;;; rfc2047.el --- functions for encoding and decoding rfc2047 messages
-;; Copyright (C) 1998, 1999, 2000, 2002, 2003, 2004
-;; Free Software Foundation, Inc.
+;; Copyright (C) 1998, 1999, 2000, 2002, 2003, 2004,
+;; 2005, 2006 Free Software Foundation, Inc.
;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; MORIOKA Tomohiko <morioka@jaist.ac.jp>
;; 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., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
(require 'qp)
(require 'mm-util)
+(require 'ietf-drums)
;; Fixme: Avoid this (used for mail-parse-charset) mm dependence on gnus.
(require 'mail-prsvr)
(require 'base64)
'(("Newsgroups" . nil)
("Followup-To" . nil)
("Message-ID" . nil)
- ("\\(Resent-\\)?\\(From\\|Cc\\|To\\|Bcc\\|Reply-To\\|Sender\
+ ("\\(Resent-\\)?\\(From\\|Cc\\|To\\|Bcc\\|\\(In-\\)?Reply-To\\|Sender\
\\|Mail-Followup-To\\|Mail-Copies-To\\|Approved\\)" . address-mime)
(t . mime))
"*Header/encoding method alist.
"[^\000-\177]+\\|=\\?"
"[^\000-\177]+"))
start ; start of current token
- end begin
+ end begin csyntax
;; Whether there's an encoded word before the current token,
;; either immediately or separated by space.
last-encoded
;; `address-mime' case -- take care of quoted words, comments.
(with-syntax-table rfc2047-syntax-table
(goto-char (point-min))
- (condition-case nil ; in case of unbalanced quotes
+ (condition-case err ; in case of unbalanced quotes
;; Look for rfc2822-style: sequences of atoms, quoted
;; strings, specials, whitespace. (Specials mustn't be
;; encoded.)
(cond
((not (char-after))) ; eob
;; else token start
- ((eq ?\" (char-syntax (char-after)))
+ ((eq ?\" (setq csyntax (char-syntax (char-after))))
;; Quoted word.
(forward-sexp)
(setq end (point))
(rfc2047-encode start (- end 2))
(setq last-encoded t)) ; record that it was encoded
(setq last-encoded nil)))
- ((eq ?. (char-syntax (char-after)))
+ ((eq ?. csyntax)
;; Skip other delimiters, but record that they've
;; potentially separated quoted words.
(forward-char)
(setq last-encoded nil))
- ((eq ?\) (char-syntax (char-after)))
+ ((eq ?\) csyntax)
(error "Unbalanced parentheses"))
- ((eq ?\( (char-syntax (char-after)))
+ ((eq ?\( csyntax)
;; Look for the end of parentheses.
(forward-list)
;; Encode text as an unstructured field.
(let ((rfc2047-encoding-type 'mime))
- (rfc2047-encode-region (1+ start) (1- (point)))
- (forward-char)))
+ (rfc2047-encode-region (1+ start) (1- (point))))
+ (skip-chars-forward ")"))
(t ; normal token/whitespace sequence
;; Find the end.
;; Skip one ASCII word, or encode continuous words
;; in which all those contain non-ASCII characters.
(setq end nil)
- (while (not end)
+ (while (not (or end (eobp)))
(when (looking-at "[\000-\177]+")
(setq begin (point)
end (match-end 0))
- (if (re-search-forward "[ \t\n]\\|\\Sw" end 'move)
- (progn
- (setq end (match-beginning 0))
- (if rfc2047-encode-encoded-words
- (progn
- (goto-char begin)
- (when (search-forward "=?" end 'move)
- (goto-char (match-beginning 0))
- (setq end nil)))
- (goto-char end)))
- (setq end nil)))
+ (when (progn
+ (while (and (or (re-search-forward
+ "[ \t\n]\\|\\Sw" end 'move)
+ (setq end nil))
+ (eq ?\\ (char-syntax (char-before))))
+ ;; Skip backslash-quoted characters.
