2 * Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
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
14 #include <openssl/crypto.h>
15 #include "internal/property.h"
16 #include "crypto/ctype.h"
17 #include <openssl/lhash.h>
18 #include <openssl/rand.h>
19 #include "internal/thread_once.h"
20 #include "crypto/lhash.h"
21 #include "crypto/sparse_array.h"
22 #include "property_local.h"
25 * The number of elements in the query cache before we initiate a flush.
26 * If reducing this, also ensure the stochastic test in test/property_test.c
27 * isn't likely to fail.
29 #define IMPL_CACHE_FLUSH_THRESHOLD 500
33 int (*up_ref)(void *);
38 const OSSL_PROVIDER *provider;
39 OSSL_PROPERTY_LIST *properties;
43 DEFINE_STACK_OF(IMPLEMENTATION)
51 DEFINE_LHASH_OF(QUERY);
55 STACK_OF(IMPLEMENTATION) *impls;
56 LHASH_OF(QUERY) *cache;
59 struct ossl_method_store_st {
62 SPARSE_ARRAY_OF(ALGORITHM) *algs;
68 LHASH_OF(QUERY) *cache;
73 DEFINE_SPARSE_ARRAY_OF(ALGORITHM);
75 static void ossl_method_cache_flush(OSSL_METHOD_STORE *store, int nid);
77 /* Global properties are stored per library context */
78 static void ossl_ctx_global_properties_free(void *vstore)
80 OSSL_PROPERTY_LIST **plp = vstore;
83 ossl_property_free(*plp);
88 static void *ossl_ctx_global_properties_new(OSSL_LIB_CTX *ctx)
90 return OPENSSL_zalloc(sizeof(OSSL_PROPERTY_LIST **));
94 static const OSSL_LIB_CTX_METHOD ossl_ctx_global_properties_method = {
95 ossl_ctx_global_properties_new,
96 ossl_ctx_global_properties_free,
99 OSSL_PROPERTY_LIST **ossl_ctx_global_properties(OSSL_LIB_CTX *libctx,
103 if (loadconfig && !OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CONFIG, NULL))
106 return ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_GLOBAL_PROPERTIES,
107 &ossl_ctx_global_properties_method);
110 static int ossl_method_up_ref(METHOD *method)
112 return (*method->up_ref)(method->method);
115 static void ossl_method_free(METHOD *method)
117 (*method->free)(method->method);
120 int ossl_property_read_lock(OSSL_METHOD_STORE *p)
122 return p != NULL ? CRYPTO_THREAD_read_lock(p->lock) : 0;
125 int ossl_property_write_lock(OSSL_METHOD_STORE *p)
127 return p != NULL ? CRYPTO_THREAD_write_lock(p->lock) : 0;
130 int ossl_property_unlock(OSSL_METHOD_STORE *p)
132 return p != 0 ? CRYPTO_THREAD_unlock(p->lock) : 0;
135 static unsigned long query_hash(const QUERY *a)
137 return OPENSSL_LH_strhash(a->query);
140 static int query_cmp(const QUERY *a, const QUERY *b)
142 return strcmp(a->query, b->query);
145 static void impl_free(IMPLEMENTATION *impl)
148 ossl_method_free(&impl->method);
153 static void impl_cache_free(QUERY *elem)
156 ossl_method_free(&elem->method);
161 static void alg_cleanup(ossl_uintmax_t idx, ALGORITHM *a)
164 sk_IMPLEMENTATION_pop_free(a->impls, &impl_free);
165 lh_QUERY_doall(a->cache, &impl_cache_free);
166 lh_QUERY_free(a->cache);
172 * The OSSL_LIB_CTX param here allows access to underlying property data needed
175 OSSL_METHOD_STORE *ossl_method_store_new(OSSL_LIB_CTX *ctx)
177 OSSL_METHOD_STORE *res;
179 res = OPENSSL_zalloc(sizeof(*res));
182 if ((res->algs = ossl_sa_ALGORITHM_new()) == NULL) {
186 if ((res->lock = CRYPTO_THREAD_lock_new()) == NULL) {
187 ossl_sa_ALGORITHM_free(res->algs);
195 void ossl_method_store_free(OSSL_METHOD_STORE *store)
198 ossl_sa_ALGORITHM_doall(store->algs, &alg_cleanup);
199 ossl_sa_ALGORITHM_free(store->algs);
200 CRYPTO_THREAD_lock_free(store->lock);
205 static ALGORITHM *ossl_method_store_retrieve(OSSL_METHOD_STORE *store, int nid)
207 return ossl_sa_ALGORITHM_get(store->algs, nid);
210 static int ossl_method_store_insert(OSSL_METHOD_STORE *store, ALGORITHM *alg)
212 return ossl_sa_ALGORITHM_set(store->algs, alg->nid, alg);
215 int ossl_method_store_add(OSSL_METHOD_STORE *store, const OSSL_PROVIDER *prov,
216 int nid, const char *properties, void *method,
217 int (*method_up_ref)(void *),
218 void (*method_destruct)(void *))
220 ALGORITHM *alg = NULL;
221 IMPLEMENTATION *impl;
225 if (nid <= 0 || method == NULL || store == NULL)
227 if (properties == NULL)
230 /* Create new entry */
231 impl = OPENSSL_malloc(sizeof(*impl));
234 impl->method.method = method;
235 impl->method.up_ref = method_up_ref;
236 impl->method.free = method_destruct;
237 if (!ossl_method_up_ref(&impl->method)) {
241 impl->provider = prov;
244 * Insert into the hash table if required.
