[tor-commits] [tor/master] Merge branch 'bug23818_029' into bug23818_035
dgoulet at torproject.org
dgoulet at torproject.org
Thu Aug 29 12:59:05 UTC 2019
commit 14b5f40b54e41a2eb6cf73b2a4f42193b9f2d6d2
Merge: 5653b93a1 231a74363
Author: teor <teor at torproject.org>
Date: Fri Aug 23 15:09:19 2019 +1000
Merge branch 'bug23818_029' into bug23818_035
changes/bug23818_v2 | 6 ++++++
src/feature/rend/rendservice.c | 19 +++++++++++++++----
2 files changed, 21 insertions(+), 4 deletions(-)
diff --cc src/feature/rend/rendservice.c
index 5ee084b0b,000000000..c96ecec30
mode 100644,000000..100644
--- a/src/feature/rend/rendservice.c
+++ b/src/feature/rend/rendservice.c
@@@ -1,4487 -1,0 +1,4498 @@@
+/* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file rendservice.c
+ * \brief The hidden-service side of rendezvous functionality.
+ **/
+
+#define RENDSERVICE_PRIVATE
+
+#include "core/or/or.h"
+
+#include "app/config/config.h"
+#include "core/mainloop/mainloop.h"
+#include "core/or/circuitbuild.h"
+#include "core/or/circuitlist.h"
+#include "core/or/circuituse.h"
+#include "core/or/policies.h"
+#include "core/or/relay.h"
+#include "feature/client/circpathbias.h"
+#include "feature/control/control.h"
+#include "feature/dirclient/dirclient.h"
+#include "feature/dircommon/directory.h"
+#include "feature/hs/hs_common.h"
+#include "feature/hs/hs_config.h"
+#include "feature/hs_common/replaycache.h"
+#include "feature/keymgt/loadkey.h"
+#include "feature/nodelist/describe.h"
+#include "feature/nodelist/networkstatus.h"
+#include "feature/nodelist/nickname.h"
+#include "feature/nodelist/node_select.h"
+#include "feature/nodelist/nodelist.h"
+#include "feature/nodelist/routerset.h"
+#include "feature/rend/rendclient.h"
+#include "feature/rend/rendcommon.h"
+#include "feature/rend/rendparse.h"
+#include "feature/rend/rendservice.h"
+#include "feature/stats/predict_ports.h"
+#include "lib/crypt_ops/crypto_dh.h"
+#include "lib/crypt_ops/crypto_rand.h"
+#include "lib/crypt_ops/crypto_util.h"
+#include "lib/encoding/confline.h"
+#include "lib/net/resolve.h"
+
+#include "core/or/cpath_build_state_st.h"
+#include "core/or/crypt_path_st.h"
+#include "core/or/crypt_path_reference_st.h"
+#include "core/or/edge_connection_st.h"
+#include "core/or/extend_info_st.h"
+#include "feature/nodelist/networkstatus_st.h"
+#include "core/or/origin_circuit_st.h"
+#include "feature/rend/rend_authorized_client_st.h"
+#include "feature/rend/rend_encoded_v2_service_descriptor_st.h"
+#include "feature/rend/rend_intro_point_st.h"
+#include "feature/rend/rend_service_descriptor_st.h"
+#include "feature/nodelist/routerstatus_st.h"
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+
+struct rend_service_t;
+static origin_circuit_t *find_intro_circuit(rend_intro_point_t *intro,
+ const char *pk_digest);
+static rend_intro_point_t *find_intro_point(origin_circuit_t *circ);
+static rend_intro_point_t *find_expiring_intro_point(
+ struct rend_service_t *service, origin_circuit_t *circ);
+
+static extend_info_t *find_rp_for_intro(
+ const rend_intro_cell_t *intro,
+ char **err_msg_out);
+
+static int intro_point_accepted_intro_count(rend_intro_point_t *intro);
+static int intro_point_should_expire_now(rend_intro_point_t *intro,
+ time_t now);
+static int rend_service_derive_key_digests(struct rend_service_t *s);
+static int rend_service_load_keys(struct rend_service_t *s);
+static int rend_service_load_auth_keys(struct rend_service_t *s,
+ const char *hfname);
+static struct rend_service_t *rend_service_get_by_pk_digest(
+ const char* digest);
+static struct rend_service_t *rend_service_get_by_service_id(const char *id);
+static const char *rend_service_escaped_dir(
+ const struct rend_service_t *s);
+
+static ssize_t rend_service_parse_intro_for_v0_or_v1(
+ rend_intro_cell_t *intro,
+ const uint8_t *buf,
+ size_t plaintext_len,
+ char **err_msg_out);
+static ssize_t rend_service_parse_intro_for_v2(
+ rend_intro_cell_t *intro,
+ const uint8_t *buf,
+ size_t plaintext_len,
+ char **err_msg_out);
+static ssize_t rend_service_parse_intro_for_v3(
+ rend_intro_cell_t *intro,
+ const uint8_t *buf,
+ size_t plaintext_len,
+ char **err_msg_out);
+
+static int rend_service_check_private_dir(const or_options_t *options,
+ const rend_service_t *s,
+ int create);
+static const smartlist_t* rend_get_service_list(
+ const smartlist_t* substitute_service_list);
+static smartlist_t* rend_get_service_list_mutable(
+ smartlist_t* substitute_service_list);
+static int rend_max_intro_circs_per_period(unsigned int n_intro_points_wanted);
+
+/* Hidden service directory file names:
+ * new file names should be added to rend_service_add_filenames_to_list()
+ * for sandboxing purposes. */
+static const char *private_key_fname = "private_key";
+static const char *hostname_fname = "hostname";
+static const char *client_keys_fname = "client_keys";
+static const char *sos_poison_fname = "onion_service_non_anonymous";
+
+/** A list of rend_service_t's for services run on this OP. */
+static smartlist_t *rend_service_list = NULL;
+/** A list of rend_service_t's for services run on this OP which is used as a
+ * staging area before they are put in the main list in order to prune dying
+ * service on config reload. */
+static smartlist_t *rend_service_staging_list = NULL;
+
+/* Like rend_get_service_list_mutable, but returns a read-only list. */
+static const smartlist_t*
+rend_get_service_list(const smartlist_t* substitute_service_list)
+{
+ /* It is safe to cast away the const here, because
+ * rend_get_service_list_mutable does not actually modify the list */
+ return rend_get_service_list_mutable((smartlist_t*)substitute_service_list);
+}
+
+/* Return a mutable list of hidden services.
+ * If substitute_service_list is not NULL, return it.
+ * Otherwise, check if the global rend_service_list is non-NULL, and if so,
+ * return it.
+ * Otherwise, log a BUG message and return NULL.
+ * */
+static smartlist_t*
+rend_get_service_list_mutable(smartlist_t* substitute_service_list)
+{
+ if (substitute_service_list) {
+ return substitute_service_list;
+ }
+
+ /* If no special service list is provided, then just use the global one. */
+
+ if (BUG(!rend_service_list)) {
+ /* No global HS list, which is a programmer error. */
+ return NULL;
+ }
+
+ return rend_service_list;
+}
+
+/** Tells if onion service <b>s</b> is ephemeral.
+ */
+static unsigned int
+rend_service_is_ephemeral(const struct rend_service_t *s)
+{
+ return (s->directory == NULL);
+}
+
+/** Returns a escaped string representation of the service, <b>s</b>.
+ */
+static const char *
+rend_service_escaped_dir(const struct rend_service_t *s)
+{
+ return rend_service_is_ephemeral(s) ? "[EPHEMERAL]" : escaped(s->directory);
+}
+
+/** Return the number of rendezvous services we have configured. */
+int
+rend_num_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. */
+void
+rend_authorized_client_free_(rend_authorized_client_t *client)
+{
+ if (!client)
+ return;
+ if (client->client_key)
+ crypto_pk_free(client->client_key);
+ if (client->client_name)
+ memwipe(client->client_name, 0, strlen(client->client_name));
+ tor_free(client->client_name);
+ memwipe(client->descriptor_cookie, 0, sizeof(client->descriptor_cookie));
+ tor_free(client);
+}
+
+/** Helper for strmap_free. */
+static void
+rend_authorized_client_free_void(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);
+ if (service->ports) {
+ SMARTLIST_FOREACH(service->ports, rend_service_port_config_t*, p,
+ rend_service_port_config_free(p));
+ smartlist_free(service->ports);
+ }
+ if (service->private_key)
+ crypto_pk_free(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);
+ }
+ if (service->expiring_nodes) {
+ SMARTLIST_FOREACH(service->expiring_nodes, rend_intro_point_t *, intro,
+ rend_intro_point_free(intro););
+ smartlist_free(service->expiring_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);
+ }
+ if (service->accepted_intro_dh_parts) {
+ replaycache_free(service->accepted_intro_dh_parts);
+ }
+ tor_free(service);
+}
+
+/* Release all the storage held in rend_service_staging_list. */
+void
+rend_service_free_staging_list(void)
+{
+ if (rend_service_staging_list) {
+ SMARTLIST_FOREACH(rend_service_staging_list, rend_service_t*, ptr,
+ rend_service_free(ptr));
+ smartlist_free(rend_service_staging_list);
+ rend_service_staging_list = NULL;
+ }
+}
+
+/** Release all the storage held in both rend_service_list and
+ * rend_service_staging_list. */
+void
+rend_service_free_all(void)
+{
+ if (rend_service_list) {
+ SMARTLIST_FOREACH(rend_service_list, rend_service_t*, ptr,
+ rend_service_free(ptr));
+ smartlist_free(rend_service_list);
+ rend_service_list = NULL;
+ }
+ rend_service_free_staging_list();
+}
+
+/* Initialize the subsystem. */
+void
+rend_service_init(void)
+{
+ tor_assert(!rend_service_list);
+ tor_assert(!rend_service_staging_list);
+
+ rend_service_list = smartlist_new();
+ rend_service_staging_list = smartlist_new();
+}
+
+/* Validate a <b>service</b>. Use the <b>service_list</b> to make sure there
+ * is no duplicate entry for the given service object. Return 0 if valid else
+ * -1 if not.*/
+static int
+rend_validate_service(const smartlist_t *service_list,
+ const rend_service_t *service)
+{
+ tor_assert(service_list);
+ tor_assert(service);
+
+ if (service->max_streams_per_circuit < 0) {
+ log_warn(LD_CONFIG, "Hidden service (%s) configured with negative max "
+ "streams per circuit.",
+ rend_service_escaped_dir(service));
+ goto invalid;
+ }
+
+ if (service->max_streams_close_circuit < 0 ||
+ service->max_streams_close_circuit > 1) {
+ log_warn(LD_CONFIG, "Hidden service (%s) configured with invalid "
+ "max streams handling.",
+ rend_service_escaped_dir(service));
+ goto invalid;
+ }
+
+ if (service->auth_type != REND_NO_AUTH &&
+ (!service->clients || smartlist_len(service->clients) == 0)) {
+ log_warn(LD_CONFIG, "Hidden service (%s) with client authorization but "
+ "no clients.",
+ rend_service_escaped_dir(service));
+ goto invalid;
+ }
+
+ if (!service->ports || !smartlist_len(service->ports)) {
+ log_warn(LD_CONFIG, "Hidden service (%s) with no ports configured.",
+ rend_service_escaped_dir(service));
+ goto invalid;
+ }
+
+ /* Valid. */
+ return 0;
+ invalid:
+ return -1;
+}
+
+/** Add it to <b>service_list</b>, or to the global rend_service_list if
+ * <b>service_list</b> is NULL. Return 0 on success. On failure, free
+ * <b>service</b> and return -1. Takes ownership of <b>service</b>. */
+static int
+rend_add_service(smartlist_t *service_list, rend_service_t *service)
+{
+ int i;
+ rend_service_port_config_t *p;
+
+ tor_assert(service);
+
+ smartlist_t *s_list = rend_get_service_list_mutable(service_list);
+ /* We must have a service list, even if it's a temporary one, so we can
+ * check for duplicate services */
+ if (BUG(!s_list)) {
+ rend_service_free(service);
+ return -1;
+ }
+
+ service->intro_nodes = smartlist_new();
+ service->expiring_nodes = smartlist_new();
+
+ log_debug(LD_REND,"Configuring service with directory %s",
+ rend_service_escaped_dir(service));
+ for (i = 0; i < smartlist_len(service->ports); ++i) {
+ p = smartlist_get(service->ports, i);
+ if (!(p->is_unix_addr)) {
+ log_debug(LD_REND,
+ "Service maps port %d to %s",
+ p->virtual_port,
+ fmt_addrport(&p->real_addr, p->real_port));
+ } else {
+#ifdef HAVE_SYS_UN_H
+ log_debug(LD_REND,
+ "Service maps port %d to socket at \"%s\"",
+ p->virtual_port, p->unix_addr);
+#else
+ log_warn(LD_BUG,
+ "Service maps port %d to an AF_UNIX socket, but we "
+ "have no AF_UNIX support on this platform. This is "
+ "probably a bug.",
+ p->virtual_port);
+ rend_service_free(service);
+ return -1;
+#endif /* defined(HAVE_SYS_UN_H) */
+ }
+ }
+ /* The service passed all the checks */
+ tor_assert(s_list);
+ smartlist_add(s_list, service);
+
+ /* Notify that our global service list has changed only if this new service
+ * went into our global list. If not, when we move service from the staging
+ * list to the new list, a notify is triggered. */
+ if (s_list == rend_service_list) {
+ hs_service_map_has_changed();
+ }
+ return 0;
+}
+
+/** Return a new rend_service_port_config_t with its path set to
+ * <b>socket_path</b> or empty if <b>socket_path</b> is NULL */
+static rend_service_port_config_t *
+rend_service_port_config_new(const char *socket_path)
+{
+ if (!socket_path)
+ return tor_malloc_zero(sizeof(rend_service_port_config_t) + 1);
+
+ const size_t pathlen = strlen(socket_path) + 1;
+ rend_service_port_config_t *conf =
+ tor_malloc_zero(sizeof(rend_service_port_config_t) + pathlen);
+ memcpy(conf->unix_addr, socket_path, pathlen);
+ conf->is_unix_addr = 1;
+ return conf;
+}
+
+/** Parses a virtual-port to real-port/socket mapping separated by
+ * the provided separator and returns a new rend_service_port_config_t,
+ * or NULL and an optional error string on failure.
+ *
+ * The format is: VirtualPort SEP (IP|RealPort|IP:RealPort|'socket':path)?
+ *
+ * IP defaults to 127.0.0.1; RealPort defaults to VirtualPort.
+ */
+rend_service_port_config_t *
+rend_service_parse_port_config(const char *string, const char *sep,
+ char **err_msg_out)
+{
+ smartlist_t *sl;
+ int virtport;
+ int realport = 0;
+ uint16_t p;
+ tor_addr_t addr;
+ rend_service_port_config_t *result = NULL;
+ unsigned int is_unix_addr = 0;
+ const char *socket_path = NULL;
+ char *err_msg = NULL;
+ char *addrport = NULL;
+
+ sl = smartlist_new();
+ smartlist_split_string(sl, string, sep,
+ SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 2);
+ if (smartlist_len(sl) < 1 || BUG(smartlist_len(sl) > 2)) {
+ err_msg = tor_strdup("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) {
+ tor_asprintf(&err_msg, "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 {
+ int ret;
+
+ const char *addrport_element = smartlist_get(sl,1);
+ const char *rest = NULL;
+ int is_unix;
+ ret = port_cfg_line_extract_addrport(addrport_element, &addrport,
+ &is_unix, &rest);
+
+ if (ret < 0) {
+ tor_asprintf(&err_msg, "Couldn't process address <%s> from hidden "
+ "service configuration", addrport_element);
+ goto err;
+ }
+
+ if (rest && strlen(rest)) {
+ err_msg = tor_strdup("HiddenServicePort parse error: invalid port "
+ "mapping");
+ goto err;
+ }
+
+ if (is_unix) {
+ socket_path = addrport;
+ is_unix_addr = 1;
+ } else if (strchr(addrport, ':') || strchr(addrport, '.')) {
+ /* else try it as an IP:port pair if it has a : or . in it */
+ if (tor_addr_port_lookup(addrport, &addr, &p)<0) {
+ err_msg = tor_strdup("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) {
+ tor_asprintf(&err_msg, "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 */
+ }
+ }
+
+ /* Allow room for unix_addr */
+ result = rend_service_port_config_new(socket_path);
+ result->virtual_port = virtport;
+ result->is_unix_addr = is_unix_addr;
+ if (!is_unix_addr) {
+ result->real_port = realport;
+ tor_addr_copy(&result->real_addr, &addr);
+ result->unix_addr[0] = '\0';
+ }
+
+ err:
+ tor_free(addrport);
+ if (err_msg_out != NULL) {
+ *err_msg_out = err_msg;
+ } else {
+ tor_free(err_msg);
+ }
+ SMARTLIST_FOREACH(sl, char *, c, tor_free(c));
+ smartlist_free(sl);
+
+ return result;
+}
+
+/** Release all storage held in a rend_service_port_config_t. */
+void
+rend_service_port_config_free_(rend_service_port_config_t *p)
+{
+ tor_free(p);
+}
+
+/* Copy relevant data from service src to dst while pruning the service lists.
+ * This should only be called during the pruning process which takes existing
+ * services and copy their data to the newly configured services. The src
+ * service replaycache will be set to NULL after this call. */
+static void
+copy_service_on_prunning(rend_service_t *dst, rend_service_t *src)
+{
+ tor_assert(dst);
+ tor_assert(src);
+
+ /* Keep the timestamps for when the content changed and the next upload
+ * time so we can properly upload the descriptor if needed for the new
+ * service object. */
+ dst->desc_is_dirty = src->desc_is_dirty;
+ dst->next_upload_time = src->next_upload_time;
+ /* Move the replaycache to the new object. */
+ dst->accepted_intro_dh_parts = src->accepted_intro_dh_parts;
+ src->accepted_intro_dh_parts = NULL;
+ /* Copy intro point information to destination service. */
+ dst->intro_period_started = src->intro_period_started;
+ dst->n_intro_circuits_launched = src->n_intro_circuits_launched;
+ dst->n_intro_points_wanted = src->n_intro_points_wanted;
+}
+
+/* Helper: Actual implementation of the pruning on reload which we've
+ * decoupled in order to make the unit test workeable without ugly hacks.
