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[wxWidgets.git] / src / png / pngpread.c
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1
2/* pngpread.c - read a png file in push mode
3 *
4 * Last changed in libpng 1.4.3 [June 26, 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 =
333 (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
334 png_ptr->iwidth) + 1;
335 png_ptr->zstream.next_out = png_ptr->row_buf;
336 return;
337 }
338
339#ifdef PNG_READ_gAMA_SUPPORTED
340 else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
341 {
342 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
343 {
344 png_push_save_buffer(png_ptr);
345 return;
346 }
347
348 png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
349 }
350
351#endif
352#ifdef PNG_READ_sBIT_SUPPORTED
353 else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
354 {
355 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
356 {
357 png_push_save_buffer(png_ptr);
358 return;
359 }
360
361 png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
362 }
363
364#endif
365#ifdef PNG_READ_cHRM_SUPPORTED
366 else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
367 {
368 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
369 {
370 png_push_save_buffer(png_ptr);
371 return;
372 }
373
374 png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
375 }
376
377#endif
378#ifdef PNG_READ_sRGB_SUPPORTED
379 else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
380 {
381 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
382 {
383 png_push_save_buffer(png_ptr);
384 return;
385 }
386
387 png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
388 }
389
390#endif
391#ifdef PNG_READ_iCCP_SUPPORTED
392 else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
393 {
394 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
395 {
396 png_push_save_buffer(png_ptr);
397 return;
398 }
399
400 png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
401 }
402
403#endif
404#ifdef PNG_READ_sPLT_SUPPORTED
405 else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
406 {
407 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
408 {
409 png_push_save_buffer(png_ptr);
410 return;
411 }
412
413 png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
414 }
415
416#endif
417#ifdef PNG_READ_tRNS_SUPPORTED
418 else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
419 {
420 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
421 {
422 png_push_save_buffer(png_ptr);
423 return;
424 }
425
426 png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
427 }
428
429#endif
430#ifdef PNG_READ_bKGD_SUPPORTED
431 else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
432 {
433 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
434 {
435 png_push_save_buffer(png_ptr);
436 return;
437 }
438
439 png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
440 }
441
442#endif
443#ifdef PNG_READ_hIST_SUPPORTED
444 else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
445 {
446 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
447 {
448 png_push_save_buffer(png_ptr);
449 return;
450 }
451
452 png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
453 }
454
455#endif
456#ifdef PNG_READ_pHYs_SUPPORTED
457 else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
458 {
459 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
460 {
461 png_push_save_buffer(png_ptr);
462 return;
463 }
464
465 png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
466 }
467
468#endif
469#ifdef PNG_READ_oFFs_SUPPORTED
470 else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
471 {
472 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
473 {
474 png_push_save_buffer(png_ptr);
475 return;
476 }
477
478 png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
479 }
480#endif
481
482#ifdef PNG_READ_pCAL_SUPPORTED
483 else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
484 {
485 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
486 {
487 png_push_save_buffer(png_ptr);
488 return;
489 }
490
491 png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
492 }
493
494#endif
495#ifdef PNG_READ_sCAL_SUPPORTED
496 else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
497 {
498 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
499 {
500 png_push_save_buffer(png_ptr);
501 return;
502 }
503
504 png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
505 }
506
507#endif
508#ifdef PNG_READ_tIME_SUPPORTED
509 else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
510 {
511 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
512 {
513 png_push_save_buffer(png_ptr);
514 return;
515 }
516
517 png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
518 }
519
520#endif
521#ifdef PNG_READ_tEXt_SUPPORTED
522 else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
523 {
524 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
525 {
526 png_push_save_buffer(png_ptr);
527 return;
528 }
529
530 png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
531 }
532
533#endif
534#ifdef PNG_READ_zTXt_SUPPORTED
535 else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
536 {
537 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
538 {
539 png_push_save_buffer(png_ptr);
540 return;
541 }
542
543 png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
544 }
545
546#endif
547#ifdef PNG_READ_iTXt_SUPPORTED
