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4681 lines
144 KiB
4681 lines
144 KiB
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/* pngrutil.c - utilities to read a PNG file |
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* |
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* Copyright (c) 2018 Cosmin Truta |
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* Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson |
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* Copyright (c) 1996-1997 Andreas Dilger |
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* Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. |
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* |
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* This code is released under the libpng license. |
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* For conditions of distribution and use, see the disclaimer |
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* and license in png.h |
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* |
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* This file contains routines that are only called from within |
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* libpng itself during the course of reading an image. |
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*/ |
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#include "pngpriv.h" |
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#ifdef PNG_READ_SUPPORTED |
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png_uint_32 PNGAPI |
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png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf) |
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{ |
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png_uint_32 uval = png_get_uint_32(buf); |
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if (uval > PNG_UINT_31_MAX) |
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png_error(png_ptr, "PNG unsigned integer out of range"); |
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return (uval); |
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} |
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#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED) |
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/* The following is a variation on the above for use with the fixed |
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* point values used for gAMA and cHRM. Instead of png_error it |
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* issues a warning and returns (-1) - an invalid value because both |
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* gAMA and cHRM use *unsigned* integers for fixed point values. |
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*/ |
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#define PNG_FIXED_ERROR (-1) |
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static png_fixed_point /* PRIVATE */ |
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png_get_fixed_point(png_structrp png_ptr, png_const_bytep buf) |
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{ |
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png_uint_32 uval = png_get_uint_32(buf); |
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if (uval <= PNG_UINT_31_MAX) |
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return (png_fixed_point)uval; /* known to be in range */ |
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/* The caller can turn off the warning by passing NULL. */ |
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if (png_ptr != NULL) |
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png_warning(png_ptr, "PNG fixed point integer out of range"); |
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return PNG_FIXED_ERROR; |
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} |
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#endif |
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#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED |
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/* NOTE: the read macros will obscure these definitions, so that if |
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* PNG_USE_READ_MACROS is set the library will not use them internally, |
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* but the APIs will still be available externally. |
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* |
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* The parentheses around "PNGAPI function_name" in the following three |
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* functions are necessary because they allow the macros to co-exist with |
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* these (unused but exported) functions. |
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*/ |
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/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */ |
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png_uint_32 (PNGAPI |
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png_get_uint_32)(png_const_bytep buf) |
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{ |
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png_uint_32 uval = |
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((png_uint_32)(*(buf )) << 24) + |
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((png_uint_32)(*(buf + 1)) << 16) + |
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((png_uint_32)(*(buf + 2)) << 8) + |
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((png_uint_32)(*(buf + 3)) ) ; |
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return uval; |
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} |
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/* Grab a signed 32-bit integer from a buffer in big-endian format. The |
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* data is stored in the PNG file in two's complement format and there |
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* is no guarantee that a 'png_int_32' is exactly 32 bits, therefore |
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* the following code does a two's complement to native conversion. |
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*/ |
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png_int_32 (PNGAPI |
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png_get_int_32)(png_const_bytep buf) |
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{ |
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png_uint_32 uval = png_get_uint_32(buf); |
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if ((uval & 0x80000000) == 0) /* non-negative */ |
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return (png_int_32)uval; |
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uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */ |
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if ((uval & 0x80000000) == 0) /* no overflow */ |
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return -(png_int_32)uval; |
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/* The following has to be safe; this function only gets called on PNG data |
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* and if we get here that data is invalid. 0 is the most safe value and |
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* if not then an attacker would surely just generate a PNG with 0 instead. |
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*/ |
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return 0; |
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} |
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/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */ |
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png_uint_16 (PNGAPI |
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png_get_uint_16)(png_const_bytep buf) |
