code: private static int initializeClockSkew() {
  //        Integer tmp = java.security.AccessController.doPrivileged(
  //                new GetIntegerAction("com.sun.security.ocsp.clockSkew"));
          Integer tmp = Integer.getInteger("com.sun.security.ocsp.clockSkew");
          if (tmp == null || tmp < 0) {
              return DEFAULT_MAX_CLOCK_SKEW;
          }
          // Convert to milliseconds, as the system property will be
          // specified in seconds
          return tmp * 1000;
      }
docs: Initialize the maximum allowable clock skew by getting the OCSP
  clock skew system property. If the property has not been set, or if its
  value is negative, set the skew to the default.