548 else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
549 {
550 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
551 {
552 png_push_save_buffer(png_ptr);
553 return;
554 }
555
556 png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
557 }
558
559#endif
560 else
561 {
562 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
563 {
564 png_push_save_buffer(png_ptr);
565 return;
566 }
567 png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
568 }
569
570 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
571}
572
573void /* PRIVATE */
574png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
575{
576 png_ptr->process_mode = PNG_SKIP_MODE;
577 png_ptr->skip_length = skip;
578}
579
580void /* PRIVATE */
581png_push_crc_finish(png_structp png_ptr)
582{
583 if (png_ptr->skip_length && png_ptr->save_buffer_size)
584 {
585 png_size_t save_size;
586
587 if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
588 save_size = (png_size_t)png_ptr->skip_length;
589 else
590 save_size = png_ptr->save_buffer_size;
591
592 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
593
594 png_ptr->skip_length -= save_size;
595 png_ptr->buffer_size -= save_size;
596 png_ptr->save_buffer_size -= save_size;
597 png_ptr->save_buffer_ptr += save_size;
598 }
599 if (png_ptr->skip_length && png_ptr->current_buffer_size)
600 {
601 png_size_t save_size;
602
603 if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
604 save_size = (png_size_t)png_ptr->skip_length;
605 else
606 save_size = png_ptr->current_buffer_size;
607
608 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
609
610 png_ptr->skip_length -= save_size;
611 png_ptr->buffer_size -= save_size;
612 png_ptr->current_buffer_size -= save_size;
613 png_ptr->current_buffer_ptr += save_size;
614 }
615 if (!png_ptr->skip_length)
616 {
617 if (png_ptr->buffer_size < 4)
618 {
619 png_push_save_buffer(png_ptr);
620 return;
621 }
622
623 png_crc_finish(png_ptr, 0);
624 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
625 }
626}
627
628void PNGAPI
629png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
630{
631 png_bytep ptr;
632
633 if (png_ptr == NULL)
634 return;
635
636 ptr = buffer;
637 if (png_ptr->save_buffer_size)
638 {
639 png_size_t save_size;
640
641 if (length < png_ptr->save_buffer_size)
642 save_size = length;
643 else
644 save_size = png_ptr->save_buffer_size;
645
646 png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
647 length -= save_size;
648 ptr += save_size;
649 png_ptr->buffer_size -= save_size;
650 png_ptr->save_buffer_size -= save_size;
651 png_ptr->save_buffer_ptr += save_size;
652 }
653 if (length && png_ptr->current_buffer_size)
654 {
655 png_size_t save_size;
656
657 if (length < png_ptr->current_buffer_size)
658 save_size = length;
659
660 else
661 save_size = png_ptr->current_buffer_size;
662
663 png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
664 png_ptr->buffer_size -= save_size;
665 png_ptr->current_buffer_size -= save_size;
666 png_ptr->current_buffer_ptr += save_size;
667 }
668}
669
670void /* PRIVATE */
671png_push_save_buffer(png_structp png_ptr)
672{
673 if (png_ptr->save_buffer_size)
674 {
675 if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
676 {
677 png_size_t i, istop;
678 png_bytep sp;
679 png_bytep dp;
680
681 istop = png_ptr->save_buffer_size;
682 for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
683 i < istop; i++, sp++, dp++)
684 {
685 *dp = *sp;
686 }
687 }
688 }
689 if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
690 png_ptr->save_buffer_max)
691 {
692 png_size_t new_max;
693 png_bytep old_buffer;
694
695 if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
696 (png_ptr->current_buffer_size + 256))
697 {
698 png_error(png_ptr, "Potential overflow of save_buffer");
699 }
700
701 new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
702 old_buffer = png_ptr->save_buffer;
703 png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr,
704 (png_size_t)new_max);
705 if (png_ptr->save_buffer == NULL)
706 {
707 png_free(png_ptr, old_buffer);
708 png_error(png_ptr, "Insufficient memory for save_buffer");
709 }
710 png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
711 png_free(png_ptr, old_buffer);
712 png_ptr->save_buffer_max = new_max;
713 }
714 if (png_ptr->current_buffer_size)
715 {
716 png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
717 png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
718 png_ptr->save_buffer_size += png_ptr->current_buffer_size;
719 png_ptr->current_buffer_size = 0;
720 }
721 png_ptr->save_buffer_ptr = png_ptr->save_buffer;
722 png_ptr->buffer_size = 0;
723}
724
725void /* PRIVATE */
726png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
727 png_size_t buffer_length)
728{
729 png_ptr->current_buffer = buffer;
730 png_ptr->current_buffer_size = buffer_length;
731 png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
732 png_ptr->current_buffer_ptr = png_ptr->current_buffer;
733}
734
735void /* PRIVATE */
736png_push_read_IDAT(png_structp png_ptr)
737{
738 PNG_IDAT;
739 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
740 {
741 png_byte chunk_length[4];
742
743 if (png_ptr->buffer_size < 8)
744 {
745 png_push_save_buffer(png_ptr);
746 return;
747 }
748
749 png_push_fill_buffer(png_ptr, chunk_length, 4);
750 png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