+ * Furthermore, this function does NOT free any memory but will nullify the
+ * temporary list pointer whatever happens. */
+STATIC void
+rend_service_prune_list_impl_(void)
+{
+ origin_circuit_t *ocirc = NULL;
+ smartlist_t *surviving_services, *old_service_list, *new_service_list;
+
+ /* When pruning our current service list, we must have a staging list that
+ * contains what we want to check else it's a code flow error. */
+ tor_assert(rend_service_staging_list);
+
+ /* We are about to prune the current list of its dead service so set the
+ * semantic for that list to be the "old" one. */
+ old_service_list = rend_service_list;
+ /* The staging list is now the "new" list so set this semantic. */
+ new_service_list = rend_service_staging_list;
+ /* After this, whatever happens, we'll use our new list. */
+ rend_service_list = new_service_list;
+ /* Finally, nullify the staging list pointer as we don't need it anymore
+ * and it needs to be NULL before the next reload. */
+ rend_service_staging_list = NULL;
+ /* Nothing to prune if we have no service list so stop right away. */
+ if (!old_service_list) {
+ return;
+ }
+
+ /* This contains all _existing_ services that survives the relaod that is
+ * that haven't been removed from the configuration. The difference between
+ * this list and the new service list is that the new list can possibly
+ * contain newly configured service that have no introduction points opened
+ * yet nor key material loaded or generated. */
+ surviving_services = smartlist_new();
+
+ /* Preserve the existing ephemeral services.
+ *
+ * This is the ephemeral service equivalent of the "Copy introduction
+ * points to new services" block, except there's no copy required since
+ * the service structure isn't regenerated.
+ *
+ * After this is done, all ephemeral services will be:
+ * * Removed from old_service_list, so the equivalent non-ephemeral code
+ * will not attempt to preserve them.
+ * * Added to the new_service_list (that previously only had the
+ * services listed in the configuration).
+ * * Added to surviving_services, which is the list of services that
+ * will NOT have their intro point closed.
+ */
+ SMARTLIST_FOREACH_BEGIN(old_service_list, rend_service_t *, old) {
+ if (rend_service_is_ephemeral(old)) {
+ SMARTLIST_DEL_CURRENT(old_service_list, old);
+ smartlist_add(surviving_services, old);
+ smartlist_add(new_service_list, old);
+ }
+ } SMARTLIST_FOREACH_END(old);
+
+ /* Copy introduction points to new services. This is O(n^2), but it's only
+ * called on reconfigure, so it's ok performance wise. */
+ SMARTLIST_FOREACH_BEGIN(new_service_list, rend_service_t *, new) {
+ SMARTLIST_FOREACH_BEGIN(old_service_list, rend_service_t *, old) {
+ /* Skip ephemeral services as we only want to copy introduction points
+ * from current services to newly configured one that already exists.
+ * The same directory means it's the same service. */
+ if (rend_service_is_ephemeral(new) || rend_service_is_ephemeral(old) ||
+ strcmp(old->directory, new->directory)) {
+ continue;
+ }
+ smartlist_add_all(new->intro_nodes, old->intro_nodes);
+ smartlist_clear(old->intro_nodes);
+ smartlist_add_all(new->expiring_nodes, old->expiring_nodes);
+ smartlist_clear(old->expiring_nodes);
+
+ /* Copy needed information from old to new. */
+ copy_service_on_prunning(new, old);
+
+ /* This regular service will survive the closing IPs step after. */
+ smartlist_add(surviving_services, old);
+ break;
+ } SMARTLIST_FOREACH_END(old);
+ } SMARTLIST_FOREACH_END(new);
+
+ /* For every service introduction circuit we can find, see if we have a
+ * matching surviving configured service. If not, close the circuit. */
+ while ((ocirc = circuit_get_next_intro_circ(ocirc, false))) {
+ int keep_it = 0;
+ if (ocirc->rend_data == NULL) {
+ /* This is a v3 circuit, ignore it. */
+ continue;
+ }
+ SMARTLIST_FOREACH_BEGIN(surviving_services, const rend_service_t *, s) {
+ if (rend_circuit_pk_digest_eq(ocirc, (uint8_t *) s->pk_digest)) {
+ /* Keep this circuit as we have a matching configured service. */
+ keep_it = 1;
+ break;
+ }
+ } SMARTLIST_FOREACH_END(s);
+ if (keep_it) {
+ continue;
+ }
+ log_info(LD_REND, "Closing intro point %s for service %s.",
+ safe_str_client(extend_info_describe(
+ ocirc->build_state->chosen_exit)),
+ safe_str_client(rend_data_get_address(ocirc->rend_data)));
+ /* Reason is FINISHED because service has been removed and thus the
+ * circuit is considered old/uneeded. */
+ circuit_mark_for_close(TO_CIRCUIT(ocirc), END_CIRC_REASON_FINISHED);
+ }
+ smartlist_free(surviving_services);
+ /* Notify that our global service list has changed. */
+ hs_service_map_has_changed();
+}
+
+/* Try to prune our main service list using the temporary one that we just
+ * loaded and parsed successfully. The pruning process decides which onion
+ * services to keep and which to discard after a reload. */
+void
+rend_service_prune_list(void)
+{
+ smartlist_t *old_service_list = rend_service_list;
+
+ if (!rend_service_staging_list) {
+ rend_service_staging_list = smartlist_new();
+ }
+
+ rend_service_prune_list_impl_();
+ if (old_service_list) {
+ /* Every remaining service in the old list have been removed from the
+ * configuration so clean them up safely. */
+ SMARTLIST_FOREACH(old_service_list, rend_service_t *, s,
+ rend_service_free(s));
+ smartlist_free(old_service_list);
+ }
+}
+
+/* Copy all the relevant data that the hs_service object contains over to the
+ * rend_service_t object. The reason to do so is because when configuring a
+ * service, we go through a generic handler that creates an hs_service_t
+ * object which so we have to copy the parsed values to a rend service object
+ * which is version 2 specific. */
+static void
+service_config_shadow_copy(rend_service_t *service,
+ hs_service_config_t *config)
+{
+ tor_assert(service);
+ tor_assert(config);
+
+ service->directory = tor_strdup(config->directory_path);
+ service->dir_group_readable = config->dir_group_readable;
+ service->allow_unknown_ports = config->allow_unknown_ports;
+ /* This value can't go above HS_CONFIG_MAX_STREAMS_PER_RDV_CIRCUIT (65535)
+ * if the code flow is right so this cast is safe. But just in case, we'll
+ * check it. */
+ service->max_streams_per_circuit = (int) config->max_streams_per_rdv_circuit;
+ if (BUG(config->max_streams_per_rdv_circuit >
+ HS_CONFIG_MAX_STREAMS_PER_RDV_CIRCUIT)) {
+ service->max_streams_per_circuit = HS_CONFIG_MAX_STREAMS_PER_RDV_CIRCUIT;
+ }
+ service->max_streams_close_circuit = config->max_streams_close_circuit;
+ service->n_intro_points_wanted = config->num_intro_points;
+ /* Switching ownership of the ports to the rend service object. */
+ smartlist_add_all(service->ports, config->ports);
+ smartlist_free(config->ports);
+ config->ports = NULL;
+}
+
+/* Parse the hidden service configuration starting at <b>line_</b> using the
+ * already configured generic service configuration in <b>config</b>. This
+ * function will translate the config object to a rend_service_t and add it to
+ * the temporary list if valid. If <b>validate_only</b> is set, parse, warn
+ * and return as normal but don't actually add the service to the list. */
+int
+rend_config_service(const config_line_t *line_,
+ const or_options_t *options,
+ hs_service_config_t *config)
+{
+ const config_line_t *line;
+ rend_service_t *service = NULL;
+
+ /* line_ can be NULL which would mean that the service configuration only
+ * have one line that is the directory directive. */
+ tor_assert(options);
+ tor_assert(config);
+
+ /* Use the staging service list so that we can check then do the pruning
+ * process using the main list at the end. */
+ if (rend_service_staging_list == NULL) {
+ rend_service_staging_list = smartlist_new();
+ }
+
+ /* Initialize service. */
+ service = tor_malloc_zero(sizeof(rend_service_t));
+ service->intro_period_started = time(NULL);
+ service->ports = smartlist_new();
+ /* From the hs_service object which has been used to load the generic
+ * options, we'll copy over the useful data to the rend_service_t object. */
+ service_config_shadow_copy(service, config);
+
+ for (line = line_; line; line = line->next) {
+ if (!strcasecmp(line->key, "HiddenServiceDir")) {
+ /* We just hit the next hidden service, stop right now. */
+ break;
+ }
+ /* Number of introduction points. */
+ if (!strcasecmp(line->key, "HiddenServiceNumIntroductionPoints")) {
+ int ok = 0;
+ /* Those are specific defaults for version 2. */
+ service->n_intro_points_wanted =
+ (unsigned int) tor_parse_long(line->value, 10,
+ 0, NUM_INTRO_POINTS_MAX, &ok, NULL);
+ if (!ok) {
+ log_warn(LD_CONFIG,
+ "HiddenServiceNumIntroductionPoints "
+ "should be between %d and %d, not %s",
+ 0, NUM_INTRO_POINTS_MAX, line->value);
+ goto err;
+ }
+ log_info(LD_CONFIG, "HiddenServiceNumIntroductionPoints=%d for %s",
+ service->n_intro_points_wanted, escaped(service->directory));
+ continue;
+ }
+ 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;
+ if (service->auth_type != REND_NO_AUTH) {
+ log_warn(LD_CONFIG, "Got multiple HiddenServiceAuthorizeClient "
+ "lines for a single service.");
+ goto err;
+ }
+ type_names_split = smartlist_new();
+ 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);
+ goto err;
+ }
+ 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);
+ goto err;
+ }
+ service->clients = smartlist_new();
+ 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_new();
+ 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. */
+ {
+ int 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));
+ }
+ }
+ SMARTLIST_FOREACH_BEGIN(clients, const char *, client_name)
+ {
+ rend_authorized_client_t *client;
+ if (!rend_valid_client_name(client_name)) {
+ log_warn(LD_CONFIG, "HiddenServiceAuthorizeClient contains an "
+ "illegal client name: '%s'. Names must be "
+ "between 1 and %d characters and contain "
+ "only [A-Za-z0-9+_-].",
+ client_name, REND_CLIENTNAME_MAX_LEN);
+ SMARTLIST_FOREACH(clients, char *, cp, tor_free(cp));
+ smartlist_free(clients);
+ goto err;
+ }
+ 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");
+ goto err;
+ }
+ continue;
+ }
+ }
+ /* Validate the service just parsed. */
+ if (rend_validate_service(rend_service_staging_list, service) < 0) {
+ /* Service is in the staging list so don't try to free it. */
+ goto err;
+ }
+
+ /* Add it to the temporary list which we will use to prune our current
+ * list if any after configuring all services. */
+ if (rend_add_service(rend_service_staging_list, service) < 0) {
+ /* The object has been freed on error already. */
+ service = NULL;
+ goto err;
+ }
+
+ return 0;
+ err:
+ rend_service_free(service);
+ return -1;
+}
+
+/** Add the ephemeral service <b>pk</b>/<b>ports</b> if possible, using
+ * client authorization <b>auth_type</b> and an optional list of
+ * rend_authorized_client_t in <b>auth_clients</b>, with
+ * <b>max_streams_per_circuit</b> streams allowed per rendezvous circuit,
+ * and circuit closure on max streams being exceeded set by
+ * <b>max_streams_close_circuit</b>.
+ *
+ * Ownership of pk, ports, and auth_clients is passed to this routine.
+ * Regardless of success/failure, callers should not touch these values
+ * after calling this routine, and may assume that correct cleanup has
+ * been done on failure.
+ *
+ * Return an appropriate hs_service_add_ephemeral_status_t.
+ */
+hs_service_add_ephemeral_status_t
+rend_service_add_ephemeral(crypto_pk_t *pk,
+ smartlist_t *ports,
+ int max_streams_per_circuit,
+ int max_streams_close_circuit,
+ rend_auth_type_t auth_type,
+ smartlist_t *auth_clients,
+ char **service_id_out)
+{
+ *service_id_out = NULL;
+ /* Allocate the service structure, and initialize the key, and key derived
+ * parameters.
+ */
+ rend_service_t *s = tor_malloc_zero(sizeof(rend_service_t));
+ s->directory = NULL; /* This indicates the service is ephemeral. */
+ s->private_key = pk;
+ s->auth_type = auth_type;
+ s->clients = auth_clients;
+ s->ports = ports;
+ s->intro_period_started = time(NULL);
+ s->n_intro_points_wanted = NUM_INTRO_POINTS_DEFAULT;
+ s->max_streams_per_circuit = max_streams_per_circuit;
+ s->max_streams_close_circuit = max_streams_close_circuit;
+ if (rend_service_derive_key_digests(s) < 0) {
+ rend_service_free(s);
+ return RSAE_BADPRIVKEY;
+ }
+
+ if (!s->ports || smartlist_len(s->ports) == 0) {
+ log_warn(LD_CONFIG, "At least one VIRTPORT/TARGET must be specified.");
+ rend_service_free(s);
+ return RSAE_BADVIRTPORT;
+ }
+ if (s->auth_type != REND_NO_AUTH &&
+ (!s->clients || smartlist_len(s->clients) == 0)) {
+ log_warn(LD_CONFIG, "At least one authorized client must be specified.");
+ rend_service_free(s);
+ return RSAE_BADAUTH;
+ }
+
+ /* Enforcing pk/id uniqueness should be done by rend_service_load_keys(), but
+ * it's not, see #14828.
+ */
+ if (rend_service_get_by_pk_digest(s->pk_digest)) {
+ log_warn(LD_CONFIG, "Onion Service private key collides with an "
+ "existing service.");
+ rend_service_free(s);
+ return RSAE_ADDREXISTS;
+ }
+ if (rend_service_get_by_service_id(s->service_id)) {
+ log_warn(LD_CONFIG, "Onion Service id collides with an existing service.");
+ rend_service_free(s);
+ return RSAE_ADDREXISTS;
+ }
+
+ /* Initialize the service. */
+ if (rend_add_service(NULL, s)) {
+ return RSAE_INTERNAL;
+ }
+ *service_id_out = tor_strdup(s->service_id);
+
+ log_debug(LD_CONFIG, "Added ephemeral Onion Service: %s", s->service_id);
+ return RSAE_OKAY;
+}
+
+/** Remove the ephemeral service <b>service_id</b> if possible. Returns 0 on
+ * success, and -1 on failure.
+ */
+int
+rend_service_del_ephemeral(const char *service_id)
+{
+ rend_service_t *s;
+ if (!rend_valid_v2_service_id(service_id)) {
+ log_warn(LD_CONFIG, "Requested malformed Onion Service id for removal.");
+ return -1;
+ }
+ if ((s = rend_service_get_by_service_id(service_id)) == NULL) {
+ log_warn(LD_CONFIG, "Requested non-existent Onion Service id for "
+ "removal.");
+ return -1;
+ }
+ if (!rend_service_is_ephemeral(s)) {
+ log_warn(LD_CONFIG, "Requested non-ephemeral Onion Service for removal.");
+ return -1;
+ }
+
+ /* Kill the intro point circuit for the Onion Service, and remove it from
+ * the list. Closing existing connections is the application's problem.
+ *
+ * XXX: As with the comment in rend_config_services(), a nice abstraction
+ * would be ideal here, but for now just duplicate the code.
+ */
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ if (!circ->marked_for_close &&
+ (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 == NULL ||
+ !rend_circuit_pk_digest_eq(oc, (uint8_t *) s->pk_digest)) {
+ continue;
+ }
+ log_debug(LD_REND, "Closing intro point %s for service %s.",
+ safe_str_client(extend_info_describe(
+ oc->build_state->chosen_exit)),
+ rend_data_get_address(oc->rend_data));
+ circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
+ }
+ } SMARTLIST_FOREACH_END(circ);
+ smartlist_remove(rend_service_list, s);
+ /* Notify that we just removed a service from our global list. */
+ hs_service_map_has_changed();
+ rend_service_free(s);
+
+ log_debug(LD_CONFIG, "Removed ephemeral Onion Service: %s", service_id);
+
+ return 0;
+}
+
+/* There can be 1 second's delay due to second_elapsed_callback, and perhaps
+ * another few seconds due to blocking calls. */
+#define INTRO_CIRC_RETRY_PERIOD_SLOP 10
+
+/** Log information about the intro point creation rate and current intro
+ * points for service, upgrading the log level from min_severity to warn if
+ * we have stopped launching new intro point circuits. */
+static void
+rend_log_intro_limit(const rend_service_t *service, int min_severity)
+{
+ int exceeded_limit = (service->n_intro_circuits_launched >=
+ rend_max_intro_circs_per_period(
+ service->n_intro_points_wanted));
+ int severity = min_severity;
+ /* We stopped creating circuits */
+ if (exceeded_limit) {
+ severity = LOG_WARN;
+ }
+ time_t intro_period_elapsed = time(NULL) - service->intro_period_started;
+ tor_assert_nonfatal(intro_period_elapsed >= 0);
+ {
+ char *msg;
+ static ratelim_t rlimit = RATELIM_INIT(INTRO_CIRC_RETRY_PERIOD);
+ if ((msg = rate_limit_log(&rlimit, approx_time()))) {
+ log_fn(severity, LD_REND,
+ "Hidden service %s %s %d intro points in the last %d seconds. "
+ "Intro circuit launches are limited to %d per %d seconds.%s",
+ service->service_id,
+ exceeded_limit ? "exceeded launch limit with" : "launched",
+ service->n_intro_circuits_launched,
+ (int)intro_period_elapsed,
+ rend_max_intro_circs_per_period(service->n_intro_points_wanted),
+ INTRO_CIRC_RETRY_PERIOD, msg);
+ rend_service_dump_stats(severity);
+ tor_free(msg);
+ }
+ }
+}
+
+/** 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;
+ 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->timestamp -= d->timestamp % 3600; /* Round down to nearest hour */
+ d->intro_nodes = smartlist_new();
+ /* 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;
+
+ /* This intro point won't be listed in the descriptor... */
+ intro_svc->listed_in_last_desc = 0;
+
+ /* circuit_established is set in rend_service_intro_established(), and
+ * checked every second in rend_consider_services_intro_points(), so it's
+ * safe to use it here */
+ if (!intro_svc->circuit_established) {
+ continue;
+ }
+
+ /* ...unless this intro point is listed in the descriptor. */
+ intro_svc->listed_in_last_desc = 1;
+
+ /* We have an entirely established intro circuit. Publish it in
+ * our descriptor. */
+ 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);
+
+ if (intro_svc->time_published == -1) {
+ /* We are publishing this intro point in a descriptor for the
+ * first time -- note the current time in the service's copy of
+ * the intro point. */
+ intro_svc->time_published = time(NULL);
+ }
+ }
+
+ /* Check that we have the right number of intro points */
+ unsigned int have_intro = (unsigned int)smartlist_len(d->intro_nodes);
+ if (have_intro != service->n_intro_points_wanted) {
+ int severity;
+ /* Getting less than we wanted or more than we're allowed is serious */
+ if (have_intro < service->n_intro_points_wanted ||
+ have_intro > NUM_INTRO_POINTS_MAX) {
+ severity = LOG_WARN;
+ } else {
+ /* Getting more than we wanted is weird, but less of a problem */
+ severity = LOG_NOTICE;
+ }
+ log_fn(severity, LD_REND, "Hidden service %s wanted %d intro points, but "
+ "descriptor was updated with %d instead.",
+ service->service_id,
+ service->n_intro_points_wanted, have_intro);
+ /* Now log an informative message about how we might have got here. */
+ rend_log_intro_limit(service, severity);
+ }
+}
+
+/* Allocate and return a string containing the path to file_name in
+ * service->directory. Asserts that service has a directory.
