1 
2 /* pngset.c - storage of image information into info struct
3  *
4  * Last changed in libpng 1.6.26 [October 20, 2016]
5  * Copyright (c) 1998-2016 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  * The functions here are used during reads to store data from the file
14  * into the info struct, and during writes to store application data
15  * into the info struct for writing into the file.  This abstracts the
16  * info struct and allows us to change the structure in the future.
17  */
18 
19 #include "pngpriv.h"
20 
21 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
22 
23 #ifdef PNG_bKGD_SUPPORTED
24 void PNGAPI
png_set_bKGD(png_const_structrp png_ptr,png_inforp info_ptr,png_const_color_16p background)25 png_set_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
26     png_const_color_16p background)
27 {
28    png_debug1(1, "in %s storage function", "bKGD");
29 
30    if (png_ptr == NULL || info_ptr == NULL || background == NULL)
31       return;
32 
33    info_ptr->background = *background;
34    info_ptr->valid |= PNG_INFO_bKGD;
35 }
36 #endif
37 
38 #ifdef PNG_cHRM_SUPPORTED
39 void PNGFAPI
png_set_cHRM_fixed(png_const_structrp png_ptr,png_inforp info_ptr,png_fixed_point white_x,png_fixed_point white_y,png_fixed_point red_x,png_fixed_point red_y,png_fixed_point green_x,png_fixed_point green_y,png_fixed_point blue_x,png_fixed_point blue_y)40 png_set_cHRM_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
41     png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
42     png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
43     png_fixed_point blue_x, png_fixed_point blue_y)
44 {
45    png_xy xy;
46 
47    png_debug1(1, "in %s storage function", "cHRM fixed");
48 
49    if (png_ptr == NULL || info_ptr == NULL)
50       return;
51 
52    xy.redx = red_x;
53    xy.redy = red_y;
54    xy.greenx = green_x;
55    xy.greeny = green_y;
56    xy.bluex = blue_x;
57    xy.bluey = blue_y;
58    xy.whitex = white_x;
59    xy.whitey = white_y;
60 
61    if (png_colorspace_set_chromaticities(png_ptr, &info_ptr->colorspace, &xy,
62        2/* override with app values*/) != 0)
63       info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
64 
65    png_colorspace_sync_info(png_ptr, info_ptr);
66 }
67 
68 void PNGFAPI
png_set_cHRM_XYZ_fixed(png_const_structrp png_ptr,png_inforp info_ptr,png_fixed_point int_red_X,png_fixed_point int_red_Y,png_fixed_point int_red_Z,png_fixed_point int_green_X,png_fixed_point int_green_Y,png_fixed_point int_green_Z,png_fixed_point int_blue_X,png_fixed_point int_blue_Y,png_fixed_point int_blue_Z)69 png_set_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
70     png_fixed_point int_red_X, png_fixed_point int_red_Y,
71     png_fixed_point int_red_Z, png_fixed_point int_green_X,
72     png_fixed_point int_green_Y, png_fixed_point int_green_Z,
73     png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
74     png_fixed_point int_blue_Z)
75 {
76    png_XYZ XYZ;
77 
78    png_debug1(1, "in %s storage function", "cHRM XYZ fixed");
79 
80    if (png_ptr == NULL || info_ptr == NULL)
81       return;
82 
83    XYZ.red_X = int_red_X;
84    XYZ.red_Y = int_red_Y;
85    XYZ.red_Z = int_red_Z;
86    XYZ.green_X = int_green_X;
87    XYZ.green_Y = int_green_Y;
88    XYZ.green_Z = int_green_Z;
89    XYZ.blue_X = int_blue_X;
90    XYZ.blue_Y = int_blue_Y;
91    XYZ.blue_Z = int_blue_Z;
92 
93    if (png_colorspace_set_endpoints(png_ptr, &info_ptr->colorspace,
94        &XYZ, 2) != 0)
95       info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
96 
97    png_colorspace_sync_info(png_ptr, info_ptr);
98 }
99 
100 #  ifdef PNG_FLOATING_POINT_SUPPORTED
101 void PNGAPI
png_set_cHRM(png_const_structrp png_ptr,png_inforp info_ptr,double white_x,double white_y,double red_x,double red_y,double green_x,double green_y,double blue_x,double blue_y)102 png_set_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
103     double white_x, double white_y, double red_x, double red_y,
104     double green_x, double green_y, double blue_x, double blue_y)
105 {
106    png_set_cHRM_fixed(png_ptr, info_ptr,
107        png_fixed(png_ptr, white_x, "cHRM White X"),
108        png_fixed(png_ptr, white_y, "cHRM White Y"),
109        png_fixed(png_ptr, red_x, "cHRM Red X"),
110        png_fixed(png_ptr, red_y, "cHRM Red Y"),
111        png_fixed(png_ptr, green_x, "cHRM Green X"),
112        png_fixed(png_ptr, green_y, "cHRM Green Y"),
113        png_fixed(png_ptr, blue_x, "cHRM Blue X"),
114        png_fixed(png_ptr, blue_y, "cHRM Blue Y"));
115 }
116 
117 void PNGAPI
png_set_cHRM_XYZ(png_const_structrp png_ptr,png_inforp info_ptr,double red_X,double red_Y,double red_Z,double green_X,double green_Y,double green_Z,double blue_X,double blue_Y,double blue_Z)118 png_set_cHRM_XYZ(png_const_structrp png_ptr, png_inforp info_ptr, double red_X,
119     double red_Y, double red_Z, double green_X, double green_Y, double green_Z,
120     double blue_X, double blue_Y, double blue_Z)
121 {
122    png_set_cHRM_XYZ_fixed(png_ptr, info_ptr,
123        png_fixed(png_ptr, red_X, "cHRM Red X"),
124        png_fixed(png_ptr, red_Y, "cHRM Red Y"),
125        png_fixed(png_ptr, red_Z, "cHRM Red Z"),
126        png_fixed(png_ptr, green_X, "cHRM Green X"),
127        png_fixed(png_ptr, green_Y, "cHRM Green Y"),
128        png_fixed(png_ptr, green_Z, "cHRM Green Z"),
129        png_fixed(png_ptr, blue_X, "cHRM Blue X"),
130        png_fixed(png_ptr, blue_Y, "cHRM Blue Y"),
131        png_fixed(png_ptr, blue_Z, "cHRM Blue Z"));
132 }
133 #  endif /* FLOATING_POINT */
134 
135 #endif /* cHRM */
136 
137 #ifdef PNG_gAMA_SUPPORTED
138 void PNGFAPI
png_set_gAMA_fixed(png_const_structrp png_ptr,png_inforp info_ptr,png_fixed_point file_gamma)139 png_set_gAMA_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
140     png_fixed_point file_gamma)
141 {
142    png_debug1(1, "in %s storage function", "gAMA");
143 
144    if (png_ptr == NULL || info_ptr == NULL)
145       return;
146 
147    png_colorspace_set_gamma(png_ptr, &info_ptr->colorspace, file_gamma);
148    png_colorspace_sync_info(png_ptr, info_ptr);
149 }
150 
151 #  ifdef PNG_FLOATING_POINT_SUPPORTED
152 void PNGAPI
png_set_gAMA(png_const_structrp png_ptr,png_inforp info_ptr,double file_gamma)153 png_set_gAMA(png_const_structrp png_ptr, png_inforp info_ptr, double file_gamma)
154 {
155    png_set_gAMA_fixed(png_ptr, info_ptr, png_fixed(png_ptr, file_gamma,
156        "png_set_gAMA"));
157 }
158 #  endif
159 #endif
160 
161 #ifdef PNG_hIST_SUPPORTED
162 void PNGAPI
png_set_hIST(png_const_structrp png_ptr,png_inforp info_ptr,png_const_uint_16p hist)163 png_set_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
164     png_const_uint_16p hist)
165 {
166    int i;
167 
168    png_debug1(1, "in %s storage function", "hIST");
169 
170    if (png_ptr == NULL || info_ptr == NULL)
171       return;
172 
173    if (info_ptr->num_palette == 0 || info_ptr->num_palette
174        > PNG_MAX_PALETTE_LENGTH)
175    {
176       png_warning(png_ptr,
177           "Invalid palette size, hIST allocation skipped");
178 
179       return;
180    }
181 
182    png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0);
183 