751 png_reset_crc(png_ptr);
752 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
753 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
754
755 if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
756 {
757 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
758 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
759 png_error(png_ptr, "Not enough compressed data");
760 return;
761 }
762
763 png_ptr->idat_size = png_ptr->push_length;
764 }
765 if (png_ptr->idat_size && png_ptr->save_buffer_size)
766 {
767 png_size_t save_size;
768
769 if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
770 {
771 save_size = (png_size_t)png_ptr->idat_size;
772
773 /* Check for overflow */
774 if ((png_uint_32)save_size != png_ptr->idat_size)
775 png_error(png_ptr, "save_size overflowed in pngpread");
776 }
777 else
778 save_size = png_ptr->save_buffer_size;
779
780 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
781
782 png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
783
784 png_ptr->idat_size -= save_size;
785 png_ptr->buffer_size -= save_size;
786 png_ptr->save_buffer_size -= save_size;
787 png_ptr->save_buffer_ptr += save_size;
788 }
789 if (png_ptr->idat_size && png_ptr->current_buffer_size)
790 {
791 png_size_t save_size;
792
793 if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
794 {
795 save_size = (png_size_t)png_ptr->idat_size;
796
797 /* Check for overflow */
798 if ((png_uint_32)save_size != png_ptr->idat_size)
799 png_error(png_ptr, "save_size overflowed in pngpread");
800 }
801 else
802 save_size = png_ptr->current_buffer_size;
803
804 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
805
806 png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
807
808 png_ptr->idat_size -= save_size;
809 png_ptr->buffer_size -= save_size;
810 png_ptr->current_buffer_size -= save_size;
811 png_ptr->current_buffer_ptr += save_size;
812 }
813 if (!png_ptr->idat_size)
814 {
815 if (png_ptr->buffer_size < 4)
816 {
817 png_push_save_buffer(png_ptr);
818 return;
819 }
820
821 png_crc_finish(png_ptr, 0);
822 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
823 png_ptr->mode |= PNG_AFTER_IDAT;
824 }
825}
826
827void /* PRIVATE */
828png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
829 png_size_t buffer_length)
830{
831 /* The caller checks for a non-zero buffer length. */
832 if (!(buffer_length > 0) || buffer == NULL)
833 png_error(png_ptr, "No IDAT data (internal error)");
834
835 /* This routine must process all the data it has been given
836 * before returning, calling the row callback as required to
837 * handle the uncompressed results.
838 */
839 png_ptr->zstream.next_in = buffer;
840 png_ptr->zstream.avail_in = (uInt)buffer_length;
841
842 /* Keep going until the decompressed data is all processed
843 * or the stream marked as finished.
844 */
845 while (png_ptr->zstream.avail_in > 0 &&
846 !(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
847 {
848 int ret;
849
850 /* We have data for zlib, but we must check that zlib
851 * has somewhere to put the results. It doesn't matter
852 * if we don't expect any results -- it may be the input
853 * data is just the LZ end code.
854 */
855 if (!(png_ptr->zstream.avail_out > 0))
856 {
857 png_ptr->zstream.avail_out =
858 (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
859 png_ptr->iwidth) + 1;
860 png_ptr->zstream.next_out = png_ptr->row_buf;
861 }
862
863 /* Using Z_SYNC_FLUSH here means that an unterminated
864 * LZ stream can still be handled (a stream with a missing
865 * end code), otherwise (Z_NO_FLUSH) a future zlib
866 * implementation might defer output and, therefore,
867 * change the current behavior. (See comments in inflate.c
868 * for why this doesn't happen at present with zlib 1.2.5.)
869 */
870 ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH);
871
872 /* Check for any failure before proceeding. */
873 if (ret != Z_OK && ret != Z_STREAM_END)
874 {
875 /* Terminate the decompression. */
876 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
877
878 /* This may be a truncated stream (missing or
879 * damaged end code). Treat that as a warning.
880 */
881 if (png_ptr->row_number >= png_ptr->num_rows ||
882 png_ptr->pass > 6)
883 png_warning(png_ptr, "Truncated compressed data in IDAT");
884 else
885 png_error(png_ptr, "Decompression error in IDAT");
886
887 /* Skip the check on unprocessed input */
888 return;
889 }
890
891 /* Did inflate output any data? */
892 if (png_ptr->zstream.next_out != png_ptr->row_buf)
893 {
894 /* Is this unexpected data after the last row?
895 * If it is, artificially terminate the LZ output
896 * here.
897 */
898 if (png_ptr->row_number >= png_ptr->num_rows ||
899 png_ptr->pass > 6)
900 {
901 /* Extra data. */
902 png_warning(png_ptr, "Extra compressed data in IDAT");
903 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
904 /* Do no more processing; skip the unprocessed
905 * input check below.
906 */
907 return;
908 }
909
910 /* Do we have a complete row? */
911 if (png_ptr->zstream.avail_out == 0)
912 png_push_process_row(png_ptr);
913 }
914
915 /* And check for the end of the stream. */
916 if (ret == Z_STREAM_END)
917 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
918 }
919
920 /* All the data should have been processed, if anything
921 * is left at this point we have bytes of IDAT data
922 * after the zlib end code.
