/* 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 "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 "hs_circuit.h"
#include "hs_common.h"
#include "hs_config.h"
#include "hs_circuit.h"
#include "hs_descriptor.h"
#include "hs_ident.h"
#include "hs_intropoint.h"
#include "hs_service.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 seperated because
* loading keys requires that we are an actual running tor process. */
static smartlist_t *hs_service_staging_list;
/* 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 transfered 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);
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));
}
}
/* Set the default values for a service configuration object c. */
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 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_intro_free_content(&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 *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. */
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);
/* XXX: These will be controlled by consensus params. (#20961) */
ip->introduce2_max =
crypto_rand_int_range(INTRO_POINT_MIN_LIFETIME_INTRODUCTIONS,
INTRO_POINT_MAX_LIFETIME_INTRODUCTIONS);
ip->time_to_expire = time(NULL) +
crypto_rand_int_range(INTRO_POINT_LIFETIME_MIN_SECONDS,
INTRO_POINT_LIFETIME_MAX_SECONDS);
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 (ei == NULL) {
goto done;
}
/* We'll try to add all link specifier. Legacy, IPv4 and ed25519 are
* mandatory. */
ls = hs_desc_link_specifier_new(ei, LS_IPV4);
/* It is impossible to have an extend info object without a v4. */
tor_assert(ls);
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. */
tor_assert(ls);
smartlist_add(ip->base.link_specifiers, ls);
ls = hs_desc_link_specifier_new(ei, LS_ED25519_ID);
/* It is impossible to have an extend info object without an ed25519
* identity key. */
tor_assert(ls);
smartlist_add(ip->base.link_specifiers, ls);
/* IPv6 is optional. */
ls = hs_desc_link_specifier_new(ei, LS_IPV6);
if (ls) {
smartlist_add(ip->base.link_specifiers, ls);
}
/* 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)
{
tor_assert(map);
tor_assert(ip);
digest256map_set(map, ip->auth_key_kp.pubkey.pubkey, ip);
}
/* For a given service, remove the intro point from that service which will
* look in both descriptors. */
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. */
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);
/* Legacy ID is mandatory for an intro point object to have. */
tor_assert(ls);
/* 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 an introduction point circuit matching the given intro point object.
* NULL is returned is no such circuit can be found. */
static origin_circuit_t *
get_intro_circuit(const hs_service_intro_point_t *ip)
{
origin_circuit_t *circ = NULL;
tor_assert(ip);
if (ip->base.is_only_legacy) {
uint8_t digest[DIGEST_LEN];
if (BUG(crypto_pk_get_digest(ip->legacy_key, (char *) digest) < 0)) {
goto end;
}
circ = hs_circuitmap_get_intro_circ_v2_service_side(digest);
} else {
circ = hs_circuitmap_get_intro_circ_v3_service_side(
&ip->auth_key_kp.pubkey);
}
end:
return circ;
}
/* 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;
}
/* 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(ô->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 = get_intro_circuit(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 introduction points from the src descriptor to the dst descriptor. The
* destination service intropoints are wiped out if any before moving. */
static void
move_descriptor_intro_points(hs_service_descriptor_t *src,
hs_service_descriptor_t *dst)
{
tor_assert(src);
tor_assert(dst);
digest256map_free(dst->intro_points.map, service_intro_point_free_);
dst->intro_points.map = src->intro_points.map;
/* Nullify the source. */
src->intro_points.map = NULL;
}
/* Move introduction points from the src service to the dst service. The
* destination service intropoints are wiped out if any before moving. */
static void
move_intro_points(hs_service_t *src, hs_service_t *dst)
{
tor_assert(src);
tor_assert(dst);
if (src->desc_current && dst->desc_current) {
move_descriptor_intro_points(src->desc_current, dst->desc_current);
}
if (src->desc_next && dst->desc_next) {
move_descriptor_intro_points(src->desc_next, dst->desc_next);
}
}
/* 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);
}
/* 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);
/* We'll save us some allocation and computing time. */
if (smartlist_len(hs_service_staging_list) == 0) {
return;
}
/* 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 intro points from s (the current service) to snew
* (the newly configured one). */
move_intro_points(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);
}
/* 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;
}
/* 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;
/* Length of an address plus the sizeof the address tld (onion) which counts
* the NUL terminated byte so we keep it for the "." and the newline. */
char buf[HS_SERVICE_ADDR_LEN_BASE32 + sizeof(address_tld) + 1];
tor_assert(service);
