1 ;;; gnus-nocem.el --- NoCeM pseudo-cancellation treatment
3 ;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
4 ;; 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
6 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software: you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation, either version 3 of the License, or
14 ;; (at your option) any later version.
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
28 (eval-when-compile (require 'cl
))
36 (defgroup gnus-nocem nil
37 "NoCeM pseudo-cancellation treatment."
40 (defcustom gnus-nocem-groups
41 '("news.lists.filters" "alt.nocem.misc")
42 "*List of groups that will be searched for NoCeM messages."
45 :type
'(repeat (string :tag
"Group")))
47 (defcustom gnus-nocem-issuers
49 "alba-nocem@albasani.net"
50 "bleachbot@httrack.com"
51 "news@arcor-online.net"
54 "pgpmoose@killfile.org"
56 "*List of NoCeM issuers to pay attention to.
58 This can also be a list of `(ISSUER CONDITION ...)' elements.
60 See <URL:http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html> for an
63 :link
'(url-link "http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html")
65 :type
'(repeat (cons :format
"%v" (string :tag
"Issuer")
66 (repeat :tag
"Condition"
67 (group (checklist :inline t
(const not
))
68 (regexp :tag
"Type" :value
".*")))))
70 (mapcar (lambda (elem)
74 (if (consp elt
) elt
(list elt
)))
77 (default-value symbol
)))
78 :set
(lambda (symbol value
)
81 (mapcar (lambda (elem)
86 (if (cdr elt
) elt
(car elt
))
93 (defcustom gnus-nocem-directory
94 (nnheader-concat gnus-article-save-directory
"NoCeM/")
95 "*Directory where NoCeM files will be stored."
99 (defcustom gnus-nocem-expiry-wait
15
100 "*Number of days to keep NoCeM headers in the cache."
104 (defcustom gnus-nocem-verifyer
(if (locate-library "epg")
105 'gnus-nocem-epg-verify
107 "*Function called to verify that the NoCeM message is valid.
108 If the function in this variable isn't bound, the message will be used
112 :type
'(radio (function-item gnus-nocem-epg-verify
)
113 (function-item pgg-verify
)
114 (function-item mc-verify
)
115 (function :tag
"other"))
116 :set
(lambda (symbol value
)
117 (custom-set-default symbol
118 (if (and (eq value
'gnus-nocem-epg-verify
)
119 (not (locate-library "epg")))
123 (defcustom gnus-nocem-liberal-fetch nil
124 "*If t try to fetch all messages which have @@NCM in the subject.
125 Otherwise don't fetch messages which have references or whose message-id
126 matches a previously scanned and verified nocem message."
130 (defcustom gnus-nocem-check-article-limit
500
131 "*If non-nil, the maximum number of articles to check in any NoCeM group."
134 :type
'(choice (const :tag
"unlimited" nil
)
137 (defcustom gnus-nocem-check-from t
138 "Non-nil means check for valid issuers in message bodies.
139 Otherwise don't bother fetching articles unless their author matches a
140 valid issuer, which is much faster if you are selective about the issuers."
145 ;;; Internal variables
147 (defvar gnus-nocem-active nil
)
148 (defvar gnus-nocem-alist nil
)
149 (defvar gnus-nocem-touched-alist nil
)
150 (defvar gnus-nocem-hashtb nil
)
151 (defvar gnus-nocem-seen-message-ids nil
)
155 (defun gnus-nocem-active-file ()
156 (concat (file-name-as-directory gnus-nocem-directory
) "active"))
158 (defun gnus-nocem-cache-file ()
159 (concat (file-name-as-directory gnus-nocem-directory
) "cache"))
162 ;; faster lookups for group names:
165 (defvar gnus-nocem-real-group-hashtb nil
166 "Real-name mappings of subscribed groups.")
168 (defun gnus-fill-real-hashtb ()
169 "Fill up a hash table with the real-name mappings from the user's active file."
170 (if (hash-table-p gnus-nocem-real-group-hashtb
)
171 (clrhash gnus-nocem-real-group-hashtb
)
172 (setq gnus-nocem-real-group-hashtb
(make-hash-table :test
'equal
)))
173 (mapcar (lambda (group)
174 (setq group
(gnus-group-real-name (car group
)))
175 (puthash group t gnus-nocem-real-group-hashtb
))
179 (defun gnus-nocem-scan-groups ()
180 "Scan all NoCeM groups for new NoCeM messages."
182 (let ((groups gnus-nocem-groups
)
183 (gnus-inhibit-demon t
)
184 group active gactive articles check-headers
)
185 (gnus-make-directory gnus-nocem-directory
)
186 ;; Load any previous NoCeM headers.
187 (gnus-nocem-load-cache)
188 ;; Get the group name mappings:
189 (gnus-fill-real-hashtb)
190 ;; Read the active file if it hasn't been read yet.
