sarah
/
tor
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
tor/src/or/hs_service.c

3627 lines
127 KiB
C
Raw Permalink Blame History

/* Copyright (c) 2016-2017, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file hs_service.c
* \brief Implement next generation hidden service functionality
**/
#define HS_SERVICE_PRIVATE
#include "or.h"
#include "circpathbias.h"
#include "circuitbuild.h"
#include "circuitlist.h"
#include "circuituse.h"
#include "config.h"
#include "connection.h"
#include "crypto_rand.h"
#include "crypto_util.h"
#include "directory.h"
#include "main.h"
#include "networkstatus.h"
#include "nodelist.h"
#include "relay.h"
#include "rendservice.h"
#include "router.h"
#include "routerkeys.h"
#include "routerlist.h"
#include "shared_random_client.h"
#include "statefile.h"
#include "hs_circuit.h"
#include "hs_common.h"
#include "hs_config.h"
#include "hs_control.h"
#include "hs_descriptor.h"
#include "hs_ident.h"
#include "hs_intropoint.h"
#include "hs_service.h"
#include "hs_stats.h"
/* Trunnel */
#include "ed25519_cert.h"
#include "hs/cell_common.h"
#include "hs/cell_establish_intro.h"
/* Helper macro. Iterate over every service in the global map. The var is the
* name of the service pointer. */
#define FOR_EACH_SERVICE_BEGIN(var) \
STMT_BEGIN \
hs_service_t **var##_iter, *var; \
HT_FOREACH(var##_iter, hs_service_ht, hs_service_map) { \
var = *var##_iter;
#define FOR_EACH_SERVICE_END } STMT_END ;
/* Helper macro. Iterate over both current and previous descriptor of a
* service. The var is the name of the descriptor pointer. This macro skips
* any descriptor object of the service that is NULL. */
#define FOR_EACH_DESCRIPTOR_BEGIN(service, var) \
STMT_BEGIN \
hs_service_descriptor_t *var; \
for (int var ## _loop_idx = 0; var ## _loop_idx < 2; \
++var ## _loop_idx) { \
(var ## _loop_idx == 0) ? (var = service->desc_current) : \
(var = service->desc_next); \
if (var == NULL) continue;
#define FOR_EACH_DESCRIPTOR_END } STMT_END ;
/* Onion service directory file names. */
static const char fname_keyfile_prefix[] = "hs_ed25519";
static const char fname_hostname[] = "hostname";
static const char address_tld[] = "onion";
/* Staging list of service object. When configuring service, we add them to
* this list considered a staging area and they will get added to our global
* map once the keys have been loaded. These two steps are separated because
* loading keys requires that we are an actual running tor process. */
static smartlist_t *hs_service_staging_list;
/** True if the list of available router descriptors might have changed which
* might result in an altered hash ring. Check if the hash ring changed and
* reupload if needed */
static int consider_republishing_hs_descriptors = 0;
/* Static declaration. */
static void set_descriptor_revision_counter(hs_descriptor_t *hs_desc);
static void move_descriptors(hs_service_t *src, hs_service_t *dst);
/* Helper: Function to compare two objects in the service map. Return 1 if the
* two service have the same master public identity key. */
static inline int
hs_service_ht_eq(const hs_service_t *first, const hs_service_t *second)
{
tor_assert(first);
tor_assert(second);
/* Simple key compare. */
return ed25519_pubkey_eq(&first->keys.identity_pk,
&second->keys.identity_pk);
}
/* Helper: Function for the service hash table code below. The key used is the
* master public identity key which is ultimately the onion address. */
static inline unsigned int
hs_service_ht_hash(const hs_service_t *service)
{
tor_assert(service);
return (unsigned int) siphash24g(service->keys.identity_pk.pubkey,
sizeof(service->keys.identity_pk.pubkey));
}
/* This is _the_ global hash map of hidden services which indexed the service
* contained in it by master public identity key which is roughly the onion
* address of the service. */
static struct hs_service_ht *hs_service_map;
/* Register the service hash table. */
HT_PROTOTYPE(hs_service_ht, /* Name of hashtable. */
hs_service_t, /* Object contained in the map. */
hs_service_node, /* The name of the HT_ENTRY member. */
hs_service_ht_hash, /* Hashing function. */
hs_service_ht_eq) /* Compare function for objects. */
HT_GENERATE2(hs_service_ht, hs_service_t, hs_service_node,
hs_service_ht_hash, hs_service_ht_eq,
0.6, tor_reallocarray, tor_free_)
/* Query the given service map with a public key and return a service object
* if found else NULL. It is also possible to set a directory path in the
* search query. If pk is NULL, then it will be set to zero indicating the
* hash table to compare the directory path instead. */
STATIC hs_service_t *
find_service(hs_service_ht *map, const ed25519_public_key_t *pk)
{
hs_service_t dummy_service;
tor_assert(map);
tor_assert(pk);
memset(&dummy_service, 0, sizeof(dummy_service));
ed25519_pubkey_copy(&dummy_service.keys.identity_pk, pk);
return HT_FIND(hs_service_ht, map, &dummy_service);
}
/* Register the given service in the given map. If the service already exists
* in the map, -1 is returned. On success, 0 is returned and the service
* ownership has been transferred to the global map. */
STATIC int
register_service(hs_service_ht *map, hs_service_t *service)
{
tor_assert(map);
tor_assert(service);
tor_assert(!ed25519_public_key_is_zero(&service->keys.identity_pk));
if (find_service(map, &service->keys.identity_pk)) {
/* Existing service with the same key. Do not register it. */
return -1;
}
/* Taking ownership of the object at this point. */
HT_INSERT(hs_service_ht, map, service);
/* If we just modified the global map, we notify. */
if (map == hs_service_map) {
hs_service_map_has_changed();
}
return 0;
}
/* Remove a given service from the given map. If service is NULL or the
* service key is unset, return gracefully. */
STATIC void
remove_service(hs_service_ht *map, hs_service_t *service)
{
hs_service_t *elm;
tor_assert(map);
/* Ignore if no service or key is zero. */
if (BUG(service == NULL) ||
BUG(ed25519_public_key_is_zero(&service->keys.identity_pk))) {
return;
}
elm = HT_REMOVE(hs_service_ht, map, service);
if (elm) {
tor_assert(elm == service);
} else {
log_warn(LD_BUG, "Could not find service in the global map "
"while removing service %s",
escaped(service->config.directory_path));
}
/* If we just modified the global map, we notify. */
if (map == hs_service_map) {
hs_service_map_has_changed();
}
}
/* Set the default values for a service configuration object <b>c</b>. */
static void
set_service_default_config(hs_service_config_t *c,
const or_options_t *options)
{
(void) options;
tor_assert(c);
c->ports = smartlist_new();
c->directory_path = NULL;
c->max_streams_per_rdv_circuit = 0;
c->max_streams_close_circuit = 0;
c->num_intro_points = NUM_INTRO_POINTS_DEFAULT;
c->allow_unknown_ports = 0;
c->is_single_onion = 0;
c->dir_group_readable = 0;
c->is_ephemeral = 0;
}
/* From a service configuration object config, clear everything from it
* meaning free allocated pointers and reset the values. */
static void
service_clear_config(hs_service_config_t *config)
{
if (config == NULL) {
return;
}
tor_free(config->directory_path);
if (config->ports) {
SMARTLIST_FOREACH(config->ports, rend_service_port_config_t *, p,
rend_service_port_config_free(p););
smartlist_free(config->ports);
}
memset(config, 0, sizeof(*config));
}
/* Helper function to return a human readable description of the given intro
* point object.
*
* This function is not thread-safe. Each call to this invalidates the
* previous values returned by it. */
static const char *
describe_intro_point(const hs_service_intro_point_t *ip)
{
/* Hex identity digest of the IP prefixed by the $ sign and ends with NUL
* byte hence the plus two. */
static char buf[HEX_DIGEST_LEN + 2];
const char *legacy_id = NULL;
SMARTLIST_FOREACH_BEGIN(ip->base.link_specifiers,
const hs_desc_link_specifier_t *, lspec) {
if (lspec->type == LS_LEGACY_ID) {
legacy_id = (const char *) lspec->u.legacy_id;
break;
}
} SMARTLIST_FOREACH_END(lspec);
/* For now, we only print the identity digest but we could improve this with
* much more information such as the ed25519 identity has well. */
buf[0] = '$';
if (legacy_id) {
base16_encode(buf + 1, HEX_DIGEST_LEN + 1, legacy_id, DIGEST_LEN);
}
return buf;
}
/* Return the lower bound of maximum INTRODUCE2 cells per circuit before we
* rotate intro point (defined by a consensus parameter or the default
* value). */
static int32_t
get_intro_point_min_introduce2(void)
{
/* The [0, 2147483647] range is quite large to accommodate anything we decide
* in the future. */
return networkstatus_get_param(NULL, "hs_intro_min_introduce2",
INTRO_POINT_MIN_LIFETIME_INTRODUCTIONS,
0, INT32_MAX);
}
/* Return the upper bound of maximum INTRODUCE2 cells per circuit before we
* rotate intro point (defined by a consensus parameter or the default
* value). */
static int32_t
get_intro_point_max_introduce2(void)
{
/* The [0, 2147483647] range is quite large to accommodate anything we decide
* in the future. */
return networkstatus_get_param(NULL, "hs_intro_max_introduce2",
INTRO_POINT_MAX_LIFETIME_INTRODUCTIONS,
0, INT32_MAX);
}
/* Return the minimum lifetime in seconds of an introduction point defined by a
* consensus parameter or the default value. */
static int32_t
get_intro_point_min_lifetime(void)
{
#define MIN_INTRO_POINT_LIFETIME_TESTING 10
if (get_options()->TestingTorNetwork) {
return MIN_INTRO_POINT_LIFETIME_TESTING;
}
/* The [0, 2147483647] range is quite large to accommodate anything we decide
* in the future. */
return networkstatus_get_param(NULL, "hs_intro_min_lifetime",
INTRO_POINT_LIFETIME_MIN_SECONDS,
0, INT32_MAX);
}
/* Return the maximum lifetime in seconds of an introduction point defined by a
* consensus parameter or the default value. */
static int32_t
get_intro_point_max_lifetime(void)
{
#define MAX_INTRO_POINT_LIFETIME_TESTING 30
if (get_options()->TestingTorNetwork) {
return MAX_INTRO_POINT_LIFETIME_TESTING;
}
/* The [0, 2147483647] range is quite large to accommodate anything we decide
* in the future. */
return networkstatus_get_param(NULL, "hs_intro_max_lifetime",
INTRO_POINT_LIFETIME_MAX_SECONDS,
0, INT32_MAX);
}
/* Return the number of extra introduction point defined by a consensus
* parameter or the default value. */
static int32_t
get_intro_point_num_extra(void)
{
/* The [0, 128] range bounds the number of extra introduction point allowed.
* Above 128 intro points, it's getting a bit crazy. */
return networkstatus_get_param(NULL, "hs_intro_num_extra",
NUM_INTRO_POINTS_EXTRA, 0, 128);
}
/* Helper: Function that needs to return 1 for the HT for each loop which
* frees every service in an hash map. */
static int
ht_free_service_(struct hs_service_t *service, void *data)
{
(void) data;
hs_service_free(service);
/* This function MUST return 1 so the given object is then removed from the
* service map leading to this free of the object being safe. */
return 1;
}
/* Free every service that can be found in the global map. Once done, clear
* and free the global map. */
static void
service_free_all(void)
{
if (hs_service_map) {
/* The free helper function returns 1 so this is safe. */
hs_service_ht_HT_FOREACH_FN(hs_service_map, ht_free_service_, NULL);
HT_CLEAR(hs_service_ht, hs_service_map);
tor_free(hs_service_map);
hs_service_map = NULL;
}
if (hs_service_staging_list) {
/* Cleanup staging list. */
SMARTLIST_FOREACH(hs_service_staging_list, hs_service_t *, s,
hs_service_free(s));
smartlist_free(hs_service_staging_list);
hs_service_staging_list = NULL;
}
}
/* Free a given service intro point object. */
STATIC void
service_intro_point_free_(hs_service_intro_point_t *ip)
{
if (!ip) {
return;
}
memwipe(&ip->auth_key_kp, 0, sizeof(ip->auth_key_kp));
memwipe(&ip->enc_key_kp, 0, sizeof(ip->enc_key_kp));
crypto_pk_free(ip->legacy_key);
replaycache_free(ip->replay_cache);
hs_intropoint_clear(&ip->base);
tor_free(ip);
}
/* Helper: free an hs_service_intro_point_t object. This function is used by
* digest256map_free() which requires a void * pointer. */
static void
service_intro_point_free_void(void *obj)
{
service_intro_point_free_(obj);
}
/* Return a newly allocated service intro point and fully initialized from the
* given extend_info_t ei if non NULL. If is_legacy is true, we also generate
* the legacy key. On error, NULL is returned.
*
* If ei is NULL, returns a hs_service_intro_point_t with an empty link
* specifier list and no onion key. (This is used for testing.)
*
* ei must be an extend_info_t containing an IPv4 address. (We will add supoort
* for IPv6 in a later release.) When calling extend_info_from_node(), pass
* 0 in for_direct_connection to make sure ei always has an IPv4 address. */
STATIC hs_service_intro_point_t *
service_intro_point_new(const extend_info_t *ei, unsigned int is_legacy)
{
hs_desc_link_specifier_t *ls;
hs_service_intro_point_t *ip;
ip = tor_malloc_zero(sizeof(*ip));
/* We'll create the key material. No need for extra strong, those are short
* term keys. */
ed25519_keypair_generate(&ip->auth_key_kp, 0);
{ /* Set introduce2 max cells limit */
int32_t min_introduce2_cells = get_intro_point_min_introduce2();
int32_t max_introduce2_cells = get_intro_point_max_introduce2();
if (BUG(max_introduce2_cells < min_introduce2_cells)) {
goto err;
}
ip->introduce2_max = crypto_rand_int_range(min_introduce2_cells,
max_introduce2_cells);
}
{ /* Set intro point lifetime */
int32_t intro_point_min_lifetime = get_intro_point_min_lifetime();
int32_t intro_point_max_lifetime = get_intro_point_max_lifetime();
if (BUG(intro_point_max_lifetime < intro_point_min_lifetime)) {
goto err;
}
ip->time_to_expire = time(NULL) +
crypto_rand_int_range(intro_point_min_lifetime,intro_point_max_lifetime);
}
ip->replay_cache = replaycache_new(0, 0);
/* Initialize the base object. We don't need the certificate object. */
ip->base.link_specifiers = smartlist_new();
/* Generate the encryption key for this intro point. */
curve25519_keypair_generate(&ip->enc_key_kp, 0);
/* Figure out if this chosen node supports v3 or is legacy only. */
if (is_legacy) {
ip->base.is_only_legacy = 1;
/* Legacy mode that is doesn't support v3+ with ed25519 auth key. */
ip->legacy_key = crypto_pk_new();
if (crypto_pk_generate_key(ip->legacy_key) < 0) {
goto err;
}
if (crypto_pk_get_digest(ip->legacy_key,
(char *) ip->legacy_key_digest) < 0) {
goto err;
}
}
if (ei == NULL) {
goto done;
}
/* We'll try to add all link specifiers. Legacy is mandatory.
