Line data Source code
1 : /* b64enc.c - Simple Base64 encoder.
2 : * Copyright (C) 2001, 2003, 2004, 2008, 2010,
3 : * 2011 Free Software Foundation, Inc.
4 : * Copyright (C) 2001, 2003, 2004, 2008, 2010,
5 : * 2011 g10 Code GmbH
6 : *
7 : * This file is part of GnuPG.
8 : *
9 : * This file is free software; you can redistribute it and/or modify
10 : * it under the terms of the GNU Lesser General Public License as
11 : * published by the Free Software Foundation; either version 2.1 of
12 : * the License, or (at your option) any later version.
13 : *
14 : * This file is distributed in the hope that it will be useful,
15 : * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 : * GNU General Public License for more details.
18 : *
19 : * You should have received a copy of the GNU Lesser General Public License
20 : * along with this program; if not, see <http://www.gnu.org/licenses/>.
21 : */
22 :
23 : #include <config.h>
24 : #include <stdio.h>
25 : #include <stdlib.h>
26 : #include <string.h>
27 : #include <errno.h>
28 : #include <assert.h>
29 :
30 : #include "i18n.h"
31 : #include "util.h"
32 :
33 : #define B64ENC_DID_HEADER 1
34 : #define B64ENC_DID_TRAILER 2
35 : #define B64ENC_NO_LINEFEEDS 16
36 : #define B64ENC_USE_PGPCRC 32
37 :
38 : /* The base-64 character list */
39 : static unsigned char bintoasc[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
40 : "abcdefghijklmnopqrstuvwxyz"
41 : "0123456789+/";
42 :
43 : /* Stuff required to create the OpenPGP CRC. This crc_table has been
44 : created using this code:
45 :
46 : #include <stdio.h>
47 : #include <stdint.h>
48 :
49 : #define CRCPOLY 0x864CFB
50 :
51 : int
52 : main (void)
53 : {
54 : int i, j;
55 : uint32_t t;
56 : uint32_t crc_table[256];
57 :
58 : crc_table[0] = 0;
59 : for (i=j=0; j < 128; j++ )
60 : {
61 : t = crc_table[j];
62 : if ( (t & 0x00800000) )
63 : {
64 : t <<= 1;
65 : crc_table[i++] = t ^ CRCPOLY;
66 : crc_table[i++] = t;
67 : }
68 : else
69 : {
70 : t <<= 1;
71 : crc_table[i++] = t;
72 : crc_table[i++] = t ^ CRCPOLY;
73 : }
74 : }
75 :
76 : puts ("static const u32 crc_table[256] = {");
77 : for (i=j=0; i < 256; i++)
78 : {
79 : printf ("%s 0x%08lx", j? "":" ", (unsigned long)crc_table[i]);
80 : if (i != 255)
81 : {
82 : putchar (',');
83 : if ( ++j > 5)
84 : {
85 : j = 0;
86 : putchar ('\n');
87 : }
88 : }
89 : }
90 : puts ("\n};");
91 : return 0;
92 : }
93 : */
94 : #define CRCINIT 0xB704CE
95 : static const u32 crc_table[256] = {
96 : 0x00000000, 0x00864cfb, 0x018ad50d, 0x010c99f6, 0x0393e6e1, 0x0315aa1a,
97 : 0x021933ec, 0x029f7f17, 0x07a18139, 0x0727cdc2, 0x062b5434, 0x06ad18cf,
98 : 0x043267d8, 0x04b42b23, 0x05b8b2d5, 0x053efe2e, 0x0fc54e89, 0x0f430272,
99 : 0x0e4f9b84, 0x0ec9d77f, 0x0c56a868, 0x0cd0e493, 0x0ddc7d65, 0x0d5a319e,