+ (forward-char))
+ end)
+ (setq end (match-beginning 0))
+ (if rfc2047-encode-encoded-words
+ (progn
+ (goto-char begin)
+ (when (search-forward "=?" end 'move)
+ (goto-char (match-beginning 0))
+ (setq end nil)))
+ (goto-char end))))
+ ;; Where the value nil of `end' means there may be
+ ;; text to have to be encoded following the point.
+ ;; Otherwise, the point reached to the end of ASCII
+ ;; words separated by whitespace or a special char.
(unless end
- (setq end t)
(when (looking-at encodable-regexp)
- (goto-char (match-end 0))
+ (goto-char (setq begin (match-end 0)))
(while (and (looking-at "[ \t\n]+\\([^ \t\n]+\\)")
(setq end (match-end 0))
- (string-match encodable-regexp
- (match-string 1)))
+ (progn
+ (while (re-search-forward
+ encodable-regexp end t))
+ (< begin (point)))
+ (goto-char begin)
+ (or (not (re-search-forward "\\Sw" end t))
+ (progn
+ (goto-char (match-beginning 0))
+ nil)))
(goto-char end))
(when (looking-at "[^ \t\n]+")
(setq end (match-end 0))
;; to be encoded so that MTAs may parse
;; them safely.
(cond ((= end (point)))
- ((looking-at encodable-regexp)
+ ((looking-at (concat "\\sw*\\("
+ encodable-regexp
+ "\\)"))
(setq end nil))
(t
(goto-char (1- (match-end 0)))
(unless (= (point) (match-beginning 0))
+ ;; Separate encodable text and
+ ;; delimiter.
(insert " "))))
(goto-char end)
(skip-chars-forward " \t\n")
(goto-char start)
(if (re-search-forward encodable-regexp end 'move)
(progn
+ (unless (memq (char-before start) '(nil ?\t ? ))
+ (if (progn
+ (goto-char start)
+ (skip-chars-backward "^ \t\n")
+ (and (looking-at "\\Sw+")
+ (= (match-end 0) start)))
+ ;; Also encode bogus delimiters.
+ (setq start (point))
+ ;; Separate encodable text and delimiter.
+ (goto-char start)
+ (insert " ")
+ (setq start (1+ start)
+ end (1+ end))))
(rfc2047-encode start end)
(setq last-encoded t))
- (setq last-encoded nil))
- )))
+ (setq last-encoded nil)))))
(error
- (error "Invalid data for rfc2047 encoding: %s"
- (mm-replace-in-string orig-text "[ \t\n]+" " ")))))))
- (rfc2047-fold-region b (point))))
+ (if (or debug-on-quit debug-on-error)
+ (signal (car err) (cdr err))
+ (error "Invalid data for rfc2047 encoding: %s"
+ (mm-replace-in-string orig-text "[ \t\n]+" " "))))))))
+ (rfc2047-fold-region b (point))
+ (goto-char (point-max))))
(defun rfc2047-encode-string (string)
"Encode words in STRING.
By default, the string is treated as containing addresses (see
`rfc2047-encoding-type')."
- (with-temp-buffer
+ (mm-with-multibyte-buffer
(insert string)
(rfc2047-encode-region (point-min) (point-max))
(buffer-string)))
-(defun rfc2047-encode-1 (column string cs encoder start space &optional eword)
+(defvar rfc2047-encode-max-chars 76
+ "Maximum characters of each header line that contain encoded-words.
+If it is nil, encoded-words will not be folded. Too small value may
+cause an error. Don't change this for no particular reason.")
+
+(defun rfc2047-encode-1 (column string cs encoder start crest tail
+ &optional eword)
"Subroutine used by `rfc2047-encode'."
(cond ((string-equal string "")
(or eword ""))
- ((>= column 76)
- (when (and eword
- (string-match "\n[ \t]+\\'" eword))
- ;; Reomove a superfluous empty line.
