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).
31 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
32 * All rights reserved.
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.
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).
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.
52 * Redistribution and use in source and binary forms, with or without
53 * modification, are permitted provided that the following conditions
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)"
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
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.]
87 /* ====================================================================
88 * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved.
90 * Redistribution and use in source and binary forms, with or without
91 * modification, are permitted provided that the following conditions
94 * 1. Redistributions of source code must retain the above copyright
95 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
116 * 6. Redistributions of any form whatsoever must retain the following
118 * "This product includes software developed by the OpenSSL Project
119 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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 * ====================================================================
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).
141 #include "cryptlib.h"
142 #include <openssl/lhash.h>
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, CRYPTO_EX_DATA *ad);
160 /* Duplicate a CRYPTO_EX_DATA of a given class onto a copy */
161 int (*cb_dup_ex_data) (int class_index, CRYPTO_EX_DATA *to,
162 CRYPTO_EX_DATA *from);
163 /* Cleanup a CRYPTO_EX_DATA of a given class */
164 void (*cb_free_ex_data) (int class_index, void *obj, CRYPTO_EX_DATA *ad);
167 /* The implementation we use at run-time */
168 static const CRYPTO_EX_DATA_IMPL *impl = NULL;
171 * To call "impl" functions, use this macro rather than referring to 'impl'
172 * directly, eg. EX_IMPL(get_new_index)(...);
174 #define EX_IMPL(a) impl->cb_##a
176 /* Predeclare the "default" ex_data implementation */
177 static int int_new_class(void);
178 static void int_cleanup(void);
179 static int int_get_new_index(int class_index, long argl, void *argp,
180 CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
181 CRYPTO_EX_free *free_func);
182 static int int_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad);
183 static int int_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
184 CRYPTO_EX_DATA *from);
185 static void int_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad);
186 static CRYPTO_EX_DATA_IMPL impl_default = {
196 * Internal function that checks whether "impl" is set and if not, sets it to
199 static void impl_check(void)
201 CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
203 impl = &impl_default;
204 CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
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).
211 #define IMPL_CHECK if(!impl) impl_check();
213 /* API functions to get/set the "ex_data" implementation */
214 const CRYPTO_EX_DATA_IMPL *CRYPTO_get_ex_data_implementation(void)
216 IMPL_CHECK return impl;
219 int CRYPTO_set_ex_data_implementation(const CRYPTO_EX_DATA_IMPL *i)
222 CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
227 CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
231 /****************************************************************************/
233 * Interal (default) implementation of "ex_data" support. API functions are
238 * The type that represents what each "class" used to implement locally. A
239 * STACK of CRYPTO_EX_DATA_FUNCS plus a index-counter. The 'class_index' is
240 * the global value representing the class that is used to distinguish these
243 typedef struct st_ex_class_item {
245 STACK_OF(CRYPTO_EX_DATA_FUNCS) *meth;
249 /* When assigning new class indexes, this is our counter */
250 static int ex_class = CRYPTO_EX_INDEX_USER;
252 /* The global hash table of EX_CLASS_ITEM items */
253 static LHASH *ex_data = NULL;
255 /* The callbacks required in the "ex_data" hash table */
256 static unsigned long ex_hash_cb(const void *a_void)
258 return ((const EX_CLASS_ITEM *)a_void)->class_index;
261 static int ex_cmp_cb(const void *a_void, const void *b_void)
263 return (((const EX_CLASS_ITEM *)a_void)->class_index -
264 ((const EX_CLASS_ITEM *)b_void)->class_index);
268 * Internal functions used by the "impl_default" implementation to access the
272 static int ex_data_check(void)
275 CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
276 if (!ex_data && ((ex_data = lh_new(ex_hash_cb, ex_cmp_cb)) == NULL))
278 CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
283 * This macros helps reduce the locking from repeated checks because the
284 * ex_data_check() function checks ex_data again inside a lock.
