;;; rfc2047.el --- functions for encoding and decoding rfc2047 messages
-;; Copyright (C) 1998, 1999, 2000, 2002, 2003 Free Software Foundation, Inc.
+
+;; Copyright (C) 1998, 1999, 2000, 2002, 2003, 2004
+;; Free Software Foundation, Inc.
;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; MORIOKA Tomohiko <morioka@jaist.ac.jp>
Valid encodings are nil, `Q' and `B'. These indicate binary (no) encoding,
quoted-printable and base64 respectively.")
-(defvar rfc2047-encoding-function-alist
- '((Q . rfc2047-q-encode-region)
- (B . rfc2047-b-encode-region)
- (nil . ignore))
+(defvar rfc2047-encode-function-alist
+ '((Q . rfc2047-q-encode-string)
+ (B . rfc2047-b-encode-string)
+ (nil . identity))
"Alist of RFC2047 encodings to encoding functions.")
(defvar rfc2047-encode-encoded-words t
Dynamically bind `rfc2047-encoding-type' to change that."
(save-restriction
(narrow-to-region b e)
- (if (eq 'mime rfc2047-encoding-type)
- ;; Simple case. Treat as single word after any initial ASCII
- ;; part and before any tailing ASCII part. The leading ASCII
- ;; is relevant for instance in Subject headers with `Re:' for
- ;; interoperability with non-MIME clients, and we might as
- ;; well avoid the tail too.
- (let ((encodable-regexp
- (if rfc2047-encode-encoded-words
- "[^\000-\177]\\|=\\?"
- "[^\000-\177]")))
- (goto-char (point-min))
- ;; Does it need encoding?
- (re-search-forward encodable-regexp (point-max) 'move)
- (unless (eobp)
- (skip-chars-backward "^ \n") ; beginning of space-delimited word
- (rfc2047-encode
- (point)
- (progn
- (goto-char e)
- (re-search-backward encodable-regexp (point-max) 'move)
- (skip-chars-forward "^ \n")
- ;; end of space-delimited word
- (point)))))
- ;; `address-mime' case -- take care of quoted words, comments.
- (with-syntax-table rfc2047-syntax-table
- (let ((start) ; start of current token
- end ; end of current token
- ;; Whether there's an encoded word before the current
- ;; token, either immediately or separated by space.
- last-encoded)
+ (let ((encodable-regexp (if rfc2047-encode-encoded-words
+ "[^\000-\177]\\|=\\?"
+ "[^\000-\177]"))
+ start ; start of current token
+ end ; end of current token
+ ;; Whether there's an encoded word before the current token,
+ ;; either immediately or separated by space.
+ last-encoded)
+ (if (eq 'mime rfc2047-encoding-type)
+ ;; Simple case. Continuous words in which all those contain
+ ;; non-ASCII characters are encoded collectively. Encoding
+ ;; ASCII words, including `Re:' used in Subject headers, is
+ ;; avoided for interoperability with non-MIME clients and
+ ;; for making it easy to find keywords.
+ (progn
+ (goto-char (point-min))
+ (while (progn (skip-chars-forward " \t\n")
+ (not (eobp)))
+ (setq start (point))
+ (while (and (looking-at "[ \t\n]*\\([^ \t\n]+\\)")
+ (progn
+ (setq end (match-end 0))
+ (re-search-forward encodable-regexp end t)))
+ (goto-char end))
+ (if (> (point) start)
+ (rfc2047-encode start (point))
+ (goto-char end))))
+ ;; `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
;; Look for rfc2822-style: sequences of atoms, quoted
;; strings, specials, whitespace. (Specials mustn't be
;; encoded.)
(while (not (eobp))
- (setq start (point))
;; Skip whitespace.
- (unless (= 0 (skip-chars-forward " \t\n"))
- (setq start (point)))
+ (skip-chars-forward " \t\n")
+ (setq start (point))
(cond
((not (char-after))) ; eob
;; else token start
(setq last-encoded nil))
(t ; normal token/whitespace sequence
;; Find the end.
- (forward-word 1)
- (skip-chars-backward " \t")
- (setq end (point))
- ;; Deal with encoding and leading space as for
- ;; quoted words.
