crypto/ex_data.c

   1 /*
   2  * Copyright 1995-2023 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 <stdlib.h>
  11 #include "crypto/cryptlib.h"
  12 #include "internal/thread_once.h"
  13
  14 int ossl_do_ex_data_init(OSSL_LIB_CTX *ctx)
  15 {
  16     OSSL_EX_DATA_GLOBAL *global = ossl_lib_ctx_get_ex_data_global(ctx);
  17
  18     if (global == NULL)
  19         return 0;
  20
  21     global->ex_data_lock = CRYPTO_THREAD_lock_new();
  22     return global->ex_data_lock != NULL;
  23 }
  24
  25 /*
  26  * Return the EX_CALLBACKS from the |ex_data| array that corresponds to
  27  * a given class.  On success, *holds the lock.*
  28  * The |global| parameter is assumed to be non null (checked by the caller).
  29  * If |read| is 1 then a read lock is obtained. Otherwise it is a write lock.
  30  */
  31 static EX_CALLBACKS *get_and_lock(OSSL_EX_DATA_GLOBAL *global, int class_index,
  32                                   int read)
  33 {
  34     EX_CALLBACKS *ip;
  35
  36     if (class_index < 0 || class_index >= CRYPTO_EX_INDEX__COUNT) {
  37         ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_INVALID_ARGUMENT);
  38         return NULL;
  39     }
  40
  41     if (global->ex_data_lock == NULL) {
  42         /*
  43          * If we get here, someone (who?) cleaned up the lock, so just
  44          * treat it as an error.
  45          */
  46          return NULL;
  47     }
  48
  49     if (read) {
  50         if (!CRYPTO_THREAD_read_lock(global->ex_data_lock))
  51             return NULL;
  52     } else {
  53         if (!CRYPTO_THREAD_write_lock(global->ex_data_lock))
  54             return NULL;
  55     }
  56
  57     ip = &global->ex_data[class_index];
  58     return ip;
  59 }
  60
  61 static void cleanup_cb(EX_CALLBACK *funcs)
  62 {
  63     OPENSSL_free(funcs);
  64 }
  65
  66 /*
  67  * Release all "ex_data" state to prevent memory leaks. This can't be made
  68  * thread-safe without overhauling a lot of stuff, and shouldn't really be
  69  * called under potential race-conditions anyway (it's for program shutdown
  70  * after all).
  71  */
  72 void ossl_crypto_cleanup_all_ex_data_int(OSSL_LIB_CTX *ctx)
  73 {
  74     int i;
  75     OSSL_EX_DATA_GLOBAL *global = ossl_lib_ctx_get_ex_data_global(ctx);
  76
  77     if (global == NULL)
  78         return;
  79
  80     for (i = 0; i < CRYPTO_EX_INDEX__COUNT; ++i) {
  81         EX_CALLBACKS *ip = &global->ex_data[i];
  82
  83         sk_EX_CALLBACK_pop_free(ip->meth, cleanup_cb);
  84         ip->meth = NULL;
  85     }
  86
  87     CRYPTO_THREAD_lock_free(global->ex_data_lock);
  88     global->ex_data_lock = NULL;
  89 }
  90
  91
  92 /*
  93  * Unregister a new index by replacing the callbacks with no-ops.
  94  * Any in-use instances are leaked.
  95  */
  96 static void dummy_new(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
  97                      long argl, void *argp)
  98 {
  99 }
 100
 101 static void dummy_free(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
 102                        long argl, void *argp)
 103 {
 104 }
 105
 106 static int dummy_dup(CRYPTO_EX_DATA *to, const CRYPTO_EX_DATA *from,
 107                      void **from_d, int idx,
 108                      long argl, void *argp)
 109 {
 110     return 1;
 111 }
 112
 113 int ossl_crypto_free_ex_index_ex(OSSL_LIB_CTX *ctx, int class_index, int idx)
 114 {
 115     EX_CALLBACKS *ip;
 116     EX_CALLBACK *a;
 117     int toret = 0;
 118     OSSL_EX_DATA_GLOBAL *global = ossl_lib_ctx_get_ex_data_global(ctx);
 119
 120     if (global == NULL)
 121         return 0;
 122
 123     ip = get_and_lock(global, class_index, 0);
 124     if (ip == NULL)
 125         return 0;
 126
 127     if (idx < 0 || idx >= sk_EX_CALLBACK_num(ip->meth))
 128         goto err;
 129     a = sk_EX_CALLBACK_value(ip->meth, idx);
 130     if (a == NULL)
 131         goto err;
 132     a->new_func = dummy_new;
 133     a->dup_func = dummy_dup;
 134     a->free_func = dummy_free;
 135     toret = 1;
 136 err:
 137     CRYPTO_THREAD_unlock(global->ex_data_lock);
 138     return toret;
 139 }
 140
 141 int CRYPTO_free_ex_index(int class_index, int idx)
 142 {
 143     return ossl_crypto_free_ex_index_ex(NULL, class_index, idx);
 144 }
 145
 146 /*
 147  * Register a new index.
