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[tor-commits] [tor/master] Merge remote-tracking branch 'dgoulet/ticket27410_032_01'



commit 2ed0d240e8dea9a789bd6969112a1df4d0363947
Merge: 813019cc5 fa6d5dd26
Author: Nick Mathewson <nickm@xxxxxxxxxxxxxx>
Date:   Thu Sep 20 16:22:02 2018 -0400

    Merge remote-tracking branch 'dgoulet/ticket27410_032_01'

 changes/ticket27410        | 5 +++++
 src/feature/hs/hs_client.c | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --cc src/feature/hs/hs_client.c
index a6384b87a,000000000..fa7c78c8f
mode 100644,000000..100644
--- a/src/feature/hs/hs_client.c
+++ b/src/feature/hs/hs_client.c
@@@ -1,1886 -1,0 +1,1886 @@@
 +/* Copyright (c) 2016-2018, The Tor Project, Inc. */
 +/* See LICENSE for licensing information */
 +
 +/**
 + * \file hs_client.c
 + * \brief Implement next generation hidden service client functionality
 + **/
 +
 +#define HS_CLIENT_PRIVATE
 +
 +#include "core/or/or.h"
 +#include "feature/client/circpathbias.h"
 +#include "core/or/circuitbuild.h"
 +#include "core/or/circuitlist.h"
 +#include "core/or/circuituse.h"
 +#include "app/config/config.h"
 +#include "core/mainloop/connection.h"
 +#include "core/or/connection_edge.h"
 +#include "lib/crypt_ops/crypto_format.h"
 +#include "lib/crypt_ops/crypto_rand.h"
 +#include "lib/crypt_ops/crypto_util.h"
 +#include "feature/dircache/directory.h"
 +#include "feature/hs/hs_cache.h"
 +#include "feature/hs/hs_cell.h"
 +#include "feature/hs/hs_circuit.h"
 +#include "feature/hs/hs_circuitmap.h"
 +#include "feature/hs/hs_client.h"
 +#include "feature/hs/hs_control.h"
 +#include "feature/hs/hs_descriptor.h"
 +#include "feature/hs/hs_ident.h"
 +#include "core/crypto/hs_ntor.h"
 +#include "feature/nodelist/networkstatus.h"
 +#include "feature/nodelist/nodelist.h"
 +#include "core/or/reasons.h"
 +#include "feature/rend/rendclient.h"
 +#include "feature/relay/router.h"
 +#include "feature/nodelist/routerset.h"
 +
 +#include "core/or/cpath_build_state_st.h"
 +#include "feature/dircommon/dir_connection_st.h"
 +#include "core/or/entry_connection_st.h"
 +#include "core/or/extend_info_st.h"
 +#include "core/or/origin_circuit_st.h"
 +
 +/* Client-side authorizations for hidden services; map of service identity
 + * public key to hs_client_service_authorization_t *. */
 +static digest256map_t *client_auths = NULL;
 +
 +/* Return a human-readable string for the client fetch status code. */
 +static const char *
 +fetch_status_to_string(hs_client_fetch_status_t status)
 +{
 +  switch (status) {
 +  case HS_CLIENT_FETCH_ERROR:
 +    return "Internal error";
 +  case HS_CLIENT_FETCH_LAUNCHED:
 +    return "Descriptor fetch launched";
 +  case HS_CLIENT_FETCH_HAVE_DESC:
 +    return "Already have descriptor";
 +  case HS_CLIENT_FETCH_NO_HSDIRS:
 +    return "No more HSDir available to query";
 +  case HS_CLIENT_FETCH_NOT_ALLOWED:
 +    return "Fetching descriptors is not allowed";
 +  case HS_CLIENT_FETCH_MISSING_INFO:
 +    return "Missing directory information";
 +  case HS_CLIENT_FETCH_PENDING:
 +    return "Pending descriptor fetch";
 +  default:
 +    return "(Unknown client fetch status code)";
 +  }
 +}
 +
 +/* Return true iff tor should close the SOCKS request(s) for the descriptor
 + * fetch that ended up with this given status code. */
 +static int
 +fetch_status_should_close_socks(hs_client_fetch_status_t status)
 +{
 +  switch (status) {
 +  case HS_CLIENT_FETCH_NO_HSDIRS:
 +    /* No more HSDir to query, we can't complete the SOCKS request(s). */
 +  case HS_CLIENT_FETCH_ERROR:
 +    /* The fetch triggered an internal error. */
 +  case HS_CLIENT_FETCH_NOT_ALLOWED:
 +    /* Client is not allowed to fetch (FetchHidServDescriptors 0). */
 +    goto close;
 +  case HS_CLIENT_FETCH_MISSING_INFO:
 +  case HS_CLIENT_FETCH_HAVE_DESC:
 +  case HS_CLIENT_FETCH_PENDING:
 +  case HS_CLIENT_FETCH_LAUNCHED:
 +    /* The rest doesn't require tor to close the SOCKS request(s). */
 +    goto no_close;
 +  }
 +
 + no_close:
 +  return 0;
 + close:
 +  return 1;
 +}
 +
 +/* Cancel all descriptor fetches currently in progress. */
 +static void
 +cancel_descriptor_fetches(void)
 +{
 +  smartlist_t *conns =
 +    connection_list_by_type_state(CONN_TYPE_DIR, DIR_PURPOSE_FETCH_HSDESC);
 +  SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
 +    const hs_ident_dir_conn_t *ident = TO_DIR_CONN(conn)->hs_ident;
 +    if (BUG(ident == NULL)) {
 +      /* A directory connection fetching a service descriptor can't have an
 +       * empty hidden service identifier. */
 +      continue;
 +    }
 +    log_debug(LD_REND, "Marking for close a directory connection fetching "
 +                       "a hidden service descriptor for service %s.",
 +              safe_str_client(ed25519_fmt(&ident->identity_pk)));
 +    connection_mark_for_close(conn);
 +  } SMARTLIST_FOREACH_END(conn);
 +
 +  /* No ownership of the objects in this list. */
 +  smartlist_free(conns);
 +  log_info(LD_REND, "Hidden service client descriptor fetches cancelled.");
 +}
 +
 +/* Get all connections that are waiting on a circuit and flag them back to
 + * waiting for a hidden service descriptor for the given service key
 + * service_identity_pk. */
 +static void
 +flag_all_conn_wait_desc(const ed25519_public_key_t *service_identity_pk)
 +{
 +  tor_assert(service_identity_pk);
 +
 +  smartlist_t *conns =
 +    connection_list_by_type_state(CONN_TYPE_AP, AP_CONN_STATE_CIRCUIT_WAIT);
 +
 +  SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
 +    edge_connection_t *edge_conn;
 +    if (BUG(!CONN_IS_EDGE(conn))) {
 +      continue;
 +    }
 +    edge_conn = TO_EDGE_CONN(conn);
 +    if (edge_conn->hs_ident &&
 +        ed25519_pubkey_eq(&edge_conn->hs_ident->identity_pk,
 +                          service_identity_pk)) {
 +      connection_ap_mark_as_non_pending_circuit(TO_ENTRY_CONN(conn));
 +      conn->state = AP_CONN_STATE_RENDDESC_WAIT;
 +    }
 +  } SMARTLIST_FOREACH_END(conn);
 +
 +  smartlist_free(conns);
 +}
 +
 +/* Remove tracked HSDir requests from our history for this hidden service
 + * identity public key. */
 +static void
 +purge_hid_serv_request(const ed25519_public_key_t *identity_pk)
 +{
 +  char base64_blinded_pk[ED25519_BASE64_LEN + 1];
 +  ed25519_public_key_t blinded_pk;
 +
 +  tor_assert(identity_pk);
 +
 +  /* Get blinded pubkey of hidden service. It is possible that we just moved
 +   * to a new time period meaning that we won't be able to purge the request
 +   * from the previous time period. That is fine because they will expire at
 +   * some point and we don't care about those anymore. */
 +  hs_build_blinded_pubkey(identity_pk, NULL, 0,
 +                          hs_get_time_period_num(0), &blinded_pk);
 +  if (BUG(ed25519_public_to_base64(base64_blinded_pk, &blinded_pk) < 0)) {
 +    return;
 +  }
 +  /* Purge last hidden service request from cache for this blinded key. */
 +  hs_purge_hid_serv_from_last_hid_serv_requests(base64_blinded_pk);
 +}
 +
 +/* Return true iff there is at least one pending directory descriptor request
 + * for the service identity_pk. */
 +static int
 +directory_request_is_pending(const ed25519_public_key_t *identity_pk)
 +{
 +  int ret = 0;
 +  smartlist_t *conns =
 +    connection_list_by_type_purpose(CONN_TYPE_DIR, DIR_PURPOSE_FETCH_HSDESC);
 +
 +  SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
 +    const hs_ident_dir_conn_t *ident = TO_DIR_CONN(conn)->hs_ident;
 +    if (BUG(ident == NULL)) {
 +      /* A directory connection fetching a service descriptor can't have an
 +       * empty hidden service identifier. */
 +      continue;
 +    }
 +    if (!ed25519_pubkey_eq(identity_pk, &ident->identity_pk)) {
 +      continue;
 +    }
 +    ret = 1;
 +    break;
 +  } SMARTLIST_FOREACH_END(conn);
 +
 +  /* No ownership of the objects in this list. */
 +  smartlist_free(conns);
 +  return ret;
 +}
 +
 +/* We failed to fetch a descriptor for the service with <b>identity_pk</b>
 + * because of <b>status</b>. Find all pending SOCKS connections for this
 + * service that are waiting on the descriptor and close them with
 + * <b>reason</b>. */
 +static void
 +close_all_socks_conns_waiting_for_desc(const ed25519_public_key_t *identity_pk,
 +                                       hs_client_fetch_status_t status,
 +                                       int reason)
 +{
 +  unsigned int count = 0;
 +  time_t now = approx_time();
 +  smartlist_t *conns =
 +    connection_list_by_type_state(CONN_TYPE_AP, AP_CONN_STATE_RENDDESC_WAIT);
 +
 +  SMARTLIST_FOREACH_BEGIN(conns, connection_t *, base_conn) {
 +    entry_connection_t *entry_conn = TO_ENTRY_CONN(base_conn);
 +    const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(entry_conn);
 +
 +    /* Only consider the entry connections that matches the service for which
 +     * we tried to get the descriptor */
 +    if (!edge_conn->hs_ident ||
 +        !ed25519_pubkey_eq(identity_pk,
 +                           &edge_conn->hs_ident->identity_pk)) {
 +      continue;
 +    }
 +    assert_connection_ok(base_conn, now);
 +    /* Unattach the entry connection which will close for the reason. */
 +    connection_mark_unattached_ap(entry_conn, reason);
 +    count++;
 +  } SMARTLIST_FOREACH_END(base_conn);
 +
 +  if (count > 0) {
 +    char onion_address[HS_SERVICE_ADDR_LEN_BASE32 + 1];
 +    hs_build_address(identity_pk, HS_VERSION_THREE, onion_address);
 +    log_notice(LD_REND, "Closed %u streams for service %s.onion "
 +                        "for reason %s. Fetch status: %s.",
 +               count, safe_str_client(onion_address),
 +               stream_end_reason_to_string(reason),
 +               fetch_status_to_string(status));
 +  }
 +
 +  /* No ownership of the object(s) in this list. */
 +  smartlist_free(conns);
 +}
 +
 +/* Find all pending SOCKS connection waiting for a descriptor and retry them
 + * all. This is called when the directory information changed. */
 +static void
 +retry_all_socks_conn_waiting_for_desc(void)
 +{
 +  smartlist_t *conns =
 +    connection_list_by_type_state(CONN_TYPE_AP, AP_CONN_STATE_RENDDESC_WAIT);
 +
 +  SMARTLIST_FOREACH_BEGIN(conns, connection_t *, base_conn) {
 +    hs_client_fetch_status_t status;
 +    const edge_connection_t *edge_conn =
 +      ENTRY_TO_EDGE_CONN(TO_ENTRY_CONN(base_conn));
 +
 +    /* Ignore non HS or non v3 connection. */
 +    if (edge_conn->hs_ident == NULL) {
 +      continue;
 +    }
 +    /* In this loop, we will possibly try to fetch a descriptor for the
 +     * pending connections because we just got more directory information.
