/* pngrutil.c - utilities to read a PNG file | |
* | |
* Last changed in libpng 1.6.3 [July 18, 2013] | |
* Copyright (c) 1998-2013 Glenn Randers-Pehrson | |
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) | |
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) | |
* | |
* This code is released under the libpng license. | |
* For conditions of distribution and use, see the disclaimer | |
* and license in png.h | |
* | |
* This file contains routines that are only called from within | |
* libpng itself during the course of reading an image. | |
*/ | |
#include "pngpriv.h" | |
#ifdef PNG_READ_SUPPORTED | |
png_uint_32 PNGAPI | |
png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf) | |
{ | |
png_uint_32 uval = png_get_uint_32(buf); | |
if (uval > PNG_UINT_31_MAX) | |
png_error(png_ptr, "PNG unsigned integer out of range"); | |
return (uval); | |
} | |
#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED) | |
/* The following is a variation on the above for use with the fixed | |
* point values used for gAMA and cHRM. Instead of png_error it | |
* issues a warning and returns (-1) - an invalid value because both | |
* gAMA and cHRM use *unsigned* integers for fixed point values. | |
*/ | |
#define PNG_FIXED_ERROR (-1) | |
static png_fixed_point /* PRIVATE */ | |
png_get_fixed_point(png_structrp png_ptr, png_const_bytep buf) | |
{ | |
png_uint_32 uval = png_get_uint_32(buf); | |
if (uval <= PNG_UINT_31_MAX) | |
return (png_fixed_point)uval; /* known to be in range */ | |
/* The caller can turn off the warning by passing NULL. */ | |
if (png_ptr != NULL) | |
png_warning(png_ptr, "PNG fixed point integer out of range"); | |
return PNG_FIXED_ERROR; | |
} | |
#endif | |
#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED | |
/* NOTE: the read macros will obscure these definitions, so that if | |
* PNG_USE_READ_MACROS is set the library will not use them internally, | |
* but the APIs will still be available externally. | |
* | |
* The parentheses around "PNGAPI function_name" in the following three | |
* functions are necessary because they allow the macros to co-exist with | |
* these (unused but exported) functions. | |
*/ | |
/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */ | |
png_uint_32 (PNGAPI | |
png_get_uint_32)(png_const_bytep buf) | |
{ | |
png_uint_32 uval = | |
((png_uint_32)(*(buf )) << 24) + | |
((png_uint_32)(*(buf + 1)) << 16) + | |
((png_uint_32)(*(buf + 2)) << 8) + | |
((png_uint_32)(*(buf + 3)) ) ; | |
return uval; | |
} | |
/* Grab a signed 32-bit integer from a buffer in big-endian format. The | |
* data is stored in the PNG file in two's complement format and there | |
* is no guarantee that a 'png_int_32' is exactly 32 bits, therefore | |
* the following code does a two's complement to native conversion. | |
*/ | |
png_int_32 (PNGAPI | |
png_get_int_32)(png_const_bytep buf) | |
{ | |
png_uint_32 uval = png_get_uint_32(buf); | |
if ((uval & 0x80000000) == 0) /* non-negative */ | |
return uval; | |
uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */ | |
return -(png_int_32)uval; | |
} | |
/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */ | |
png_uint_16 (PNGAPI | |
png_get_uint_16)(png_const_bytep buf) | |
{ | |
/* ANSI-C requires an int value to accomodate at least 16 bits so this | |
* works and allows the compiler not to worry about possible narrowing | |
* on 32 bit systems. (Pre-ANSI systems did not make integers smaller | |
* than 16 bits either.) | |
*/ | |
unsigned int val = | |
((unsigned int)(*buf) << 8) + | |
((unsigned int)(*(buf + 1))); | |
return (png_uint_16)val; | |
} | |
#endif /* PNG_READ_INT_FUNCTIONS_SUPPORTED */ | |
/* Read and check the PNG file signature */ | |
void /* PRIVATE */ | |
png_read_sig(png_structrp png_ptr, png_inforp info_ptr) | |
{ | |
png_size_t num_checked, num_to_check; | |
/* Exit if the user application does not expect a signature. */ | |
if (png_ptr->sig_bytes >= 8) | |
return; | |
num_checked = png_ptr->sig_bytes; | |
num_to_check = 8 - num_checked; | |
#ifdef PNG_IO_STATE_SUPPORTED | |
png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE; | |
#endif | |
/* The signature must be serialized in a single I/O call. */ | |
png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); | |
png_ptr->sig_bytes = 8; | |
if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) | |
{ | |
if (num_checked < 4 && | |
png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) | |
png_error(png_ptr, "Not a PNG file"); | |
else | |
png_error(png_ptr, "PNG file corrupted by ASCII conversion"); | |
} | |
if (num_checked < 3) | |
png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; | |
} | |
/* Read the chunk header (length + type name). | |
* Put the type name into png_ptr->chunk_name, and return the length. | |
*/ | |
png_uint_32 /* PRIVATE */ | |
png_read_chunk_header(png_structrp png_ptr) | |
{ | |
png_byte buf[8]; | |
png_uint_32 length; | |
#ifdef PNG_IO_STATE_SUPPORTED | |
png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR; | |
#endif | |
/* Read the length and the chunk name. | |
* This must be performed in a single I/O call. | |
*/ | |
png_read_data(png_ptr, buf, 8); | |
length = png_get_uint_31(png_ptr, buf); | |
/* Put the chunk name into png_ptr->chunk_name. */ | |
png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4); | |
png_debug2(0, "Reading %lx chunk, length = %lu", | |
(unsigned long)png_ptr->chunk_name, (unsigned long)length); | |
/* Reset the crc and run it over the chunk name. */ | |
png_reset_crc(png_ptr); | |
png_calculate_crc(png_ptr, buf + 4, 4); | |
/* Check to see if chunk name is valid. */ | |
png_check_chunk_name(png_ptr, png_ptr->chunk_name); | |
#ifdef PNG_IO_STATE_SUPPORTED | |
png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA; | |
#endif | |
return length; | |
} | |
/* Read data, and (optionally) run it through the CRC. */ | |
void /* PRIVATE */ | |
png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length) | |
{ | |
if (png_ptr == NULL) | |
return; | |
png_read_data(png_ptr, buf, length); | |
png_calculate_crc(png_ptr, buf, length); | |
} | |
/* Optionally skip data and then check the CRC. Depending on whether we | |
* are reading an ancillary or critical chunk, and how the program has set | |
* things up, we may calculate the CRC on the data and print a message. | |
* Returns '1' if there was a CRC error, '0' otherwise. | |
*/ | |
int /* PRIVATE */ | |
png_crc_finish(png_structrp png_ptr, png_uint_32 skip) | |
{ | |
/* The size of the local buffer for inflate is a good guess as to a | |
* reasonable size to use for buffering reads from the application. | |
*/ | |
while (skip > 0) | |
{ | |
png_uint_32 len; | |
png_byte tmpbuf[PNG_INFLATE_BUF_SIZE]; | |
len = (sizeof tmpbuf); | |
if (len > skip) | |
len = skip; | |
skip -= len; | |
png_crc_read(png_ptr, tmpbuf, len); | |
} | |
if (png_crc_error(png_ptr)) | |
{ | |
if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) ? | |
!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) : | |
(png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)) | |
{ | |
png_chunk_warning(png_ptr, "CRC error"); | |
} | |
else | |
{ | |
png_chunk_benign_error(png_ptr, "CRC error"); | |
return (0); | |
} | |
return (1); | |
} | |
return (0); | |
} | |
/* Compare the CRC stored in the PNG file with that calculated by libpng from | |
* the data it has read thus far. | |
*/ | |
int /* PRIVATE */ | |
png_crc_error(png_structrp png_ptr) | |
{ | |
png_byte crc_bytes[4]; | |
png_uint_32 crc; | |
int need_crc = 1; | |
if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)) | |
{ | |
if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == | |
(PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) | |
need_crc = 0; | |
} | |
else /* critical */ | |
{ | |
if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) | |
need_crc = 0; | |
} | |
#ifdef PNG_IO_STATE_SUPPORTED | |
png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC; | |
#endif | |
/* The chunk CRC must be serialized in a single I/O call. */ | |
png_read_data(png_ptr, crc_bytes, 4); | |
if (need_crc) | |
{ | |
crc = png_get_uint_32(crc_bytes); | |
return ((int)(crc != png_ptr->crc)); | |
} | |
else | |
return (0); | |
} | |
/* Manage the read buffer; this simply reallocates the buffer if it is not small | |
* enough (or if it is not allocated). The routine returns a pointer to the | |
* buffer; if an error occurs and 'warn' is set the routine returns NULL, else | |
* it will call png_error (via png_malloc) on failure. (warn == 2 means | |
* 'silent'). | |
*/ | |
static png_bytep | |
png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn) | |
{ | |
png_bytep buffer = png_ptr->read_buffer; | |
if (buffer != NULL && new_size > png_ptr->read_buffer_size) | |
{ | |
png_ptr->read_buffer = NULL; | |
png_ptr->read_buffer = NULL; | |
png_ptr->read_buffer_size = 0; | |
png_free(png_ptr, buffer); | |
buffer = NULL; | |
} | |
if (buffer == NULL) | |
{ | |
buffer = png_voidcast(png_bytep, png_malloc_base(png_ptr, new_size)); | |
if (buffer != NULL) | |
{ | |
png_ptr->read_buffer = buffer; | |
png_ptr->read_buffer_size = new_size; | |
} | |
else if (warn < 2) /* else silent */ | |
{ | |
#ifdef PNG_WARNINGS_SUPPORTED | |
if (warn) | |
png_chunk_warning(png_ptr, "insufficient memory to read chunk"); | |
else | |
#endif | |
{ | |
#ifdef PNG_ERROR_TEXT_SUPPORTED | |
png_chunk_error(png_ptr, "insufficient memory to read chunk"); | |
#endif | |
} | |
} | |
} | |
return buffer; | |
} | |
/* png_inflate_claim: claim the zstream for some nefarious purpose that involves | |
* decompression. Returns Z_OK on success, else a zlib error code. It checks | |
* the owner but, in final release builds, just issues a warning if some other | |
* chunk apparently owns the stream. Prior to release it does a png_error. | |
*/ | |
static int | |
png_inflate_claim(png_structrp png_ptr, png_uint_32 owner) | |
{ | |
if (png_ptr->zowner != 0) | |
{ | |
char msg[64]; | |
PNG_STRING_FROM_CHUNK(msg, png_ptr->zowner); | |
/* So the message that results is "<chunk> using zstream"; this is an | |
* internal error, but is very useful for debugging. i18n requirements | |
* are minimal. | |
*/ | |
(void)png_safecat(msg, (sizeof msg), 4, " using zstream"); | |
# if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC | |
png_chunk_warning(png_ptr, msg); | |
png_ptr->zowner = 0; | |
# else | |
png_chunk_error(png_ptr, msg); | |
# endif | |
} | |
/* Implementation note: unlike 'png_deflate_claim' this internal function | |
* does not take the size of the data as an argument. Some efficiency could | |
* be gained by using this when it is known *if* the zlib stream itself does | |
* not record the number; however, this is an illusion: the original writer | |
* of the PNG may have selected a lower window size, and we really must | |
* follow that because, for systems with with limited capabilities, we | |
* would otherwise reject the application's attempts to use a smaller window | |
* size (zlib doesn't have an interface to say "this or lower"!). | |
* | |
* inflateReset2 was added to zlib 1.2.4; before this the window could not be | |
* reset, therefore it is necessary to always allocate the maximum window | |
* size with earlier zlibs just in case later compressed chunks need it. | |
*/ | |
{ | |
int ret; /* zlib return code */ | |
# if PNG_ZLIB_VERNUM >= 0x1240 | |
# if defined(PNG_SET_OPTION_SUPPORTED) && \ | |
defined(PNG_MAXIMUM_INFLATE_WINDOW) | |
int window_bits; | |
if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) == | |
PNG_OPTION_ON) | |
window_bits = 15; | |
else | |
window_bits = 0; | |
# else | |
# define window_bits 0 | |
# endif | |
# endif | |
/* Set this for safety, just in case the previous owner left pointers to | |
* memory allocations. | |
*/ | |
png_ptr->zstream.next_in = NULL; | |
png_ptr->zstream.avail_in = 0; | |
png_ptr->zstream.next_out = NULL; | |
png_ptr->zstream.avail_out = 0; | |
if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) | |
{ | |
# if PNG_ZLIB_VERNUM < 0x1240 | |
ret = inflateReset(&png_ptr->zstream); | |
# else | |
ret = inflateReset2(&png_ptr->zstream, window_bits); | |
# endif | |
} | |
else | |
{ | |
# if PNG_ZLIB_VERNUM < 0x1240 | |
ret = inflateInit(&png_ptr->zstream); | |
# else | |
ret = inflateInit2(&png_ptr->zstream, window_bits); | |
# endif | |
if (ret == Z_OK) | |
png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED; | |
} | |
if (ret == Z_OK) | |
png_ptr->zowner = owner; | |
else | |
png_zstream_error(png_ptr, ret); | |
return ret; | |
} | |
# ifdef window_bits | |
# undef window_bits | |
# endif | |
} | |
#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED | |
/* png_inflate now returns zlib error codes including Z_OK and Z_STREAM_END to | |
* allow the caller to do multiple calls if required. If the 'finish' flag is | |
* set Z_FINISH will be passed to the final inflate() call and Z_STREAM_END must | |
* be returned or there has been a problem, otherwise Z_SYNC_FLUSH is used and | |
* Z_OK or Z_STREAM_END will be returned on success. | |
* | |
* The input and output sizes are updated to the actual amounts of data consumed | |
* or written, not the amount available (as in a z_stream). The data pointers | |
* are not changed, so the next input is (data+input_size) and the next | |
* available output is (output+output_size). | |
*/ | |
static int | |
png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish, | |
/* INPUT: */ png_const_bytep input, png_uint_32p input_size_ptr, | |
/* OUTPUT: */ png_bytep output, png_alloc_size_t *output_size_ptr) | |
{ | |
if (png_ptr->zowner == owner) /* Else not claimed */ | |
{ | |
int ret; | |
png_alloc_size_t avail_out = *output_size_ptr; | |
png_uint_32 avail_in = *input_size_ptr; | |
/* zlib can't necessarily handle more than 65535 bytes at once (i.e. it | |
* can't even necessarily handle 65536 bytes) because the type uInt is | |
* "16 bits or more". Consequently it is necessary to chunk the input to | |
* zlib. This code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the | |
* maximum value that can be stored in a uInt.) It is possible to set | |
* ZLIB_IO_MAX to a lower value in pngpriv.h and this may sometimes have | |
* a performance advantage, because it reduces the amount of data accessed | |
* at each step and that may give the OS more time to page it in. | |
*/ | |
png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input); | |
/* avail_in and avail_out are set below from 'size' */ | |
png_ptr->zstream.avail_in = 0; | |
png_ptr->zstream.avail_out = 0; | |
/* Read directly into the output if it is available (this is set to | |
* a local buffer below if output is NULL). | |
*/ | |
if (output != NULL) | |
png_ptr->zstream.next_out = output; | |
do | |
{ | |
uInt avail; | |
Byte local_buffer[PNG_INFLATE_BUF_SIZE]; | |
/* zlib INPUT BUFFER */ | |
/* The setting of 'avail_in' used to be outside the loop; by setting it | |
* inside it is possible to chunk the input to zlib and simply rely on | |
* zlib to advance the 'next_in' pointer. This allows arbitrary | |
* amounts of data to be passed through zlib at the unavoidable cost of | |
* requiring a window save (memcpy of up to 32768 output bytes) | |
* every ZLIB_IO_MAX input bytes. | |
*/ | |
avail_in += png_ptr->zstream.avail_in; /* not consumed last time */ | |