191 (and (file-exists-p (gnus-nocem-active-file))
192 (not gnus-nocem-active
)
194 (load (gnus-nocem-active-file) t t t
)))
195 ;; Go through all groups and see whether new articles have
197 (while (setq group
(pop groups
))
198 (if (not (setq gactive
(gnus-activate-group group
)))
199 () ; This group doesn't exist.
200 (setq active
(nth 1 (assoc group gnus-nocem-active
)))
201 (when (and (not (< (cdr gactive
) (car gactive
))) ; Empty group.
203 (< (cdr active
) (cdr gactive
))))
204 ;; Ok, there are new articles in this group, se we fetch the
207 (let ((dependencies (make-vector 10 nil
))
212 (gnus-retrieve-headers
214 (gnus-uncompress-range
216 (if active
(1+ (cdr active
))
220 (gnus-get-newsgroup-headers-xover
221 articles nil dependencies
)
222 (gnus-get-newsgroup-headers dependencies
)))
223 (while (setq header
(pop headers
))
224 ;; We take a closer look on all articles that have
225 ;; "@@NCM" in the subject. Unless we already read
226 ;; this cross posted message. Nocem messages
227 ;; are not allowed to have references, so we can
228 ;; ignore scanning followups.
229 (and (string-match "@@NCM" (mail-header-subject header
))
230 (and gnus-nocem-check-from
231 (let ((case-fold-search t
))
236 (setq author
(car author
)))
238 author
(mail-header-from header
))
242 (or gnus-nocem-liberal-fetch
243 (and (or (string= "" (mail-header-references
245 (null (mail-header-references header
)))
246 (not (member (mail-header-message-id header
)
247 gnus-nocem-seen-message-ids
))))
248 (push header check-headers
)))
249 (setq check-headers
(last (nreverse check-headers
)
250 gnus-nocem-check-article-limit
))
252 (len (length check-headers
)))
253 (dolist (h check-headers
)
255 7 "Checking article %d in %s for NoCeM (%d of %d)..."
256 (mail-header-number h
) group
(incf i
) len
)
257 (gnus-nocem-check-article group h
)))))))
258 (setq gnus-nocem-active
259 (cons (list group gactive
)
260 (delq (assoc group gnus-nocem-active
)
261 gnus-nocem-active
)))))
262 ;; Save the results, if any.
263 (gnus-nocem-save-cache)
264 (gnus-nocem-save-active)))
266 (defun gnus-nocem-check-article (group header
)
267 "Check whether the current article is an NCM article and that we want it."
269 (let ((date (mail-header-date header
))
270 (gnus-newsgroup-name group
)
274 (time-since (date-to-time date
))
275 (days-to-time gnus-nocem-expiry-wait
)))
276 (gnus-request-article-this-buffer (mail-header-number header
) group
)
277 (goto-char (point-min))
278 (when (re-search-forward
279 "-----BEGIN PGP\\(?: SIGNED\\)? MESSAGE-----"
281 (delete-region (point-min) (match-beginning 0)))
282 (when (re-search-forward
283 "-----END PGP \\(?:MESSAGE\\|SIGNATURE\\)-----\n?"
285 (delete-region (match-end 0) (point-max)))
286 (goto-char (point-min))
287 ;; The article has to have proper NoCeM headers.
288 (when (and (setq b
(search-forward "\n@@BEGIN NCM HEADERS\n" nil t
))
289 (setq e
(search-forward "\n@@BEGIN NCM BODY\n" nil t
)))
290 ;; We get the name of the issuer.
291 (narrow-to-region b e
)
292 (setq issuer
(mail-fetch-field "issuer")
293 type
(mail-fetch-field "type"))
295 (if (not (gnus-nocem-message-wanted-p issuer type
))
296 (message "invalid NoCeM issuer: %s" issuer
)
297 (and (gnus-nocem-verify-issuer issuer
) ; She is who she says she is.
298 (gnus-nocem-enter-article) ; We gobble the message.
299 (push (mail-header-message-id header
) ; But don't come back for
300 gnus-nocem-seen-message-ids
))))))) ; second helpings.
302 (defun gnus-nocem-message-wanted-p (issuer type
)
303 (let ((issuers gnus-nocem-issuers
)
304 wanted conditions condition
)
306 ;; Do the quick check first.
307 ((member issuer issuers
)
309 ((setq conditions
(cdr (assoc issuer issuers
)))
310 ;; Check whether we want this type.
311 (while (setq condition
(pop conditions
))
314 (when (string-match condition type
)
316 ((and (consp condition
)
317 (eq (car condition
) 'not
)
318 (stringp (cadr condition
)))
319 (when (string-match (cadr condition
) type
)
322 (error "Invalid NoCeM condition: %S" condition
))))
325 (defun gnus-nocem-verify-issuer (person)
326 "Verify using PGP that the canceler is who she says she is."