 +     * However, the refetch process can cleanup all SOCKS request so the same
 +     * service if an internal error happens. Thus, we can end up with closed
 +     * connections in our list. */
 +    if (base_conn->marked_for_close) {
 +      continue;
 +    }
 +
 +    /* XXX: There is an optimization we could do which is that for a service
 +     * key, we could check if we can fetch and remember that decision. */
 +
 +    /* Order a refetch in case it works this time. */
 +    status = hs_client_refetch_hsdesc(&edge_conn->hs_ident->identity_pk);
 +    if (BUG(status == HS_CLIENT_FETCH_HAVE_DESC)) {
 +      /* This case is unique because it can NOT happen in theory. Once we get
 +       * a new descriptor, the HS client subsystem is notified immediately and
 +       * the connections waiting for it are handled which means the state will
 +       * change from renddesc wait state. Log this and continue to next
 +       * connection. */
 +      continue;
 +    }
 +    /* In the case of an error, either all SOCKS connections have been
 +     * closed or we are still missing directory information. Leave the
 +     * connection in renddesc wait state so when we get more info, we'll be
 +     * able to try it again. */
 +  } SMARTLIST_FOREACH_END(base_conn);
 +
 +  /* We don't have ownership of those objects. */
 +  smartlist_free(conns);
 +}
 +
 +/* A v3 HS circuit successfully connected to the hidden service. Update the
 + * stream state at <b>hs_conn_ident</b> appropriately. */
 +static void
 +note_connection_attempt_succeeded(const hs_ident_edge_conn_t *hs_conn_ident)
 +{
 +  tor_assert(hs_conn_ident);
 +
 +  /* Remove from the hid serv cache all requests for that service so we can
 +   * query the HSDir again later on for various reasons. */
 +  purge_hid_serv_request(&hs_conn_ident->identity_pk);
 +
 +  /* The v2 subsystem cleans up the intro point time out flag at this stage.
 +   * We don't try to do it here because we still need to keep intact the intro
 +   * point state for future connections. Even though we are able to connect to
 +   * the service, doesn't mean we should reset the timed out intro points.
 +   *
 +   * It is not possible to have successfully connected to an intro point
 +   * present in our cache that was on error or timed out. Every entry in that
 +   * cache have a 2 minutes lifetime so ultimately the intro point(s) state
 +   * will be reset and thus possible to be retried. */
 +}
 +
 +/* Given the pubkey of a hidden service in <b>onion_identity_pk</b>, fetch its
 + * descriptor by launching a dir connection to <b>hsdir</b>. Return a
 + * hs_client_fetch_status_t status code depending on how it went. */
 +static hs_client_fetch_status_t
 +directory_launch_v3_desc_fetch(const ed25519_public_key_t *onion_identity_pk,
 +                               const routerstatus_t *hsdir)
 +{
 +  uint64_t current_time_period = hs_get_time_period_num(0);
 +  ed25519_public_key_t blinded_pubkey;
 +  char base64_blinded_pubkey[ED25519_BASE64_LEN + 1];
 +  hs_ident_dir_conn_t hs_conn_dir_ident;
 +  int retval;
 +
 +  tor_assert(hsdir);
 +  tor_assert(onion_identity_pk);
 +
 +  /* Get blinded pubkey */
 +  hs_build_blinded_pubkey(onion_identity_pk, NULL, 0,
 +                          current_time_period, &blinded_pubkey);
 +  /* ...and base64 it. */
 +  retval = ed25519_public_to_base64(base64_blinded_pubkey, &blinded_pubkey);
 +  if (BUG(retval < 0)) {
 +    return HS_CLIENT_FETCH_ERROR;
 +  }
 +
 +  /* Copy onion pk to a dir_ident so that we attach it to the dir conn */
 +  hs_ident_dir_conn_init(onion_identity_pk, &blinded_pubkey,
 +                         &hs_conn_dir_ident);
 +
 +  /* Setup directory request */
 +  directory_request_t *req =
 +    directory_request_new(DIR_PURPOSE_FETCH_HSDESC);
 +  directory_request_set_routerstatus(req, hsdir);
 +  directory_request_set_indirection(req, DIRIND_ANONYMOUS);
 +  directory_request_set_resource(req, base64_blinded_pubkey);
 +  directory_request_fetch_set_hs_ident(req, &hs_conn_dir_ident);
 +  directory_initiate_request(req);
 +  directory_request_free(req);
 +
 +  log_info(LD_REND, "Descriptor fetch request for service %s with blinded "
 +                    "key %s to directory %s",
 +           safe_str_client(ed25519_fmt(onion_identity_pk)),
 +           safe_str_client(base64_blinded_pubkey),
 +           safe_str_client(routerstatus_describe(hsdir)));
 +
 +  /* Fire a REQUESTED event on the control port. */
 +  hs_control_desc_event_requested(onion_identity_pk, base64_blinded_pubkey,
 +                                  hsdir);
 +
 +  /* Cleanup memory. */
 +  memwipe(&blinded_pubkey, 0, sizeof(blinded_pubkey));
 +  memwipe(base64_blinded_pubkey, 0, sizeof(base64_blinded_pubkey));
 +  memwipe(&hs_conn_dir_ident, 0, sizeof(hs_conn_dir_ident));
 +
 +  return HS_CLIENT_FETCH_LAUNCHED;
 +}
 +
 +/** Return the HSDir we should use to fetch the descriptor of the hidden
 + *  service with identity key <b>onion_identity_pk</b>. */
 +STATIC routerstatus_t *
 +pick_hsdir_v3(const ed25519_public_key_t *onion_identity_pk)
 +{
 +  int retval;
 +  char base64_blinded_pubkey[ED25519_BASE64_LEN + 1];
 +  uint64_t current_time_period = hs_get_time_period_num(0);
 +  smartlist_t *responsible_hsdirs = NULL;
 +  ed25519_public_key_t blinded_pubkey;
 +  routerstatus_t *hsdir_rs = NULL;
 +
 +  tor_assert(onion_identity_pk);
 +
 +  /* Get blinded pubkey of hidden service */
 +  hs_build_blinded_pubkey(onion_identity_pk, NULL, 0,
 +                          current_time_period, &blinded_pubkey);
 +  /* ...and base64 it. */
 +  retval = ed25519_public_to_base64(base64_blinded_pubkey, &blinded_pubkey);
 +  if (BUG(retval < 0)) {
 +    return NULL;
 +  }
 +
 +  /* Get responsible hsdirs of service for this time period */
 +  responsible_hsdirs = smartlist_new();
 +
 +  hs_get_responsible_hsdirs(&blinded_pubkey, current_time_period,
 +                            0, 1, responsible_hsdirs);
 +
 +  log_debug(LD_REND, "Found %d responsible HSDirs and about to pick one.",
 +           smartlist_len(responsible_hsdirs));
 +
 +  /* Pick an HSDir from the responsible ones. The ownership of
 +   * responsible_hsdirs is given to this function so no need to free it. */
 +  hsdir_rs = hs_pick_hsdir(responsible_hsdirs, base64_blinded_pubkey);
 +
 +  return hsdir_rs;
 +}
 +
 +/** Fetch a v3 descriptor using the given <b>onion_identity_pk</b>.
