source: trunk/src/3rdparty/libpng/pngpread.c@ 900

Last change on this file since 900 was 846, checked in by Dmitry A. Kuminov, 14 years ago

trunk: Merged in qt 4.7.2 sources from branches/vendor/nokia/qt.
File size: 45.5 KB
Line 
1
2/* pngpread.c - read a png file in push mode
3 *
4 * Last changed in libpng 1.4.0 [January 3, 2010]
5 * Copyright (c) 1998-2010 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8 *
9 * This code is released under the libpng license.
10 * For conditions of distribution and use, see the disclaimer
11 * and license in png.h
12 */
13
14#define PNG_NO_PEDANTIC_WARNINGS
15#include "png.h"
16#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
17#include "pngpriv.h"
18
19/* Push model modes */
20#define PNG_READ_SIG_MODE 0
21#define PNG_READ_CHUNK_MODE 1
22#define PNG_READ_IDAT_MODE 2
23#define PNG_SKIP_MODE 3
24#define PNG_READ_tEXt_MODE 4
25#define PNG_READ_zTXt_MODE 5
26#define PNG_READ_DONE_MODE 6
27#define PNG_READ_iTXt_MODE 7
28#define PNG_ERROR_MODE 8
29
30void PNGAPI
31png_process_data(png_structp png_ptr, png_infop info_ptr,
32 png_bytep buffer, png_size_t buffer_size)
33{
34 if (png_ptr == NULL || info_ptr == NULL)
35 return;
36
37 png_push_restore_buffer(png_ptr, buffer, buffer_size);
38
39 while (png_ptr->buffer_size)
40 {
41 png_process_some_data(png_ptr, info_ptr);
42 }
43}
44
45/* What we do with the incoming data depends on what we were previously
46 * doing before we ran out of data...
47 */
48void /* PRIVATE */
49png_process_some_data(png_structp png_ptr, png_infop info_ptr)
50{
51 if (png_ptr == NULL)
52 return;
53
54 switch (png_ptr->process_mode)
55 {
56 case PNG_READ_SIG_MODE:
57 {
58 png_push_read_sig(png_ptr, info_ptr);
59 break;
60 }
61
62 case PNG_READ_CHUNK_MODE:
63 {
64 png_push_read_chunk(png_ptr, info_ptr);
65 break;
66 }
67
68 case PNG_READ_IDAT_MODE:
69 {
70 png_push_read_IDAT(png_ptr);
71 break;
72 }
73
74#ifdef PNG_READ_tEXt_SUPPORTED
75 case PNG_READ_tEXt_MODE:
76 {
77 png_push_read_tEXt(png_ptr, info_ptr);
78 break;
79 }
80
81#endif
82#ifdef PNG_READ_zTXt_SUPPORTED
83 case PNG_READ_zTXt_MODE:
84 {
85 png_push_read_zTXt(png_ptr, info_ptr);
86 break;
87 }
88
89#endif
90#ifdef PNG_READ_iTXt_SUPPORTED
91 case PNG_READ_iTXt_MODE:
92 {
93 png_push_read_iTXt(png_ptr, info_ptr);
94 break;
95 }
96
97#endif
98 case PNG_SKIP_MODE:
99 {
100 png_push_crc_finish(png_ptr);
101 break;
102 }
103
104 default:
105 {
106 png_ptr->buffer_size = 0;
107 break;
108 }
109 }
110}
111
112/* Read any remaining signature bytes from the stream and compare them with
113 * the correct PNG signature. It is possible that this routine is called
114 * with bytes already read from the signature, either because they have been
115 * checked by the calling application, or because of multiple calls to this
116 * routine.
117 */
118void /* PRIVATE */
119png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
120{
121 png_size_t num_checked = png_ptr->sig_bytes,
122 num_to_check = 8 - num_checked;
123
124 if (png_ptr->buffer_size < num_to_check)
125 {
126 num_to_check = png_ptr->buffer_size;
127 }
128
129 png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
130 num_to_check);
131 png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
132
133 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
134 {
135 if (num_checked < 4 &&
136 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
137 png_error(png_ptr, "Not a PNG file");
138 else
139 png_error(png_ptr, "PNG file corrupted by ASCII conversion");
140 }
141 else
142 {
143 if (png_ptr->sig_bytes >= 8)
144 {
145 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
146 }
147 }
148}
149
150void /* PRIVATE */
151png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
152{
153 PNG_IHDR;
154 PNG_IDAT;
155 PNG_IEND;
156 PNG_PLTE;
157#ifdef PNG_READ_bKGD_SUPPORTED
158 PNG_bKGD;
159#endif
160#ifdef PNG_READ_cHRM_SUPPORTED
161 PNG_cHRM;
162#endif
163#ifdef PNG_READ_gAMA_SUPPORTED
164 PNG_gAMA;
165#endif
166#ifdef PNG_READ_hIST_SUPPORTED
167 PNG_hIST;
168#endif
169#ifdef PNG_READ_iCCP_SUPPORTED
170 PNG_iCCP;
171#endif
172#ifdef PNG_READ_iTXt_SUPPORTED
173 PNG_iTXt;
174#endif
175#ifdef PNG_READ_oFFs_SUPPORTED
176 PNG_oFFs;
177#endif
178#ifdef PNG_READ_pCAL_SUPPORTED
179 PNG_pCAL;
180#endif
181#ifdef PNG_READ_pHYs_SUPPORTED
182 PNG_pHYs;
183#endif
184#ifdef PNG_READ_sBIT_SUPPORTED
185 PNG_sBIT;
186#endif
187#ifdef PNG_READ_sCAL_SUPPORTED
188 PNG_sCAL;
189#endif
190#ifdef PNG_READ_sRGB_SUPPORTED
191 PNG_sRGB;
192#endif
193#ifdef PNG_READ_sPLT_SUPPORTED
194 PNG_sPLT;
195#endif
196#ifdef PNG_READ_tEXt_SUPPORTED
197 PNG_tEXt;
198#endif
199#ifdef PNG_READ_tIME_SUPPORTED
200 PNG_tIME;
201#endif
202#ifdef PNG_READ_tRNS_SUPPORTED
203 PNG_tRNS;
204#endif
205#ifdef PNG_READ_zTXt_SUPPORTED
206 PNG_zTXt;
207#endif
208
209 /* First we make sure we have enough data for the 4 byte chunk name
210 * and the 4 byte chunk length before proceeding with decoding the
211 * chunk data. To fully decode each of these chunks, we also make
212 * sure we have enough data in the buffer for the 4 byte CRC at the
213 * end of every chunk (except IDAT, which is handled separately).
