3662 lines
99 KiB
C
3662 lines
99 KiB
C
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/* pngrutil.c - utilities to read a PNG file
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*
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* Last changed in libpng 1.5.3 [(PENDING RELEASE)]
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* Copyright (c) 1998-2011 Glenn Randers-Pehrson
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* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
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* (Version 0.88 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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#define png_strtod(p,a,b) strtod(a,b)
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png_uint_32 PNGAPI
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png_get_uint_31(png_structp 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_structp 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 & 0x80000000L) == 0) /* non-negative */
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return uval;
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uval = (uval ^ 0xffffffffL) + 1; /* 2's complement: -x = ~x+1 */
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return -(png_int_32)uval;
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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 accomodate 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 /* PNG_READ_INT_FUNCTIONS_SUPPORTED */
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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_structp png_ptr, png_infop info_ptr)
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{
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png_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))
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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_structp 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_memcpy(png_ptr->chunk_name, buf + 4, 4);
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png_debug2(0, "Reading %s chunk, length = %u",
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png_ptr->chunk_name, 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, png_ptr->chunk_name, 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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#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_structp png_ptr, png_bytep buf, png_size_t 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 a 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_structp png_ptr, png_uint_32 skip)
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{
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png_size_t i;
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png_size_t istop = png_ptr->zbuf_size;
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for (i = (png_size_t)skip; i > istop; i -= istop)
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{
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png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
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}
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if (i)
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{
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png_crc_read(png_ptr, png_ptr->zbuf, i);
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}
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if (png_crc_error(png_ptr))
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{
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if (((png_ptr->chunk_name[0] & 0x20) && /* Ancillary */
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!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) ||
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(!(png_ptr->chunk_name[0] & 0x20) && /* Critical */
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(png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)))
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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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{
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png_chunk_benign_error(png_ptr, "CRC error");
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return (0);
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}
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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_structp 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_ptr->chunk_name[0] & 0x20) /* ancillary */
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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)
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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)
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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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#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
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static png_size_t
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png_inflate(png_structp png_ptr, png_bytep data, png_size_t size,
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png_bytep output, png_size_t output_size)
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{
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png_size_t count = 0;
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/* zlib can't necessarily handle more than 65535 bytes at once (i.e. it can't
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* even necessarily handle 65536 bytes) because the type uInt is "16 bits or
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* more". Consequently it is necessary to chunk the input to zlib. This
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* code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the maximum value
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* that can be stored in a uInt.) It is possible to set ZLIB_IO_MAX to a
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* lower value in pngpriv.h and this may sometimes have a performance
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* advantage, because it forces access of the input data to be separated from
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* at least some of the use by some period of time.
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*/
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png_ptr->zstream.next_in = data;
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/* avail_in is set below from 'size' */
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png_ptr->zstream.avail_in = 0;
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while (1)
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{
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int ret, avail;
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/* The setting of 'avail_in' used to be outside the loop, by setting it
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* inside it is possible to chunk the input to zlib and simply rely on
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* zlib to advance the 'next_in' pointer. This allows arbitrary amounts o
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* data to be passed through zlib at the unavoidable cost of requiring a
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* window save (memcpy of up to 32768 output bytes) every ZLIB_IO_MAX
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* input bytes.
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*/
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if (png_ptr->zstream.avail_in == 0 && size > 0)
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{
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if (size <= ZLIB_IO_MAX)
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{
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/* The value is less than ZLIB_IO_MAX so the cast is safe: */
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png_ptr->zstream.avail_in = (uInt)size;
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size = 0;
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}
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else
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{
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png_ptr->zstream.avail_in = ZLIB_IO_MAX;
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size -= ZLIB_IO_MAX;
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}
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}
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/* Reset the output buffer each time round - we empty it
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* after every inflate call.
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*/
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png_ptr->zstream.next_out = png_ptr->zbuf;
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png_ptr->zstream.avail_out = png_ptr->zbuf_size;
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ret = inflate(&png_ptr->zstream, Z_NO_FLUSH);
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avail = png_ptr->zbuf_size - png_ptr->zstream.avail_out;
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/* First copy/count any new output - but only if we didn't
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* get an error code.