+ * This function will never return NULL.
+ * The caller must free this path. */
+static char *
+rend_service_path(const rend_service_t *service, const char *file_name)
+{
+ tor_assert(service->directory);
+ return hs_path_from_filename(service->directory, file_name);
+}
+
+/* Allocate and return a string containing the path to the single onion
+ * service poison file in service->directory. Asserts that service has a
+ * directory.
+ * The caller must free this path. */
+STATIC char *
+rend_service_sos_poison_path(const rend_service_t *service)
+{
+ return rend_service_path(service, sos_poison_fname);
+}
+
+/** Return True if hidden services <b>service</b> has been poisoned by single
+ * onion mode. */
+static int
+service_is_single_onion_poisoned(const rend_service_t *service)
+{
+ char *poison_fname = NULL;
+ file_status_t fstatus;
+
+ /* Passing a NULL service is a bug */
+ if (BUG(!service)) {
+ return 0;
+ }
+
+ if (rend_service_is_ephemeral(service)) {
+ return 0;
+ }
+
+ poison_fname = rend_service_sos_poison_path(service);
+
+ fstatus = file_status(poison_fname);
+ tor_free(poison_fname);
+
+ /* If this fname is occupied, the hidden service has been poisoned.
+ * fstatus can be FN_ERROR if the service directory does not exist, in that
+ * case, there is obviously no private key. */
+ if (fstatus == FN_FILE || fstatus == FN_EMPTY) {
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Return 1 if the private key file for service exists and has a non-zero size,
+ * and 0 otherwise. */
+static int
+rend_service_private_key_exists(const rend_service_t *service)
+{
+ char *private_key_path = rend_service_path(service, private_key_fname);
+ const file_status_t private_key_status = file_status(private_key_path);
+ tor_free(private_key_path);
+ /* Only non-empty regular private key files could have been used before.
+ * fstatus can be FN_ERROR if the service directory does not exist, in that
+ * case, there is obviously no private key. */
+ return private_key_status == FN_FILE;
+}
+
+/** Check the single onion service poison state of the directory for s:
+ * - If the service is poisoned, and we are in Single Onion Mode,
+ * return 0,
+ * - If the service is not poisoned, and we are not in Single Onion Mode,
+ * return 0,
+ * - Otherwise, the poison state is invalid: the service was created in one
+ * mode, and is being used in the other, return -1.
+ * Hidden service directories without keys are always considered consistent.
+ * They will be poisoned after their directory is created (if needed). */
+STATIC int
+rend_service_verify_single_onion_poison(const rend_service_t* s,
+ const or_options_t* options)
+{
+ /* Passing a NULL service is a bug */
+ if (BUG(!s)) {
+ return -1;
+ }
+
+ /* Ephemeral services are checked at ADD_ONION time */
+ if (BUG(rend_service_is_ephemeral(s))) {
+ return -1;
+ }
+
+ /* Service is expected to have a directory */
+ if (BUG(!s->directory)) {
+ return -1;
+ }
+
+ /* Services without keys are always ok - their keys will only ever be used
+ * in the current mode */
+ if (!rend_service_private_key_exists(s)) {
+ return 0;
+ }
+
+ /* The key has been used before in a different mode */
+ if (service_is_single_onion_poisoned(s) !=
+ rend_service_non_anonymous_mode_enabled(options)) {
+ return -1;
+ }
+
+ /* The key exists and is consistent with the current mode */
+ return 0;
+}
+
+/*** Helper for rend_service_poison_new_single_onion_dir(). Add a file to
+ * the hidden service directory for s that marks it as a single onion service.
+ * Tor must be in single onion mode before calling this function, and the
+ * service directory must already have been created.
+ * Returns 0 when a directory is successfully poisoned, or if it is already
+ * poisoned. Returns -1 on a failure to read the directory or write the poison
+ * file, or if there is an existing private key file in the directory. (The
+ * service should have been poisoned when the key was created.) */
+static int
+poison_new_single_onion_hidden_service_dir_impl(const rend_service_t *service,
+ const or_options_t* options)
+{
+ /* Passing a NULL service is a bug */
+ if (BUG(!service)) {
+ return -1;
+ }
+
+ /* We must only poison directories if we're in Single Onion mode */
+ tor_assert(rend_service_non_anonymous_mode_enabled(options));
+
+ int fd;
+ int retval = -1;
+ char *poison_fname = NULL;
+
+ if (rend_service_is_ephemeral(service)) {
+ log_info(LD_REND, "Ephemeral HS started in non-anonymous mode.");
+ return 0;
+ }
+
+ /* Make sure we're only poisoning new hidden service directories */
+ if (rend_service_private_key_exists(service)) {
+ log_warn(LD_BUG, "Tried to single onion poison a service directory after "
+ "the private key was created.");
+ return -1;
+ }
+
+ /* Make sure the directory was created before calling this function. */
+ if (BUG(hs_check_service_private_dir(options->User, service->directory,
+ service->dir_group_readable, 0) < 0))
+ return -1;
+
+ poison_fname = rend_service_sos_poison_path(service);
+
+ switch (file_status(poison_fname)) {
+ case FN_DIR:
+ case FN_ERROR:
+ log_warn(LD_FS, "Can't read single onion poison file \"%s\"",
+ poison_fname);
+ goto done;
+ case FN_FILE: /* single onion poison file already exists. NOP. */
+ case FN_EMPTY: /* single onion poison file already exists. NOP. */
+ log_debug(LD_FS, "Tried to re-poison a single onion poisoned file \"%s\"",
+ poison_fname);
+ break;
+ case FN_NOENT:
+ fd = tor_open_cloexec(poison_fname, O_RDWR|O_CREAT|O_TRUNC, 0600);
+ if (fd < 0) {
+ log_warn(LD_FS, "Could not create single onion poison file %s",
+ poison_fname);
+ goto done;
+ }
+ close(fd);
+ break;
+ default:
+ tor_assert(0);
+ }
+
+ retval = 0;
+
+ done:
+ tor_free(poison_fname);
+
+ return retval;
+}
+
+/** We just got launched in Single Onion Mode. That's a non-anonymous mode for
+ * hidden services. If s is new, we should mark its hidden service
+ * directory appropriately so that it is never launched as a location-private
+ * hidden service. (New directories don't have private key files.)
+ * Return 0 on success, -1 on fail. */
+STATIC int
+rend_service_poison_new_single_onion_dir(const rend_service_t *s,
+ const or_options_t* options)
+{
+ /* Passing a NULL service is a bug */
+ if (BUG(!s)) {
+ return -1;
+ }
+
+ /* We must only poison directories if we're in Single Onion mode */
+ tor_assert(rend_service_non_anonymous_mode_enabled(options));
+
+ /* Ephemeral services aren't allowed in non-anonymous mode */
+ if (BUG(rend_service_is_ephemeral(s))) {
+ return -1;
+ }
+
+ /* Service is expected to have a directory */
+ if (BUG(!s->directory)) {
+ return -1;
+ }
+
+ if (!rend_service_private_key_exists(s)) {
+ if (poison_new_single_onion_hidden_service_dir_impl(s, options)
+ < 0) {
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/* Return true iff the given service identity key is present on disk. This is
+ * used to try to learn the service version during configuration time. */
+int
+rend_service_key_on_disk(const char *directory_path)
+{
+ int ret = 0;
+ char *fname;
+ crypto_pk_t *pk = NULL;
+
+ tor_assert(directory_path);
+
+ /* Load key */
+ fname = hs_path_from_filename(directory_path, private_key_fname);
+ pk = init_key_from_file(fname, 0, LOG_DEBUG, NULL);
+ if (pk) {
+ ret = 1;
+ }
+
+ crypto_pk_free(pk);
+ tor_free(fname);
+ return ret;
+}
+
+/** Load and/or generate private keys for all hidden services, possibly
+ * including keys for client authorization.
+ * If a <b>service_list</b> is provided, treat it as the list of hidden
+ * services (used in unittests). Otherwise, require that rend_service_list is
+ * not NULL.
+ * Return 0 on success, -1 on failure. */
+int
+rend_service_load_all_keys(const smartlist_t *service_list)
+{
+ /* Use service_list for unit tests */
+ const smartlist_t *s_list = rend_get_service_list(service_list);
+ if (BUG(!s_list)) {
+ return -1;
+ }
+
+ SMARTLIST_FOREACH_BEGIN(s_list, rend_service_t *, s) {
+ if (s->private_key)
+ continue;
+ log_info(LD_REND, "Loading hidden-service keys from %s",
+ rend_service_escaped_dir(s));
+
+ if (rend_service_load_keys(s) < 0)
+ return -1;
+ } SMARTLIST_FOREACH_END(s);
+
+ return 0;
+}
+
+/** Add to <b>lst</b> every filename used by <b>s</b>. */
+static void
+rend_service_add_filenames_to_list(smartlist_t *lst, const rend_service_t *s)
+{
+ tor_assert(lst);
+ tor_assert(s);
+ tor_assert(s->directory);
+ smartlist_add(lst, rend_service_path(s, private_key_fname));
+ smartlist_add(lst, rend_service_path(s, hostname_fname));
+ smartlist_add(lst, rend_service_path(s, client_keys_fname));
+ smartlist_add(lst, rend_service_sos_poison_path(s));
+}
+
+/** Add to <b>open_lst</b> every filename used by a configured hidden service,
+ * and to <b>stat_lst</b> every directory used by a configured hidden
+ * service */
+void
+rend_services_add_filenames_to_lists(smartlist_t *open_lst,
+ smartlist_t *stat_lst)
+{
+ if (!rend_service_list)
+ return;
+ SMARTLIST_FOREACH_BEGIN(rend_service_list, rend_service_t *, s) {
+ if (!rend_service_is_ephemeral(s)) {
+ rend_service_add_filenames_to_list(open_lst, s);
+ smartlist_add_strdup(stat_lst, s->directory);
+ }
+ } SMARTLIST_FOREACH_END(s);
+}
+
+/** Derive all rend_service_t internal material based on the service's key.
+ * Returns 0 on success, -1 on failure.
+ */
+static int
+rend_service_derive_key_digests(struct rend_service_t *s)
+{
+ 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;
+ }
+
+ return 0;
+}
+
+/** Make sure that the directory for <b>s</b> is private, using the config in
+ * <b>options</b>.
+ * If <b>create</b> is true:
+ * - if the directory exists, change permissions if needed,
+ * - if the directory does not exist, create it with the correct permissions.
+ * If <b>create</b> is false:
+ * - if the directory exists, check permissions,
+ * - if the directory does not exist, check if we think we can create it.
+ * Return 0 on success, -1 on failure. */
+static int
+rend_service_check_private_dir(const or_options_t *options,
+ const rend_service_t *s,
+ int create)
+{
+ /* Passing a NULL service is a bug */
+ if (BUG(!s)) {
+ return -1;
+ }
+
+ /* Check/create directory */
+ if (hs_check_service_private_dir(options->User, s->directory,
+ s->dir_group_readable, create) < 0) {
+ return -1;
+ }
+
+ /* Check if the hidden service key exists, and was created in a different
+ * single onion service mode, and refuse to launch if it has.
+ * This is safe to call even when create is false, as it ignores missing
+ * keys and directories: they are always valid.
+ */
+ if (rend_service_verify_single_onion_poison(s, options) < 0) {
+ /* We can't use s->service_id here, as the key may not have been loaded */
+ log_warn(LD_GENERAL, "We are configured with "
+ "HiddenServiceNonAnonymousMode %d, but the hidden "
+ "service key in directory %s was created in %s mode. "
+ "This is not allowed.",
+ rend_service_non_anonymous_mode_enabled(options) ? 1 : 0,
+ rend_service_escaped_dir(s),
+ rend_service_non_anonymous_mode_enabled(options) ?
+ "an anonymous" : "a non-anonymous"
+ );
+ return -1;
+ }
+
+ /* Poison new single onion directories immediately after they are created,
+ * so that we never accidentally launch non-anonymous hidden services
+ * thinking they are anonymous. Any keys created later will end up with the
+ * correct poisoning state.
+ */
+ if (create && rend_service_non_anonymous_mode_enabled(options)) {
+ static int logged_warning = 0;
+
+ if (rend_service_poison_new_single_onion_dir(s, options) < 0) {
+ log_warn(LD_GENERAL,"Failed to mark new hidden services as non-anonymous"
+ ".");
+ return -1;
+ }
+
+ if (!logged_warning) {
+ /* The keys for these services are linked to the server IP address */
+ log_notice(LD_REND, "The configured onion service directories have been "
+ "used in single onion mode. They can not be used for "
+ "anonymous hidden services.");
+ logged_warning = 1;
+ }
+ }
+
+ return 0;
+}
+
+/** Load and/or generate private keys for the hidden service <b>s</b>,
+ * possibly including keys for client authorization. Return 0 on success, -1
+ * on failure. */
+static int
+rend_service_load_keys(rend_service_t *s)
+{
+ char *fname = NULL;
+ char buf[128];
+
+ /* Create the directory if needed which will also poison it in case of
+ * single onion service. */
+ if (rend_service_check_private_dir(get_options(), s, 1) < 0)
+ goto err;
+
+ /* Load key */
+ fname = rend_service_path(s, private_key_fname);
+ s->private_key = init_key_from_file(fname, 1, LOG_ERR, NULL);
+
+ if (!s->private_key)
+ goto err;
+
+ if (rend_service_derive_key_digests(s) < 0)
+ goto err;
+
+ tor_free(fname);
+ /* Create service file */
+ fname = rend_service_path(s, hostname_fname);
+
+ 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.");
+ goto err;
+ }
+#ifndef _WIN32
+ if (s->dir_group_readable) {
+ /* Also verify hostname file created with group read. */
+ if (chmod(fname, 0640))
+ log_warn(LD_FS,"Unable to make hidden hostname file %s group-readable.",
+ fname);
+ }
+#endif /* !defined(_WIN32) */
+
+ /* If client authorization is configured, load or generate keys. */
+ if (s->auth_type != REND_NO_AUTH) {
+ if (rend_service_load_auth_keys(s, fname) < 0) {
+ goto err;
+ }
+ }
+
+ int r = 0;
+ goto done;
+ err:
+ r = -1;
+ done:
+ memwipe(buf, 0, sizeof(buf));
+ tor_free(fname);
+ return r;
+}
+
+/** Load and/or generate client authorization keys for the hidden service
+ * <b>s</b>, which stores its hostname in <b>hfname</b>. Return 0 on success,
+ * -1 on failure. */
+static int
+rend_service_load_auth_keys(rend_service_t *s, const char *hfname)
+{
+ int r = 0;
+ char *cfname = NULL;
+ char *client_keys_str = NULL;
+ strmap_t *parsed_clients = strmap_new();
+ FILE *cfile, *hfile;
+ open_file_t *open_cfile = NULL, *open_hfile = NULL;
+ char desc_cook_out[3*REND_DESC_COOKIE_LEN_BASE64+1];
+ char service_id[16+1];
+ char buf[1500];
+
+ /* Load client keys and descriptor cookies, if available. */
+ cfname = rend_service_path(s, client_keys_fname);
+ 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));
+ }
+ }
+
+ /* Prepare client_keys and hostname files. */
+ if (!(cfile = start_writing_to_stdio_file(cfname,
+ OPEN_FLAGS_REPLACE | O_TEXT,
+ 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(hfname,
+ OPEN_FLAGS_REPLACE | O_TEXT,
+ 0600, &open_hfile))) {
+ log_warn(LD_CONFIG, "Could not open hostname file %s", escaped(hfname));
+ 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) {
+ 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((char *) client->descriptor_cookie, REND_DESC_COOKIE_LEN);
+ }
+ /* For compatibility with older tor clients, this does not
+ * truncate the padding characters, unlike rend_auth_encode_cookie. */
+ if (base64_encode(desc_cook_out, 3*REND_DESC_COOKIE_LEN_BASE64+1,
+ (char *) client->descriptor_cookie,
+ REND_DESC_COOKIE_LEN, 0) < 0) {
+ log_warn(LD_BUG, "Could not base64-encode descriptor cookie.");
+ goto err;
+ }
+ /* 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_t *prkey = NULL;
+ if (!(prkey = crypto_pk_new())) {
+ 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_pk_free(prkey);
+ goto err;
+ }
+ if (! crypto_pk_is_valid_private_key(prkey)) {
+ log_warn(LD_BUG,"Generated client key seems invalid");
+ crypto_pk_free(prkey);
+ goto err;
+ }
+ client->client_key = prkey;
+ }
+ /* Add entry to client_keys file. */
+ 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;
+ if (crypto_pk_write_private_key_to_string(client->client_key,
+ &client_key_out, &len) != 0) {
+ log_warn(LD_BUG, "Internal error: "
+ "crypto_pk_write_private_key_to_string() failed.");
+ goto err;
+ }
+ if (rend_get_service_id(client->client_key, service_id)<0) {
+ log_warn(LD_BUG, "Internal error: couldn't encode service ID.");
+ /*
+ * len is string length, not buffer length, but last byte is NUL
+ * anyway.
