/* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2010, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file rendservice.c
* \brief The hidden-service side of rendezvous functionality.
**/
#include "or.h"
static origin_circuit_t *find_intro_circuit(rend_intro_point_t *intro,
const char *pk_digest);
/** Represents the mapping from a virtual port of a rendezvous service to
* a real port on some IP.
*/
typedef struct rend_service_port_config_t {
uint16_t virtual_port;
uint16_t real_port;
tor_addr_t real_addr;
} rend_service_port_config_t;
/** Try to maintain this many intro points per service if possible. */
#define NUM_INTRO_POINTS 3
/** If we can't build our intro circuits, don't retry for this long. */
#define INTRO_CIRC_RETRY_PERIOD (60*5)
/** Don't try to build more than this many circuits before giving up
* for a while.*/
#define MAX_INTRO_CIRCS_PER_PERIOD 10
/** How many times will a hidden service operator attempt to connect to
* a requested rendezvous point before giving up? */
#define MAX_REND_FAILURES 30
/** How many seconds should we spend trying to connect to a requested
* rendezvous point before giving up? */
#define MAX_REND_TIMEOUT 30
/** Represents a single hidden service running at this OP. */
typedef struct rend_service_t {
/* Fields specified in config file */
char *directory; /**< where in the filesystem it stores it */
smartlist_t *ports; /**< List of rend_service_port_config_t */
rend_auth_type_t auth_type; /**< Client authorization type or 0 if no client
* authorization is performed. */
smartlist_t *clients; /**< List of rend_authorized_client_t's of
* clients that may access our service. Can be NULL
* if no client authorization is performed. */
/* Other fields */
crypto_pk_env_t *private_key; /**< Permanent hidden-service key. */
char service_id[REND_SERVICE_ID_LEN_BASE32+1]; /**< Onion address without
* '.onion' */
char pk_digest[DIGEST_LEN]; /**< Hash of permanent hidden-service key. */
smartlist_t *intro_nodes; /**< List of rend_intro_point_t's we have,
* or are trying to establish. */
time_t intro_period_started; /**< Start of the current period to build
* introduction points. */
int n_intro_circuits_launched; /**< Count of intro circuits we have
* established in this period. */
rend_service_descriptor_t *desc; /**< Current hidden service descriptor. */
time_t desc_is_dirty; /**< Time at which changes to the hidden service
* descriptor content occurred, or 0 if it's
* up-to-date. */
time_t next_upload_time; /**< Scheduled next hidden service descriptor
* upload time. */
/** Map from digests of Diffie-Hellman values INTRODUCE2 to time_t of when
* they were received; used to prevent replays. */
digestmap_t *accepted_intros;
/** Time at which we last removed expired values from accepted_intros. */
time_t last_cleaned_accepted_intros;
} rend_service_t;
/** A list of rend_service_t's for services run on this OP.
*/
static smartlist_t *rend_service_list = NULL;
/** Return the number of rendezvous services we have configured. */
int
num_rend_services(void)
{
if (!rend_service_list)
return 0;
return smartlist_len(rend_service_list);
}
/** Helper: free storage held by a single service authorized client entry. */
static void
rend_authorized_client_free(rend_authorized_client_t *client)
{
if (!client)
return;
if (client->client_key)
crypto_free_pk_env(client->client_key);
tor_free(client->client_name);
tor_free(client);
}
/** Helper for strmap_free. */
static void
rend_authorized_client_strmap_item_free(void *authorized_client)
{
rend_authorized_client_free(authorized_client);
}
/** Release the storage held by <b>service</b>.
*/
static void
rend_service_free(rend_service_t *service)
{
if (!service)
return;
tor_free(service->directory);
SMARTLIST_FOREACH(service->ports, void*, p, tor_free(p));
smartlist_free(service->ports);
if (service->private_key)
crypto_free_pk_env(service->private_key);
if (service->intro_nodes) {
SMARTLIST_FOREACH(service->intro_nodes, rend_intro_point_t *, intro,
rend_intro_point_free(intro););
smartlist_free(service->intro_nodes);
}
rend_service_descriptor_free(service->desc);
if (service->clients) {
SMARTLIST_FOREACH(service->clients, rend_authorized_client_t *, c,
rend_authorized_client_free(c););
smartlist_free(service->clients);
}
digestmap_free(service->accepted_intros, _tor_free);
tor_free(service);
}
/** Release all the storage held in rend_service_list.
*/
void
rend_service_free_all(void)
{
if (!rend_service_list)
return;
SMARTLIST_FOREACH(rend_service_list, rend_service_t*, ptr,
rend_service_free(ptr));
smartlist_free(rend_service_list);
rend_service_list = NULL;
}
/** Validate <b>service</b> and add it to rend_service_list if possible.
*/
static void
rend_add_service(rend_service_t *service)
{
int i;
rend_service_port_config_t *p;
service->intro_nodes = smartlist_create();
if (service->auth_type != REND_NO_AUTH &&
smartlist_len(service->clients) == 0) {
log_warn(LD_CONFIG, "Hidden service with client authorization but no "
"clients; ignoring.");
rend_service_free(service);
return;
}
if (!smartlist_len(service->ports)) {
log_warn(LD_CONFIG, "Hidden service with no ports configured; ignoring.");
rend_service_free(service);
} else {
smartlist_add(rend_service_list, service);
log_debug(LD_REND,"Configuring service with directory \"%s\"",
service->directory);
for (i = 0; i < smartlist_len(service->ports); ++i) {
p = smartlist_get(service->ports, i);
log_debug(LD_REND,"Service maps port %d to %s:%d",
p->virtual_port, fmt_addr(&p->real_addr), p->real_port);
}
}
}
/** Parses a real-port to virtual-port mapping and returns a new
* rend_service_port_config_t.
*
* The format is: VirtualPort (IP|RealPort|IP:RealPort)?
*
* IP defaults to 127.0.0.1; RealPort defaults to VirtualPort.
*/
static rend_service_port_config_t *
parse_port_config(const char *string)
{
smartlist_t *sl;
int virtport;
int realport;
uint16_t p;
tor_addr_t addr;
const char *addrport;
rend_service_port_config_t *result = NULL;
sl = smartlist_create();
smartlist_split_string(sl, string, " ",
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
if (smartlist_len(sl) < 1 || smartlist_len(sl) > 2) {
log_warn(LD_CONFIG, "Bad syntax in hidden service port configuration.");
goto err;
}
virtport = (int)tor_parse_long(smartlist_get(sl,0), 10, 1, 65535, NULL,NULL);
if (!virtport) {
log_warn(LD_CONFIG, "Missing or invalid port %s in hidden service port "
"configuration", escaped(smartlist_get(sl,0)));
goto err;
}
if (smartlist_len(sl) == 1) {
/* No addr:port part; use default. */
realport = virtport;
tor_addr_from_ipv4h(&addr, 0x7F000001u); /* 127.0.0.1 */
} else {
addrport = smartlist_get(sl,1);
if (strchr(addrport, ':') || strchr(addrport, '.')) {
if (tor_addr_port_parse(addrport, &addr, &p)<0) {
log_warn(LD_CONFIG,"Unparseable address in hidden service port "
"configuration.");
goto err;
}
realport = p?p:virtport;
} else {
/* No addr:port, no addr -- must be port. */
realport = (int)tor_parse_long(addrport, 10, 1, 65535, NULL, NULL);
if (!realport) {
log_warn(LD_CONFIG,"Unparseable or out-of-range port %s in hidden "
"service port configuration.", escaped(addrport));
goto err;
}
tor_addr_from_ipv4h(&addr, 0x7F000001u); /* Default to 127.0.0.1 */
}
}
result = tor_malloc(sizeof(rend_service_port_config_t));
result->virtual_port = virtport;
result->real_port = realport;
tor_addr_copy(&result->real_addr, &addr);
err:
SMARTLIST_FOREACH(sl, char *, c, tor_free(c));
smartlist_free(sl);
return result;
}
/** Set up rend_service_list, based on the values of HiddenServiceDir and
* HiddenServicePort in <b>options</b>. Return 0 on success and -1 on
* failure. (If <b>validate_only</b> is set, parse, warn and return as
* normal, but don't actually change the configured services.)