184    /* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in
185     * version 1.2.1
186     */
187    info_ptr->hist = png_voidcast(png_uint_16p, png_malloc_warn(png_ptr,
188        PNG_MAX_PALETTE_LENGTH * (sizeof (png_uint_16))));
189 
190    if (info_ptr->hist == NULL)
191    {
192       png_warning(png_ptr, "Insufficient memory for hIST chunk data");
193 
194       return;
195    }
196 
197    info_ptr->free_me |= PNG_FREE_HIST;
198 
199    for (i = 0; i < info_ptr->num_palette; i++)
200       info_ptr->hist[i] = hist[i];
201 
202    info_ptr->valid |= PNG_INFO_hIST;
203 }
204 #endif
205 
206 void PNGAPI
png_set_IHDR(png_const_structrp png_ptr,png_inforp info_ptr,png_uint_32 width,png_uint_32 height,int bit_depth,int color_type,int interlace_type,int compression_type,int filter_type)207 png_set_IHDR(png_const_structrp png_ptr, png_inforp info_ptr,
208     png_uint_32 width, png_uint_32 height, int bit_depth,
209     int color_type, int interlace_type, int compression_type,
210     int filter_type)
211 {
212    png_debug1(1, "in %s storage function", "IHDR");
213 
214    if (png_ptr == NULL || info_ptr == NULL)
215       return;
216 
217    info_ptr->width = width;
218    info_ptr->height = height;
219    info_ptr->bit_depth = (png_byte)bit_depth;
220    info_ptr->color_type = (png_byte)color_type;
221    info_ptr->compression_type = (png_byte)compression_type;
222    info_ptr->filter_type = (png_byte)filter_type;
223    info_ptr->interlace_type = (png_byte)interlace_type;
224 
225    png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
226        info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
227        info_ptr->compression_type, info_ptr->filter_type);
228 
229    if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
230       info_ptr->channels = 1;
231 
232    else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
233       info_ptr->channels = 3;
234 
235    else
236       info_ptr->channels = 1;
237 
238    if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
239       info_ptr->channels++;
240 
241    info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);
242 
243    info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
244 }
245 
246 #ifdef PNG_oFFs_SUPPORTED
247 void PNGAPI
png_set_oFFs(png_const_structrp png_ptr,png_inforp info_ptr,png_int_32 offset_x,png_int_32 offset_y,int unit_type)248 png_set_oFFs(png_const_structrp png_ptr, png_inforp info_ptr,
249     png_int_32 offset_x, png_int_32 offset_y, int unit_type)
250 {
251    png_debug1(1, "in %s storage function", "oFFs");
252 
253    if (png_ptr == NULL || info_ptr == NULL)
254       return;
255 
256    info_ptr->x_offset = offset_x;
257    info_ptr->y_offset = offset_y;
258    info_ptr->offset_unit_type = (png_byte)unit_type;
259    info_ptr->valid |= PNG_INFO_oFFs;
260 }
261 #endif
262 
263 #ifdef PNG_pCAL_SUPPORTED
264 void PNGAPI
png_set_pCAL(png_const_structrp png_ptr,png_inforp info_ptr,png_const_charp purpose,png_int_32 X0,png_int_32 X1,int type,int nparams,png_const_charp units,png_charpp params)265 png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
266     png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type,
267     int nparams, png_const_charp units, png_charpp params)
268 {
269    png_size_t length;
270    int i;
271 
272    png_debug1(1, "in %s storage function", "pCAL");
273 
274    if (png_ptr == NULL || info_ptr == NULL || purpose == NULL || units == NULL
275        || (nparams > 0 && params == NULL))
276       return;
277 
278    length = strlen(purpose) + 1;
279    png_debug1(3, "allocating purpose for info (%lu bytes)",
280        (unsigned long)length);
281 
282    /* TODO: validate format of calibration name and unit name */
283 
284    /* Check that the type matches the specification. */
285    if (type < 0 || type > 3)
286    {
287       png_chunk_report(png_ptr, "Invalid pCAL equation type",
288             PNG_CHUNK_WRITE_ERROR);
289       return;
290    }
291 
292    if (nparams < 0 || nparams > 255)
293    {
294       png_chunk_report(png_ptr, "Invalid pCAL parameter count",
295             PNG_CHUNK_WRITE_ERROR);
296       return;
297    }
298 
299    /* Validate params[nparams] */
300    for (i=0; i<nparams; ++i)
301    {
302       if (params[i] == NULL ||
303           !png_check_fp_string(params[i], strlen(params[i])))
304       {
305          png_chunk_report(png_ptr, "Invalid format for pCAL parameter",
306                PNG_CHUNK_WRITE_ERROR);
307          return;
308       }
309    }
310 
311    info_ptr->pcal_purpose = png_voidcast(png_charp,
312        png_malloc_warn(png_ptr, length));
313 
314    if (info_ptr->pcal_purpose == NULL)
315    {
316       png_chunk_report(png_ptr, "Insufficient memory for pCAL purpose",
317             PNG_CHUNK_WRITE_ERROR);
318       return;
319    }
320 
321    memcpy(info_ptr->pcal_purpose, purpose, length);
322 
323    png_debug(3, "storing X0, X1, type, and nparams in info");
324    info_ptr->pcal_X0 = X0;
325    info_ptr->pcal_X1 = X1;
326    info_ptr->pcal_type = (png_byte)type;
327    info_ptr->pcal_nparams = (png_byte)nparams;
328 
329    length = strlen(units) + 1;
330    png_debug1(3, "allocating units for info (%lu bytes)",
331        (unsigned long)length);
332 
333    info_ptr->pcal_units = png_voidcast(png_charp,
334        png_malloc_warn(png_ptr, length));
335 
336    if (info_ptr->pcal_units == NULL)
337    {
338       png_warning(png_ptr, "Insufficient memory for pCAL units");
339 
340       return;
341    }
342 
343    memcpy(info_ptr->pcal_units, units, length);
344 
345    info_ptr->pcal_params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
346        (png_size_t)(((unsigned int)nparams + 1) * (sizeof (png_charp)))));
347 
348    if (info_ptr->pcal_params == NULL)
349    {
350       png_warning(png_ptr, "Insufficient memory for pCAL params");
351 
352       return;
353    }
354 
355    memset(info_ptr->pcal_params, 0, ((unsigned int)nparams + 1) *
356        (sizeof (png_charp)));
357 
358    for (i = 0; i < nparams; i++)
359    {
360       length = strlen(params[i]) + 1;
361       png_debug2(3, "allocating parameter %d for info (%lu bytes)", i,
362           (unsigned long)length);
363 
364       info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length);
365 
366       if (info_ptr->pcal_params[i] == NULL)
367       {
368          png_warning(png_ptr, "Insufficient memory for pCAL parameter");
369 
370          return;
371       }
372 
373       memcpy(info_ptr->pcal_params[i], params[i], length);
374    }
375 
376    info_ptr->valid |= PNG_INFO_pCAL;
377    info_ptr->free_me |= PNG_FREE_PCAL;
378 }
379 #endif
380 
381 #ifdef PNG_sCAL_SUPPORTED
382 void PNGAPI
png_set_sCAL_s(png_const_structrp png_ptr,png_inforp info_ptr,int unit,png_const_charp swidth,png_const_charp sheight)383 png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
384     int unit, png_const_charp swidth, png_const_charp sheight)
385 {
386    png_size_t lengthw = 0, lengthh = 0;
387 
388    png_debug1(1, "in %s storage function", "sCAL");
389 
390    if (png_ptr == NULL || info_ptr == NULL)
391       return;
392 
393    /* Double check the unit (should never get here with an invalid
394     * unit unless this is an API call.)
