(eval-when-compile (require 'cl))
(require 'qp)
(require 'mm-util)
(require 'ietf-drums)
(require 'mail-prsvr)
(require 'base64)
(require 'gnus-util)
(autoload 'mm-body-7-or-8 "mm-bodies")
(defvar rfc2047-header-encoding-alist
'(("Newsgroups" . nil)
("Message-ID" . nil)
(t . mime))
"*Header/encoding method alist.
The list is traversed sequentially. The keys can either be
header regexps or t.
The values can be:
1) nil, in which case no encoding is done;
2) `mime', in which case the header will be encoded according to RFC2047;
3) a charset, in which case it will be encoded as that charset;
4) `default', in which case the field will be encoded as the rest
of the article.")
(defvar rfc2047-charset-encoding-alist
'((us-ascii . nil)
(iso-8859-1 . Q)
(iso-8859-2 . Q)
(iso-8859-3 . Q)
(iso-8859-4 . Q)
(iso-8859-5 . B)
(koi8-r . B)
(iso-8859-7 . Q)
(iso-8859-8 . Q)
(iso-8859-9 . Q)
(iso-8859-14 . Q)
(iso-8859-15 . Q)
(iso-2022-jp . B)
(iso-2022-kr . B)
(gb2312 . B)
(big5 . B)
(cn-big5 . B)
(cn-gb . B)
(cn-gb-2312 . B)
(euc-kr . B)
(iso-2022-jp-2 . B)
(iso-2022-int-1 . B))
"Alist of MIME charsets to RFC2047 encodings.
Valid encodings are nil, `Q' and `B'.")
(defvar rfc2047-encoding-function-alist
'((Q . rfc2047-q-encode-region)
(B . rfc2047-b-encode-region)
(nil . ignore))
"Alist of RFC2047 encodings to encoding functions.")
(defvar rfc2047-q-encoding-alist
'(("\\(From\\|Cc\\|To\\|Bcc\||Reply-To\\):" . "-A-Za-z0-9!*+/")
("." . "\010\012\014\040-\074\076\100-\136\140-\177"))
"Alist of header regexps and valid Q characters.")
(defun rfc2047-narrow-to-field ()
"Narrow the buffer to the header on the current line."
(beginning-of-line)
(narrow-to-region
(point)
(progn
(forward-line 1)
(if (re-search-forward "^[^ \n\t]" nil t)
(progn
(beginning-of-line)
(point))
(point-max))))
(goto-char (point-min)))
(defun rfc2047-encode-message-header ()
"Encode the message header according to `rfc2047-header-encoding-alist'.
Should be called narrowed to the head of the message."
(interactive "*")
(save-excursion
(goto-char (point-min))
(let (alist elem method)
(while (not (eobp))
(save-restriction
(rfc2047-narrow-to-field)
(if (not (rfc2047-encodable-p))
(if (and (eq (mm-body-7-or-8) '8bit)
(mm-multibyte-p)
(mm-coding-system-p
(car message-posting-charset)))
(mm-encode-coding-region
(point-min) (point-max)
(car message-posting-charset)))
(setq method nil
alist rfc2047-header-encoding-alist)
(while (setq elem (pop alist))
(when (or (and (stringp (car elem))
(looking-at (car elem)))
(eq (car elem) t))
(setq alist nil
method (cdr elem))))
(cond
((eq method 'mime)
(rfc2047-encode-region (point-min) (point-max)))
((eq method 'default)
(if (and (featurep 'mule)
(if (boundp 'default-enable-multibyte-characters)
default-enable-multibyte-characters)
mail-parse-charset)
(mm-encode-coding-region (point-min) (point-max)
mail-parse-charset)))
((mm-coding-system-p method)
(if (and (featurep 'mule)
(if (boundp 'default-enable-multibyte-characters)
default-enable-multibyte-characters))
(mm-encode-coding-region (point-min) (point-max) method)))
(t)))
(goto-char (point-max)))))))
(eval-when-compile (defvar message-posting-charset))
(defun rfc2047-encodable-p ()
"Return non-nil if any characters in current buffer need encoding in headers.
The buffer may be narrowed."
(require 'message) (let ((charsets
(mapcar
'mm-mime-charset
(mm-find-charset-region (point-min) (point-max))))
(cs (list 'us-ascii (car message-posting-charset)))
found)
(while charsets
(unless (memq (pop charsets) cs)
(setq found t)))
found))
(defun rfc2047-dissect-region (b e)
"Dissect the region between B and E into words."
