crypto/property/property.c

   1 /*
   2  * Copyright 2019-2021 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 "crypto/ctype.h"
  19 #include <openssl/lhash.h>
  20 #include <openssl/rand.h>
  21 #include "internal/thread_once.h"
  22 #include "crypto/lhash.h"
  23 #include "crypto/sparse_array.h"
  24 #include "property_local.h"
  25
  26 /*
  27  * The number of elements in the query cache before we initiate a flush.
  28  * If reducing this, also ensure the stochastic test in test/property_test.c
  29  * isn't likely to fail.
  30  */
  31 #define IMPL_CACHE_FLUSH_THRESHOLD  500
  32
  33 typedef struct {
  34     void *method;
  35     int (*up_ref)(void *);
  36     void (*free)(void *);
  37 } METHOD;
  38
  39 typedef struct {
  40     const OSSL_PROVIDER *provider;
  41     OSSL_PROPERTY_LIST *properties;
  42     METHOD method;
  43 } IMPLEMENTATION;
  44
  45 DEFINE_STACK_OF(IMPLEMENTATION)
  46
  47 typedef struct {
  48     const char *query;
  49     METHOD method;
  50     char body[1];
  51 } QUERY;
  52
  53 DEFINE_LHASH_OF(QUERY);
  54
  55 typedef struct {
  56     int nid;
  57     STACK_OF(IMPLEMENTATION) *impls;
  58     LHASH_OF(QUERY) *cache;
  59 } ALGORITHM;
  60
  61 struct ossl_method_store_st {
  62     OSSL_LIB_CTX *ctx;
  63     size_t nelem;
  64     SPARSE_ARRAY_OF(ALGORITHM) *algs;
  65     int need_flush;
  66     CRYPTO_RWLOCK *lock;
  67 };
  68
  69 typedef struct {
  70     LHASH_OF(QUERY) *cache;
  71     size_t nelem;
  72     uint32_t seed;
  73 } IMPL_CACHE_FLUSH;
  74
  75 DEFINE_SPARSE_ARRAY_OF(ALGORITHM);
  76
  77 typedef struct ossl_global_properties_st {
  78     OSSL_PROPERTY_LIST *list;
  79 #ifndef FIPS_MODULE
  80     unsigned int no_mirrored : 1;
  81 #endif
  82 } OSSL_GLOBAL_PROPERTIES;
  83
  84 static void ossl_method_cache_flush(OSSL_METHOD_STORE *store, int nid);
  85
  86 /* Global properties are stored per library context */
  87 static void ossl_ctx_global_properties_free(void *vglobp)
  88 {
  89     OSSL_GLOBAL_PROPERTIES *globp = vglobp;
  90
  91     if (globp != NULL) {
  92         ossl_property_free(globp->list);
  93         OPENSSL_free(globp);
  94     }
  95 }
  96
  97 static void *ossl_ctx_global_properties_new(OSSL_LIB_CTX *ctx)
  98 {
  99     return OPENSSL_zalloc(sizeof(OSSL_GLOBAL_PROPERTIES));
 100 }
 101
 102 static const OSSL_LIB_CTX_METHOD ossl_ctx_global_properties_method = {
 103     OSSL_LIB_CTX_METHOD_DEFAULT_PRIORITY,
 104     ossl_ctx_global_properties_new,
 105     ossl_ctx_global_properties_free,
 106 };
 107
 108 OSSL_PROPERTY_LIST **ossl_ctx_global_properties(OSSL_LIB_CTX *libctx,
 109                                                 int loadconfig)
 110 {
 111     OSSL_GLOBAL_PROPERTIES *globp;
 112
 113 #ifndef FIPS_MODULE
 114     if (loadconfig && !OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CONFIG, NULL))
 115         return NULL;
 116 #endif
 117     globp = ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_GLOBAL_PROPERTIES,
 118                                   &ossl_ctx_global_properties_method);
 119
 120     return &globp->list;
 121 }
 122
 123 #ifndef FIPS_MODULE
 124 int ossl_global_properties_no_mirrored(OSSL_LIB_CTX *libctx)
 125 {
 126     OSSL_GLOBAL_PROPERTIES *globp
 127         = ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_GLOBAL_PROPERTIES,
 128                                 &ossl_ctx_global_properties_method);
 129
 130     return globp->no_mirrored ? 1 : 0;
 131 }
 132
