tor/src/or/hs_cache.h
David Goulet 05766eae30 hs-v3: Add an encoded descriptor client cache lookup function
This commit adds hs_cache_lookup_encoded_as_client() function that returns the
encoded descriptor for a given service public key. This will be needed by the
"GETINFO hs/client/desc/id/<ADDR>" control port command.

Signed-off-by: David Goulet <dgoulet@torproject.org>
2017-11-20 11:02:30 -05:00

130 lines
4.4 KiB
C

/* Copyright (c) 2016-2017, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file hs_cache.h
* \brief Header file for hs_cache.c
**/
#ifndef TOR_HS_CACHE_H
#define TOR_HS_CACHE_H
#include <stdint.h>
#include "crypto.h"
#include "crypto_ed25519.h"
#include "hs_common.h"
#include "hs_descriptor.h"
#include "rendcommon.h"
#include "torcert.h"
/* This is the maximum time an introduction point state object can stay in the
* client cache in seconds (2 mins or 120 seconds). */
#define HS_CACHE_CLIENT_INTRO_STATE_MAX_AGE (2 * 60)
/* Introduction point state. */
typedef struct hs_cache_intro_state_t {
/* When this entry was created and put in the cache. */
time_t created_ts;
/* Did it suffered a generic error? */
unsigned int error : 1;
/* Did it timed out? */
unsigned int timed_out : 1;
/* How many times we tried to reached it and it was unreachable. */
uint32_t unreachable_count;
} hs_cache_intro_state_t;
typedef struct hs_cache_client_intro_state_t {
/* Contains hs_cache_intro_state_t object indexed by introduction point
* authentication key. */
digest256map_t *intro_points;
} hs_cache_client_intro_state_t;
/* Descriptor representation on the directory side which is a subset of
* information that the HSDir can decode and serve it. */
typedef struct hs_cache_dir_descriptor_t {
/* This object is indexed using the blinded pubkey located in the plaintext
* data which is populated only once the descriptor has been successfully
* decoded and validated. This simply points to that pubkey. */
const uint8_t *key;
/* When does this entry has been created. Used to expire entries. */
time_t created_ts;
/* Descriptor plaintext information. Obviously, we can't decrypt the
* encrypted part of the descriptor. */
hs_desc_plaintext_data_t *plaintext_data;
/* Encoded descriptor which is basically in text form. It's a NUL terminated
* string thus safe to strlen(). */
char *encoded_desc;
} hs_cache_dir_descriptor_t;
/* Public API */
void hs_cache_init(void);
void hs_cache_free_all(void);
void hs_cache_clean_as_dir(time_t now);
size_t hs_cache_handle_oom(time_t now, size_t min_remove_bytes);
unsigned int hs_cache_get_max_descriptor_size(void);
/* Store and Lookup function. They are version agnostic that is depending on
* the requested version of the descriptor, it will be re-routed to the
* right function. */
int hs_cache_store_as_dir(const char *desc);
int hs_cache_lookup_as_dir(uint32_t version, const char *query,
const char **desc_out);
const hs_descriptor_t *
hs_cache_lookup_as_client(const ed25519_public_key_t *key);
const char *
hs_cache_lookup_encoded_as_client(const ed25519_public_key_t *key);
int hs_cache_store_as_client(const char *desc_str,
const ed25519_public_key_t *identity_pk);
void hs_cache_clean_as_client(time_t now);
void hs_cache_purge_as_client(void);
/* Client failure cache. */
void hs_cache_client_intro_state_note(const ed25519_public_key_t *service_pk,
const ed25519_public_key_t *auth_key,
rend_intro_point_failure_t failure);
const hs_cache_intro_state_t *hs_cache_client_intro_state_find(
const ed25519_public_key_t *service_pk,
const ed25519_public_key_t *auth_key);
void hs_cache_client_intro_state_clean(time_t now);
void hs_cache_client_intro_state_purge(void);
#ifdef HS_CACHE_PRIVATE
/** Represents a locally cached HS descriptor on a hidden service client. */
typedef struct hs_cache_client_descriptor_t {
/* This object is indexed using the service identity public key */
ed25519_public_key_t key;
/* When will this entry expire? We expire cached client descriptors in the
* start of the next time period, since that's when clients need to start
* using the next blinded key of the service. */
time_t expiration_ts;
/* The cached descriptor, this object is the owner. It can't be NULL. A
* cache object without a valid descriptor is not possible. */
hs_descriptor_t *desc;
/* Encoded descriptor in string form. Can't be NULL. */
char *encoded_desc;
} hs_cache_client_descriptor_t;
STATIC size_t cache_clean_v3_as_dir(time_t now, time_t global_cutoff);
STATIC hs_cache_client_descriptor_t *
lookup_v3_desc_as_client(const uint8_t *key);
#endif /* defined(HS_CACHE_PRIVATE) */
#endif /* !defined(TOR_HS_CACHE_H) */