tor_assert(fname_);
/* Construct the full address with the onion tld and write the hostname file
* to disk. */
tor_snprintf(buf, sizeof(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, 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 /* _WIN32 */
/* Success. */
ret = 0;
end:
tor_free(fname);
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, 0, 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));
SMARTLIST_FOREACH(desc->hsdir_missing_info, char *, id, tor_free(id));
smartlist_free(desc->hsdir_missing_info);
/* Cleanup all intro points. */
digest256map_free(desc->intro_points.map, service_intro_point_free_);
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->hsdir_missing_info = smartlist_new();
return sdesc;
}
/* 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 *dup = tor_malloc_zero(sizeof(*dup));
link_specifier_copy(dup, ls);
smartlist_add(desc_ip->link_specifiers, dup);
} 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_free_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 fomr 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;
}
/* Populare 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;
}
/* 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;
return;
err:
service_descriptor_free(desc);
}
/* 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) {
if (service->desc_current == NULL) {
/* This means we just booted up because else this descriptor will never
* be NULL as it should always point to the descriptor that was in
* desc_next after rotation. */
build_service_descriptor(service, now, hs_get_time_period_num(now),
&service->desc_current);
log_info(LD_REND, "Hidden service %s current descriptor successfully "
"built. Now scheduled for upload.",
safe_str_client(service->onion_address));
}
/* A next descriptor to NULL indicate that we need to build a fresh one if
* we are in the overlap period for the _next_ time period since it means
* we either just booted or we just rotated our descriptors. */
if (hs_overlap_mode_is_active(NULL, now) && service->desc_next == NULL) {
build_service_descriptor(service, now, hs_get_next_time_period_num(now),
&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 to directly connect to and if not,
* fallback to a normal 3-hop node. Return a newly allocated service intro
* point ready to be used for encoding. 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);
if (node == NULL && direct_conn) {
/* Unable to find a node for direct connection, let's fall back to a
* normal 3-hop node. */
node = router_choose_random_node(exclude_nodes,
get_options()->ExcludeNodes, flags);
}
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. */
info = extend_info_from_node(node, direct_conn);
if (BUG(info == NULL)) {
goto err;
}
/* 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;
}
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 NUM_INTRO_POINTS_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) {
/* XXX: Should a consensus param control that value? */
num_needed_ip += NUM_INTRO_POINTS_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) {
smartlist_add(exclude_nodes, (void *) get_node_from_intro_point(ip));
} DIGEST256MAP_FOREACH_END;
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;
}
/* 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. 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,
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. */
desc->next_upload_time = now;
}
/* 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)
{
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);
origin_circuit_t *ocirc = get_intro_circuit(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 ||
(ocirc == NULL &&
ip->circuit_retries >= MAX_INTRO_POINT_CIRCUIT_RETRIES)) {
MAP_DEL_CURRENT(key);
service_intro_point_free(ip);
/* XXX: Legacy code does NOT do that, 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?). */
if (ocirc) {
/* After this, no new cells will be handled on the circuit. */
circuit_mark_for_close(TO_CIRCUIT(ocirc), END_CIRC_REASON_FINISHED);
}
continue;
}
if (ocirc == NULL) {
/* 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;
}
} DIGEST256MAP_FOREACH_END;
} FOR_EACH_DESCRIPTOR_END;
}
/** We just entered overlap period and we need to rotate our service
* descriptors */
static void
rotate_service_descriptors(hs_service_t *service)
{
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;
}
/* Rotate descriptors for each service if needed. If we are just entering
* the overlap period, rotate them that is point the previous descriptor to
* the current and cleanup the previous one. A non existing current
* descriptor will trigger a descriptor build for the next time period. */
static void
rotate_all_descriptors(time_t now)
{
FOR_EACH_SERVICE_BEGIN(service) {
/* We are _not_ in the overlap period so skip rotation. */
if (!hs_overlap_mode_is_active(NULL, now)) {
service->state.in_overlap_period = 0;
continue;
}
/* We've entered the overlap period already so skip rotation. */
if (service->state.in_overlap_period) {
continue;
}
/* It's the first time the service encounters the overlap period so flag
* it in order to make sure we don't rotate at next check. */
