openssl/crypto/property/property.c
Pauli 8ab53b193a Make the sparse array code use ossl_uintmax_t as its index rather than size_t.
This should never reduce the range covered and might increase it on some
platforms.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8415)
2019-03-06 13:50:54 +10:00

510 lines
14 KiB
C

/*
* Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <string.h>
#include <stdio.h>
#include <stdarg.h>
#include <openssl/crypto.h>
#include "internal/property.h"
#include "internal/ctype.h"
#include <openssl/lhash.h>
#include <openssl/rand.h>
#include "internal/thread_once.h"
#include "internal/lhash.h"
#include "internal/sparse_array.h"
#include "property_lcl.h"
/* The number of elements in the query cache before we initiate a flush */
#define IMPL_CACHE_FLUSH_THRESHOLD 500
typedef struct {
OSSL_PROPERTY_LIST *properties;
void *method;
void (*method_destruct)(void *);
} IMPLEMENTATION;
DEFINE_STACK_OF(IMPLEMENTATION)
typedef struct {
const char *query;
void *method;
char body[1];
} QUERY;
DEFINE_LHASH_OF(QUERY);
typedef struct {
int nid;
STACK_OF(IMPLEMENTATION) *impls;
LHASH_OF(QUERY) *cache;
} ALGORITHM;
struct ossl_method_store_st {
size_t nelem;
SPARSE_ARRAY_OF(ALGORITHM) *algs;
OSSL_PROPERTY_LIST *global_properties;
int need_flush;
unsigned int nbits;
unsigned char rand_bits[(IMPL_CACHE_FLUSH_THRESHOLD + 7) / 8];
CRYPTO_RWLOCK *lock;
};
typedef struct {
OSSL_METHOD_STORE *store;
LHASH_OF(QUERY) *cache;
size_t nelem;
} IMPL_CACHE_FLUSH;
DEFINE_SPARSE_ARRAY_OF(ALGORITHM);
static void ossl_method_cache_flush(OSSL_METHOD_STORE *store, int nid);
static void ossl_method_cache_flush_all(OSSL_METHOD_STORE *c);
int ossl_property_read_lock(OSSL_METHOD_STORE *p)
{
return p != NULL ? CRYPTO_THREAD_read_lock(p->lock) : 0;
}
int ossl_property_write_lock(OSSL_METHOD_STORE *p)
{
return p != NULL ? CRYPTO_THREAD_write_lock(p->lock) : 0;
}
int ossl_property_unlock(OSSL_METHOD_STORE *p)
{
return p != 0 ? CRYPTO_THREAD_unlock(p->lock) : 0;
}
int ossl_method_store_init(void)
{
if (ossl_property_string_init()
&& ossl_prop_defn_init()
&& ossl_property_parse_init())
return 1;
ossl_method_store_cleanup();
return 0;
}
void ossl_method_store_cleanup(void)
{
ossl_property_string_cleanup();
ossl_prop_defn_cleanup();
}
static CRYPTO_ONCE method_store_init_flag = CRYPTO_ONCE_STATIC_INIT;
DEFINE_RUN_ONCE_STATIC(do_method_store_init)
{
return OPENSSL_init_crypto(0, NULL)
&& ossl_method_store_init()
&& OPENSSL_atexit(&ossl_method_store_cleanup);
}
static unsigned long query_hash(const QUERY *a)
{
return OPENSSL_LH_strhash(a->query);
}
static int query_cmp(const QUERY *a, const QUERY *b)
{
return strcmp(a->query, b->query);
}
static void impl_free(IMPLEMENTATION *impl)
{
if (impl != NULL) {
if (impl->method_destruct)
impl->method_destruct(impl->method);
OPENSSL_free(impl);
}
}
static void impl_cache_free(QUERY *elem)
{
OPENSSL_free(elem);
}
static void alg_cleanup(ossl_uintmax_t idx, ALGORITHM *a)
{
if (a != NULL) {
sk_IMPLEMENTATION_pop_free(a->impls, &impl_free);
lh_QUERY_doall(a->cache, &impl_cache_free);
lh_QUERY_free(a->cache);
OPENSSL_free(a);
}
}
OSSL_METHOD_STORE *ossl_method_store_new(void)
{
OSSL_METHOD_STORE *res;
if (!RUN_ONCE(&method_store_init_flag, do_method_store_init))
return 0;
res = OPENSSL_zalloc(sizeof(*res));
if (res != NULL) {
if ((res->algs = ossl_sa_ALGORITHM_new()) == NULL) {
OPENSSL_free(res);
return NULL;
}
if ((res->lock = CRYPTO_THREAD_lock_new()) == NULL) {
OPENSSL_free(res->algs);
OPENSSL_free(res);
return NULL;
}
}
return res;
}
void ossl_method_store_free(OSSL_METHOD_STORE *store)
{
if (store != NULL) {
ossl_sa_ALGORITHM_doall(store->algs, &alg_cleanup);
ossl_sa_ALGORITHM_free(store->algs);
ossl_property_free(store->global_properties);
CRYPTO_THREAD_lock_free(store->lock);
OPENSSL_free(store);
}
}
static ALGORITHM *ossl_method_store_retrieve(OSSL_METHOD_STORE *store, int nid)
{
return ossl_sa_ALGORITHM_get(store->algs, nid);
}
static int ossl_method_store_insert(OSSL_METHOD_STORE *store, ALGORITHM *alg)
{
return ossl_sa_ALGORITHM_set(store->algs, alg->nid, alg);
}
int ossl_method_store_add(OSSL_METHOD_STORE *store,
int nid, const char *properties,
void *method, void (*method_destruct)(void *))
{
ALGORITHM *alg = NULL;
IMPLEMENTATION *impl;
int ret = 0;
if (nid <= 0 || method == NULL || store == NULL)
return 0;
if (properties == NULL)
properties = "";
/* Create new entry */
impl = OPENSSL_malloc(sizeof(*impl));
if (impl == NULL)
return 0;
impl->method = method;
impl->method_destruct = method_destruct;
/*
* Insert into the hash table if required.
