elmo-read-passwd

(defun elmo-read-passwd (prompt &optional stars)
  "Read a single line of text from user without echoing, and return it."
  (let ((ans "")
        (c 0)
        (echo-keystrokes 0)
        (cursor-in-echo-area t)
        (log-message-max-size 0)
        message-log-max done msg truncate)
    (while (not done)
      (if (or (not stars) (string= "" ans))
          (setq msg prompt)
        (setq msg (concat prompt (make-string (length ans) ?.)))
        (setq truncate
              (1+ (- (length msg) (window-width (minibuffer-window)))))
        (and (> truncate 0)
             (setq msg (concat "$" (substring msg (1+ truncate))))))
      (message "%s" msg)
      (setq c (elmo-read-char-exclusive))
      (cond ((= c ?\C-g)
             (setq quit-flag t
                   done t))
            ((or (= c ?\r) (= c ?\n) (= c ?\e))
             (setq done t))
            ((= c ?\C-u)
             (setq ans ""))
            ((and (/= c ?\b) (/= c ?\177))
             (setq ans (concat ans (char-to-string c))))
            ((> (length ans) 0)
             (setq ans (substring ans 0 -1)))))
    (if quit-flag
        (prog1
            (setq quit-flag nil)
          (message "Quit")
          (beep t))
      (message "")
      ans)))