246 * A write lock is used unconditionally because we wend our way down to the
247 * property string code which isn't locking friendly.
249 ossl_property_write_lock(store);
250 ossl_method_cache_flush(store, nid);
251 if ((impl->properties = ossl_prop_defn_get(store->ctx, properties)) == NULL) {
252 impl->properties = ossl_parse_property(store->ctx, properties);
253 if (impl->properties == NULL)
255 ossl_prop_defn_set(store->ctx, properties, impl->properties);
258 alg = ossl_method_store_retrieve(store, nid);
260 if ((alg = OPENSSL_zalloc(sizeof(*alg))) == NULL
261 || (alg->impls = sk_IMPLEMENTATION_new_null()) == NULL
262 || (alg->cache = lh_QUERY_new(&query_hash, &query_cmp)) == NULL)
265 if (!ossl_method_store_insert(store, alg))
269 /* Push onto stack if there isn't one there already */
270 for (i = 0; i < sk_IMPLEMENTATION_num(alg->impls); i++) {
271 const IMPLEMENTATION *tmpimpl = sk_IMPLEMENTATION_value(alg->impls, i);
273 if (tmpimpl->provider == impl->provider
274 && tmpimpl->properties == impl->properties)
277 if (i == sk_IMPLEMENTATION_num(alg->impls)
278 && sk_IMPLEMENTATION_push(alg->impls, impl))
280 ossl_property_unlock(store);
286 ossl_property_unlock(store);
292 int ossl_method_store_remove(OSSL_METHOD_STORE *store, int nid,
295 ALGORITHM *alg = NULL;
298 if (nid <= 0 || method == NULL || store == NULL)
301 ossl_property_write_lock(store);
302 ossl_method_cache_flush(store, nid);
303 alg = ossl_method_store_retrieve(store, nid);
305 ossl_property_unlock(store);
310 * A sorting find then a delete could be faster but these stacks should be
311 * relatively small, so we avoid the overhead. Sorting could also surprise
312 * users when result orderings change (even though they are not guaranteed).
314 for (i = 0; i < sk_IMPLEMENTATION_num(alg->impls); i++) {
315 IMPLEMENTATION *impl = sk_IMPLEMENTATION_value(alg->impls, i);
317 if (impl->method.method == method) {
319 (void)sk_IMPLEMENTATION_delete(alg->impls, i);
320 ossl_property_unlock(store);
324 ossl_property_unlock(store);
328 int ossl_method_store_fetch(OSSL_METHOD_STORE *store, int nid,
329 const char *prop_query,
332 OSSL_PROPERTY_LIST **plp;
334 IMPLEMENTATION *impl;
335 OSSL_PROPERTY_LIST *pq = NULL, *p2 = NULL;
336 METHOD *best_method = NULL;
338 int j, best = -1, score, optional;
341 OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CONFIG, NULL);
344 if (nid <= 0 || method == NULL || store == NULL)
348 * This only needs to be a read lock, because queries never create property
349 * names or value and thus don't modify any of the property string layer.
351 ossl_property_read_lock(store);
352 alg = ossl_method_store_retrieve(store, nid);
354 ossl_property_unlock(store);
358 if (prop_query != NULL)
359 p2 = pq = ossl_parse_query(store->ctx, prop_query);
360 plp = ossl_ctx_global_properties(store->ctx, 1);
361 if (plp != NULL && *plp != NULL) {
365 p2 = ossl_property_merge(pq, *plp);
366 ossl_property_free(pq);
374 if ((impl = sk_IMPLEMENTATION_value(alg->impls, 0)) != NULL) {
375 best_method = &impl->method;
380 optional = ossl_property_has_optional(pq);
381 for (j = 0; j < sk_IMPLEMENTATION_num(alg->impls); j++) {
382 impl = sk_IMPLEMENTATION_value(alg->impls, j);
383 score = ossl_property_match_count(pq, impl->properties);
385 best_method = &impl->method;
393 if (ret && ossl_method_up_ref(best_method))
394 *method = best_method->method;
397 ossl_property_unlock(store);
398 ossl_property_free(p2);
402 static void impl_cache_flush_alg(ossl_uintmax_t idx, ALGORITHM *alg, void *arg)
404 SPARSE_ARRAY_OF(ALGORITHM) *algs = arg;
406 lh_QUERY_doall(alg->cache, &impl_cache_free);
408 sk_IMPLEMENTATION_pop_free(alg->impls, &impl_free);
409 lh_QUERY_free(alg->cache);
411 ossl_sa_ALGORITHM_set(algs, idx, NULL);
413 lh_QUERY_flush(alg->cache);
417 static void ossl_method_cache_flush(OSSL_METHOD_STORE *store, int nid)
419 ALGORITHM *alg = ossl_method_store_retrieve(store, nid);
422 store->nelem -= lh_QUERY_num_items(alg->cache);
423 impl_cache_flush_alg(0, alg, NULL);
427 void ossl_method_store_flush_cache(OSSL_METHOD_STORE *store, int all)
429 void *arg = (all != 0 ? store->algs : NULL);
431 ossl_property_write_lock(store);
432 ossl_sa_ALGORITHM_doall_arg(store->algs, &impl_cache_flush_alg, arg);
434 ossl_property_unlock(store);
437 IMPLEMENT_LHASH_DOALL_ARG(QUERY, IMPL_CACHE_FLUSH);
440 * Flush an element from the query cache (perhaps).
