generate 'privatekey.pem' and certificate.pem on windows with nodejs

1.how to generate privatekey.pem and certificate.pem files using nodejs server in windows application?

var privateKey = fs.readFileSync( 'privatekey.pem' );
var certificate = fs.readFileSync( 'certificate.pem' );

https.createServer({
    key: privateKey,
    cert: certificate
}, app).listen(port);

via eswara prasad