crypto/property/property.c

   1 /*
   2  * Copyright 2019-2023 The OpenSSL Project Authors. All Rights Reserved.
   3  * Copyright (c) 2019, Oracle and/or its affiliates.  All rights reserved.
   4  *
   5  * Licensed under the Apache License 2.0 (the "License").  You may not use
   6  * this file except in compliance with the License.  You can obtain a copy
   7  * in the file LICENSE in the source distribution or at
   8  * https://www.openssl.org/source/license.html
   9  */
  10
  11 #include <string.h>
  12 #include <stdio.h>
  13 #include <stdarg.h>
  14 #include <openssl/crypto.h>
  15 #include "internal/core.h"
  16 #include "internal/property.h"
  17 #include "internal/provider.h"
  18 #include "internal/tsan_assist.h"
  19 #include "crypto/ctype.h"
  20 #include <openssl/lhash.h>
  21 #include <openssl/rand.h>
  22 #include "internal/thread_once.h"
  23 #include "crypto/lhash.h"
  24 #include "crypto/sparse_array.h"
  25 #include "property_local.h"
  26 #include "crypto/context.h"
  27
  28 /*
  29  * The number of elements in the query cache before we initiate a flush.
  30  * If reducing this, also ensure the stochastic test in test/property_test.c
  31  * isn't likely to fail.
  32  */
  33 #define IMPL_CACHE_FLUSH_THRESHOLD  500
  34
  35 typedef struct {
  36     void *method;
  37     int (*up_ref)(void *);
  38     void (*free)(void *);
  39 } METHOD;
  40
  41 typedef struct {
  42     const OSSL_PROVIDER *provider;
  43     OSSL_PROPERTY_LIST *properties;
  44     METHOD method;
  45 } IMPLEMENTATION;
  46
  47 DEFINE_STACK_OF(IMPLEMENTATION)
  48
  49 typedef struct {
  50     const OSSL_PROVIDER *provider;
  51     const char *query;
  52     METHOD method;
  53     char body[1];
  54 } QUERY;
  55
  56 DEFINE_LHASH_OF_EX(QUERY);
  57
  58 typedef struct {
  59     int nid;
  60     STACK_OF(IMPLEMENTATION) *impls;
  61     LHASH_OF(QUERY) *cache;
  62 } ALGORITHM;
  63
  64 struct ossl_method_store_st {
  65     OSSL_LIB_CTX *ctx;
  66     SPARSE_ARRAY_OF(ALGORITHM) *algs;
  67     /*
  68      * Lock to protect the |algs| array from concurrent writing, when
  69      * individual implementations or queries are inserted.  This is used
  70      * by the appropriate functions here.
  71      */
  72     CRYPTO_RWLOCK *lock;
  73     /*
  74      * Lock to reserve the whole store.  This is used when fetching a set
  75      * of algorithms, via these functions, found in crypto/core_fetch.c:
  76      * ossl_method_construct_reserve_store()
  77      * ossl_method_construct_unreserve_store()
  78      */
  79     CRYPTO_RWLOCK *biglock;
  80
  81     /* query cache specific values */
  82
  83     /* Count of the query cache entries for all algs */
  84     size_t cache_nelem;
  85
  86     /* Flag: 1 if query cache entries for all algs need flushing */
  87     int cache_need_flush;
  88 };
  89
  90 typedef struct {
  91     LHASH_OF(QUERY) *cache;
  92     size_t nelem;
  93     uint32_t seed;
  94     unsigned char using_global_seed;
  95 } IMPL_CACHE_FLUSH;
  96
  97 DEFINE_SPARSE_ARRAY_OF(ALGORITHM);
  98
  99 typedef struct ossl_global_properties_st {
 100     OSSL_PROPERTY_LIST *list;
 101 #ifndef FIPS_MODULE
 102     unsigned int no_mirrored : 1;
 103 #endif
 104 } OSSL_GLOBAL_PROPERTIES;
 105
 106 static void ossl_method_cache_flush_alg(OSSL_METHOD_STORE *store,
 107                                         ALGORITHM *alg);
 108 static void ossl_method_cache_flush(OSSL_METHOD_STORE *store, int nid);
 109
 110 /* Global properties are stored per library context */
 111 void ossl_ctx_global_properties_free(void *vglobp)
