[bpt/emacs.git] / lisp / gnus / gnus-nocem.el

;;; gnus-nocem.el --- NoCeM pseudo-cancellation treatment

;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Keywords: news

;; 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 3, 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., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;;; Code:

(eval-when-compile (require 'cl))

(require 'gnus)
(require 'nnmail)
(require 'gnus-art)
(require 'gnus-sum)
(require 'gnus-range)

(defgroup gnus-nocem nil
  "NoCeM pseudo-cancellation treatment."
  :group 'gnus-score)

(defcustom gnus-nocem-groups
  '("news.lists.filters" "news.admin.net-abuse.bulletins"
    "alt.nocem.misc" "news.admin.net-abuse.announce")
  "*List of groups that will be searched for NoCeM messages."
  :group 'gnus-nocem
  :type '(repeat (string :tag "Group")))

(defcustom gnus-nocem-issuers
  '("AutoMoose-1"			; CancelMoose[tm]
    "clewis@ferret.ocunix"		; Chris Lewis
    "cosmo.roadkill"
    "SpamHippo"
    "hweede@snafu.de")
  "*List of NoCeM issuers to pay attention to.

This can also be a list of `(ISSUER CONDITION ...)' elements.

See <URL:http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html> for an
issuer registry."
  :group 'gnus-nocem
  :link '(url-link "http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html")
  :type '(repeat (choice string sexp)))

(defcustom gnus-nocem-directory
  (nnheader-concat gnus-article-save-directory "NoCeM/")
  "*Directory where NoCeM files will be stored."
  :group 'gnus-nocem
  :type 'directory)

(defcustom gnus-nocem-expiry-wait 15
  "*Number of days to keep NoCeM headers in the cache."
  :group 'gnus-nocem
  :type 'integer)

(defcustom gnus-nocem-verifyer 'pgg-verify
  "*Function called to verify that the NoCeM message is valid.
One likely value is `pgg-verify'.  If the function in this variable
isn't bound, the message will be used unconditionally."
  :group 'gnus-nocem
  :type '(radio (function-item pgg-verify)
		(function-item mc-verify)
		(function :tag "other")))

(defcustom gnus-nocem-liberal-fetch nil
  "*If t try to fetch all messages which have @@NCM in the subject.
Otherwise don't fetch messages which have references or whose message-id
matches a previously scanned and verified nocem message."
  :group 'gnus-nocem
  :type 'boolean)

(defcustom gnus-nocem-check-article-limit 500
  "*If non-nil, the maximum number of articles to check in any NoCeM group."
  :group 'gnus-nocem
  :version "21.1"
  :type '(choice (const :tag "unlimited" nil)
		 (integer 1000)))

(defcustom gnus-nocem-check-from t
  "Non-nil means check for valid issuers in message bodies.
Otherwise don't bother fetching articles unless their author matches a
valid issuer, which is much faster if you are selective about the issuers."
  :group 'gnus-nocem
  :version "21.1"
  :type 'boolean)

;;; Internal variables

(defvar gnus-nocem-active nil)
(defvar gnus-nocem-alist nil)
(defvar gnus-nocem-touched-alist nil)
(defvar gnus-nocem-hashtb nil)
(defvar gnus-nocem-seen-message-ids nil)

;;; Functions

(defun gnus-nocem-active-file ()
  (concat (file-name-as-directory gnus-nocem-directory) "active"))

(defun gnus-nocem-cache-file ()
  (concat (file-name-as-directory gnus-nocem-directory) "cache"))

;;
;; faster lookups for group names:
;;

(defvar gnus-nocem-real-group-hashtb nil
  "Real-name mappings of subscribed groups.")