214 */
215 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
216 {
217 png_byte chunk_length[4];
218
219 if (png_ptr->buffer_size < 8)
220 {
221 png_push_save_buffer(png_ptr);
222 return;
223 }
224
225 png_push_fill_buffer(png_ptr, chunk_length, 4);
226 png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
227 png_reset_crc(png_ptr);
228 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
229 png_check_chunk_name(png_ptr, png_ptr->chunk_name);
230 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
231 }
232
233 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
234 if (png_ptr->mode & PNG_AFTER_IDAT)
235 png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
236
237 if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
238 {
239 if (png_ptr->push_length != 13)
240 png_error(png_ptr, "Invalid IHDR length");
241
242 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
243 {
244 png_push_save_buffer(png_ptr);
245 return;
246 }
247
248 png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
249 }
250
251 else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
252 {
253 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
254 {
255 png_push_save_buffer(png_ptr);
256 return;
257 }
258
259 png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
260
261 png_ptr->process_mode = PNG_READ_DONE_MODE;
262 png_push_have_end(png_ptr, info_ptr);
263 }
264
265#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
266 else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
267 {
268 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
269 {
270 png_push_save_buffer(png_ptr);
271 return;
272 }
273
274 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
275 png_ptr->mode |= PNG_HAVE_IDAT;
276
277 png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
278
279 if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
280 png_ptr->mode |= PNG_HAVE_PLTE;
281
282 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
283 {
284 if (!(png_ptr->mode & PNG_HAVE_IHDR))
285 png_error(png_ptr, "Missing IHDR before IDAT");
286
287 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
288 !(png_ptr->mode & PNG_HAVE_PLTE))
289 png_error(png_ptr, "Missing PLTE before IDAT");
290 }
291 }
292
293#endif
294 else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
295 {
296 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
297 {
298 png_push_save_buffer(png_ptr);
299 return;
300 }
301 png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
302 }
303
304 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
305 {
306 /* If we reach an IDAT chunk, this means we have read all of the
307 * header chunks, and we can start reading the image (or if this
308 * is called after the image has been read - we have an error).
309 */
310
311 if (!(png_ptr->mode & PNG_HAVE_IHDR))
312 png_error(png_ptr, "Missing IHDR before IDAT");
313
314 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
315 !(png_ptr->mode & PNG_HAVE_PLTE))
316 png_error(png_ptr, "Missing PLTE before IDAT");
317
318 if (png_ptr->mode & PNG_HAVE_IDAT)
319 {
320 if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
321 if (png_ptr->push_length == 0)
322 return;
323
324 if (png_ptr->mode & PNG_AFTER_IDAT)
325 png_benign_error(png_ptr, "Too many IDATs found");
326 }
327
328 png_ptr->idat_size = png_ptr->push_length;
329 png_ptr->mode |= PNG_HAVE_IDAT;
330 png_ptr->process_mode = PNG_READ_IDAT_MODE;
331 png_push_have_info(png_ptr, info_ptr);
332 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
333 png_ptr->zstream.next_out = png_ptr->row_buf;
334 return;
335 }
336
337#ifdef PNG_READ_gAMA_SUPPORTED
338 else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
339 {
340 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
341 {
342 png_push_save_buffer(png_ptr);
343 return;
344 }
345
346 png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
347 }
348
349#endif
350#ifdef PNG_READ_sBIT_SUPPORTED
351 else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
352 {
353 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
354 {
355 png_push_save_buffer(png_ptr);
356 return;
357 }
358
359 png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
360 }
361
362#endif
363#ifdef PNG_READ_cHRM_SUPPORTED
364 else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
365 {
366 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
367 {
368 png_push_save_buffer(png_ptr);
369 return;
370 }
371
372 png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
373 }
374
375#endif
376#ifdef PNG_READ_sRGB_SUPPORTED
377 else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
378 {
379 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
380 {
381 png_push_save_buffer(png_ptr);
382 return;
383 }
384
385 png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
386 }
387
388#endif
389#ifdef PNG_READ_iCCP_SUPPORTED
390 else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
391 {
392 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
393 {
394 png_push_save_buffer(png_ptr);
395 return;
396 }
397
398 png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
399 }
400
401#endif
402#ifdef PNG_READ_sPLT_SUPPORTED
403 else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
404 {
405 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
406 {
407 png_push_save_buffer(png_ptr);
408 return;
409 }
410
411 png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
412 }
413
414#endif
415#ifdef PNG_READ_tRNS_SUPPORTED
416 else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
417 {
418 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
419 {
420 png_push_save_buffer(png_ptr);
421 return;
422 }
423
424 png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
425 }
426
427#endif
428#ifdef PNG_READ_bKGD_SUPPORTED
429 else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
430 {
431 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
432 {
433 png_push_save_buffer(png_ptr);
434 return;