*/
int
rend_config_services(or_options_t *options, int validate_only)
{
config_line_t *line;
rend_service_t *service = NULL;
rend_service_port_config_t *portcfg;
smartlist_t *old_service_list = NULL;
if (!validate_only) {
old_service_list = rend_service_list;
rend_service_list = smartlist_create();
}
for (line = options->RendConfigLines; line; line = line->next) {
if (!strcasecmp(line->key, "HiddenServiceDir")) {
if (service) { /* register the one we just finished parsing */
if (validate_only)
rend_service_free(service);
else
rend_add_service(service);
}
service = tor_malloc_zero(sizeof(rend_service_t));
service->directory = tor_strdup(line->value);
service->ports = smartlist_create();
service->intro_period_started = time(NULL);
continue;
}
if (!service) {
log_warn(LD_CONFIG, "%s with no preceding HiddenServiceDir directive",
line->key);
rend_service_free(service);
return -1;
}
if (!strcasecmp(line->key, "HiddenServicePort")) {
portcfg = parse_port_config(line->value);
if (!portcfg) {
rend_service_free(service);
return -1;
}
smartlist_add(service->ports, portcfg);
} else if (!strcasecmp(line->key, "HiddenServiceAuthorizeClient")) {
/* Parse auth type and comma-separated list of client names and add a
* rend_authorized_client_t for each client to the service's list
* of authorized clients. */
smartlist_t *type_names_split, *clients;
const char *authname;
int num_clients;
if (service->auth_type != REND_NO_AUTH) {
log_warn(LD_CONFIG, "Got multiple HiddenServiceAuthorizeClient "
"lines for a single service.");
rend_service_free(service);
return -1;
}
type_names_split = smartlist_create();
smartlist_split_string(type_names_split, line->value, " ", 0, 2);
if (smartlist_len(type_names_split) < 1) {
log_warn(LD_BUG, "HiddenServiceAuthorizeClient has no value. This "
"should have been prevented when parsing the "
"configuration.");
smartlist_free(type_names_split);
rend_service_free(service);
return -1;
}
authname = smartlist_get(type_names_split, 0);
if (!strcasecmp(authname, "basic")) {
service->auth_type = REND_BASIC_AUTH;
} else if (!strcasecmp(authname, "stealth")) {
service->auth_type = REND_STEALTH_AUTH;
} else {
log_warn(LD_CONFIG, "HiddenServiceAuthorizeClient contains "
"unrecognized auth-type '%s'. Only 'basic' or 'stealth' "
"are recognized.",
(char *) smartlist_get(type_names_split, 0));
SMARTLIST_FOREACH(type_names_split, char *, cp, tor_free(cp));
smartlist_free(type_names_split);
rend_service_free(service);
return -1;
}
service->clients = smartlist_create();
if (smartlist_len(type_names_split) < 2) {
log_warn(LD_CONFIG, "HiddenServiceAuthorizeClient contains "
"auth-type '%s', but no client names.",
service->auth_type == REND_BASIC_AUTH ? "basic" : "stealth");
SMARTLIST_FOREACH(type_names_split, char *, cp, tor_free(cp));
smartlist_free(type_names_split);
continue;
}
clients = smartlist_create();
smartlist_split_string(clients, smartlist_get(type_names_split, 1),
",", SPLIT_SKIP_SPACE, 0);
SMARTLIST_FOREACH(type_names_split, char *, cp, tor_free(cp));
smartlist_free(type_names_split);
/* Remove duplicate client names. */
num_clients = smartlist_len(clients);
smartlist_sort_strings(clients);
smartlist_uniq_strings(clients);
if (smartlist_len(clients) < num_clients) {
log_info(LD_CONFIG, "HiddenServiceAuthorizeClient contains %d "
"duplicate client name(s); removing.",
num_clients - smartlist_len(clients));
num_clients = smartlist_len(clients);
}
SMARTLIST_FOREACH_BEGIN(clients, const char *, client_name)
{
rend_authorized_client_t *client;
size_t len = strlen(client_name);
if (len < 1 || len > REND_CLIENTNAME_MAX_LEN) {
log_warn(LD_CONFIG, "HiddenServiceAuthorizeClient contains an "
"illegal client name: '%s'. Length must be "
"between 1 and %d characters.",
client_name, REND_CLIENTNAME_MAX_LEN);
SMARTLIST_FOREACH(clients, char *, cp, tor_free(cp));
smartlist_free(clients);
rend_service_free(service);
return -1;
}
if (strspn(client_name, REND_LEGAL_CLIENTNAME_CHARACTERS) != len) {
log_warn(LD_CONFIG, "HiddenServiceAuthorizeClient contains an "
"illegal client name: '%s'. Valid "
"characters are [A-Za-z0-9+-_].",
client_name);
SMARTLIST_FOREACH(clients, char *, cp, tor_free(cp));
smartlist_free(clients);
rend_service_free(service);
return -1;
}
client = tor_malloc_zero(sizeof(rend_authorized_client_t));
client->client_name = tor_strdup(client_name);
smartlist_add(service->clients, client);
log_debug(LD_REND, "Adding client name '%s'", client_name);
}
SMARTLIST_FOREACH_END(client_name);
SMARTLIST_FOREACH(clients, char *, cp, tor_free(cp));
smartlist_free(clients);
/* Ensure maximum number of clients. */
if ((service->auth_type == REND_BASIC_AUTH &&
smartlist_len(service->clients) > 512) ||
(service->auth_type == REND_STEALTH_AUTH &&
smartlist_len(service->clients) > 16)) {
log_warn(LD_CONFIG, "HiddenServiceAuthorizeClient contains %d "
"client authorization entries, but only a "
"maximum of %d entries is allowed for "
"authorization type '%s'.",
smartlist_len(service->clients),
service->auth_type == REND_BASIC_AUTH ? 512 : 16,
service->auth_type == REND_BASIC_AUTH ? "basic" : "stealth");
rend_service_free(service);
return -1;
}
} else {
tor_assert(!strcasecmp(line->key, "HiddenServiceVersion"));
if (strcmp(line->value, "2")) {
log_warn(LD_CONFIG,
"The only supported HiddenServiceVersion is 2.");
rend_service_free(service);
return -1;
}
}
}
if (service) {
if (validate_only)
rend_service_free(service);
else
rend_add_service(service);
}
/* If this is a reload and there were hidden services configured before,
* keep the introduction points that are still needed and close the
* other ones. */
if (old_service_list && !validate_only) {
smartlist_t *surviving_services = smartlist_create();
circuit_t *circ;
/* Copy introduction points to new services. */
/* XXXX This is O(n^2), but it's only called on reconfigure, so it's
* probably ok? */
SMARTLIST_FOREACH(rend_service_list, rend_service_t *, new, {
SMARTLIST_FOREACH(old_service_list, rend_service_t *, old, {
if (!strcmp(old->directory, new->directory)) {
smartlist_add_all(new->intro_nodes, old->intro_nodes);
smartlist_clear(old->intro_nodes);
smartlist_add(surviving_services, old);
break;
}
});
});
/* Close introduction circuits of services we don't serve anymore. */
/* XXXX it would be nicer if we had a nicer abstraction to use here,
* so we could just iterate over the list of services to close, but
* once again, this isn't critical-path code. */
for (circ = _circuit_get_global_list(); circ; circ = circ->next) {
if (!circ->marked_for_close &&
circ->state == CIRCUIT_STATE_OPEN &&
(circ->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO ||
circ->purpose == CIRCUIT_PURPOSE_S_INTRO)) {
origin_circuit_t *oc = TO_ORIGIN_CIRCUIT(circ);
int keep_it = 0;
tor_assert(oc->rend_data);
SMARTLIST_FOREACH(surviving_services, rend_service_t *, ptr, {
if (!memcmp(ptr->pk_digest, oc->rend_data->rend_pk_digest,
DIGEST_LEN)) {
keep_it = 1;
break;
}
});
if (keep_it)
continue;
log_info(LD_REND, "Closing intro point %s for service %s.",
safe_str_client(oc->build_state->chosen_exit->nickname),
oc->rend_data->onion_address);
circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
/* XXXX Is there another reason we should use here? */
}
}
smartlist_free(surviving_services);
SMARTLIST_FOREACH(old_service_list, rend_service_t *, ptr,
rend_service_free(ptr));
smartlist_free(old_service_list);
}
return 0;
}
/** Replace the old value of <b>service</b>-\>desc with one that reflects
* the other fields in service.
*/
static void
rend_service_update_descriptor(rend_service_t *service)
{
rend_service_descriptor_t *d;
origin_circuit_t *circ;
int i;
rend_service_descriptor_free(service->desc);
service->desc = NULL;
d = service->desc = tor_malloc_zero(sizeof(rend_service_descriptor_t));
d->pk = crypto_pk_dup_key(service->private_key);
d->timestamp = time(NULL);
d->intro_nodes = smartlist_create();
/* Support intro protocols 2 and 3. */
d->protocols = (1 << 2) + (1 << 3);
for (i = 0; i < smartlist_len(service->intro_nodes); ++i) {
rend_intro_point_t *intro_svc = smartlist_get(service->intro_nodes, i);
rend_intro_point_t *intro_desc;
circ = find_intro_circuit(intro_svc, service->pk_digest);
if (!circ || circ->_base.purpose != CIRCUIT_PURPOSE_S_INTRO)
continue;
/* We have an entirely established intro circuit. */
intro_desc = tor_malloc_zero(sizeof(rend_intro_point_t));
intro_desc->extend_info = extend_info_dup(intro_svc->extend_info);
if (intro_svc->intro_key)
intro_desc->intro_key = crypto_pk_dup_key(intro_svc->intro_key);
smartlist_add(d->intro_nodes, intro_desc);
}
}
/** Load and/or generate private keys for all hidden services, possibly
* including keys for client authorization. Return 0 on success, -1 on
* failure.
