openssl_pkcs7_sign

Supported Versions: PHP 4 >= 4.0.6, PHP 5, PHP 7, PHP 8

Sign an S/MIME message

        <?php openssl_pkcs7_sign(    string $input_filename,    string $output_filename,    OpenSSLCertificate|string $certificate,    OpenSSLAsymmetricKey|OpenSSLCertificate|array|string $private_key,    ?array $headers,    int $flags = PKCS7_DETACHED,    ?string $untrusted_certificates_filename = null): bool
    