- (goto-char start)
- (skip-chars-forward "\000-\177" end)
- (if (= end (point))
- (setq last-encoded nil)
- (when last-encoded
- (goto-char start)
- (skip-chars-backward " \t")
- (insert ? )
- (setq start (point)
- end (1+ end)))
- (rfc2047-encode start end)
- (setq last-encoded t)))))
+ (skip-chars-backward " \t\n")
+ (if (and (eq (char-before) ?\()
+ ;; Look for the end of parentheses.
+ (let ((string (buffer-substring (point)
+ (point-max)))
+ (default-major-mode 'fundamental-mode))
+ ;; Use `standard-syntax-table'.
+ (with-temp-buffer
+ (insert "(" string)
+ (goto-char (point-min))
+ (condition-case nil
+ (progn
+ (forward-list 1)
+ (setq end (- (point) 3)))
+ (error nil)))))
+ ;; Encode text as an unstructured field.
+ (let ((rfc2047-encoding-type 'mime))
+ (rfc2047-encode-region start (+ (point) end))
+ (forward-char))
+ ;; Skip one ASCII word, or encode continuous words
+ ;; in which all those contain non-ASCII characters.
+ (skip-chars-forward " \t\n")
+ (setq end nil)
+ (while (not end)
+ (when (looking-at "[\000-\177]+")
+ (setq end (match-end 0))
+ (if (re-search-forward "[ \t\n]\\|\\Sw" end t)
+ (goto-char (match-beginning 0))
+ (goto-char end)
+ (setq end nil)))
+ (unless end
+ (setq end t)
+ (when (looking-at "[^\000-\177]+")
+ (goto-char (match-end 0))
+ (while (and (looking-at "[ \t\n]+\\([^ \t\n]+\\)")
+ (setq end (match-end 0))
+ (string-match "[^\000-\177]"
+ (match-string 1)))
+ (goto-char end))
+ (when (looking-at "[^ \t\n]+")
+ (setq end (match-end 0))
+ (if (re-search-forward "\\Sw+" end t)
+ ;; There are special characters better
+ ;; to be encoded so that MTAs may parse
+ ;; them safely.
+ (cond ((= end (point)))
+ ((looking-at "[^\000-\177]")
+ (setq end nil))
+ (t
+ (goto-char (1- (match-end 0)))
+ (unless (= (point) (match-beginning 0))
+ (insert " "))))
+ (goto-char end)
+ (skip-chars-forward " \t\n")
+ (if (and (looking-at "[^ \t\n]+")
+ (string-match "[^\000-\177]"
+ (match-string 0)))
+ (setq end nil)
+ (goto-char end)))))))
+ (skip-chars-backward " \t\n")
+ (setq end (point))
+ (goto-char start)
+ (skip-chars-forward "\000-\177" end)
+ (if (= end (point))
+ (setq last-encoded nil)
+ (rfc2047-encode start end)
+ (setq last-encoded t))))))
(error
(error "Invalid data for rfc2047 encoding: %s"
(buffer-substring b e)))))))
(rfc2047-encode-region (point-min) (point-max))
(buffer-string)))
+(defun rfc2047-encode-1 (column string cs encoder start space &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)))
+ (t
+ (let ((index 0)
+ (limit (1- (length string)))
+ (prev "")
+ next)
+ (while (and prev
+ (<= index limit))
+ (setq next (concat start
+ (funcall encoder
+ (if cs
+ (mm-encode-coding-string
+ (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))
+ (if (> index limit)
+ eword
+ (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)))))))
+
(defun rfc2047-encode (b e)
"Encode the word(s) in the region B to E.
By default, the region is treated as containing addresses (see
`rfc2047-encoding-type')."
- (let* ((mime-charset (or (mm-find-mime-charset-region b e) (list 'us-ascii)))
- (cs (if (> (length mime-charset) 1)
- ;; Fixme: Instead of this, try to break region into
- ;; parts that can be encoded separately.
- (error "Can't rfc2047-encode `%s'"
- (buffer-substring b e))
- (setq mime-charset (car mime-charset))
- (mm-charset-to-coding-system mime-charset)))
- ;; Fixme: Better, calculate the number of non-ASCII
- ;; characters, at least for 8-bit charsets.