395     */
396    if (unit != 1 && unit != 2)
397       png_error(png_ptr, "Invalid sCAL unit");
398 
399    if (swidth == NULL || (lengthw = strlen(swidth)) == 0 ||
400        swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw))
401       png_error(png_ptr, "Invalid sCAL width");
402 
403    if (sheight == NULL || (lengthh = strlen(sheight)) == 0 ||
404        sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh))
405       png_error(png_ptr, "Invalid sCAL height");
406 
407    info_ptr->scal_unit = (png_byte)unit;
408 
409    ++lengthw;
410 
411    png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw);
412 
413    info_ptr->scal_s_width = png_voidcast(png_charp,
414        png_malloc_warn(png_ptr, lengthw));
415 
416    if (info_ptr->scal_s_width == NULL)
417    {
418       png_warning(png_ptr, "Memory allocation failed while processing sCAL");
419 
420       return;
421    }
422 
423    memcpy(info_ptr->scal_s_width, swidth, lengthw);
424 
425    ++lengthh;
426 
427    png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh);
428 
429    info_ptr->scal_s_height = png_voidcast(png_charp,
430        png_malloc_warn(png_ptr, lengthh));
431 
432    if (info_ptr->scal_s_height == NULL)
433    {
434       png_free (png_ptr, info_ptr->scal_s_width);
435       info_ptr->scal_s_width = NULL;
436 
437       png_warning(png_ptr, "Memory allocation failed while processing sCAL");
438 
439       return;
440    }
441 
442    memcpy(info_ptr->scal_s_height, sheight, lengthh);
443 
444    info_ptr->valid |= PNG_INFO_sCAL;
445    info_ptr->free_me |= PNG_FREE_SCAL;
446 }
447 
448 #  ifdef PNG_FLOATING_POINT_SUPPORTED
449 void PNGAPI
png_set_sCAL(png_const_structrp png_ptr,png_inforp info_ptr,int unit,double width,double height)450 png_set_sCAL(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
451     double width, double height)
452 {
453    png_debug1(1, "in %s storage function", "sCAL");
454 
455    /* Check the arguments. */
456    if (width <= 0)
457       png_warning(png_ptr, "Invalid sCAL width ignored");
458 
459    else if (height <= 0)
460       png_warning(png_ptr, "Invalid sCAL height ignored");
461 
462    else
463    {
464       /* Convert 'width' and 'height' to ASCII. */
465       char swidth[PNG_sCAL_MAX_DIGITS+1];
466       char sheight[PNG_sCAL_MAX_DIGITS+1];
467 
468       png_ascii_from_fp(png_ptr, swidth, (sizeof swidth), width,
469           PNG_sCAL_PRECISION);
470       png_ascii_from_fp(png_ptr, sheight, (sizeof sheight), height,
471           PNG_sCAL_PRECISION);
472 
473       png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
474    }
475 }
476 #  endif
477 
478 #  ifdef PNG_FIXED_POINT_SUPPORTED
479 void PNGAPI
png_set_sCAL_fixed(png_const_structrp png_ptr,png_inforp info_ptr,int unit,png_fixed_point width,png_fixed_point height)480 png_set_sCAL_fixed(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
481     png_fixed_point width, png_fixed_point height)
482 {
483    png_debug1(1, "in %s storage function", "sCAL");
484 
485    /* Check the arguments. */
486    if (width <= 0)
487       png_warning(png_ptr, "Invalid sCAL width ignored");
488 
489    else if (height <= 0)
490       png_warning(png_ptr, "Invalid sCAL height ignored");
491 
492    else
493    {
494       /* Convert 'width' and 'height' to ASCII. */
495       char swidth[PNG_sCAL_MAX_DIGITS+1];
496       char sheight[PNG_sCAL_MAX_DIGITS+1];
497 
498       png_ascii_from_fixed(png_ptr, swidth, (sizeof swidth), width);
499       png_ascii_from_fixed(png_ptr, sheight, (sizeof sheight), height);
500 
501       png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
502    }
503 }
504 #  endif
505 #endif
506 
507 #ifdef PNG_pHYs_SUPPORTED
508 void PNGAPI
png_set_pHYs(png_const_structrp png_ptr,png_inforp info_ptr,png_uint_32 res_x,png_uint_32 res_y,int unit_type)509 png_set_pHYs(png_const_structrp png_ptr, png_inforp info_ptr,
510     png_uint_32 res_x, png_uint_32 res_y, int unit_type)
511 {
512    png_debug1(1, "in %s storage function", "pHYs");
513 
514    if (png_ptr == NULL || info_ptr == NULL)
515       return;
516 
517    info_ptr->x_pixels_per_unit = res_x;
518    info_ptr->y_pixels_per_unit = res_y;
519    info_ptr->phys_unit_type = (png_byte)unit_type;
520    info_ptr->valid |= PNG_INFO_pHYs;
521 }
522 #endif
523 
524 void PNGAPI
png_set_PLTE(png_structrp png_ptr,png_inforp info_ptr,png_const_colorp palette,int num_palette)525 png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
526     png_const_colorp palette, int num_palette)
527 {
528 
529    png_uint_32 max_palette_length;
530 
531    png_debug1(1, "in %s storage function", "PLTE");
532 
533    if (png_ptr == NULL || info_ptr == NULL)
534       return;
535 
536    max_palette_length = (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
537       (1 << info_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
538 
539    if (num_palette < 0 || num_palette > (int) max_palette_length)
540    {
541       if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
542          png_error(png_ptr, "Invalid palette length");
543 
544       else
545       {
546          png_warning(png_ptr, "Invalid palette length");
547 
548          return;
549       }
550    }
551 
552    if ((num_palette > 0 && palette == NULL) ||
553       (num_palette == 0
554 #        ifdef PNG_MNG_FEATURES_SUPPORTED
555             && (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0
556 #        endif
557       ))
558    {
559       png_error(png_ptr, "Invalid palette");
560    }
561 
562    /* It may not actually be necessary to set png_ptr->palette here;
563     * we do it for backward compatibility with the way the png_handle_tRNS
564     * function used to do the allocation.
565     *
566     * 1.6.0: the above statement appears to be incorrect; something has to set
567     * the palette inside png_struct on read.
568     */
569    png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0);
570 
571    /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
572     * of num_palette entries, in case of an invalid PNG file or incorrect
573     * call to png_set_PLTE() with too-large sample values.
574     */
575    png_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr,
576        PNG_MAX_PALETTE_LENGTH * (sizeof (png_color))));
577 
578    if (num_palette > 0)
579       memcpy(png_ptr->palette, palette, (unsigned int)num_palette *
580           (sizeof (png_color)));
581    info_ptr->palette = png_ptr->palette;
582    info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;
583 
584    info_ptr->free_me |= PNG_FREE_PLTE;
585 
586    info_ptr->valid |= PNG_INFO_PLTE;
587 }
588 
589 #ifdef PNG_sBIT_SUPPORTED
590 void PNGAPI
png_set_sBIT(png_const_structrp png_ptr,png_inforp info_ptr,png_const_color_8p sig_bit)591 png_set_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
592     png_const_color_8p sig_bit)
593 {
594    png_debug1(1, "in %s storage function", "sBIT");
595 
596    if (png_ptr == NULL || info_ptr == NULL || sig_bit == NULL)
597       return;
598 
599    info_ptr->sig_bit = *sig_bit;
600    info_ptr->valid |= PNG_INFO_sBIT;
601 }
602 #endif
603 
604 #ifdef PNG_sRGB_SUPPORTED
605 void PNGAPI
png_set_sRGB(png_const_structrp png_ptr,png_inforp info_ptr,int srgb_intent)606 png_set_sRGB(png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent)
607 {
608    png_debug1(1, "in %s storage function", "sRGB");
609 
610    if (png_ptr == NULL || info_ptr == NULL)
611       return;
612 
613    (void)png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent);
614    png_colorspace_sync_info(png_ptr, info_ptr);
615 }
616 
617 void PNGAPI
png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr,png_inforp info_ptr,int srgb_intent)618 png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
619     int srgb_intent)
620 {
621    png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM");
622 
623    if (png_ptr == NULL || info_ptr == NULL)
624       return;
625 
626    if (png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace,
627        srgb_intent) != 0)
628    {
629       /* This causes the gAMA and cHRM to be written too */
630       info_ptr->colorspace.flags |=
631          PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
632    }
633 
634    png_colorspace_sync_info(png_ptr, info_ptr);
635 }
636 #endif /* sRGB */
637 
638 
639 #ifdef PNG_iCCP_SUPPORTED
640 void PNGAPI
png_set_iCCP(png_const_structrp png_ptr,png_inforp info_ptr,png_const_charp name,int compression_type,png_const_bytep profile,png_uint_32 proflen)641 png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
642     png_const_charp name, int compression_type,
643     png_const_bytep profile, png_uint_32 proflen)
644 {
645    png_charp new_iccp_name;
646    png_bytep new_iccp_profile;
647    png_size_t length;
648 
649    png_debug1(1, "in %s storage function", "iCCP");
650 
651    if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL)
652       return;
653 
654    if (compression_type != PNG_COMPRESSION_TYPE_BASE)
655       png_app_error(png_ptr, "Invalid iCCP compression method");
656 
657    /* Set the colorspace first because this validates the profile; do not
658     * override previously set app cHRM or gAMA here (because likely as not the
659     * application knows better than libpng what the correct values are.)  Pass
660     * the info_ptr color_type field to png_colorspace_set_ICC because in the
661     * write case it has not yet been stored in png_ptr.