*/
int
rend_service_load_keys(void)
{
int r = 0;
char fname[512];
char buf[1500];
SMARTLIST_FOREACH_BEGIN(rend_service_list, rend_service_t *, s) {
if (s->private_key)
continue;
log_info(LD_REND, "Loading hidden-service keys from \"%s\"",
s->directory);
/* Check/create directory */
if (check_private_dir(s->directory, CPD_CREATE) < 0)
return -1;
/* Load key */
if (strlcpy(fname,s->directory,sizeof(fname)) >= sizeof(fname) ||
strlcat(fname,PATH_SEPARATOR"private_key",sizeof(fname))
>= sizeof(fname)) {
log_warn(LD_CONFIG, "Directory name too long to store key file: \"%s\".",
s->directory);
return -1;
}
s->private_key = init_key_from_file(fname, 1, LOG_ERR);
if (!s->private_key)
return -1;
/* Create service file */
if (rend_get_service_id(s->private_key, s->service_id)<0) {
log_warn(LD_BUG, "Internal error: couldn't encode service ID.");
return -1;
}
if (crypto_pk_get_digest(s->private_key, s->pk_digest)<0) {
log_warn(LD_BUG, "Couldn't compute hash of public key.");
return -1;
}
if (strlcpy(fname,s->directory,sizeof(fname)) >= sizeof(fname) ||
strlcat(fname,PATH_SEPARATOR"hostname",sizeof(fname))
>= sizeof(fname)) {
log_warn(LD_CONFIG, "Directory name too long to store hostname file:"
" \"%s\".", s->directory);
return -1;
}
tor_snprintf(buf, sizeof(buf),"%s.onion\n", s->service_id);
if (write_str_to_file(fname,buf,0)<0) {
log_warn(LD_CONFIG, "Could not write onion address to hostname file.");
return -1;
}
/* If client authorization is configured, load or generate keys. */
if (s->auth_type != REND_NO_AUTH) {
char *client_keys_str = NULL;
strmap_t *parsed_clients = strmap_new();
char cfname[512];
FILE *cfile, *hfile;
open_file_t *open_cfile = NULL, *open_hfile = NULL;
/* Load client keys and descriptor cookies, if available. */
if (tor_snprintf(cfname, sizeof(cfname), "%s"PATH_SEPARATOR"client_keys",
s->directory)<0) {
log_warn(LD_CONFIG, "Directory name too long to store client keys "
"file: \"%s\".", s->directory);
goto err;
}
client_keys_str = read_file_to_str(cfname, RFTS_IGNORE_MISSING, NULL);
if (client_keys_str) {
if (rend_parse_client_keys(parsed_clients, client_keys_str) < 0) {
log_warn(LD_CONFIG, "Previously stored client_keys file could not "
"be parsed.");
goto err;
} else {
log_info(LD_CONFIG, "Parsed %d previously stored client entries.",
strmap_size(parsed_clients));
tor_free(client_keys_str);
}
}
/* Prepare client_keys and hostname files. */
if (!(cfile = start_writing_to_stdio_file(cfname, OPEN_FLAGS_REPLACE,
0600, &open_cfile))) {
log_warn(LD_CONFIG, "Could not open client_keys file %s",
escaped(cfname));
goto err;
}
if (!(hfile = start_writing_to_stdio_file(fname, OPEN_FLAGS_REPLACE,
0600, &open_hfile))) {
log_warn(LD_CONFIG, "Could not open hostname file %s", escaped(fname));
goto err;
}
/* Either use loaded keys for configured clients or generate new
* ones if a client is new. */
SMARTLIST_FOREACH_BEGIN(s->clients, rend_authorized_client_t *, client)
{
char desc_cook_out[3*REND_DESC_COOKIE_LEN_BASE64+1];
char service_id[16+1];
rend_authorized_client_t *parsed =
strmap_get(parsed_clients, client->client_name);
int written;
size_t len;
/* Copy descriptor cookie from parsed entry or create new one. */
if (parsed) {
memcpy(client->descriptor_cookie, parsed->descriptor_cookie,
REND_DESC_COOKIE_LEN);
} else {
crypto_rand(client->descriptor_cookie, REND_DESC_COOKIE_LEN);
}
if (base64_encode(desc_cook_out, 3*REND_DESC_COOKIE_LEN_BASE64+1,
client->descriptor_cookie,
REND_DESC_COOKIE_LEN) < 0) {
log_warn(LD_BUG, "Could not base64-encode descriptor cookie.");
strmap_free(parsed_clients, rend_authorized_client_strmap_item_free);
return -1;
}
/* Copy client key from parsed entry or create new one if required. */
if (parsed && parsed->client_key) {
client->client_key = crypto_pk_dup_key(parsed->client_key);
} else if (s->auth_type == REND_STEALTH_AUTH) {
/* Create private key for client. */
crypto_pk_env_t *prkey = NULL;
if (!(prkey = crypto_new_pk_env())) {
log_warn(LD_BUG,"Error constructing client key");
goto err;
}
if (crypto_pk_generate_key(prkey)) {
log_warn(LD_BUG,"Error generating client key");
crypto_free_pk_env(prkey);
goto err;
}
if (crypto_pk_check_key(prkey) <= 0) {
log_warn(LD_BUG,"Generated client key seems invalid");
crypto_free_pk_env(prkey);
goto err;
}
client->client_key = prkey;
}
/* Add entry to client_keys file. */
desc_cook_out[strlen(desc_cook_out)-1] = '\0'; /* Remove newline. */
written = tor_snprintf(buf, sizeof(buf),
"client-name %s\ndescriptor-cookie %s\n",
client->client_name, desc_cook_out);
if (written < 0) {
log_warn(LD_BUG, "Could not write client entry.");
goto err;
}
if (client->client_key) {
char *client_key_out = NULL;
crypto_pk_write_private_key_to_string(client->client_key,
&client_key_out, &len);
if (rend_get_service_id(client->client_key, service_id)<0) {
log_warn(LD_BUG, "Internal error: couldn't encode service ID.");
tor_free(client_key_out);
goto err;
}
written = tor_snprintf(buf + written, sizeof(buf) - written,
"client-key\n%s", client_key_out);
tor_free(client_key_out);
if (written < 0) {
log_warn(LD_BUG, "Could not write client entry.");
goto err;
}
}
if (fputs(buf, cfile) < 0) {
log_warn(LD_FS, "Could not append client entry to file: %s",
strerror(errno));
goto err;
}
/* Add line to hostname file. */
if (s->auth_type == REND_BASIC_AUTH) {
/* Remove == signs (newline has been removed above). */
desc_cook_out[strlen(desc_cook_out)-2] = '\0';
tor_snprintf(buf, sizeof(buf),"%s.onion %s # client: %s\n",
s->service_id, desc_cook_out, client->client_name);
} else {
char extended_desc_cookie[REND_DESC_COOKIE_LEN+1];
memcpy(extended_desc_cookie, client->descriptor_cookie,
REND_DESC_COOKIE_LEN);
extended_desc_cookie[REND_DESC_COOKIE_LEN] =
((int)s->auth_type - 1) << 4;
if (base64_encode(desc_cook_out, 3*REND_DESC_COOKIE_LEN_BASE64+1,
extended_desc_cookie,
REND_DESC_COOKIE_LEN+1) < 0) {
log_warn(LD_BUG, "Could not base64-encode descriptor cookie.");
goto err;
}
desc_cook_out[strlen(desc_cook_out)-3] = '\0'; /* Remove A= and
newline. */
tor_snprintf(buf, sizeof(buf),"%s.onion %s # client: %s\n",
service_id, desc_cook_out, client->client_name);
}
if (fputs(buf, hfile)<0) {
log_warn(LD_FS, "Could not append host entry to file: %s",
strerror(errno));
goto err;
}
}
SMARTLIST_FOREACH_END(client);
goto done;
err:
r = -1;
done:
tor_free(client_keys_str);
strmap_free(parsed_clients, rend_authorized_client_strmap_item_free);
if (r<0) {
if (open_cfile)
abort_writing_to_file(open_cfile);
if (open_hfile)
abort_writing_to_file(open_hfile);
return r;
} else {
finish_writing_to_file(open_cfile);
finish_writing_to_file(open_hfile);
}
}
} SMARTLIST_FOREACH_END(s);
return r;
}
/** Return the service whose public key has a digest of <b>digest</b>, or
* NULL if no such service exists.
*/
static rend_service_t *
rend_service_get_by_pk_digest(const char* digest)
{
SMARTLIST_FOREACH(rend_service_list, rend_service_t*, s,
if (!memcmp(s->pk_digest,digest,DIGEST_LEN))
return s);
return NULL;
}
/** Return 1 if any virtual port in <b>service</b> wants a circuit
* to have good uptime. Else return 0.