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{ |
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/* ANSI-C requires an int value to accommodate at least 16 bits so this |
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* works and allows the compiler not to worry about possible narrowing |
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* on 32-bit systems. (Pre-ANSI systems did not make integers smaller |
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* than 16 bits either.) |
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*/ |
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unsigned int val = |
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((unsigned int)(*buf) << 8) + |
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((unsigned int)(*(buf + 1))); |
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return (png_uint_16)val; |
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} |
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#endif /* READ_INT_FUNCTIONS */ |
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/* Read and check the PNG file signature */ |
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void /* PRIVATE */ |
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png_read_sig(png_structrp png_ptr, png_inforp info_ptr) |
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{ |
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size_t num_checked, num_to_check; |
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/* Exit if the user application does not expect a signature. */ |
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if (png_ptr->sig_bytes >= 8) |
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return; |
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num_checked = png_ptr->sig_bytes; |
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num_to_check = 8 - num_checked; |
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#ifdef PNG_IO_STATE_SUPPORTED |
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png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE; |
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#endif |
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/* The signature must be serialized in a single I/O call. */ |
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png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); |
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png_ptr->sig_bytes = 8; |
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if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check) != 0) |
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{ |
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if (num_checked < 4 && |
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png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) |
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png_error(png_ptr, "Not a PNG file"); |
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else |
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png_error(png_ptr, "PNG file corrupted by ASCII conversion"); |
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} |
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if (num_checked < 3) |
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png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; |
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} |
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/* Read the chunk header (length + type name). |
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* Put the type name into png_ptr->chunk_name, and return the length. |
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*/ |
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png_uint_32 /* PRIVATE */ |
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png_read_chunk_header(png_structrp png_ptr) |
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{ |
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png_byte buf[8]; |
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png_uint_32 length; |
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#ifdef PNG_IO_STATE_SUPPORTED |
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png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR; |
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#endif |
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/* Read the length and the chunk name. |
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* This must be performed in a single I/O call. |
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*/ |
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png_read_data(png_ptr, buf, 8); |
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length = png_get_uint_31(png_ptr, buf); |
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/* Put the chunk name into png_ptr->chunk_name. */ |
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png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4); |
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png_debug2(0, "Reading %lx chunk, length = %lu", |
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(unsigned long)png_ptr->chunk_name, (unsigned long)length); |
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/* Reset the crc and run it over the chunk name. */ |
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png_reset_crc(png_ptr); |
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png_calculate_crc(png_ptr, buf + 4, 4); |
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/* Check to see if chunk name is valid. */ |
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png_check_chunk_name(png_ptr, png_ptr->chunk_name); |
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/* Check for too-large chunk length */ |
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png_check_chunk_length(png_ptr, length); |
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#ifdef PNG_IO_STATE_SUPPORTED |
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png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA; |
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#endif |
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return length; |
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} |
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/* Read data, and (optionally) run it through the CRC. */ |
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void /* PRIVATE */ |
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png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length) |
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{ |
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if (png_ptr == NULL) |
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return; |
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png_read_data(png_ptr, buf, length); |
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png_calculate_crc(png_ptr, buf, length); |
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} |
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/* Optionally skip data and then check the CRC. Depending on whether we |
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* are reading an ancillary or critical chunk, and how the program has set |
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* things up, we may calculate the CRC on the data and print a message. |
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* Returns '1' if there was a CRC error, '0' otherwise. |
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*/ |
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int /* PRIVATE */ |
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png_crc_finish(png_structrp png_ptr, png_uint_32 skip) |
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{ |
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/* The size of the local buffer for inflate is a good guess as to a |
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* reasonable size to use for buffering reads from the application. |
