docs: function _rsapem_readPrivateKeyFromPEMString(keyPEM) {
    var keyB64 = _rsapem_pemToBase64(keyPEM);
    var keyHex = b64tohex(keyB64) // depends base64.js
    var a = _rsapem_getHexValueArrayOfChildrenFromHex(keyHex);
    this.setPrivateEx(a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8]);
  }