 148  */
 149 int ossl_crypto_get_ex_new_index_ex(OSSL_LIB_CTX *ctx, int class_index,
 150                                     long argl, void *argp,
 151                                     CRYPTO_EX_new *new_func,
 152                                     CRYPTO_EX_dup *dup_func,
 153                                     CRYPTO_EX_free *free_func,
 154                                     int priority)
 155 {
 156     int toret = -1;
 157     EX_CALLBACK *a;
 158     EX_CALLBACKS *ip;
 159     OSSL_EX_DATA_GLOBAL *global = ossl_lib_ctx_get_ex_data_global(ctx);
 160
 161     if (global == NULL)
 162         return -1;
 163
 164     ip = get_and_lock(global, class_index, 0);
 165     if (ip == NULL)
 166         return -1;
 167
 168     if (ip->meth == NULL) {
 169         ip->meth = sk_EX_CALLBACK_new_null();
 170         /* We push an initial value on the stack because the SSL
 171          * "app_data" routines use ex_data index zero.  See RT 3710. */
 172         if (ip->meth == NULL
 173             || !sk_EX_CALLBACK_push(ip->meth, NULL)) {
 174             sk_EX_CALLBACK_free(ip->meth);
 175             ip->meth = NULL;
 176             ERR_raise(ERR_LIB_CRYPTO, ERR_R_CRYPTO_LIB);
 177             goto err;
 178         }
 179     }
 180
 181     a = (EX_CALLBACK *)OPENSSL_malloc(sizeof(*a));
 182     if (a == NULL)
 183         goto err;
 184     a->argl = argl;
 185     a->argp = argp;
 186     a->new_func = new_func;
 187     a->dup_func = dup_func;
 188     a->free_func = free_func;
 189     a->priority = priority;
 190
 191     if (!sk_EX_CALLBACK_push(ip->meth, NULL)) {
 192         ERR_raise(ERR_LIB_CRYPTO, ERR_R_CRYPTO_LIB);
 193         OPENSSL_free(a);
 194         goto err;
 195     }
 196     toret = sk_EX_CALLBACK_num(ip->meth) - 1;
 197     (void)sk_EX_CALLBACK_set(ip->meth, toret, a);
 198
 199  err:
 200     CRYPTO_THREAD_unlock(global->ex_data_lock);
 201     return toret;
 202 }
 203
 204 int CRYPTO_get_ex_new_index(int class_index, long argl, void *argp,
 205                             CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
 206                             CRYPTO_EX_free *free_func)
 207 {
 208     return ossl_crypto_get_ex_new_index_ex(NULL, class_index, argl, argp,
 209                                            new_func, dup_func, free_func, 0);
 210 }
 211
 212 /*
 213  * Initialise a new CRYPTO_EX_DATA for use in a particular class - including
 214  * calling new() callbacks for each index in the class used by this variable
 215  * Thread-safe by copying a class's array of "EX_CALLBACK" entries
 216  * in the lock, then using them outside the lock. Note this only applies
 217  * to the global "ex_data" state (ie. class definitions), not 'ad' itself.