* IPv4 or IPv6 is required, and we always send IPv4. */
ls = hs_desc_link_specifier_new(ei, LS_IPV4);
/* It is impossible to have an extend info object without a v4. */
if (BUG(!ls)) {
goto err;
}
smartlist_add(ip->base.link_specifiers, ls);
ls = hs_desc_link_specifier_new(ei, LS_LEGACY_ID);
/* It is impossible to have an extend info object without an identity
* digest. */
if (BUG(!ls)) {
goto err;
}
smartlist_add(ip->base.link_specifiers, ls);
/* ed25519 identity key is optional for intro points */
ls = hs_desc_link_specifier_new(ei, LS_ED25519_ID);
if (ls) {
smartlist_add(ip->base.link_specifiers, ls);
}
/* IPv6 is not supported in this release. */
/* Finally, copy onion key from the extend_info_t object. */
memcpy(&ip->onion_key, &ei->curve25519_onion_key, sizeof(ip->onion_key));
done:
return ip;
err:
service_intro_point_free(ip);
return NULL;
}
/* Add the given intro point object to the given intro point map. The intro
* point MUST have its RSA encryption key set if this is a legacy type or the
* authentication key set otherwise. */
STATIC void
service_intro_point_add(digest256map_t *map, hs_service_intro_point_t *ip)
{
hs_service_intro_point_t *old_ip_entry;
tor_assert(map);
tor_assert(ip);
old_ip_entry = digest256map_set(map, ip->auth_key_kp.pubkey.pubkey, ip);
/* Make sure we didn't just try to double-add an intro point */
tor_assert_nonfatal(!old_ip_entry);
}
/* For a given service, remove the intro point from that service's descriptors
* (check both current and next descriptor) */
STATIC void
service_intro_point_remove(const hs_service_t *service,
const hs_service_intro_point_t *ip)
{
tor_assert(service);
tor_assert(ip);
/* Trying all descriptors. */
FOR_EACH_DESCRIPTOR_BEGIN(service, desc) {
/* We'll try to remove the descriptor on both descriptors which is not
* very expensive to do instead of doing loopup + remove. */
digest256map_remove(desc->intro_points.map,
ip->auth_key_kp.pubkey.pubkey);
} FOR_EACH_DESCRIPTOR_END;
}
/* For a given service and authentication key, return the intro point or NULL
* if not found. This will check both descriptors in the service. */
STATIC hs_service_intro_point_t *
service_intro_point_find(const hs_service_t *service,
const ed25519_public_key_t *auth_key)
{
hs_service_intro_point_t *ip = NULL;
tor_assert(service);
tor_assert(auth_key);
/* Trying all descriptors to find the right intro point.
*
* Even if we use the same node as intro point in both descriptors, the node
* will have a different intro auth key for each descriptor since we generate
* a new one everytime we pick an intro point.
*
* After #22893 gets implemented, intro points will be moved to be
* per-service instead of per-descriptor so this function will need to
* change.
*/
FOR_EACH_DESCRIPTOR_BEGIN(service, desc) {
if ((ip = digest256map_get(desc->intro_points.map,
auth_key->pubkey)) != NULL) {
break;
}
} FOR_EACH_DESCRIPTOR_END;
return ip;
}
/* For a given service and intro point, return the descriptor for which the
* intro point is assigned to. NULL is returned if not found. */
STATIC hs_service_descriptor_t *
service_desc_find_by_intro(const hs_service_t *service,
const hs_service_intro_point_t *ip)
{
hs_service_descriptor_t *descp = NULL;
tor_assert(service);
tor_assert(ip);
FOR_EACH_DESCRIPTOR_BEGIN(service, desc) {
if (digest256map_get(desc->intro_points.map,
ip->auth_key_kp.pubkey.pubkey)) {
descp = desc;
break;
}
} FOR_EACH_DESCRIPTOR_END;
return descp;
}
/* From a circuit identifier, get all the possible objects associated with the
* ident. If not NULL, service, ip or desc are set if the object can be found.
* They are untouched if they can't be found.
*
* This is an helper function because we do those lookups often so it's more
* convenient to simply call this functions to get all the things at once. */
STATIC void
get_objects_from_ident(const hs_ident_circuit_t *ident,
hs_service_t **service, hs_service_intro_point_t **ip,
hs_service_descriptor_t **desc)
{
hs_service_t *s;
tor_assert(ident);
/* Get service object from the circuit identifier. */
s = find_service(hs_service_map, &ident->identity_pk);
if (s && service) {
*service = s;
}
/* From the service object, get the intro point object of that circuit. The
* following will query both descriptors intro points list. */
if (s && ip) {
*ip = service_intro_point_find(s, &ident->intro_auth_pk);
}
/* Get the descriptor for this introduction point and service. */
if (s && ip && *ip && desc) {
*desc = service_desc_find_by_intro(s, *ip);
}
}
/* From a given intro point, return the first link specifier of type
* encountered in the link specifier list. Return NULL if it can't be found.
*
* The caller does NOT have ownership of the object, the intro point does. */
static hs_desc_link_specifier_t *
get_link_spec_by_type(const hs_service_intro_point_t *ip, uint8_t type)
{
hs_desc_link_specifier_t *lnk_spec = NULL;
tor_assert(ip);
SMARTLIST_FOREACH_BEGIN(ip->base.link_specifiers,
hs_desc_link_specifier_t *, ls) {
if (ls->type == type) {
lnk_spec = ls;
goto end;
}
} SMARTLIST_FOREACH_END(ls);
end:
return lnk_spec;
}
/* Given a service intro point, return the node_t associated to it. This can
* return NULL if the given intro point has no legacy ID or if the node can't
* be found in the consensus. */
STATIC const node_t *
get_node_from_intro_point(const hs_service_intro_point_t *ip)
{
const hs_desc_link_specifier_t *ls;
tor_assert(ip);
ls = get_link_spec_by_type(ip, LS_LEGACY_ID);
if (BUG(!ls)) {
return NULL;
}
/* XXX In the future, we want to only use the ed25519 ID (#22173). */
return node_get_by_id((const char *) ls->u.legacy_id);
}
/* Given a service intro point, return the extend_info_t for it. This can
* return NULL if the node can't be found for the intro point or the extend
* info can't be created for the found node. If direct_conn is set, the extend
* info is validated on if we can connect directly. */
static extend_info_t *
get_extend_info_from_intro_point(const hs_service_intro_point_t *ip,
unsigned int direct_conn)
{
extend_info_t *info = NULL;
const node_t *node;
tor_assert(ip);
node = get_node_from_intro_point(ip);
if (node == NULL) {
/* This can happen if the relay serving as intro point has been removed
* from the consensus. In that case, the intro point will be removed from
* the descriptor during the scheduled events. */
goto end;
}
/* In the case of a direct connection (single onion service), it is possible
* our firewall policy won't allow it so this can return a NULL value. */
info = extend_info_from_node(node, direct_conn);
end:
return info;
}
/* Return the number of introduction points that are established for the
* given descriptor. */
static unsigned int
count_desc_circuit_established(const hs_service_descriptor_t *desc)
{
unsigned int count = 0;
tor_assert(desc);
DIGEST256MAP_FOREACH(desc->intro_points.map, key,
const hs_service_intro_point_t *, ip) {
count += ip->circuit_established;
} DIGEST256MAP_FOREACH_END;
return count;
}
/* For a given service and descriptor of that service, close all active
* directory connections. */
static void
close_directory_connections(const hs_service_t *service,
const hs_service_descriptor_t *desc)
{
unsigned int count = 0;
smartlist_t *dir_conns;
tor_assert(service);
tor_assert(desc);
/* Close pending HS desc upload connections for the blinded key of 'desc'. */
dir_conns = connection_list_by_type_purpose(CONN_TYPE_DIR,
DIR_PURPOSE_UPLOAD_HSDESC);
SMARTLIST_FOREACH_BEGIN(dir_conns, connection_t *, conn) {
dir_connection_t *dir_conn = TO_DIR_CONN(conn);
if (ed25519_pubkey_eq(&dir_conn->hs_ident->identity_pk,
&service->keys.identity_pk) &&
ed25519_pubkey_eq(&dir_conn->hs_ident->blinded_pk,
&desc->blinded_kp.pubkey)) {
connection_mark_for_close(conn);
count++;
continue;
}
} SMARTLIST_FOREACH_END(conn);
log_info(LD_REND, "Closed %u active service directory connections for "
"descriptor %s of service %s",
count, safe_str_client(ed25519_fmt(&desc->blinded_kp.pubkey)),
safe_str_client(service->onion_address));
/* We don't have ownership of the objects in this list. */
smartlist_free(dir_conns);
}
/* Close all rendezvous circuits for the given service. */
static void
close_service_rp_circuits(hs_service_t *service)
{
origin_circuit_t *ocirc = NULL;
tor_assert(service);
/* The reason we go over all circuit instead of using the circuitmap API is
* because most hidden service circuits are rendezvous circuits so there is
* no real improvement at getting all rendezvous circuits from the
* circuitmap and then going over them all to find the right ones.
* Furthermore, another option would have been to keep a list of RP cookies
* for a service but it creates an engineering complexity since we don't
* have a "RP circuit closed" event to clean it up properly so we avoid a
* memory DoS possibility. */
while ((ocirc = circuit_get_next_service_rp_circ(ocirc))) {
/* Only close circuits that are v3 and for this service. */
if (ocirc->hs_ident != NULL &&
ed25519_pubkey_eq(&ocirc->hs_ident->identity_pk,
&service->keys.identity_pk)) {
/* Reason is FINISHED because service has been removed and thus the
* circuit is considered old/uneeded. When freed, it is removed from the
* hs circuitmap. */
circuit_mark_for_close(TO_CIRCUIT(ocirc), END_CIRC_REASON_FINISHED);
}
}
}
/* Close the circuit(s) for the given map of introduction points. */
static void
close_intro_circuits(hs_service_intropoints_t *intro_points)
{
tor_assert(intro_points);
DIGEST256MAP_FOREACH(intro_points->map, key,
const hs_service_intro_point_t *, ip) {
origin_circuit_t *ocirc = hs_circ_service_get_intro_circ(ip);
if (ocirc) {
/* Reason is FINISHED because service has been removed and thus the
* circuit is considered old/uneeded. When freed, the circuit is removed
* from the HS circuitmap. */
circuit_mark_for_close(TO_CIRCUIT(ocirc), END_CIRC_REASON_FINISHED);
}
} DIGEST256MAP_FOREACH_END;
}
/* Close all introduction circuits for the given service. */
static void
close_service_intro_circuits(hs_service_t *service)
{
tor_assert(service);
FOR_EACH_DESCRIPTOR_BEGIN(service, desc) {
close_intro_circuits(&desc->intro_points);
} FOR_EACH_DESCRIPTOR_END;
}
/* Close any circuits related to the given service. */
static void
close_service_circuits(hs_service_t *service)
{
tor_assert(service);
/* Only support for version >= 3. */
if (BUG(service->config.version < HS_VERSION_THREE)) {
return;
}
/* Close intro points. */
close_service_intro_circuits(service);
/* Close rendezvous points. */
close_service_rp_circuits(service);
}
/* Move every ephemeral services from the src service map to the dst service
* map. It is possible that a service can't be register to the dst map which
* won't stop the process of moving them all but will trigger a log warn. */
static void
move_ephemeral_services(hs_service_ht *src, hs_service_ht *dst)
{
hs_service_t **iter, **next;
tor_assert(src);
tor_assert(dst);
/* Iterate over the map to find ephemeral service and move them to the other
* map. We loop using this method to have a safe removal process. */
for (iter = HT_START(hs_service_ht, src); iter != NULL; iter = next) {
hs_service_t *s = *iter;
if (!s->config.is_ephemeral) {
/* Yeah, we are in a very manual loop :). */
next = HT_NEXT(hs_service_ht, src, iter);
continue;
}
/* Remove service from map and then register to it to the other map.