(defun gnus-fill-real-hashtb ()
  "Fill up a hash table with the real-name mappings from the user's active file."
  (if (hash-table-p gnus-nocem-real-group-hashtb)
      (clrhash gnus-nocem-real-group-hashtb)
    (setq gnus-nocem-real-group-hashtb (make-hash-table :test 'equal)))
  (mapcar (lambda (group)
	    (setq group (gnus-group-real-name (car group)))
	    (puthash group t gnus-nocem-real-group-hashtb))
	  gnus-newsrc-alist))

;;;###autoload
(defun gnus-nocem-scan-groups ()
  "Scan all NoCeM groups for new NoCeM messages."
  (interactive)
  (let ((groups gnus-nocem-groups)
	(gnus-inhibit-demon t)
	group active gactive articles check-headers)
    (gnus-make-directory gnus-nocem-directory)
    ;; Load any previous NoCeM headers.
    (gnus-nocem-load-cache)
    ;; Get the group name mappings:
    (gnus-fill-real-hashtb)
    ;; Read the active file if it hasn't been read yet.
    (and (file-exists-p (gnus-nocem-active-file))
	 (not gnus-nocem-active)
	 (ignore-errors
	   (load (gnus-nocem-active-file) t t t)))
    ;; Go through all groups and see whether new articles have
    ;; arrived.
    (while (setq group (pop groups))
      (if (not (setq gactive (gnus-activate-group group)))
	  ()				; This group doesn't exist.
	(setq active (nth 1 (assoc group gnus-nocem-active)))
	(when (and (not (< (cdr gactive) (car gactive))) ; Empty group.
		   (or (not active)
		       (< (cdr active) (cdr gactive))))
	  ;; Ok, there are new articles in this group, se we fetch the
	  ;; headers.
	  (save-excursion
	    (let ((dependencies (make-vector 10 nil))
		  headers header)
	      (with-temp-buffer
		(setq headers
		      (if (eq 'nov
			      (gnus-retrieve-headers
			       (setq articles
				     (gnus-uncompress-range
				      (cons
				       (if active (1+ (cdr active))
					 (car gactive))
				       (cdr gactive))))
			       group))
			  (gnus-get-newsgroup-headers-xover
			   articles nil dependencies)
			(gnus-get-newsgroup-headers dependencies)))
		(while (setq header (pop headers))
		  ;; We take a closer look on all articles that have
		  ;; "@@NCM" in the subject.  Unless we already read
		  ;; this cross posted message.  Nocem messages
		  ;; are not allowed to have references, so we can
		  ;; ignore scanning followups.
		  (and (string-match "@@NCM" (mail-header-subject header))
		       (and gnus-nocem-check-from
			    (let ((case-fold-search t))
			      (catch 'ok
				(mapc
				 (lambda (author)
				   (if (consp author)
				       (setq author (car author)))
				   (if (string-match
					author (mail-header-from header))
				       (throw 'ok t)))
				 gnus-nocem-issuers)
				nil)))
		       (or gnus-nocem-liberal-fetch
			   (and (or (string= "" (mail-header-references
						 header))
				    (null (mail-header-references header)))
				(not (member (mail-header-message-id header)
					     gnus-nocem-seen-message-ids))))
		       (push header check-headers)))
		(setq check-headers (last (nreverse check-headers)
					  gnus-nocem-check-article-limit))
		(let ((i 0)
		      (len (length check-headers)))
		  (dolist (h check-headers)
		    (gnus-message
		     7 "Checking article %d in %s for NoCeM (%d of %d)..."
		     (mail-header-number h) group (incf i) len)
		    (gnus-nocem-check-article group h)))))))
	(setq gnus-nocem-active
	      (cons (list group gactive)
		    (delq (assoc group gnus-nocem-active)
			  gnus-nocem-active)))))
    ;; Save the results, if any.
    (gnus-nocem-save-cache)
    (gnus-nocem-save-active)))

