void PNGAPI
png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
png_const_colorp palette, int num_palette)
{
png_debug1(1, "in %s storage function", "PLTE");
if (png_ptr == NULL || info_ptr == NULL)
return;
if (num_palette < 0 || num_palette > PNG_MAX_PALETTE_LENGTH)
{
if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
png_error(png_ptr, "Invalid palette length");
else
{
png_warning(png_ptr, "Invalid palette length");
return;
}
}
if ((num_palette > 0 && palette == NULL) ||
(num_palette == 0
# ifdef PNG_MNG_FEATURES_SUPPORTED
&& (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0
# endif
))
{
png_error(png_ptr, "Invalid palette");
}
/* It may not actually be necessary to set png_ptr->palette here;
* we do it for backward compatibility with the way the png_handle_tRNS
* function used to do the allocation.
*
* 1.6.0: the above statement appears to be incorrect; something has to set
* the palette inside png_struct on read.
*/
png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0);
/* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
* of num_palette entries, in case of an invalid PNG file that has
* too-large sample values.
*/
png_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr,
PNG_MAX_PALETTE_LENGTH * (sizeof (png_color))));
if (num_palette > 0)
memcpy(png_ptr->palette, palette, num_palette * (sizeof (png_color)));
info_ptr->palette = png_ptr->palette;
info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;
info_ptr->free_me |= PNG_FREE_PLTE;
info_ptr->valid |= PNG_INFO_PLTE;
}
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)
{
png_debug1(1, "in %s storage function", "tRNS");
if (png_ptr == NULL || info_ptr == NULL)
return;
if (trans_alpha != NULL)
{
/* It may not actually be necessary to set png_ptr->trans_alpha here;
* we do it for backward compatibility with the way the png_handle_tRNS
* function used to do the allocation.
*
* 1.6.0: The above statement is incorrect; png_handle_tRNS effectively
* relies on png_set_tRNS storing the information in png_struct
* (otherwise it won't be there for the code in pngrtran.c).
*/
png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
/* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */
png_ptr->trans_alpha = info_ptr->trans_alpha = png_voidcast(png_bytep,
png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH));
if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans);
}
if (trans_color != NULL)
{
int sample_max = (1 << info_ptr->bit_depth);
if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
trans_color->gray > sample_max) ||
(info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
(trans_color->red > sample_max ||
trans_color->green > sample_max ||
trans_color->blue > sample_max)))
png_warning(png_ptr,
"tRNS chunk has out-of-range samples for bit_depth");
info_ptr->trans_color = *trans_color;
if (num_trans == 0)
num_trans = 1;
}
info_ptr->num_trans = (png_uint_16)num_trans;
if (num_trans != 0)
{
info_ptr->valid |= PNG_INFO_tRNS;
info_ptr->free_me |= PNG_FREE_TRNS;
}
}
void PNGCBAPI
png_default_flush(png_structp png_ptr)
{
png_FILE_p io_ptr;
if (png_ptr == NULL)
return;
io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr));
fflush(io_ptr);
}
/* This is the function that does the actual reading of data. If you are
* not reading from a standard C stream, you should create a replacement
* read_data function and use it at run time with png_set_read_fn(), rather
* than changing the library.
*/
void PNGCBAPI
png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
png_size_t check;
if (png_ptr == NULL)
return;
/* fread() returns 0 on error, so it is OK to store this in a png_size_t
* instead of an int, which is what fread() actually returns.
*/
check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr));
if (check != length)
png_error(png_ptr, "Read Error");
}
void PNGAPI
png_set_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
png_const_uint_16p hist)
{
int i;
png_debug1(1, "in %s storage function", "hIST");
if (png_ptr == NULL || info_ptr == NULL)
return;
if (info_ptr->num_palette == 0 || info_ptr->num_palette
> PNG_MAX_PALETTE_LENGTH)
{
png_warning(png_ptr,
"Invalid palette size, hIST allocation skipped");
return;
}
png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0);
/* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in
* version 1.2.1
*/
info_ptr->hist = png_voidcast(png_uint_16p, png_malloc_warn(png_ptr,
PNG_MAX_PALETTE_LENGTH * (sizeof (png_uint_16))));
if (info_ptr->hist == NULL)
{
png_warning(png_ptr, "Insufficient memory for hIST chunk data");
return;
}
info_ptr->free_me |= PNG_FREE_HIST;
for (i = 0; i < info_ptr->num_palette; i++)
info_ptr->hist[i] = hist[i];
info_ptr->valid |= PNG_INFO_hIST;
}
void PNGAPI
png_set_sPLT(png_const_structrp png_ptr,
png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)
/*
* entries - array of png_sPLT_t structures
* to be added to the list of palettes
* in the info structure.