435 }
436
437 png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
438 }
439
440#endif
441#ifdef PNG_READ_hIST_SUPPORTED
442 else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
443 {
444 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
445 {
446 png_push_save_buffer(png_ptr);
447 return;
448 }
449
450 png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
451 }
452
453#endif
454#ifdef PNG_READ_pHYs_SUPPORTED
455 else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
456 {
457 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
458 {
459 png_push_save_buffer(png_ptr);
460 return;
461 }
462
463 png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
464 }
465
466#endif
467#ifdef PNG_READ_oFFs_SUPPORTED
468 else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
469 {
470 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
471 {
472 png_push_save_buffer(png_ptr);
473 return;
474 }
475
476 png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
477 }
478#endif
479
480#ifdef PNG_READ_pCAL_SUPPORTED
481 else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
482 {
483 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
484 {
485 png_push_save_buffer(png_ptr);
486 return;
487 }
488
489 png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
490 }
491
492#endif
493#ifdef PNG_READ_sCAL_SUPPORTED
494 else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
495 {
496 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
497 {
498 png_push_save_buffer(png_ptr);
499 return;
500 }
501
502 png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
503 }
504
505#endif
506#ifdef PNG_READ_tIME_SUPPORTED
507 else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
508 {
509 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
510 {
511 png_push_save_buffer(png_ptr);
512 return;
513 }
514
515 png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
516 }
517
518#endif
519#ifdef PNG_READ_tEXt_SUPPORTED
520 else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
521 {
522 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
523 {
524 png_push_save_buffer(png_ptr);
525 return;
526 }
527
528 png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
529 }
530
531#endif
532#ifdef PNG_READ_zTXt_SUPPORTED
533 else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
534 {
535 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
536 {
537 png_push_save_buffer(png_ptr);
538 return;
539 }
540
541 png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
542 }
543
544#endif
545#ifdef PNG_READ_iTXt_SUPPORTED
546 else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
547 {
548 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
549 {
550 png_push_save_buffer(png_ptr);
551 return;
552 }
553
554 png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
555 }
556
557#endif
558 else
559 {
560 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
561 {
562 png_push_save_buffer(png_ptr);
563 return;
564 }
565 png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
566 }
567
568 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
569}
570
571void /* PRIVATE */
572png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
573{
574 png_ptr->process_mode = PNG_SKIP_MODE;
575 png_ptr->skip_length = skip;
576}
577
578void /* PRIVATE */
579png_push_crc_finish(png_structp png_ptr)
580{
581 if (png_ptr->skip_length && png_ptr->save_buffer_size)
582 {
583 png_size_t save_size;
584
585 if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
586 save_size = (png_size_t)png_ptr->skip_length;
587 else
588 save_size = png_ptr->save_buffer_size;
589
590 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
591
592 png_ptr->skip_length -= save_size;
593 png_ptr->buffer_size -= save_size;
594 png_ptr->save_buffer_size -= save_size;
595 png_ptr->save_buffer_ptr += save_size;
596 }
597 if (png_ptr->skip_length && png_ptr->current_buffer_size)
598 {
599 png_size_t save_size;
600
601 if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
602 save_size = (png_size_t)png_ptr->skip_length;
603 else
604 save_size = png_ptr->current_buffer_size;
605
606 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
607
608 png_ptr->skip_length -= save_size;
609 png_ptr->buffer_size -= save_size;
610 png_ptr->current_buffer_size -= save_size;
611 png_ptr->current_buffer_ptr += save_size;
612 }
613 if (!png_ptr->skip_length)
614 {
615 if (png_ptr->buffer_size < 4)
616 {
617 png_push_save_buffer(png_ptr);
618 return;
619 }
620
621 png_crc_finish(png_ptr, 0);
622 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
623 }
624}
625
626void PNGAPI
627png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
628{
629 png_bytep ptr;
630
631 if (png_ptr == NULL)
632 return;
633
634 ptr = buffer;
635 if (png_ptr->save_buffer_size)
636 {
637 png_size_t save_size;
638
639 if (length < png_ptr->save_buffer_size)
640 save_size = length;
641 else
642 save_size = png_ptr->save_buffer_size;
643
644 png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
645 length -= save_size;
646 ptr += save_size;
647 png_ptr->buffer_size -= save_size;
648 png_ptr->save_buffer_size -= save_size;
649 png_ptr->save_buffer_ptr += save_size;
650 }
651 if (length && png_ptr->current_buffer_size)
652 {
653 png_size_t save_size;
654
655 if (length < png_ptr->current_buffer_size)
656 save_size = length;
657
658 else
659 save_size = png_ptr->current_buffer_size;
660
661 png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
662 png_ptr->buffer_size -= save_size;
663 png_ptr->current_buffer_size -= save_size;
664 png_ptr->current_buffer_ptr += save_size;
665 }
666}
667
668void /* PRIVATE */
669png_push_save_buffer(png_structp png_ptr)
670{
671 if (png_ptr->save_buffer_size)
672 {
673 if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
674 {
675 png_size_t i, istop;
676 png_bytep sp;
677 png_bytep dp;
678
679 istop = png_ptr->save_buffer_size;
