1 
2 /* pngset.c - storage of image information into info struct
3  *
4  * Last changed in libpng 1.6.21 [(PENDING RELEASE)]
5  * Copyright (c) 1998-2015 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       png_error(png_ptr, "Invalid pCAL equation type");
287 
288    if (nparams < 0 || nparams > 255)
289       png_error(png_ptr, "Invalid pCAL parameter count");
290 
291    /* Validate params[nparams] */
292    for (i=0; i<nparams; ++i)
293    {
294       if (params[i] == NULL ||
295           !png_check_fp_string(params[i], strlen(params[i])))
296          png_error(png_ptr, "Invalid format for pCAL parameter");
297    }
298 
299    info_ptr->pcal_purpose = png_voidcast(png_charp,
300        png_malloc_warn(png_ptr, length));
301 
302    if (info_ptr->pcal_purpose == NULL)
303    {
304       png_warning(png_ptr, "Insufficient memory for pCAL purpose");
305 
306       return;
307    }
308 
309    memcpy(info_ptr->pcal_purpose, purpose, length);
310 
311    png_debug(3, "storing X0, X1, type, and nparams in info");
312    info_ptr->pcal_X0 = X0;
313    info_ptr->pcal_X1 = X1;
314    info_ptr->pcal_type = (png_byte)type;
315    info_ptr->pcal_nparams = (png_byte)nparams;
316 
317    length = strlen(units) + 1;
318    png_debug1(3, "allocating units for info (%lu bytes)",
319      (unsigned long)length);
320 
321    info_ptr->pcal_units = png_voidcast(png_charp,
322       png_malloc_warn(png_ptr, length));
323 
324    if (info_ptr->pcal_units == NULL)
325    {
326       png_warning(png_ptr, "Insufficient memory for pCAL units");
327 
328       return;
329    }
330 
331    memcpy(info_ptr->pcal_units, units, length);
332 
333    info_ptr->pcal_params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
334        (png_size_t)((nparams + 1) * (sizeof (png_charp)))));
335 
336    if (info_ptr->pcal_params == NULL)
337    {
338       png_warning(png_ptr, "Insufficient memory for pCAL params");
339 
340       return;
341    }
342 
343    memset(info_ptr->pcal_params, 0, (nparams + 1) * (sizeof (png_charp)));
344 
345    for (i = 0; i < nparams; i++)
346    {
347       length = strlen(params[i]) + 1;
348       png_debug2(3, "allocating parameter %d for info (%lu bytes)", i,
349           (unsigned long)length);
350 
351       info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length);
352 
353       if (info_ptr->pcal_params[i] == NULL)
354       {
355          png_warning(png_ptr, "Insufficient memory for pCAL parameter");
356 
357          return;
358       }
359 
360       memcpy(info_ptr->pcal_params[i], params[i], length);
361    }
362 
363    info_ptr->valid |= PNG_INFO_pCAL;
364    info_ptr->free_me |= PNG_FREE_PCAL;
365 }
366 #endif
367 
368 #ifdef PNG_sCAL_SUPPORTED
369 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)370 png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
371     int unit, png_const_charp swidth, png_const_charp sheight)
372 {
373    png_size_t lengthw = 0, lengthh = 0;
374 
375    png_debug1(1, "in %s storage function", "sCAL");
376 
377    if (png_ptr == NULL || info_ptr == NULL)
378       return;
379 
380    /* Double check the unit (should never get here with an invalid
381     * unit unless this is an API call.)
382     */
383    if (unit != 1 && unit != 2)
384       png_error(png_ptr, "Invalid sCAL unit");
385 
386    if (swidth == NULL || (lengthw = strlen(swidth)) == 0 ||
387        swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw))
388       png_error(png_ptr, "Invalid sCAL width");
389 
390    if (sheight == NULL || (lengthh = strlen(sheight)) == 0 ||
391        sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh))
392       png_error(png_ptr, "Invalid sCAL height");
393 
394    info_ptr->scal_unit = (png_byte)unit;
395 
396    ++lengthw;
397 
398    png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw);
399 
400    info_ptr->scal_s_width = png_voidcast(png_charp,
401       png_malloc_warn(png_ptr, lengthw));
402 
403    if (info_ptr->scal_s_width == NULL)
404    {
405       png_warning(png_ptr, "Memory allocation failed while processing sCAL");
406 
407       return;
408    }
409 
410    memcpy(info_ptr->scal_s_width, swidth, lengthw);
411 
412    ++lengthh;
413 
414    png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh);
415 
416    info_ptr->scal_s_height = png_voidcast(png_charp,
417       png_malloc_warn(png_ptr, lengthh));
418 
419    if (info_ptr->scal_s_height == NULL)
420    {
421       png_free (png_ptr, info_ptr->scal_s_width);
422       info_ptr->scal_s_width = NULL;
423 
424       png_warning(png_ptr, "Memory allocation failed while processing sCAL");
425 
426       return;
427    }
428 
429    memcpy(info_ptr->scal_s_height, sheight, lengthh);
430 
431    info_ptr->valid |= PNG_INFO_sCAL;
432    info_ptr->free_me |= PNG_FREE_SCAL;
433 }
434 
435 #  ifdef PNG_FLOATING_POINT_SUPPORTED
436 void PNGAPI
png_set_sCAL(png_const_structrp png_ptr,png_inforp info_ptr,int unit,double width,double height)437 png_set_sCAL(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
438     double width, double height)
439 {
440    png_debug1(1, "in %s storage function", "sCAL");
441 
442    /* Check the arguments. */
443    if (width <= 0)
444       png_warning(png_ptr, "Invalid sCAL width ignored");
445 
446    else if (height <= 0)
447       png_warning(png_ptr, "Invalid sCAL height ignored");
448 
449    else
450    {
451       /* Convert 'width' and 'height' to ASCII. */
452       char swidth[PNG_sCAL_MAX_DIGITS+1];
453       char sheight[PNG_sCAL_MAX_DIGITS+1];
454 
455       png_ascii_from_fp(png_ptr, swidth, (sizeof swidth), width,
456          PNG_sCAL_PRECISION);
457       png_ascii_from_fp(png_ptr, sheight, (sizeof sheight), height,
458          PNG_sCAL_PRECISION);
459 
460       png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
461    }
462 }
463 #  endif
464 
465 #  ifdef PNG_FIXED_POINT_SUPPORTED
466 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)467 png_set_sCAL_fixed(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
468     png_fixed_point width, png_fixed_point height)
469 {
470    png_debug1(1, "in %s storage function", "sCAL");
471 
472    /* Check the arguments. */
473    if (width <= 0)
