Commit b67657bd authored by Sebastian Hahn's avatar Sebastian Hahn
Browse files

Properly handle non-terminated strings 

Treat strings returned from signed_descriptor_get_body_impl() as not
NUL-terminated. Since the length of the strings is available, this is
not a big problem.

Discovered by rieo.
parent 86828e20

ChangeLog

+2 −0
Original line number Diff line number Diff line
@@ -9,6 +9,8 @@ Changes in version 0.2.1.25 - 2010-??-?? 
      fixes bug 1255.

    - Fix another dereference-then-NULL-check sequence. Bugfix on

      0.2.1.14-rc. Discovered by ekir, fixes bug 1256.

    - Make sure we treat potentially not NUL-terminated strings correctly.

      Bugfix on 0.1.1.13-alpha. Discovered by rieo, fixes bug 1257.



Changes in version 0.2.1.24 - 2010-02-21

  Tor 0.2.1.24 makes Tor work again on the latest OS X -- this time

src/or/or.h

+1 −1
Original line number Diff line number Diff line
@@ -4566,7 +4566,7 @@ typedef struct tor_version_t { 
  int svn_revision;

} tor_version_t;



int router_get_router_hash(const char *s, char *digest);

int router_get_router_hash(const char *s, size_t s_len, char *digest);

int router_get_dir_hash(const char *s, char *digest);

int router_get_runningrouters_hash(const char *s, char *digest);

int router_get_networkstatus_v2_hash(const char *s, char *digest);

src/or/router.c

+2 −1
Original line number Diff line number Diff line
@@ -1418,6 +1418,7 @@ router_rebuild_descriptor(int force) 
    ei->cache_info.send_unencrypted = 1;



  router_get_router_hash(ri->cache_info.signed_descriptor_body,

                         strlen(ri->cache_info.signed_descriptor_body),

                         ri->cache_info.signed_descriptor_digest);



  routerinfo_set_country(ri);
@@ -1784,7 +1785,7 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router, 
  strlcpy(s+written, "router-signature\n", maxlen-written);

  written += strlen(s+written);

  s[written] = '\0';

  if (router_get_router_hash(s, digest) < 0) {

  if (router_get_router_hash(s, strlen(s), digest) < 0) {

    return -1;

  }

src/or/routerlist.c

+0 −2
Original line number Diff line number Diff line
@@ -577,8 +577,6 @@ signed_desc_append_to_journal(signed_descriptor_t *desc, 
  const char *body = signed_descriptor_get_body_impl(desc,1);

  size_t len = desc->signed_descriptor_len + desc->annotations_len;



  tor_assert(len == strlen(body));



  if (append_bytes_to_file(fname, body, len, 1)) {

    log_warn(LD_FS, "Unable to store router descriptor");

    tor_free(fname);

src/or/routerparse.c

+26 −19
Original line number Diff line number Diff line
@@ -451,9 +451,10 @@ static int router_add_exit_policy(routerinfo_t *router,directory_token_t *tok); 
static addr_policy_t *router_parse_addr_policy(directory_token_t *tok);

static addr_policy_t *router_parse_addr_policy_private(directory_token_t *tok);



static int router_get_hash_impl(const char *s, char *digest,

static int router_get_hash_impl(const char *s, size_t s_len, char *digest,

                                const char *start_str, const char *end_str,

                                char end_char);



static void token_free(directory_token_t *tok);

static smartlist_t *find_all_exitpolicy(smartlist_t *s);

static directory_token_t *_find_by_keyword(smartlist_t *s,
@@ -504,7 +505,7 @@ static int tor_version_same_series(tor_version_t *a, tor_version_t *b); 
int

router_get_dir_hash(const char *s, char *digest)

{

  return router_get_hash_impl(s,digest,

  return router_get_hash_impl(s, strlen(s), digest,

                              "signed-directory","\ndirectory-signature",'\n');

}
@@ -512,9 +513,9 @@ router_get_dir_hash(const char *s, char *digest) 
 * <b>s</b>. Return 0 on success, -1 on failure.

