Mercurial > code
comparison modules/zip/libzip/lib/zip_open.c @ 527:8f8c32f102f1
Zip: resurrection
author | David Demelier <markand@malikania.fr> |
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date | Wed, 01 Jun 2016 17:36:52 +0200 |
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526:b26d8be94adb | 527:8f8c32f102f1 |
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1 /* | |
2 zip_open.c -- open zip archive by name | |
3 Copyright (C) 1999-2015 Dieter Baron and Thomas Klausner | |
4 | |
5 This file is part of libzip, a library to manipulate ZIP archives. | |
6 The authors can be contacted at <libzip@nih.at> | |
7 | |
8 Redistribution and use in source and binary forms, with or without | |
9 modification, are permitted provided that the following conditions | |
10 are met: | |
11 1. Redistributions of source code must retain the above copyright | |
12 notice, this list of conditions and the following disclaimer. | |
13 2. Redistributions in binary form must reproduce the above copyright | |
14 notice, this list of conditions and the following disclaimer in | |
15 the documentation and/or other materials provided with the | |
16 distribution. | |
17 3. The names of the authors may not be used to endorse or promote | |
18 products derived from this software without specific prior | |
19 written permission. | |
20 | |
21 THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS | |
22 OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | |
23 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
24 ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY | |
25 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
26 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE | |
27 GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
28 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER | |
29 IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR | |
30 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN | |
31 IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
32 */ | |
33 | |
34 | |
35 #include <sys/stat.h> | |
36 #include <limits.h> | |
37 #include <stdio.h> | |
38 #include <stdlib.h> | |
39 #include <string.h> | |
40 | |
41 #include "zipint.h" | |
42 | |
43 typedef enum { | |
44 EXISTS_ERROR = -1, | |
45 EXISTS_NOT = 0, | |
46 EXISTS_EMPTY, | |
47 EXISTS_NONEMPTY, | |
48 } exists_t; | |
49 static zip_t *_zip_allocate_new(zip_source_t *src, unsigned int flags, zip_error_t *error); | |
50 static zip_int64_t _zip_checkcons(zip_t *za, zip_cdir_t *cdir, zip_error_t *error); | |
51 static zip_cdir_t *_zip_find_central_dir(zip_t *za, zip_uint64_t len); | |
52 static exists_t _zip_file_exists(zip_source_t *src, zip_error_t *error); | |
53 static int _zip_headercomp(const zip_dirent_t *, const zip_dirent_t *); | |
54 static unsigned char *_zip_memmem(const unsigned char *, size_t, const unsigned char *, size_t); | |
55 static zip_cdir_t *_zip_read_cdir(zip_t *za, zip_buffer_t *buffer, zip_uint64_t buf_offset, zip_error_t *error); | |
56 static zip_cdir_t *_zip_read_eocd(zip_buffer_t *buffer, zip_uint64_t buf_offset, unsigned int flags, zip_error_t *error); | |
57 static zip_cdir_t *_zip_read_eocd64(zip_source_t *src, zip_buffer_t *buffer, zip_uint64_t buf_offset, unsigned int flags, zip_error_t *error); | |
58 | |
59 | |
60 ZIP_EXTERN zip_t * | |
61 zip_open(const char *fn, int _flags, int *zep) | |
62 { | |
63 zip_t *za; | |
64 zip_source_t *src; | |
65 struct zip_error error; | |
66 | |
67 zip_error_init(&error); | |
