2 * Copyright 2019 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;
63 OSSL_PROPERTY_LIST *global_properties;
69 LHASH_OF(QUERY) *cache;
74 DEFINE_SPARSE_ARRAY_OF(ALGORITHM);
76 static void ossl_method_cache_flush(OSSL_METHOD_STORE *store, int nid);
77 static void ossl_method_cache_flush_all(OSSL_METHOD_STORE *c);
79 static int ossl_method_up_ref(METHOD *method)
81 return (*method->up_ref)(method->method);
84 static void ossl_method_free(METHOD *method)
86 (*method->free)(method->method);
89 int ossl_property_read_lock(OSSL_METHOD_STORE *p)
91 return p != NULL ? CRYPTO_THREAD_read_lock(p->lock) : 0;
94 int ossl_property_write_lock(OSSL_METHOD_STORE *p)
96 return p != NULL ? CRYPTO_THREAD_write_lock(p->lock) : 0;
99 int ossl_property_unlock(OSSL_METHOD_STORE *p)
101 return p != 0 ? CRYPTO_THREAD_unlock(p->lock) : 0;
104 static unsigned long query_hash(const QUERY *a)
106 return OPENSSL_LH_strhash(a->query);
109 static int query_cmp(const QUERY *a, const QUERY *b)
111 return strcmp(a->query, b->query);
114 static void impl_free(IMPLEMENTATION *impl)
117 ossl_method_free(&impl->method);
122 static void impl_cache_free(QUERY *elem)
125 ossl_method_free(&elem->method);
130 static void alg_cleanup(ossl_uintmax_t idx, ALGORITHM *a)
133 sk_IMPLEMENTATION_pop_free(a->impls, &impl_free);
134 lh_QUERY_doall(a->cache, &impl_cache_free);
135 lh_QUERY_free(a->cache);
141 * The OPENSSL_CTX param here allows access to underlying property data needed
144 OSSL_METHOD_STORE *ossl_method_store_new(OPENSSL_CTX *ctx)
146 OSSL_METHOD_STORE *res;
148 res = OPENSSL_zalloc(sizeof(*res));
151 if ((res->algs = ossl_sa_ALGORITHM_new()) == NULL) {
155 if ((res->lock = CRYPTO_THREAD_lock_new()) == NULL) {
156 ossl_sa_ALGORITHM_free(res->algs);
164 void ossl_method_store_free(OSSL_METHOD_STORE *store)
167 ossl_sa_ALGORITHM_doall(store->algs, &alg_cleanup);
168 ossl_sa_ALGORITHM_free(store->algs);
169 ossl_property_free(store->global_properties);
170 CRYPTO_THREAD_lock_free(store->lock);
175 static ALGORITHM *ossl_method_store_retrieve(OSSL_METHOD_STORE *store, int nid)
177 return ossl_sa_ALGORITHM_get(store->algs, nid);
180 static int ossl_method_store_insert(OSSL_METHOD_STORE *store, ALGORITHM *alg)
182 return ossl_sa_ALGORITHM_set(store->algs, alg->nid, alg);
185 int ossl_method_store_add(OSSL_METHOD_STORE *store, const OSSL_PROVIDER *prov,
186 int nid, const char *properties, void *method,
187 int (*method_up_ref)(void *),
188 void (*method_destruct)(void *))
190 ALGORITHM *alg = NULL;
191 IMPLEMENTATION *impl;
195 if (nid <= 0 || method == NULL || store == NULL)
197 if (properties == NULL)
200 /* Create new entry */
201 impl = OPENSSL_malloc(sizeof(*impl));
204 impl->method.method = method;
205 impl->method.up_ref = method_up_ref;
206 impl->method.free = method_destruct;
207 if (!ossl_method_up_ref(&impl->method)) {
211 impl->provider = prov;
214 * Insert into the hash table if required.
216 * A write lock is used unconditionally because we wend our way down to the
217 * property string code which isn't locking friendly.