286 #define EX_DATA_CHECK(iffail) if(!ex_data && !ex_data_check()) {iffail}
288 /* This "inner" callback is used by the callback function that follows it */
289 static void def_cleanup_util_cb(CRYPTO_EX_DATA_FUNCS *funcs)
295 * This callback is used in lh_doall to destroy all EX_CLASS_ITEM values from
296 * "ex_data" prior to the ex_data hash table being itself destroyed. Doesn't
299 static void def_cleanup_cb(void *a_void)
301 EX_CLASS_ITEM *item = (EX_CLASS_ITEM *)a_void;
302 sk_CRYPTO_EX_DATA_FUNCS_pop_free(item->meth, def_cleanup_util_cb);
307 * Return the EX_CLASS_ITEM from the "ex_data" hash table that corresponds to
308 * a given class. Handles locking.
310 static EX_CLASS_ITEM *def_get_class(int class_index)
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_retrieve(ex_data, &d);
318 gen = OPENSSL_malloc(sizeof(EX_CLASS_ITEM));
320 gen->class_index = class_index;
322 gen->meth = sk_CRYPTO_EX_DATA_FUNCS_new_null();
327 * Because we're inside the ex_data lock, the return value
328 * from the insert will be NULL
330 lh_insert(ex_data, gen);
335 CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
337 CRYPTOerr(CRYPTO_F_DEF_GET_CLASS, ERR_R_MALLOC_FAILURE);
342 * Add a new method to the given EX_CLASS_ITEM and return the corresponding
343 * index (or -1 for error). Handles locking.
345 static int def_add_index(EX_CLASS_ITEM *item, long argl, void *argp,
346 CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
347 CRYPTO_EX_free *free_func)
350 CRYPTO_EX_DATA_FUNCS *a =
351 (CRYPTO_EX_DATA_FUNCS *)OPENSSL_malloc(sizeof(CRYPTO_EX_DATA_FUNCS));
353 CRYPTOerr(CRYPTO_F_DEF_ADD_INDEX, ERR_R_MALLOC_FAILURE);
358 a->new_func = new_func;
359 a->dup_func = dup_func;
360 a->free_func = free_func;
361 CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
362 while (sk_CRYPTO_EX_DATA_FUNCS_num(item->meth) <= item->meth_num) {
363 if (!sk_CRYPTO_EX_DATA_FUNCS_push(item->meth, NULL)) {
364 CRYPTOerr(CRYPTO_F_DEF_ADD_INDEX, ERR_R_MALLOC_FAILURE);
369 toret = item->meth_num++;
370 (void)sk_CRYPTO_EX_DATA_FUNCS_set(item->meth, toret, a);
372 CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
376 /**************************************************************/
377 /* The functions in the default CRYPTO_EX_DATA_IMPL structure */
379 static int int_new_class(void)
382 CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
384 CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
388 static void int_cleanup(void)
390 EX_DATA_CHECK(return;)
391 lh_doall(ex_data, def_cleanup_cb);
397 static int 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)
401 EX_CLASS_ITEM *item = def_get_class(class_index);
404 return def_add_index(item, argl, argp, new_func, dup_func, free_func);
408 * Thread-safe by copying a class's array of "CRYPTO_EX_DATA_FUNCS" entries
409 * in the lock, then using them outside the lock. NB: Thread-safety only
410 * applies to the global "ex_data" state (ie. class definitions), not
411 * thread-safe on 'ad' itself.