*/
static int
rend_service_requires_uptime(rend_service_t *service)
{
int i;
rend_service_port_config_t *p;
for (i=0; i < smartlist_len(service->ports); ++i) {
p = smartlist_get(service->ports, i);
if (smartlist_string_num_isin(get_options()->LongLivedPorts,
p->virtual_port))
return 1;
}
return 0;
}
/** Check client authorization of a given <b>descriptor_cookie</b> for
* <b>service</b>. Return 1 for success and 0 for failure. */
static int
rend_check_authorization(rend_service_t *service,
const char *descriptor_cookie)
{
rend_authorized_client_t *auth_client = NULL;
tor_assert(service);
tor_assert(descriptor_cookie);
if (!service->clients) {
log_warn(LD_BUG, "Can't check authorization for a service that has no "
"authorized clients configured.");
return 0;
}
/* Look up client authorization by descriptor cookie. */
SMARTLIST_FOREACH(service->clients, rend_authorized_client_t *, client, {
if (!memcmp(client->descriptor_cookie, descriptor_cookie,
REND_DESC_COOKIE_LEN)) {
auth_client = client;
break;
}
});
if (!auth_client) {
char descriptor_cookie_base64[3*REND_DESC_COOKIE_LEN_BASE64];
base64_encode(descriptor_cookie_base64, sizeof(descriptor_cookie_base64),
descriptor_cookie, REND_DESC_COOKIE_LEN);
log_info(LD_REND, "No authorization found for descriptor cookie '%s'! "
"Dropping cell!",
descriptor_cookie_base64);
return 0;
}
/* Allow the request. */
log_debug(LD_REND, "Client %s authorized for service %s.",
auth_client->client_name, service->service_id);
return 1;
}
/** Remove elements from <b>service</b>'s replay cache that are old enough to
* be noticed by timestamp checking. */
static void
clean_accepted_intros(rend_service_t *service, time_t now)
{
const time_t cutoff = now - REND_REPLAY_TIME_INTERVAL;
service->last_cleaned_accepted_intros = now;
if (!service->accepted_intros)
return;
DIGESTMAP_FOREACH_MODIFY(service->accepted_intros, digest, time_t *, t) {
if (*t < cutoff) {
tor_free(t);
MAP_DEL_CURRENT(digest);
}
} DIGESTMAP_FOREACH_END;
}
/******
* Handle cells
******/
/** Respond to an INTRODUCE2 cell by launching a circuit to the chosen
* rendezvous point.
*/
int
rend_service_introduce(origin_circuit_t *circuit, const char *request,
size_t request_len)
{
char *ptr, *r_cookie;
extend_info_t *extend_info = NULL;
char buf[RELAY_PAYLOAD_SIZE];
char keys[DIGEST_LEN+CPATH_KEY_MATERIAL_LEN]; /* Holds KH, Df, Db, Kf, Kb */
rend_service_t *service;
int r, i, v3_shift = 0;
size_t len, keylen;
crypto_dh_env_t *dh = NULL;
origin_circuit_t *launched = NULL;
crypt_path_t *cpath = NULL;
char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
char hexcookie[9];
int circ_needs_uptime;
int reason = END_CIRC_REASON_TORPROTOCOL;
crypto_pk_env_t *intro_key;
char intro_key_digest[DIGEST_LEN];
int auth_type;
size_t auth_len = 0;
char auth_data[REND_DESC_COOKIE_LEN];
crypto_digest_env_t *digest = NULL;
time_t now = time(NULL);
char diffie_hellman_hash[DIGEST_LEN];
time_t *access_time;
tor_assert(circuit->rend_data);
base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32+1,
circuit->rend_data->rend_pk_digest, REND_SERVICE_ID_LEN);
log_info(LD_REND, "Received INTRODUCE2 cell for service %s on circ %d.",
escaped(serviceid), circuit->_base.n_circ_id);
if (circuit->_base.purpose != CIRCUIT_PURPOSE_S_INTRO) {
log_warn(LD_PROTOCOL,
"Got an INTRODUCE2 over a non-introduction circuit %d.",
circuit->_base.n_circ_id);
return -1;
}
/* min key length plus digest length plus nickname length */
if (request_len < DIGEST_LEN+REND_COOKIE_LEN+(MAX_NICKNAME_LEN+1)+
DH_KEY_LEN+42) {
log_warn(LD_PROTOCOL, "Got a truncated INTRODUCE2 cell on circ %d.",
circuit->_base.n_circ_id);
return -1;
}
/* look up service depending on circuit. */
service = rend_service_get_by_pk_digest(
circuit->rend_data->rend_pk_digest);
if (!service) {
log_warn(LD_REND, "Got an INTRODUCE2 cell for an unrecognized service %s.",
escaped(serviceid));
return -1;
}
/* use intro key instead of service key. */
intro_key = circuit->intro_key;
/* first DIGEST_LEN bytes of request is intro or service pk digest */
crypto_pk_get_digest(intro_key, intro_key_digest);
if (memcmp(intro_key_digest, request, DIGEST_LEN)) {
base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32+1,
request, REND_SERVICE_ID_LEN);
log_warn(LD_REND, "Got an INTRODUCE2 cell for the wrong service (%s).",
escaped(serviceid));
return -1;
}
keylen = crypto_pk_keysize(intro_key);
if (request_len < keylen+DIGEST_LEN) {
log_warn(LD_PROTOCOL,
"PK-encrypted portion of INTRODUCE2 cell was truncated.");
return -1;
}
/* Next N bytes is encrypted with service key */
note_crypto_pk_op(REND_SERVER);
r = crypto_pk_private_hybrid_decrypt(
intro_key,buf,request+DIGEST_LEN,request_len-DIGEST_LEN,
PK_PKCS1_OAEP_PADDING,1);
if (r<0) {
log_warn(LD_PROTOCOL, "Couldn't decrypt INTRODUCE2 cell.");
return -1;
}
len = r;
if (*buf == 3) {
/* Version 3 INTRODUCE2 cell. */
time_t ts = 0;
v3_shift = 1;
auth_type = buf[1];
switch (auth_type) {
case REND_BASIC_AUTH:
/* fall through */
case REND_STEALTH_AUTH:
auth_len = ntohs(get_uint16(buf+2));
if (auth_len != REND_DESC_COOKIE_LEN) {
log_info(LD_REND, "Wrong auth data size %d, should be %d.",
(int)auth_len, REND_DESC_COOKIE_LEN);
return -1;
}
memcpy(auth_data, buf+4, sizeof(auth_data));
v3_shift += 2+REND_DESC_COOKIE_LEN;
break;
case REND_NO_AUTH:
break;
default:
log_info(LD_REND, "Unknown authorization type '%d'", auth_type);
}
/* Check timestamp. */
ts = ntohl(get_uint32(buf+1+v3_shift));
v3_shift += 4;
if ((now - ts) < -1 * REND_REPLAY_TIME_INTERVAL / 2 ||
(now - ts) > REND_REPLAY_TIME_INTERVAL / 2) {
log_warn(LD_REND, "INTRODUCE2 cell is too %s. Discarding.",
(now - ts) < 0 ? "old" : "new");
return -1;
}
}
if (*buf == 2 || *buf == 3) {
/* Version 2 INTRODUCE2 cell. */
int klen;
extend_info = tor_malloc_zero(sizeof(extend_info_t));
tor_addr_from_ipv4n(&extend_info->addr, get_uint32(buf+v3_shift+1));
extend_info->port = ntohs(get_uint16(buf+v3_shift+5));
memcpy(extend_info->identity_digest, buf+v3_shift+7,
DIGEST_LEN);
extend_info->nickname[0] = '$';
base16_encode(extend_info->nickname+1, sizeof(extend_info->nickname)-1,
extend_info->identity_digest, DIGEST_LEN);
klen = ntohs(get_uint16(buf+v3_shift+7+DIGEST_LEN));
if ((int)len != v3_shift+7+DIGEST_LEN+2+klen+20+128) {
log_warn(LD_PROTOCOL, "Bad length %u for version %d INTRODUCE2 cell.",
(int)len, *buf);
reason = END_CIRC_REASON_TORPROTOCOL;
goto err;
}
extend_info->onion_key =
crypto_pk_asn1_decode(buf+v3_shift+7+DIGEST_LEN+2, klen);
if (!extend_info->onion_key) {
log_warn(LD_PROTOCOL, "Error decoding onion key in version %d "
"INTRODUCE2 cell.", *buf);
reason = END_CIRC_REASON_TORPROTOCOL;
goto err;
}
ptr = buf+v3_shift+7+DIGEST_LEN+2+klen;
len -= v3_shift+7+DIGEST_LEN+2+klen;
} else {
char *rp_nickname;
size_t nickname_field_len;
routerinfo_t *router;
int version;
if (*buf == 1) {
rp_nickname = buf+1;
nickname_field_len = MAX_HEX_NICKNAME_LEN+1;
version = 1;
} else {
nickname_field_len = MAX_NICKNAME_LEN+1;
rp_nickname = buf;
version = 0;
}
ptr=memchr(rp_nickname,0,nickname_field_len);
if (!ptr || ptr == rp_nickname) {
log_warn(LD_PROTOCOL,
"Couldn't find a nul-padded nickname in INTRODUCE2 cell.");
return -1;
}
if ((version == 0 && !is_legal_nickname(rp_nickname)) ||
(version == 1 && !is_legal_nickname_or_hexdigest(rp_nickname))) {
log_warn(LD_PROTOCOL, "Bad nickname in INTRODUCE2 cell.");
return -1;
}
/* Okay, now we know that a nickname is at the start of the buffer. */
ptr = rp_nickname+nickname_field_len;
len -= nickname_field_len;
len -= rp_nickname - buf; /* also remove header space used by version, if
* any */
router = router_get_by_nickname(rp_nickname, 0);
if (!router) {
log_info(LD_REND, "Couldn't find router %s named in introduce2 cell.",
escaped_safe_str_client(rp_nickname));
/* XXXX Add a no-such-router reason? */
reason = END_CIRC_REASON_TORPROTOCOL;
goto err;
}
extend_info = extend_info_from_router(router);
}
if (len != REND_COOKIE_LEN+DH_KEY_LEN) {
log_warn(LD_PROTOCOL, "Bad length %u for INTRODUCE2 cell.", (int)len);
reason = END_CIRC_REASON_TORPROTOCOL;
goto err;
}
r_cookie = ptr;
base16_encode(hexcookie,9,r_cookie,4);
/* Determine hash of Diffie-Hellman, part 1 to detect replays. */
digest = crypto_new_digest_env();