662     */
663    {
664       int result = png_colorspace_set_ICC(png_ptr, &info_ptr->colorspace, name,
665           proflen, profile, info_ptr->color_type);
666 
667       png_colorspace_sync_info(png_ptr, info_ptr);
668 
669       /* Don't do any of the copying if the profile was bad, or inconsistent. */
670       if (result == 0)
671          return;
672 
673       /* But do write the gAMA and cHRM chunks from the profile. */
674       info_ptr->colorspace.flags |=
675          PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
676    }
677 
678    length = strlen(name)+1;
679    new_iccp_name = png_voidcast(png_charp, png_malloc_warn(png_ptr, length));
680 
681    if (new_iccp_name == NULL)
682    {
683       png_benign_error(png_ptr, "Insufficient memory to process iCCP chunk");
684 
685       return;
686    }
687 
688    memcpy(new_iccp_name, name, length);
689    new_iccp_profile = png_voidcast(png_bytep,
690        png_malloc_warn(png_ptr, proflen));
691 
692    if (new_iccp_profile == NULL)
693    {
694       png_free(png_ptr, new_iccp_name);
695       png_benign_error(png_ptr,
696           "Insufficient memory to process iCCP profile");
697 
698       return;
699    }
700 
701    memcpy(new_iccp_profile, profile, proflen);
702 
703    png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0);
704 
705    info_ptr->iccp_proflen = proflen;
706    info_ptr->iccp_name = new_iccp_name;
707    info_ptr->iccp_profile = new_iccp_profile;
708    info_ptr->free_me |= PNG_FREE_ICCP;
709    info_ptr->valid |= PNG_INFO_iCCP;
710 }
711 #endif
712 
713 #ifdef PNG_TEXT_SUPPORTED
714 void PNGAPI
png_set_text(png_const_structrp png_ptr,png_inforp info_ptr,png_const_textp text_ptr,int num_text)715 png_set_text(png_const_structrp png_ptr, png_inforp info_ptr,
716     png_const_textp text_ptr, int num_text)
717 {
718    int ret;
719    ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text);
720 
721    if (ret != 0)
722       png_error(png_ptr, "Insufficient memory to store text");
723 }
724 
725 int /* PRIVATE */
png_set_text_2(png_const_structrp png_ptr,png_inforp info_ptr,png_const_textp text_ptr,int num_text)726 png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
727     png_const_textp text_ptr, int num_text)
728 {
729    int i;
730 
731    png_debug1(1, "in %lx storage function", png_ptr == NULL ? 0xabadca11U :
732       (unsigned long)png_ptr->chunk_name);
733 
734    if (png_ptr == NULL || info_ptr == NULL || num_text <= 0 || text_ptr == NULL)
735       return(0);
736 
737    /* Make sure we have enough space in the "text" array in info_struct
738     * to hold all of the incoming text_ptr objects.  This compare can't overflow
739     * because max_text >= num_text (anyway, subtract of two positive integers
740     * can't overflow in any case.)
741     */
742    if (num_text > info_ptr->max_text - info_ptr->num_text)
743    {
744       int old_num_text = info_ptr->num_text;
745       int max_text;
746       png_textp new_text = NULL;
747 
748       /* Calculate an appropriate max_text, checking for overflow. */
749       max_text = old_num_text;
750       if (num_text <= INT_MAX - max_text)
751       {
752          max_text += num_text;
753 
754          /* Round up to a multiple of 8 */
755          if (max_text < INT_MAX-8)
756             max_text = (max_text + 8) & ~0x7;
757 
758          else
759             max_text = INT_MAX;
760 
761          /* Now allocate a new array and copy the old members in; this does all
762           * the overflow checks.
763           */
764          new_text = png_voidcast(png_textp,png_realloc_array(png_ptr,
765              info_ptr->text, old_num_text, max_text-old_num_text,
766              sizeof *new_text));
767       }
768 
769       if (new_text == NULL)
770       {
771          png_chunk_report(png_ptr, "too many text chunks",
772              PNG_CHUNK_WRITE_ERROR);
773 
774          return 1;
775       }
776 
777       png_free(png_ptr, info_ptr->text);
778 
779       info_ptr->text = new_text;
780       info_ptr->free_me |= PNG_FREE_TEXT;
781       info_ptr->max_text = max_text;
782       /* num_text is adjusted below as the entries are copied in */
783 
784       png_debug1(3, "allocated %d entries for info_ptr->text", max_text);
785    }
786 
787    for (i = 0; i < num_text; i++)
788    {
789       size_t text_length, key_len;
790       size_t lang_len, lang_key_len;
791       png_textp textp = &(info_ptr->text[info_ptr->num_text]);
792 
793       if (text_ptr[i].key == NULL)
794           continue;
795 
796       if (text_ptr[i].compression < PNG_TEXT_COMPRESSION_NONE ||
797           text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST)
798       {
799          png_chunk_report(png_ptr, "text compression mode is out of range",
800              PNG_CHUNK_WRITE_ERROR);
801          continue;
802       }
803 
804       key_len = strlen(text_ptr[i].key);
805 
806       if (text_ptr[i].compression <= 0)
807       {
808          lang_len = 0;
809          lang_key_len = 0;
810       }
811 
812       else
813 #  ifdef PNG_iTXt_SUPPORTED
814       {
815          /* Set iTXt data */
816 
817          if (text_ptr[i].lang != NULL)
818             lang_len = strlen(text_ptr[i].lang);
819 
820          else
821             lang_len = 0;
822 
823          if (text_ptr[i].lang_key != NULL)
824             lang_key_len = strlen(text_ptr[i].lang_key);
825 
826          else
827             lang_key_len = 0;
828       }
829 #  else /* iTXt */
830       {
831          png_chunk_report(png_ptr, "iTXt chunk not supported",
832              PNG_CHUNK_WRITE_ERROR);
833          continue;
834       }
835 #  endif
836 
837       if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0')
838       {
839          text_length = 0;
840 #  ifdef PNG_iTXt_SUPPORTED
841          if (text_ptr[i].compression > 0)
842             textp->compression = PNG_ITXT_COMPRESSION_NONE;
843 
844          else
845 #  endif
846             textp->compression = PNG_TEXT_COMPRESSION_NONE;
847       }
848 
849       else
850       {
851          text_length = strlen(text_ptr[i].text);
852          textp->compression = text_ptr[i].compression;
853       }
854 
855       textp->key = png_voidcast(png_charp,png_malloc_base(png_ptr,
856           key_len + text_length + lang_len + lang_key_len + 4));
857 
858       if (textp->key == NULL)
859       {
860          png_chunk_report(png_ptr, "text chunk: out of memory",
861              PNG_CHUNK_WRITE_ERROR);
862 
863          return 1;
864       }
865 
866       png_debug2(2, "Allocated %lu bytes at %p in png_set_text",
867           (unsigned long)(png_uint_32)
868           (key_len + lang_len + lang_key_len + text_length + 4),
869           textp->key);
870 
871       memcpy(textp->key, text_ptr[i].key, key_len);
872       *(textp->key + key_len) = '\0';
873 
874       if (text_ptr[i].compression > 0)
875       {
876          textp->lang = textp->key + key_len + 1;
877          memcpy(textp->lang, text_ptr[i].lang, lang_len);
878          *(textp->lang + lang_len) = '\0';
879          textp->lang_key = textp->lang + lang_len + 1;
880          memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
881          *(textp->lang_key + lang_key_len) = '\0';