68 if ((src = zip_source_file_create(fn, 0, -1, &error)) == NULL) { | |
69 _zip_set_open_error(zep, &error, 0); | |
70 zip_error_fini(&error); | |
71 return NULL; | |
72 } | |
73 | |
74 if ((za = zip_open_from_source(src, _flags, &error)) == NULL) { | |
75 zip_source_free(src); | |
76 _zip_set_open_error(zep, &error, 0); | |
77 zip_error_fini(&error); | |
78 return NULL; | |
79 } | |
80 | |
81 zip_error_fini(&error); | |
82 return za; | |
83 } | |
84 | |
85 | |
86 ZIP_EXTERN zip_t * | |
87 zip_open_from_source(zip_source_t *src, int _flags, zip_error_t *error) | |
88 { | |
89 static zip_int64_t needed_support_read = -1; | |
90 static zip_int64_t needed_support_write = -1; | |
91 | |
92 unsigned int flags; | |
93 zip_int64_t supported; | |
94 exists_t exists; | |
95 | |
96 if (_flags < 0 || src == NULL) { | |
97 zip_error_set(error, ZIP_ER_INVAL, 0); | |
98 return NULL; | |
99 } | |
100 flags = (unsigned int)_flags; | |
101 | |
102 supported = zip_source_supports(src); | |
103 if (needed_support_read == -1) { | |
104 needed_support_read = zip_source_make_command_bitmap(ZIP_SOURCE_OPEN, ZIP_SOURCE_READ, ZIP_SOURCE_CLOSE, ZIP_SOURCE_SEEK, ZIP_SOURCE_TELL, ZIP_SOURCE_STAT, -1); | |
105 needed_support_write = zip_source_make_command_bitmap(ZIP_SOURCE_BEGIN_WRITE, ZIP_SOURCE_COMMIT_WRITE, ZIP_SOURCE_ROLLBACK_WRITE, ZIP_SOURCE_SEEK_WRITE, ZIP_SOURCE_TELL_WRITE, ZIP_SOURCE_REMOVE, -1); | |
106 } | |
107 if ((supported & needed_support_read) != needed_support_read) { | |
108 zip_error_set(error, ZIP_ER_OPNOTSUPP, 0); | |
109 return NULL; | |
110 } | |
111 if ((supported & needed_support_write) != needed_support_write) { | |
112 flags |= ZIP_RDONLY; | |
113 } | |
114 | |
115 if ((flags & (ZIP_RDONLY|ZIP_TRUNCATE)) == (ZIP_RDONLY|ZIP_TRUNCATE)) { | |
116 zip_error_set(error, ZIP_ER_RDONLY, 0); | |
117 return NULL; | |
118 } | |
119 | |
120 exists = _zip_file_exists(src, error); | |
121 switch (exists) { | |
122 case EXISTS_ERROR: | |
123 return NULL; | |
124 | |
125 case EXISTS_NOT: | |
126 if ((flags & ZIP_CREATE) == 0) { | |
127 zip_error_set(error, ZIP_ER_NOENT, 0); | |
128 return NULL; | |
129 } | |
130 return _zip_allocate_new(src, flags, error); | |
131 | |
132 default: { | |
133 zip_t *za; | |
134 if (flags & ZIP_EXCL) { | |
135 zip_error_set(error, ZIP_ER_EXISTS, 0); | |
136 return NULL; | |
137 } | |
138 if (zip_source_open(src) < 0) { | |
139 _zip_error_set_from_source(error, src); | |
140 return NULL; | |
141 } | |
142 | |
143 if (flags & ZIP_TRUNCATE) { | |
144 za = _zip_allocate_new(src, flags, error); | |
145 } | |
146 else { | |
147 /* ZIP_CREATE gets ignored if file exists and not ZIP_EXCL, just like open() */ | |
148 za = _zip_open(src, flags, error); | |
149 } | |
150 | |
151 if (za == NULL) { | |
152 zip_source_close(src); | |
153 return NULL; | |
154 } | |
155 return za; | |
156 } | |
157 } | |
158 } | |
159 | |
160 ZIP_EXTERN int | |
161 zip_archive_set_tempdir(zip_t *za, const char *tempdir) | |
162 { | |
163 char *new_tempdir; | |
164 | |
165 if (tempdir) { | |
166 if ((new_tempdir = strdup(tempdir)) == NULL) { | |
167 zip_error_set(&za->error, ZIP_ER_MEMORY, errno); | |
168 return -1; | |
169 } | |
170 } | |
171 else | |
172 new_tempdir = NULL; | |
173 | |
174 free(za->tempdir); | |
175 za->tempdir = new_tempdir; | |
176 | |
177 return 0; | |
178 } | |
179 | |
180 zip_t * | |
181 _zip_open(zip_source_t *src, unsigned int flags, zip_error_t *error) | |
182 { | |
183 zip_t *za; | |
184 zip_cdir_t *cdir; | |