219 ossl_property_write_lock(store);
220 ossl_method_cache_flush(store, nid);
221 if ((impl->properties = ossl_prop_defn_get(store->ctx, properties)) == NULL) {
222 impl->properties = ossl_parse_property(store->ctx, properties);
223 if (impl->properties == NULL)
225 ossl_prop_defn_set(store->ctx, properties, impl->properties);
228 alg = ossl_method_store_retrieve(store, nid);
230 if ((alg = OPENSSL_zalloc(sizeof(*alg))) == NULL
231 || (alg->impls = sk_IMPLEMENTATION_new_null()) == NULL
232 || (alg->cache = lh_QUERY_new(&query_hash, &query_cmp)) == NULL)
235 if (!ossl_method_store_insert(store, alg))
239 /* Push onto stack if there isn't one there already */
240 for (i = 0; i < sk_IMPLEMENTATION_num(alg->impls); i++) {
241 const IMPLEMENTATION *tmpimpl = sk_IMPLEMENTATION_value(alg->impls, i);
243 if (tmpimpl->provider == impl->provider
244 && tmpimpl->properties == impl->properties)
247 if (i == sk_IMPLEMENTATION_num(alg->impls)
248 && sk_IMPLEMENTATION_push(alg->impls, impl))
250 ossl_property_unlock(store);
256 ossl_property_unlock(store);
262 int ossl_method_store_remove(OSSL_METHOD_STORE *store, int nid,
265 ALGORITHM *alg = NULL;
268 if (nid <= 0 || method == NULL || store == NULL)
271 ossl_property_write_lock(store);
272 ossl_method_cache_flush(store, nid);
273 alg = ossl_method_store_retrieve(store, nid);
275 ossl_property_unlock(store);
280 * A sorting find then a delete could be faster but these stacks should be
281 * relatively small, so we avoid the overhead. Sorting could also surprise
282 * users when result orderings change (even though they are not guaranteed).
284 for (i = 0; i < sk_IMPLEMENTATION_num(alg->impls); i++) {
285 IMPLEMENTATION *impl = sk_IMPLEMENTATION_value(alg->impls, i);
287 if (impl->method.method == method) {
289 sk_IMPLEMENTATION_delete(alg->impls, i);
290 ossl_property_unlock(store);
294 ossl_property_unlock(store);
298 int ossl_method_store_fetch(OSSL_METHOD_STORE *store, int nid,
299 const char *prop_query, void **method)
302 IMPLEMENTATION *impl;
303 OSSL_PROPERTY_LIST *pq = NULL, *p2;
304 METHOD *best_method = NULL;
306 int j, best = -1, score, optional;
309 OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CONFIG, NULL);
312 if (nid <= 0 || method == NULL || store == NULL)
316 * This only needs to be a read lock, because queries never create property
317 * names or value and thus don't modify any of the property string layer.
319 ossl_property_read_lock(store);
320 alg = ossl_method_store_retrieve(store, nid);
322 ossl_property_unlock(store);
326 if (prop_query == NULL) {
327 if ((impl = sk_IMPLEMENTATION_value(alg->impls, 0)) != NULL) {
328 best_method = &impl->method;
333 pq = ossl_parse_query(store->ctx, prop_query);
336 if (store->global_properties != NULL) {
337 p2 = ossl_property_merge(pq, store->global_properties);
340 ossl_property_free(pq);
343 optional = ossl_property_has_optional(pq);
344 for (j = 0; j < sk_IMPLEMENTATION_num(alg->impls); j++) {
345 impl = sk_IMPLEMENTATION_value(alg->impls, j);
346 score = ossl_property_match_count(pq, impl->properties);
348 best_method = &impl->method;
356 if (ret && ossl_method_up_ref(best_method))
357 *method = best_method->method;
360 ossl_property_unlock(store);
361 ossl_property_free(pq);
365 int ossl_method_store_set_global_properties(OSSL_METHOD_STORE *store,
366 const char *prop_query) {
372 ossl_property_write_lock(store);
373 ossl_method_cache_flush_all(store);
374 if (prop_query == NULL) {
375 ossl_property_free(store->global_properties);
376 store->global_properties = NULL;
377 ossl_property_unlock(store);
380 store->global_properties = ossl_parse_query(store->ctx, prop_query);
381 ret = store->global_properties != NULL;
382 ossl_property_unlock(store);
386 static void impl_cache_flush_alg(ossl_uintmax_t idx, ALGORITHM *alg)
388 lh_QUERY_doall(alg->cache, &impl_cache_free);
389 lh_QUERY_flush(alg->cache);
392 static void ossl_method_cache_flush(OSSL_METHOD_STORE *store, int nid)
394 ALGORITHM *alg = ossl_method_store_retrieve(store, nid);
397 store->nelem -= lh_QUERY_num_items(alg->cache);
398 impl_cache_flush_alg(0, alg);
402 static void ossl_method_cache_flush_all(OSSL_METHOD_STORE *store)
404 ossl_sa_ALGORITHM_doall(store->algs, &impl_cache_flush_alg);
408 IMPLEMENT_LHASH_DOALL_ARG(QUERY, IMPL_CACHE_FLUSH);
411 * Flush an element from the query cache (perhaps).