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*/
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if ((ret == Z_OK || ret == Z_STREAM_END) && avail > 0)
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{
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png_size_t space = avail; /* > 0, see above */
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if (output != 0 && output_size > count)
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{
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png_size_t copy = output_size - count;
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if (space < copy)
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copy = space;
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png_memcpy(output + count, png_ptr->zbuf, copy);
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}
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count += space;
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}
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if (ret == Z_OK)
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continue;
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/* Termination conditions - always reset the zstream, it
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* must be left in inflateInit state.
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*/
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png_ptr->zstream.avail_in = 0;
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inflateReset(&png_ptr->zstream);
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if (ret == Z_STREAM_END)
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return count; /* NOTE: may be zero. */
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/* Now handle the error codes - the API always returns 0
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* and the error message is dumped into the uncompressed
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* buffer if available.
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*/
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# ifdef PNG_WARNINGS_SUPPORTED
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{
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png_const_charp msg;
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if (png_ptr->zstream.msg != 0)
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msg = png_ptr->zstream.msg;
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else switch (ret)
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{
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case Z_BUF_ERROR:
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msg = "Buffer error in compressed datastream";
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break;
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case Z_DATA_ERROR:
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msg = "Data error in compressed datastream";
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break;
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default:
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msg = "Incomplete compressed datastream";
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break;
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}
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png_chunk_warning(png_ptr, msg);
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}
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# endif
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/* 0 means an error - notice that this code simply ignores
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* zero length compressed chunks as a result.
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*/
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return 0;
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}
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}
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/*
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* Decompress trailing data in a chunk. The assumption is that chunkdata
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* points at an allocated area holding the contents of a chunk with a
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* trailing compressed part. What we get back is an allocated area
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* holding the original prefix part and an uncompressed version of the
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* trailing part (the malloc area passed in is freed).
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*/
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void /* PRIVATE */
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png_decompress_chunk(png_structp png_ptr, int comp_type,
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png_size_t chunklength,
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png_size_t prefix_size, png_size_t *newlength)
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{
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/* The caller should guarantee this */
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if (prefix_size > chunklength)
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{
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/* The recovery is to delete the chunk. */
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png_warning(png_ptr, "invalid chunklength");
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prefix_size = 0; /* To delete everything */
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}
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else if (comp_type == PNG_COMPRESSION_TYPE_BASE)
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{
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png_size_t expanded_size = png_inflate(png_ptr,
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(png_bytep)(png_ptr->chunkdata + prefix_size),
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chunklength - prefix_size,
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0, /* output */
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0); /* output size */
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/* Now check the limits on this chunk - if the limit fails the
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* compressed data will be removed, the prefix will remain.
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*/
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#ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
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if (png_ptr->user_chunk_malloc_max &&
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(prefix_size + expanded_size >= png_ptr->user_chunk_malloc_max - 1))
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#else
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# ifdef PNG_USER_CHUNK_MALLOC_MAX
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if ((PNG_USER_CHUNK_MALLOC_MAX > 0) &&
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prefix_size + expanded_size >= PNG_USER_CHUNK_MALLOC_MAX - 1)
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# endif
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#endif
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png_warning(png_ptr, "Exceeded size limit while expanding chunk");
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|
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/* If the size is zero either there was an error and a message
|
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* has already been output (warning) or the size really is zero
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* and we have nothing to do - the code will exit through the
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* error case below.