185 struct zip_stat st; | |
186 zip_uint64_t len, idx; | |
187 | |
188 zip_stat_init(&st); | |
189 if (zip_source_stat(src, &st) < 0) { | |
190 _zip_error_set_from_source(error, src); | |
191 return NULL; | |
192 } | |
193 if ((st.valid & ZIP_STAT_SIZE) == 0) { | |
194 zip_error_set(error, ZIP_ER_SEEK, EOPNOTSUPP); | |
195 return NULL; | |
196 } | |
197 len = st.size; | |
198 | |
199 /* treat empty files as empty archives */ | |
200 if (len == 0) { | |
201 if ((za=_zip_allocate_new(src, flags, error)) == NULL) { | |
202 zip_source_free(src); | |
203 return NULL; | |
204 } | |
205 | |
206 return za; | |
207 } | |
208 | |
209 if ((za=_zip_allocate_new(src, flags, error)) == NULL) { | |
210 return NULL; | |
211 } | |
212 | |
213 if ((cdir = _zip_find_central_dir(za, len)) == NULL) { | |
214 _zip_error_copy(error, &za->error); | |
215 /* keep src so discard does not get rid of it */ | |
216 zip_source_keep(src); | |
217 zip_discard(za); | |
218 return NULL; | |
219 } | |
220 | |
221 za->entry = cdir->entry; | |
222 za->nentry = cdir->nentry; | |
223 za->nentry_alloc = cdir->nentry_alloc; | |
224 za->comment_orig = cdir->comment; | |
225 | |
226 free(cdir); | |
227 | |
228 for (idx = 0; idx < za->nentry; idx++) { | |
229 const zip_uint8_t *name = _zip_string_get(za->entry[idx].orig->filename, NULL, 0, error); | |
230 if (name == NULL) { | |
231 /* keep src so discard does not get rid of it */ | |
232 zip_source_keep(src); | |
233 zip_discard(za); | |
234 return NULL; | |
235 } | |
236 | |
237 if (_zip_hash_add(za->names, name, idx, ZIP_FL_UNCHANGED, &za->error) == false) { | |
238 if (za->error.zip_err != ZIP_ER_EXISTS || (flags & ZIP_CHECKCONS)) { | |
239 _zip_error_copy(error, &za->error); | |
240 /* keep src so discard does not get rid of it */ | |
241 zip_source_keep(src); | |
242 zip_discard(za); | |
243 return NULL; | |
244 } | |
245 } | |
246 } | |
247 | |
248 za->ch_flags = za->flags; | |
249 | |
250 return za; | |
251 } | |
252 | |
253 | |
254 void | |
255 _zip_set_open_error(int *zep, const zip_error_t *err, int ze) | |
256 { | |
257 if (err) { | |
258 ze = zip_error_code_zip(err); | |
259 if (zip_error_system_type(err) == ZIP_ET_SYS) { | |
260 errno = zip_error_code_system(err); | |
261 } | |
262 } | |
263 | |
264 if (zep) | |
265 *zep = ze; | |
266 } | |
267 | |
268 | |
269 /* _zip_readcdir: | |
270 tries to find a valid end-of-central-directory at the beginning of | |
271 buf, and then the corresponding central directory entries. | |
272 Returns a struct zip_cdir which contains the central directory | |
273 entries, or NULL if unsuccessful. */ | |
274 | |
275 static zip_cdir_t * | |
276 _zip_read_cdir(zip_t *za, zip_buffer_t *buffer, zip_uint64_t buf_offset, zip_error_t *error) | |
277 { | |
278 zip_cdir_t *cd; | |
279 zip_uint16_t comment_len; | |
280 zip_uint64_t i, left; | |
281 zip_uint64_t eocd_offset = _zip_buffer_offset(buffer); | |
282 zip_buffer_t *cd_buffer; | |
283 | |
284 if (_zip_buffer_left(buffer) < EOCDLEN) { | |
285 /* not enough bytes left for comment */ | |
286 zip_error_set(error, ZIP_ER_NOZIP, 0); | |
287 return NULL; | |
288 } | |
289 | |
290 /* check for end-of-central-dir magic */ | |
291 if (memcmp(_zip_buffer_get(buffer, 4), EOCD_MAGIC, 4) != 0) { | |
292 zip_error_set(error, ZIP_ER_NOZIP, 0); | |
293 return NULL; | |
294 } | |
295 | |
296 if (eocd_offset >= EOCD64LOCLEN && memcmp(_zip_buffer_data(buffer) + eocd_offset - EOCD64LOCLEN, EOCD64LOC_MAGIC, 4) == 0) { | |
