Commit 50ad3939 authored by Nick Mathewson's avatar Nick Mathewson 🦀
Browse files

Code to blacklist authority signing keys 

(I need a list of actual signing keys to blacklist.)
parent 2658e70d

changes/bug11464_023

0 → 100644
+5 −0
Original line number Diff line number Diff line 
  o Major features (security):

    - Block every authority signing key that was used on an authority

      vulnerable to the "heartbleed" bug in openssl (CVE-2014-0160).

      (We don't have any evidence that these keys _were_ compromised;

      we're doing this to be prudent.) Resolves ticket 11464.

src/or/networkstatus.c

+11 −0
Original line number Diff line number Diff line
@@ -453,6 +453,17 @@ networkstatus_check_document_signature(const networkstatus_t *consensus, 
                 DIGEST_LEN))

    return -1;



  if (authority_cert_is_blacklisted(cert)) {

    /* We implement blacklisting for authority signing keys by treating

     * all their signatures as always bad. That way we don't get into

     * crazy loops of dropping and re-fetching signatures. */

    log_warn(LD_DIR, "Ignoring a consensus signature made with deprecated"

             " signing key %s",

             hex_str(cert->signing_key_digest, DIGEST_LEN));

    sig->bad_signature = 1;

    return 0;

  }



  signed_digest_len = crypto_pk_keysize(cert->signing_key);

  signed_digest = tor_malloc(signed_digest_len);

  if (crypto_pk_public_checksig(cert->signing_key,

src/or/routerlist.c

+22 −0
Original line number Diff line number Diff line
@@ -458,6 +458,28 @@ authority_cert_dl_failed(const char *id_digest, int status) 
  download_status_failed(&cl->dl_status, status);

}



static const char *BAD_SIGNING_KEYS[] = {

  "----------------------------------------",

  NULL,

};



/** DOCDOC */

int

authority_cert_is_blacklisted(const authority_cert_t *cert)

{

  char hex_digest[HEX_DIGEST_LEN+1];

  int i;

  base16_encode(hex_digest, sizeof(hex_digest),

                cert->signing_key_digest, sizeof(cert->signing_key_digest));



  for (i = 0; BAD_SIGNING_KEYS[i]; ++i) {

    if (!strcasecmp(hex_digest, BAD_SIGNING_KEYS[i])) {

      return 1;

    }

  }

  return 0;

}



/** Return true iff when we've been getting enough failures when trying to

 * download the certificate with ID digest <b>id_digest</b> that we're willing

 * to start bugging the user about it. */

src/or/routerlist.h

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ void authority_cert_dl_failed(const char *id_digest, int status); 
void authority_certs_fetch_missing(networkstatus_t *status, time_t now);

int router_reload_router_list(void);

int authority_cert_dl_looks_uncertain(const char *id_digest);

int authority_cert_is_blacklisted(const authority_cert_t *cert);

smartlist_t *router_get_trusted_dir_servers(void);



const routerstatus_t *router_pick_directory_server(dirinfo_type_t type,

src/or/routerparse.c

+8 −0
Original line number Diff line number Diff line
@@ -3053,6 +3053,14 @@ networkstatus_parse_vote_from_string(const char *s, const char **eos_out, 
        log_warn(LD_DIR,"Mismatch between identities in certificate and vote");

        goto err;

      }

      if (ns->type != NS_TYPE_CONSENSUS) {

        if (authority_cert_is_blacklisted(ns->cert)) {

          log_warn(LD_DIR, "Rejecting vote signature made with blacklisted "

                   "signing key %s",

                   hex_str(ns->cert->signing_key_digest, DIGEST_LEN));

          goto err;

        }

      }

      voter->address = tor_strdup(tok->args[2]);

      if (!tor_inet_aton(tok->args[3], &in)) {

        log_warn(LD_DIR, "Error decoding IP address %s in network-status.",