avail = ZLIB_IO_MAX; | |
if (avail_in < avail) | |
avail = (uInt)avail_in; /* safe: < than ZLIB_IO_MAX */ | |
avail_in -= avail; | |
png_ptr->zstream.avail_in = avail; | |
/* zlib OUTPUT BUFFER */ | |
avail_out += png_ptr->zstream.avail_out; /* not written last time */ | |
avail = ZLIB_IO_MAX; /* maximum zlib can process */ | |
if (output == NULL) | |
{ | |
/* Reset the output buffer each time round if output is NULL and | |
* make available the full buffer, up to 'remaining_space' | |
*/ | |
png_ptr->zstream.next_out = local_buffer; | |
if ((sizeof local_buffer) < avail) | |
avail = (sizeof local_buffer); | |
} | |
if (avail_out < avail) | |
avail = (uInt)avail_out; /* safe: < ZLIB_IO_MAX */ | |
png_ptr->zstream.avail_out = avail; | |
avail_out -= avail; | |
/* zlib inflate call */ | |
/* In fact 'avail_out' may be 0 at this point, that happens at the end | |
* of the read when the final LZ end code was not passed at the end of | |
* the previous chunk of input data. Tell zlib if we have reached the | |
* end of the output buffer. | |
*/ | |
ret = inflate(&png_ptr->zstream, avail_out > 0 ? Z_NO_FLUSH : | |
(finish ? Z_FINISH : Z_SYNC_FLUSH)); | |
} while (ret == Z_OK); | |
/* For safety kill the local buffer pointer now */ | |
if (output == NULL) | |
png_ptr->zstream.next_out = NULL; | |
/* Claw back the 'size' and 'remaining_space' byte counts. */ | |
avail_in += png_ptr->zstream.avail_in; | |
avail_out += png_ptr->zstream.avail_out; | |
/* Update the input and output sizes; the updated values are the amount | |
* consumed or written, effectively the inverse of what zlib uses. | |
*/ | |
if (avail_out > 0) | |
*output_size_ptr -= avail_out; | |
if (avail_in > 0) | |
*input_size_ptr -= avail_in; | |
/* Ensure png_ptr->zstream.msg is set (even in the success case!) */ | |
png_zstream_error(png_ptr, ret); | |
return ret; | |
} | |
else | |
{ | |
/* This is a bad internal error. The recovery assigns to the zstream msg | |
* pointer, which is not owned by the caller, but this is safe; it's only | |
* used on errors! | |
*/ | |
png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed"); | |
return Z_STREAM_ERROR; | |
} | |
} | |
/* | |
* Decompress trailing data in a chunk. The assumption is that read_buffer | |
* points at an allocated area holding the contents of a chunk with a | |
* trailing compressed part. What we get back is an allocated area | |
* holding the original prefix part and an uncompressed version of the | |
* trailing part (the malloc area passed in is freed). | |
*/ | |
static int | |
png_decompress_chunk(png_structrp png_ptr, | |
png_uint_32 chunklength, png_uint_32 prefix_size, | |
png_alloc_size_t *newlength /* must be initialized to the maximum! */, | |
int terminate /*add a '\0' to the end of the uncompressed data*/) | |
{ | |
/* TODO: implement different limits for different types of chunk. | |
* | |
* The caller supplies *newlength set to the maximum length of the | |
* uncompressed data, but this routine allocates space for the prefix and | |
* maybe a '\0' terminator too. We have to assume that 'prefix_size' is | |
* limited only by the maximum chunk size. | |
*/ | |
png_alloc_size_t limit = PNG_SIZE_MAX; | |
# ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED | |
if (png_ptr->user_chunk_malloc_max > 0 && | |
png_ptr->user_chunk_malloc_max < limit) | |
limit = png_ptr->user_chunk_malloc_max; | |
# elif PNG_USER_CHUNK_MALLOC_MAX > 0 | |
if (PNG_USER_CHUNK_MALLOC_MAX < limit) | |
limit = PNG_USER_CHUNK_MALLOC_MAX; | |
# endif | |
if (limit >= prefix_size + (terminate != 0)) | |
{ | |
int ret; | |
limit -= prefix_size + (terminate != 0); | |
if (limit < *newlength) | |
*newlength = limit; | |
/* Now try to claim the stream. */ | |
ret = png_inflate_claim(png_ptr, png_ptr->chunk_name); | |
if (ret == Z_OK) | |
{ | |
png_uint_32 lzsize = chunklength - prefix_size; | |
ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/, | |
/* input: */ png_ptr->read_buffer + prefix_size, &lzsize, | |
/* output: */ NULL, newlength); | |
if (ret == Z_STREAM_END) | |
{ | |
/* Use 'inflateReset' here, not 'inflateReset2' because this | |
* preserves the previously decided window size (otherwise it would | |
* be necessary to store the previous window size.) In practice | |
* this doesn't matter anyway, because png_inflate will call inflate | |
* with Z_FINISH in almost all cases, so the window will not be | |
* maintained. | |
*/ | |
if (inflateReset(&png_ptr->zstream) == Z_OK) | |
{ | |
/* Because of the limit checks above we know that the new, | |
* expanded, size will fit in a size_t (let alone an | |
* png_alloc_size_t). Use png_malloc_base here to avoid an | |
* extra OOM message. | |
*/ | |
png_alloc_size_t new_size = *newlength; | |
png_alloc_size_t buffer_size = prefix_size + new_size + | |
(terminate != 0); | |
png_bytep text = png_voidcast(png_bytep, png_malloc_base(png_ptr, | |
buffer_size)); | |
if (text != NULL) | |
{ | |
ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/, | |
png_ptr->read_buffer + prefix_size, &lzsize, | |
text + prefix_size, newlength); | |
if (ret == Z_STREAM_END) | |
{ | |
if (new_size == *newlength) | |
{ | |
if (terminate) | |
text[prefix_size + *newlength] = 0; | |
if (prefix_size > 0) | |
memcpy(text, png_ptr->read_buffer, prefix_size); | |
{ | |
png_bytep old_ptr = png_ptr->read_buffer; | |
png_ptr->read_buffer = text; | |
png_ptr->read_buffer_size = buffer_size; | |
text = old_ptr; /* freed below */ | |
} | |
} | |
else | |
{ | |
/* The size changed on the second read, there can be no | |
* guarantee that anything is correct at this point. | |
* The 'msg' pointer has been set to "unexpected end of | |
* LZ stream", which is fine, but return an error code | |
* that the caller won't accept. | |
*/ | |
ret = PNG_UNEXPECTED_ZLIB_RETURN; | |
} | |
} | |
else if (ret == Z_OK) | |
ret = PNG_UNEXPECTED_ZLIB_RETURN; /* for safety */ | |
/* Free the text pointer (this is the old read_buffer on | |
* success) | |
*/ | |
png_free(png_ptr, text); | |
/* This really is very benign, but it's still an error because | |
* the extra space may otherwise be used as a Trojan Horse. | |
*/ | |
if (ret == Z_STREAM_END && | |
chunklength - prefix_size != lzsize) | |
png_chunk_benign_error(png_ptr, "extra compressed data"); | |
} | |
else | |
{ | |
/* Out of memory allocating the buffer */ | |
ret = Z_MEM_ERROR; | |
png_zstream_error(png_ptr, Z_MEM_ERROR); | |
} | |
} | |
else | |
{ | |
/* inflateReset failed, store the error message */ | |
png_zstream_error(png_ptr, ret); | |
if (ret == Z_STREAM_END) | |
ret = PNG_UNEXPECTED_ZLIB_RETURN; | |
} | |
} | |
else if (ret == Z_OK) | |
ret = PNG_UNEXPECTED_ZLIB_RETURN; | |
/* Release the claimed stream */ | |
png_ptr->zowner = 0; | |
} | |
else /* the claim failed */ if (ret == Z_STREAM_END) /* impossible! */ | |
ret = PNG_UNEXPECTED_ZLIB_RETURN; | |
return ret; | |
} | |
else | |
{ | |
/* Application/configuration limits exceeded */ | |
png_zstream_error(png_ptr, Z_MEM_ERROR); | |
return Z_MEM_ERROR; | |
} | |
} | |
#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */ | |
#ifdef PNG_READ_iCCP_SUPPORTED | |
/* Perform a partial read and decompress, producing 'avail_out' bytes and | |
* reading from the current chunk as required. | |
*/ | |
static int | |
png_inflate_read(png_structrp png_ptr, png_bytep read_buffer, uInt read_size, | |
png_uint_32p chunk_bytes, png_bytep next_out, png_alloc_size_t *out_size, | |
int finish) | |
{ | |
if (png_ptr->zowner == png_ptr->chunk_name) | |
{ | |
int ret; | |
/* next_in and avail_in must have been initialized by the caller. */ | |
png_ptr->zstream.next_out = next_out; | |
png_ptr->zstream.avail_out = 0; /* set in the loop */ | |
do | |
{ | |
if (png_ptr->zstream.avail_in == 0) | |
{ | |
if (read_size > *chunk_bytes) | |
read_size = (uInt)*chunk_bytes; | |
*chunk_bytes -= read_size; | |
if (read_size > 0) | |
png_crc_read(png_ptr, read_buffer, read_size); | |
png_ptr->zstream.next_in = read_buffer; | |
png_ptr->zstream.avail_in = read_size; | |
} | |
if (png_ptr->zstream.avail_out == 0) | |
{ | |
uInt avail = ZLIB_IO_MAX; | |
if (avail > *out_size) | |
avail = (uInt)*out_size; | |
*out_size -= avail; | |
png_ptr->zstream.avail_out = avail; | |
} | |
/* Use Z_SYNC_FLUSH when there is no more chunk data to ensure that all | |
* the available output is produced; this allows reading of truncated | |
* streams. | |
*/ | |
ret = inflate(&png_ptr->zstream, | |
*chunk_bytes > 0 ? Z_NO_FLUSH : (finish ? Z_FINISH : Z_SYNC_FLUSH)); | |
} | |
while (ret == Z_OK && (*out_size > 0 || png_ptr->zstream.avail_out > 0)); | |
*out_size += png_ptr->zstream.avail_out; | |
png_ptr->zstream.avail_out = 0; /* Should not be required, but is safe */ | |
/* Ensure the error message pointer is always set: */ | |
png_zstream_error(png_ptr, ret); | |
return ret; | |
} | |
else | |
{ | |
png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed"); | |
return Z_STREAM_ERROR; | |
} | |
} | |
#endif | |
/* Read and check the IDHR chunk */ | |
void /* PRIVATE */ | |
png_handle_IHDR(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_byte buf[13]; | |
png_uint_32 width, height; | |
int bit_depth, color_type, compression_type, filter_type; | |
int interlace_type; | |
png_debug(1, "in png_handle_IHDR"); | |
if (png_ptr->mode & PNG_HAVE_IHDR) | |
png_chunk_error(png_ptr, "out of place"); | |
/* Check the length */ | |
if (length != 13) | |
png_chunk_error(png_ptr, "invalid"); | |
png_ptr->mode |= PNG_HAVE_IHDR; | |
png_crc_read(png_ptr, buf, 13); | |
png_crc_finish(png_ptr, 0); | |
width = png_get_uint_31(png_ptr, buf); | |
height = png_get_uint_31(png_ptr, buf + 4); | |
bit_depth = buf[8]; | |
color_type = buf[9]; | |
compression_type = buf[10]; | |
filter_type = buf[11]; | |
interlace_type = buf[12]; | |
/* Set internal variables */ | |
png_ptr->width = width; | |
png_ptr->height = height; | |
png_ptr->bit_depth = (png_byte)bit_depth; | |
png_ptr->interlaced = (png_byte)interlace_type; | |
png_ptr->color_type = (png_byte)color_type; | |
#ifdef PNG_MNG_FEATURES_SUPPORTED | |
png_ptr->filter_type = (png_byte)filter_type; | |
#endif | |
png_ptr->compression_type = (png_byte)compression_type; | |
/* Find number of channels */ | |
switch (png_ptr->color_type) | |
{ | |
default: /* invalid, png_set_IHDR calls png_error */ | |
case PNG_COLOR_TYPE_GRAY: | |
case PNG_COLOR_TYPE_PALETTE: | |
png_ptr->channels = 1; | |
break; | |
case PNG_COLOR_TYPE_RGB: | |
png_ptr->channels = 3; | |
break; | |
case PNG_COLOR_TYPE_GRAY_ALPHA: | |
png_ptr->channels = 2; | |
break; | |
case PNG_COLOR_TYPE_RGB_ALPHA: | |
png_ptr->channels = 4; | |
break; | |
} | |
/* Set up other useful info */ | |
png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * | |
png_ptr->channels); | |
png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width); | |
png_debug1(3, "bit_depth = %d", png_ptr->bit_depth); | |
png_debug1(3, "channels = %d", png_ptr->channels); | |
png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes); | |
png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, | |
color_type, interlace_type, compression_type, filter_type); | |
} | |
/* Read and check the palette */ | |
void /* PRIVATE */ | |
png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_color palette[PNG_MAX_PALETTE_LENGTH]; | |
int num, i; | |
#ifdef PNG_POINTER_INDEXING_SUPPORTED | |
png_colorp pal_ptr; | |
#endif | |
png_debug(1, "in png_handle_PLTE"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
/* Moved to before the 'after IDAT' check below because otherwise duplicate | |
* PLTE chunks are potentially ignored (the spec says there shall not be more | |
* than one PLTE, the error is not treated as benign, so this check trumps | |
* the requirement that PLTE appears before IDAT.) | |
*/ | |
else if (png_ptr->mode & PNG_HAVE_PLTE) | |
png_chunk_error(png_ptr, "duplicate"); | |
else if (png_ptr->mode & PNG_HAVE_IDAT) | |
{ | |
/* This is benign because the non-benign error happened before, when an | |
* IDAT was encountered in a color-mapped image with no PLTE. | |
*/ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
png_ptr->mode |= PNG_HAVE_PLTE; | |
if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "ignored in grayscale PNG"); | |
return; | |
} | |
#ifndef PNG_READ_OPT_PLTE_SUPPORTED | |
if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) | |
{ | |
png_crc_finish(png_ptr, length); | |
return; | |
} | |
#endif | |
if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3) | |
{ | |
png_crc_finish(png_ptr, length); | |
if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) | |
png_chunk_benign_error(png_ptr, "invalid"); | |
else | |
png_chunk_error(png_ptr, "invalid"); | |
return; | |
} | |
/* The cast is safe because 'length' is less than 3*PNG_MAX_PALETTE_LENGTH */ | |
num = (int)length / 3; | |
#ifdef PNG_POINTER_INDEXING_SUPPORTED | |
for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++) | |
{ | |
png_byte buf[3]; | |
png_crc_read(png_ptr, buf, 3); | |
pal_ptr->red = buf[0]; | |
pal_ptr->green = buf[1]; | |
pal_ptr->blue = buf[2]; | |
} | |
#else | |
for (i = 0; i < num; i++) | |
{ | |
png_byte buf[3]; | |
png_crc_read(png_ptr, buf, 3); | |
/* Don't depend upon png_color being any order */ | |
palette[i].red = buf[0]; | |
palette[i].green = buf[1]; | |
palette[i].blue = buf[2]; | |
} | |
#endif | |
/* If we actually need the PLTE chunk (ie for a paletted image), we do | |
* whatever the normal CRC configuration tells us. However, if we | |
* have an RGB image, the PLTE can be considered ancillary, so | |
* we will act as though it is. | |
*/ | |
#ifndef PNG_READ_OPT_PLTE_SUPPORTED | |
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | |
#endif | |
{ | |
png_crc_finish(png_ptr, 0); | |
} | |
#ifndef PNG_READ_OPT_PLTE_SUPPORTED | |
else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */ | |
{ | |
/* If we don't want to use the data from an ancillary chunk, | |
* we have two options: an error abort, or a warning and we | |
* ignore the data in this chunk (which should be OK, since | |
* it's considered ancillary for a RGB or RGBA image). | |
* | |
* IMPLEMENTATION NOTE: this is only here because png_crc_finish uses the | |
* chunk type to determine whether to check the ancillary or the critical | |
* flags. | |
*/ | |
if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE)) | |
{ | |
if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) | |
{ | |
png_chunk_benign_error(png_ptr, "CRC error"); | |
} | |
else | |
{ | |
png_chunk_warning(png_ptr, "CRC error"); | |
return; | |
} | |
} | |
/* Otherwise, we (optionally) emit a warning and use the chunk. */ | |
else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) | |
{ | |
png_chunk_warning(png_ptr, "CRC error"); | |
} | |
} | |
#endif | |
/* TODO: png_set_PLTE has the side effect of setting png_ptr->palette to its | |
* own copy of the palette. This has the side effect that when png_start_row | |
* is called (this happens after any call to png_read_update_info) the | |
* info_ptr palette gets changed. This is extremely unexpected and | |
* confusing. | |
* | |
* Fix this by not sharing the palette in this way. | |
*/ | |
png_set_PLTE(png_ptr, info_ptr, palette, num); | |
/* The three chunks, bKGD, hIST and tRNS *must* appear after PLTE and before | |
* IDAT. Prior to 1.6.0 this was not checked; instead the code merely | |
