summaryrefslogtreecommitdiffstats
path: root/crypto/ex_data.c
blob: 8914218fe8f9c00430d9ab66af4be84e11c376d0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
/* crypto/ex_data.c */

/*
 * Overhaul notes;
 *
 * This code is now *mostly* thread-safe. It is now easier to understand in what
 * ways it is safe and in what ways it is not, which is an improvement. Firstly,
 * all per-class stacks and index-counters for ex_data are stored in the same
 * global LHASH table (keyed by class). This hash table uses locking for all
 * access with the exception of CRYPTO_cleanup_all_ex_data(), which must only be
 * called when no other threads can possibly race against it (even if it was
 * locked, the race would mean it's possible the hash table might have been
 * recreated after the cleanup). As classes can only be added to the hash table,
 * and within each class, the stack of methods can only be incremented, the
 * locking mechanics are simpler than they would otherwise be. For example, the
 * new/dup/free ex_data functions will lock the hash table, copy the method
 * pointers it needs from the relevant class, then unlock the hash table before
 * actually applying those method pointers to the task of the new/dup/free
 * operations. As they can't be removed from the method-stack, only
 * supplemented, there's no race conditions associated with using them outside
 * the lock. The get/set_ex_data functions are not locked because they do not
 * involve this global state at all - they operate directly with a previously
 * obtained per-class method index and a particular "ex_data" variable. These
 * variables are usually instantiated per-context (eg. each RSA structure has
 * one) so locking on read/write access to that variable can be locked locally
 * if required (eg. using the "RSA" lock to synchronise access to a
 * per-RSA-structure ex_data variable if required).
 * [Geoff]
 */

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */
/* ====================================================================
 * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include "cryptlib.h"
#include <openssl/lhash.h>

/* What an "implementation of ex_data functionality" looks like */
struct st_CRYPTO_EX_DATA_IMPL
	{
	/*********************/
	/* GLOBAL OPERATIONS */
	/* Return a new class index */
	int (*cb_new_class)(void);
	/* Cleanup all state used by the implementation */
	void (*cb_cleanup)(void);
	/************************/
	/* PER-CLASS OPERATIONS */
	/* Get a new method index within a class */
	int (*cb_get_new_index)(int class_index, long argl, void *argp,
			CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
			CRYPTO_EX_free *free_func);
	/* Initialise a new CRYPTO_EX_DATA of a given class */
	int (*cb_new_ex_data)(int class_index, void *obj,
			CRYPTO_EX_DATA *ad);
	/* Duplicate a CRYPTO_EX_DATA of a given class onto a copy */
	int (*cb_dup_ex_data)(int class_index, CRYPTO_EX_DATA *to,
			CRYPTO_EX_DATA *from);
	/* Cleanup a CRYPTO_EX_DATA of a given class */
	void (*cb_free_ex_data)(int class_index, void *obj,
			CRYPTO_EX_DATA *ad);
	};

/* The implementation we use at run-time */
static const CRYPTO_EX_DATA_IMPL *impl = NULL;

/* To call "impl" functions, use this macro rather than referring to 'impl' directly, eg.
 * EX_IMPL(get_new_index)(...); */
#define EX_IMPL(a) impl->cb_##a

/* Predeclare the "default" ex_data implementation */
static int int_new_class(void);
static void int_cleanup(void);
static int int_get_new_index(int class_index, long argl, void *argp,
		CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
		CRYPTO_EX_free *free_func);
static int int_new_ex_data(int class_index, void *obj,
		CRYPTO_EX_DATA *ad);
static int int_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
		CRYPTO_EX_DATA *from);
static void int_free_ex_data(int class_index, void *obj,
		CRYPTO_EX_DATA *ad);
static CRYPTO_EX_DATA_IMPL impl_default =
	{
	int_new_class,
	int_cleanup,
	int_get_new_index,
	int_new_ex_data,
	int_dup_ex_data,
	int_free_ex_data
	};

/* Internal function that checks whether "impl" is set and if not, sets it to
 * the default. */
static void impl_check(void)
	{
	CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
	if(!impl)
		impl = &impl_default;
	CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
	}
/* A macro wrapper for impl_check that first uses a non-locked test before
 * invoking the function (which checks again inside a lock). */
#define IMPL_CHECK if(!impl) impl_check();