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*/
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#if defined(PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED) || \
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defined(PNG_USER_CHUNK_MALLOC_MAX)
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else if (expanded_size > 0)
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#else
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if (expanded_size > 0)
|
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#endif
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{
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/* Success (maybe) - really uncompress the chunk. */
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png_size_t new_size = 0;
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png_charp text = png_malloc_warn(png_ptr,
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prefix_size + expanded_size + 1);
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|
|
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if (text != NULL)
|
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{
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png_memcpy(text, png_ptr->chunkdata, prefix_size);
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new_size = png_inflate(png_ptr,
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(png_bytep)(png_ptr->chunkdata + prefix_size),
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chunklength - prefix_size,
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(png_bytep)(text + prefix_size), expanded_size);
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text[prefix_size + expanded_size] = 0; /* just in case */
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|
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if (new_size == expanded_size)
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{
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png_free(png_ptr, png_ptr->chunkdata);
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png_ptr->chunkdata = text;
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*newlength = prefix_size + expanded_size;
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return; /* The success return! */
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}
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|
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png_warning(png_ptr, "png_inflate logic error");
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png_free(png_ptr, text);
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}
|
|
|
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else
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png_warning(png_ptr, "Not enough memory to decompress chunk");
|
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}
|
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}
|
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|
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else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
|
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{
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PNG_WARNING_PARAMETERS(p)
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png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, comp_type);
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png_formatted_warning(png_ptr, p, "Unknown zTXt compression type @1");
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|
|
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/* The recovery is to simply drop the data. */
|
|
}
|
|
|
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/* Generic error return - leave the prefix, delete the compressed
|
|
* data, reallocate the chunkdata to remove the potentially large
|
|
* amount of compressed data.
|
|
*/
|
|
{
|
|
png_charp text = png_malloc_warn(png_ptr, prefix_size + 1);
|
|
|
|
if (text != NULL)
|
|
{
|
|
if (prefix_size > 0)
|
|
png_memcpy(text, png_ptr->chunkdata, prefix_size);
|
|
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = text;
|
|
|
|
/* This is an extra zero in the 'uncompressed' part. */
|
|
*(png_ptr->chunkdata + prefix_size) = 0x00;
|
|
}
|
|
/* Ignore a malloc error here - it is safe. */
|
|
}
|
|
|
|
*newlength = prefix_size;
|
|
}
|
|
#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */
|
|
|
|
/* Read and check the IDHR chunk */
|
|
void /* PRIVATE */
|
|
png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_byte buf[13];
|
|
png_uint_32 width, height;
|
|
int bit_depth, color_type, compression_type, filter_type;
|
|
int interlace_type;
|
|
|
|
png_debug(1, "in png_handle_IHDR");
|
|
|
|
if (png_ptr->mode & PNG_HAVE_IHDR)
|
|
png_error(png_ptr, "Out of place IHDR");
|
|
|
|
/* Check the length */
|
|
if (length != 13)
|
|
png_error(png_ptr, "Invalid IHDR chunk");
|
|
|
|
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_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_color palette[PNG_MAX_PALETTE_LENGTH];
|
|
int num, i;
|
|
#ifdef PNG_POINTER_INDEXING_SUPPORTED
|
|
png_colorp pal_ptr;
|
|
#endif
|
|
|
|
png_debug(1, "in png_handle_PLTE");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before PLTE");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid PLTE after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_PLTE)
|
|
png_error(png_ptr, "Duplicate PLTE chunk");
|
|
|
|
png_ptr->mode |= PNG_HAVE_PLTE;
|
|
|
|
if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
|
|
{
|
|
png_warning(png_ptr,
|
|
"Ignoring PLTE chunk in grayscale PNG");
|
|
png_crc_finish(png_ptr, length);
|
|
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)
|
|
{
|
|
if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
png_warning(png_ptr, "Invalid palette chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else
|
|
{
|
|
png_error(png_ptr, "Invalid palette chunk");
|
|
}
|
|
}
|
|
|
|
num = (int)length / 3;
|
|
|
|
#ifdef PNG_POINTER_INDEXING_SUPPORTED
|
|
for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
|
|
{
|
|
png_byte buf[3];
|
|
|
|
png_crc_read(png_ptr, buf, 3);
|
|
pal_ptr->red = buf[0];
|
|
pal_ptr->green = buf[1];
|
|
pal_ptr->blue = buf[2];
|
|
}
|
|
#else
|
|
for (i = 0; i < num; i++)
|
|
{
|
|
png_byte buf[3];
|
|
|
|
png_crc_read(png_ptr, buf, 3);
|
|
/* Don't depend upon png_color being any order */
|
|
palette[i].red = buf[0];
|
|
palette[i].green = buf[1];
|
|
palette[i].blue = buf[2];
|
|
}
|
|
#endif
|
|
|
|
/* If we actually need the PLTE chunk (ie for a paletted image), we do
|
|
* whatever the normal CRC configuration tells us. However, if we
|
|
* have an RGB image, the PLTE can be considered ancillary, so
|
|
* we will act as though it is.
