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 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  * The |global| parameter is assumed to be non null (checked by the caller).
  28  */
  29 static EX_CALLBACKS *get_and_lock(OSSL_EX_DATA_GLOBAL *global, int class_index)
  30 {
  31     EX_CALLBACKS *ip;
  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     if (global->ex_data_lock == NULL) {
  39         /*
  40          * If we get here, someone (who?) cleaned up the lock, so just
  41          * treat it as an error.
  42          */
  43          return NULL;
  44     }
  45
  46     CRYPTO_THREAD_write_lock(global->ex_data_lock);
  47     ip = &global->ex_data[class_index];
  48     return ip;
  49 }
  50
  51 static void cleanup_cb(EX_CALLBACK *funcs)
  52 {
  53     OPENSSL_free(funcs);
  54 }
  55
  56 /*
  57  * Release all "ex_data" state to prevent memory leaks. This can't be made
  58  * thread-safe without overhauling a lot of stuff, and shouldn't really be
  59  * called under potential race-conditions anyway (it's for program shutdown
  60  * after all).
  61  */
  62 void crypto_cleanup_all_ex_data_int(OPENSSL_CTX *ctx)
  63 {
  64     int i;
  65     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
  66
  67     if (global == NULL)
  68         return;
  69
  70     for (i = 0; i < CRYPTO_EX_INDEX__COUNT; ++i) {
  71         EX_CALLBACKS *ip = &global->ex_data[i];
  72
  73         sk_EX_CALLBACK_pop_free(ip->meth, cleanup_cb);
  74         ip->meth = NULL;
  75     }
  76
  77     CRYPTO_THREAD_lock_free(global->ex_data_lock);
  78     global->ex_data_lock = NULL;
  79 }
  80
  81
  82 /*
  83  * Unregister a new index by replacing the callbacks with no-ops.
  84  * Any in-use instances are leaked.
  85  */
  86 static void dummy_new(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
  87                      long argl, void *argp)
  88 {
  89 }
  90
  91 static void dummy_free(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
  92                        long argl, void *argp)
  93 {
  94 }
  95
  96 static int dummy_dup(CRYPTO_EX_DATA *to, const CRYPTO_EX_DATA *from,
  97                      void **from_d, int idx,
  98                      long argl, void *argp)
  99 {
 100     return 1;
 101 }
 102
 103 int crypto_free_ex_index_ex(OPENSSL_CTX *ctx, int class_index, int idx)
 104 {
 105     EX_CALLBACKS *ip;
 106     EX_CALLBACK *a;
 107     int toret = 0;
 108     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ctx);
 109
 110     if (global == NULL)
 111         return 0;
 112
 113     ip = get_and_lock(global, class_index);
 114     if (ip == NULL)
 115         return 0;
 116
 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(global, 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(global, class_index);
 220     if (ip == NULL)
 221         return 0;
 222
 223     ad->ctx = ctx;
 224     ad->sk = NULL;
 225     mx = sk_EX_CALLBACK_num(ip->meth);
 226     if (mx > 0) {
 227         if (mx < (int)OSSL_NELEM(stack))
 228             storage = stack;
 229         else
 230             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 231         if (storage != NULL)
 232             for (i = 0; i < mx; i++)
 233                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 234     }
 235     CRYPTO_THREAD_unlock(global->ex_data_lock);
 236
 237     if (mx > 0 && storage == NULL) {
 238         CRYPTOerr(CRYPTO_F_CRYPTO_NEW_EX_DATA_EX, ERR_R_MALLOC_FAILURE);
 239         return 0;
 240     }
 241     for (i = 0; i < mx; i++) {
 242         if (storage[i] != NULL && storage[i]->new_func != NULL) {
 243             ptr = CRYPTO_get_ex_data(ad, i);
 244             storage[i]->new_func(obj, ptr, ad, i,
 245                                  storage[i]->argl, storage[i]->argp);
 246         }
 247     }
 248     if (storage != stack)
 249         OPENSSL_free(storage);
 250     return 1;
 251 }
 252
 253 int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 254 {
 255     return crypto_new_ex_data_ex(NULL, class_index, obj, ad);
 256 }
 257
 258 /*
 259  * Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks
 260  * for each index in the class used by this variable
 261  */
 262 int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
 263                        const CRYPTO_EX_DATA *from)
 264 {
 265     int mx, j, i;
 266     void *ptr;
 267     EX_CALLBACK *stack[10];
 268     EX_CALLBACK **storage = NULL;
 269     EX_CALLBACKS *ip;
 270     int toret = 0;
 271     OSSL_EX_DATA_GLOBAL *global;
 272
 273     to->ctx = from->ctx;
 274     if (from->sk == NULL)
 275         /* Nothing to copy over */
 276         return 1;
 277
 278     global = openssl_ctx_get_ex_data_global(from->ctx);
 279     if (global == NULL)
 280         return 0;
 281
 282     ip = get_and_lock(global, class_index);
 283     if (ip == NULL)
 284         return 0;
 285
 286     mx = sk_EX_CALLBACK_num(ip->meth);
 287     j = sk_void_num(from->sk);
 288     if (j < mx)
 289         mx = j;
 290     if (mx > 0) {
 291         if (mx < (int)OSSL_NELEM(stack))
 292             storage = stack;
 293         else
 294             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 295         if (storage != NULL)
 296             for (i = 0; i < mx; i++)
 297                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 298     }
 299     CRYPTO_THREAD_unlock(global->ex_data_lock);
 300
 301     if (mx == 0)
 302         return 1;
