1 ;;; base64.el,v --- Base64 encoding functions
2 ;; Author: Kyle E. Jones
3 ;; Created: 1997/03/12 14:37:09
5 ;; Keywords: extensions
7 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
8 ;;; Copyright (C) 1997 Kyle E. Jones
10 ;;; This file is not part of GNU Emacs, but the same permissions apply.
12 ;;; GNU Emacs is free software; you can redistribute it and/or modify
13 ;;; it under the terms of the GNU General Public License as published by
14 ;;; the Free Software Foundation; either version 2, or (at your option)
15 ;;; any later version.
17 ;;; GNU Emacs is distributed in the hope that it will be useful,
18 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;;; GNU General Public License for more details.
22 ;;; You should have received a copy of the GNU General Public License
23 ;;; along with GNU Emacs; see the file COPYING. If not, write to the
24 ;;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
25 ;;; Boston, MA 02111-1307, USA.
26 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
29 (if (not (fboundp 'char-int))
30 (fset 'char-int 'identity))
32 (defvar base64-alphabet
33 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/")
35 (defvar base64-decoder-program nil
36 "*Non-nil value should be a string that names a MIME base64 decoder.
37 The program should expect to read base64 data on its standard
38 input and write the converted data to its standard output.")
40 (defvar base64-decoder-switches nil
41 "*List of command line flags passed to the command named by
42 base64-decoder-program.")
44 (defvar base64-encoder-program nil
45 "*Non-nil value should be a string that names a MIME base64 encoder.
46 The program should expect arbitrary data on its standard
47 input and write base64 data to its standard output.")
49 (defvar base64-encoder-switches nil
50 "*List of command line flags passed to the command named by
51 base64-encoder-program.")
53 (defconst base64-alphabet-decoding-alist
55 ( ?A . 00) ( ?B . 01) ( ?C . 02) ( ?D . 03) ( ?E . 04) ( ?F . 05)
56 ( ?G . 06) ( ?H . 07) ( ?I . 08) ( ?J . 09) ( ?K . 10) ( ?L . 11)
57 ( ?M . 12) ( ?N . 13) ( ?O . 14) ( ?P . 15) ( ?Q . 16) ( ?R . 17)
58 ( ?S . 18) ( ?T . 19) ( ?U . 20) ( ?V . 21) ( ?W . 22) ( ?X . 23)
59 ( ?Y . 24) ( ?Z . 25) ( ?a . 26) ( ?b . 27) ( ?c . 28) ( ?d . 29)
60 ( ?e . 30) ( ?f . 31) ( ?g . 32) ( ?h . 33) ( ?i . 34) ( ?j . 35)
61 ( ?k . 36) ( ?l . 37) ( ?m . 38) ( ?n . 39) ( ?o . 40) ( ?p . 41)
62 ( ?q . 42) ( ?r . 43) ( ?s . 44) ( ?t . 45) ( ?u . 46) ( ?v . 47)
63 ( ?w . 48) ( ?x . 49) ( ?y . 50) ( ?z . 51) ( ?0 . 52) ( ?1 . 53)
64 ( ?2 . 54) ( ?3 . 55) ( ?4 . 56) ( ?5 . 57) ( ?6 . 58) ( ?7 . 59)
65 ( ?8 . 60) ( ?9 . 61) ( ?+ . 62) ( ?/ . 63)
68 (defvar base64-alphabet-decoding-vector
69 (let ((v (make-vector 123 nil))
70 (p base64-alphabet-decoding-alist))
72 (aset v (car (car p)) (cdr (car p)))
76 (defun base64-run-command-on-region (start end output-buffer command
78 (let ((tempfile nil) status errstring default-process-coding-system)
81 (setq tempfile (make-temp-name "base64"))
83 (apply 'call-process-region
85 (list output-buffer tempfile)
87 (cond ((equal status 0) t)
88 ((zerop (save-excursion
89 (set-buffer (find-file-noselect tempfile))
93 (set-buffer (find-file-noselect tempfile))
94 (setq errstring (buffer-string))
96 (cons status errstring)))))
98 (delete-file tempfile)
101 (if (string-match "XEmacs" emacs-version)
102 (defalias 'base64-insert-char 'insert-char)
103 (defun base64-insert-char (char &optional count ignored buffer)
104 (if (or (null buffer) (eq buffer (current-buffer)))
105 (insert-char char count)
106 (with-current-buffer buffer
107 (insert-char char count)))))
109 (defun base64-decode-region (start end)
111 ;;(message "Decoding base64...")