* checked the apparent validity of a tRNS chunk inserted before PLTE on a | |
* palette PNG. 1.6.0 attempts to rigorously follow the standard and | |
* therefore does a benign error if the erroneous condition is detected *and* | |
* cancels the tRNS if the benign error returns. The alternative is to | |
* amend the standard since it would be rather hypocritical of the standards | |
* maintainers to ignore it. | |
*/ | |
#ifdef PNG_READ_tRNS_SUPPORTED | |
if (png_ptr->num_trans > 0 || | |
(info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0)) | |
{ | |
/* Cancel this because otherwise it would be used if the transforms | |
* require it. Don't cancel the 'valid' flag because this would prevent | |
* detection of duplicate chunks. | |
*/ | |
png_ptr->num_trans = 0; | |
if (info_ptr != NULL) | |
info_ptr->num_trans = 0; | |
png_chunk_benign_error(png_ptr, "tRNS must be after"); | |
} | |
#endif | |
#ifdef PNG_READ_hIST_SUPPORTED | |
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0) | |
png_chunk_benign_error(png_ptr, "hIST must be after"); | |
#endif | |
#ifdef PNG_READ_bKGD_SUPPORTED | |
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0) | |
png_chunk_benign_error(png_ptr, "bKGD must be after"); | |
#endif | |
} | |
void /* PRIVATE */ | |
png_handle_IEND(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_debug(1, "in png_handle_IEND"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT)) | |
png_chunk_error(png_ptr, "out of place"); | |
png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND); | |
png_crc_finish(png_ptr, length); | |
if (length != 0) | |
png_chunk_benign_error(png_ptr, "invalid"); | |
PNG_UNUSED(info_ptr) | |
} | |
#ifdef PNG_READ_gAMA_SUPPORTED | |
void /* PRIVATE */ | |
png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_fixed_point igamma; | |
png_byte buf[4]; | |
png_debug(1, "in png_handle_gAMA"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
if (length != 4) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "invalid"); | |
return; | |
} | |
png_crc_read(png_ptr, buf, 4); | |
if (png_crc_finish(png_ptr, 0)) | |
return; | |
igamma = png_get_fixed_point(NULL, buf); | |
png_colorspace_set_gamma(png_ptr, &png_ptr->colorspace, igamma); | |
png_colorspace_sync(png_ptr, info_ptr); | |
} | |
#endif | |
#ifdef PNG_READ_sBIT_SUPPORTED | |
void /* PRIVATE */ | |
png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
unsigned int truelen; | |
png_byte buf[4]; | |
png_debug(1, "in png_handle_sBIT"); | |
buf[0] = buf[1] = buf[2] = buf[3] = 0; | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "duplicate"); | |
return; | |
} | |
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | |
truelen = 3; | |
else | |
truelen = png_ptr->channels; | |
if (length != truelen || length > 4) | |
{ | |
png_chunk_benign_error(png_ptr, "invalid"); | |
png_crc_finish(png_ptr, length); | |
return; | |
} | |
png_crc_read(png_ptr, buf, truelen); | |
if (png_crc_finish(png_ptr, 0)) | |
return; | |
if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) | |
{ | |
png_ptr->sig_bit.red = buf[0]; | |
png_ptr->sig_bit.green = buf[1]; | |
png_ptr->sig_bit.blue = buf[2]; | |
png_ptr->sig_bit.alpha = buf[3]; | |
} | |
else | |
{ | |
png_ptr->sig_bit.gray = buf[0]; | |
png_ptr->sig_bit.red = buf[0]; | |
png_ptr->sig_bit.green = buf[0]; | |
png_ptr->sig_bit.blue = buf[0]; | |
png_ptr->sig_bit.alpha = buf[1]; | |
} | |
png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit)); | |
} | |
#endif | |
#ifdef PNG_READ_cHRM_SUPPORTED | |
void /* PRIVATE */ | |
png_handle_cHRM(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_byte buf[32]; | |
png_xy xy; | |
png_debug(1, "in png_handle_cHRM"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
if (length != 32) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "invalid"); | |
return; | |
} | |
png_crc_read(png_ptr, buf, 32); | |
if (png_crc_finish(png_ptr, 0)) | |
return; | |
xy.whitex = png_get_fixed_point(NULL, buf); | |
xy.whitey = png_get_fixed_point(NULL, buf + 4); | |
xy.redx = png_get_fixed_point(NULL, buf + 8); | |
xy.redy = png_get_fixed_point(NULL, buf + 12); | |
xy.greenx = png_get_fixed_point(NULL, buf + 16); | |
xy.greeny = png_get_fixed_point(NULL, buf + 20); | |
xy.bluex = png_get_fixed_point(NULL, buf + 24); | |
xy.bluey = png_get_fixed_point(NULL, buf + 28); | |
if (xy.whitex == PNG_FIXED_ERROR || | |
xy.whitey == PNG_FIXED_ERROR || | |
xy.redx == PNG_FIXED_ERROR || | |
xy.redy == PNG_FIXED_ERROR || | |
xy.greenx == PNG_FIXED_ERROR || | |
xy.greeny == PNG_FIXED_ERROR || | |
xy.bluex == PNG_FIXED_ERROR || | |
xy.bluey == PNG_FIXED_ERROR) | |
{ | |
png_chunk_benign_error(png_ptr, "invalid values"); | |
return; | |
} | |
/* If a colorspace error has already been output skip this chunk */ | |
if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) | |
return; | |
if (png_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) | |
{ | |
png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID; | |
png_colorspace_sync(png_ptr, info_ptr); | |
png_chunk_benign_error(png_ptr, "duplicate"); | |
return; | |
} | |
png_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM; | |
(void)png_colorspace_set_chromaticities(png_ptr, &png_ptr->colorspace, &xy, | |
1/*prefer cHRM values*/); | |
png_colorspace_sync(png_ptr, info_ptr); | |
} | |
#endif | |
#ifdef PNG_READ_sRGB_SUPPORTED | |
void /* PRIVATE */ | |
png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_byte intent; | |
png_debug(1, "in png_handle_sRGB"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
if (length != 1) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "invalid"); | |
return; | |
} | |
png_crc_read(png_ptr, &intent, 1); | |
if (png_crc_finish(png_ptr, 0)) | |
return; | |
/* If a colorspace error has already been output skip this chunk */ | |
if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) | |
return; | |
/* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect | |
* this. | |
*/ | |
if (png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) | |
{ | |
png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID; | |
png_colorspace_sync(png_ptr, info_ptr); | |
png_chunk_benign_error(png_ptr, "too many profiles"); | |
return; | |
} | |
(void)png_colorspace_set_sRGB(png_ptr, &png_ptr->colorspace, intent); | |
png_colorspace_sync(png_ptr, info_ptr); | |
} | |
#endif /* PNG_READ_sRGB_SUPPORTED */ | |
#ifdef PNG_READ_iCCP_SUPPORTED | |
void /* PRIVATE */ | |
png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
/* Note: this does not properly handle profiles that are > 64K under DOS */ | |
{ | |
png_const_charp errmsg = NULL; /* error message output, or no error */ | |
int finished = 0; /* crc checked */ | |
png_debug(1, "in png_handle_iCCP"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
/* Consistent with all the above colorspace handling an obviously *invalid* | |
* chunk is just ignored, so does not invalidate the color space. An | |
* alternative is to set the 'invalid' flags at the start of this routine | |
* and only clear them in they were not set before and all the tests pass. | |
* The minimum 'deflate' stream is assumed to be just the 2 byte header and 4 | |
* byte checksum. The keyword must be one character and there is a | |
* terminator (0) byte and the compression method. | |
*/ | |
if (length < 9) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "too short"); | |
return; | |
} | |
/* If a colorspace error has already been output skip this chunk */ | |
if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) | |
{ | |
png_crc_finish(png_ptr, length); | |
return; | |
} | |
/* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect | |
* this. | |
*/ | |
if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) == 0) | |
{ | |
uInt read_length, keyword_length; | |
char keyword[81]; | |
/* Find the keyword; the keyword plus separator and compression method | |
* bytes can be at most 81 characters long. | |
*/ | |
read_length = 81; /* maximum */ | |
if (read_length > length) | |
read_length = (uInt)length; | |
png_crc_read(png_ptr, (png_bytep)keyword, read_length); | |
length -= read_length; | |
keyword_length = 0; | |
while (keyword_length < 80 && keyword_length < read_length && | |
keyword[keyword_length] != 0) | |
++keyword_length; | |
/* TODO: make the keyword checking common */ | |
if (keyword_length >= 1 && keyword_length <= 79) | |
{ | |
/* We only understand '0' compression - deflate - so if we get a | |
* different value we can't safely decode the chunk. | |
*/ | |
if (keyword_length+1 < read_length && | |
keyword[keyword_length+1] == PNG_COMPRESSION_TYPE_BASE) | |
{ | |
read_length -= keyword_length+2; | |
if (png_inflate_claim(png_ptr, png_iCCP) == Z_OK) | |
{ | |
Byte profile_header[132]; | |
Byte local_buffer[PNG_INFLATE_BUF_SIZE]; | |
png_alloc_size_t size = (sizeof profile_header); | |
png_ptr->zstream.next_in = (Bytef*)keyword + (keyword_length+2); | |
png_ptr->zstream.avail_in = read_length; | |
(void)png_inflate_read(png_ptr, local_buffer, | |
(sizeof local_buffer), &length, profile_header, &size, | |
0/*finish: don't, because the output is too small*/); | |
if (size == 0) | |
{ | |
/* We have the ICC profile header; do the basic header checks. | |
*/ | |
const png_uint_32 profile_length = | |
png_get_uint_32(profile_header); | |
if (png_icc_check_length(png_ptr, &png_ptr->colorspace, | |
keyword, profile_length)) | |
{ | |
/* The length is apparently ok, so we can check the 132 | |
* byte header. | |
*/ | |
if (png_icc_check_header(png_ptr, &png_ptr->colorspace, | |
keyword, profile_length, profile_header, | |
png_ptr->color_type)) | |
{ | |
/* Now read the tag table; a variable size buffer is | |
* needed at this point, allocate one for the whole | |
* profile. The header check has already validated | |
* that none of these stuff will overflow. | |
*/ | |
const png_uint_32 tag_count = png_get_uint_32( | |
profile_header+128); | |
png_bytep profile = png_read_buffer(png_ptr, | |
profile_length, 2/*silent*/); | |
if (profile != NULL) | |
{ | |
memcpy(profile, profile_header, | |
(sizeof profile_header)); | |
size = 12 * tag_count; | |
(void)png_inflate_read(png_ptr, local_buffer, | |
(sizeof local_buffer), &length, | |
profile + (sizeof profile_header), &size, 0); | |
/* Still expect a a buffer error because we expect | |
* there to be some tag data! | |
*/ | |
if (size == 0) | |
{ | |
if (png_icc_check_tag_table(png_ptr, | |
&png_ptr->colorspace, keyword, profile_length, | |
profile)) | |
{ | |
/* The profile has been validated for basic | |
* security issues, so read the whole thing in. | |
*/ | |
size = profile_length - (sizeof profile_header) | |
- 12 * tag_count; | |
(void)png_inflate_read(png_ptr, local_buffer, | |
(sizeof local_buffer), &length, | |
profile + (sizeof profile_header) + | |
12 * tag_count, &size, 1/*finish*/); | |
if (length > 0 && !(png_ptr->flags & | |
PNG_FLAG_BENIGN_ERRORS_WARN)) | |
errmsg = "extra compressed data"; | |
/* But otherwise allow extra data: */ | |
else if (size == 0) | |
{ | |
if (length > 0) | |
{ | |
/* This can be handled completely, so | |
* keep going. | |
*/ | |
png_chunk_warning(png_ptr, | |
"extra compressed data"); | |
} | |
png_crc_finish(png_ptr, length); | |
finished = 1; | |
# ifdef PNG_sRGB_SUPPORTED | |
/* Check for a match against sRGB */ | |
png_icc_set_sRGB(png_ptr, | |
&png_ptr->colorspace, profile, | |
png_ptr->zstream.adler); | |
# endif | |
/* Steal the profile for info_ptr. */ | |
if (info_ptr != NULL) | |
{ | |
png_free_data(png_ptr, info_ptr, | |
PNG_FREE_ICCP, 0); | |
info_ptr->iccp_name = png_voidcast(char*, | |
png_malloc_base(png_ptr, | |
keyword_length+1)); | |
if (info_ptr->iccp_name != NULL) | |
{ | |
memcpy(info_ptr->iccp_name, keyword, | |
keyword_length+1); | |
info_ptr->iccp_proflen = | |
profile_length; | |
info_ptr->iccp_profile = profile; | |
png_ptr->read_buffer = NULL; /*steal*/ | |
info_ptr->free_me |= PNG_FREE_ICCP; | |
info_ptr->valid |= PNG_INFO_iCCP; | |
} | |
else | |
{ | |
png_ptr->colorspace.flags |= | |
PNG_COLORSPACE_INVALID; | |
errmsg = "out of memory"; | |
} | |
} | |
/* else the profile remains in the read | |
* buffer which gets reused for subsequent | |
* chunks. | |
*/ | |
if (info_ptr != NULL) | |
png_colorspace_sync(png_ptr, info_ptr); | |
if (errmsg == NULL) | |
{ | |
png_ptr->zowner = 0; | |
return; | |
} | |
} | |
else if (size > 0) | |
errmsg = "truncated"; | |
else | |
errmsg = png_ptr->zstream.msg; | |
} | |
/* else png_icc_check_tag_table output an error */ | |
} | |
else /* profile truncated */ | |
errmsg = png_ptr->zstream.msg; | |
} | |
else | |
errmsg = "out of memory"; | |
} | |
/* else png_icc_check_header output an error */ | |
} | |
/* else png_icc_check_length output an error */ | |
} | |
else /* profile truncated */ | |
errmsg = png_ptr->zstream.msg; | |
/* Release the stream */ | |
png_ptr->zowner = 0; | |
} | |
else /* png_inflate_claim failed */ | |
errmsg = png_ptr->zstream.msg; | |
} | |
else | |
errmsg = "bad compression method"; /* or missing */ | |
} | |
else | |
errmsg = "bad keyword"; | |
} | |
else | |
errmsg = "too many profiles"; | |
/* Failure: the reason is in 'errmsg' */ | |
if (!finished) | |
png_crc_finish(png_ptr, length); | |
png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID; | |
png_colorspace_sync(png_ptr, info_ptr); | |
if (errmsg != NULL) /* else already output */ | |
png_chunk_benign_error(png_ptr, errmsg); | |
} | |
#endif /* PNG_READ_iCCP_SUPPORTED */ | |
#ifdef PNG_READ_sPLT_SUPPORTED | |
void /* PRIVATE */ | |
png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
/* Note: this does not properly handle chunks that are > 64K under DOS */ | |
{ | |
png_bytep entry_start, buffer; | |
png_sPLT_t new_palette; | |
png_sPLT_entryp pp; | |
png_uint_32 data_length; | |
int entry_size, i; | |
png_uint_32 skip = 0; | |
png_uint_32 dl; | |
png_size_t max_dl; | |
png_debug(1, "in png_handle_sPLT"); | |
#ifdef PNG_USER_LIMITS_SUPPORTED | |
if (png_ptr->user_chunk_cache_max != 0) | |
{ | |
if (png_ptr->user_chunk_cache_max == 1) | |
{ | |
png_crc_finish(png_ptr, length); | |
return; | |
} | |
if (--png_ptr->user_chunk_cache_max == 1) | |
{ | |
png_warning(png_ptr, "No space in chunk cache for sPLT"); | |
png_crc_finish(png_ptr, length); | |
return; | |
} | |
} | |
#endif | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if (png_ptr->mode & PNG_HAVE_IDAT) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
#ifdef PNG_MAX_MALLOC_64K | |
if (length > 65535U) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "too large to fit in memory"); | |
return; | |
} | |
#endif | |
buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/); | |
if (buffer == NULL) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of memory"); | |
return; | |
} | |
/* WARNING: this may break if size_t is less than 32 bits; it is assumed | |
* that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a | |
* potential breakage point if the types in pngconf.h aren't exactly right. | |
*/ | |
png_crc_read(png_ptr, buffer, length); | |
if (png_crc_finish(png_ptr, skip)) | |
return; | |
buffer[length] = 0; | |
for (entry_start = buffer; *entry_start; entry_start++) | |
/* Empty loop to find end of name */ ; | |
++entry_start; | |
/* A sample depth should follow the separator, and we should be on it */ | |
