crypto/openssl-0.9/crypto/ex_data.c

   1 /* crypto/ex_data.c */
   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 "cryptlib.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         /*********************/
 148         /* GLOBAL OPERATIONS */
 149         /* Return a new class index */
 150         int (*cb_new_class)(void);
 151         /* Cleanup all state used by the implementation */
 152         void (*cb_cleanup)(void);
 153         /************************/
 154         /* PER-CLASS OPERATIONS */
 155         /* Get a new method index within a class */
 156         int (*cb_get_new_index)(int class_index, long argl, void *argp,
 157                         CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
 158                         CRYPTO_EX_free *free_func);
 159         /* Initialise a new CRYPTO_EX_DATA of a given class */
 160         int (*cb_new_ex_data)(int class_index, void *obj,
 161                         CRYPTO_EX_DATA *ad);
 162         /* Duplicate a CRYPTO_EX_DATA of a given class onto a copy */
 163         int (*cb_dup_ex_data)(int class_index, CRYPTO_EX_DATA *to,
 164                         CRYPTO_EX_DATA *from);
 165         /* Cleanup a CRYPTO_EX_DATA of a given class */
 166         void (*cb_free_ex_data)(int class_index, void *obj,
 167                         CRYPTO_EX_DATA *ad);
 168         };
 169
 170 /* The implementation we use at run-time */
 171 static const CRYPTO_EX_DATA_IMPL *impl = NULL;
 172
 173 /* To call "impl" functions, use this macro rather than referring to 'impl' directly, eg.
 174  * EX_IMPL(get_new_index)(...); */
 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 static CRYPTO_EX_DATA_IMPL impl_default =
 190         {
 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 impl_check(void)
 202         {
 203         CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
 204         if(!impl)
 205                 impl = &impl_default;
 206         CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
 207         }
 208 /* A macro wrapper for impl_check that first uses a non-locked test before
 209  * invoking the function (which checks again inside a lock). */
 210 #define IMPL_CHECK if(!impl) impl_check();
 211
 212 /* API functions to get/set the "ex_data" implementation */
 213 const CRYPTO_EX_DATA_IMPL *CRYPTO_get_ex_data_implementation(void)
 214         {
 215         IMPL_CHECK
 216         return impl;
 217         }
 218 int CRYPTO_set_ex_data_implementation(const CRYPTO_EX_DATA_IMPL *i)
 219         {
 220         int toret = 0;
 221         CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
 222         if(!impl)
 223                 {
 224                 impl = i;
 225                 toret = 1;
 226                 }
 227         CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
 228         return toret;
 229         }
 230
 231 /****************************************************************************/
 232 /* Interal (default) implementation of "ex_data" support. API functions are
 233  * further down. */
 234
 235 /* The type that represents what each "class" used to implement locally. A STACK
 236  * of CRYPTO_EX_DATA_FUNCS plus a index-counter. The 'class_index' is the global
 237  * value representing the class that is used to distinguish these items. */
 238 typedef struct st_ex_class_item {
 239         int class_index;
 240         STACK_OF(CRYPTO_EX_DATA_FUNCS) *meth;
 241         int meth_num;
 242 } EX_CLASS_ITEM;
 243
 244 /* When assigning new class indexes, this is our counter */
 245 static int ex_class = CRYPTO_EX_INDEX_USER;
 246
 247 /* The global hash table of EX_CLASS_ITEM items */
 248 static LHASH *ex_data = NULL;
 249
 250 /* The callbacks required in the "ex_data" hash table */
 251 static unsigned long ex_hash_cb(const void *a_void)
 252         {
 253         return ((const EX_CLASS_ITEM *)a_void)->class_index;
 254         }
 255 static int ex_cmp_cb(const void *a_void, const void *b_void)
 256         {
 257         return (((const EX_CLASS_ITEM *)a_void)->class_index -
 258                 ((const EX_CLASS_ITEM *)b_void)->class_index);
 259         }
 260
 261 /* Internal functions used by the "impl_default" implementation to access the
 262  * state */
 263
 264 static int ex_data_check(void)
 265         {
 266         int toret = 1;
 267         CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
 268         if(!ex_data && ((ex_data = lh_new(ex_hash_cb, ex_cmp_cb)) == NULL))
 269                 toret = 0;
 270         CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
 271         return toret;
 272         }
 273 /* This macros helps reduce the locking from repeated checks because the
 274  * ex_data_check() function checks ex_data again inside a lock. */
 275 #define EX_DATA_CHECK(iffail) if(!ex_data && !ex_data_check()) {iffail}