100 : 0x0864cfb0, 0x08e2834b, 0x09ee1abd, 0x09685646, 0x0bf72951, 0x0b7165aa,
101 : 0x0a7dfc5c, 0x0afbb0a7, 0x1f0cd1e9, 0x1f8a9d12, 0x1e8604e4, 0x1e00481f,
102 : 0x1c9f3708, 0x1c197bf3, 0x1d15e205, 0x1d93aefe, 0x18ad50d0, 0x182b1c2b,
103 : 0x192785dd, 0x19a1c926, 0x1b3eb631, 0x1bb8faca, 0x1ab4633c, 0x1a322fc7,
104 : 0x10c99f60, 0x104fd39b, 0x11434a6d, 0x11c50696, 0x135a7981, 0x13dc357a,
105 : 0x12d0ac8c, 0x1256e077, 0x17681e59, 0x17ee52a2, 0x16e2cb54, 0x166487af,
106 : 0x14fbf8b8, 0x147db443, 0x15712db5, 0x15f7614e, 0x3e19a3d2, 0x3e9fef29,
107 : 0x3f9376df, 0x3f153a24, 0x3d8a4533, 0x3d0c09c8, 0x3c00903e, 0x3c86dcc5,
108 : 0x39b822eb, 0x393e6e10, 0x3832f7e6, 0x38b4bb1d, 0x3a2bc40a, 0x3aad88f1,
109 : 0x3ba11107, 0x3b275dfc, 0x31dced5b, 0x315aa1a0, 0x30563856, 0x30d074ad,
110 : 0x324f0bba, 0x32c94741, 0x33c5deb7, 0x3343924c, 0x367d6c62, 0x36fb2099,
111 : 0x37f7b96f, 0x3771f594, 0x35ee8a83, 0x3568c678, 0x34645f8e, 0x34e21375,
112 : 0x2115723b, 0x21933ec0, 0x209fa736, 0x2019ebcd, 0x228694da, 0x2200d821,
113 : 0x230c41d7, 0x238a0d2c, 0x26b4f302, 0x2632bff9, 0x273e260f, 0x27b86af4,
114 : 0x252715e3, 0x25a15918, 0x24adc0ee, 0x242b8c15, 0x2ed03cb2, 0x2e567049,
115 : 0x2f5ae9bf, 0x2fdca544, 0x2d43da53, 0x2dc596a8, 0x2cc90f5e, 0x2c4f43a5,
116 : 0x2971bd8b, 0x29f7f170, 0x28fb6886, 0x287d247d, 0x2ae25b6a, 0x2a641791,
117 : 0x2b688e67, 0x2beec29c, 0x7c3347a4, 0x7cb50b5f, 0x7db992a9, 0x7d3fde52,
118 : 0x7fa0a145, 0x7f26edbe, 0x7e2a7448, 0x7eac38b3, 0x7b92c69d, 0x7b148a66,
119 : 0x7a181390, 0x7a9e5f6b, 0x7801207c, 0x78876c87, 0x798bf571, 0x790db98a,
120 : 0x73f6092d, 0x737045d6, 0x727cdc20, 0x72fa90db, 0x7065efcc, 0x70e3a337,
121 : 0x71ef3ac1, 0x7169763a, 0x74578814, 0x74d1c4ef, 0x75dd5d19, 0x755b11e2,
122 : 0x77c46ef5, 0x7742220e, 0x764ebbf8, 0x76c8f703, 0x633f964d, 0x63b9dab6,
123 : 0x62b54340, 0x62330fbb, 0x60ac70ac, 0x602a3c57, 0x6126a5a1, 0x61a0e95a,
124 : 0x649e1774, 0x64185b8f, 0x6514c279, 0x65928e82, 0x670df195, 0x678bbd6e,
125 : 0x66872498, 0x66016863, 0x6cfad8c4, 0x6c7c943f, 0x6d700dc9, 0x6df64132,
126 : 0x6f693e25, 0x6fef72de, 0x6ee3eb28, 0x6e65a7d3, 0x6b5b59fd, 0x6bdd1506,
127 : 0x6ad18cf0, 0x6a57c00b, 0x68c8bf1c, 0x684ef3e7, 0x69426a11, 0x69c426ea,
128 : 0x422ae476, 0x42aca88d, 0x43a0317b, 0x43267d80, 0x41b90297, 0x413f4e6c,
129 : 0x4033d79a, 0x40b59b61, 0x458b654f, 0x450d29b4, 0x4401b042, 0x4487fcb9,
130 : 0x461883ae, 0x469ecf55, 0x479256a3, 0x47141a58, 0x4defaaff, 0x4d69e604,
131 : 0x4c657ff2, 0x4ce33309, 0x4e7c4c1e, 0x4efa00e5, 0x4ff69913, 0x4f70d5e8,
132 : 0x4a4e2bc6, 0x4ac8673d, 0x4bc4fecb, 0x4b42b230, 0x49ddcd27, 0x495b81dc,
133 : 0x4857182a, 0x48d154d1, 0x5d26359f, 0x5da07964, 0x5cace092, 0x5c2aac69,
134 : 0x5eb5d37e, 0x5e339f85, 0x5f3f0673, 0x5fb94a88, 0x5a87b4a6, 0x5a01f85d,