+ */
+ memwipe(client_key_out, 0, len);
+ tor_free(client_key_out);
+ goto err;
+ }
+ written = tor_snprintf(buf + written, sizeof(buf) - written,
+ "client-key\n%s", client_key_out);
+ memwipe(client_key_out, 0, len);
+ tor_free(client_key_out);
+ if (written < 0) {
+ log_warn(LD_BUG, "Could not write client entry.");
+ goto err;
+ }
+ } else {
+ strlcpy(service_id, s->service_id, sizeof(service_id));
+ }
+
+ 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. This is not the same encoding as in
+ * client_keys. */
+ char *encoded_cookie = rend_auth_encode_cookie(client->descriptor_cookie,
+ s->auth_type);
+ if (!encoded_cookie) {
+ log_warn(LD_BUG, "Could not base64-encode descriptor cookie.");
+ goto err;
+ }
+ tor_snprintf(buf, sizeof(buf), "%s.onion %s # client: %s\n",
+ service_id, encoded_cookie, client->client_name);
+ memwipe(encoded_cookie, 0, strlen(encoded_cookie));
+ tor_free(encoded_cookie);
+
+ 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);
+
+ finish_writing_to_file(open_cfile);
+ finish_writing_to_file(open_hfile);
+
+ goto done;
+ err:
+ r = -1;
+ if (open_cfile)
+ abort_writing_to_file(open_cfile);
+ if (open_hfile)
+ abort_writing_to_file(open_hfile);
+ done:
+ if (client_keys_str) {
+ memwipe(client_keys_str, 0, strlen(client_keys_str));
+ tor_free(client_keys_str);
+ }
+ strmap_free(parsed_clients, rend_authorized_client_free_void);
+
+ if (cfname) {
+ memwipe(cfname, 0, strlen(cfname));
+ tor_free(cfname);
+ }
+
+ /* Clear stack buffers that held key-derived material. */
+ memwipe(buf, 0, sizeof(buf));
+ memwipe(desc_cook_out, 0, sizeof(desc_cook_out));
+ memwipe(service_id, 0, sizeof(service_id));
+
+ 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 (tor_memeq(s->pk_digest,digest,DIGEST_LEN))
+ return s);
+ return NULL;
+}
+
+/** Return the service whose service id is <b>id</b>, or NULL if no such
+ * service exists.
+ */
+static struct rend_service_t *
+rend_service_get_by_service_id(const char *id)
+{
+ tor_assert(strlen(id) == REND_SERVICE_ID_LEN_BASE32);
+ SMARTLIST_FOREACH(rend_service_list, rend_service_t*, s, {
+ if (tor_memeq(s->service_id, id, REND_SERVICE_ID_LEN_BASE32))
+ return s;
+ });
+ return NULL;
+}
+
+/** Check client authorization of a given <b>descriptor_cookie</b> of
+ * length <b>cookie_len</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,
+ size_t cookie_len)
+{
+ 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;
+ }
+
+ if (cookie_len != REND_DESC_COOKIE_LEN) {
+ log_info(LD_REND, "Descriptor cookie is %lu bytes, but we expected "
+ "%lu bytes. Dropping cell.",
+ (unsigned long)cookie_len, (unsigned long)REND_DESC_COOKIE_LEN);
+ return 0;
+ }
+
+ /* Look up client authorization by descriptor cookie. */
+ SMARTLIST_FOREACH(service->clients, rend_authorized_client_t *, client, {
+ if (tor_memeq(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, 0);
+ log_info(LD_REND, "No authorization found for descriptor cookie '%s'! "
+ "Dropping cell!",
+ descriptor_cookie_base64);
+ return 0;
+ }
+
+ /* Allow the request. */
+ log_info(LD_REND, "Client %s authorized for service %s.",
+ auth_client->client_name, service->service_id);
+ return 1;
+}
+
+/* Can this service make a direct connection to ei?
+ * It must be a single onion service, and the firewall rules must allow ei. */
+static int
+rend_service_use_direct_connection(const or_options_t* options,
+ const extend_info_t* ei)
+{
+ /* We'll connect directly all reachable addresses, whether preferred or not.
+ * The prefer_ipv6 argument to fascist_firewall_allows_address_addr is
+ * ignored, because pref_only is 0. */
+ return (rend_service_allow_non_anonymous_connection(options) &&
+ fascist_firewall_allows_address_addr(&ei->addr, ei->port,
+ FIREWALL_OR_CONNECTION, 0, 0));
+}
+
+/* Like rend_service_use_direct_connection, but to a node. */
+static int
+rend_service_use_direct_connection_node(const or_options_t* options,
+ const node_t* node)
+{
+ /* We'll connect directly all reachable addresses, whether preferred or not.
+ */
+ return (rend_service_allow_non_anonymous_connection(options) &&
+ fascist_firewall_allows_node(node, FIREWALL_OR_CONNECTION, 0));
+}
+
+/******
+ * Handle cells
+ ******/
+
+/** Respond to an INTRODUCE2 cell by launching a circuit to the chosen
+ * rendezvous point.
+ */
+int
+rend_service_receive_introduction(origin_circuit_t *circuit,
+ const uint8_t *request,
+ size_t request_len)
+{
+ /* Global status stuff */
+ int status = 0, result;
+ const or_options_t *options = get_options();
+ char *err_msg = NULL;
+ int err_msg_severity = LOG_WARN;
+ const char *stage_descr = NULL, *rend_pk_digest;
+ int reason = END_CIRC_REASON_TORPROTOCOL;
+ /* Service/circuit/key stuff we can learn before parsing */
+ char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
+ rend_service_t *service = NULL;
+ rend_intro_point_t *intro_point = NULL;
+ crypto_pk_t *intro_key = NULL;
+ /* Parsed cell */
+ rend_intro_cell_t *parsed_req = NULL;
+ /* Rendezvous point */
+ extend_info_t *rp = NULL;
+ /* XXX not handled yet */
+ char buf[RELAY_PAYLOAD_SIZE];
+ char keys[DIGEST_LEN+CPATH_KEY_MATERIAL_LEN]; /* Holds KH, Df, Db, Kf, Kb */
+ int i;
+ crypto_dh_t *dh = NULL;
+ origin_circuit_t *launched = NULL;
+ crypt_path_t *cpath = NULL;
+ char hexcookie[9];
+ int circ_needs_uptime;
+ time_t now = time(NULL);
+ time_t elapsed;
+ int replay;
+ ssize_t keylen;
+
+ /* Do some initial validation and logging before we parse the cell */
+ if (circuit->base_.purpose != CIRCUIT_PURPOSE_S_INTRO) {
+ log_warn(LD_PROTOCOL,
+ "Got an INTRODUCE2 over a non-introduction circuit %u.",
+ (unsigned) circuit->base_.n_circ_id);
+ goto err;
+ }
+
+ assert_circ_anonymity_ok(circuit, options);
+ tor_assert(circuit->rend_data);
+ /* XXX: This is version 2 specific (only one supported). */
+ rend_pk_digest = (char *) rend_data_get_pk_digest(circuit->rend_data, NULL);
+
+ /* We'll use this in a bazillion log messages */
+ base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32+1,
+ rend_pk_digest, REND_SERVICE_ID_LEN);
+
+ /* look up service depending on circuit. */
+ service = rend_service_get_by_pk_digest(rend_pk_digest);
+ if (!service) {
+ log_warn(LD_BUG,
+ "Internal error: Got an INTRODUCE2 cell on an intro "
+ "circ for an unrecognized service %s.",
+ escaped(serviceid));
+ goto err;
+ }
+
+ intro_point = find_intro_point(circuit);
+ if (intro_point == NULL) {
+ intro_point = find_expiring_intro_point(service, circuit);
+ if (intro_point == NULL) {
+ log_warn(LD_BUG,
+ "Internal error: Got an INTRODUCE2 cell on an "
+ "intro circ (for service %s) with no corresponding "
+ "rend_intro_point_t.",
+ escaped(serviceid));
+ goto err;
+ }
+ }
+
+ log_info(LD_REND, "Received INTRODUCE2 cell for service %s on circ %u.",
+ escaped(serviceid), (unsigned)circuit->base_.n_circ_id);
+
+ /* use intro key instead of service key. */
+ intro_key = circuit->intro_key;
+
+ tor_free(err_msg);
+ stage_descr = NULL;
+
+ stage_descr = "early parsing";
+ /* Early parsing pass (get pk, ciphertext); type 2 is INTRODUCE2 */
+ parsed_req =
+ rend_service_begin_parse_intro(request, request_len, 2, &err_msg);
+ if (!parsed_req) {
+ goto log_error;
+ } else if (err_msg) {
+ log_info(LD_REND, "%s on circ %u.", err_msg,
+ (unsigned)circuit->base_.n_circ_id);
+ tor_free(err_msg);
+ }
+
+ /* make sure service replay caches are present */
+ if (!service->accepted_intro_dh_parts) {
+ service->accepted_intro_dh_parts =
+ replaycache_new(REND_REPLAY_TIME_INTERVAL,
+ REND_REPLAY_TIME_INTERVAL);
+ }
+
+ if (!intro_point->accepted_intro_rsa_parts) {
+ intro_point->accepted_intro_rsa_parts = replaycache_new(0, 0);
+ }
+
+ /* check for replay of PK-encrypted portion. */
+ keylen = crypto_pk_keysize(intro_key);
+ replay = replaycache_add_test_and_elapsed(
+ intro_point->accepted_intro_rsa_parts,
+ parsed_req->ciphertext, MIN(parsed_req->ciphertext_len, keylen),
+ &elapsed);
+
+ if (replay) {
+ log_warn(LD_REND,
+ "Possible replay detected! We received an "
+ "INTRODUCE2 cell with same PK-encrypted part %d "
+ "seconds ago. Dropping cell.",
+ (int)elapsed);
+ goto err;
+ }
+
+ stage_descr = "decryption";
+ /* Now try to decrypt it */
+ result = rend_service_decrypt_intro(parsed_req, intro_key, &err_msg);
+ if (result < 0) {
+ goto log_error;
+ } else if (err_msg) {
+ log_info(LD_REND, "%s on circ %u.", err_msg,
+ (unsigned)circuit->base_.n_circ_id);
+ tor_free(err_msg);
+ }
+
+ stage_descr = "late parsing";
+ /* Parse the plaintext */
+ result = rend_service_parse_intro_plaintext(parsed_req, &err_msg);
+ if (result < 0) {
+ goto log_error;
+ } else if (err_msg) {
+ log_info(LD_REND, "%s on circ %u.", err_msg,
+ (unsigned)circuit->base_.n_circ_id);
+ tor_free(err_msg);
+ }
+
+ stage_descr = "late validation";
+ /* Validate the parsed plaintext parts */
+ result = rend_service_validate_intro_late(parsed_req, &err_msg);
+ if (result < 0) {
+ goto log_error;
+ } else if (err_msg) {
+ log_info(LD_REND, "%s on circ %u.", err_msg,
+ (unsigned)circuit->base_.n_circ_id);
+ tor_free(err_msg);
+ }
+ stage_descr = NULL;
+
+ /* Increment INTRODUCE2 counter */
+ ++(intro_point->accepted_introduce2_count);
+
+ /* Find the rendezvous point */
+ rp = find_rp_for_intro(parsed_req, &err_msg);
+ if (!rp) {
+ err_msg_severity = LOG_PROTOCOL_WARN;
+ goto log_error;
+ }
+
+ /* Check if we'd refuse to talk to this router */
+ if (options->StrictNodes &&
+ routerset_contains_extendinfo(options->ExcludeNodes, rp)) {
+ log_warn(LD_REND, "Client asked to rendezvous at a relay that we "
+ "exclude, and StrictNodes is set. Refusing service.");
+ reason = END_CIRC_REASON_INTERNAL; /* XXX might leak why we refused */
+ goto err;
+ }
+
+ base16_encode(hexcookie, 9, (const char *)(parsed_req->rc), 4);
+
+ /* Check whether there is a past request with the same Diffie-Hellman,
+ * part 1. */
+ replay = replaycache_add_test_and_elapsed(
+ service->accepted_intro_dh_parts,
+ parsed_req->dh, DH1024_KEY_LEN,
+ &elapsed);
+
+ if (replay) {
+ /* A Tor client will send a new INTRODUCE1 cell with the same rend
+ * cookie and DH public key as its previous one if its intro circ
+ * times out while in state CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT .
+ * If we received the first INTRODUCE1 cell (the intro-point relay
+ * converts it into an INTRODUCE2 cell), we are already trying to
+ * connect to that rend point (and may have already succeeded);
+ * drop this cell. */
+ log_info(LD_REND, "We received an "
+ "INTRODUCE2 cell with same first part of "
+ "Diffie-Hellman handshake %d seconds ago. Dropping "
+ "cell.",
+ (int) elapsed);
+ goto err;
+ }
+
+ /* If the service performs client authorization, check included auth data. */
+ if (service->clients) {
+ if (parsed_req->version == 3 && parsed_req->u.v3.auth_len > 0) {
+ if (rend_check_authorization(service,
+ (const char*)parsed_req->u.v3.auth_data,
+ parsed_req->u.v3.auth_len)) {
+ 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(DH_TYPE_REND);
+ 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,
+ (char *)(parsed_req->dh),
+ DH1024_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 = hs_service_requires_uptime_circ(service->ports);
+
+ /* help predict this next time */
+ rep_hist_note_used_internal(now, circ_needs_uptime, 1);
+
+ /* Launch a circuit to the client's chosen rendezvous point.
+ */
+ int max_rend_failures=hs_get_service_max_rend_failures();
+ for (i=0;i<max_rend_failures;i++) {
+ int flags = CIRCLAUNCH_NEED_CAPACITY | CIRCLAUNCH_IS_INTERNAL;
+ if (circ_needs_uptime) flags |= CIRCLAUNCH_NEED_UPTIME;
+ /* A Single Onion Service only uses a direct connection if its
- * firewall rules permit direct connections to the address. */
- if (rend_service_use_direct_connection(options, rp)) {
++ * firewall rules permit direct connections to the address.
++ *
++ * We only use a one-hop path on the first attempt. If the first attempt
++ * fails, we use a 3-hop path for reachability / reliability.
++ * See the comment in rend_service_relauch_rendezvous() for details. */
++ if (rend_service_use_direct_connection(options, rp) && i == 0) {
+ flags = flags | CIRCLAUNCH_ONEHOP_TUNNEL;
+ }
+ launched = circuit_launch_by_extend_info(
+ CIRCUIT_PURPOSE_S_CONNECT_REND, rp, 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.",
+ safe_str_client(extend_info_describe(rp)),
+ serviceid);
+ reason = END_CIRC_REASON_CONNECTFAILED;
+ goto err;
+ }
+ log_info(LD_REND,
+ "Accepted intro; launching circuit to %s "
+ "(cookie %s) for service %s.",
+ safe_str_client(extend_info_describe(rp)),
+ hexcookie, serviceid);
+ tor_assert(launched->build_state);
+ /* Fill in the circuit's state. */
+
+ launched->rend_data =
+ rend_data_service_create(service->service_id, rend_pk_digest,
+ parsed_req->rc, service->auth_type);
+
+ launched->build_state->service_pending_final_cpath_ref =
+ tor_malloc_zero(sizeof(crypt_path_reference_t));
+ launched->build_state->service_pending_final_cpath_ref->refcount = 1;
+
+ launched->build_state->service_pending_final_cpath_ref->cpath = cpath =
+ tor_malloc_zero(sizeof(crypt_path_t));
+ cpath->magic = CRYPT_PATH_MAGIC;
+ launched->build_state->expiry_time = now + MAX_REND_TIMEOUT;
+
+ cpath->rend_dh_handshake_state = dh;
+ dh = NULL;
+ if (circuit_init_cpath_crypto(cpath,
+ keys+DIGEST_LEN, sizeof(keys)-DIGEST_LEN,
+ 1, 0)<0)
+ goto err;
+ memcpy(cpath->rend_circ_nonce, keys, DIGEST_LEN);
+
+ goto done;
+
+ log_error:
+ if (!err_msg) {
+ if (stage_descr) {
+ tor_asprintf(&err_msg,
+ "unknown %s error for INTRODUCE2", stage_descr);
+ } else {
+ err_msg = tor_strdup("unknown error for INTRODUCE2");
+ }
+ }
+
+ log_fn(err_msg_severity, LD_REND, "%s on circ %u", err_msg,
+ (unsigned)circuit->base_.n_circ_id);
+ err:
+ status = -1;
+ if (dh) crypto_dh_free(dh);
+ if (launched) {
+ circuit_mark_for_close(TO_CIRCUIT(launched), reason);
+ }
+ tor_free(err_msg);
+
+ done:
+ memwipe(keys, 0, sizeof(keys));
+ memwipe(buf, 0, sizeof(buf));
+ memwipe(serviceid, 0, sizeof(serviceid));
+ memwipe(hexcookie, 0, sizeof(hexcookie));
+
+ /* Free the parsed cell */
+ rend_service_free_intro(parsed_req);
+
+ /* Free rp */
+ extend_info_free(rp);
+
+ return status;
+}
+
+/** Given a parsed and decrypted INTRODUCE2, find the rendezvous point or
+ * return NULL and an error string if we can't. Return a newly allocated
+ * extend_info_t* for the rendezvous point. */
+static extend_info_t *
+find_rp_for_intro(const rend_intro_cell_t *intro,
+ char **err_msg_out)
+{
+ extend_info_t *rp = NULL;
+ char *err_msg = NULL;
+ const char *rp_nickname = NULL;
+ const node_t *node = NULL;
+
+ if (!intro) {
+ if (err_msg_out)
+ err_msg = tor_strdup("Bad parameters to find_rp_for_intro()");
+
+ goto err;
+ }
+
+ if (intro->version == 0 || intro->version == 1) {
+ rp_nickname = (const char *)(intro->u.v0_v1.rp);
+
+ node = node_get_by_nickname(rp_nickname, NNF_NO_WARN_UNNAMED);
+ if (!node) {
+ if (err_msg_out) {
+ tor_asprintf(&err_msg,
+ "Couldn't find router %s named in INTRODUCE2 cell",
+ escaped_safe_str_client(rp_nickname));
+ }
+
+ goto err;
+ }
+
+ /* Are we in single onion mode? */
+ const int allow_direct = rend_service_allow_non_anonymous_connection(
+ get_options());
+ rp = extend_info_from_node(node, allow_direct);
+ if (!rp) {
+ if (err_msg_out) {
+ tor_asprintf(&err_msg,
+ "Couldn't build extend_info_t for router %s named "
+ "in INTRODUCE2 cell",
+ escaped_safe_str_client(rp_nickname));
+ }
+
+ goto err;
+ }
+ } else if (intro->version == 2) {
+ rp = extend_info_dup(intro->u.v2.extend_info);
+ } else if (intro->version == 3) {
+ rp = extend_info_dup(intro->u.v3.extend_info);
+ } else {
+ if (err_msg_out) {
+ tor_asprintf(&err_msg,
+ "Unknown version %d in INTRODUCE2 cell",
+ (int)(intro->version));
+ }
+
+ goto err;
+ }
+
+ /* rp is always set here: extend_info_dup guarantees a non-NULL result, and
+ * the other cases goto err. */
+ tor_assert(rp);
+
+ /* Make sure the RP we are being asked to connect to is _not_ a private
+ * address unless it's allowed. Let's avoid to build a circuit to our
+ * second middle node and fail right after when extending to the RP. */
+ if (!extend_info_addr_is_allowed(&rp->addr)) {
+ if (err_msg_out) {
+ tor_asprintf(&err_msg,
+ "Relay IP in INTRODUCE2 cell is private address.");
+ }
+ extend_info_free(rp);
+ rp = NULL;
+ goto err;
+ }
+ goto done;
+
+ err:
+ if (err_msg_out)
+ *err_msg_out = err_msg;
+ else
+ tor_free(err_msg);
+
+ done:
+ return rp;
+}
+
+/** Free a parsed INTRODUCE1 or INTRODUCE2 cell that was allocated by
+ * rend_service_parse_intro().
