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 "internal/cryptlib_int.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->ex_data_lock == NULL) {
  40         /*
  41          * This can happen in normal operation when using CRYPTO_mem_leaks().
  42          * The CRYPTO_mem_leaks() function calls OPENSSL_cleanup() which cleans
  43          * up the locks. Subsequently the BIO that CRYPTO_mem_leaks() uses gets
  44          * freed, which also attempts to free the ex_data. However
  45          * CRYPTO_mem_leaks() ensures that the ex_data is freed early (i.e.
  46          * before OPENSSL_cleanup() is called), so if we get here we can safely
  47          * ignore this operation. We just treat it as an error.
  48          */
  49          return NULL;
  50     }
  51
  52     ip = &global->ex_data[class_index];
  53     CRYPTO_THREAD_write_lock(global->ex_data_lock);
  54     return ip;
  55 }
  56
  57 static void cleanup_cb(EX_CALLBACK *funcs)
  58 {
  59     OPENSSL_free(funcs);
  60 }
  61
  62 /*
  63  * Release all "ex_data" state to prevent memory leaks. This can't be made
  64  * thread-safe without overhauling a lot of stuff, and shouldn't really be
  65  * called under potential race-conditions anyway (it's for program shutdown
  66  * after all).
  67  */
  68 void crypto_cleanup_all_ex_data_int(OPENSSL_CTX *ctx)
  69 {
  70     int i;
  71     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
  72
  73     if (global == NULL)
  74         return;
  75
  76     for (i = 0; i < CRYPTO_EX_INDEX__COUNT; ++i) {
  77         EX_CALLBACKS *ip = &global->ex_data[i];
  78
  79         sk_EX_CALLBACK_pop_free(ip->meth, cleanup_cb);
  80         ip->meth = NULL;
  81     }
  82
  83     CRYPTO_THREAD_lock_free(global->ex_data_lock);
  84     global->ex_data_lock = NULL;
  85 }
  86
  87
  88 /*
  89  * Unregister a new index by replacing the callbacks with no-ops.
  90  * Any in-use instances are leaked.
  91  */
  92 static void dummy_new(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
  93                      long argl, void *argp)
  94 {
  95 }
  96
  97 static void dummy_free(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
  98                        long argl, void *argp)
  99 {
 100 }
 101
 102 static int dummy_dup(CRYPTO_EX_DATA *to, const CRYPTO_EX_DATA *from,
 103                      void *from_d, int idx,
 104                      long argl, void *argp)
 105 {
 106     return 1;
 107 }
 108
 109 int crypto_free_ex_index_ex(OPENSSL_CTX *ctx, int class_index, int idx)
 110 {
 111     EX_CALLBACKS *ip = get_and_lock(ctx, class_index);
 112     EX_CALLBACK *a;
 113     int toret = 0;
 114     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
 115
 116     if (global == NULL)
 117         goto err;
 118
 119     ip = get_and_lock(ctx, class_index);
 120     if (ip == NULL)
 121         return 0;
 122     if (idx < 0 || idx >= sk_EX_CALLBACK_num(ip->meth))
 123         goto err;
 124     a = sk_EX_CALLBACK_value(ip->meth, idx);
 125     if (a == NULL)
 126         goto err;
 127     a->new_func = dummy_new;
 128     a->dup_func = dummy_dup;
 129     a->free_func = dummy_free;
 130     toret = 1;
 131 err:
 132     CRYPTO_THREAD_unlock(global->ex_data_lock);
 133     return toret;
 134 }
 135
 136 int CRYPTO_free_ex_index(int class_index, int idx)
 137 {
 138     return crypto_free_ex_index_ex(NULL, class_index, idx);
 139 }
 140
 141 /*
 142  * Register a new index.