(defun gnus-nocem-check-article (group header)
  "Check whether the current article is an NCM article and that we want it."
  ;; Get the article.
  (let ((date (mail-header-date header))
	(gnus-newsgroup-name group)
	issuer b e type)
    (when (or (not date)
	      (time-less-p
	       (time-since (date-to-time date))
	       (days-to-time gnus-nocem-expiry-wait)))
      (gnus-request-article-this-buffer (mail-header-number header) group)
      (goto-char (point-min))
      (when (re-search-forward
	     "-----BEGIN PGP\\(?: SIGNED\\)? MESSAGE-----"
	     nil t)
	(delete-region (point-min) (match-beginning 0)))
      (when (re-search-forward
	     "-----END PGP \\(?:MESSAGE\\|SIGNATURE\\)-----\n?"
	     nil t)
	(delete-region (match-end 0) (point-max)))
      (goto-char (point-min))
      ;; The article has to have proper NoCeM headers.
      (when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t))
		 (setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t)))
	;; We get the name of the issuer.
	(narrow-to-region b e)
	(setq issuer (mail-fetch-field "issuer")
	      type (mail-fetch-field "type"))
	(widen)
	(if (not (gnus-nocem-message-wanted-p issuer type))
	    (message "invalid NoCeM issuer: %s" issuer)
	  (and (gnus-nocem-verify-issuer issuer) ; She is who she says she is.
	       (gnus-nocem-enter-article) ; We gobble the message.
	       (push (mail-header-message-id header) ; But don't come back for
		     gnus-nocem-seen-message-ids))))))) ; second helpings.

(defun gnus-nocem-message-wanted-p (issuer type)
  (let ((issuers gnus-nocem-issuers)
	wanted conditions condition)
    (cond
     ;; Do the quick check first.
     ((member issuer issuers)
      t)
     ((setq conditions (cdr (assoc issuer issuers)))
      ;; Check whether we want this type.
      (while (setq condition (pop conditions))
	(cond
	 ((stringp condition)
	  (when (string-match condition type)
	    (setq wanted t)))
	 ((and (consp condition)
	       (eq (car condition) 'not)
	       (stringp (cadr condition)))
	  (when (string-match (cadr condition) type)
	    (setq wanted nil)))
	 (t
	  (error "Invalid NoCeM condition: %S" condition))))
      wanted))))

(defun gnus-nocem-verify-issuer (person)
  "Verify using PGP that the canceler is who she says she is."
  (if (functionp gnus-nocem-verifyer)
      (ignore-errors
	(funcall gnus-nocem-verifyer))
    ;; If we don't have Mailcrypt, then we use the message anyway.
    t))

(defun gnus-nocem-enter-article ()
  "Enter the current article into the NoCeM cache."
  (goto-char (point-min))
  (let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t))
	(e (search-forward "\n@@END NCM BODY\n" nil t))
	(buf (current-buffer))
	ncm id group)
    (when (and b e)
      (narrow-to-region b (1+ (match-beginning 0)))
      (goto-char (point-min))
      (while (search-forward "\t" nil t)
	(cond
	 ((not (ignore-errors
		 (setq group (gnus-group-real-name (symbol-name (read buf))))
		 (gethash group gnus-nocem-real-group-hashtb)))
	  ;; An error.
	  )
	 (t
	  ;; Valid group.
	  (beginning-of-line)
	  (while (eq (char-after) ?\t)
	    (forward-line -1))
	  (setq id (buffer-substring (point) (1- (search-forward "\t"))))
	  (unless (if (hash-table-p gnus-nocem-hashtb)
		      (gethash id gnus-nocem-hashtb)
		    (setq gnus-nocem-hashtb (make-hash-table :test 'equal))
		    nil)
	    ;; only store if not already present
	    (puthash id t gnus-nocem-hashtb)
	    (push id ncm))
	  (forward-line 1)
	  (while (eq (char-after) ?\t)
	    (forward-line 1)))))
      (when ncm
	(setq gnus-nocem-touched-alist t)
	(push (cons (let ((time (current-time))) (setcdr (cdr time) nil) time)
		    ncm)
	      gnus-nocem-alist))
      t)))

;;;###autoload
(defun gnus-nocem-load-cache ()
  "Load the NoCeM cache."
  (interactive)
  (unless gnus-nocem-alist
    ;; The buffer doesn't exist, so we create it and load the NoCeM
    ;; cache.
    (when (file-exists-p (gnus-nocem-cache-file))
      (load (gnus-nocem-cache-file) t t t)
      (gnus-nocem-alist-to-hashtb))))

(defun gnus-nocem-save-cache ()
  "Save the NoCeM cache."
  (when (and gnus-nocem-alist
	     gnus-nocem-touched-alist)
    (with-temp-file (gnus-nocem-cache-file)
      (gnus-prin1 `(setq gnus-nocem-alist ',gnus-nocem-alist)))
    (setq gnus-nocem-touched-alist nil)))