if (entry_start > buffer + length - 2) | |
{ | |
png_warning(png_ptr, "malformed sPLT chunk"); | |
return; | |
} | |
new_palette.depth = *entry_start++; | |
entry_size = (new_palette.depth == 8 ? 6 : 10); | |
/* This must fit in a png_uint_32 because it is derived from the original | |
* chunk data length. | |
*/ | |
data_length = length - (png_uint_32)(entry_start - buffer); | |
/* Integrity-check the data length */ | |
if (data_length % entry_size) | |
{ | |
png_warning(png_ptr, "sPLT chunk has bad length"); | |
return; | |
} | |
dl = (png_int_32)(data_length / entry_size); | |
max_dl = PNG_SIZE_MAX / (sizeof (png_sPLT_entry)); | |
if (dl > max_dl) | |
{ | |
png_warning(png_ptr, "sPLT chunk too long"); | |
return; | |
} | |
new_palette.nentries = (png_int_32)(data_length / entry_size); | |
new_palette.entries = (png_sPLT_entryp)png_malloc_warn( | |
png_ptr, new_palette.nentries * (sizeof (png_sPLT_entry))); | |
if (new_palette.entries == NULL) | |
{ | |
png_warning(png_ptr, "sPLT chunk requires too much memory"); | |
return; | |
} | |
#ifdef PNG_POINTER_INDEXING_SUPPORTED | |
for (i = 0; i < new_palette.nentries; i++) | |
{ | |
pp = new_palette.entries + i; | |
if (new_palette.depth == 8) | |
{ | |
pp->red = *entry_start++; | |
pp->green = *entry_start++; | |
pp->blue = *entry_start++; | |
pp->alpha = *entry_start++; | |
} | |
else | |
{ | |
pp->red = png_get_uint_16(entry_start); entry_start += 2; | |
pp->green = png_get_uint_16(entry_start); entry_start += 2; | |
pp->blue = png_get_uint_16(entry_start); entry_start += 2; | |
pp->alpha = png_get_uint_16(entry_start); entry_start += 2; | |
} | |
pp->frequency = png_get_uint_16(entry_start); entry_start += 2; | |
} | |
#else | |
pp = new_palette.entries; | |
for (i = 0; i < new_palette.nentries; i++) | |
{ | |
if (new_palette.depth == 8) | |
{ | |
pp[i].red = *entry_start++; | |
pp[i].green = *entry_start++; | |
pp[i].blue = *entry_start++; | |
pp[i].alpha = *entry_start++; | |
} | |
else | |
{ | |
pp[i].red = png_get_uint_16(entry_start); entry_start += 2; | |
pp[i].green = png_get_uint_16(entry_start); entry_start += 2; | |
pp[i].blue = png_get_uint_16(entry_start); entry_start += 2; | |
pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2; | |
} | |
pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2; | |
} | |
#endif | |
/* Discard all chunk data except the name and stash that */ | |
new_palette.name = (png_charp)buffer; | |
png_set_sPLT(png_ptr, info_ptr, &new_palette, 1); | |
png_free(png_ptr, new_palette.entries); | |
} | |
#endif /* PNG_READ_sPLT_SUPPORTED */ | |
#ifdef PNG_READ_tRNS_SUPPORTED | |
void /* PRIVATE */ | |
png_handle_tRNS(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_byte readbuf[PNG_MAX_PALETTE_LENGTH]; | |
png_debug(1, "in png_handle_tRNS"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if (png_ptr->mode & PNG_HAVE_IDAT) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "duplicate"); | |
return; | |
} | |
if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) | |
{ | |
png_byte buf[2]; | |
if (length != 2) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "invalid"); | |
return; | |
} | |
png_crc_read(png_ptr, buf, 2); | |
png_ptr->num_trans = 1; | |
png_ptr->trans_color.gray = png_get_uint_16(buf); | |
} | |
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) | |
{ | |
png_byte buf[6]; | |
if (length != 6) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "invalid"); | |
return; | |
} | |
png_crc_read(png_ptr, buf, length); | |
png_ptr->num_trans = 1; | |
png_ptr->trans_color.red = png_get_uint_16(buf); | |
png_ptr->trans_color.green = png_get_uint_16(buf + 2); | |
png_ptr->trans_color.blue = png_get_uint_16(buf + 4); | |
} | |
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | |
{ | |
if (!(png_ptr->mode & PNG_HAVE_PLTE)) | |
{ | |
/* TODO: is this actually an error in the ISO spec? */ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
if (length > png_ptr->num_palette || length > PNG_MAX_PALETTE_LENGTH || | |
length == 0) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "invalid"); | |
return; | |
} | |
png_crc_read(png_ptr, readbuf, length); | |
png_ptr->num_trans = (png_uint_16)length; | |
} | |
else | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "invalid with alpha channel"); | |
return; | |
} | |
if (png_crc_finish(png_ptr, 0)) | |
{ | |
png_ptr->num_trans = 0; | |
return; | |
} | |
/* TODO: this is a horrible side effect in the palette case because the | |
* png_struct ends up with a pointer to the tRNS buffer owned by the | |
* png_info. Fix this. | |
*/ | |
png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans, | |
&(png_ptr->trans_color)); | |
} | |
#endif | |
#ifdef PNG_READ_bKGD_SUPPORTED | |
void /* PRIVATE */ | |
png_handle_bKGD(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
unsigned int truelen; | |
png_byte buf[6]; | |
png_color_16 background; | |
png_debug(1, "in png_handle_bKGD"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if ((png_ptr->mode & PNG_HAVE_IDAT) || | |
(png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && | |
!(png_ptr->mode & PNG_HAVE_PLTE))) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "duplicate"); | |
return; | |
} | |
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | |
truelen = 1; | |
else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) | |
truelen = 6; | |
else | |
truelen = 2; | |
if (length != truelen) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "invalid"); | |
return; | |
} | |
png_crc_read(png_ptr, buf, truelen); | |
if (png_crc_finish(png_ptr, 0)) | |
return; | |
/* We convert the index value into RGB components so that we can allow | |
* arbitrary RGB values for background when we have transparency, and | |
* so it is easy to determine the RGB values of the background color | |
* from the info_ptr struct. | |
*/ | |
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | |
{ | |
background.index = buf[0]; | |
if (info_ptr && info_ptr->num_palette) | |
{ | |
if (buf[0] >= info_ptr->num_palette) | |
{ | |
png_chunk_benign_error(png_ptr, "invalid index"); | |
return; | |
} | |
background.red = (png_uint_16)png_ptr->palette[buf[0]].red; | |
background.green = (png_uint_16)png_ptr->palette[buf[0]].green; | |
background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue; | |
} | |
else | |
background.red = background.green = background.blue = 0; | |
background.gray = 0; | |
} | |
else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */ | |
{ | |
background.index = 0; | |
background.red = | |
background.green = | |
background.blue = | |
background.gray = png_get_uint_16(buf); | |
} | |
else | |
{ | |
background.index = 0; | |
background.red = png_get_uint_16(buf); | |
background.green = png_get_uint_16(buf + 2); | |
background.blue = png_get_uint_16(buf + 4); | |
background.gray = 0; | |
} | |
png_set_bKGD(png_ptr, info_ptr, &background); | |
} | |
#endif | |
#ifdef PNG_READ_hIST_SUPPORTED | |
void /* PRIVATE */ | |
png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
unsigned int num, i; | |
png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH]; | |
png_debug(1, "in png_handle_hIST"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if ((png_ptr->mode & PNG_HAVE_IDAT) || !(png_ptr->mode & PNG_HAVE_PLTE)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "duplicate"); | |
return; | |
} | |
num = length / 2 ; | |
if (num != png_ptr->num_palette || num > PNG_MAX_PALETTE_LENGTH) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "invalid"); | |
return; | |
} | |
for (i = 0; i < num; i++) | |
{ | |
png_byte buf[2]; | |
png_crc_read(png_ptr, buf, 2); | |
readbuf[i] = png_get_uint_16(buf); | |
} | |
if (png_crc_finish(png_ptr, 0)) | |
return; | |
png_set_hIST(png_ptr, info_ptr, readbuf); | |
} | |
#endif | |
#ifdef PNG_READ_pHYs_SUPPORTED | |
void /* PRIVATE */ | |
png_handle_pHYs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_byte buf[9]; | |
png_uint_32 res_x, res_y; | |
int unit_type; | |
png_debug(1, "in png_handle_pHYs"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if (png_ptr->mode & PNG_HAVE_IDAT) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "duplicate"); | |
return; | |
} | |
if (length != 9) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "invalid"); | |
return; | |
} | |
png_crc_read(png_ptr, buf, 9); | |
if (png_crc_finish(png_ptr, 0)) | |
return; | |
res_x = png_get_uint_32(buf); | |
res_y = png_get_uint_32(buf + 4); | |
unit_type = buf[8]; | |
png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type); | |
} | |
#endif | |
#ifdef PNG_READ_oFFs_SUPPORTED | |
void /* PRIVATE */ | |
png_handle_oFFs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_byte buf[9]; | |
png_int_32 offset_x, offset_y; | |
int unit_type; | |
png_debug(1, "in png_handle_oFFs"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if (png_ptr->mode & PNG_HAVE_IDAT) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "duplicate"); | |
return; | |
} | |
if (length != 9) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "invalid"); | |
return; | |
} | |
png_crc_read(png_ptr, buf, 9); | |
if (png_crc_finish(png_ptr, 0)) | |
return; | |
offset_x = png_get_int_32(buf); | |
offset_y = png_get_int_32(buf + 4); | |
unit_type = buf[8]; | |
png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type); | |
} | |
#endif | |
#ifdef PNG_READ_pCAL_SUPPORTED | |
/* Read the pCAL chunk (described in the PNG Extensions document) */ | |
void /* PRIVATE */ | |
png_handle_pCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_int_32 X0, X1; | |
png_byte type, nparams; | |
png_bytep buffer, buf, units, endptr; | |
png_charpp params; | |
int i; | |
png_debug(1, "in png_handle_pCAL"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if (png_ptr->mode & PNG_HAVE_IDAT) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "duplicate"); | |
return; | |
} | |
png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)", | |
length + 1); | |
buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/); | |
if (buffer == NULL) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of memory"); | |
return; | |
} | |
png_crc_read(png_ptr, buffer, length); | |
if (png_crc_finish(png_ptr, 0)) | |
return; | |
buffer[length] = 0; /* Null terminate the last string */ | |
png_debug(3, "Finding end of pCAL purpose string"); | |
for (buf = buffer; *buf; buf++) | |
/* Empty loop */ ; | |
endptr = buffer + length; | |
/* We need to have at least 12 bytes after the purpose string | |
* in order to get the parameter information. | |
*/ | |
if (endptr <= buf + 12) | |
{ | |
png_chunk_benign_error(png_ptr, "invalid"); | |
return; | |
} | |
png_debug(3, "Reading pCAL X0, X1, type, nparams, and units"); | |
X0 = png_get_int_32((png_bytep)buf+1); | |
X1 = png_get_int_32((png_bytep)buf+5); | |
type = buf[9]; | |
nparams = buf[10]; | |
units = buf + 11; | |
png_debug(3, "Checking pCAL equation type and number of parameters"); | |
/* Check that we have the right number of parameters for known | |
* equation types. | |
*/ | |
if ((type == PNG_EQUATION_LINEAR && nparams != 2) || | |
(type == PNG_EQUATION_BASE_E && nparams != 3) || | |
(type == PNG_EQUATION_ARBITRARY && nparams != 3) || | |
(type == PNG_EQUATION_HYPERBOLIC && nparams != 4)) | |
{ | |
png_chunk_benign_error(png_ptr, "invalid parameter count"); | |
return; | |
} | |
else if (type >= PNG_EQUATION_LAST) | |
{ | |
png_chunk_benign_error(png_ptr, "unrecognized equation type"); | |
} | |
for (buf = units; *buf; buf++) | |
/* Empty loop to move past the units string. */ ; | |
png_debug(3, "Allocating pCAL parameters array"); | |
params = png_voidcast(png_charpp, png_malloc_warn(png_ptr, | |
nparams * (sizeof (png_charp)))); | |
if (params == NULL) | |
{ | |
png_chunk_benign_error(png_ptr, "out of memory"); | |
return; | |
} | |
/* Get pointers to the start of each parameter string. */ | |
for (i = 0; i < nparams; i++) | |
{ | |
buf++; /* Skip the null string terminator from previous parameter. */ | |
png_debug1(3, "Reading pCAL parameter %d", i); | |
for (params[i] = (png_charp)buf; buf <= endptr && *buf != 0; buf++) | |
/* Empty loop to move past each parameter string */ ; | |
/* Make sure we haven't run out of data yet */ | |
if (buf > endptr) | |
{ | |
png_free(png_ptr, params); | |
png_chunk_benign_error(png_ptr, "invalid data"); | |
return; | |
} | |
} | |
png_set_pCAL(png_ptr, info_ptr, (png_charp)buffer, X0, X1, type, nparams, | |
(png_charp)units, params); | |
png_free(png_ptr, params); | |
} | |
#endif | |
#ifdef PNG_READ_sCAL_SUPPORTED | |
/* Read the sCAL chunk */ | |
void /* PRIVATE */ | |
png_handle_sCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_bytep buffer; | |
png_size_t i; | |
int state; | |
png_debug(1, "in png_handle_sCAL"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if (png_ptr->mode & PNG_HAVE_IDAT) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of place"); | |
return; | |
} | |
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "duplicate"); | |
return; | |
} | |
/* Need unit type, width, \0, height: minimum 4 bytes */ | |
else if (length < 4) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "invalid"); | |
return; | |
} | |
png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)", | |
length + 1); | |
buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/); | |
if (buffer == NULL) | |
{ | |
png_chunk_benign_error(png_ptr, "out of memory"); | |
png_crc_finish(png_ptr, length); | |
return; | |
} | |
png_crc_read(png_ptr, buffer, length); | |
buffer[length] = 0; /* Null terminate the last string */ | |
if (png_crc_finish(png_ptr, 0)) | |
return; | |
/* Validate the unit. */ | |
if (buffer[0] != 1 && buffer[0] != 2) | |
{ | |
png_chunk_benign_error(png_ptr, "invalid unit"); | |
return; | |
} | |
/* Validate the ASCII numbers, need two ASCII numbers separated by | |
* a '\0' and they need to fit exactly in the chunk data. | |
*/ | |
i = 1; | |
state = 0; | |
if (!png_check_fp_number((png_const_charp)buffer, length, &state, &i) || | |
i >= length || buffer[i++] != 0) | |
png_chunk_benign_error(png_ptr, "bad width format"); | |
else if (!PNG_FP_IS_POSITIVE(state)) | |
png_chunk_benign_error(png_ptr, "non-positive width"); | |
else | |
{ | |
png_size_t heighti = i; | |
state = 0; | |
if (!png_check_fp_number((png_const_charp)buffer, length, &state, &i) || | |
i != length) | |
png_chunk_benign_error(png_ptr, "bad height format"); | |
else if (!PNG_FP_IS_POSITIVE(state)) | |
png_chunk_benign_error(png_ptr, "non-positive height"); | |
else | |
/* This is the (only) success case. */ | |
png_set_sCAL_s(png_ptr, info_ptr, buffer[0], | |
(png_charp)buffer+1, (png_charp)buffer+heighti); | |
} | |
} | |
#endif | |
#ifdef PNG_READ_tIME_SUPPORTED | |
void /* PRIVATE */ | |
png_handle_tIME(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_byte buf[7]; | |
png_time mod_time; | |
png_debug(1, "in png_handle_tIME"); | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME)) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "duplicate"); | |
return; | |
} | |
if (png_ptr->mode & PNG_HAVE_IDAT) | |
png_ptr->mode |= PNG_AFTER_IDAT; | |
if (length != 7) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "invalid"); | |
return; | |
} | |
png_crc_read(png_ptr, buf, 7); | |
if (png_crc_finish(png_ptr, 0)) | |
return; | |
mod_time.second = buf[6]; | |
mod_time.minute = buf[5]; | |