680 for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
681 i < istop; i++, sp++, dp++)
682 {
683 *dp = *sp;
684 }
685 }
686 }
687 if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
688 png_ptr->save_buffer_max)
689 {
690 png_size_t new_max;
691 png_bytep old_buffer;
692
693 if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
694 (png_ptr->current_buffer_size + 256))
695 {
696 png_error(png_ptr, "Potential overflow of save_buffer");
697 }
698
699 new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
700 old_buffer = png_ptr->save_buffer;
701 png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,
702 (png_size_t)new_max);
703 png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
704 png_free(png_ptr, old_buffer);
705 png_ptr->save_buffer_max = new_max;
706 }
707 if (png_ptr->current_buffer_size)
708 {
709 png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
710 png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
711 png_ptr->save_buffer_size += png_ptr->current_buffer_size;
712 png_ptr->current_buffer_size = 0;
713 }
714 png_ptr->save_buffer_ptr = png_ptr->save_buffer;
715 png_ptr->buffer_size = 0;
716}
717
718void /* PRIVATE */
719png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
720 png_size_t buffer_length)
721{
722 png_ptr->current_buffer = buffer;
723 png_ptr->current_buffer_size = buffer_length;
724 png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
725 png_ptr->current_buffer_ptr = png_ptr->current_buffer;
726}
727
728void /* PRIVATE */
729png_push_read_IDAT(png_structp png_ptr)
730{
731 PNG_IDAT;
732 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
733 {
734 png_byte chunk_length[4];
735
736 if (png_ptr->buffer_size < 8)
737 {
738 png_push_save_buffer(png_ptr);
739 return;
740 }
741
742 png_push_fill_buffer(png_ptr, chunk_length, 4);
743 png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
744 png_reset_crc(png_ptr);
745 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
746 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
747
748 if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
749 {
750 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
751 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
752 png_error(png_ptr, "Not enough compressed data");
753 return;
754 }
755
756 png_ptr->idat_size = png_ptr->push_length;
757 }
758 if (png_ptr->idat_size && png_ptr->save_buffer_size)
759 {
760 png_size_t save_size;
761
762 if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
763 {
764 save_size = (png_size_t)png_ptr->idat_size;
765
766 /* Check for overflow */
767 if ((png_uint_32)save_size != png_ptr->idat_size)
768 png_error(png_ptr, "save_size overflowed in pngpread");
769 }
770 else
771 save_size = png_ptr->save_buffer_size;
772
773 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
774
775 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
776 png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
777
778 png_ptr->idat_size -= save_size;
779 png_ptr->buffer_size -= save_size;
780 png_ptr->save_buffer_size -= save_size;
781 png_ptr->save_buffer_ptr += save_size;
782 }
783 if (png_ptr->idat_size && png_ptr->current_buffer_size)
784 {
785 png_size_t save_size;
786
787 if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
788 {
789 save_size = (png_size_t)png_ptr->idat_size;
790
791 /* Check for overflow */
792 if ((png_uint_32)save_size != png_ptr->idat_size)
793 png_error(png_ptr, "save_size overflowed in pngpread");
794 }
795 else
796 save_size = png_ptr->current_buffer_size;
797
798 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
799 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
800 png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
801
802 png_ptr->idat_size -= save_size;
803 png_ptr->buffer_size -= save_size;
804 png_ptr->current_buffer_size -= save_size;
805 png_ptr->current_buffer_ptr += save_size;
806 }
807 if (!png_ptr->idat_size)
808 {
809 if (png_ptr->buffer_size < 4)
810 {
811 png_push_save_buffer(png_ptr);
812 return;
813 }
814
815 png_crc_finish(png_ptr, 0);
816 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
817 png_ptr->mode |= PNG_AFTER_IDAT;
818 }
819}
820
821void /* PRIVATE */
822png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
823 png_size_t buffer_length)
824{
825 int ret;
826
827 if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
828 png_benign_error(png_ptr, "Extra compression data");
829
830 png_ptr->zstream.next_in = buffer;
831 png_ptr->zstream.avail_in = (uInt)buffer_length;
832 for (;;)
833 {
834 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
835 if (ret != Z_OK)
836 {
837 if (ret == Z_STREAM_END)
838 {
839 if (png_ptr->zstream.avail_in)
840 png_benign_error(png_ptr, "Extra compressed data");
841
842 if (!(png_ptr->zstream.avail_out))
843 {
844 png_push_process_row(png_ptr);
845 }
846
847 png_ptr->mode |= PNG_AFTER_IDAT;
848 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
849 break;
850 }
851 else if (ret == Z_BUF_ERROR)
852 break;
853
854 else
855 png_error(png_ptr, "Decompression Error");
856 }
857 if (!(png_ptr->zstream.avail_out))
858 {
859 if ((
860#ifdef PNG_READ_INTERLACING_SUPPORTED
861 png_ptr->interlaced && png_ptr->pass > 6) ||
862 (!png_ptr->interlaced &&
863#endif
864 png_ptr->row_number == png_ptr->num_rows))
865 {
866 if (png_ptr->zstream.avail_in)
867 png_warning(png_ptr, "Too much data in IDAT chunks");
868 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
869 break;
870 }
871 png_push_process_row(png_ptr);
872 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
873 png_ptr->zstream.next_out = png_ptr->row_buf;
874 }
875
876 else
877 break;
878 }
879}
880
881void /* PRIVATE */
882png_push_process_row(png_structp png_ptr)
883{
884 png_ptr->row_info.color_type = png_ptr->color_type;
885 png_ptr->row_info.width = png_ptr->iwidth;
886 png_ptr->row_info.channels = png_ptr->channels;
887 png_ptr->row_info.bit_depth = png_ptr->bit_depth;