|
|
*/
|
|
#ifndef PNG_READ_OPT_PLTE_SUPPORTED
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
#endif
|
|
{
|
|
png_crc_finish(png_ptr, 0);
|
|
}
|
|
|
|
#ifndef PNG_READ_OPT_PLTE_SUPPORTED
|
|
else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */
|
|
{
|
|
/* If we don't want to use the data from an ancillary chunk,
|
|
* we have two options: an error abort, or a warning and we
|
|
* ignore the data in this chunk (which should be OK, since
|
|
* it's considered ancillary for a RGB or RGBA image).
|
|
*/
|
|
if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE))
|
|
{
|
|
if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)
|
|
{
|
|
png_chunk_benign_error(png_ptr, "CRC error");
|
|
}
|
|
|
|
else
|
|
{
|
|
png_chunk_warning(png_ptr, "CRC error");
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* Otherwise, we (optionally) emit a warning and use the chunk. */
|
|
else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
|
|
{
|
|
png_chunk_warning(png_ptr, "CRC error");
|
|
}
|
|
}
|
|
#endif
|
|
|
|
png_set_PLTE(png_ptr, info_ptr, palette, num);
|
|
|
|
#ifdef PNG_READ_tRNS_SUPPORTED
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
|
|
{
|
|
if (png_ptr->num_trans > (png_uint_16)num)
|
|
{
|
|
png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
|
|
png_ptr->num_trans = (png_uint_16)num;
|
|
}
|
|
|
|
if (info_ptr->num_trans > (png_uint_16)num)
|
|
{
|
|
png_warning(png_ptr, "Truncating incorrect info tRNS chunk length");
|
|
info_ptr->num_trans = (png_uint_16)num;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
}
|
|
|
|
void /* PRIVATE */
|
|
png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_debug(1, "in png_handle_IEND");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT))
|
|
{
|
|
png_error(png_ptr, "No image in file");
|
|
}
|
|
|
|
png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
|
|
|
|
if (length != 0)
|
|
{
|
|
png_warning(png_ptr, "Incorrect IEND chunk length");
|
|
}
|
|
|
|
png_crc_finish(png_ptr, length);
|
|
|
|
PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */
|
|
}
|
|
|
|
#ifdef PNG_READ_gAMA_SUPPORTED
|
|
void /* PRIVATE */
|
|
png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_fixed_point igamma;
|
|
png_byte buf[4];
|
|
|
|
png_debug(1, "in png_handle_gAMA");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before gAMA");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid gAMA after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_PLTE)
|
|
/* Should be an error, but we can cope with it */
|
|
png_warning(png_ptr, "Out of place gAMA chunk");
|
|
|
|
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
|
|
#ifdef PNG_READ_sRGB_SUPPORTED
|
|
&& !(info_ptr->valid & PNG_INFO_sRGB)
|
|
#endif
|
|
)
|
|
{
|
|
png_warning(png_ptr, "Duplicate gAMA chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (length != 4)
|
|
{
|
|
png_warning(png_ptr, "Incorrect gAMA chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, 4);
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
return;
|
|
|
|
igamma = png_get_fixed_point(NULL, buf);
|
|
|
|
/* Check for zero gamma or an error. */
|
|
if (igamma <= 0)
|
|
{
|
|
png_warning(png_ptr,
|
|
"Ignoring gAMA chunk with out of range gamma");
|
|
|
|
return;
|
|
}
|
|
|
|
# ifdef PNG_READ_sRGB_SUPPORTED
|
|
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
|
|
{
|
|
