crypto/ex_data.c

   1 /*
   2  * Copyright 1995-2020 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 DEFINE_STACK_OF(void)
  14
  15 int do_ex_data_init(OPENSSL_CTX *ctx)
  16 {
  17     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
  18
  19     if (global == NULL)
  20         return 0;
  21
  22     global->ex_data_lock = CRYPTO_THREAD_lock_new();
  23     return global->ex_data_lock != NULL;
  24 }
  25
  26 /*
  27  * Return the EX_CALLBACKS from the |ex_data| array that corresponds to
  28  * a given class.  On success, *holds the lock.*
  29  * The |global| parameter is assumed to be non null (checked by the caller).
  30  */
  31 static EX_CALLBACKS *get_and_lock(OSSL_EX_DATA_GLOBAL *global, int class_index)
  32 {
  33     EX_CALLBACKS *ip;
  34
  35     if (class_index < 0 || class_index >= CRYPTO_EX_INDEX__COUNT) {
  36         CRYPTOerr(CRYPTO_F_GET_AND_LOCK, ERR_R_PASSED_INVALID_ARGUMENT);
  37         return NULL;
  38     }
  39
  40     if (global->ex_data_lock == NULL) {
  41         /*
  42          * If we get here, someone (who?) cleaned up the lock, so just
  43          * treat it as an error.
  44          */
  45          return NULL;
  46     }
  47
  48     CRYPTO_THREAD_write_lock(global->ex_data_lock);
  49     ip = &global->ex_data[class_index];
  50     return ip;
  51 }
  52
  53 static void cleanup_cb(EX_CALLBACK *funcs)
  54 {
  55     OPENSSL_free(funcs);
  56 }
  57
  58 /*
  59  * Release all "ex_data" state to prevent memory leaks. This can't be made
  60  * thread-safe without overhauling a lot of stuff, and shouldn't really be
  61  * called under potential race-conditions anyway (it's for program shutdown
  62  * after all).
  63  */
  64 void crypto_cleanup_all_ex_data_int(OPENSSL_CTX *ctx)
  65 {
  66     int i;
  67     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
  68
  69     if (global == NULL)
  70         return;
  71
  72     for (i = 0; i < CRYPTO_EX_INDEX__COUNT; ++i) {
  73         EX_CALLBACKS *ip = &global->ex_data[i];
  74
  75         sk_EX_CALLBACK_pop_free(ip->meth, cleanup_cb);
  76         ip->meth = NULL;
  77     }
  78
  79     CRYPTO_THREAD_lock_free(global->ex_data_lock);
  80     global->ex_data_lock = NULL;
  81 }
  82
  83
  84 /*
  85  * Unregister a new index by replacing the callbacks with no-ops.
  86  * Any in-use instances are leaked.
  87  */
  88 static void dummy_new(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
  89                      long argl, void *argp)
  90 {
  91 }
  92
  93 static void dummy_free(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
  94                        long argl, void *argp)
  95 {
  96 }
  97
  98 static int dummy_dup(CRYPTO_EX_DATA *to, const CRYPTO_EX_DATA *from,
  99                      void *from_d, int idx,
 100                      long argl, void *argp)
 101 {
 102     return 1;
 103 }
 104
 105 int crypto_free_ex_index_ex(OPENSSL_CTX *ctx, int class_index, int idx)
 106 {
 107     EX_CALLBACKS *ip;
 108     EX_CALLBACK *a;
 109     int toret = 0;
 110     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
 111
 112     if (global == NULL)
 113         return 0;
 114
 115     ip = get_and_lock(global, class_index);
 116     if (ip == NULL)
 117         return 0;
 118
 119     if (idx < 0 || idx >= sk_EX_CALLBACK_num(ip->meth))
 120         goto err;
 121     a = sk_EX_CALLBACK_value(ip->meth, idx);
 122     if (a == NULL)
 123         goto err;
 124     a->new_func = dummy_new;
 125     a->dup_func = dummy_dup;
 126     a->free_func = dummy_free;
 127     toret = 1;
 128 err:
 129     CRYPTO_THREAD_unlock(global->ex_data_lock);
 130     return toret;
 131 }
 132
 133 int CRYPTO_free_ex_index(int class_index, int idx)
 134 {
 135     return crypto_free_ex_index_ex(NULL, class_index, idx);
 136 }
 137
 138 /*
 139  * Register a new index.