- (setq eword (substring eword 0 (match-beginning 0))))
- (rfc2047-encode-1 (length space) string cs encoder start " "
- (concat eword "\n" space)))
+ ((not rfc2047-encode-max-chars)
+ (concat start
+ (funcall encoder (if cs
+ (mm-encode-coding-string string cs)
+ string))
+ "?="))
+ ((>= column rfc2047-encode-max-chars)
+ (when eword
+ (cond ((string-match "\n[ \t]+\\'" eword)
+ ;; Reomove a superfluous empty line.
+ (setq eword (substring eword 0 (match-beginning 0))))
+ ((string-match "(+\\'" eword)
+ ;; Break the line before the open parenthesis.
+ (setq crest (concat crest (match-string 0 eword))
+ eword (substring eword 0 (match-beginning 0))))))
+ (rfc2047-encode-1 (length crest) string cs encoder start " " tail
+ (concat eword "\n" crest)))
(t
(let ((index 0)
(limit (1- (length string)))
(prev "")
- next)
+ next len)
(while (and prev
(<= index limit))
(setq next (concat start
(substring string 0 (1+ index))
cs)
(substring string 0 (1+ index))))
- "?="))
- (if (<= (+ column (length next)) 76)
- (setq prev next
- index (1+ index))
- (setq next prev
- prev nil)))
- (setq eword (concat eword next))
+ "?=")
+ len (+ column (length next)))
+ (if (> len rfc2047-encode-max-chars)
+ (setq next prev
+ prev nil)
+ (if (or (< index limit)
+ (<= (+ len (or (string-match "\n" tail)
+ (length tail)))
+ rfc2047-encode-max-chars))
+ (setq prev next
+ index (1+ index))
+ (if (string-match "\\`)+" tail)
+ ;; Break the line after the close parenthesis.
+ (setq tail (concat (substring tail 0 (match-end 0))
+ "\n "
+ (substring tail (match-end 0)))
+ prev next
+ index (1+ index))
+ (setq next prev
+ prev nil)))))
(if (> index limit)
- eword
+ (concat eword next tail)
+ (if (= 0 index)
+ (if (and eword
+ (string-match "(+\\'" eword))
+ (setq crest (concat crest (match-string 0 eword))
+ eword (substring eword 0 (match-beginning 0)))
+ (setq eword (concat eword next)))
+ (setq crest " "
+ eword (concat eword next)))
(when (string-match "\n[ \t]+\\'" eword)
;; Reomove a superfluous empty line.
(setq eword (substring eword 0 (match-beginning 0))))
- (rfc2047-encode-1 (length space) (substring string index)
- cs encoder start " "
- (concat eword "\n" space)))))))
+ (rfc2047-encode-1 (length crest) (substring string index)
+ cs encoder start " " tail
+ (concat eword "\n" crest)))))))
(defun rfc2047-encode (b e)
"Encode the word(s) in the region B to E.
Point moves to the end of the region."
(let ((mime-charset (or (mm-find-mime-charset-region b e) (list 'us-ascii)))
- cs encoding space eword)
+ cs encoding tail crest eword)
(cond ((> (length mime-charset) 1)
(error "Can't rfc2047-encode `%s'"
(buffer-substring-no-properties b e)))
'B
'Q)))
(widen)
+ (goto-char e)
+ (skip-chars-forward "^ \t\n")
+ ;; `tail' may contain a close parenthesis.
+ (setq tail (buffer-substring-no-properties e (point)))
(goto-char b)
(setq b (point-marker)
e (set-marker (make-marker) e))
(rfc2047-fold-region (point-at-bol) b)
+ (goto-char b)
+ (skip-chars-backward "^ \t\n")
(unless (= 0 (skip-chars-backward " \t"))
- (setq space (buffer-substring-no-properties (point) b)))
+ ;; `crest' may contain whitespace and an open parenthesis.
+ (setq crest (buffer-substring-no-properties (point) b)))
(setq eword (rfc2047-encode-1
(- b (point-at-bol))
(mm-replace-in-string
'identity)
(concat "=?" (downcase (symbol-name mime-charset))
"?" (upcase (symbol-name encoding)) "?")