135 : 0x5b0d61ab, 0x5b8b2d50, 0x59145247, 0x59921ebc, 0x589e874a, 0x5818cbb1,
136 : 0x52e37b16, 0x526537ed, 0x5369ae1b, 0x53efe2e0, 0x51709df7, 0x51f6d10c,
137 : 0x50fa48fa, 0x507c0401, 0x5542fa2f, 0x55c4b6d4, 0x54c82f22, 0x544e63d9,
138 : 0x56d11cce, 0x56575035, 0x575bc9c3, 0x57dd8538
139 : };
140 :
141 :
142 : static gpg_error_t
143 0 : enc_start (struct b64state *state, FILE *fp, estream_t stream,
144 : const char *title)
145 : {
146 0 : memset (state, 0, sizeof *state);
147 0 : state->fp = fp;
148 0 : state->stream = stream;
149 0 : state->lasterr = 0;
150 0 : if (title && !*title)
151 0 : state->flags |= B64ENC_NO_LINEFEEDS;
152 0 : else if (title)
153 : {
154 0 : if (!strncmp (title, "PGP ", 4))
155 : {
156 0 : state->flags |= B64ENC_USE_PGPCRC;
157 0 : state->crc = CRCINIT;
158 : }
159 0 : state->title = xtrystrdup (title);
160 0 : if (!state->title)
161 0 : state->lasterr = gpg_error_from_syserror ();
162 : }
163 0 : return state->lasterr;
164 : }
165 :
166 :
167 : /* Prepare for base-64 writing to the stream FP. If TITLE is not NULL
168 : and not an empty string, this string will be used as the title for
169 : the armor lines, with TITLE being an empty string, we don't write
170 : the header lines and furthermore even don't write any linefeeds.
171 : If TITLE starts with "PGP " the OpenPGP CRC checksum will be
172 : written as well. With TITLE beeing NULL, we merely don't write
173 : header but make sure that lines are not too long. Note, that we
174 : don't write any output unless at least one byte get written using
175 : b64enc_write. */
176 : gpg_error_t
177 0 : b64enc_start (struct b64state *state, FILE *fp, const char *title)
178 : {
179 0 : return enc_start (state, fp, NULL, title);
180 : }
181 :
182 : /* Same as b64enc_start but takes an estream. */
183 : gpg_error_t
184 0 : b64enc_start_es (struct b64state *state, estream_t fp, const char *title)
185 : {
186 0 : return enc_start (state, NULL, fp, title);
187 : }
188 :
189 :
190 : static int
191 0 : my_fputs (const char *string, struct b64state *state)
192 : {
193 0 : if (state->stream)
194 0 : return es_fputs (string, state->stream);
195 : else
196 0 : return fputs (string, state->fp);
197 : }
198 :
199 :
200 : /* Write NBYTES from BUFFER to the Base 64 stream identified by
201 : STATE. With BUFFER and NBYTES being 0, merely do a fflush on the
202 : stream. */
203 : gpg_error_t
204 0 : b64enc_write (struct b64state *state, const void *buffer, size_t nbytes)
205 : {
206 : unsigned char radbuf[4];
207 : int idx, quad_count;
208 : const unsigned char *p;
209 :
210 0 : if (state->lasterr)
211 0 : return state->lasterr;
212 :
213 0 : if (!nbytes)
214 : {
215 0 : if (buffer)
216 0 : if (state->stream? es_fflush (state->stream) : fflush (state->fp))