 276
 277 /* This "inner" callback is used by the callback function that follows it */
 278 static void def_cleanup_util_cb(CRYPTO_EX_DATA_FUNCS *funcs)
 279         {
 280         OPENSSL_free(funcs);
 281         }
 282
 283 /* This callback is used in lh_doall to destroy all EX_CLASS_ITEM values from
 284  * "ex_data" prior to the ex_data hash table being itself destroyed. Doesn't do
 285  * any locking. */
 286 static void def_cleanup_cb(void *a_void)
 287         {
 288         EX_CLASS_ITEM *item = (EX_CLASS_ITEM *)a_void;
 289         sk_CRYPTO_EX_DATA_FUNCS_pop_free(item->meth, def_cleanup_util_cb);
 290         OPENSSL_free(item);
 291         }
 292
 293 /* Return the EX_CLASS_ITEM from the "ex_data" hash table that corresponds to a
 294  * given class. Handles locking. */
 295 static EX_CLASS_ITEM *def_get_class(int class_index)
 296         {
 297         EX_CLASS_ITEM d, *p, *gen;
 298         EX_DATA_CHECK(return NULL;)
 299         d.class_index = class_index;
 300         CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
 301         p = lh_retrieve(ex_data, &d);
 302         if(!p)
 303                 {
 304                 gen = OPENSSL_malloc(sizeof(EX_CLASS_ITEM));
 305                 if(gen)
 306                         {
 307                         gen->class_index = class_index;
 308                         gen->meth_num = 0;
 309                         gen->meth = sk_CRYPTO_EX_DATA_FUNCS_new_null();
 310                         if(!gen->meth)
 311                                 OPENSSL_free(gen);
 312                         else
 313                                 {
 314                                 /* Because we're inside the ex_data lock, the
 315                                  * return value from the insert will be NULL */
 316                                 lh_insert(ex_data, gen);
 317                                 p = gen;
 318                                 }
 319                         }
 320                 }
 321         CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
 322         if(!p)
 323                 CRYPTOerr(CRYPTO_F_DEF_GET_CLASS,ERR_R_MALLOC_FAILURE);
 324         return p;
 325         }
 326
 327 /* Add a new method to the given EX_CLASS_ITEM and return the corresponding
 328  * index (or -1 for error). Handles locking. */
 329 static int def_add_index(EX_CLASS_ITEM *item, long argl, void *argp,
 330                 CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
 331                 CRYPTO_EX_free *free_func)
 332         {
 333         int toret = -1;
 334         CRYPTO_EX_DATA_FUNCS *a = (CRYPTO_EX_DATA_FUNCS *)OPENSSL_malloc(
 335                                         sizeof(CRYPTO_EX_DATA_FUNCS));
 336         if(!a)
 337                 {
 338                 CRYPTOerr(CRYPTO_F_DEF_ADD_INDEX,ERR_R_MALLOC_FAILURE);
 339                 return -1;
 340                 }
 341         a->argl=argl;
 342         a->argp=argp;
 343         a->new_func=new_func;
 344         a->dup_func=dup_func;
 345         a->free_func=free_func;
 346         CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
 347         while (sk_CRYPTO_EX_DATA_FUNCS_num(item->meth) <= item->meth_num)
 348                 {
 349                 if (!sk_CRYPTO_EX_DATA_FUNCS_push(item->meth, NULL))
 350                         {
 351                         CRYPTOerr(CRYPTO_F_DEF_ADD_INDEX,ERR_R_MALLOC_FAILURE);
 352                         OPENSSL_free(a);
 353                         goto err;
 354                         }
 355                 }
 356         toret = item->meth_num++;
 357         (void)sk_CRYPTO_EX_DATA_FUNCS_set(item->meth, toret, a);
 358 err:
 359         CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
 360         return toret;
 361         }
 362
 363 /**************************************************************/
 364 /* The functions in the default CRYPTO_EX_DATA_IMPL structure */
 365
 366 static int int_new_class(void)
 367         {
 368         int toret;
 369         CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
 370         toret = ex_class++;
 371         CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
 372         return toret;
 373         }
 374
 375 static void int_cleanup(void)
 376         {
 377         EX_DATA_CHECK(return;)
 378         lh_doall(ex_data, def_cleanup_cb);
 379         lh_free(ex_data);
 380         ex_data = NULL;
 381         impl = NULL;
 382         }
 383
 384 static int int_get_new_index(int class_index, long argl, void *argp,
 385                 CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
 386                 CRYPTO_EX_free *free_func)
 387         {
 388         EX_CLASS_ITEM *item = def_get_class(class_index);
 389         if(!item)
 390                 return -1;
 391         return def_add_index(item, argl, argp, new_func, dup_func, free_func);
