crypto/ex_data.c

   1 /*
   2  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   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
   8  */
   9
  10 #include "crypto/cryptlib.h"
  11 #include "internal/thread_once.h"
  12
  13 int do_ex_data_init(OPENSSL_CTX *ctx)
  14 {
  15     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
  16
  17     if (global == NULL)
  18         return 0;
  19
  20     global->ex_data_lock = CRYPTO_THREAD_lock_new();
  21     return global->ex_data_lock != NULL;
  22 }
  23
  24 /*
  25  * Return the EX_CALLBACKS from the |ex_data| array that corresponds to
  26  * a given class.  On success, *holds the lock.*
  27  */
  28 static EX_CALLBACKS *get_and_lock(OPENSSL_CTX *ctx, int class_index)
  29 {
  30     EX_CALLBACKS *ip;
  31     OSSL_EX_DATA_GLOBAL *global = NULL;
  32
  33     if (class_index < 0 || class_index >= CRYPTO_EX_INDEX__COUNT) {
  34         CRYPTOerr(CRYPTO_F_GET_AND_LOCK, ERR_R_PASSED_INVALID_ARGUMENT);
  35         return NULL;
  36     }
  37
  38     global = openssl_ctx_get_ex_data_global(ctx);
  39     if (global == NULL || global->ex_data_lock == NULL) {
  40         /*
  41          * If we get here, someone (who?) cleaned up the lock, so just
  42          * treat it as an error.
  43          */
  44          return NULL;
  45     }
  46
  47     CRYPTO_THREAD_write_lock(global->ex_data_lock);
  48     ip = &global->ex_data[class_index];
  49     return ip;
  50 }
  51
  52 static void cleanup_cb(EX_CALLBACK *funcs)
  53 {
  54     OPENSSL_free(funcs);
  55 }
  56
  57 /*
  58  * Release all "ex_data" state to prevent memory leaks. This can't be made
  59  * thread-safe without overhauling a lot of stuff, and shouldn't really be
  60  * called under potential race-conditions anyway (it's for program shutdown
  61  * after all).
  62  */
  63 void crypto_cleanup_all_ex_data_int(OPENSSL_CTX *ctx)
  64 {
  65     int i;
  66     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
  67
  68     if (global == NULL)
  69         return;
  70
  71     for (i = 0; i < CRYPTO_EX_INDEX__COUNT; ++i) {
  72         EX_CALLBACKS *ip = &global->ex_data[i];
  73
  74         sk_EX_CALLBACK_pop_free(ip->meth, cleanup_cb);
  75         ip->meth = NULL;
  76     }
  77
  78     CRYPTO_THREAD_lock_free(global->ex_data_lock);
  79     global->ex_data_lock = NULL;
  80 }
  81
  82
  83 /*
  84  * Unregister a new index by replacing the callbacks with no-ops.
  85  * Any in-use instances are leaked.
  86  */
  87 static void dummy_new(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
  88                      long argl, void *argp)
  89 {
  90 }
  91
  92 static void dummy_free(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
  93                        long argl, void *argp)
  94 {
  95 }
  96
  97 static int dummy_dup(CRYPTO_EX_DATA *to, const CRYPTO_EX_DATA *from,
  98                      void *from_d, int idx,
  99                      long argl, void *argp)
 100 {
 101     return 1;
 102 }
 103
 104 int crypto_free_ex_index_ex(OPENSSL_CTX *ctx, int class_index, int idx)
 105 {
 106     EX_CALLBACKS *ip;
 107     EX_CALLBACK *a;
 108     int toret = 0;
 109     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
 110
 111     if (global == NULL)
 112         return 0;
 113
 114     ip = get_and_lock(ctx, class_index);
 115     if (ip == NULL)
 116         return 0;
 117     if (idx < 0 || idx >= sk_EX_CALLBACK_num(ip->meth))
 118         goto err;
 119     a = sk_EX_CALLBACK_value(ip->meth, idx);
 120     if (a == NULL)
 121         goto err;
 122     a->new_func = dummy_new;
 123     a->dup_func = dummy_dup;
 124     a->free_func = dummy_free;
 125     toret = 1;
 126 err:
 127     CRYPTO_THREAD_unlock(global->ex_data_lock);
 128     return toret;
 129 }
 130
 131 int CRYPTO_free_ex_index(int class_index, int idx)
 132 {
 133     return crypto_free_ex_index_ex(NULL, class_index, idx);
 134 }
 135
 136 /*
 137  * Register a new index.