888 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
889
890 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
891 png_ptr->row_info.width);
892
893 png_read_filter_row(png_ptr, &(png_ptr->row_info),
894 png_ptr->row_buf + 1, png_ptr->prev_row + 1,
895 (int)(png_ptr->row_buf[0]));
896
897 png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1);
898
899 if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
900 png_do_read_transformations(png_ptr);
901
902#ifdef PNG_READ_INTERLACING_SUPPORTED
903 /* Blow up interlaced rows to full size */
904 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
905 {
906 if (png_ptr->pass < 6)
907/* old interface (pre-1.0.9):
908 png_do_read_interlace(&(png_ptr->row_info),
909 png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
910 */
911 png_do_read_interlace(png_ptr);
912
913 switch (png_ptr->pass)
914 {
915 case 0:
916 {
917 int i;
918 for (i = 0; i < 8 && png_ptr->pass == 0; i++)
919 {
920 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
921 png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
922 }
923
924 if (png_ptr->pass == 2) /* Pass 1 might be empty */
925 {
926 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
927 {
928 png_push_have_row(png_ptr, NULL);
929 png_read_push_finish_row(png_ptr);
930 }
931 }
932
933 if (png_ptr->pass == 4 && png_ptr->height <= 4)
934 {
935 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
936 {
937 png_push_have_row(png_ptr, NULL);
938 png_read_push_finish_row(png_ptr);
939 }
940 }
941
942 if (png_ptr->pass == 6 && png_ptr->height <= 4)
943 {
944 png_push_have_row(png_ptr, NULL);
945 png_read_push_finish_row(png_ptr);
946 }
947
948 break;
949 }
950
951 case 1:
952 {
953 int i;
954 for (i = 0; i < 8 && png_ptr->pass == 1; i++)
955 {
956 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
957 png_read_push_finish_row(png_ptr);
958 }
959
960 if (png_ptr->pass == 2) /* Skip top 4 generated rows */
961 {
962 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
963 {
964 png_push_have_row(png_ptr, NULL);
965 png_read_push_finish_row(png_ptr);
966 }
967 }
968
969 break;
970 }
971
972 case 2:
973 {
974 int i;
975
976 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
977 {
978 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
979 png_read_push_finish_row(png_ptr);
980 }
981
982 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
983 {
984 png_push_have_row(png_ptr, NULL);
985 png_read_push_finish_row(png_ptr);
986 }
987
988 if (png_ptr->pass == 4) /* Pass 3 might be empty */
989 {
990 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
991 {
992 png_push_have_row(png_ptr, NULL);
993 png_read_push_finish_row(png_ptr);
994 }
995 }
996
997 break;
998 }
999
1000 case 3:
1001 {
1002 int i;
1003
1004 for (i = 0; i < 4 && png_ptr->pass == 3; i++)
1005 {
1006 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1007 png_read_push_finish_row(png_ptr);
1008 }
1009
1010 if (png_ptr->pass == 4) /* Skip top two generated rows */
1011 {
1012 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1013 {
1014 png_push_have_row(png_ptr, NULL);
1015 png_read_push_finish_row(png_ptr);
1016 }
1017 }
1018
1019 break;
1020 }
1021
1022 case 4:
1023 {
1024 int i;
1025
1026 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1027 {
1028 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1029 png_read_push_finish_row(png_ptr);
1030 }
1031
1032 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1033 {
1034 png_push_have_row(png_ptr, NULL);
1035 png_read_push_finish_row(png_ptr);
1036 }
1037
1038 if (png_ptr->pass == 6) /* Pass 5 might be empty */
1039 {
1040 png_push_have_row(png_ptr, NULL);
1041 png_read_push_finish_row(png_ptr);
1042 }
1043
1044 break;
1045 }
1046
1047 case 5:
1048 {
1049 int i;
1050
1051 for (i = 0; i < 2 && png_ptr->pass == 5; i++)
1052 {
1053 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1054 png_read_push_finish_row(png_ptr);
1055 }
1056
1057 if (png_ptr->pass == 6) /* Skip top generated row */
1058 {
1059 png_push_have_row(png_ptr, NULL);
1060 png_read_push_finish_row(png_ptr);
1061 }
1062
1063 break;
1064 }
1065 case 6:
1066 {
1067 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1068 png_read_push_finish_row(png_ptr);
1069
1070 if (png_ptr->pass != 6)
1071 break;
1072
1073 png_push_have_row(png_ptr, NULL);
1074 png_read_push_finish_row(png_ptr);
1075 }
1076 }
1077 }
1078 else
1079#endif
1080 {
1081 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1082 png_read_push_finish_row(png_ptr);
1083 }
1084}
1085
1086void /* PRIVATE */
1087png_read_push_finish_row(png_structp png_ptr)
1088{
1089 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1090
1091 /* Start of interlace block */
1092 PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
1093
1094 /* Offset to next interlace block */
1095 PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
1096
1097 /* Start of interlace block in the y direction */
1098 PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
1099
1100 /* Offset to next interlace block in the y direction */
1101 PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
1102
1103 /* Height of interlace block. This is not currently used - if you need
1104 * it, uncomment it here and in png.h
1105 PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
1106 */
1107
1108 png_ptr->row_number++;
1109 if (png_ptr->row_number < png_ptr->num_rows)
1110 return;
1111
1112#ifdef PNG_READ_INTERLACING_SUPPORTED
1113 if (png_ptr->interlaced)
1114 {
1115 png_ptr->row_number = 0;
1116 png_memset(png_ptr->prev_row, 0,
1117 png_ptr->rowbytes + 1);
1118 do
1119 {
1120 png_ptr->pass++;
1121 if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
1122 (png_ptr->pass == 3 && png_ptr->width < 3) ||
1123 (png_ptr->pass == 5 && png_ptr->width < 2))
1124 png_ptr->pass++;
1125
1126 if (png_ptr->pass > 7)
1127 png_ptr->pass--;
1128
1129 if (png_ptr->pass >= 7)
1130 break;
1131
1132 png_ptr->iwidth = (png_ptr->width +