service->state.in_overlap_period = 1;
/* If we have a next descriptor lined up, rotate the descriptors so that it
* becomes current. */
if (service->desc_next) {
rotate_service_descriptors(service);
}
log_info(LD_REND, "We've just entered the overlap period. Service %s "
"descriptors have been rotated!",
safe_str_client(service->onion_address));
} 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 uneeded elements. */
FOR_EACH_SERVICE_BEGIN(service) {
/* Cleanup invalid intro points from the service descriptor. */
cleanup_intro_points(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, time_t now)
{
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 (get_intro_circuit(ip)) {
continue;
}
ei = get_extend_info_from_intro_point(ip, direct_conn);
if (ei == NULL) {
if (!direct_conn) {
/* In case of a multi-hop connection, it should never happen that we
* can't get the extend info from the node. Avoid connection and
* remove intro point from descriptor in order to recover from this
* potential bug. */
tor_assert_nonfatal(ei);
}
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, now) < 0) {
log_warn(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);
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 + NUM_INTRO_POINTS_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, elapsed_time,
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 (num_rend_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, now);
/* 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 version_str[4] = {0}, *encoded_desc = NULL;
directory_request_t *dir_req;
hs_ident_dir_conn_t ident;
tor_assert(service);
tor_assert(desc);
tor_assert(hsdir);
memset(&ident, 0, sizeof(ident));
/* 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;
}
/* Setup the connection identifier. */
ed25519_pubkey_copy(&ident.identity_pk, &service->keys.identity_pk);
/* This is our resource when uploading which is used to construct the URL
* with the version number: "/tor/hs//publish". */
tor_snprintf(version_str, sizeof(version_str), "%u",
service->config.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_set_hs_ident(dir_req, &ident);
/* Initiate the directory request to the hsdir.*/
directory_initiate_request(dir_req);
directory_request_free(dir_req);
/* Logging so we know where it was sent. */
{
int is_next_desc = (service->desc_next == desc);
const uint8_t *index = (is_next_desc) ? hsdir->hsdir_index->next :
hsdir->hsdir_index->current;
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 *) index, 32)));
}
/* XXX: Inform control port of the upload event (#20699). */
end:
tor_free(encoded_desc);
return;
}
/* 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, int for_next_period)
{
smartlist_t *responsible_dirs = NULL;
tor_assert(service);
tor_assert(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,
for_next_period, 0, responsible_dirs);
/* 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);
/* Do not upload to an HSDir we don't have a descriptor for. */
if (!node_has_descriptor(hsdir_node)) {
log_info(LD_REND, "Missing descriptor for HSDir %s. Not uploading "
"descriptor. We'll try later once we have it.",
safe_str_client(node_describe(hsdir_node)));
/* Once we get new directory information, this HSDir will be retried if
* we ever get the descriptor. */
smartlist_add(desc->hsdir_missing_info,
tor_memdup(hsdir_rs->identity_digest, DIGEST_LEN));
continue;
}
/* 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);
}
/* Increment the revision counter 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. */
desc->desc->plaintext_data.revision_counter += 1;
smartlist_free(responsible_dirs);
return;
}
/* 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. */
(desc->missing_intro_points) ?
(num_intro_points = digest256map_size(desc->intro_points.map)) :
(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;
}
/* 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 (num_rend_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) {
int for_next_period = 0;
/* Can this descriptor be uploaed? */
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);
/* If the service is in the overlap period and this descriptor is the
* next one, it has to be uploaded for the next time period meaning
* we'll use the next node_t hsdir_index to pick the HSDirs. */
if (desc == service->desc_next) {
for_next_period = 1;
}
upload_descriptor_to_all(service, desc, for_next_period);
} FOR_EACH_DESCRIPTOR_END;
} FOR_EACH_SERVICE_END;
}
/* 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);
tor_assert(circ->cpath);
/* Getting here means this is a v3 intro circuit. */
tor_assert(circ->hs_ident);
tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO);
/* 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 intro 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 */
if (!TO_CIRCUIT(circ)->timestamp_dirty)
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;
}
/* Handle an 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 is updated. */
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;
}
/* Handle an INTRODUCE2 cell arriving on the given introduction circuit.