923 */
924 if (png_ptr->zstream.avail_in > 0)
925 png_warning(png_ptr, "Extra compression data");
926}
927
928void /* PRIVATE */
929png_push_process_row(png_structp png_ptr)
930{
931 png_ptr->row_info.color_type = png_ptr->color_type;
932 png_ptr->row_info.width = png_ptr->iwidth;
933 png_ptr->row_info.channels = png_ptr->channels;
934 png_ptr->row_info.bit_depth = png_ptr->bit_depth;
935 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
936
937 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
938 png_ptr->row_info.width);
939
940 png_read_filter_row(png_ptr, &(png_ptr->row_info),
941 png_ptr->row_buf + 1, png_ptr->prev_row + 1,
942 (int)(png_ptr->row_buf[0]));
943
944 png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1);
945
946 if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
947 png_do_read_transformations(png_ptr);
948
949#ifdef PNG_READ_INTERLACING_SUPPORTED
950 /* Blow up interlaced rows to full size */
951 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
952 {
953 if (png_ptr->pass < 6)
954/* old interface (pre-1.0.9):
955 png_do_read_interlace(&(png_ptr->row_info),
956 png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
957 */
958 png_do_read_interlace(png_ptr);
959
960 switch (png_ptr->pass)
961 {
962 case 0:
963 {
964 int i;
965 for (i = 0; i < 8 && png_ptr->pass == 0; i++)
966 {
967 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
968 png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
969 }
970
971 if (png_ptr->pass == 2) /* Pass 1 might be empty */
972 {
973 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
974 {
975 png_push_have_row(png_ptr, NULL);
976 png_read_push_finish_row(png_ptr);
977 }
978 }
979
980 if (png_ptr->pass == 4 && png_ptr->height <= 4)
981 {
982 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
983 {
984 png_push_have_row(png_ptr, NULL);
985 png_read_push_finish_row(png_ptr);
986 }
987 }
988
989 if (png_ptr->pass == 6 && png_ptr->height <= 4)
990 {
991 png_push_have_row(png_ptr, NULL);
992 png_read_push_finish_row(png_ptr);
993 }
994
995 break;
996 }
997
998 case 1:
999 {
1000 int i;
1001 for (i = 0; i < 8 && png_ptr->pass == 1; i++)
1002 {
1003 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1004 png_read_push_finish_row(png_ptr);
1005 }
1006
1007 if (png_ptr->pass == 2) /* Skip top 4 generated rows */
1008 {
1009 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
1010 {
1011 png_push_have_row(png_ptr, NULL);
1012 png_read_push_finish_row(png_ptr);
1013 }
1014 }
1015
1016 break;
1017 }
1018
1019 case 2:
1020 {
1021 int i;
1022
1023 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
1024 {
1025 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1026 png_read_push_finish_row(png_ptr);
1027 }
1028
1029 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
1030 {
1031 png_push_have_row(png_ptr, NULL);
1032 png_read_push_finish_row(png_ptr);
1033 }
1034
1035 if (png_ptr->pass == 4) /* Pass 3 might be empty */
1036 {
1037 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1038 {
1039 png_push_have_row(png_ptr, NULL);
1040 png_read_push_finish_row(png_ptr);
1041 }
1042 }
1043
1044 break;
1045 }
1046
1047 case 3:
1048 {
1049 int i;
1050
1051 for (i = 0; i < 4 && png_ptr->pass == 3; 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 == 4) /* Skip top two generated rows */
1058 {
1059 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1060 {
1061 png_push_have_row(png_ptr, NULL);
1062 png_read_push_finish_row(png_ptr);
1063 }
1064 }
1065
1066 break;
1067 }
1068
1069 case 4:
1070 {
1071 int i;
1072
1073 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1074 {
1075 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1076 png_read_push_finish_row(png_ptr);
1077 }
1078
1079 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1080 {
1081 png_push_have_row(png_ptr, NULL);
1082 png_read_push_finish_row(png_ptr);
1083 }
1084
1085 if (png_ptr->pass == 6) /* Pass 5 might be empty */
1086 {
1087 png_push_have_row(png_ptr, NULL);
1088 png_read_push_finish_row(png_ptr);
1089 }
1090
1091 break;
1092 }
1093
1094 case 5:
1095 {
1096 int i;
1097
1098 for (i = 0; i < 2 && png_ptr->pass == 5; i++)
1099 {
1100 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1101 png_read_push_finish_row(png_ptr);
1102 }
1103
1104 if (png_ptr->pass == 6) /* Skip top generated row */
1105 {
1106 png_push_have_row(png_ptr, NULL);
1107 png_read_push_finish_row(png_ptr);
1108 }
1109
1110 break;
1111 }
1112 case 6:
1113 {
1114 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1115 png_read_push_finish_row(png_ptr);
1116
1117 if (png_ptr->pass != 6)
1118 break;
1119
1120 png_push_have_row(png_ptr, NULL);
1121 png_read_push_finish_row(png_ptr);
1122 }
1123 }
1124 }
1125 else
1126#endif
1127 {
1128 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1129 png_read_push_finish_row(png_ptr);
1130 }
1131}
1132
1133void /* PRIVATE */
1134png_read_push_finish_row(png_structp png_ptr)
1135{
1136 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1137