 + *
 + * On success, HS_CLIENT_FETCH_LAUNCHED is returned. Otherwise, an error from
 + * hs_client_fetch_status_t is returned. */
 +MOCK_IMPL(STATIC hs_client_fetch_status_t,
 +fetch_v3_desc, (const ed25519_public_key_t *onion_identity_pk))
 +{
 +  routerstatus_t *hsdir_rs =NULL;
 +
 +  tor_assert(onion_identity_pk);
 +
 +  hsdir_rs = pick_hsdir_v3(onion_identity_pk);
 +  if (!hsdir_rs) {
 +    log_info(LD_REND, "Couldn't pick a v3 hsdir.");
 +    return HS_CLIENT_FETCH_NO_HSDIRS;
 +  }
 +
 +  return directory_launch_v3_desc_fetch(onion_identity_pk, hsdir_rs);
 +}
 +
 +/* Make sure that the given v3 origin circuit circ is a valid correct
 + * introduction circuit. This will BUG() on any problems and hard assert if
 + * the anonymity of the circuit is not ok. Return 0 on success else -1 where
 + * the circuit should be mark for closed immediately. */
 +static int
 +intro_circ_is_ok(const origin_circuit_t *circ)
 +{
 +  int ret = 0;
 +
 +  tor_assert(circ);
 +
 +  if (BUG(TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_C_INTRODUCING &&
 +          TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT &&
 +          TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_C_INTRODUCE_ACKED)) {
 +    ret = -1;
 +  }
 +  if (BUG(circ->hs_ident == NULL)) {
 +    ret = -1;
 +  }
 +  if (BUG(!hs_ident_intro_circ_is_valid(circ->hs_ident))) {
 +    ret = -1;
 +  }
 +
 +  /* This can stop the tor daemon but we want that since if we don't have
 +   * anonymity on this circuit, something went really wrong. */
 +  assert_circ_anonymity_ok(circ, get_options());
 +  return ret;
 +}
 +
 +/* Find a descriptor intro point object that matches the given ident in the
 + * given descriptor desc. Return NULL if not found. */
 +static const hs_desc_intro_point_t *
 +find_desc_intro_point_by_ident(const hs_ident_circuit_t *ident,
 +                               const hs_descriptor_t *desc)
 +{
 +  const hs_desc_intro_point_t *intro_point = NULL;
 +
 +  tor_assert(ident);
 +  tor_assert(desc);
 +
 +  SMARTLIST_FOREACH_BEGIN(desc->encrypted_data.intro_points,
 +                          const hs_desc_intro_point_t *, ip) {
 +    if (ed25519_pubkey_eq(&ident->intro_auth_pk,
 +                          &ip->auth_key_cert->signed_key)) {
 +      intro_point = ip;
 +      break;
 +    }
 +  } SMARTLIST_FOREACH_END(ip);
 +
 +  return intro_point;
 +}
 +
 +/* Find a descriptor intro point object from the descriptor object desc that
 + * matches the given legacy identity digest in legacy_id. Return NULL if not
 + * found. */
 +static hs_desc_intro_point_t *
 +find_desc_intro_point_by_legacy_id(const char *legacy_id,
 +                                   const hs_descriptor_t *desc)
 +{
 +  hs_desc_intro_point_t *ret_ip = NULL;
 +
 +  tor_assert(legacy_id);
 +  tor_assert(desc);
 +
 +  /* We will go over every intro point and try to find which one is linked to
 +   * that circuit. Those lists are small so it's not that expensive. */
 +  SMARTLIST_FOREACH_BEGIN(desc->encrypted_data.intro_points,
 +                          hs_desc_intro_point_t *, ip) {
 +    SMARTLIST_FOREACH_BEGIN(ip->link_specifiers,
 +                            const hs_desc_link_specifier_t *, lspec) {
 +      /* Not all tor node have an ed25519 identity key so we still rely on the
 +       * legacy identity digest. */
 +      if (lspec->type != LS_LEGACY_ID) {
 +        continue;
 +      }
 +      if (fast_memneq(legacy_id, lspec->u.legacy_id, DIGEST_LEN)) {
 +        break;
 +      }
 +      /* Found it. */
 +      ret_ip = ip;
 +      goto end;
 +    } SMARTLIST_FOREACH_END(lspec);
 +  } SMARTLIST_FOREACH_END(ip);
 +
 + end:
 +  return ret_ip;
 +}
 +
 +/* Send an INTRODUCE1 cell along the intro circuit and populate the rend
 + * circuit identifier with the needed key material for the e2e encryption.
 + * Return 0 on success, -1 if there is a transient error such that an action
 + * has been taken to recover and -2 if there is a permanent error indicating
 + * that both circuits were closed. */
 +static int
 +send_introduce1(origin_circuit_t *intro_circ,
 +                origin_circuit_t *rend_circ)
 +{
 +  int status;
 +  char onion_address[HS_SERVICE_ADDR_LEN_BASE32 + 1];
 +  const ed25519_public_key_t *service_identity_pk = NULL;
 +  const hs_desc_intro_point_t *ip;
 +
 +  tor_assert(rend_circ);
 +  if (intro_circ_is_ok(intro_circ) < 0) {
 +    goto perm_err;
 +  }
 +
 +  service_identity_pk = &intro_circ->hs_ident->identity_pk;
 +  /* For logging purposes. There will be a time where the hs_ident will have a
 +   * version number but for now there is none because it's all v3. */
 +  hs_build_address(service_identity_pk, HS_VERSION_THREE, onion_address);
 +
 +  log_info(LD_REND, "Sending INTRODUCE1 cell to service %s on circuit %u",
 +           safe_str_client(onion_address), TO_CIRCUIT(intro_circ)->n_circ_id);
 +
 +  /* 1) Get descriptor from our cache. */
 +  const hs_descriptor_t *desc =
 +    hs_cache_lookup_as_client(service_identity_pk);
 +  if (desc == NULL || !hs_client_any_intro_points_usable(service_identity_pk,
 +                                                         desc)) {
 +    log_info(LD_REND, "Request to %s %s. Trying to fetch a new descriptor.",
 +             safe_str_client(onion_address),
 +             (desc) ? "didn't have usable intro points" :
 +             "didn't have a descriptor");
 +    hs_client_refetch_hsdesc(service_identity_pk);
 +    /* We just triggered a refetch, make sure every connections are back
 +     * waiting for that descriptor. */
 +    flag_all_conn_wait_desc(service_identity_pk);
 +    /* We just asked for a refetch so this is a transient error. */
 +    goto tran_err;
 +  }
 +
 +  /* We need to find which intro point in the descriptor we are connected to
 +   * on intro_circ. */
 +  ip = find_desc_intro_point_by_ident(intro_circ->hs_ident, desc);
 +  if (BUG(ip == NULL)) {
 +    /* If we can find a descriptor from this introduction circuit ident, we
 +     * must have a valid intro point object. Permanent error. */
 +    goto perm_err;
 +  }
 +
 +  /* Send the INTRODUCE1 cell. */
 +  if (hs_circ_send_introduce1(intro_circ, rend_circ, ip,
 +                              desc->subcredential) < 0) {
 +    /* Unable to send the cell, the intro circuit has been marked for close so
 +     * this is a permanent error. */
 +    tor_assert_nonfatal(TO_CIRCUIT(intro_circ)->marked_for_close);
 +    goto perm_err;
 +  }
 +
 +  /* Cell has been sent successfully. Copy the introduction point
 +   * authentication and encryption key in the rendezvous circuit identifier so
 +   * we can compute the ntor keys when we receive the RENDEZVOUS2 cell. */
 +  memcpy(&rend_circ->hs_ident->intro_enc_pk, &ip->enc_key,
 +         sizeof(rend_circ->hs_ident->intro_enc_pk));
 +  ed25519_pubkey_copy(&rend_circ->hs_ident->intro_auth_pk,
 +                      &intro_circ->hs_ident->intro_auth_pk);
 +
 +  /* Now, we wait for an ACK or NAK on this circuit. */
 +  circuit_change_purpose(TO_CIRCUIT(intro_circ),
 +                         CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT);
 +  /* Set timestamp_dirty, because circuit_expire_building expects it to
 +   * specify when a circuit entered the _C_INTRODUCE_ACK_WAIT state. */
 +  TO_CIRCUIT(intro_circ)->timestamp_dirty = time(NULL);
 +  pathbias_count_use_attempt(intro_circ);
 +
 +  /* Success. */
 +  status = 0;
 +  goto end;
 +
 + perm_err:
 +  /* Permanent error: it is possible that the intro circuit was closed prior
 +   * because we weren't able to send the cell. Make sure we don't double close
 +   * it which would result in a warning. */
 +  if (!TO_CIRCUIT(intro_circ)->marked_for_close) {
 +    circuit_mark_for_close(TO_CIRCUIT(intro_circ), END_CIRC_REASON_INTERNAL);
 +  }
 +  circuit_mark_for_close(TO_CIRCUIT(rend_circ), END_CIRC_REASON_INTERNAL);
 +  status = -2;
 +  goto end;
 +
 + tran_err:
 +  status = -1;
 +
 + end:
 +  memwipe(onion_address, 0, sizeof(onion_address));
 +  return status;
 +}
 +
 +/* Using the introduction circuit circ, setup the authentication key of the
 + * intro point this circuit has extended to. */
 +static void
 +setup_intro_circ_auth_key(origin_circuit_t *circ)
 +{
 +  const hs_descriptor_t *desc;
 +  const hs_desc_intro_point_t *ip;
 +
 +  tor_assert(circ);
 +
 +  desc = hs_cache_lookup_as_client(&circ->hs_ident->identity_pk);
 +  if (BUG(desc == NULL)) {
 +    /* Opening intro circuit without the descriptor is no good... */
 +    goto end;
 +  }
 +
 +  /* We will go over every intro point and try to find which one is linked to
 +   * that circuit. Those lists are small so it's not that expensive. */
 +  ip = find_desc_intro_point_by_legacy_id(
 +                       circ->build_state->chosen_exit->identity_digest, desc);
 +  if (ip) {
 +    /* We got it, copy its authentication key to the identifier. */
 +    ed25519_pubkey_copy(&circ->hs_ident->intro_auth_pk,
 +                        &ip->auth_key_cert->signed_key);
 +    goto end;
 +  }
 +
 +  /* Reaching this point means we didn't find any intro point for this circuit
 +   * which is not suppose to happen. */
 +  tor_assert_nonfatal_unreached();
 +
 + end:
 +  return;
 +}
 +
 +/* Called when an introduction circuit has opened. */
 +static void
 +client_intro_circ_has_opened(origin_circuit_t *circ)
 +{
