Self-signed certificate

self_sign_cert.php

$domain = 'conovaloff.com';

$configParams = [
    "private_key_bits" => 2048,
    'private_key_type' => OPENSSL_KEYTYPE_RSA
];

$privkey = openssl_pkey_new($configParams);

$data = array(
    "countryName" => "RU",
    "stateOrProvinceName" => "Moscow",
    "localityName" => "Moscow",
    "organizationName" => "Company",
    "organizationalUnitName" => "Development",
    "commonName" => $domain,
    "emailAddress" => "admin@" . $domain
);

$csr = openssl_csr_new($data, $privkey, $configParams);

$sscert = openssl_csr_sign($csr, null, $privkey, $duration, $configParams);

openssl_x509_export($sscert, $certout);
openssl_pkey_export($privkey, $pkout, $password, $configParams);

var_dump($certout);
var_dump($pkout);