*
* A write lock is used unconditionally because we wend our way down to the
* property string code which isn't locking friendly.
*/
ossl_property_write_lock(store);
ossl_method_cache_flush(store, nid);
if ((impl->properties = ossl_prop_defn_get(properties)) == NULL) {
if ((impl->properties = ossl_parse_property(properties)) == NULL)
goto err;
ossl_prop_defn_set(properties, impl->properties);
}
alg = ossl_method_store_retrieve(store, nid);
if (alg == NULL) {
if ((alg = OPENSSL_zalloc(sizeof(*alg))) == NULL
|| (alg->impls = sk_IMPLEMENTATION_new_null()) == NULL
|| (alg->cache = lh_QUERY_new(&query_hash, &query_cmp)) == NULL)
goto err;
alg->nid = nid;
if (!ossl_method_store_insert(store, alg))
goto err;
}
/* Push onto stack */
if (sk_IMPLEMENTATION_push(alg->impls, impl))
ret = 1;
ossl_property_unlock(store);
if (ret == 0)
impl_free(impl);
return ret;
err:
ossl_property_unlock(store);
alg_cleanup(0, alg);
impl_free(impl);
return 0;
}
int ossl_method_store_remove(OSSL_METHOD_STORE *store, int nid,
const void *method)
{
ALGORITHM *alg = NULL;
int i;
if (nid <= 0 || method == NULL || store == NULL)
return 0;
ossl_property_write_lock(store);
ossl_method_cache_flush(store, nid);
alg = ossl_method_store_retrieve(store, nid);
if (alg == NULL) {
ossl_property_unlock(store);
return 0;
}
/*
* A sorting find then a delete could be faster but these stacks should be
* relatively small, so we avoid the overhead. Sorting could also surprise
* users when result orderings change (even though they are not guaranteed).
*/
for (i = 0; i < sk_IMPLEMENTATION_num(alg->impls); i++) {
IMPLEMENTATION *impl = sk_IMPLEMENTATION_value(alg->impls, i);
if (impl->method == method) {
sk_IMPLEMENTATION_delete(alg->impls, i);
ossl_property_unlock(store);
impl_free(impl);
return 1;
}
}
ossl_property_unlock(store);
return 0;
}
int ossl_method_store_fetch(OSSL_METHOD_STORE *store, int nid,
const char *prop_query, void **method)
{
ALGORITHM *alg;
IMPLEMENTATION *impl;
OSSL_PROPERTY_LIST *pq = NULL, *p2;
int ret = 0;
int j;
if (nid <= 0 || method == NULL || store == NULL)
return 0;
/*
* This only needs to be a read lock, because queries never create property
* names or value and thus don't modify any of the property string layer.
*/
ossl_property_read_lock(store);
alg = ossl_method_store_retrieve(store, nid);
if (alg == NULL) {
ossl_property_unlock(store);
return 0;
}
if (prop_query == NULL) {
if ((impl = sk_IMPLEMENTATION_value(alg->impls, 0)) != NULL) {
*method = impl->method;
ret = 1;
}
goto fin;
}
pq = ossl_parse_query(prop_query);
if (pq == NULL)
goto fin;
if (store->global_properties != NULL) {
p2 = ossl_property_merge(pq, store->global_properties);
if (p2 == NULL)
goto fin;
ossl_property_free(pq);
pq = p2;
}
for (j = 0; j < sk_IMPLEMENTATION_num(alg->impls); j++) {
impl = sk_IMPLEMENTATION_value(alg->impls, j);
if (ossl_property_match(pq, impl->properties)) {
*method = impl->method;
ret = 1;
goto fin;
}
}
fin:
ossl_property_unlock(store);
ossl_property_free(pq);
return ret;
}
int ossl_method_store_set_global_properties(OSSL_METHOD_STORE *store,
const char *prop_query) {
int ret = 0;
if (store == NULL)
return 1;
ossl_property_write_lock(store);
ossl_method_cache_flush_all(store);
if (prop_query == NULL) {
ossl_property_free(store->global_properties);
store->global_properties = NULL;
ossl_property_unlock(store);
return 1;
}
store->global_properties = ossl_parse_query(prop_query);
ret = store->global_properties != NULL;
ossl_property_unlock(store);
return ret;
}
static void impl_cache_flush_alg(ossl_uintmax_t idx, ALGORITHM *alg)
{
lh_QUERY_doall(alg->cache, &impl_cache_free);
lh_QUERY_flush(alg->cache);
}
static void ossl_method_cache_flush(OSSL_METHOD_STORE *store, int nid)
{
ALGORITHM *alg = ossl_method_store_retrieve(store, nid);
if (alg != NULL) {
store->nelem -= lh_QUERY_num_items(alg->cache);
impl_cache_flush_alg(0, alg);
}
}
static void ossl_method_cache_flush_all(OSSL_METHOD_STORE *store)
{
ossl_sa_ALGORITHM_doall(store->algs, &impl_cache_flush_alg);
store->nelem = 0;
}
IMPLEMENT_LHASH_DOALL_ARG(QUERY, IMPL_CACHE_FLUSH);
/*
* Flush an element from the query cache (perhaps).