* Reminder that "*iter" and "s" are the same thing. */
next = HT_NEXT_RMV(hs_service_ht, src, iter);
if (register_service(dst, s) < 0) {
log_warn(LD_BUG, "Ephemeral service key is already being used. "
"Skipping.");
}
}
}
/* Return a const string of the directory path escaped. If this is an
* ephemeral service, it returns "[EPHEMERAL]". This can only be called from
* the main thread because escaped() uses a static variable. */
static const char *
service_escaped_dir(const hs_service_t *s)
{
return (s->config.is_ephemeral) ? "[EPHEMERAL]" :
escaped(s->config.directory_path);
}
/** Move the hidden service state from <b>src</b> to <b>dst</b>. We do this
* when we receive a SIGHUP: <b>dst</b> is the post-HUP service */
static void
move_hs_state(hs_service_t *src_service, hs_service_t *dst_service)
{
tor_assert(src_service);
tor_assert(dst_service);
hs_service_state_t *src = &src_service->state;
hs_service_state_t *dst = &dst_service->state;
/* Let's do a shallow copy */
dst->intro_circ_retry_started_time = src->intro_circ_retry_started_time;
dst->num_intro_circ_launched = src->num_intro_circ_launched;
/* Freeing a NULL replaycache triggers an info LD_BUG. */
if (dst->replay_cache_rend_cookie != NULL) {
replaycache_free(dst->replay_cache_rend_cookie);
}
dst->replay_cache_rend_cookie = src->replay_cache_rend_cookie;
src->replay_cache_rend_cookie = NULL; /* steal pointer reference */
}
/* Register services that are in the staging list. Once this function returns,
* the global service map will be set with the right content and all non
* surviving services will be cleaned up. */
static void
register_all_services(void)
{
struct hs_service_ht *new_service_map;
tor_assert(hs_service_staging_list);
/* Allocate a new map that will replace the current one. */
new_service_map = tor_malloc_zero(sizeof(*new_service_map));
HT_INIT(hs_service_ht, new_service_map);
/* First step is to transfer all ephemeral services from the current global
* map to the new one we are constructing. We do not prune ephemeral
* services as the only way to kill them is by deleting it from the control
* port or stopping the tor daemon. */
move_ephemeral_services(hs_service_map, new_service_map);
SMARTLIST_FOREACH_BEGIN(hs_service_staging_list, hs_service_t *, snew) {
hs_service_t *s;
/* Check if that service is already in our global map and if so, we'll
* transfer the intro points to it. */
s = find_service(hs_service_map, &snew->keys.identity_pk);
if (s) {
/* Pass ownership of the descriptors from s (the current service) to
* snew (the newly configured one). */
move_descriptors(s, snew);
move_hs_state(s, snew);
/* Remove the service from the global map because after this, we need to
* go over the remaining service in that map that aren't surviving the
* reload to close their circuits. */
remove_service(hs_service_map, s);
hs_service_free(s);
}
/* Great, this service is now ready to be added to our new map. */
if (BUG(register_service(new_service_map, snew) < 0)) {
/* This should never happen because prior to registration, we validate
* every service against the entire set. Not being able to register a
* service means we failed to validate correctly. In that case, don't
* break tor and ignore the service but tell user. */
log_warn(LD_BUG, "Unable to register service with directory %s",
service_escaped_dir(snew));
SMARTLIST_DEL_CURRENT(hs_service_staging_list, snew);
hs_service_free(snew);
}
} SMARTLIST_FOREACH_END(snew);
/* Close any circuits associated with the non surviving services. Every
* service in the current global map are roaming. */
FOR_EACH_SERVICE_BEGIN(service) {
close_service_circuits(service);
} FOR_EACH_SERVICE_END;
/* Time to make the switch. We'll clear the staging list because its content
* has now changed ownership to the map. */
smartlist_clear(hs_service_staging_list);
service_free_all();
hs_service_map = new_service_map;
/* We've just register services into the new map and now we've replaced the
* global map with it so we have to notify that the change happened. When
* registering a service, the notify is only triggered if the destination
* map is the global map for which in here it was not. */
hs_service_map_has_changed();
}
/* Write the onion address of a given service to the given filename fname_ in
* the service directory. Return 0 on success else -1 on error. */
STATIC int
write_address_to_file(const hs_service_t *service, const char *fname_)
{
int ret = -1;
char *fname = NULL;
char *addr_buf = NULL;
tor_assert(service);
tor_assert(fname_);
/* Construct the full address with the onion tld and write the hostname file
* to disk. */
tor_asprintf(&addr_buf, "%s.%s\n", service->onion_address, address_tld);
/* Notice here that we use the given "fname_". */
fname = hs_path_from_filename(service->config.directory_path, fname_);
if (write_str_to_file(fname, addr_buf, 0) < 0) {
log_warn(LD_REND, "Could not write onion address to hostname file %s",
escaped(fname));
goto end;
}
#ifndef _WIN32
if (service->config.dir_group_readable) {
/* Mode to 0640. */
if (chmod(fname, S_IRUSR | S_IWUSR | S_IRGRP) < 0) {
log_warn(LD_FS, "Unable to make onion service hostname file %s "
"group-readable.", escaped(fname));
}
}
#endif /* !defined(_WIN32) */
/* Success. */
ret = 0;
end:
tor_free(fname);
tor_free(addr_buf);
return ret;
}
/* Load and/or generate private keys for the given service. On success, the
* hostname file will be written to disk along with the master private key iff
* the service is not configured for offline keys. Return 0 on success else -1
* on failure. */
static int
load_service_keys(hs_service_t *service)
{
int ret = -1;
char *fname = NULL;
ed25519_keypair_t *kp;
const hs_service_config_t *config;
tor_assert(service);
config = &service->config;
/* Create and fix permission on service directory. We are about to write
* files to that directory so make sure it exists and has the right
* permissions. We do this here because at this stage we know that Tor is
* actually running and the service we have has been validated. */
if (BUG(hs_check_service_private_dir(get_options()->User,
config->directory_path,
config->dir_group_readable, 1) < 0)) {
goto end;
}
/* Try to load the keys from file or generate it if not found. */
fname = hs_path_from_filename(config->directory_path, fname_keyfile_prefix);
/* Don't ask for key creation, we want to know if we were able to load it or
* we had to generate it. Better logging! */
kp = ed_key_init_from_file(fname, INIT_ED_KEY_SPLIT, LOG_INFO, NULL, 0, 0,
0, NULL);
if (!kp) {
log_info(LD_REND, "Unable to load keys from %s. Generating it...", fname);
/* We'll now try to generate the keys and for it we want the strongest
* randomness for it. The keypair will be written in different files. */
uint32_t key_flags = INIT_ED_KEY_CREATE | INIT_ED_KEY_EXTRA_STRONG |
INIT_ED_KEY_SPLIT;
kp = ed_key_init_from_file(fname, key_flags, LOG_WARN, NULL, 0, 0, 0,
NULL);
if (!kp) {
log_warn(LD_REND, "Unable to generate keys and save in %s.", fname);
goto end;
}
}
/* Copy loaded or generated keys to service object. */
ed25519_pubkey_copy(&service->keys.identity_pk, &kp->pubkey);
memcpy(&service->keys.identity_sk, &kp->seckey,
sizeof(service->keys.identity_sk));
/* This does a proper memory wipe. */
ed25519_keypair_free(kp);
/* Build onion address from the newly loaded keys. */
tor_assert(service->config.version <= UINT8_MAX);
hs_build_address(&service->keys.identity_pk,
(uint8_t) service->config.version,
service->onion_address);
/* Write onion address to hostname file. */
if (write_address_to_file(service, fname_hostname) < 0) {
goto end;
}
/* Succes. */
ret = 0;
end:
tor_free(fname);
return ret;
}
/* Free a given service descriptor object and all key material is wiped. */
STATIC void
service_descriptor_free_(hs_service_descriptor_t *desc)
{
if (!desc) {
return;
}
hs_descriptor_free(desc->desc);
memwipe(&desc->signing_kp, 0, sizeof(desc->signing_kp));
memwipe(&desc->blinded_kp, 0, sizeof(desc->blinded_kp));
/* Cleanup all intro points. */
digest256map_free(desc->intro_points.map, service_intro_point_free_void);
digestmap_free(desc->intro_points.failed_id, tor_free_);
if (desc->previous_hsdirs) {
SMARTLIST_FOREACH(desc->previous_hsdirs, char *, s, tor_free(s));
smartlist_free(desc->previous_hsdirs);
}
tor_free(desc);
}
/* Return a newly allocated service descriptor object. */
STATIC hs_service_descriptor_t *
service_descriptor_new(void)
{
hs_service_descriptor_t *sdesc = tor_malloc_zero(sizeof(*sdesc));
sdesc->desc = tor_malloc_zero(sizeof(hs_descriptor_t));
/* Initialize the intro points map. */
sdesc->intro_points.map = digest256map_new();
sdesc->intro_points.failed_id = digestmap_new();
sdesc->previous_hsdirs = smartlist_new();
return sdesc;
}
/* Move descriptor(s) from the src service to the dst service. We do this
* during SIGHUP when we re-create our hidden services. */
static void
move_descriptors(hs_service_t *src, hs_service_t *dst)
{
tor_assert(src);
tor_assert(dst);
if (src->desc_current) {
/* Nothing should be there, but clean it up just in case */
if (BUG(dst->desc_current)) {
service_descriptor_free(dst->desc_current);
}
dst->desc_current = src->desc_current;
src->desc_current = NULL;
}
if (src->desc_next) {
/* Nothing should be there, but clean it up just in case */
if (BUG(dst->desc_next)) {
service_descriptor_free(dst->desc_next);
}
dst->desc_next = src->desc_next;
src->desc_next = NULL;
}
}
/* From the given service, remove all expired failing intro points for each
* descriptor. */
static void
remove_expired_failing_intro(hs_service_t *service, time_t now)
{
tor_assert(service);
/* For both descriptors, cleanup the failing intro points list. */
FOR_EACH_DESCRIPTOR_BEGIN(service, desc) {
DIGESTMAP_FOREACH_MODIFY(desc->intro_points.failed_id, key, time_t *, t) {
time_t failure_time = *t;
if ((failure_time + INTRO_CIRC_RETRY_PERIOD) <= now) {
MAP_DEL_CURRENT(key);
tor_free(t);
}
} DIGESTMAP_FOREACH_END;
} FOR_EACH_DESCRIPTOR_END;
}
/* For the given descriptor desc, put all node_t object found from its failing
* intro point list and put them in the given node_list. */
static void
setup_intro_point_exclude_list(const hs_service_descriptor_t *desc,
smartlist_t *node_list)
{
tor_assert(desc);
tor_assert(node_list);
DIGESTMAP_FOREACH(desc->intro_points.failed_id, key, time_t *, t) {
(void) t; /* Make gcc happy. */
const node_t *node = node_get_by_id(key);
if (node) {
smartlist_add(node_list, (void *) node);
}
} DIGESTMAP_FOREACH_END;
}
/* For the given failing intro point ip, we add its time of failure to the
* failed map and index it by identity digest (legacy ID) in the descriptor
* desc failed id map. */
static void
remember_failing_intro_point(const hs_service_intro_point_t *ip,
hs_service_descriptor_t *desc, time_t now)
{
time_t *time_of_failure, *prev_ptr;
const hs_desc_link_specifier_t *legacy_ls;
tor_assert(ip);
tor_assert(desc);
time_of_failure = tor_malloc_zero(sizeof(time_t));
*time_of_failure = now;
legacy_ls = get_link_spec_by_type(ip, LS_LEGACY_ID);
tor_assert(legacy_ls);
prev_ptr = digestmap_set(desc->intro_points.failed_id,
(const char *) legacy_ls->u.legacy_id,
time_of_failure);
tor_free(prev_ptr);
}
/* Copy the descriptor link specifier object from src to dst. */
static void
link_specifier_copy(hs_desc_link_specifier_t *dst,
const hs_desc_link_specifier_t *src)
{
tor_assert(dst);
tor_assert(src);
memcpy(dst, src, sizeof(hs_desc_link_specifier_t));
}
/* Using a given descriptor signing keypair signing_kp, a service intro point
* object ip and the time now, setup the content of an already allocated
* descriptor intro desc_ip.
*
* Return 0 on success else a negative value. */
static int
setup_desc_intro_point(const ed25519_keypair_t *signing_kp,
const hs_service_intro_point_t *ip,
time_t now, hs_desc_intro_point_t *desc_ip)
{
int ret = -1;
time_t nearest_hour = now - (now % 3600);
tor_assert(signing_kp);
tor_assert(ip);
tor_assert(desc_ip);
/* Copy the onion key. */
memcpy(&desc_ip->onion_key, &ip->onion_key, sizeof(desc_ip->onion_key));
/* Key and certificate material. */
desc_ip->auth_key_cert = tor_cert_create(signing_kp,
CERT_TYPE_AUTH_HS_IP_KEY,
&ip->auth_key_kp.pubkey,
nearest_hour,
HS_DESC_CERT_LIFETIME,
CERT_FLAG_INCLUDE_SIGNING_KEY);
if (desc_ip->auth_key_cert == NULL) {
log_warn(LD_REND, "Unable to create intro point auth-key certificate");
goto done;
}
/* Copy link specifier(s). */
SMARTLIST_FOREACH_BEGIN(ip->base.link_specifiers,
const hs_desc_link_specifier_t *, ls) {
hs_desc_link_specifier_t *copy = tor_malloc_zero(sizeof(*copy));
link_specifier_copy(copy, ls);
smartlist_add(desc_ip->link_specifiers, copy);
} SMARTLIST_FOREACH_END(ls);
/* For a legacy intro point, we'll use an RSA/ed cross certificate. */
if (ip->base.is_only_legacy) {
desc_ip->legacy.key = crypto_pk_dup_key(ip->legacy_key);
/* Create cross certification cert. */
ssize_t cert_len = tor_make_rsa_ed25519_crosscert(
&signing_kp->pubkey,
desc_ip->legacy.key,
nearest_hour + HS_DESC_CERT_LIFETIME,
&desc_ip->legacy.cert.encoded);
if (cert_len < 0) {
log_warn(LD_REND, "Unable to create enc key legacy cross cert.");
goto done;
}
desc_ip->legacy.cert.len = cert_len;
}
/* Encryption key and its cross certificate. */
{
ed25519_public_key_t ed25519_pubkey;
/* Use the public curve25519 key. */
memcpy(&desc_ip->enc_key, &ip->enc_key_kp.pubkey,
sizeof(desc_ip->enc_key));
/* The following can't fail. */
ed25519_public_key_from_curve25519_public_key(&ed25519_pubkey,
&ip->enc_key_kp.pubkey,
0);
desc_ip->enc_key_cert = tor_cert_create(signing_kp,
CERT_TYPE_CROSS_HS_IP_KEYS,
&ed25519_pubkey, nearest_hour,
HS_DESC_CERT_LIFETIME,
CERT_FLAG_INCLUDE_SIGNING_KEY);
if (desc_ip->enc_key_cert == NULL) {
log_warn(LD_REND, "Unable to create enc key curve25519 cross cert.");
goto done;
}
}
/* Success. */
ret = 0;
done:
return ret;
}
/* Using the given descriptor from the given service, build the descriptor
* intro point list so we can then encode the descriptor for publication. This
* function does not pick intro points, they have to be in the descriptor
* current map. Cryptographic material (keys) must be initialized in the
* descriptor for this function to make sense. */
static void
build_desc_intro_points(const hs_service_t *service,
hs_service_descriptor_t *desc, time_t now)
{
hs_desc_encrypted_data_t *encrypted;
tor_assert(service);
tor_assert(desc);
/* Ease our life. */
encrypted = &desc->desc->encrypted_data;
/* Cleanup intro points, we are about to set them from scratch. */
hs_descriptor_clear_intro_points(desc->desc);
DIGEST256MAP_FOREACH(desc->intro_points.map, key,
const hs_service_intro_point_t *, ip) {
hs_desc_intro_point_t *desc_ip = hs_desc_intro_point_new();
if (setup_desc_intro_point(&desc->signing_kp, ip, now, desc_ip) < 0) {
hs_desc_intro_point_free(desc_ip);
continue;
}
/* We have a valid descriptor intro point. Add it to the list. */
smartlist_add(encrypted->intro_points, desc_ip);
} DIGEST256MAP_FOREACH_END;
}
/* Populate the descriptor encrypted section from the given service object.
* This will generate a valid list of introduction points that can be used
* after for circuit creation. Return 0 on success else -1 on error. */
static int
build_service_desc_encrypted(const hs_service_t *service,
hs_service_descriptor_t *desc)
{
hs_desc_encrypted_data_t *encrypted;
tor_assert(service);
tor_assert(desc);
encrypted = &desc->desc->encrypted_data;
encrypted->create2_ntor = 1;
encrypted->single_onion_service = service->config.is_single_onion;
/* Setup introduction points from what we have in the service. */
if (encrypted->intro_points == NULL) {
encrypted->intro_points = smartlist_new();
}
/* We do NOT build introduction point yet, we only do that once the circuit
* have been opened. Until we have the right number of introduction points,
* we do not encode anything in the descriptor. */
/* XXX: Support client authorization (#20700). */
encrypted->intro_auth_types = NULL;
return 0;
}
/* Populate the descriptor plaintext section from the given service object.
