Commit 196e6c1c authored by Nick Mathewson's avatar Nick Mathewson 🤹
Browse files

Support new INTRODUCE2 cell format 


svn:r2270
parent 86980cf6

src/or/rendservice.c

+21 −9
Original line number Diff line number Diff line
@@ -354,6 +354,8 @@ rend_service_introduce(circuit_t *circuit, const char *request, int request_len) 
  crypt_path_t *cpath = NULL;

  char serviceid[REND_SERVICE_ID_LEN+1];

  char hexcookie[9];

  int version;

  int nickname_field_len;



  base32_encode(serviceid, REND_SERVICE_ID_LEN+1,

                circuit->rend_pk_digest,10);
@@ -367,7 +369,7 @@ rend_service_introduce(circuit_t *circuit, const char *request, int request_len) 
  }



  /* min key length plus digest length plus nickname length */

  if (request_len < DIGEST_LEN+REND_COOKIE_LEN+(MAX_NICKNAME_LEN+1)+

  if (request_len < DIGEST_LEN+REND_COOKIE_LEN+(HEX_DIGEST_LEN+2)+

      DH_KEY_LEN+42){

    log_fn(LOG_WARN, "Got a truncated INTRODUCE2 cell on circ %d",

           circuit->n_circ_id);
@@ -401,19 +403,29 @@ rend_service_introduce(circuit_t *circuit, const char *request, int request_len) 
    log_fn(LOG_WARN, "Couldn't decrypt INTRODUCE2 cell");

    return -1;

  }

  ptr=memchr(buf,0,MAX_NICKNAME_LEN+1);

  if (!ptr || ptr == buf) {

  if (*buf == 1) {

    rp_nickname = buf+1;

    nickname_field_len = HEX_DIGEST_LEN+2;

    version = 1;

  } else {

    nickname_field_len = MAX_NICKNAME_LEN+1;

    rp_nickname = buf;

    version = 0;

  }

  ptr=memchr(rp_nickname,0,nickname_field_len);

  if (!ptr || ptr == rp_nickname) {

    log_fn(LOG_WARN, "Couldn't find a null-padded nickname in INTRODUCE2 cell");

    return -1;

  }

  if ((int)strspn(buf,LEGAL_NICKNAME_CHARACTERS) != ptr-buf) {

    log_fn(LOG_WARN, "Nickname in INTRODUCE2 cell contains illegal character.");

  if ((version == 0 && !is_legal_nickname(rp_nickname)) ||

      (version == 1 && !is_legal_nickname_or_hexdigest(rp_nickname)) ||

      (int)strspn(buf,LEGAL_NICKNAME_CHARACTERS) != ptr-buf) {

    log_fn(LOG_WARN, "Bad nickname in INTRODUCE2 cell.");

    return -1;

  }

  /* Okay, now we know that the nickname is at the start of the buffer. */

  rp_nickname = buf;

  ptr = buf+(MAX_NICKNAME_LEN+1);

  len -= (MAX_NICKNAME_LEN+1);

  /* Okay, now we know that a nickname is at the start of the buffer. */

  ptr = rp_nickname+nickname_field_len;

  len -= nickname_field_len;

  if (len != REND_COOKIE_LEN+DH_KEY_LEN) {

    log_fn(LOG_WARN, "Bad length for INTRODUCE2 cell.");

    return -1;