297 _zip_buffer_set_offset(buffer, eocd_offset - EOCD64LOCLEN); | |
298 cd = _zip_read_eocd64(za->src, buffer, buf_offset, za->flags, error); | |
299 } | |
300 else { | |
301 _zip_buffer_set_offset(buffer, eocd_offset); | |
302 cd = _zip_read_eocd(buffer, buf_offset, za->flags, error); | |
303 } | |
304 | |
305 if (cd == NULL) | |
306 return NULL; | |
307 | |
308 _zip_buffer_set_offset(buffer, eocd_offset + 20); | |
309 comment_len = _zip_buffer_get_16(buffer); | |
310 | |
311 if (cd->offset + cd->size > buf_offset + eocd_offset) { | |
312 /* cdir spans past EOCD record */ | |
313 zip_error_set(error, ZIP_ER_INCONS, 0); | |
314 _zip_cdir_free(cd); | |
315 return NULL; | |
316 } | |
317 | |
318 if (comment_len || (za->open_flags & ZIP_CHECKCONS)) { | |
319 zip_uint64_t tail_len; | |
320 | |
321 _zip_buffer_set_offset(buffer, eocd_offset + EOCDLEN); | |
322 tail_len = _zip_buffer_left(buffer); | |
323 | |
324 if (tail_len < comment_len || ((za->open_flags & ZIP_CHECKCONS) && tail_len != comment_len)) { | |
325 zip_error_set(error, ZIP_ER_INCONS, 0); | |
326 _zip_cdir_free(cd); | |
327 return NULL; | |
328 } | |
329 | |
330 if (comment_len) { | |
331 if ((cd->comment=_zip_string_new(_zip_buffer_get(buffer, comment_len), comment_len, ZIP_FL_ENC_GUESS, error)) == NULL) { | |
332 _zip_cdir_free(cd); | |
333 return NULL; | |
334 } | |
335 } | |
336 } | |
337 | |
338 if (cd->offset >= buf_offset) { | |
339 zip_uint8_t *data; | |
340 /* if buffer already read in, use it */ | |
341 _zip_buffer_set_offset(buffer, cd->offset - buf_offset); | |
342 | |
343 if ((data = _zip_buffer_get(buffer, cd->size)) == NULL) { | |
344 zip_error_set(error, ZIP_ER_INCONS, 0); | |
345 _zip_cdir_free(cd); | |
346 return NULL; | |
347 } | |
348 if ((cd_buffer = _zip_buffer_new(data, cd->size)) == NULL) { | |
349 zip_error_set(error, ZIP_ER_MEMORY, 0); | |
350 _zip_cdir_free(cd); | |
351 return NULL; | |
352 } | |
353 } | |
354 else { | |
355 cd_buffer = NULL; | |
356 | |
357 if (zip_source_seek(za->src, (zip_int64_t)cd->offset, SEEK_SET) < 0) { | |
358 _zip_error_set_from_source(error, za->src); | |
359 _zip_cdir_free(cd); | |
360 return NULL; | |
361 } | |
362 | |
363 /* possible consistency check: cd->offset = len-(cd->size+cd->comment_len+EOCDLEN) ? */ | |
364 if (zip_source_tell(za->src) != (zip_int64_t)cd->offset) { | |
365 zip_error_set(error, ZIP_ER_NOZIP, 0); | |
366 _zip_cdir_free(cd); | |
367 return NULL; | |
368 } | |
369 } | |
370 | |
371 left = (zip_uint64_t)cd->size; | |
372 i=0; | |
373 while (i<cd->nentry && left > 0) { | |
374 zip_int64_t entry_size; | |
375 if ((cd->entry[i].orig=_zip_dirent_new()) == NULL || (entry_size = _zip_dirent_read(cd->entry[i].orig, za->src, cd_buffer, false, error)) < 0) { | |
376 _zip_cdir_free(cd); | |
377 _zip_buffer_free(cd_buffer); | |
378 return NULL; | |
379 } | |
380 i++; | |
381 left -= (zip_uint64_t)entry_size; | |
382 } | |
383 | |
384 if (i != cd->nentry) { | |
385 zip_error_set(error, ZIP_ER_INCONS, 0); | |
386 _zip_buffer_free(cd_buffer); | |
387 _zip_cdir_free(cd); | |
388 return NULL; | |
389 } | |
390 | |
391 if (za->open_flags & ZIP_CHECKCONS) { | |
392 bool ok; | |
393 | |
394 if (cd_buffer) { | |
395 ok = _zip_buffer_eof(cd_buffer); | |
396 } | |
397 else { | |
398 zip_int64_t offset = zip_source_tell(za->src); | |
399 | |
400 if (offset < 0) { | |
401 _zip_error_set_from_source(error, za->src); | |
402 _zip_buffer_free(cd_buffer); | |
403 _zip_cdir_free(cd); | |
404 return NULL; | |
405 } | |
406 ok = ((zip_uint64_t)offset == cd->offset + cd->size); | |
