52 lines
1.7 KiB
C
52 lines
1.7 KiB
C
|
/* SPDX-License-Identifier: GPL-3.0-or-later
|
||
|
|
* Copyright © 2022 The TokTok team.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef C_TOXCORE_TOXCORE_SHARED_KEY_CACHE_H
|
||
|
|
#define C_TOXCORE_TOXCORE_SHARED_KEY_CACHE_H
|
||
|
|
|
||
|
|
#include <stdint.h> // uint*_t
|
||
|
|
|
||
|
|
#include "crypto_core.h"
|
||
|
|
#include "mono_time.h"
|
||
|
|
|
||
|
|
/**
|
||
|
|
* This implements a cache for shared keys, since key generation is expensive.
|
||
|
|
*/
|
||
|
|
|
||
|
|
typedef struct Shared_Key_Cache Shared_Key_Cache;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @brief Initializes a new shared key cache.
|
||
|
|
* @param time Time object for retrieving current time.
|
||
|
|
* @param self_secret_key Our own secret key of length CRYPTO_SECRET_KEY_SIZE,
|
||
|
|
* it must not change during the lifetime of the cache.
|
||
|
|
* @param timeout Number of milliseconds, after which a key should be evicted.
|
||
|
|
* @param keys_per_slot There are 256 slots, this controls how many keys are stored per slot and the size of the cache.
|
||
|
|
* @return nullptr on error.
|
||
|
|
*/
|
||
|
|
non_null()
|
||
|
|
Shared_Key_Cache *shared_key_cache_new(const Mono_Time *time,
|
||
|
|
const uint8_t *self_secret_key,
|
||
|
|
uint64_t timeout, uint8_t keys_per_slot);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @brief Deletes the cache and frees all resources.
|
||
|
|
* @param cache Cache to delete or nullptr.
|
||
|
|
*/
|
||
|
|
nullable(1)
|
||
|
|
void shared_key_cache_free(Shared_Key_Cache *cache);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @brief Looks up a key from the cache or computes it if it didn't exist yet.
|
||
|
|
* @param cache Cache to perform the lookup on.
|
||
|
|
* @param public_key Public key, used for the lookup and computation.
|
||
|
|
*
|
||
|
|
* @return The shared key of length CRYPTO_SHARED_KEY_SIZE, matching the public key and our secret key.
|
||
|
|
* @return nullptr on error.
|
||
|
|
*/
|
||
|
|
non_null()
|
||
|
|
const uint8_t* shared_key_cache_lookup(Shared_Key_Cache *cache, const uint8_t public_key[CRYPTO_PUBLIC_KEY_SIZE]);
|
||
|
|
|
||
|
|
#endif // C_TOXCORE_TOXCORE_SHARED_KEY_CACHE_H
|