+ */
+void
+rend_service_free_intro_(rend_intro_cell_t *request)
+{
+ if (!request) {
+ return;
+ }
+
+ /* Free ciphertext */
+ tor_free(request->ciphertext);
+ request->ciphertext_len = 0;
+
+ /* Have plaintext? */
+ if (request->plaintext) {
+ /* Zero it out just to be safe */
+ memwipe(request->plaintext, 0, request->plaintext_len);
+ tor_free(request->plaintext);
+ request->plaintext_len = 0;
+ }
+
+ /* Have parsed plaintext? */
+ if (request->parsed) {
+ switch (request->version) {
+ case 0:
+ case 1:
+ /*
+ * Nothing more to do; these formats have no further pointers
+ * in them.
+ */
+ break;
+ case 2:
+ extend_info_free(request->u.v2.extend_info);
+ request->u.v2.extend_info = NULL;
+ break;
+ case 3:
+ if (request->u.v3.auth_data) {
+ memwipe(request->u.v3.auth_data, 0, request->u.v3.auth_len);
+ tor_free(request->u.v3.auth_data);
+ }
+
+ extend_info_free(request->u.v3.extend_info);
+ request->u.v3.extend_info = NULL;
+ break;
+ default:
+ log_info(LD_BUG,
+ "rend_service_free_intro() saw unknown protocol "
+ "version %d.",
+ request->version);
+ }
+ }
+
+ /* Zero it out to make sure sensitive stuff doesn't hang around in memory */
+ memwipe(request, 0, sizeof(*request));
+
+ tor_free(request);
+}
+
+/** Parse an INTRODUCE1 or INTRODUCE2 cell into a newly allocated
+ * rend_intro_cell_t structure. Free it with rend_service_free_intro()
+ * when finished. The type parameter should be 1 or 2 to indicate whether
+ * this is INTRODUCE1 or INTRODUCE2. This parses only the non-encrypted
+ * parts; after this, call rend_service_decrypt_intro() with a key, then
+ * rend_service_parse_intro_plaintext() to finish parsing. The optional
+ * err_msg_out parameter is set to a string suitable for log output
+ * if parsing fails. This function does some validation, but only
+ * that which depends solely on the contents of the cell and the
+ * key; it can be unit-tested. Further validation is done in
+ * rend_service_validate_intro().
+ */
+
+rend_intro_cell_t *
+rend_service_begin_parse_intro(const uint8_t *request,
+ size_t request_len,
+ uint8_t type,
+ char **err_msg_out)
+{
+ rend_intro_cell_t *rv = NULL;
+ char *err_msg = NULL;
+
+ if (!request || request_len <= 0) goto err;
+ if (!(type == 1 || type == 2)) goto err;
+
+ /* First, check that the cell is long enough to be a sensible INTRODUCE */
+
+ /* min key length plus digest length plus nickname length */
+ if (request_len <
+ (DIGEST_LEN + REND_COOKIE_LEN + (MAX_NICKNAME_LEN + 1) +
+ DH1024_KEY_LEN + 42)) {
+ if (err_msg_out) {
+ tor_asprintf(&err_msg,
+ "got a truncated INTRODUCE%d cell",
+ (int)type);
+ }
+ goto err;
+ }
+
+ /* Allocate a new parsed cell structure */
+ rv = tor_malloc_zero(sizeof(*rv));
+
+ /* Set the type */
+ rv->type = type;
+
+ /* Copy in the ID */
+ memcpy(rv->pk, request, DIGEST_LEN);
+
+ /* Copy in the ciphertext */
+ rv->ciphertext = tor_malloc(request_len - DIGEST_LEN);
+ memcpy(rv->ciphertext, request + DIGEST_LEN, request_len - DIGEST_LEN);
+ rv->ciphertext_len = request_len - DIGEST_LEN;
+
+ goto done;
+
+ err:
+ rend_service_free_intro(rv);
+ rv = NULL;
+
+ if (err_msg_out && !err_msg) {
+ tor_asprintf(&err_msg,
+ "unknown INTRODUCE%d error",
+ (int)type);
+ }
+
+ done:
+ if (err_msg_out) *err_msg_out = err_msg;
+ else tor_free(err_msg);
+
+ return rv;
+}
+
+/** Parse the version-specific parts of a v0 or v1 INTRODUCE1 or INTRODUCE2
+ * cell
+ */
+
+static ssize_t
+rend_service_parse_intro_for_v0_or_v1(
+ rend_intro_cell_t *intro,
+ const uint8_t *buf,
+ size_t plaintext_len,
+ char **err_msg_out)
+{
+ const char *rp_nickname, *endptr;
+ size_t nickname_field_len, ver_specific_len;
+
+ if (intro->version == 1) {
+ ver_specific_len = MAX_HEX_NICKNAME_LEN + 2;
+ rp_nickname = ((const char *)buf) + 1;
+ nickname_field_len = MAX_HEX_NICKNAME_LEN + 1;
+ } else if (intro->version == 0) {
+ ver_specific_len = MAX_NICKNAME_LEN + 1;
+ rp_nickname = (const char *)buf;
+ nickname_field_len = MAX_NICKNAME_LEN + 1;
+ } else {
+ if (err_msg_out)
+ tor_asprintf(err_msg_out,
+ "rend_service_parse_intro_for_v0_or_v1() called with "
+ "bad version %d on INTRODUCE%d cell (this is a bug)",
+ intro->version,
+ (int)(intro->type));
+ goto err;
+ }
+
+ if (plaintext_len < ver_specific_len) {
+ if (err_msg_out)
+ tor_asprintf(err_msg_out,
+ "short plaintext of encrypted part in v1 INTRODUCE%d "
+ "cell (%lu bytes, needed %lu)",
+ (int)(intro->type),
+ (unsigned long)plaintext_len,
+ (unsigned long)ver_specific_len);
+ goto err;
+ }
+
+ endptr = memchr(rp_nickname, 0, nickname_field_len);
+ if (!endptr || endptr == rp_nickname) {
+ if (err_msg_out) {
+ tor_asprintf(err_msg_out,
+ "couldn't find a nul-padded nickname in "
+ "INTRODUCE%d cell",
+ (int)(intro->type));
+ }
+ goto err;
+ }
+
+ if ((intro->version == 0 &&
+ !is_legal_nickname(rp_nickname)) ||
+ (intro->version == 1 &&
+ !is_legal_nickname_or_hexdigest(rp_nickname))) {
+ if (err_msg_out) {
+ tor_asprintf(err_msg_out,
+ "bad nickname in INTRODUCE%d cell",
+ (int)(intro->type));
+ }
+ goto err;
+ }
+
+ memcpy(intro->u.v0_v1.rp, rp_nickname, endptr - rp_nickname + 1);
+
+ return ver_specific_len;
+
+ err:
+ return -1;
+}
+
+/** Parse the version-specific parts of a v2 INTRODUCE1 or INTRODUCE2 cell
+ */
+
+static ssize_t
+rend_service_parse_intro_for_v2(
+ rend_intro_cell_t *intro,
+ const uint8_t *buf,
+ size_t plaintext_len,
+ char **err_msg_out)
+{
+ unsigned int klen;
+ extend_info_t *extend_info = NULL;
+ ssize_t ver_specific_len;
+
+ /*
+ * We accept version 3 too so that the v3 parser can call this with
+ * an adjusted buffer for the latter part of a v3 cell, which is
+ * identical to a v2 cell.
+ */
+ if (!(intro->version == 2 ||
+ intro->version == 3)) {
+ if (err_msg_out)
+ tor_asprintf(err_msg_out,
+ "rend_service_parse_intro_for_v2() called with "
+ "bad version %d on INTRODUCE%d cell (this is a bug)",
+ intro->version,
+ (int)(intro->type));
+ goto err;
+ }
+
+ /* 7 == version, IP and port, DIGEST_LEN == id, 2 == key length */
+ if (plaintext_len < 7 + DIGEST_LEN + 2) {
+ if (err_msg_out) {
+ tor_asprintf(err_msg_out,
+ "truncated plaintext of encrypted parted of "
+ "version %d INTRODUCE%d cell",
+ intro->version,
+ (int)(intro->type));
+ }
+
+ goto err;
+ }
+
+ extend_info = tor_malloc_zero(sizeof(extend_info_t));
+ tor_addr_from_ipv4n(&extend_info->addr, get_uint32(buf + 1));
+ extend_info->port = ntohs(get_uint16(buf + 5));
+ memcpy(extend_info->identity_digest, buf + 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 + 7 + DIGEST_LEN));
+
+ /* 7 == version, IP and port, DIGEST_LEN == id, 2 == key length */
+ if (plaintext_len < 7 + DIGEST_LEN + 2 + klen) {
+ if (err_msg_out) {
+ tor_asprintf(err_msg_out,
+ "truncated plaintext of encrypted parted of "
+ "version %d INTRODUCE%d cell",
+ intro->version,
+ (int)(intro->type));
+ }
+
+ goto err;
+ }
+
+ extend_info->onion_key =
+ crypto_pk_asn1_decode((const char *)(buf + 7 + DIGEST_LEN + 2), klen);
+ if (!extend_info->onion_key) {
+ if (err_msg_out) {
+ tor_asprintf(err_msg_out,
+ "error decoding onion key in version %d "
+ "INTRODUCE%d cell",
+ intro->version,
+ (intro->type));
+ }
+
+ goto err;
+ }
+ if (128 != crypto_pk_keysize(extend_info->onion_key)) {
+ if (err_msg_out) {
+ tor_asprintf(err_msg_out,
+ "invalid onion key size in version %d INTRODUCE%d cell",
+ intro->version,
+ (intro->type));
+ }
+
+ goto err;
+ }
+
+ ver_specific_len = 7+DIGEST_LEN+2+klen;
+
+ if (intro->version == 2) intro->u.v2.extend_info = extend_info;
+ else intro->u.v3.extend_info = extend_info;
+
+ return ver_specific_len;
+
+ err:
+ extend_info_free(extend_info);
+
+ return -1;
+}
+
+/** Parse the version-specific parts of a v3 INTRODUCE1 or INTRODUCE2 cell
+ */
+
+static ssize_t
+rend_service_parse_intro_for_v3(
+ rend_intro_cell_t *intro,
+ const uint8_t *buf,
+ size_t plaintext_len,
+ char **err_msg_out)
+{
+ ssize_t adjust, v2_ver_specific_len, ts_offset;
+
+ /* This should only be called on v3 cells */
+ if (intro->version != 3) {
+ if (err_msg_out)
+ tor_asprintf(err_msg_out,
+ "rend_service_parse_intro_for_v3() called with "
+ "bad version %d on INTRODUCE%d cell (this is a bug)",
+ intro->version,
+ (int)(intro->type));
+ goto err;
+ }
+
+ /*
+ * Check that we have at least enough to get auth_len:
+ *
+ * 1 octet for version, 1 for auth_type, 2 for auth_len
+ */
+ if (plaintext_len < 4) {
+ if (err_msg_out) {
+ tor_asprintf(err_msg_out,
+ "truncated plaintext of encrypted parted of "
+ "version %d INTRODUCE%d cell",
+ intro->version,
+ (int)(intro->type));
+ }
+
+ goto err;
+ }
+
+ /*
+ * The rend_client_send_introduction() function over in rendclient.c is
+ * broken (i.e., fails to match the spec) in such a way that we can't
+ * change it without breaking the protocol. Specifically, it doesn't
+ * emit auth_len when auth-type is REND_NO_AUTH, so everything is off
+ * by two bytes after that. Calculate ts_offset and do everything from
+ * the timestamp on relative to that to handle this dain bramage.
+ */
+
+ intro->u.v3.auth_type = buf[1];
+ if (intro->u.v3.auth_type != REND_NO_AUTH) {
+ intro->u.v3.auth_len = ntohs(get_uint16(buf + 2));
+ ts_offset = 4 + intro->u.v3.auth_len;
+ } else {
+ intro->u.v3.auth_len = 0;
+ ts_offset = 2;
+ }
+
+ /* Check that auth len makes sense for this auth type */
+ if (intro->u.v3.auth_type == REND_BASIC_AUTH ||
+ intro->u.v3.auth_type == REND_STEALTH_AUTH) {
+ if (intro->u.v3.auth_len != REND_DESC_COOKIE_LEN) {
+ if (err_msg_out) {
+ tor_asprintf(err_msg_out,
+ "wrong auth data size %d for INTRODUCE%d cell, "
+ "should be %d",
+ (int)(intro->u.v3.auth_len),
+ (int)(intro->type),
+ REND_DESC_COOKIE_LEN);
+ }
+
+ goto err;
+ }
+ }
+
+ /* Check that we actually have everything up through the timestamp */
+ if (plaintext_len < (size_t)(ts_offset)+4) {
+ if (err_msg_out) {
+ tor_asprintf(err_msg_out,
+ "truncated plaintext of encrypted parted of "
+ "version %d INTRODUCE%d cell",
+ intro->version,
+ (int)(intro->type));
+ }
+
+ goto err;
+ }
+
+ if (intro->u.v3.auth_type != REND_NO_AUTH &&
+ intro->u.v3.auth_len > 0) {
+ /* Okay, we can go ahead and copy auth_data */
+ intro->u.v3.auth_data = tor_malloc(intro->u.v3.auth_len);
+ /*
+ * We know we had an auth_len field in this case, so 4 is
+ * always right.
+ */
+ memcpy(intro->u.v3.auth_data, buf + 4, intro->u.v3.auth_len);
+ }
+
+ /*
+ * From here on, the format is as in v2, so we call the v2 parser with
+ * adjusted buffer and length. We are 4 + ts_offset octets in, but the
+ * v2 parser expects to skip over a version byte at the start, so we
+ * adjust by 3 + ts_offset.
+ */
+ adjust = 3 + ts_offset;
+
+ v2_ver_specific_len =
+ rend_service_parse_intro_for_v2(intro,
+ buf + adjust, plaintext_len - adjust,
+ err_msg_out);
+
+ /* Success in v2 parser */
+ if (v2_ver_specific_len >= 0) return v2_ver_specific_len + adjust;
+ /* Failure in v2 parser; it will have provided an err_msg */
+ else return v2_ver_specific_len;
+
+ err:
+ return -1;
+}
+
+/** Table of parser functions for version-specific parts of an INTRODUCE2
+ * cell.
+ */
+
+static ssize_t
+ (*intro_version_handlers[])(
+ rend_intro_cell_t *,
+ const uint8_t *,
+ size_t,
+ char **) =
+{ rend_service_parse_intro_for_v0_or_v1,
+ rend_service_parse_intro_for_v0_or_v1,
+ rend_service_parse_intro_for_v2,
+ rend_service_parse_intro_for_v3 };
+
+/** Decrypt the encrypted part of an INTRODUCE1 or INTRODUCE2 cell,
+ * return 0 if successful, or < 0 and write an error message to
+ * *err_msg_out if provided.