mod_time.hour = buf[4]; | |
mod_time.day = buf[3]; | |
mod_time.month = buf[2]; | |
mod_time.year = png_get_uint_16(buf); | |
png_set_tIME(png_ptr, info_ptr, &mod_time); | |
} | |
#endif | |
#ifdef PNG_READ_tEXt_SUPPORTED | |
/* Note: this does not properly handle chunks that are > 64K under DOS */ | |
void /* PRIVATE */ | |
png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_text text_info; | |
png_bytep buffer; | |
png_charp key; | |
png_charp text; | |
png_uint_32 skip = 0; | |
png_debug(1, "in png_handle_tEXt"); | |
#ifdef PNG_USER_LIMITS_SUPPORTED | |
if (png_ptr->user_chunk_cache_max != 0) | |
{ | |
if (png_ptr->user_chunk_cache_max == 1) | |
{ | |
png_crc_finish(png_ptr, length); | |
return; | |
} | |
if (--png_ptr->user_chunk_cache_max == 1) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "no space in chunk cache"); | |
return; | |
} | |
} | |
#endif | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
if (png_ptr->mode & PNG_HAVE_IDAT) | |
png_ptr->mode |= PNG_AFTER_IDAT; | |
#ifdef PNG_MAX_MALLOC_64K | |
if (length > 65535U) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "too large to fit in memory"); | |
return; | |
} | |
#endif | |
buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/); | |
if (buffer == NULL) | |
{ | |
png_chunk_benign_error(png_ptr, "out of memory"); | |
return; | |
} | |
png_crc_read(png_ptr, buffer, length); | |
if (png_crc_finish(png_ptr, skip)) | |
return; | |
key = (png_charp)buffer; | |
key[length] = 0; | |
for (text = key; *text; text++) | |
/* Empty loop to find end of key */ ; | |
if (text != key + length) | |
text++; | |
text_info.compression = PNG_TEXT_COMPRESSION_NONE; | |
text_info.key = key; | |
text_info.lang = NULL; | |
text_info.lang_key = NULL; | |
text_info.itxt_length = 0; | |
text_info.text = text; | |
text_info.text_length = strlen(text); | |
if (png_set_text_2(png_ptr, info_ptr, &text_info, 1)) | |
png_warning(png_ptr, "Insufficient memory to process text chunk"); | |
} | |
#endif | |
#ifdef PNG_READ_zTXt_SUPPORTED | |
/* Note: this does not correctly handle chunks that are > 64K under DOS */ | |
void /* PRIVATE */ | |
png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_const_charp errmsg = NULL; | |
png_bytep buffer; | |
png_uint_32 keyword_length; | |
png_debug(1, "in png_handle_zTXt"); | |
#ifdef PNG_USER_LIMITS_SUPPORTED | |
if (png_ptr->user_chunk_cache_max != 0) | |
{ | |
if (png_ptr->user_chunk_cache_max == 1) | |
{ | |
png_crc_finish(png_ptr, length); | |
return; | |
} | |
if (--png_ptr->user_chunk_cache_max == 1) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "no space in chunk cache"); | |
return; | |
} | |
} | |
#endif | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
if (png_ptr->mode & PNG_HAVE_IDAT) | |
png_ptr->mode |= PNG_AFTER_IDAT; | |
buffer = png_read_buffer(png_ptr, length, 2/*silent*/); | |
if (buffer == NULL) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of memory"); | |
return; | |
} | |
png_crc_read(png_ptr, buffer, length); | |
if (png_crc_finish(png_ptr, 0)) | |
return; | |
/* TODO: also check that the keyword contents match the spec! */ | |
for (keyword_length = 0; | |
keyword_length < length && buffer[keyword_length] != 0; | |
++keyword_length) | |
/* Empty loop to find end of name */ ; | |
if (keyword_length > 79 || keyword_length < 1) | |
errmsg = "bad keyword"; | |
/* zTXt must have some LZ data after the keyword, although it may expand to | |
* zero bytes; we need a '\0' at the end of the keyword, the compression type | |
* then the LZ data: | |
*/ | |
else if (keyword_length + 3 > length) | |
errmsg = "truncated"; | |
else if (buffer[keyword_length+1] != PNG_COMPRESSION_TYPE_BASE) | |
errmsg = "unknown compression type"; | |
else | |
{ | |
png_alloc_size_t uncompressed_length = PNG_SIZE_MAX; | |
/* TODO: at present png_decompress_chunk imposes a single application | |
* level memory limit, this should be split to different values for iCCP | |
* and text chunks. | |
*/ | |
if (png_decompress_chunk(png_ptr, length, keyword_length+2, | |
&uncompressed_length, 1/*terminate*/) == Z_STREAM_END) | |
{ | |
png_text text; | |
/* It worked; png_ptr->read_buffer now looks like a tEXt chunk except | |
* for the extra compression type byte and the fact that it isn't | |
* necessarily '\0' terminated. | |
*/ | |
buffer = png_ptr->read_buffer; | |
buffer[uncompressed_length+(keyword_length+2)] = 0; | |
text.compression = PNG_TEXT_COMPRESSION_zTXt; | |
text.key = (png_charp)buffer; | |
text.text = (png_charp)(buffer + keyword_length+2); | |
text.text_length = uncompressed_length; | |
text.itxt_length = 0; | |
text.lang = NULL; | |
text.lang_key = NULL; | |
if (png_set_text_2(png_ptr, info_ptr, &text, 1)) | |
errmsg = "insufficient memory"; | |
} | |
else | |
errmsg = png_ptr->zstream.msg; | |
} | |
if (errmsg != NULL) | |
png_chunk_benign_error(png_ptr, errmsg); | |
} | |
#endif | |
#ifdef PNG_READ_iTXt_SUPPORTED | |
/* Note: this does not correctly handle chunks that are > 64K under DOS */ | |
void /* PRIVATE */ | |
png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) | |
{ | |
png_const_charp errmsg = NULL; | |
png_bytep buffer; | |
png_uint_32 prefix_length; | |
png_debug(1, "in png_handle_iTXt"); | |
#ifdef PNG_USER_LIMITS_SUPPORTED | |
if (png_ptr->user_chunk_cache_max != 0) | |
{ | |
if (png_ptr->user_chunk_cache_max == 1) | |
{ | |
png_crc_finish(png_ptr, length); | |
return; | |
} | |
if (--png_ptr->user_chunk_cache_max == 1) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "no space in chunk cache"); | |
return; | |
} | |
} | |
#endif | |
if (!(png_ptr->mode & PNG_HAVE_IHDR)) | |
png_chunk_error(png_ptr, "missing IHDR"); | |
if (png_ptr->mode & PNG_HAVE_IDAT) | |
png_ptr->mode |= PNG_AFTER_IDAT; | |
buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/); | |
if (buffer == NULL) | |
{ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "out of memory"); | |
return; | |
} | |
png_crc_read(png_ptr, buffer, length); | |
if (png_crc_finish(png_ptr, 0)) | |
return; | |
/* First the keyword. */ | |
for (prefix_length=0; | |
prefix_length < length && buffer[prefix_length] != 0; | |
++prefix_length) | |
/* Empty loop */ ; | |
/* Perform a basic check on the keyword length here. */ | |
if (prefix_length > 79 || prefix_length < 1) | |
errmsg = "bad keyword"; | |
/* Expect keyword, compression flag, compression type, language, translated | |
* keyword (both may be empty but are 0 terminated) then the text, which may | |
* be empty. | |
*/ | |
else if (prefix_length + 5 > length) | |
errmsg = "truncated"; | |
else if (buffer[prefix_length+1] == 0 || | |
(buffer[prefix_length+1] == 1 && | |
buffer[prefix_length+2] == PNG_COMPRESSION_TYPE_BASE)) | |
{ | |
int compressed = buffer[prefix_length+1] != 0; | |
png_uint_32 language_offset, translated_keyword_offset; | |
png_alloc_size_t uncompressed_length = 0; | |
/* Now the language tag */ | |
prefix_length += 3; | |
language_offset = prefix_length; | |
for (; prefix_length < length && buffer[prefix_length] != 0; | |
++prefix_length) | |
/* Empty loop */ ; | |
/* WARNING: the length may be invalid here, this is checked below. */ | |
translated_keyword_offset = ++prefix_length; | |
for (; prefix_length < length && buffer[prefix_length] != 0; | |
++prefix_length) | |
/* Empty loop */ ; | |
/* prefix_length should now be at the trailing '\0' of the translated | |
* keyword, but it may already be over the end. None of this arithmetic | |
* can overflow because chunks are at most 2^31 bytes long, but on 16-bit | |
* systems the available allocaton may overflow. | |
*/ | |
++prefix_length; | |
if (!compressed && prefix_length <= length) | |
uncompressed_length = length - prefix_length; | |
else if (compressed && prefix_length < length) | |
{ | |
uncompressed_length = PNG_SIZE_MAX; | |
/* TODO: at present png_decompress_chunk imposes a single application | |
* level memory limit, this should be split to different values for | |
* iCCP and text chunks. | |
*/ | |
if (png_decompress_chunk(png_ptr, length, prefix_length, | |
&uncompressed_length, 1/*terminate*/) == Z_STREAM_END) | |
buffer = png_ptr->read_buffer; | |
else | |
errmsg = png_ptr->zstream.msg; | |
} | |
else | |
errmsg = "truncated"; | |
if (errmsg == NULL) | |
{ | |
png_text text; | |
buffer[uncompressed_length+prefix_length] = 0; | |
if (compressed) | |
text.compression = PNG_ITXT_COMPRESSION_NONE; | |
else | |
text.compression = PNG_ITXT_COMPRESSION_zTXt; | |
text.key = (png_charp)buffer; | |
text.lang = (png_charp)buffer + language_offset; | |
text.lang_key = (png_charp)buffer + translated_keyword_offset; | |
text.text = (png_charp)buffer + prefix_length; | |
text.text_length = 0; | |
text.itxt_length = uncompressed_length; | |
if (png_set_text_2(png_ptr, info_ptr, &text, 1)) | |
errmsg = "insufficient memory"; | |
} | |
} | |
else | |
errmsg = "bad compression info"; | |
if (errmsg != NULL) | |
png_chunk_benign_error(png_ptr, errmsg); | |
} | |
#endif | |
#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED | |
/* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */ | |
static int | |
png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length) | |
{ | |
png_alloc_size_t limit = PNG_SIZE_MAX; | |
if (png_ptr->unknown_chunk.data != NULL) | |
{ | |
png_free(png_ptr, png_ptr->unknown_chunk.data); | |
png_ptr->unknown_chunk.data = NULL; | |
} | |
# ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED | |
if (png_ptr->user_chunk_malloc_max > 0 && | |
png_ptr->user_chunk_malloc_max < limit) | |
limit = png_ptr->user_chunk_malloc_max; | |
# elif PNG_USER_CHUNK_MALLOC_MAX > 0 | |
if (PNG_USER_CHUNK_MALLOC_MAX < limit) | |
limit = PNG_USER_CHUNK_MALLOC_MAX; | |
# endif | |
if (length <= limit) | |
{ | |
PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name); | |
/* The following is safe because of the PNG_SIZE_MAX init above */ | |
png_ptr->unknown_chunk.size = (png_size_t)length/*SAFE*/; | |
/* 'mode' is a flag array, only the bottom four bits matter here */ | |
png_ptr->unknown_chunk.location = (png_byte)png_ptr->mode/*SAFE*/; | |
if (length == 0) | |
png_ptr->unknown_chunk.data = NULL; | |
else | |
{ | |
/* Do a 'warn' here - it is handled below. */ | |
png_ptr->unknown_chunk.data = png_voidcast(png_bytep, | |
png_malloc_warn(png_ptr, length)); | |
} | |
} | |
if (png_ptr->unknown_chunk.data == NULL && length > 0) | |
{ | |
/* This is benign because we clean up correctly */ | |
png_crc_finish(png_ptr, length); | |
png_chunk_benign_error(png_ptr, "unknown chunk exceeds memory limits"); | |
return 0; | |
} | |
else | |
{ | |
if (length > 0) | |
png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length); | |
png_crc_finish(png_ptr, 0); | |
return 1; | |
} | |
} | |
#endif /* PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */ | |
/* Handle an unknown, or known but disabled, chunk */ | |
void /* PRIVATE */ | |
png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr, | |
png_uint_32 length, int keep) | |
{ | |
int handled = 0; /* the chunk was handled */ | |
png_debug(1, "in png_handle_unknown"); | |
#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED | |
/* NOTE: this code is based on the code in libpng-1.4.12 except for fixing | |
* the bug which meant that setting a non-default behavior for a specific | |
* chunk would be ignored (the default was always used unless a user | |
* callback was installed). | |
* | |
* 'keep' is the value from the png_chunk_unknown_handling, the setting for | |
* this specific chunk_name, if PNG_HANDLE_AS_UNKNOWN_SUPPORTED, if not it | |
* will always be PNG_HANDLE_CHUNK_AS_DEFAULT and it needs to be set here. | |
* This is just an optimization to avoid multiple calls to the lookup | |
* function. | |
*/ | |
# ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED | |
# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED | |
keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name); | |
# endif | |
# endif | |
/* One of the following methods will read the chunk or skip it (at least one | |
* of these is always defined because this is the only way to switch on | |
* PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) | |
*/ | |
# ifdef PNG_READ_USER_CHUNKS_SUPPORTED | |
/* The user callback takes precedence over the chunk keep value, but the | |
* keep value is still required to validate a save of a critical chunk. | |
*/ | |
if (png_ptr->read_user_chunk_fn != NULL) | |
{ | |
if (png_cache_unknown_chunk(png_ptr, length)) | |
{ | |
/* Callback to user unknown chunk handler */ | |
int ret = (*(png_ptr->read_user_chunk_fn))(png_ptr, | |
&png_ptr->unknown_chunk); | |
/* ret is: | |
* negative: An error occured, png_chunk_error will be called. | |
* zero: The chunk was not handled, the chunk will be discarded | |
* unless png_set_keep_unknown_chunks has been used to set | |
* a 'keep' behavior for this particular chunk, in which | |
* case that will be used. A critical chunk will cause an | |
* error at this point unless it is to be saved. | |
* positive: The chunk was handled, libpng will ignore/discard it. | |
*/ | |
if (ret < 0) | |
png_chunk_error(png_ptr, "error in user chunk"); | |
else if (ret == 0) | |
{ | |
/* If the keep value is 'default' or 'never' override it, but | |
* still error out on critical chunks unless the keep value is | |
* 'always' While this is weird it is the behavior in 1.4.12. | |
* A possible improvement would be to obey the value set for the | |
* chunk, but this would be an API change that would probably | |
* damage some applications. | |
* | |
* The png_app_warning below catches the case that matters, where | |
* the application has not set specific save or ignore for this | |
* chunk or global save or ignore. | |
*/ | |
if (keep < PNG_HANDLE_CHUNK_IF_SAFE) | |
{ | |
# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED | |
if (png_ptr->unknown_default < PNG_HANDLE_CHUNK_IF_SAFE) | |
{ | |
png_chunk_warning(png_ptr, "Saving unknown chunk:"); | |
png_app_warning(png_ptr, | |
"forcing save of an unhandled chunk;" | |
" please call png_set_keep_unknown_chunks"); | |
/* with keep = PNG_HANDLE_CHUNK_IF_SAFE */ | |
} | |
# endif | |
keep = PNG_HANDLE_CHUNK_IF_SAFE; | |
} | |
} | |
else /* chunk was handled */ | |
{ | |
handled = 1; | |
/* Critical chunks can be safely discarded at this point. */ | |
keep = PNG_HANDLE_CHUNK_NEVER; | |
} | |
} | |
else | |
keep = PNG_HANDLE_CHUNK_NEVER; /* insufficient memory */ | |
} | |
else | |
/* Use the SAVE_UNKNOWN_CHUNKS code or skip the chunk */ | |
# endif /* PNG_READ_USER_CHUNKS_SUPPORTED */ | |
# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED | |
{ | |
/* keep is currently just the per-chunk setting, if there was no | |
* setting change it to the global default now (not that this may | |
* still be AS_DEFAULT) then obtain the cache of the chunk if required, | |
* if not simply skip the chunk. | |
*/ | |
if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT) | |
keep = png_ptr->unknown_default; | |
if (keep == PNG_HANDLE_CHUNK_ALWAYS || | |
(keep == PNG_HANDLE_CHUNK_IF_SAFE && | |
PNG_CHUNK_ANCILLARY(png_ptr->chunk_name))) | |
{ | |
if (!png_cache_unknown_chunk(png_ptr, length)) | |
keep = PNG_HANDLE_CHUNK_NEVER; | |
} | |
else | |
png_crc_finish(png_ptr, length); | |
} | |
# else | |
# ifndef PNG_READ_USER_CHUNKS_SUPPORTED | |
# error no method to support READ_UNKNOWN_CHUNKS | |
# endif | |
{ | |
