code: func getRandom(c context.Context, want int) ([]byte, error) {
  	ret := make([]byte, want)
  	_, err := cryptorand.Read(c, ret)
  	if err != nil {
  		logging.WithError(err).Errorf(c, "could not generate random data")
  		return nil, err
  	}
  	return ret, nil
  }
docs: // getRandom returns a random byte sequence of `want` length, or an error if
  // that number of random bytes could not be generated.
  //
  // This uses cryptorand to generate cryptographically secure random numbers.