private function initPublicKey()
{
$oid_sequence = new Sequence();
$oid_sequence->addChild(new ObjectIdentifier('1.2.840.113549.1.1.1'));
$oid_sequence->addChild(new NullObject());
$this->addChild($oid_sequence);
$n = new Integer($this->fromBase64ToInteger($this->values['n']));
$e = new Integer($this->fromBase64ToInteger($this->values['e']));
$key_sequence = new Sequence();
$key_sequence->addChild($n);
$key_sequence->addChild($e);
$key_bit_string = new BitString(bin2hex($key_sequence->getBinary()));
$this->addChild($key_bit_string);
}