* 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;
}
/* For a given service and a descriptor of that service, consider retrying to
* upload the descriptor to any directories from which we had missing
* information when originally tried to be uploaded. This is called when our
* directory information has changed. */
static void
consider_hsdir_retry(const hs_service_t *service,
hs_service_descriptor_t *desc)
{
smartlist_t *responsible_dirs = NULL;
smartlist_t *still_missing_dirs = NULL;
tor_assert(service);
tor_assert(desc);
responsible_dirs = smartlist_new();
still_missing_dirs = smartlist_new();
/* We first need to get responsible directories from the latest consensus so
* we can then make sure that the node that we were missing information for
* is still responsible for this descriptor. */
hs_get_responsible_hsdirs(&desc->blinded_kp.pubkey, desc->time_period_num,
service->desc_next == desc, 0, responsible_dirs);
SMARTLIST_FOREACH_BEGIN(responsible_dirs, const routerstatus_t *, rs) {
const node_t *node;
const char *id = rs->identity_digest;
if (!smartlist_contains_digest(desc->hsdir_missing_info, id)) {
continue;
}
/* We do need a node_t object and descriptor to perform an upload. If
* found, we remove the id from the missing dir list else we add it to the
* still missing dir list to keep track of id that are still missing. */
node = node_get_by_id(id);
if (node && node_has_descriptor(node)) {
upload_descriptor_to_hsdir(service, desc, node);
smartlist_remove(desc->hsdir_missing_info, id);
} else {
smartlist_add(still_missing_dirs, tor_memdup(id, DIGEST_LEN));
}
} SMARTLIST_FOREACH_END(rs);
/* Switch the still missing dir list with the current missing dir list in
* the descriptor. It is possible that the list ends up empty which is what
* we want if we have no more missing dir. */
SMARTLIST_FOREACH(desc->hsdir_missing_info, char *, id, tor_free(id));
smartlist_free(desc->hsdir_missing_info);
desc->hsdir_missing_info = still_missing_dirs;
/* No ownership of the routerstatus_t object in this list. */
smartlist_free(responsible_dirs);
}
/* ========== */
/* Public API */
/* ========== */
/* Called when our internal view of the directory has changed. We might have
* new descriptors for hidden service directories that we didn't have before
* so try them if it's the case. */
void
hs_service_dir_info_changed(void)
{
/* For each service we have, check every descriptor and consider retrying to
* upload it to directories that we might have had missing information
* previously that is missing a router descriptor. */
FOR_EACH_SERVICE_BEGIN(service) {
FOR_EACH_DESCRIPTOR_BEGIN(service, desc) {
/* This cleans up the descriptor missing hsdir information list if a
* successful upload is made or if any of the directory aren't
* responsible anymore for the service descriptor. */
consider_hsdir_retry(service, desc);
} FOR_EACH_DESCRIPTOR_END;
} FOR_EACH_SERVICE_END;
}
/* 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;
}
ret = (circ->hs_ident) ? service_handle_introduce2(circ, payload,
payload_len) :
rend_service_receive_introduction(circ, payload,
payload_len);
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. */
ret = (circ->hs_ident) ? service_handle_intro_established(circ, payload,
payload_len) :
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:
(circ->hs_ident) ? service_intro_circ_has_opened(circ) :
rend_service_intro_has_opened(circ);
break;
case CIRCUIT_PURPOSE_S_CONNECT_REND:
(circ->hs_ident) ? service_rendezvous_circ_has_opened(circ) :
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 (num_rend_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 service 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();
}
/* XXX We don't currently use these functions, apart from generating unittest
data. When we start implementing the service-side support for prop224 we
should revisit these functions and use them. */
/** Given an ESTABLISH_INTRO cell, encode it and place its payload in
* buf_out which has size buf_out_len. Return the number of
* bytes written, or a negative integer if there was an error. */
ssize_t
get_establish_intro_payload(uint8_t *buf_out, size_t buf_out_len,