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*/ |
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while (skip > 0) |
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{ |
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png_uint_32 len; |
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png_byte tmpbuf[PNG_INFLATE_BUF_SIZE]; |
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len = (sizeof tmpbuf); |
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if (len > skip) |
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len = skip; |
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skip -= len; |
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png_crc_read(png_ptr, tmpbuf, len); |
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} |
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if (png_crc_error(png_ptr) != 0) |
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{ |
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if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0 ? |
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(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0 : |
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(png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE) != 0) |
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{ |
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png_chunk_warning(png_ptr, "CRC error"); |
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} |
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else |
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png_chunk_error(png_ptr, "CRC error"); |
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return (1); |
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} |
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return (0); |
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} |
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/* Compare the CRC stored in the PNG file with that calculated by libpng from |
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* the data it has read thus far. |
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*/ |
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int /* PRIVATE */ |
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png_crc_error(png_structrp png_ptr) |
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{ |
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png_byte crc_bytes[4]; |
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png_uint_32 crc; |
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int need_crc = 1; |
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if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0) |
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{ |
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if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == |
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(PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) |
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need_crc = 0; |
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} |
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else /* critical */ |
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{ |
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if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0) |
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need_crc = 0; |
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} |
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#ifdef PNG_IO_STATE_SUPPORTED |
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png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC; |
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#endif |
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/* The chunk CRC must be serialized in a single I/O call. */ |
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png_read_data(png_ptr, crc_bytes, 4); |
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if (need_crc != 0) |
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{ |
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crc = png_get_uint_32(crc_bytes); |
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return ((int)(crc != png_ptr->crc)); |
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} |
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else |
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return (0); |
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} |
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#if defined(PNG_READ_iCCP_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) ||\ |
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defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_sCAL_SUPPORTED) ||\ |
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defined(PNG_READ_sPLT_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) ||\ |
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defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_SEQUENTIAL_READ_SUPPORTED) |
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/* Manage the read buffer; this simply reallocates the buffer if it is not small |
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* enough (or if it is not allocated). The routine returns a pointer to the |
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* buffer; if an error occurs and 'warn' is set the routine returns NULL, else |
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* it will call png_error (via png_malloc) on failure. (warn == 2 means |
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* 'silent'). |
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*/ |
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static png_bytep |
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png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn) |
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{ |
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png_bytep buffer = png_ptr->read_buffer; |
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if (buffer != NULL && new_size > png_ptr->read_buffer_size) |
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{ |
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png_ptr->read_buffer = NULL; |
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png_ptr->read_buffer = NULL; |
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png_ptr->read_buffer_size = 0; |
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png_free(png_ptr, buffer); |
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buffer = NULL; |
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} |
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if (buffer == NULL) |
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{ |
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buffer = png_voidcast(png_bytep, png_malloc_base(png_ptr, new_size)); |
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if (buffer != NULL) |
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{ |
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memset(buffer, 0, new_size); /* just in case */ |
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png_ptr->read_buffer = buffer; |
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png_ptr->read_buffer_size = new_size; |
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} |
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else if (warn < 2) /* else silent */ |
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{ |
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if (warn != 0) |
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png_chunk_warning(png_ptr, "insufficient memory to read chunk"); |
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else |
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png_chunk_error(png_ptr, "insufficient memory to read chunk"); |
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} |