 133 void ossl_global_properties_stop_mirroring(OSSL_LIB_CTX *libctx)
 134 {
 135     OSSL_GLOBAL_PROPERTIES *globp
 136         = ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_GLOBAL_PROPERTIES,
 137                                 &ossl_ctx_global_properties_method);
 138
 139     globp->no_mirrored = 1;
 140 }
 141 #endif
 142
 143 static int ossl_method_up_ref(METHOD *method)
 144 {
 145     return (*method->up_ref)(method->method);
 146 }
 147
 148 static void ossl_method_free(METHOD *method)
 149 {
 150     (*method->free)(method->method);
 151 }
 152
 153 static __owur int ossl_property_read_lock(OSSL_METHOD_STORE *p)
 154 {
 155     return p != NULL ? CRYPTO_THREAD_read_lock(p->lock) : 0;
 156 }
 157
 158 static __owur int ossl_property_write_lock(OSSL_METHOD_STORE *p)
 159 {
 160     return p != NULL ? CRYPTO_THREAD_write_lock(p->lock) : 0;
 161 }
 162
 163 static int ossl_property_unlock(OSSL_METHOD_STORE *p)
 164 {
 165     return p != 0 ? CRYPTO_THREAD_unlock(p->lock) : 0;
 166 }
 167
 168 static unsigned long query_hash(const QUERY *a)
 169 {
 170     return OPENSSL_LH_strhash(a->query);
 171 }
 172
 173 static int query_cmp(const QUERY *a, const QUERY *b)
 174 {
 175     return strcmp(a->query, b->query);
 176 }
 177
 178 static void impl_free(IMPLEMENTATION *impl)
 179 {
 180     if (impl != NULL) {
 181         ossl_method_free(&impl->method);
 182         OPENSSL_free(impl);
 183     }
 184 }
 185
 186 static void impl_cache_free(QUERY *elem)
 187 {
 188     if (elem != NULL) {
 189         ossl_method_free(&elem->method);
 190         OPENSSL_free(elem);
 191     }
 192 }
 193
 194 static void alg_cleanup(ossl_uintmax_t idx, ALGORITHM *a)
 195 {
 196     if (a != NULL) {
 197         sk_IMPLEMENTATION_pop_free(a->impls, &impl_free);
 198         lh_QUERY_doall(a->cache, &impl_cache_free);
 199         lh_QUERY_free(a->cache);
 200         OPENSSL_free(a);
 201     }
 202 }
 203
 204 /*
 205  * The OSSL_LIB_CTX param here allows access to underlying property data needed
 206  * for computation
 207  */
 208 OSSL_METHOD_STORE *ossl_method_store_new(OSSL_LIB_CTX *ctx)
 209 {
 210     OSSL_METHOD_STORE *res;
 211
 212     res = OPENSSL_zalloc(sizeof(*res));
 213     if (res != NULL) {
 214         res->ctx = ctx;
 215         if ((res->algs = ossl_sa_ALGORITHM_new()) == NULL) {
 216             OPENSSL_free(res);
 217             return NULL;
 218         }
 219         if ((res->lock = CRYPTO_THREAD_lock_new()) == NULL) {
 220             ossl_sa_ALGORITHM_free(res->algs);
 221             OPENSSL_free(res);
 222             return NULL;
 223         }
 224     }
 225     return res;
 226 }
 227
 228 void ossl_method_store_free(OSSL_METHOD_STORE *store)
 229 {
 230     if (store != NULL) {
 231         ossl_sa_ALGORITHM_doall(store->algs, &alg_cleanup);
 232         ossl_sa_ALGORITHM_free(store->algs);
 233         CRYPTO_THREAD_lock_free(store->lock);
 234         OPENSSL_free(store);
 235     }
 236 }
 237
 238 static ALGORITHM *ossl_method_store_retrieve(OSSL_METHOD_STORE *store, int nid)
 239 {
 240     return ossl_sa_ALGORITHM_get(store->algs, nid);
 241 }
 242
 243 static int ossl_method_store_insert(OSSL_METHOD_STORE *store, ALGORITHM *alg)
 244 {
 245         return ossl_sa_ALGORITHM_set(store->algs, alg->nid, alg);
 246 }
 247
 248 int ossl_method_store_add(OSSL_METHOD_STORE *store, const OSSL_PROVIDER *prov,
 249                           int nid, const char *properties, void *method,
 250                           int (*method_up_ref)(void *),