 112 {
 113     OSSL_GLOBAL_PROPERTIES *globp = vglobp;
 114
 115     if (globp != NULL) {
 116         ossl_property_free(globp->list);
 117         OPENSSL_free(globp);
 118     }
 119 }
 120
 121 void *ossl_ctx_global_properties_new(OSSL_LIB_CTX *ctx)
 122 {
 123     return OPENSSL_zalloc(sizeof(OSSL_GLOBAL_PROPERTIES));
 124 }
 125
 126 OSSL_PROPERTY_LIST **ossl_ctx_global_properties(OSSL_LIB_CTX *libctx,
 127                                                 ossl_unused int loadconfig)
 128 {
 129     OSSL_GLOBAL_PROPERTIES *globp;
 130
 131 #if !defined(FIPS_MODULE) && !defined(OPENSSL_NO_AUTOLOAD_CONFIG)
 132     if (loadconfig && !OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CONFIG, NULL))
 133         return NULL;
 134 #endif
 135     globp = ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_GLOBAL_PROPERTIES);
 136
 137     return globp != NULL ? &globp->list : NULL;
 138 }
 139
 140 #ifndef FIPS_MODULE
 141 int ossl_global_properties_no_mirrored(OSSL_LIB_CTX *libctx)
 142 {
 143     OSSL_GLOBAL_PROPERTIES *globp
 144         = ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_GLOBAL_PROPERTIES);
 145
 146     return globp != NULL && globp->no_mirrored ? 1 : 0;
 147 }
 148
 149 void ossl_global_properties_stop_mirroring(OSSL_LIB_CTX *libctx)
 150 {
 151     OSSL_GLOBAL_PROPERTIES *globp
 152         = ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_GLOBAL_PROPERTIES);
 153
 154     if (globp != NULL)
 155         globp->no_mirrored = 1;
 156 }
 157 #endif
 158
 159 static int ossl_method_up_ref(METHOD *method)
 160 {
 161     return (*method->up_ref)(method->method);
 162 }
 163
 164 static void ossl_method_free(METHOD *method)
 165 {
 166     (*method->free)(method->method);
 167 }
 168
 169 static __owur int ossl_property_read_lock(OSSL_METHOD_STORE *p)
 170 {
 171     return p != NULL ? CRYPTO_THREAD_read_lock(p->lock) : 0;
 172 }
 173
 174 static __owur int ossl_property_write_lock(OSSL_METHOD_STORE *p)
 175 {
 176     return p != NULL ? CRYPTO_THREAD_write_lock(p->lock) : 0;
 177 }
 178
 179 static int ossl_property_unlock(OSSL_METHOD_STORE *p)
 180 {
 181     return p != 0 ? CRYPTO_THREAD_unlock(p->lock) : 0;
 182 }
 183
 184 static unsigned long query_hash(const QUERY *a)
 185 {
 186     return OPENSSL_LH_strhash(a->query);
 187 }
 188
 189 static int query_cmp(const QUERY *a, const QUERY *b)
 190 {
 191     int res = strcmp(a->query, b->query);
 192
 193     if (res == 0 && a->provider != NULL && b->provider != NULL)
 194         res = b->provider > a->provider ? 1
 195             : b->provider < a->provider ? -1
 196             : 0;
 197     return res;
 198 }
 199
 200 static void impl_free(IMPLEMENTATION *impl)
 201 {
 202     if (impl != NULL) {
 203         ossl_method_free(&impl->method);
 204         OPENSSL_free(impl);
 205     }
 206 }
 207
 208 static void impl_cache_free(QUERY *elem)
 209 {
 210     if (elem != NULL) {
 211         ossl_method_free(&elem->method);
 212         OPENSSL_free(elem);
 213     }
 214 }
 215
 216 static void impl_cache_flush_alg(ossl_uintmax_t idx, ALGORITHM *alg)
 217 {
 218     lh_QUERY_doall(alg->cache, &impl_cache_free);
 219     lh_QUERY_flush(alg->cache);
 220 }
 221
 222 static void alg_cleanup(ossl_uintmax_t idx, ALGORITHM *a, void *arg)
 223 {
 224     OSSL_METHOD_STORE *store = arg;
 225
 226     if (a != NULL) {
 227         sk_IMPLEMENTATION_pop_free(a->impls, &impl_free);
 228         lh_QUERY_doall(a->cache, &impl_cache_free);
 229         lh_QUERY_free(a->cache);
 230         OPENSSL_free(a);
 231     }