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} |
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return buffer; |
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} |
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#endif /* READ_iCCP|iTXt|pCAL|sCAL|sPLT|tEXt|zTXt|SEQUENTIAL_READ */ |
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/* png_inflate_claim: claim the zstream for some nefarious purpose that involves |
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* decompression. Returns Z_OK on success, else a zlib error code. It checks |
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* the owner but, in final release builds, just issues a warning if some other |
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* chunk apparently owns the stream. Prior to release it does a png_error. |
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*/ |
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static int |
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png_inflate_claim(png_structrp png_ptr, png_uint_32 owner) |
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{ |
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if (png_ptr->zowner != 0) |
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{ |
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char msg[64]; |
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PNG_STRING_FROM_CHUNK(msg, png_ptr->zowner); |
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/* So the message that results is "<chunk> using zstream"; this is an |
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* internal error, but is very useful for debugging. i18n requirements |
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* are minimal. |
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*/ |
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(void)png_safecat(msg, (sizeof msg), 4, " using zstream"); |
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#if PNG_RELEASE_BUILD |
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png_chunk_warning(png_ptr, msg); |
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png_ptr->zowner = 0; |
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#else |
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png_chunk_error(png_ptr, msg); |
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#endif |
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} |
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|
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/* Implementation note: unlike 'png_deflate_claim' this internal function |
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* does not take the size of the data as an argument. Some efficiency could |
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* be gained by using this when it is known *if* the zlib stream itself does |
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* not record the number; however, this is an illusion: the original writer |
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* of the PNG may have selected a lower window size, and we really must |
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* follow that because, for systems with with limited capabilities, we |
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* would otherwise reject the application's attempts to use a smaller window |
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* size (zlib doesn't have an interface to say "this or lower"!). |
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* |
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* inflateReset2 was added to zlib 1.2.4; before this the window could not be |
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* reset, therefore it is necessary to always allocate the maximum window |
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* size with earlier zlibs just in case later compressed chunks need it. |
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*/ |
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{ |
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int ret; /* zlib return code */ |
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#if ZLIB_VERNUM >= 0x1240 |
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int window_bits = 0; |
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# if defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_MAXIMUM_INFLATE_WINDOW) |
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if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) == |
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PNG_OPTION_ON) |
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{ |
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window_bits = 15; |
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png_ptr->zstream_start = 0; /* fixed window size */ |
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} |
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else |
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{ |
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png_ptr->zstream_start = 1; |
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} |
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# endif |
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#endif /* ZLIB_VERNUM >= 0x1240 */ |
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|
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/* Set this for safety, just in case the previous owner left pointers to |
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* memory allocations. |
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*/ |
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png_ptr->zstream.next_in = NULL; |
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png_ptr->zstream.avail_in = 0; |
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png_ptr->zstream.next_out = NULL; |
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png_ptr->zstream.avail_out = 0; |
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if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0) |
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{ |
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#if ZLIB_VERNUM >= 0x1240 |
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ret = inflateReset2(&png_ptr->zstream, window_bits); |
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#else |
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ret = inflateReset(&png_ptr->zstream); |
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#endif |
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} |
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else |
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{ |
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#if ZLIB_VERNUM >= 0x1240 |
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ret = inflateInit2(&png_ptr->zstream, window_bits); |
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#else |
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ret = inflateInit(&png_ptr->zstream); |
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#endif |
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if (ret == Z_OK) |
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png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED; |
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} |
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#if ZLIB_VERNUM >= 0x1290 && \ |
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defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_IGNORE_ADLER32) |
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if (((png_ptr->options >> PNG_IGNORE_ADLER32) & 3) == PNG_OPTION_ON) |
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/* Turn off validation of the ADLER32 checksum in IDAT chunks */ |
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ret = inflateValidate(&png_ptr->zstream, 0); |