const trn_cell_establish_intro_t *cell)
{
ssize_t bytes_used = 0;
if (buf_out_len < RELAY_PAYLOAD_SIZE) {
return -1;
}
bytes_used = trn_cell_establish_intro_encode(buf_out, buf_out_len,
cell);
return bytes_used;
}
/* Set the cell extensions of cell. */
static void
set_trn_cell_extensions(trn_cell_establish_intro_t *cell)
{
trn_cell_extension_t *trn_cell_extensions = trn_cell_extension_new();
/* For now, we don't use extensions at all. */
trn_cell_extensions->num = 0; /* It's already zeroed, but be explicit. */
trn_cell_establish_intro_set_extensions(cell, trn_cell_extensions);
}
/** Given the circuit handshake info in circuit_key_material, create and
* return an ESTABLISH_INTRO cell. Return NULL if something went wrong. The
* returned cell is allocated on the heap and it's the responsibility of the
* caller to free it. */
trn_cell_establish_intro_t *
generate_establish_intro_cell(const uint8_t *circuit_key_material,
size_t circuit_key_material_len)
{
trn_cell_establish_intro_t *cell = NULL;
ssize_t encoded_len;
log_warn(LD_GENERAL,
"Generating ESTABLISH_INTRO cell (key_material_len: %u)",
(unsigned) circuit_key_material_len);
/* Generate short-term keypair for use in ESTABLISH_INTRO */
ed25519_keypair_t key_struct;
if (ed25519_keypair_generate(&key_struct, 0) < 0) {
goto err;
}
cell = trn_cell_establish_intro_new();
/* Set AUTH_KEY_TYPE: 2 means ed25519 */
trn_cell_establish_intro_set_auth_key_type(cell,
HS_INTRO_AUTH_KEY_TYPE_ED25519);
/* Set AUTH_KEY_LEN field */
/* Must also set byte-length of AUTH_KEY to match */
int auth_key_len = ED25519_PUBKEY_LEN;
trn_cell_establish_intro_set_auth_key_len(cell, auth_key_len);
trn_cell_establish_intro_setlen_auth_key(cell, auth_key_len);
/* Set AUTH_KEY field */
uint8_t *auth_key_ptr = trn_cell_establish_intro_getarray_auth_key(cell);
memcpy(auth_key_ptr, key_struct.pubkey.pubkey, auth_key_len);
/* No cell extensions needed */
set_trn_cell_extensions(cell);
/* Set signature size.
We need to do this up here, because _encode() needs it and we need to call
_encode() to calculate the MAC and signature.
*/
int sig_len = ED25519_SIG_LEN;
trn_cell_establish_intro_set_sig_len(cell, sig_len);
trn_cell_establish_intro_setlen_sig(cell, sig_len);
/* XXX How to make this process easier and nicer? */
/* Calculate the cell MAC (aka HANDSHAKE_AUTH). */
{
/* To calculate HANDSHAKE_AUTH, we dump the cell in bytes, and then derive
the MAC from it. */
uint8_t cell_bytes_tmp[RELAY_PAYLOAD_SIZE] = {0};
uint8_t mac[TRUNNEL_SHA3_256_LEN];
encoded_len = trn_cell_establish_intro_encode(cell_bytes_tmp,
sizeof(cell_bytes_tmp),
cell);
if (encoded_len < 0) {
log_warn(LD_OR, "Unable to pre-encode ESTABLISH_INTRO cell.");
goto err;
}
/* sanity check */
tor_assert(encoded_len > ED25519_SIG_LEN + 2 + TRUNNEL_SHA3_256_LEN);
/* Calculate MAC of all fields before HANDSHAKE_AUTH */
crypto_mac_sha3_256(mac, sizeof(mac),
circuit_key_material, circuit_key_material_len,
cell_bytes_tmp,
encoded_len -
(ED25519_SIG_LEN + 2 + TRUNNEL_SHA3_256_LEN));
/* Write the MAC to the cell */
uint8_t *handshake_ptr =
trn_cell_establish_intro_getarray_handshake_mac(cell);
memcpy(handshake_ptr, mac, sizeof(mac));
}
/* Calculate the cell signature */
{
/* To calculate the sig we follow the same procedure as above. We first
dump the cell up to the sig, and then calculate the sig */
uint8_t cell_bytes_tmp[RELAY_PAYLOAD_SIZE] = {0};
ed25519_signature_t sig;
encoded_len = trn_cell_establish_intro_encode(cell_bytes_tmp,
sizeof(cell_bytes_tmp),
cell);
if (encoded_len < 0) {
log_warn(LD_OR, "Unable to pre-encode ESTABLISH_INTRO cell (2).");
goto err;
}
tor_assert(encoded_len > ED25519_SIG_LEN);
if (ed25519_sign_prefixed(&sig,
cell_bytes_tmp,
encoded_len -
(ED25519_SIG_LEN + sizeof(cell->sig_len)),
ESTABLISH_INTRO_SIG_PREFIX,
&key_struct)) {
log_warn(LD_BUG, "Unable to gen signature for ESTABLISH_INTRO cell.");
goto err;
}
/* And write the signature to the cell */
uint8_t *sig_ptr = trn_cell_establish_intro_getarray_sig(cell);
memcpy(sig_ptr, sig.sig, sig_len);
}
/* We are done! Return the cell! */
return cell;
err:
trn_cell_establish_intro_free(cell);
return NULL;
}
#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 /* TOR_UNIT_TESTS */