if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
|
|
{
|
|
PNG_WARNING_PARAMETERS(p)
|
|
png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, igamma);
|
|
png_formatted_warning(png_ptr, p,
|
|
"Ignoring incorrect gAMA value @1 when sRGB is also present");
|
|
return;
|
|
}
|
|
}
|
|
# endif /* PNG_READ_sRGB_SUPPORTED */
|
|
|
|
# ifdef PNG_READ_GAMMA_SUPPORTED
|
|
/* Gamma correction on read is supported. */
|
|
png_ptr->gamma = igamma;
|
|
# endif
|
|
/* And set the 'info' structure members. */
|
|
png_set_gAMA_fixed(png_ptr, info_ptr, igamma);
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_sBIT_SUPPORTED
|
|
void /* PRIVATE */
|
|
png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_size_t truelen;
|
|
png_byte buf[4];
|
|
|
|
png_debug(1, "in png_handle_sBIT");
|
|
|
|
buf[0] = buf[1] = buf[2] = buf[3] = 0;
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before sBIT");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid sBIT after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_PLTE)
|
|
{
|
|
/* Should be an error, but we can cope with it */
|
|
png_warning(png_ptr, "Out of place sBIT chunk");
|
|
}
|
|
|
|
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
|
|
{
|
|
png_warning(png_ptr, "Duplicate sBIT chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
truelen = 3;
|
|
|
|
else
|
|
truelen = (png_size_t)png_ptr->channels;
|
|
|
|
if (length != truelen || length > 4)
|
|
{
|
|
png_warning(png_ptr, "Incorrect sBIT chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, truelen);
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
return;
|
|
|
|
if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
|
|
{
|
|
png_ptr->sig_bit.red = buf[0];
|
|
png_ptr->sig_bit.green = buf[1];
|
|
png_ptr->sig_bit.blue = buf[2];
|
|
png_ptr->sig_bit.alpha = buf[3];
|
|
}
|
|
|
|
else
|
|
{
|
|
png_ptr->sig_bit.gray = buf[0];
|
|
png_ptr->sig_bit.red = buf[0];
|
|
png_ptr->sig_bit.green = buf[0];
|
|
png_ptr->sig_bit.blue = buf[0];
|
|
png_ptr->sig_bit.alpha = buf[1];
|
|
}
|
|
|
|
png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_cHRM_SUPPORTED
|
|
void /* PRIVATE */
|
|
png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_byte buf[32];
|
|
png_fixed_point x_white, y_white, x_red, y_red, x_green, y_green, x_blue,
|
|
y_blue;
|
|
|
|
png_debug(1, "in png_handle_cHRM");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before cHRM");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid cHRM after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_PLTE)
|
|
/* Should be an error, but we can cope with it */
|
|
png_warning(png_ptr, "Missing PLTE before cHRM");
|
|
|
|
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)
|
|
# ifdef PNG_READ_sRGB_SUPPORTED
|
|
&& !(info_ptr->valid & PNG_INFO_sRGB)
|
|
# endif
|
|
)
|
|
{
|
|
png_warning(png_ptr, "Duplicate cHRM chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (length != 32)
|
|
{
|
|
png_warning(png_ptr, "Incorrect cHRM chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, 32);
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
return;
|
|
|
|
x_white = png_get_fixed_point(NULL, buf);
|
|
y_white = png_get_fixed_point(NULL, buf + 4);
|
|
x_red = png_get_fixed_point(NULL, buf + 8);
|
|
y_red = png_get_fixed_point(NULL, buf + 12);
|
|
x_green = png_get_fixed_point(NULL, buf + 16);
|
|
y_green = png_get_fixed_point(NULL, buf + 20);