 140  */
 141 int crypto_get_ex_new_index_ex(OPENSSL_CTX *ctx, int class_index, long argl,
 142                                void *argp, CRYPTO_EX_new *new_func,
 143                                CRYPTO_EX_dup *dup_func,
 144                                CRYPTO_EX_free *free_func)
 145 {
 146     int toret = -1;
 147     EX_CALLBACK *a;
 148     EX_CALLBACKS *ip;
 149     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
 150
 151     if (global == NULL)
 152         return -1;
 153
 154     ip = get_and_lock(global, class_index);
 155     if (ip == NULL)
 156         return -1;
 157
 158     if (ip->meth == NULL) {
 159         ip->meth = sk_EX_CALLBACK_new_null();
 160         /* We push an initial value on the stack because the SSL
 161          * "app_data" routines use ex_data index zero.  See RT 3710. */
 162         if (ip->meth == NULL
 163             || !sk_EX_CALLBACK_push(ip->meth, NULL)) {
 164             CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX_EX, ERR_R_MALLOC_FAILURE);
 165             goto err;
 166         }
 167     }
 168
 169     a = (EX_CALLBACK *)OPENSSL_malloc(sizeof(*a));
 170     if (a == NULL) {
 171         CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX_EX, ERR_R_MALLOC_FAILURE);
 172         goto err;
 173     }
 174     a->argl = argl;
 175     a->argp = argp;
 176     a->new_func = new_func;
 177     a->dup_func = dup_func;
 178     a->free_func = free_func;
 179
 180     if (!sk_EX_CALLBACK_push(ip->meth, NULL)) {
 181         CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX_EX, ERR_R_MALLOC_FAILURE);
 182         OPENSSL_free(a);
 183         goto err;
 184     }
 185     toret = sk_EX_CALLBACK_num(ip->meth) - 1;
 186     (void)sk_EX_CALLBACK_set(ip->meth, toret, a);
 187
 188  err:
 189     CRYPTO_THREAD_unlock(global->ex_data_lock);
 190     return toret;
 191 }
 192
 193 int CRYPTO_get_ex_new_index(int class_index, long argl, void *argp,
 194                             CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
 195                             CRYPTO_EX_free *free_func)
 196 {
 197     return crypto_get_ex_new_index_ex(NULL, class_index, argl, argp, new_func,
 198                                       dup_func, free_func);
 199 }
 200
 201 /*
 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.
