code: func (p *PAM) readStream(echo bool) (string, error) {
  	reader := bufio.NewReader(p.stdin)
  	text, err := reader.ReadString('\n')
  	if err != nil {
  		return "", trace.Wrap(err)
  	}
  
  	return text, nil
  }
docs: // readStream will read from the input stream (stdin or equivalent).
  // TODO(russjones): At some point in the future if this becomes an issue, we
  // should consider supporting echo = false.