* The caller must make sure that the keys in the descriptors are valid that
* is are non-zero. Return 0 on success else -1 on error. */
static int
build_service_desc_plaintext(const hs_service_t *service,
hs_service_descriptor_t *desc, time_t now)
{
int ret = -1;
hs_desc_plaintext_data_t *plaintext;
tor_assert(service);
tor_assert(desc);
/* XXX: Use a "assert_desc_ok()" ? */
tor_assert(!tor_mem_is_zero((char *) &desc->blinded_kp,
sizeof(desc->blinded_kp)));
tor_assert(!tor_mem_is_zero((char *) &desc->signing_kp,
sizeof(desc->signing_kp)));
/* Set the subcredential. */
hs_get_subcredential(&service->keys.identity_pk, &desc->blinded_kp.pubkey,
desc->desc->subcredential);
plaintext = &desc->desc->plaintext_data;
plaintext->version = service->config.version;
plaintext->lifetime_sec = HS_DESC_DEFAULT_LIFETIME;
plaintext->signing_key_cert =
tor_cert_create(&desc->blinded_kp, CERT_TYPE_SIGNING_HS_DESC,
&desc->signing_kp.pubkey, now, HS_DESC_CERT_LIFETIME,
CERT_FLAG_INCLUDE_SIGNING_KEY);
if (plaintext->signing_key_cert == NULL) {
log_warn(LD_REND, "Unable to create descriptor signing certificate for "
"service %s",
safe_str_client(service->onion_address));
goto end;
}
/* Copy public key material to go in the descriptor. */
ed25519_pubkey_copy(&plaintext->signing_pubkey, &desc->signing_kp.pubkey);
ed25519_pubkey_copy(&plaintext->blinded_pubkey, &desc->blinded_kp.pubkey);
/* Success. */
ret = 0;
end:
return ret;
}
/* For the given service and descriptor object, create the key material which
* is the blinded keypair and the descriptor signing keypair. Return 0 on
* success else -1 on error where the generated keys MUST be ignored. */
static int
build_service_desc_keys(const hs_service_t *service,
hs_service_descriptor_t *desc,
uint64_t time_period_num)
{
int ret = 0;
ed25519_keypair_t kp;
tor_assert(desc);
tor_assert(!tor_mem_is_zero((char *) &service->keys.identity_pk,
ED25519_PUBKEY_LEN));
/* XXX: Support offline key feature (#18098). */
/* Copy the identity keys to the keypair so we can use it to create the
* blinded key. */
memcpy(&kp.pubkey, &service->keys.identity_pk, sizeof(kp.pubkey));
memcpy(&kp.seckey, &service->keys.identity_sk, sizeof(kp.seckey));
/* Build blinded keypair for this time period. */
hs_build_blinded_keypair(&kp, NULL, 0, time_period_num, &desc->blinded_kp);
/* Let's not keep too much traces of our keys in memory. */
memwipe(&kp, 0, sizeof(kp));
/* No need for extra strong, this is a temporary key only for this
* descriptor. Nothing long term. */
if (ed25519_keypair_generate(&desc->signing_kp, 0) < 0) {
log_warn(LD_REND, "Can't generate descriptor signing keypair for "
"service %s",
safe_str_client(service->onion_address));
ret = -1;
}
return ret;
}
/* Given a service and the current time, build a descriptor for the service.
* This function does not pick introduction point, this needs to be done by
* the update function. On success, desc_out will point to the newly allocated
* descriptor object.
*
* This can error if we are unable to create keys or certificate. */
static void
build_service_descriptor(hs_service_t *service, time_t now,
uint64_t time_period_num,
hs_service_descriptor_t **desc_out)
{
char *encoded_desc;
hs_service_descriptor_t *desc;
tor_assert(service);
tor_assert(desc_out);
desc = service_descriptor_new();
desc->time_period_num = time_period_num;
/* Create the needed keys so we can setup the descriptor content. */
if (build_service_desc_keys(service, desc, time_period_num) < 0) {
goto err;
}
/* Setup plaintext descriptor content. */
if (build_service_desc_plaintext(service, desc, now) < 0) {
goto err;
}
/* Setup encrypted descriptor content. */
if (build_service_desc_encrypted(service, desc) < 0) {
goto err;
}
/* Set the revision counter for this descriptor */
set_descriptor_revision_counter(desc->desc);
/* Let's make sure that we've created a descriptor that can actually be
* encoded properly. This function also checks if the encoded output is
* decodable after. */
if (BUG(hs_desc_encode_descriptor(desc->desc, &desc->signing_kp,
&encoded_desc) < 0)) {
goto err;
}
tor_free(encoded_desc);
/* Assign newly built descriptor to the next slot. */
*desc_out = desc;
/* Fire a CREATED control port event. */
hs_control_desc_event_created(service->onion_address,
&desc->blinded_kp.pubkey);
return;
err:
service_descriptor_free(desc);
}
/* Build both descriptors for the given service that has just booted up.
* Because it's a special case, it deserves its special function ;). */
static void
build_descriptors_for_new_service(hs_service_t *service, time_t now)
{
uint64_t current_desc_tp, next_desc_tp;
tor_assert(service);
/* These are the conditions for a new service. */
tor_assert(!service->desc_current);
tor_assert(!service->desc_next);
/*
* +------------------------------------------------------------------+
* | |
* | 00:00 12:00 00:00 12:00 00:00 12:00 |
* | SRV#1 TP#1 SRV#2 TP#2 SRV#3 TP#3 |
* | |
* | $==========|-----------$===========|-----------$===========| |
* | ^ ^ |
* | A B |
* +------------------------------------------------------------------+
*
* Case A: The service boots up before a new time period, the current time
* period is thus TP#1 and the next is TP#2 which for both we have access to
* their SRVs.
*
* Case B: The service boots up inside TP#2, we can't use the TP#3 for the
* next descriptor because we don't have the SRV#3 so the current should be
* TP#1 and next TP#2.
*/
if (hs_in_period_between_tp_and_srv(NULL, now)) {
/* Case B from the above, inside of the new time period. */
current_desc_tp = hs_get_previous_time_period_num(0); /* TP#1 */
next_desc_tp = hs_get_time_period_num(0); /* TP#2 */
} else {
/* Case A from the above, outside of the new time period. */
current_desc_tp = hs_get_time_period_num(0); /* TP#1 */
next_desc_tp = hs_get_next_time_period_num(0); /* TP#2 */
}
/* Build descriptors. */
build_service_descriptor(service, now, current_desc_tp,
&service->desc_current);
build_service_descriptor(service, now, next_desc_tp,
&service->desc_next);
log_info(LD_REND, "Hidden service %s has just started. Both descriptors "
"built. Now scheduled for upload.",
safe_str_client(service->onion_address));
}
/* Build descriptors for each service if needed. There are conditions to build
* a descriptor which are details in the function. */
STATIC void
build_all_descriptors(time_t now)
{
FOR_EACH_SERVICE_BEGIN(service) {
/* A service booting up will have both descriptors to NULL. No other cases
* makes both descriptor non existent. */
if (service->desc_current == NULL && service->desc_next == NULL) {
build_descriptors_for_new_service(service, now);
continue;
}
/* Reaching this point means we are pass bootup so at runtime. We should
* *never* have an empty current descriptor. If the next descriptor is
* empty, we'll try to build it for the next time period. This only
* happens when we rotate meaning that we are guaranteed to have a new SRV
* at that point for the next time period. */
if (BUG(service->desc_current == NULL)) {
continue;
}
if (service->desc_next == NULL) {
build_service_descriptor(service, now, hs_get_next_time_period_num(0),
&service->desc_next);
log_info(LD_REND, "Hidden service %s next descriptor successfully "
"built. Now scheduled for upload.",
safe_str_client(service->onion_address));
}
} FOR_EACH_DESCRIPTOR_END;
}
/* Randomly pick a node to become an introduction point but not present in the
* given exclude_nodes list. The chosen node is put in the exclude list
* regardless of success or not because in case of failure, the node is simply
* unsusable from that point on.
*
* If direct_conn is set, try to pick a node that our local firewall/policy
* allows us to connect to directly. If we can't find any, return NULL.
* This function supports selecting dual-stack nodes for direct single onion
* service IPv6 connections. But it does not send IPv6 addresses in link
* specifiers. (Current clients don't use IPv6 addresses to extend, and
* direct client connections to intro points are not supported.)
*
* Return a newly allocated service intro point ready to be used for encoding.
* Return NULL on error. */
static hs_service_intro_point_t *
pick_intro_point(unsigned int direct_conn, smartlist_t *exclude_nodes)
{
const node_t *node;
extend_info_t *info = NULL;
hs_service_intro_point_t *ip = NULL;
/* Normal 3-hop introduction point flags. */
router_crn_flags_t flags = CRN_NEED_UPTIME | CRN_NEED_DESC;
/* Single onion flags. */
router_crn_flags_t direct_flags = flags | CRN_PREF_ADDR | CRN_DIRECT_CONN;
node = router_choose_random_node(exclude_nodes, get_options()->ExcludeNodes,
direct_conn ? direct_flags : flags);
/* Unable to find a node. When looking for a node for a direct connection,
* we could try a 3-hop path instead. We'll add support for this in a later
* release. */
if (!node) {
goto err;
}
/* We have a suitable node, add it to the exclude list. We do this *before*
* we can validate the extend information because even in case of failure,
* we don't want to use that node anymore. */
smartlist_add(exclude_nodes, (void *) node);
/* We do this to ease our life but also this call makes appropriate checks
* of the node object such as validating ntor support for instance.
*
* We must provide an extend_info for clients to connect over a 3-hop path,
* so we don't pass direct_conn here. */
info = extend_info_from_node(node, 0);
if (BUG(info == NULL)) {
goto err;
}
/* Let's do a basic sanity check here so that we don't end up advertising the
* ed25519 identity key of relays that don't actually support the link
* protocol */
if (!node_supports_ed25519_link_authentication(node, 0)) {
tor_assert_nonfatal(ed25519_public_key_is_zero(&info->ed_identity));
} else {
/* Make sure we *do* have an ed key if we support the link authentication.
* Sending an empty key would result in a failure to extend. */
tor_assert_nonfatal(!ed25519_public_key_is_zero(&info->ed_identity));
}
/* Create our objects and populate them with the node information. */
ip = service_intro_point_new(info, !node_supports_ed25519_hs_intro(node));
if (ip == NULL) {
goto err;
}
log_info(LD_REND, "Picked intro point: %s", extend_info_describe(info));
extend_info_free(info);
return ip;
err:
service_intro_point_free(ip);
extend_info_free(info);
return NULL;
}
/* For a given descriptor from the given service, pick any needed intro points
* and update the current map with those newly picked intro points. Return the
* number node that might have been added to the descriptor current map. */
static unsigned int
pick_needed_intro_points(hs_service_t *service,
hs_service_descriptor_t *desc)
{
int i = 0, num_needed_ip;
smartlist_t *exclude_nodes = smartlist_new();
tor_assert(service);
tor_assert(desc);
/* Compute how many intro points we actually need to open. */
num_needed_ip = service->config.num_intro_points -
digest256map_size(desc->intro_points.map);
if (BUG(num_needed_ip < 0)) {
/* Let's not make tor freak out here and just skip this. */
goto done;
}
/* We want to end up with config.num_intro_points intro points, but if we
* have no intro points at all (chances are they all cycled or we are
* starting up), we launch get_intro_point_num_extra() extra circuits and
* use the first config.num_intro_points that complete. See proposal #155,
* section 4 for the rationale of this which is purely for performance.
*
* The ones after the first config.num_intro_points will be converted to
* 'General' internal circuits and then we'll drop them from the list of
* intro points. */
if (digest256map_size(desc->intro_points.map) == 0) {
num_needed_ip += get_intro_point_num_extra();
}
/* Build an exclude list of nodes of our intro point(s). The expiring intro
* points are OK to pick again because this is afterall a concept of round
* robin so they are considered valid nodes to pick again. */
DIGEST256MAP_FOREACH(desc->intro_points.map, key,
hs_service_intro_point_t *, ip) {
const node_t *intro_node = get_node_from_intro_point(ip);
if (intro_node) {
smartlist_add(exclude_nodes, (void*)intro_node);
}
} DIGEST256MAP_FOREACH_END;
/* Also, add the failing intro points that our descriptor encounteered in
* the exclude node list. */
setup_intro_point_exclude_list(desc, exclude_nodes);
for (i = 0; i < num_needed_ip; i++) {
hs_service_intro_point_t *ip;
/* This function will add the picked intro point node to the exclude nodes
* list so we don't pick the same one at the next iteration. */
ip = pick_intro_point(service->config.is_single_onion, exclude_nodes);
if (ip == NULL) {
/* If we end up unable to pick an introduction point it is because we
* can't find suitable node and calling this again is highly unlikely to
* give us a valid node all of the sudden. */
log_info(LD_REND, "Unable to find a suitable node to be an "
"introduction point for service %s.",
safe_str_client(service->onion_address));
goto done;
}
/* Valid intro point object, add it to the descriptor current map. */
service_intro_point_add(desc->intro_points.map, ip);
}
/* We've successfully picked all our needed intro points thus none are
* missing which will tell our upload process to expect the number of
* circuits to be the number of configured intro points circuits and not the
* number of intro points object that we have. */
desc->missing_intro_points = 0;
/* Success. */
done:
/* We don't have ownership of the node_t object in this list. */
smartlist_free(exclude_nodes);
return i;
}
/** Clear previous cached HSDirs in <b>desc</b>. */
static void
service_desc_clear_previous_hsdirs(hs_service_descriptor_t *desc)
{
if (BUG(!desc->previous_hsdirs)) {
return;
}
SMARTLIST_FOREACH(desc->previous_hsdirs, char*, s, tor_free(s));
smartlist_clear(desc->previous_hsdirs);
}
/** Note that we attempted to upload <b>desc</b> to <b>hsdir</b>. */
static void
service_desc_note_upload(hs_service_descriptor_t *desc, const node_t *hsdir)
{
char b64_digest[BASE64_DIGEST_LEN+1] = {0};
digest_to_base64(b64_digest, hsdir->identity);
if (BUG(!desc->previous_hsdirs)) {
return;
}
if (!smartlist_contains_string(desc->previous_hsdirs, b64_digest)) {
smartlist_add_strdup(desc->previous_hsdirs, b64_digest);
}
}
/** Schedule an upload of <b>desc</b>. If <b>descriptor_changed</b> is set, it
* means that this descriptor is dirty. */
STATIC void
service_desc_schedule_upload(hs_service_descriptor_t *desc,
time_t now,
int descriptor_changed)
{
desc->next_upload_time = now;
/* If the descriptor changed, clean up the old HSDirs list. We want to
* re-upload no matter what. */
if (descriptor_changed) {
service_desc_clear_previous_hsdirs(desc);
}
}
/* Update the given descriptor from the given service. The possible update
* actions includes:
* - Picking missing intro points if needed.
* - Incrementing the revision counter if needed.