 251                           void (*method_destruct)(void *))
 252 {
 253     ALGORITHM *alg = NULL;
 254     IMPLEMENTATION *impl;
 255     int ret = 0;
 256     int i;
 257
 258     if (nid <= 0 || method == NULL || store == NULL)
 259         return 0;
 260     if (properties == NULL)
 261         properties = "";
 262
 263     /* Create new entry */
 264     impl = OPENSSL_malloc(sizeof(*impl));
 265     if (impl == NULL)
 266         return 0;
 267     impl->method.method = method;
 268     impl->method.up_ref = method_up_ref;
 269     impl->method.free = method_destruct;
 270     if (!ossl_method_up_ref(&impl->method)) {
 271         OPENSSL_free(impl);
 272         return 0;
 273     }
 274     impl->provider = prov;
 275
 276     /*
 277      * Insert into the hash table if required.
 278      *
 279      * A write lock is used unconditionally because we wend our way down to the
 280      * property string code which isn't locking friendly.
 281      */
 282     if (!ossl_property_write_lock(store)) {
 283         OPENSSL_free(impl);
 284         return 0;
 285     }
 286     ossl_method_cache_flush(store, nid);
 287     if ((impl->properties = ossl_prop_defn_get(store->ctx, properties)) == NULL) {
 288         impl->properties = ossl_parse_property(store->ctx, properties);
 289         if (impl->properties == NULL)
 290             goto err;
 291         ossl_prop_defn_set(store->ctx, properties, impl->properties);
 292     }
 293
 294     alg = ossl_method_store_retrieve(store, nid);
 295     if (alg == NULL) {
 296         if ((alg = OPENSSL_zalloc(sizeof(*alg))) == NULL
 297                 || (alg->impls = sk_IMPLEMENTATION_new_null()) == NULL
 298                 || (alg->cache = lh_QUERY_new(&query_hash, &query_cmp)) == NULL)
 299             goto err;
 300         alg->nid = nid;
 301         if (!ossl_method_store_insert(store, alg))
 302             goto err;
 303     }
 304
 305     /* Push onto stack if there isn't one there already */
 306     for (i = 0; i < sk_IMPLEMENTATION_num(alg->impls); i++) {
 307         const IMPLEMENTATION *tmpimpl = sk_IMPLEMENTATION_value(alg->impls, i);
 308
 309         if (tmpimpl->provider == impl->provider
 310             && tmpimpl->properties == impl->properties)
 311             break;
 312     }
 313     if (i == sk_IMPLEMENTATION_num(alg->impls)
 314         && sk_IMPLEMENTATION_push(alg->impls, impl))
 315         ret = 1;
 316     ossl_property_unlock(store);
 317     if (ret == 0)
 318         impl_free(impl);
 319     return ret;
 320
 321 err:
 322     ossl_property_unlock(store);
 323     alg_cleanup(0, alg);
 324     impl_free(impl);
 325     return 0;
 326 }
 327
 328 int ossl_method_store_remove(OSSL_METHOD_STORE *store, int nid,
 329                              const void *method)
 330 {
 331     ALGORITHM *alg = NULL;
 332     int i;
 333
 334     if (nid <= 0 || method == NULL || store == NULL)
 335         return 0;
 336
 337     if (!ossl_property_write_lock(store))
 338         return 0;
 339     ossl_method_cache_flush(store, nid);
 340     alg = ossl_method_store_retrieve(store, nid);
 341     if (alg == NULL) {
 342         ossl_property_unlock(store);
 343         return 0;
 344     }
 345
 346     /*
 347      * A sorting find then a delete could be faster but these stacks should be
 348      * relatively small, so we avoid the overhead.  Sorting could also surprise
 349      * users when result orderings change (even though they are not guaranteed).