327 (if (functionp gnus-nocem-verifyer
)
329 (funcall gnus-nocem-verifyer
))
330 ;; If we don't have Mailcrypt, then we use the message anyway.
333 (defun gnus-nocem-enter-article ()
334 "Enter the current article into the NoCeM cache."
335 (goto-char (point-min))
336 (let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t
))
337 (e (search-forward "\n@@END NCM BODY\n" nil t
))
338 (buf (current-buffer))
341 (narrow-to-region b
(1+ (match-beginning 0)))
342 (goto-char (point-min))
343 (while (search-forward "\t" nil t
)
346 (setq group
(gnus-group-real-name (symbol-name (read buf
))))
347 (gethash group gnus-nocem-real-group-hashtb
)))
353 (while (eq (char-after) ?
\t)
355 (setq id
(buffer-substring (point) (1- (search-forward "\t"))))
356 (unless (if (hash-table-p gnus-nocem-hashtb
)
357 (gethash id gnus-nocem-hashtb
)
358 (setq gnus-nocem-hashtb
(make-hash-table :test
'equal
))
360 ;; only store if not already present
361 (puthash id t gnus-nocem-hashtb
)
364 (while (eq (char-after) ?
\t)
367 (setq gnus-nocem-touched-alist t
)
368 (push (cons (let ((time (current-time))) (setcdr (cdr time
) nil
) time
)
374 (defun gnus-nocem-load-cache ()
375 "Load the NoCeM cache."
377 (unless gnus-nocem-alist
378 ;; The buffer doesn't exist, so we create it and load the NoCeM
380 (when (file-exists-p (gnus-nocem-cache-file))
381 (load (gnus-nocem-cache-file) t t t
)
382 (gnus-nocem-alist-to-hashtb))))
384 (defun gnus-nocem-save-cache ()
385 "Save the NoCeM cache."
386 (when (and gnus-nocem-alist
387 gnus-nocem-touched-alist
)
388 (with-temp-file (gnus-nocem-cache-file)
389 (gnus-prin1 `(setq gnus-nocem-alist
',gnus-nocem-alist
)))
390 (setq gnus-nocem-touched-alist nil
)))
392 (defun gnus-nocem-save-active ()
393 "Save the NoCeM active file."
394 (with-temp-file (gnus-nocem-active-file)
395 (gnus-prin1 `(setq gnus-nocem-active
',gnus-nocem-active
))))
397 (defun gnus-nocem-alist-to-hashtb ()
398 "Create a hashtable from the Message-IDs we have."
399 (let* ((alist gnus-nocem-alist
)
400 (pprev (cons nil alist
))
402 (expiry (days-to-time gnus-nocem-expiry-wait
))
404 (if (hash-table-p gnus-nocem-hashtb
)
405 (clrhash gnus-nocem-hashtb
)
406 (setq gnus-nocem-hashtb
(make-hash-table :test
'equal
)))
407 (while (setq entry
(car alist
))
408 (if (not (time-less-p (time-since (car entry
)) expiry
))
409 ;; This entry has expired, so we remove it.
410 (setcdr prev
(cdr alist
))
412 ;; This is ok, so we enter it into the hashtable.
413 (setq entry
(cdr entry
))
415 (puthash (car entry
) t gnus-nocem-hashtb
)
416 (setq entry
(cdr entry
))))
417 (setq alist
(cdr alist
)))))
419 (gnus-add-shutdown 'gnus-nocem-close
'gnus
)
421 (defun gnus-nocem-close ()
422 "Clear internal NoCeM variables."
423 (setq gnus-nocem-alist nil
424 gnus-nocem-hashtb nil
425 gnus-nocem-active nil
426 gnus-nocem-touched-alist nil
427 gnus-nocem-seen-message-ids nil
428 gnus-nocem-real-group-hashtb nil
))
430 (defun gnus-nocem-unwanted-article-p (id)
431 "Say whether article ID in the current group is wanted."
432 (and gnus-nocem-hashtb
433 (gethash id gnus-nocem-hashtb
)))
435 (autoload 'epg-make-context
"epg")
437 (autoload 'epg-verify-string
"epg")
438 (autoload 'epg-context-result-for
"epg")
439 (autoload 'epg-signature-status
"epg"))
441 (defun gnus-nocem-epg-verify ()
442 "Return t if EasyPG verifies a signed message in the current buffer."
443 (let ((context (epg-make-context 'OpenPGP
))
445 (epg-verify-string context
(buffer-string))
446 (and (setq result
(epg-context-result-for context
'verify
))
448 (eq (epg-signature-status (car result
)) 'good
))))
450 (provide 'gnus-nocem
)
452 ;; arch-tag: 0e0c74ea-2f8e-4f3e-8fff-09f767c1adef
453 ;;; gnus-nocem.el ends here