*/
static void
update_service_descriptor(hs_service_t *service,
hs_service_descriptor_t *desc, time_t now)
{
unsigned int num_intro_points;
tor_assert(service);
tor_assert(desc);
tor_assert(desc->desc);
num_intro_points = digest256map_size(desc->intro_points.map);
/* Pick any missing introduction point(s). */
if (num_intro_points < service->config.num_intro_points) {
unsigned int num_new_intro_points = pick_needed_intro_points(service,
desc);
if (num_new_intro_points != 0) {
log_info(LD_REND, "Service %s just picked %u intro points and wanted "
"%u for %s descriptor. It currently has %d intro "
"points. Launching ESTABLISH_INTRO circuit shortly.",
safe_str_client(service->onion_address),
num_new_intro_points,
service->config.num_intro_points - num_intro_points,
(desc == service->desc_current) ? "current" : "next",
num_intro_points);
/* We'll build those introduction point into the descriptor once we have
* confirmation that the circuits are opened and ready. However,
* indicate that this descriptor should be uploaded from now on. */
service_desc_schedule_upload(desc, now, 1);
}
/* Were we able to pick all the intro points we needed? If not, we'll
* flag the descriptor that it's missing intro points because it
* couldn't pick enough which will trigger a descriptor upload. */
if ((num_new_intro_points + num_intro_points) <
service->config.num_intro_points) {
desc->missing_intro_points = 1;
}
}
}
/* Update descriptors for each service if needed. */
STATIC void
update_all_descriptors(time_t now)
{
FOR_EACH_SERVICE_BEGIN(service) {
/* We'll try to update each descriptor that is if certain conditions apply
* in order for the descriptor to be updated. */
FOR_EACH_DESCRIPTOR_BEGIN(service, desc) {
update_service_descriptor(service, desc, now);
} FOR_EACH_DESCRIPTOR_END;
} FOR_EACH_SERVICE_END;
}
/* Return true iff the given intro point has expired that is it has been used
* for too long or we've reached our max seen INTRODUCE2 cell. */
STATIC int
intro_point_should_expire(const hs_service_intro_point_t *ip,
time_t now)
{
tor_assert(ip);
if (ip->introduce2_count >= ip->introduce2_max) {
goto expired;
}
if (ip->time_to_expire <= now) {
goto expired;
}
/* Not expiring. */
return 0;
expired:
return 1;
}
/* Go over the given set of intro points for each service and remove any
* invalid ones. The conditions for removal are:
*
* - The node doesn't exists anymore (not in consensus)
* OR
* - The intro point maximum circuit retry count has been reached and no
* circuit can be found associated with it.
* OR
* - The intro point has expired and we should pick a new one.
*
* If an intro point is removed, the circuit (if any) is immediately close.
* If a circuit can't be found, the intro point is kept if it hasn't reached
* its maximum circuit retry value and thus should be retried. */
static void
cleanup_intro_points(hs_service_t *service, time_t now)
{
/* List of intro points to close. We can't mark the intro circuits for close
* in the modify loop because doing so calls
* hs_service_intro_circ_has_closed() which does a digest256map_get() on the
* intro points map (that we are iterating over). This can't be done in a
* single iteration after a MAP_DEL_CURRENT, the object will still be
* returned leading to a use-after-free. So, we close the circuits and free
* the intro points after the loop if any. */
smartlist_t *ips_to_free = smartlist_new();
tor_assert(service);
/* For both descriptors, cleanup the intro points. */
FOR_EACH_DESCRIPTOR_BEGIN(service, desc) {
/* Go over the current intro points we have, make sure they are still
* valid and remove any of them that aren't. */
DIGEST256MAP_FOREACH_MODIFY(desc->intro_points.map, key,
hs_service_intro_point_t *, ip) {
const node_t *node = get_node_from_intro_point(ip);
int has_expired = intro_point_should_expire(ip, now);
/* We cleanup an intro point if it has expired or if we do not know the
* node_t anymore (removed from our latest consensus) or if we've
* reached the maximum number of retry with a non existing circuit. */
if (has_expired || node == NULL ||
ip->circuit_retries > MAX_INTRO_POINT_CIRCUIT_RETRIES) {
log_info(LD_REND, "Intro point %s%s (retried: %u times). "
"Removing it.",
describe_intro_point(ip),
has_expired ? " has expired" :
(node == NULL) ? " fell off the consensus" : "",
ip->circuit_retries);
/* We've retried too many times, remember it as a failed intro point
* so we don't pick it up again for INTRO_CIRC_RETRY_PERIOD sec. */
if (ip->circuit_retries > MAX_INTRO_POINT_CIRCUIT_RETRIES) {
remember_failing_intro_point(ip, desc, approx_time());
}
/* Remove intro point from descriptor map and add it to the list of
* ips to free for which we'll also try to close the intro circuit. */
MAP_DEL_CURRENT(key);
smartlist_add(ips_to_free, ip);
}
} DIGEST256MAP_FOREACH_END;
} FOR_EACH_DESCRIPTOR_END;
/* Go over the intro points to free and close their circuit if any. */
SMARTLIST_FOREACH_BEGIN(ips_to_free, hs_service_intro_point_t *, ip) {
/* See if we need to close the intro point circuit as well */
/* XXX: Legacy code does NOT close circuits like this: it keeps the circuit
* open until a new descriptor is uploaded and then closed all expiring
* intro point circuit. Here, we close immediately and because we just
* discarded the intro point, a new one will be selected, a new descriptor
* created and uploaded. There is no difference to an attacker between the
* timing of a new consensus and intro point rotation (possibly?). */
origin_circuit_t *ocirc = hs_circ_service_get_intro_circ(ip);
if (ocirc && !TO_CIRCUIT(ocirc)->marked_for_close) {
circuit_mark_for_close(TO_CIRCUIT(ocirc), END_CIRC_REASON_FINISHED);
}
/* Cleanup the intro point */
service_intro_point_free(ip);
} SMARTLIST_FOREACH_END(ip);
smartlist_free(ips_to_free);
}
/* Set the next rotation time of the descriptors for the given service for the
* time now. */
static void
set_rotation_time(hs_service_t *service, time_t now)
{
time_t valid_after;
const networkstatus_t *ns = networkstatus_get_live_consensus(now);
if (ns) {
valid_after = ns->valid_after;
} else {
valid_after = now;
}
tor_assert(service);
service->state.next_rotation_time =
sr_state_get_start_time_of_current_protocol_run(valid_after) +
sr_state_get_protocol_run_duration();
{
char fmt_time[ISO_TIME_LEN + 1];
format_local_iso_time(fmt_time, service->state.next_rotation_time);
log_info(LD_REND, "Next descriptor rotation time set to %s for %s",
fmt_time, safe_str_client(service->onion_address));
}
}
/* Return true iff the service should rotate its descriptor. The time now is
* only used to fetch the live consensus and if none can be found, this
* returns false. */
static unsigned int
should_rotate_descriptors(hs_service_t *service, time_t now)
{
const networkstatus_t *ns;
tor_assert(service);
ns = networkstatus_get_live_consensus(now);
if (ns == NULL) {
goto no_rotation;
}
if (ns->valid_after >= service->state.next_rotation_time) {
/* In theory, we should never get here with no descriptors. We can never
* have a NULL current descriptor except when tor starts up. The next
* descriptor can be NULL after a rotation but we build a new one right
* after.
*
* So, when tor starts, the next rotation time is set to the start of the
* next SRV period using the consensus valid after time so it should
* always be set to a future time value. This means that we should never
* reach this point at bootup that is this check safeguards tor in never
* allowing a rotation if the valid after time is smaller than the next
* rotation time.
*
* This is all good in theory but we've had a NULL descriptor issue here
* so this is why we BUG() on both with extra logging to try to understand
* how this can possibly happens. We'll simply ignore and tor should
* recover from this by skipping rotation and building the missing
* descriptors just after this. */
if (BUG(service->desc_current == NULL || service->desc_next == NULL)) {
log_warn(LD_BUG, "Service descriptor is NULL (%p/%p). Next rotation "
"time is %ld (now: %ld). Valid after time from "
"consensus is %ld",
service->desc_current, service->desc_next,
(long)service->state.next_rotation_time,
(long)now,
(long)ns->valid_after);
goto no_rotation;
}
goto rotation;
}
no_rotation:
return 0;
rotation:
return 1;
}
/* Rotate the service descriptors of the given service. The current descriptor
* will be freed, the next one put in as the current and finally the next
* descriptor pointer is NULLified. */
static void
rotate_service_descriptors(hs_service_t *service, time_t now)
{
if (service->desc_current) {
/* Close all IP circuits for the descriptor. */
close_intro_circuits(&service->desc_current->intro_points);
/* We don't need this one anymore, we won't serve any clients coming with
* this service descriptor. */
service_descriptor_free(service->desc_current);
}
/* The next one become the current one and emptying the next will trigger
* a descriptor creation for it. */
service->desc_current = service->desc_next;
service->desc_next = NULL;
/* We've just rotated, set the next time for the rotation. */
set_rotation_time(service, now);
}
/* Rotate descriptors for each service if needed. A non existing current
* descriptor will trigger a descriptor build for the next time period. */
STATIC void
rotate_all_descriptors(time_t now)
{
/* XXX We rotate all our service descriptors at once. In the future it might
* be wise, to rotate service descriptors independently to hide that all
* those descriptors are on the same tor instance */
FOR_EACH_SERVICE_BEGIN(service) {
/* Note for a service booting up: Both descriptors are NULL in that case
* so this function might return true if we are in the timeframe for a
* rotation leading to basically swapping two NULL pointers which is
* harmless. However, the side effect is that triggering a rotation will
* update the service state and avoid doing anymore rotations after the
* two descriptors have been built. */
if (!should_rotate_descriptors(service, now)) {
continue;
}
log_info(LD_REND, "Time to rotate our descriptors (%p / %p) for %s",
service->desc_current, service->desc_next,
safe_str_client(service->onion_address));
rotate_service_descriptors(service, now);
} FOR_EACH_SERVICE_END;
}
/* Scheduled event run from the main loop. Make sure all our services are up
* to date and ready for the other scheduled events. This includes looking at
* the introduction points status and descriptor rotation time. */
STATIC void
run_housekeeping_event(time_t now)
{
/* Note that nothing here opens circuit(s) nor uploads descriptor(s). We are
* simply moving things around or removing unneeded elements. */
FOR_EACH_SERVICE_BEGIN(service) {
/* If the service is starting off, set the rotation time. We can't do that
* at configure time because the get_options() needs to be set for setting
* that time that uses the voting interval. */
if (service->state.next_rotation_time == 0) {
/* Set the next rotation time of the descriptors. If it's Oct 25th
* 23:47:00, the next rotation time is when the next SRV is computed
* which is at Oct 26th 00:00:00 that is in 13 minutes. */
set_rotation_time(service, now);
}
/* Cleanup invalid intro points from the service descriptor. */
cleanup_intro_points(service, now);
/* Remove expired failing intro point from the descriptor failed list. We
* reset them at each INTRO_CIRC_RETRY_PERIOD. */
remove_expired_failing_intro(service, now);
/* At this point, the service is now ready to go through the scheduled
* events guaranteeing a valid state. Intro points might be missing from
* the descriptors after the cleanup but the update/build process will
* make sure we pick those missing ones. */
} FOR_EACH_SERVICE_END;
}
/* Scheduled event run from the main loop. Make sure all descriptors are up to
* date. Once this returns, each service descriptor needs to be considered for
* new introduction circuits and then for upload. */
static void
run_build_descriptor_event(time_t now)
{
/* For v2 services, this step happens in the upload event. */
/* Run v3+ events. */
/* We start by rotating the descriptors only if needed. */
rotate_all_descriptors(now);
/* Then, we'll try to build new descriptors that we might need. The
* condition is that the next descriptor is non existing because it has
* been rotated or we just started up. */
build_all_descriptors(now);
/* Finally, we'll check if we should update the descriptors. Missing
* introduction points will be picked in this function which is useful for
* newly built descriptors. */
update_all_descriptors(now);
}
/* For the given service, launch any intro point circuits that could be
* needed. This considers every descriptor of the service. */
static void
launch_intro_point_circuits(hs_service_t *service)
{
tor_assert(service);
/* For both descriptors, try to launch any missing introduction point
* circuits using the current map. */
FOR_EACH_DESCRIPTOR_BEGIN(service, desc) {
/* Keep a ref on if we need a direct connection. We use this often. */
unsigned int direct_conn = service->config.is_single_onion;
DIGEST256MAP_FOREACH_MODIFY(desc->intro_points.map, key,
hs_service_intro_point_t *, ip) {
extend_info_t *ei;
/* Skip the intro point that already has an existing circuit
* (established or not). */
if (hs_circ_service_get_intro_circ(ip)) {
continue;
}
ei = get_extend_info_from_intro_point(ip, direct_conn);
if (ei == NULL) {
/* This is possible if we can get a node_t but not the extend info out
* of it. In this case, we remove the intro point and a new one will
* be picked at the next main loop callback. */
MAP_DEL_CURRENT(key);
service_intro_point_free(ip);
continue;
}
/* Launch a circuit to the intro point. */
ip->circuit_retries++;
if (hs_circ_launch_intro_point(service, ip, ei) < 0) {
log_info(LD_REND, "Unable to launch intro circuit to node %s "
"for service %s.",
safe_str_client(extend_info_describe(ei)),
safe_str_client(service->onion_address));
/* Intro point will be retried if possible after this. */
}
extend_info_free(ei);
} DIGEST256MAP_FOREACH_END;
} FOR_EACH_DESCRIPTOR_END;
}
/* Don't try to build more than this many circuits before giving up for a
* while. Dynamically calculated based on the configured number of intro
* points for the given service and how many descriptor exists. The default
* use case of 3 introduction points and two descriptors will allow 28
* circuits for a retry period (((3 + 2) + (3 * 3)) * 2). */
static unsigned int
get_max_intro_circ_per_period(const hs_service_t *service)
{
unsigned int count = 0;
unsigned int multiplier = 0;
unsigned int num_wanted_ip;
tor_assert(service);
tor_assert(service->config.num_intro_points <=
HS_CONFIG_V3_MAX_INTRO_POINTS);
/* For a testing network, allow to do it for the maximum amount so circuit
* creation and rotation and so on can actually be tested without limit. */
#define MAX_INTRO_POINT_CIRCUIT_RETRIES_TESTING -1
if (get_options()->TestingTorNetwork) {
return MAX_INTRO_POINT_CIRCUIT_RETRIES_TESTING;
}
num_wanted_ip = service->config.num_intro_points;
/* The calculation is as follow. We have a number of intro points that we
* want configured as a torrc option (num_intro_points). We then add an