crypto_digest_add_bytes(digest, ptr+REND_COOKIE_LEN, DH_KEY_LEN);
crypto_digest_get_digest(digest, diffie_hellman_hash, DIGEST_LEN);
crypto_free_digest_env(digest);
/* Check whether there is a past request with the same Diffie-Hellman,
* part 1. */
if (!service->accepted_intros)
service->accepted_intros = digestmap_new();
access_time = digestmap_get(service->accepted_intros, diffie_hellman_hash);
if (access_time != NULL) {
log_warn(LD_REND, "Possible replay detected! We received an "
"INTRODUCE2 cell with same first part of "
"Diffie-Hellman handshake %d seconds ago. Dropping "
"cell.",
(int) (now - *access_time));
goto err;
}
/* Add request to access history, including time and hash of Diffie-Hellman,
* part 1, and possibly remove requests from the history that are older than
* one hour. */
access_time = tor_malloc(sizeof(time_t));
*access_time = now;
digestmap_set(service->accepted_intros, diffie_hellman_hash, access_time);
if (service->last_cleaned_accepted_intros + REND_REPLAY_TIME_INTERVAL < now)
clean_accepted_intros(service, now);
/* If the service performs client authorization, check included auth data. */
if (service->clients) {
if (auth_len > 0) {
if (rend_check_authorization(service, auth_data)) {
log_info(LD_REND, "Authorization data in INTRODUCE2 cell are valid.");
} else {
log_info(LD_REND, "The authorization data that are contained in "
"the INTRODUCE2 cell are invalid. Dropping cell.");
reason = END_CIRC_REASON_CONNECTFAILED;
goto err;
}
} else {
log_info(LD_REND, "INTRODUCE2 cell does not contain authentication "
"data, but we require client authorization. Dropping cell.");
reason = END_CIRC_REASON_CONNECTFAILED;
goto err;
}
}
/* Try DH handshake... */
dh = crypto_dh_new();
if (!dh || crypto_dh_generate_public(dh)<0) {
log_warn(LD_BUG,"Internal error: couldn't build DH state "
"or generate public key.");
reason = END_CIRC_REASON_INTERNAL;
goto err;
}
if (crypto_dh_compute_secret(LOG_PROTOCOL_WARN, dh, ptr+REND_COOKIE_LEN,
DH_KEY_LEN, keys,
DIGEST_LEN+CPATH_KEY_MATERIAL_LEN)<0) {
log_warn(LD_BUG, "Internal error: couldn't complete DH handshake");
reason = END_CIRC_REASON_INTERNAL;
goto err;
}
circ_needs_uptime = rend_service_requires_uptime(service);
/* help predict this next time */
rep_hist_note_used_internal(now, circ_needs_uptime, 1);
/* Launch a circuit to alice's chosen rendezvous point.
*/
for (i=0;i<MAX_REND_FAILURES;i++) {
int flags = CIRCLAUNCH_NEED_CAPACITY | CIRCLAUNCH_IS_INTERNAL;
if (circ_needs_uptime) flags |= CIRCLAUNCH_NEED_UPTIME;
launched = circuit_launch_by_extend_info(
CIRCUIT_PURPOSE_S_CONNECT_REND, extend_info, flags);
if (launched)
break;
}
if (!launched) { /* give up */
log_warn(LD_REND, "Giving up launching first hop of circuit to rendezvous "
"point %s for service %s.",
escaped_safe_str_client(extend_info->nickname),
serviceid);
reason = END_CIRC_REASON_CONNECTFAILED;
goto err;
}
log_info(LD_REND,
"Accepted intro; launching circuit to %s "
"(cookie %s) for service %s.",
escaped_safe_str_client(extend_info->nickname),
hexcookie, serviceid);
tor_assert(launched->build_state);
/* Fill in the circuit's state. */
launched->rend_data = tor_malloc_zero(sizeof(rend_data_t));
memcpy(launched->rend_data->rend_pk_digest,
circuit->rend_data->rend_pk_digest,
DIGEST_LEN);
memcpy(launched->rend_data->rend_cookie, r_cookie, REND_COOKIE_LEN);
strlcpy(launched->rend_data->onion_address, service->service_id,
sizeof(launched->rend_data->onion_address));
launched->build_state->pending_final_cpath = cpath =
tor_malloc_zero(sizeof(crypt_path_t));
cpath->magic = CRYPT_PATH_MAGIC;
launched->build_state->expiry_time = now + MAX_REND_TIMEOUT;
cpath->dh_handshake_state = dh;
dh = NULL;
if (circuit_init_cpath_crypto(cpath,keys+DIGEST_LEN,1)<0)
goto err;
memcpy(cpath->handshake_digest, keys, DIGEST_LEN);
if (extend_info) extend_info_free(extend_info);
return 0;
err:
if (dh) crypto_dh_free(dh);
if (launched)
circuit_mark_for_close(TO_CIRCUIT(launched), reason);
if (extend_info) extend_info_free(extend_info);
return -1;
}
/** Called when we fail building a rendezvous circuit at some point other
* than the last hop: launches a new circuit to the same rendezvous point.
*/
void
rend_service_relaunch_rendezvous(origin_circuit_t *oldcirc)
{
origin_circuit_t *newcirc;
cpath_build_state_t *newstate, *oldstate;
tor_assert(oldcirc->_base.purpose == CIRCUIT_PURPOSE_S_CONNECT_REND);
if (!oldcirc->build_state ||
oldcirc->build_state->failure_count > MAX_REND_FAILURES ||
oldcirc->build_state->expiry_time < time(NULL)) {
log_info(LD_REND,
"Attempt to build circuit to %s for rendezvous has failed "
"too many times or expired; giving up.",
oldcirc->build_state ?
oldcirc->build_state->chosen_exit->nickname : "*unknown*");
return;
}
oldstate = oldcirc->build_state;
tor_assert(oldstate);
if (oldstate->pending_final_cpath == NULL) {
log_info(LD_REND,"Skipping relaunch of circ that failed on its first hop. "
"Initiator will retry.");
return;
}
log_info(LD_REND,"Reattempting rendezvous circuit to '%s'",
oldstate->chosen_exit->nickname);
newcirc = circuit_launch_by_extend_info(CIRCUIT_PURPOSE_S_CONNECT_REND,
oldstate->chosen_exit,
CIRCLAUNCH_NEED_CAPACITY|CIRCLAUNCH_IS_INTERNAL);
if (!newcirc) {
log_warn(LD_REND,"Couldn't relaunch rendezvous circuit to '%s'.",
oldstate->chosen_exit->nickname);
return;
}
newstate = newcirc->build_state;
tor_assert(newstate);
newstate->failure_count = oldstate->failure_count+1;
newstate->expiry_time = oldstate->expiry_time;
newstate->pending_final_cpath = oldstate->pending_final_cpath;
oldstate->pending_final_cpath = NULL;
newcirc->rend_data = rend_data_dup(oldcirc->rend_data);
}
/** Launch a circuit to serve as an introduction point for the service
* <b>service</b> at the introduction point <b>nickname</b>
*/
static int
rend_service_launch_establish_intro(rend_service_t *service,
rend_intro_point_t *intro)
{
origin_circuit_t *launched;
log_info(LD_REND,
"Launching circuit to introduction point %s for service %s",
escaped_safe_str_client(intro->extend_info->nickname),
service->service_id);
rep_hist_note_used_internal(time(NULL), 1, 0);
++service->n_intro_circuits_launched;
launched = circuit_launch_by_extend_info(CIRCUIT_PURPOSE_S_ESTABLISH_INTRO,
intro->extend_info,
CIRCLAUNCH_NEED_UPTIME|CIRCLAUNCH_IS_INTERNAL);
if (!launched) {
log_info(LD_REND,
"Can't launch circuit to establish introduction at %s.",
escaped_safe_str_client(intro->extend_info->nickname));
return -1;
}
if (memcmp(intro->extend_info->identity_digest,
launched->build_state->chosen_exit->identity_digest, DIGEST_LEN)) {
char cann[HEX_DIGEST_LEN+1], orig[HEX_DIGEST_LEN+1];
base16_encode(cann, sizeof(cann),
launched->build_state->chosen_exit->identity_digest,
DIGEST_LEN);
base16_encode(orig, sizeof(orig),
intro->extend_info->identity_digest, DIGEST_LEN);
log_info(LD_REND, "The intro circuit we just cannibalized ends at $%s, "
"but we requested an intro circuit to $%s. Updating "
"our service.", cann, orig);
extend_info_free(intro->extend_info);
intro->extend_info = extend_info_dup(launched->build_state->chosen_exit);
}
launched->rend_data = tor_malloc_zero(sizeof(rend_data_t));
strlcpy(launched->rend_data->onion_address, service->service_id,
sizeof(launched->rend_data->onion_address));
memcpy(launched->rend_data->rend_pk_digest, service->pk_digest, DIGEST_LEN);
launched->intro_key = crypto_pk_dup_key(intro->intro_key);
if (launched->_base.state == CIRCUIT_STATE_OPEN)
rend_service_intro_has_opened(launched);
return 0;
}
/** Return the number of introduction points that are or have been
* established for the given service address in <b>query</b>. */
static int
count_established_intro_points(const char *query)
{
int num_ipos = 0;
circuit_t *circ;
for (circ = _circuit_get_global_list(); circ; circ = circ->next) {
if (!circ->marked_for_close &&
circ->state == CIRCUIT_STATE_OPEN &&
(circ->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO ||
circ->purpose == CIRCUIT_PURPOSE_S_INTRO)) {
origin_circuit_t *oc = TO_ORIGIN_CIRCUIT(circ);
if (oc->rend_data &&
!rend_cmp_service_ids(query, oc->rend_data->onion_address))
num_ipos++;
}
}
return num_ipos;
}
/** Called when we're done building a circuit to an introduction point:
* sends a RELAY_ESTABLISH_INTRO cell.