217 0 : goto write_error;
218 0 : return 0;
219 : }
220 :
221 0 : if (!(state->flags & B64ENC_DID_HEADER))
222 : {
223 0 : if (state->title)
224 : {
225 0 : if ( my_fputs ("-----BEGIN ", state) == EOF
226 0 : || my_fputs (state->title, state) == EOF
227 0 : || my_fputs ("-----\n", state) == EOF)
228 : goto write_error;
229 0 : if ( (state->flags & B64ENC_USE_PGPCRC)
230 0 : && my_fputs ("\n", state) == EOF)
231 0 : goto write_error;
232 : }
233 :
234 0 : state->flags |= B64ENC_DID_HEADER;
235 : }
236 :
237 0 : idx = state->idx;
238 0 : quad_count = state->quad_count;
239 0 : assert (idx < 4);
240 0 : memcpy (radbuf, state->radbuf, idx);
241 :
242 0 : if ( (state->flags & B64ENC_USE_PGPCRC) )
243 : {
244 : size_t n;
245 0 : u32 crc = state->crc;
246 :
247 0 : for (p=buffer, n=nbytes; n; p++, n-- )
248 0 : crc = ((u32)crc << 8) ^ crc_table[((crc >> 16)&0xff) ^ *p];
249 0 : state->crc = (crc & 0x00ffffff);
250 : }
251 :
252 0 : for (p=buffer; nbytes; p++, nbytes--)
253 : {
254 0 : radbuf[idx++] = *p;
255 0 : if (idx > 2)
256 : {
257 : char tmp[4];
258 :
259 0 : tmp[0] = bintoasc[(*radbuf >> 2) & 077];
260 0 : tmp[1] = bintoasc[(((*radbuf<<4)&060)|((radbuf[1] >> 4)&017))&077];
261 0 : tmp[2] = bintoasc[(((radbuf[1]<<2)&074)|((radbuf[2]>>6)&03))&077];
262 0 : tmp[3] = bintoasc[radbuf[2]&077];
263 0 : if (state->stream)
264 : {
265 0 : for (idx=0; idx < 4; idx++)
266 0 : es_putc (tmp[idx], state->stream);
267 0 : idx = 0;
268 0 : if (es_ferror (state->stream))
269 0 : goto write_error;
270 : }
271 : else
272 : {
273 0 : for (idx=0; idx < 4; idx++)
274 0 : putc (tmp[idx], state->fp);
275 0 : idx = 0;
276 0 : if (ferror (state->fp))
277 0 : goto write_error;
278 : }
279 0 : if (++quad_count >= (64/4))
280 : {
281 0 : quad_count = 0;
282 0 : if (!(state->flags & B64ENC_NO_LINEFEEDS)
283 0 : && my_fputs ("\n", state) == EOF)
284 0 : goto write_error;
285 : }
286 : }
287 : }
288 0 : memcpy (state->radbuf, radbuf, idx);
289 0 : state->idx = idx;
290 0 : state->quad_count = quad_count;
291 0 : return 0;
292 :
293 : write_error:
294 0 : state->lasterr = gpg_error_from_syserror ();
295 0 : if (state->title)
296 : {
297 0 : xfree (state->title);
298 0 : state->title = NULL;
299 : }
300 0 : return state->lasterr;
301 : }
302 :
303 :
304 : gpg_error_t
305 0 : b64enc_finish (struct b64state *state)
306 : {
307 0 : gpg_error_t err = 0;
308 : unsigned char radbuf[4];
309 : int idx, quad_count;
310 : char tmp[4];
311 :
312 0 : if (state->lasterr)
313 0 : return state->lasterr;
314 :
315 0 : if (!(state->flags & B64ENC_DID_HEADER))
316 0 : goto cleanup;
317 :
318 : /* Flush the base64 encoding */
319 0 : idx = state->idx;
320 0 : quad_count = state->quad_count;
321 0 : assert (idx < 4);