* extra value so we can launch multiple circuits at once and pick the
* quickest ones. For instance, we want 3 intros, we add 2 extra so we'll
* pick 5 intros and launch 5 circuits. */
count += (num_wanted_ip + get_intro_point_num_extra());
/* Then we add the number of retries that is possible to do for each intro
* point. If we want 3 intros, we'll allow 3 times the number of possible
* retry. */
count += (num_wanted_ip * MAX_INTRO_POINT_CIRCUIT_RETRIES);
/* Then, we multiply by a factor of 2 if we have both descriptor or 0 if we
* have none. */
multiplier += (service->desc_current) ? 1 : 0;
multiplier += (service->desc_next) ? 1 : 0;
return (count * multiplier);
}
/* For the given service, return 1 if the service is allowed to launch more
* introduction circuits else 0 if the maximum has been reached for the retry
* period of INTRO_CIRC_RETRY_PERIOD. */
STATIC int
can_service_launch_intro_circuit(hs_service_t *service, time_t now)
{
tor_assert(service);
/* Consider the intro circuit retry period of the service. */
if (now > (service->state.intro_circ_retry_started_time +
INTRO_CIRC_RETRY_PERIOD)) {
service->state.intro_circ_retry_started_time = now;
service->state.num_intro_circ_launched = 0;
goto allow;
}
/* Check if we can still launch more circuits in this period. */
if (service->state.num_intro_circ_launched <=
get_max_intro_circ_per_period(service)) {
goto allow;
}
/* Rate limit log that we've reached our circuit creation limit. */
{
char *msg;
time_t elapsed_time = now - service->state.intro_circ_retry_started_time;
static ratelim_t rlimit = RATELIM_INIT(INTRO_CIRC_RETRY_PERIOD);
if ((msg = rate_limit_log(&rlimit, now))) {
log_info(LD_REND, "Hidden service %s exceeded its circuit launch limit "
"of %u per %d seconds. It launched %u circuits in "
"the last %ld seconds. Will retry in %ld seconds.",
safe_str_client(service->onion_address),
get_max_intro_circ_per_period(service),
INTRO_CIRC_RETRY_PERIOD,
service->state.num_intro_circ_launched,
(long int) elapsed_time,
(long int) (INTRO_CIRC_RETRY_PERIOD - elapsed_time));
tor_free(msg);
}
}
/* Not allow. */
return 0;
allow:
return 1;
}
/* Scheduled event run from the main loop. Make sure we have all the circuits
* we need for each service. */
static void
run_build_circuit_event(time_t now)
{
/* Make sure we can actually have enough information or able to build
* internal circuits as required by services. */
if (router_have_consensus_path() == CONSENSUS_PATH_UNKNOWN ||
!have_completed_a_circuit()) {
return;
}
/* Run v2 check. */
if (rend_num_services() > 0) {
rend_consider_services_intro_points(now);
}
/* Run v3+ check. */
FOR_EACH_SERVICE_BEGIN(service) {
/* For introduction circuit, we need to make sure we don't stress too much
* circuit creation so make sure this service is respecting that limit. */
if (can_service_launch_intro_circuit(service, now)) {
/* Launch intro point circuits if needed. */
launch_intro_point_circuits(service);
/* Once the circuits have opened, we'll make sure to update the
* descriptor intro point list and cleanup any extraneous. */
}
} FOR_EACH_SERVICE_END;
}
/* Encode and sign the service descriptor desc and upload it to the given
* hidden service directory. This does nothing if PublishHidServDescriptors
* is false. */
static void
upload_descriptor_to_hsdir(const hs_service_t *service,
hs_service_descriptor_t *desc, const node_t *hsdir)
{
char *encoded_desc = NULL;
tor_assert(service);
tor_assert(desc);
tor_assert(hsdir);
/* Let's avoid doing that if tor is configured to not publish. */
if (!get_options()->PublishHidServDescriptors) {
log_info(LD_REND, "Service %s not publishing descriptor. "
"PublishHidServDescriptors is set to 1.",
safe_str_client(service->onion_address));
goto end;
}
/* First of all, we'll encode the descriptor. This should NEVER fail but
* just in case, let's make sure we have an actual usable descriptor. */
if (BUG(hs_desc_encode_descriptor(desc->desc, &desc->signing_kp,
&encoded_desc) < 0)) {
goto end;
}
/* Time to upload the descriptor to the directory. */
hs_service_upload_desc_to_dir(encoded_desc, service->config.version,
&service->keys.identity_pk,
&desc->blinded_kp.pubkey, hsdir->rs);
/* Add this node to previous_hsdirs list */
service_desc_note_upload(desc, hsdir);
/* Logging so we know where it was sent. */
{
int is_next_desc = (service->desc_next == desc);
const uint8_t *idx = (is_next_desc) ? hsdir->hsdir_index.store_second:
hsdir->hsdir_index.store_first;
log_info(LD_REND, "Service %s %s descriptor of revision %" PRIu64
" initiated upload request to %s with index %s",
safe_str_client(service->onion_address),
(is_next_desc) ? "next" : "current",
desc->desc->plaintext_data.revision_counter,
safe_str_client(node_describe(hsdir)),
safe_str_client(hex_str((const char *) idx, 32)));
/* Fire a UPLOAD control port event. */
hs_control_desc_event_upload(service->onion_address, hsdir->identity,
&desc->blinded_kp.pubkey, idx);
}
end:
tor_free(encoded_desc);
return;
}
/** Return a newly-allocated string for our state file which contains revision
* counter information for <b>desc</b>. The format is:
*
* HidServRevCounter <blinded_pubkey> <rev_counter>
*/
STATIC char *
encode_desc_rev_counter_for_state(const hs_service_descriptor_t *desc)
{
char *state_str = NULL;
char blinded_pubkey_b64[ED25519_BASE64_LEN+1];
uint64_t rev_counter = desc->desc->plaintext_data.revision_counter;
const ed25519_public_key_t *blinded_pubkey = &desc->blinded_kp.pubkey;
/* Turn the blinded key into b64 so that we save it on state */
tor_assert(blinded_pubkey);
if (ed25519_public_to_base64(blinded_pubkey_b64, blinded_pubkey) < 0) {
goto done;
}
/* Format is: <blinded key> <rev counter> */
tor_asprintf(&state_str, "%s %" PRIu64, blinded_pubkey_b64, rev_counter);
log_info(LD_GENERAL, "[!] Adding rev counter %" PRIu64 " for %s!",
rev_counter, blinded_pubkey_b64);
done:
return state_str;
}
/** Update HS descriptor revision counters in our state by removing the old
* ones and writing down the ones that are currently active. */
static void
update_revision_counters_in_state(void)
{
config_line_t *lines = NULL;
config_line_t **nextline = &lines;
or_state_t *state = get_or_state();
/* Prepare our state structure with the rev counters */
FOR_EACH_SERVICE_BEGIN(service) {
FOR_EACH_DESCRIPTOR_BEGIN(service, desc) {
/* We don't want to save zero counters */
if (desc->desc->plaintext_data.revision_counter == 0) {
continue;
}
*nextline = tor_malloc_zero(sizeof(config_line_t));
(*nextline)->key = tor_strdup("HidServRevCounter");
(*nextline)->value = encode_desc_rev_counter_for_state(desc);
nextline = &(*nextline)->next;
} FOR_EACH_DESCRIPTOR_END;
} FOR_EACH_SERVICE_END;
/* Remove the old rev counters, and replace them with the new ones */
config_free_lines(state->HidServRevCounter);
state->HidServRevCounter = lines;
/* Set the state as dirty since we just edited it */
if (!get_options()->AvoidDiskWrites) {
or_state_mark_dirty(state, 0);
}
}
/** Scan the string <b>state_line</b> for the revision counter of the service
* with <b>blinded_pubkey</b>. Set <b>service_found_out</b> to True if the
* line is relevant to this service, and return the cached revision
* counter. Else set <b>service_found_out</b> to False. */
STATIC uint64_t
check_state_line_for_service_rev_counter(const char *state_line,
const ed25519_public_key_t *blinded_pubkey,
int *service_found_out)
{
smartlist_t *items = NULL;
int ok;
ed25519_public_key_t pubkey_in_state;
uint64_t rev_counter = 0;
tor_assert(service_found_out);
tor_assert(state_line);
tor_assert(blinded_pubkey);
/* Assume that the line is not for this service */
*service_found_out = 0;
/* Start parsing the state line */
items = smartlist_new();
smartlist_split_string(items, state_line, NULL,
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, -1);
if (smartlist_len(items) < 2) {
log_warn(LD_GENERAL, "Incomplete rev counter line. Ignoring.");
goto done;
}
char *b64_key_str = smartlist_get(items, 0);
char *saved_rev_counter_str = smartlist_get(items, 1);
/* Parse blinded key to check if it's for this hidden service */
if (ed25519_public_from_base64(&pubkey_in_state, b64_key_str) < 0) {
log_warn(LD_GENERAL, "Unable to base64 key in revcount line. Ignoring.");
goto done;
}
/* State line not for this hidden service */
if (!ed25519_pubkey_eq(&pubkey_in_state, blinded_pubkey)) {
goto done;
}
rev_counter = tor_parse_uint64(saved_rev_counter_str,
10, 0, UINT64_MAX, &ok, NULL);
if (!ok) {
log_warn(LD_GENERAL, "Unable to parse rev counter. Ignoring.");
goto done;
}
/* Since we got this far, the line was for this service */
*service_found_out = 1;
log_info(LD_GENERAL, "Found rev counter for %s: %" PRIu64,
b64_key_str, rev_counter);
done:
tor_assert(items);
SMARTLIST_FOREACH(items, char*, s, tor_free(s));
smartlist_free(items);
return rev_counter;
}
/** Dig into our state file and find the current revision counter for the
* service with blinded key <b>blinded_pubkey</b>. If no revision counter is
* found, return 0. */
static uint64_t
get_rev_counter_for_service(const ed25519_public_key_t *blinded_pubkey)
{
or_state_t *state = get_or_state();
config_line_t *line;
/* Set default value for rev counters (if not found) to 0 */
uint64_t final_rev_counter = 0;
for (line = state->HidServRevCounter ; line ; line = line->next) {
int service_found = 0;
uint64_t rev_counter = 0;
tor_assert(!strcmp(line->key, "HidServRevCounter"));
/* Scan all the HidServRevCounter lines till we find the line for this
service: */
rev_counter = check_state_line_for_service_rev_counter(line->value,
blinded_pubkey,
&service_found);
if (service_found) {
final_rev_counter = rev_counter;
goto done;
}
}
done:
return final_rev_counter;
}
/** Update the value of the revision counter for <b>hs_desc</b> and save it on
our state file. */
static void
increment_descriptor_revision_counter(hs_descriptor_t *hs_desc)
{
/* Find stored rev counter if it exists */
uint64_t rev_counter =
get_rev_counter_for_service(&hs_desc->plaintext_data.blinded_pubkey);
/* Increment the revision counter of <b>hs_desc</b> so the next update (which
* will trigger an upload) will have the right value. We do this at this
* stage to only do it once because a descriptor can have many updates before
* being uploaded. By doing it at upload, we are sure to only increment by 1
* and thus avoid leaking how many operations we made on the descriptor from
* the previous one before uploading. */
rev_counter++;
hs_desc->plaintext_data.revision_counter = rev_counter;
update_revision_counters_in_state();
}
/** Set the revision counter in <b>hs_desc</b>, using the state file to find
* the current counter value if it exists. */
static void
set_descriptor_revision_counter(hs_descriptor_t *hs_desc)
{
/* Find stored rev counter if it exists */
uint64_t rev_counter =
get_rev_counter_for_service(&hs_desc->plaintext_data.blinded_pubkey);
hs_desc->plaintext_data.revision_counter = rev_counter;
}
/* Encode and sign the service descriptor desc and upload it to the
* responsible hidden service directories. If for_next_period is true, the set
* of directories are selected using the next hsdir_index. This does nothing
* if PublishHidServDescriptors is false. */
STATIC void
upload_descriptor_to_all(const hs_service_t *service,
hs_service_descriptor_t *desc)
{
smartlist_t *responsible_dirs = NULL;
tor_assert(service);
tor_assert(desc);
/* We'll first cancel any directory request that are ongoing for this
* descriptor. It is possible that we can trigger multiple uploads in a
* short time frame which can lead to a race where the second upload arrives
* before the first one leading to a 400 malformed descriptor response from
* the directory. Closing all pending requests avoids that. */
close_directory_connections(service, desc);
/* Get our list of responsible HSDir. */
responsible_dirs = smartlist_new();
/* The parameter 0 means that we aren't a client so tell the function to use
* the spread store consensus paremeter. */
hs_get_responsible_hsdirs(&desc->blinded_kp.pubkey, desc->time_period_num,
service->desc_next == desc, 0, responsible_dirs);
/** Clear list of previous hsdirs since we are about to upload to a new
* list. Let's keep it up to date. */
service_desc_clear_previous_hsdirs(desc);
/* For each responsible HSDir we have, initiate an upload command. */
SMARTLIST_FOREACH_BEGIN(responsible_dirs, const routerstatus_t *,
hsdir_rs) {
const node_t *hsdir_node = node_get_by_id(hsdir_rs->identity_digest);
/* Getting responsible hsdir implies that the node_t object exists for the
* routerstatus_t found in the consensus else we have a problem. */
tor_assert(hsdir_node);
/* Upload this descriptor to the chosen directory. */
upload_descriptor_to_hsdir(service, desc, hsdir_node);
} SMARTLIST_FOREACH_END(hsdir_rs);
/* Set the next upload time for this descriptor. Even if we are configured
* to not upload, we still want to follow the right cycle of life for this
* descriptor. */
desc->next_upload_time =
(time(NULL) + crypto_rand_int_range(HS_SERVICE_NEXT_UPLOAD_TIME_MIN,
HS_SERVICE_NEXT_UPLOAD_TIME_MAX));
{
char fmt_next_time[ISO_TIME_LEN+1];
format_local_iso_time(fmt_next_time, desc->next_upload_time);
log_debug(LD_REND, "Service %s set to upload a descriptor at %s",
safe_str_client(service->onion_address), fmt_next_time);
}
/* Update the revision counter of this descriptor */
increment_descriptor_revision_counter(desc->desc);
smartlist_free(responsible_dirs);
return;
}
/** The set of HSDirs have changed: check if the change affects our descriptor
* HSDir placement, and if it does, reupload the desc. */
STATIC int
service_desc_hsdirs_changed(const hs_service_t *service,
const hs_service_descriptor_t *desc)
{
int should_reupload = 0;
smartlist_t *responsible_dirs = smartlist_new();
/* No desc upload has happened yet: it will happen eventually */
if (!desc->previous_hsdirs || !smartlist_len(desc->previous_hsdirs)) {
goto done;
}
/* Get list of responsible hsdirs */
hs_get_responsible_hsdirs(&desc->blinded_kp.pubkey, desc->time_period_num,
service->desc_next == desc, 0, responsible_dirs);
/* Check if any new hsdirs have been added to the responsible hsdirs set:
* Iterate over the list of new hsdirs, and reupload if any of them is not
* present in the list of previous hsdirs.
*/
SMARTLIST_FOREACH_BEGIN(responsible_dirs, const routerstatus_t *, hsdir_rs) {
char b64_digest[BASE64_DIGEST_LEN+1] = {0};
digest_to_base64(b64_digest, hsdir_rs->identity_digest);
if (!smartlist_contains_string(desc->previous_hsdirs, b64_digest)) {
should_reupload = 1;
break;
}
} SMARTLIST_FOREACH_END(hsdir_rs);
done:
smartlist_free(responsible_dirs);
return should_reupload;
}
/* Return 1 if the given descriptor from the given service can be uploaded
* else return 0 if it can not. */
static int
should_service_upload_descriptor(const hs_service_t *service,
const hs_service_descriptor_t *desc, time_t now)
{
unsigned int num_intro_points;
tor_assert(service);
tor_assert(desc);
/* If this descriptors has missing intro points that is that it couldn't get
* them all when it was time to pick them, it means that we should upload
* instead of waiting an arbitrary amount of time breaking the service.