(defun gnus-nocem-save-active ()
  "Save the NoCeM active file."
  (with-temp-file (gnus-nocem-active-file)
    (gnus-prin1 `(setq gnus-nocem-active ',gnus-nocem-active))))

(defun gnus-nocem-alist-to-hashtb ()
  "Create a hashtable from the Message-IDs we have."
  (let* ((alist gnus-nocem-alist)
	 (pprev (cons nil alist))
	 (prev pprev)
	 (expiry (days-to-time gnus-nocem-expiry-wait))
	 entry)
    (if (hash-table-p gnus-nocem-hashtb)
	(clrhash gnus-nocem-hashtb)
      (setq gnus-nocem-hashtb (make-hash-table :test 'equal)))
    (while (setq entry (car alist))
      (if (not (time-less-p (time-since (car entry)) expiry))
	  ;; This entry has expired, so we remove it.
	  (setcdr prev (cdr alist))
	(setq prev alist)
	;; This is ok, so we enter it into the hashtable.
	(setq entry (cdr entry))
	(while entry
	  (puthash (car entry) t gnus-nocem-hashtb)
	  (setq entry (cdr entry))))
      (setq alist (cdr alist)))))

(gnus-add-shutdown 'gnus-nocem-close 'gnus)

(defun gnus-nocem-close ()
  "Clear internal NoCeM variables."
  (setq gnus-nocem-alist nil
	gnus-nocem-hashtb nil
	gnus-nocem-active nil
	gnus-nocem-touched-alist nil
	gnus-nocem-seen-message-ids nil
	gnus-nocem-real-group-hashtb nil))

(defun gnus-nocem-unwanted-article-p (id)
  "Say whether article ID in the current group is wanted."
  (and gnus-nocem-hashtb
       (gethash id gnus-nocem-hashtb)))

(provide 'gnus-nocem)

