Commit 01966479 authored by Roger Dingledine's avatar Roger Dingledine
Browse files

start part-way through the ssl cert lifetime 

also, snap the start time and end time to a day boundary, since most
certs in the wild seem to do this.
parent edd6f022

src/common/tortls.c

+11 −5
Original line number Diff line number Diff line
@@ -234,7 +234,7 @@ static X509* tor_tls_create_certificate(crypto_pk_t *rsa, 
                                        crypto_pk_t *rsa_sign,

                                        const char *cname,

                                        const char *cname_sign,

                                        unsigned int lifetime);

                                        unsigned int cert_lifetime);



static int tor_tls_context_init_one(tor_tls_context_t **ppcontext,

                                    crypto_pk_t *identity,
@@ -608,9 +608,10 @@ tor_x509_name_new(const char *cname) 
/** Generate and sign an X509 certificate with the public key <b>rsa</b>,

 * signed by the private key <b>rsa_sign</b>.  The commonName of the

 * certificate will be <b>cname</b>; the commonName of the issuer will be

 * <b>cname_sign</b>. The cert will be valid for <b>cert_lifetime</b> seconds

 * starting from now.  Return a certificate on success, NULL on

 * failure.

 * <b>cname_sign</b>. The cert will be valid for <b>cert_lifetime</b>

 * seconds, starting from some time in the past.

 *

 * Return a certificate on success, NULL on failure.

 */

static X509 *

tor_tls_create_certificate(crypto_pk_t *rsa,
@@ -632,7 +633,12 @@ tor_tls_create_certificate(crypto_pk_t *rsa, 


  tor_tls_init();



  start_time = time(NULL);

  /* Make sure we're part-way through the certificate lifetime, rather

   * than having it start right now. Don't choose quite uniformly, since

   * then we might pick a time where we're about to expire. Lastly, be

   * sure to start on a day boundary. */

  start_time = time(NULL) - crypto_rand_int(cert_lifetime) + 2*24*3600;

  start_time -= start_time % (24*3600);



  tor_assert(rsa);

  tor_assert(cname);

src/or/router.c

+12 −2
Original line number Diff line number Diff line
@@ -660,8 +660,18 @@ router_initialize_tls_context(void) 
      flags |= TOR_TLS_CTX_USE_ECDHE_P224;

  }

  if (!lifetime) { /* we should guess a good ssl cert lifetime */

    /* choose between 1 and 365 days */

    lifetime = 1*24*3600 + crypto_rand_int(364*24*3600);



    /* choose between 5 and 365 days, and round to the day */

    lifetime = 5*24*3600 + crypto_rand_int(361*24*3600);

    lifetime -= lifetime % (24*3600);



    if (crypto_rand_int(2)) {

      /* Half the time we expire at midnight, and half the time we expire

       * one second before midnight. (Some CAs wobble their expiry times a

       * bit in practice, perhaps to reduce collision attacks; see ticket

       * 8443 for details about observed certs in the wild.) */

      lifetime--;

    }

  }



  /* It's ok to pass lifetime in as an unsigned int, since