 218  */
 219 int ossl_crypto_new_ex_data_ex(OSSL_LIB_CTX *ctx, int class_index, void *obj,
 220                                CRYPTO_EX_DATA *ad)
 221 {
 222     int mx, i;
 223     void *ptr;
 224     EX_CALLBACK **storage = NULL;
 225     EX_CALLBACK *stack[10];
 226     EX_CALLBACKS *ip;
 227     OSSL_EX_DATA_GLOBAL *global = ossl_lib_ctx_get_ex_data_global(ctx);
 228
 229     if (global == NULL)
 230         return 0;
 231
 232     ip = get_and_lock(global, class_index, 1);
 233     if (ip == NULL)
 234         return 0;
 235
 236     ad->ctx = ctx;
 237     ad->sk = NULL;
 238     mx = sk_EX_CALLBACK_num(ip->meth);
 239     if (mx > 0) {
 240         if (mx < (int)OSSL_NELEM(stack))
 241             storage = stack;
 242         else
 243             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 244         if (storage != NULL)
 245             for (i = 0; i < mx; i++)
 246                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 247     }
 248     CRYPTO_THREAD_unlock(global->ex_data_lock);
 249
 250     if (mx > 0 && storage == NULL)
 251         return 0;
 252     for (i = 0; i < mx; i++) {
 253         if (storage[i] != NULL && storage[i]->new_func != NULL) {
 254             ptr = CRYPTO_get_ex_data(ad, i);
 255             storage[i]->new_func(obj, ptr, ad, i,
 256                                  storage[i]->argl, storage[i]->argp);
 257         }
 258     }
 259     if (storage != stack)
 260         OPENSSL_free(storage);
 261     return 1;
 262 }
 263
 264 int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 265 {
 266     return ossl_crypto_new_ex_data_ex(NULL, class_index, obj, ad);
 267 }
 268
 269 /*
 270  * Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks
 271  * for each index in the class used by this variable
 272  */
 273 int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
 274                        const CRYPTO_EX_DATA *from)
 275 {
 276     int mx, j, i;
 277     void *ptr;
 278     EX_CALLBACK *stack[10];
 279     EX_CALLBACK **storage = NULL;
 280     EX_CALLBACKS *ip;
 281     int toret = 0;
 282     OSSL_EX_DATA_GLOBAL *global;
 283
 284     to->ctx = from->ctx;
 285     if (from->sk == NULL)
 286         /* Nothing to copy over */
 287         return 1;
 288
 289     global = ossl_lib_ctx_get_ex_data_global(from->ctx);
 290     if (global == NULL)
 291         return 0;
 292
 293     ip = get_and_lock(global, class_index, 1);
 294     if (ip == NULL)
 295         return 0;
 296
 297     mx = sk_EX_CALLBACK_num(ip->meth);
 298     j = sk_void_num(from->sk);
 299     if (j < mx)
 300         mx = j;
 301     if (mx > 0) {
 302         if (mx < (int)OSSL_NELEM(stack))
 303             storage = stack;
 304         else
 305             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 306         if (storage != NULL)
 307             for (i = 0; i < mx; i++)
 308                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 309     }
 310     CRYPTO_THREAD_unlock(global->ex_data_lock);
 311
 312     if (mx == 0)
 313         return 1;
 314     if (storage == NULL)
 315         return 0;
 316     /*
 317      * Make sure the ex_data stack is at least |mx| elements long to avoid
 318      * issues in the for loop that follows; so go get the |mx|'th element
 319      * (if it does not exist CRYPTO_get_ex_data() returns NULL), and assign
 320      * to itself. This is normally a no-op; but ensures the stack is the
 321      * proper size
 322      */
 323     if (!CRYPTO_set_ex_data(to, mx - 1, CRYPTO_get_ex_data(to, mx - 1)))
 324         goto err;
 325
 326     for (i = 0; i < mx; i++) {
 327         ptr = CRYPTO_get_ex_data(from, i);
 328         if (storage[i] != NULL && storage[i]->dup_func != NULL)
 329             if (!storage[i]->dup_func(to, from, &ptr, i,
 330                                       storage[i]->argl, storage[i]->argp))
 331                 goto err;
 332         CRYPTO_set_ex_data(to, i, ptr);
 333     }
 334     toret = 1;
 335  err:
 336     if (storage != stack)
 337         OPENSSL_free(storage);
 338     return toret;
 339 }
 340
 341 struct ex_callback_entry {
 342     const EX_CALLBACK *excb;
 343     int index;
 344 };
 345
 346 static int ex_callback_compare(const void *a, const void *b)
 347 {
 348     const struct ex_callback_entry *ap = (const struct ex_callback_entry *)a;
 349     const struct ex_callback_entry *bp = (const struct ex_callback_entry *)b;
 350
 351     if (ap->excb == bp->excb)
 352         return 0;
 353
 354     if (ap->excb == NULL)
 355         return 1;
 356     if (bp->excb == NULL)
 357         return -1;
 358     if (ap->excb->priority == bp->excb->priority)
 359         return 0;
 360     return ap->excb->priority > bp->excb->priority ? -1 : 1;