 392         }
 393
 394 /* Thread-safe by copying a class's array of "CRYPTO_EX_DATA_FUNCS" entries in
 395  * the lock, then using them outside the lock. NB: Thread-safety only applies to
 396  * the global "ex_data" state (ie. class definitions), not thread-safe on 'ad'
 397  * itself. */
 398 static int int_new_ex_data(int class_index, void *obj,
 399                 CRYPTO_EX_DATA *ad)
 400         {
 401         int mx,i;
 402         void *ptr;
 403         CRYPTO_EX_DATA_FUNCS **storage = NULL;
 404         EX_CLASS_ITEM *item = def_get_class(class_index);
 405         if(!item)
 406                 /* error is already set */
 407                 return 0;
 408         ad->sk = NULL;
 409         CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
 410         mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
 411         if(mx > 0)
 412                 {
 413                 storage = OPENSSL_malloc(mx * sizeof(CRYPTO_EX_DATA_FUNCS*));
 414                 if(!storage)
 415                         goto skip;
 416                 for(i = 0; i < mx; i++)
 417                         storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(item->meth,i);
 418                 }
 419 skip:
 420         CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
 421         if((mx > 0) && !storage)
 422                 {
 423                 CRYPTOerr(CRYPTO_F_INT_NEW_EX_DATA,ERR_R_MALLOC_FAILURE);
 424                 return 0;
 425                 }
 426         for(i = 0; i < mx; i++)
 427                 {
 428                 if(storage[i] && storage[i]->new_func)
 429                         {
 430                         ptr = CRYPTO_get_ex_data(ad, i);
 431                         storage[i]->new_func(obj,ptr,ad,i,
 432                                 storage[i]->argl,storage[i]->argp);
 433                         }
 434                 }
 435         if(storage)
 436                 OPENSSL_free(storage);
 437         return 1;
 438         }
 439
 440 /* Same thread-safety notes as for "int_new_ex_data" */
 441 static int int_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
 442                 CRYPTO_EX_DATA *from)
 443         {
 444         int mx, j, i;
 445         char *ptr;
 446         CRYPTO_EX_DATA_FUNCS **storage = NULL;
 447         EX_CLASS_ITEM *item;
 448         if(!from->sk)
 449                 /* 'to' should be "blank" which *is* just like 'from' */
 450                 return 1;
 451         if((item = def_get_class(class_index)) == NULL)
 452                 return 0;
 453         CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
 454         mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
 455         j = sk_num(from->sk);
 456         if(j < mx)
 457                 mx = j;
 458         if(mx > 0)
 459                 {
 460                 storage = OPENSSL_malloc(mx * sizeof(CRYPTO_EX_DATA_FUNCS*));
 461                 if(!storage)
 462                         goto skip;
 463                 for(i = 0; i < mx; i++)
 464                         storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(item->meth,i);
 465                 }
 466 skip:
 467         CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
 468         if((mx > 0) && !storage)
 469                 {
 470                 CRYPTOerr(CRYPTO_F_INT_DUP_EX_DATA,ERR_R_MALLOC_FAILURE);
 471                 return 0;
 472                 }
 473         for(i = 0; i < mx; i++)
 474                 {
 475                 ptr = CRYPTO_get_ex_data(from, i);
 476                 if(storage[i] && storage[i]->dup_func)
 477                         storage[i]->dup_func(to,from,&ptr,i,
 478                                 storage[i]->argl,storage[i]->argp);
 479                 CRYPTO_set_ex_data(to,i,ptr);
 480                 }
 481         if(storage)
 482                 OPENSSL_free(storage);
 483         return 1;
 484         }
 485
 486 /* Same thread-safety notes as for "int_new_ex_data" */
 487 static void int_free_ex_data(int class_index, void *obj,
 488                 CRYPTO_EX_DATA *ad)
 489         {
 490         int mx,i;
 491         EX_CLASS_ITEM *item;
 492         void *ptr;
 493         CRYPTO_EX_DATA_FUNCS **storage = NULL;
 494         if((item = def_get_class(class_index)) == NULL)
 495                 return;
 496         CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
 497         mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
 498         if(mx > 0)
 499                 {
 500                 storage = OPENSSL_malloc(mx * sizeof(CRYPTO_EX_DATA_FUNCS*));
 501                 if(!storage)
 502                         goto skip;
 503                 for(i = 0; i < mx; i++)
 504                         storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(item->meth,i);
 505                 }
