Add dispass.el

dispass.el is an emacs wrapper script for dispass, it provides the
ability to recall or create the passwords.

dispass.el

@@ -0,0 +1,127 @@
+;;; dispass.el --- Generate and disperse/dispell passwords
+
+;; Copyright (C) 2012 Tom Willemsen <tom@ryuslash.org>
+
+;; Author: Tom Willemsen <tom@ryuslash.org>
+;; Created: Jun 8, 2012
+;; Version: 0.1a7.2
+;; Keywords: encryption, security
+
+;; Permission to use, copy, modify, and distribute this software for any
+;; purpose with or without fee is hereby granted, provided that the
+;; above copyright notice and this permission notice appear in all
+;; copies.
+
+;; THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+;; WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+;; WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+;; AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+;; CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+;; OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+;; NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+;; CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+;;; Commentary:
+
+;; dispass.el is an emacs wrapper around dispass
+;; (http://dispass.babab.nl).
+
+;;; Installation:
+
+;; Place this file somewhere on your filesystem, either in your
+;; `load-path' or somewhere else which you will have to add to your
+;; `load-path', like so:
+
+;;     (add-to-list 'load-path "/location/of/dispass.el")
+
+;; And then `load', `require' or `autoload' it in your emacs init
+;; file, for example:
+
+;;     (require 'dispass)
+
+;; _Or_ if you have package.el you could use `package-install-file'.
+
+;;; Usage:
+
+;; Using dispass.el is simple, once installed. Either call `dispass'
+;; to recall a priviously generated password or call `dispass-create'
+;; to generate a new password.
+
+;; The only real difference between the two is that `dispass-create'
+;; asks to confirm the password. Both will ask for a label.
+
+;; Once a password has been generated it is inserted into the kill
+;; ring and the system's clipboard so it can be easily inserted into
+;; password field, this makes the generated password easy to see in
+;; plaintext in the `kill-ring' variable, though.
+
+;;; Change Log:
+
+;; 0.1a7 - Initial release.
+
+;; 0.1a7.1 - Don't show password, copy directly into the clipboard.
+
+;; 0.1a7.2 - Kill buffer whenever we're finished with it.
+
+;;; Code:
+
+(defun dispass-process-sentinel (proc status)
+  "Report PROC's status change to STATUS."
+  (let ((status (substring status 0 -1))
+        (buffer (process-buffer proc)))
+    (unless (string-equal status "finished")
+      (message "dispass %s" (substring status 0 -1)))
+
+    (unless (eq (current-buffer) proc)
+      (kill-buffer buffer))))
+
+(defun dispass-erase-buffer (buffer)
+  "Completely erase the contents of BUFFER"
+  (save-current-buffer
+    (set-buffer buffer)
+    (buffer-disable-undo buffer)
+    (kill-buffer buffer)))
+
+(defun dispass-process-filter-for (label)
+  "Create a function that will process any lines whilst keeping
+an eye out for LABEL."
+  `(lambda (proc string)
+     "Process STRING coming from PROC."
+     (cond ((string-match "^\\(Password\\|Again\\): ?$" string)
+            (process-send-string proc
+                                 (concat (read-passwd string nil) "\n")))
+
+           ((string-match (concat "^[ ]+" ,label " \\(.\\{30\\}\\)$")
+                          string)
+            (let ((buffer (process-buffer proc)))
+              (with-current-buffer buffer
+                (insert (match-string 1 string))
+                (clipboard-kill-ring-save (point-min) (point-max))
+                (message "Password copied to clipboard.")
+
+                (unless (eq (process-status proc) 'run)
+                  (kill-buffer buffer))))))))
+
+(defun dispass-start-process (label &optional create)
+  "Start dispass process. When CREATE is non-nil send along the
+  -c switch to make it ask for a password twice."
+  (let ((proc (start-process "dispass" "*dispass*" "dispass"
+                             (if create "-co" "-o") label)))
+    (set-process-sentinel proc 'dispass-process-sentinel)
+    (set-process-filter proc (dispass-process-filter-for label))))
+
+;;;###autoload
+(defun dispass-create (label)
+  (interactive "MLabel: ")
+  "Create a new password for LABEL."
+  (dispass-start-process label t))
+
+;;;###autoload
+(defun dispass (label)
+  (interactive "MLabel: ")
+  "Recreate a password previously used."
+  (dispass-start-process label))
+
+(provide 'dispass)
+
+;;; dispass.el ends here