 138  */
 139 int crypto_get_ex_new_index_ex(OPENSSL_CTX *ctx, int class_index, long argl,
 140                                void *argp, CRYPTO_EX_new *new_func,
 141                                CRYPTO_EX_dup *dup_func,
 142                                CRYPTO_EX_free *free_func)
 143 {
 144     int toret = -1;
 145     EX_CALLBACK *a;
 146     EX_CALLBACKS *ip;
 147     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
 148
 149     if (global == NULL)
 150         return -1;
 151
 152     ip = get_and_lock(ctx, class_index);
 153     if (ip == NULL)
 154         return -1;
 155
 156     if (ip->meth == NULL) {
 157         ip->meth = sk_EX_CALLBACK_new_null();
 158         /* We push an initial value on the stack because the SSL
 159          * "app_data" routines use ex_data index zero.  See RT 3710. */
 160         if (ip->meth == NULL
 161             || !sk_EX_CALLBACK_push(ip->meth, NULL)) {
 162             CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX_EX, ERR_R_MALLOC_FAILURE);
 163             goto err;
 164         }
 165     }
 166
 167     a = (EX_CALLBACK *)OPENSSL_malloc(sizeof(*a));
 168     if (a == NULL) {
 169         CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX_EX, ERR_R_MALLOC_FAILURE);
 170         goto err;
 171     }
 172     a->argl = argl;
 173     a->argp = argp;
 174     a->new_func = new_func;
 175     a->dup_func = dup_func;
 176     a->free_func = free_func;
 177
 178     if (!sk_EX_CALLBACK_push(ip->meth, NULL)) {
 179         CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX_EX, ERR_R_MALLOC_FAILURE);
 180         OPENSSL_free(a);
 181         goto err;
 182     }
 183     toret = sk_EX_CALLBACK_num(ip->meth) - 1;
 184     (void)sk_EX_CALLBACK_set(ip->meth, toret, a);
 185
 186  err:
 187     CRYPTO_THREAD_unlock(global->ex_data_lock);
 188     return toret;
 189 }
 190
 191 int CRYPTO_get_ex_new_index(int class_index, long argl, void *argp,
 192                             CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
 193                             CRYPTO_EX_free *free_func)
 194 {
 195     return crypto_get_ex_new_index_ex(NULL, class_index, argl, argp, new_func,
 196                                       dup_func, free_func);
 197 }
 198
 199 /*
 200  * Initialise a new CRYPTO_EX_DATA for use in a particular class - including
 201  * calling new() callbacks for each index in the class used by this variable
 202  * Thread-safe by copying a class's array of "EX_CALLBACK" entries
 203  * in the lock, then using them outside the lock. Note this only applies
 204  * to the global "ex_data" state (ie. class definitions), not 'ad' itself.