407 } | |
408 | |
409 if (!ok) { | |
410 zip_error_set(error, ZIP_ER_INCONS, 0); | |
411 _zip_buffer_free(cd_buffer); | |
412 _zip_cdir_free(cd); | |
413 return NULL; | |
414 } | |
415 } | |
416 | |
417 _zip_buffer_free(cd_buffer); | |
418 return cd; | |
419 } | |
420 | |
421 | |
422 /* _zip_checkcons: | |
423 Checks the consistency of the central directory by comparing central | |
424 directory entries with local headers and checking for plausible | |
425 file and header offsets. Returns -1 if not plausible, else the | |
426 difference between the lowest and the highest fileposition reached */ | |
427 | |
428 static zip_int64_t | |
429 _zip_checkcons(zip_t *za, zip_cdir_t *cd, zip_error_t *error) | |
430 { | |
431 zip_uint64_t i; | |
432 zip_uint64_t min, max, j; | |
433 struct zip_dirent temp; | |
434 | |
435 _zip_dirent_init(&temp); | |
436 if (cd->nentry) { | |
437 max = cd->entry[0].orig->offset; | |
438 min = cd->entry[0].orig->offset; | |
439 } | |
440 else | |
441 min = max = 0; | |
442 | |
443 for (i=0; i<cd->nentry; i++) { | |
444 if (cd->entry[i].orig->offset < min) | |
445 min = cd->entry[i].orig->offset; | |
446 if (min > (zip_uint64_t)cd->offset) { | |
447 zip_error_set(error, ZIP_ER_NOZIP, 0); | |
448 return -1; | |
449 } | |
450 | |
451 j = cd->entry[i].orig->offset + cd->entry[i].orig->comp_size | |
452 + _zip_string_length(cd->entry[i].orig->filename) + LENTRYSIZE; | |
453 if (j > max) | |
454 max = j; | |
455 if (max > (zip_uint64_t)cd->offset) { | |
456 zip_error_set(error, ZIP_ER_NOZIP, 0); | |
457 return -1; | |
458 } | |
459 | |
460 if (zip_source_seek(za->src, (zip_int64_t)cd->entry[i].orig->offset, SEEK_SET) < 0) { | |
461 _zip_error_set_from_source(error, za->src); | |
462 return -1; | |
463 } | |
464 | |
465 if (_zip_dirent_read(&temp, za->src, NULL, true, error) == -1) { | |
466 _zip_dirent_finalize(&temp); | |
467 return -1; | |
468 } | |
469 | |
470 if (_zip_headercomp(cd->entry[i].orig, &temp) != 0) { | |
471 zip_error_set(error, ZIP_ER_INCONS, 0); | |
472 _zip_dirent_finalize(&temp); | |
473 return -1; | |
474 } | |
475 | |
476 cd->entry[i].orig->extra_fields = _zip_ef_merge(cd->entry[i].orig->extra_fields, temp.extra_fields); | |
477 cd->entry[i].orig->local_extra_fields_read = 1; | |
478 temp.extra_fields = NULL; | |
479 | |
480 _zip_dirent_finalize(&temp); | |
481 } | |
482 | |
483 return (max-min) < ZIP_INT64_MAX ? (zip_int64_t)(max-min) : ZIP_INT64_MAX; | |
484 } | |
485 | |
486 | |
487 /* _zip_headercomp: | |
488 compares a central directory entry and a local file header | |
489 Return 0 if they are consistent, -1 if not. */ | |
490 | |
491 static int | |
492 _zip_headercomp(const zip_dirent_t *central, const zip_dirent_t *local) | |
493 { | |
494 if ((central->version_needed != local->version_needed) | |
495 #if 0 | |
496 /* some zip-files have different values in local | |
497 and global headers for the bitflags */ | |
498 || (central->bitflags != local->bitflags) | |
499 #endif | |
500 || (central->comp_method != local->comp_method) | |
501 || (central->last_mod != local->last_mod) | |
502 || !_zip_string_equal(central->filename, local->filename)) | |
503 return -1; | |
504 | |
505 if ((central->crc != local->crc) || (central->comp_size != local->comp_size) | |
506 || (central->uncomp_size != local->uncomp_size)) { | |
507 /* InfoZip stores valid values in local header even when data descriptor is used. | |
508 This is in violation of the appnote. */ | |