 232     if (store != NULL)
 233         ossl_sa_ALGORITHM_set(store->algs, idx, NULL);
 234 }
 235
 236 /*
 237  * The OSSL_LIB_CTX param here allows access to underlying property data needed
 238  * for computation
 239  */
 240 OSSL_METHOD_STORE *ossl_method_store_new(OSSL_LIB_CTX *ctx)
 241 {
 242     OSSL_METHOD_STORE *res;
 243
 244     res = OPENSSL_zalloc(sizeof(*res));
 245     if (res != NULL) {
 246         res->ctx = ctx;
 247         if ((res->algs = ossl_sa_ALGORITHM_new()) == NULL
 248             || (res->lock = CRYPTO_THREAD_lock_new()) == NULL
 249             || (res->biglock = CRYPTO_THREAD_lock_new()) == NULL) {
 250             ossl_method_store_free(res);
 251             return NULL;
 252         }
 253     }
 254     return res;
 255 }
 256
 257 void ossl_method_store_free(OSSL_METHOD_STORE *store)
 258 {
 259     if (store != NULL) {
 260         if (store->algs != NULL)
 261             ossl_sa_ALGORITHM_doall_arg(store->algs, &alg_cleanup, store);
 262         ossl_sa_ALGORITHM_free(store->algs);
 263         CRYPTO_THREAD_lock_free(store->lock);
 264         CRYPTO_THREAD_lock_free(store->biglock);
 265         OPENSSL_free(store);
 266     }
 267 }
 268
 269 int ossl_method_lock_store(OSSL_METHOD_STORE *store)
 270 {
 271     return store != NULL ? CRYPTO_THREAD_write_lock(store->biglock) : 0;
 272 }
 273
 274 int ossl_method_unlock_store(OSSL_METHOD_STORE *store)
 275 {
 276     return store != NULL ? CRYPTO_THREAD_unlock(store->biglock) : 0;
 277 }
 278
 279 static ALGORITHM *ossl_method_store_retrieve(OSSL_METHOD_STORE *store, int nid)
 280 {
 281     return ossl_sa_ALGORITHM_get(store->algs, nid);
 282 }
 283
 284 static int ossl_method_store_insert(OSSL_METHOD_STORE *store, ALGORITHM *alg)
 285 {
 286     return ossl_sa_ALGORITHM_set(store->algs, alg->nid, alg);
 287 }
 288
 289 int ossl_method_store_add(OSSL_METHOD_STORE *store, const OSSL_PROVIDER *prov,
 290                           int nid, const char *properties, void *method,
 291                           int (*method_up_ref)(void *),
 292                           void (*method_destruct)(void *))
 293 {
 294     ALGORITHM *alg = NULL;
 295     IMPLEMENTATION *impl;
 296     int ret = 0;
 297     int i;
 298
 299     if (nid <= 0 || method == NULL || store == NULL)
 300         return 0;
 301     if (properties == NULL)
 302         properties = "";
 303
 304     if (!ossl_assert(prov != NULL))
 305         return 0;
 306
 307     /* Create new entry */
 308     impl = OPENSSL_malloc(sizeof(*impl));
 309     if (impl == NULL)
 310         return 0;
 311     impl->method.method = method;
 312     impl->method.up_ref = method_up_ref;
 313     impl->method.free = method_destruct;
 314     if (!ossl_method_up_ref(&impl->method)) {
 315         OPENSSL_free(impl);
 316         return 0;
 317     }
 318     impl->provider = prov;
 319
 320     /* Insert into the hash table if required */
 321     if (!ossl_property_write_lock(store)) {
 322         OPENSSL_free(impl);
 323         return 0;
 324     }
 325     ossl_method_cache_flush(store, nid);
 326     if ((impl->properties = ossl_prop_defn_get(store->ctx, properties)) == NULL) {
 327         impl->properties = ossl_parse_property(store->ctx, properties);
 328         if (impl->properties == NULL)
 329             goto err;
 330         if (!ossl_prop_defn_set(store->ctx, properties, &impl->properties)) {
 331             ossl_property_free(impl->properties);
 332             impl->properties = NULL;
 333             goto err;
 334         }
 335     }
 336