882          textp->text = textp->lang_key + lang_key_len + 1;
883       }
884 
885       else
886       {
887          textp->lang=NULL;
888          textp->lang_key=NULL;
889          textp->text = textp->key + key_len + 1;
890       }
891 
892       if (text_length != 0)
893          memcpy(textp->text, text_ptr[i].text, text_length);
894 
895       *(textp->text + text_length) = '\0';
896 
897 #  ifdef PNG_iTXt_SUPPORTED
898       if (textp->compression > 0)
899       {
900          textp->text_length = 0;
901          textp->itxt_length = text_length;
902       }
903 
904       else
905 #  endif
906       {
907          textp->text_length = text_length;
908          textp->itxt_length = 0;
909       }
910 
911       info_ptr->num_text++;
912       png_debug1(3, "transferred text chunk %d", info_ptr->num_text);
913    }
914 
915    return(0);
916 }
917 #endif
918 
919 #ifdef PNG_tIME_SUPPORTED
920 void PNGAPI
png_set_tIME(png_const_structrp png_ptr,png_inforp info_ptr,png_const_timep mod_time)921 png_set_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
922     png_const_timep mod_time)
923 {
924    png_debug1(1, "in %s storage function", "tIME");
925 
926    if (png_ptr == NULL || info_ptr == NULL || mod_time == NULL ||
927        (png_ptr->mode & PNG_WROTE_tIME) != 0)
928       return;
929 
930    if (mod_time->month == 0   || mod_time->month > 12  ||
931        mod_time->day   == 0   || mod_time->day   > 31  ||
932        mod_time->hour  > 23   || mod_time->minute > 59 ||
933        mod_time->second > 60)
934    {
935       png_warning(png_ptr, "Ignoring invalid time value");
936 
937       return;
938    }
939 
940    info_ptr->mod_time = *mod_time;
941    info_ptr->valid |= PNG_INFO_tIME;
942 }
943 #endif
944 
945 #ifdef PNG_tRNS_SUPPORTED
946 void PNGAPI
png_set_tRNS(png_structrp png_ptr,png_inforp info_ptr,png_const_bytep trans_alpha,int num_trans,png_const_color_16p trans_color)947 png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
948     png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color)
949 {
950    png_debug1(1, "in %s storage function", "tRNS");
951 
952    if (png_ptr == NULL || info_ptr == NULL)
953 
954       return;
955 
956    if (trans_alpha != NULL)
957    {
958        /* It may not actually be necessary to set png_ptr->trans_alpha here;
959         * we do it for backward compatibility with the way the png_handle_tRNS
960         * function used to do the allocation.
961         *
962         * 1.6.0: The above statement is incorrect; png_handle_tRNS effectively
963         * relies on png_set_tRNS storing the information in png_struct
964         * (otherwise it won't be there for the code in pngrtran.c).
965         */
966 
967        png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
968 
969        if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
970        {
971          /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */
972           info_ptr->trans_alpha = png_voidcast(png_bytep,
973               png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH));
974           memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans);
975        }
976        png_ptr->trans_alpha = info_ptr->trans_alpha;
977    }
978 
979    if (trans_color != NULL)
980    {
981 #ifdef PNG_WARNINGS_SUPPORTED
982       if (info_ptr->bit_depth < 16)
983       {
984          int sample_max = (1 << info_ptr->bit_depth) - 1;
985 
986          if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
987              trans_color->gray > sample_max) ||
988              (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
989              (trans_color->red > sample_max ||
990              trans_color->green > sample_max ||
991              trans_color->blue > sample_max)))
992             png_warning(png_ptr,
993                 "tRNS chunk has out-of-range samples for bit_depth");
994       }
995 #endif
996 
997       info_ptr->trans_color = *trans_color;
998 
999       if (num_trans == 0)
1000          num_trans = 1;
1001    }
1002 
1003    info_ptr->num_trans = (png_uint_16)num_trans;
1004 
1005    if (num_trans != 0)
1006    {
1007       info_ptr->valid |= PNG_INFO_tRNS;
1008       info_ptr->free_me |= PNG_FREE_TRNS;
1009    }
1010 }
1011 #endif
1012 
1013 #ifdef PNG_sPLT_SUPPORTED
1014 void PNGAPI
png_set_sPLT(png_const_structrp png_ptr,png_inforp info_ptr,png_const_sPLT_tp entries,int nentries)1015 png_set_sPLT(png_const_structrp png_ptr,
1016     png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)
1017 /*
1018  *  entries        - array of png_sPLT_t structures
1019  *                   to be added to the list of palettes
1020  *                   in the info structure.
1021  *
1022  *  nentries       - number of palette structures to be
1023  *                   added.
1024  */
1025 {
1026    png_sPLT_tp np;
1027 
1028    if (png_ptr == NULL || info_ptr == NULL || nentries <= 0 || entries == NULL)
1029       return;
1030 
1031    /* Use the internal realloc function, which checks for all the possible
1032     * overflows.  Notice that the parameters are (int) and (size_t)
1033     */
1034    np = png_voidcast(png_sPLT_tp,png_realloc_array(png_ptr,
1035        info_ptr->splt_palettes, info_ptr->splt_palettes_num, nentries,
1036        sizeof *np));
1037 
1038    if (np == NULL)
1039    {
1040       /* Out of memory or too many chunks */
1041       png_chunk_report(png_ptr, "too many sPLT chunks", PNG_CHUNK_WRITE_ERROR);
1042 
1043       return;
1044    }
1045 
1046    png_free(png_ptr, info_ptr->splt_palettes);
1047    info_ptr->splt_palettes = np;
1048    info_ptr->free_me |= PNG_FREE_SPLT;
1049 
1050    np += info_ptr->splt_palettes_num;
1051 
1052    do
1053    {
1054       png_size_t length;
1055 
1056       /* Skip invalid input entries */
1057       if (entries->name == NULL || entries->entries == NULL)
1058       {
1059          /* png_handle_sPLT doesn't do this, so this is an app error */
1060          png_app_error(png_ptr, "png_set_sPLT: invalid sPLT");
1061          /* Just skip the invalid entry */
1062          continue;
1063       }
1064 
1065       np->depth = entries->depth;
1066 
1067       /* In the event of out-of-memory just return - there's no point keeping
1068        * on trying to add sPLT chunks.
1069        */
1070       length = strlen(entries->name) + 1;
1071       np->name = png_voidcast(png_charp, png_malloc_base(png_ptr, length));
1072 
1073       if (np->name == NULL)
1074          break;
1075 
1076       memcpy(np->name, entries->name, length);
1077 
1078       /* IMPORTANT: we have memory now that won't get freed if something else
1079        * goes wrong; this code must free it.  png_malloc_array produces no
1080        * warnings; use a png_chunk_report (below) if there is an error.
1081        */
1082       np->entries = png_voidcast(png_sPLT_entryp, png_malloc_array(png_ptr,
1083           entries->nentries, sizeof (png_sPLT_entry)));
1084 
1085       if (np->entries == NULL)
1086       {
1087          png_free(png_ptr, np->name);
1088          np->name = NULL;
1089          break;
1090       }
1091 
1092       np->nentries = entries->nentries;
1093       /* This multiply can't overflow because png_malloc_array has already
1094        * checked it when doing the allocation.