509 if (((local->bitflags & ZIP_GPBF_DATA_DESCRIPTOR) == 0 | |
510 || local->crc != 0 || local->comp_size != 0 || local->uncomp_size != 0)) | |
511 return -1; | |
512 } | |
513 | |
514 return 0; | |
515 } | |
516 | |
517 | |
518 static zip_t * | |
519 _zip_allocate_new(zip_source_t *src, unsigned int flags, zip_error_t *error) | |
520 { | |
521 zip_t *za; | |
522 | |
523 if ((za = _zip_new(error)) == NULL) { | |
524 return NULL; | |
525 } | |
526 | |
527 za->src = src; | |
528 za->open_flags = flags; | |
529 if (flags & ZIP_RDONLY) { | |
530 za->flags |= ZIP_AFL_RDONLY; | |
531 za->ch_flags |= ZIP_AFL_RDONLY; | |
532 } | |
533 return za; | |
534 } | |
535 | |
536 | |
537 /* | |
538 * tests for file existence | |
539 */ | |
540 static exists_t | |
541 _zip_file_exists(zip_source_t *src, zip_error_t *error) | |
542 { | |
543 struct zip_stat st; | |
544 | |
545 zip_stat_init(&st); | |
546 if (zip_source_stat(src, &st) != 0) { | |
547 zip_error_t *src_error = zip_source_error(src); | |
548 if (zip_error_code_zip(src_error) == ZIP_ER_READ && zip_error_code_system(src_error) == ENOENT) { | |
549 return EXISTS_NOT; | |
550 } | |
551 _zip_error_copy(error, src_error); | |
552 return EXISTS_ERROR; | |
553 } | |
554 | |
555 return (st.valid & ZIP_STAT_SIZE) && st.size == 0 ? EXISTS_EMPTY : EXISTS_NONEMPTY; | |
556 } | |
557 | |
558 | |
559 static zip_cdir_t * | |
560 _zip_find_central_dir(zip_t *za, zip_uint64_t len) | |
561 { | |
562 zip_cdir_t *cdir, *cdirnew; | |
563 zip_uint8_t *match; | |
564 zip_int64_t buf_offset; | |
565 zip_uint64_t buflen; | |
566 zip_int64_t a; | |
567 zip_int64_t best; | |
568 zip_error_t error; | |
569 zip_buffer_t *buffer; | |
570 | |
571 if (len < EOCDLEN) { | |
572 zip_error_set(&za->error, ZIP_ER_NOZIP, 0); | |
573 return NULL; | |
574 } | |
575 | |
576 buflen = (len < CDBUFSIZE ? len : CDBUFSIZE); | |
577 if (zip_source_seek(za->src, -(zip_int64_t)buflen, SEEK_END) < 0) { | |
578 zip_error_t *src_error = zip_source_error(za->src); | |
579 if (zip_error_code_zip(src_error) != ZIP_ER_SEEK || zip_error_code_system(src_error) != EFBIG) { | |
580 /* seek before start of file on my machine */ | |
581 _zip_error_copy(&za->error, src_error); | |
582 return NULL; | |
583 } | |
584 } | |
585 if ((buf_offset = zip_source_tell(za->src)) < 0) { | |
586 _zip_error_set_from_source(&za->error, za->src); | |
587 return NULL; | |
588 } | |
589 | |
590 if ((buffer = _zip_buffer_new_from_source(za->src, buflen, NULL, &za->error)) == NULL) { | |
591 return NULL; | |
592 } | |
593 | |
594 best = -1; | |
595 cdir = NULL; | |
596 if (buflen >= CDBUFSIZE) { | |
597 /* EOCD64 locator is before EOCD, so leave place for it */ | |
598 _zip_buffer_set_offset(buffer, EOCD64LOCLEN); | |
599 } | |
600 zip_error_set(&error, ZIP_ER_NOZIP, 0); | |
601 | |
602 match = _zip_buffer_get(buffer, 0); | |
603 while ((match=_zip_memmem(match, _zip_buffer_left(buffer)-(EOCDLEN-4), (const unsigned char *)EOCD_MAGIC, 4)) != NULL) { | |
604 _zip_buffer_set_offset(buffer, (zip_uint64_t)(match - _zip_buffer_data(buffer))); | |
605 if ((cdirnew = _zip_read_cdir(za, buffer, (zip_uint64_t)buf_offset, &error)) != NULL) { | |
606 if (cdir) { | |
607 if (best <= 0) { | |
608 best = _zip_checkcons(za, cdir, &error); | |
609 } | |
610 | |
611 a = _zip_checkcons(za, cdirnew, &error); | |
612 if (best < a) { | |
613 _zip_cdir_free(cdir); | |
614 cdir = cdirnew; | |
615 best = a; | |
616 } | |
617 else { | |
618 _zip_cdir_free(cdirnew); | |
619 } | |
620 } | |
621 else { | |
