include '../phpseclib/vendor/autoload.php';
$privKey = new \phpseclib\Crypt\RSA();
$private = file_get_contents('private.pem');
$privKey->setPassword('VdcpDTWTc5Aehxgv2uL9haaFddDBhrc8uCMG3ykg');
$privKey->load($private);
$pubKey = new \phpseclib\Crypt\RSA();
$public = file_get_contents('public.pem');
$pubKey->load($public);
$subject = new \phpseclib\File\X509();
$subject->setDNProp('id-at-organizationName', 'www.test.com');
$subject->setDNProp('name', 'Name Inc.');
$subject->setDNProp('emailaddress', '*****@*****.**');
$subject->setDNProp('postalcode', '90210');
$subject->setDNProp('state', 'California');
$subject->setDNProp('streetaddress', 'Infinite Loop 1');
$subject->setPublicKey($pubKey);
$issuer = new \phpseclib\File\X509();
$issuer->setPrivateKey($privKey);
$issuer->setDN($subject->getDN());
$x509 = new \phpseclib\File\X509();
$x509->setStartDate(date('Y-m-d H:i:s'));
$x509->setEndDate(date('Y-m-d H:i:s', strtotime('+1 year')));
$result = $x509->sign($issuer, $subject, 'sha512WithRSAEncryption');
$certificate = $x509->saveX509($result);
$filepublic = fopen('cert.crt', 'w');
fwrite($filepublic, $certificate);
fclose($filepublic);
echo 'Cert has been generated' . PHP_EOL;
echo $certificate . PHP_EOL;
echo 'Valid from= ' . $x509->startDate . PHP_EOL;
echo 'Valid to= ' . $x509->endDate . PHP_EOL;
<?php
include '../phpseclib/vendor/autoload.php';
$x509 = new \phpseclib\File\X509();
$cert = file_get_contents('cert.crt');
$x509->loadX509($cert);
echo '<pre>';
#INFORMATIONS
echo 'Certificate for website: ' . $x509->getDN('id-ce-subjectAltName')['rdnSequence']['0']['0']['value']['utf8String'] . "\r\n";
echo 'Valid from: ' . $x509->startDate . ' to: ' . $x509->endDate . "\r\n";
echo 'SignatureSubject: ' . $x509->signatureSubject . "\r\n";
echo '-------------------------------CERTIFICATE SIGNING KEY INFORMATION------------------------------------' . "\r\n";
echo 'Certificate version: ' . $x509->currentCert['tbsCertificate']['version'] . "\r\n";
echo 'Serial Number: ' . $x509->currentCert['tbsCertificate']['serialNumber']->toString() . "\r\n";
echo 'Algorithm: ' . $x509->currentCert['tbsCertificate']['signature']['algorithm'] . "\r\n";
echo 'Issuer Public Key: ' . $x509->currentCert['tbsCertificate']['subjectPublicKeyInfo']['subjectPublicKey'] . "\r\n";
echo 'Properties: ' . "\r\n";
foreach ($x509->currentCert['tbsCertificate']['issuer']['rdnSequence'] as $object) {
echo $object['0']['type'] . ':' . (isset($object['0']['value']['printableString']) ? $object['0']['value']['printableString'] : NULL) . "\r\n";
}