code: function _rsapem_derEncodeNumber(number) {
      var numberString = _rsapem_padWithZero(number.toString(16));
      if (numberString[0] > '7') {
      	numberString = "00" + numberString;
      }
      var lenString = _rsapem_encodeLength(numberString.length / 2);
      return "02" + lenString + numberString;
  }
docs: Encode number in DER encoding ("02" + length + number).