ref: 2cdc6577ef8a251bf1740439cf5bfc47050dab41
dir: /third_party/boringssl/src/crypto/pool/pool.c/
/* Copyright (c) 2016, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include <openssl/pool.h>
#include <assert.h>
#include <string.h>
#include <openssl/bytestring.h>
#include <openssl/mem.h>
#include <openssl/thread.h>
#include "../internal.h"
#include "internal.h"
static uint32_t CRYPTO_BUFFER_hash(const CRYPTO_BUFFER *buf) {
return OPENSSL_hash32(buf->data, buf->len);
}
static int CRYPTO_BUFFER_cmp(const CRYPTO_BUFFER *a, const CRYPTO_BUFFER *b) {
if (a->len != b->len) {
return 1;
}
return OPENSSL_memcmp(a->data, b->data, a->len);
}
CRYPTO_BUFFER_POOL* CRYPTO_BUFFER_POOL_new(void) {
CRYPTO_BUFFER_POOL *pool = OPENSSL_malloc(sizeof(CRYPTO_BUFFER_POOL));
if (pool == NULL) {
return NULL;
}
OPENSSL_memset(pool, 0, sizeof(CRYPTO_BUFFER_POOL));
pool->bufs = lh_CRYPTO_BUFFER_new(CRYPTO_BUFFER_hash, CRYPTO_BUFFER_cmp);
if (pool->bufs == NULL) {
OPENSSL_free(pool);
return NULL;
}
CRYPTO_MUTEX_init(&pool->lock);
return pool;
}
void CRYPTO_BUFFER_POOL_free(CRYPTO_BUFFER_POOL *pool) {
if (pool == NULL) {
return;
}
#if !defined(NDEBUG)
CRYPTO_MUTEX_lock_write(&pool->lock);
assert(lh_CRYPTO_BUFFER_num_items(pool->bufs) == 0);
CRYPTO_MUTEX_unlock_write(&pool->lock);
#endif
lh_CRYPTO_BUFFER_free(pool->bufs);
CRYPTO_MUTEX_cleanup(&pool->lock);
OPENSSL_free(pool);
}
static void crypto_buffer_free_object(CRYPTO_BUFFER *buf) {
if (!buf->data_is_static) {
OPENSSL_free(buf->data);
}
OPENSSL_free(buf);
}
static CRYPTO_BUFFER *crypto_buffer_new(const uint8_t *data, size_t len,
int data_is_static,
CRYPTO_BUFFER_POOL *pool) {
if (pool != NULL) {
CRYPTO_BUFFER tmp;
tmp.data = (uint8_t *) data;
tmp.len = len;
CRYPTO_MUTEX_lock_read(&pool->lock);
CRYPTO_BUFFER *duplicate = lh_CRYPTO_BUFFER_retrieve(pool->bufs, &tmp);
if (data_is_static && duplicate != NULL && !duplicate->data_is_static) {
// If the new |CRYPTO_BUFFER| would have static data, but the duplicate
// does not, we replace the old one with the new static version.
duplicate = NULL;
}
if (duplicate != NULL) {
CRYPTO_refcount_inc(&duplicate->references);
}
CRYPTO_MUTEX_unlock_read(&pool->lock);
if (duplicate != NULL) {
return duplicate;
}
}
CRYPTO_BUFFER *const buf = OPENSSL_malloc(sizeof(CRYPTO_BUFFER));
if (buf == NULL) {
return NULL;
}
OPENSSL_memset(buf, 0, sizeof(CRYPTO_BUFFER));
if (data_is_static) {
buf->data = (uint8_t *)data;
buf->data_is_static = 1;
} else {
buf->data = OPENSSL_memdup(data, len);
if (len != 0 && buf->data == NULL) {
OPENSSL_free(buf);
return NULL;
}
}
buf->len = len;
buf->references = 1;
if (pool == NULL) {
return buf;
}
buf->pool = pool;
CRYPTO_MUTEX_lock_write(&pool->lock);
CRYPTO_BUFFER *duplicate = lh_CRYPTO_BUFFER_retrieve(pool->bufs, buf);
if (data_is_static && duplicate != NULL && !duplicate->data_is_static) {
// If the new |CRYPTO_BUFFER| would have static data, but the duplicate does
// not, we replace the old one with the new static version.
duplicate = NULL;
}
int inserted = 0;
if (duplicate == NULL) {
CRYPTO_BUFFER *old = NULL;
inserted = lh_CRYPTO_BUFFER_insert(pool->bufs, &old, buf);
// |old| may be non-NULL if a match was found but ignored. |pool->bufs| does
// not increment refcounts, so there is no need to clean up after the
// replacement.
