the class that is used to distinguish these items. */
 241 typedef struct st_ex_class_item {
 242         int class_index;
 243         STACK_OF(CRYPTO_EX_DATA_FUNCS) *meth;
 244         int meth_num;
 245 } EX_CLASS_ITEM;
 246
 247 /* When assigning new class indexes, this is our counter */
 248 static int ex_class = CRYPTO_EX_INDEX_USER;
 249
 250 /* The global hash table of EX_CLASS_ITEM items */
 251 DECLARE_LHASH_OF(EX_CLASS_ITEM);
 252 static LHASH_OF(EX_CLASS_ITEM) *ex_data = NULL;
 253
 254 /* The callbacks required in the "ex_data" hash table */
 255 static unsigned long
 256 ex_class_item_hash(const EX_CLASS_ITEM *a)
 257 {
 258         return a->class_index;
 259 }
 260
 261 static IMPLEMENT_LHASH_HASH_FN(ex_class_item, EX_CLASS_ITEM)
 262
 263 static int
 264 ex_class_item_cmp(const EX_CLASS_ITEM *a, const EX_CLASS_ITEM *b)
 265 {
 266         return a->class_index - b->class_index;
 267 }
 268
 269 static IMPLEMENT_LHASH_COMP_FN(ex_class_item, EX_CLASS_ITEM)
 270
 271 /* Internal functions used by the "impl_default" implementation to access the
 272  * state */
 273
 274 static int
 275 ex_data_check(void)
 276 {
 277         int toret = 1;
 278         CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
 279         if (!ex_data &&
 280             (ex_data = lh_EX_CLASS_ITEM_new()) == NULL)
 281                 toret = 0;
 282         CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
 283         return toret;
 284 }
 285 /* This macros helps reduce the locking from repeated checks because the
 286  * ex_data_check() function checks ex_data again inside a lock. */
 287 #define EX_DATA_CHECK(iffail) if(!ex_data && !ex_data_check()) {iffail}
 288
 289 /* This "inner" callback is used by the callback function that follows it */
 290 static void
 291 def_cleanup_util_cb(CRYPTO_EX_DATA_FUNCS *funcs)
 292 {
 293         free(funcs);
 294 }
 295
 296 /* This callback is used in lh_doall to destroy all EX_CLASS_ITEM values from
 297  * "ex_data" prior to the ex_data hash table being itself destroyed. Doesn't do
 298  * any locking. */
 299 static void
 300 def_cleanup_cb(void *a_void)
 301 {
 302         EX_CLASS_ITEM *item = (EX_CLASS_ITEM *)a_void;
 303         sk_CRYPTO_EX_DATA_FUNCS_pop_free(item->meth, def_cleanup_util_cb);
 304         free(item);
 305 }
 306
 307 /* Return the EX_CLASS_ITEM from the "ex_data" hash table that corresponds to a
 308  * given class. Handles locking. */
 309 static EX_CLASS_ITEM *
 310 def_get_class(int class_index)
 311 {
 312         EX_CLASS_ITEM d, *p, *gen;
 313         EX_DATA_CHECK(return NULL;)
 314         d.class_index = class_index;
 315         CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
 316         p = lh_EX_CLASS_ITEM_retrieve(ex_data, &d);
 317         if (!p) {
 318                 gen = malloc(sizeof(EX_CLASS_ITEM));
 319                 if (gen) {
 320                         gen->class_index = class_index;
 321                         gen->meth_num = 0;
 322                         gen->meth = sk_CRYPTO_EX_DATA_FUNCS_new_null();
 323                         if (!gen->meth)
 324                                 free(gen);
 325                         else {
 326                                 /* Because we're inside the ex_data lock, the
 327                                  * return value from the insert will be NULL */
 328                                 (void)lh_EX_CLASS_ITEM_insert(ex_data, gen);
 329                                 p = gen;
 330                         }
 331                 }
 332         }
 333         CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
 334         if (!p)
 335                 CRYPTOerror(ERR_R_MALLOC_FAILURE);
 336         return p;
 337 }
 338
 339 /* Add a new method to the given EX_CLASS_ITEM and return the corresponding
 340  * index (or -1 for error). Handles locking. */
 341 static int
 342 def_add_index(EX_CLASS_ITEM *item, long argl, void *argp,
 343     CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
 344 {
 345         int toret = -1;
 346         CRYPTO_EX_DATA_FUNCS *a = malloc(sizeof(CRYPTO_EX_DATA_FUNCS));
 347
 348         if (!a) {
 349                 CRYPTOerror(ERR_R_MALLOC_FAILURE);
 350                 return -1;
 351         }
 352         a->argl = argl;
 353         a->argp = argp;
 354         a->new_func = new_func;
 355         a->dup_func = dup_func;
 356         a->free_func = free_func;
 357         CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
 358         while (sk_CRYPTO_EX_DATA_FUNCS_num(item->meth) <= item->meth_num) {
 359                 if (!sk_CRYPTO_EX_DATA_FUNCS_push(item->meth, NULL)) {
 360                         CRYPTOerror(ERR_R_MALLOC_FAILURE);
 361                         free(a);
 362                         goto err;
 363                 }
 364         }
 365         toret = item->meth_num++;
 366         (void)sk_CRYPTO_EX_DATA_FUNCS_set(item->meth, toret, a);
 367 err:
