escribed <a href="https://www.openssl.org/docs/manmaster/apps/ciphers.html">here</a>.
      <br/>
      Default is expected to change overtime to provide highest security level. Do not rely on its exact value.
    </p>
    <p>
      <tt>pem-password-callback</tt>. Sets the default password callback called when loading/storing a PEM certificate with encryption.
      <br/>
      Please note: this must be CFFI callback i.e. defined as <tt>(cffi:defcallback <name> :int
        ((buf :pointer) (size :int) (rwfl