async function generatePrivateKeyFileJSRSA(privateKeyFilename: string, modulusLength: 2048 | 3072 | 4096) {
    const kp = jsrsasign.KEYUTIL.generateKeypair("RSA", modulusLength);
    const prv = kp.prvKeyObj;
    const pub = kp.pubKeyObj;
    const prvpem = jsrsasign.KEYUTIL.getPEM(prv, "PKCS8PRV");