1138 /* Start of interlace block */
1139 PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
1140
1141 /* Offset to next interlace block */
1142 PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
1143
1144 /* Start of interlace block in the y direction */
1145 PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
1146
1147 /* Offset to next interlace block in the y direction */
1148 PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
1149
1150 /* Height of interlace block. This is not currently used - if you need
1151 * it, uncomment it here and in png.h
1152 PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
1153 */
1154
1155 png_ptr->row_number++;
1156 if (png_ptr->row_number < png_ptr->num_rows)
1157 return;
1158
1159#ifdef PNG_READ_INTERLACING_SUPPORTED
1160 if (png_ptr->interlaced)
1161 {
1162 png_ptr->row_number = 0;
1163 png_memset(png_ptr->prev_row, 0,
1164 png_ptr->rowbytes + 1);
1165 do
1166 {
1167 png_ptr->pass++;
1168 if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
1169 (png_ptr->pass == 3 && png_ptr->width < 3) ||
1170 (png_ptr->pass == 5 && png_ptr->width < 2))
1171 png_ptr->pass++;
1172
1173 if (png_ptr->pass > 7)
1174 png_ptr->pass--;
1175
1176 if (png_ptr->pass >= 7)
1177 break;
1178
1179 png_ptr->iwidth = (png_ptr->width +
1180 png_pass_inc[png_ptr->pass] - 1 -
1181 png_pass_start[png_ptr->pass]) /
1182 png_pass_inc[png_ptr->pass];
1183
1184 if (png_ptr->transformations & PNG_INTERLACE)
1185 break;
1186
1187 png_ptr->num_rows = (png_ptr->height +
1188 png_pass_yinc[png_ptr->pass] - 1 -
1189 png_pass_ystart[png_ptr->pass]) /
1190 png_pass_yinc[png_ptr->pass];
1191
1192 } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
1193 }
1194#endif /* PNG_READ_INTERLACING_SUPPORTED */
1195}
1196
1197#ifdef PNG_READ_tEXt_SUPPORTED
1198void /* PRIVATE */
1199png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1200 length)
1201{
1202 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1203 {
1204 png_error(png_ptr, "Out of place tEXt");
1205 info_ptr = info_ptr; /* To quiet some compiler warnings */
1206 }
1207
1208#ifdef PNG_MAX_MALLOC_64K
1209 png_ptr->skip_length = 0; /* This may not be necessary */
1210
1211 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1212 {
1213 png_warning(png_ptr, "tEXt chunk too large to fit in memory");
1214 png_ptr->skip_length = length - (png_uint_32)65535L;
1215 length = (png_uint_32)65535L;
1216 }
1217#endif
1218
1219 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1220 (png_size_t)(length + 1));
1221 png_ptr->current_text[length] = '\0';
1222 png_ptr->current_text_ptr = png_ptr->current_text;
1223 png_ptr->current_text_size = (png_size_t)length;
1224 png_ptr->current_text_left = (png_size_t)length;
1225 png_ptr->process_mode = PNG_READ_tEXt_MODE;
1226}
1227
1228void /* PRIVATE */
1229png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
1230{
1231 if (png_ptr->buffer_size && png_ptr->current_text_left)
1232 {
1233 png_size_t text_size;
1234
1235 if (png_ptr->buffer_size < png_ptr->current_text_left)
1236 text_size = png_ptr->buffer_size;
1237
1238 else
1239 text_size = png_ptr->current_text_left;
1240
1241 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1242 png_ptr->current_text_left -= text_size;
1243 png_ptr->current_text_ptr += text_size;
1244 }
1245 if (!(png_ptr->current_text_left))
1246 {
1247 png_textp text_ptr;
1248 png_charp text;
1249 png_charp key;
1250 int ret;
1251
1252 if (png_ptr->buffer_size < 4)
1253 {
1254 png_push_save_buffer(png_ptr);
1255 return;
1256 }
1257
1258 png_push_crc_finish(png_ptr);
1259
1260#ifdef PNG_MAX_MALLOC_64K
1261 if (png_ptr->skip_length)
1262 return;
1263#endif
1264
1265 key = png_ptr->current_text;
1266
1267 for (text = key; *text; text++)
1268 /* Empty loop */ ;
1269
1270 if (text < key + png_ptr->current_text_size)
1271 text++;
1272
1273 text_ptr = (png_textp)png_malloc(png_ptr,
1274 png_sizeof(png_text));
1275 text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
1276 text_ptr->key = key;
1277#ifdef PNG_iTXt_SUPPORTED
1278 text_ptr->lang = NULL;
1279 text_ptr->lang_key = NULL;
1280#endif
1281 text_ptr->text = text;
1282
1283 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1284
1285 png_free(png_ptr, key);
1286 png_free(png_ptr, text_ptr);
1287 png_ptr->current_text = NULL;
1288
1289 if (ret)
1290 png_warning(png_ptr, "Insufficient memory to store text chunk");
1291 }
1292}
1293#endif
1294
1295#ifdef PNG_READ_zTXt_SUPPORTED
1296void /* PRIVATE */
1297png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1298 length)
1299{
1300 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1301 {
1302 png_error(png_ptr, "Out of place zTXt");
1303 info_ptr = info_ptr; /* To quiet some compiler warnings */
1304 }
1305
1306#ifdef PNG_MAX_MALLOC_64K
1307 /* We can't handle zTXt chunks > 64K, since we don't have enough space
1308 * to be able to store the uncompressed data. Actually, the threshold
1309 * is probably around 32K, but it isn't as definite as 64K is.