 350      */
 351     for (i = 0; i < sk_IMPLEMENTATION_num(alg->impls); i++) {
 352         IMPLEMENTATION *impl = sk_IMPLEMENTATION_value(alg->impls, i);
 353
 354         if (impl->method.method == method) {
 355             impl_free(impl);
 356             (void)sk_IMPLEMENTATION_delete(alg->impls, i);
 357             ossl_property_unlock(store);
 358             return 1;
 359         }
 360     }
 361     ossl_property_unlock(store);
 362     return 0;
 363 }
 364
 365 static void alg_do_one(ALGORITHM *alg, IMPLEMENTATION *impl,
 366                        void (*fn)(int id, void *method, void *fnarg),
 367                        void *fnarg)
 368 {
 369     fn(alg->nid, impl->method.method, fnarg);
 370 }
 371
 372 struct alg_do_each_data_st {
 373     void (*fn)(int id, void *method, void *fnarg);
 374     void *fnarg;
 375 };
 376
 377 static void alg_do_each(ossl_uintmax_t idx, ALGORITHM *alg, void *arg)
 378 {
 379     struct alg_do_each_data_st *data = arg;
 380     int i, end = sk_IMPLEMENTATION_num(alg->impls);
 381
 382     for (i = 0; i < end; i++) {
 383         IMPLEMENTATION *impl = sk_IMPLEMENTATION_value(alg->impls, i);
 384
 385         alg_do_one(alg, impl, data->fn, data->fnarg);
 386     }
 387 }
 388
 389 void ossl_method_store_do_all(OSSL_METHOD_STORE *store,
 390                               void (*fn)(int id, void *method, void *fnarg),
 391                               void *fnarg)
 392 {
 393     struct alg_do_each_data_st data;
 394
 395     data.fn = fn;
 396     data.fnarg = fnarg;
 397     if (store != NULL)
 398         ossl_sa_ALGORITHM_doall_arg(store->algs, alg_do_each, &data);
 399 }
 400
 401 int ossl_method_store_fetch(OSSL_METHOD_STORE *store, int nid,
 402                             const char *prop_query,
 403                             void **method)
 404 {
 405     OSSL_PROPERTY_LIST **plp;
 406     ALGORITHM *alg;
 407     IMPLEMENTATION *impl;
 408     OSSL_PROPERTY_LIST *pq = NULL, *p2 = NULL;
 409     METHOD *best_method = NULL;
 410     int ret = 0;
 411     int j, best = -1, score, optional;
 412
 413 #ifndef FIPS_MODULE
 414     if (!OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CONFIG, NULL))
 415         return 0;
 416 #endif
 417
 418     if (nid <= 0 || method == NULL || store == NULL)
 419         return 0;
 420
 421     /*
 422      * This only needs to be a read lock, because queries never create property
 423      * names or value and thus don't modify any of the property string layer.