 337     alg = ossl_method_store_retrieve(store, nid);
 338     if (alg == NULL) {
 339         if ((alg = OPENSSL_zalloc(sizeof(*alg))) == NULL
 340                 || (alg->impls = sk_IMPLEMENTATION_new_null()) == NULL
 341                 || (alg->cache = lh_QUERY_new(&query_hash, &query_cmp)) == NULL)
 342             goto err;
 343         alg->nid = nid;
 344         if (!ossl_method_store_insert(store, alg))
 345             goto err;
 346     }
 347
 348     /* Push onto stack if there isn't one there already */
 349     for (i = 0; i < sk_IMPLEMENTATION_num(alg->impls); i++) {
 350         const IMPLEMENTATION *tmpimpl = sk_IMPLEMENTATION_value(alg->impls, i);
 351
 352         if (tmpimpl->provider == impl->provider
 353             && tmpimpl->properties == impl->properties)
 354             break;
 355     }
 356     if (i == sk_IMPLEMENTATION_num(alg->impls)
 357         && sk_IMPLEMENTATION_push(alg->impls, impl))
 358         ret = 1;
 359     ossl_property_unlock(store);
 360     if (ret == 0)
 361         impl_free(impl);
 362     return ret;
 363
 364 err:
 365     ossl_property_unlock(store);
 366     alg_cleanup(0, alg, NULL);
 367     impl_free(impl);
 368     return 0;
 369 }
 370
 371 int ossl_method_store_remove(OSSL_METHOD_STORE *store, int nid,
 372                              const void *method)
 373 {
 374     ALGORITHM *alg = NULL;
 375     int i;
 376
 377     if (nid <= 0 || method == NULL || store == NULL)
 378         return 0;
 379
 380     if (!ossl_property_write_lock(store))
 381         return 0;
 382     ossl_method_cache_flush(store, nid);
 383     alg = ossl_method_store_retrieve(store, nid);
 384     if (alg == NULL) {
 385         ossl_property_unlock(store);
 386         return 0;
 387     }
 388
 389     /*
 390      * A sorting find then a delete could be faster but these stacks should be
 391      * relatively small, so we avoid the overhead.  Sorting could also surprise
 392      * users when result orderings change (even though they are not guaranteed).
 393      */
 394     for (i = 0; i < sk_IMPLEMENTATION_num(alg->impls); i++) {
 395         IMPLEMENTATION *impl = sk_IMPLEMENTATION_value(alg->impls, i);
 396
 397         if (impl->method.method == method) {
 398             impl_free(impl);
 399             (void)sk_IMPLEMENTATION_delete(alg->impls, i);
 400             ossl_property_unlock(store);
 401             return 1;
 402         }
 403     }
 404     ossl_property_unlock(store);
 405     return 0;
 406 }
 407
 408 struct alg_cleanup_by_provider_data_st {
 409     OSSL_METHOD_STORE *store;
 410     const OSSL_PROVIDER *prov;
 411 };
 412
 413 static void
 414 alg_cleanup_by_provider(ossl_uintmax_t idx, ALGORITHM *alg, void *arg)
 415 {
 416     struct alg_cleanup_by_provider_data_st *data = arg;
 417     int i, count;
 418
 419     /*
 420      * We walk the stack backwards, to avoid having to deal with stack shifts
 421      * caused by deletion
 422      */
 423     for (count = 0, i = sk_IMPLEMENTATION_num(alg->impls); i-- > 0;) {
 424         IMPLEMENTATION *impl = sk_IMPLEMENTATION_value(alg->impls, i);
 425
 426         if (impl->provider == data->prov) {
 427             impl_free(impl);
 428             (void)sk_IMPLEMENTATION_delete(alg->impls, i);
 429             count++;
 430         }
 431     }
 432
 433     /*
 434      * If we removed any implementation, we also clear the whole associated
 435      * cache, 'cause that's the sensible thing to do.
 436      * There's no point flushing the cache entries where we didn't remove
 437      * any implementation, though.