} else {
CRYPTO_refcount_inc(&duplicate->references);
}
CRYPTO_MUTEX_unlock_write(&pool->lock);
if (!inserted) {
// We raced to insert |buf| into the pool and lost, or else there was an
// error inserting.
crypto_buffer_free_object(buf);
return duplicate;
}
return buf;
}
CRYPTO_BUFFER *CRYPTO_BUFFER_new(const uint8_t *data, size_t len,
CRYPTO_BUFFER_POOL *pool) {
return crypto_buffer_new(data, len, /*data_is_static=*/0, pool);
}
CRYPTO_BUFFER *CRYPTO_BUFFER_alloc(uint8_t **out_data, size_t len) {
CRYPTO_BUFFER *const buf = OPENSSL_malloc(sizeof(CRYPTO_BUFFER));
if (buf == NULL) {
return NULL;
}
OPENSSL_memset(buf, 0, sizeof(CRYPTO_BUFFER));
buf->data = OPENSSL_malloc(len);
if (len != 0 && buf->data == NULL) {
OPENSSL_free(buf);
return NULL;
}
buf->len = len;
buf->references = 1;
*out_data = buf->data;
return buf;
}
CRYPTO_BUFFER *CRYPTO_BUFFER_new_from_CBS(const CBS *cbs,
CRYPTO_BUFFER_POOL *pool) {
return CRYPTO_BUFFER_new(CBS_data(cbs), CBS_len(cbs), pool);
}
CRYPTO_BUFFER *CRYPTO_BUFFER_new_from_static_data_unsafe(
const uint8_t *data, size_t len, CRYPTO_BUFFER_POOL *pool) {
return crypto_buffer_new(data, len, /*data_is_static=*/1, pool);
}
void CRYPTO_BUFFER_free(CRYPTO_BUFFER *buf) {
if (buf == NULL) {
return;
}
CRYPTO_BUFFER_POOL *const pool = buf->pool;
if (pool == NULL) {
if (CRYPTO_refcount_dec_and_test_zero(&buf->references)) {
// If a reference count of zero is observed, there cannot be a reference
// from any pool to this buffer and thus we are able to free this
// buffer.
crypto_buffer_free_object(buf);
}
return;
}
CRYPTO_MUTEX_lock_write(&pool->lock);
if (!CRYPTO_refcount_dec_and_test_zero(&buf->references)) {
CRYPTO_MUTEX_unlock_write(&buf->pool->lock);
return;
}
// We have an exclusive lock on the pool, therefore no concurrent lookups can
// find this buffer and increment the reference count. Thus, if the count is
// zero there are and can never be any more references and thus we can free
// this buffer.
//
// Note it is possible |buf| is no longer in the pool, if it was replaced by a
// static version. If that static version was since removed, it is even
// possible for |found| to be NULL.
CRYPTO_BUFFER *found = lh_CRYPTO_BUFFER_retrieve(pool->bufs, buf);
if (found == buf) {
found = lh_CRYPTO_BUFFER_delete(pool->bufs, buf);
assert(found == buf);
(void)found;
}
CRYPTO_MUTEX_unlock_write(&buf->pool->lock);
crypto_buffer_free_object(buf);
}
int CRYPTO_BUFFER_up_ref(CRYPTO_BUFFER *buf) {
// This is safe in the case that |buf->pool| is NULL because it's just
// standard reference counting in that case.
//
// This is also safe if |buf->pool| is non-NULL because, if it were racing
// with |CRYPTO_BUFFER_free| then the two callers must have independent
// references already and so the reference count will never hit zero.
CRYPTO_refcount_inc(&buf->references);
return 1;
}
const uint8_t *CRYPTO_BUFFER_data(const CRYPTO_BUFFER *buf) {
return buf->data;
}
size_t CRYPTO_BUFFER_len(const CRYPTO_BUFFER *buf) {
return buf->len;
}
void CRYPTO_BUFFER_init_CBS(const CRYPTO_BUFFER *buf, CBS *out) {
CBS_init(out, buf->data, buf->len);
}