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/*
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
#include <string.h>
#include <stdio.h>
#include "error/s2n_errno.h"
#include "crypto/s2n_hash.h"
#include "utils/s2n_safety.h"
#include "utils/s2n_result.h"
#include "utils/s2n_blob.h"
#include "utils/s2n_mem.h"
#include "utils/s2n_map.h"
#include "utils/s2n_map_internal.h"
#include <s2n.h>
#define S2N_INITIAL_TABLE_SIZE 1024
static S2N_RESULT s2n_map_slot(const struct s2n_map *map, struct s2n_blob *key, uint32_t *slot)
{
union {
uint8_t u8[32];
uint32_t u32[8];
} digest;
DEFER_CLEANUP(struct s2n_hash_state sha256 = {0}, s2n_hash_free);
GUARD_AS_RESULT(s2n_hash_new(&sha256));
GUARD_AS_RESULT(s2n_hash_init(&sha256, S2N_HASH_SHA256));
GUARD_AS_RESULT(s2n_hash_update(&sha256, key->data, key->size));
GUARD_AS_RESULT(s2n_hash_digest(&sha256, digest.u8, sizeof(digest)));
*slot = digest.u32[0] % map->capacity;
return S2N_RESULT_OK;
}
static S2N_RESULT s2n_map_embiggen(struct s2n_map *map, uint32_t capacity)
{
struct s2n_blob mem = {0};
struct s2n_map tmp = {0};
ENSURE(!map->immutable, S2N_ERR_MAP_IMMUTABLE);
GUARD_AS_RESULT(s2n_alloc(&mem, (capacity * sizeof(struct s2n_map_entry))));
GUARD_AS_RESULT(s2n_blob_zero(&mem));
tmp.capacity = capacity;
tmp.size = 0;
tmp.table = (void *) mem.data;
tmp.immutable = 0;
for (int i = 0; i < map->capacity; i++) {
if (map->table[i].key.size) {
GUARD_RESULT(s2n_map_add(&tmp, &map->table[i].key, &map->table[i].value));
GUARD_AS_RESULT(s2n_free(&map->table[i].key));
GUARD_AS_RESULT(s2n_free(&map->table[i].value));
}
}
GUARD_AS_RESULT(s2n_free_object((uint8_t **)&map->table, map->capacity * sizeof(struct s2n_map_entry)));
/* Clone the temporary map */
map->capacity = tmp.capacity;
map->size = tmp.size;
map->table = tmp.table;
map->immutable = 0;
return S2N_RESULT_OK;
}
struct s2n_map *s2n_map_new()
{
return s2n_map_new_with_initial_capacity(S2N_INITIAL_TABLE_SIZE);
}
struct s2n_map *s2n_map_new_with_initial_capacity(uint32_t capacity)
{
S2N_ERROR_IF_PTR(capacity == 0, S2N_ERR_MAP_INVALID_MAP_SIZE);
struct s2n_blob mem = {0};
struct s2n_map *map;
GUARD_POSIX_PTR(s2n_alloc(&mem, sizeof(struct s2n_map)));
map = (void *) mem.data;
map->capacity = 0;
map->size = 0;
map->immutable = 0;
map->table = NULL;
GUARD_RESULT_PTR(s2n_map_embiggen(map, capacity));
return map;
}
S2N_RESULT s2n_map_add(struct s2n_map *map, struct s2n_blob *key, struct s2n_blob *value)
{
ENSURE(!map->immutable, S2N_ERR_MAP_IMMUTABLE);
if (map->capacity < (map->size * 2)) {
/* Embiggen the map */
GUARD_RESULT(s2n_map_embiggen(map, map->capacity * 2));
}
uint32_t slot = 0;
GUARD_RESULT(s2n_map_slot(map, key, &slot));
/* Linear probing until we find an empty slot */
while(map->table[slot].key.size) {
if (key->size != map->table[slot].key.size ||
memcmp(key->data, map->table[slot].key.data, key->size)) {
slot++;
slot %= map->capacity;
continue;
}
/* We found a duplicate key */
BAIL(S2N_ERR_MAP_DUPLICATE);
}
GUARD_AS_RESULT(s2n_dup(key, &map->table[slot].key));
GUARD_AS_RESULT(s2n_dup(value, &map->table[slot].value));
map->size++;
return S2N_RESULT_OK;
}
S2N_RESULT s2n_map_put(struct s2n_map *map, struct s2n_blob *key, struct s2n_blob *value)
{
ENSURE(!map->immutable, S2N_ERR_MAP_IMMUTABLE);
if (map->capacity < (map->size * 2)) {
/* Embiggen the map */
GUARD_RESULT(s2n_map_embiggen(map, map->capacity * 2));
}
uint32_t slot = 0;
GUARD_RESULT(s2n_map_slot(map, key, &slot));
/* Linear probing until we find an empty slot */
while(map->table[slot].key.size) {
if (key->size != map->table[slot].key.size ||
memcmp(key->data, map->table[slot].key.data, key->size)) {
slot++;
slot %= map->capacity;
continue;
}
/* We found a duplicate key that will be overwritten */
GUARD_AS_RESULT(s2n_free(&map->table[slot].key));
GUARD_AS_RESULT(s2n_free(&map->table[slot].value));
map->size--;
break;
}
GUARD_AS_RESULT(s2n_dup(key, &map->table[slot].key));
GUARD_AS_RESULT(s2n_dup(value, &map->table[slot].value));
map->size++;
return S2N_RESULT_OK;
}
S2N_RESULT s2n_map_complete(struct s2n_map *map)
{
map->immutable = 1;
return S2N_RESULT_OK;
}
S2N_RESULT s2n_map_unlock(struct s2n_map *map)
{
map->immutable = 0;
return S2N_RESULT_OK;
}
S2N_RESULT s2n_map_lookup(const struct s2n_map *map, struct s2n_blob *key, struct s2n_blob *value, bool *key_found)
{
ENSURE(map->immutable, S2N_ERR_MAP_MUTABLE);
uint32_t slot = 0;
GUARD_RESULT(s2n_map_slot(map, key, &slot));
const uint32_t initial_slot = slot;
while(map->table[slot].key.size) {
if (key->size != map->table[slot].key.size ||
memcmp(key->data, map->table[slot].key.data, key->size)) {
slot++;
slot %= map->capacity;
/* We went over all the slots but found no match */
if (slot == initial_slot) {
break;
}
continue;
}
/* We found a match */
value->data = map->table[slot].value.data;
value->size = map->table[slot].value.size;
*key_found = true;
return S2N_RESULT_OK;
}
*key_found = false;
return S2N_RESULT_OK;
}
S2N_RESULT s2n_map_free(struct s2n_map *map)
{
/* Free the keys and values */
for (int i = 0; i < map->capacity; i++) {
if (map->table[i].key.size) {
GUARD_AS_RESULT(s2n_free(&map->table[i].key));
GUARD_AS_RESULT(s2n_free(&map->table[i].value));
}
}
/* Free the table */
GUARD_AS_RESULT(s2n_free_object((uint8_t **)&map->table, map->capacity * sizeof(struct s2n_map_entry)));
/* And finally the map */
GUARD_AS_RESULT(s2n_free_object((uint8_t **)&map, sizeof(struct s2n_map)));
return S2N_RESULT_OK;
}
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