442 * In order to avoid taking a write lock or using atomic operations
443 * to keep accurate least recently used (LRU) or least frequently used
444 * (LFU) information, the procedure used here is to stochastically
445 * flush approximately half the cache.
447 * This procedure isn't ideal, LRU or LFU would be better. However,
448 * in normal operation, reaching a full cache would be unexpected.
449 * It means that no steady state of algorithm queries has been reached.
450 * That is, it is most likely an attack of some form. A suboptimal clearance
451 * strategy that doesn't degrade performance of the normal case is
452 * preferable to a more refined approach that imposes a performance
455 static void impl_cache_flush_cache(QUERY *c, IMPL_CACHE_FLUSH *state)
460 * Implement the 32 bit xorshift as suggested by George Marsaglia in:
461 * https://doi.org/10.18637/jss.v008.i14
463 * This is a very fast PRNG so there is no need to extract bits one at a
464 * time and use the entire value each time.
473 impl_cache_free(lh_QUERY_delete(state->cache, c));
478 static void impl_cache_flush_one_alg(ossl_uintmax_t idx, ALGORITHM *alg,
481 IMPL_CACHE_FLUSH *state = (IMPL_CACHE_FLUSH *)v;
483 state->cache = alg->cache;
484 lh_QUERY_doall_IMPL_CACHE_FLUSH(state->cache, &impl_cache_flush_cache,
488 static void ossl_method_cache_flush_some(OSSL_METHOD_STORE *store)
490 IMPL_CACHE_FLUSH state;
493 if ((state.seed = OPENSSL_rdtsc()) == 0)
495 store->need_flush = 0;
496 ossl_sa_ALGORITHM_doall_arg(store->algs, &impl_cache_flush_one_alg, &state);
497 store->nelem = state.nelem;
500 int ossl_method_store_cache_get(OSSL_METHOD_STORE *store, int nid,
501 const char *prop_query, void **method)
507 if (nid <= 0 || store == NULL)
510 ossl_property_read_lock(store);
511 alg = ossl_method_store_retrieve(store, nid);
515 elem.query = prop_query != NULL ? prop_query : "";
516 r = lh_QUERY_retrieve(alg->cache, &elem);
519 if (ossl_method_up_ref(&r->method)) {
520 *method = r->method.method;
524 ossl_property_unlock(store);
528 int ossl_method_store_cache_set(OSSL_METHOD_STORE *store, int nid,
529 const char *prop_query, void *method,
530 int (*method_up_ref)(void *),
531 void (*method_destruct)(void *))
533 QUERY elem, *old, *p = NULL;
538 if (nid <= 0 || store == NULL)
540 if (prop_query == NULL)
543 ossl_property_write_lock(store);
544 if (store->need_flush)
545 ossl_method_cache_flush_some(store);
546 alg = ossl_method_store_retrieve(store, nid);
550 if (method == NULL) {
551 elem.query = prop_query;
552 if ((old = lh_QUERY_delete(alg->cache, &elem)) != NULL) {
553 impl_cache_free(old);
558 p = OPENSSL_malloc(sizeof(*p) + (len = strlen(prop_query)));
561 p->method.method = method;
562 p->method.up_ref = method_up_ref;
563 p->method.free = method_destruct;
564 if (!ossl_method_up_ref(&p->method))
566 memcpy((char *)p->query, prop_query, len + 1);
567 if ((old = lh_QUERY_insert(alg->cache, p)) != NULL) {
568 impl_cache_free(old);
571 if (!lh_QUERY_error(alg->cache)) {
572 if (++store->nelem >= IMPL_CACHE_FLUSH_THRESHOLD)
573 store->need_flush = 1;
576 ossl_method_free(&p->method);
582 ossl_property_unlock(store);