/* API functions to get/set the "ex_data" implementation */
const CRYPTO_EX_DATA_IMPL *CRYPTO_get_ex_data_implementation(void)
	{
	IMPL_CHECK
	return impl;
	}
int CRYPTO_set_ex_data_implementation(const CRYPTO_EX_DATA_IMPL *i)
	{
	int toret = 0;
	CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
	if(!impl)
		{
		impl = i;
		toret = 1;
		}
	CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
	return toret;
	}

/****************************************************************************/
/* Interal (default) implementation of "ex_data" support. API functions are
 * further down. */

/* The type that represents what each "class" used to implement locally. A STACK
 * of CRYPTO_EX_DATA_FUNCS plus a index-counter. The 'class_index' is the global
 * value representing the class that is used to distinguish these items. */
typedef struct st_ex_class_item {
	int class_index;
	STACK_OF(CRYPTO_EX_DATA_FUNCS) *meth;
	int meth_num;
} EX_CLASS_ITEM;

/* When assigning new class indexes, this is our counter */
static int ex_class = CRYPTO_EX_INDEX_USER;

/* The global hash table of EX_CLASS_ITEM items */
static LHASH *ex_data = NULL;

/* The callbacks required in the "ex_data" hash table */
static unsigned long ex_hash_cb(const void *a_void)
	{
	return ((const EX_CLASS_ITEM *)a_void)->class_index;
	}
static int ex_cmp_cb(const void *a_void, const void *b_void)
	{
	return (((const EX_CLASS_ITEM *)a_void)->class_index -
		((const EX_CLASS_ITEM *)b_void)->class_index);
	}

/* Internal functions used by the "impl_default" implementation to access the
 * state */

static int ex_data_check(void)
	{
	int toret = 1;
	CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
	if(!ex_data && ((ex_data = lh_new(ex_hash_cb, ex_cmp_cb)) == NULL))
		toret = 0;
	CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
	return toret;
	}
/* This macros helps reduce the locking from repeated checks because the
 * ex_data_check() function checks ex_data again inside a lock. */
#define EX_DATA_CHECK(iffail) if(!ex_data && !ex_data_check()) {iffail}

/* This "inner" callback is used by the callback function that follows it */
static void def_cleanup_util_cb(CRYPTO_EX_DATA_FUNCS *funcs)
	{
	OPENSSL_free(funcs);
	}

/* This callback is used in lh_doall to destroy all EX_CLASS_ITEM values from
 * "ex_data" prior to the ex_data hash table being itself destroyed. Doesn't do
 * any locking. */
static void def_cleanup_cb(void *a_void)
	{
	EX_CLASS_ITEM *item = (EX_CLASS_ITEM *)a_void;
	sk_CRYPTO_EX_DATA_FUNCS_pop_free(item->meth, def_cleanup_util_cb);
	OPENSSL_free(item);
	}

/* Return the EX_CLASS_ITEM from the "ex_data" hash table that corresponds to a
 * given class. Handles locking. */
static EX_CLASS_ITEM *def_get_class(int class_index)
	{
	EX_CLASS_ITEM d, *p, *gen;
	EX_DATA_CHECK(return NULL;)
	d.class_index = class_index;
	CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
	p = lh_retrieve(ex_data, &d);
	if(!p)
		{
		gen = OPENSSL_malloc(sizeof(EX_CLASS_ITEM));
		if(gen)
			{
			gen->class_index = class_index;
			gen->meth_num = 0;
			gen->meth = sk_CRYPTO_EX_DATA_FUNCS_new_null();
			if(!gen->meth)
				OPENSSL_free(gen);
			else
				{
				/* Because we're inside the ex_data lock, the
				 * return value from the insert will be NULL */
				lh_insert(ex_data, gen);
				p = gen;
				}
			}
		}
	CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
	if(!p)
		CRYPTOerr(CRYPTO_F_DEF_GET_CLASS,ERR_R_MALLOC_FAILURE);
	return p;
	}