+ */
+
+int
+rend_service_decrypt_intro(
+ rend_intro_cell_t *intro,
+ crypto_pk_t *key,
+ char **err_msg_out)
+{
+ char *err_msg = NULL;
+ uint8_t key_digest[DIGEST_LEN];
+ char service_id[REND_SERVICE_ID_LEN_BASE32+1];
+ ssize_t key_len;
+ uint8_t buf[RELAY_PAYLOAD_SIZE];
+ int result, status = -1;
+
+ if (!intro || !key) {
+ if (err_msg_out) {
+ err_msg =
+ tor_strdup("rend_service_decrypt_intro() called with bad "
+ "parameters");
+ }
+
+ status = -2;
+ goto err;
+ }
+
+ /* Make sure we have ciphertext */
+ if (!(intro->ciphertext) || intro->ciphertext_len <= 0) {
+ if (err_msg_out) {
+ tor_asprintf(&err_msg,
+ "rend_intro_cell_t was missing ciphertext for "
+ "INTRODUCE%d cell",
+ (int)(intro->type));
+ }
+ status = -3;
+ goto err;
+ }
+
+ /* Check that this cell actually matches this service key */
+
+ /* first DIGEST_LEN bytes of request is intro or service pk digest */
+ if (crypto_pk_get_digest(key, (char *)key_digest) < 0) {
+ if (err_msg_out)
+ *err_msg_out = tor_strdup("Couldn't compute RSA digest.");
+ log_warn(LD_BUG, "Couldn't compute key digest.");
+ status = -7;
+ goto err;
+ }
+
+ if (tor_memneq(key_digest, intro->pk, DIGEST_LEN)) {
+ if (err_msg_out) {
+ base32_encode(service_id, REND_SERVICE_ID_LEN_BASE32 + 1,
+ (char*)(intro->pk), REND_SERVICE_ID_LEN);
+ tor_asprintf(&err_msg,
+ "got an INTRODUCE%d cell for the wrong service (%s)",
+ (int)(intro->type),
+ escaped(service_id));
+ }
+
+ status = -4;
+ goto err;
+ }
+
+ /* Make sure the encrypted part is long enough to decrypt */
+
+ key_len = crypto_pk_keysize(key);
+ if (intro->ciphertext_len < key_len) {
+ if (err_msg_out) {
+ tor_asprintf(&err_msg,
+ "got an INTRODUCE%d cell with a truncated PK-encrypted "
+ "part",
+ (int)(intro->type));
+ }
+
+ status = -5;
+ goto err;
+ }
+
+ /* Decrypt the encrypted part */
+ result =
+ crypto_pk_obsolete_private_hybrid_decrypt(
+ key, (char *)buf, sizeof(buf),
+ (const char *)(intro->ciphertext), intro->ciphertext_len,
+ PK_PKCS1_OAEP_PADDING, 1);
+ if (result < 0) {
+ if (err_msg_out) {
+ tor_asprintf(&err_msg,
+ "couldn't decrypt INTRODUCE%d cell",
+ (int)(intro->type));
+ }
+ status = -6;
+ goto err;
+ }
+ intro->plaintext_len = result;
+ intro->plaintext = tor_malloc(intro->plaintext_len);
+ memcpy(intro->plaintext, buf, intro->plaintext_len);
+
+ status = 0;
+
+ goto done;
+
+ err:
+ if (err_msg_out && !err_msg) {
+ tor_asprintf(&err_msg,
+ "unknown INTRODUCE%d error decrypting encrypted part",
+ intro ? (int)(intro->type) : -1);
+ }
+
+ done:
+ if (err_msg_out) *err_msg_out = err_msg;
+ else tor_free(err_msg);
+
+ /* clean up potentially sensitive material */
+ memwipe(buf, 0, sizeof(buf));
+ memwipe(key_digest, 0, sizeof(key_digest));
+ memwipe(service_id, 0, sizeof(service_id));
+
+ return status;
+}
+
+/** Parse the plaintext of the encrypted part of an INTRODUCE1 or
+ * INTRODUCE2 cell, return 0 if successful, or < 0 and write an error
+ * message to *err_msg_out if provided.
+ */
+
+int
+rend_service_parse_intro_plaintext(
+ rend_intro_cell_t *intro,
+ char **err_msg_out)
+{
+ char *err_msg = NULL;
+ ssize_t ver_specific_len, ver_invariant_len;
+ uint8_t version;
+ int status = -1;
+
+ if (!intro) {
+ if (err_msg_out) {
+ err_msg =
+ tor_strdup("rend_service_parse_intro_plaintext() called with NULL "
+ "rend_intro_cell_t");
+ }
+
+ status = -2;
+ goto err;
+ }
+
+ /* Check that we have plaintext */
+ if (!(intro->plaintext) || intro->plaintext_len <= 0) {
+ if (err_msg_out) {
+ err_msg = tor_strdup("rend_intro_cell_t was missing plaintext");
+ }
+ status = -3;
+ goto err;
+ }
+
+ /* In all formats except v0, the first byte is a version number */
+ version = intro->plaintext[0];
+
+ /* v0 has no version byte (stupid...), so handle it as a fallback */
+ if (version > 3) version = 0;
+
+ /* Copy the version into the parsed cell structure */
+ intro->version = version;
+
+ /* Call the version-specific parser from the table */
+ ver_specific_len =
+ intro_version_handlers[version](intro,
+ intro->plaintext, intro->plaintext_len,
+ &err_msg);
+ if (ver_specific_len < 0) {
+ status = -4;
+ goto err;
+ }
+
+ /** The rendezvous cookie and Diffie-Hellman stuff are version-invariant
+ * and at the end of the plaintext of the encrypted part of the cell.
+ */
+
+ ver_invariant_len = intro->plaintext_len - ver_specific_len;
+ if (ver_invariant_len < REND_COOKIE_LEN + DH1024_KEY_LEN) {
+ tor_asprintf(&err_msg,
+ "decrypted plaintext of INTRODUCE%d cell was truncated (%ld bytes)",
+ (int)(intro->type),
+ (long)(intro->plaintext_len));
+ status = -5;
+ goto err;
+ } else if (ver_invariant_len > REND_COOKIE_LEN + DH1024_KEY_LEN) {
+ tor_asprintf(&err_msg,
+ "decrypted plaintext of INTRODUCE%d cell was too long (%ld bytes)",
+ (int)(intro->type),
+ (long)(intro->plaintext_len));
+ status = -6;
+ goto err;
+ } else {
+ memcpy(intro->rc,
+ intro->plaintext + ver_specific_len,
+ REND_COOKIE_LEN);
+ memcpy(intro->dh,
+ intro->plaintext + ver_specific_len + REND_COOKIE_LEN,
+ DH1024_KEY_LEN);
+ }
+
+ /* Flag it as being fully parsed */
+ intro->parsed = 1;
+
+ status = 0;
+ goto done;
+
+ err:
+ if (err_msg_out && !err_msg) {
+ tor_asprintf(&err_msg,
+ "unknown INTRODUCE%d error parsing encrypted part",
+ intro ? (int)(intro->type) : -1);
+ }
+
+ done:
+ if (err_msg_out) *err_msg_out = err_msg;
+ else tor_free(err_msg);
+
+ return status;
+}
+
+/** Do validity checks on a parsed intro cell after decryption; some of
+ * these are not done in rend_service_parse_intro_plaintext() itself because
+ * they depend on a lot of other state and would make it hard to unit test.
+ * Returns >= 0 if successful or < 0 if the intro cell is invalid, and
+ * optionally writes out an error message for logging. If an err_msg
+ * pointer is provided, it is the caller's responsibility to free any
+ * provided message.
+ */
+
+int
+rend_service_validate_intro_late(const rend_intro_cell_t *intro,
+ char **err_msg_out)
+{
+ int status = 0;
+
+ if (!intro) {
+ if (err_msg_out)
+ *err_msg_out =
+ tor_strdup("NULL intro cell passed to "
+ "rend_service_validate_intro_late()");
+
+ status = -1;
+ goto err;
+ }
+
+ if (intro->version == 3 && intro->parsed) {
+ if (!(intro->u.v3.auth_type == REND_NO_AUTH ||
+ intro->u.v3.auth_type == REND_BASIC_AUTH ||
+ intro->u.v3.auth_type == REND_STEALTH_AUTH)) {
+ /* This is an informative message, not an error, as in the old code */
+ if (err_msg_out)
+ tor_asprintf(err_msg_out,
+ "unknown authorization type %d",
+ intro->u.v3.auth_type);
+ }
+ }
+
+ err:
+ return status;
+}
+
+/** 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);
+ oldstate = oldcirc->build_state;
+ tor_assert(oldstate);
+
+ if (oldstate->service_pending_final_cpath_ref == 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'",
+ safe_str(extend_info_describe(oldstate->chosen_exit)));
+
+ /* You'd think Single Onion Services would want to retry the rendezvous
+ * using a direct connection. But if it's blocked by a firewall, or the
+ * service is IPv6-only, or the rend point avoiding becoming a one-hop
+ * proxy, we need a 3-hop connection. */
+ 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'.",
+ safe_str(extend_info_describe(oldstate->chosen_exit)));
+ return;
+ }
+ newstate = newcirc->build_state;
+ tor_assert(newstate);
+ newstate->failure_count = oldstate->failure_count+1;
+ newstate->expiry_time = oldstate->expiry_time;
+ newstate->service_pending_final_cpath_ref =
+ oldstate->service_pending_final_cpath_ref;
+ ++(newstate->service_pending_final_cpath_ref->refcount);
+
+ 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;
+ int flags = CIRCLAUNCH_NEED_UPTIME|CIRCLAUNCH_IS_INTERNAL;
+ const or_options_t *options = get_options();
+ extend_info_t *launch_ei = intro->extend_info;
+ extend_info_t *direct_ei = NULL;
+
- /* Are we in single onion mode? */
- if (rend_service_allow_non_anonymous_connection(options)) {
++ /* Are we in single onion mode?
++ *
++ * We only use a one-hop path on the first attempt. If the first attempt
++ * fails, we use a 3-hop path for reachability / reliability.
++ * (Unlike v3, retries is incremented by the caller after it calls this
++ * function.)
++ */
++ if (rend_service_allow_non_anonymous_connection(options) &&
++ intro->circuit_retries == 0) {
+ /* Do we have a descriptor for the node?
+ * We've either just chosen it from the consensus, or we've just reviewed
+ * our intro points to see which ones are still valid, and deleted the ones
+ * that aren't in the consensus any more. */
+ const node_t *node = node_get_by_id(launch_ei->identity_digest);
+ if (BUG(!node)) {
+ /* The service has kept an intro point after it went missing from the
+ * consensus. If we did anything else here, it would be a consensus
+ * distinguisher. Which are less of an issue for single onion services,
+ * but still a bug. */
+ return -1;
+ }
+ /* Can we connect to the node directly? If so, replace launch_ei
+ * (a multi-hop extend_info) with one suitable for direct connection. */
+ if (rend_service_use_direct_connection_node(options, node)) {
+ direct_ei = extend_info_from_node(node, 1);
+ if (BUG(!direct_ei)) {
+ /* rend_service_use_direct_connection_node and extend_info_from_node
+ * disagree about which addresses on this node are permitted. This
+ * should never happen. Avoiding the connection is a safe response. */
+ return -1;
+ }
+ flags = flags | CIRCLAUNCH_ONEHOP_TUNNEL;
+ launch_ei = direct_ei;
+ }
+ }
+ /* launch_ei is either intro->extend_info, or has been replaced with a valid
+ * extend_info for single onion service direct connection. */
+ tor_assert(launch_ei);
+ /* We must have the same intro when making a direct connection. */
+ tor_assert(tor_memeq(intro->extend_info->identity_digest,
+ launch_ei->identity_digest,
+ DIGEST_LEN));
+
+ log_info(LD_REND,
+ "Launching circuit to introduction point %s%s%s for service %s",
+ safe_str_client(extend_info_describe(intro->extend_info)),
+ direct_ei ? " via direct address " : "",
+ direct_ei ? safe_str_client(extend_info_describe(direct_ei)) : "",
+ 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,
+ launch_ei, flags);
+
+ if (!launched) {
+ log_info(LD_REND,
+ "Can't launch circuit to establish introduction at %s%s%s.",
+ safe_str_client(extend_info_describe(intro->extend_info)),
+ direct_ei ? " via direct address " : "",
+ direct_ei ? safe_str_client(extend_info_describe(direct_ei)) : ""
+ );
+ extend_info_free(direct_ei);
+ return -1;
+ }
+ /* We must have the same exit node even if cannibalized or direct connection.
+ */
+ tor_assert(tor_memeq(intro->extend_info->identity_digest,
+ launched->build_state->chosen_exit->identity_digest,
+ DIGEST_LEN));
+
+ launched->rend_data = rend_data_service_create(service->service_id,
+ service->pk_digest, NULL,
+ service->auth_type);
+ launched->intro_key = crypto_pk_dup_key(intro->intro_key);
+ if (launched->base_.state == CIRCUIT_STATE_OPEN)
+ rend_service_intro_has_opened(launched);
+ extend_info_free(direct_ei);
+ return 0;
+}
+
+/** Return the number of introduction points that are established for the
+ * given service. */
+static unsigned int
+count_established_intro_points(const rend_service_t *service)
+{
+ unsigned int num = 0;
+
+ SMARTLIST_FOREACH(service->intro_nodes, rend_intro_point_t *, intro,
+ num += intro->circuit_established
+ );
+ return num;
+}
+
+/** Return the number of introduction points that are or are being
+ * established for the given service. This function iterates over all
+ * circuit and count those that are linked to the service and are waiting
+ * for the intro point to respond. */
+static unsigned int
+count_intro_point_circuits(const rend_service_t *service)
+{
+ unsigned int num_ipos = 0;
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ 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_circuit_pk_digest_eq(oc, (uint8_t *) service->pk_digest)) {
+ num_ipos++;
+ }
+ }
+ }
+ SMARTLIST_FOREACH_END(circ);
+ return num_ipos;
+}
+
+/* Given a buffer of at least RELAY_PAYLOAD_SIZE bytes in <b>cell_body_out</b>,
+ write the body of a legacy ESTABLISH_INTRO cell in it. Use <b>intro_key</b>
+ as the intro point auth key, and <b>rend_circ_nonce</b> as the circuit
+ crypto material. On success, fill <b>cell_body_out</b> and return the number
+ of bytes written. On fail, return -1.
+ */
+ssize_t
+rend_service_encode_establish_intro_cell(char *cell_body_out,
+ size_t cell_body_out_len,
+ crypto_pk_t *intro_key,
+ const char *rend_circ_nonce)
+{
+ int retval = -1;
+ int r;
+ int len = 0;
+ char auth[DIGEST_LEN + 9];
+
+ tor_assert(intro_key);
+ tor_assert(rend_circ_nonce);
+
+ /* Build the payload for a RELAY_ESTABLISH_INTRO cell. */
+ r = crypto_pk_asn1_encode(intro_key, cell_body_out+2,
+ RELAY_PAYLOAD_SIZE-2);
+ if (r < 0) {
+ log_warn(LD_BUG, "Internal error; failed to establish intro point.");
+ goto err;
+ }
+ len = r;
+ set_uint16(cell_body_out, htons((uint16_t)len));
+ len += 2;
+ memcpy(auth, rend_circ_nonce, DIGEST_LEN);
+ memcpy(auth+DIGEST_LEN, "INTRODUCE", 9);
+ if (crypto_digest(cell_body_out+len, auth, DIGEST_LEN+9))
+ goto err;
+ len += 20;
+ r = crypto_pk_private_sign_digest(intro_key, cell_body_out+len,
+ cell_body_out_len - len,
+ cell_body_out, len);
+ if (r<0) {
+ log_warn(LD_BUG, "Internal error: couldn't sign introduction request.");
+ goto err;
+ }
+ len += r;
+
+ retval = len;
+
+ err:
+ memwipe(auth, 0, sizeof(auth));
+
+ return retval;
+}
+
+/** 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;
+ char buf[RELAY_PAYLOAD_SIZE];
+ char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
+ unsigned int expiring_nodes_len, num_ip_circuits, valid_ip_circuits = 0;
+ int reason = END_CIRC_REASON_TORPROTOCOL;
+ const char *rend_pk_digest;
+
+ tor_assert(circuit->base_.purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO);
+ assert_circ_anonymity_ok(circuit, get_options());
+ tor_assert(circuit->cpath);
+ tor_assert(circuit->rend_data);
+ /* XXX: This is version 2 specific (only on supported). */
+ rend_pk_digest = (char *) rend_data_get_pk_digest(circuit->rend_data, NULL);
+
+ base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32+1,
+ rend_pk_digest, REND_SERVICE_ID_LEN);
+
+ service = rend_service_get_by_pk_digest(rend_pk_digest);
+ if (!service) {
+ log_warn(LD_REND, "Unrecognized service ID %s on introduction circuit %u.",
+ safe_str_client(serviceid), (unsigned)circuit->base_.n_circ_id);
+ reason = END_CIRC_REASON_NOSUCHSERVICE;
+ goto err;
+ }
+
+ /* Take the current amount of expiring nodes and the current amount of IP
+ * circuits and compute how many valid IP circuits we have. */
+ expiring_nodes_len = (unsigned int) smartlist_len(service->expiring_nodes);
+ num_ip_circuits = count_intro_point_circuits(service);
+ /* Let's avoid an underflow. The valid_ip_circuits is initialized to 0 in
+ * case this condition turns out false because it means that all circuits
+ * are expiring so we need to keep this circuit. */
+ if (num_ip_circuits > expiring_nodes_len) {
+ valid_ip_circuits = num_ip_circuits - expiring_nodes_len;
+ }
+
+ /* If we already have enough introduction circuits for this service,
+ * redefine this one as a general circuit or close it, depending.
