1 ;;; gnus-encrypt.el --- file encryption routines for Gnus
2 ;; Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
4 ;; Author: Teodor Zlatanov <tzz@lifelogs.com>
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software; you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation; either version 2, or (at your option)
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs; see the file COPYING. If not, write to the
22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 ;; Boston, MA 02111-1307, USA.
27 ;;; This module addresses data encryption under Gnus. Page breaks are
28 ;;; used for grouping declarations and documentation relating to each
29 ;;; particular aspect.
35 (autoload 'password-read "password"))
37 (defgroup gnus-encrypt nil
38 "Gnus encryption configuration.")
40 (defcustom gnus-encrypt-password-cache-expiry 200
41 "Gnus encryption password timeout.
42 When set, directly sets password-cache-expiry"
45 :set (lambda (symbol value)
47 (setq password-cache-expiry value)))
49 (defcustom gnus-encrypt-file-alist nil
50 "List of file names or regexes matched with encryptions.
55 (gnus-encrypt-xor \"Semi-Secret\")))"
58 (list :tag "Encryption entry"
59 (radio :tag "What to encrypt"
60 (file :tag "Filename")
61 (regexp :tag "Regular expression match"))
62 (radio :tag "How to encrypt it"
65 (const :tag "GPG Program" gpg)
66 (radio :tag "Choose a cipher"
67 (const :tag "3DES Encryption" "3DES")
68 (const :tag "CAST5 Encryption" "CAST5")
69 (const :tag "Blowfish Encryption" "BLOWFISH")
70 (const :tag "AES Encryption" "AES")
71 (const :tag "AES192 Encryption" "AES192")
72 (const :tag "AES256 Encryption" "AES256")
73 (const :tag "Twofish Encryption" "TWOFISH")
74 (string :tag "Cipher Name")))
76 :tag "Built-in simple XOR"
77 (const :tag "XOR Encryption" gnus-encrypt-xor)
78 (string :tag "XOR Cipher Value (seed value)")))))
81 ;; TODO: now, load gencrypt.el and if successful, modify the
82 ;; custom-type of gnus-encrypt-file-alist to add the gencrypt.el options
84 ;; (plist-get (symbol-plist 'gnus-encrypt-file-alist) 'custom-type)
87 (defcustom gnus-encrypt-gpg-path (executable-find "gpg")
88 "Path to the GPG program."
90 (file :tag "Location of the GPG executable")
91 (const :tag "GPG is not installed" nil))
94 (defvar gnus-encrypt-temp-prefix "gnus-encrypt"
95 "Prefix for temporary filenames")
97 (defun gnus-encrypt-find-model (filename)
98 "Given a filename, find a gnus-encrypt-file-alist entry"
99 (dolist (entry gnus-encrypt-file-alist)
100 (let ((match (nth 0 entry))
101 (model (nth 1 entry)))
102 (when (or (eq match filename)
103 (string-match match filename))
106 (defun gnus-encrypt-insert-file-contents (file &optional model)
107 "Decrypt FILE into the current buffer."
108 (interactive "fFile to insert: ")
109 (let* ((model (or model (gnus-encrypt-find-model file)))
110 (method (nth 0 model))
111 (cipher (nth 1 model))
112 (password-key (format "gnus-encrypt-password-%s-%s %s"
113 (symbol-name method) cipher file))
115 (password-read-and-add
116 (format "%s password for cipher %s? "
117 (symbol-name method) cipher)
119 (buffer-file-coding-system 'binary)
120 (coding-system-for-read 'binary)
123 ;; note we only insert-file-contents if the method is known to be valid
126 (insert-file-contents file)
127 (setq outdata (gnus-encrypt-gpg-decode-buffer passphrase cipher)))
128 ((eq method 'gnus-encrypt-xor)
129 (insert-file-contents file)
130 (setq outdata (gnus-encrypt-xor-decode-buffer passphrase cipher))))
134 (gnus-message 9 "%s was decrypted with %s (cipher %s)"
135 file (symbol-name method) cipher)
136 (delete-region (point-min) (point-max))
137 (goto-char (point-min))
139 ;; the decryption failed, alas
140 (password-cache-remove password-key)
141 (gnus-error 5 "%s was NOT decrypted with %s (cipher %s)"
142 file (symbol-name method) cipher))))
144 (defun gnus-encrypt-get-file-contents (file &optional model)
145 "Decrypt FILE and return the contents."
146 (interactive "fFile to decrypt: ")
148 (gnus-encrypt-insert-file-contents file model)
151 (defun gnus-encrypt-put-file-contents (file data &optional model)
152 "Encrypt the DATA to FILE, then continue normally."
155 (gnus-encrypt-write-file-contents file model)))
157 (defun gnus-encrypt-write-file-contents (file &optional model)
158 "Encrypt the current buffer to FILE, then continue normally."
159 (interactive "fFile to write: ")
160 (let* ((model (or model (gnus-encrypt-find-model file)))
161 (method (nth 0 model))
162 (cipher (nth 1 model))
163 (password-key (format "gnus-encrypt-password-%s-%s %s"
164 (symbol-name method) cipher file))
167 (format "%s password for cipher %s? "
168 (symbol-name method) cipher)
174 (setq outdata (gnus-encrypt-gpg-encode-buffer passphrase cipher)))
175 ((eq method 'gnus-encrypt-xor)
176 (setq outdata (gnus-encrypt-xor-encode-buffer passphrase cipher))))
180 (gnus-message 9 "%s was encrypted with %s (cipher %s)"
181 file (symbol-name method) cipher)
182 (delete-region (point-min) (point-max))
183 (goto-char (point-min))
185 ;; do not confirm overwrites
186 (write-file file nil))
187 ;; the decryption failed, alas
188 (password-cache-remove password-key)
189 (gnus-error 5 "%s was NOT encrypted with %s (cipher %s)"
190 file (symbol-name method) cipher))))
192 (defun gnus-encrypt-xor-encode-buffer (passphrase cipher)
193 (gnus-encrypt-xor-process-buffer passphrase cipher t))
195 (defun gnus-encrypt-xor-decode-buffer (passphrase cipher)
196 (gnus-encrypt-xor-process-buffer passphrase cipher nil))
198 (defun gnus-encrypt-xor-process-buffer (passphrase
201 "Given PASSPHRASE, xor-encode or decode the contents of the current buffer."