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#endif |
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if (ret == Z_OK) |
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png_ptr->zowner = owner; |
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else |
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png_zstream_error(png_ptr, ret); |
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return ret; |
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} |
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|
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#ifdef window_bits |
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# undef window_bits |
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#endif |
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} |
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|
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#if ZLIB_VERNUM >= 0x1240 |
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/* Handle the start of the inflate stream if we called inflateInit2(strm,0); |
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* in this case some zlib versions skip validation of the CINFO field and, in |
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* certain circumstances, libpng may end up displaying an invalid image, in |
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* contrast to implementations that call zlib in the normal way (e.g. libpng |
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* 1.5). |
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*/ |
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int /* PRIVATE */ |
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png_zlib_inflate(png_structrp png_ptr, int flush) |
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{ |
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if (png_ptr->zstream_start && png_ptr->zstream.avail_in > 0) |
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{ |
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if ((*png_ptr->zstream.next_in >> 4) > 7) |
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{ |
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png_ptr->zstream.msg = "invalid window size (libpng)"; |
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return Z_DATA_ERROR; |
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} |
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png_ptr->zstream_start = 0; |
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} |
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|
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return inflate(&png_ptr->zstream, flush); |
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} |
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#endif /* Zlib >= 1.2.4 */ |
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|
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#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED |
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#if defined(PNG_READ_zTXt_SUPPORTED) || defined (PNG_READ_iTXt_SUPPORTED) |
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/* png_inflate now returns zlib error codes including Z_OK and Z_STREAM_END to |
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* allow the caller to do multiple calls if required. If the 'finish' flag is |
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* set Z_FINISH will be passed to the final inflate() call and Z_STREAM_END must |
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* be returned or there has been a problem, otherwise Z_SYNC_FLUSH is used and |
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* Z_OK or Z_STREAM_END will be returned on success. |
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* |
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* The input and output sizes are updated to the actual amounts of data consumed |
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* or written, not the amount available (as in a z_stream). The data pointers |
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* are not changed, so the next input is (data+input_size) and the next |
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* available output is (output+output_size). |
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*/ |
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static int |
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png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish, |
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/* INPUT: */ png_const_bytep input, png_uint_32p input_size_ptr, |
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/* OUTPUT: */ png_bytep output, png_alloc_size_t *output_size_ptr) |
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{ |
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if (png_ptr->zowner == owner) /* Else not claimed */ |
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{ |
|
int ret; |
|
png_alloc_size_t avail_out = *output_size_ptr; |
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png_uint_32 avail_in = *input_size_ptr; |
|
|
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/* 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 |
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* "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 |
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* maximum value that can be stored in a uInt.) It is possible to set |
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* ZLIB_IO_MAX to a lower value in pngpriv.h and this may sometimes have |
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* 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); |
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/* 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; |
|
|
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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 = PNG_INFLATE(png_ptr, 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_USER_LIMITS_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) |
|
{ |
|
memset(text, 0, buffer_size); |
|
|
|
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 != 0) |
|
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); |
|
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 /* READ_zTXt || READ_iTXt */ |
|
#endif /* READ_COMPRESSED_TEXT */ |
|
|
|
#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 = PNG_INFLATE(png_ptr, *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_iCCP */ |
|
|
|
/* 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) != 0) |
|
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 max_palette_length, 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) == 0) |
|
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) != 0) |
|
png_chunk_error(png_ptr, "duplicate"); |
|
|
|
else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) |
|
{ |
|
/* 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) == 0) |
|
{ |
|
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; |
|
|
|
/* If the palette has 256 or fewer entries but is too large for the bit |
|
* depth, we don't issue an error, to preserve the behavior of previous |
|
* libpng versions. We silently truncate the unused extra palette entries |
|
* here. |
|
*/ |
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
max_palette_length = (1 << png_ptr->bit_depth); |
|
else |
|
max_palette_length = PNG_MAX_PALETTE_LENGTH; |
|
|
|
if (num > max_palette_length) |
|
num = max_palette_length; |
|
|
|
#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, (png_uint_32) (length - (unsigned int)num * 3)); |
|
} |
|
|
|
#ifndef PNG_READ_OPT_PLTE_SUPPORTED |
|
else if (png_crc_error(png_ptr) != 0) /* 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) == 0) |
|
{ |
|
if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) != 0) |
|
return; |
|
|
|
else |
|
png_chunk_error(png_ptr, "CRC error"); |
|
} |
|
|
|