/* If here there is no read callback pointer set and no support is | |
* compiled in to just save the unknown chunks, so simply skip this | |
* chunk. If 'keep' is something other than AS_DEFAULT or NEVER then | |
* the app has erroneously asked for unknown chunk saving when there | |
* is no support. | |
*/ | |
if (keep > PNG_HANDLE_CHUNK_NEVER) | |
png_app_error(png_ptr, "no unknown chunk support available"); | |
png_crc_finish(png_ptr, length); | |
} | |
# endif | |
# ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED | |
/* Now store the chunk in the chunk list if appropriate, and if the limits | |
* permit it. | |
*/ | |
if (keep == PNG_HANDLE_CHUNK_ALWAYS || | |
(keep == PNG_HANDLE_CHUNK_IF_SAFE && | |
PNG_CHUNK_ANCILLARY(png_ptr->chunk_name))) | |
{ | |
# ifdef PNG_USER_LIMITS_SUPPORTED | |
switch (png_ptr->user_chunk_cache_max) | |
{ | |
case 2: | |
png_ptr->user_chunk_cache_max = 1; | |
png_chunk_benign_error(png_ptr, "no space in chunk cache"); | |
/* FALL THROUGH */ | |
case 1: | |
/* NOTE: prior to 1.6.0 this case resulted in an unknown critical | |
* chunk being skipped, now there will be a hard error below. | |
*/ | |
break; | |
default: /* not at limit */ | |
--(png_ptr->user_chunk_cache_max); | |
/* FALL THROUGH */ | |
case 0: /* no limit */ | |
# endif /* PNG_USER_LIMITS_SUPPORTED */ | |
/* Here when the limit isn't reached or when limits are compiled | |
* out; store the chunk. | |
*/ | |
png_set_unknown_chunks(png_ptr, info_ptr, | |
&png_ptr->unknown_chunk, 1); | |
handled = 1; | |
# ifdef PNG_USER_LIMITS_SUPPORTED | |
break; | |
} | |
# endif | |
} | |
# else /* no store support! */ | |
PNG_UNUSED(info_ptr) | |
# error untested code (reading unknown chunks with no store support) | |
# endif | |
/* Regardless of the error handling below the cached data (if any) can be | |
* freed now. Notice that the data is not freed if there is a png_error, but | |
* it will be freed by destroy_read_struct. | |
*/ | |
if (png_ptr->unknown_chunk.data != NULL) | |
png_free(png_ptr, png_ptr->unknown_chunk.data); | |
png_ptr->unknown_chunk.data = NULL; | |
#else /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */ | |
/* There is no support to read an unknown chunk, so just skip it. */ | |
png_crc_finish(png_ptr, length); | |
PNG_UNUSED(info_ptr) | |
PNG_UNUSED(keep) | |
#endif /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */ | |
/* Check for unhandled critical chunks */ | |
if (!handled && PNG_CHUNK_CRITICAL(png_ptr->chunk_name)) | |
png_chunk_error(png_ptr, "unhandled critical chunk"); | |
} | |
/* This function is called to verify that a chunk name is valid. | |
* This function can't have the "critical chunk check" incorporated | |
* into it, since in the future we will need to be able to call user | |
* functions to handle unknown critical chunks after we check that | |
* the chunk name itself is valid. | |
*/ | |
/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is: | |
* | |
* ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) | |
*/ | |
void /* PRIVATE */ | |
png_check_chunk_name(png_structrp png_ptr, png_uint_32 chunk_name) | |
{ | |
int i; | |
png_debug(1, "in png_check_chunk_name"); | |
for (i=1; i<=4; ++i) | |
{ | |
int c = chunk_name & 0xff; | |
if (c < 65 || c > 122 || (c > 90 && c < 97)) | |
png_chunk_error(png_ptr, "invalid chunk type"); | |
chunk_name >>= 8; | |
} | |
} | |
/* Combines the row recently read in with the existing pixels in the row. This | |
* routine takes care of alpha and transparency if requested. This routine also | |
* handles the two methods of progressive display of interlaced images, | |
* depending on the 'display' value; if 'display' is true then the whole row | |
* (dp) is filled from the start by replicating the available pixels. If | |
* 'display' is false only those pixels present in the pass are filled in. | |
*/ | |
void /* PRIVATE */ | |
png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display) | |
{ | |
unsigned int pixel_depth = png_ptr->transformed_pixel_depth; | |
png_const_bytep sp = png_ptr->row_buf + 1; | |
png_uint_32 row_width = png_ptr->width; | |
unsigned int pass = png_ptr->pass; | |
png_bytep end_ptr = 0; | |
png_byte end_byte = 0; | |
unsigned int end_mask; | |
png_debug(1, "in png_combine_row"); | |
/* Added in 1.5.6: it should not be possible to enter this routine until at | |
* least one row has been read from the PNG data and transformed. | |
*/ | |
if (pixel_depth == 0) | |
png_error(png_ptr, "internal row logic error"); | |
/* Added in 1.5.4: the pixel depth should match the information returned by | |
* any call to png_read_update_info at this point. Do not continue if we got | |
* this wrong. | |
*/ | |
if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes != | |
PNG_ROWBYTES(pixel_depth, row_width)) | |
png_error(png_ptr, "internal row size calculation error"); | |
/* Don't expect this to ever happen: */ | |
if (row_width == 0) | |
png_error(png_ptr, "internal row width error"); | |
/* Preserve the last byte in cases where only part of it will be overwritten, | |
* the multiply below may overflow, we don't care because ANSI-C guarantees | |
* we get the low bits. | |
*/ | |
end_mask = (pixel_depth * row_width) & 7; | |
if (end_mask != 0) | |
{ | |
/* end_ptr == NULL is a flag to say do nothing */ | |
end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1; | |
end_byte = *end_ptr; | |
# ifdef PNG_READ_PACKSWAP_SUPPORTED | |
if (png_ptr->transformations & PNG_PACKSWAP) /* little-endian byte */ | |
end_mask = 0xff << end_mask; | |
else /* big-endian byte */ | |
# endif | |
end_mask = 0xff >> end_mask; | |
/* end_mask is now the bits to *keep* from the destination row */ | |
} | |
/* For non-interlaced images this reduces to a memcpy(). A memcpy() | |
* will also happen if interlacing isn't supported or if the application | |
* does not call png_set_interlace_handling(). In the latter cases the | |
* caller just gets a sequence of the unexpanded rows from each interlace | |
* pass. | |
*/ | |
#ifdef PNG_READ_INTERLACING_SUPPORTED | |
if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE) && | |
pass < 6 && (display == 0 || | |
/* The following copies everything for 'display' on passes 0, 2 and 4. */ | |
(display == 1 && (pass & 1) != 0))) | |
{ | |
/* Narrow images may have no bits in a pass; the caller should handle | |
* this, but this test is cheap: | |
*/ | |
if (row_width <= PNG_PASS_START_COL(pass)) | |
return; | |
if (pixel_depth < 8) | |
{ | |
/* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit | |
* into 32 bits, then a single loop over the bytes using the four byte | |
* values in the 32-bit mask can be used. For the 'display' option the | |
* expanded mask may also not require any masking within a byte. To | |
* make this work the PACKSWAP option must be taken into account - it | |
* simply requires the pixels to be reversed in each byte. | |
* | |
* The 'regular' case requires a mask for each of the first 6 passes, | |
* the 'display' case does a copy for the even passes in the range | |
* 0..6. This has already been handled in the test above. | |
* | |
* The masks are arranged as four bytes with the first byte to use in | |
* the lowest bits (little-endian) regardless of the order (PACKSWAP or | |
* not) of the pixels in each byte. | |
* | |
* NOTE: the whole of this logic depends on the caller of this function | |
* only calling it on rows appropriate to the pass. This function only | |
* understands the 'x' logic; the 'y' logic is handled by the caller. | |
* | |
* The following defines allow generation of compile time constant bit | |
* masks for each pixel depth and each possibility of swapped or not | |
* swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index, | |
* is in the range 0..7; and the result is 1 if the pixel is to be | |
* copied in the pass, 0 if not. 'S' is for the sparkle method, 'B' | |
* for the block method. | |
* | |
* With some compilers a compile time expression of the general form: | |
* | |
* (shift >= 32) ? (a >> (shift-32)) : (b >> shift) | |
* | |
* Produces warnings with values of 'shift' in the range 33 to 63 | |
* because the right hand side of the ?: expression is evaluated by | |
* the compiler even though it isn't used. Microsoft Visual C (various | |
* versions) and the Intel C compiler are known to do this. To avoid | |
* this the following macros are used in 1.5.6. This is a temporary | |
* solution to avoid destabilizing the code during the release process. | |
*/ | |
# if PNG_USE_COMPILE_TIME_MASKS | |
# define PNG_LSR(x,s) ((x)>>((s) & 0x1f)) | |
# define PNG_LSL(x,s) ((x)<<((s) & 0x1f)) | |
# else | |
# define PNG_LSR(x,s) ((x)>>(s)) | |
# define PNG_LSL(x,s) ((x)<<(s)) | |
# endif | |
# define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\ | |
PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1) | |
# define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\ | |
PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1) | |
/* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is | |
* little endian - the first pixel is at bit 0 - however the extra | |
* parameter 's' can be set to cause the mask position to be swapped | |
* within each byte, to match the PNG format. This is done by XOR of | |
* the shift with 7, 6 or 4 for bit depths 1, 2 and 4. | |
*/ | |
# define PIXEL_MASK(p,x,d,s) \ | |
(PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0)))) | |
/* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask. | |
*/ | |
# define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) | |
# define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) | |
/* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp | |
* cases the result needs replicating, for the 4-bpp case the above | |
* generates a full 32 bits. | |
*/ | |
# define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1))) | |
# define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\ | |
S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\ | |
S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d) | |
# define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\ | |
B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\ | |
B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d) | |
#if PNG_USE_COMPILE_TIME_MASKS | |
/* Utility macros to construct all the masks for a depth/swap | |
* combination. The 's' parameter says whether the format is PNG | |
* (big endian bytes) or not. Only the three odd-numbered passes are | |
* required for the display/block algorithm. | |
*/ | |
# define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\ | |
S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) } | |
# define B_MASKS(d,s) { B_MASK(1,d,s), S_MASK(3,d,s), S_MASK(5,d,s) } | |
# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2)) | |
/* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and | |
* then pass: | |
*/ | |
static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] = | |
{ | |
/* Little-endian byte masks for PACKSWAP */ | |
{ S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) }, | |
/* Normal (big-endian byte) masks - PNG format */ | |
{ S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) } | |
}; | |
/* display_mask has only three entries for the odd passes, so index by | |
* pass>>1. | |
*/ | |
static PNG_CONST png_uint_32 display_mask[2][3][3] = | |
{ | |
/* Little-endian byte masks for PACKSWAP */ | |
{ B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) }, | |
/* Normal (big-endian byte) masks - PNG format */ | |
{ B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) } | |
}; | |
# define MASK(pass,depth,display,png)\ | |
((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\ | |
row_mask[png][DEPTH_INDEX(depth)][pass]) | |
#else /* !PNG_USE_COMPILE_TIME_MASKS */ | |
/* This is the runtime alternative: it seems unlikely that this will | |
* ever be either smaller or faster than the compile time approach. | |
*/ | |
# define MASK(pass,depth,display,png)\ | |
((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png)) | |
#endif /* !PNG_USE_COMPILE_TIME_MASKS */ | |
/* Use the appropriate mask to copy the required bits. In some cases | |
* the byte mask will be 0 or 0xff, optimize these cases. row_width is | |
* the number of pixels, but the code copies bytes, so it is necessary | |
* to special case the end. | |
*/ | |
png_uint_32 pixels_per_byte = 8 / pixel_depth; | |
png_uint_32 mask; | |
# ifdef PNG_READ_PACKSWAP_SUPPORTED | |
if (png_ptr->transformations & PNG_PACKSWAP) | |
mask = MASK(pass, pixel_depth, display, 0); | |
else | |
# endif | |
mask = MASK(pass, pixel_depth, display, 1); | |
for (;;) | |
{ | |
png_uint_32 m; | |
/* It doesn't matter in the following if png_uint_32 has more than | |
* 32 bits because the high bits always match those in m<<24; it is, | |
* however, essential to use OR here, not +, because of this. | |
*/ | |
m = mask; | |
mask = (m >> 8) | (m << 24); /* rotate right to good compilers */ | |
m &= 0xff; | |
if (m != 0) /* something to copy */ | |
{ | |
if (m != 0xff) | |
*dp = (png_byte)((*dp & ~m) | (*sp & m)); | |
else | |
*dp = *sp; | |
} | |
/* NOTE: this may overwrite the last byte with garbage if the image | |
* is not an exact number of bytes wide; libpng has always done | |
* this. | |
*/ | |
if (row_width <= pixels_per_byte) | |
break; /* May need to restore part of the last byte */ | |
row_width -= pixels_per_byte; | |
++dp; | |
++sp; | |
} | |
} | |
else /* pixel_depth >= 8 */ | |
{ | |
unsigned int bytes_to_copy, bytes_to_jump; | |
/* Validate the depth - it must be a multiple of 8 */ | |
if (pixel_depth & 7) | |
png_error(png_ptr, "invalid user transform pixel depth"); | |
pixel_depth >>= 3; /* now in bytes */ | |
row_width *= pixel_depth; | |
/* Regardless of pass number the Adam 7 interlace always results in a | |
* fixed number of pixels to copy then to skip. There may be a | |
* different number of pixels to skip at the start though. | |
*/ | |
{ | |
unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth; | |
row_width -= offset; | |
dp += offset; | |
sp += offset; | |
} | |
/* Work out the bytes to copy. */ | |
if (display) | |
{ | |
/* When doing the 'block' algorithm the pixel in the pass gets | |
* replicated to adjacent pixels. This is why the even (0,2,4,6) | |
* passes are skipped above - the entire expanded row is copied. | |
*/ | |
bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth; | |
/* But don't allow this number to exceed the actual row width. */ | |
if (bytes_to_copy > row_width) | |
bytes_to_copy = row_width; | |
} | |
else /* normal row; Adam7 only ever gives us one pixel to copy. */ | |
bytes_to_copy = pixel_depth; | |
/* In Adam7 there is a constant offset between where the pixels go. */ | |
bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth; | |
/* And simply copy these bytes. Some optimization is possible here, | |
* depending on the value of 'bytes_to_copy'. Special case the low | |
* byte counts, which we know to be frequent. | |
* | |
* Notice that these cases all 'return' rather than 'break' - this | |
* avoids an unnecessary test on whether to restore the last byte | |
* below. | |
*/ | |
switch (bytes_to_copy) | |
{ | |
case 1: | |
for (;;) | |
{ | |
*dp = *sp; | |
if (row_width <= bytes_to_jump) | |
return; | |
