code: function _rsapem_privateKeyToPkcs1HexString(rsaKey) {
      var result = _rsapem_derEncodeNumber(0);
      result += _rsapem_derEncodeNumber(rsaKey.n);
      result += _rsapem_derEncodeNumber(rsaKey.e);
      result += _rsapem_derEncodeNumber(rsaKey.d);
      result += _rsapem_derEncodeNumber(rsaKey.p);
      result += _rsapem_derEncodeNumber(rsaKey.q);
      result += _rsapem_derEncodeNumber(rsaKey.dmp1);
      result += _rsapem_derEncodeNumber(rsaKey.dmq1);
      result += _rsapem_derEncodeNumber(rsaKey.coeff);
  
      var fullLen = _rsapem_encodeLength(result.length / 2);
      return '30' + fullLen + result;
  }
docs: Converts private & public part of given key to ASN1 Hex String.