Commit 466abece authored by Roger Dingledine's avatar Roger Dingledine
Browse files

Our new v2 hidden service descriptor format allows descriptors 

that have no introduction points. But Tor crashed when we tried
to build a descriptor with no intro points (and it would have
crashed if we had tried to parse one). Bugfix on 0.2.0.x; patch
by Karsten Loesing.


svn:r12579
parent 86551d41

ChangeLog

+5 −0
Original line number Diff line number Diff line
@@ -13,6 +13,11 @@ Changes in version 0.2.0.13-alpha - 2007-11-?? 
    - Don't crash if we get an unexpected value for the

      PublishServerDescriptor config option. Reported by Matt Edman;

      bugfix on 0.2.0.9-alpha.

    - Our new v2 hidden service descriptor format allows descriptors

      that have no introduction points. But Tor crashed when we tried

      to build a descriptor with no intro points (and it would have

      crashed if we had tried to parse one). Bugfix on 0.2.0.x; patch

      by Karsten Loesing.





Changes in version 0.2.0.12-alpha - 2007-11-16

src/or/rendcommon.c

+22 −8
Original line number Diff line number Diff line
@@ -354,7 +354,8 @@ rend_encode_v2_descriptors(smartlist_t *desc_strs_out, 
  seconds_valid = period * REND_TIME_PERIOD_V2_DESC_VALIDITY +

                  get_seconds_valid(now, service_id);

  /* Assemble, possibly encrypt, and encode introduction points. */

  if (rend_encode_v2_intro_points(&ipos_base64, desc, descriptor_cookie) < 0) {

  if (desc->n_intro_points > 0 &&

      rend_encode_v2_intro_points(&ipos_base64, desc, descriptor_cookie) < 0) {

    log_warn(LD_REND, "Encoding of introduction points did not succeed.");

    tor_free(ipos_base64);

    return -1;
@@ -418,16 +419,12 @@ rend_encode_v2_descriptors(smartlist_t *desc_strs_out, 
             "permanent-key\n%s"

             "secret-id-part %s\n"

             "publication-time %s\n"

             "protocol-versions %s\n"

             "introduction-points\n"

             "-----BEGIN MESSAGE-----\n%s"

             "-----END MESSAGE-----\n",

             "protocol-versions %s\n",

        desc_id_base32,

        permanent_key,

        secret_id_part_base32,

        published,

        protocol_versions_string,

        ipos_base64);

        protocol_versions_string);

    tor_free(permanent_key);

    if (result < 0) {

      log_warn(LD_BUG, "Descriptor ran out of room.");
@@ -435,6 +432,20 @@ rend_encode_v2_descriptors(smartlist_t *desc_strs_out, 
      goto err;

    }

    written = result;

    /* Add introduction points. */

    if (ipos_base64) {

      result = tor_snprintf(desc_str + written, desc_len - written,

                            "introduction-points\n"

                            "-----BEGIN MESSAGE-----\n%s"

                            "-----END MESSAGE-----\n",

                            ipos_base64);

      if (result < 0) {

        log_warn(LD_BUG, "could not write introduction points.");

        tor_free(desc_str);

        goto err;

      }

      written += result;

    }

    /* Add signature. */

    strlcpy(desc_str + written, "signature\n", desc_len - written);

    written += strlen(desc_str + written);
@@ -1075,12 +1086,15 @@ rend_cache_store_v2_desc_as_client(const char *desc, 
    return -1;

  }

  /* Decode/decrypt introduction points. */

  if (rend_decrypt_introduction_points(parsed, descriptor_cookie,

  if (intro_content &&

      rend_decrypt_introduction_points(parsed, descriptor_cookie,

                                       intro_content, intro_size) < 0) {

    log_warn(LD_PROTOCOL,"Couldn't decode/decrypt introduction points.");

    rend_service_descriptor_free(parsed);

    tor_free(intro_content);

    return -1;

  } else {

    parsed->n_intro_points = 0;

  }

  /* We don't need the encoded/encrypted introduction points any longer. */

  tor_free(intro_content);

src/or/routerparse.c

+14 −10
Original line number Diff line number Diff line
@@ -324,7 +324,7 @@ static token_rule_t desc_token_table[] = { 
  T1("secret-id-part", R_SECRET_ID_PART, EQ(1), NO_OBJ),

  T1("publication-time", R_PUBLICATION_TIME, CONCAT_ARGS, NO_OBJ),

  T1("protocol-versions", R_PROTOCOL_VERSIONS, EQ(1), NO_OBJ),

  T1("introduction-points", R_INTRODUCTION_POINTS, NO_ARGS, NEED_OBJ),

  T01("introduction-points", R_INTRODUCTION_POINTS, NO_ARGS, NEED_OBJ),

  T1_END("signature", R_SIGNATURE, NO_ARGS, NEED_OBJ),

  END_OF_TABLE

};
@@ -3232,7 +3232,7 @@ rend_parse_v2_service_descriptor(rend_service_descriptor_t **parsed_out, 
  /* Set length of encoded descriptor. */

  *encoded_size_out = eos - desc;

  /* Check min allowed length of token list. */

  if (smartlist_len(tokens) < 8) {

  if (smartlist_len(tokens) < 7) {

    log_warn(LD_REND, "Impossibly short descriptor.");

    goto err;

  }
@@ -3318,7 +3318,7 @@ rend_parse_v2_service_descriptor(rend_service_descriptor_t **parsed_out, 
  smartlist_free(versions);

  /* Parse encrypted introduction points. Don't verify. */

  tok = find_first_by_keyword(tokens, R_INTRODUCTION_POINTS);

  tor_assert(tok);

  if (tok) {

    if (strcmp(tok->object_type, "MESSAGE")) {

      log_warn(LD_DIR, "Bad object type: introduction points should be of "

               "type MESSAGE");
@@ -3327,6 +3327,10 @@ rend_parse_v2_service_descriptor(rend_service_descriptor_t **parsed_out, 
    *intro_points_encrypted_out = tok->object_body;

    *intro_points_encrypted_size_out = tok->object_size;

    tok->object_body = NULL; /* Prevent free. */

  } else {

    *intro_points_encrypted_out = NULL;

    *intro_points_encrypted_size_out = 0;

  }

  /* Parse and verify signature. */

  tok = find_first_by_keyword(tokens, R_SIGNATURE);

  tor_assert(tok);