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 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
28 (eval-when-compile (require 'cl))
31 (if (not (fboundp 'char-int))
32 (defalias 'char-int 'identity))
34 (defvar base64-alphabet
35 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/")
37 (defvar base64-decoder-program nil
38 "*Non-nil value should be a string that names a MIME base64 decoder.
39 The program should expect to read base64 data on its standard
40 input and write the converted data to its standard output.")
42 (defvar base64-decoder-switches nil
43 "*List of command line flags passed to the command named by
44 base64-decoder-program.")
46 (defvar base64-encoder-program nil
47 "*Non-nil value should be a string that names a MIME base64 encoder.
48 The program should expect arbitrary data on its standard
49 input and write base64 data to its standard output.")
51 (defvar base64-encoder-switches nil
52 "*List of command line flags passed to the command named by
53 base64-encoder-program.")
55 (defconst base64-alphabet-decoding-alist
57 ( ?A . 00) ( ?B . 01) ( ?C . 02) ( ?D . 03) ( ?E . 04) ( ?F . 05)
58 ( ?G . 06) ( ?H . 07) ( ?I . 08) ( ?J . 09) ( ?K . 10) ( ?L . 11)
59 ( ?M . 12) ( ?N . 13) ( ?O . 14) ( ?P . 15) ( ?Q . 16) ( ?R . 17)
60 ( ?S . 18) ( ?T . 19) ( ?U . 20) ( ?V . 21) ( ?W . 22) ( ?X . 23)
61 ( ?Y . 24) ( ?Z . 25) ( ?a . 26) ( ?b . 27) ( ?c . 28) ( ?d . 29)
62 ( ?e . 30) ( ?f . 31) ( ?g . 32) ( ?h . 33) ( ?i . 34) ( ?j . 35)
63 ( ?k . 36) ( ?l . 37) ( ?m . 38) ( ?n . 39) ( ?o . 40) ( ?p . 41)
64 ( ?q . 42) ( ?r . 43) ( ?s . 44) ( ?t . 45) ( ?u . 46) ( ?v . 47)
65 ( ?w . 48) ( ?x . 49) ( ?y . 50) ( ?z . 51) ( ?0 . 52) ( ?1 . 53)
66 ( ?2 . 54) ( ?3 . 55) ( ?4 . 56) ( ?5 . 57) ( ?6 . 58) ( ?7 . 59)
67 ( ?8 . 60) ( ?9 . 61) ( ?+ . 62) ( ?/ . 63)
70 (defvar base64-alphabet-decoding-vector
71 (let ((v (make-vector 123 nil))
72 (p base64-alphabet-decoding-alist))
74 (aset v (car (car p)) (cdr (car p)))
78 (defvar base64-binary-coding-system 'binary)
80 (defun base64-run-command-on-region (start end output-buffer command
82 (let ((tempfile nil) status errstring default-process-coding-system
83 (coding-system-for-write base64-binary-coding-system)
84 (coding-system-for-read base64-binary-coding-system))
87 (setq tempfile (make-temp-name "base64"))
89 (apply 'call-process-region
91 (list output-buffer tempfile)
93 (cond ((equal status 0) t)
94 ((zerop (save-excursion
95 (set-buffer (find-file-noselect tempfile))
99 (set-buffer (find-file-noselect tempfile))
100 (setq errstring (buffer-string))
102 (cons status errstring)))))
104 (delete-file tempfile)))))
106 (if (featurep 'xemacs)
107 (defalias 'base64-insert-char 'insert-char)
108 (defun base64-insert-char (char &optional count ignored buffer)
109 (if (or (null buffer) (eq buffer (current-buffer)))
110 (insert-char char count)
111 (with-current-buffer buffer
112 (insert-char char count))))
113 (setq base64-binary-coding-system 'no-conversion))
115 (defun base64-decode-region (start end)
117 ;;(message "Decoding base64...")