*/
void
rend_service_intro_has_opened(origin_circuit_t *circuit)
{
rend_service_t *service;
size_t len;
int r;
char buf[RELAY_PAYLOAD_SIZE];
char auth[DIGEST_LEN + 9];
char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
int reason = END_CIRC_REASON_TORPROTOCOL;
crypto_pk_env_t *intro_key;
tor_assert(circuit->_base.purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO);
tor_assert(circuit->cpath);
tor_assert(circuit->rend_data);
base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32+1,
circuit->rend_data->rend_pk_digest, REND_SERVICE_ID_LEN);
service = rend_service_get_by_pk_digest(
circuit->rend_data->rend_pk_digest);
if (!service) {
log_warn(LD_REND, "Unrecognized service ID %s on introduction circuit %d.",
serviceid, circuit->_base.n_circ_id);
reason = END_CIRC_REASON_NOSUCHSERVICE;
goto err;
}
/* If we already have enough introduction circuits for this service,
* redefine this one as a general circuit. */
if (count_established_intro_points(serviceid) > NUM_INTRO_POINTS) {
log_info(LD_CIRC|LD_REND, "We have just finished an introduction "
"circuit, but we already have enough. Redefining purpose to "
"general.");
TO_CIRCUIT(circuit)->purpose = CIRCUIT_PURPOSE_C_GENERAL;
circuit_has_opened(circuit);
return;
}
log_info(LD_REND,
"Established circuit %d as introduction point for service %s",
circuit->_base.n_circ_id, serviceid);
/* Use the intro key instead of the service key in ESTABLISH_INTRO. */
intro_key = circuit->intro_key;
/* Build the payload for a RELAY_ESTABLISH_INTRO cell. */
r = crypto_pk_asn1_encode(intro_key, buf+2,
RELAY_PAYLOAD_SIZE-2);
if (r < 0) {
log_warn(LD_BUG, "Internal error; failed to establish intro point.");
reason = END_CIRC_REASON_INTERNAL;
goto err;
}
len = r;
set_uint16(buf, htons((uint16_t)len));
len += 2;
memcpy(auth, circuit->cpath->prev->handshake_digest, DIGEST_LEN);
memcpy(auth+DIGEST_LEN, "INTRODUCE", 9);
if (crypto_digest(buf+len, auth, DIGEST_LEN+9))
goto err;
len += 20;
note_crypto_pk_op(REND_SERVER);
r = crypto_pk_private_sign_digest(intro_key, buf+len, buf, len);
if (r<0) {
log_warn(LD_BUG, "Internal error: couldn't sign introduction request.");
reason = END_CIRC_REASON_INTERNAL;
goto err;
}
len += r;
if (relay_send_command_from_edge(0, TO_CIRCUIT(circuit),
RELAY_COMMAND_ESTABLISH_INTRO,
buf, len, circuit->cpath->prev)<0) {
log_info(LD_GENERAL,
"Couldn't send introduction request for service %s on circuit %d",
serviceid, circuit->_base.n_circ_id);
reason = END_CIRC_REASON_INTERNAL;
goto err;
}
return;
err:
circuit_mark_for_close(TO_CIRCUIT(circuit), reason);
}
/** Called when we get an INTRO_ESTABLISHED cell; mark the circuit as a
* live introduction point, and note that the service descriptor is
* now out-of-date.*/
int
rend_service_intro_established(origin_circuit_t *circuit, const char *request,
size_t request_len)
{
rend_service_t *service;
char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
(void) request;
(void) request_len;
if (circuit->_base.purpose != CIRCUIT_PURPOSE_S_ESTABLISH_INTRO) {
log_warn(LD_PROTOCOL,
"received INTRO_ESTABLISHED cell on non-intro circuit.");
goto err;
}
tor_assert(circuit->rend_data);
service = rend_service_get_by_pk_digest(
circuit->rend_data->rend_pk_digest);
if (!service) {
log_warn(LD_REND, "Unknown service on introduction circuit %d.",
circuit->_base.n_circ_id);
goto err;
}
service->desc_is_dirty = time(NULL);
circuit->_base.purpose = CIRCUIT_PURPOSE_S_INTRO;
base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32 + 1,
circuit->rend_data->rend_pk_digest, REND_SERVICE_ID_LEN);
log_info(LD_REND,
"Received INTRO_ESTABLISHED cell on circuit %d for service %s",
circuit->_base.n_circ_id, serviceid);
return 0;
err:
circuit_mark_for_close(TO_CIRCUIT(circuit), END_CIRC_REASON_TORPROTOCOL);
return -1;
}
/** Called once a circuit to a rendezvous point is established: sends a
* RELAY_COMMAND_RENDEZVOUS1 cell.
*/
void
rend_service_rendezvous_has_opened(origin_circuit_t *circuit)
{
rend_service_t *service;
char buf[RELAY_PAYLOAD_SIZE];
crypt_path_t *hop;
char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
char hexcookie[9];
int reason;
tor_assert(circuit->_base.purpose == CIRCUIT_PURPOSE_S_CONNECT_REND);
tor_assert(circuit->cpath);
tor_assert(circuit->build_state);
tor_assert(circuit->rend_data);
hop = circuit->build_state->pending_final_cpath;
tor_assert(hop);
base16_encode(hexcookie,9,circuit->rend_data->rend_cookie,4);
base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32+1,
circuit->rend_data->rend_pk_digest, REND_SERVICE_ID_LEN);
log_info(LD_REND,
"Done building circuit %d to rendezvous with "
"cookie %s for service %s",
circuit->_base.n_circ_id, hexcookie, serviceid);
service = rend_service_get_by_pk_digest(
circuit->rend_data->rend_pk_digest);
if (!service) {
log_warn(LD_GENERAL, "Internal error: unrecognized service ID on "
"introduction circuit.");
reason = END_CIRC_REASON_INTERNAL;
goto err;
}
/* All we need to do is send a RELAY_RENDEZVOUS1 cell... */
memcpy(buf, circuit->rend_data->rend_cookie, REND_COOKIE_LEN);
if (crypto_dh_get_public(hop->dh_handshake_state,
buf+REND_COOKIE_LEN, DH_KEY_LEN)<0) {
log_warn(LD_GENERAL,"Couldn't get DH public key.");
reason = END_CIRC_REASON_INTERNAL;
goto err;
}
memcpy(buf+REND_COOKIE_LEN+DH_KEY_LEN, hop->handshake_digest,
DIGEST_LEN);
/* Send the cell */
if (relay_send_command_from_edge(0, TO_CIRCUIT(circuit),
RELAY_COMMAND_RENDEZVOUS1,
buf, REND_COOKIE_LEN+DH_KEY_LEN+DIGEST_LEN,
circuit->cpath->prev)<0) {
log_warn(LD_GENERAL, "Couldn't send RENDEZVOUS1 cell.");
reason = END_CIRC_REASON_INTERNAL;
goto err;
}
crypto_dh_free(hop->dh_handshake_state);
hop->dh_handshake_state = NULL;
/* Append the cpath entry. */
hop->state = CPATH_STATE_OPEN;
/* set the windows to default. these are the windows
* that bob thinks alice has.
*/
hop->package_window = circuit_initial_package_window();
hop->deliver_window = CIRCWINDOW_START;
onion_append_to_cpath(&circuit->cpath, hop);
circuit->build_state->pending_final_cpath = NULL; /* prevent double-free */
/* Change the circuit purpose. */
circuit->_base.purpose = CIRCUIT_PURPOSE_S_REND_JOINED;
return;
err:
circuit_mark_for_close(TO_CIRCUIT(circuit), reason);
}
/*
* Manage introduction points
*/
/** Return the (possibly non-open) introduction circuit ending at
* <b>intro</b> for the service whose public key is <b>pk_digest</b>.