 207  */
 208 int crypto_new_ex_data_ex(OPENSSL_CTX *ctx, int class_index, void *obj,
 209                           CRYPTO_EX_DATA *ad)
 210 {
 211     int mx, i;
 212     void *ptr;
 213     EX_CALLBACK **storage = NULL;
 214     EX_CALLBACK *stack[10];
 215     EX_CALLBACKS *ip;
 216     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
 217
 218     if (global == NULL)
 219         return 0;
 220
 221     ip = get_and_lock(global, class_index);
 222     if (ip == NULL)
 223         return 0;
 224
 225     ad->ctx = ctx;
 226     ad->sk = NULL;
 227     mx = sk_EX_CALLBACK_num(ip->meth);
 228     if (mx > 0) {
 229         if (mx < (int)OSSL_NELEM(stack))
 230             storage = stack;
 231         else
 232             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 233         if (storage != NULL)
 234             for (i = 0; i < mx; i++)
 235                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 236     }
 237     CRYPTO_THREAD_unlock(global->ex_data_lock);
 238
 239     if (mx > 0 && storage == NULL) {
 240         CRYPTOerr(CRYPTO_F_CRYPTO_NEW_EX_DATA_EX, ERR_R_MALLOC_FAILURE);
 241         return 0;
 242     }
 243     for (i = 0; i < mx; i++) {
 244         if (storage[i] != NULL && storage[i]->new_func != NULL) {
 245             ptr = CRYPTO_get_ex_data(ad, i);
 246             storage[i]->new_func(obj, ptr, ad, i,
 247                                  storage[i]->argl, storage[i]->argp);
 248         }
 249     }
 250     if (storage != stack)
 251         OPENSSL_free(storage);
 252     return 1;
 253 }
 254
 255 int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 256 {
 257     return crypto_new_ex_data_ex(NULL, class_index, obj, ad);
 258 }
 259
 260 /*
 261  * Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks
 262  * for each index in the class used by this variable
 263  */
 264 int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
 265                        const CRYPTO_EX_DATA *from)
 266 {
 267     int mx, j, i;
 268     void *ptr;
 269     EX_CALLBACK *stack[10];
 270     EX_CALLBACK **storage = NULL;
 271     EX_CALLBACKS *ip;
 272     int toret = 0;
 273     OSSL_EX_DATA_GLOBAL *global;
 274
 275     to->ctx = from->ctx;
 276     if (from->sk == NULL)
 277         /* Nothing to copy over */
 278         return 1;
 279
 280     global = openssl_ctx_get_ex_data_global(from->ctx);
 281     if (global == NULL)
 282         return 0;
 283
 284     ip = get_and_lock(global, class_index);
 285     if (ip == NULL)
 286         return 0;
 287
 288     mx = sk_EX_CALLBACK_num(ip->meth);
 289     j = sk_void_num(from->sk);
 290     if (j < mx)
 291         mx = j;
 292     if (mx > 0) {
 293         if (mx < (int)OSSL_NELEM(stack))
 294             storage = stack;
 295         else
 296             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 297         if (storage != NULL)
 298             for (i = 0; i < mx; i++)
 299                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 300     }
 301     CRYPTO_THREAD_unlock(global->ex_data_lock);
 302
 303     if (mx == 0)
 304         return 1;
 305     if (storage == NULL) {
 306         CRYPTOerr(CRYPTO_F_CRYPTO_DUP_EX_DATA, ERR_R_MALLOC_FAILURE);
 307         return 0;
 308     }
 309     /*
 310      * Make sure the ex_data stack is at least |mx| elements long to avoid
 311      * issues in the for loop that follows; so go get the |mx|'th element
 312      * (if it does not exist CRYPTO_get_ex_data() returns NULL), and assign
 313      * to itself. This is normally a no-op; but ensures the stack is the
 314      * proper size
 315      */
 316     if (!CRYPTO_set_ex_data(to, mx - 1, CRYPTO_get_ex_data(to, mx - 1)))
 317         goto err;
 318
 319     for (i = 0; i < mx; i++) {
 320         ptr = CRYPTO_get_ex_data(from, i);
 321         if (storage[i] != NULL && storage[i]->dup_func != NULL)
 322             if (!storage[i]->dup_func(to, from, &ptr, i,
 323                                       storage[i]->argl, storage[i]->argp))
 324                 goto err;
 325         CRYPTO_set_ex_data(to, i, ptr);
 326     }
 327     toret = 1;
 328  err:
 329     if (storage != stack)
 330         OPENSSL_free(storage);