 368         CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
 369         return toret;
 370 }
 371
 372 /**************************************************************/
 373 /* The functions in the default CRYPTO_EX_DATA_IMPL structure */
 374
 375 static int
 376 int_new_class(void)
 377 {
 378         int toret;
 379
 380         CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
 381         toret = ex_class++;
 382         CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
 383         return toret;
 384 }
 385
 386 static void
 387 int_cleanup(void)
 388 {
 389         EX_DATA_CHECK(return;)
 390         lh_EX_CLASS_ITEM_doall(ex_data, def_cleanup_cb);
 391         lh_EX_CLASS_ITEM_free(ex_data);
 392         ex_data = NULL;
 393         impl = NULL;
 394 }
 395
 396 static int
 397 int_get_new_index(int class_index, long argl, void *argp,
 398     CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
 399     CRYPTO_EX_free *free_func)
 400 {
 401         EX_CLASS_ITEM *item = def_get_class(class_index);
 402
 403         if (!item)
 404                 return -1;
 405         return def_add_index(item, argl, argp, new_func, dup_func, free_func);
 406 }
 407
 408 /* Thread-safe by copying a class's array of "CRYPTO_EX_DATA_FUNCS" entries in
 409  * the lock, then using them outside the lock. NB: Thread-safety only applies to
 410  * the global "ex_data" state (ie. class definitions), not thread-safe on 'ad'
 411  * itself. */
 412 static int
 413 int_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 414 {
 415         int mx, i;
 416         void *ptr;
 417         CRYPTO_EX_DATA_FUNCS **storage = NULL;
 418         EX_CLASS_ITEM *item = def_get_class(class_index);
 419
 420         if (!item)
 421                 /* error is already set */
 422                 return 0;
 423         ad->sk = NULL;
 424         CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
 425         mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
 426         if (mx > 0) {
 427                 storage = reallocarray(NULL, mx, sizeof(CRYPTO_EX_DATA_FUNCS*));
 428                 if (!storage)
 429                         goto skip;
 430                 for (i = 0; i < mx; i++)
 431                         storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(
 432                             item->meth, i);
 433         }
 434 skip:
 435         CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
 436         if ((mx > 0) && !storage) {
 437                 CRYPTOerror(ERR_R_MALLOC_FAILURE);
 438                 return 0;
 439         }
 440         for (i = 0; i < mx; i++) {
 441                 if (storage[i] && storage[i]->new_func) {
 442                         ptr = CRYPTO_get_ex_data(ad, i);
 443                         storage[i]->new_func(obj, ptr, ad, i,
 444                             storage[i]->argl, storage[i]->argp);
 445                 }
 446         }
 447         free(storage);
 448         return 1;
 449 }
 450
 451 /* Same thread-safety notes as for "int_new_ex_data" */
 452 static int
 453 int_dup_ex_data(int class_index, CRYPTO_EX_DATA *to, CRYPTO_EX_DATA *from)
 454 {
 455         int mx, j, i;
 456         char *ptr;
 457         CRYPTO_EX_DATA_FUNCS **storage = NULL;
 458         EX_CLASS_ITEM *item;
 459
 460         if (!from->sk)
 461                 /* 'to' should be "blank" which *is* just like 'from' */
 462                 return 1;
 463         if ((item = def_get_class(class_index)) == NULL)
 464                 return 0;
 465         CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
 466         mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
 467         j = sk_void_num(from->sk);
 468         if (j < mx)
 469                 mx = j;
 470         if (mx > 0) {
 471                 storage = reallocarray(NULL, mx, sizeof(CRYPTO_EX_DATA_FUNCS*));
 472                 if (!storage)
 473                         goto skip;
 474                 for (i = 0; i < mx; i++)
 475                         storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(
 476                             item->meth, i);
 477         }
 478 skip:
 479         CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
 480         if ((mx > 0) && !storage) {
 481                 CRYPTOerror(ERR_R_MALLOC_FAILURE);
 482                 return 0;
 483         }
 484         for (i = 0; i < mx; i++) {
 485                 ptr = CRYPTO_get_ex_data(from, i);
 486                 if (storage[i] && storage[i]->dup_func)
 487                         storage[i]->dup_func(to, from, &ptr, i,
 488                             storage[i]->argl, storage[i]->argp);
 489                 CRYPTO_set_ex_data(to, i, ptr);
 490         }
 491         free(storage);
 492         return 1;
 493 }
 494
 495 /* Same thread-safety notes as for "int_new_ex_data" */
 496 static void
 497 int_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 498 {
 499         int mx, i;
 500         EX_CLASS_ITEM *item;