622 cdir = cdirnew; | |
623 if (za->open_flags & ZIP_CHECKCONS) | |
624 best = _zip_checkcons(za, cdir, &error); | |
625 else { | |
626 best = 0; | |
627 } | |
628 } | |
629 cdirnew = NULL; | |
630 } | |
631 | |
632 match++; | |
633 _zip_buffer_set_offset(buffer, (zip_uint64_t)(match - _zip_buffer_data(buffer))); | |
634 } | |
635 | |
636 _zip_buffer_free(buffer); | |
637 | |
638 if (best < 0) { | |
639 _zip_error_copy(&za->error, &error); | |
640 _zip_cdir_free(cdir); | |
641 return NULL; | |
642 } | |
643 | |
644 return cdir; | |
645 } | |
646 | |
647 | |
648 static unsigned char * | |
649 _zip_memmem(const unsigned char *big, size_t biglen, const unsigned char *little, size_t littlelen) | |
650 { | |
651 const unsigned char *p; | |
652 | |
653 if ((biglen < littlelen) || (littlelen == 0)) | |
654 return NULL; | |
655 p = big-1; | |
656 while ((p=(const unsigned char *) | |
657 memchr(p+1, little[0], (size_t)(big-(p+1))+(size_t)(biglen-littlelen)+1)) != NULL) { | |
658 if (memcmp(p+1, little+1, littlelen-1)==0) | |
659 return (unsigned char *)p; | |
660 } | |
661 | |
662 return NULL; | |
663 } | |
664 | |
665 | |
666 static zip_cdir_t * | |
667 _zip_read_eocd(zip_buffer_t *buffer, zip_uint64_t buf_offset, unsigned int flags, zip_error_t *error) | |
668 { | |
669 zip_cdir_t *cd; | |
670 zip_uint64_t i, nentry, size, offset, eocd_offset; | |
671 | |
672 if (_zip_buffer_left(buffer) < EOCDLEN) { | |
673 zip_error_set(error, ZIP_ER_INCONS, 0); | |
674 return NULL; | |
675 } | |
676 | |
677 eocd_offset = _zip_buffer_offset(buffer); | |
678 | |
679 _zip_buffer_get(buffer, 4); /* magic already verified */ | |
680 | |
681 if (_zip_buffer_get_32(buffer) != 0) { | |
682 zip_error_set(error, ZIP_ER_MULTIDISK, 0); | |
683 return NULL; | |
684 } | |
685 | |
686 /* number of cdir-entries on this disk */ | |
687 i = _zip_buffer_get_16(buffer); | |
688 /* number of cdir-entries */ | |
689 nentry = _zip_buffer_get_16(buffer); | |
690 | |
691 if (nentry != i) { | |
692 zip_error_set(error, ZIP_ER_NOZIP, 0); | |
693 return NULL; | |
694 } | |
695 | |
696 size = _zip_buffer_get_32(buffer); | |
697 offset = _zip_buffer_get_32(buffer); | |
698 | |
699 if (offset+size < offset) { | |
700 zip_error_set(error, ZIP_ER_SEEK, EFBIG); | |
701 return NULL; | |
702 } | |
703 | |
704 if (offset+size > buf_offset + eocd_offset) { | |
705 /* cdir spans past EOCD record */ | |
706 zip_error_set(error, ZIP_ER_INCONS, 0); | |
707 return NULL; | |
708 } | |
709 | |
710 if ((flags & ZIP_CHECKCONS) && offset+size != buf_offset + eocd_offset) { | |
711 zip_error_set(error, ZIP_ER_INCONS, 0); | |
712 return NULL; | |
713 } | |
714 | |
715 if ((cd=_zip_cdir_new(nentry, error)) == NULL) | |
716 return NULL; | |
717 | |
718 cd->size = size; | |
719 cd->offset = offset; | |
720 | |
721 return cd; | |
722 } | |
723 | |
724 | |
725 static zip_cdir_t * | |
726 _zip_read_eocd64(zip_source_t *src, zip_buffer_t *buffer, zip_uint64_t buf_offset, unsigned int flags, zip_error_t *error) | |
727 { | |
728 zip_cdir_t *cd; | |
729 zip_uint64_t offset; | |
730 zip_uint8_t eocd[EOCD64LEN]; | |
731 zip_uint64_t eocd_offset; | |
732 zip_uint64_t size, nentry, i, eocdloc_offset; | |
733 bool free_buffer; | |
734 zip_uint32_t num_disks, num_disks64, eocd_disk, eocd_disk64; | |
735 | |
736 eocdloc_offset = _zip_buffer_offset(buffer); | |
737 | |
738 _zip_buffer_get(buffer, 4); /* magic already verified */ | |
739 | |
740 num_disks = _zip_buffer_get_16(buffer); | |
741 eocd_disk = _zip_buffer_get_16(buffer); | |