118 (let ((work-buffer nil)
123 (non-data-chars (concat "^=" base64-alphabet)))
126 (setq work-buffer (generate-new-buffer " *base64-work*"))
127 (buffer-disable-undo work-buffer)
128 (if base64-decoder-program
129 (let* ((binary-process-output t) ; any text already has CRLFs
130 (status (apply 'base64-run-command-on-region
131 start end work-buffer
132 base64-decoder-program
133 base64-decoder-switches)))
134 (if (not (eq status t))
135 (error "%s" (cdr status))))
137 (skip-chars-forward non-data-chars end)
139 (setq inputpos (point))
141 ((> (skip-chars-forward base64-alphabet end) 0)
143 (while (< inputpos lim)
145 (aref base64-alphabet-decoding-vector
146 (char-int (char-after inputpos)))))
147 (setq counter (1+ counter)
148 inputpos (1+ inputpos))
150 (base64-insert-char (lsh bits -16) 1 nil work-buffer)
151 (base64-insert-char (logand (lsh bits -8) 255) 1 nil
153 (base64-insert-char (logand bits 255) 1 nil
155 (setq bits 0 counter 0))
156 (t (setq bits (lsh bits 6)))))))
159 (eq (char-after (point)) ?=))
160 (if (and (= (point) end) (> counter 1))
162 "at least %d bits missing at end of base64 encoding"
163 (* (- 4 counter) 6)))
166 (error "at least 2 bits missing at end of base64 encoding"))
168 (base64-insert-char (lsh bits -10) 1 nil work-buffer))
170 (base64-insert-char (lsh bits -16) 1 nil work-buffer)
171 (base64-insert-char (logand (lsh bits -8) 255)
174 (t (skip-chars-forward non-data-chars end)))))
175 (or (markerp end) (setq end (set-marker (make-marker) end)))
177 (insert-buffer-substring work-buffer)
178 (delete-region (point) end))
179 (and work-buffer (kill-buffer work-buffer))))
180 ;;(message "Decoding base64... done")
183 (defun base64-encode-region (start end &optional no-line-break)
185 (message "Encoding base64...")
186 (let ((work-buffer nil)
190 (alphabet base64-alphabet)
194 (setq work-buffer (generate-new-buffer " *base64-work*"))
195 (buffer-disable-undo work-buffer)
196 (if base64-encoder-program
197 (let ((status (apply 'base64-run-command-on-region
198 start end work-buffer
199 base64-encoder-program
200 base64-encoder-switches)))
201 (if (not (eq status t))
202 (error "%s" (cdr status))))
203 (setq inputpos start)
204 (while (< inputpos end)
205 (setq bits (+ bits (char-int (char-after inputpos))))
206 (setq counter (1+ counter))
208 (base64-insert-char (aref alphabet (lsh bits -18)) 1 nil
211 (aref alphabet (logand (lsh bits -12) 63))
214 (aref alphabet (logand (lsh bits -6) 63))
217 (aref alphabet (logand bits 63))
219 (setq cols (+ cols 4))
220 (cond ((and (= cols 72)
222 (base64-insert-char ?\n 1 nil work-buffer)
224 (setq bits 0 counter 0))
225 (t (setq bits (lsh bits 8))))
226 (setq inputpos (1+ inputpos)))
227 ;; write out any remaining bits with appropriate padding
230 (setq bits (lsh bits (- 16 (* 8 counter))))
231 (base64-insert-char (aref alphabet (lsh bits -18)) 1 nil
233 (base64-insert-char (aref alphabet (logand (lsh bits -12) 63))
236 (base64-insert-char ?= 2 nil work-buffer)
237 (base64-insert-char (aref alphabet (logand (lsh bits -6) 63))
239 (base64-insert-char ?= 1 nil work-buffer)))
242 (base64-insert-char ?\n 1 nil work-buffer)))
243 (or (markerp end) (setq end (set-marker (make-marker) end)))
245 (insert-buffer-substring work-buffer)
246 (delete-region (point) end))
247 (and work-buffer (kill-buffer work-buffer))))
248 (message "Encoding base64... done"))
250 (defun base64-encode (string &optional no-line-break)
252 (set-buffer (get-buffer-create " *base64-encode*"))
255 (base64-encode-region (point-min) (point-max) no-line-break)
256 (skip-chars-backward " \t\r\n")
257 (delete-region (point-max) (point))
260 (kill-buffer (current-buffer)))))
262 (defun base64-decode (string)
264 (set-buffer (get-buffer-create " *base64-decode*"))
267 (base64-decode-region (point-min) (point-max))
268 (goto-char (point-max))
269 (skip-chars-backward " \t\r\n")
270 (delete-region (point-max) (point))
273 (kill-buffer (current-buffer)))))
275 (defalias 'base64-decode-string 'base64-decode)
276 (defalias 'base64-encode-string 'base64-encode)