- (or space " ")))
+ (or crest " ")
+ tail))
(delete-region (if (eq (aref eword 0) ?\n)
- (point)
+ (if (bolp)
+ ;; The line was folded before encoding.
+ (1- (point))
+ (point))
(goto-char b))
- e)
+ (+ e (length tail)))
+ ;; `eword' contains `crest' and `tail'.
(insert eword)
(set-marker b nil)
(set-marker e nil)
- (unless (or (eolp)
+ (unless (or (/= 0 (length tail))
+ (eobp)
(looking-at "[ \t\n)]"))
(insert " "))))
(t
(goto-char (or break qword-break))
(setq break nil
qword-break nil)
- (if (looking-at "[ \t]")
- (insert ?\n)
- (insert "\n "))
+ (if (or (> 0 (skip-chars-backward " \t"))
+ (looking-at "[ \t]"))
+ (insert ?\n)
+ (insert "\n "))
(setq bol (1- (point)))
;; Don't break before the first non-LWSP characters.
(skip-chars-forward " \t")
(subst-char-in-region (point-min) (point-max) ? ?_)
(buffer-string)))
+(defun rfc2047-encode-parameter (param value)
+ "Return and PARAM=VALUE string encoded in the RFC2047-like style.
+This is a replacement for the `rfc2231-encode-string' function.
+
+When attaching files as MIME parts, we should use the RFC2231 encoding
+to specify the file names containing non-ASCII characters. However,
+many mail softwares don't support it in practice and recipients won't
+be able to extract files with correct names. Instead, the RFC2047-like
+encoding is acceptable generally. This function provides the very
+RFC2047-like encoding, resigning to such a regrettable trend. To use
+it, put the following line in your ~/.gnus.el file:
+
+\(defalias 'mail-header-encode-parameter 'rfc2047-encode-parameter)
+"
+ (let* ((rfc2047-encoding-type 'mime)
+ (rfc2047-encode-max-chars nil)
+ (string (rfc2047-encode-string value)))
+ (if (string-match (concat "[" ietf-drums-tspecials "]") string)
+ (format "%s=%S" param string)
+ (concat param "=" string))))
+
;;;
;;; Functions for decoding RFC2047 messages
;;;
"=\\?\\([^][\000-\040()<>@,\;:*\\\"/?.=]+\\)\\(?:\\*[^?]+\\)?\
\\?\\(B\\|Q\\)\\?\\([!->@-~ ]*\\)\\?="))
+(defvar rfc2047-quote-decoded-words-containing-tspecials nil
+ "If non-nil, quote decoded words containing special characters.")
+
+(defvar rfc2047-allow-incomplete-encoded-text t
+ "*Non-nil means allow incomplete encoded-text in successive encoded-words.
+Dividing of encoded-text in the place other than character boundaries
+violates RFC2047 section 5, while we have a capability to decode it.
+If it is non-nil, the decoder will decode B- or Q-encoding in each
+encoded-word, concatenate them, and decode it by charset. Otherwise,
+the decoder will fully decode each encoded-word before concatenating
+them.")
+
+(defun rfc2047-charset-to-coding-system (charset)
+ "Return coding-system corresponding to MIME CHARSET.
+If your Emacs implementation can't decode CHARSET, return nil."
+ (when (stringp charset)
+ (setq charset (intern (downcase charset))))
+ (when (or (not charset)
+ (eq 'gnus-all mail-parse-ignored-charsets)
+ (memq 'gnus-all mail-parse-ignored-charsets)
+ (memq charset mail-parse-ignored-charsets))
+ (setq charset mail-parse-charset))
+ (let ((cs (mm-charset-to-coding-system charset)))
+ (cond ((eq cs 'ascii)
+ (setq cs (or (mm-charset-to-coding-system mail-parse-charset)
+ 'raw-text)))
+ ((setq cs (mm-coding-system-p cs)))
+ ((and charset
+ (listp mail-parse-ignored-charsets)
+ (memq 'gnus-unknown mail-parse-ignored-charsets))
+ (setq cs (mm-charset-to-coding-system mail-parse-charset))))
+ (if (eq cs 'ascii)
+ 'raw-text
+ cs)))
+
+(defun rfc2047-decode-encoded-words (words)
+ "Decode successive encoded-words in WORDS and return a decoded string.