 +  tor_assert(circ);
 +  tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_C_INTRODUCING);
 +  log_info(LD_REND, "Introduction circuit %u has opened. Attaching streams.",
 +           (unsigned int) TO_CIRCUIT(circ)->n_circ_id);
 +
 +  /* This is an introduction circuit so we'll attach the correct
 +   * authentication key to the circuit identifier so it can be identified
 +   * properly later on. */
 +  setup_intro_circ_auth_key(circ);
 +
 +  connection_ap_attach_pending(1);
 +}
 +
 +/* Called when a rendezvous circuit has opened. */
 +static void
 +client_rendezvous_circ_has_opened(origin_circuit_t *circ)
 +{
 +  tor_assert(circ);
 +  tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND);
 +
 +  const extend_info_t *rp_ei = circ->build_state->chosen_exit;
 +
 +  /* Check that we didn't accidentally choose a node that does not understand
 +   * the v3 rendezvous protocol */
 +  if (rp_ei) {
 +    const node_t *rp_node = node_get_by_id(rp_ei->identity_digest);
 +    if (rp_node) {
 +      if (BUG(!node_supports_v3_rendezvous_point(rp_node))) {
 +        return;
 +      }
 +    }
 +  }
 +
 +  log_info(LD_REND, "Rendezvous circuit has opened to %s.",
 +           safe_str_client(extend_info_describe(rp_ei)));
 +
 +  /* Ignore returned value, nothing we can really do. On failure, the circuit
 +   * will be marked for close. */
 +  hs_circ_send_establish_rendezvous(circ);
 +
 +  /* Register rend circuit in circuitmap if it's still alive. */
 +  if (!TO_CIRCUIT(circ)->marked_for_close) {
 +    hs_circuitmap_register_rend_circ_client_side(circ,
 +                                     circ->hs_ident->rendezvous_cookie);
 +  }
 +}
 +
 +/* This is an helper function that convert a descriptor intro point object ip
 + * to a newly allocated extend_info_t object fully initialized. Return NULL if
 + * we can't convert it for which chances are that we are missing or malformed
 + * link specifiers. */
 +STATIC extend_info_t *
 +desc_intro_point_to_extend_info(const hs_desc_intro_point_t *ip)
 +{
 +  extend_info_t *ei;
 +  smartlist_t *lspecs = smartlist_new();
 +
 +  tor_assert(ip);
 +
 +  /* We first encode the descriptor link specifiers into the binary
 +   * representation which is a trunnel object. */
 +  SMARTLIST_FOREACH_BEGIN(ip->link_specifiers,
 +                          const hs_desc_link_specifier_t *, desc_lspec) {
 +    link_specifier_t *lspec = hs_desc_lspec_to_trunnel(desc_lspec);
 +    smartlist_add(lspecs, lspec);
 +  } SMARTLIST_FOREACH_END(desc_lspec);
 +
 +  /* Explicitly put the direct connection option to 0 because this is client
 +   * side and there is no such thing as a non anonymous client. */
 +  ei = hs_get_extend_info_from_lspecs(lspecs, &ip->onion_key, 0);
 +
 +  SMARTLIST_FOREACH(lspecs, link_specifier_t *, ls, link_specifier_free(ls));
 +  smartlist_free(lspecs);
 +  return ei;
 +}
 +
 +/* Return true iff the intro point ip for the service service_pk is usable.
 + * This function checks if the intro point is in the client intro state cache
 + * and checks at the failures. It is considered usable if:
 + *   - No error happened (INTRO_POINT_FAILURE_GENERIC)
 + *   - It is not flagged as timed out (INTRO_POINT_FAILURE_TIMEOUT)
 + *   - The unreachable count is lower than
 + *     MAX_INTRO_POINT_REACHABILITY_FAILURES (INTRO_POINT_FAILURE_UNREACHABLE)
 + */
 +static int
 +intro_point_is_usable(const ed25519_public_key_t *service_pk,
 +                      const hs_desc_intro_point_t *ip)
 +{
 +  const hs_cache_intro_state_t *state;
 +
 +  tor_assert(service_pk);
 +  tor_assert(ip);
 +
 +  state = hs_cache_client_intro_state_find(service_pk,
 +                                           &ip->auth_key_cert->signed_key);
 +  if (state == NULL) {
 +    /* This means we've never encountered any problem thus usable. */
 +    goto usable;
 +  }
 +  if (state->error) {
 +    log_info(LD_REND, "Intro point with auth key %s had an error. Not usable",
 +             safe_str_client(ed25519_fmt(&ip->auth_key_cert->signed_key)));
 +    goto not_usable;
 +  }
 +  if (state->timed_out) {
 +    log_info(LD_REND, "Intro point with auth key %s timed out. Not usable",
 +             safe_str_client(ed25519_fmt(&ip->auth_key_cert->signed_key)));
 +    goto not_usable;
 +  }
 +  if (state->unreachable_count >= MAX_INTRO_POINT_REACHABILITY_FAILURES) {
 +    log_info(LD_REND, "Intro point with auth key %s unreachable. Not usable",
 +             safe_str_client(ed25519_fmt(&ip->auth_key_cert->signed_key)));
 +    goto not_usable;
 +  }
 +
 + usable:
 +  return 1;
 + not_usable:
 +  return 0;
 +}
 +
 +/* Using a descriptor desc, return a newly allocated extend_info_t object of a
 + * randomly picked introduction point from its list. Return NULL if none are
 + * usable. */
 +STATIC extend_info_t *
 +client_get_random_intro(const ed25519_public_key_t *service_pk)
 +{
 +  extend_info_t *ei = NULL, *ei_excluded = NULL;
 +  smartlist_t *usable_ips = NULL;
 +  const hs_descriptor_t *desc;
 +  const hs_desc_encrypted_data_t *enc_data;
 +  const or_options_t *options = get_options();
 +  /* Calculate the onion address for logging purposes */
 +  char onion_address[HS_SERVICE_ADDR_LEN_BASE32 + 1];
 +
 +  tor_assert(service_pk);
 +
 +  desc = hs_cache_lookup_as_client(service_pk);
 +  /* Assume the service is v3 if the descriptor is missing. This is ok,
 +   * because we only use the address in log messages */
 +  hs_build_address(service_pk,
 +                   desc ? desc->plaintext_data.version : HS_VERSION_THREE,
 +                   onion_address);
 +  if (desc == NULL || !hs_client_any_intro_points_usable(service_pk,
 +                                                         desc)) {
 +    log_info(LD_REND, "Unable to randomly select an introduction point "
 +             "for service %s because descriptor %s. We can't connect.",
 +             safe_str_client(onion_address),
 +             (desc) ? "doesn't have any usable intro points"
 +                    : "is missing (assuming v3 onion address)");
 +    goto end;
 +  }
 +
 +  enc_data = &desc->encrypted_data;
 +  usable_ips = smartlist_new();
 +  smartlist_add_all(usable_ips, enc_data->intro_points);
 +  while (smartlist_len(usable_ips) != 0) {
 +    int idx;
 +    const hs_desc_intro_point_t *ip;
 +
 +    /* Pick a random intro point and immediately remove it from the usable
 +     * list so we don't pick it again if we have to iterate more. */
 +    idx = crypto_rand_int(smartlist_len(usable_ips));
 +    ip = smartlist_get(usable_ips, idx);
 +    smartlist_del(usable_ips, idx);
 +
 +    /* We need to make sure we have a usable intro points which is in a good
 +     * state in our cache. */
 +    if (!intro_point_is_usable(service_pk, ip)) {
 +      continue;
 +    }
 +
 +    /* Generate an extend info object from the intro point object. */
 +    ei = desc_intro_point_to_extend_info(ip);
 +    if (ei == NULL) {
 +      /* We can get here for instance if the intro point is a private address
 +       * and we aren't allowed to extend to those. */
 +      log_info(LD_REND, "Unable to select introduction point with auth key %s "
 +               "for service %s, because we could not extend to it.",
 +               safe_str_client(ed25519_fmt(&ip->auth_key_cert->signed_key)),
 +               safe_str_client(onion_address));
 +      continue;
 +    }
 +
 +    /* Test the pick against ExcludeNodes. */
 +    if (routerset_contains_extendinfo(options->ExcludeNodes, ei)) {
 +      /* If this pick is in the ExcludeNodes list, we keep its reference so if
 +       * we ever end up not being able to pick anything else and StrictNodes is
 +       * unset, we'll use it. */
 +      if (ei_excluded) {
 +        /* If something was already here free it. After the loop is gone we
 +         * will examine the last excluded intro point, and that's fine since
 +         * that's random anyway */
 +        extend_info_free(ei_excluded);
 +      }
 +      ei_excluded = ei;
 +      continue;
 +    }
 +
 +    /* Good pick! Let's go with this. */
 +    goto end;
 +  }
 +
 +  /* Reaching this point means a couple of things. Either we can't use any of
 +   * the intro point listed because the IP address can't be extended to or it
 +   * is listed in the ExcludeNodes list. In the later case, if StrictNodes is
 +   * set, we are forced to not use anything. */
 +  ei = ei_excluded;
 +  if (options->StrictNodes) {
 +    log_warn(LD_REND, "Every introduction point for service %s is in the "
 +             "ExcludeNodes set and StrictNodes is set. We can't connect.",
 +             safe_str_client(onion_address));
 +    extend_info_free(ei);
 +    ei = NULL;
 +  } else {
 +    log_fn(LOG_PROTOCOL_WARN, LD_REND, "Every introduction point for service "
 +           "%s is unusable or we can't extend to it. We can't connect.",
 +           safe_str_client(onion_address));
 +  }
 +
 + end:
 +  smartlist_free(usable_ips);
 +  memwipe(onion_address, 0, sizeof(onion_address));
 +  return ei;
 +}
 +
 +/* For this introduction circuit, we'll look at if we have any usable
 + * introduction point left for this service. If so, we'll use the circuit to
 + * re-extend to a new intro point. Else, we'll close the circuit and its
 + * corresponding rendezvous circuit. Return 0 if we are re-extending else -1
 + * if we are closing the circuits.