474       png_warning(png_ptr, "Invalid sCAL width ignored");
475 
476    else if (height <= 0)
477       png_warning(png_ptr, "Invalid sCAL height ignored");
478 
479    else
480    {
481       /* Convert 'width' and 'height' to ASCII. */
482       char swidth[PNG_sCAL_MAX_DIGITS+1];
483       char sheight[PNG_sCAL_MAX_DIGITS+1];
484 
485       png_ascii_from_fixed(png_ptr, swidth, (sizeof swidth), width);
486       png_ascii_from_fixed(png_ptr, sheight, (sizeof sheight), height);
487 
488       png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
489    }
490 }
491 #  endif
492 #endif
493 
494 #ifdef PNG_pHYs_SUPPORTED
495 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)496 png_set_pHYs(png_const_structrp png_ptr, png_inforp info_ptr,
497     png_uint_32 res_x, png_uint_32 res_y, int unit_type)
498 {
499    png_debug1(1, "in %s storage function", "pHYs");
500 
501    if (png_ptr == NULL || info_ptr == NULL)
502       return;
503 
504    info_ptr->x_pixels_per_unit = res_x;
505    info_ptr->y_pixels_per_unit = res_y;
506    info_ptr->phys_unit_type = (png_byte)unit_type;
507    info_ptr->valid |= PNG_INFO_pHYs;
508 }
509 #endif
510 
511 void PNGAPI
png_set_PLTE(png_structrp png_ptr,png_inforp info_ptr,png_const_colorp palette,int num_palette)512 png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
513     png_const_colorp palette, int num_palette)
514 {
515 
516    png_uint_32 max_palette_length;
517 
518    png_debug1(1, "in %s storage function", "PLTE");
519 
520    if (png_ptr == NULL || info_ptr == NULL)
521       return;
522 
523    max_palette_length = (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
524       (1 << info_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
525 
526    if (num_palette < 0 || num_palette > (int) max_palette_length)
527    {
528       if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
529          png_error(png_ptr, "Invalid palette length");
530 
531       else
532       {
533          png_warning(png_ptr, "Invalid palette length");
534 
535          return;
536       }
537    }
538 
539    if ((num_palette > 0 && palette == NULL) ||
540       (num_palette == 0
541 #        ifdef PNG_MNG_FEATURES_SUPPORTED
542             && (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0
543 #        endif
544       ))
545    {
546       png_error(png_ptr, "Invalid palette");
547    }
548 
549    /* It may not actually be necessary to set png_ptr->palette here;
550     * we do it for backward compatibility with the way the png_handle_tRNS
551     * function used to do the allocation.
552     *
553     * 1.6.0: the above statement appears to be incorrect; something has to set
554     * the palette inside png_struct on read.
555     */
556    png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0);
557 
558    /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
559     * of num_palette entries, in case of an invalid PNG file or incorrect
560     * call to png_set_PLTE() with too-large sample values.
561     */
562    png_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr,
563        PNG_MAX_PALETTE_LENGTH * (sizeof (png_color))));
564 
565    if (num_palette > 0)
566       memcpy(png_ptr->palette, palette, num_palette * (sizeof (png_color)));
567    info_ptr->palette = png_ptr->palette;
568    info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;
569 
570    info_ptr->free_me |= PNG_FREE_PLTE;
571 
572    info_ptr->valid |= PNG_INFO_PLTE;
573 }
574 
575 #ifdef PNG_sBIT_SUPPORTED
576 void PNGAPI
png_set_sBIT(png_const_structrp png_ptr,png_inforp info_ptr,png_const_color_8p sig_bit)577 png_set_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
578     png_const_color_8p sig_bit)
579 {
580    png_debug1(1, "in %s storage function", "sBIT");
581 
582    if (png_ptr == NULL || info_ptr == NULL || sig_bit == NULL)
583       return;
584 
585    info_ptr->sig_bit = *sig_bit;
586    info_ptr->valid |= PNG_INFO_sBIT;
587 }
588 #endif
589 
590 #ifdef PNG_sRGB_SUPPORTED
591 void PNGAPI
png_set_sRGB(png_const_structrp png_ptr,png_inforp info_ptr,int srgb_intent)592 png_set_sRGB(png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent)
593 {
594    png_debug1(1, "in %s storage function", "sRGB");
595 
596    if (png_ptr == NULL || info_ptr == NULL)
597       return;
598 
599    (void)png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent);
600    png_colorspace_sync_info(png_ptr, info_ptr);
601 }
602 
603 void PNGAPI
png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr,png_inforp info_ptr,int srgb_intent)604 png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
605     int srgb_intent)
606 {
607    png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM");
608 
609    if (png_ptr == NULL || info_ptr == NULL)
610       return;
611 
612    if (png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace,
613        srgb_intent) != 0)
614    {
615       /* This causes the gAMA and cHRM to be written too */
616       info_ptr->colorspace.flags |=
617          PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
618    }
619 
620    png_colorspace_sync_info(png_ptr, info_ptr);
621 }
622 #endif /* sRGB */
623 
624 
625 #ifdef PNG_iCCP_SUPPORTED
626 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)627 png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
628     png_const_charp name, int compression_type,
629     png_const_bytep profile, png_uint_32 proflen)
630 {
631    png_charp new_iccp_name;
632    png_bytep new_iccp_profile;
633    png_size_t length;
634 
635    png_debug1(1, "in %s storage function", "iCCP");
636 
637    if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL)
638       return;
639 
640    if (compression_type != PNG_COMPRESSION_TYPE_BASE)
641       png_app_error(png_ptr, "Invalid iCCP compression method");
642 
643    /* Set the colorspace first because this validates the profile; do not
644     * override previously set app cHRM or gAMA here (because likely as not the
645     * application knows better than libpng what the correct values are.)  Pass
646     * the info_ptr color_type field to png_colorspace_set_ICC because in the
647     * write case it has not yet been stored in png_ptr.