/* Add a new method to the given EX_CLASS_ITEM and return the corresponding
 * index (or -1 for error). Handles locking. */
static int def_add_index(EX_CLASS_ITEM *item, long argl, void *argp,
		CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
		CRYPTO_EX_free *free_func)
	{
	int toret = -1;
	CRYPTO_EX_DATA_FUNCS *a = (CRYPTO_EX_DATA_FUNCS *)OPENSSL_malloc(
					sizeof(CRYPTO_EX_DATA_FUNCS));
	if(!a)
		{
		CRYPTOerr(CRYPTO_F_DEF_ADD_INDEX,ERR_R_MALLOC_FAILURE);
		return -1;
		}
	a->argl=argl;
	a->argp=argp;
	a->new_func=new_func;
	a->dup_func=dup_func;
	a->free_func=free_func;
	CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
	while (sk_CRYPTO_EX_DATA_FUNCS_num(item->meth) <= item->meth_num)
		{
		if (!sk_CRYPTO_EX_DATA_FUNCS_push(item->meth, NULL))
			{
			CRYPTOerr(CRYPTO_F_DEF_ADD_INDEX,ERR_R_MALLOC_FAILURE);
			OPENSSL_free(a);
			goto err;
			}
		}
	toret = item->meth_num++;
	sk_CRYPTO_EX_DATA_FUNCS_set(item->meth, toret, a);
err:
	CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
	return toret;
	}

/**************************************************************/
/* The functions in the default CRYPTO_EX_DATA_IMPL structure */

static int int_new_class(void)
	{
	int toret;
	CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
	toret = ex_class++;
	CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
	return toret;
	}

static void int_cleanup(void)
	{
	EX_DATA_CHECK(return;)
	lh_doall(ex_data, def_cleanup_cb);
	lh_free(ex_data);
	ex_data = NULL;
	impl = NULL;
	}

static int int_get_new_index(int class_index, long argl, void *argp,
		CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
		CRYPTO_EX_free *free_func)
	{
	EX_CLASS_ITEM *item = def_get_class(class_index);
	if(!item)
		return -1;
	return def_add_index(item, argl, argp, new_func, dup_func, free_func);
	}

/* Thread-safe by copying a class's array of "CRYPTO_EX_DATA_FUNCS" entries in
 * the lock, then using them outside the lock. NB: Thread-safety only applies to
 * the global "ex_data" state (ie. class definitions), not thread-safe on 'ad'
 * itself. */
static int int_new_ex_data(int class_index, void *obj,
		CRYPTO_EX_DATA *ad)
	{
	int mx,i;
	void *ptr;
	CRYPTO_EX_DATA_FUNCS **storage = NULL;
	EX_CLASS_ITEM *item = def_get_class(class_index);
	if(!item)
		/* error is already set */
		return 0;
	ad->sk = NULL;
	CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
	mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
	if(mx > 0)
		{
		storage = OPENSSL_malloc(mx * sizeof(CRYPTO_EX_DATA_FUNCS*));
		if(!storage)
			goto skip;
		for(i = 0; i < mx; i++)
			storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(item->meth,i);
		}
skip:
	CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
	if((mx > 0) && !storage)
		{
		CRYPTOerr(CRYPTO_F_INT_NEW_EX_DATA,ERR_R_MALLOC_FAILURE);
		return 0;
		}
	for(i = 0; i < mx; i++)
		{
		if(storage[i] && storage[i]->new_func)
			{
			ptr = CRYPTO_get_ex_data(ad, i);
			storage[i]->new_func(obj,ptr,ad,i,
				storage[i]->argl,storage[i]->argp);
			}
		}
	if(storage)
		OPENSSL_free(storage);
	return 1;
	}

/* Same thread-safety notes as for "int_new_ex_data" */
static int int_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
		CRYPTO_EX_DATA *from)
	{
	int mx, j, i;
	char *ptr;
	CRYPTO_EX_DATA_FUNCS **storage = NULL;
	EX_CLASS_ITEM *item;
	if(!from->sk)
		/* 'to' should be "blank" which *is* just like 'from' */
		return 1;
	if((item = def_get_class(class_index)) == NULL)
		return 0;
	CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
	mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
	j = sk_num(from->sk);
	if(j < mx)
		mx = j;
	if(mx > 0)
		{
		storage = OPENSSL_malloc(mx * sizeof(CRYPTO_EX_DATA_FUNCS*));
		if(!storage)
			goto skip;
		for(i = 0; i < mx; i++)
			storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(item->meth,i);
		}
skip:
	CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
	if((mx > 0) && !storage)
		{
		CRYPTOerr(CRYPTO_F_INT_DUP_EX_DATA,ERR_R_MALLOC_FAILURE);
		return 0;
		}
	for(i = 0; i < mx; i++)
		{
		ptr = CRYPTO_get_ex_data(from, i);
		if(storage[i] && storage[i]->dup_func)
			storage[i]->dup_func(to,from,&ptr,i,
				storage[i]->argl,storage[i]->argp);
		CRYPTO_set_ex_data(to,i,ptr);
		}
	if(storage)
		OPENSSL_free(storage);
	return 1;
	}