 + *
 + * This is called when getting an INTRODUCE_ACK cell with a NACK. */
 +static int
 +close_or_reextend_intro_circ(origin_circuit_t *intro_circ)
 +{
 +  int ret = -1;
 +  const hs_descriptor_t *desc;
 +  origin_circuit_t *rend_circ;
 +
 +  tor_assert(intro_circ);
 +
 +  desc = hs_cache_lookup_as_client(&intro_circ->hs_ident->identity_pk);
 +  if (BUG(desc == NULL)) {
 +    /* We can't continue without a descriptor. */
 +    goto close;
 +  }
 +  /* We still have the descriptor, great! Let's try to see if we can
 +   * re-extend by looking up if there are any usable intro points. */
 +  if (!hs_client_any_intro_points_usable(&intro_circ->hs_ident->identity_pk,
 +                                         desc)) {
 +    goto close;
 +  }
 +  /* Try to re-extend now. */
 +  if (hs_client_reextend_intro_circuit(intro_circ) < 0) {
 +    goto close;
 +  }
 +  /* Success on re-extending. Don't return an error. */
 +  ret = 0;
 +  goto end;
 +
 + close:
 +  /* Change the intro circuit purpose before so we don't report an intro point
 +   * failure again triggering an extra descriptor fetch. The circuit can
 +   * already be closed on failure to re-extend. */
 +  if (!TO_CIRCUIT(intro_circ)->marked_for_close) {
 +    circuit_change_purpose(TO_CIRCUIT(intro_circ),
 +                           CIRCUIT_PURPOSE_C_INTRODUCE_ACKED);
 +    circuit_mark_for_close(TO_CIRCUIT(intro_circ), END_CIRC_REASON_FINISHED);
 +  }
 +  /* Close the related rendezvous circuit. */
 +  rend_circ = hs_circuitmap_get_rend_circ_client_side(
 +                                     intro_circ->hs_ident->rendezvous_cookie);
 +  /* The rendezvous circuit might have collapsed while the INTRODUCE_ACK was
 +   * inflight so we can't expect one every time. */
 +  if (rend_circ) {
 +    circuit_mark_for_close(TO_CIRCUIT(rend_circ), END_CIRC_REASON_FINISHED);
 +  }
 +
 + end:
 +  return ret;
 +}
 +
 +/* Called when we get an INTRODUCE_ACK success status code. Do the appropriate
 + * actions for the rendezvous point and finally close intro_circ. */
 +static void
 +handle_introduce_ack_success(origin_circuit_t *intro_circ)
 +{
 +  origin_circuit_t *rend_circ = NULL;
 +
 +  tor_assert(intro_circ);
 +
 +  log_info(LD_REND, "Received INTRODUCE_ACK ack! Informing rendezvous");
 +
 +  /* Get the rendezvous circuit for this rendezvous cookie. */
 +  uint8_t *rendezvous_cookie = intro_circ->hs_ident->rendezvous_cookie;
 +  rend_circ =
 +  hs_circuitmap_get_established_rend_circ_client_side(rendezvous_cookie);
 +  if (rend_circ == NULL) {
 +    log_warn(LD_REND, "Can't find any rendezvous circuit. Stopping");
 +    goto end;
 +  }
 +
 +  assert_circ_anonymity_ok(rend_circ, get_options());
 +
 +  /* It is possible to get a RENDEZVOUS2 cell before the INTRODUCE_ACK which
 +   * means that the circuit will be joined and already transmitting data. In
 +   * that case, simply skip the purpose change and close the intro circuit
 +   * like it should be. */
 +  if (TO_CIRCUIT(rend_circ)->purpose == CIRCUIT_PURPOSE_C_REND_JOINED) {
 +    goto end;
 +  }
 +  circuit_change_purpose(TO_CIRCUIT(rend_circ),
 +                         CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED);
 +  /* Set timestamp_dirty, because circuit_expire_building expects it to
 +   * specify when a circuit entered the
 +   * CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED state. */
 +  TO_CIRCUIT(rend_circ)->timestamp_dirty = time(NULL);
 +
 + end:
 +  /* We don't need the intro circuit anymore. It did what it had to do! */
 +  circuit_change_purpose(TO_CIRCUIT(intro_circ),
 +                         CIRCUIT_PURPOSE_C_INTRODUCE_ACKED);
 +  circuit_mark_for_close(TO_CIRCUIT(intro_circ), END_CIRC_REASON_FINISHED);
 +
 +  /* XXX: Close pending intro circuits we might have in parallel. */
 +  return;
 +}
 +
 +/* Called when we get an INTRODUCE_ACK failure status code. Depending on our
 + * failure cache status, either close the circuit or re-extend to a new
 + * introduction point. */
 +static void
 +handle_introduce_ack_bad(origin_circuit_t *circ, int status)
 +{
 +  tor_assert(circ);
 +
 +  log_info(LD_REND, "Received INTRODUCE_ACK nack by %s. Reason: %u",
 +      safe_str_client(extend_info_describe(circ->build_state->chosen_exit)),
 +      status);
 +
 +  /* It's a NAK. The introduction point didn't relay our request. */
 +  circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_C_INTRODUCING);
 +
 +  /* Note down this failure in the intro point failure cache. Depending on how
 +   * many times we've tried this intro point, close it or reextend. */
 +  hs_cache_client_intro_state_note(&circ->hs_ident->identity_pk,
 +                                   &circ->hs_ident->intro_auth_pk,
 +                                   INTRO_POINT_FAILURE_GENERIC);
 +}
 +
 +/* Called when we get an INTRODUCE_ACK on the intro circuit circ. The encoded
 + * cell is in payload of length payload_len. Return 0 on success else a
 + * negative value. The circuit is either close or reuse to re-extend to a new
 + * introduction point. */
 +static int
 +handle_introduce_ack(origin_circuit_t *circ, const uint8_t *payload,
 +                     size_t payload_len)
 +{
 +  int status, ret = -1;
 +
 +  tor_assert(circ);
 +  tor_assert(circ->build_state);
 +  tor_assert(circ->build_state->chosen_exit);
 +  assert_circ_anonymity_ok(circ, get_options());
 +  tor_assert(payload);
 +
 +  status = hs_cell_parse_introduce_ack(payload, payload_len);
 +  switch (status) {
 +  case HS_CELL_INTRO_ACK_SUCCESS:
 +    ret = 0;
 +    handle_introduce_ack_success(circ);
 +    goto end;
 +  case HS_CELL_INTRO_ACK_FAILURE:
 +  case HS_CELL_INTRO_ACK_BADFMT:
 +  case HS_CELL_INTRO_ACK_NORELAY:
 +    handle_introduce_ack_bad(circ, status);
 +    /* We are going to see if we have to close the circuits (IP and RP) or we
 +     * can re-extend to a new intro point. */
 +    ret = close_or_reextend_intro_circ(circ);
 +    break;
 +  default:
 +    log_info(LD_PROTOCOL, "Unknown INTRODUCE_ACK status code %u from %s",
 +        status,
 +        safe_str_client(extend_info_describe(circ->build_state->chosen_exit)));
 +    break;
 +  }
 +
 + end:
 +  return ret;
 +}
 +
 +/* Called when we get a RENDEZVOUS2 cell on the rendezvous circuit circ. The
 + * encoded cell is in payload of length payload_len. Return 0 on success or a
 + * negative value on error. On error, the circuit is marked for close. */
 +STATIC int
 +handle_rendezvous2(origin_circuit_t *circ, const uint8_t *payload,
 +                   size_t payload_len)
 +{
 +  int ret = -1;
 +  curve25519_public_key_t server_pk;
 +  uint8_t auth_mac[DIGEST256_LEN] = {0};
 +  uint8_t handshake_info[CURVE25519_PUBKEY_LEN + sizeof(auth_mac)] = {0};
 +  hs_ntor_rend_cell_keys_t keys;
 +  const hs_ident_circuit_t *ident;
 +
 +  tor_assert(circ);
 +  tor_assert(payload);
 +
 +  /* Make things easier. */
 +  ident = circ->hs_ident;
 +  tor_assert(ident);
 +
 +  if (hs_cell_parse_rendezvous2(payload, payload_len, handshake_info,
 +                                sizeof(handshake_info)) < 0) {
 +    goto err;
 +  }
 +  /* Get from the handshake info the SERVER_PK and AUTH_MAC. */
 +  memcpy(&server_pk, handshake_info, CURVE25519_PUBKEY_LEN);
 +  memcpy(auth_mac, handshake_info + CURVE25519_PUBKEY_LEN, sizeof(auth_mac));
 +
 +  /* Generate the handshake info. */
 +  if (hs_ntor_client_get_rendezvous1_keys(&ident->intro_auth_pk,
 +                                          &ident->rendezvous_client_kp,
 +                                          &ident->intro_enc_pk, &server_pk,
 +                                          &keys) < 0) {
 +    log_info(LD_REND, "Unable to compute the rendezvous keys.");
 +    goto err;
 +  }
 +
 +  /* Critical check, make sure that the MAC matches what we got with what we
 +   * computed just above. */
 +  if (!hs_ntor_client_rendezvous2_mac_is_good(&keys, auth_mac)) {
 +    log_info(LD_REND, "Invalid MAC in RENDEZVOUS2. Rejecting cell.");
 +    goto err;
 +  }
 +
 +  /* Setup the e2e encryption on the circuit and finalize its state. */
 +  if (hs_circuit_setup_e2e_rend_circ(circ, keys.ntor_key_seed,
 +                                     sizeof(keys.ntor_key_seed), 0) < 0) {
 +    log_info(LD_REND, "Unable to setup the e2e encryption.");
 +    goto err;
 +  }
 +  /* Success. Hidden service connection finalized! */
 +  ret = 0;
 +  goto end;
 +
 + err:
 +  circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