413 * In order to avoid taking a write lock or using atomic operations
414 * to keep accurate least recently used (LRU) or least frequently used
415 * (LFU) information, the procedure used here is to stochastically
416 * flush approximately half the cache.
418 * This procedure isn't ideal, LRU or LFU would be better. However,
419 * in normal operation, reaching a full cache would be unexpected.
420 * It means that no steady state of algorithm queries has been reached.
421 * That is, it is most likely an attack of some form. A suboptimal clearance
422 * strategy that doesn't degrade performance of the normal case is
423 * preferable to a more refined approach that imposes a performance
426 static void impl_cache_flush_cache(QUERY *c, IMPL_CACHE_FLUSH *state)
431 * Implement the 32 bit xorshift as suggested by George Marsaglia in:
432 * https://doi.org/10.18637/jss.v008.i14
434 * This is a very fast PRNG so there is no need to extract bits one at a
435 * time and use the entire value each time.
444 impl_cache_free(lh_QUERY_delete(state->cache, c));
449 static void impl_cache_flush_one_alg(ossl_uintmax_t idx, ALGORITHM *alg,
452 IMPL_CACHE_FLUSH *state = (IMPL_CACHE_FLUSH *)v;
454 state->cache = alg->cache;
455 lh_QUERY_doall_IMPL_CACHE_FLUSH(state->cache, &impl_cache_flush_cache,
459 static void ossl_method_cache_flush_some(OSSL_METHOD_STORE *store)
461 IMPL_CACHE_FLUSH state;
464 if ((state.seed = OPENSSL_rdtsc()) == 0)
466 store->need_flush = 0;
467 ossl_sa_ALGORITHM_doall_arg(store->algs, &impl_cache_flush_one_alg, &state);
468 store->nelem = state.nelem;
471 int ossl_method_store_cache_get(OSSL_METHOD_STORE *store, int nid,
472 const char *prop_query, void **method)
478 if (nid <= 0 || store == NULL)
481 ossl_property_read_lock(store);
482 alg = ossl_method_store_retrieve(store, nid);
486 elem.query = prop_query != NULL ? prop_query : "";
487 r = lh_QUERY_retrieve(alg->cache, &elem);
490 if (ossl_method_up_ref(&r->method)) {
491 *method = r->method.method;
495 ossl_property_unlock(store);
499 int ossl_method_store_cache_set(OSSL_METHOD_STORE *store, int nid,
500 const char *prop_query, void *method,
501 int (*method_up_ref)(void *),
502 void (*method_destruct)(void *))
504 QUERY elem, *old, *p = NULL;
509 if (nid <= 0 || store == NULL)
511 if (prop_query == NULL)
514 ossl_property_write_lock(store);
515 if (store->need_flush)
516 ossl_method_cache_flush_some(store);
517 alg = ossl_method_store_retrieve(store, nid);
521 if (method == NULL) {
522 elem.query = prop_query;
523 if ((old = lh_QUERY_delete(alg->cache, &elem)) != NULL) {
524 impl_cache_free(old);
529 p = OPENSSL_malloc(sizeof(*p) + (len = strlen(prop_query)));
532 p->method.method = method;
533 p->method.up_ref = method_up_ref;
534 p->method.free = method_destruct;
535 if (!ossl_method_up_ref(&p->method))
537 memcpy((char *)p->query, prop_query, len + 1);
538 if ((old = lh_QUERY_insert(alg->cache, p)) != NULL) {
539 impl_cache_free(old);
542 if (!lh_QUERY_error(alg->cache)) {
543 if (++store->nelem >= IMPL_CACHE_FLUSH_THRESHOLD)
544 store->need_flush = 1;
547 ossl_method_free(&p->method);
553 ossl_property_unlock(store);