648     */
649    {
650       int result = png_colorspace_set_ICC(png_ptr, &info_ptr->colorspace, name,
651          proflen, profile, info_ptr->color_type);
652 
653       png_colorspace_sync_info(png_ptr, info_ptr);
654 
655       /* Don't do any of the copying if the profile was bad, or inconsistent. */
656       if (result == 0)
657          return;
658 
659       /* But do write the gAMA and cHRM chunks from the profile. */
660       info_ptr->colorspace.flags |=
661          PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
662    }
663 
664    length = strlen(name)+1;
665    new_iccp_name = png_voidcast(png_charp, png_malloc_warn(png_ptr, length));
666 
667    if (new_iccp_name == NULL)
668    {
669       png_benign_error(png_ptr, "Insufficient memory to process iCCP chunk");
670 
671       return;
672    }
673 
674    memcpy(new_iccp_name, name, length);
675    new_iccp_profile = png_voidcast(png_bytep,
676       png_malloc_warn(png_ptr, proflen));
677 
678    if (new_iccp_profile == NULL)
679    {
680       png_free(png_ptr, new_iccp_name);
681       png_benign_error(png_ptr,
682           "Insufficient memory to process iCCP profile");
683 
684       return;
685    }
686 
687    memcpy(new_iccp_profile, profile, proflen);
688 
689    png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0);
690 
691    info_ptr->iccp_proflen = proflen;
692    info_ptr->iccp_name = new_iccp_name;
693    info_ptr->iccp_profile = new_iccp_profile;
694    info_ptr->free_me |= PNG_FREE_ICCP;
695    info_ptr->valid |= PNG_INFO_iCCP;
696 }
697 #endif
698 
699 #ifdef PNG_TEXT_SUPPORTED
700 void PNGAPI
png_set_text(png_const_structrp png_ptr,png_inforp info_ptr,png_const_textp text_ptr,int num_text)701 png_set_text(png_const_structrp png_ptr, png_inforp info_ptr,
702     png_const_textp text_ptr, int num_text)
703 {
704    int ret;
705    ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text);
706 
707    if (ret != 0)
708       png_error(png_ptr, "Insufficient memory to store text");
709 }
710 
711 int /* PRIVATE */
png_set_text_2(png_const_structrp png_ptr,png_inforp info_ptr,png_const_textp text_ptr,int num_text)712 png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
713     png_const_textp text_ptr, int num_text)
714 {
715    int i;
716 
717    png_debug1(1, "in %lx storage function", png_ptr == NULL ? 0xabadca11U :
718       (unsigned long)png_ptr->chunk_name);
719 
720    if (png_ptr == NULL || info_ptr == NULL || num_text <= 0 || text_ptr == NULL)
721       return(0);
722 
723    /* Make sure we have enough space in the "text" array in info_struct
724     * to hold all of the incoming text_ptr objects.  This compare can't overflow
725     * because max_text >= num_text (anyway, subtract of two positive integers
726     * can't overflow in any case.)
727     */
728    if (num_text > info_ptr->max_text - info_ptr->num_text)
729    {
730       int old_num_text = info_ptr->num_text;
731       int max_text;
732       png_textp new_text = NULL;
733 
734       /* Calculate an appropriate max_text, checking for overflow. */
735       max_text = old_num_text;
736       if (num_text <= INT_MAX - max_text)
737       {
738          max_text += num_text;
739 
740          /* Round up to a multiple of 8 */
741          if (max_text < INT_MAX-8)
742             max_text = (max_text + 8) & ~0x7;
743 
744          else
745             max_text = INT_MAX;
746 
747          /* Now allocate a new array and copy the old members in; this does all
748           * the overflow checks.
749           */
750          new_text = png_voidcast(png_textp,png_realloc_array(png_ptr,
751             info_ptr->text, old_num_text, max_text-old_num_text,
752             sizeof *new_text));
753       }
754 
755       if (new_text == NULL)
756       {
757          png_chunk_report(png_ptr, "too many text chunks",
758             PNG_CHUNK_WRITE_ERROR);
759 
760          return 1;
761       }
762 
763       png_free(png_ptr, info_ptr->text);
764 
765       info_ptr->text = new_text;
766       info_ptr->free_me |= PNG_FREE_TEXT;
767       info_ptr->max_text = max_text;
768       /* num_text is adjusted below as the entries are copied in */
769 
770       png_debug1(3, "allocated %d entries for info_ptr->text", max_text);
771    }
772 
773    for (i = 0; i < num_text; i++)
774    {
775       size_t text_length, key_len;
776       size_t lang_len, lang_key_len;
777       png_textp textp = &(info_ptr->text[info_ptr->num_text]);
778 
779       if (text_ptr[i].key == NULL)
780           continue;
781 
782       if (text_ptr[i].compression < PNG_TEXT_COMPRESSION_NONE ||
783           text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST)
784       {
785          png_chunk_report(png_ptr, "text compression mode is out of range",
786             PNG_CHUNK_WRITE_ERROR);
787          continue;
788       }
789 
790       key_len = strlen(text_ptr[i].key);
791 
792       if (text_ptr[i].compression <= 0)
793       {
794          lang_len = 0;
795          lang_key_len = 0;
796       }
797 
798       else
799 #  ifdef PNG_iTXt_SUPPORTED
800       {
801          /* Set iTXt data */
802 
803          if (text_ptr[i].lang != NULL)
804             lang_len = strlen(text_ptr[i].lang);
805 
806          else
807             lang_len = 0;
808 
809          if (text_ptr[i].lang_key != NULL)
810             lang_key_len = strlen(text_ptr[i].lang_key);
811 
812          else
813             lang_key_len = 0;
814       }
815 #  else /* iTXt */
816       {
817          png_chunk_report(png_ptr, "iTXt chunk not supported",
818             PNG_CHUNK_WRITE_ERROR);
819          continue;
820       }
821 #  endif
822 
823       if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0')
824       {
825          text_length = 0;
826 #  ifdef PNG_iTXt_SUPPORTED
827          if (text_ptr[i].compression > 0)
828             textp->compression = PNG_ITXT_COMPRESSION_NONE;
829 
830          else
831 #  endif
832             textp->compression = PNG_TEXT_COMPRESSION_NONE;
833       }
834 
835       else
836       {
837          text_length = strlen(text_ptr[i].text);
838          textp->compression = text_ptr[i].compression;
839       }
840 
841       textp->key = png_voidcast(png_charp,png_malloc_base(png_ptr,
842           key_len + text_length + lang_len + lang_key_len + 4));
843 
844       if (textp->key == NULL)
845       {
846          png_chunk_report(png_ptr, "text chunk: out of memory",
847                PNG_CHUNK_WRITE_ERROR);
848 
849          return 1;
850       }
851 
852       png_debug2(2, "Allocated %lu bytes at %p in png_set_text",
853           (unsigned long)(png_uint_32)
854           (key_len + lang_len + lang_key_len + text_length + 4),