 + end:
 +  memwipe(&keys, 0, sizeof(keys));
 +  return ret;
 +}
 +
 +/* Return true iff the client can fetch a descriptor for this service public
 + * identity key and status_out if not NULL is untouched. If the client can
 + * _not_ fetch the descriptor and if status_out is not NULL, it is set with
 + * the fetch status code. */
 +static unsigned int
 +can_client_refetch_desc(const ed25519_public_key_t *identity_pk,
 +                        hs_client_fetch_status_t *status_out)
 +{
 +  hs_client_fetch_status_t status;
 +
 +  tor_assert(identity_pk);
 +
 +  /* Are we configured to fetch descriptors? */
 +  if (!get_options()->FetchHidServDescriptors) {
 +    log_warn(LD_REND, "We received an onion address for a hidden service "
 +                      "descriptor but we are configured to not fetch.");
 +    status = HS_CLIENT_FETCH_NOT_ALLOWED;
 +    goto cannot;
 +  }
 +
 +  /* Without a live consensus we can't do any client actions. It is needed to
 +   * compute the hashring for a service. */
 +  if (!networkstatus_get_live_consensus(approx_time())) {
 +    log_info(LD_REND, "Can't fetch descriptor for service %s because we "
 +                      "are missing a live consensus. Stalling connection.",
 +             safe_str_client(ed25519_fmt(identity_pk)));
 +    status = HS_CLIENT_FETCH_MISSING_INFO;
 +    goto cannot;
 +  }
 +
 +  if (!router_have_minimum_dir_info()) {
 +    log_info(LD_REND, "Can't fetch descriptor for service %s because we "
 +                      "dont have enough descriptors. Stalling connection.",
 +             safe_str_client(ed25519_fmt(identity_pk)));
 +    status = HS_CLIENT_FETCH_MISSING_INFO;
 +    goto cannot;
 +  }
 +
 +  /* Check if fetching a desc for this HS is useful to us right now */
 +  {
 +    const hs_descriptor_t *cached_desc = NULL;
 +    cached_desc = hs_cache_lookup_as_client(identity_pk);
 +    if (cached_desc && hs_client_any_intro_points_usable(identity_pk,
 +                                                         cached_desc)) {
 +      log_info(LD_GENERAL, "We would fetch a v3 hidden service descriptor "
 +                           "but we already have a usable descriptor.");
 +      status = HS_CLIENT_FETCH_HAVE_DESC;
 +      goto cannot;
 +    }
 +  }
 +
 +  /* Don't try to refetch while we have a pending request for it. */
 +  if (directory_request_is_pending(identity_pk)) {
 +    log_info(LD_REND, "Already a pending directory request. Waiting on it.");
 +    status = HS_CLIENT_FETCH_PENDING;
 +    goto cannot;
 +  }
 +
 +  /* Yes, client can fetch! */
 +  return 1;
 + cannot:
 +  if (status_out) {
 +    *status_out = status;
 +  }
 +  return 0;
 +}
 +
 +/* Return the client auth in the map using the service identity public key.
 + * Return NULL if it does not exist in the map. */
 +static hs_client_service_authorization_t *
 +find_client_auth(const ed25519_public_key_t *service_identity_pk)
 +{
 +  /* If the map is not allocated, we can assume that we do not have any client
 +   * auth information. */
 +  if (!client_auths) {
 +    return NULL;
 +  }
 +  return digest256map_get(client_auths, service_identity_pk->pubkey);
 +}
 +
 +/* ========== */
 +/* Public API */
 +/* ========== */
 +
 +/** A circuit just finished connecting to a hidden service that the stream
 + *  <b>conn</b> has been waiting for. Let the HS subsystem know about this. */
 +void
 +hs_client_note_connection_attempt_succeeded(const edge_connection_t *conn)
 +{
 +  tor_assert(connection_edge_is_rendezvous_stream(conn));
 +
 +  if (BUG(conn->rend_data && conn->hs_ident)) {
 +    log_warn(LD_BUG, "Stream had both rend_data and hs_ident..."
 +             "Prioritizing hs_ident");
 +  }
 +
 +  if (conn->hs_ident) { /* It's v3: pass it to the prop224 handler */
 +    note_connection_attempt_succeeded(conn->hs_ident);
 +    return;
 +  } else if (conn->rend_data) { /* It's v2: pass it to the legacy handler */
 +    rend_client_note_connection_attempt_ended(conn->rend_data);
 +    return;
 +  }
 +}
 +
 +/* With the given encoded descriptor in desc_str and the service key in
 + * service_identity_pk, decode the descriptor and set the desc pointer with a
 + * newly allocated descriptor object.
 + *
 + * Return 0 on success else a negative value and desc is set to NULL. */
 +int
 +hs_client_decode_descriptor(const char *desc_str,
 +                            const ed25519_public_key_t *service_identity_pk,
 +                            hs_descriptor_t **desc)
 +{
 +  int ret;
 +  uint8_t subcredential[DIGEST256_LEN];
 +  ed25519_public_key_t blinded_pubkey;
 +  hs_client_service_authorization_t *client_auth = NULL;
 +  curve25519_secret_key_t *client_auht_sk = NULL;
 +
 +  tor_assert(desc_str);
 +  tor_assert(service_identity_pk);
 +  tor_assert(desc);
 +
 +  /* Check if we have a client authorization for this service in the map. */
 +  client_auth = find_client_auth(service_identity_pk);
 +  if (client_auth) {
 +    client_auht_sk = &client_auth->enc_seckey;
 +  }
 +
 +  /* Create subcredential for this HS so that we can decrypt */
 +  {
 +    uint64_t current_time_period = hs_get_time_period_num(0);
 +    hs_build_blinded_pubkey(service_identity_pk, NULL, 0, current_time_period,
 +                            &blinded_pubkey);
 +    hs_get_subcredential(service_identity_pk, &blinded_pubkey, subcredential);
 +  }
 +
 +  /* Parse descriptor */
 +  ret = hs_desc_decode_descriptor(desc_str, subcredential,
 +                                  client_auht_sk, desc);
 +  memwipe(subcredential, 0, sizeof(subcredential));
 +  if (ret < 0) {
 +    log_warn(LD_GENERAL, "Could not parse received descriptor as client.");
 +    if (get_options()->SafeLogging_ == SAFELOG_SCRUB_NONE) {
 +      log_warn(LD_GENERAL, "%s", escaped(desc_str));
 +    }
 +    goto err;
 +  }
 +
 +  /* Make sure the descriptor signing key cross certifies with the computed
 +   * blinded key. Without this validation, anyone knowing the subcredential
 +   * and onion address can forge a descriptor. */
 +  tor_cert_t *cert = (*desc)->plaintext_data.signing_key_cert;
 +  if (tor_cert_checksig(cert,
 +                        &blinded_pubkey, approx_time()) < 0) {
 +    log_warn(LD_GENERAL, "Descriptor signing key certificate signature "
 +             "doesn't validate with computed blinded key: %s",
 +             tor_cert_describe_signature_status(cert));
 +    goto err;
 +  }
 +
 +  return 0;
 + err:
 +  return -1;
 +}
 +
 +/* Return true iff there are at least one usable intro point in the service
 + * descriptor desc. */
 +int
 +hs_client_any_intro_points_usable(const ed25519_public_key_t *service_pk,
 +                                  const hs_descriptor_t *desc)
 +{
 +  tor_assert(service_pk);
 +  tor_assert(desc);
 +
 +  SMARTLIST_FOREACH_BEGIN(desc->encrypted_data.intro_points,
 +                          const hs_desc_intro_point_t *, ip) {
 +    if (intro_point_is_usable(service_pk, ip)) {
 +      goto usable;
 +    }
 +  } SMARTLIST_FOREACH_END(ip);
 +
 +  return 0;
 + usable:
 +  return 1;
 +}
 +
 +/** Launch a connection to a hidden service directory to fetch a hidden
 + * service descriptor using <b>identity_pk</b> to get the necessary keys.
 + *
 + * A hs_client_fetch_status_t code is returned. */
 +int
 +hs_client_refetch_hsdesc(const ed25519_public_key_t *identity_pk)
 +{
 +  hs_client_fetch_status_t status;
 +
 +  tor_assert(identity_pk);
 +
 +  if (!can_client_refetch_desc(identity_pk, &status)) {
 +    return status;
 +  }
 +
 +  /* Try to fetch the desc and if we encounter an unrecoverable error, mark
 +   * the desc as unavailable for now. */
 +  status = fetch_v3_desc(identity_pk);
 +  if (fetch_status_should_close_socks(status)) {
 +    close_all_socks_conns_waiting_for_desc(identity_pk, status,
 +                                           END_STREAM_REASON_RESOLVEFAILED);
 +    /* Remove HSDir fetch attempts so that we can retry later if the user
 +     * wants us to regardless of if we closed any connections. */
 +    purge_hid_serv_request(identity_pk);
 +  }
 +  return status;
 +}
 +
 +/* This is called when we are trying to attach an AP connection to these
 + * hidden service circuits from connection_ap_handshake_attach_circuit().
 + * Return 0 on success, -1 for a transient error that is actions were
 + * triggered to recover or -2 for a permenent error where both circuits will
 + * marked for close.