1133 png_pass_inc[png_ptr->pass] - 1 -
1134 png_pass_start[png_ptr->pass]) /
1135 png_pass_inc[png_ptr->pass];
1136
1137 png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
1138 png_ptr->iwidth) + 1;
1139
1140 if (png_ptr->transformations & PNG_INTERLACE)
1141 break;
1142
1143 png_ptr->num_rows = (png_ptr->height +
1144 png_pass_yinc[png_ptr->pass] - 1 -
1145 png_pass_ystart[png_ptr->pass]) /
1146 png_pass_yinc[png_ptr->pass];
1147
1148 } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
1149 }
1150#endif /* PNG_READ_INTERLACING_SUPPORTED */
1151}
1152
1153#ifdef PNG_READ_tEXt_SUPPORTED
1154void /* PRIVATE */
1155png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1156 length)
1157{
1158 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1159 {
1160 png_error(png_ptr, "Out of place tEXt");
1161 info_ptr = info_ptr; /* To quiet some compiler warnings */
1162 }
1163
1164#ifdef PNG_MAX_MALLOC_64K
1165 png_ptr->skip_length = 0; /* This may not be necessary */
1166
1167 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1168 {
1169 png_warning(png_ptr, "tEXt chunk too large to fit in memory");
1170 png_ptr->skip_length = length - (png_uint_32)65535L;
1171 length = (png_uint_32)65535L;
1172 }
1173#endif
1174
1175 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1176 (png_size_t)(length + 1));
1177 png_ptr->current_text[length] = '\0';
1178 png_ptr->current_text_ptr = png_ptr->current_text;
1179 png_ptr->current_text_size = (png_size_t)length;
1180 png_ptr->current_text_left = (png_size_t)length;
1181 png_ptr->process_mode = PNG_READ_tEXt_MODE;
1182}
1183
1184void /* PRIVATE */
1185png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
1186{
1187 if (png_ptr->buffer_size && png_ptr->current_text_left)
1188 {
1189 png_size_t text_size;
1190
1191 if (png_ptr->buffer_size < png_ptr->current_text_left)
1192 text_size = png_ptr->buffer_size;
1193
1194 else
1195 text_size = png_ptr->current_text_left;
1196
1197 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1198 png_ptr->current_text_left -= text_size;
1199 png_ptr->current_text_ptr += text_size;
1200 }
1201 if (!(png_ptr->current_text_left))
1202 {
1203 png_textp text_ptr;
1204 png_charp text;
1205 png_charp key;
1206 int ret;
1207
1208 if (png_ptr->buffer_size < 4)
1209 {
1210 png_push_save_buffer(png_ptr);
1211 return;
1212 }
1213
1214 png_push_crc_finish(png_ptr);
1215
1216#ifdef PNG_MAX_MALLOC_64K
1217 if (png_ptr->skip_length)
1218 return;
1219#endif
1220
1221 key = png_ptr->current_text;
1222
1223 for (text = key; *text; text++)
1224 /* Empty loop */ ;
1225
1226 if (text < key + png_ptr->current_text_size)
1227 text++;
1228
1229 text_ptr = (png_textp)png_malloc(png_ptr,
1230 png_sizeof(png_text));
1231 text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
1232 text_ptr->key = key;
1233#ifdef PNG_iTXt_SUPPORTED
1234 text_ptr->lang = NULL;
1235 text_ptr->lang_key = NULL;
1236#endif
1237 text_ptr->text = text;
1238
1239 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1240
1241 png_free(png_ptr, key);
1242 png_free(png_ptr, text_ptr);
1243 png_ptr->current_text = NULL;
1244
1245 if (ret)
1246 png_warning(png_ptr, "Insufficient memory to store text chunk");
1247 }
1248}
1249#endif
1250
1251#ifdef PNG_READ_zTXt_SUPPORTED
1252void /* PRIVATE */
1253png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1254 length)
1255{
1256 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1257 {
1258 png_error(png_ptr, "Out of place zTXt");
1259 info_ptr = info_ptr; /* To quiet some compiler warnings */
1260 }
1261
1262#ifdef PNG_MAX_MALLOC_64K
1263 /* We can't handle zTXt chunks > 64K, since we don't have enough space
1264 * to be able to store the uncompressed data. Actually, the threshold
1265 * is probably around 32K, but it isn't as definite as 64K is.
1266 */
1267 if (length > (png_uint_32)65535L)
1268 {
1269 png_warning(png_ptr, "zTXt chunk too large to fit in memory");
1270 png_push_crc_skip(png_ptr, length);
1271 return;
1272 }
1273#endif
1274
1275 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1276 (png_size_t)(length + 1));
1277 png_ptr->current_text[length] = '\0';
1278 png_ptr->current_text_ptr = png_ptr->current_text;
1279 png_ptr->current_text_size = (png_size_t)length;
1280 png_ptr->current_text_left = (png_size_t)length;
1281 png_ptr->process_mode = PNG_READ_zTXt_MODE;
1282}
1283
1284void /* PRIVATE */
1285png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
1286{
1287 if (png_ptr->buffer_size && png_ptr->current_text_left)
1288 {
1289 png_size_t text_size;
1290
1291 if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
1292 text_size = png_ptr->buffer_size;
1293
1294 else
1295 text_size = png_ptr->current_text_left;
1296
1297 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1298 png_ptr->current_text_left -= text_size;
1299 png_ptr->current_text_ptr += text_size;
1300 }
1301 if (!(png_ptr->current_text_left))
1302 {
1303 png_textp text_ptr;
1304 png_charp text;
1305 png_charp key;
1306 int ret;
1307 png_size_t text_size, key_size;
1308
1309 if (png_ptr->buffer_size < 4)
1310 {
1311 png_push_save_buffer(png_ptr);
1312 return;
1313 }
1314
1315 png_push_crc_finish(png_ptr);
1316
1317 key = png_ptr->current_text;
1318
1319 for (text = key; *text; text++)
1320 /* Empty loop */ ;
1321
1322 /* zTXt can't have zero text */
1323 if (text >= key + png_ptr->current_text_size)
1324 {
1325 png_ptr->current_text = NULL;
1326 png_free(png_ptr, key);
1327 return;
1328 }
1329
1330 text++;
1331
1332 if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */
1333 {
1334 png_ptr->current_text = NULL;
1335 png_free(png_ptr, key);
1336 return;
1337 }
1338
1339 text++;
1340
1341 png_ptr->zstream.next_in = (png_bytep )text;
1342 png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
1343 (text - key));
1344 png_ptr->zstream.next_out = png_ptr->zbuf;
1345 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1346
1347 key_size = text - key;
