code: function _rsapem_privateKeyToPkcs8HexString(rsaKey) {
  	var zeroInteger = "020100";
      var encodedIdentifier = "06092A864886F70D010101";
      var encodedNull = "0500";
      var headerSequence = "300D" + encodedIdentifier + encodedNull;
      var keySequence = _rsapem_privateKeyToPkcs1HexString(rsaKey);
      
      var keyOctetString = "04" + _rsapem_encodeLength(keySequence.length / 2) + keySequence;
      
      var mainSequence = zeroInteger + headerSequence + keyOctetString;
      return "30" + _rsapem_encodeLength(mainSequence.length / 2) + mainSequence;
  }
docs: Converts private & public part of given key to PKCS#8 Hex String.