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simon  committed 362c37f

2004-01-16 Simon Josefsson <jas@extundo.com>

* password.el: Add.

* Makefile (REQUIRES): Add xemacs-base.
(ELCS): Add password.el.

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  • Parent commits f912fda

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+2004-01-16  Simon Josefsson  <jas@extundo.com>
+
+	* password.el: Add.
+
+	* Makefile (REQUIRES): Add xemacs-base.
+	(ELCS): Add password.el.
+
 2003-12-16  Norbert Koch  <viteno@xemacs.org>
 
 	* Makefile (VERSION): XEmacs package 0.15 released.
 MAINTAINER = Simon Josefsson <simon@josefsson.org>
 PACKAGE = ecrypto
 PKG_TYPE = regular
-REQUIRES = 
+# xemacs-base is needed by password.el for `read-passwd'.
+REQUIRES = xemacs-base
 CATEGORY = standard
 
 ELCS = ascii-armor.elc blowfish.elc des.elc paranoid.elc rander.elc \
 	rc16.elc sha1.elc sha1-el.elc sha1-dl.elc md4.elc md5.elc md5-el.elc \
-	md5-dl.elc hex-util.elc rijndael.elc
+	md5-dl.elc hex-util.elc rijndael.elc password.elc
 
 include ../../XEmacs.rules
+;;; password.el --- Read passwords from user, possibly using a password cache.
+
+;; Copyright (C) 1999, 2000, 2003, 2004 Free Software Foundation, Inc.
+
+;; Author: Simon Josefsson <simon@josefsson.org>
+;; Created: 2003-12-21
+;; Keywords: password cache passphrase key
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;; Commentary:
+
+;; Greatly influenced by pgg.el written by Daiki Ueno, with timer
+;; fixes for XEmacs by Katsumi Yamaoka.  In fact, this is mostly just
+;; a rip-off.
+;;
+;; (password-read "Password? " "test")
+;; ;; Minibuffer prompt for password.
+;;  => "foo"
+;;
+;; (password-cache-add "test" "foo")
+;;  => nil
+;;
+;; (password-read "Password? " "test")
+;; ;; No minibuffer prompt
+;;  => "foo"
+;;
+;; (password-read "Password? " "test")
+;; ;; No minibuffer prompt
+;;  => "foo"
+;;
+;; ;; Wait `password-cache-expiry' seconds.
+;;
+;; (password-read "Password? " "test")
+;; ;; Minibuffer prompt for password is back.
+;;  => "foo"
+
+;;; Code:
+
+(eval-when-compile
+  (require 'cl))
+
+(defalias
+  'password-run-at-time
+  (if (condition-case nil
+	  (progn
+	    (unless (or itimer-process itimer-timer)
+	      (itimer-driver-start))
+	    ;; Check whether there is a bug to which the difference of
+	    ;; the present time and the time when the itimer driver was
+	    ;; woken up is subtracted from the initial itimer value.
+	    (let* ((inhibit-quit t)
+		   (ctime (current-time))
+		   (itimer-timer-last-wakeup
+		    (prog1
+			ctime
+		      (setcar ctime (1- (car ctime)))))
+		   (itimer-list nil)
+		   (itimer (start-itimer "run-at-time" 'ignore 5)))
+	      (sleep-for 0.1) ;; Accept the timeout interrupt.
+	      (prog1
+		  (> (itimer-value itimer) 0)
+		(delete-itimer itimer))))
+	(error nil))
+      (lambda (time repeat function &rest args)
+	"Function emulating the function of the same name of Emacs.
+TIME should be nil meaning now, or a number of seconds from now.
+Return an itimer object which can be used in either `delete-itimer'
+or `cancel-timer'."
+	(apply #'start-itimer "run-at-time"
+	       function (if time (max time 1e-9) 1e-9)
+	       repeat nil t args))
+    (lambda (time repeat function &rest args)
+      "Function emulating the function of the same name of Emacs.
+It works correctly for TIME even if there is a bug in the XEmacs core.
+TIME should be nil meaning now, or a number of seconds from now.
+Return an itimer object which can be used in either `delete-itimer'
+or `cancel-timer'."
+      (let ((itimers (list nil)))
+	(setcar
+	 itimers
+	 (apply #'start-itimer "fixed-run-at-time"
+		(lambda (itimers repeat function &rest args)
+		  (let ((itimer (car itimers)))
+		    (if repeat
+			(progn
+			  (set-itimer-function
+			   itimer
+			   (lambda (itimer repeat function &rest args)
+			     (set-itimer-restart itimer repeat)
+			     (set-itimer-function itimer function)
+			     (set-itimer-function-arguments itimer args)
+			     (apply function args)))
+			  (set-itimer-function-arguments
+			   itimer
+			   (append (list itimer repeat function) args)))
+		      (set-itimer-function
+		       itimer
+		       (lambda (itimer function &rest args)
+			 (delete-itimer itimer)
+			 (apply function args)))
+		      (set-itimer-function-arguments
+		       itimer
+		       (append (list itimer function) args)))))
+		1e-9 (if time (max time 1e-9) 1e-9)
+		nil t itimers repeat function args))))))
+
+(defcustom password-cache t
+  "Whether to cache passwords."
+  :group 'password
+  :type 'boolean)
+
+(defcustom password-cache-expiry 16
+  "How many seconds passwords are cached, or nil to disable expiring.
+Whether passwords are cached at all is controlled by `password-cache'."
+  :group 'password
+  :type '(choice (const :tag "Never" nil)
+		 (integer :tag "Seconds")))
+
+(defvar password-data (make-vector 7 0))
+
+(defun password-read (prompt &optional key)
+  "Read password, for use with KEY, from user, or from cache if wanted.
+KEY indicate the purpose of the password, so the cache can
+separate passwords.  The cache is not used if KEY is nil.  It is
+typically a string.
+The variable `password-cache' control whether the cache is used."
+  (or (and password-cache
+	   key
+	   (symbol-value (intern-soft key password-data)))
+      (read-passwd prompt)))
+
+(defun password-cache-remove (key)
+  "Remove password indexed by KEY from password cache.
+This is typically run be a timer setup from `password-cache-add',
+but can be invoked at any time to forcefully remove passwords
+from the cache.  This may be useful when it has been detected
+that a password is invalid, so that `password-read' query the
+user again."
+  (let ((password (symbol-value (intern-soft key password-data))))
+    (when password
+      (fillarray password ?_)
+      (unintern key password-data))))
+
+(defun password-cache-add (key password)
+  "Add password to cache.
+The password is removed by a timer after `password-cache-expiry'
+seconds."
+  (set (intern key password-data) password)
+  (when password-cache-expiry
+    (password-run-at-time password-cache-expiry nil
+			  #'password-cache-remove
+			  key))
+  nil)
+
+(provide 'password)
+
+;;; password.el ends here