1348 text_size = 0;
1349 text = NULL;
1350 ret = Z_STREAM_END;
1351
1352 while (png_ptr->zstream.avail_in)
1353 {
1354 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
1355 if (ret != Z_OK && ret != Z_STREAM_END)
1356 {
1357 inflateReset(&png_ptr->zstream);
1358 png_ptr->zstream.avail_in = 0;
1359 png_ptr->current_text = NULL;
1360 png_free(png_ptr, key);
1361 png_free(png_ptr, text);
1362 return;
1363 }
1364 if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
1365 {
1366 if (text == NULL)
1367 {
1368 text = (png_charp)png_malloc(png_ptr,
1369 (png_ptr->zbuf_size
1370 - png_ptr->zstream.avail_out + key_size + 1));
1371
1372 png_memcpy(text + key_size, png_ptr->zbuf,
1373 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1374
1375 png_memcpy(text, key, key_size);
1376
1377 text_size = key_size + png_ptr->zbuf_size -
1378 png_ptr->zstream.avail_out;
1379
1380 *(text + text_size) = '\0';
1381 }
1382 else
1383 {
1384 png_charp tmp;
1385
1386 tmp = text;
1387 text = (png_charp)png_malloc(png_ptr, text_size +
1388 (png_ptr->zbuf_size
1389 - png_ptr->zstream.avail_out + 1));
1390
1391 png_memcpy(text, tmp, text_size);
1392 png_free(png_ptr, tmp);
1393
1394 png_memcpy(text + text_size, png_ptr->zbuf,
1395 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1396
1397 text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
1398 *(text + text_size) = '\0';
1399 }
1400 if (ret != Z_STREAM_END)
1401 {
1402 png_ptr->zstream.next_out = png_ptr->zbuf;
1403 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1404 }
1405 }
1406 else
1407 {
1408 break;
1409 }
1410
1411 if (ret == Z_STREAM_END)
1412 break;
1413 }
1414
1415 inflateReset(&png_ptr->zstream);
1416 png_ptr->zstream.avail_in = 0;
1417
1418 if (ret != Z_STREAM_END)
1419 {
1420 png_ptr->current_text = NULL;
1421 png_free(png_ptr, key);
1422 png_free(png_ptr, text);
1423 return;
1424 }
1425
1426 png_ptr->current_text = NULL;
1427 png_free(png_ptr, key);
1428 key = text;
1429 text += key_size;
1430
1431 text_ptr = (png_textp)png_malloc(png_ptr,
1432 png_sizeof(png_text));
1433 text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
1434 text_ptr->key = key;
1435#ifdef PNG_iTXt_SUPPORTED
1436 text_ptr->lang = NULL;
1437 text_ptr->lang_key = NULL;
1438#endif
1439 text_ptr->text = text;
1440
1441 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1442
1443 png_free(png_ptr, key);
1444 png_free(png_ptr, text_ptr);
1445
1446 if (ret)
1447 png_warning(png_ptr, "Insufficient memory to store text chunk");
1448 }
1449}
1450#endif
1451
1452#ifdef PNG_READ_iTXt_SUPPORTED
1453void /* PRIVATE */
1454png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1455 length)
1456{
1457 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1458 {
1459 png_error(png_ptr, "Out of place iTXt");
1460 info_ptr = info_ptr; /* To quiet some compiler warnings */
1461 }
1462
1463#ifdef PNG_MAX_MALLOC_64K
1464 png_ptr->skip_length = 0; /* This may not be necessary */
1465
1466 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1467 {
1468 png_warning(png_ptr, "iTXt chunk too large to fit in memory");
1469 png_ptr->skip_length = length - (png_uint_32)65535L;
1470 length = (png_uint_32)65535L;
1471 }
1472#endif
1473
1474 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1475 (png_size_t)(length + 1));
1476 png_ptr->current_text[length] = '\0';
1477 png_ptr->current_text_ptr = png_ptr->current_text;
1478 png_ptr->current_text_size = (png_size_t)length;
1479 png_ptr->current_text_left = (png_size_t)length;
1480 png_ptr->process_mode = PNG_READ_iTXt_MODE;
1481}
1482
1483void /* PRIVATE */
1484png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
1485{
1486
1487 if (png_ptr->buffer_size && png_ptr->current_text_left)
1488 {
1489 png_size_t text_size;
1490
1491 if (png_ptr->buffer_size < png_ptr->current_text_left)
1492 text_size = png_ptr->buffer_size;
1493
1494 else
1495 text_size = png_ptr->current_text_left;
1496
1497 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1498 png_ptr->current_text_left -= text_size;
1499 png_ptr->current_text_ptr += text_size;
1500 }
1501 if (!(png_ptr->current_text_left))
1502 {
1503 png_textp text_ptr;
1504 png_charp key;
1505 int comp_flag;
1506 png_charp lang;
1507 png_charp lang_key;
1508 png_charp text;
1509 int ret;
1510
1511 if (png_ptr->buffer_size < 4)
1512 {
1513 png_push_save_buffer(png_ptr);
1514 return;
1515 }
1516
1517 png_push_crc_finish(png_ptr);
1518
1519#ifdef PNG_MAX_MALLOC_64K
1520 if (png_ptr->skip_length)
1521 return;
1522#endif
1523
1524 key = png_ptr->current_text;
1525
1526 for (lang = key; *lang; lang++)
1527 /* Empty loop */ ;
1528
1529 if (lang < key + png_ptr->current_text_size - 3)
1530 lang++;
1531
1532 comp_flag = *lang++;
1533 lang++; /* Skip comp_type, always zero */
1534
1535 for (lang_key = lang; *lang_key; lang_key++)
1536 /* Empty loop */ ;
1537
1538 lang_key++; /* Skip NUL separator */
1539
1540 text=lang_key;
1541
1542 if (lang_key < key + png_ptr->current_text_size - 1)
1543 {
1544 for (; *text; text++)
1545 /* Empty loop */ ;
1546 }
1547
1548 if (text < key + png_ptr->current_text_size)
1549 text++;
1550
1551 text_ptr = (png_textp)png_malloc(png_ptr,
1552 png_sizeof(png_text));
1553
1554 text_ptr->compression = comp_flag + 2;
1555 text_ptr->key = key;
1556 text_ptr->lang = lang;
1557 text_ptr->lang_key = lang_key;
1558 text_ptr->text = text;
1559 text_ptr->text_length = 0;
1560 text_ptr->itxt_length = png_strlen(text);
1561
1562 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1563
1564 png_ptr->current_text = NULL;
1565
1566 png_free(png_ptr, text_ptr);
1567 if (ret)
1568 png_warning(png_ptr, "Insufficient memory to store iTXt chunk");
1569 }
1570}
1571#endif
1572
1573/* This function is called when we haven't found a handler for this
1574 * chunk. If there isn't a problem with the chunk itself (ie a bad chunk
1575 * name or a critical chunk), the chunk is (currently) silently ignored.