+ * Subtract the amount of expiring nodes here because the circuits are
+ * still opened. */
+ if (valid_ip_circuits > service->n_intro_points_wanted) {
+ const or_options_t *options = get_options();
+ /* Remove the intro point associated with this circuit, it's being
+ * repurposed or closed thus cleanup memory. */
+ rend_intro_point_t *intro = find_intro_point(circuit);
+ if (intro != NULL) {
+ smartlist_remove(service->intro_nodes, intro);
+ rend_intro_point_free(intro);
+ }
+
+ if (options->ExcludeNodes) {
+ /* XXXX in some future version, we can test whether the transition is
+ allowed or not given the actual nodes in the circuit. But for now,
+ this case, we might as well close the thing. */
+ log_info(LD_CIRC|LD_REND, "We have just finished an introduction "
+ "circuit, but we already have enough. Closing it.");
+ reason = END_CIRC_REASON_NONE;
+ goto err;
+ } else {
+ tor_assert(circuit->build_state->is_internal);
+ log_info(LD_CIRC|LD_REND, "We have just finished an introduction "
+ "circuit, but we already have enough. Redefining purpose to "
+ "general; leaving as internal.");
+
+ if (circuit_should_use_vanguards(TO_CIRCUIT(circuit)->purpose)) {
+ circuit_change_purpose(TO_CIRCUIT(circuit),
+ CIRCUIT_PURPOSE_HS_VANGUARDS);
+ } else {
+ circuit_change_purpose(TO_CIRCUIT(circuit), CIRCUIT_PURPOSE_C_GENERAL);
+ }
+
+ {
+ rend_data_free(circuit->rend_data);
+ circuit->rend_data = NULL;
+ }
+ {
+ crypto_pk_t *intro_key = circuit->intro_key;
+ circuit->intro_key = NULL;
+ crypto_pk_free(intro_key);
+ }
+
+ circuit_has_opened(circuit);
+ goto done;
+ }
+ }
+
+ log_info(LD_REND,
+ "Established circuit %u as introduction point for service %s",
+ (unsigned)circuit->base_.n_circ_id, serviceid);
+ circuit_log_path(LOG_INFO, LD_REND, circuit);
+
+ /* Send the ESTABLISH_INTRO cell */
+ {
+ ssize_t len;
+ len = rend_service_encode_establish_intro_cell(buf, sizeof(buf),
+ circuit->intro_key,
+ circuit->cpath->prev->rend_circ_nonce);
+ if (len < 0) {
+ reason = END_CIRC_REASON_INTERNAL;
+ goto err;
+ }
+
+ 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 %u",
+ serviceid, (unsigned)circuit->base_.n_circ_id);
+ goto done;
+ }
+ }
+
+ /* We've attempted to use this circuit */
+ pathbias_count_use_attempt(circuit);
+
+ goto done;
+
+ err:
+ circuit_mark_for_close(TO_CIRCUIT(circuit), reason);
+ done:
+ memwipe(buf, 0, sizeof(buf));
+ memwipe(serviceid, 0, sizeof(serviceid));
+
+ return;
+}
+
+/** 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 uint8_t *request,
+ size_t request_len)
+{
+ rend_service_t *service;
+ rend_intro_point_t *intro;
+ char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
+ (void) request;
+ (void) request_len;
+ tor_assert(circuit->rend_data);
+ /* XXX: This is version 2 specific (only supported one for now). */
+ const char *rend_pk_digest =
+ (char *) rend_data_get_pk_digest(circuit->rend_data, NULL);
+
+ if (circuit->base_.purpose != CIRCUIT_PURPOSE_S_ESTABLISH_INTRO) {
+ log_warn(LD_PROTOCOL,
+ "received INTRO_ESTABLISHED cell on non-intro circuit.");
+ goto err;
+ }
+ service = rend_service_get_by_pk_digest(rend_pk_digest);
+ if (!service) {
+ log_warn(LD_REND, "Unknown service on introduction circuit %u.",
+ (unsigned)circuit->base_.n_circ_id);
+ goto err;
+ }
+ base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32 + 1,
+ rend_pk_digest, REND_SERVICE_ID_LEN);
+ /* We've just successfully established a intro circuit to one of our
+ * introduction point, account for it. */
+ intro = find_intro_point(circuit);
+ if (intro == NULL) {
+ log_warn(LD_REND,
+ "Introduction circuit established without a rend_intro_point_t "
+ "object for service %s on circuit %u",
+ safe_str_client(serviceid), (unsigned)circuit->base_.n_circ_id);
+ goto err;
+ }
+ intro->circuit_established = 1;
+ /* We might not have every introduction point ready but at this point we
+ * know that the descriptor needs to be uploaded. */
+ service->desc_is_dirty = time(NULL);
+ circuit_change_purpose(TO_CIRCUIT(circuit), CIRCUIT_PURPOSE_S_INTRO);
+
+ log_info(LD_REND,
+ "Received INTRO_ESTABLISHED cell on circuit %u for service %s",
+ (unsigned)circuit->base_.n_circ_id, serviceid);
+
+ /* Getting a valid INTRODUCE_ESTABLISHED means we've successfully
+ * used the circ */
+ pathbias_mark_use_success(circuit);
+
+ 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;
+ const char *rend_cookie, *rend_pk_digest;
+
+ tor_assert(circuit->base_.purpose == CIRCUIT_PURPOSE_S_CONNECT_REND);
+ tor_assert(circuit->cpath);
+ tor_assert(circuit->build_state);
+ assert_circ_anonymity_ok(circuit, get_options());
+ tor_assert(circuit->rend_data);
+
+ /* XXX: This is version 2 specific (only one supported). */
+ rend_pk_digest = (char *) rend_data_get_pk_digest(circuit->rend_data,
+ NULL);
+ rend_cookie = circuit->rend_data->rend_cookie;
+
+ /* Declare the circuit dirty to avoid reuse, and for path-bias. We set the
+ * timestamp regardless of its content because that circuit could have been
+ * cannibalized so in any cases, we are about to use that circuit more. */
+ circuit->base_.timestamp_dirty = time(NULL);
+
+ /* This may be redundant */
+ pathbias_count_use_attempt(circuit);
+
+ hop = circuit->build_state->service_pending_final_cpath_ref->cpath;
+
+ base16_encode(hexcookie,9, rend_cookie,4);
+ base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32+1,
+ rend_pk_digest, REND_SERVICE_ID_LEN);
+
+ log_info(LD_REND,
+ "Done building circuit %u to rendezvous with "
+ "cookie %s for service %s",
+ (unsigned)circuit->base_.n_circ_id, hexcookie, serviceid);
+ circuit_log_path(LOG_INFO, LD_REND, circuit);
+
+ /* Clear the 'in-progress HS circ has timed out' flag for
+ * consistency with what happens on the client side; this line has
+ * no effect on Tor's behaviour. */
+ circuit->hs_circ_has_timed_out = 0;
+
+ /* If hop is NULL, another rend circ has already connected to this
+ * rend point. Close this circ. */
+ if (hop == NULL) {
+ log_info(LD_REND, "Another rend circ has already reached this rend point; "
+ "closing this rend circ.");
+ reason = END_CIRC_REASON_NONE;
+ goto err;
+ }
+
+ /* Remove our final cpath element from the reference, so that no
+ * other circuit will try to use it. Store it in
+ * pending_final_cpath for now to ensure that it will be freed if
+ * our rendezvous attempt fails. */
+ circuit->build_state->pending_final_cpath = hop;
+ circuit->build_state->service_pending_final_cpath_ref->cpath = NULL;
+
+ service = rend_service_get_by_pk_digest(rend_pk_digest);
+ if (!service) {
+ log_warn(LD_GENERAL, "Internal error: unrecognized service ID on "
+ "rendezvous circuit.");
+ reason = END_CIRC_REASON_INTERNAL;
+ goto err;
+ }
+
+ /* All we need to do is send a RELAY_RENDEZVOUS1 cell... */
+ memcpy(buf, rend_cookie, REND_COOKIE_LEN);
+ if (crypto_dh_get_public(hop->rend_dh_handshake_state,
+ buf+REND_COOKIE_LEN, DH1024_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+DH1024_KEY_LEN, hop->rend_circ_nonce,
+ DIGEST_LEN);
+
+ /* Send the cell */
+ if (relay_send_command_from_edge(0, TO_CIRCUIT(circuit),
+ RELAY_COMMAND_RENDEZVOUS1,
+ buf, HS_LEGACY_RENDEZVOUS_CELL_SIZE,
+ circuit->cpath->prev)<0) {
+ log_warn(LD_GENERAL, "Couldn't send RENDEZVOUS1 cell.");
+ goto done;
+ }
+
+ crypto_dh_free(hop->rend_dh_handshake_state);
+ hop->rend_dh_handshake_state = NULL;
+
+ /* Append the cpath entry. */
+ hop->state = CPATH_STATE_OPEN;
+ /* set the windows to default. these are the windows
+ * that the service thinks the client 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_change_purpose(TO_CIRCUIT(circuit), CIRCUIT_PURPOSE_S_REND_JOINED);
+
+ goto done;
+
+ err:
+ circuit_mark_for_close(TO_CIRCUIT(circuit), reason);
+ done:
+ memwipe(buf, 0, sizeof(buf));
+ memwipe(serviceid, 0, sizeof(serviceid));
+ memwipe(hexcookie, 0, sizeof(hexcookie));
+
+ return;
+}
+
+/*
+ * 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,
+ (uint8_t *) pk_digest, CIRCUIT_PURPOSE_S_INTRO))) {
+ if (tor_memeq(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,
+ (uint8_t *) pk_digest,
+ CIRCUIT_PURPOSE_S_ESTABLISH_INTRO))) {
+ if (tor_memeq(circ->build_state->chosen_exit->identity_digest,
+ intro->extend_info->identity_digest, DIGEST_LEN) &&
+ circ->rend_data) {
+ return circ;
+ }
+ }
+ return NULL;
+}
+
+/** Return the corresponding introdution point using the circuit <b>circ</b>
+ * found in the <b>service</b>. NULL is returned if not found. */
+static rend_intro_point_t *
+find_expiring_intro_point(rend_service_t *service, origin_circuit_t *circ)
+{
+ tor_assert(service);
+ tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO ||
+ TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_INTRO);
+
+ SMARTLIST_FOREACH(service->expiring_nodes, rend_intro_point_t *,
+ intro_point,
+ if (crypto_pk_eq_keys(intro_point->intro_key, circ->intro_key)) {
+ return intro_point;
+ });
+
+ return NULL;
+}
+
+/** Return a pointer to the rend_intro_point_t corresponding to the
+ * service-side introduction circuit <b>circ</b>. */
+static rend_intro_point_t *
+find_intro_point(origin_circuit_t *circ)
+{
+ const char *serviceid;
+ rend_service_t *service = NULL;
+
+ tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO ||
+ TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_INTRO);
+ tor_assert(circ->rend_data);
+ serviceid = rend_data_get_address(circ->rend_data);
+
+ SMARTLIST_FOREACH(rend_service_list, rend_service_t *, s,
+ if (tor_memeq(s->service_id, serviceid, REND_SERVICE_ID_LEN_BASE32)) {
+ service = s;
+ break;
+ });
+
+ if (service == NULL) return NULL;
+
+ SMARTLIST_FOREACH(service->intro_nodes, rend_intro_point_t *, intro_point,
+ if (crypto_pk_eq_keys(intro_point->intro_key, circ->intro_key)) {
+ return intro_point;
+ });
+
+ return NULL;
+}
+
+/** Upload the rend_encoded_v2_service_descriptor_t's in <b>descs</b>
+ * associated with the rend_service_descriptor_t <b>renddesc</b> to
+ * the responsible hidden service directories OR the hidden service
+ * directories specified by <b>hs_dirs</b>; <b>service_id</b> and
+ * <b>seconds_valid</b> are only passed for logging purposes.
+ */
+void
+directory_post_to_hs_dir(rend_service_descriptor_t *renddesc,
+ smartlist_t *descs, smartlist_t *hs_dirs,
+ const char *service_id, int seconds_valid)
+{
+ int i, j, failed_upload = 0;
+ smartlist_t *responsible_dirs = smartlist_new();
+ smartlist_t *successful_uploads = smartlist_new();
+ routerstatus_t *hs_dir;
+ for (i = 0; i < smartlist_len(descs); i++) {
+ rend_encoded_v2_service_descriptor_t *desc = smartlist_get(descs, i);
+ /** If any HSDirs are specified, they should be used instead of
+ * the responsible directories */
+ if (hs_dirs && smartlist_len(hs_dirs) > 0) {
+ smartlist_add_all(responsible_dirs, hs_dirs);
+ } else {
+ /* 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.");
+ control_event_hs_descriptor_upload(service_id,
+ "UNKNOWN",
+ "UNKNOWN", NULL);
+ goto done;
+ }
+ }
+ for (j = 0; j < smartlist_len(responsible_dirs); j++) {
+ char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
+ char *hs_dir_ip;
+ const node_t *node;
+ rend_data_t *rend_data;
+ hs_dir = smartlist_get(responsible_dirs, j);
+ if (smartlist_contains_digest(renddesc->successful_uploads,
+ hs_dir->identity_digest))
+ /* Don't upload descriptor if we succeeded in doing so last time. */
+ continue;
+ node = node_get_by_id(hs_dir->identity_digest);
+ if (!node || !node_has_preferred_descriptor(node,0)) {
+ log_info(LD_REND, "Not launching upload for for v2 descriptor to "
+ "hidden service directory %s; we don't have its "
+ "router descriptor. Queuing for later upload.",
+ safe_str_client(routerstatus_describe(hs_dir)));
+ failed_upload = -1;
+ continue;
+ }
+ /* Send publish request. */
+
+ /* We need the service ID to identify which service did the upload
+ * request. Lookup is made in rend_service_desc_has_uploaded(). */
+ rend_data = rend_data_client_create(service_id, desc->desc_id, NULL,
+ REND_NO_AUTH);
+ directory_request_t *req =
+ directory_request_new(DIR_PURPOSE_UPLOAD_RENDDESC_V2);
+ directory_request_set_routerstatus(req, hs_dir);
+ directory_request_set_indirection(req, DIRIND_ANONYMOUS);
+ directory_request_set_payload(req,
+ desc->desc_str, strlen(desc->desc_str));
+ directory_request_set_rend_query(req, rend_data);
+ directory_initiate_request(req);
+ directory_request_free(req);
+
+ rend_data_free(rend_data);
+ 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, "Launching upload 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);
+ control_event_hs_descriptor_upload(service_id,
+ hs_dir->identity_digest,
+ desc_id_base32, NULL);
+ tor_free(hs_dir_ip);
+ /* Remember successful upload to this router for next time. */
+ if (!smartlist_contains_digest(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_new();
+ SMARTLIST_FOREACH(successful_uploads, const char *, c, {
+ if (!smartlist_contains_digest(renddesc->successful_uploads, c)) {
+ char *hsdir_id = tor_memdup(c, DIGEST_LEN);
+ smartlist_add(renddesc->successful_uploads, hsdir_id);
+ }
+ });
+ }
+ done:
+ 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;
+
+ 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_new();
+ smartlist_t *client_cookies = smartlist_new();
+ /* 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_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;
+ }
+ rend_get_service_id(service->desc->pk, serviceid);
+ if (get_options()->PublishHidServDescriptors) {
+ /* Post the current descriptors to the hidden service directories. */
+ log_info(LD_REND, "Launching upload for hidden service %s",
+ serviceid);
+ directory_post_to_hs_dir(service->desc, descs, NULL, 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;
+ }
+ if (get_options()->PublishHidServDescriptors) {
+ directory_post_to_hs_dir(service->desc, descs, NULL, 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;
+ if (get_options()->PublishHidServDescriptors) {
+ log_info(LD_REND, "Successfully uploaded v2 rend descriptors!");
+ } else {
+ log_info(LD_REND, "Successfully stored created 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;
+}
+
+/** Return the number of INTRODUCE2 cells this hidden service has received
+ * from this intro point. */
+static int
+intro_point_accepted_intro_count(rend_intro_point_t *intro)
+{
+ return intro->accepted_introduce2_count;
+}
+
+/** Return non-zero iff <b>intro</b> should 'expire' now (i.e. we
+ * should stop publishing it in new descriptors and eventually close
+ * it). */
+static int
+intro_point_should_expire_now(rend_intro_point_t *intro,
+ time_t now)
+{
+ tor_assert(intro != NULL);
+
+ if (intro->time_published == -1) {
+ /* Don't expire an intro point if we haven't even published it yet. */
+ return 0;
+ }
+
+ if (intro_point_accepted_intro_count(intro) >=
+ intro->max_introductions) {
+ /* This intro point has been used too many times. Expire it now. */
+ return 1;
+ }
+
+ if (intro->time_to_expire == -1) {
+ /* This intro point has been published, but we haven't picked an
+ * expiration time for it. Pick one now. */
+ int intro_point_lifetime_seconds =
+ crypto_rand_int_range(INTRO_POINT_LIFETIME_MIN_SECONDS,
+ INTRO_POINT_LIFETIME_MAX_SECONDS);
+
+ /* Start the expiration timer now, rather than when the intro
+ * point was first published. There shouldn't be much of a time
+ * difference. */
+ intro->time_to_expire = now + intro_point_lifetime_seconds;
+
+ return 0;
+ }
+
+ /* This intro point has a time to expire set already. Use it. */
+ return (now >= intro->time_to_expire);
+}
+
+/** Iterate over intro points in the given service and remove the invalid
+ * ones. For an intro point object to be considered invalid, the circuit
+ * _and_ node need to have disappeared.
+ *
+ * If the intro point should expire, it's placed into the expiring_nodes
+ * list of the service and removed from the active intro nodes list.
+ *
+ * If <b>exclude_nodes</b> is not NULL, add the valid nodes to it.
+ *
+ * If <b>retry_nodes</b> is not NULL, add the valid node to it if the
+ * circuit disappeared but the node is still in the consensus. */
+static void
+remove_invalid_intro_points(rend_service_t *service,
+ smartlist_t *exclude_nodes,
+ smartlist_t *retry_nodes, time_t now)
+{
+ tor_assert(service);
+
+ /* Remove any expired nodes that doesn't have a circuit. */
+ SMARTLIST_FOREACH_BEGIN(service->expiring_nodes, rend_intro_point_t *,
+ intro) {
+ origin_circuit_t *intro_circ =
+ find_intro_circuit(intro, service->pk_digest);
+ if (intro_circ) {
+ continue;
+ }
+ /* No more circuit, cleanup the into point object. */
+ SMARTLIST_DEL_CURRENT(service->expiring_nodes, intro);
+ rend_intro_point_free(intro);
+ } SMARTLIST_FOREACH_END(intro);
+
+ SMARTLIST_FOREACH_BEGIN(service->intro_nodes, rend_intro_point_t *,
+ intro) {
+ /* Find the introduction point node object. */
+ const node_t *node =
+ node_get_by_id(intro->extend_info->identity_digest);
+ /* Find the intro circuit, this might be NULL. */
+ origin_circuit_t *intro_circ =
+ find_intro_circuit(intro, service->pk_digest);
+
+ /* Add the valid node to the exclusion list so we don't try to establish
+ * an introduction point to it again. */
+ if (node && exclude_nodes) {
+ smartlist_add(exclude_nodes, (void*) node);
+ }
+
+ /* First, make sure we still have a valid circuit for this intro point.