*
* In order to avoid taking a write lock to keep accurate LRU information or
* using atomic operations to approximate similar, the procedure used here
* is to stochastically flush approximately half the cache. Since generating
* random numbers is relatively expensive, we produce them in blocks and
* consume them as we go, saving generated bits between generations of flushes.
*
* This procedure isn't ideal, LRU would be better. However, in normal
* operation, reaching a full cache would be quite unexpected. It means
* that no steady state of algorithm queries has been reached. I.e. it is most
* likely an attack of some form. A suboptimal clearance strategy that doesn't
* degrade performance of the normal case is preferable to a more refined
* approach that imposes a performance impact.
*/
static void impl_cache_flush_cache(QUERY *c, IMPL_CACHE_FLUSH *state)
{
OSSL_METHOD_STORE *store = state->store;
unsigned int n;
if (store->nbits == 0) {
if (!RAND_bytes(store->rand_bits, sizeof(store->rand_bits)))
return;
store->nbits = sizeof(store->rand_bits) * 8;
}
n = --store->nbits;
if ((store->rand_bits[n >> 3] & (1 << (n & 7))) != 0)
OPENSSL_free(lh_QUERY_delete(state->cache, c));
else
state->nelem++;
}
static void impl_cache_flush_one_alg(ossl_uintmax_t idx, ALGORITHM *alg,
void *v)
{
IMPL_CACHE_FLUSH *state = (IMPL_CACHE_FLUSH *)v;
state->cache = alg->cache;
lh_QUERY_doall_IMPL_CACHE_FLUSH(state->cache, &impl_cache_flush_cache,
state);
}
static void ossl_method_cache_flush_some(OSSL_METHOD_STORE *store)
{
IMPL_CACHE_FLUSH state;
state.nelem = 0;
state.store = store;
ossl_sa_ALGORITHM_doall_arg(store->algs, &impl_cache_flush_one_alg, &state);
store->need_flush = 0;
store->nelem = state.nelem;
}
int ossl_method_store_cache_get(OSSL_METHOD_STORE *store, int nid,
const char *prop_query, void **method)
{
ALGORITHM *alg;
QUERY elem, *r;
if (nid <= 0 || store == NULL)
return 0;
ossl_property_read_lock(store);
alg = ossl_method_store_retrieve(store, nid);
if (alg == NULL) {
ossl_property_unlock(store);
return 0;
}
elem.query = prop_query;
r = lh_QUERY_retrieve(alg->cache, &elem);
if (r == NULL) {
ossl_property_unlock(store);
return 0;
}
*method = r->method;
ossl_property_unlock(store);
return 1;
}
int ossl_method_store_cache_set(OSSL_METHOD_STORE *store, int nid,
const char *prop_query, void *method)
{
QUERY elem, *old, *p = NULL;
ALGORITHM *alg;
size_t len;
if (nid <= 0 || store == NULL)
return 0;
if (prop_query == NULL)
return 1;
ossl_property_write_lock(store);
if (store->need_flush)
ossl_method_cache_flush_some(store);
alg = ossl_method_store_retrieve(store, nid);
if (alg == NULL) {
ossl_property_unlock(store);
return 0;
}
if (method == NULL) {
elem.query = prop_query;
lh_QUERY_delete(alg->cache, &elem);
ossl_property_unlock(store);
return 1;
}
p = OPENSSL_malloc(sizeof(*p) + (len = strlen(prop_query)));
if (p != NULL) {
p->query = p->body;
p->method = method;
memcpy((char *)p->query, prop_query, len + 1);
if ((old = lh_QUERY_insert(alg->cache, p)) != NULL)
OPENSSL_free(old);
if (old != NULL || !lh_QUERY_error(alg->cache)) {
store->nelem++;
if (store->nelem >= IMPL_CACHE_FLUSH_THRESHOLD)
store->need_flush = 1;
ossl_property_unlock(store);
return 1;
}
}
ossl_property_unlock(store);
OPENSSL_free(p);
return 0;
}