;;; arch-tag: 0e0c74ea-2f8e-4f3e-8fff-09f767c1adef
;;; gnus-nocem.el ends here
Commit	Line	Data
eec82323	1	;;; gnus-nocem.el --- NoCeM pseudo-cancellation treatment
16409b0b	2
b6c2d8c6	3	;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
e3fe4da0	4	;; 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
eec82323	5
6748645f	6	;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
eec82323 LMI	7	;; Keywords: news
	8
	9	;; This file is part of GNU Emacs.
	10
	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
5a9dffec	13	;; the Free Software Foundation; either version 3, or (at your option)
eec82323 LMI	14	;; any later version.
	15
	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.
	20
	21	;; You should have received a copy of the GNU General Public License
	22	;; along with GNU Emacs; see the file COPYING. If not, write to the
3a35cf56 LK	23	;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
3a35cf56 LK	24	;; Boston, MA 02110-1301, USA.
eec82323 LMI	25
	26	;;; Commentary:
	27
	28	;;; Code:
	29
0b9d8890 RS	30	(eval-when-compile (require 'cl))
0b9d8890 RS	31
eec82323 LMI	32	(require 'gnus)
	33	(require 'nnmail)
	34	(require 'gnus-art)
	35	(require 'gnus-sum)
	36	(require 'gnus-range)
	37
	38	(defgroup gnus-nocem nil
80a14ae0	39	"NoCeM pseudo-cancellation treatment."
eec82323 LMI	40	:group 'gnus-score)
	41
	42	(defcustom gnus-nocem-groups
	43	'("news.lists.filters" "news.admin.net-abuse.bulletins"
	44	"alt.nocem.misc" "news.admin.net-abuse.announce")
6748645f	45	"*List of groups that will be searched for NoCeM messages."
eec82323 LMI	46	:group 'gnus-nocem
	47	:type '(repeat (string :tag "Group")))
	48
	49	(defcustom gnus-nocem-issuers
f49c4ef7 DL	50	'("AutoMoose-1" ; CancelMoose[tm]
	51	"clewis@ferret.ocunix" ; Chris Lewis
	52	"cosmo.roadkill"
	53	"SpamHippo"
	54	"hweede@snafu.de")
6748645f LMI	55	"*List of NoCeM issuers to pay attention to.
6748645f LMI	56
f49c4ef7 DL	57	This can also be a list of `(ISSUER CONDITION ...)' elements.
	58
	59	See <URL:http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html> for an
	60	issuer registry."
eec82323	61	:group 'gnus-nocem
23f87bed	62	:link '(url-link "http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html")
6748645f	63	:type '(repeat (choice string sexp)))
eec82323 LMI	64
	65	(defcustom gnus-nocem-directory
	66	(nnheader-concat gnus-article-save-directory "NoCeM/")
	67	"*Directory where NoCeM files will be stored."
	68	:group 'gnus-nocem
	69	:type 'directory)
	70
	71	(defcustom gnus-nocem-expiry-wait 15
	72	"*Number of days to keep NoCeM headers in the cache."
	73	:group 'gnus-nocem
	74	:type 'integer)
	75
84861437	76	(defcustom gnus-nocem-verifyer 'pgg-verify
eec82323	77	"*Function called to verify that the NoCeM message is valid.
84861437	78	One likely value is `pgg-verify'. If the function in this variable
eec82323 LMI	79	isn't bound, the message will be used unconditionally."
eec82323 LMI	80	:group 'gnus-nocem
84861437 MB	81	:type '(radio (function-item pgg-verify)
84861437 MB	82	(function-item mc-verify)
eec82323 LMI	83	(function :tag "other")))
	84
	85	(defcustom gnus-nocem-liberal-fetch nil
	86	"*If t try to fetch all messages which have @@NCM in the subject.
	87	Otherwise don't fetch messages which have references or whose message-id
1dda7cc8	88	matches a previously scanned and verified nocem message."
eec82323 LMI	89	:group 'gnus-nocem
	90	:type 'boolean)
	91
fd1d9d98	92	(defcustom gnus-nocem-check-article-limit 500
e76ef45b MB	93	"*If non-nil, the maximum number of articles to check in any NoCeM group."
e76ef45b MB	94	:group 'gnus-nocem
f49c4ef7	95	:version "21.1"
e76ef45b MB	96	:type '(choice (const :tag "unlimited" nil)
	97	(integer 1000)))
	98
f49c4ef7 DL	99	(defcustom gnus-nocem-check-from t
	100	"Non-nil means check for valid issuers in message bodies.