 424      */
 425     if (!ossl_property_read_lock(store))
 426         return 0;
 427     alg = ossl_method_store_retrieve(store, nid);
 428     if (alg == NULL) {
 429         ossl_property_unlock(store);
 430         return 0;
 431     }
 432
 433     if (prop_query != NULL)
 434         p2 = pq = ossl_parse_query(store->ctx, prop_query, 0);
 435     plp = ossl_ctx_global_properties(store->ctx, 0);
 436     if (plp != NULL && *plp != NULL) {
 437         if (pq == NULL) {
 438             pq = *plp;
 439         } else {
 440             p2 = ossl_property_merge(pq, *plp);
 441             ossl_property_free(pq);
 442             if (p2 == NULL)
 443                 goto fin;
 444             pq = p2;
 445         }
 446     }
 447
 448     if (pq == NULL) {
 449         if ((impl = sk_IMPLEMENTATION_value(alg->impls, 0)) != NULL) {
 450             best_method = &impl->method;
 451             ret = 1;
 452         }
 453         goto fin;
 454     }
 455     optional = ossl_property_has_optional(pq);
 456     for (j = 0; j < sk_IMPLEMENTATION_num(alg->impls); j++) {
 457         impl = sk_IMPLEMENTATION_value(alg->impls, j);
 458         score = ossl_property_match_count(pq, impl->properties);
 459         if (score > best) {
 460             best_method = &impl->method;
 461             best = score;
 462             ret = 1;
 463             if (!optional)
 464                 goto fin;
 465         }
 466     }
 467 fin:
 468     if (ret && ossl_method_up_ref(best_method))
 469         *method = best_method->method;
 470     else
 471         ret = 0;
 472     ossl_property_unlock(store);
 473     ossl_property_free(p2);
 474     return ret;
 475 }
 476
 477 static void impl_cache_flush_alg(ossl_uintmax_t idx, ALGORITHM *alg, void *arg)
 478 {
 479     SPARSE_ARRAY_OF(ALGORITHM) *algs = arg;
 480
 481     lh_QUERY_doall(alg->cache, &impl_cache_free);
 482     if (algs != NULL) {
 483         sk_IMPLEMENTATION_pop_free(alg->impls, &impl_free);
 484         lh_QUERY_free(alg->cache);
 485         OPENSSL_free(alg);
 486         ossl_sa_ALGORITHM_set(algs, idx, NULL);
 487     } else {
 488         lh_QUERY_flush(alg->cache);
 489     }
 490 }
 491
 492 static void ossl_method_cache_flush(OSSL_METHOD_STORE *store, int nid)
 493 {
 494     ALGORITHM *alg = ossl_method_store_retrieve(store, nid);
 495
 496     if (alg != NULL) {
 497         ossl_provider_clear_all_operation_bits(store->ctx);
 498         store->nelem -= lh_QUERY_num_items(alg->cache);
 499         impl_cache_flush_alg(0, alg, NULL);
 500     }
 501 }
 502
 503 int ossl_method_store_flush_cache(OSSL_METHOD_STORE *store, int all)
 504 {
 505     void *arg = (all != 0 ? store->algs : NULL);
 506
 507     if (!ossl_property_write_lock(store))
 508         return 0;
 509     ossl_provider_clear_all_operation_bits(store->ctx);
 510     ossl_sa_ALGORITHM_doall_arg(store->algs, &impl_cache_flush_alg, arg);
 511     store->nelem = 0;
 512     ossl_property_unlock(store);
 513     return 1;
 514 }
 515
 516 IMPLEMENT_LHASH_DOALL_ARG(QUERY, IMPL_CACHE_FLUSH);
 517
 518 /*
 519  * Flush an element from the query cache (perhaps).
 520  *
 521  * In order to avoid taking a write lock or using atomic operations
 522  * to keep accurate least recently used (LRU) or least frequently used
 523  * (LFU) information, the procedure used here is to stochastically
 524  * flush approximately half the cache.
 525  *
 526  * This procedure isn't ideal, LRU or LFU would be better.  However,
 527  * in normal operation, reaching a full cache would be unexpected.
 528  * It means that no steady state of algorithm queries has been reached.
 529  * That is, it is most likely an attack of some form.  A suboptimal clearance
 530  * strategy that doesn't degrade performance of the normal case is
 531  * preferable to a more refined approach that imposes a performance
 532  * impact.
 533  */
 534 static void impl_cache_flush_cache(QUERY *c, IMPL_CACHE_FLUSH *state)
 535 {
 536     uint32_t n;
 537
 538     /*
 539      * Implement the 32 bit xorshift as suggested by George Marsaglia in:
 540      *      https://doi.org/10.18637/jss.v008.i14
 541      *
 542      * This is a very fast PRNG so there is no need to extract bits one at a
 543      * time and use the entire value each time.
