phpseclib3 crypto

require '../vendor/autoload.php';

use phpseclib3\File\X509;
use phpseclib3\Crypt\PublicKeyLoader;
use phpseclib3\Crypt\RSA;

$texto_para_criptografar = "teste";
$x509 = new X509();
$cert = $x509->loadX509(file_get_contents('./teste.crt'));
$rsa = PublicKeyLoader::load($x509->getPublicKey());
$rsa = $rsa->withPadding(RSA::ENCRYPTION_PKCS1);
$cipher_text = base64_encode($rsa->encrypt($texto_para_criptografar));