 303     if (storage == NULL) {
 304         CRYPTOerr(CRYPTO_F_CRYPTO_DUP_EX_DATA, ERR_R_MALLOC_FAILURE);
 305         return 0;
 306     }
 307     /*
 308      * Make sure the ex_data stack is at least |mx| elements long to avoid
 309      * issues in the for loop that follows; so go get the |mx|'th element
 310      * (if it does not exist CRYPTO_get_ex_data() returns NULL), and assign
 311      * to itself. This is normally a no-op; but ensures the stack is the
 312      * proper size
 313      */
 314     if (!CRYPTO_set_ex_data(to, mx - 1, CRYPTO_get_ex_data(to, mx - 1)))
 315         goto err;
 316
 317     for (i = 0; i < mx; i++) {
 318         ptr = CRYPTO_get_ex_data(from, i);
 319         if (storage[i] != NULL && storage[i]->dup_func != NULL)
 320             if (!storage[i]->dup_func(to, from, &ptr, i,
 321                                       storage[i]->argl, storage[i]->argp))
 322                 goto err;
 323         CRYPTO_set_ex_data(to, i, ptr);
 324     }
 325     toret = 1;
 326  err:
 327     if (storage != stack)
 328         OPENSSL_free(storage);
 329     return toret;
 330 }
 331
 332
 333 /*
 334  * Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for
 335  * each index in the class used by this variable
 336  */
 337 void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 338 {
 339     int mx, i;
 340     EX_CALLBACKS *ip;
 341     void *ptr;
 342     EX_CALLBACK *f;
 343     EX_CALLBACK *stack[10];
 344     EX_CALLBACK **storage = NULL;
 345     OSSL_EX_DATA_GLOBAL *global = openssl_ctx_get_ex_data_global(ad->ctx);
 346
 347     if (global == NULL)
 348         goto err;
 349
 350     ip = get_and_lock(global, class_index);
 351     if (ip == NULL)
 352         goto err;
 353
 354     mx = sk_EX_CALLBACK_num(ip->meth);
 355     if (mx > 0) {
 356         if (mx < (int)OSSL_NELEM(stack))
 357             storage = stack;
 358         else
 359             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 360         if (storage != NULL)
 361             for (i = 0; i < mx; i++)
 362                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 363     }
 364     CRYPTO_THREAD_unlock(global->ex_data_lock);
 365
 366     for (i = 0; i < mx; i++) {
 367         if (storage != NULL)
 368             f = storage[i];
 369         else {
 370             CRYPTO_THREAD_write_lock(global->ex_data_lock);
 371             f = sk_EX_CALLBACK_value(ip->meth, i);
 372             CRYPTO_THREAD_unlock(global->ex_data_lock);
 373         }
 374         if (f != NULL && f->free_func != NULL) {
 375             ptr = CRYPTO_get_ex_data(ad, i);
 376             f->free_func(obj, ptr, ad, i, f->argl, f->argp);
 377         }
 378     }
 379
 380     if (storage != stack)
 381         OPENSSL_free(storage);
 382  err:
 383     sk_void_free(ad->sk);
 384     ad->sk = NULL;
 385     ad->ctx = NULL;
 386 }
 387
 388 /*
 389  * Allocate a given CRYPTO_EX_DATA item using the class specific allocation
 390  * function
 391  */
 392 int CRYPTO_alloc_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad,
 393                          int idx)
 394 {
 395     EX_CALLBACK *f;
 396     EX_CALLBACKS *ip;
 397     void *curval;
 398     OSSL_EX_DATA_GLOBAL *global;
 399
 400     curval = CRYPTO_get_ex_data(ad, idx);
 401     /* Already there, no need to allocate */
 402     if (curval != NULL)
 403         return 1;
 404
 405     global = openssl_ctx_get_ex_data_global(ad->ctx);
 406     if (global == NULL)
 407         return 0;
 408
 409     ip = get_and_lock(global, class_index);
 410     if (ip == NULL)
 411         return 0;
 412     f = sk_EX_CALLBACK_value(ip->meth, idx);
 413     CRYPTO_THREAD_unlock(global->ex_data_lock);
 414
 415     /*
 416      * This should end up calling CRYPTO_set_ex_data(), which allocates
 417      * everything necessary to support placing the new data in the right spot.
 418      */
 419     if (f->new_func == NULL)
 420         return 0;
 421
 422     f->new_func(obj, NULL, ad, idx, f->argl, f->argp);
 423
 424     return 1;
 425 }
 426
 427 /*
 428  * For a given CRYPTO_EX_DATA variable, set the value corresponding to a
 429  * particular index in the class used by this variable
 430  */
 431 int CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val)
 432 {
 433     int i;
 434
 435     if (ad->sk == NULL) {
 436         if ((ad->sk = sk_void_new_null()) == NULL) {
 437             CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
 438             return 0;
 439         }
 440     }
 441
 442     for (i = sk_void_num(ad->sk); i <= idx; ++i) {
 443         if (!sk_void_push(ad->sk, NULL)) {
 444             CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
 445             return 0;
 446         }
 447     }
 448     if (sk_void_set(ad->sk, idx, val) != val) {
 449         /* Probably the index is out of bounds */
 450         CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_PASSED_INVALID_ARGUMENT);
 451         return 0;
 452     }
 453     return 1;
 454 }
 455
 456 /*
 457  * For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a
 458  * particular index in the class used by this variable
 459  */
 460 void *CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx)
 461 {
 462     if (ad->sk == NULL || idx >= sk_void_num(ad->sk))
 463         return NULL;
 464     return sk_void_value(ad->sk, idx);
 465 }
 466
 467 OPENSSL_CTX *crypto_ex_data_get_openssl_ctx(const CRYPTO_EX_DATA *ad)
 468 {
 469     return ad->ctx;
 470 }