855           textp->key);
856 
857       memcpy(textp->key, text_ptr[i].key, key_len);
858       *(textp->key + key_len) = '\0';
859 
860       if (text_ptr[i].compression > 0)
861       {
862          textp->lang = textp->key + key_len + 1;
863          memcpy(textp->lang, text_ptr[i].lang, lang_len);
864          *(textp->lang + lang_len) = '\0';
865          textp->lang_key = textp->lang + lang_len + 1;
866          memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
867          *(textp->lang_key + lang_key_len) = '\0';
868          textp->text = textp->lang_key + lang_key_len + 1;
869       }
870 
871       else
872       {
873          textp->lang=NULL;
874          textp->lang_key=NULL;
875          textp->text = textp->key + key_len + 1;
876       }
877 
878       if (text_length != 0)
879          memcpy(textp->text, text_ptr[i].text, text_length);
880 
881       *(textp->text + text_length) = '\0';
882 
883 #  ifdef PNG_iTXt_SUPPORTED
884       if (textp->compression > 0)
885       {
886          textp->text_length = 0;
887          textp->itxt_length = text_length;
888       }
889 
890       else
891 #  endif
892       {
893          textp->text_length = text_length;
894          textp->itxt_length = 0;
895       }
896 
897       info_ptr->num_text++;
898       png_debug1(3, "transferred text chunk %d", info_ptr->num_text);
899    }
900 
901    return(0);
902 }
903 #endif
904 
905 #ifdef PNG_tIME_SUPPORTED
906 void PNGAPI
png_set_tIME(png_const_structrp png_ptr,png_inforp info_ptr,png_const_timep mod_time)907 png_set_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
908     png_const_timep mod_time)
909 {
910    png_debug1(1, "in %s storage function", "tIME");
911 
912    if (png_ptr == NULL || info_ptr == NULL || mod_time == NULL ||
913        (png_ptr->mode & PNG_WROTE_tIME) != 0)
914       return;
915 
916    if (mod_time->month == 0   || mod_time->month > 12  ||
917        mod_time->day   == 0   || mod_time->day   > 31  ||
918        mod_time->hour  > 23   || mod_time->minute > 59 ||
919        mod_time->second > 60)
920    {
921       png_warning(png_ptr, "Ignoring invalid time value");
922 
923       return;
924    }
925 
926    info_ptr->mod_time = *mod_time;
927    info_ptr->valid |= PNG_INFO_tIME;
928 }
929 #endif
930 
931 #ifdef PNG_tRNS_SUPPORTED
932 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)933 png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
934     png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color)
935 {
936    png_debug1(1, "in %s storage function", "tRNS");
937 
938    if (png_ptr == NULL || info_ptr == NULL)
939 
940       return;
941 
942    if (trans_alpha != NULL)
943    {
944        /* It may not actually be necessary to set png_ptr->trans_alpha here;
945         * we do it for backward compatibility with the way the png_handle_tRNS
946         * function used to do the allocation.
947         *
948         * 1.6.0: The above statement is incorrect; png_handle_tRNS effectively
949         * relies on png_set_tRNS storing the information in png_struct
950         * (otherwise it won't be there for the code in pngrtran.c).
951         */
952 
953        png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
954 
955        /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */
956        png_ptr->trans_alpha = info_ptr->trans_alpha = png_voidcast(png_bytep,
957          png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH));
958 
959        if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
960           memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans);
961    }
962 
963    if (trans_color != NULL)
964    {
965 #ifdef PNG_WARNINGS_SUPPORTED
966       if (info_ptr->bit_depth < 16)
967       {
968          int sample_max = (1 << info_ptr->bit_depth) - 1;
969 
970          if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
971              trans_color->gray > sample_max) ||
972              (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
973              (trans_color->red > sample_max ||
974              trans_color->green > sample_max ||
975              trans_color->blue > sample_max)))
976             png_warning(png_ptr,
977                "tRNS chunk has out-of-range samples for bit_depth");
978       }
979 #endif
980 
981       info_ptr->trans_color = *trans_color;
982 
983       if (num_trans == 0)
984          num_trans = 1;
985    }
986 
987    info_ptr->num_trans = (png_uint_16)num_trans;
988 
989    if (num_trans != 0)
990    {
991       info_ptr->valid |= PNG_INFO_tRNS;
992       info_ptr->free_me |= PNG_FREE_TRNS;
993    }
994 }
995 #endif
996 
997 #ifdef PNG_sPLT_SUPPORTED
998 void PNGAPI
png_set_sPLT(png_const_structrp png_ptr,png_inforp info_ptr,png_const_sPLT_tp entries,int nentries)999 png_set_sPLT(png_const_structrp png_ptr,
1000     png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)
1001 /*
1002  *  entries        - array of png_sPLT_t structures
1003  *                   to be added to the list of palettes
1004  *                   in the info structure.
1005  *
1006  *  nentries       - number of palette structures to be
1007  *                   added.
1008  */
1009 {
1010    png_sPLT_tp np;
1011 
1012    if (png_ptr == NULL || info_ptr == NULL || nentries <= 0 || entries == NULL)
1013       return;
1014 
1015    /* Use the internal realloc function, which checks for all the possible
1016     * overflows.  Notice that the parameters are (int) and (size_t)
1017     */
1018    np = png_voidcast(png_sPLT_tp,png_realloc_array(png_ptr,
1019       info_ptr->splt_palettes, info_ptr->splt_palettes_num, nentries,
1020       sizeof *np));
1021 
1022    if (np == NULL)
1023    {
1024       /* Out of memory or too many chunks */
1025       png_chunk_report(png_ptr, "too many sPLT chunks", PNG_CHUNK_WRITE_ERROR);
1026 
1027       return;
1028    }
1029 
1030    png_free(png_ptr, info_ptr->splt_palettes);
1031    info_ptr->splt_palettes = np;
1032    info_ptr->free_me |= PNG_FREE_SPLT;
1033 
1034    np += info_ptr->splt_palettes_num;
1035 
1036    do
1037    {
1038       png_size_t length;
1039 
1040       /* Skip invalid input entries */
1041       if (entries->name == NULL || entries->entries == NULL)
1042       {
1043          /* png_handle_sPLT doesn't do this, so this is an app error */
1044          png_app_error(png_ptr, "png_set_sPLT: invalid sPLT");
1045          /* Just skip the invalid entry */
1046          continue;
1047       }
1048 
1049       np->depth = entries->depth;
1050 
1051       /* In the event of out-of-memory just return - there's no point keeping
1052        * on trying to add sPLT chunks.