*
* nentries - number of palette structures to be
* added.
*/
{
png_sPLT_tp np;
if (png_ptr == NULL || info_ptr == NULL || nentries <= 0 || entries == NULL)
return;
/* Use the internal realloc function, which checks for all the possible
* overflows. Notice that the parameters are (int) and (size_t)
*/
np = png_voidcast(png_sPLT_tp,png_realloc_array(png_ptr,
info_ptr->splt_palettes, info_ptr->splt_palettes_num, nentries,
sizeof *np));
if (np == NULL)
{
/* Out of memory or too many chunks */
png_chunk_report(png_ptr, "too many sPLT chunks", PNG_CHUNK_WRITE_ERROR);
return;
}
png_free(png_ptr, info_ptr->splt_palettes);
info_ptr->splt_palettes = np;
info_ptr->free_me |= PNG_FREE_SPLT;
np += info_ptr->splt_palettes_num;
do
{
png_size_t length;
/* Skip invalid input entries */
if (entries->name == NULL || entries->entries == NULL)
{
/* png_handle_sPLT doesn't do this, so this is an app error */
png_app_error(png_ptr, "png_set_sPLT: invalid sPLT");
/* Just skip the invalid entry */
continue;
}
np->depth = entries->depth;
/* In the event of out-of-memory just return - there's no point keeping
* on trying to add sPLT chunks.
*/
length = strlen(entries->name) + 1;
np->name = png_voidcast(png_charp, png_malloc_base(png_ptr, length));
if (np->name == NULL)
break;
memcpy(np->name, entries->name, length);
/* IMPORTANT: we have memory now that won't get freed if something else
* goes wrong; this code must free it. png_malloc_array produces no
* warnings; use a png_chunk_report (below) if there is an error.
*/
np->entries = png_voidcast(png_sPLT_entryp, png_malloc_array(png_ptr,
entries->nentries, sizeof (png_sPLT_entry)));
if (np->entries == NULL)
{
png_free(png_ptr, np->name);
np->name = NULL;
break;
}
np->nentries = entries->nentries;
/* This multiply can't overflow because png_malloc_array has already
* checked it when doing the allocation.
*/
memcpy(np->entries, entries->entries,
entries->nentries * sizeof (png_sPLT_entry));
/* Note that 'continue' skips the advance of the out pointer and out
* count, so an invalid entry is not added.
*/
info_ptr->valid |= PNG_INFO_sPLT;
++(info_ptr->splt_palettes_num);
++np;
}
while (++entries, --nentries);
if (nentries > 0)
png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR);
}
int /* PRIVATE */
png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
png_const_textp text_ptr, int num_text)
{
int i;
png_debug1(1, "in %lx storage function", png_ptr == NULL ? 0xabadca11U :
(unsigned long)png_ptr->chunk_name);
if (png_ptr == NULL || info_ptr == NULL || num_text <= 0 || text_ptr == NULL)
return(0);
/* Make sure we have enough space in the "text" array in info_struct
* to hold all of the incoming text_ptr objects. This compare can't overflow
* because max_text >= num_text (anyway, subtract of two positive integers
* can't overflow in any case.)
*/
if (num_text > info_ptr->max_text - info_ptr->num_text)
{
int old_num_text = info_ptr->num_text;
int max_text;
png_textp new_text = NULL;
/* Calculate an appropriate max_text, checking for overflow. */
max_text = old_num_text;
if (num_text <= INT_MAX - max_text)
{
max_text += num_text;
/* Round up to a multiple of 8 */
if (max_text < INT_MAX-8)
max_text = (max_text + 8) & ~0x7;
else
max_text = INT_MAX;
/* Now allocate a new array and copy the old members in; this does all
* the overflow checks.