	101	Otherwise don't bother fetching articles unless their author matches a
	102	valid issuer, which is much faster if you are selective about the issuers."
	103	:group 'gnus-nocem
	104	:version "21.1"
	105	:type 'boolean)
	106
eec82323 LMI	107	;;; Internal variables
	108
	109	(defvar gnus-nocem-active nil)
	110	(defvar gnus-nocem-alist nil)
	111	(defvar gnus-nocem-touched-alist nil)
	112	(defvar gnus-nocem-hashtb nil)
	113	(defvar gnus-nocem-seen-message-ids nil)
	114
	115	;;; Functions
	116
	117	(defun gnus-nocem-active-file ()
	118	(concat (file-name-as-directory gnus-nocem-directory) "active"))
	119
	120	(defun gnus-nocem-cache-file ()
	121	(concat (file-name-as-directory gnus-nocem-directory) "cache"))
	122
a8151ef7 LMI	123	;;
	124	;; faster lookups for group names:
	125	;;
	126
	127	(defvar gnus-nocem-real-group-hashtb nil
	128	"Real-name mappings of subscribed groups.")
	129
	130	(defun gnus-fill-real-hashtb ()
6748645f	131	"Fill up a hash table with the real-name mappings from the user's active file."
01c52d31 MB	132	(if (hash-table-p gnus-nocem-real-group-hashtb)
	133	(clrhash gnus-nocem-real-group-hashtb)
	134	(setq gnus-nocem-real-group-hashtb (make-hash-table :test 'equal)))
a8151ef7 LMI	135	(mapcar (lambda (group)
a8151ef7 LMI	136	(setq group (gnus-group-real-name (car group)))
01c52d31	137	(puthash group t gnus-nocem-real-group-hashtb))
a8151ef7 LMI	138	gnus-newsrc-alist))
a8151ef7 LMI	139
ea8ae765	140	;;;###autoload
eec82323 LMI	141	(defun gnus-nocem-scan-groups ()
	142	"Scan all NoCeM groups for new NoCeM messages."
	143	(interactive)
	144	(let ((groups gnus-nocem-groups)
	145	(gnus-inhibit-demon t)
16409b0b	146	group active gactive articles check-headers)
eec82323 LMI	147	(gnus-make-directory gnus-nocem-directory)
	148	;; Load any previous NoCeM headers.
	149	(gnus-nocem-load-cache)
a8151ef7 LMI	150	;; Get the group name mappings:
a8151ef7 LMI	151	(gnus-fill-real-hashtb)
eec82323 LMI	152	;; Read the active file if it hasn't been read yet.
	153	(and (file-exists-p (gnus-nocem-active-file))
	154	(not gnus-nocem-active)
	155	(ignore-errors
	156	(load (gnus-nocem-active-file) t t t)))
	157	;; Go through all groups and see whether new articles have
	158	;; arrived.
	159	(while (setq group (pop groups))
	160	(if (not (setq gactive (gnus-activate-group group)))
	161	() ; This group doesn't exist.
	162	(setq active (nth 1 (assoc group gnus-nocem-active)))
	163	(when (and (not (< (cdr gactive) (car gactive))) ; Empty group.
	164	(or (not active)
	165	(< (cdr active) (cdr gactive))))
	166	;; Ok, there are new articles in this group, se we fetch the
	167	;; headers.
	168	(save-excursion
	169	(let ((dependencies (make-vector 10 nil))
	170	headers header)
16409b0b	171	(with-temp-buffer
eec82323 LMI	172	(setq headers
	173	(if (eq 'nov
	174	(gnus-retrieve-headers
	175	(setq articles
	176	(gnus-uncompress-range
	177	(cons
	178	(if active (1+ (cdr active))
	179	(car gactive))
	180	(cdr gactive))))
	181	group))
	182	(gnus-get-newsgroup-headers-xover
	183	articles nil dependencies)
	184	(gnus-get-newsgroup-headers dependencies)))
	185	(while (setq header (pop headers))
	186	;; We take a closer look on all articles that have
	187	;; "@@NCM" in the subject. Unless we already read
	188	;; this cross posted message. Nocem messages
	189	;; are not allowed to have references, so we can
	190	;; ignore scanning followups.
	191	(and (string-match "@@NCM" (mail-header-subject header))
f49c4ef7 DL	192	(and gnus-nocem-check-from
	193	(let ((case-fold-search t))
	194	(catch 'ok
01c52d31	195	(mapc
f49c4ef7 DL	196	(lambda (author)
	197	(if (consp author)
	198	(setq author (car author)))
	199	(if (string-match
	200	author (mail-header-from header))
	201	(throw 'ok t)))
	202	gnus-nocem-issuers)
	203	nil)))