1053        */
1054       length = strlen(entries->name) + 1;
1055       np->name = png_voidcast(png_charp, png_malloc_base(png_ptr, length));
1056 
1057       if (np->name == NULL)
1058          break;
1059 
1060       memcpy(np->name, entries->name, length);
1061 
1062       /* IMPORTANT: we have memory now that won't get freed if something else
1063        * goes wrong; this code must free it.  png_malloc_array produces no
1064        * warnings; use a png_chunk_report (below) if there is an error.
1065        */
1066       np->entries = png_voidcast(png_sPLT_entryp, png_malloc_array(png_ptr,
1067           entries->nentries, sizeof (png_sPLT_entry)));
1068 
1069       if (np->entries == NULL)
1070       {
1071          png_free(png_ptr, np->name);
1072          np->name = NULL;
1073          break;
1074       }
1075 
1076       np->nentries = entries->nentries;
1077       /* This multiply can't overflow because png_malloc_array has already
1078        * checked it when doing the allocation.
1079        */
1080       memcpy(np->entries, entries->entries,
1081          entries->nentries * sizeof (png_sPLT_entry));
1082 
1083       /* Note that 'continue' skips the advance of the out pointer and out
1084        * count, so an invalid entry is not added.
1085        */
1086       info_ptr->valid |= PNG_INFO_sPLT;
1087       ++(info_ptr->splt_palettes_num);
1088       ++np;
1089    }
1090    while (++entries, --nentries);
1091 
1092    if (nentries > 0)
1093       png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR);
1094 }
1095 #endif /* sPLT */
1096 
1097 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1098 static png_byte
check_location(png_const_structrp png_ptr,int location)1099 check_location(png_const_structrp png_ptr, int location)
1100 {
1101    location &= (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT);
1102 
1103    /* New in 1.6.0; copy the location and check it.  This is an API
1104     * change; previously the app had to use the
1105     * png_set_unknown_chunk_location API below for each chunk.
1106     */
1107    if (location == 0 && (png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
1108    {
1109       /* Write struct, so unknown chunks come from the app */
1110       png_app_warning(png_ptr,
1111          "png_set_unknown_chunks now expects a valid location");
1112       /* Use the old behavior */
1113       location = (png_byte)(png_ptr->mode &
1114          (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT));
1115    }
1116 
1117    /* This need not be an internal error - if the app calls
1118     * png_set_unknown_chunks on a read pointer it must get the location right.
1119     */
1120    if (location == 0)
1121       png_error(png_ptr, "invalid location in png_set_unknown_chunks");
1122 
1123    /* Now reduce the location to the top-most set bit by removing each least
1124     * significant bit in turn.
1125     */
1126    while (location != (location & -location))
1127       location &= ~(location & -location);
1128 
1129    /* The cast is safe because 'location' is a bit mask and only the low four
1130     * bits are significant.
1131     */
1132    return (png_byte)location;
1133 }
1134 
1135 void PNGAPI
png_set_unknown_chunks(png_const_structrp png_ptr,png_inforp info_ptr,png_const_unknown_chunkp unknowns,int num_unknowns)1136 png_set_unknown_chunks(png_const_structrp png_ptr,
1137    png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
1138 {
1139    png_unknown_chunkp np;
1140 
1141    if (png_ptr == NULL || info_ptr == NULL || num_unknowns <= 0 ||
1142        unknowns == NULL)
1143       return;
1144 
1145    /* Check for the failure cases where support has been disabled at compile
1146     * time.  This code is hardly ever compiled - it's here because
1147     * STORE_UNKNOWN_CHUNKS is set by both read and write code (compiling in this
1148     * code) but may be meaningless if the read or write handling of unknown
1149     * chunks is not compiled in.
1150     */
1151 #  if !defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) && \
1152       defined(PNG_READ_SUPPORTED)
1153       if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
1154       {
1155          png_app_error(png_ptr, "no unknown chunk support on read");
1156 
1157          return;
1158       }
1159 #  endif
1160 #  if !defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) && \
1161       defined(PNG_WRITE_SUPPORTED)
1162       if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
1163       {
1164          png_app_error(png_ptr, "no unknown chunk support on write");
1165 
1166          return;
1167       }
1168 #  endif
1169 
1170    /* Prior to 1.6.0 this code used png_malloc_warn; however, this meant that
1171     * unknown critical chunks could be lost with just a warning resulting in
1172     * undefined behavior.  Now png_chunk_report is used to provide behavior
1173     * appropriate to read or write.
1174     */
1175    np = png_voidcast(png_unknown_chunkp, png_realloc_array(png_ptr,
1176          info_ptr->unknown_chunks, info_ptr->unknown_chunks_num, num_unknowns,
1177          sizeof *np));
1178 
1179    if (np == NULL)
1180    {
1181       png_chunk_report(png_ptr, "too many unknown chunks",
1182          PNG_CHUNK_WRITE_ERROR);
1183 
1184       return;
1185    }
1186 
1187    png_free(png_ptr, info_ptr->unknown_chunks);
1188    info_ptr->unknown_chunks = np; /* safe because it is initialized */
1189    info_ptr->free_me |= PNG_FREE_UNKN;
1190 
1191    np += info_ptr->unknown_chunks_num;
1192 
1193    /* Increment unknown_chunks_num each time round the loop to protect the
1194     * just-allocated chunk data.