413 static int int_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
417 CRYPTO_EX_DATA_FUNCS **storage = NULL;
418 EX_CLASS_ITEM *item = def_get_class(class_index);
420 /* error is already set */
423 CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
424 mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
426 storage = OPENSSL_malloc(mx * sizeof(CRYPTO_EX_DATA_FUNCS *));
429 for (i = 0; i < mx; i++)
430 storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(item->meth, i);
433 CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
434 if ((mx > 0) && !storage) {
435 CRYPTOerr(CRYPTO_F_INT_NEW_EX_DATA, ERR_R_MALLOC_FAILURE);
438 for (i = 0; i < mx; i++) {
439 if (storage[i] && storage[i]->new_func) {
440 ptr = CRYPTO_get_ex_data(ad, i);
441 storage[i]->new_func(obj, ptr, ad, i,
442 storage[i]->argl, storage[i]->argp);
446 OPENSSL_free(storage);
450 /* Same thread-safety notes as for "int_new_ex_data" */
451 static int int_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
452 CRYPTO_EX_DATA *from)
456 CRYPTO_EX_DATA_FUNCS **storage = NULL;
459 /* 'to' should be "blank" which *is* just like 'from' */
461 if ((item = def_get_class(class_index)) == NULL)
463 CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
464 mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
465 j = sk_num(from->sk);
469 storage = OPENSSL_malloc(mx * sizeof(CRYPTO_EX_DATA_FUNCS *));
472 for (i = 0; i < mx; i++)
473 storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(item->meth, i);
476 CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
477 if ((mx > 0) && !storage) {
478 CRYPTOerr(CRYPTO_F_INT_DUP_EX_DATA, ERR_R_MALLOC_FAILURE);
481 for (i = 0; i < mx; i++) {
482 ptr = CRYPTO_get_ex_data(from, i);
483 if (storage[i] && storage[i]->dup_func)
484 storage[i]->dup_func(to, from, &ptr, i,
485 storage[i]->argl, storage[i]->argp);
486 CRYPTO_set_ex_data(to, i, ptr);
489 OPENSSL_free(storage);
493 /* Same thread-safety notes as for "int_new_ex_data" */
494 static void int_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
499 CRYPTO_EX_DATA_FUNCS **storage = NULL;
500 if ((item = def_get_class(class_index)) == NULL)
502 CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
503 mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
505 storage = OPENSSL_malloc(mx * sizeof(CRYPTO_EX_DATA_FUNCS *));
508 for (i = 0; i < mx; i++)
509 storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(item->meth, i);
512 CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
513 if ((mx > 0) && !storage) {
514 CRYPTOerr(CRYPTO_F_INT_FREE_EX_DATA, ERR_R_MALLOC_FAILURE);
517 for (i = 0; i < mx; i++) {
518 if (storage[i] && storage[i]->free_func) {
519 ptr = CRYPTO_get_ex_data(ad, i);
520 storage[i]->free_func(obj, ptr, ad, i,
521 storage[i]->argl, storage[i]->argp);
525 OPENSSL_free(storage);
532 /********************************************************************/
534 * API functions that defer all "state" operations to the "ex_data"
535 * implementation we have set.
539 * Obtain an index for a new class (not the same as getting a new index
540 * within an existing class - this is actually getting a new *class*)
542 int CRYPTO_ex_data_new_class(void)
544 IMPL_CHECK return EX_IMPL(new_class) ();
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
553 void CRYPTO_cleanup_all_ex_data(void)
555 IMPL_CHECK EX_IMPL(cleanup) ();
558 /* Inside an existing class, get/register a new index. */
559 int CRYPTO_get_ex_new_index(int class_index, long argl, void *argp,
560 CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
561 CRYPTO_EX_free *free_func)
566 ret = EX_IMPL(get_new_index) (class_index,
567 argl, argp, new_func, dup_func,
573 * Initialise a new CRYPTO_EX_DATA for use in a particular class - including
574 * calling new() callbacks for each index in the class used by this variable
576 int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
578 IMPL_CHECK return EX_IMPL(new_ex_data) (class_index, obj, ad);
582 * Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks
583 * for each index in the class used by this variable
585 int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
586 CRYPTO_EX_DATA *from)
588 IMPL_CHECK return EX_IMPL(dup_ex_data) (class_index, to, from);
592 * Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for
593 * each index in the class used by this variable
595 void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
597 IMPL_CHECK EX_IMPL(free_ex_data) (class_index, obj, ad);
601 * For a given CRYPTO_EX_DATA variable, set the value corresponding to a
602 * particular index in the class used by this variable
604 int CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val)
608 if (ad->sk == NULL) {
609 if ((ad->sk = sk_new_null()) == NULL) {
610 CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
617 if (!sk_push(ad->sk, NULL)) {
618 CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
623 sk_set(ad->sk, idx, val);
628 * For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a
629 * particular index in the class used by this variable
631 void *CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx)
635 else if (idx >= sk_num(ad->sk))
638 return (sk_value(ad->sk, idx));
641 IMPLEMENT_STACK_OF(CRYPTO_EX_DATA_FUNCS)