 + *
 + * The following supports every hidden service version. */
 +int
 +hs_client_send_introduce1(origin_circuit_t *intro_circ,
 +                          origin_circuit_t *rend_circ)
 +{
 +  return (intro_circ->hs_ident) ? send_introduce1(intro_circ, rend_circ) :
 +                                  rend_client_send_introduction(intro_circ,
 +                                                                rend_circ);
 +}
 +
 +/* Called when the client circuit circ has been established. It can be either
 + * an introduction or rendezvous circuit. This function handles all hidden
 + * service versions. */
 +void
 +hs_client_circuit_has_opened(origin_circuit_t *circ)
 +{
 +  tor_assert(circ);
 +
 +  /* Handle both version. v2 uses rend_data and v3 uses the hs circuit
 +   * identifier hs_ident. Can't be both. */
 +  switch (TO_CIRCUIT(circ)->purpose) {
 +  case CIRCUIT_PURPOSE_C_INTRODUCING:
 +    if (circ->hs_ident) {
 +      client_intro_circ_has_opened(circ);
 +    } else {
 +      rend_client_introcirc_has_opened(circ);
 +    }
 +    break;
 +  case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
 +    if (circ->hs_ident) {
 +      client_rendezvous_circ_has_opened(circ);
 +    } else {
 +      rend_client_rendcirc_has_opened(circ);
 +    }
 +    break;
 +  default:
 +    tor_assert_nonfatal_unreached();
 +  }
 +}
 +
 +/* Called when we receive a RENDEZVOUS_ESTABLISHED cell. Change the state of
 + * the circuit to CIRCUIT_PURPOSE_C_REND_READY. Return 0 on success else a
 + * negative value and the circuit marked for close. */
 +int
 +hs_client_receive_rendezvous_acked(origin_circuit_t *circ,
 +                                   const uint8_t *payload, size_t payload_len)
 +{
 +  tor_assert(circ);
 +  tor_assert(payload);
 +
 +  (void) payload_len;
 +
 +  if (TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_C_ESTABLISH_REND) {
 +    log_warn(LD_PROTOCOL, "Got a RENDEZVOUS_ESTABLISHED but we were not "
 +                          "expecting one. Closing circuit.");
 +    goto err;
 +  }
 +
 +  log_info(LD_REND, "Received an RENDEZVOUS_ESTABLISHED. This circuit is "
 +                    "now ready for rendezvous.");
 +  circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_C_REND_READY);
 +
 +  /* Set timestamp_dirty, because circuit_expire_building expects it to
 +   * specify when a circuit entered the _C_REND_READY state. */
 +  TO_CIRCUIT(circ)->timestamp_dirty = time(NULL);
 +
 +  /* From a path bias point of view, this circuit is now successfully used.
 +   * Waiting any longer opens us up to attacks from malicious hidden services.
 +   * They could induce the client to attempt to connect to their hidden
 +   * service and never reply to the client's rend requests */
 +  pathbias_mark_use_success(circ);
 +
 +  /* If we already have the introduction circuit built, make sure we send
 +   * the INTRODUCE cell _now_ */
 +  connection_ap_attach_pending(1);
 +
 +  return 0;
 + err:
 +  circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
 +  return -1;
 +}
 +
 +#define client_service_authorization_free(auth)                      \
 +  FREE_AND_NULL(hs_client_service_authorization_t,                   \
 +                client_service_authorization_free_, (auth))
 +
 +static void
 +client_service_authorization_free_(hs_client_service_authorization_t *auth)
 +{
 +  if (auth) {
 +    memwipe(auth, 0, sizeof(*auth));
 +  }
 +  tor_free(auth);
 +}
 +
 +/** Helper for digest256map_free. */
 +static void
 +client_service_authorization_free_void(void *auth)
 +{
 +  client_service_authorization_free_(auth);
 +}
 +
 +static void
 +client_service_authorization_free_all(void)
 +{
 +  if (!client_auths) {
 +    return;
 +  }
 +  digest256map_free(client_auths, client_service_authorization_free_void);
 +}
 +
 +/* Check if the auth key file name is valid or not. Return 1 if valid,
 + * otherwise return 0. */
 +STATIC int
 +auth_key_filename_is_valid(const char *filename)
 +{
 +  int ret = 1;
 +  const char *valid_extension = ".auth_private";
 +
 +  tor_assert(filename);
 +
 +  /* The length of the filename must be greater than the length of the
 +   * extension and the valid extension must be at the end of filename. */
 +  if (!strcmpend(filename, valid_extension) &&
 +      strlen(filename) != strlen(valid_extension)) {
 +    ret = 1;
 +  } else {
 +    ret = 0;
 +  }
 +
 +  return ret;
 +}
 +
 +STATIC hs_client_service_authorization_t *
 +parse_auth_file_content(const char *client_key_str)
 +{
 +  char *onion_address = NULL;
 +  char *auth_type = NULL;
 +  char *key_type = NULL;
 +  char *seckey_b32 = NULL;
 +  hs_client_service_authorization_t *auth = NULL;
 +  smartlist_t *fields = smartlist_new();
 +
 +  tor_assert(client_key_str);
 +
 +  smartlist_split_string(fields, client_key_str, ":",
 +                         SPLIT_SKIP_SPACE, 0);
 +  /* Wrong number of fields. */
 +  if (smartlist_len(fields) != 4) {
 +    goto err;
 +  }
 +
 +  onion_address = smartlist_get(fields, 0);
 +  auth_type = smartlist_get(fields, 1);
 +  key_type = smartlist_get(fields, 2);
 +  seckey_b32 = smartlist_get(fields, 3);
 +
 +  /* Currently, the only supported auth type is "descriptor" and the only
 +   * supported key type is "x25519". */
 +  if (strcmp(auth_type, "descriptor") || strcmp(key_type, "x25519")) {
 +    goto err;
 +  }
 +
 +  if (strlen(seckey_b32) != BASE32_NOPAD_LEN(CURVE25519_PUBKEY_LEN)) {
 +    log_warn(LD_REND, "Client authorization encoded base32 private key "
 +                      "length is invalid: %s", seckey_b32);
 +    goto err;
 +  }
 +
 +  auth = tor_malloc_zero(sizeof(hs_client_service_authorization_t));
 +  if (base32_decode((char *) auth->enc_seckey.secret_key,
 +                    sizeof(auth->enc_seckey.secret_key),
 +                    seckey_b32, strlen(seckey_b32)) < 0) {
 +    goto err;
 +  }
 +  strncpy(auth->onion_address, onion_address, HS_SERVICE_ADDR_LEN_BASE32);
 +
 +  /* Success. */
 +  goto done;
 +
 + err:
 +  client_service_authorization_free(auth);
 + done:
 +  /* It is also a good idea to wipe the private key. */
 +  if (seckey_b32) {
 +    memwipe(seckey_b32, 0, strlen(seckey_b32));
 +  }
 +  tor_assert(fields);
 +  SMARTLIST_FOREACH(fields, char *, s, tor_free(s));
 +  smartlist_free(fields);
 +  return auth;
 +}
 +
 +/* From a set of <b>options</b>, setup every client authorization detail
 + * found. Return 0 on success or -1 on failure. If <b>validate_only</b>
 + * is set, parse, warn and return as normal, but don't actually change
 + * the configuration. */
 +int
 +hs_config_client_authorization(const or_options_t *options,
 +                               int validate_only)
 +{
 +  int ret = -1;
 +  digest256map_t *auths = digest256map_new();
 +  char *key_dir = NULL;
 +  smartlist_t *file_list = NULL;
 +  char *client_key_str = NULL;
 +  char *client_key_file_path = NULL;
 +
 +  tor_assert(options);
 +
 +  /* There is no client auth configured. We can just silently ignore this
 +   * function. */
 +  if (!options->ClientOnionAuthDir) {
 +    ret = 0;
 +    goto end;
 +  }
 +
 +  key_dir = tor_strdup(options->ClientOnionAuthDir);
 +
 +  /* Make sure the directory exists and is private enough. */
 +  if (check_private_dir(key_dir, 0, options->User) < 0) {
 +    goto end;
 +  }
 +
 +  file_list = tor_listdir(key_dir);
 +  if (file_list == NULL) {
 +    log_warn(LD_REND, "Client authorization key directory %s can't be listed.",
 +             key_dir);
 +    goto end;
 +  }
 +
 +  SMARTLIST_FOREACH_BEGIN(file_list, char *, filename) {
 +
 +    hs_client_service_authorization_t *auth = NULL;
 +    ed25519_public_key_t identity_pk;
 +    log_info(LD_REND, "Loading a client authorization key file %s...",
 +             filename);
 +
 +    if (!auth_key_filename_is_valid(filename)) {
 +      log_notice(LD_REND, "Client authorization unrecognized filename %s. "
 +                          "File must end in .auth_private. Ignoring.",
 +                 filename);
 +      continue;
 +    }
 +
 +    /* Create a full path for a file. */
 +    client_key_file_path = hs_path_from_filename(key_dir, filename);
 +    client_key_str = read_file_to_str(client_key_file_path, 0, NULL);
 +    /* Free the file path immediately after using it. */
 +    tor_free(client_key_file_path);
 +
 +    /* If we cannot read the file, continue with the next file. */
 +    if (!client_key_str) {
 +      log_warn(LD_REND, "The file %s cannot be read.", filename);
 +      continue;
 +    }
 +
 +    auth = parse_auth_file_content(client_key_str);
 +    /* Free immediately after using it. */
 +    tor_free(client_key_str);
 +
 +    if (auth) {
 +      /* Parse the onion address to get an identity public key and use it
 +       * as a key of global map in the future. */
 +      if (hs_parse_address(auth->onion_address, &identity_pk,
 +                           NULL, NULL) < 0) {
 +        client_service_authorization_free(auth);
 +        log_warn(LD_REND, "The onion address \"%s\" is invalid in "
 +                          "file %s", filename, auth->onion_address);
 +        continue;
 +      }
 +
 +      if (digest256map_get(auths, identity_pk.pubkey)) {
 +        client_service_authorization_free(auth);
 +        log_warn(LD_REND, "Duplicate authorization for the same hidden "
 +                          "service address %s.",
 +                 safe_str_client(auth->onion_address));
 +        goto end;
 +      }
 +
 +      digest256map_set(auths, identity_pk.pubkey, auth);
 +      log_info(LD_REND, "Loaded a client authorization key file %s.",
 +               filename);
 +    }
 +  } SMARTLIST_FOREACH_END(filename);
 +
 +  /* Success. */
 +  ret = 0;
 +