- (encoding (or (cdr (assq mime-charset
+ (let ((mime-charset (or (mm-find-mime-charset-region b e) (list 'us-ascii)))
+ cs encoding space eword)
+ (cond ((> (length mime-charset) 1)
+ (error "Can't rfc2047-encode `%s'"
+ (buffer-substring-no-properties b e)))
+ ((= (length mime-charset) 1)
+ (setq mime-charset (car mime-charset)
+ cs (mm-charset-to-coding-system mime-charset))
+ (unless (and (mm-multibyte-p)
+ (mm-coding-system-p cs))
+ (setq cs nil))
+ (save-restriction
+ (narrow-to-region b e)
+ (setq encoding
+ (or (cdr (assq mime-charset
rfc2047-charset-encoding-alist))
;; For the charsets that don't have a preferred
;; encoding, choose the one that's shorter.
- (save-restriction
- (narrow-to-region b e)
- (if (eq (rfc2047-qp-or-base64) 'base64)
- 'B
- 'Q))))
- (start (concat
- "=?" (downcase (symbol-name mime-charset)) "?"
- (upcase (symbol-name encoding)) "?"))
- (factor (case mime-charset
- ((iso-8859-5 iso-8859-7 iso-8859-8 koi8-r) 1)
- ((big5 gb2312 euc-kr) 2)
- (utf-8 4)
- (t 8)))
- (pre (- b (save-restriction
- (widen)
- (point-at-bol))))
- ;; encoded-words must not be longer than 75 characters,
- ;; including charset, encoding etc. This leaves us with
- ;; 75 - (length start) - 2 - 2 characters. The last 2 is for
- ;; possible base64 padding. In the worst case (iso-2022-*)
- ;; each character expands to 8 bytes which is expanded by a
- ;; factor of 4/3 by base64 encoding.
- (length (floor (- 75 (length start) 4) (* factor (/ 4.0 3.0))))
- ;; Limit line length to 76 characters.
- (length1 (max 1 (floor (- 76 (length start) 4 pre)
- (* factor (/ 4.0 3.0)))))
- (first t))
- (if mime-charset
- (save-restriction
- (narrow-to-region b e)
- (when (eq encoding 'B)
- ;; break into lines before encoding
- (goto-char (point-min))
- (while (not (eobp))
- (if first
- (progn
- (goto-char (min (point-max) (+ length1 (point))))
- (setq first nil))
- (goto-char (min (point-max) (+ length (point)))))
- (unless (eobp)
- (insert ?\n)))
- (setq first t))
- (if (and (mm-multibyte-p)
- (mm-coding-system-p cs))
- (mm-encode-coding-region (point-min) (point-max) cs))
- (funcall (cdr (assq encoding rfc2047-encoding-function-alist))
- (point-min) (point-max))
- (goto-char (point-min))
- (while (not (eobp))
- (unless first
- (insert ? ))
- (setq first nil)
- (insert start)
- (end-of-line)
- (insert "?=")
- (forward-line 1))))))
+ (if (eq (rfc2047-qp-or-base64) 'base64)
+ 'B
+ 'Q)))
+ (widen)
+ (goto-char b)
+ (unless (= 0 (skip-chars-backward " \t"))
+ (setq space (buffer-substring-no-properties (point) b)))
+ (setq eword (rfc2047-encode-1
+ (- b (point-at-bol))
+ (mm-replace-in-string
+ (buffer-substring-no-properties b e)
+ "\n\\([ \t]?\\)" "\\1")
+ cs
+ (or (cdr (assq encoding
+ rfc2047-encode-function-alist))
+ 'identity)
+ (concat "=?" (downcase (symbol-name mime-charset))
+ "?" (upcase (symbol-name encoding)) "?")
+ (or space " ")))
+ (delete-region (if (eq (aref eword 0) ?\n)
+ (point)
+ (goto-char b))
+ e)
+ (insert eword)
+ (unless (or (eolp)
+ (looking-at "[ \t\n)]"))
+ (insert " "))))
+ (t
+ (goto-char e)))))
(defun rfc2047-fold-field ()
"Fold the current header field."
