/*
* libZRTP SDK library, implements the ZRTP secure VoIP protocol.
* Copyright (c) 2006-2009 Philip R. Zimmermann. All rights reserved.
* Contact: http://philzimmermann.com
* For licensing and other legal details, see the file zrtp_legal.c.
*
* Viktor Krykun <v.krikun at zfoneproject.com>
*/
#ifndef __ZRTP_IFACE_CACHE_H__
#define __ZRTP_IFACE_CACHE_H__
#include "zrtp_config.h"
#include "zrtp_base.h"
#include "zrtp_string.h"
#include "zrtp_error.h"
#include "zrtp_iface.h"
#if defined(__cplusplus)
extern "C"
{
#endif
#if defined(ZRTP_USE_BUILTIN_CACHE) && (ZRTP_USE_BUILTIN_CACHE == 1)
#define ZRTP_DEF_CACHE_VERSION_STR "libZRTP cache version="
#define ZRTP_DEF_CACHE_VERSION_VAL "1.0"
/**
* @brief Cache element identifier type
* Elements of this type link cache data with a pair of ZIDs.
* (constructed as: [ZID1][ZID2], where ZID1 - ZID with greater binary value)
* This type is used to identify cache elements in the built-in implementation.
*/
typedef uint8_t zrtp_cache_id_t[24];
#define ZRTP_MITMCACHE_ELEM_LENGTH ( sizeof(zrtp_cache_id_t) + sizeof(zrtp_string64_t) )
#define ZRTP_CACHE_ELEM_LENGTH ( sizeof(zrtp_cache_elem_t) - sizeof(mlist_t) - (sizeof(uint32_t)*2) )
#define ZFONE_CACHE_NAME_LENGTH 256
/**
* @brief Secret cache element structure
* This structure is used to store cache data in the built-in implementation
* of the caching system.
*/
typedef struct zrtp_cache_elem
{
zrtp_cache_id_t id; /** Cache element identifier */
zrtp_string64_t curr_cache; /** Current cache value */
zrtp_string64_t prev_cache; /** Prev cache value */
uint32_t verified; /** Verified flag for the cache value */
uint32_t lastused_at; /** Last usage time-stamp in seconds */
uint32_t ttl; /** Cache TTL since lastused_at in seconds */
uint32_t secure_since; /** Secure since date in seconds. Utility field. Don't required by libzrtp. */
char name[ZFONE_CACHE_NAME_LENGTH]; /** name of the user associated with this cache entry */
uint32_t name_length; /** cache name lengths */
uint32_t presh_counter; /** number of Preshared streams made since last DH exchange */
uint32_t _index; /** cache element index in the cache file */
uint32_t _is_dirty; /** dirty flag means the entry has unsaved changes */
mlist_t _mlist;
} zrtp_cache_elem_t;
#endif /* ZRTP_USE_BUILTIN_CACHE */
zrtp_status_t zrtp_def_cache_init(zrtp_global_t* zrtp);
void zrtp_def_cache_down();
zrtp_status_t zrtp_def_cache_set_verified( const zrtp_stringn_t* one_zid,
const zrtp_stringn_t* another_zid,
uint32_t verified);
zrtp_status_t zrtp_def_cache_get_verified( const zrtp_stringn_t* one_zid,
const zrtp_stringn_t* another_zid,
uint32_t* verified);
zrtp_status_t zrtp_def_cache_put( const zrtp_stringn_t* one_zid,
const zrtp_stringn_t* another_zid,
zrtp_shared_secret_t *rss);
zrtp_status_t zrtp_def_cache_put_mitm( const zrtp_stringn_t* one_zid,
const zrtp_stringn_t* another_zid,
zrtp_shared_secret_t *rss);
zrtp_status_t zrtp_def_cache_get( const zrtp_stringn_t* one_zid,
const zrtp_stringn_t* another_zid,
zrtp_shared_secret_t *rss,
int prev_requested);
zrtp_status_t zrtp_def_cache_get_mitm( const zrtp_stringn_t* one_zid,
const zrtp_stringn_t* another_zid,
zrtp_shared_secret_t *rss);
zrtp_status_t zrtp_def_cache_set_presh_counter( const zrtp_stringn_t* one_zid,
const zrtp_stringn_t* another_zid,
uint32_t counter);
zrtp_status_t zrtp_def_cache_get_presh_counter( const zrtp_stringn_t* one_zid,
const zrtp_stringn_t* another_zid,
uint32_t* counter);
#if defined(ZRTP_USE_BUILTIN_CACHE) && (ZRTP_USE_BUILTIN_CACHE == 1)
/**
* @brief Cache iterator
* zrtp_def_cache_foreach() calls this function for every cache entry.
* @param elem - cache element;
* @param is_mitm - is 1 when callback was called for MiTM for each.
* @param del - callback may return 1 to this to remove cache entry from the list.
* @param data - pointer to some user data from zrtp_def_cache_foreach();
* @return
* - 0 - if element was requested for reading only and wasn't changed;
* - 1 - if element was modified and cache should be updated.
*/
typedef int (*zrtp_cache_callback_t)(zrtp_cache_elem_t* elem, int is_mitm, void* data, int* del);
/**
* @brief Iterate over all cache entries.
* Can be used for searching and modifying cache entries. Protected by mutex.
* Can be called in parallel with other cache operations when protocol is
* running.
* @param global - libzrtp global context;
* @param is_mitm - if value of this flag is 1 - fore_each will be applied for MiTM secrets;
* @param callback - function to be called for every cache entry;
* @param data - this pointer will be passed to every \c callback call.
*/
void zrtp_def_cache_foreach( zrtp_global_t *global,
int is_mitm,
zrtp_cache_callback_t callback,
void *data);
#endif /* ZRTP_USE_BUILTIN_CACHE */
/**
* @brief Store shared secrets cache to the persistent storage
* May be used in server solutions for periodically flushing the cache to prevent data loss.
*
* @return
* - zrtp_status_ok - if operation completed successfully;
* - zrtp_status_wrong_state - if a call is performed from a routine which
* doesn't use the default cache.
*/
zrtp_status_t zrtp_def_cache_store(zrtp_global_t *global);
zrtp_status_t zrtp_def_cache_reset_since( const zrtp_stringn_t* one_zid,
const zrtp_stringn_t* another_zid);
zrtp_status_t zrtp_def_cache_get_since( const zrtp_stringn_t* one_zid,
const zrtp_stringn_t* another_zid,
uint32_t* since);
zrtp_status_t zrtp_def_cache_get_name( const zrtp_stringn_t* one_zid,
const zrtp_stringn_t* another_zid,
zrtp_stringn_t* name);
zrtp_status_t zrtp_def_cache_put_name( const zrtp_stringn_t* one_zid,
const zrtp_stringn_t* another_zid,
const zrtp_stringn_t* name);
#if defined(ZRTP_USE_BUILTIN_CACHE) && (ZRTP_USE_BUILTIN_CACHE == 1)
zrtp_cache_elem_t* zrtp_def_cache_get2(const zrtp_cache_id_t id, int is_mitm);
#endif /* ZRTP_USE_BUILTIN_CACHE */
#if defined(__cplusplus)
}
#endif
#endif /*__ZRTP_IFACE_CACHE_H__*/