/* Same thread-safety notes as for "int_new_ex_data" */
static void int_free_ex_data(int class_index, void *obj,
		CRYPTO_EX_DATA *ad)
	{
	int mx,i;
	EX_CLASS_ITEM *item;
	void *ptr;
	CRYPTO_EX_DATA_FUNCS **storage = NULL;
	if((item = def_get_class(class_index)) == NULL)
		return;
	CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
	mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
	if(mx > 0)
		{
		storage = OPENSSL_malloc(mx * sizeof(CRYPTO_EX_DATA_FUNCS*));
		if(!storage)
			goto skip;
		for(i = 0; i < mx; i++)
			storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(item->meth,i);
		}
skip:
	CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
	if((mx > 0) && !storage)
		{
		CRYPTOerr(CRYPTO_F_INT_FREE_EX_DATA,ERR_R_MALLOC_FAILURE);
		return;
		}
	for(i = 0; i < mx; i++)
		{
		if(storage[i] && storage[i]->free_func)
			{
			ptr = CRYPTO_get_ex_data(ad,i);
			storage[i]->free_func(obj,ptr,ad,i,
				storage[i]->argl,storage[i]->argp);
			}
		}
	if(storage)
		OPENSSL_free(storage);
	if(ad->sk)
		{
		sk_free(ad->sk);
		ad->sk=NULL;
		}
	}

/********************************************************************/
/* API functions that defer all "state" operations to the "ex_data"
 * implementation we have set. */

/* Obtain an index for a new class (not the same as getting a new index within
 * an existing class - this is actually getting a new *class*) */
int CRYPTO_ex_data_new_class(void)
	{
	IMPL_CHECK
	return EX_IMPL(new_class)();
	}

/* Release all "ex_data" state to prevent memory leaks. This can't be made
 * thread-safe without overhauling a lot of stuff, and shouldn't really be
 * called under potential race-conditions anyway (it's for program shutdown
 * after all). */
void CRYPTO_cleanup_all_ex_data(void)
	{
	IMPL_CHECK
	EX_IMPL(cleanup)();
	}

/* Inside an existing class, get/register a new index. */
int CRYPTO_get_ex_new_index(int class_index, long argl, void *argp,
		CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
		CRYPTO_EX_free *free_func)
	{
	int ret = -1;

	IMPL_CHECK
	ret = EX_IMPL(get_new_index)(class_index,
			argl, argp, new_func, dup_func, free_func);
	return ret;
	}

/* Initialise a new CRYPTO_EX_DATA for use in a particular class - including
 * calling new() callbacks for each index in the class used by this variable */
int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
	{
	IMPL_CHECK
	return EX_IMPL(new_ex_data)(class_index, obj, ad);
	}

/* Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks for
 * each index in the class used by this variable */
int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
	     CRYPTO_EX_DATA *from)
	{
	IMPL_CHECK
	return EX_IMPL(dup_ex_data)(class_index, to, from);
	}

/* Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for
 * each index in the class used by this variable */
void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
	{
	IMPL_CHECK
	EX_IMPL(free_ex_data)(class_index, obj, ad);
	}

/* For a given CRYPTO_EX_DATA variable, set the value corresponding to a
 * particular index in the class used by this variable */
int CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val)
	{
	int i;

	if (ad->sk == NULL)
		{
		if ((ad->sk=sk_new_null()) == NULL)
			{
			CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA,ERR_R_MALLOC_FAILURE);
			return(0);
			}
		}
	i=sk_num(ad->sk);

	while (i <= idx)
		{
		if (!sk_push(ad->sk,NULL))
			{
			CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA,ERR_R_MALLOC_FAILURE);
			return(0);
			}
		i++;
		}
	sk_set(ad->sk,idx,val);
	return(1);
	}

/* For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a
 * particular index in the class used by this variable */
void *CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx)
	{
	if (ad->sk == NULL)
		return(0);
	else if (idx >= sk_num(ad->sk))
		return(0);
	else
		return(sk_value(ad->sk,idx));
	}

IMPLEMENT_STACK_OF(CRYPTO_EX_DATA_FUNCS)