1576 */
1577void /* PRIVATE */
1578png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
1579 length)
1580{
1581 png_uint_32 skip = 0;
1582
1583 if (!(png_ptr->chunk_name[0] & 0x20))
1584 {
1585#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
1586 if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1587 PNG_HANDLE_CHUNK_ALWAYS
1588#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1589 && png_ptr->read_user_chunk_fn == NULL
1590#endif
1591 )
1592#endif
1593 png_chunk_error(png_ptr, "unknown critical chunk");
1594
1595 info_ptr = info_ptr; /* To quiet some compiler warnings */
1596 }
1597
1598#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
1599 if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
1600 {
1601#ifdef PNG_MAX_MALLOC_64K
1602 if (length > (png_uint_32)65535L)
1603 {
1604 png_warning(png_ptr, "unknown chunk too large to fit in memory");
1605 skip = length - (png_uint_32)65535L;
1606 length = (png_uint_32)65535L;
1607 }
1608#endif
1609 png_memcpy((png_charp)png_ptr->unknown_chunk.name,
1610 (png_charp)png_ptr->chunk_name,
1611 png_sizeof(png_ptr->unknown_chunk.name));
1612 png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1]
1613 = '\0';
1614
1615 png_ptr->unknown_chunk.size = (png_size_t)length;
1616
1617 if (length == 0)
1618 png_ptr->unknown_chunk.data = NULL;
1619
1620 else
1621 {
1622 png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,
1623 (png_size_t)length);
1624 png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
1625 }
1626
1627#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1628 if (png_ptr->read_user_chunk_fn != NULL)
1629 {
1630 /* Callback to user unknown chunk handler */
1631 int ret;
1632 ret = (*(png_ptr->read_user_chunk_fn))
1633 (png_ptr, &png_ptr->unknown_chunk);
1634
1635 if (ret < 0)
1636 png_chunk_error(png_ptr, "error in user chunk");
1637
1638 if (ret == 0)
1639 {
1640 if (!(png_ptr->chunk_name[0] & 0x20))
1641 if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1642 PNG_HANDLE_CHUNK_ALWAYS)
1643 png_chunk_error(png_ptr, "unknown critical chunk");
1644 png_set_unknown_chunks(png_ptr, info_ptr,
1645 &png_ptr->unknown_chunk, 1);
1646 }
1647 }
1648
1649 else
1650#endif
1651 png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
1652 png_free(png_ptr, png_ptr->unknown_chunk.data);
1653 png_ptr->unknown_chunk.data = NULL;
1654 }
1655
1656 else
1657#endif
1658 skip=length;
1659 png_push_crc_skip(png_ptr, skip);
1660}
1661
1662void /* PRIVATE */
1663png_push_have_info(png_structp png_ptr, png_infop info_ptr)
1664{
1665 if (png_ptr->info_fn != NULL)
1666 (*(png_ptr->info_fn))(png_ptr, info_ptr);
1667}
1668
1669void /* PRIVATE */
1670png_push_have_end(png_structp png_ptr, png_infop info_ptr)
1671{
1672 if (png_ptr->end_fn != NULL)
1673 (*(png_ptr->end_fn))(png_ptr, info_ptr);
1674}
1675
1676void /* PRIVATE */
1677png_push_have_row(png_structp png_ptr, png_bytep row)
1678{
1679 if (png_ptr->row_fn != NULL)
1680 (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
1681 (int)png_ptr->pass);
1682}
1683
1684void PNGAPI
1685png_progressive_combine_row (png_structp png_ptr,
1686 png_bytep old_row, png_bytep new_row)
1687{
1688 PNG_CONST int FARDATA png_pass_dsp_mask[7] =
1689 {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
1690
1691 if (png_ptr == NULL)
1692 return;
1693
1694 if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */
1695 png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
1696}
1697
1698void PNGAPI
1699png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
1700 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1701 png_progressive_end_ptr end_fn)
1702{
1703 if (png_ptr == NULL)
1704 return;
1705
1706 png_ptr->info_fn = info_fn;
1707 png_ptr->row_fn = row_fn;
1708 png_ptr->end_fn = end_fn;
1709
1710 png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
1711}
1712
1713png_voidp PNGAPI
1714png_get_progressive_ptr(png_structp png_ptr)
1715{
1716 if (png_ptr == NULL)
1717 return (NULL);
1718
1719 return png_ptr->io_ptr;
1720}
1721#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
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