* (<b>desc_version</b> is ignored). Return NULL if no such service is
* found.
*/
static origin_circuit_t *
find_intro_circuit(rend_intro_point_t *intro, const char *pk_digest)
{
origin_circuit_t *circ = NULL;
tor_assert(intro);
while ((circ = circuit_get_next_by_pk_and_purpose(circ,pk_digest,
CIRCUIT_PURPOSE_S_INTRO))) {
if (!memcmp(circ->build_state->chosen_exit->identity_digest,
intro->extend_info->identity_digest, DIGEST_LEN) &&
circ->rend_data) {
return circ;
}
}
circ = NULL;
while ((circ = circuit_get_next_by_pk_and_purpose(circ,pk_digest,
CIRCUIT_PURPOSE_S_ESTABLISH_INTRO))) {
if (!memcmp(circ->build_state->chosen_exit->identity_digest,
intro->extend_info->identity_digest, DIGEST_LEN) &&
circ->rend_data) {
return circ;
}
}
return NULL;
}
/** Determine the responsible hidden service directories for the
* rend_encoded_v2_service_descriptor_t's in <b>descs</b> and upload them;
* <b>service_id</b> and <b>seconds_valid</b> are only passed for logging
* purposes. */
static void
directory_post_to_hs_dir(rend_service_descriptor_t *renddesc,
smartlist_t *descs, const char *service_id,
int seconds_valid)
{
int i, j, failed_upload = 0;
smartlist_t *responsible_dirs = smartlist_create();
smartlist_t *successful_uploads = smartlist_create();
routerstatus_t *hs_dir;
for (i = 0; i < smartlist_len(descs); i++) {
rend_encoded_v2_service_descriptor_t *desc = smartlist_get(descs, i);
/* Determine responsible dirs. */
if (hid_serv_get_responsible_directories(responsible_dirs,
desc->desc_id) < 0) {
log_warn(LD_REND, "Could not determine the responsible hidden service "
"directories to post descriptors to.");
smartlist_free(responsible_dirs);
smartlist_free(successful_uploads);
return;
}
for (j = 0; j < smartlist_len(responsible_dirs); j++) {
char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
char *hs_dir_ip;
hs_dir = smartlist_get(responsible_dirs, j);
if (smartlist_digest_isin(renddesc->successful_uploads,
hs_dir->identity_digest))
/* Don't upload descriptor if we succeeded in doing so last time. */
continue;
if (!router_get_by_digest(hs_dir->identity_digest)) {
log_info(LD_REND, "Not sending publish request for v2 descriptor to "
"hidden service directory '%s'; we don't have its "
"router descriptor. Queuing for later upload.",
hs_dir->nickname);
failed_upload = -1;
continue;
}
/* Send publish request. */
directory_initiate_command_routerstatus(hs_dir,
DIR_PURPOSE_UPLOAD_RENDDESC_V2,
ROUTER_PURPOSE_GENERAL,
1, NULL, desc->desc_str,
strlen(desc->desc_str), 0);
base32_encode(desc_id_base32, sizeof(desc_id_base32),
desc->desc_id, DIGEST_LEN);
hs_dir_ip = tor_dup_ip(hs_dir->addr);
log_info(LD_REND, "Sending publish request for v2 descriptor for "
"service '%s' with descriptor ID '%s' with validity "
"of %d seconds to hidden service directory '%s' on "
"%s:%d.",
safe_str_client(service_id),
safe_str_client(desc_id_base32),
seconds_valid,
hs_dir->nickname,
hs_dir_ip,
hs_dir->or_port);
tor_free(hs_dir_ip);
/* Remember successful upload to this router for next time. */
if (!smartlist_digest_isin(successful_uploads, hs_dir->identity_digest))
smartlist_add(successful_uploads, hs_dir->identity_digest);
}
smartlist_clear(responsible_dirs);
}
if (!failed_upload) {
if (renddesc->successful_uploads) {
SMARTLIST_FOREACH(renddesc->successful_uploads, char *, c, tor_free(c););
smartlist_free(renddesc->successful_uploads);
renddesc->successful_uploads = NULL;
}
renddesc->all_uploads_performed = 1;
} else {
/* Remember which routers worked this time, so that we don't upload the
* descriptor to them again. */
if (!renddesc->successful_uploads)
renddesc->successful_uploads = smartlist_create();
SMARTLIST_FOREACH(successful_uploads, const char *, c, {
if (!smartlist_digest_isin(renddesc->successful_uploads, c)) {
char *hsdir_id = tor_memdup(c, DIGEST_LEN);
smartlist_add(renddesc->successful_uploads, hsdir_id);
}
});
}
smartlist_free(responsible_dirs);
smartlist_free(successful_uploads);
}
/** Encode and sign an up-to-date service descriptor for <b>service</b>,
* and upload it/them to the responsible hidden service directories.
*/
static void
upload_service_descriptor(rend_service_t *service)
{
time_t now = time(NULL);
int rendpostperiod;
char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
int uploaded = 0;
rendpostperiod = get_options()->RendPostPeriod;
/* Upload descriptor? */
if (get_options()->PublishHidServDescriptors) {
networkstatus_t *c = networkstatus_get_latest_consensus();
if (c && smartlist_len(c->routerstatus_list) > 0) {
int seconds_valid, i, j, num_descs;
smartlist_t *descs = smartlist_create();
smartlist_t *client_cookies = smartlist_create();
/* Either upload a single descriptor (including replicas) or one
* descriptor for each authorized client in case of authorization
* type 'stealth'. */
num_descs = service->auth_type == REND_STEALTH_AUTH ?
smartlist_len(service->clients) : 1;
for (j = 0; j < num_descs; j++) {
crypto_pk_env_t *client_key = NULL;
rend_authorized_client_t *client = NULL;
smartlist_clear(client_cookies);
switch (service->auth_type) {
case REND_NO_AUTH:
/* Do nothing here. */
break;
case REND_BASIC_AUTH:
SMARTLIST_FOREACH(service->clients, rend_authorized_client_t *,
cl, smartlist_add(client_cookies, cl->descriptor_cookie));
break;
case REND_STEALTH_AUTH:
client = smartlist_get(service->clients, j);
client_key = client->client_key;
smartlist_add(client_cookies, client->descriptor_cookie);
break;
}
/* Encode the current descriptor. */
seconds_valid = rend_encode_v2_descriptors(descs, service->desc,
now, 0,
service->auth_type,
client_key,
client_cookies);
if (seconds_valid < 0) {
log_warn(LD_BUG, "Internal error: couldn't encode service "
"descriptor; not uploading.");
smartlist_free(descs);
smartlist_free(client_cookies);
return;
}
/* Post the current descriptors to the hidden service directories. */
rend_get_service_id(service->desc->pk, serviceid);
log_info(LD_REND, "Sending publish request for hidden service %s",
serviceid);
directory_post_to_hs_dir(service->desc, descs, serviceid,
seconds_valid);
/* Free memory for descriptors. */
for (i = 0; i < smartlist_len(descs); i++)
rend_encoded_v2_service_descriptor_free(smartlist_get(descs, i));
smartlist_clear(descs);
/* Update next upload time. */
if (seconds_valid - REND_TIME_PERIOD_OVERLAPPING_V2_DESCS
> rendpostperiod)
service->next_upload_time = now + rendpostperiod;
else if (seconds_valid < REND_TIME_PERIOD_OVERLAPPING_V2_DESCS)
service->next_upload_time = now + seconds_valid + 1;
else
service->next_upload_time = now + seconds_valid -
REND_TIME_PERIOD_OVERLAPPING_V2_DESCS + 1;
/* Post also the next descriptors, if necessary. */
if (seconds_valid < REND_TIME_PERIOD_OVERLAPPING_V2_DESCS) {
seconds_valid = rend_encode_v2_descriptors(descs, service->desc,
now, 1,
service->auth_type,
client_key,
client_cookies);
if (seconds_valid < 0) {
log_warn(LD_BUG, "Internal error: couldn't encode service "
"descriptor; not uploading.");
smartlist_free(descs);
smartlist_free(client_cookies);
return;
}
directory_post_to_hs_dir(service->desc, descs, serviceid,
seconds_valid);
/* Free memory for descriptors. */
for (i = 0; i < smartlist_len(descs); i++)
rend_encoded_v2_service_descriptor_free(smartlist_get(descs, i));
smartlist_clear(descs);
}
}
smartlist_free(descs);
smartlist_free(client_cookies);
uploaded = 1;
log_info(LD_REND, "Successfully uploaded v2 rend descriptors!");
}
}
/* If not uploaded, try again in one minute. */
if (!uploaded)
service->next_upload_time = now + 60;
/* Unmark dirty flag of this service. */
service->desc_is_dirty = 0;
}
/** For every service, check how many intro points it currently has, and:
* - Pick new intro points as necessary.
* - Launch circuits to any new intro points.