*/
new_text = png_voidcast(png_textp,png_realloc_array(png_ptr,
info_ptr->text, old_num_text, max_text-old_num_text,
sizeof *new_text));
}
if (new_text == NULL)
{
png_chunk_report(png_ptr, "too many text chunks",
PNG_CHUNK_WRITE_ERROR);
return 1;
}
png_free(png_ptr, info_ptr->text);
info_ptr->text = new_text;
info_ptr->free_me |= PNG_FREE_TEXT;
info_ptr->max_text = max_text;
/* num_text is adjusted below as the entries are copied in */
png_debug1(3, "allocated %d entries for info_ptr->text", max_text);
}
for (i = 0; i < num_text; i++)
{
size_t text_length, key_len;
size_t lang_len, lang_key_len;
png_textp textp = &(info_ptr->text[info_ptr->num_text]);
if (text_ptr[i].key == NULL)
continue;
if (text_ptr[i].compression < PNG_TEXT_COMPRESSION_NONE ||
text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST)
{
png_chunk_report(png_ptr, "text compression mode is out of range",
PNG_CHUNK_WRITE_ERROR);
continue;
}
key_len = strlen(text_ptr[i].key);
if (text_ptr[i].compression <= 0)
{
lang_len = 0;
lang_key_len = 0;
}
else
# ifdef PNG_iTXt_SUPPORTED
{
/* Set iTXt data */
if (text_ptr[i].lang != NULL)
lang_len = strlen(text_ptr[i].lang);
else
lang_len = 0;
if (text_ptr[i].lang_key != NULL)
lang_key_len = strlen(text_ptr[i].lang_key);
else
lang_key_len = 0;
}
# else /* iTXt */
{
png_chunk_report(png_ptr, "iTXt chunk not supported",
PNG_CHUNK_WRITE_ERROR);
continue;
}
# endif
if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0')
{
text_length = 0;
# ifdef PNG_iTXt_SUPPORTED
if (text_ptr[i].compression > 0)
textp->compression = PNG_ITXT_COMPRESSION_NONE;
else
# endif
textp->compression = PNG_TEXT_COMPRESSION_NONE;
}
else
{
text_length = strlen(text_ptr[i].text);
textp->compression = text_ptr[i].compression;
}
textp->key = png_voidcast(png_charp,png_malloc_base(png_ptr,
key_len + text_length + lang_len + lang_key_len + 4));
if (textp->key == NULL)
{
png_chunk_report(png_ptr, "text chunk: out of memory",
PNG_CHUNK_WRITE_ERROR);
return 1;
}
png_debug2(2, "Allocated %lu bytes at %p in png_set_text",
(unsigned long)(png_uint_32)
(key_len + lang_len + lang_key_len + text_length + 4),
textp->key);
memcpy(textp->key, text_ptr[i].key, key_len);
*(textp->key + key_len) = '\0';
if (text_ptr[i].compression > 0)
{
textp->lang = textp->key + key_len + 1;
memcpy(textp->lang, text_ptr[i].lang, lang_len);
*(textp->lang + lang_len) = '\0';
textp->lang_key = textp->lang + lang_len + 1;
memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
*(textp->lang_key + lang_key_len) = '\0';
textp->text = textp->lang_key + lang_key_len + 1;
}
else
{
textp->lang=NULL;
textp->lang_key=NULL;
textp->text = textp->key + key_len + 1;
}
if (text_length != 0)
memcpy(textp->text, text_ptr[i].text, text_length);
*(textp->text + text_length) = '\0';
# ifdef PNG_iTXt_SUPPORTED
if (textp->compression > 0)
{
textp->text_length = 0;
textp->itxt_length = text_length;
}
else
# endif
{
textp->text_length = text_length;
textp->itxt_length = 0;
}
info_ptr->num_text++;
png_debug1(3, "transferred text chunk %d", info_ptr->num_text);
}
return(0);
}
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)
{
png_charp new_iccp_name;
png_bytep new_iccp_profile;
png_size_t length;
png_debug1(1, "in %s storage function", "iCCP");
if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL)
return;
if (compression_type != PNG_COMPRESSION_TYPE_BASE)
png_app_error(png_ptr, "Invalid iCCP compression method");
/* Set the colorspace first because this validates the profile; do not
* override previously set app cHRM or gAMA here (because likely as not the
* application knows better than libpng what the correct values are.) Pass
* the info_ptr color_type field to png_colorspace_set_ICC because in the
* write case it has not yet been stored in png_ptr.