1310 */
1311 if (length > (png_uint_32)65535L)
1312 {
1313 png_warning(png_ptr, "zTXt chunk too large to fit in memory");
1314 png_push_crc_skip(png_ptr, length);
1315 return;
1316 }
1317#endif
1318
1319 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1320 (png_size_t)(length + 1));
1321 png_ptr->current_text[length] = '\0';
1322 png_ptr->current_text_ptr = png_ptr->current_text;
1323 png_ptr->current_text_size = (png_size_t)length;
1324 png_ptr->current_text_left = (png_size_t)length;
1325 png_ptr->process_mode = PNG_READ_zTXt_MODE;
1326}
1327
1328void /* PRIVATE */
1329png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
1330{
1331 if (png_ptr->buffer_size && png_ptr->current_text_left)
1332 {
1333 png_size_t text_size;
1334
1335 if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
1336 text_size = png_ptr->buffer_size;
1337
1338 else
1339 text_size = png_ptr->current_text_left;
1340
1341 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1342 png_ptr->current_text_left -= text_size;
1343 png_ptr->current_text_ptr += text_size;
1344 }
1345 if (!(png_ptr->current_text_left))
1346 {
1347 png_textp text_ptr;
1348 png_charp text;
1349 png_charp key;
1350 int ret;
1351 png_size_t text_size, key_size;
1352
1353 if (png_ptr->buffer_size < 4)
1354 {
1355 png_push_save_buffer(png_ptr);
1356 return;
1357 }
1358
1359 png_push_crc_finish(png_ptr);
1360
1361 key = png_ptr->current_text;
1362
1363 for (text = key; *text; text++)
1364 /* Empty loop */ ;
1365
1366 /* zTXt can't have zero text */
1367 if (text >= key + png_ptr->current_text_size)
1368 {
1369 png_ptr->current_text = NULL;
1370 png_free(png_ptr, key);
1371 return;
1372 }
1373
1374 text++;
1375
1376 if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */
1377 {
1378 png_ptr->current_text = NULL;
1379 png_free(png_ptr, key);
1380 return;
1381 }
1382
1383 text++;
1384
1385 png_ptr->zstream.next_in = (png_bytep )text;
1386 png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
1387 (text - key));
1388 png_ptr->zstream.next_out = png_ptr->zbuf;
1389 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1390
1391 key_size = text - key;
1392 text_size = 0;
1393 text = NULL;
1394 ret = Z_STREAM_END;
1395
1396 while (png_ptr->zstream.avail_in)
1397 {
1398 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
1399 if (ret != Z_OK && ret != Z_STREAM_END)
1400 {
1401 inflateReset(&png_ptr->zstream);
1402 png_ptr->zstream.avail_in = 0;
1403 png_ptr->current_text = NULL;
1404 png_free(png_ptr, key);
1405 png_free(png_ptr, text);
1406 return;
1407 }
1408 if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
1409 {
1410 if (text == NULL)
1411 {
1412 text = (png_charp)png_malloc(png_ptr,
1413 (png_ptr->zbuf_size
1414 - png_ptr->zstream.avail_out + key_size + 1));
1415
1416 png_memcpy(text + key_size, png_ptr->zbuf,
1417 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1418
1419 png_memcpy(text, key, key_size);
1420
1421 text_size = key_size + png_ptr->zbuf_size -
1422 png_ptr->zstream.avail_out;
1423
1424 *(text + text_size) = '\0';
1425 }
1426 else
1427 {
1428 png_charp tmp;
1429
1430 tmp = text;
1431 text = (png_charp)png_malloc(png_ptr, text_size +
1432 (png_ptr->zbuf_size
1433 - png_ptr->zstream.avail_out + 1));
1434
1435 png_memcpy(text, tmp, text_size);
1436 png_free(png_ptr, tmp);
1437
1438 png_memcpy(text + text_size, png_ptr->zbuf,
1439 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1440
1441 text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
1442 *(text + text_size) = '\0';
1443 }
1444 if (ret != Z_STREAM_END)
1445 {
1446 png_ptr->zstream.next_out = png_ptr->zbuf;
1447 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1448 }
1449 }
1450 else
1451 {
1452 break;
1453 }
1454
1455 if (ret == Z_STREAM_END)
1456 break;
1457 }
1458
1459 inflateReset(&png_ptr->zstream);
1460 png_ptr->zstream.avail_in = 0;
1461
1462 if (ret != Z_STREAM_END)
1463 {
1464 png_ptr->current_text = NULL;
1465 png_free(png_ptr, key);
1466 png_free(png_ptr, text);
1467 return;
1468 }
1469