(let ((word-chars "-A-Za-z0-9!*+/")
mail-parse-mule-charset
words point current
result word)
(save-restriction
(narrow-to-region b e)
(goto-char (point-min))
(skip-chars-forward "\000-\177")
(while (not (eobp))
(setq point (point))
(skip-chars-backward word-chars b)
(unless (eq b (point))
(push (cons (buffer-substring b (point)) nil) words))
(setq b (point))
(goto-char point)
(setq current (mm-charset-after))
(forward-char 1)
(skip-chars-forward word-chars)
(while (and (not (eobp))
(eq (mm-charset-after) current))
(forward-char 1)
(skip-chars-forward word-chars))
(unless (eq b (point))
(push (cons (buffer-substring b (point)) current) words))
(setq b (point))
(skip-chars-forward "\000-\177"))
(unless (eq b (point))
(push (cons (buffer-substring b (point)) nil) words)))
(setq word (pop words))
(while word
(if (and (cdr word)
(caar words)
(not (cdar words))
(not (string-match "[^ \t]" (caar words))))
(if (eq (cdr (nth 1 words)) (cdr word))
(progn
(setq word (cons (concat
(car (nth 1 words)) (caar words)
(car word))
(cdr word)))
(pop words)
(pop words))
(push (cons (concat (caar words) (car word)) (cdr word))
result)
(pop words)
(setq word (pop words)))
(push word result)
(setq word (pop words))))
result))
(defun rfc2047-encode-region (b e)
"Encode all encodable words in region B to E."
(let ((words (rfc2047-dissect-region b e)) word)
(save-restriction
(narrow-to-region b e)
(delete-region (point-min) (point-max))
(while (setq word (pop words))
(if (not (cdr word))
(insert (car word))
(rfc2047-fold-region (gnus-point-at-bol) (point))
(goto-char (point-max))
(if (> (- (point) (save-restriction
(widen)
(gnus-point-at-bol))) 76)
(insert "\n "))
(if (eq (char-before) ?=) (insert " "))
(rfc2047-encode (point)
(progn (insert (car word)) (point))
(cdr word))))
(rfc2047-fold-region (point-min) (point-max)))))
(defun rfc2047-encode-string (string)
"Encode words in STRING."
(with-temp-buffer
(insert string)
(rfc2047-encode-region (point-min) (point-max))
(buffer-string)))
(defun rfc2047-encode (b e charset)
"Encode the word in the region B to E with CHARSET."
(let* ((mime-charset (mm-mime-charset charset))
(cs (mm-charset-to-coding-system mime-charset))
(encoding (or (cdr (assq mime-charset
rfc2047-charset-encoding-alist))
'B))
(start (concat
"=?" (downcase (symbol-name mime-charset)) "?"
(downcase (symbol-name encoding)) "?"))
(first t))
(save-restriction
(narrow-to-region b e)
(when (eq encoding 'B)
(goto-char (point-min))
(while (not (eobp))
(goto-char (min (point-max) (+ 15 (point))))
(unless (eobp)
(insert "\n"))))
(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)))))
(defun rfc2047-fold-region (b e)
"Fold long lines in region B to E."
(save-restriction
(narrow-to-region b e)
(goto-char (point-min))
(let ((break nil)
(qword-break nil)
(bol (save-restriction
(widen)
(gnus-point-at-bol))))
(while (not (eobp))
(when (and (or break qword-break) (> (- (point) bol) 76))
(goto-char (or break qword-break))
(setq break nil
qword-break nil)
(if (looking-at " \t")
(insert "\n")
(insert "\n "))
(setq bol (1- (point)))
(skip-chars-forward " \t")
(unless (eobp) (forward-char 1)))
(cond
((eq (char-after) ?\n)
(forward-char 1)
(setq bol (point)
break nil
qword-break nil)
(skip-chars-forward " \t")
(unless (or (eobp) (eq (char-after) ?\n))
(forward-char 1)))
((eq (char-after) ?\r)
(forward-char 1))
((memq (char-after) '(? ?\t))
(skip-chars-forward " \t")
(setq break (1- (point))))
((not break)
(if (not (looking-at "=\\?[^=]"))
(if (eq (char-after) ?=)
(forward-char 1)
(skip-chars-forward "^ \t\n\r="))
(setq qword-break (point))
(skip-chars-forward "^ \t\n\r")))
(t
(skip-chars-forward "^ \t\n\r"))))
(when (and (or break qword-break) (> (- (point) bol) 76))
(goto-char (or break qword-break))
(setq break nil
qword-break nil)
(if (looking-at " \t")
(insert "\n")
(insert "\n "))
(setq bol (1- (point)))
(skip-chars-forward " \t")
(unless (eobp) (forward-char 1))))))
(defun rfc2047-unfold-region (b e)
"Unfold lines in region B to E."