* Else, if we have no missing intro points, we use the value taken from the
* service configuration. */
if (desc->missing_intro_points) {
num_intro_points = digest256map_size(desc->intro_points.map);
} else {
num_intro_points = service->config.num_intro_points;
}
/* This means we tried to pick intro points but couldn't get any so do not
* upload descriptor in this case. We need at least one for the service to
* be reachable. */
if (desc->missing_intro_points && num_intro_points == 0) {
goto cannot;
}
/* Check if all our introduction circuit have been established for all the
* intro points we have selected. */
if (count_desc_circuit_established(desc) != num_intro_points) {
goto cannot;
}
/* Is it the right time to upload? */
if (desc->next_upload_time > now) {
goto cannot;
}
/* Don't upload desc if we don't have a live consensus */
if (!networkstatus_get_live_consensus(now)) {
goto cannot;
}
/* Do we know enough router descriptors to have adequate vision of the HSDir
hash ring? */
if (!router_have_minimum_dir_info()) {
goto cannot;
}
/* Can upload! */
return 1;
cannot:
return 0;
}
/* Scheduled event run from the main loop. Try to upload the descriptor for
* each service. */
STATIC void
run_upload_descriptor_event(time_t now)
{
/* v2 services use the same function for descriptor creation and upload so
* we do everything here because the intro circuits were checked before. */
if (rend_num_services() > 0) {
rend_consider_services_upload(now);
rend_consider_descriptor_republication();
}
/* Run v3+ check. */
FOR_EACH_SERVICE_BEGIN(service) {
FOR_EACH_DESCRIPTOR_BEGIN(service, desc) {
/* If we were asked to re-examine the hash ring, and it changed, then
schedule an upload */
if (consider_republishing_hs_descriptors &&
service_desc_hsdirs_changed(service, desc)) {
service_desc_schedule_upload(desc, now, 0);
}
/* Can this descriptor be uploaded? */
if (!should_service_upload_descriptor(service, desc, now)) {
continue;
}
log_info(LD_REND, "Initiating upload for hidden service %s descriptor "
"for service %s with %u/%u introduction points%s.",
(desc == service->desc_current) ? "current" : "next",
safe_str_client(service->onion_address),
digest256map_size(desc->intro_points.map),
service->config.num_intro_points,
(desc->missing_intro_points) ? " (couldn't pick more)" : "");
/* At this point, we have to upload the descriptor so start by building
* the intro points descriptor section which we are now sure to be
* accurate because all circuits have been established. */
build_desc_intro_points(service, desc, now);
upload_descriptor_to_all(service, desc);
} FOR_EACH_DESCRIPTOR_END;
} FOR_EACH_SERVICE_END;
/* We are done considering whether to republish rend descriptors */
consider_republishing_hs_descriptors = 0;
}
/* Called when the introduction point circuit is done building and ready to be
* used. */
static void
service_intro_circ_has_opened(origin_circuit_t *circ)
{
hs_service_t *service = NULL;
hs_service_intro_point_t *ip = NULL;
hs_service_descriptor_t *desc = NULL;
tor_assert(circ);
/* Let's do some basic sanity checking of the circ state */
if (BUG(!circ->cpath)) {
return;
}
if (BUG(TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_S_ESTABLISH_INTRO)) {
return;
}
if (BUG(!circ->hs_ident)) {
return;
}
/* Get the corresponding service and intro point. */
get_objects_from_ident(circ->hs_ident, &service, &ip, &desc);
if (service == NULL) {
log_warn(LD_REND, "Unknown service identity key %s on the introduction "
"circuit %u. Can't find onion service.",
safe_str_client(ed25519_fmt(&circ->hs_ident->identity_pk)),
TO_CIRCUIT(circ)->n_circ_id);
goto err;
}
if (ip == NULL) {
log_warn(LD_REND, "Unknown introduction point auth key on circuit %u "
"for service %s",
TO_CIRCUIT(circ)->n_circ_id,
safe_str_client(service->onion_address));
goto err;
}
/* We can't have an IP object without a descriptor. */
tor_assert(desc);
if (hs_circ_service_intro_has_opened(service, ip, desc, circ)) {
/* Getting here means that the circuit has been re-purposed because we
* have enough intro circuit opened. Remove the IP from the service. */
service_intro_point_remove(service, ip);
service_intro_point_free(ip);
}
goto done;
err:
/* Close circuit, we can't use it. */
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_NOSUCHSERVICE);
done:
return;
}
/* Called when a rendezvous circuit is done building and ready to be used. */
static void
service_rendezvous_circ_has_opened(origin_circuit_t *circ)
{
hs_service_t *service = NULL;
tor_assert(circ);
tor_assert(circ->cpath);
/* Getting here means this is a v3 rendezvous circuit. */
tor_assert(circ->hs_ident);
tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND);
/* Declare the circuit dirty to avoid reuse, and for path-bias. We set the
* timestamp regardless of its content because that circuit could have been
* cannibalized so in any cases, we are about to use that circuit more. */
TO_CIRCUIT(circ)->timestamp_dirty = time(NULL);
pathbias_count_use_attempt(circ);
/* Get the corresponding service and intro point. */
get_objects_from_ident(circ->hs_ident, &service, NULL, NULL);
if (service == NULL) {
log_warn(LD_REND, "Unknown service identity key %s on the rendezvous "
"circuit %u with cookie %s. Can't find onion service.",
safe_str_client(ed25519_fmt(&circ->hs_ident->identity_pk)),
TO_CIRCUIT(circ)->n_circ_id,
hex_str((const char *) circ->hs_ident->rendezvous_cookie,
REND_COOKIE_LEN));
goto err;
}
/* If the cell can't be sent, the circuit will be closed within this
* function. */
hs_circ_service_rp_has_opened(service, circ);
goto done;
err:
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_NOSUCHSERVICE);
done:
return;
}
/* We've been expecting an INTRO_ESTABLISHED cell on this circuit and it just
* arrived. Handle the INTRO_ESTABLISHED cell arriving on the given
* introduction circuit. Return 0 on success else a negative value. */
static int
service_handle_intro_established(origin_circuit_t *circ,
const uint8_t *payload,
size_t payload_len)
{
hs_service_t *service = NULL;
hs_service_intro_point_t *ip = NULL;
tor_assert(circ);
tor_assert(payload);
tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO);
/* We need the service and intro point for this cell. */
get_objects_from_ident(circ->hs_ident, &service, &ip, NULL);
/* Get service object from the circuit identifier. */
if (service == NULL) {
log_warn(LD_REND, "Unknown service identity key %s on the introduction "
"circuit %u. Can't find onion service.",
safe_str_client(ed25519_fmt(&circ->hs_ident->identity_pk)),
TO_CIRCUIT(circ)->n_circ_id);
goto err;
}
if (ip == NULL) {
/* We don't recognize the key. */
log_warn(LD_REND, "Introduction circuit established without an intro "
"point object on circuit %u for service %s",
TO_CIRCUIT(circ)->n_circ_id,
safe_str_client(service->onion_address));
goto err;
}
/* Try to parse the payload into a cell making sure we do actually have a
* valid cell. On success, the ip object and circuit purpose is updated to
* reflect the fact that the introduction circuit is established. */
if (hs_circ_handle_intro_established(service, ip, circ, payload,
payload_len) < 0) {
goto err;
}
/* Flag that we have an established circuit for this intro point. This value
* is what indicates the upload scheduled event if we are ready to build the
* intro point into the descriptor and upload. */
ip->circuit_established = 1;
log_info(LD_REND, "Successfully received an INTRO_ESTABLISHED cell "
"on circuit %u for service %s",
TO_CIRCUIT(circ)->n_circ_id,
safe_str_client(service->onion_address));
return 0;
err:
return -1;
}
/* We just received an INTRODUCE2 cell on the established introduction circuit
* circ. Handle the cell and return 0 on success else a negative value. */
static int
service_handle_introduce2(origin_circuit_t *circ, const uint8_t *payload,
size_t payload_len)
{
hs_service_t *service = NULL;
hs_service_intro_point_t *ip = NULL;
hs_service_descriptor_t *desc = NULL;
tor_assert(circ);
tor_assert(payload);
tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_INTRO);
/* We'll need every object associated with this circuit. */
get_objects_from_ident(circ->hs_ident, &service, &ip, &desc);
/* Get service object from the circuit identifier. */
if (service == NULL) {
log_warn(LD_BUG, "Unknown service identity key %s when handling "
"an INTRODUCE2 cell on circuit %u",
safe_str_client(ed25519_fmt(&circ->hs_ident->identity_pk)),
TO_CIRCUIT(circ)->n_circ_id);
goto err;
}
if (ip == NULL) {
/* We don't recognize the key. */
log_warn(LD_BUG, "Unknown introduction auth key when handling "
"an INTRODUCE2 cell on circuit %u for service %s",
TO_CIRCUIT(circ)->n_circ_id,
safe_str_client(service->onion_address));
goto err;
}
/* If we have an IP object, we MUST have a descriptor object. */
tor_assert(desc);
/* The following will parse, decode and launch the rendezvous point circuit.
* Both current and legacy cells are handled. */
if (hs_circ_handle_introduce2(service, circ, ip, desc->desc->subcredential,
payload, payload_len) < 0) {
goto err;
}
return 0;
err:
return -1;
}
/* Add to list every filename used by service. This is used by the sandbox
* subsystem. */
static void
service_add_fnames_to_list(const hs_service_t *service, smartlist_t *list)
{
const char *s_dir;
char fname[128] = {0};
tor_assert(service);
tor_assert(list);
/* Ease our life. */
s_dir = service->config.directory_path;
/* The hostname file. */
smartlist_add(list, hs_path_from_filename(s_dir, fname_hostname));
/* The key files splitted in two. */
tor_snprintf(fname, sizeof(fname), "%s_secret_key", fname_keyfile_prefix);
smartlist_add(list, hs_path_from_filename(s_dir, fname));
tor_snprintf(fname, sizeof(fname), "%s_public_key", fname_keyfile_prefix);
smartlist_add(list, hs_path_from_filename(s_dir, fname));
}
/* ========== */
/* Public API */
/* ========== */
/* This is called everytime the service map (v2 or v3) changes that is if an
* element is added or removed. */
void
hs_service_map_has_changed(void)
{
/* If we now have services where previously we had not, we need to enable
* the HS service main loop event. If we changed to having no services, we
* need to disable the event. */
rescan_periodic_events(get_options());
}
/* Upload an encoded descriptor in encoded_desc of the given version. This
* descriptor is for the service identity_pk and blinded_pk used to setup the
* directory connection identifier. It is uploaded to the directory hsdir_rs
* routerstatus_t object.
*
* NOTE: This function does NOT check for PublishHidServDescriptors because it
* is only used by the control port command HSPOST outside of this subsystem.
* Inside this code, upload_descriptor_to_hsdir() should be used. */
void
hs_service_upload_desc_to_dir(const char *encoded_desc,
const uint8_t version,
const ed25519_public_key_t *identity_pk,
const ed25519_public_key_t *blinded_pk,
const routerstatus_t *hsdir_rs)
{
char version_str[4] = {0};
directory_request_t *dir_req;
hs_ident_dir_conn_t ident;
tor_assert(encoded_desc);
tor_assert(identity_pk);
tor_assert(blinded_pk);
tor_assert(hsdir_rs);
/* Setup the connection identifier. */
memset(&ident, 0, sizeof(ident));
hs_ident_dir_conn_init(identity_pk, blinded_pk, &ident);
/* This is our resource when uploading which is used to construct the URL
* with the version number: "/tor/hs/<version>/publish". */
tor_snprintf(version_str, sizeof(version_str), "%u", version);
/* Build the directory request for this HSDir. */
dir_req = directory_request_new(DIR_PURPOSE_UPLOAD_HSDESC);
directory_request_set_routerstatus(dir_req, hsdir_rs);
directory_request_set_indirection(dir_req, DIRIND_ANONYMOUS);
directory_request_set_resource(dir_req, version_str);
directory_request_set_payload(dir_req, encoded_desc,
strlen(encoded_desc));
/* The ident object is copied over the directory connection object once
* the directory request is initiated. */
directory_request_upload_set_hs_ident(dir_req, &ident);
/* Initiate the directory request to the hsdir.*/
directory_initiate_request(dir_req);
directory_request_free(dir_req);
}
/* Add the ephemeral service using the secret key sk and ports. Both max
* streams parameter will be set in the newly created service.
*
* Ownership of sk and ports is passed to this routine. Regardless of
* success/failure, callers should not touch these values after calling this
* routine, and may assume that correct cleanup has been done on failure.
*
* Return an appropriate hs_service_add_ephemeral_status_t. */
hs_service_add_ephemeral_status_t
hs_service_add_ephemeral(ed25519_secret_key_t *sk, smartlist_t *ports,
int max_streams_per_rdv_circuit,
int max_streams_close_circuit, char **address_out)
{
hs_service_add_ephemeral_status_t ret;
hs_service_t *service = NULL;
tor_assert(sk);
tor_assert(ports);
tor_assert(address_out);
service = hs_service_new(get_options());
/* Setup the service configuration with specifics. A default service is
* HS_VERSION_TWO so explicitly set it. */
service->config.version = HS_VERSION_THREE;
service->config.max_streams_per_rdv_circuit = max_streams_per_rdv_circuit;
service->config.max_streams_close_circuit = !!max_streams_close_circuit;
service->config.is_ephemeral = 1;
smartlist_free(service->config.ports);
service->config.ports = ports;
/* Handle the keys. */
memcpy(&service->keys.identity_sk, sk, sizeof(service->keys.identity_sk));
if (ed25519_public_key_generate(&service->keys.identity_pk,
&service->keys.identity_sk) < 0) {
log_warn(LD_CONFIG, "Unable to generate ed25519 public key"
"for v3 service.");
ret = RSAE_BADPRIVKEY;
goto err;
}
/* Make sure we have at least one port. */
if (smartlist_len(service->config.ports) == 0) {
log_warn(LD_CONFIG, "At least one VIRTPORT/TARGET must be specified "
"for v3 service.");
ret = RSAE_BADVIRTPORT;
goto err;
}
/* Build the onion address for logging purposes but also the control port
* uses it for the HS_DESC event. */
hs_build_address(&service->keys.identity_pk,
(uint8_t) service->config.version,
service->onion_address);
/* The only way the registration can fail is if the service public key
* already exists. */
if (BUG(register_service(hs_service_map, service) < 0)) {
log_warn(LD_CONFIG, "Onion Service private key collides with an "
"existing v3 service.");
ret = RSAE_ADDREXISTS;
goto err;
}
log_info(LD_CONFIG, "Added ephemeral v3 onion service: %s",
safe_str_client(service->onion_address));
*address_out = tor_strdup(service->onion_address);
ret = RSAE_OKAY;
goto end;
err:
hs_service_free(service);
end:
memwipe(sk, 0, sizeof(ed25519_secret_key_t));
tor_free(sk);
return ret;
}
/* For the given onion address, delete the ephemeral service. Return 0 on
* success else -1 on error. */
int
hs_service_del_ephemeral(const char *address)
{
uint8_t version;
ed25519_public_key_t pk;
hs_service_t *service = NULL;
tor_assert(address);
if (hs_parse_address(address, &pk, NULL, &version) < 0) {
log_warn(LD_CONFIG, "Requested malformed v3 onion address for removal.");
goto err;
}
if (version != HS_VERSION_THREE) {
log_warn(LD_CONFIG, "Requested version of onion address for removal "
"is not supported.");
goto err;
}
service = find_service(hs_service_map, &pk);
if (service == NULL) {
log_warn(LD_CONFIG, "Requested non-existent v3 hidden service for "
"removal.");
goto err;
}
if (!service->config.is_ephemeral) {
log_warn(LD_CONFIG, "Requested non-ephemeral v3 hidden service for "
"removal.");
goto err;
}
/* Close circuits, remove from map and finally free. */
close_service_circuits(service);
remove_service(hs_service_map, service);
hs_service_free(service);
log_info(LD_CONFIG, "Removed ephemeral v3 hidden service: %s",
safe_str_client(address));
return 0;
err:
return -1;
}
/* Using the ed25519 public key pk, find a service for that key and return the
* current encoded descriptor as a newly allocated string or NULL if not
* found. This is used by the control port subsystem. */
char *
hs_service_lookup_current_desc(const ed25519_public_key_t *pk)
{
const hs_service_t *service;
tor_assert(pk);
service = find_service(hs_service_map, pk);
if (service && service->desc_current) {
char *encoded_desc = NULL;
/* No matter what is the result (which should never be a failure), return
* the encoded variable, if success it will contain the right thing else
* it will be NULL. */
hs_desc_encode_descriptor(service->desc_current->desc,
&service->desc_current->signing_kp,
&encoded_desc);
return encoded_desc;
}
return NULL;
}
/* Return the number of service we have configured and usable. */
unsigned int
hs_service_get_num_services(void)
{
if (hs_service_map == NULL) {
return 0;
}
return HT_SIZE(hs_service_map);
}
/* Called once an introduction circuit is closed. If the circuit doesn't have
* a v3 identifier, it is ignored. */
void
hs_service_intro_circ_has_closed(origin_circuit_t *circ)
{
hs_service_t *service = NULL;
hs_service_intro_point_t *ip = NULL;
hs_service_descriptor_t *desc = NULL;
tor_assert(circ);
if (circ->hs_ident == NULL) {
/* This is not a v3 circuit, ignore. */
goto end;
}
get_objects_from_ident(circ->hs_ident, &service, &ip, &desc);
if (service == NULL) {
/* This is possible if the circuits are closed and the service is
* immediately deleted. */
log_info(LD_REND, "Unable to find any hidden service associated "
"identity key %s on intro circuit %u.",
ed25519_fmt(&circ->hs_ident->identity_pk),
TO_CIRCUIT(circ)->n_circ_id);
goto end;
}
if (ip == NULL) {
/* The introduction point object has already been removed probably by our
* cleanup process so ignore. */
goto end;
}
/* Can't have an intro point object without a descriptor. */
tor_assert(desc);
/* Circuit disappeared so make sure the intro point is updated. By
* keeping the object in the descriptor, we'll be able to retry. */
ip->circuit_established = 0;
end:
return;
}
/* Given conn, a rendezvous edge connection acting as an exit stream, look up
* the hidden service for the circuit circ, and look up the port and address
* based on the connection port. Assign the actual connection address.