1195     */
1196    for (; num_unknowns > 0; --num_unknowns, ++unknowns)
1197    {
1198       memcpy(np->name, unknowns->name, (sizeof np->name));
1199       np->name[(sizeof np->name)-1] = '\0';
1200       np->location = check_location(png_ptr, unknowns->location);
1201 
1202       if (unknowns->size == 0)
1203       {
1204          np->data = NULL;
1205          np->size = 0;
1206       }
1207 
1208       else
1209       {
1210          np->data = png_voidcast(png_bytep,
1211             png_malloc_base(png_ptr, unknowns->size));
1212 
1213          if (np->data == NULL)
1214          {
1215             png_chunk_report(png_ptr, "unknown chunk: out of memory",
1216                PNG_CHUNK_WRITE_ERROR);
1217             /* But just skip storing the unknown chunk */
1218             continue;
1219          }
1220 
1221          memcpy(np->data, unknowns->data, unknowns->size);
1222          np->size = unknowns->size;
1223       }
1224 
1225       /* These increments are skipped on out-of-memory for the data - the
1226        * unknown chunk entry gets overwritten if the png_chunk_report returns.
1227        * This is correct in the read case (the chunk is just dropped.)
1228        */
1229       ++np;
1230       ++(info_ptr->unknown_chunks_num);
1231    }
1232 }
1233 
1234 void PNGAPI
png_set_unknown_chunk_location(png_const_structrp png_ptr,png_inforp info_ptr,int chunk,int location)1235 png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
1236     int chunk, int location)
1237 {
1238    /* This API is pretty pointless in 1.6.0 because the location can be set
1239     * before the call to png_set_unknown_chunks.
1240     *
1241     * TODO: add a png_app_warning in 1.7
1242     */
1243    if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 &&
1244       chunk < info_ptr->unknown_chunks_num)
1245    {
1246       if ((location & (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)) == 0)
1247       {
1248          png_app_error(png_ptr, "invalid unknown chunk location");
1249          /* Fake out the pre 1.6.0 behavior: */
1250          if ((location & PNG_HAVE_IDAT) != 0) /* undocumented! */
1251             location = PNG_AFTER_IDAT;
1252 
1253          else
1254             location = PNG_HAVE_IHDR; /* also undocumented */
1255       }
1256 
1257       info_ptr->unknown_chunks[chunk].location =
1258          check_location(png_ptr, location);
1259    }
1260 }
1261 #endif /* STORE_UNKNOWN_CHUNKS */
1262 
1263 #ifdef PNG_MNG_FEATURES_SUPPORTED
1264 png_uint_32 PNGAPI
png_permit_mng_features(png_structrp png_ptr,png_uint_32 mng_features)1265 png_permit_mng_features (png_structrp png_ptr, png_uint_32 mng_features)
1266 {
1267    png_debug(1, "in png_permit_mng_features");
1268 
1269    if (png_ptr == NULL)
1270       return 0;
1271 
1272    png_ptr->mng_features_permitted = mng_features & PNG_ALL_MNG_FEATURES;
1273 
1274    return png_ptr->mng_features_permitted;
1275 }
1276 #endif
1277 
1278 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1279 static unsigned int
add_one_chunk(png_bytep list,unsigned int count,png_const_bytep add,int keep)1280 add_one_chunk(png_bytep list, unsigned int count, png_const_bytep add, int keep)
1281 {
1282    unsigned int i;
1283 
1284    /* Utility function: update the 'keep' state of a chunk if it is already in
1285     * the list, otherwise add it to the list.
1286     */
1287    for (i=0; i<count; ++i, list += 5)
1288    {
1289       if (memcmp(list, add, 4) == 0)
1290       {
1291          list[4] = (png_byte)keep;
1292 
1293          return count;
1294       }
1295    }
1296 
1297    if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT)
1298    {
1299       ++count;
1300       memcpy(list, add, 4);
1301       list[4] = (png_byte)keep;
1302    }
1303 
1304    return count;
1305 }
1306 
1307 void PNGAPI
png_set_keep_unknown_chunks(png_structrp png_ptr,int keep,png_const_bytep chunk_list,int num_chunks_in)1308 png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
1309     png_const_bytep chunk_list, int num_chunks_in)
1310 {
1311    png_bytep new_list;
1312    unsigned int num_chunks, old_num_chunks;
1313 
1314    if (png_ptr == NULL)
1315       return;
1316 
1317    if (keep < 0 || keep >= PNG_HANDLE_CHUNK_LAST)
1318    {
1319       png_app_error(png_ptr, "png_set_keep_unknown_chunks: invalid keep");
1320 
1321       return;
1322    }
1323 
1324    if (num_chunks_in <= 0)
1325    {
1326       png_ptr->unknown_default = keep;
1327 
1328       /* '0' means just set the flags, so stop here */
1329       if (num_chunks_in == 0)
1330         return;
1331    }
1332 
1333    if (num_chunks_in < 0)
1334    {
1335       /* Ignore all unknown chunks and all chunks recognized by
1336        * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND
1337        */
1338       static PNG_CONST png_byte chunks_to_ignore[] = {
1339          98,  75,  71,  68, '\0',  /* bKGD */
1340          99,  72,  82,  77, '\0',  /* cHRM */
1341         103,  65,  77,  65, '\0',  /* gAMA */
1342         104,  73,  83,  84, '\0',  /* hIST */
1343         105,  67,  67,  80, '\0',  /* iCCP */
1344         105,  84,  88, 116, '\0',  /* iTXt */
1345         111,  70,  70, 115, '\0',  /* oFFs */
1346         112,  67,  65,  76, '\0',  /* pCAL */
1347         112,  72,  89, 115, '\0',  /* pHYs */
1348         115,  66,  73,  84, '\0',  /* sBIT */
1349         115,  67,  65,  76, '\0',  /* sCAL */
1350         115,  80,  76,  84, '\0',  /* sPLT */
1351         115,  84,  69,  82, '\0',  /* sTER */
1352         115,  82,  71,  66, '\0',  /* sRGB */
1353         116,  69,  88, 116, '\0',  /* tEXt */
1354         116,  73,  77,  69, '\0',  /* tIME */
1355         122,  84,  88, 116, '\0'   /* zTXt */
1356       };
1357 
1358       chunk_list = chunks_to_ignore;
1359       num_chunks = (unsigned int)/*SAFE*/(sizeof chunks_to_ignore)/5U;
1360    }
1361 
1362    else /* num_chunks_in > 0 */
1363    {
1364       if (chunk_list == NULL)
1365       {
1366          /* Prior to 1.6.0 this was silently ignored, now it is an app_error
1367           * which can be switched off.