*/
{
int result = png_colorspace_set_ICC(png_ptr, &info_ptr->colorspace, name,
proflen, profile, info_ptr->color_type);
png_colorspace_sync_info(png_ptr, info_ptr);
/* Don't do any of the copying if the profile was bad, or inconsistent. */
if (result == 0)
return;
/* But do write the gAMA and cHRM chunks from the profile. */
info_ptr->colorspace.flags |=
PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
}
length = strlen(name)+1;
new_iccp_name = png_voidcast(png_charp, png_malloc_warn(png_ptr, length));
if (new_iccp_name == NULL)
{
png_benign_error(png_ptr, "Insufficient memory to process iCCP chunk");
return;
}
memcpy(new_iccp_name, name, length);
new_iccp_profile = png_voidcast(png_bytep,
png_malloc_warn(png_ptr, proflen));
if (new_iccp_profile == NULL)
{
png_free(png_ptr, new_iccp_name);
png_benign_error(png_ptr,
"Insufficient memory to process iCCP profile");
return;
}
memcpy(new_iccp_profile, profile, proflen);
png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0);
info_ptr->iccp_proflen = proflen;
info_ptr->iccp_name = new_iccp_name;
info_ptr->iccp_profile = new_iccp_profile;
info_ptr->free_me |= PNG_FREE_ICCP;
info_ptr->valid |= PNG_INFO_iCCP;
}
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)
{
png_size_t lengthw = 0, lengthh = 0;
png_debug1(1, "in %s storage function", "sCAL");
if (png_ptr == NULL || info_ptr == NULL)
return;
/* Double check the unit (should never get here with an invalid
* unit unless this is an API call.)
*/
if (unit != 1 && unit != 2)
png_error(png_ptr, "Invalid sCAL unit");
if (swidth == NULL || (lengthw = strlen(swidth)) == 0 ||
swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw))
png_error(png_ptr, "Invalid sCAL width");
if (sheight == NULL || (lengthh = strlen(sheight)) == 0 ||
sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh))
png_error(png_ptr, "Invalid sCAL height");
info_ptr->scal_unit = (png_byte)unit;
++lengthw;
png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw);
info_ptr->scal_s_width = png_voidcast(png_charp,
png_malloc_warn(png_ptr, lengthw));
if (info_ptr->scal_s_width == NULL)
{
png_warning(png_ptr, "Memory allocation failed while processing sCAL");
return;
}
memcpy(info_ptr->scal_s_width, swidth, lengthw);
++lengthh;
png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh);
info_ptr->scal_s_height = png_voidcast(png_charp,
png_malloc_warn(png_ptr, lengthh));
if (info_ptr->scal_s_height == NULL)
{
png_free (png_ptr, info_ptr->scal_s_width);
info_ptr->scal_s_width = NULL;
png_warning(png_ptr, "Memory allocation failed while processing sCAL");
return;
}
memcpy(info_ptr->scal_s_height, sheight, lengthh);
info_ptr->valid |= PNG_INFO_sCAL;
info_ptr->free_me |= PNG_FREE_SCAL;
}
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)
{
png_size_t length;
int i;
png_debug1(1, "in %s storage function", "pCAL");
if (png_ptr == NULL || info_ptr == NULL || purpose == NULL || units == NULL
|| (nparams > 0 && params == NULL))
return;
length = strlen(purpose) + 1;
png_debug1(3, "allocating purpose for info (%lu bytes)",
(unsigned long)length);
/* TODO: validate format of calibration name and unit name */
/* Check that the type matches the specification. */
if (type < 0 || type > 3)
png_error(png_ptr, "Invalid pCAL equation type");
if (nparams < 0 || nparams > 255)
png_error(png_ptr, "Invalid pCAL parameter count");
/* Validate params[nparams] */
for (i=0; i<nparams; ++i)
{
if (params[i] == NULL ||
!png_check_fp_string(params[i], strlen(params[i])))
png_error(png_ptr, "Invalid format for pCAL parameter");
}
info_ptr->pcal_purpose = png_voidcast(png_charp,
