/** Send the establish-rendezvous cell along a rendezvous circuit. if
* it fails, mark the circ for close and return -1. else return 0.
*/
static int
rend_client_send_establish_rendezvous(origin_circuit_t *circ)
{
tor_assert(circ->base_.purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND);
tor_assert(circ->rend_data);
log_info(LD_REND, "Sending an ESTABLISH_RENDEZVOUS cell");
if (crypto_rand(circ->rend_data->rend_cookie, REND_COOKIE_LEN) < 0) {
log_warn(LD_BUG, "Internal error: Couldn't produce random cookie.");
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
return -1;
}
/* Set timestamp_dirty, because circuit_expire_building expects it,
* and the rend cookie also means we've used the circ. */
circ->base_.timestamp_dirty = time(NULL);
/* We've attempted to use this circuit. Probe it if we fail */
pathbias_count_use_attempt(circ);
if (relay_send_command_from_edge(0, TO_CIRCUIT(circ),
RELAY_COMMAND_ESTABLISH_RENDEZVOUS,
circ->rend_data->rend_cookie,
REND_COOKIE_LEN,
circ->cpath->prev)<0) {
/* circ is already marked for close */
log_warn(LD_GENERAL, "Couldn't send ESTABLISH_RENDEZVOUS cell");
return -1;
}
return 0;
}
/* Send an ESTABLISH_RENDEZVOUS cell along the rendezvous circuit circ. On
* success, 0 is returned else -1 and the circuit is marked for close. */
int
hs_circ_send_establish_rendezvous(origin_circuit_t *circ)
{
ssize_t cell_len = 0;
uint8_t cell[RELAY_PAYLOAD_SIZE] = {0};
tor_assert(circ);
tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND);
log_info(LD_REND, "Send an ESTABLISH_RENDEZVOUS cell on circuit %u",
TO_CIRCUIT(circ)->n_circ_id);
/* Set timestamp_dirty, because circuit_expire_building expects it,
* and the rend cookie also means we've used the circ. */
TO_CIRCUIT(circ)->timestamp_dirty = time(NULL);
/* We've attempted to use this circuit. Probe it if we fail */
pathbias_count_use_attempt(circ);
/* Generate the RENDEZVOUS_COOKIE and place it in the identifier so we can
* complete the handshake when receiving the acknowledgement. */
crypto_rand((char *) circ->hs_ident->rendezvous_cookie, HS_REND_COOKIE_LEN);
/* Generate the client keypair. No need to be extra strong, not long term */
curve25519_keypair_generate(&circ->hs_ident->rendezvous_client_kp, 0);
cell_len =
hs_cell_build_establish_rendezvous(circ->hs_ident->rendezvous_cookie,
cell);
if (BUG(cell_len < 0)) {
goto err;
}
if (relay_send_command_from_edge(CONTROL_CELL_ID, TO_CIRCUIT(circ),
RELAY_COMMAND_ESTABLISH_RENDEZVOUS,
(const char *) cell, cell_len,
circ->cpath->prev) < 0) {
/* Circuit has been marked for close */
log_warn(LD_REND, "Unable to send ESTABLISH_RENDEZVOUS cell on "
"circuit %u", TO_CIRCUIT(circ)->n_circ_id);
memwipe(cell, 0, cell_len);
goto err;
}
memwipe(cell, 0, cell_len);
return 0;
err:
return -1;
}
/* For a given introduction point and an introduction circuit, send the
* ESTABLISH_INTRO cell. The service object is used for logging. This can fail
* and if so, the circuit is closed and the intro point object is flagged
* that the circuit is not established anymore which is important for the
* retry mechanism. */
static void
send_establish_intro(const hs_service_t *service,
hs_service_intro_point_t *ip, origin_circuit_t *circ)
{
ssize_t cell_len;
uint8_t payload[RELAY_PAYLOAD_SIZE];
tor_assert(service);
tor_assert(ip);
tor_assert(circ);
/* Encode establish intro cell. */
cell_len = hs_cell_build_establish_intro(circ->cpath->prev->rend_circ_nonce,
ip, payload);
if (cell_len < 0) {
log_warn(LD_REND, "Unable to encode ESTABLISH_INTRO cell for service %s "
"on circuit %u. Closing circuit.",
safe_str_client(service->onion_address),
TO_CIRCUIT(circ)->n_circ_id);
goto err;
}
/* Send the cell on the circuit. */
if (relay_send_command_from_edge(CONTROL_CELL_ID, TO_CIRCUIT(circ),
RELAY_COMMAND_ESTABLISH_INTRO,
(char *) payload, cell_len,
circ->cpath->prev) < 0) {
log_info(LD_REND, "Unable to send ESTABLISH_INTRO cell for service %s "
"on circuit %u.",
safe_str_client(service->onion_address),
TO_CIRCUIT(circ)->n_circ_id);
/* On error, the circuit has been closed. */
goto done;
}
/* Record the attempt to use this circuit. */
pathbias_count_use_attempt(circ);
goto done;
err:
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
done:
memwipe(payload, 0, sizeof(payload));
}