dp += bytes_to_jump; | |
sp += bytes_to_jump; | |
row_width -= bytes_to_jump; | |
} | |
case 2: | |
/* There is a possibility of a partial copy at the end here; this | |
* slows the code down somewhat. | |
*/ | |
do | |
{ | |
dp[0] = sp[0], dp[1] = sp[1]; | |
if (row_width <= bytes_to_jump) | |
return; | |
sp += bytes_to_jump; | |
dp += bytes_to_jump; | |
row_width -= bytes_to_jump; | |
} | |
while (row_width > 1); | |
/* And there can only be one byte left at this point: */ | |
*dp = *sp; | |
return; | |
case 3: | |
/* This can only be the RGB case, so each copy is exactly one | |
* pixel and it is not necessary to check for a partial copy. | |
*/ | |
for(;;) | |
{ | |
dp[0] = sp[0], dp[1] = sp[1], dp[2] = sp[2]; | |
if (row_width <= bytes_to_jump) | |
return; | |
sp += bytes_to_jump; | |
dp += bytes_to_jump; | |
row_width -= bytes_to_jump; | |
} | |
default: | |
#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE | |
/* Check for double byte alignment and, if possible, use a | |
* 16-bit copy. Don't attempt this for narrow images - ones that | |
* are less than an interlace panel wide. Don't attempt it for | |
* wide bytes_to_copy either - use the memcpy there. | |
*/ | |
if (bytes_to_copy < 16 /*else use memcpy*/ && | |
png_isaligned(dp, png_uint_16) && | |
png_isaligned(sp, png_uint_16) && | |
bytes_to_copy % (sizeof (png_uint_16)) == 0 && | |
bytes_to_jump % (sizeof (png_uint_16)) == 0) | |
{ | |
/* Everything is aligned for png_uint_16 copies, but try for | |
* png_uint_32 first. | |
*/ | |
if (png_isaligned(dp, png_uint_32) && | |
png_isaligned(sp, png_uint_32) && | |
bytes_to_copy % (sizeof (png_uint_32)) == 0 && | |
bytes_to_jump % (sizeof (png_uint_32)) == 0) | |
{ | |
png_uint_32p dp32 = png_aligncast(png_uint_32p,dp); | |
png_const_uint_32p sp32 = png_aligncastconst( | |
png_const_uint_32p, sp); | |
size_t skip = (bytes_to_jump-bytes_to_copy) / | |
(sizeof (png_uint_32)); | |
do | |
{ | |
size_t c = bytes_to_copy; | |
do | |
{ | |
*dp32++ = *sp32++; | |
c -= (sizeof (png_uint_32)); | |
} | |
while (c > 0); | |
if (row_width <= bytes_to_jump) | |
return; | |
dp32 += skip; | |
sp32 += skip; | |
row_width -= bytes_to_jump; | |
} | |
while (bytes_to_copy <= row_width); | |
/* Get to here when the row_width truncates the final copy. | |
* There will be 1-3 bytes left to copy, so don't try the | |
* 16-bit loop below. | |
*/ | |
dp = (png_bytep)dp32; | |
sp = (png_const_bytep)sp32; | |
do | |
*dp++ = *sp++; | |
while (--row_width > 0); | |
return; | |
} | |
/* Else do it in 16-bit quantities, but only if the size is | |
* not too large. | |
*/ | |
else | |
{ | |
png_uint_16p dp16 = png_aligncast(png_uint_16p, dp); | |
png_const_uint_16p sp16 = png_aligncastconst( | |
png_const_uint_16p, sp); | |
size_t skip = (bytes_to_jump-bytes_to_copy) / | |
(sizeof (png_uint_16)); | |
do | |
{ | |
size_t c = bytes_to_copy; | |
do | |
{ | |
*dp16++ = *sp16++; | |
c -= (sizeof (png_uint_16)); | |
} | |
while (c > 0); | |
if (row_width <= bytes_to_jump) | |
return; | |
dp16 += skip; | |
sp16 += skip; | |
row_width -= bytes_to_jump; | |
} | |
while (bytes_to_copy <= row_width); | |
/* End of row - 1 byte left, bytes_to_copy > row_width: */ | |
dp = (png_bytep)dp16; | |
sp = (png_const_bytep)sp16; | |
do | |
*dp++ = *sp++; | |
while (--row_width > 0); | |
return; | |
} | |
} | |
#endif /* PNG_ALIGN_ code */ | |
/* The true default - use a memcpy: */ | |
for (;;) | |
{ | |
memcpy(dp, sp, bytes_to_copy); | |
if (row_width <= bytes_to_jump) | |
return; | |
sp += bytes_to_jump; | |
dp += bytes_to_jump; | |
row_width -= bytes_to_jump; | |
if (bytes_to_copy > row_width) | |
bytes_to_copy = row_width; | |
} | |
} | |
/* NOT REACHED*/ | |
} /* pixel_depth >= 8 */ | |
/* Here if pixel_depth < 8 to check 'end_ptr' below. */ | |
} | |
else | |
#endif | |
/* If here then the switch above wasn't used so just memcpy the whole row | |
* from the temporary row buffer (notice that this overwrites the end of the | |
* destination row if it is a partial byte.) | |
*/ | |
memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width)); | |
/* Restore the overwritten bits from the last byte if necessary. */ | |
if (end_ptr != NULL) | |
*end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask)); | |
} | |
#ifdef PNG_READ_INTERLACING_SUPPORTED | |
void /* PRIVATE */ | |
png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass, | |
png_uint_32 transformations /* Because these may affect the byte layout */) | |
{ | |
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ | |
/* Offset to next interlace block */ | |
static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; | |
png_debug(1, "in png_do_read_interlace"); | |
if (row != NULL && row_info != NULL) | |
{ | |
png_uint_32 final_width; | |
final_width = row_info->width * png_pass_inc[pass]; | |
switch (row_info->pixel_depth) | |
{ | |
case 1: | |
{ | |
png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3); | |
png_bytep dp = row + (png_size_t)((final_width - 1) >> 3); | |
int sshift, dshift; | |
int s_start, s_end, s_inc; | |
int jstop = png_pass_inc[pass]; | |
png_byte v; | |
png_uint_32 i; | |
int j; | |
#ifdef PNG_READ_PACKSWAP_SUPPORTED | |
if (transformations & PNG_PACKSWAP) | |
{ | |
sshift = (int)((row_info->width + 7) & 0x07); | |
dshift = (int)((final_width + 7) & 0x07); | |
s_start = 7; | |
s_end = 0; | |
s_inc = -1; | |
} | |
else | |
#endif | |
{ | |
sshift = 7 - (int)((row_info->width + 7) & 0x07); | |
dshift = 7 - (int)((final_width + 7) & 0x07); | |
s_start = 0; | |
s_end = 7; | |
s_inc = 1; | |
} | |
for (i = 0; i < row_info->width; i++) | |
{ | |
v = (png_byte)((*sp >> sshift) & 0x01); | |
for (j = 0; j < jstop; j++) | |
{ | |
unsigned int tmp = *dp & (0x7f7f >> (7 - dshift)); | |
tmp |= v << dshift; | |
*dp = (png_byte)(tmp & 0xff); | |
if (dshift == s_end) | |
{ | |
dshift = s_start; | |
dp--; | |
} | |
else | |
dshift += s_inc; | |
} | |
if (sshift == s_end) | |
{ | |
sshift = s_start; | |
sp--; | |
} | |
else | |
sshift += s_inc; | |
} | |
break; | |
} | |
case 2: | |
{ | |
png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2); | |
png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2); | |
int sshift, dshift; | |
int s_start, s_end, s_inc; | |
int jstop = png_pass_inc[pass]; | |
png_uint_32 i; | |
#ifdef PNG_READ_PACKSWAP_SUPPORTED | |
if (transformations & PNG_PACKSWAP) | |
{ | |
sshift = (int)(((row_info->width + 3) & 0x03) << 1); | |
dshift = (int)(((final_width + 3) & 0x03) << 1); | |
s_start = 6; | |
s_end = 0; | |
s_inc = -2; | |
} | |
else | |
#endif | |
{ | |
sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1); | |
dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1); | |
s_start = 0; | |
s_end = 6; | |
s_inc = 2; | |
} | |
for (i = 0; i < row_info->width; i++) | |
{ | |
png_byte v; | |
int j; | |
v = (png_byte)((*sp >> sshift) & 0x03); | |
for (j = 0; j < jstop; j++) | |
{ | |
unsigned int tmp = *dp & (0x3f3f >> (6 - dshift)); | |
tmp |= v << dshift; | |
*dp = (png_byte)(tmp & 0xff); | |
if (dshift == s_end) | |
{ | |
dshift = s_start; | |
dp--; | |
} | |
else | |
dshift += s_inc; | |
} | |
if (sshift == s_end) | |
{ | |
sshift = s_start; | |
sp--; | |
} | |
else | |
sshift += s_inc; | |
} | |
break; | |
} | |
case 4: | |
{ | |
png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1); | |
png_bytep dp = row + (png_size_t)((final_width - 1) >> 1); | |
int sshift, dshift; | |
int s_start, s_end, s_inc; | |
png_uint_32 i; | |
int jstop = png_pass_inc[pass]; | |
#ifdef PNG_READ_PACKSWAP_SUPPORTED | |
if (transformations & PNG_PACKSWAP) | |
{ | |
sshift = (int)(((row_info->width + 1) & 0x01) << 2); | |
dshift = (int)(((final_width + 1) & 0x01) << 2); | |
s_start = 4; | |
s_end = 0; | |
s_inc = -4; | |
} | |
else | |
#endif | |
{ | |
sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2); | |
dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2); | |
s_start = 0; | |
s_end = 4; | |
s_inc = 4; | |
} | |
for (i = 0; i < row_info->width; i++) | |
{ | |
png_byte v = (png_byte)((*sp >> sshift) & 0x0f); | |
int j; | |
for (j = 0; j < jstop; j++) | |
{ | |
unsigned int tmp = *dp & (0xf0f >> (4 - dshift)); | |
tmp |= v << dshift; | |
*dp = (png_byte)(tmp & 0xff); | |
if (dshift == s_end) | |
{ | |
dshift = s_start; | |
dp--; | |
} | |
else | |
dshift += s_inc; | |
} | |
if (sshift == s_end) | |
{ | |
sshift = s_start; | |
sp--; | |
} | |
else | |
sshift += s_inc; | |
} | |
break; | |
} | |
default: | |
{ | |
png_size_t pixel_bytes = (row_info->pixel_depth >> 3); | |
png_bytep sp = row + (png_size_t)(row_info->width - 1) | |
* pixel_bytes; | |
png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes; | |
int jstop = png_pass_inc[pass]; | |
png_uint_32 i; | |
for (i = 0; i < row_info->width; i++) | |
{ | |
png_byte v[8]; /* SAFE; pixel_depth does not exceed 64 */ | |
int j; | |
memcpy(v, sp, pixel_bytes); | |
for (j = 0; j < jstop; j++) | |
{ | |
memcpy(dp, v, pixel_bytes); | |
dp -= pixel_bytes; | |
} | |
sp -= pixel_bytes; | |
} | |
break; | |
} | |
} | |
row_info->width = final_width; | |
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width); | |
} | |
#ifndef PNG_READ_PACKSWAP_SUPPORTED | |
PNG_UNUSED(transformations) /* Silence compiler warning */ | |
#endif | |
} | |
#endif /* PNG_READ_INTERLACING_SUPPORTED */ | |
static void | |
png_read_filter_row_sub(png_row_infop row_info, png_bytep row, | |
png_const_bytep prev_row) | |
{ | |
png_size_t i; | |
png_size_t istop = row_info->rowbytes; | |
unsigned int bpp = (row_info->pixel_depth + 7) >> 3; | |
png_bytep rp = row + bpp; | |
PNG_UNUSED(prev_row) | |
for (i = bpp; i < istop; i++) | |
{ | |
*rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); | |
rp++; | |
} | |
} | |
static void | |
png_read_filter_row_up(png_row_infop row_info, png_bytep row, | |
png_const_bytep prev_row) | |
{ | |
png_size_t i; | |
png_size_t istop = row_info->rowbytes; | |
png_bytep rp = row; | |
png_const_bytep pp = prev_row; | |
for (i = 0; i < istop; i++) | |
{ | |
*rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); | |
rp++; | |
} | |
} | |
static void | |
png_read_filter_row_avg(png_row_infop row_info, png_bytep row, | |
png_const_bytep prev_row) | |
{ | |
png_size_t i; | |
png_bytep rp = row; | |
png_const_bytep pp = prev_row; | |
unsigned int bpp = (row_info->pixel_depth + 7) >> 3; | |
png_size_t istop = row_info->rowbytes - bpp; | |
for (i = 0; i < bpp; i++) | |
{ | |
*rp = (png_byte)(((int)(*rp) + | |
((int)(*pp++) / 2 )) & 0xff); | |
rp++; | |
} | |
for (i = 0; i < istop; i++) | |
{ | |
*rp = (png_byte)(((int)(*rp) + | |
(int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); | |
rp++; | |
} | |
} | |
static void | |
png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row, | |
png_const_bytep prev_row) | |
{ | |
png_bytep rp_end = row + row_info->rowbytes; | |
int a, c; | |
/* First pixel/byte */ | |
c = *prev_row++; | |
a = *row + c; | |
*row++ = (png_byte)a; | |
/* Remainder */ | |
while (row < rp_end) | |
{ | |
int b, pa, pb, pc, p; | |
a &= 0xff; /* From previous iteration or start */ | |
b = *prev_row++; | |
p = b - c; | |
pc = a - c; | |
# ifdef PNG_USE_ABS | |
pa = abs(p); | |
pb = abs(pc); | |
pc = abs(p + pc); | |
# else | |
pa = p < 0 ? -p : p; | |
pb = pc < 0 ? -pc : pc; | |
pc = (p + pc) < 0 ? -(p + pc) : p + pc; | |
# endif | |
/* Find the best predictor, the least of pa, pb, pc favoring the earlier | |
* ones in the case of a tie. | |
*/ | |
if (pb < pa) pa = pb, a = b; | |
if (pc < pa) a = c; | |
/* Calculate the current pixel in a, and move the previous row pixel to c | |
* for the next time round the loop | |
*/ | |
c = b; | |
a += *row; | |
*row++ = (png_byte)a; | |
} | |
} | |
static void | |
png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row, | |
png_const_bytep prev_row) | |
{ | |
int bpp = (row_info->pixel_depth + 7) >> 3; | |
png_bytep rp_end = row + bpp; | |
/* Process the first pixel in the row completely (this is the same as 'up' | |
* because there is only one candidate predictor for the first row). | |
*/ | |
while (row < rp_end) | |
{ | |
int a = *row + *prev_row++; | |
*row++ = (png_byte)a; | |
} | |
/* Remainder */ | |
rp_end += row_info->rowbytes - bpp; | |
while (row < rp_end) | |
{ | |
int a, b, c, pa, pb, pc, p; | |
c = *(prev_row - bpp); | |
a = *(row - bpp); | |
b = *prev_row++; | |
p = b - c; | |
pc = a - c; | |
# ifdef PNG_USE_ABS | |
pa = abs(p); | |
pb = abs(pc); | |
pc = abs(p + pc); | |
# else | |
pa = p < 0 ? -p : p; | |
pb = pc < 0 ? -pc : pc; | |
pc = (p + pc) < 0 ? -(p + pc) : p + pc; | |
# endif | |
if (pb < pa) pa = pb, a = b; | |
if (pc < pa) a = c; | |
c = b; | |
a += *row; | |
*row++ = (png_byte)a; | |
} | |
} | |
static void | |
png_init_filter_functions(png_structrp pp) | |
/* This function is called once for every PNG image to set the | |
* implementations required to reverse the filtering of PNG rows. Reversing | |
* the filter is the first transformation performed on the row data. It is | |
* performed in place, therefore an implementation can be selected based on | |
* the image pixel format. If the implementation depends on image width then | |
* take care to ensure that it works correctly if the image is interlaced - | |
* interlacing causes the actual row width to vary. | |
*/ | |
{ | |
unsigned int bpp = (pp->pixel_depth + 7) >> 3; | |
pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub; | |
pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up; | |
pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg; | |
if (bpp == 1) | |
pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = | |
png_read_filter_row_paeth_1byte_pixel; | |
else | |
pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = | |
png_read_filter_row_paeth_multibyte_pixel; | |
#ifdef PNG_FILTER_OPTIMIZATIONS | |
/* To use this define PNG_FILTER_OPTIMIZATIONS as the name of a function to | |
* call to install hardware optimizations for the above functions; simply | |
* replace whatever elements of the pp->read_filter[] array with a hardware | |
* specific (or, for that matter, generic) optimization. | |
* | |
* To see an example of this examine what configure.ac does when | |
* --enable-arm-neon is specified on the command line. | |
*/ | |
PNG_FILTER_OPTIMIZATIONS(pp, bpp); | |
#endif | |
} | |
void /* PRIVATE */ | |
png_read_filter_row(png_structrp pp, png_row_infop row_info, png_bytep row, | |
png_const_bytep prev_row, int filter) | |
{ | |
/* OPTIMIZATION: DO NOT MODIFY THIS FUNCTION, instead #define | |
* PNG_FILTER_OPTIMIZATIONS to a function that overrides the generic | |
* implementations. See png_init_filter_functions above. | |
*/ | |
if (pp->read_filter[0] == NULL) | |
png_init_filter_functions(pp); | |
if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST) | |
pp->read_filter[filter-1](row_info, row, prev_row); | |
} | |
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED | |
void /* PRIVATE */ | |
png_read_IDAT_data(png_structrp png_ptr, png_bytep output, | |
png_alloc_size_t avail_out) | |
{ | |
/* Loop reading IDATs and decompressing the result into output[avail_out] */ | |
png_ptr->zstream.next_out = output; | |
png_ptr->zstream.avail_out = 0; /* safety: set below */ | |
if (output == NULL) | |
avail_out = 0; | |
do | |
{ | |
int ret; | |
png_byte tmpbuf[PNG_INFLATE_BUF_SIZE]; | |
if (png_ptr->zstream.avail_in == 0) | |
{ | |
uInt avail_in; | |