+Each element of WORDS looks like (CHARSET ENCODING ENCODED-TEXT
+ENCODED-WORD)."
+ (let (word charset cs encoding text rest)
+ (while words
+ (setq word (pop words))
+ (if (and (or (setq cs (rfc2047-charset-to-coding-system
+ (setq charset (car word))))
+ (progn
+ (message "Unknown charset: %s" charset)
+ nil))
+ (condition-case code
+ (cond ((char-equal ?B (nth 1 word))
+ (setq text (base64-decode-string
+ (rfc2047-pad-base64 (nth 2 word)))))
+ ((char-equal ?Q (nth 1 word))
+ (setq text (quoted-printable-decode-string
+ (mm-subst-char-in-string
+ ?_ ? (nth 2 word) t)))))
+ (error
+ (message "%s" (error-message-string code))
+ nil)))
+ (if (and rfc2047-allow-incomplete-encoded-text
+ (eq cs (caar rest)))
+ ;; Concatenate text of which the charset is the same.
+ (setcdr (car rest) (concat (cdar rest) text))
+ (push (cons cs text) rest))
+ ;; Don't decode encoded-word.
+ (push (cons nil (nth 3 word)) rest)))
+ (while rest
+ (setq words (concat
+ (or (and (setq cs (caar rest))
+ (condition-case code
+ (mm-decode-coding-string (cdar rest) cs)
+ (error
+ (message "%s" (error-message-string code))
+ nil)))
+ (concat (when (cdr rest) " ")
+ (cdar rest)
+ (when (and words
+ (not (eq (string-to-char words) ? )))
+ " ")))
+ words)
+ rest (cdr rest)))
+ words))
+
;; Fixme: This should decode in place, not cons intermediate strings.
;; Also check whether it needs to worry about delimiting fields like
;; encoding.
"Decode MIME-encoded words in region between START and END."
(interactive "r")
(let ((case-fold-search t)
- b e)
+ (eword-regexp (eval-when-compile
+ ;; Ignore whitespace between encoded-words.
+ (concat "[\n\t ]*\\(" rfc2047-encoded-word-regexp
+ "\\)")))
+ b e match words)
(save-excursion
(save-restriction
(narrow-to-region start end)
- (goto-char (point-min))
- ;; Remove whitespace between encoded words.
- (while (re-search-forward
- (eval-when-compile
- (concat "\\(" rfc2047-encoded-word-regexp "\\)"
- "\\(\n?[ \t]\\)+"
- "\\(" rfc2047-encoded-word-regexp "\\)"))
- nil t)
- (delete-region (goto-char (match-end 1)) (match-beginning 6)))
- ;; Decode the encoded words.
- (setq b (goto-char (point-min)))
- (while (re-search-forward rfc2047-encoded-word-regexp nil t)
- (setq e (match-beginning 0))
- (insert (rfc2047-parse-and-decode
- (prog1
- (match-string 0)
- (delete-region (match-beginning 0) (match-end 0)))))
- ;; Remove newlines between decoded words, though such things
- ;; essentially must not be there.
+ (goto-char (setq b start))
+ ;; Look for the encoded-words.
+ (while (setq match (re-search-forward eword-regexp nil t))
+ (setq e (match-beginning 1)
+ end (match-end 0)
+ words nil)
+ (while match
+ (push (list (match-string 2) ;; charset
+ (char-after (match-beginning 3)) ;; encoding
+ (match-string 4) ;; encoded-text
+ (match-string 1)) ;; encoded-word
+ words)
+ ;; Look for the subsequent encoded-words.
+ (when (setq match (looking-at eword-regexp))
+ (goto-char (setq end (match-end 0)))))
+ ;; Replace the encoded-words with the decoded one.
+ (delete-region e end)
+ (insert (rfc2047-decode-encoded-words (nreverse words)))
(save-restriction
(narrow-to-region e (point))
(goto-char e)
+ ;; Remove newlines between decoded words, though such
+ ;; things essentially must not be there.