 438      */
 439     if (count > 0)
 440         ossl_method_cache_flush_alg(data->store, alg);
 441 }
 442
 443 int ossl_method_store_remove_all_provided(OSSL_METHOD_STORE *store,
 444                                           const OSSL_PROVIDER *prov)
 445 {
 446     struct alg_cleanup_by_provider_data_st data;
 447
 448     if (!ossl_property_write_lock(store))
 449         return 0;
 450     data.prov = prov;
 451     data.store = store;
 452     ossl_sa_ALGORITHM_doall_arg(store->algs, &alg_cleanup_by_provider, &data);
 453     ossl_property_unlock(store);
 454     return 1;
 455 }
 456
 457 static void alg_do_one(ALGORITHM *alg, IMPLEMENTATION *impl,
 458                        void (*fn)(int id, void *method, void *fnarg),
 459                        void *fnarg)
 460 {
 461     fn(alg->nid, impl->method.method, fnarg);
 462 }
 463
 464 struct alg_do_each_data_st {
 465     void (*fn)(int id, void *method, void *fnarg);
 466     void *fnarg;
 467 };
 468
 469 static void alg_do_each(ossl_uintmax_t idx, ALGORITHM *alg, void *arg)
 470 {
 471     struct alg_do_each_data_st *data = arg;
 472     int i, end = sk_IMPLEMENTATION_num(alg->impls);
 473
 474     for (i = 0; i < end; i++) {
 475         IMPLEMENTATION *impl = sk_IMPLEMENTATION_value(alg->impls, i);
 476
 477         alg_do_one(alg, impl, data->fn, data->fnarg);
 478     }
 479 }
 480
 481 void ossl_method_store_do_all(OSSL_METHOD_STORE *store,
 482                               void (*fn)(int id, void *method, void *fnarg),
 483                               void *fnarg)
 484 {
 485     struct alg_do_each_data_st data;
 486
 487     data.fn = fn;
 488     data.fnarg = fnarg;
 489     if (store != NULL)
 490         ossl_sa_ALGORITHM_doall_arg(store->algs, alg_do_each, &data);
 491 }
 492
 493 int ossl_method_store_fetch(OSSL_METHOD_STORE *store,
 494                             int nid, const char *prop_query,
 495                             const OSSL_PROVIDER **prov_rw, void **method)
 496 {
 497     OSSL_PROPERTY_LIST **plp;
 498     ALGORITHM *alg;
 499     IMPLEMENTATION *impl, *best_impl = NULL;
 500     OSSL_PROPERTY_LIST *pq = NULL, *p2 = NULL;
 501     const OSSL_PROVIDER *prov = prov_rw != NULL ? *prov_rw : NULL;
 502     int ret = 0;
 503     int j, best = -1, score, optional;
 504
 505     if (nid <= 0 || method == NULL || store == NULL)
 506         return 0;
 507
 508 #if !defined(FIPS_MODULE) && !defined(OPENSSL_NO_AUTOLOAD_CONFIG)
 509     if (ossl_lib_ctx_is_default(store->ctx)
 510             && !OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CONFIG, NULL))
 511         return 0;
 512 #endif
 513
 514     /* This only needs to be a read lock, because the query won't create anything */
 515     if (!ossl_property_read_lock(store))
 516         return 0;
 517     alg = ossl_method_store_retrieve(store, nid);
 518     if (alg == NULL) {
 519         ossl_property_unlock(store);
 520         return 0;
 521     }
 522
 523     if (prop_query != NULL)
 524         p2 = pq = ossl_parse_query(store->ctx, prop_query, 0);
 525     plp = ossl_ctx_global_properties(store->ctx, 0);
 526     if (plp != NULL && *plp != NULL) {
 527         if (pq == NULL) {
 528             pq = *plp;
 529         } else {
 530             p2 = ossl_property_merge(pq, *plp);
 531             ossl_property_free(pq);
 532             if (p2 == NULL)
 533                 goto fin;
 534             pq = p2;
 535         }
 536     }
 537