1095        */
1096       memcpy(np->entries, entries->entries,
1097           (unsigned int)entries->nentries * sizeof (png_sPLT_entry));
1098 
1099       /* Note that 'continue' skips the advance of the out pointer and out
1100        * count, so an invalid entry is not added.
1101        */
1102       info_ptr->valid |= PNG_INFO_sPLT;
1103       ++(info_ptr->splt_palettes_num);
1104       ++np;
1105    }
1106    while (++entries, --nentries);
1107 
1108    if (nentries > 0)
1109       png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR);
1110 }
1111 #endif /* sPLT */
1112 
1113 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1114 static png_byte
check_location(png_const_structrp png_ptr,int location)1115 check_location(png_const_structrp png_ptr, int location)
1116 {
1117    location &= (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT);
1118 
1119    /* New in 1.6.0; copy the location and check it.  This is an API
1120     * change; previously the app had to use the
1121     * png_set_unknown_chunk_location API below for each chunk.
1122     */
1123    if (location == 0 && (png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
1124    {
1125       /* Write struct, so unknown chunks come from the app */
1126       png_app_warning(png_ptr,
1127           "png_set_unknown_chunks now expects a valid location");
1128       /* Use the old behavior */
1129       location = (png_byte)(png_ptr->mode &
1130           (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT));
1131    }
1132 
1133    /* This need not be an internal error - if the app calls
1134     * png_set_unknown_chunks on a read pointer it must get the location right.
1135     */
1136    if (location == 0)
1137       png_error(png_ptr, "invalid location in png_set_unknown_chunks");
1138 
1139    /* Now reduce the location to the top-most set bit by removing each least
1140     * significant bit in turn.
1141     */
1142    while (location != (location & -location))
1143       location &= ~(location & -location);
1144 
1145    /* The cast is safe because 'location' is a bit mask and only the low four
1146     * bits are significant.
1147     */
1148    return (png_byte)location;
1149 }
1150 
1151 void PNGAPI
png_set_unknown_chunks(png_const_structrp png_ptr,png_inforp info_ptr,png_const_unknown_chunkp unknowns,int num_unknowns)1152 png_set_unknown_chunks(png_const_structrp png_ptr,
1153     png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
1154 {
1155    png_unknown_chunkp np;
1156 
1157    if (png_ptr == NULL || info_ptr == NULL || num_unknowns <= 0 ||
1158        unknowns == NULL)
1159       return;
1160 
1161    /* Check for the failure cases where support has been disabled at compile
1162     * time.  This code is hardly ever compiled - it's here because
1163     * STORE_UNKNOWN_CHUNKS is set by both read and write code (compiling in this
1164     * code) but may be meaningless if the read or write handling of unknown
1165     * chunks is not compiled in.
1166     */
1167 #  if !defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) && \
1168       defined(PNG_READ_SUPPORTED)
1169       if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
1170       {
1171          png_app_error(png_ptr, "no unknown chunk support on read");
1172 
1173          return;
1174       }
1175 #  endif
1176 #  if !defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) && \
1177       defined(PNG_WRITE_SUPPORTED)
1178       if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
1179       {
1180          png_app_error(png_ptr, "no unknown chunk support on write");
1181 
1182          return;
1183       }
1184 #  endif
1185 
1186    /* Prior to 1.6.0 this code used png_malloc_warn; however, this meant that
1187     * unknown critical chunks could be lost with just a warning resulting in
1188     * undefined behavior.  Now png_chunk_report is used to provide behavior
1189     * appropriate to read or write.
1190     */
1191    np = png_voidcast(png_unknown_chunkp, png_realloc_array(png_ptr,
1192        info_ptr->unknown_chunks, info_ptr->unknown_chunks_num, num_unknowns,
1193        sizeof *np));
1194 
1195    if (np == NULL)
1196    {
1197       png_chunk_report(png_ptr, "too many unknown chunks",
1198           PNG_CHUNK_WRITE_ERROR);
1199 
1200       return;
1201    }
1202 
1203    png_free(png_ptr, info_ptr->unknown_chunks);
1204    info_ptr->unknown_chunks = np; /* safe because it is initialized */
1205    info_ptr->free_me |= PNG_FREE_UNKN;
1206 
1207    np += info_ptr->unknown_chunks_num;
1208 
1209    /* Increment unknown_chunks_num each time round the loop to protect the
1210     * just-allocated chunk data.
1211     */
1212    for (; num_unknowns > 0; --num_unknowns, ++unknowns)
1213    {
1214       memcpy(np->name, unknowns->name, (sizeof np->name));
1215       np->name[(sizeof np->name)-1] = '\0';
1216       np->location = check_location(png_ptr, unknowns->location);
1217 
1218       if (unknowns->size == 0)
1219       {
1220          np->data = NULL;
1221          np->size = 0;
1222       }
1223 
1224       else
1225       {
1226          np->data = png_voidcast(png_bytep,
1227              png_malloc_base(png_ptr, unknowns->size));
1228 
1229          if (np->data == NULL)
1230          {
1231             png_chunk_report(png_ptr, "unknown chunk: out of memory",
1232                 PNG_CHUNK_WRITE_ERROR);
1233             /* But just skip storing the unknown chunk */
1234             continue;
1235          }
1236 
1237          memcpy(np->data, unknowns->data, unknowns->size);
1238          np->size = unknowns->size;
1239       }
1240 
1241       /* These increments are skipped on out-of-memory for the data - the
1242        * unknown chunk entry gets overwritten if the png_chunk_report returns.
1243        * This is correct in the read case (the chunk is just dropped.)
1244        */
1245       ++np;
1246       ++(info_ptr->unknown_chunks_num);
1247    }
1248 }
1249 
1250 void PNGAPI
png_set_unknown_chunk_location(png_const_structrp png_ptr,png_inforp info_ptr,int chunk,int location)1251 png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
1252     int chunk, int location)
1253 {
1254    /* This API is pretty pointless in 1.6.0 because the location can be set
1255     * before the call to png_set_unknown_chunks.
1256     *
1257     * TODO: add a png_app_warning in 1.7
1258     */
1259    if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 &&
1260       chunk < info_ptr->unknown_chunks_num)
1261    {
1262       if ((location & (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)) == 0)
1263       {
1264          png_app_error(png_ptr, "invalid unknown chunk location");
1265          /* Fake out the pre 1.6.0 behavior: */
1266          if (((unsigned int)location & PNG_HAVE_IDAT) != 0) /* undocumented! */
1267             location = PNG_AFTER_IDAT;
1268 
1269          else
1270             location = PNG_HAVE_IHDR; /* also undocumented */
1271       }
1272 
1273       info_ptr->unknown_chunks[chunk].location =
1274          check_location(png_ptr, location);
1275    }
1276 }
1277 #endif /* STORE_UNKNOWN_CHUNKS */
1278 
1279 #ifdef PNG_MNG_FEATURES_SUPPORTED
1280 png_uint_32 PNGAPI
png_permit_mng_features(png_structrp png_ptr,png_uint_32 mng_features)1281 png_permit_mng_features (png_structrp png_ptr, png_uint_32 mng_features)
1282 {
1283    png_debug(1, "in png_permit_mng_features");
1284 
1285    if (png_ptr == NULL)
1286       return 0;
1287 
1288    png_ptr->mng_features_permitted = mng_features & PNG_ALL_MNG_FEATURES;
1289 
1290    return png_ptr->mng_features_permitted;
1291 }
1292 #endif
1293 
1294 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1295 static unsigned int
add_one_chunk(png_bytep list,unsigned int count,png_const_bytep add,int keep)1296 add_one_chunk(png_bytep list, unsigned int count, png_const_bytep add, int keep)
1297 {
1298    unsigned int i;
1299 
1300    /* Utility function: update the 'keep' state of a chunk if it is already in
1301     * the list, otherwise add it to the list.