(while (re-search-forward "[\n\r]+" nil t)
(replace-match " "))
+ ;; Quote decoded words if there are special characters
+ ;; which might violate RFC2822.
+ (when (and rfc2047-quote-decoded-words-containing-tspecials
+ (let ((regexp (car (rassq
+ 'address-mime
+ rfc2047-header-encoding-alist))))
+ (when regexp
+ (save-restriction
+ (widen)
+ (beginning-of-line)
+ (while (and (memq (char-after) '(? ?\t))
+ (zerop (forward-line -1))))
+ (looking-at regexp)))))
+ (let (quoted)
+ (goto-char e)
+ (skip-chars-forward " \t")
+ (setq start (point))
+ (setq quoted (eq (char-after) ?\"))
+ (goto-char (point-max))
+ (skip-chars-backward " \t")
+ (if (setq quoted (and quoted
+ (> (point) (1+ start))
+ (eq (char-before) ?\")))
+ (progn
+ (backward-char)
+ (setq start (1+ start)
+ end (point-marker)))
+ (setq end (point-marker)))
+ (goto-char start)
+ (while (search-forward "\"" end t)
+ (when (prog2
+ (backward-char)
+ (zerop (% (skip-chars-backward "\\\\") 2))
+ (goto-char (match-beginning 0)))
+ (insert "\\"))
+ (forward-char))
+ (when (and (not quoted)
+ (progn
+ (goto-char start)
+ (re-search-forward
+ (concat "[" ietf-drums-tspecials "]")
+ end t)))
+ (goto-char start)
+ (insert "\"")
+ (goto-char end)
+ (insert "\""))
+ (set-marker end nil)))
(goto-char (point-max)))
(when (and (mm-multibyte-p)
mail-parse-charset
(mm-decode-coding-string string mail-parse-charset))
(mm-string-as-multibyte string)))))
-(defun rfc2047-parse-and-decode (word)
- "Decode WORD and return it if it is an encoded word.
-Return WORD if it is not not an encoded word or if the charset isn't
-decodable."
- (if (not (string-match rfc2047-encoded-word-regexp word))
- word
- (or
- (condition-case nil
- (rfc2047-decode
- (match-string 1 word)
- (string-to-char (match-string 2 word))
- (match-string 3 word))
- (error word))
- word))) ; un-decodable
-
(defun rfc2047-pad-base64 (string)
"Pad STRING to quartets."
;; Be more liberal to accept buggy base64 strings. If
(2 (concat string "=="))
(3 (concat string "=")))))
-(defun rfc2047-decode (charset encoding string)
- "Decode STRING from the given MIME CHARSET in the given ENCODING.
-Valid ENCODINGs are the characters \"B\" and \"Q\".
-If your Emacs implementation can't decode CHARSET, return nil."
- (if (stringp charset)
- (setq charset (intern (downcase charset))))
- (if (or (not charset)
- (eq 'gnus-all mail-parse-ignored-charsets)
- (memq 'gnus-all mail-parse-ignored-charsets)
- (memq charset mail-parse-ignored-charsets))
- (setq charset mail-parse-charset))
- (let ((cs (mm-charset-to-coding-system charset)))
- (if (and (not cs) charset
- (listp mail-parse-ignored-charsets)
- (memq 'gnus-unknown mail-parse-ignored-charsets))
- (setq cs (mm-charset-to-coding-system mail-parse-charset)))
- (when cs
- (when (eq cs 'ascii)
- (setq cs (or mail-parse-charset 'raw-text)))
- (mm-decode-coding-string
- (cond
- ((char-equal ?B encoding)
- (base64-decode-string
- (rfc2047-pad-base64 string)))
- ((char-equal ?Q encoding)
- (quoted-printable-decode-string
- (mm-subst-char-in-string ?_ ? string t)))
- (t (error "Invalid encoding: %c" encoding)))
- cs))))
-
(provide 'rfc2047)
;;; rfc2047.el ends here