 506 skip:
 507         CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
 508         if((mx > 0) && !storage)
 509                 {
 510                 CRYPTOerr(CRYPTO_F_INT_FREE_EX_DATA,ERR_R_MALLOC_FAILURE);
 511                 return;
 512                 }
 513         for(i = 0; i < mx; i++)
 514                 {
 515                 if(storage[i] && storage[i]->free_func)
 516                         {
 517                         ptr = CRYPTO_get_ex_data(ad,i);
 518                         storage[i]->free_func(obj,ptr,ad,i,
 519                                 storage[i]->argl,storage[i]->argp);
 520                         }
 521                 }
 522         if(storage)
 523                 OPENSSL_free(storage);
 524         if(ad->sk)
 525                 {
 526                 sk_free(ad->sk);
 527                 ad->sk=NULL;
 528                 }
 529         }
 530
 531 /********************************************************************/
 532 /* API functions that defer all "state" operations to the "ex_data"
 533  * implementation we have set. */
 534
 535 /* Obtain an index for a new class (not the same as getting a new index within
 536  * an existing class - this is actually getting a new *class*) */
 537 int CRYPTO_ex_data_new_class(void)
 538         {
 539         IMPL_CHECK
 540         return EX_IMPL(new_class)();
 541         }
 542
 543 /* Release all "ex_data" state to prevent memory leaks. This can't be made
 544  * thread-safe without overhauling a lot of stuff, and shouldn't really be
 545  * called under potential race-conditions anyway (it's for program shutdown
 546  * after all). */
 547 void CRYPTO_cleanup_all_ex_data(void)
 548         {
 549         IMPL_CHECK
 550         EX_IMPL(cleanup)();
 551         }
 552
 553 /* Inside an existing class, get/register a new index. */
 554 int CRYPTO_get_ex_new_index(int class_index, long argl, void *argp,
 555                 CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
 556                 CRYPTO_EX_free *free_func)
 557         {
 558         int ret = -1;
 559
 560         IMPL_CHECK
 561         ret = EX_IMPL(get_new_index)(class_index,
 562                         argl, argp, new_func, dup_func, free_func);
 563         return ret;
 564         }
 565
 566 /* Initialise a new CRYPTO_EX_DATA for use in a particular class - including
 567  * calling new() callbacks for each index in the class used by this variable */
 568 int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 569         {
 570         IMPL_CHECK
 571         return EX_IMPL(new_ex_data)(class_index, obj, ad);
 572         }
 573
 574 /* Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks for
 575  * each index in the class used by this variable */
 576 int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
 577              CRYPTO_EX_DATA *from)
 578         {
 579         IMPL_CHECK
 580         return EX_IMPL(dup_ex_data)(class_index, to, from);
 581         }
 582
 583 /* Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for
 584  * each index in the class used by this variable */
 585 void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 586         {
 587         IMPL_CHECK
 588         EX_IMPL(free_ex_data)(class_index, obj, ad);
 589         }
 590
 591 /* For a given CRYPTO_EX_DATA variable, set the value corresponding to a
 592  * particular index in the class used by this variable */
 593 int CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val)
 594         {
 595         int i;
 596
 597         if (ad->sk == NULL)
 598                 {
 599                 if ((ad->sk=sk_new_null()) == NULL)
 600                         {
 601                         CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA,ERR_R_MALLOC_FAILURE);
 602                         return(0);
 603                         }
 604                 }
 605         i=sk_num(ad->sk);
 606
 607         while (i <= idx)
 608                 {
 609                 if (!sk_push(ad->sk,NULL))
 610                         {
 611                         CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA,ERR_R_MALLOC_FAILURE);
 612                         return(0);
 613                         }
 614                 i++;
 615                 }
 616         sk_set(ad->sk,idx,val);
 617         return(1);
 618         }
 619
 620 /* For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a
 621  * particular index in the class used by this variable */
 622 void *CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx)
 623         {
 624         if (ad->sk == NULL)
 625                 return(0);
 626         else if (idx >= sk_num(ad->sk))
 627                 return(0);
 628         else
 629                 return(sk_value(ad->sk,idx));
 630         }
 631
 632 IMPLEMENT_STACK_OF(CRYPTO_EX_DATA_FUNCS)