1302     */
1303    for (i=0; i<count; ++i, list += 5)
1304    {
1305       if (memcmp(list, add, 4) == 0)
1306       {
1307          list[4] = (png_byte)keep;
1308 
1309          return count;
1310       }
1311    }
1312 
1313    if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT)
1314    {
1315       ++count;
1316       memcpy(list, add, 4);
1317       list[4] = (png_byte)keep;
1318    }
1319 
1320    return count;
1321 }
1322 
1323 void PNGAPI
png_set_keep_unknown_chunks(png_structrp png_ptr,int keep,png_const_bytep chunk_list,int num_chunks_in)1324 png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
1325     png_const_bytep chunk_list, int num_chunks_in)
1326 {
1327    png_bytep new_list;
1328    unsigned int num_chunks, old_num_chunks;
1329 
1330    if (png_ptr == NULL)
1331       return;
1332 
1333    if (keep < 0 || keep >= PNG_HANDLE_CHUNK_LAST)
1334    {
1335       png_app_error(png_ptr, "png_set_keep_unknown_chunks: invalid keep");
1336 
1337       return;
1338    }
1339 
1340    if (num_chunks_in <= 0)
1341    {
1342       png_ptr->unknown_default = keep;
1343 
1344       /* '0' means just set the flags, so stop here */
1345       if (num_chunks_in == 0)
1346         return;
1347    }
1348 
1349    if (num_chunks_in < 0)
1350    {
1351       /* Ignore all unknown chunks and all chunks recognized by
1352        * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND
1353        */
1354       static PNG_CONST png_byte chunks_to_ignore[] = {
1355          98,  75,  71,  68, '\0',  /* bKGD */
1356          99,  72,  82,  77, '\0',  /* cHRM */
1357         103,  65,  77,  65, '\0',  /* gAMA */
1358         104,  73,  83,  84, '\0',  /* hIST */
1359         105,  67,  67,  80, '\0',  /* iCCP */
1360         105,  84,  88, 116, '\0',  /* iTXt */
1361         111,  70,  70, 115, '\0',  /* oFFs */
1362         112,  67,  65,  76, '\0',  /* pCAL */
1363         112,  72,  89, 115, '\0',  /* pHYs */
1364         115,  66,  73,  84, '\0',  /* sBIT */
1365         115,  67,  65,  76, '\0',  /* sCAL */
1366         115,  80,  76,  84, '\0',  /* sPLT */
1367         115,  84,  69,  82, '\0',  /* sTER */
1368         115,  82,  71,  66, '\0',  /* sRGB */
1369         116,  69,  88, 116, '\0',  /* tEXt */
1370         116,  73,  77,  69, '\0',  /* tIME */
1371         122,  84,  88, 116, '\0'   /* zTXt */
1372       };
1373 
1374       chunk_list = chunks_to_ignore;
1375       num_chunks = (unsigned int)/*SAFE*/(sizeof chunks_to_ignore)/5U;
1376    }
1377 
1378    else /* num_chunks_in > 0 */
1379    {
1380       if (chunk_list == NULL)
1381       {
1382          /* Prior to 1.6.0 this was silently ignored, now it is an app_error
1383           * which can be switched off.
1384           */
1385          png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list");
1386 
1387          return;
1388       }
1389 
1390       num_chunks = (unsigned int)num_chunks_in;
1391    }
1392 
1393    old_num_chunks = png_ptr->num_chunk_list;
1394    if (png_ptr->chunk_list == NULL)
1395       old_num_chunks = 0;
1396 
1397    /* Since num_chunks is always restricted to UINT_MAX/5 this can't overflow.
1398     */
1399    if (num_chunks + old_num_chunks > UINT_MAX/5)
1400    {
1401       png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks");
1402 
1403       return;
1404    }
1405 
1406    /* If these chunks are being reset to the default then no more memory is
1407     * required because add_one_chunk above doesn't extend the list if the 'keep'
1408     * parameter is the default.
1409     */
1410    if (keep != 0)
1411    {
1412       new_list = png_voidcast(png_bytep, png_malloc(png_ptr,
1413           5 * (num_chunks + old_num_chunks)));
1414 
1415       if (old_num_chunks > 0)
1416          memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks);
1417    }
1418 
1419    else if (old_num_chunks > 0)
1420       new_list = png_ptr->chunk_list;
1421 
1422    else
1423       new_list = NULL;
1424 
1425    /* Add the new chunks together with each one's handling code.  If the chunk
1426     * already exists the code is updated, otherwise the chunk is added to the
1427     * end.  (In libpng 1.6.0 order no longer matters because this code enforces
1428     * the earlier convention that the last setting is the one that is used.)
1429     */
1430    if (new_list != NULL)
1431    {
1432       png_const_bytep inlist;
1433       png_bytep outlist;
1434       unsigned int i;
1435 
1436       for (i=0; i<num_chunks; ++i)
1437       {
1438          old_num_chunks = add_one_chunk(new_list, old_num_chunks,
1439              chunk_list+5*i, keep);
1440       }
1441 
1442       /* Now remove any spurious 'default' entries. */
1443       num_chunks = 0;
1444       for (i=0, inlist=outlist=new_list; i<old_num_chunks; ++i, inlist += 5)
1445       {
1446          if (inlist[4])
1447          {
1448             if (outlist != inlist)
1449                memcpy(outlist, inlist, 5);
1450             outlist += 5;
1451             ++num_chunks;
1452          }
1453       }
1454 
1455       /* This means the application has removed all the specialized handling. */
1456       if (num_chunks == 0)
1457       {
1458          if (png_ptr->chunk_list != new_list)
1459             png_free(png_ptr, new_list);
1460 
1461          new_list = NULL;
1462       }
1463    }
1464 
1465    else
1466       num_chunks = 0;
1467 
1468    png_ptr->num_chunk_list = num_chunks;
1469 
1470    if (png_ptr->chunk_list != new_list)
1471    {
1472       if (png_ptr->chunk_list != NULL)
1473          png_free(png_ptr, png_ptr->chunk_list);
1474 
1475       png_ptr->chunk_list = new_list;
1476    }
1477 }
1478 #endif
1479 
1480 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1481 void PNGAPI
png_set_read_user_chunk_fn(png_structrp png_ptr,png_voidp user_chunk_ptr,png_user_chunk_ptr read_user_chunk_fn)1482 png_set_read_user_chunk_fn(png_structrp png_ptr, png_voidp user_chunk_ptr,
1483     png_user_chunk_ptr read_user_chunk_fn)
1484 {
1485    png_debug(1, "in png_set_read_user_chunk_fn");
1486 
1487    if (png_ptr == NULL)
1488       return;
1489 
1490    png_ptr->read_user_chunk_fn = read_user_chunk_fn;
1491    png_ptr->user_chunk_ptr = user_chunk_ptr;
1492 }
1493 #endif
1494 
1495 #ifdef PNG_INFO_IMAGE_SUPPORTED
1496 void PNGAPI
png_set_rows(png_const_structrp png_ptr,png_inforp info_ptr,png_bytepp row_pointers)1497 png_set_rows(png_const_structrp png_ptr, png_inforp info_ptr,
1498     png_bytepp row_pointers)
1499 {
1500    png_debug1(1, "in %s storage function", "rows");
1501 
1502    if (png_ptr == NULL || info_ptr == NULL)
1503       return;
1504 
1505    if (info_ptr->row_pointers != NULL &&
1506        (info_ptr->row_pointers != row_pointers))
1507       png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
1508 
1509    info_ptr->row_pointers = row_pointers;
1510 
1511    if (row_pointers != NULL)
1512       info_ptr->valid |= PNG_INFO_IDAT;
1513 }
1514 #endif
1515 
1516 void PNGAPI
png_set_compression_buffer_size(png_structrp png_ptr,png_size_t size)1517 png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size)
1518 {
1519    if (png_ptr == NULL)
1520       return;
1521 
1522    if (size == 0 || size > PNG_UINT_31_MAX)
1523       png_error(png_ptr, "invalid compression buffer size");
1524 
1525 #  ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1526    if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
1527    {
1528       png_ptr->IDAT_read_size = (png_uint_32)size; /* checked above */
1529       return;
1530    }
1531 #  endif
1532 
1533 #  ifdef PNG_WRITE_SUPPORTED
1534    if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
1535    {
1536       if (png_ptr->zowner != 0)
1537       {
1538          png_warning(png_ptr,
1539              "Compression buffer size cannot be changed because it is in use");
1540 
1541          return;
1542       }
1543 
1544 #ifndef __COVERITY__
1545       /* Some compilers complain that this is always false.  However, it
1546        * can be true when integer overflow happens.