 544      */
 545     n = state->seed;
 546     n ^= n << 13;
 547     n ^= n >> 17;
 548     n ^= n << 5;
 549     state->seed = n;
 550
 551     if ((n & 1) != 0)
 552         impl_cache_free(lh_QUERY_delete(state->cache, c));
 553     else
 554         state->nelem++;
 555 }
 556
 557 static void impl_cache_flush_one_alg(ossl_uintmax_t idx, ALGORITHM *alg,
 558                                      void *v)
 559 {
 560     IMPL_CACHE_FLUSH *state = (IMPL_CACHE_FLUSH *)v;
 561
 562     state->cache = alg->cache;
 563     lh_QUERY_doall_IMPL_CACHE_FLUSH(state->cache, &impl_cache_flush_cache,
 564                                     state);
 565 }
 566
 567 static void ossl_method_cache_flush_some(OSSL_METHOD_STORE *store)
 568 {
 569     IMPL_CACHE_FLUSH state;
 570
 571     state.nelem = 0;
 572     if ((state.seed = OPENSSL_rdtsc()) == 0)
 573         state.seed = 1;
 574     ossl_provider_clear_all_operation_bits(store->ctx);
 575     store->need_flush = 0;
 576     ossl_sa_ALGORITHM_doall_arg(store->algs, &impl_cache_flush_one_alg, &state);
 577     store->nelem = state.nelem;
 578 }
 579
 580 int ossl_method_store_cache_get(OSSL_METHOD_STORE *store, int nid,
 581                                 const char *prop_query, void **method)
 582 {
 583     ALGORITHM *alg;
 584     QUERY elem, *r;
 585     int res = 0;
 586
 587     if (nid <= 0 || store == NULL)
 588         return 0;
 589
 590     if (!ossl_property_read_lock(store))
 591         return 0;
 592     alg = ossl_method_store_retrieve(store, nid);
 593     if (alg == NULL)
 594         goto err;
 595
 596     elem.query = prop_query != NULL ? prop_query : "";
 597     r = lh_QUERY_retrieve(alg->cache, &elem);
 598     if (r == NULL)
 599         goto err;
 600     if (ossl_method_up_ref(&r->method)) {
 601         *method = r->method.method;
 602         res = 1;
 603     }
 604 err:
 605     ossl_property_unlock(store);
 606     return res;
 607 }
 608
 609 int ossl_method_store_cache_set(OSSL_METHOD_STORE *store, int nid,
 610                                 const char *prop_query, void *method,
 611                                 int (*method_up_ref)(void *),
 612                                 void (*method_destruct)(void *))
 613 {
 614     QUERY elem, *old, *p = NULL;
 615     ALGORITHM *alg;
 616     size_t len;
 617     int res = 1;
 618
 619     if (nid <= 0 || store == NULL)
 620         return 0;
 621     if (prop_query == NULL)
 622         return 1;
 623
 624     if (!ossl_property_write_lock(store))
 625         return 0;
 626     if (store->need_flush)
 627         ossl_method_cache_flush_some(store);
 628     alg = ossl_method_store_retrieve(store, nid);
 629     if (alg == NULL)
 630         goto err;
 631
 632     if (method == NULL) {
 633         elem.query = prop_query;
 634         if ((old = lh_QUERY_delete(alg->cache, &elem)) != NULL) {
 635             impl_cache_free(old);
 636             store->nelem--;
 637         }
 638         goto end;
 639     }
 640     p = OPENSSL_malloc(sizeof(*p) + (len = strlen(prop_query)));
 641     if (p != NULL) {
 642         p->query = p->body;
 643         p->method.method = method;
 644         p->method.up_ref = method_up_ref;
 645         p->method.free = method_destruct;
 646         if (!ossl_method_up_ref(&p->method))
 647             goto err;
 648         memcpy((char *)p->query, prop_query, len + 1);
 649         if ((old = lh_QUERY_insert(alg->cache, p)) != NULL) {
 650             impl_cache_free(old);
 651             goto end;
 652         }
 653         if (!lh_QUERY_error(alg->cache)) {
 654             if (++store->nelem >= IMPL_CACHE_FLUSH_THRESHOLD)
 655                 store->need_flush = 1;
 656             goto end;
 657         }
 658         ossl_method_free(&p->method);
 659     }
 660 err:
 661     res = 0;
 662     OPENSSL_free(p);
 663 end:
 664     ossl_property_unlock(store);
 665     return res;
 666 }