 143  */
 144 int crypto_get_ex_new_index_ex(OPENSSL_CTX *ctx, int class_index, long argl,
 145                                void *argp, CRYPTO_EX_new *new_func,
 146                                CRYPTO_EX_dup *dup_func,
 147                                CRYPTO_EX_free *free_func)
 148 {
 149     int toret = -1;
 150     EX_CALLBACK *a;
 151     EX_CALLBACKS *ip;
 152     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
 153
 154     if (global == NULL)
 155         goto err;
 156
 157     ip = get_and_lock(ctx, class_index);
 158     if (ip == NULL)
 159         return -1;
 160
 161     if (ip->meth == NULL) {
 162         ip->meth = sk_EX_CALLBACK_new_null();
 163         /* We push an initial value on the stack because the SSL
 164          * "app_data" routines use ex_data index zero.  See RT 3710. */
 165         if (ip->meth == NULL
 166             || !sk_EX_CALLBACK_push(ip->meth, NULL)) {
 167             CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX_EX, ERR_R_MALLOC_FAILURE);
 168             goto err;
 169         }
 170     }
 171
 172     a = (EX_CALLBACK *)OPENSSL_malloc(sizeof(*a));
 173     if (a == NULL) {
 174         CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX_EX, ERR_R_MALLOC_FAILURE);
 175         goto err;
 176     }
 177     a->argl = argl;
 178     a->argp = argp;
 179     a->new_func = new_func;
 180     a->dup_func = dup_func;
 181     a->free_func = free_func;
 182
 183     if (!sk_EX_CALLBACK_push(ip->meth, NULL)) {
 184         CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX_EX, ERR_R_MALLOC_FAILURE);
 185         OPENSSL_free(a);
 186         goto err;
 187     }
 188     toret = sk_EX_CALLBACK_num(ip->meth) - 1;
 189     (void)sk_EX_CALLBACK_set(ip->meth, toret, a);
 190
 191  err:
 192     CRYPTO_THREAD_unlock(global->ex_data_lock);
 193     return toret;
 194 }
 195
 196 int CRYPTO_get_ex_new_index(int class_index, long argl, void *argp,
 197                             CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
 198                             CRYPTO_EX_free *free_func)
 199 {
 200     return crypto_get_ex_new_index_ex(NULL, class_index, argl, argp, new_func,
 201                                       dup_func, free_func);
 202 }
 203
 204 /*
 205  * Initialise a new CRYPTO_EX_DATA for use in a particular class - including
 206  * calling new() callbacks for each index in the class used by this variable
 207  * Thread-safe by copying a class's array of "EX_CALLBACK" entries
 208  * in the lock, then using them outside the lock. Note this only applies
 209  * to the global "ex_data" state (ie. class definitions), not 'ad' itself.
 210  */
 211 int crypto_new_ex_data_ex(OPENSSL_CTX *ctx, int class_index, void *obj,
 212                           CRYPTO_EX_DATA *ad)
 213 {
 214     int mx, i;
 215     void *ptr;
 216     EX_CALLBACK **storage = NULL;
 217     EX_CALLBACK *stack[10];
 218     EX_CALLBACKS *ip;
 219     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
 220
 221     if (global == NULL)
 222         return 0;
 223
 224     ip = get_and_lock(ctx, class_index);
 225     if (ip == NULL)
 226         return 0;
 227
 228     ad->ctx = ctx;
 229     ad->sk = NULL;
 230
 231     mx = sk_EX_CALLBACK_num(ip->meth);
 232     if (mx > 0) {
 233         if (mx < (int)OSSL_NELEM(stack))
 234             storage = stack;
 235         else
 236             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 237         if (storage != NULL)
 238             for (i = 0; i < mx; i++)
 239                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 240     }
 241     CRYPTO_THREAD_unlock(global->ex_data_lock);
 242
 243     if (mx > 0 && storage == NULL) {
 244         CRYPTOerr(CRYPTO_F_CRYPTO_NEW_EX_DATA_EX, ERR_R_MALLOC_FAILURE);
 245         return 0;
 246     }
 247     for (i = 0; i < mx; i++) {
 248         if (storage[i] != NULL && storage[i]->new_func != NULL) {
 249             ptr = CRYPTO_get_ex_data(ad, i);