(goto-char (or break qword-break))
(setq break nil
qword-break nil)
+ (skip-chars-backward " \t")
(if (looking-at "[ \t]")
(insert ?\n)
(insert "\n "))
(forward-char 1))
((memq (char-after) '(? ?\t))
(skip-chars-forward " \t")
- (if first
- ;; Don't break just after the header name.
- (setq first nil)
- (setq break (1- (point)))))
+ (unless first ;; Don't break just after the header name.
+ (setq break (point))))
((not break)
(if (not (looking-at "=\\?[^=]"))
(if (eq (char-after) ?=)
(setq qword-break (point)))
(skip-chars-forward "^ \t\n\r")))
(t
- (skip-chars-forward "^ \t\n\r"))))
+ (skip-chars-forward "^ \t\n\r")))
+ (setq first nil))
(when (and (or break qword-break)
(> (- (point) bol) 76))
(goto-char (or break qword-break))
(setq eol (point-at-eol))
(forward-line 1)))))
-(defun rfc2047-b-encode-region (b e)
- "Base64-encode the header contained in region B to E."
- (save-restriction
- (narrow-to-region (goto-char b) e)
- (while (not (eobp))
- (base64-encode-region (point) (progn (end-of-line) (point)) t)
- (if (and (bolp) (eolp))
- (delete-backward-char 1))
- (forward-line))))
-
-(defun rfc2047-q-encode-region (b e)
- "Quoted-printable-encode the header in region B to E."
- (save-excursion
- (save-restriction
- (narrow-to-region (goto-char b) e)
- (let ((bol (save-restriction
- (widen)
- (point-at-bol))))
- (quoted-printable-encode-region
- b e nil
- ;; = (\075), _ (\137), ? (\077) are used in the encoded word.
- ;; Avoid using 8bit characters.
- ;; This list excludes `especials' (see the RFC2047 syntax),
- ;; meaning that some characters in non-structured fields will
- ;; get encoded when they con't need to be. The following is
- ;; what it used to be.
-;;; ;; Equivalent to "^\000-\007\011\013\015-\037\200-\377=_?"
-;;; "\010\012\014\040-\074\076\100-\136\140-\177")
- "-\b\n\f !#-'*+0-9A-Z\\^`-~\d")
- (subst-char-in-region (point-min) (point-max) ? ?_)
- ;; The size of QP encapsulation is about 20, so set limit to
- ;; 56=76-20.
- (unless (< (- (point-max) (point-min)) 56)
- ;; Don't break if it could fit in one line.
- ;; Let rfc2047-encode-region break it later.
- (goto-char (1+ (point-min)))
- (while (and (not (bobp)) (not (eobp)))
- (goto-char (min (point-max) (+ 56 bol)))
- (search-backward "=" (- (point) 2) t)
- (unless (or (bobp) (eobp))
- (insert ?\n)
- (setq bol (point)))))))))
+(defun rfc2047-b-encode-string (string)
+ "Base64-encode the header contained in STRING."
+ (base64-encode-string string t))
+
+(defun rfc2047-q-encode-string (string)
+ "Quoted-printable-encode the header in STRING."
+ (mm-with-unibyte-buffer
+ (insert string)
+ (quoted-printable-encode-region
+ (point-min) (point-max) nil
+ ;; = (\075), _ (\137), ? (\077) are used in the encoded word.
+ ;; Avoid using 8bit characters.
+ ;; This list excludes `especials' (see the RFC2047 syntax),
+ ;; meaning that some characters in non-structured fields will
+ ;; get encoded when they con't need to be. The following is
+ ;; what it used to be.
+ ;;; ;; Equivalent to "^\000-\007\011\013\015-\037\200-\377=_?"
+ ;;; "\010\012\014\040-\074\076\100-\136\140-\177")
+ "-\b\n\f !#-'*+0-9A-Z\\^`-~\d")
+ (subst-char-in-region (point-min) (point-max) ? ?_)
+ (buffer-string)))
;;;
;;; Functions for decoding RFC2047 messages
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