/* Otherwise, we (optionally) emit a warning and use the chunk. */ |
|
else if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0) |
|
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) == 0 || |
|
(png_ptr->mode & PNG_HAVE_IDAT) == 0) |
|
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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) |
|
{ |
|
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) != 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, i; |
|
png_byte sample_depth; |
|
png_byte buf[4]; |
|
|
|
png_debug(1, "in png_handle_sBIT"); |
|
|
|
if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) |
|
{ |
|
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) != 0) |
|
{ |
|
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; |
|
sample_depth = 8; |
|
} |
|
|
|
else |
|
{ |
|
truelen = png_ptr->channels; |
|
sample_depth = png_ptr->bit_depth; |
|
} |
|
|
|
if (length != truelen || length > 4) |
|
{ |
|
png_chunk_benign_error(png_ptr, "invalid"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
buf[0] = buf[1] = buf[2] = buf[3] = sample_depth; |
|
png_crc_read(png_ptr, buf, truelen); |
|
|
|
if (png_crc_finish(png_ptr, 0) != 0) |
|
return; |
|
|
|
for (i=0; i<truelen; ++i) |
|
{ |
|
if (buf[i] == 0 || buf[i] > sample_depth) |
|
{ |
|
png_chunk_benign_error(png_ptr, "invalid"); |
|
return; |
|
} |
|
} |
|
|
|
if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) |
|
{ |
|
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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) |
|
{ |
|
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) != 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) != 0) |
|
return; |
|
|
|
if ((png_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0) |
|
{ |
|
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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) |
|
{ |
|
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) != 0) |
|
return; |
|
|
|
/* If a colorspace error has already been output skip this chunk */ |
|
if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0) |
|
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) |
|
{ |
|
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 /* READ_sRGB */ |
|
|
|
#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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) |
|
{ |
|
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 keyword must be at least one character and there is a |
|
* terminator (0) byte and the compression method byte, and the |
|
* 'zlib' datastream is at least 11 bytes. |
|
*/ |
|
if (length < 14) |
|
{ |
|
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) != 0) |
|
{ |
|
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; |
|
|
|
/* The minimum 'zlib' stream is assumed to be just the 2 byte header, |
|
* 5 bytes minimum 'deflate' stream, and the 4 byte checksum. |
|
*/ |
|
if (length < 11) |
|
{ |
|
png_crc_finish(png_ptr, length); |
|
png_chunk_benign_error(png_ptr, "too short"); |
|
return; |
|
} |
|
|
|
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]={0}; |
|
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. |
|
*/ |
|
png_uint_32 profile_length = png_get_uint_32(profile_header); |
|
|
|
if (png_icc_check_length(png_ptr, &png_ptr->colorspace, |
|
keyword, profile_length) != 0) |
|
{ |
|
/* 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) != 0) |
|
{ |
|
/* 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 this stuff will overflow. |
|
*/ |
|
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 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) != 0) |
|
{ |
|
/* 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; |
|
|
|
# if defined(PNG_sRGB_SUPPORTED) && PNG_sRGB_PROFILE_CHECKS >= 0 |
|
/* 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; |
|
} |
|
} |
|
if (errmsg == NULL) |
|
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 == 0) |
|
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 /* READ_iCCP */ |
|
|
|
#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; |
|
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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) |
|
{ |
|
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) != 0) |
|
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 (length < 2U || entry_start > buffer + (length - 2U)) |
|
{ |
|
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 % (unsigned int)entry_size) != 0) |
|
{ |
|
png_warning(png_ptr, "sPLT chunk has bad length"); |
|
return; |
|
} |
|
|
|
dl = (png_uint_32)(data_length / (unsigned int)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 / (unsigned int)entry_size); |
|
|
|
new_palette.entries = (png_sPLT_entryp)png_malloc_warn(png_ptr, |
|
(png_alloc_size_t) 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 /* READ_sPLT */ |
|
|
|
#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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) |
|
{ |
|
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) != 0) |
|
{ |
|
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) == 0) |
|
{ |
|
/* 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 > (unsigned int) png_ptr->num_palette || |
|
length > (unsigned int) 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) != 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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 || |
|
(png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && |
|
(png_ptr->mode & PNG_HAVE_PLTE) == 0)) |
|
{ |
|
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) != 0) |
|
{ |
|
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) != 0) |
|
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) != 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 != NULL && info_ptr->num_palette != 0) |
|
{ |
|
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) == 0) /* GRAY */ |
|
{ |
|
if (png_ptr->bit_depth <= 8) |
|
{ |
|
if (buf[0] != 0 || buf[1] >= (unsigned int)(1 << png_ptr->bit_depth)) |
|
{ |
|
png_chunk_benign_error(png_ptr, "invalid gray level"); |
|
return; |
|
} |
|
} |
|
|
|
background.index = 0; |
|
background.red = |
|
background.green = |
|
background.blue = |
|
background.gray = png_get_uint_16(buf); |
|
} |
|
|
|
else |
|
{ |
|
if (png_ptr->bit_depth <= 8) |
|
{ |
|
if (buf[0] != 0 || buf[2] != 0 || buf[4] != 0) |
|
{ |
|
png_chunk_benign_error(png_ptr, "invalid color"); |
|
return; |
|
} |
|
} |
|
|
|
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_eXIf_SUPPORTED |
|
void /* PRIVATE */ |
|
png_handle_eXIf(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) |
|
{ |
|
unsigned int i; |
|
|
|
png_debug(1, "in png_handle_eXIf"); |
|
|
|
if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
if (length < 2) |
|
{ |
|
png_crc_finish(png_ptr, length); |
|
png_chunk_benign_error(png_ptr, "too short"); |
|
return; |
|
} |
|
|
|
else if (info_ptr == NULL || (info_ptr->valid & PNG_INFO_eXIf) != 0) |
|
{ |
|
png_crc_finish(png_ptr, length); |
|
png_chunk_benign_error(png_ptr, "duplicate"); |
|
return; |
|
} |
|
|
|
info_ptr->free_me |= PNG_FREE_EXIF; |
|
|
|
info_ptr->eXIf_buf = png_voidcast(png_bytep, |
|
png_malloc_warn(png_ptr, length)); |
|
|
|
if (info_ptr->eXIf_buf == NULL) |
|
{ |
|
png_crc_finish(png_ptr, length); |
|
png_chunk_benign_error(png_ptr, "out of memory"); |
|
return; |
|
} |
|
|
|
for (i = 0; i < length; i++) |
|
{ |
|
png_byte buf[1]; |
|
png_crc_read(png_ptr, buf, 1); |
|
info_ptr->eXIf_buf[i] = buf[0]; |
|
if (i == 1 && buf[0] != 'M' && buf[0] != 'I' |
|
&& info_ptr->eXIf_buf[0] != buf[0]) |
|
{ |
|
png_crc_finish(png_ptr, length); |
|
png_chunk_benign_error(png_ptr, "incorrect byte-order specifier"); |
|
png_free(png_ptr, info_ptr->eXIf_buf); |
|
info_ptr->eXIf_buf = NULL; |
|
return; |
|
} |
|
} |
|
|
|
if (png_crc_finish(png_ptr, 0) != 0) |
|
return; |
|
|
|
png_set_eXIf_1(png_ptr, info_ptr, length, info_ptr->eXIf_buf); |
|
|
|
png_free(png_ptr, info_ptr->eXIf_buf); |
|
info_ptr->eXIf_buf = NULL; |
|
} |
|