eec82323 LMI	204	(or gnus-nocem-liberal-fetch
	205	(and (or (string= "" (mail-header-references
	206	header))
	207	(null (mail-header-references header)))
	208	(not (member (mail-header-message-id header)
	209	gnus-nocem-seen-message-ids))))
16409b0b	210	(push header check-headers)))
ea8ae765 MB	211	(setq check-headers (last (nreverse check-headers)
	212	gnus-nocem-check-article-limit))
	213	(let ((i 0)
	214	(len (length check-headers)))
16409b0b GM	215	(dolist (h check-headers)
	216	(gnus-message
	217	7 "Checking article %d in %s for NoCeM (%d of %d)..."
	218	(mail-header-number h) group (incf i) len)
	219	(gnus-nocem-check-article group h)))))))
eec82323 LMI	220	(setq gnus-nocem-active
	221	(cons (list group gactive)
	222	(delq (assoc group gnus-nocem-active)
	223	gnus-nocem-active)))))
	224	;; Save the results, if any.
	225	(gnus-nocem-save-cache)
	226	(gnus-nocem-save-active)))
	227
	228	(defun gnus-nocem-check-article (group header)
	229	"Check whether the current article is an NCM article and that we want it."
	230	;; Get the article.
eec82323	231	(let ((date (mail-header-date header))
f49c4ef7	232	(gnus-newsgroup-name group)
6748645f	233	issuer b e type)
eec82323	234	(when (or (not date)
16409b0b GM	235	(time-less-p
	236	(time-since (date-to-time date))
	237	(days-to-time gnus-nocem-expiry-wait)))
eec82323 LMI	238	(gnus-request-article-this-buffer (mail-header-number header) group)
eec82323 LMI	239	(goto-char (point-min))
ea8ae765	240	(when (re-search-forward
01c52d31	241	"-----BEGIN PGP\\(?: SIGNED\\)? MESSAGE-----"
ea8ae765	242	nil t)
eec82323	243	(delete-region (point-min) (match-beginning 0)))
ea8ae765	244	(when (re-search-forward
01c52d31	245	"-----END PGP \\(?:MESSAGE\\\|SIGNATURE\\)-----\n?"
ea8ae765	246	nil t)
eec82323 LMI	247	(delete-region (match-end 0) (point-max)))
	248	(goto-char (point-min))
	249	;; The article has to have proper NoCeM headers.
	250	(when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t))
	251	(setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t)))
	252	;; We get the name of the issuer.
	253	(narrow-to-region b e)
6748645f	254	(setq issuer (mail-fetch-field "issuer")
84861437	255	type (mail-fetch-field "type"))
eec82323	256	(widen)
6748645f LMI	257	(if (not (gnus-nocem-message-wanted-p issuer type))
	258	(message "invalid NoCeM issuer: %s" issuer)
	259	(and (gnus-nocem-verify-issuer issuer) ; She is who she says she is.
	260	(gnus-nocem-enter-article) ; We gobble the message.
	261	(push (mail-header-message-id header) ; But don't come back for
	262	gnus-nocem-seen-message-ids))))))) ; second helpings.
	263
	264	(defun gnus-nocem-message-wanted-p (issuer type)
	265	(let ((issuers gnus-nocem-issuers)
	266	wanted conditions condition)
	267	(cond
	268	;; Do the quick check first.
	269	((member issuer issuers)
	270	t)
	271	((setq conditions (cdr (assoc issuer issuers)))
	272	;; Check whether we want this type.
	273	(while (setq condition (pop conditions))
	274	(cond
	275	((stringp condition)
84861437 MB	276	(when (string-match condition type)
84861437 MB	277	(setq wanted t)))
6748645f LMI	278	((and (consp condition)
	279	(eq (car condition) 'not)
	280	(stringp (cadr condition)))
84861437 MB	281	(when (string-match (cadr condition) type)
84861437 MB	282	(setq wanted nil)))
6748645f LMI	283	(t
	284	(error "Invalid NoCeM condition: %S" condition))))
	285	wanted))))
eec82323 LMI	286
	287	(defun gnus-nocem-verify-issuer (person)
	288	"Verify using PGP that the canceler is who she says she is."
84861437	289	(if (functionp gnus-nocem-verifyer)
a8151ef7 LMI	290	(ignore-errors
a8151ef7 LMI	291	(funcall gnus-nocem-verifyer))
eec82323 LMI	292	;; If we don't have Mailcrypt, then we use the message anyway.
	293	t))
	294
	295	(defun gnus-nocem-enter-article ()
	296	"Enter the current article into the NoCeM cache."