png_malloc_warn(png_ptr, length));
if (info_ptr->pcal_purpose == NULL)
{
png_warning(png_ptr, "Insufficient memory for pCAL purpose");
return;
}
memcpy(info_ptr->pcal_purpose, purpose, length);
png_debug(3, "storing X0, X1, type, and nparams in info");
info_ptr->pcal_X0 = X0;
info_ptr->pcal_X1 = X1;
info_ptr->pcal_type = (png_byte)type;
info_ptr->pcal_nparams = (png_byte)nparams;
length = strlen(units) + 1;
png_debug1(3, "allocating units for info (%lu bytes)",
(unsigned long)length);
info_ptr->pcal_units = png_voidcast(png_charp,
png_malloc_warn(png_ptr, length));
if (info_ptr->pcal_units == NULL)
{
png_warning(png_ptr, "Insufficient memory for pCAL units");
return;
}
memcpy(info_ptr->pcal_units, units, length);
info_ptr->pcal_params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
(png_size_t)((nparams + 1) * (sizeof (png_charp)))));
if (info_ptr->pcal_params == NULL)
{
png_warning(png_ptr, "Insufficient memory for pCAL params");
return;
}
memset(info_ptr->pcal_params, 0, (nparams + 1) * (sizeof (png_charp)));
for (i = 0; i < nparams; i++)
{
length = strlen(params[i]) + 1;
png_debug2(3, "allocating parameter %d for info (%lu bytes)", i,
(unsigned long)length);
info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length);
if (info_ptr->pcal_params[i] == NULL)
{
png_warning(png_ptr, "Insufficient memory for pCAL parameter");
return;
}
memcpy(info_ptr->pcal_params[i], params[i], length);
}
info_ptr->valid |= PNG_INFO_pCAL;
info_ptr->free_me |= PNG_FREE_PCAL;
}
void PNGAPI
png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
png_const_bytep chunk_list, int num_chunks_in)
{
png_bytep new_list;
unsigned int num_chunks, old_num_chunks;
if (png_ptr == NULL)
return;
if (keep < 0 || keep >= PNG_HANDLE_CHUNK_LAST)
{
png_app_error(png_ptr, "png_set_keep_unknown_chunks: invalid keep");
return;
}
if (num_chunks_in <= 0)
{
png_ptr->unknown_default = keep;
/* '0' means just set the flags, so stop here */
if (num_chunks_in == 0)
return;
}
if (num_chunks_in < 0)
{
/* Ignore all unknown chunks and all chunks recognized by
* libpng except for IHDR, PLTE, tRNS, IDAT, and IEND
*/
static PNG_CONST png_byte chunks_to_ignore[] = {
98, 75, 71, 68, '\0', /* bKGD */
99, 72, 82, 77, '\0', /* cHRM */
103, 65, 77, 65, '\0', /* gAMA */
104, 73, 83, 84, '\0', /* hIST */
105, 67, 67, 80, '\0', /* iCCP */
105, 84, 88, 116, '\0', /* iTXt */
111, 70, 70, 115, '\0', /* oFFs */
112, 67, 65, 76, '\0', /* pCAL */
112, 72, 89, 115, '\0', /* pHYs */
115, 66, 73, 84, '\0', /* sBIT */
115, 67, 65, 76, '\0', /* sCAL */
115, 80, 76, 84, '\0', /* sPLT */
115, 84, 69, 82, '\0', /* sTER */
115, 82, 71, 66, '\0', /* sRGB */
116, 69, 88, 116, '\0', /* tEXt */
116, 73, 77, 69, '\0', /* tIME */
122, 84, 88, 116, '\0' /* zTXt */
};
chunk_list = chunks_to_ignore;
num_chunks = (unsigned int)/*SAFE*/(sizeof chunks_to_ignore)/5U;
}
else /* num_chunks_in > 0 */
{
if (chunk_list == NULL)
{
/* Prior to 1.6.0 this was silently ignored, now it is an app_error
* which can be switched off.
*/
png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list");
return;
}
num_chunks = num_chunks_in;
}
old_num_chunks = png_ptr->num_chunk_list;
if (png_ptr->chunk_list == NULL)
old_num_chunks = 0;
/* Since num_chunks is always restricted to UINT_MAX/5 this can't overflow.
*/
if (num_chunks + old_num_chunks > UINT_MAX/5)
{
png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks");
return;
}
/* If these chunks are being reset to the default then no more memory is
* required because add_one_chunk above doesn't extend the list if the 'keep'
* parameter is the default.
