1 /* gbase64.c - Base64 encoding/decoding
3 * Copyright (C) 2006 Alexander Larsson <alexl@redhat.com>
4 * Copyright (C) 2000-2003 Ximian Inc.
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 02111-1307, USA.
21 * This is based on code in camel, written by:
22 * Michael Zucchi <notzed@ximian.com>
23 * Jeffrey Stedfast <fejj@ximian.com>
36 static const char base64_alphabet[] =
37 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
40 * g_base64_encode_step:
41 * @in: the binary data to encode.
42 * @len: the length of @in.
43 * @break_lines: whether to break long lines
44 * @out: pointer to destination buffer
45 * @state: Saved state between steps, initialize to 0
46 * @save: Saved state between steps, initialize to 0
48 * Incrementally encode a sequence of binary data into it's Base-64 stringified
49 * representation. By calling this functions multiple times you can convert data
50 * in chunks to avoid having to have the full encoded data in memory.
52 * When all the data has been converted you must call g_base64_encode_close()
53 * to flush the saved state.
55 * The output buffer must be large enough to fit all the data that will
56 * be written to it. Due to the way base64 encodes you will need
57 * at least: @len * 4 / 3 + 6 bytes. If you enable line-breaking you will
58 * need at least: @len * 4 / 3 + @len * 4 / (3 * 72) + 7 bytes.
60 * @break_lines is typically used when putting base64-encoded data in emails.
61 * It breaks the lines at 72 columns instead of putting all text on the same
62 * line. This avoids problems with long lines in the email system.
64 * Return value: The number of bytes of output that was written
69 g_base64_encode_step (const guchar *in,
85 if (len + ((char *) save) [0] > 2)
87 const guchar *inend = in+len-2;
93 switch (((char *) save) [0])
95 case 1: c1 = ((unsigned char *) save) [1]; goto skip1;
96 case 2: c1 = ((unsigned char *) save) [1];
97 c2 = ((unsigned char *) save) [2]; goto skip2;
101 * yes, we jump into the loop, no i'm not going to change it,
104 while (inptr < inend)
111 *outptr++ = base64_alphabet [ c1 >> 2 ];
112 *outptr++ = base64_alphabet [ c2 >> 4 |
114 *outptr++ = base64_alphabet [ ((c2 &0x0f) << 2) |
116 *outptr++ = base64_alphabet [ c3 & 0x3f ];
117 /* this is a bit ugly ... */
118 if (break_lines && (++already)>=19)
125 ((char *)save)[0] = 0;
126 len = 2-(inptr-inend);
134 /* points to the slot for the next char to save */
135 saveout = & (((char *)save)[1]) + ((char *)save)[0];
137 /* len can only be 0 1 or 2 */
140 case 2: *saveout++ = *inptr++;
141 case 1: *saveout++ = *inptr++;
143 ((char *)save)[0]+=len;
150 * g_base64_encode_close:
151 * @break_lines: whether to break long lines
152 * @out: pointer to destination buffer
153 * @state: Saved state from g_base64_encode_step()
154 * @save: Saved state from g_base64_encode_step()
156 * Flush the status from a sequence of calls to g_base64_encode_step().
158 * Return value: The number of bytes of output that was written
163 g_base64_encode_close (gboolean break_lines,
171 c1 = ((unsigned char *) save) [1];
172 c2 = ((unsigned char *) save) [2];
174 switch (((char *) save) [0])
177 outptr [2] = base64_alphabet[ ( (c2 &0x0f) << 2 ) ];
178 g_assert (outptr [2] != 0);
183 outptr [0] = base64_alphabet [ c1 >> 2 ];
184 outptr [1] = base64_alphabet [ c2 >> 4 | ( (c1&0x3) << 4 )];
200 * @data: the binary data to encode.
201 * @len: the length of @data.
203 * Encode a sequence of binary data into it's Base-64 stringified
206 * Return value: a newly allocated, zero-terminated Base-64 encoded
207 * string representing @data.
212 g_base64_encode (const guchar *data, gsize len)
215 int state = 0, outlen;
218 /* We can use a smaller limit here, since we know the saved state is 0 */
219 out = g_malloc (len * 4 / 3 + 4);
220 outlen = g_base64_encode_step (data, len, FALSE, out, &state, &save);
221 outlen += g_base64_encode_close (FALSE,
229 static const unsigned char mime_base64_rank[256] = {
230 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
231 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
232 255,255,255,255,255,255,255,255,255,255,255, 62,255,255,255, 63,
233 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,255,255,255, 0,255,255,
234 255, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
235 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,255,255,255,255,255,
236 255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
237 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,255,255,255,255,255,
238 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
239 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
240 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
241 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
242 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
243 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
244 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
245 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
249 * g_base64_decode_step: decode a chunk of base64 encoded data
250 * @in: binary input data
251 * @len: max length of @in data to decode
252 * @out: output buffer
253 * @state: Saved state between steps, initialize to 0
254 * @save: Saved state between steps, initialize to 0
256 * Incrementally decode a sequence of binary data from it's Base-64 stringified
257 * representation. By calling this functions multiple times you can convert data
258 * in chunks to avoid having to have the full encoded data in memory.
260 * The output buffer must be large enough to fit all the data that will
261 * be written to it. Since base64 encodes 3 bytes in 4 chars you need
262 * at least: @len * 3 / 4 bytes.
264 * Return value: The number of bytes of output that was written
269 g_base64_decode_step (const char *in,
282 inend = (const guchar *)in+len;
285 /* convert 4 base64 bytes to 3 normal bytes */
288 inptr = (const guchar *)in;
289 while (inptr < inend)
291 c = mime_base64_rank [*inptr++];
309 /* quick scan back for '=' on the end somewhere */
310 /* fortunately we can drop 1 output char for each trailing = (upto 2) */
312 while (inptr > (const guchar *)in && i)
315 if (mime_base64_rank [*inptr] != 0xff)
323 /* if i!= 0 then there is a truncation error! */
329 * @text: zero-terminated string with base64 text to decode.
330 * @out_len: The lenght of the decoded data is written here.
332 * Decode a sequence of Base-64 encoded text into binary data
334 * Return value: a newly allocated, buffer containing the binary data
335 * that @text represents
340 g_base64_decode (const char *text,
344 int inlen, state = 0;
347 inlen = strlen (text);
348 ret = g_malloc0 (inlen * 3 / 4);
350 *out_len = g_base64_decode_step (text, inlen, ret, &state, &save);
355 #define __G_BASE64_C__
356 #include "galiasdef.c"