 501         void *ptr;
 502         CRYPTO_EX_DATA_FUNCS **storage = NULL;
 503         if ((item = def_get_class(class_index)) == NULL)
 504                 return;
 505         CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
 506         mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
 507         if (mx > 0) {
 508                 storage = reallocarray(NULL, mx, sizeof(CRYPTO_EX_DATA_FUNCS*));
 509                 if (!storage)
 510                         goto skip;
 511                 for (i = 0; i < mx; i++)
 512                         storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(
 513                             item->meth, i);
 514         }
 515 skip:
 516         CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
 517         if ((mx > 0) && !storage) {
 518                 CRYPTOerror(ERR_R_MALLOC_FAILURE);
 519                 return;
 520         }
 521         for (i = 0; i < mx; i++) {
 522                 if (storage[i] && storage[i]->free_func) {
 523                         ptr = CRYPTO_get_ex_data(ad, i);
 524                         storage[i]->free_func(obj, ptr, ad, i,
 525                             storage[i]->argl, storage[i]->argp);
 526                 }
 527         }
 528         free(storage);
 529         if (ad->sk) {
 530                 sk_void_free(ad->sk);
 531                 ad->sk = NULL;
 532         }
 533 }
 534
 535 /********************************************************************/
 536 /* API functions that defer all "state" operations to the "ex_data"
 537  * implementation we have set. */
 538
 539 /* Obtain an index for a new class (not the same as getting a new index within
 540  * an existing class - this is actually getting a new *class*) */
 541 int
 542 CRYPTO_ex_data_new_class(void)
 543 {
 544         IMPL_CHECK
 545         return EX_IMPL(new_class)();
 546 }
 547
 548 /* Release all "ex_data" state to prevent memory leaks. This can't be made
 549  * thread-safe without overhauling a lot of stuff, and shouldn't really be
 550  * called under potential race-conditions anyway (it's for program shutdown
 551  * after all). */
 552 void
 553 CRYPTO_cleanup_all_ex_data(void)
 554 {
 555         IMPL_CHECK
 556         EX_IMPL(cleanup)();
 557 }
 558
 559 /* Inside an existing class, get/register a new index. */
 560 int
 561 CRYPTO_get_ex_new_index(int class_index, long argl, void *argp,
 562     CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
 563 {
 564         int ret = -1;
 565
 566         IMPL_CHECK
 567         ret = EX_IMPL(get_new_index)(class_index,
 568             argl, argp, new_func, dup_func, free_func);
 569         return ret;
 570 }
 571
 572 /* Initialise a new CRYPTO_EX_DATA for use in a particular class - including
 573  * calling new() callbacks for each index in the class used by this variable */
 574 int
 575 CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 576 {
 577         IMPL_CHECK
 578         return EX_IMPL(new_ex_data)(class_index, obj, ad);
 579 }
 580
 581 /* Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks for
 582  * each index in the class used by this variable */
 583 int
 584 CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to, CRYPTO_EX_DATA *from)
 585 {
 586         IMPL_CHECK
 587         return EX_IMPL(dup_ex_data)(class_index, to, from);
 588 }
 589
 590 /* Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for
 591  * each index in the class used by this variable */
 592 void
 593 CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 594 {
 595         IMPL_CHECK
 596         EX_IMPL(free_ex_data)(class_index, obj, ad);
 597 }
 598
 599 /* For a given CRYPTO_EX_DATA variable, set the value corresponding to a
 600  * particular index in the class used by this variable */
 601 int
 602 CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val)
 603 {
 604         int i;
 605
 606         if (ad->sk == NULL) {
 607                 if ((ad->sk = sk_void_new_null()) == NULL) {
 608                         CRYPTOerror(ERR_R_MALLOC_FAILURE);
 609                         return (0);
 610                 }
 611         }
 612         i = sk_void_num(ad->sk);
 613
 614         while (i <= idx) {
 615                 if (!sk_void_push(ad->sk, NULL)) {
 616                         CRYPTOerror(ERR_R_MALLOC_FAILURE);
 617                         return (0);
 618                 }
 619                 i++;
 620         }
 621         sk_void_set(ad->sk, idx, val);
 622         return (1);
 623 }
 624
 625 /* For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a
 626  * particular index in the class used by this variable */
 627 void *
 628 CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx)
 629 {
 630         if (ad->sk == NULL)
 631                 return (0);
 632         else if (idx >= sk_void_num(ad->sk))
 633                 return (0);
 634         else
 635                 return (sk_void_value(ad->sk, idx));
 636 }