1470 png_ptr->current_text = NULL;
1471 png_free(png_ptr, key);
1472 key = text;
1473 text += key_size;
1474
1475 text_ptr = (png_textp)png_malloc(png_ptr,
1476 png_sizeof(png_text));
1477 text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
1478 text_ptr->key = key;
1479#ifdef PNG_iTXt_SUPPORTED
1480 text_ptr->lang = NULL;
1481 text_ptr->lang_key = NULL;
1482#endif
1483 text_ptr->text = text;
1484
1485 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1486
1487 png_free(png_ptr, key);
1488 png_free(png_ptr, text_ptr);
1489
1490 if (ret)
1491 png_warning(png_ptr, "Insufficient memory to store text chunk");
1492 }
1493}
1494#endif
1495
1496#ifdef PNG_READ_iTXt_SUPPORTED
1497void /* PRIVATE */
1498png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1499 length)
1500{
1501 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1502 {
1503 png_error(png_ptr, "Out of place iTXt");
1504 info_ptr = info_ptr; /* To quiet some compiler warnings */
1505 }
1506
1507#ifdef PNG_MAX_MALLOC_64K
1508 png_ptr->skip_length = 0; /* This may not be necessary */
1509
1510 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1511 {
1512 png_warning(png_ptr, "iTXt chunk too large to fit in memory");
1513 png_ptr->skip_length = length - (png_uint_32)65535L;
1514 length = (png_uint_32)65535L;
1515 }
1516#endif
1517
1518 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1519 (png_size_t)(length + 1));
1520 png_ptr->current_text[length] = '\0';
1521 png_ptr->current_text_ptr = png_ptr->current_text;
1522 png_ptr->current_text_size = (png_size_t)length;
1523 png_ptr->current_text_left = (png_size_t)length;
1524 png_ptr->process_mode = PNG_READ_iTXt_MODE;
1525}
1526
1527void /* PRIVATE */
1528png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
1529{
1530
1531 if (png_ptr->buffer_size && png_ptr->current_text_left)
1532 {
1533 png_size_t text_size;
1534
1535 if (png_ptr->buffer_size < png_ptr->current_text_left)
1536 text_size = png_ptr->buffer_size;
1537
1538 else
1539 text_size = png_ptr->current_text_left;
1540
1541 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1542 png_ptr->current_text_left -= text_size;
1543 png_ptr->current_text_ptr += text_size;
1544 }
1545 if (!(png_ptr->current_text_left))
1546 {
1547 png_textp text_ptr;
1548 png_charp key;
1549 int comp_flag;
1550 png_charp lang;
1551 png_charp lang_key;
1552 png_charp text;
1553 int ret;
1554
1555 if (png_ptr->buffer_size < 4)
1556 {
1557 png_push_save_buffer(png_ptr);
1558 return;
1559 }
1560
1561 png_push_crc_finish(png_ptr);
1562
1563#ifdef PNG_MAX_MALLOC_64K
1564 if (png_ptr->skip_length)
1565 return;
1566#endif
1567
1568 key = png_ptr->current_text;
1569
1570 for (lang = key; *lang; lang++)
1571 /* Empty loop */ ;
1572
1573 if (lang < key + png_ptr->current_text_size - 3)
1574 lang++;
1575
1576 comp_flag = *lang++;
1577 lang++; /* Skip comp_type, always zero */
1578
1579 for (lang_key = lang; *lang_key; lang_key++)
1580 /* Empty loop */ ;
1581
1582 lang_key++; /* Skip NUL separator */
1583
1584 text=lang_key;
1585
1586 if (lang_key < key + png_ptr->current_text_size - 1)
1587 {
1588 for (; *text; text++)
1589 /* Empty loop */ ;
1590 }
1591
1592 if (text < key + png_ptr->current_text_size)
1593 text++;
1594
1595 text_ptr = (png_textp)png_malloc(png_ptr,
1596 png_sizeof(png_text));
1597
1598 text_ptr->compression = comp_flag + 2;
1599 text_ptr->key = key;
1600 text_ptr->lang = lang;
1601 text_ptr->lang_key = lang_key;
1602 text_ptr->text = text;
1603 text_ptr->text_length = 0;
1604 text_ptr->itxt_length = png_strlen(text);
1605
1606 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1607
1608 png_ptr->current_text = NULL;
1609
1610 png_free(png_ptr, text_ptr);
1611 if (ret)
1612 png_warning(png_ptr, "Insufficient memory to store iTXt chunk");
1613 }
1614}
1615#endif
1616
1617/* This function is called when we haven't found a handler for this
1618 * chunk. If there isn't a problem with the chunk itself (ie a bad chunk
1619 * name or a critical chunk), the chunk is (currently) silently ignored.