202 (let* ((bs (buffer-substring-no-properties (point-min) (point-max)))
203 ;; passphrase-sum is a simple additive checksum of the
204 ;; passphrase and the cipher
206 (when (stringp passphrase)
207 (apply '+ (append cipher passphrase nil))))
213 (dolist (x (append bs nil))
214 (setq new-list (cons (logxor x passphrase-sum) new-list)))
217 (insert (format "%d " x))))
219 (setq new-list (reverse (split-string bs)))
221 (setq x (string-to-int x))
222 (insert (format "%c" (logxor x passphrase-sum))))))
223 (buffer-substring-no-properties (point-min) (point-max)))))
225 (defun gnus-encrypt-gpg-encode-buffer (passphrase cipher)
226 (gnus-encrypt-gpg-process-buffer passphrase cipher t))
228 (defun gnus-encrypt-gpg-decode-buffer (passphrase cipher)
229 (gnus-encrypt-gpg-process-buffer passphrase cipher nil))
231 (defun gnus-encrypt-gpg-process-buffer (passphrase
234 "With PASSPHRASE, use GPG to encode or decode the current buffer."
235 (let* ((program gnus-encrypt-gpg-path)
236 (input (buffer-substring-no-properties (point-min) (point-max)))
237 (temp-maker (if (fboundp 'make-temp-file)
240 (temp-file (funcall temp-maker gnus-encrypt-temp-prefix))
241 (default-enable-multibyte-characters nil)
242 (args `("--cipher-algo" ,cipher
245 "--passphrase-fd" "0"
247 exit-status exit-data)
258 (insert passphrase "\n"))
261 (apply #'call-process-region (point-min) (point-max) program
262 t `(t ,temp-file) nil args))
263 (if (equal exit-status 0)
265 (buffer-substring-no-properties (point-min) (point-max)))
267 (when (file-exists-p temp-file)
268 (insert-file-contents temp-file))
269 (gnus-error 5 (format "%s exited abnormally: '%s' [%s]"
270 program exit-status (buffer-string)))))
271 (delete-file temp-file))
272 (gnus-error 5 "GPG is not installed."))
275 (provide 'gnus-encrypt)
276 ;;; gnus-encrypt.el ends here
278 ;; (defcustom netrc-encrypting-method nil
279 ;; "Decoding method used for the netrc file.
280 ;; Use the OpenSSL symmetric ciphers here. Leave nil for no
281 ;; decoding. Encrypt the file with netrc-encrypt, but make sure you
282 ;; have set netrc-encrypting-method to a non-nil value."
284 ;; (const :tag "DES-3" "des3")
285 ;; (const :tag "IDEA" "idea")
286 ;; (const :tag "RC4" "rc4")
287 ;; (string :tag "Explicit cipher name")
288 ;; (const :tag "None" nil))
291 ;; (defcustom netrc-openssl-path (executable-find "openssl")
292 ;; "File path of the OpenSSL shell."
293 ;; :type '(choice (file :tag "Location of openssl")
294 ;; (const :tag "openssl is not installed" nil))
297 ;; (defun netrc-encrypt (plain-file encrypted-file)
298 ;; (interactive "fPlain File: \nFEncrypted File: ")
299 ;; "Encrypt FILE to ENCRYPTED-FILE with netrc-encrypting-method cipher."
300 ;; (when (and (file-exists-p plain-file)
301 ;; (stringp encrypted-file)
302 ;; netrc-encrypting-method
303 ;; netrc-openssl-path)
304 ;; (let ((buffer-file-coding-system 'binary)
305 ;; (coding-system-for-read 'binary)
306 ;; (coding-system-for-write 'binary)
309 ;; (format "OpenSSL Password for cipher %s? "
310 ;; netrc-encrypting-method)
311 ;; (format "netrc-openssl-password-%s"
312 ;; netrc-encrypting-method))))
315 ;; (insert-file-contents plain-file)
316 ;; (setenv "NETRC_OPENSSL_PASSWORD" password)
317 ;; (shell-command-on-region
320 ;; (format "%s %s -pass env:NETRC_OPENSSL_PASSWORD -e"
321 ;; netrc-openssl-path
322 ;; netrc-encrypting-method)
325 ;; (write-file encrypted-file t))))))
327 ;; (if (and netrc-encrypting-method
328 ;; netrc-openssl-path)
329 ;; (let ((buffer-file-coding-system 'binary)
330 ;; (coding-system-for-read 'binary)
331 ;; (coding-system-for-write 'binary)
334 ;; (format "OpenSSL Password for cipher %s? "
335 ;; netrc-encrypting-method)
336 ;; (format "netrc-openssl-password-%s"
337 ;; netrc-encrypting-method))))
339 ;; (insert-file-contents file)
340 ;; (setenv "NETRC_OPENSSL_PASSWORD" password)
341 ;; (shell-command-on-region
344 ;; (format "%s %s -pass env:NETRC_OPENSSL_PASSWORD -d"
345 ;; netrc-openssl-path
346 ;; netrc-encrypting-method)