Commit e17cc3f0 authored by George Kadianakis's avatar George Kadianakis Committed by Nick Mathewson
Browse files

prop224 prepwork: Finish decoupling old ESTABLISH_INTRO creation logic.

parent b5b34e62

src/or/rendservice.c

+46 −21
Original line number Diff line number Diff line
@@ -2986,38 +2986,55 @@ count_intro_point_circuits(const rend_service_t *service) 
  return num_ipos;

}



static size_t

/* 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.

 */

STATIC ssize_t

encode_establish_intro_cell_legacy(char *cell_body_out, crypto_pk_t *intro_key,

                                   char *rend_circ_nonce)

{

/* Use the intro key instead of the service key in ESTABLISH_INTRO. */

  crypto_pk_t *intro_key = circuit->intro_key;

  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, buf+2,

  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.");

    reason = END_CIRC_REASON_INTERNAL;

    goto err;

  }

  len = r;

  set_uint16(buf, htons((uint16_t)len));

  set_uint16(cell_body_out, htons((uint16_t)len));

  len += 2;

  memcpy(auth, circuit->cpath->prev->rend_circ_nonce, DIGEST_LEN);

  memcpy(auth, rend_circ_nonce, DIGEST_LEN);

  memcpy(auth+DIGEST_LEN, "INTRODUCE", 9);

  if (crypto_digest(buf+len, auth, DIGEST_LEN+9))



  if (crypto_digest(cell_body_out+len, auth, DIGEST_LEN+9))

    goto err;

  len += 20;

  note_crypto_pk_op(REND_SERVER);

  r = crypto_pk_private_sign_digest(intro_key, buf+len, sizeof(buf)-len,

                                    buf, len);

  r = crypto_pk_private_sign_digest(intro_key, cell_body_out+len,

                                    sizeof(cell_body_out)-len,

                                    cell_body_out, len);

  if (r<0) {

    log_warn(LD_BUG, "Internal error: couldn't sign introduction request.");

    reason = END_CIRC_REASON_INTERNAL;

    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:
@@ -3027,8 +3044,7 @@ void 
rend_service_intro_has_opened(origin_circuit_t *circuit)

{

  rend_service_t *service;

  int r;

  char auth[DIGEST_LEN + 9];

  char buf[RELAY_PAYLOAD_SIZE];

  char serviceid[REND_SERVICE_ID_LEN_BASE32+1];

  int reason = END_CIRC_REASON_TORPROTOCOL;

  const char *rend_pk_digest;
@@ -3103,6 +3119,16 @@ rend_service_intro_has_opened(origin_circuit_t *circuit) 
           (unsigned)circuit->base_.n_circ_id, serviceid);

  circuit_log_path(LOG_INFO, LD_REND, circuit);



  /* Send the ESTABLISH_INTRO cell */

  {

    ssize_t len;

    len = encode_establish_intro_cell_legacy(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) {
@@ -3111,6 +3137,7 @@ rend_service_intro_has_opened(origin_circuit_t *circuit) 
             serviceid, (unsigned)circuit->base_.n_circ_id);

      goto done;

    }

  }



  /* We've attempted to use this circuit */

  pathbias_count_use_attempt(circuit);
@@ -3121,7 +3148,6 @@ rend_service_intro_has_opened(origin_circuit_t *circuit) 
  circuit_mark_for_close(TO_CIRCUIT(circuit), reason);

 done:

  memwipe(buf, 0, sizeof(buf));

  memwipe(auth, 0, sizeof(auth));

  memwipe(serviceid, 0, sizeof(serviceid));



  return;
@@ -4284,4 +4310,3 @@ 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;

}

src/or/rendservice.h

+3 −1
Original line number Diff line number Diff line
@@ -119,7 +119,9 @@ typedef struct rend_service_t { 


STATIC void rend_service_free(rend_service_t *service);

STATIC char *rend_service_sos_poison_path(const rend_service_t *service);



STATIC ssize_t encode_establish_intro_cell_legacy(char *cell_body_out,

                                                  crypto_pk_t *intro_key,

                                                  char *rend_circ_nonce);

#endif



int num_rend_services(void);