*/
if (keep != 0)
{
new_list = png_voidcast(png_bytep, png_malloc(png_ptr,
5 * (num_chunks + old_num_chunks)));
if (old_num_chunks > 0)
memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks);
}
else if (old_num_chunks > 0)
new_list = png_ptr->chunk_list;
else
new_list = NULL;
/* Add the new chunks together with each one's handling code. If the chunk
* already exists the code is updated, otherwise the chunk is added to the
* end. (In libpng 1.6.0 order no longer matters because this code enforces
* the earlier convention that the last setting is the one that is used.)
*/
if (new_list != NULL)
{
png_const_bytep inlist;
png_bytep outlist;
unsigned int i;
for (i=0; i<num_chunks; ++i)
{
old_num_chunks = add_one_chunk(new_list, old_num_chunks,
chunk_list+5*i, keep);
}
/* Now remove any spurious 'default' entries. */
num_chunks = 0;
for (i=0, inlist=outlist=new_list; i<old_num_chunks; ++i, inlist += 5)
{
if (inlist[4])
{
if (outlist != inlist)
memcpy(outlist, inlist, 5);
outlist += 5;
++num_chunks;
}
}
/* This means the application has removed all the specialized handling. */
if (num_chunks == 0)
{
if (png_ptr->chunk_list != new_list)
png_free(png_ptr, new_list);
new_list = NULL;
}
}
else
num_chunks = 0;
png_ptr->num_chunk_list = num_chunks;
if (png_ptr->chunk_list != new_list)
{
if (png_ptr->chunk_list != NULL)
png_free(png_ptr, png_ptr->chunk_list);
png_ptr->chunk_list = new_list;
}
}
void PNGAPI
png_set_unknown_chunks(png_const_structrp png_ptr,
png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
{
png_unknown_chunkp np;
if (png_ptr == NULL || info_ptr == NULL || num_unknowns <= 0 ||
unknowns == NULL)
return;
/* Check for the failure cases where support has been disabled at compile
* time. This code is hardly ever compiled - it's here because
* STORE_UNKNOWN_CHUNKS is set by both read and write code (compiling in this
* code) but may be meaningless if the read or write handling of unknown
* chunks is not compiled in.
*/
# if !defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) && \
defined(PNG_READ_SUPPORTED)
if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
{
png_app_error(png_ptr, "no unknown chunk support on read");
return;
}
# endif
# if !defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) && \
defined(PNG_WRITE_SUPPORTED)
if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
{
png_app_error(png_ptr, "no unknown chunk support on write");
return;
}
# endif
/* Prior to 1.6.0 this code used png_malloc_warn; however, this meant that
* unknown critical chunks could be lost with just a warning resulting in
* undefined behavior. Now png_chunk_report is used to provide behavior
* appropriate to read or write.
*/
np = png_voidcast(png_unknown_chunkp, png_realloc_array(png_ptr,
info_ptr->unknown_chunks, info_ptr->unknown_chunks_num, num_unknowns,
sizeof *np));
if (np == NULL)
{
png_chunk_report(png_ptr, "too many unknown chunks",
PNG_CHUNK_WRITE_ERROR);
return;
}
png_free(png_ptr, info_ptr->unknown_chunks);
info_ptr->unknown_chunks = np; /* safe because it is initialized */
info_ptr->free_me |= PNG_FREE_UNKN;
np += info_ptr->unknown_chunks_num;
/* Increment unknown_chunks_num each time round the loop to protect the
* just-allocated chunk data.
*/
for (; num_unknowns > 0; --num_unknowns, ++unknowns)
{
memcpy(np->name, unknowns->name, (sizeof np->name));
np->name[(sizeof np->name)-1] = '\0';
np->location = check_location(png_ptr, unknowns->location);
if (unknowns->size == 0)
{
np->data = NULL;
np->size = 0;
}
else
{
np->data = png_voidcast(png_bytep,
png_malloc_base(png_ptr, unknowns->size));
if (np->data == NULL)
{
png_chunk_report(png_ptr, "unknown chunk: out of memory",
PNG_CHUNK_WRITE_ERROR);
/* But just skip storing the unknown chunk */
continue;
}
memcpy(np->data, unknowns->data, unknowns->size);
np->size = unknowns->size;
}
/* These increments are skipped on out-of-memory for the data - the
* unknown chunk entry gets overwritten if the png_chunk_report returns.
* This is correct in the read case (the chunk is just dropped.)
*/
++np;
++(info_ptr->unknown_chunks_num);
}
}