+ * If we dont, we'll give up on it and make a new one. */
+ if (intro_circ == NULL) {
+ log_info(LD_REND, "Attempting to retry on %s as intro point for %s"
+ " (circuit disappeared).",
+ safe_str_client(extend_info_describe(intro->extend_info)),
+ safe_str_client(service->service_id));
+ /* We've lost the circuit for this intro point, flag it so it can be
+ * accounted for when considiring uploading a descriptor. */
+ intro->circuit_established = 0;
+
+ /* Node is gone or we've reached our maximum circuit creationg retry
+ * count, clean up everything, we'll find a new one. */
+ if (node == NULL ||
+ intro->circuit_retries >= MAX_INTRO_POINT_CIRCUIT_RETRIES) {
+ rend_intro_point_free(intro);
+ SMARTLIST_DEL_CURRENT(service->intro_nodes, intro);
+ /* We've just killed the intro point, nothing left to do. */
+ continue;
+ }
+
+ /* The intro point is still alive so let's try to use it again because
+ * we have a published descriptor containing it. Keep the intro point
+ * in the intro_nodes list because it's still valid, we are rebuilding
+ * a circuit to it. */
+ if (retry_nodes) {
+ smartlist_add(retry_nodes, intro);
+ }
+ }
+ /* else, the circuit is valid so in both cases, node being alive or not,
+ * we leave the circuit and intro point object as is. Closing the
+ * circuit here would leak new consensus timing and freeing the intro
+ * point object would make the intro circuit unusable. */
+
+ /* Now, check if intro point should expire. If it does, queue it so
+ * it can be cleaned up once it has been replaced properly. */
+ if (intro_point_should_expire_now(intro, now)) {
+ log_info(LD_REND, "Expiring %s as intro point for %s.",
+ safe_str_client(extend_info_describe(intro->extend_info)),
+ safe_str_client(service->service_id));
+ /* We might have put it in the retry list if so, undo. */
+ if (retry_nodes) {
+ smartlist_remove(retry_nodes, intro);
+ }
+ smartlist_add(service->expiring_nodes, intro);
+ SMARTLIST_DEL_CURRENT(service->intro_nodes, intro);
+ /* Intro point is expired, we need a new one thus don't consider it
+ * anymore has a valid established intro point. */
+ intro->circuit_established = 0;
+ }
+ } SMARTLIST_FOREACH_END(intro);
+}
+
+/** A new descriptor has been successfully uploaded for the given
+ * <b>rend_data</b>. Remove and free the expiring nodes from the associated
+ * service. */
+void
+rend_service_desc_has_uploaded(const rend_data_t *rend_data)
+{
+ rend_service_t *service;
+ const char *onion_address;
+
+ tor_assert(rend_data);
+
+ onion_address = rend_data_get_address(rend_data);
+
+ service = rend_service_get_by_service_id(onion_address);
+ if (service == NULL) {
+ return;
+ }
+
+ SMARTLIST_FOREACH_BEGIN(service->expiring_nodes, rend_intro_point_t *,
+ intro) {
+ origin_circuit_t *intro_circ =
+ find_intro_circuit(intro, service->pk_digest);
+ if (intro_circ != NULL) {
+ circuit_mark_for_close(TO_CIRCUIT(intro_circ),
+ END_CIRC_REASON_FINISHED);
+ }
+ SMARTLIST_DEL_CURRENT(service->expiring_nodes, intro);
+ rend_intro_point_free(intro);
+ } SMARTLIST_FOREACH_END(intro);
+}
+
+/** Don't try to build more than this many circuits before giving up
+ * for a while. Dynamically calculated based on the configured number of
+ * introduction points for the service, n_intro_points_wanted. */
+static int
+rend_max_intro_circs_per_period(unsigned int n_intro_points_wanted)
+{
+ /* Allow all but one of the initial connections to fail and be
+ * retried. (If all fail, we *want* to wait, because something is broken.) */
+ tor_assert(n_intro_points_wanted <= NUM_INTRO_POINTS_MAX);
+
+ /* For the normal use case, 3 intro points plus 2 extra for performance and
+ * allow that twice because once every 24h or so, we can do it twice for two
+ * descriptors that is the current one and the next one. So (3 + 2) * 2 ==
+ * 12 allowed attempts for one period. */
+ return ((n_intro_points_wanted + NUM_INTRO_POINTS_EXTRA) * 2);
+}
+
+/** For every service, check how many intro points it currently has, and:
+ * - Invalidate introdution points based on specific criteria, see
+ * remove_invalid_intro_points comments.
+ * - Pick new intro points as necessary.
+ * - Launch circuits to any new intro points.
+ *
+ * This is called once a second by the main loop.
+ */
+void
+rend_consider_services_intro_points(time_t now)
+{
+ int i;
+ const or_options_t *options = get_options();
+ /* Are we in single onion mode? */
+ const int allow_direct = rend_service_allow_non_anonymous_connection(
+ get_options());
+ /* List of nodes we need to _exclude_ when choosing a new node to
+ * establish an intro point to. */
+ smartlist_t *exclude_nodes;
+ /* List of nodes we need to retry to build a circuit on them because the
+ * node is valid but circuit died. */
+ smartlist_t *retry_nodes;
+
+ if (!have_completed_a_circuit())
+ return;
+
+ exclude_nodes = smartlist_new();
+ retry_nodes = smartlist_new();
+
+ SMARTLIST_FOREACH_BEGIN(rend_service_list, rend_service_t *, service) {
+ int r;
+ /* Number of intro points we want to open and add to the intro nodes
+ * list of the service. */
+ unsigned int n_intro_points_to_open;
+ /* Have an unsigned len so we can use it to compare values else gcc is
+ * not happy with unmatching signed comparaison. */
+ unsigned int intro_nodes_len;
+ /* Different service are allowed to have the same introduction point as
+ * long as they are on different circuit thus why we clear this list. */
+ smartlist_clear(exclude_nodes);
+ smartlist_clear(retry_nodes);
+
+ /* Cleanup the invalid intro points and save the node objects, if any,
+ * in the exclude_nodes and retry_nodes lists. */
+ remove_invalid_intro_points(service, exclude_nodes, retry_nodes, now);
+
+ /* This retry period is important here so we don't stress circuit
+ * creation. */
+
+ if (now > service->intro_period_started + INTRO_CIRC_RETRY_PERIOD) {
+ /* One period has elapsed:
+ * - if we stopped, we can try building circuits again,
+ * - if we haven't, we reset the circuit creation counts. */
+ rend_log_intro_limit(service, LOG_INFO);
+ service->intro_period_started = now;
+ service->n_intro_circuits_launched = 0;
+ } else if (service->n_intro_circuits_launched >=
+ rend_max_intro_circs_per_period(
+ service->n_intro_points_wanted)) {
+ /* We have failed too many times in this period; wait for the next
+ * one before we try to initiate any more connections. */
+ rend_log_intro_limit(service, LOG_WARN);
+ continue;
+ }
+
+ /* Let's try to rebuild circuit on the nodes we want to retry on. */
+ SMARTLIST_FOREACH_BEGIN(retry_nodes, rend_intro_point_t *, intro) {
+ r = rend_service_launch_establish_intro(service, intro);
+ if (r < 0) {
+ log_warn(LD_REND, "Error launching circuit to node %s for service %s.",
+ safe_str_client(extend_info_describe(intro->extend_info)),
+ safe_str_client(service->service_id));
+ /* Unable to launch a circuit to that intro point, remove it from
+ * the valid list so we can create a new one. */
+ smartlist_remove(service->intro_nodes, intro);
+ rend_intro_point_free(intro);
+ continue;
+ }
+ intro->circuit_retries++;
+ } SMARTLIST_FOREACH_END(intro);
+
+ /* Avoid mismatched signed comparaison below. */
+ intro_nodes_len = (unsigned int) smartlist_len(service->intro_nodes);
+
+ /* Quiescent state, we have more or the equal amount of wanted node for
+ * this service. Proceed to the next service. We can have more nodes
+ * because we launch extra preemptive circuits if our intro nodes list was
+ * originally empty for performance reasons. */
+ if (intro_nodes_len >= service->n_intro_points_wanted) {
+ continue;
+ }
+
+ /* Number of intro points we want to open which is the wanted amount minus
+ * the current amount of valid nodes. We know that this won't underflow
+ * because of the check above. */
+ n_intro_points_to_open = service->n_intro_points_wanted - intro_nodes_len;
+ if (intro_nodes_len == 0) {
+ /* We want to end up with n_intro_points_wanted 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 n_intro_points_wanted that complete. See proposal
+ * #155, section 4 for the rationale of this which is purely for
+ * performance.
+ *
+ * The ones after the first n_intro_points_to_open 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. */
+ n_intro_points_to_open += NUM_INTRO_POINTS_EXTRA;
+ }
+
+ for (i = 0; i < (int) n_intro_points_to_open; i++) {
+ const node_t *node;
+ rend_intro_point_t *intro;
+ router_crn_flags_t flags = CRN_NEED_UPTIME|CRN_NEED_DESC;
+ router_crn_flags_t direct_flags = flags;
+ direct_flags |= CRN_PREF_ADDR;
+ direct_flags |= CRN_DIRECT_CONN;
+
+ node = router_choose_random_node(exclude_nodes,
+ options->ExcludeNodes,
+ allow_direct ? direct_flags : flags);
+ /* If we are in single onion mode, retry node selection for a 3-hop
+ * path */
+ if (allow_direct && !node) {
+ log_info(LD_REND,
+ "Unable to find an intro point that we can connect to "
+ "directly for %s, falling back to a 3-hop path.",
+ safe_str_client(service->service_id));
+ node = router_choose_random_node(exclude_nodes,
+ options->ExcludeNodes, flags);
+ }
+
+ if (!node) {
+ log_warn(LD_REND,
+ "We only have %d introduction points established for %s; "
+ "wanted %u.",
+ smartlist_len(service->intro_nodes),
+ safe_str_client(service->service_id),
+ n_intro_points_to_open);
+ break;
+ }
+ /* Add the chosen node to the exclusion list in order to avoid picking
+ * it again in the next iteration. */
+ smartlist_add(exclude_nodes, (void*)node);
+ intro = tor_malloc_zero(sizeof(rend_intro_point_t));
+ /* extend_info is for clients, so we want the multi-hop primary ORPort,
+ * even if we are a single onion service and intend to connect to it
+ * directly ourselves. */
+ intro->extend_info = extend_info_from_node(node, 0);
+ if (BUG(intro->extend_info == NULL)) {
+ break;
+ }
+ intro->intro_key = crypto_pk_new();
+ const int fail = crypto_pk_generate_key(intro->intro_key);
+ tor_assert(!fail);
+ intro->time_published = -1;
+ intro->time_to_expire = -1;
+ intro->max_introductions =
+ crypto_rand_int_range(INTRO_POINT_MIN_LIFETIME_INTRODUCTIONS,
+ INTRO_POINT_MAX_LIFETIME_INTRODUCTIONS);
+ smartlist_add(service->intro_nodes, intro);
+ log_info(LD_REND, "Picked router %s as an intro point for %s.",
+ safe_str_client(node_describe(node)),
+ safe_str_client(service->service_id));
+ /* Establish new introduction circuit to our chosen intro point. */
+ r = rend_service_launch_establish_intro(service, intro);
+ if (r < 0) {
+ log_warn(LD_REND, "Error launching circuit to node %s for service %s.",
+ safe_str_client(extend_info_describe(intro->extend_info)),
+ safe_str_client(service->service_id));
+ /* This funcion will be called again by the main loop so this intro
+ * point without a intro circuit will be retried on or removed after
+ * a maximum number of attempts. */
+ }
+ }
+ } SMARTLIST_FOREACH_END(service);
+ smartlist_free(exclude_nodes);
+ smartlist_free(retry_nodes);
+}
+
+#define MIN_REND_INITIAL_POST_DELAY (30)
+#define MIN_REND_INITIAL_POST_DELAY_TESTING (5)
+
+/** 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;
+ const or_options_t *options = get_options();
+ int rendpostperiod = options->RendPostPeriod;
+ int rendinitialpostdelay = (options->TestingTorNetwork ?
+ MIN_REND_INITIAL_POST_DELAY_TESTING :
+ MIN_REND_INITIAL_POST_DELAY);
+
+ 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 rendinitialpostdelay seconds ensures that
+ * the descriptor is stable before being published. See comment below. */
+ service->next_upload_time =
+ now + rendinitialpostdelay + crypto_rand_int(2*rendpostperiod);
+ /* Single Onion Services prioritise availability over hiding their
+ * startup time, as their IP address is publicly discoverable anyway.
+ */
+ if (rend_service_reveal_startup_time(options)) {
+ service->next_upload_time = now + rendinitialpostdelay;
+ }
+ }
+ /* Does every introduction points have been established? */
+ unsigned int intro_points_ready =
+ count_established_intro_points(service) >=
+ service->n_intro_points_wanted;
+ if (intro_points_ready &&
+ (service->next_upload_time < now ||
+ (service->desc_is_dirty &&
+ service->desc_is_dirty < now-rendinitialpostdelay))) {
+ /* if it's time, or if the directory servers have a wrong service
+ * descriptor and ours has been stable for rendinitialpostdelay 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);
+ tor_log(severity, LD_GENERAL, "Service configured in %s:",
+ rend_service_escaped_dir(service));
+ 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) {
+ tor_log(severity, LD_GENERAL, " Intro point %d at %s: no circuit",
+ j, safe_name);
+ continue;
+ }
+ tor_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
+ * <b>circ</b>, and look up the port and address based on conn-\>port.
+ * Assign the actual conn-\>addr and conn-\>port. Return -2 on failure
+ * for which the circuit should be closed, -1 on other 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];
+ const char *rend_pk_digest;
+
+ 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");
+ rend_pk_digest = (char *) rend_data_get_pk_digest(circ->rend_data, NULL);
+ base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32+1,
+ rend_pk_digest, REND_SERVICE_ID_LEN);
+ service = rend_service_get_by_pk_digest(rend_pk_digest);
+ if (!service) {
+ log_warn(LD_REND, "Couldn't find any service associated with pk %s on "
+ "rendezvous circuit %u; closing.",
+ serviceid, (unsigned)circ->base_.n_circ_id);
+ return -2;
+ }
+ if (service->max_streams_per_circuit > 0) {
+ /* Enforce the streams-per-circuit limit, and refuse to provide a
+ * mapping if this circuit will exceed the limit. */
+#define MAX_STREAM_WARN_INTERVAL 600
+ static struct ratelim_t stream_ratelim =
+ RATELIM_INIT(MAX_STREAM_WARN_INTERVAL);
+ if (circ->rend_data->nr_streams >= service->max_streams_per_circuit) {
+ log_fn_ratelim(&stream_ratelim, LOG_WARN, LD_REND,
+ "Maximum streams per circuit limit reached on rendezvous "
+ "circuit %u; %s. Circuit has %d out of %d streams.",
+ (unsigned)circ->base_.n_circ_id,
+ service->max_streams_close_circuit ?
+ "closing circuit" :
+ "ignoring open stream request",
+ circ->rend_data->nr_streams,
+ service->max_streams_per_circuit);
+ return service->max_streams_close_circuit ? -2 : -1;
+ }
+ }
+
+ if (hs_set_conn_addr_port(service->ports, conn) == 0) {
+ /* Successfully set the port to the connection. We are done. */
+ return 0;
+ }
+
+ log_info(LD_REND,
+ "No virtual port mapping exists for port %d on service %s",
+ conn->base_.port, serviceid);
+
+ if (service->allow_unknown_ports)
+ return -1;
+ else
+ return -2;
+}
+
+/* Are HiddenServiceSingleHopMode and HiddenServiceNonAnonymousMode consistent?
+ */
+static int
+rend_service_non_anonymous_mode_consistent(const or_options_t *options)
+{
+ /* !! is used to make these options boolean */
+ return (!! options->HiddenServiceSingleHopMode ==
+ !! options->HiddenServiceNonAnonymousMode);
+}
+
+/* Do the options allow onion services to make direct (non-anonymous)
+ * connections to introduction or rendezvous points?
+ * Must only be called after options_validate_single_onion() has successfully
+ * checked onion service option consistency.
+ * Returns true if tor is in HiddenServiceSingleHopMode. */
+int
+rend_service_allow_non_anonymous_connection(const or_options_t *options)
+{
+ tor_assert(rend_service_non_anonymous_mode_consistent(options));
+ return options->HiddenServiceSingleHopMode ? 1 : 0;
+}
+
+/* Do the options allow us to reveal the exact startup time of the onion
+ * service?
+ * Single Onion Services prioritise availability over hiding their
+ * startup time, as their IP address is publicly discoverable anyway.
+ * Must only be called after options_validate_single_onion() has successfully
+ * checked onion service option consistency.
+ * Returns true if tor is in non-anonymous hidden service mode. */
+int
+rend_service_reveal_startup_time(const or_options_t *options)
+{
+ tor_assert(rend_service_non_anonymous_mode_consistent(options));
+ return rend_service_non_anonymous_mode_enabled(options);
+}
+
+/* Is non-anonymous mode enabled using the HiddenServiceNonAnonymousMode
+ * config option?
+ * Must only be called after options_validate_single_onion() has successfully
+ * checked onion service option consistency.
+ */
+int
+rend_service_non_anonymous_mode_enabled(const or_options_t *options)
+{
+ tor_assert(rend_service_non_anonymous_mode_consistent(options));
+ return options->HiddenServiceNonAnonymousMode ? 1 : 0;
+}
+
+#ifdef TOR_UNIT_TESTS
+
+STATIC void
+set_rend_service_list(smartlist_t *new_list)
+{
+ rend_service_list = new_list;
+}
+
+STATIC void
+set_rend_rend_service_staging_list(smartlist_t *new_list)
+{
+ rend_service_staging_list = new_list;
+}
+
+#endif /* defined(TOR_UNIT_TESTS) */
More information about the tor-commits
mailing list