1368           */
1369          png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list");
1370 
1371          return;
1372       }
1373 
1374       num_chunks = num_chunks_in;
1375    }
1376 
1377    old_num_chunks = png_ptr->num_chunk_list;
1378    if (png_ptr->chunk_list == NULL)
1379       old_num_chunks = 0;
1380 
1381    /* Since num_chunks is always restricted to UINT_MAX/5 this can't overflow.
1382     */
1383    if (num_chunks + old_num_chunks > UINT_MAX/5)
1384    {
1385       png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks");
1386 
1387       return;
1388    }
1389 
1390    /* If these chunks are being reset to the default then no more memory is
1391     * required because add_one_chunk above doesn't extend the list if the 'keep'
1392     * parameter is the default.
1393     */
1394    if (keep != 0)
1395    {
1396       new_list = png_voidcast(png_bytep, png_malloc(png_ptr,
1397           5 * (num_chunks + old_num_chunks)));
1398 
1399       if (old_num_chunks > 0)
1400          memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks);
1401    }
1402 
1403    else if (old_num_chunks > 0)
1404       new_list = png_ptr->chunk_list;
1405 
1406    else
1407       new_list = NULL;
1408 
1409    /* Add the new chunks together with each one's handling code.  If the chunk
1410     * already exists the code is updated, otherwise the chunk is added to the
1411     * end.  (In libpng 1.6.0 order no longer matters because this code enforces
1412     * the earlier convention that the last setting is the one that is used.)
1413     */
1414    if (new_list != NULL)
1415    {
1416       png_const_bytep inlist;
1417       png_bytep outlist;
1418       unsigned int i;
1419 
1420       for (i=0; i<num_chunks; ++i)
1421       {
1422          old_num_chunks = add_one_chunk(new_list, old_num_chunks,
1423             chunk_list+5*i, keep);
1424       }
1425 
1426       /* Now remove any spurious 'default' entries. */
1427       num_chunks = 0;
1428       for (i=0, inlist=outlist=new_list; i<old_num_chunks; ++i, inlist += 5)
1429       {
1430          if (inlist[4])
1431          {
1432             if (outlist != inlist)
1433                memcpy(outlist, inlist, 5);
1434             outlist += 5;
1435             ++num_chunks;
1436          }
1437       }
1438 
1439       /* This means the application has removed all the specialized handling. */
1440       if (num_chunks == 0)
1441       {
1442          if (png_ptr->chunk_list != new_list)
1443             png_free(png_ptr, new_list);
1444 
1445          new_list = NULL;
1446       }
1447    }
1448 
1449    else
1450       num_chunks = 0;
1451 
1452    png_ptr->num_chunk_list = num_chunks;
1453 
1454    if (png_ptr->chunk_list != new_list)
1455    {
1456       if (png_ptr->chunk_list != NULL)
1457          png_free(png_ptr, png_ptr->chunk_list);
1458 
1459       png_ptr->chunk_list = new_list;
1460    }
1461 }
1462 #endif
1463 
1464 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1465 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)1466 png_set_read_user_chunk_fn(png_structrp png_ptr, png_voidp user_chunk_ptr,
1467     png_user_chunk_ptr read_user_chunk_fn)
1468 {
1469    png_debug(1, "in png_set_read_user_chunk_fn");
1470 
1471    if (png_ptr == NULL)
1472       return;
1473 
1474    png_ptr->read_user_chunk_fn = read_user_chunk_fn;
1475    png_ptr->user_chunk_ptr = user_chunk_ptr;
1476 }
1477 #endif
1478 
1479 #ifdef PNG_INFO_IMAGE_SUPPORTED
1480 void PNGAPI
png_set_rows(png_const_structrp png_ptr,png_inforp info_ptr,png_bytepp row_pointers)1481 png_set_rows(png_const_structrp png_ptr, png_inforp info_ptr,
1482     png_bytepp row_pointers)
1483 {
1484    png_debug1(1, "in %s storage function", "rows");
1485 
1486    if (png_ptr == NULL || info_ptr == NULL)
1487       return;
1488 
1489    if (info_ptr->row_pointers != NULL &&
1490        (info_ptr->row_pointers != row_pointers))
1491       png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
1492 
1493    info_ptr->row_pointers = row_pointers;
1494 
1495    if (row_pointers != NULL)
1496       info_ptr->valid |= PNG_INFO_IDAT;
1497 }
1498 #endif
1499 
1500 void PNGAPI
png_set_compression_buffer_size(png_structrp png_ptr,png_size_t size)1501 png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size)
1502 {
1503     if (png_ptr == NULL)
1504        return;
1505 
1506     if (size == 0 || size > PNG_UINT_31_MAX)
1507        png_error(png_ptr, "invalid compression buffer size");
1508 
1509 #  ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1510       if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
1511       {
1512          png_ptr->IDAT_read_size = (png_uint_32)size; /* checked above */
1513          return;
1514       }
1515 #  endif
1516 
1517 #  ifdef PNG_WRITE_SUPPORTED
1518       if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
1519       {
1520          if (png_ptr->zowner != 0)
1521          {
1522             png_warning(png_ptr,
1523               "Compression buffer size cannot be changed because it is in use");
1524 
1525             return;
1526          }
1527 
1528 #ifndef __COVERITY__
1529          /* Some compilers complain that this is always false.  However, it
1530           * can be true when integer overflow happens.
1531           */
1532          if (size > ZLIB_IO_MAX)
1533          {
1534             png_warning(png_ptr,
1535                "Compression buffer size limited to system maximum");
1536             size = ZLIB_IO_MAX; /* must fit */
1537          }
1538 #endif
1539 
1540          if (size < 6)
1541          {
1542             /* Deflate will potentially go into an infinite loop on a SYNC_FLUSH
1543              * if this is permitted.
1544              */
1545             png_warning(png_ptr,
1546                "Compression buffer size cannot be reduced below 6");
1547 
1548             return;
1549          }
1550 
1551          if (png_ptr->zbuffer_size != size)
1552          {
1553             png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
1554             png_ptr->zbuffer_size = (uInt)size;
1555          }
1556       }
1557 #  endif
1558 }
1559 
1560 void PNGAPI
png_set_invalid(png_const_structrp png_ptr,png_inforp info_ptr,int mask)1561 png_set_invalid(png_const_structrp png_ptr, png_inforp info_ptr, int mask)
1562 {
1563    if (png_ptr != NULL && info_ptr != NULL)
1564       info_ptr->valid &= ~mask;
1565 }
1566 
1567 
1568 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
1569 /* This function was added to libpng 1.2.6 */
1570 void PNGAPI
png_set_user_limits(png_structrp png_ptr,png_uint_32 user_width_max,png_uint_32 user_height_max)1571 png_set_user_limits (png_structrp png_ptr, png_uint_32 user_width_max,
1572     png_uint_32 user_height_max)
1573 {
1574    /* Images with dimensions larger than these limits will be
1575     * rejected by png_set_IHDR().  To accept any PNG datastream
1576     * regardless of dimensions, set both limits to 0x7fffffff.