png_bytep buffer; | |
while (png_ptr->idat_size == 0) | |
{ | |
png_crc_finish(png_ptr, 0); | |
png_ptr->idat_size = png_read_chunk_header(png_ptr); | |
/* This is an error even in the 'check' case because the code just | |
* consumed a non-IDAT header. | |
*/ | |
if (png_ptr->chunk_name != png_IDAT) | |
png_error(png_ptr, "Not enough image data"); | |
} | |
avail_in = png_ptr->IDAT_read_size; | |
if (avail_in > png_ptr->idat_size) | |
avail_in = (uInt)png_ptr->idat_size; | |
/* A PNG with a gradually increasing IDAT size will defeat this attempt | |
* to minimize memory usage by causing lots of re-allocs, but | |
* realistically doing IDAT_read_size re-allocs is not likely to be a | |
* big problem. | |
*/ | |
buffer = png_read_buffer(png_ptr, avail_in, 0/*error*/); | |
png_crc_read(png_ptr, buffer, avail_in); | |
png_ptr->idat_size -= avail_in; | |
png_ptr->zstream.next_in = buffer; | |
png_ptr->zstream.avail_in = avail_in; | |
} | |
/* And set up the output side. */ | |
if (output != NULL) /* standard read */ | |
{ | |
uInt out = ZLIB_IO_MAX; | |
if (out > avail_out) | |
out = (uInt)avail_out; | |
avail_out -= out; | |
png_ptr->zstream.avail_out = out; | |
} | |
else /* after last row, checking for end */ | |
{ | |
png_ptr->zstream.next_out = tmpbuf; | |
png_ptr->zstream.avail_out = (sizeof tmpbuf); | |
} | |
/* Use NO_FLUSH; this gives zlib the maximum opportunity to optimize the | |
* process. If the LZ stream is truncated the sequential reader will | |
* terminally damage the stream, above, by reading the chunk header of the | |
* following chunk (it then exits with png_error). | |
* | |
* TODO: deal more elegantly with truncated IDAT lists. | |
*/ | |
ret = inflate(&png_ptr->zstream, Z_NO_FLUSH); | |
/* Take the unconsumed output back. */ | |
if (output != NULL) | |
avail_out += png_ptr->zstream.avail_out; | |
else /* avail_out counts the extra bytes */ | |
avail_out += (sizeof tmpbuf) - png_ptr->zstream.avail_out; | |
png_ptr->zstream.avail_out = 0; | |
if (ret == Z_STREAM_END) | |
{ | |
/* Do this for safety; we won't read any more into this row. */ | |
png_ptr->zstream.next_out = NULL; | |
png_ptr->mode |= PNG_AFTER_IDAT; | |
png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; | |
if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0) | |
png_chunk_benign_error(png_ptr, "Extra compressed data"); | |
break; | |
} | |
if (ret != Z_OK) | |
{ | |
png_zstream_error(png_ptr, ret); | |
if (output != NULL) | |
png_chunk_error(png_ptr, png_ptr->zstream.msg); | |
else /* checking */ | |
{ | |
png_chunk_benign_error(png_ptr, png_ptr->zstream.msg); | |
return; | |
} | |
} | |
} while (avail_out > 0); | |
if (avail_out > 0) | |
{ | |
/* The stream ended before the image; this is the same as too few IDATs so | |
* should be handled the same way. | |
*/ | |
if (output != NULL) | |
png_error(png_ptr, "Not enough image data"); | |
else /* the deflate stream contained extra data */ | |
png_chunk_benign_error(png_ptr, "Too much image data"); | |
} | |
} | |
void /* PRIVATE */ | |
png_read_finish_IDAT(png_structrp png_ptr) | |
{ | |
/* We don't need any more data and the stream should have ended, however the | |
* LZ end code may actually not have been processed. In this case we must | |
* read it otherwise stray unread IDAT data or, more likely, an IDAT chunk | |
* may still remain to be consumed. | |
*/ | |
if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED)) | |
{ | |
/* The NULL causes png_read_IDAT_data to swallow any remaining bytes in | |
* the compressed stream, but the stream may be damaged too, so even after | |
* this call we may need to terminate the zstream ownership. | |
*/ | |
png_read_IDAT_data(png_ptr, NULL, 0); | |
png_ptr->zstream.next_out = NULL; /* safety */ | |
/* Now clear everything out for safety; the following may not have been | |
* done. | |
*/ | |
if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED)) | |
{ | |
png_ptr->mode |= PNG_AFTER_IDAT; | |
png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; | |
} | |
} | |
/* If the zstream has not been released do it now *and* terminate the reading | |
* of the final IDAT chunk. | |
*/ | |
if (png_ptr->zowner == png_IDAT) | |
{ | |
/* Always do this; the pointers otherwise point into the read buffer. */ | |
png_ptr->zstream.next_in = NULL; | |
png_ptr->zstream.avail_in = 0; | |
/* Now we no longer own the zstream. */ | |
png_ptr->zowner = 0; | |
/* The slightly weird semantics of the sequential IDAT reading is that we | |
* are always in or at the end of an IDAT chunk, so we always need to do a | |
* crc_finish here. If idat_size is non-zero we also need to read the | |
* spurious bytes at the end of the chunk now. | |
*/ | |
(void)png_crc_finish(png_ptr, png_ptr->idat_size); | |
} | |
} | |
void /* PRIVATE */ | |
png_read_finish_row(png_structrp png_ptr) | |
{ | |
#ifdef PNG_READ_INTERLACING_SUPPORTED | |
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ | |
/* Start of interlace block */ | |
static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; | |
/* Offset to next interlace block */ | |
static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; | |
/* Start of interlace block in the y direction */ | |
static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; | |
/* Offset to next interlace block in the y direction */ | |
static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; | |
#endif /* PNG_READ_INTERLACING_SUPPORTED */ | |
png_debug(1, "in png_read_finish_row"); | |
png_ptr->row_number++; | |
if (png_ptr->row_number < png_ptr->num_rows) | |
return; | |
#ifdef PNG_READ_INTERLACING_SUPPORTED | |
if (png_ptr->interlaced) | |
{ | |
png_ptr->row_number = 0; | |
/* TO DO: don't do this if prev_row isn't needed (requires | |
* read-ahead of the next row's filter byte. | |
*/ | |
memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); | |
do | |
{ | |
png_ptr->pass++; | |
if (png_ptr->pass >= 7) | |
break; | |
png_ptr->iwidth = (png_ptr->width + | |
png_pass_inc[png_ptr->pass] - 1 - | |
png_pass_start[png_ptr->pass]) / | |
png_pass_inc[png_ptr->pass]; | |
if (!(png_ptr->transformations & PNG_INTERLACE)) | |
{ | |
png_ptr->num_rows = (png_ptr->height + | |
png_pass_yinc[png_ptr->pass] - 1 - | |
png_pass_ystart[png_ptr->pass]) / | |
png_pass_yinc[png_ptr->pass]; | |
} | |
else /* if (png_ptr->transformations & PNG_INTERLACE) */ | |
break; /* libpng deinterlacing sees every row */ | |
} while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0); | |
if (png_ptr->pass < 7) | |
return; | |
} | |
#endif /* PNG_READ_INTERLACING_SUPPORTED */ | |
/* Here after at the end of the last row of the last pass. */ | |
png_read_finish_IDAT(png_ptr); | |
} | |
#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ | |
void /* PRIVATE */ | |
png_read_start_row(png_structrp png_ptr) | |
{ | |
#ifdef PNG_READ_INTERLACING_SUPPORTED | |
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ | |
/* Start of interlace block */ | |
static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; | |
/* Offset to next interlace block */ | |
static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; | |
/* Start of interlace block in the y direction */ | |
static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; | |
/* Offset to next interlace block in the y direction */ | |
static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; | |
#endif | |
int max_pixel_depth; | |
png_size_t row_bytes; | |
png_debug(1, "in png_read_start_row"); | |
#ifdef PNG_READ_TRANSFORMS_SUPPORTED | |
png_init_read_transformations(png_ptr); | |
#endif | |
#ifdef PNG_READ_INTERLACING_SUPPORTED | |
if (png_ptr->interlaced) | |
{ | |
if (!(png_ptr->transformations & PNG_INTERLACE)) | |
png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - | |
png_pass_ystart[0]) / png_pass_yinc[0]; | |
else | |
png_ptr->num_rows = png_ptr->height; | |
png_ptr->iwidth = (png_ptr->width + | |
png_pass_inc[png_ptr->pass] - 1 - | |
png_pass_start[png_ptr->pass]) / | |
png_pass_inc[png_ptr->pass]; | |
} | |
else | |
#endif /* PNG_READ_INTERLACING_SUPPORTED */ | |
{ | |
png_ptr->num_rows = png_ptr->height; | |
png_ptr->iwidth = png_ptr->width; | |
} | |
max_pixel_depth = png_ptr->pixel_depth; | |
/* WARNING: * png_read_transform_info (pngrtran.c) performs a simpliar set of | |
* calculations to calculate the final pixel depth, then | |
* png_do_read_transforms actually does the transforms. This means that the | |
* code which effectively calculates this value is actually repeated in three | |
* separate places. They must all match. Innocent changes to the order of | |
* transformations can and will break libpng in a way that causes memory | |
* overwrites. | |
* | |
* TODO: fix this. | |
*/ | |
#ifdef PNG_READ_PACK_SUPPORTED | |
if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8) | |
max_pixel_depth = 8; | |
#endif | |
#ifdef PNG_READ_EXPAND_SUPPORTED | |
if (png_ptr->transformations & PNG_EXPAND) | |
{ | |
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | |
{ | |
if (png_ptr->num_trans) | |
max_pixel_depth = 32; | |
else | |
max_pixel_depth = 24; | |
} | |
else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) | |
{ | |
if (max_pixel_depth < 8) | |
max_pixel_depth = 8; | |
if (png_ptr->num_trans) | |
max_pixel_depth *= 2; | |
} | |
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) | |
{ | |
if (png_ptr->num_trans) | |
{ | |
max_pixel_depth *= 4; | |
max_pixel_depth /= 3; | |
} | |
} | |
} | |
#endif | |
#ifdef PNG_READ_EXPAND_16_SUPPORTED | |
if (png_ptr->transformations & PNG_EXPAND_16) | |
{ | |
# ifdef PNG_READ_EXPAND_SUPPORTED | |
/* In fact it is an error if it isn't supported, but checking is | |
* the safe way. | |
*/ | |
if (png_ptr->transformations & PNG_EXPAND) | |
{ | |
if (png_ptr->bit_depth < 16) | |
max_pixel_depth *= 2; | |
} | |
else | |
# endif | |
png_ptr->transformations &= ~PNG_EXPAND_16; | |
} | |
#endif | |
#ifdef PNG_READ_FILLER_SUPPORTED | |
if (png_ptr->transformations & (PNG_FILLER)) | |
{ | |
if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) | |
{ | |
if (max_pixel_depth <= 8) | |
max_pixel_depth = 16; | |
else | |
max_pixel_depth = 32; | |
} | |
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB || | |
png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | |
{ | |
if (max_pixel_depth <= 32) | |
max_pixel_depth = 32; | |
else | |
max_pixel_depth = 64; | |
} | |
} | |
#endif | |
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED | |
if (png_ptr->transformations & PNG_GRAY_TO_RGB) | |
{ | |
if ( | |
#ifdef PNG_READ_EXPAND_SUPPORTED | |
(png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) || | |
#endif | |
#ifdef PNG_READ_FILLER_SUPPORTED | |
(png_ptr->transformations & (PNG_FILLER)) || | |
#endif | |
png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) | |
{ | |
if (max_pixel_depth <= 16) | |
max_pixel_depth = 32; | |
else | |
max_pixel_depth = 64; | |
} | |
else | |
{ | |
if (max_pixel_depth <= 8) | |
{ | |
if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) | |
max_pixel_depth = 32; | |
else | |
max_pixel_depth = 24; | |
} | |
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) | |
max_pixel_depth = 64; | |
else | |
max_pixel_depth = 48; | |
} | |
} | |
#endif | |
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \ | |
defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) | |
if (png_ptr->transformations & PNG_USER_TRANSFORM) | |
{ | |
int user_pixel_depth = png_ptr->user_transform_depth * | |
png_ptr->user_transform_channels; | |
if (user_pixel_depth > max_pixel_depth) | |
max_pixel_depth = user_pixel_depth; | |
} | |
#endif | |
/* This value is stored in png_struct and double checked in the row read | |
* code. | |
*/ | |
png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth; | |
png_ptr->transformed_pixel_depth = 0; /* calculated on demand */ | |
/* Align the width on the next larger 8 pixels. Mainly used | |
* for interlacing | |
*/ | |
row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7)); | |
/* Calculate the maximum bytes needed, adding a byte and a pixel | |
* for safety's sake | |
*/ | |
row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) + | |
1 + ((max_pixel_depth + 7) >> 3); | |
#ifdef PNG_MAX_MALLOC_64K | |
if (row_bytes > (png_uint_32)65536L) | |
png_error(png_ptr, "This image requires a row greater than 64KB"); | |
#endif | |
if (row_bytes + 48 > png_ptr->old_big_row_buf_size) | |
{ | |
png_free(png_ptr, png_ptr->big_row_buf); | |
png_free(png_ptr, png_ptr->big_prev_row); | |
if (png_ptr->interlaced) | |
png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr, | |
row_bytes + 48); | |
else | |
png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48); | |
png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48); | |
#ifdef PNG_ALIGNED_MEMORY_SUPPORTED | |
/* Use 16-byte aligned memory for row_buf with at least 16 bytes | |
* of padding before and after row_buf; treat prev_row similarly. | |
* NOTE: the alignment is to the start of the pixels, one beyond the start | |
* of the buffer, because of the filter byte. Prior to libpng 1.5.6 this | |
* was incorrect; the filter byte was aligned, which had the exact | |
* opposite effect of that intended. | |
*/ | |
{ | |
png_bytep temp = png_ptr->big_row_buf + 32; | |
int extra = (int)((temp - (png_bytep)0) & 0x0f); | |
png_ptr->row_buf = temp - extra - 1/*filter byte*/; | |
temp = png_ptr->big_prev_row + 32; | |
extra = (int)((temp - (png_bytep)0) & 0x0f); | |
png_ptr->prev_row = temp - extra - 1/*filter byte*/; | |
} | |
#else | |
/* Use 31 bytes of padding before and 17 bytes after row_buf. */ | |
png_ptr->row_buf = png_ptr->big_row_buf + 31; | |
png_ptr->prev_row = png_ptr->big_prev_row + 31; | |
#endif | |
png_ptr->old_big_row_buf_size = row_bytes + 48; | |
} | |
#ifdef PNG_MAX_MALLOC_64K | |
if (png_ptr->rowbytes > 65535) | |
png_error(png_ptr, "This image requires a row greater than 64KB"); | |
#endif | |
if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1)) | |
png_error(png_ptr, "Row has too many bytes to allocate in memory"); | |
memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); | |
png_debug1(3, "width = %u,", png_ptr->width); | |
png_debug1(3, "height = %u,", png_ptr->height); | |
png_debug1(3, "iwidth = %u,", png_ptr->iwidth); | |
png_debug1(3, "num_rows = %u,", png_ptr->num_rows); | |
png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes); | |
png_debug1(3, "irowbytes = %lu", | |
(unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1); | |
/* The sequential reader needs a buffer for IDAT, but the progressive reader | |
* does not, so free the read buffer now regardless; the sequential reader | |
* reallocates it on demand. | |
*/ | |
if (png_ptr->read_buffer) | |
{ | |
png_bytep buffer = png_ptr->read_buffer; | |
png_ptr->read_buffer_size = 0; | |
png_ptr->read_buffer = NULL; | |
png_free(png_ptr, buffer); | |
} | |
/* Finally claim the zstream for the inflate of the IDAT data, use the bits | |
* value from the stream (note that this will result in a fatal error if the | |
* IDAT stream has a bogus deflate header window_bits value, but this should | |
* not be happening any longer!) | |
*/ | |
if (png_inflate_claim(png_ptr, png_IDAT) != Z_OK) | |
png_error(png_ptr, png_ptr->zstream.msg); | |
png_ptr->flags |= PNG_FLAG_ROW_INIT; | |
} | |
#endif /* PNG_READ_SUPPORTED */ |