322 0 : memcpy (radbuf, state->radbuf, idx);
323 :
324 0 : if (idx)
325 : {
326 0 : tmp[0] = bintoasc[(*radbuf>>2)&077];
327 0 : if (idx == 1)
328 : {
329 0 : tmp[1] = bintoasc[((*radbuf << 4) & 060) & 077];
330 0 : tmp[2] = '=';
331 0 : tmp[3] = '=';
332 : }
333 : else
334 : {
335 0 : tmp[1] = bintoasc[(((*radbuf<<4)&060)|((radbuf[1]>>4)&017))&077];
336 0 : tmp[2] = bintoasc[((radbuf[1] << 2) & 074) & 077];
337 0 : tmp[3] = '=';
338 : }
339 0 : if (state->stream)
340 : {
341 0 : for (idx=0; idx < 4; idx++)
342 0 : es_putc (tmp[idx], state->stream);
343 0 : if (es_ferror (state->stream))
344 0 : goto write_error;
345 : }
346 : else
347 : {
348 0 : for (idx=0; idx < 4; idx++)
349 0 : putc (tmp[idx], state->fp);
350 0 : if (ferror (state->fp))
351 0 : goto write_error;
352 : }
353 :
354 0 : if (++quad_count >= (64/4))
355 : {
356 0 : quad_count = 0;
357 0 : if (!(state->flags & B64ENC_NO_LINEFEEDS)
358 0 : && my_fputs ("\n", state) == EOF)
359 0 : goto write_error;
360 : }
361 : }
362 :
363 : /* Finish the last line and write the trailer. */
364 0 : if (quad_count
365 0 : && !(state->flags & B64ENC_NO_LINEFEEDS)
366 0 : && my_fputs ("\n", state) == EOF)
367 0 : goto write_error;
368 :
369 0 : if ( (state->flags & B64ENC_USE_PGPCRC) )
370 : {
371 : /* Write the CRC. */
372 0 : my_fputs ("=", state);
373 0 : radbuf[0] = state->crc >>16;
374 0 : radbuf[1] = state->crc >> 8;
375 0 : radbuf[2] = state->crc;
376 0 : tmp[0] = bintoasc[(*radbuf>>2)&077];
377 0 : tmp[1] = bintoasc[(((*radbuf<<4)&060)|((radbuf[1]>>4)&017))&077];
378 0 : tmp[2] = bintoasc[(((radbuf[1]<<2)&074)|((radbuf[2]>>6)&03))&077];
379 0 : tmp[3] = bintoasc[radbuf[2]&077];
380 0 : if (state->stream)
381 : {
382 0 : for (idx=0; idx < 4; idx++)
383 0 : es_putc (tmp[idx], state->stream);
384 0 : if (es_ferror (state->stream))
385 0 : goto write_error;
386 : }
387 : else
388 : {
389 0 : for (idx=0; idx < 4; idx++)
390 0 : putc (tmp[idx], state->fp);
391 0 : if (ferror (state->fp))
392 0 : goto write_error;
393 : }
394 0 : if (!(state->flags & B64ENC_NO_LINEFEEDS)
395 0 : && my_fputs ("\n", state) == EOF)
396 0 : goto write_error;
397 : }
398 :
399 0 : if (state->title)
400 : {
401 0 : if ( my_fputs ("-----END ", state) == EOF
402 0 : || my_fputs (state->title, state) == EOF
403 0 : || my_fputs ("-----\n", state) == EOF)
404 : goto write_error;
405 : }
406 :
407 0 : goto cleanup;
408 :
409 : write_error:
410 0 : err = gpg_error_from_syserror ();
411 :
412 : cleanup:
413 0 : if (state->title)
414 : {
415 0 : xfree (state->title);
416 0 : state->title = NULL;
417 : }
418 0 : state->fp = NULL;
419 0 : state->stream = NULL;
420 0 : state->lasterr = err;
421 0 : return err;
422 : }
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