1547        */
1548       if (size > ZLIB_IO_MAX)
1549       {
1550          png_warning(png_ptr,
1551              "Compression buffer size limited to system maximum");
1552          size = ZLIB_IO_MAX; /* must fit */
1553       }
1554 #endif
1555 
1556       if (size < 6)
1557       {
1558          /* Deflate will potentially go into an infinite loop on a SYNC_FLUSH
1559           * if this is permitted.
1560           */
1561          png_warning(png_ptr,
1562              "Compression buffer size cannot be reduced below 6");
1563 
1564          return;
1565       }
1566 
1567       if (png_ptr->zbuffer_size != size)
1568       {
1569          png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
1570          png_ptr->zbuffer_size = (uInt)size;
1571       }
1572    }
1573 #  endif
1574 }
1575 
1576 void PNGAPI
png_set_invalid(png_const_structrp png_ptr,png_inforp info_ptr,int mask)1577 png_set_invalid(png_const_structrp png_ptr, png_inforp info_ptr, int mask)
1578 {
1579    if (png_ptr != NULL && info_ptr != NULL)
1580       info_ptr->valid &= (unsigned int)(~mask);
1581 }
1582 
1583 
1584 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
1585 /* This function was added to libpng 1.2.6 */
1586 void PNGAPI
png_set_user_limits(png_structrp png_ptr,png_uint_32 user_width_max,png_uint_32 user_height_max)1587 png_set_user_limits (png_structrp png_ptr, png_uint_32 user_width_max,
1588     png_uint_32 user_height_max)
1589 {
1590    /* Images with dimensions larger than these limits will be
1591     * rejected by png_set_IHDR().  To accept any PNG datastream
1592     * regardless of dimensions, set both limits to 0x7fffffff.
1593     */
1594    if (png_ptr == NULL)
1595       return;
1596 
1597    png_ptr->user_width_max = user_width_max;
1598    png_ptr->user_height_max = user_height_max;
1599 }
1600 
1601 /* This function was added to libpng 1.4.0 */
1602 void PNGAPI
png_set_chunk_cache_max(png_structrp png_ptr,png_uint_32 user_chunk_cache_max)1603 png_set_chunk_cache_max (png_structrp png_ptr, png_uint_32 user_chunk_cache_max)
1604 {
1605    if (png_ptr != NULL)
1606       png_ptr->user_chunk_cache_max = user_chunk_cache_max;
1607 }
1608 
1609 /* This function was added to libpng 1.4.1 */
1610 void PNGAPI
png_set_chunk_malloc_max(png_structrp png_ptr,png_alloc_size_t user_chunk_malloc_max)1611 png_set_chunk_malloc_max (png_structrp png_ptr,
1612     png_alloc_size_t user_chunk_malloc_max)
1613 {
1614    if (png_ptr != NULL)
1615       png_ptr->user_chunk_malloc_max = user_chunk_malloc_max;
1616 }
1617 #endif /* ?SET_USER_LIMITS */
1618 
1619 
1620 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1621 void PNGAPI
png_set_benign_errors(png_structrp png_ptr,int allowed)1622 png_set_benign_errors(png_structrp png_ptr, int allowed)
1623 {
1624    png_debug(1, "in png_set_benign_errors");
1625 
1626    /* If allowed is 1, png_benign_error() is treated as a warning.
1627     *
1628     * If allowed is 0, png_benign_error() is treated as an error (which
1629     * is the default behavior if png_set_benign_errors() is not called).
1630     */
1631 
1632    if (allowed != 0)
1633       png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN |
1634          PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN;
1635 
1636    else
1637       png_ptr->flags &= ~(PNG_FLAG_BENIGN_ERRORS_WARN |
1638          PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN);
1639 }
1640 #endif /* BENIGN_ERRORS */
1641 
1642 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
1643    /* Whether to report invalid palette index; added at libng-1.5.10.
1644     * It is possible for an indexed (color-type==3) PNG file to contain
1645     * pixels with invalid (out-of-range) indexes if the PLTE chunk has
1646     * fewer entries than the image's bit-depth would allow. We recover
1647     * from this gracefully by filling any incomplete palette with zeros
1648     * (opaque black).  By default, when this occurs libpng will issue
1649     * a benign error.  This API can be used to override that behavior.
1650     */
1651 void PNGAPI
png_set_check_for_invalid_index(png_structrp png_ptr,int allowed)1652 png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)
1653 {
1654    png_debug(1, "in png_set_check_for_invalid_index");
1655 
1656    if (allowed > 0)
1657       png_ptr->num_palette_max = 0;
1658 
1659    else
1660       png_ptr->num_palette_max = -1;
1661 }
1662 #endif
1663 
1664 #if defined(PNG_TEXT_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) || \
1665     defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
1666 /* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
1667  * and if invalid, correct the keyword rather than discarding the entire
1668  * chunk.  The PNG 1.0 specification requires keywords 1-79 characters in
1669  * length, forbids leading or trailing whitespace, multiple internal spaces,
1670  * and the non-break space (0x80) from ISO 8859-1.  Returns keyword length.
1671  *
1672  * The 'new_key' buffer must be 80 characters in size (for the keyword plus a
1673  * trailing '\0').  If this routine returns 0 then there was no keyword, or a
1674  * valid one could not be generated, and the caller must png_error.
1675  */
1676 png_uint_32 /* PRIVATE */
png_check_keyword(png_structrp png_ptr,png_const_charp key,png_bytep new_key)1677 png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
1678 {
1679 #ifdef PNG_WARNINGS_SUPPORTED
1680    png_const_charp orig_key = key;
1681 #endif
1682    png_uint_32 key_len = 0;
1683    int bad_character = 0;
1684    int space = 1;
1685 
1686    png_debug(1, "in png_check_keyword");
1687 
1688    if (key == NULL)
1689    {
1690       *new_key = 0;
1691       return 0;
1692    }
1693 
1694    while (*key && key_len < 79)
1695    {
1696       png_byte ch = (png_byte)*key++;
1697 
1698       if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/))
1699          *new_key++ = ch, ++key_len, space = 0;
1700 
1701       else if (space == 0)
1702       {
1703          /* A space or an invalid character when one wasn't seen immediately
1704           * before; output just a space.
1705           */
1706          *new_key++ = 32, ++key_len, space = 1;
1707 
1708          /* If the character was not a space then it is invalid. */
1709          if (ch != 32)
1710             bad_character = ch;
1711       }
1712 
1713       else if (bad_character == 0)
1714          bad_character = ch; /* just skip it, record the first error */
1715    }
1716 
1717    if (key_len > 0 && space != 0) /* trailing space */
1718    {
1719       --key_len, --new_key;
1720       if (bad_character == 0)
1721          bad_character = 32;
1722    }
1723 
1724    /* Terminate the keyword */
1725    *new_key = 0;
1726 
1727    if (key_len == 0)
1728       return 0;
1729 
1730 #ifdef PNG_WARNINGS_SUPPORTED
1731    /* Try to only output one warning per keyword: */
1732    if (*key != 0) /* keyword too long */
1733       png_warning(png_ptr, "keyword truncated");
1734 
1735    else if (bad_character != 0)
1736    {
1737       PNG_WARNING_PARAMETERS(p)
1738 
1739       png_warning_parameter(p, 1, orig_key);
1740       png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character);
1741 
1742       png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'");
1743    }
1744 #else /* !WARNINGS */
1745    PNG_UNUSED(png_ptr)
1746 #endif /* !WARNINGS */
1747 
1748    return key_len;
1749 }
1750 #endif /* TEXT || pCAL || iCCP || sPLT */
1751 #endif /* READ || WRITE */
1752