 538     if (pq == NULL) {
 539         for (j = 0; j < sk_IMPLEMENTATION_num(alg->impls); j++) {
 540             if ((impl = sk_IMPLEMENTATION_value(alg->impls, j)) != NULL
 541                 && (prov == NULL || impl->provider == prov)) {
 542                 best_impl = impl;
 543                 ret = 1;
 544                 break;
 545             }
 546         }
 547         goto fin;
 548     }
 549     optional = ossl_property_has_optional(pq);
 550     for (j = 0; j < sk_IMPLEMENTATION_num(alg->impls); j++) {
 551         if ((impl = sk_IMPLEMENTATION_value(alg->impls, j)) != NULL
 552             && (prov == NULL || impl->provider == prov)) {
 553             score = ossl_property_match_count(pq, impl->properties);
 554             if (score > best) {
 555                 best_impl = impl;
 556                 best = score;
 557                 ret = 1;
 558                 if (!optional)
 559                     goto fin;
 560             }
 561         }
 562     }
 563 fin:
 564     if (ret && ossl_method_up_ref(&best_impl->method)) {
 565         *method = best_impl->method.method;
 566         if (prov_rw != NULL)
 567             *prov_rw = best_impl->provider;
 568     } else {
 569         ret = 0;
 570     }
 571     ossl_property_unlock(store);
 572     ossl_property_free(p2);
 573     return ret;
 574 }
 575
 576 static void ossl_method_cache_flush_alg(OSSL_METHOD_STORE *store,
 577                                         ALGORITHM *alg)
 578 {
 579     store->cache_nelem -= lh_QUERY_num_items(alg->cache);
 580     impl_cache_flush_alg(0, alg);
 581 }
 582
 583 static void ossl_method_cache_flush(OSSL_METHOD_STORE *store, int nid)
 584 {
 585     ALGORITHM *alg = ossl_method_store_retrieve(store, nid);
 586
 587     if (alg != NULL)
 588         ossl_method_cache_flush_alg(store, alg);
 589 }
 590
 591 int ossl_method_store_cache_flush_all(OSSL_METHOD_STORE *store)
 592 {
 593     if (!ossl_property_write_lock(store))
 594         return 0;
 595     ossl_sa_ALGORITHM_doall(store->algs, &impl_cache_flush_alg);
 596     store->cache_nelem = 0;
 597     ossl_property_unlock(store);
 598     return 1;
 599 }
 600
 601 IMPLEMENT_LHASH_DOALL_ARG(QUERY, IMPL_CACHE_FLUSH);
 602
 603 /*
 604  * Flush an element from the query cache (perhaps).
 605  *
 606  * In order to avoid taking a write lock or using atomic operations
 607  * to keep accurate least recently used (LRU) or least frequently used
 608  * (LFU) information, the procedure used here is to stochastically
 609  * flush approximately half the cache.
 610  *
 611  * This procedure isn't ideal, LRU or LFU would be better.  However,
 612  * in normal operation, reaching a full cache would be unexpected.
 613  * It means that no steady state of algorithm queries has been reached.
 614  * That is, it is most likely an attack of some form.  A suboptimal clearance
 615  * strategy that doesn't degrade performance of the normal case is
 616  * preferable to a more refined approach that imposes a performance
 617  * impact.
 618  */
 619 static void impl_cache_flush_cache(QUERY *c, IMPL_CACHE_FLUSH *state)
 620 {
 621     uint32_t n;
 622
 623     /*
 624      * Implement the 32 bit xorshift as suggested by George Marsaglia in:
 625      *      https://doi.org/10.18637/jss.v008.i14
 626      *
 627      * This is a very fast PRNG so there is no need to extract bits one at a
 628      * time and use the entire value each time.