 205  */
 206 int crypto_new_ex_data_ex(OPENSSL_CTX *ctx, int class_index, void *obj,
 207                           CRYPTO_EX_DATA *ad)
 208 {
 209     int mx, i;
 210     void *ptr;
 211     EX_CALLBACK **storage = NULL;
 212     EX_CALLBACK *stack[10];
 213     EX_CALLBACKS *ip;
 214     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
 215
 216     if (global == NULL)
 217         return 0;
 218
 219     ip = get_and_lock(ctx, class_index);
 220     if (ip == NULL)
 221         return 0;
 222
 223     ad->ctx = ctx;
 224     ad->sk = NULL;
 225
 226     mx = sk_EX_CALLBACK_num(ip->meth);
 227     if (mx > 0) {
 228         if (mx < (int)OSSL_NELEM(stack))
 229             storage = stack;
 230         else
 231             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 232         if (storage != NULL)
 233             for (i = 0; i < mx; i++)
 234                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 235     }
 236     CRYPTO_THREAD_unlock(global->ex_data_lock);
 237
 238     if (mx > 0 && storage == NULL) {
 239         CRYPTOerr(CRYPTO_F_CRYPTO_NEW_EX_DATA_EX, ERR_R_MALLOC_FAILURE);
 240         return 0;
 241     }
 242     for (i = 0; i < mx; i++) {
 243         if (storage[i] != NULL && storage[i]->new_func != NULL) {
 244             ptr = CRYPTO_get_ex_data(ad, i);
 245             storage[i]->new_func(obj, ptr, ad, i,
 246                                  storage[i]->argl, storage[i]->argp);
 247         }
 248     }
 249     if (storage != stack)
 250         OPENSSL_free(storage);
 251     return 1;
 252 }
 253
 254 int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 255 {
 256     return crypto_new_ex_data_ex(NULL, class_index, obj, ad);
 257 }
 258
 259 /*
 260  * Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks
 261  * for each index in the class used by this variable
 262  */
 263 int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
 264                        const CRYPTO_EX_DATA *from)
 265 {
 266     int mx, j, i;
 267     void *ptr;
 268     EX_CALLBACK *stack[10];
 269     EX_CALLBACK **storage = NULL;
 270     EX_CALLBACKS *ip;
 271     int toret = 0;
 272     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(from->ctx);
 273
 274     if (global == NULL)
 275         return 0;
 276
 277     to->ctx = from->ctx;
 278     if (from->sk == NULL)
 279         /* Nothing to copy over */
 280         return 1;
 281     if ((ip = get_and_lock(from->ctx, class_index)) == NULL)
 282         return 0;
 283
 284     mx = sk_EX_CALLBACK_num(ip->meth);
 285     j = sk_void_num(from->sk);
 286     if (j < mx)
 287         mx = j;
 288     if (mx > 0) {
 289         if (mx < (int)OSSL_NELEM(stack))
 290             storage = stack;
 291         else
 292             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 293         if (storage != NULL)
 294             for (i = 0; i < mx; i++)
 295                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 296     }
 297     CRYPTO_THREAD_unlock(global->ex_data_lock);
 298
 299     if (mx == 0)
 300         return 1;
 301     if (storage == NULL) {
 302         CRYPTOerr(CRYPTO_F_CRYPTO_DUP_EX_DATA, ERR_R_MALLOC_FAILURE);
 303         return 0;
 304     }
 305     /*
 306      * Make sure the ex_data stack is at least |mx| elements long to avoid
 307      * issues in the for loop that follows; so go get the |mx|'th element
 308      * (if it does not exist CRYPTO_get_ex_data() returns NULL), and assign
 309      * to itself. This is normally a no-op; but ensures the stack is the
 310      * proper size
 311      */
 312     if (!CRYPTO_set_ex_data(to, mx - 1, CRYPTO_get_ex_data(to, mx - 1)))
 313         goto err;
 314
 315     for (i = 0; i < mx; i++) {
 316         ptr = CRYPTO_get_ex_data(from, i);
 317         if (storage[i] != NULL && storage[i]->dup_func != NULL)
 318             if (!storage[i]->dup_func(to, from, &ptr, i,
 319                                       storage[i]->argl, storage[i]->argp))
 320                 goto err;
 321         CRYPTO_set_ex_data(to, i, ptr);
 322     }
 323     toret = 1;
 324  err:
 325     if (storage != stack)
 326         OPENSSL_free(storage);