	297	(goto-char (point-min))
	298	(let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t))
	299	(e (search-forward "\n@@END NCM BODY\n" nil t))
	300	(buf (current-buffer))
	301	ncm id group)
	302	(when (and b e)
	303	(narrow-to-region b (1+ (match-beginning 0)))
	304	(goto-char (point-min))
	305	(while (search-forward "\t" nil t)
	306	(cond
	307	((not (ignore-errors
01c52d31 MB	308	(setq group (gnus-group-real-name (symbol-name (read buf))))
01c52d31 MB	309	(gethash group gnus-nocem-real-group-hashtb)))
eec82323 LMI	310	;; An error.
eec82323 LMI	311	)
eec82323	312	(t
01c52d31 MB	313	;; Valid group.
	314	(beginning-of-line)
	315	(while (eq (char-after) ?\t)
	316	(forward-line -1))
	317	(setq id (buffer-substring (point) (1- (search-forward "\t"))))
	318	(unless (if (hash-table-p gnus-nocem-hashtb)
	319	(gethash id gnus-nocem-hashtb)
	320	(setq gnus-nocem-hashtb (make-hash-table :test 'equal))
	321	nil)
	322	;; only store if not already present
	323	(puthash id t gnus-nocem-hashtb)
	324	(push id ncm))
	325	(forward-line 1)
	326	(while (eq (char-after) ?\t)
	327	(forward-line 1)))))
eec82323 LMI	328	(when ncm
	329	(setq gnus-nocem-touched-alist t)
	330	(push (cons (let ((time (current-time))) (setcdr (cdr time) nil) time)
	331	ncm)
	332	gnus-nocem-alist))
	333	t)))
	334
ea8ae765	335	;;;###autoload
eec82323 LMI	336	(defun gnus-nocem-load-cache ()
	337	"Load the NoCeM cache."
	338	(interactive)
	339	(unless gnus-nocem-alist
	340	;; The buffer doesn't exist, so we create it and load the NoCeM
	341	;; cache.
	342	(when (file-exists-p (gnus-nocem-cache-file))
	343	(load (gnus-nocem-cache-file) t t t)
	344	(gnus-nocem-alist-to-hashtb))))
	345
	346	(defun gnus-nocem-save-cache ()
	347	"Save the NoCeM cache."
	348	(when (and gnus-nocem-alist
	349	gnus-nocem-touched-alist)
16409b0b	350	(with-temp-file (gnus-nocem-cache-file)
eec82323 LMI	351	(gnus-prin1 `(setq gnus-nocem-alist ',gnus-nocem-alist)))
	352	(setq gnus-nocem-touched-alist nil)))
	353
	354	(defun gnus-nocem-save-active ()
	355	"Save the NoCeM active file."
16409b0b	356	(with-temp-file (gnus-nocem-active-file)
eec82323 LMI	357	(gnus-prin1 `(setq gnus-nocem-active ',gnus-nocem-active))))
	358
	359	(defun gnus-nocem-alist-to-hashtb ()
	360	"Create a hashtable from the Message-IDs we have."
	361	(let* ((alist gnus-nocem-alist)
	362	(pprev (cons nil alist))
	363	(prev pprev)
16409b0b	364	(expiry (days-to-time gnus-nocem-expiry-wait))
eec82323	365	entry)
01c52d31 MB	366	(if (hash-table-p gnus-nocem-hashtb)
	367	(clrhash gnus-nocem-hashtb)
	368	(setq gnus-nocem-hashtb (make-hash-table :test 'equal)))
eec82323	369	(while (setq entry (car alist))
16409b0b	370	(if (not (time-less-p (time-since (car entry)) expiry))
eec82323 LMI	371	;; This entry has expired, so we remove it.
	372	(setcdr prev (cdr alist))
	373	(setq prev alist)
	374	;; This is ok, so we enter it into the hashtable.
	375	(setq entry (cdr entry))
	376	(while entry
01c52d31	377	(puthash (car entry) t gnus-nocem-hashtb)
eec82323 LMI	378	(setq entry (cdr entry))))
	379	(setq alist (cdr alist)))))
	380
	381	(gnus-add-shutdown 'gnus-nocem-close 'gnus)
	382
	383	(defun gnus-nocem-close ()
	384	"Clear internal NoCeM variables."
	385	(setq gnus-nocem-alist nil
	386	gnus-nocem-hashtb nil
	387	gnus-nocem-active nil
	388	gnus-nocem-touched-alist nil
a8151ef7 LMI	389	gnus-nocem-seen-message-ids nil
a8151ef7 LMI	390	gnus-nocem-real-group-hashtb nil))
eec82323 LMI	391
	392	(defun gnus-nocem-unwanted-article-p (id)
	393	"Say whether article ID in the current group is wanted."
6748645f	394	(and gnus-nocem-hashtb
01c52d31	395	(gethash id gnus-nocem-hashtb)))
eec82323 LMI	396
	397	(provide 'gnus-nocem)
	398
ab5796a9	399	;;; arch-tag: 0e0c74ea-2f8e-4f3e-8fff-09f767c1adef
eec82323	400	;;; gnus-nocem.el ends here