112 (let ((work-buffer nil)
117 (non-data-chars (concat "^=" base64-alphabet)))
120 (setq work-buffer (generate-new-buffer " *base64-work*"))
121 (buffer-disable-undo work-buffer)
122 (if base64-decoder-program
123 (let* ((binary-process-output t) ; any text already has CRLFs
124 (status (apply 'base64-run-command-on-region
125 start end work-buffer
126 base64-decoder-program
127 base64-decoder-switches)))
128 (if (not (eq status t))
129 (error "%s" (cdr status))))
131 (skip-chars-forward non-data-chars end)
133 (setq inputpos (point))
135 ((> (skip-chars-forward base64-alphabet end) 0)
137 (while (< inputpos lim)
139 (aref base64-alphabet-decoding-vector
140 (char-int (char-after inputpos)))))
141 (setq counter (1+ counter)
142 inputpos (1+ inputpos))
144 (base64-insert-char (lsh bits -16) 1 nil work-buffer)
145 (base64-insert-char (logand (lsh bits -8) 255) 1 nil
147 (base64-insert-char (logand bits 255) 1 nil
149 (setq bits 0 counter 0))
150 (t (setq bits (lsh bits 6)))))))
153 (if (not (zerop counter))
154 (error "at least %d bits missing at end of base64 encoding"
155 (* (- 4 counter) 6)))
157 ((eq (char-after (point)) ?=)
160 (error "at least 2 bits missing at end of base64 encoding"))
162 (base64-insert-char (lsh bits -10) 1 nil work-buffer))
164 (base64-insert-char (lsh bits -16) 1 nil work-buffer)
165 (base64-insert-char (logand (lsh bits -8) 255)
168 (t (skip-chars-forward non-data-chars end)))))
169 (or (markerp end) (setq end (set-marker (make-marker) end)))
171 (insert-buffer-substring work-buffer)
172 (delete-region (point) end))
173 (and work-buffer (kill-buffer work-buffer))))
174 ;;(message "Decoding base64... done")
177 (defun base64-encode-region (start end &optional no-line-break)
179 (message "Encoding base64...")
180 (let ((work-buffer nil)
184 (alphabet base64-alphabet)
188 (setq work-buffer (generate-new-buffer " *base64-work*"))
189 (buffer-disable-undo work-buffer)
190 (if base64-encoder-program
191 (let ((status (apply 'base64-run-command-on-region
192 start end work-buffer
193 base64-encoder-program
194 base64-encoder-switches)))
195 (if (not (eq status t))
196 (error "%s" (cdr status))))
197 (setq inputpos start)
198 (while (< inputpos end)
199 (setq bits (+ bits (char-int (char-after inputpos))))
200 (setq counter (1+ counter))
202 (base64-insert-char (aref alphabet (lsh bits -18)) 1 nil
205 (aref alphabet (logand (lsh bits -12) 63))
208 (aref alphabet (logand (lsh bits -6) 63))
211 (aref alphabet (logand bits 63))
213 (setq cols (+ cols 4))
214 (cond ((and (= cols 72)
216 (base64-insert-char ?\n 1 nil work-buffer)
218 (setq bits 0 counter 0))
219 (t (setq bits (lsh bits 8))))
220 (setq inputpos (1+ inputpos)))
221 ;; write out any remaining bits with appropriate padding
224 (setq bits (lsh bits (- 16 (* 8 counter))))
225 (base64-insert-char (aref alphabet (lsh bits -18)) 1 nil
227 (base64-insert-char (aref alphabet (logand (lsh bits -12) 63))
230 (base64-insert-char ?= 2 nil work-buffer)
231 (base64-insert-char (aref alphabet (logand (lsh bits -6) 63))
233 (base64-insert-char ?= 1 nil work-buffer)))
236 (base64-insert-char ?\n 1 nil work-buffer)))
237 (or (markerp end) (setq end (set-marker (make-marker) end)))
239 (insert-buffer-substring work-buffer)
240 (delete-region (point) end))
241 (and work-buffer (kill-buffer work-buffer))))
242 (message "Encoding base64... done"))
244 (defun base64-encode (string)
246 (set-buffer (get-buffer-create " *base64-encode*"))
249 (base64-encode-region (point-min) (point-max))
250 (skip-chars-backward " \t\r\n")
251 (delete-region (point-max) (point))
254 (kill-buffer (current-buffer)))))
256 (defun base64-decode (string)
258 (set-buffer (get-buffer-create " *base64-decode*"))
261 (base64-decode-region (point-min) (point-max))
262 (goto-char (point-max))
263 (skip-chars-backward " \t\r\n")
264 (delete-region (point-max) (point))
267 (kill-buffer (current-buffer)))))
269 (fset 'base64-decode-string 'base64-decode)