 361 }
 362
 363 /*
 364  * Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for
 365  * each index in the class used by this variable
 366  */
 367 void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 368 {
 369     int mx, i;
 370     EX_CALLBACKS *ip;
 371     void *ptr;
 372     const EX_CALLBACK *f;
 373     struct ex_callback_entry stack[10];
 374     struct ex_callback_entry *storage = NULL;
 375     OSSL_EX_DATA_GLOBAL *global = ossl_lib_ctx_get_ex_data_global(ad->ctx);
 376
 377     if (global == NULL)
 378         goto err;
 379
 380     ip = get_and_lock(global, class_index, 1);
 381     if (ip == NULL)
 382         goto err;
 383
 384     mx = sk_EX_CALLBACK_num(ip->meth);
 385     if (mx > 0) {
 386         if (mx < (int)OSSL_NELEM(stack))
 387             storage = stack;
 388         else
 389             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 390         if (storage != NULL)
 391             for (i = 0; i < mx; i++) {
 392                 storage[i].excb = sk_EX_CALLBACK_value(ip->meth, i);
 393                 storage[i].index = i;
 394             }
 395     }
 396     CRYPTO_THREAD_unlock(global->ex_data_lock);
 397
 398     if (storage != NULL) {
 399         /* Sort according to priority. High priority first */
 400         qsort(storage, mx, sizeof(*storage), ex_callback_compare);
 401         for (i = 0; i < mx; i++) {
 402             f = storage[i].excb;
 403
 404             if (f != NULL && f->free_func != NULL) {
 405                 ptr = CRYPTO_get_ex_data(ad, storage[i].index);
 406                 f->free_func(obj, ptr, ad, storage[i].index, f->argl, f->argp);
 407             }
 408         }
 409     }
 410
 411     if (storage != stack)
 412         OPENSSL_free(storage);
 413  err:
 414     sk_void_free(ad->sk);
 415     ad->sk = NULL;
 416     ad->ctx = NULL;
 417 }
 418
 419 /*
 420  * Allocate a given CRYPTO_EX_DATA item using the class specific allocation
 421  * function
 422  */
 423 int CRYPTO_alloc_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad,
 424                          int idx)
 425 {
 426     void *curval;
 427
 428     curval = CRYPTO_get_ex_data(ad, idx);
 429     /* Already there, no need to allocate */
 430     if (curval != NULL)
 431         return 1;
 432
 433     return ossl_crypto_alloc_ex_data_intern(class_index, obj, ad, idx);
 434 }
 435
 436 int ossl_crypto_alloc_ex_data_intern(int class_index, void *obj,
 437                                      CRYPTO_EX_DATA *ad, int idx)
 438 {
 439     EX_CALLBACK *f;
 440     EX_CALLBACKS *ip;
 441     OSSL_EX_DATA_GLOBAL *global;
 442
 443     global = ossl_lib_ctx_get_ex_data_global(ad->ctx);
 444     if (global == NULL)
 445         return 0;
 446
 447     ip = get_and_lock(global, class_index, 1);
 448     if (ip == NULL)
 449         return 0;
 450     f = sk_EX_CALLBACK_value(ip->meth, idx);
 451     CRYPTO_THREAD_unlock(global->ex_data_lock);
 452
 453     /*
 454      * This should end up calling CRYPTO_set_ex_data(), which allocates
 455      * everything necessary to support placing the new data in the right spot.
 456      */
 457     if (f->new_func == NULL)
 458         return 0;
 459
 460     f->new_func(obj, NULL, ad, idx, f->argl, f->argp);
 461
 462     return 1;
 463 }
 464
 465 /*
 466  * For a given CRYPTO_EX_DATA variable, set the value corresponding to a
 467  * particular index in the class used by this variable
 468  */
 469 int CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val)
 470 {
 471     int i;
 472
 473     if (ad->sk == NULL) {
 474         if ((ad->sk = sk_void_new_null()) == NULL) {
 475             ERR_raise(ERR_LIB_CRYPTO, ERR_R_CRYPTO_LIB);
 476             return 0;
 477         }
 478     }
 479
 480     for (i = sk_void_num(ad->sk); i <= idx; ++i) {
 481         if (!sk_void_push(ad->sk, NULL)) {
 482             ERR_raise(ERR_LIB_CRYPTO, ERR_R_CRYPTO_LIB);
 483             return 0;
 484         }
 485     }
 486     if (sk_void_set(ad->sk, idx, val) != val) {
 487         /* Probably the index is out of bounds */
 488         ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_INVALID_ARGUMENT);
 489         return 0;
 490     }
 491     return 1;
 492 }
 493
 494 /*
 495  * For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a
 496  * particular index in the class used by this variable
 497  */
 498 void *CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx)
 499 {
 500     if (ad->sk == NULL || idx >= sk_void_num(ad->sk))
 501         return NULL;
 502     return sk_void_value(ad->sk, idx);
 503 }
 504
 505 OSSL_LIB_CTX *ossl_crypto_ex_data_get_ossl_lib_ctx(const CRYPTO_EX_DATA *ad)
 506 {
 507     return ad->ctx;
 508 }