2 * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 #include "internal/cryptlib_int.h"
11 #include "internal/thread_once.h"
14 * Each structure type (sometimes called a class), that supports
15 * exdata has a stack of callbacks for each instance.
17 struct ex_callback_st {
18 long argl; /* Arbitrary long */
19 void *argp; /* Arbitrary void * */
20 CRYPTO_EX_new *new_func;
21 CRYPTO_EX_free *free_func;
22 CRYPTO_EX_dup *dup_func;
26 * The state for each class. This could just be a typedef, but
27 * a structure allows future changes.
29 typedef struct ex_callbacks_st {
30 STACK_OF(EX_CALLBACK) *meth;
33 static EX_CALLBACKS ex_data[CRYPTO_EX_INDEX__COUNT];
35 static CRYPTO_RWLOCK *ex_data_lock = NULL;
36 static CRYPTO_ONCE ex_data_init = CRYPTO_ONCE_STATIC_INIT;
38 DEFINE_RUN_ONCE_STATIC(do_ex_data_init)
40 if (!OPENSSL_init_crypto(0, NULL))
42 ex_data_lock = CRYPTO_THREAD_lock_new();
43 return ex_data_lock != NULL;
47 * Return the EX_CALLBACKS from the |ex_data| array that corresponds to
48 * a given class. On success, *holds the lock.*
50 static EX_CALLBACKS *get_and_lock(int class_index)
54 if (class_index < 0 || class_index >= CRYPTO_EX_INDEX__COUNT) {
55 CRYPTOerr(CRYPTO_F_GET_AND_LOCK, ERR_R_PASSED_INVALID_ARGUMENT);
59 if (!RUN_ONCE(&ex_data_init, do_ex_data_init)) {
60 CRYPTOerr(CRYPTO_F_GET_AND_LOCK, ERR_R_MALLOC_FAILURE);
64 if (ex_data_lock == NULL) {
66 * This can happen in normal operation when using CRYPTO_mem_leaks().
67 * The CRYPTO_mem_leaks() function calls OPENSSL_cleanup() which cleans
68 * up the locks. Subsequently the BIO that CRYPTO_mem_leaks() uses gets
69 * freed, which also attempts to free the ex_data. However
70 * CRYPTO_mem_leaks() ensures that the ex_data is freed early (i.e.
71 * before OPENSSL_cleanup() is called), so if we get here we can safely
72 * ignore this operation. We just treat it as an error.
77 ip = &ex_data[class_index];
78 CRYPTO_THREAD_write_lock(ex_data_lock);
82 static void cleanup_cb(EX_CALLBACK *funcs)
88 * Release all "ex_data" state to prevent memory leaks. This can't be made
89 * thread-safe without overhauling a lot of stuff, and shouldn't really be
90 * called under potential race-conditions anyway (it's for program shutdown
93 void crypto_cleanup_all_ex_data_int(void)
97 for (i = 0; i < CRYPTO_EX_INDEX__COUNT; ++i) {
98 EX_CALLBACKS *ip = &ex_data[i];
100 sk_EX_CALLBACK_pop_free(ip->meth, cleanup_cb);
104 CRYPTO_THREAD_lock_free(ex_data_lock);
110 * Unregister a new index by replacing the callbacks with no-ops.
111 * Any in-use instances are leaked.
113 static void dummy_new(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
114 long argl, void *argp)
118 static void dummy_free(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
119 long argl, void *argp)
123 static int dummy_dup(CRYPTO_EX_DATA *to, const CRYPTO_EX_DATA *from,
124 void *from_d, int idx,
125 long argl, void *argp)
130 int CRYPTO_free_ex_index(int class_index, int idx)
132 EX_CALLBACKS *ip = get_and_lock(class_index);
138 if (idx < 0 || idx >= sk_EX_CALLBACK_num(ip->meth))
140 a = sk_EX_CALLBACK_value(ip->meth, idx);
143 a->new_func = dummy_new;
144 a->dup_func = dummy_dup;
145 a->free_func = dummy_free;
148 CRYPTO_THREAD_unlock(ex_data_lock);
153 * Register a new index.
155 int CRYPTO_get_ex_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)
161 EX_CALLBACKS *ip = get_and_lock(class_index);
166 if (ip->meth == NULL) {
167 ip->meth = sk_EX_CALLBACK_new_null();
168 /* We push an initial value on the stack because the SSL
169 * "app_data" routines use ex_data index zero. See RT 3710. */
171 || !sk_EX_CALLBACK_push(ip->meth, NULL)) {
172 CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX, ERR_R_MALLOC_FAILURE);
177 a = (EX_CALLBACK *)OPENSSL_malloc(sizeof(*a));
179 CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX, ERR_R_MALLOC_FAILURE);
184 a->new_func = new_func;
185 a->dup_func = dup_func;
186 a->free_func = free_func;
188 if (!sk_EX_CALLBACK_push(ip->meth, NULL)) {
189 CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX, ERR_R_MALLOC_FAILURE);
193 toret = sk_EX_CALLBACK_num(ip->meth) - 1;
194 (void)sk_EX_CALLBACK_set(ip->meth, toret, a);
197 CRYPTO_THREAD_unlock(ex_data_lock);
202 * Initialise a new CRYPTO_EX_DATA for use in a particular class - including
203 * calling new() callbacks for each index in the class used by this variable
204 * Thread-safe by copying a class's array of "EX_CALLBACK" entries
205 * in the lock, then using them outside the lock. Note this only applies
206 * to the global "ex_data" state (ie. class definitions), not 'ad' itself.
