/* Add a filler byte on read, or remove a filler or alpha byte on write.
* The filler type has changed in v0.95 to allow future 2-byte fillers
* for 48-bit input data, as well as to avoid problems with some compilers
* that don't like bytes as parameters.
*/
void PNGAPI
png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
{
png_debug(1, "in png_set_filler");
if (png_ptr == NULL)
return;
/* In libpng 1.6 it is possible to determine whether this is a read or write
* operation and therefore to do more checking here for a valid call.
*/
if (png_ptr->mode & PNG_IS_READ_STRUCT)
{
# ifdef PNG_READ_FILLER_SUPPORTED
/* On read png_set_filler is always valid, regardless of the base PNG
* format, because other transformations can give a format where the
* filler code can execute (basically an 8 or 16-bit component RGB or G
* format.)
*
* NOTE: usr_channels is not used by the read code! (This has led to
* confusion in the past.) The filler is only used in the read code.
*/
png_ptr->filler = (png_uint_16)filler;
# else
png_app_error(png_ptr, "png_set_filler not supported on read");
PNG_UNUSED(filler) /* not used in the write case */
return;
# endif
}
void PNGAPI
png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
int chunk, int location)
{
/* This API is pretty pointless in 1.6.0 because the location can be set
* before the call to png_set_unknown_chunks.
*
* TODO: add a png_app_warning in 1.7
*/
if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 &&
chunk < info_ptr->unknown_chunks_num)
{
if ((location & (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)) == 0)
{
png_app_error(png_ptr, "invalid unknown chunk location");
/* Fake out the pre 1.6.0 behavior: */
if ((location & PNG_HAVE_IDAT) != 0) /* undocumented! */
location = PNG_AFTER_IDAT;
else
location = PNG_HAVE_IHDR; /* also undocumented */
}
info_ptr->unknown_chunks[chunk].location =
check_location(png_ptr, location);
}
}
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);
}
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_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);
}
}