 629      */
 630     n = state->seed;
 631     n ^= n << 13;
 632     n ^= n >> 17;
 633     n ^= n << 5;
 634     state->seed = n;
 635
 636     if ((n & 1) != 0)
 637         impl_cache_free(lh_QUERY_delete(state->cache, c));
 638     else
 639         state->nelem++;
 640 }
 641
 642 static void impl_cache_flush_one_alg(ossl_uintmax_t idx, ALGORITHM *alg,
 643                                      void *v)
 644 {
 645     IMPL_CACHE_FLUSH *state = (IMPL_CACHE_FLUSH *)v;
 646
 647     state->cache = alg->cache;
 648     lh_QUERY_doall_IMPL_CACHE_FLUSH(state->cache, &impl_cache_flush_cache,
 649                                     state);
 650 }
 651
 652 static void ossl_method_cache_flush_some(OSSL_METHOD_STORE *store)
 653 {
 654     IMPL_CACHE_FLUSH state;
 655     static TSAN_QUALIFIER uint32_t global_seed = 1;
 656
 657     state.nelem = 0;
 658     state.using_global_seed = 0;
 659     if ((state.seed = OPENSSL_rdtsc()) == 0) {
 660         /* If there is no timer available, seed another way */
 661         state.using_global_seed = 1;
 662         state.seed = tsan_load(&global_seed);
 663     }
 664     store->cache_need_flush = 0;
 665     ossl_sa_ALGORITHM_doall_arg(store->algs, &impl_cache_flush_one_alg, &state);
 666     store->cache_nelem = state.nelem;
 667     /* Without a timer, update the global seed */
 668     if (state.using_global_seed)
 669         tsan_add(&global_seed, state.seed);
 670 }
 671
 672 int ossl_method_store_cache_get(OSSL_METHOD_STORE *store, OSSL_PROVIDER *prov,
 673                                 int nid, const char *prop_query, void **method)
 674 {
 675     ALGORITHM *alg;
 676     QUERY elem, *r;
 677     int res = 0;
 678
 679     if (nid <= 0 || store == NULL || prop_query == NULL)
 680         return 0;
 681
 682     if (!ossl_property_read_lock(store))
 683         return 0;
 684     alg = ossl_method_store_retrieve(store, nid);
 685     if (alg == NULL)
 686         goto err;
 687
 688     elem.query = prop_query;
 689     elem.provider = prov;
 690     r = lh_QUERY_retrieve(alg->cache, &elem);
 691     if (r == NULL)
 692         goto err;
 693     if (ossl_method_up_ref(&r->method)) {
 694         *method = r->method.method;
 695         res = 1;
 696     }
 697 err:
 698     ossl_property_unlock(store);
 699     return res;
 700 }
 701
 702 int ossl_method_store_cache_set(OSSL_METHOD_STORE *store, OSSL_PROVIDER *prov,
 703                                 int nid, const char *prop_query, void *method,
 704                                 int (*method_up_ref)(void *),
 705                                 void (*method_destruct)(void *))
 706 {
 707     QUERY elem, *old, *p = NULL;
 708     ALGORITHM *alg;
 709     size_t len;
 710     int res = 1;
 711
 712     if (nid <= 0 || store == NULL || prop_query == NULL)
 713         return 0;
 714
 715     if (!ossl_assert(prov != NULL))
 716         return 0;
 717
 718     if (!ossl_property_write_lock(store))
 719         return 0;
 720     if (store->cache_need_flush)
 721         ossl_method_cache_flush_some(store);
 722     alg = ossl_method_store_retrieve(store, nid);
 723     if (alg == NULL)
 724         goto err;
 725
 726     if (method == NULL) {
 727         elem.query = prop_query;
 728         elem.provider = prov;
 729         if ((old = lh_QUERY_delete(alg->cache, &elem)) != NULL) {
 730             impl_cache_free(old);
 731             store->cache_nelem--;
 732         }
 733         goto end;
 734     }
 735     p = OPENSSL_malloc(sizeof(*p) + (len = strlen(prop_query)));
 736     if (p != NULL) {
 737         p->query = p->body;
 738         p->provider = prov;
 739         p->method.method = method;
 740         p->method.up_ref = method_up_ref;
 741         p->method.free = method_destruct;
 742         if (!ossl_method_up_ref(&p->method))
 743             goto err;
 744         memcpy((char *)p->query, prop_query, len + 1);
 745         if ((old = lh_QUERY_insert(alg->cache, p)) != NULL) {
 746             impl_cache_free(old);
 747             goto end;
 748         }
 749         if (!lh_QUERY_error(alg->cache)) {
 750             if (++store->cache_nelem >= IMPL_CACHE_FLUSH_THRESHOLD)
 751                 store->cache_need_flush = 1;
 752             goto end;
 753         }
 754         ossl_method_free(&p->method);
 755     }
 756 err:
 757     res = 0;
 758     OPENSSL_free(p);
 759 end:
 760     ossl_property_unlock(store);
 761     return res;
 762 }