#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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 || |
|
(png_ptr->mode & PNG_HAVE_PLTE) == 0) |
|
{ |
|
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) != 0) |
|
{ |
|
png_crc_finish(png_ptr, length); |
|
png_chunk_benign_error(png_ptr, "duplicate"); |
|
return; |
|
} |
|
|
|
num = length / 2 ; |
|
|
|
if (num != (unsigned int) png_ptr->num_palette || |
|
num > (unsigned int) 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) != 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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) |
|
{ |
|
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) != 0) |
|
{ |
|
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) != 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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) |
|
{ |
|
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) != 0) |
|
{ |
|
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) != 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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) |
|
{ |
|
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) != 0) |
|
{ |
|
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) != 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; |
|
size_t i; |
|
int state; |
|
|
|
png_debug(1, "in png_handle_sCAL"); |
|
|
|
if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) |
|
{ |
|
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) != 0) |
|
{ |
|
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) != 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) == 0 || |
|
i >= length || buffer[i++] != 0) |
|
png_chunk_benign_error(png_ptr, "bad width format"); |
|
|
|
else if (PNG_FP_IS_POSITIVE(state) == 0) |
|
png_chunk_benign_error(png_ptr, "non-positive width"); |
|
|
|
else |
|
{ |
|
size_t heighti = i; |
|
|
|
state = 0; |
|
if (png_check_fp_number((png_const_charp)buffer, length, |
|
&state, &i) == 0 || i != length) |
|
png_chunk_benign_error(png_ptr, "bad height format"); |
|
|
|
else if (PNG_FP_IS_POSITIVE(state) == 0) |
|
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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME) != 0) |
|
{ |
|
png_crc_finish(png_ptr, length); |
|
png_chunk_benign_error(png_ptr, "duplicate"); |
|
return; |
|
} |
|
|
|
if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) |
|
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) != 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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) |
|
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) != 0) |
|
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) != 0) |
|
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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) |
|
png_ptr->mode |= PNG_AFTER_IDAT; |
|
|
|
/* Note, "length" is sufficient here; we won't be adding |
|
* a null terminator later. |
|
*/ |
|
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) != 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; |
|
|
|
if (png_ptr->read_buffer == NULL) |
|
errmsg="Read failure in png_handle_zTXt"; |
|
else |
|
{ |
|
/* 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) != 0) |
|
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) == 0) |
|
png_chunk_error(png_ptr, "missing IHDR"); |
|
|
|
if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) |
|
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) != 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 allocation may overflow. |
|
*/ |
|
++prefix_length; |
|
|
|
if (compressed == 0 && prefix_length <= length) |
|
uncompressed_length = length - prefix_length; |
|
|
|
else if (compressed != 0 && 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 == 0) |
|
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) != 0) |
|
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_USER_LIMITS_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 = (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 /* READ_UNKNOWN_CHUNKS */ |
|
|
|
/* 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) != 0) |
|
{ |
|
/* 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 occurred; 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 /* READ_USER_CHUNKS */ |
|
|
|
# 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) == 0) |
|
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"); |
|
/* FALLTHROUGH */ |
|
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); |
|
/* FALLTHROUGH */ |
|
case 0: /* no limit */ |
|
# endif /* USER_LIMITS */ |
|
/* 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: the chunk must be handled by the user callback */ |
|
PNG_UNUSED(info_ptr) |
|
# 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 /* !READ_UNKNOWN_CHUNKS */ |
|
|
|
/* Check for unhandled critical chunks */ |
|
if (handled == 0 && 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_const_structrp png_ptr, png_uint_32 chunk_name) |
|
{ |
|
int i; |
|
png_uint_32 cn=chunk_name; |
|
|
|
png_debug(1, "in png_check_chunk_name"); |
|
|
|
for (i=1; i<=4; ++i) |
|
{ |
|
int c = cn & 0xff; |
|
|
|
if (c < 65 || c > 122 || (c > 90 && c < 97)) |
|
png_chunk_error(png_ptr, "invalid chunk type"); |
|
|
|
cn >>= 8; |
|
} |
|
} |
|
|
|
void /* PRIVATE */ |
|
png_check_chunk_length(png_const_structrp png_ptr, png_uint_32 length) |
|
{ |
|
png_alloc_size_t limit = PNG_UINT_31_MAX; |
|
|
|
# ifdef PNG_SET_USER_LIMITS_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 (png_ptr->chunk_name == png_IDAT) |
|
{ |
|
png_alloc_size_t idat_limit = PNG_UINT_31_MAX; |
|
size_t row_factor = |
|
(size_t)png_ptr->width |
|
* (size_t)png_ptr->channels |
|
* (png_ptr->bit_depth > 8? 2: 1) |
|
+ 1 |
|
+ (png_ptr->interlaced? 6: 0); |
|
if (png_ptr->height > PNG_UINT_32_MAX/row_factor) |
|
idat_limit = PNG_UINT_31_MAX; |
|
else |
|
idat_limit = png_ptr->height * row_factor; |
|
row_factor = row_factor > 32566? 32566 : row_factor; |
|
idat_limit += 6 + 5*(idat_limit/row_factor+1); /* zlib+deflate overhead */ |
|
idat_limit=idat_limit < PNG_UINT_31_MAX? idat_limit : PNG_UINT_31_MAX; |
|
limit = limit < idat_limit? idat_limit : limit; |
|
} |
|
|
|
if (length > limit) |
|
{ |
|
png_debug2(0," length = %lu, limit = %lu", |
|
(unsigned long)length,(unsigned long)limit); |
|
png_chunk_error(png_ptr, "chunk data is too large"); |
|
} |
|
} |
|
|
|
/* 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_alloc_size_t 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) != 0) |
|
/* little-endian byte */ |
|
end_mask = (unsigned int)(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 != 0 && |
|
(png_ptr->transformations & PNG_INTERLACE) != 0 && |
|
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), B_MASK(3,d,s), B_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 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 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 /* !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) != 0) |
|
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 != 0) |
|
{ |
|
/* 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 = (unsigned int)/*SAFE*/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 /* ALIGN_TYPE 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 = (unsigned int)/*SAFE*/row_width; |
|
} |
|
} |
|
|
|
/* NOT REACHED*/ |
|
} /* pixel_depth >= 8 */ |
|
|
|
/* Here if pixel_depth < 8 to check 'end_ptr' below. */ |
|
} |
|
else |
|
#endif /* READ_INTERLACING */ |
|
|
|
/* 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 const unsigned 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 + (size_t)((row_info->width - 1) >> 3); |
|
png_bytep dp = row + (size_t)((final_width - 1) >> 3); |
|
unsigned int sshift, dshift; |
|
unsigned int s_start, s_end; |
|
int s_inc; |
|
int jstop = (int)png_pass_inc[pass]; |
|
png_byte v; |
|
png_uint_32 i; |
|
int j; |
|
|
|
#ifdef PNG_READ_PACKSWAP_SUPPORTED |
|
if ((transformations & PNG_PACKSWAP) != 0) |
|
{ |
|
sshift = ((row_info->width + 7) & 0x07); |
|
dshift = ((final_width + 7) & 0x07); |