*/
void
rend_services_introduce(void)
{
int i,j,r;
routerinfo_t *router;
rend_service_t *service;
rend_intro_point_t *intro;
int changed, prev_intro_nodes;
smartlist_t *intro_routers;
time_t now;
or_options_t *options = get_options();
intro_routers = smartlist_create();
now = time(NULL);
for (i=0; i < smartlist_len(rend_service_list); ++i) {
smartlist_clear(intro_routers);
service = smartlist_get(rend_service_list, i);
tor_assert(service);
changed = 0;
if (now > service->intro_period_started+INTRO_CIRC_RETRY_PERIOD) {
/* One period has elapsed; we can try building circuits again. */
service->intro_period_started = now;
service->n_intro_circuits_launched = 0;
} else if (service->n_intro_circuits_launched >=
MAX_INTRO_CIRCS_PER_PERIOD) {
/* We have failed too many times in this period; wait for the next
* one before we try again. */
continue;
}
/* Find out which introduction points we have in progress for this
service. */
for (j=0; j < smartlist_len(service->intro_nodes); ++j) {
intro = smartlist_get(service->intro_nodes, j);
router = router_get_by_digest(intro->extend_info->identity_digest);
if (!router || !find_intro_circuit(intro, service->pk_digest)) {
log_info(LD_REND,"Giving up on %s as intro point for %s.",
intro->extend_info->nickname, service->service_id);
if (service->desc) {
SMARTLIST_FOREACH(service->desc->intro_nodes, rend_intro_point_t *,
dintro, {
if (!memcmp(dintro->extend_info->identity_digest,
intro->extend_info->identity_digest, DIGEST_LEN)) {
log_info(LD_REND, "The intro point we are giving up on was "
"included in the last published descriptor. "
"Marking current descriptor as dirty.");
service->desc_is_dirty = now;
}
});
}
rend_intro_point_free(intro);
smartlist_del(service->intro_nodes,j--);
changed = 1;
}
if (router)
smartlist_add(intro_routers, router);
}
/* We have enough intro points, and the intro points we thought we had were
* all connected.
*/
if (!changed && smartlist_len(service->intro_nodes) >= NUM_INTRO_POINTS) {
/* We have all our intro points! Start a fresh period and reset the
* circuit count. */
service->intro_period_started = now;
service->n_intro_circuits_launched = 0;
continue;
}
/* Remember how many introduction circuits we started with. */
prev_intro_nodes = smartlist_len(service->intro_nodes);
/* We have enough directory information to start establishing our
* intro points. We want to end up with three intro points, but if
* we're just starting, we launch five and pick the first three that
* complete.
*
* The ones after the first three will be converted to 'general'
* internal circuits in rend_service_intro_has_opened(), and then
* we'll drop them from the list of intro points next time we
* go through the above "find out which introduction points we have
* in progress" loop. */
#define NUM_INTRO_POINTS_INIT (NUM_INTRO_POINTS + 2)
for (j=prev_intro_nodes; j < (prev_intro_nodes == 0 ?
NUM_INTRO_POINTS_INIT : NUM_INTRO_POINTS); ++j) {
router_crn_flags_t flags = CRN_NEED_UPTIME;
if (get_options()->_AllowInvalid & ALLOW_INVALID_INTRODUCTION)
flags |= CRN_ALLOW_INVALID;
router = router_choose_random_node(intro_routers,
options->ExcludeNodes, flags);
if (!router) {
log_warn(LD_REND,
"Could only establish %d introduction points for %s.",
smartlist_len(service->intro_nodes), service->service_id);
break;
}
changed = 1;
smartlist_add(intro_routers, router);
intro = tor_malloc_zero(sizeof(rend_intro_point_t));
intro->extend_info = extend_info_from_router(router);
intro->intro_key = crypto_new_pk_env();
tor_assert(!crypto_pk_generate_key(intro->intro_key));
smartlist_add(service->intro_nodes, intro);
log_info(LD_REND, "Picked router %s as an intro point for %s.",
router->nickname, service->service_id);
}
/* If there's no need to launch new circuits, stop here. */
if (!changed)
continue;
/* Establish new introduction points. */
for (j=prev_intro_nodes; j < smartlist_len(service->intro_nodes); ++j) {
intro = smartlist_get(service->intro_nodes, j);
r = rend_service_launch_establish_intro(service, intro);
if (r<0) {
log_warn(LD_REND, "Error launching circuit to node %s for service %s.",
intro->extend_info->nickname, service->service_id);
}
}
}
smartlist_free(intro_routers);
}
/** Regenerate and upload rendezvous service descriptors for all
* services, if necessary. If the descriptor has been dirty enough
* for long enough, definitely upload; else only upload when the
* periodic timeout has expired.
*
* For the first upload, pick a random time between now and two periods
* from now, and pick it independently for each service.
*/
void
rend_consider_services_upload(time_t now)
{
int i;
rend_service_t *service;
int rendpostperiod = get_options()->RendPostPeriod;
if (!get_options()->PublishHidServDescriptors)
return;
for (i=0; i < smartlist_len(rend_service_list); ++i) {
service = smartlist_get(rend_service_list, i);
if (!service->next_upload_time) { /* never been uploaded yet */
/* The fixed lower bound of 30 seconds ensures that the descriptor
* is stable before being published. See comment below. */
service->next_upload_time =
now + 30 + crypto_rand_int(2*rendpostperiod);
}
if (service->next_upload_time < now ||
(service->desc_is_dirty &&
service->desc_is_dirty < now-30)) {
/* if it's time, or if the directory servers have a wrong service
* descriptor and ours has been stable for 30 seconds, upload a
* new one of each format. */
rend_service_update_descriptor(service);
upload_service_descriptor(service);
}
}
}
/** True if the list of available router descriptors might have changed so
* that we should have a look whether we can republish previously failed
* rendezvous service descriptors. */
static int consider_republishing_rend_descriptors = 1;
/** Called when our internal view of the directory has changed, so that we
* might have router descriptors of hidden service directories available that
* we did not have before. */
void
rend_hsdir_routers_changed(void)
{
consider_republishing_rend_descriptors = 1;
}
/** Consider republication of v2 rendezvous service descriptors that failed
* previously, but without regenerating descriptor contents.
*/
void
rend_consider_descriptor_republication(void)
{
int i;
rend_service_t *service;
if (!consider_republishing_rend_descriptors)
return;
consider_republishing_rend_descriptors = 0;
if (!get_options()->PublishHidServDescriptors)
return;
for (i=0; i < smartlist_len(rend_service_list); ++i) {
service = smartlist_get(rend_service_list, i);
if (service->desc && !service->desc->all_uploads_performed) {
/* If we failed in uploading a descriptor last time, try again *without*
* updating the descriptor's contents. */
upload_service_descriptor(service);
}
}
}
/** Log the status of introduction points for all rendezvous services
* at log severity <b>severity</b>.
*/
void
rend_service_dump_stats(int severity)
{
int i,j;
rend_service_t *service;
rend_intro_point_t *intro;
const char *safe_name;
origin_circuit_t *circ;
for (i=0; i < smartlist_len(rend_service_list); ++i) {
service = smartlist_get(rend_service_list, i);
log(severity, LD_GENERAL, "Service configured in \"%s\":",
service->directory);
for (j=0; j < smartlist_len(service->intro_nodes); ++j) {
intro = smartlist_get(service->intro_nodes, j);
safe_name = safe_str_client(intro->extend_info->nickname);
circ = find_intro_circuit(intro, service->pk_digest);
if (!circ) {
log(severity, LD_GENERAL, " Intro point %d at %s: no circuit",
j, safe_name);
continue;
}
log(severity, LD_GENERAL, " Intro point %d at %s: circuit is %s",
j, safe_name, circuit_state_to_string(circ->_base.state));
}
}
}
/** Given <b>conn</b>, a rendezvous exit stream, look up the hidden service for
* 'circ', and look up the port and address based on conn-\>port.
* Assign the actual conn-\>addr and conn-\>port. Return -1 if failure,
* or 0 for success.
*/
int
rend_service_set_connection_addr_port(edge_connection_t *conn,
origin_circuit_t *circ)
{
rend_service_t *service;
char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
smartlist_t *matching_ports;
rend_service_port_config_t *chosen_port;
tor_assert(circ->_base.purpose == CIRCUIT_PURPOSE_S_REND_JOINED);
tor_assert(circ->rend_data);
log_debug(LD_REND,"beginning to hunt for addr/port");
base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32+1,
circ->rend_data->rend_pk_digest, REND_SERVICE_ID_LEN);
service = rend_service_get_by_pk_digest(
circ->rend_data->rend_pk_digest);
if (!service) {
log_warn(LD_REND, "Couldn't find any service associated with pk %s on "
"rendezvous circuit %d; closing.",
serviceid, circ->_base.n_circ_id);
return -1;
}
matching_ports = smartlist_create();
SMARTLIST_FOREACH(service->ports, rend_service_port_config_t *, p,
{
if (conn->_base.port == p->virtual_port) {
smartlist_add(matching_ports, p);
}
});
chosen_port = smartlist_choose(matching_ports);
smartlist_free(matching_ports);
if (chosen_port) {
tor_addr_copy(&conn->_base.addr, &chosen_port->real_addr);
conn->_base.port = chosen_port->real_port;
return 0;
}
log_info(LD_REND, "No virtual port mapping exists for port %d on service %s",
conn->_base.port,serviceid);
return -1;
}