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1 | ;;; password-cache.el --- Read passwords, possibly using a password cache. |
2 | ||
ae940284 | 3 | ;; Copyright (C) 1999, 2000, 2003, 2004, 2005, 2006, 2007, 2008, 2009 |
49052ec0 GM |
4 | ;; Free Software Foundation, Inc. |
5 | ||
6 | ;; Author: Simon Josefsson <simon@josefsson.org> | |
7 | ;; Created: 2003-12-21 | |
8 | ;; Keywords: password cache passphrase key | |
9 | ||
10 | ;; This file is part of GNU Emacs. | |
11 | ||
eb3fa2cf | 12 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
49052ec0 | 13 | ;; it under the terms of the GNU General Public License as published by |
eb3fa2cf GM |
14 | ;; the Free Software Foundation, either version 3 of the License, or |
15 | ;; (at your option) any later version. | |
49052ec0 GM |
16 | |
17 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
18 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | ;; GNU General Public License for more details. | |
21 | ||
22 | ;; You should have received a copy of the GNU General Public License | |
eb3fa2cf | 23 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
49052ec0 GM |
24 | |
25 | ;;; Commentary: | |
26 | ||
27 | ;; Greatly influenced by pgg.el written by Daiki Ueno, with timer | |
28 | ;; fixes for XEmacs by Katsumi Yamaoka. In fact, this is mostly just | |
29 | ;; a rip-off. | |
30 | ;; | |
31 | ;; (password-read "Password? " "test") | |
32 | ;; ;; Minibuffer prompt for password. | |
33 | ;; => "foo" | |
34 | ;; | |
35 | ;; (password-cache-add "test" "foo") | |
36 | ;; => nil | |
37 | ||
49052ec0 GM |
38 | ;; (password-read "Password? " "test") |
39 | ;; ;; No minibuffer prompt | |
40 | ;; => "foo" | |
41 | ;; | |
42 | ;; (password-read "Password? " "test") | |
43 | ;; ;; No minibuffer prompt | |
44 | ;; => "foo" | |
45 | ;; | |
46 | ;; ;; Wait `password-cache-expiry' seconds. | |
47 | ;; | |
48 | ;; (password-read "Password? " "test") | |
49 | ;; ;; Minibuffer prompt for password is back. | |
50 | ;; => "foo" | |
51 | ||
52 | ;;; Code: | |
53 | ||
49052ec0 GM |
54 | (defcustom password-cache t |
55 | "Whether to cache passwords." | |
56 | :group 'password | |
57 | :type 'boolean) | |
58 | ||
59 | (defcustom password-cache-expiry 16 | |
60 | "How many seconds passwords are cached, or nil to disable expiring. | |
61 | Whether passwords are cached at all is controlled by `password-cache'." | |
62 | :group 'password | |
63 | :type '(choice (const :tag "Never" nil) | |
64 | (integer :tag "Seconds"))) | |
65 | ||
66 | (defvar password-data (make-vector 7 0)) | |
67 | ||
68 | (defun password-read-from-cache (key) | |
69 | "Obtain passphrase for KEY from time-limited passphrase cache. | |
70 | Custom variables `password-cache' and `password-cache-expiry' | |
71 | regulate cache behavior." | |
72 | (and password-cache | |
73 | key | |
74 | (symbol-value (intern-soft key password-data)))) | |
75 | ||
76 | (defun password-read (prompt &optional key) | |
77 | "Read password, for use with KEY, from user, or from cache if wanted. | |
78 | KEY indicate the purpose of the password, so the cache can | |
79 | separate passwords. The cache is not used if KEY is nil. It is | |
80 | typically a string. | |
81 | The variable `password-cache' control whether the cache is used." | |
82 | (or (password-read-from-cache key) | |
83 | (read-passwd prompt))) | |
84 | ||
85 | (defun password-read-and-add (prompt &optional key) | |
86 | "Read password, for use with KEY, from user, or from cache if wanted. | |
87 | Then store the password in the cache. Uses `password-read' and | |
8b334673 GM |
88 | `password-cache-add'. Custom variables `password-cache' and |
89 | `password-cache-expiry' regulate cache behavior. | |
90 | ||
91 | Warning: the password is cached without checking that it is | |
92 | correct. It is better to check the password before caching. If | |
93 | you must use this function, take care to check passwords and | |
94 | remove incorrect ones from the cache." | |
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95 | (let ((password (password-read prompt key))) |
96 | (when (and password key) | |
97 | (password-cache-add key password)) | |
98 | password)) | |
99 | ||
8b334673 GM |
100 | (make-obsolete 'password-read-and-add 'password-read "23.1") |
101 | ||
49052ec0 GM |
102 | (defun password-cache-remove (key) |
103 | "Remove password indexed by KEY from password cache. | |
104 | This is typically run be a timer setup from `password-cache-add', | |
105 | but can be invoked at any time to forcefully remove passwords | |
106 | from the cache. This may be useful when it has been detected | |
107 | that a password is invalid, so that `password-read' query the | |
108 | user again." | |
109 | (let ((password (symbol-value (intern-soft key password-data)))) | |
110 | (when password | |
111 | (if (fboundp 'clear-string) | |
112 | (clear-string password) | |
113 | (fillarray password ?_)) | |
114 | (unintern key password-data)))) | |
115 | ||
116 | (defun password-cache-add (key password) | |
117 | "Add password to cache. | |
8b334673 | 118 | The password is removed by a timer after `password-cache-expiry' seconds." |
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119 | (when (and password-cache-expiry (null (intern-soft key password-data))) |
120 | (run-at-time password-cache-expiry nil | |
121 | #'password-cache-remove | |
122 | key)) | |
123 | (set (intern key password-data) password) | |
124 | nil) | |
125 | ||
126 | (defun password-reset () | |
127 | "Clear the password cache." | |
128 | (interactive) | |
129 | (fillarray password-data 0)) | |
130 | ||
131 | (provide 'password-cache) | |
132 | ||
cbee283d | 133 | ;; arch-tag: ab160494-16c8-4c68-a4a1-73eebf6686e5 |
49052ec0 | 134 | ;;; password-cache.el ends here |