|
s_start = 7; |
|
s_end = 0; |
|
s_inc = -1; |
|
} |
|
|
|
else |
|
#endif |
|
{ |
|
sshift = 7 - ((row_info->width + 7) & 0x07); |
|
dshift = 7 - ((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 |= (unsigned int)(v << dshift); |
|
*dp = (png_byte)(tmp & 0xff); |
|
|
|
if (dshift == s_end) |
|
{ |
|
dshift = s_start; |
|
dp--; |
|
} |
|
|
|
else |
|
dshift = (unsigned int)((int)dshift + s_inc); |
|
} |
|
|
|
if (sshift == s_end) |
|
{ |
|
sshift = s_start; |
|
sp--; |
|
} |
|
|
|
else |
|
sshift = (unsigned int)((int)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); |
|
unsigned int sshift, dshift; |
|
unsigned int s_start, s_end; |
|
int s_inc; |
|
int jstop = (int)png_pass_inc[pass]; |
|
png_uint_32 i; |
|
|
|
#ifdef PNG_READ_PACKSWAP_SUPPORTED |
|
if ((transformations & PNG_PACKSWAP) != 0) |
|
{ |
|
sshift = (((row_info->width + 3) & 0x03) << 1); |
|
dshift = (((final_width + 3) & 0x03) << 1); |
|
s_start = 6; |
|
s_end = 0; |
|
s_inc = -2; |
|
} |
|
|
|
else |
|
#endif |
|
{ |
|
sshift = ((3 - ((row_info->width + 3) & 0x03)) << 1); |
|
dshift = ((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 |= (unsigned int)(v << dshift); |
|
*dp = (png_byte)(tmp & 0xff); |
|
|
|
if (dshift == s_end) |
|
{ |
|
dshift = s_start; |
|
dp--; |
|
} |
|
|
|
else |
|
dshift = (unsigned int)((int)dshift + s_inc); |
|
} |
|
|
|
if (sshift == s_end) |
|
{ |
|
sshift = s_start; |
|
sp--; |
|
} |
|
|
|
else |
|
sshift = (unsigned int)((int)sshift + s_inc); |
|
} |
|
break; |
|
} |
|
|
|
case 4: |
|
{ |
|
png_bytep sp = row + (size_t)((row_info->width - 1) >> 1); |
|
png_bytep dp = row + (size_t)((final_width - 1) >> 1); |
|
unsigned int sshift, dshift; |
|
unsigned int s_start, s_end; |
|
int s_inc; |
|
png_uint_32 i; |
|
int jstop = (int)png_pass_inc[pass]; |
|
|
|
#ifdef PNG_READ_PACKSWAP_SUPPORTED |
|
if ((transformations & PNG_PACKSWAP) != 0) |
|
{ |
|
sshift = (((row_info->width + 1) & 0x01) << 2); |
|
dshift = (((final_width + 1) & 0x01) << 2); |
|
s_start = 4; |
|
s_end = 0; |
|
s_inc = -4; |
|
} |
|
|
|
else |
|
#endif |
|
{ |
|
sshift = ((1 - ((row_info->width + 1) & 0x01)) << 2); |
|
dshift = ((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 |= (unsigned int)(v << dshift); |
|
*dp = (png_byte)(tmp & 0xff); |
|
|
|
if (dshift == s_end) |
|
{ |
|
dshift = s_start; |
|
dp--; |
|
} |
|
|
|
else |
|
dshift = (unsigned int)((int)dshift + s_inc); |
|
} |
|
|
|
if (sshift == s_end) |
|
{ |
|
sshift = s_start; |
|
sp--; |
|
} |
|
|
|
else |
|
sshift = (unsigned int)((int)sshift + s_inc); |
|
} |
|
break; |
|
} |
|
|
|
default: |
|
{ |
|
size_t pixel_bytes = (row_info->pixel_depth >> 3); |
|
|
|
png_bytep sp = row + (size_t)(row_info->width - 1) |
|
* pixel_bytes; |
|
|
|
png_bytep dp = row + (size_t)(final_width - 1) * pixel_bytes; |
|
|
|
int jstop = (int)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 /* READ_INTERLACING */ |
|
|
|
static void |
|
png_read_filter_row_sub(png_row_infop row_info, png_bytep row, |
|
png_const_bytep prev_row) |
|
{ |
|
size_t i; |
|
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) |
|
{ |
|
size_t i; |
|
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) |
|
{ |
|
size_t i; |
|
png_bytep rp = row; |
|
png_const_bytep pp = prev_row; |
|
unsigned int bpp = (row_info->pixel_depth + 7) >> 3; |
|
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) |
|
{ |
|
unsigned 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 = 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; |
|
|
|
a += *row; |
|
*row++ = (png_byte)a; |
|
} |
|
} |
|
|
|
static void |
|
png_init_filter_functions(png_structrp pp) |
|
/* This function is called once for every PNG image (except for PNG images |
|
* that only use PNG_FILTER_VALUE_NONE for all rows) 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 (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST) |
|
{ |
|
if (pp->read_filter[0] == NULL) |
|
png_init_filter_functions(pp); |
|
|
|
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 = PNG_INFLATE(png_ptr, 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) == 0) |
|
{ |
|
/* 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) == 0) |
|
{ |
|
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) |
|
{ |
|
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
|
|
|
/* Start of interlace block */ |
|
static const png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; |
|
|
|
/* Offset to next interlace block */ |
|
static const png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; |
|
|
|
/* Start of interlace block in the y direction */ |
|
static const png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; |
|
|
|
/* Offset to next interlace block in the y direction */ |
|
static const png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; |
|
|
|
png_debug(1, "in png_read_finish_row"); |
|
png_ptr->row_number++; |
|
if (png_ptr->row_number < png_ptr->num_rows) |
|
return; |
|
|
|
if (png_ptr->interlaced != 0) |
|
{ |
|
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) == 0) |
|
{ |
|
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; |
|
} |
|
|
|
/* Here after at the end of the last row of the last pass. */ |
|
png_read_finish_IDAT(png_ptr); |
|
} |
|
#endif /* SEQUENTIAL_READ */ |
|
|
|
void /* PRIVATE */ |
|
png_read_start_row(png_structrp png_ptr) |
|
{ |
|
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
|
|
|
/* Start of interlace block */ |
|
static const png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; |
|
|
|
/* Offset to next interlace block */ |
|
static const png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; |
|
|
|
/* Start of interlace block in the y direction */ |
|
static const png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; |
|
|
|
/* Offset to next interlace block in the y direction */ |
|
static const png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; |
|
|
|
unsigned int max_pixel_depth; |
|
size_t row_bytes; |
|
|
|
png_debug(1, "in png_read_start_row"); |
|
|
|
#ifdef PNG_READ_TRANSFORMS_SUPPORTED |
|
png_init_read_transformations(png_ptr); |
|
#endif |
|
if (png_ptr->interlaced != 0) |
|
{ |
|
if ((png_ptr->transformations & PNG_INTERLACE) == 0) |
|
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 |
|
{ |
|
png_ptr->num_rows = png_ptr->height; |
|
png_ptr->iwidth = png_ptr->width; |
|
} |
|
|
|
max_pixel_depth = (unsigned int)png_ptr->pixel_depth; |
|
|
|
/* WARNING: * png_read_transform_info (pngrtran.c) performs a simpler 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) != 0 && png_ptr->bit_depth < 8) |
|
max_pixel_depth = 8; |
|
#endif |
|
|
|
#ifdef PNG_READ_EXPAND_SUPPORTED |
|
if ((png_ptr->transformations & PNG_EXPAND) != 0) |
|
{ |
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
{ |
|
if (png_ptr->num_trans != 0) |
|
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 != 0) |
|
max_pixel_depth *= 2; |
|
} |
|
|
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) |
|
{ |
|
if (png_ptr->num_trans != 0) |
|
{ |
|
max_pixel_depth *= 4; |
|
max_pixel_depth /= 3; |
|
} |
|
} |
|
} |
|
#endif |
|
|
|
#ifdef PNG_READ_EXPAND_16_SUPPORTED |
|
if ((png_ptr->transformations & PNG_EXPAND_16) != 0) |
|
{ |
|
# 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) != 0) |
|
{ |
|
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)) != 0) |
|
{ |
|
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) != 0) |
|
{ |
|
if ( |
|
#ifdef PNG_READ_EXPAND_SUPPORTED |
|
(png_ptr->num_trans != 0 && |
|
(png_ptr->transformations & PNG_EXPAND) != 0) || |
|
#endif |
|
#ifdef PNG_READ_FILLER_SUPPORTED |
|
(png_ptr->transformations & (PNG_FILLER)) != 0 || |
|
#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) != 0) |
|
{ |
|
unsigned 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) >> 3U); |
|
|
|
#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 != 0) |
|
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 != NULL) |
|
{ |
|
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 /* READ */
|
|
|