*
* Return 0 on success. Return -1 on failure and the caller should NOT close
* the circuit. Return -2 on failure and the caller MUST close the circuit for
* security reasons. */
int
hs_service_set_conn_addr_port(const origin_circuit_t *circ,
edge_connection_t *conn)
{
hs_service_t *service = NULL;
tor_assert(circ);
tor_assert(conn);
tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_REND_JOINED);
tor_assert(circ->hs_ident);
get_objects_from_ident(circ->hs_ident, &service, NULL, NULL);
if (service == NULL) {
log_warn(LD_REND, "Unable to find any hidden service associated "
"identity key %s on rendezvous circuit %u.",
ed25519_fmt(&circ->hs_ident->identity_pk),
TO_CIRCUIT(circ)->n_circ_id);
/* We want the caller to close the circuit because it's not a valid
* service so no danger. Attempting to bruteforce the entire key space by
* opening circuits to learn which service is being hosted here is
* impractical. */
goto err_close;
}
/* Enforce the streams-per-circuit limit, and refuse to provide a mapping if
* this circuit will exceed the limit. */
if (service->config.max_streams_per_rdv_circuit > 0 &&
(circ->hs_ident->num_rdv_streams >=
service->config.max_streams_per_rdv_circuit)) {
#define MAX_STREAM_WARN_INTERVAL 600
static struct ratelim_t stream_ratelim =
RATELIM_INIT(MAX_STREAM_WARN_INTERVAL);
log_fn_ratelim(&stream_ratelim, LOG_WARN, LD_REND,
"Maximum streams per circuit limit reached on "
"rendezvous circuit %u for service %s. Circuit has "
"%" PRIu64 " out of %" PRIu64 " streams. %s.",
TO_CIRCUIT(circ)->n_circ_id,
service->onion_address,
circ->hs_ident->num_rdv_streams,
service->config.max_streams_per_rdv_circuit,
service->config.max_streams_close_circuit ?
"Closing circuit" : "Ignoring open stream request");
if (service->config.max_streams_close_circuit) {
/* Service explicitly configured to close immediately. */
goto err_close;
}
/* Exceeding the limit makes tor silently ignore the stream creation
* request and keep the circuit open. */
goto err_no_close;
}
/* Find a virtual port of that service mathcing the one in the connection if
* successful, set the address in the connection. */
if (hs_set_conn_addr_port(service->config.ports, conn) < 0) {
log_info(LD_REND, "No virtual port mapping exists for port %d for "
"hidden service %s.",
TO_CONN(conn)->port, service->onion_address);
if (service->config.allow_unknown_ports) {
/* Service explicitly allow connection to unknown ports so close right
* away because we do not care about port mapping. */
goto err_close;
}
/* If the service didn't explicitly allow it, we do NOT close the circuit
* here to raise the bar in terms of performance for port mapping. */
goto err_no_close;
}
/* Success. */
return 0;
err_close:
/* Indicate the caller that the circuit should be closed. */
return -2;
err_no_close:
/* Indicate the caller to NOT close the circuit. */
return -1;
}
/* Add to file_list every filename used by a configured hidden service, and to
* dir_list every directory path used by a configured hidden service. This is
* used by the sandbox subsystem to whitelist those. */
void
hs_service_lists_fnames_for_sandbox(smartlist_t *file_list,
smartlist_t *dir_list)
{
tor_assert(file_list);
tor_assert(dir_list);
/* Add files and dirs for legacy services. */
rend_services_add_filenames_to_lists(file_list, dir_list);
/* Add files and dirs for v3+. */
FOR_EACH_SERVICE_BEGIN(service) {
/* Skip ephemeral service, they don't touch the disk. */
if (service->config.is_ephemeral) {
continue;
}
service_add_fnames_to_list(service, file_list);
smartlist_add_strdup(dir_list, service->config.directory_path);
} FOR_EACH_DESCRIPTOR_END;
}
/* Called when our internal view of the directory has changed. We might have
* received a new batch of descriptors which might affect the shape of the
* HSDir hash ring. Signal that we should reexamine the hash ring and
* re-upload our HS descriptors if needed. */
void
hs_service_dir_info_changed(void)
{
if (hs_service_get_num_services() > 0) {
/* New directory information usually goes every consensus so rate limit
* every 30 minutes to not be too conservative. */
static struct ratelim_t dir_info_changed_ratelim = RATELIM_INIT(30 * 60);
log_fn_ratelim(&dir_info_changed_ratelim, LOG_INFO, LD_REND,
"New dirinfo arrived: consider reuploading descriptor");
consider_republishing_hs_descriptors = 1;
}
}
/* Called when we get an INTRODUCE2 cell on the circ. Respond to the cell and
* launch a circuit to the rendezvous point. */
int
hs_service_receive_introduce2(origin_circuit_t *circ, const uint8_t *payload,
size_t payload_len)
{
int ret = -1;
tor_assert(circ);
tor_assert(payload);
/* Do some initial validation and logging before we parse the cell */
if (TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_S_INTRO) {
log_warn(LD_PROTOCOL, "Received an INTRODUCE2 cell on a "
"non introduction circuit of purpose %d",
TO_CIRCUIT(circ)->purpose);
goto done;
}
if (circ->hs_ident) {
ret = service_handle_introduce2(circ, payload, payload_len);
hs_stats_note_introduce2_cell(1);
} else {
ret = rend_service_receive_introduction(circ, payload, payload_len);
hs_stats_note_introduce2_cell(0);
}
done:
return ret;
}
/* Called when we get an INTRO_ESTABLISHED cell. Mark the circuit as an
* established introduction point. Return 0 on success else a negative value
* and the circuit is closed. */
int
hs_service_receive_intro_established(origin_circuit_t *circ,
const uint8_t *payload,
size_t payload_len)
{
int ret = -1;
tor_assert(circ);
tor_assert(payload);
if (TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_S_ESTABLISH_INTRO) {
log_warn(LD_PROTOCOL, "Received an INTRO_ESTABLISHED cell on a "
"non introduction circuit of purpose %d",
TO_CIRCUIT(circ)->purpose);
goto err;
}
/* Handle both version. v2 uses rend_data and v3 uses the hs circuit
* identifier hs_ident. Can't be both. */
if (circ->hs_ident) {
ret = service_handle_intro_established(circ, payload, payload_len);
} else {
ret = rend_service_intro_established(circ, payload, payload_len);
}
if (ret < 0) {
goto err;
}
return 0;
err:
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
return -1;
}
/* Called when any kind of hidden service circuit is done building thus
* opened. This is the entry point from the circuit subsystem. */
void
hs_service_circuit_has_opened(origin_circuit_t *circ)
{
tor_assert(circ);
/* Handle both version. v2 uses rend_data and v3 uses the hs circuit
* identifier hs_ident. Can't be both. */
switch (TO_CIRCUIT(circ)->purpose) {
case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
if (circ->hs_ident) {
service_intro_circ_has_opened(circ);
} else {
rend_service_intro_has_opened(circ);
}
break;
case CIRCUIT_PURPOSE_S_CONNECT_REND:
if (circ->hs_ident) {
service_rendezvous_circ_has_opened(circ);
} else {
rend_service_rendezvous_has_opened(circ);
}
break;
default:
tor_assert(0);
}
}
/* Load and/or generate keys for all onion services including the client
* authorization if any. Return 0 on success, -1 on failure. */
int
hs_service_load_all_keys(void)
{
/* Load v2 service keys if we have v2. */
if (rend_num_services() != 0) {
if (rend_service_load_all_keys(NULL) < 0) {
goto err;
}
}
/* Load or/and generate them for v3+. */
SMARTLIST_FOREACH_BEGIN(hs_service_staging_list, hs_service_t *, service) {
/* Ignore ephemeral service, they already have their keys set. */
if (service->config.is_ephemeral) {
continue;
}
log_info(LD_REND, "Loading v3 onion service keys from %s",
service_escaped_dir(service));
if (load_service_keys(service) < 0) {
goto err;
}
/* XXX: Load/Generate client authorization keys. (#20700) */
} SMARTLIST_FOREACH_END(service);
/* Final step, the staging list contains service in a quiescent state that
* is ready to be used. Register them to the global map. Once this is over,
* the staging list will be cleaned up. */
register_all_services();
/* All keys have been loaded successfully. */
return 0;
err:
return -1;
}
/* Put all service object in the given service list. After this, the caller
* looses ownership of every elements in the list and responsible to free the
* list pointer. */
void
hs_service_stage_services(const smartlist_t *service_list)
{
tor_assert(service_list);
/* This list is freed at registration time but this function can be called
* multiple time. */
if (hs_service_staging_list == NULL) {
hs_service_staging_list = smartlist_new();
}
/* Add all service object to our staging list. Caller is responsible for
* freeing the service_list. */
smartlist_add_all(hs_service_staging_list, service_list);
}
/* Allocate and initilize a service object. The service configuration will
* contain the default values. Return the newly allocated object pointer. This
* function can't fail. */
hs_service_t *
hs_service_new(const or_options_t *options)
{
hs_service_t *service = tor_malloc_zero(sizeof(hs_service_t));
/* Set default configuration value. */
set_service_default_config(&service->config, options);
/* Set the default service version. */
service->config.version = HS_SERVICE_DEFAULT_VERSION;
/* Allocate the CLIENT_PK replay cache in service state. */
service->state.replay_cache_rend_cookie =
replaycache_new(REND_REPLAY_TIME_INTERVAL, REND_REPLAY_TIME_INTERVAL);
return service;
}
/* Free the given <b>service</b> object and all its content. This function
* also takes care of wiping service keys from memory. It is safe to pass a
* NULL pointer. */
void
hs_service_free_(hs_service_t *service)
{
if (service == NULL) {
return;
}
/* Free descriptors. Go over both descriptor with this loop. */
FOR_EACH_DESCRIPTOR_BEGIN(service, desc) {
service_descriptor_free(desc);
} FOR_EACH_DESCRIPTOR_END;
/* Free service configuration. */
service_clear_config(&service->config);
/* Free replay cache from state. */
if (service->state.replay_cache_rend_cookie) {
replaycache_free(service->state.replay_cache_rend_cookie);
}
/* Wipe service keys. */
memwipe(&service->keys.identity_sk, 0, sizeof(service->keys.identity_sk));
tor_free(service);
}
/* Periodic callback. Entry point from the main loop to the HS service
* subsystem. This is call every second. This is skipped if tor can't build a
* circuit or the network is disabled. */
void
hs_service_run_scheduled_events(time_t now)
{
/* First thing we'll do here is to make sure our services are in a
* quiescent state for the scheduled events. */
run_housekeeping_event(now);
/* Order matters here. We first make sure the descriptor object for each
* service contains the latest data. Once done, we check if we need to open
* new introduction circuit. Finally, we try to upload the descriptor for
* each service. */
/* Make sure descriptors are up to date. */
run_build_descriptor_event(now);
/* Make sure services have enough circuits. */
run_build_circuit_event(now);
/* Upload the descriptors if needed/possible. */
run_upload_descriptor_event(now);
}
/* Initialize the service HS subsystem. */
void
hs_service_init(void)
{
/* Should never be called twice. */
tor_assert(!hs_service_map);
tor_assert(!hs_service_staging_list);
/* v2 specific. */
rend_service_init();
hs_service_map = tor_malloc_zero(sizeof(struct hs_service_ht));
HT_INIT(hs_service_ht, hs_service_map);
hs_service_staging_list = smartlist_new();
}
/* Release all global storage of the hidden service subsystem. */
void
hs_service_free_all(void)
{
rend_service_free_all();
service_free_all();
}
#ifdef TOR_UNIT_TESTS
/* Return the global service map size. Only used by unit test. */
STATIC unsigned int
get_hs_service_map_size(void)
{
return HT_SIZE(hs_service_map);
}
/* Return the staging list size. Only used by unit test. */
STATIC int
get_hs_service_staging_list_size(void)
{
return smartlist_len(hs_service_staging_list);
}
STATIC hs_service_ht *
get_hs_service_map(void)
{
return hs_service_map;
}
STATIC hs_service_t *
get_first_service(void)
{
hs_service_t **obj = HT_START(hs_service_ht, hs_service_map);
if (obj == NULL) {
return NULL;
}
return *obj;
}
#endif /* defined(TOR_UNIT_TESTS) */
Reference in New Issue View Git Blame Copy Permalink