 331     return toret;
 332 }
 333
 334
 335 /*
 336  * Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for
 337  * each index in the class used by this variable
 338  */
 339 void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 340 {
 341     int mx, i;
 342     EX_CALLBACKS *ip;
 343     void *ptr;
 344     EX_CALLBACK *f;
 345     EX_CALLBACK *stack[10];
 346     EX_CALLBACK **storage = NULL;
 347     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ad->ctx);
 348
 349     if (global == NULL)
 350         goto err;
 351
 352     ip = get_and_lock(global, class_index);
 353     if (ip == NULL)
 354         goto err;
 355
 356     mx = sk_EX_CALLBACK_num(ip->meth);
 357     if (mx > 0) {
 358         if (mx < (int)OSSL_NELEM(stack))
 359             storage = stack;
 360         else
 361             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 362         if (storage != NULL)
 363             for (i = 0; i < mx; i++)
 364                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 365     }
 366     CRYPTO_THREAD_unlock(global->ex_data_lock);
 367
 368     for (i = 0; i < mx; i++) {
 369         if (storage != NULL)
 370             f = storage[i];
 371         else {
 372             CRYPTO_THREAD_write_lock(global->ex_data_lock);
 373             f = sk_EX_CALLBACK_value(ip->meth, i);
 374             CRYPTO_THREAD_unlock(global->ex_data_lock);
 375         }
 376         if (f != NULL && f->free_func != NULL) {
 377             ptr = CRYPTO_get_ex_data(ad, i);
 378             f->free_func(obj, ptr, ad, i, f->argl, f->argp);
 379         }
 380     }
 381
 382     if (storage != stack)
 383         OPENSSL_free(storage);
 384  err:
 385     sk_void_free(ad->sk);
 386     ad->sk = NULL;
 387     ad->ctx = NULL;
 388 }
 389
 390 /*
 391  * Allocate a given CRYPTO_EX_DATA item using the class specific allocation
 392  * function
 393  */
 394 int CRYPTO_alloc_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad,
 395                          int idx)
 396 {
 397     EX_CALLBACK *f;
 398     EX_CALLBACKS *ip;
 399     void *curval;
 400     OSSL_EX_DATA_GLOBAL *global;
 401
 402     curval = CRYPTO_get_ex_data(ad, idx);
 403     /* Already there, no need to allocate */
 404     if (curval != NULL)
 405         return 1;
 406
 407     global = openssl_ctx_get_ex_data_global(ad->ctx);
 408     if (global == NULL)
 409         return 0;
 410
 411     ip = get_and_lock(global, class_index);
 412     if (ip == NULL)
 413         return 0;
 414     f = sk_EX_CALLBACK_value(ip->meth, idx);
 415     CRYPTO_THREAD_unlock(global->ex_data_lock);
 416
 417     /*
 418      * This should end up calling CRYPTO_set_ex_data(), which allocates
 419      * everything necessary to support placing the new data in the right spot.
 420      */
 421     if (f->new_func == NULL)
 422         return 0;
 423
 424     f->new_func(obj, NULL, ad, idx, f->argl, f->argp);
 425
 426     return 1;
 427 }
 428
 429 /*
 430  * For a given CRYPTO_EX_DATA variable, set the value corresponding to a
 431  * particular index in the class used by this variable
 432  */
 433 int CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val)
 434 {
 435     int i;
 436
 437     if (ad->sk == NULL) {
 438         if ((ad->sk = sk_void_new_null()) == NULL) {
 439             CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
 440             return 0;
 441         }
 442     }
 443
 444     for (i = sk_void_num(ad->sk); i <= idx; ++i) {
 445         if (!sk_void_push(ad->sk, NULL)) {
 446             CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
 447             return 0;
 448         }
 449     }
 450     sk_void_set(ad->sk, idx, val);
 451     return 1;
 452 }
 453
 454 /*
 455  * For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a
 456  * particular index in the class used by this variable
 457  */
 458 void *CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx)
 459 {
 460     if (ad->sk == NULL || idx >= sk_void_num(ad->sk))
 461         return NULL;
 462     return sk_void_value(ad->sk, idx);
 463 }
 464
 465 OPENSSL_CTX *crypto_ex_data_get_openssl_ctx(const CRYPTO_EX_DATA *ad)
 466 {
 467     return ad->ctx;
 468 }