 327     return toret;
 328 }
 329
 330
 331 /*
 332  * Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for
 333  * each index in the class used by this variable
 334  */
 335 void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 336 {
 337     int mx, i;
 338     EX_CALLBACKS *ip;
 339     void *ptr;
 340     EX_CALLBACK *f;
 341     EX_CALLBACK *stack[10];
 342     EX_CALLBACK **storage = NULL;
 343     OSSL_EX_DATA_GLOBAL *global;
 344
 345     if ((ip = get_and_lock(ad->ctx, class_index)) == NULL)
 346         goto err;
 347     global = openssl_ctx_get_ex_data_global(ad->ctx);
 348     if (global == NULL)
 349         goto err;
 350
 351     mx = sk_EX_CALLBACK_num(ip->meth);
 352     if (mx > 0) {
 353         if (mx < (int)OSSL_NELEM(stack))
 354             storage = stack;
 355         else
 356             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 357         if (storage != NULL)
 358             for (i = 0; i < mx; i++)
 359                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 360     }
 361     CRYPTO_THREAD_unlock(global->ex_data_lock);
 362
 363     for (i = 0; i < mx; i++) {
 364         if (storage != NULL)
 365             f = storage[i];
 366         else {
 367             CRYPTO_THREAD_write_lock(global->ex_data_lock);
 368             f = sk_EX_CALLBACK_value(ip->meth, i);
 369             CRYPTO_THREAD_unlock(global->ex_data_lock);
 370         }
 371         if (f != NULL && f->free_func != NULL) {
 372             ptr = CRYPTO_get_ex_data(ad, i);
 373             f->free_func(obj, ptr, ad, i, f->argl, f->argp);
 374         }
 375     }
 376
 377     if (storage != stack)
 378         OPENSSL_free(storage);
 379  err:
 380     sk_void_free(ad->sk);
 381     ad->sk = NULL;
 382     ad->ctx = NULL;
 383 }
 384
 385 /*
 386  * Allocate a given CRYPTO_EX_DATA item using the class specific allocation
 387  * function
 388  */
 389 int CRYPTO_alloc_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad,
 390                          int idx)
 391 {
 392     EX_CALLBACK *f;
 393     EX_CALLBACKS *ip;
 394     void *curval;
 395     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ad->ctx);
 396
 397     if (global == NULL)
 398         return 0;
 399
 400     curval = CRYPTO_get_ex_data(ad, idx);
 401
 402     /* Already there, no need to allocate */
 403     if (curval != NULL)
 404         return 1;
 405
 406     ip = get_and_lock(ad->ctx, class_index);
 407     if (ip == NULL)
 408         return 0;
 409     f = sk_EX_CALLBACK_value(ip->meth, idx);
 410     CRYPTO_THREAD_unlock(global->ex_data_lock);
 411
 412     /*
 413      * This should end up calling CRYPTO_set_ex_data(), which allocates
 414      * everything necessary to support placing the new data in the right spot.
 415      */
 416     if (f->new_func == NULL)
 417         return 0;
 418
 419     f->new_func(obj, NULL, ad, idx, f->argl, f->argp);
 420
 421     return 1;
 422 }
 423
 424 /*
 425  * For a given CRYPTO_EX_DATA variable, set the value corresponding to a
 426  * particular index in the class used by this variable
 427  */
 428 int CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val)
 429 {
 430     int i;
 431
 432     if (ad->sk == NULL) {
 433         if ((ad->sk = sk_void_new_null()) == NULL) {
 434             CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
 435             return 0;
 436         }
 437     }
 438
 439     for (i = sk_void_num(ad->sk); i <= idx; ++i) {
 440         if (!sk_void_push(ad->sk, NULL)) {
 441             CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
 442             return 0;
 443         }
 444     }
 445     sk_void_set(ad->sk, idx, val);
 446     return 1;
 447 }
 448
 449 /*
 450  * For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a
 451  * particular index in the class used by this variable
 452  */
 453 void *CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx)
 454 {
 455     if (ad->sk == NULL || idx >= sk_void_num(ad->sk))
 456         return NULL;
 457     return sk_void_value(ad->sk, idx);
 458 }
 459
 460 OPENSSL_CTX *crypto_ex_data_get_openssl_ctx(const CRYPTO_EX_DATA *ad)
 461 {
 462     return ad->ctx;
 463 }