Commit 41ed9e97 authored by Nick Mathewson's avatar Nick Mathewson 🦀
Browse files

Regenerate RSA->ed25519 identity crosscertificate as needed

parent 5b33d95a

changes/bug22466_regenerate

0 → 100644
+8 −0
Original line number Diff line number Diff line 
  o Minor bugfixes (link handshake):

    - Lower the lifetime of the RSA->Ed25519 cross-certificate to

      six months, and regenerate it when it is within one month of expiring.

      Previously, we had generated this certificate at startup with

      a ten-year lifetime, but that could lead to weird behavior when

      Tor was started with a grossly inaccurate clock. Mitigates

      bug 22466; mitigation on 0.3.0.1-alpha.

src/or/routerkeys.c

+12 −3
Original line number Diff line number Diff line
@@ -668,6 +668,7 @@ static tor_cert_t *auth_key_cert = NULL; 


static uint8_t *rsa_ed_crosscert = NULL;

static size_t rsa_ed_crosscert_len = 0;

static time_t rsa_ed_crosscert_expiration = 0;



/**

 * Running as a server: load, reload, or refresh our ed25519 keys and
@@ -699,8 +700,10 @@ load_ed_keys(const or_options_t *options, time_t now) 
      tor_cert_free(cert);                      \

    cert = (newval);                            \

  } while (0)

#define HAPPENS_SOON(when, interval)            \

  ((when) < now + (interval))

#define EXPIRES_SOON(cert, interval)            \

  (!(cert) || (cert)->valid_until < now + (interval))

  (!(cert) || HAPPENS_SOON((cert)->valid_until, (interval)))



  /* XXXX support encrypted identity keys fully */
@@ -899,14 +902,19 @@ load_ed_keys(const or_options_t *options, time_t now) 
  if (options->command == CMD_KEYGEN)

    goto end;



  if (!rsa_ed_crosscert && server_mode(options)) {

  if (server_mode(options) &&

      (!rsa_ed_crosscert ||

       HAPPENS_SOON(rsa_ed_crosscert_expiration, 30*86400))) {

    uint8_t *crosscert;

    time_t expiration = now+6*30*86400; /* 6 months in the future. */

    ssize_t crosscert_len = tor_make_rsa_ed25519_crosscert(&id->pubkey,

                                                   get_server_identity_key(),

                                                   now+10*365*86400,/*XXXX*/

                                                   expiration,

                                                   &crosscert);

    tor_free(rsa_ed_crosscert);

    rsa_ed_crosscert_len = crosscert_len;

    rsa_ed_crosscert = crosscert;

    rsa_ed_crosscert_expiration = expiration;

  }



  if (!current_auth_key ||
@@ -1038,6 +1046,7 @@ should_make_new_ed_keys(const or_options_t *options, const time_t now) 
}



#undef EXPIRES_SOON

#undef HAPPENS_SOON



#ifdef TOR_UNIT_TESTS

/* Helper for unit tests: populate the ed25519 keys without saving or