1620 */
1621void /* PRIVATE */
1622png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
1623 length)
1624{
1625 png_uint_32 skip = 0;
1626
1627 if (!(png_ptr->chunk_name[0] & 0x20))
1628 {
1629#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
1630 if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1631 PNG_HANDLE_CHUNK_ALWAYS
1632#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1633 && png_ptr->read_user_chunk_fn == NULL
1634#endif
1635 )
1636#endif
1637 png_chunk_error(png_ptr, "unknown critical chunk");
1638
1639 info_ptr = info_ptr; /* To quiet some compiler warnings */
1640 }
1641
1642#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
1643 if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
1644 {
1645#ifdef PNG_MAX_MALLOC_64K
1646 if (length > (png_uint_32)65535L)
1647 {
1648 png_warning(png_ptr, "unknown chunk too large to fit in memory");
1649 skip = length - (png_uint_32)65535L;
1650 length = (png_uint_32)65535L;
1651 }
1652#endif
1653 png_memcpy((png_charp)png_ptr->unknown_chunk.name,
1654 (png_charp)png_ptr->chunk_name,
1655 png_sizeof(png_ptr->unknown_chunk.name));
1656 png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1]
1657 = '\0';
1658
1659 png_ptr->unknown_chunk.size = (png_size_t)length;
1660
1661 if (length == 0)
1662 png_ptr->unknown_chunk.data = NULL;
1663
1664 else
1665 {
1666 png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,
1667 (png_size_t)length);
1668 png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
1669 }
1670
1671#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1672 if (png_ptr->read_user_chunk_fn != NULL)
1673 {
1674 /* Callback to user unknown chunk handler */
1675 int ret;
1676 ret = (*(png_ptr->read_user_chunk_fn))
1677 (png_ptr, &png_ptr->unknown_chunk);
1678
1679 if (ret < 0)
1680 png_chunk_error(png_ptr, "error in user chunk");
1681
1682 if (ret == 0)
1683 {
1684 if (!(png_ptr->chunk_name[0] & 0x20))
1685 if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1686 PNG_HANDLE_CHUNK_ALWAYS)
1687 png_chunk_error(png_ptr, "unknown critical chunk");
1688 png_set_unknown_chunks(png_ptr, info_ptr,
1689 &png_ptr->unknown_chunk, 1);
1690 }
1691 }
1692
1693 else
1694#endif
1695 png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
1696 png_free(png_ptr, png_ptr->unknown_chunk.data);
1697 png_ptr->unknown_chunk.data = NULL;
1698 }
1699
1700 else
1701#endif
1702 skip=length;
1703 png_push_crc_skip(png_ptr, skip);
1704}
1705
1706void /* PRIVATE */
1707png_push_have_info(png_structp png_ptr, png_infop info_ptr)
1708{
1709 if (png_ptr->info_fn != NULL)
1710 (*(png_ptr->info_fn))(png_ptr, info_ptr);
1711}
1712
1713void /* PRIVATE */
1714png_push_have_end(png_structp png_ptr, png_infop info_ptr)
1715{
1716 if (png_ptr->end_fn != NULL)
1717 (*(png_ptr->end_fn))(png_ptr, info_ptr);
1718}
1719
1720void /* PRIVATE */
1721png_push_have_row(png_structp png_ptr, png_bytep row)
1722{
1723 if (png_ptr->row_fn != NULL)
1724 (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
1725 (int)png_ptr->pass);
1726}
1727
1728void PNGAPI
1729png_progressive_combine_row (png_structp png_ptr,
1730 png_bytep old_row, png_bytep new_row)
1731{
1732 PNG_CONST int FARDATA png_pass_dsp_mask[7] =
1733 {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
1734
1735 if (png_ptr == NULL)
1736 return;
1737
1738 if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */
1739 png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
1740}
1741
1742void PNGAPI
1743png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
1744 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1745 png_progressive_end_ptr end_fn)
1746{
1747 if (png_ptr == NULL)
1748 return;
1749
1750 png_ptr->info_fn = info_fn;
1751 png_ptr->row_fn = row_fn;
1752 png_ptr->end_fn = end_fn;
1753
1754 png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
1755}
1756
1757png_voidp PNGAPI
1758png_get_progressive_ptr(png_structp png_ptr)
1759{
1760 if (png_ptr == NULL)
1761 return (NULL);
1762
1763 return png_ptr->io_ptr;
1764}
1765#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
wxWidgets (Impactor)