208 int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
212 EX_CALLBACK **storage = NULL;
213 EX_CALLBACK *stack[10];
214 EX_CALLBACKS *ip = get_and_lock(class_index);
221 mx = sk_EX_CALLBACK_num(ip->meth);
223 if (mx < (int)OSSL_NELEM(stack))
226 storage = OPENSSL_malloc(sizeof(*storage) * mx);
228 for (i = 0; i < mx; i++)
229 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
231 CRYPTO_THREAD_unlock(ex_data_lock);
233 if (mx > 0 && storage == NULL) {
234 CRYPTOerr(CRYPTO_F_CRYPTO_NEW_EX_DATA, ERR_R_MALLOC_FAILURE);
237 for (i = 0; i < mx; i++) {
238 if (storage[i] != NULL && storage[i]->new_func != NULL) {
239 ptr = CRYPTO_get_ex_data(ad, i);
240 storage[i]->new_func(obj, ptr, ad, i,
241 storage[i]->argl, storage[i]->argp);
244 if (storage != stack)
245 OPENSSL_free(storage);
250 * Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks
251 * for each index in the class used by this variable
253 int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
254 const CRYPTO_EX_DATA *from)
258 EX_CALLBACK *stack[10];
259 EX_CALLBACK **storage = NULL;
263 if (from->sk == NULL)
264 /* Nothing to copy over */
266 if ((ip = get_and_lock(class_index)) == NULL)
269 mx = sk_EX_CALLBACK_num(ip->meth);
270 j = sk_void_num(from->sk);
274 if (mx < (int)OSSL_NELEM(stack))
277 storage = OPENSSL_malloc(sizeof(*storage) * mx);
279 for (i = 0; i < mx; i++)
280 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
282 CRYPTO_THREAD_unlock(ex_data_lock);
286 if (storage == NULL) {
287 CRYPTOerr(CRYPTO_F_CRYPTO_DUP_EX_DATA, ERR_R_MALLOC_FAILURE);
291 * Make sure the ex_data stack is at least |mx| elements long to avoid
292 * issues in the for loop that follows; so go get the |mx|'th element
293 * (if it does not exist CRYPTO_get_ex_data() returns NULL), and assign
294 * to itself. This is normally a no-op; but ensures the stack is the
297 if (!CRYPTO_set_ex_data(to, mx - 1, CRYPTO_get_ex_data(to, mx - 1)))
300 for (i = 0; i < mx; i++) {
301 ptr = CRYPTO_get_ex_data(from, i);
302 if (storage[i] != NULL && storage[i]->dup_func != NULL)
303 if (!storage[i]->dup_func(to, from, &ptr, i,
304 storage[i]->argl, storage[i]->argp))
306 CRYPTO_set_ex_data(to, i, ptr);
310 if (storage != stack)
311 OPENSSL_free(storage);
317 * Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for
318 * each index in the class used by this variable
320 void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
326 EX_CALLBACK *stack[10];
327 EX_CALLBACK **storage = NULL;
329 if ((ip = get_and_lock(class_index)) == NULL)
332 mx = sk_EX_CALLBACK_num(ip->meth);
334 if (mx < (int)OSSL_NELEM(stack))
337 storage = OPENSSL_malloc(sizeof(*storage) * mx);
339 for (i = 0; i < mx; i++)
340 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
342 CRYPTO_THREAD_unlock(ex_data_lock);
344 for (i = 0; i < mx; i++) {
348 CRYPTO_THREAD_write_lock(ex_data_lock);
349 f = sk_EX_CALLBACK_value(ip->meth, i);
350 CRYPTO_THREAD_unlock(ex_data_lock);
352 if (f != NULL && f->free_func != NULL) {
353 ptr = CRYPTO_get_ex_data(ad, i);
354 f->free_func(obj, ptr, ad, i, f->argl, f->argp);
358 if (storage != stack)
359 OPENSSL_free(storage);
361 sk_void_free(ad->sk);
366 * Allocate a given CRYPTO_EX_DATA item using the class specific allocation
369 int CRYPTO_alloc_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad,
376 curval = CRYPTO_get_ex_data(ad, idx);
378 /* Already there, no need to allocate */
382 ip = get_and_lock(class_index);
385 f = sk_EX_CALLBACK_value(ip->meth, idx);
386 CRYPTO_THREAD_unlock(ex_data_lock);
389 * This should end up calling CRYPTO_set_ex_data(), which allocates
390 * everything necessary to support placing the new data in the right spot.
392 if (f->new_func == NULL)
395 f->new_func(obj, curval, ad, idx, f->argl, f->argp);
401 * For a given CRYPTO_EX_DATA variable, set the value corresponding to a
402 * particular index in the class used by this variable
404 int CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val)
408 if (ad->sk == NULL) {
409 if ((ad->sk = sk_void_new_null()) == NULL) {
410 CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
415 for (i = sk_void_num(ad->sk); i <= idx; ++i) {
416 if (!sk_void_push(ad->sk, NULL)) {
417 CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
421 sk_void_set(ad->sk, idx, val);
426 * For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a
427 * particular index in the class used by this variable
429 void *CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx)
431 if (ad->sk == NULL || idx >= sk_void_num(ad->sk))
433 return sk_void_value(ad->sk, idx);