Jose\KeyConverter\ECKey::initPrivateKey PHP Method

    private function initPrivateKey()
    {
        $this->addChild(new Integer(1));
        $this->addChild(new OctetString(bin2hex(Base64Url::decode($this->values['d']))));
        $oid = new ObjectIdentifier($this->getOID($this->values['crv']));
        $this->addChild(new ExplicitlyTaggedObject(0, $oid));
        $bits = '04';
        $bits .= bin2hex(Base64Url::decode($this->values['x']));
        $bits .= bin2hex(Base64Url::decode($this->values['y']));
        $bit = new BitString($bits);
        $this->addChild(new ExplicitlyTaggedObject(1, $bit));
    }