1577     */
1578    if (png_ptr == NULL)
1579       return;
1580 
1581    png_ptr->user_width_max = user_width_max;
1582    png_ptr->user_height_max = user_height_max;
1583 }
1584 
1585 /* This function was added to libpng 1.4.0 */
1586 void PNGAPI
png_set_chunk_cache_max(png_structrp png_ptr,png_uint_32 user_chunk_cache_max)1587 png_set_chunk_cache_max (png_structrp png_ptr, png_uint_32 user_chunk_cache_max)
1588 {
1589    if (png_ptr != NULL)
1590       png_ptr->user_chunk_cache_max = user_chunk_cache_max;
1591 }
1592 
1593 /* This function was added to libpng 1.4.1 */
1594 void PNGAPI
png_set_chunk_malloc_max(png_structrp png_ptr,png_alloc_size_t user_chunk_malloc_max)1595 png_set_chunk_malloc_max (png_structrp png_ptr,
1596     png_alloc_size_t user_chunk_malloc_max)
1597 {
1598    if (png_ptr != NULL)
1599       png_ptr->user_chunk_malloc_max = user_chunk_malloc_max;
1600 }
1601 #endif /* ?SET_USER_LIMITS */
1602 
1603 
1604 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1605 void PNGAPI
png_set_benign_errors(png_structrp png_ptr,int allowed)1606 png_set_benign_errors(png_structrp png_ptr, int allowed)
1607 {
1608    png_debug(1, "in png_set_benign_errors");
1609 
1610    /* If allowed is 1, png_benign_error() is treated as a warning.
1611     *
1612     * If allowed is 0, png_benign_error() is treated as an error (which
1613     * is the default behavior if png_set_benign_errors() is not called).
1614     */
1615 
1616    if (allowed != 0)
1617       png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN |
1618          PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN;
1619 
1620    else
1621       png_ptr->flags &= ~(PNG_FLAG_BENIGN_ERRORS_WARN |
1622          PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN);
1623 }
1624 #endif /* BENIGN_ERRORS */
1625 
1626 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
1627    /* Whether to report invalid palette index; added at libng-1.5.10.
1628     * It is possible for an indexed (color-type==3) PNG file to contain
1629     * pixels with invalid (out-of-range) indexes if the PLTE chunk has
1630     * fewer entries than the image's bit-depth would allow. We recover
1631     * from this gracefully by filling any incomplete palette with zeros
1632     * (opaque black).  By default, when this occurs libpng will issue
1633     * a benign error.  This API can be used to override that behavior.
1634     */
1635 void PNGAPI
png_set_check_for_invalid_index(png_structrp png_ptr,int allowed)1636 png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)
1637 {
1638    png_debug(1, "in png_set_check_for_invalid_index");
1639 
1640    if (allowed > 0)
1641       png_ptr->num_palette_max = 0;
1642 
1643    else
1644       png_ptr->num_palette_max = -1;
1645 }
1646 #endif
1647 
1648 #if defined(PNG_TEXT_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) || \
1649     defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
1650 /* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
1651  * and if invalid, correct the keyword rather than discarding the entire
1652  * chunk.  The PNG 1.0 specification requires keywords 1-79 characters in
1653  * length, forbids leading or trailing whitespace, multiple internal spaces,
1654  * and the non-break space (0x80) from ISO 8859-1.  Returns keyword length.
1655  *
1656  * The 'new_key' buffer must be 80 characters in size (for the keyword plus a
1657  * trailing '\0').  If this routine returns 0 then there was no keyword, or a
1658  * valid one could not be generated, and the caller must png_error.
1659  */
1660 png_uint_32 /* PRIVATE */
png_check_keyword(png_structrp png_ptr,png_const_charp key,png_bytep new_key)1661 png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
1662 {
1663    png_const_charp orig_key = key;
1664    png_uint_32 key_len = 0;
1665    int bad_character = 0;
1666    int space = 1;
1667 
1668    png_debug(1, "in png_check_keyword");
1669 
1670    if (key == NULL)
1671    {
1672       *new_key = 0;
1673       return 0;
1674    }
1675 
1676    while (*key && key_len < 79)
1677    {
1678       png_byte ch = (png_byte)*key++;
1679 
1680       if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/))
1681          *new_key++ = ch, ++key_len, space = 0;
1682 
1683       else if (space == 0)
1684       {
1685          /* A space or an invalid character when one wasn't seen immediately
1686           * before; output just a space.
1687           */
1688          *new_key++ = 32, ++key_len, space = 1;
1689 
1690          /* If the character was not a space then it is invalid. */
1691          if (ch != 32)
1692             bad_character = ch;
1693       }
1694 
1695       else if (bad_character == 0)
1696          bad_character = ch; /* just skip it, record the first error */
1697    }
1698 
1699    if (key_len > 0 && space != 0) /* trailing space */
1700    {
1701       --key_len, --new_key;
1702       if (bad_character == 0)
1703          bad_character = 32;
1704    }
1705 
1706    /* Terminate the keyword */
1707    *new_key = 0;
1708 
1709    if (key_len == 0)
1710       return 0;
1711 
1712 #ifdef PNG_WARNINGS_SUPPORTED
1713    /* Try to only output one warning per keyword: */
1714    if (*key != 0) /* keyword too long */
1715       png_warning(png_ptr, "keyword truncated");
1716 
1717    else if (bad_character != 0)
1718    {
1719       PNG_WARNING_PARAMETERS(p)
1720 
1721       png_warning_parameter(p, 1, orig_key);
1722       png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character);
1723 
1724       png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'");
1725    }
1726 #endif /* WARNINGS */
1727 
1728    return key_len;
1729 }
1730 #endif /* TEXT || pCAL || iCCP || sPLT */
1731 #endif /* READ || WRITE */
1732