742 eocd_offset = _zip_buffer_get_64(buffer); | |
743 | |
744 if (eocd_offset > ZIP_INT64_MAX || eocd_offset + EOCD64LEN < eocd_offset) { | |
745 zip_error_set(error, ZIP_ER_SEEK, EFBIG); | |
746 return NULL; | |
747 } | |
748 | |
749 if (eocd_offset + EOCD64LEN > eocdloc_offset + buf_offset) { | |
750 zip_error_set(error, ZIP_ER_INCONS, 0); | |
751 return NULL; | |
752 } | |
753 | |
754 if (eocd_offset >= buf_offset && eocd_offset + EOCD64LEN <= buf_offset + _zip_buffer_size(buffer)) { | |
755 _zip_buffer_set_offset(buffer, eocd_offset - buf_offset); | |
756 free_buffer = false; | |
757 } | |
758 else { | |
759 if (zip_source_seek(src, (zip_int64_t)eocd_offset, SEEK_SET) < 0) { | |
760 _zip_error_set_from_source(error, src); | |
761 return NULL; | |
762 } | |
763 if ((buffer = _zip_buffer_new_from_source(src, EOCD64LEN, eocd, error)) == NULL) { | |
764 return NULL; | |
765 } | |
766 free_buffer = true; | |
767 } | |
768 | |
769 if (memcmp(_zip_buffer_get(buffer, 4), EOCD64_MAGIC, 4) != 0) { | |
770 zip_error_set(error, ZIP_ER_INCONS, 0); | |
771 if (free_buffer) { | |
772 _zip_buffer_free(buffer); | |
773 } | |
774 return NULL; | |
775 } | |
776 | |
777 size = _zip_buffer_get_64(buffer); | |
778 | |
779 if ((flags & ZIP_CHECKCONS) && size + eocd_offset + 12 != buf_offset + eocdloc_offset) { | |
780 zip_error_set(error, ZIP_ER_INCONS, 0); | |
781 if (free_buffer) { | |
782 _zip_buffer_free(buffer); | |
783 } | |
784 return NULL; | |
785 } | |
786 | |
787 _zip_buffer_get(buffer, 4); /* skip version made by/needed */ | |
788 | |
789 num_disks64 = _zip_buffer_get_32(buffer); | |
790 eocd_disk64 = _zip_buffer_get_32(buffer); | |
791 | |
792 /* if eocd values are 0xffff, we have to use eocd64 values. | |
793 otherwise, if the values are not the same, it's inconsistent; | |
794 in any case, if the value is not 0, we don't support it */ | |
795 if (num_disks == 0xffff) { | |
796 num_disks = num_disks64; | |
797 } | |
798 if (eocd_disk == 0xffff) { | |
799 eocd_disk = eocd_disk64; | |
800 } | |
801 if ((flags & ZIP_CHECKCONS) && (eocd_disk != eocd_disk64 || num_disks != num_disks64)) { | |
802 zip_error_set(error, ZIP_ER_INCONS, 0); | |
803 return NULL; | |
804 } | |
805 if (num_disks != 0 || eocd_disk != 0) { | |
806 zip_error_set(error, ZIP_ER_MULTIDISK, 0); | |
807 return NULL; | |
808 } | |
809 | |
810 nentry = _zip_buffer_get_64(buffer); | |
811 i = _zip_buffer_get_64(buffer); | |
812 | |
813 if (nentry != i) { | |
814 zip_error_set(error, ZIP_ER_MULTIDISK, 0); | |
815 if (free_buffer) { | |
816 _zip_buffer_free(buffer); | |
817 } | |
818 return NULL; | |
819 } | |
820 | |
821 size = _zip_buffer_get_64(buffer); | |
822 offset = _zip_buffer_get_64(buffer); | |
823 | |
824 if (!_zip_buffer_ok(buffer)) { | |
825 zip_error_set(error, ZIP_ER_INTERNAL, 0); | |
826 if (free_buffer) { | |
827 _zip_buffer_free(buffer); | |
828 } | |
829 return NULL; | |
830 } | |
831 | |
832 if (free_buffer) { | |
833 _zip_buffer_free(buffer); | |
834 } | |
835 | |
836 if (offset > ZIP_INT64_MAX || offset+size < offset) { | |
837 zip_error_set(error, ZIP_ER_SEEK, EFBIG); | |
838 return NULL; | |
839 } | |
840 if ((flags & ZIP_CHECKCONS) && offset+size != eocd_offset) { | |
841 zip_error_set(error, ZIP_ER_INCONS, 0); | |
842 return NULL; | |
843 } | |
844 | |
845 if ((cd=_zip_cdir_new(nentry, error)) == NULL) | |
846 return NULL; | |
847 | |
848 | |
849 cd->size = size; | |
850 cd->offset = offset; | |
851 | |
852 return cd; | |
853 } |