 */

int

router_get_router_hash(const char *s, char *digest)

router_get_router_hash(const char *s, size_t s_len, char *digest)

{

  return router_get_hash_impl(s,digest,

  return router_get_hash_impl(s, s_len, digest,

                              "router ","\nrouter-signature", '\n');

}
@@ -524,7 +525,7 @@ router_get_router_hash(const char *s, char *digest) 
int

router_get_runningrouters_hash(const char *s, char *digest)

{

  return router_get_hash_impl(s,digest,

  return router_get_hash_impl(s, strlen(s), digest,

                              "network-status","\ndirectory-signature", '\n');

}
@@ -533,7 +534,7 @@ router_get_runningrouters_hash(const char *s, char *digest) 
int

router_get_networkstatus_v2_hash(const char *s, char *digest)

{

  return router_get_hash_impl(s,digest,

  return router_get_hash_impl(s, strlen(s), digest,

                              "network-status-version","\ndirectory-signature",

                              '\n');

}
@@ -543,8 +544,9 @@ router_get_networkstatus_v2_hash(const char *s, char *digest) 
int

router_get_networkstatus_v3_hash(const char *s, char *digest)

{

  return router_get_hash_impl(s,digest,

                              "network-status-version","\ndirectory-signature",

  return router_get_hash_impl(s, strlen(s), digest,

                              "network-status-version",

                              "\ndirectory-signature",

                              ' ');

}
@@ -553,7 +555,8 @@ router_get_networkstatus_v3_hash(const char *s, char *digest) 
int

router_get_extrainfo_hash(const char *s, char *digest)

{

  return router_get_hash_impl(s,digest,"extra-info","\nrouter-signature",'\n');

  return router_get_hash_impl(s, strlen(s), digest, "extra-info",

                              "\nrouter-signature",'\n');

}



/** Helper: used to generate signatures for routers, directories and
@@ -1118,6 +1121,8 @@ dump_distinct_digest_count(int severity) 
 * s through end into the signed_descriptor_body of the resulting

 * routerinfo_t.

 *

 * If <b>end</b> is NULL, <b>s</b> must be properly NULL-terminated.

 *

 * If <b>allow_annotations</b>, it's okay to encounter annotations in <b>s</b>

 * before the router; if it's false, reject the router if it's annotated.  If

 * <b>prepend_annotations</b> is set, it should contain some annotations:
@@ -1180,7 +1185,7 @@ router_parse_entry_from_string(const char *s, const char *end, 
    }

  }



  if (router_get_router_hash(s, digest) < 0) {

  if (router_get_router_hash(s, end - s, digest) < 0) {

    log_warn(LD_DIR, "Couldn't compute router hash.");

    goto err;

  }
@@ -1600,7 +1605,7 @@ authority_cert_parse_from_string(const char *s, const char **end_of_string) 
    log_warn(LD_DIR, "Error tokenizing key certificate");

    goto err;

  }

  if (router_get_hash_impl(s, digest, "dir-key-certificate-version",

  if (router_get_hash_impl(s, strlen(s), digest, "dir-key-certificate-version",

                           "\ndir-key-certification", '\n') < 0)

    goto err;

  tok = smartlist_get(tokens, 0);
@@ -2159,6 +2164,7 @@ networkstatus_v2_parse_from_string(const char *s) 
  return ns;

}





/** Parse a v3 networkstatus vote, opinion, or consensus (depending on

 * ns_type), from <b>s</b>, and return the result.  Return NULL on failure. */

networkstatus_t *
@@ -3295,12 +3301,12 @@ find_all_exitpolicy(smartlist_t *s) 
 * If no such substring exists, return -1.

 */

static int

router_get_hash_impl(const char *s, char *digest,

router_get_hash_impl(const char *s, size_t s_len, char *digest,

                            const char *start_str,

                            const char *end_str, char end_c)

{

  char *start, *end;

  start = strstr(s, start_str);

  const char *start, *end;

  start = tor_memstr(s, s_len, start_str);

  if (!start) {

    log_warn(LD_DIR,"couldn't find start of hashed material \"%s\"",start_str);

    return -1;
@@ -3311,12 +3317,13 @@ router_get_hash_impl(const char *s, char *digest, 
             start_str);

    return -1;

  }

  end = strstr(start+strlen(start_str), end_str);

  end = tor_memstr(start+strlen(start_str),

                   s_len - (start-s) - strlen(start_str), end_str);

  if (!end) {

    log_warn(LD_DIR,"couldn't find end of hashed material \"%s\"",end_str);

    return -1;

  }

  end = strchr(end+strlen(end_str), end_c);

  end = memchr(end+strlen(end_str), end_c, s_len - (end-s) - strlen(end_str));

  if (!end) {

    log_warn(LD_DIR,"couldn't find EOL");

    return -1;
@@ -3564,7 +3571,7 @@ rend_parse_v2_service_descriptor(rend_service_descriptor_t **parsed_out, 
    goto err;

  }

  /* Compute descriptor hash for later validation. */

  if (router_get_hash_impl(desc, desc_hash,

  if (router_get_hash_impl(desc, strlen(desc), desc_hash,

                           "rendezvous-service-descriptor ",

                           "\nsignature", '\n') < 0) {

    log_warn(LD_REND, "Couldn't compute descriptor hash.");