 + end:
 +  tor_free(key_dir);
 +  tor_free(client_key_str);
 +  tor_free(client_key_file_path);
 +  if (file_list) {
 +    SMARTLIST_FOREACH(file_list, char *, s, tor_free(s));
 +    smartlist_free(file_list);
 +  }
 +
 +  if (!validate_only && ret == 0) {
 +    client_service_authorization_free_all();
 +    client_auths = auths;
 +  } else {
 +    digest256map_free(auths, client_service_authorization_free_void);
 +  }
 +
 +  return ret;
 +}
 +
 +/* This is called when a descriptor has arrived following a fetch request and
 + * has been stored in the client cache. Every entry connection that matches
 + * the service identity key in the ident will get attached to the hidden
 + * service circuit. */
 +void
 +hs_client_desc_has_arrived(const hs_ident_dir_conn_t *ident)
 +{
 +  time_t now = time(NULL);
 +  smartlist_t *conns = NULL;
 +
 +  tor_assert(ident);
 +
 +  conns = connection_list_by_type_state(CONN_TYPE_AP,
 +                                        AP_CONN_STATE_RENDDESC_WAIT);
 +  SMARTLIST_FOREACH_BEGIN(conns, connection_t *, base_conn) {
 +    const hs_descriptor_t *desc;
 +    entry_connection_t *entry_conn = TO_ENTRY_CONN(base_conn);
 +    const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(entry_conn);
 +
 +    /* Only consider the entry connections that matches the service for which
 +     * we just fetched its descriptor. */
 +    if (!edge_conn->hs_ident ||
 +        !ed25519_pubkey_eq(&ident->identity_pk,
 +                           &edge_conn->hs_ident->identity_pk)) {
 +      continue;
 +    }
 +    assert_connection_ok(base_conn, now);
 +
 +    /* We were just called because we stored the descriptor for this service
 +     * so not finding a descriptor means we have a bigger problem. */
 +    desc = hs_cache_lookup_as_client(&ident->identity_pk);
 +    if (BUG(desc == NULL)) {
 +      goto end;
 +    }
 +
 +    if (!hs_client_any_intro_points_usable(&ident->identity_pk, desc)) {
 +      log_info(LD_REND, "Hidden service descriptor is unusable. "
 +                        "Closing streams.");
 +      connection_mark_unattached_ap(entry_conn,
 +                                    END_STREAM_REASON_RESOLVEFAILED);
 +      /* We are unable to use the descriptor so remove the directory request
 +       * from the cache so the next connection can try again. */
 +      note_connection_attempt_succeeded(edge_conn->hs_ident);
-       goto end;
++      continue;
 +    }
 +
 +    log_info(LD_REND, "Descriptor has arrived. Launching circuits.");
 +
 +    /* Because the connection can now proceed to opening circuit and
 +     * ultimately connect to the service, reset those timestamp so the
 +     * connection is considered "fresh" and can continue without being closed
 +     * too early. */
 +    base_conn->timestamp_created = now;
 +    base_conn->timestamp_last_read_allowed = now;
 +    base_conn->timestamp_last_write_allowed = now;
 +    /* Change connection's state into waiting for a circuit. */
 +    base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
 +
 +    connection_ap_mark_as_pending_circuit(entry_conn);
 +  } SMARTLIST_FOREACH_END(base_conn);
 +
 + end:
 +  /* We don't have ownership of the objects in this list. */
 +  smartlist_free(conns);
 +}
 +
 +/* Return a newly allocated extend_info_t for a randomly chosen introduction
 + * point for the given edge connection identifier ident. Return NULL if we
 + * can't pick any usable introduction points. */
 +extend_info_t *
 +hs_client_get_random_intro_from_edge(const edge_connection_t *edge_conn)
 +{
 +  tor_assert(edge_conn);
 +
 +  return (edge_conn->hs_ident) ?
 +    client_get_random_intro(&edge_conn->hs_ident->identity_pk) :
 +    rend_client_get_random_intro(edge_conn->rend_data);
 +}
 +/* Called when get an INTRODUCE_ACK cell on the introduction circuit circ.
 + * Return 0 on success else a negative value is returned. The circuit will be
 + * closed or reuse to extend again to another intro point. */
 +int
 +hs_client_receive_introduce_ack(origin_circuit_t *circ,
 +                                const uint8_t *payload, size_t payload_len)
 +{
 +  int ret = -1;
 +
 +  tor_assert(circ);
 +  tor_assert(payload);
 +
 +  if (TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) {
 +    log_warn(LD_PROTOCOL, "Unexpected INTRODUCE_ACK on circuit %u.",
 +             (unsigned int) TO_CIRCUIT(circ)->n_circ_id);
 +    circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
 +    goto end;
 +  }
 +
 +  ret = (circ->hs_ident) ? handle_introduce_ack(circ, payload, payload_len) :
 +                           rend_client_introduction_acked(circ, payload,
 +                                                          payload_len);
 +  /* For path bias: This circuit was used successfully. NACK or ACK counts. */
 +  pathbias_mark_use_success(circ);
 +
 + end:
 +  return ret;
 +}
 +
 +/* Called when get a RENDEZVOUS2 cell on the rendezvous circuit circ.  Return
 + * 0 on success else a negative value is returned. The circuit will be closed
 + * on error. */
 +int
 +hs_client_receive_rendezvous2(origin_circuit_t *circ,
 +                              const uint8_t *payload, size_t payload_len)
 +{
 +  int ret = -1;
 +
 +  tor_assert(circ);
 +  tor_assert(payload);
 +
 +  /* Circuit can possibly be in both state because we could receive a
 +   * RENDEZVOUS2 cell before the INTRODUCE_ACK has been received. */
 +  if (TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_C_REND_READY &&
 +      TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED) {
 +    log_warn(LD_PROTOCOL, "Unexpected RENDEZVOUS2 cell on circuit %u. "
 +                          "Closing circuit.",
 +             (unsigned int) TO_CIRCUIT(circ)->n_circ_id);
 +    circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
 +    goto end;
 +  }
 +
 +  log_info(LD_REND, "Got RENDEZVOUS2 cell from hidden service on circuit %u.",
 +           TO_CIRCUIT(circ)->n_circ_id);
 +
 +  ret = (circ->hs_ident) ? handle_rendezvous2(circ, payload, payload_len) :
 +                           rend_client_receive_rendezvous(circ, payload,
 +                                                          payload_len);
 + end:
 +  return ret;
 +}
 +
 +/* Extend the introduction circuit circ to another valid introduction point
 + * for the hidden service it is trying to connect to, or mark it and launch a
 + * new circuit if we can't extend it.  Return 0 on success or possible
 + * success. Return -1 and mark the introduction circuit for close on permanent
 + * failure.
 + *
 + * On failure, the caller is responsible for marking the associated rendezvous
 + * circuit for close. */
 +int
 +hs_client_reextend_intro_circuit(origin_circuit_t *circ)
 +{
 +  int ret = -1;
 +  extend_info_t *ei;
 +
 +  tor_assert(circ);
 +
 +  ei = (circ->hs_ident) ?
 +    client_get_random_intro(&circ->hs_ident->identity_pk) :
 +    rend_client_get_random_intro(circ->rend_data);
 +  if (ei == NULL) {
 +    log_warn(LD_REND, "No usable introduction points left. Closing.");
 +    circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
 +    goto end;
 +  }
 +
 +  if (circ->remaining_relay_early_cells) {
 +    log_info(LD_REND, "Re-extending circ %u, this time to %s.",
 +             (unsigned int) TO_CIRCUIT(circ)->n_circ_id,
 +             safe_str_client(extend_info_describe(ei)));
 +    ret = circuit_extend_to_new_exit(circ, ei);
 +    if (ret == 0) {
 +      /* We were able to extend so update the timestamp so we avoid expiring
 +       * this circuit too early. The intro circuit is short live so the
 +       * linkability issue is minimized, we just need the circuit to hold a
 +       * bit longer so we can introduce. */
 +      TO_CIRCUIT(circ)->timestamp_dirty = time(NULL);
 +    }
 +  } else {
 +    log_info(LD_REND, "Closing intro circ %u (out of RELAY_EARLY cells).",
 +             (unsigned int) TO_CIRCUIT(circ)->n_circ_id);
 +    circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_FINISHED);
 +    /* connection_ap_handshake_attach_circuit will launch a new intro circ. */
 +    ret = 0;
 +  }
 +
 + end:
 +  extend_info_free(ei);
 +  return ret;
 +}
 +
 +/* Release all the storage held by the client subsystem. */
 +void
 +hs_client_free_all(void)
 +{
 +  /* Purge the hidden service request cache. */
 +  hs_purge_last_hid_serv_requests();
 +  client_service_authorization_free_all();
 +}
 +
 +/* Purge all potentially remotely-detectable state held in the hidden
 + * service client code. Called on SIGNAL NEWNYM. */
 +void
 +hs_client_purge_state(void)
 +{
 +  /* v2 subsystem. */
 +  rend_client_purge_state();
 +
 +  /* Cancel all descriptor fetches. Do this first so once done we are sure
 +   * that our descriptor cache won't modified. */
 +  cancel_descriptor_fetches();
 +  /* Purge the introduction point state cache. */
 +  hs_cache_client_intro_state_purge();
 +  /* Purge the descriptor cache. */
 +  hs_cache_purge_as_client();
 +  /* Purge the last hidden service request cache. */
 +  hs_purge_last_hid_serv_requests();
 +
 +  log_info(LD_REND, "Hidden service client state has been purged.");
 +}
 +
 +/* Called when our directory information has changed. */
 +void
 +hs_client_dir_info_changed(void)
 +{
 +  /* We have possibly reached the minimum directory information or new
 +   * consensus so retry all pending SOCKS connection in
 +   * AP_CONN_STATE_RENDDESC_WAIT state in order to fetch the descriptor. */
 +  retry_all_socks_conn_waiting_for_desc();
 +}
 +
 +#ifdef TOR_UNIT_TESTS
 +
 +STATIC digest256map_t *
 +get_hs_client_auths_map(void)
 +{
 +  return client_auths;
 +}
 +
 +#endif /* defined(TOR_UNIT_TESTS) */



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