 250             storage[i]->new_func(obj, ptr, ad, i,
 251                                  storage[i]->argl, storage[i]->argp);
 252         }
 253     }
 254     if (storage != stack)
 255         OPENSSL_free(storage);
 256     return 1;
 257 }
 258
 259 int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 260 {
 261     return crypto_new_ex_data_ex(NULL, class_index, obj, ad);
 262 }
 263
 264 /*
 265  * Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks
 266  * for each index in the class used by this variable
 267  */
 268 int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
 269                        const CRYPTO_EX_DATA *from)
 270 {
 271     int mx, j, i;
 272     void *ptr;
 273     EX_CALLBACK *stack[10];
 274     EX_CALLBACK **storage = NULL;
 275     EX_CALLBACKS *ip;
 276     int toret = 0;
 277     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(from->ctx);
 278
 279     if (global == NULL)
 280         return 0;
 281
 282     to->ctx = from->ctx;
 283     if (from->sk == NULL)
 284         /* Nothing to copy over */
 285         return 1;
 286     if ((ip = get_and_lock(from->ctx, class_index)) == NULL)
 287         return 0;
 288
 289     mx = sk_EX_CALLBACK_num(ip->meth);
 290     j = sk_void_num(from->sk);
 291     if (j < mx)
 292         mx = j;
 293     if (mx > 0) {
 294         if (mx < (int)OSSL_NELEM(stack))
 295             storage = stack;
 296         else
 297             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 298         if (storage != NULL)
 299             for (i = 0; i < mx; i++)
 300                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 301     }
 302     CRYPTO_THREAD_unlock(global->ex_data_lock);
 303
 304     if (mx == 0)
 305         return 1;
 306     if (storage == NULL) {
 307         CRYPTOerr(CRYPTO_F_CRYPTO_DUP_EX_DATA, ERR_R_MALLOC_FAILURE);
 308         return 0;
 309     }
 310     /*
 311      * Make sure the ex_data stack is at least |mx| elements long to avoid
 312      * issues in the for loop that follows; so go get the |mx|'th element
 313      * (if it does not exist CRYPTO_get_ex_data() returns NULL), and assign
 314      * to itself. This is normally a no-op; but ensures the stack is the
 315      * proper size
 316      */
 317     if (!CRYPTO_set_ex_data(to, mx - 1, CRYPTO_get_ex_data(to, mx - 1)))
 318         goto err;
 319
 320     for (i = 0; i < mx; i++) {
 321         ptr = CRYPTO_get_ex_data(from, i);
 322         if (storage[i] != NULL && storage[i]->dup_func != NULL)
 323             if (!storage[i]->dup_func(to, from, &ptr, i,
 324                                       storage[i]->argl, storage[i]->argp))
 325                 goto err;
 326         CRYPTO_set_ex_data(to, i, ptr);
 327     }
 328     toret = 1;
 329  err:
 330     if (storage != stack)
 331         OPENSSL_free(storage);
 332     return toret;
 333 }
 334
 335
 336 /*
 337  * Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for
 338  * each index in the class used by this variable
 339  */
 340 void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 341 {
 342     int mx, i;
 343     EX_CALLBACKS *ip;
 344     void *ptr;
 345     EX_CALLBACK *f;
 346     EX_CALLBACK *stack[10];
 347     EX_CALLBACK **storage = NULL;
 348     OSSL_EX_DATA_GLOBAL *global;
 349
 350     if ((ip = get_and_lock(ad->ctx, class_index)) == NULL)
 351         goto err;
 352     global = openssl_ctx_get_ex_data_global(ad->ctx);
 353     if (global == 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 = openssl_ctx_get_ex_data_global(ad->ctx);
 401
 402     if (global == NULL)
 403         return 0;
 404
 405     curval = CRYPTO_get_ex_data(ad, idx);
 406
 407     /* Already there, no need to allocate */
 408     if (curval != NULL)
 409         return 1;
 410
 411     ip = get_and_lock(ad->ctx, 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, curval, 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 }