(save-restriction
(narrow-to-region b e)
(goto-char (point-min))
(let ((bol (save-restriction
(widen)
(gnus-point-at-bol)))
(eol (gnus-point-at-eol))
leading)
(forward-line 1)
(while (not (eobp))
(looking-at "[ \t]*")
(setq leading (- (match-end 0) (match-beginning 0)))
(if (< (- (gnus-point-at-eol) bol leading) 76)
(progn
(goto-char eol)
(delete-region eol (progn
(skip-chars-forward "[ \t\n\r]+")
(1- (point)))))
(setq bol (gnus-point-at-bol)))
(setq eol (gnus-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 ((alist rfc2047-q-encoding-alist)
(bol (save-restriction
(widen)
(gnus-point-at-bol))))
(while alist
(when (looking-at (caar alist))
(quoted-printable-encode-region b e nil (cdar alist))
(subst-char-in-region (point-min) (point-max) ? ?_)
(setq alist nil))
(pop alist))
(unless (< (- (point-max) (point-min)) 56)
(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)))))))))
(defvar rfc2047-encoded-word-regexp
"=\\?\\([^][\000-\040()<>@,\;:\\\"/?.=]+\\)\\?\\(B\\|Q\\)\\?\\([!->@-~ +]+\\)\\?=")
(defun rfc2047-decode-region (start end)
"Decode MIME-encoded words in region between START and END."
(interactive "r")
(let ((case-fold-search t)
b e)
(save-excursion
(save-restriction
(narrow-to-region start end)
(goto-char (point-min))
(while (re-search-forward
(concat "\\(" rfc2047-encoded-word-regexp "\\)"
"\\(\n?[ \t]\\)+"
"\\(" rfc2047-encoded-word-regexp "\\)")
nil t)
(delete-region (goto-char (match-end 1)) (match-beginning 6)))
(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)))))
(when (and (mm-multibyte-p)
mail-parse-charset
(not (eq mail-parse-charset 'gnus-decoded)))
(mm-decode-coding-region b e mail-parse-charset))
(setq b (point)))
(when (and (mm-multibyte-p)
mail-parse-charset
(not (eq mail-parse-charset 'us-ascii))
(not (eq mail-parse-charset 'gnus-decoded)))
(mm-decode-coding-region b (point-max) mail-parse-charset))
(rfc2047-unfold-region (point-min) (point-max))))))
(defun rfc2047-decode-string (string)
"Decode the quoted-printable-encoded STRING and return the results."
(let ((m (mm-multibyte-p)))
(with-temp-buffer
(when m
(mm-enable-multibyte))
(insert string)
(inline
(rfc2047-decode-region (point-min) (point-max)))
(buffer-string))))
(defun rfc2047-parse-and-decode (word)
"Decode WORD and return it if it is an encoded word.
Return WORD if not."
(if (not (string-match rfc2047-encoded-word-regexp word))
word
(or
(condition-case nil
(rfc2047-decode
(match-string 1 word)
(upcase (match-string 2 word))
(match-string 3 word))
(error word))
word)))
(defun rfc2047-decode (charset encoding string)
"Decode STRING from the given MIME CHARSET in the given ENCODING.
Valid ENCODINGs are \"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 (and (eq cs 'ascii)
mail-parse-charset)
(setq cs mail-parse-charset))
(let (default-enable-multibyte-characters)
(with-temp-buffer
(mm-decode-coding-string
(cond
((equal "B" encoding)
(base64-decode-string string))
((equal "Q" encoding)
(quoted-printable-decode-string
(mm-replace-chars-in-string string ?_ ? )))
(t (error "Invalid encoding: %s" encoding)))
cs))))))
(provide 'rfc2047)