|
|
x_blue = png_get_fixed_point(NULL, buf + 24);
|
|
y_blue = png_get_fixed_point(NULL, buf + 28);
|
|
|
|
if (x_white == PNG_FIXED_ERROR ||
|
|
y_white == PNG_FIXED_ERROR ||
|
|
x_red == PNG_FIXED_ERROR ||
|
|
y_red == PNG_FIXED_ERROR ||
|
|
x_green == PNG_FIXED_ERROR ||
|
|
y_green == PNG_FIXED_ERROR ||
|
|
x_blue == PNG_FIXED_ERROR ||
|
|
y_blue == PNG_FIXED_ERROR)
|
|
{
|
|
png_warning(png_ptr, "Ignoring cHRM chunk with negative chromaticities");
|
|
return;
|
|
}
|
|
|
|
#ifdef PNG_READ_sRGB_SUPPORTED
|
|
if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB))
|
|
{
|
|
if (PNG_OUT_OF_RANGE(x_white, 31270, 1000) ||
|
|
PNG_OUT_OF_RANGE(y_white, 32900, 1000) ||
|
|
PNG_OUT_OF_RANGE(x_red, 64000L, 1000) ||
|
|
PNG_OUT_OF_RANGE(y_red, 33000, 1000) ||
|
|
PNG_OUT_OF_RANGE(x_green, 30000, 1000) ||
|
|
PNG_OUT_OF_RANGE(y_green, 60000L, 1000) ||
|
|
PNG_OUT_OF_RANGE(x_blue, 15000, 1000) ||
|
|
PNG_OUT_OF_RANGE(y_blue, 6000, 1000))
|
|
{
|
|
PNG_WARNING_PARAMETERS(p)
|
|
|
|
png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, x_white);
|
|
png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_fixed, y_white);
|
|
png_warning_parameter_signed(p, 3, PNG_NUMBER_FORMAT_fixed, x_red);
|
|
png_warning_parameter_signed(p, 4, PNG_NUMBER_FORMAT_fixed, y_red);
|
|
png_warning_parameter_signed(p, 5, PNG_NUMBER_FORMAT_fixed, x_green);
|
|
png_warning_parameter_signed(p, 6, PNG_NUMBER_FORMAT_fixed, y_green);
|
|
png_warning_parameter_signed(p, 7, PNG_NUMBER_FORMAT_fixed, x_blue);
|
|
png_warning_parameter_signed(p, 8, PNG_NUMBER_FORMAT_fixed, y_blue);
|
|
|
|
png_formatted_warning(png_ptr, p,
|
|
"Ignoring incorrect cHRM white(@1,@2) r(@3,@4)g(@5,@6)b(@7,@8) "
|
|
"when sRGB is also present");
|
|
}
|
|
return;
|
|
}
|
|
#endif /* PNG_READ_sRGB_SUPPORTED */
|
|
|
|
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
|
/* Store the _white values as default coefficients for the rgb to gray
|
|
* operation if it is supported.
|
|
*/
|
|
if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
|
|
{
|
|
/* png_set_background has not been called, the coefficients must be in
|
|
* range for the following to work without overflow.
|
|
*/
|
|
if (y_red <= (1<<17) && y_green <= (1<<17) && y_blue <= (1<<17))
|
|
{
|
|
/* The y values are chromaticities: Y/X+Y+Z, the weights for the gray
|
|
* transformation are simply the normalized Y values for red, green and
|
|
* blue scaled by 32768.
|
|
*/
|
|
png_uint_32 w = y_red + y_green + y_blue;
|
|
|
|
png_ptr->rgb_to_gray_red_coeff = (png_uint_16)(((png_uint_32)y_red *
|
|
32768)/w);
|
|
png_ptr->rgb_to_gray_green_coeff = (png_uint_16)(((png_uint_32)y_green
|
|
* 32768)/w);
|
|
png_ptr->rgb_to_gray_blue_coeff = (png_uint_16)(((png_uint_32)y_blue *
|
|
32768)/w);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
png_set_cHRM_fixed(png_ptr, info_ptr, x_white, y_white, x_red, y_red,
|
|
x_green, y_green, x_blue, y_blue);
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_sRGB_SUPPORTED
|
|
void /* PRIVATE */
|
|
png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
int intent;
|
|
png_byte buf[1];
|
|
|
|
png_debug(1, "in png_handle_sRGB");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before sRGB");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid sRGB after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_PLTE)
|
|
/* Should be an error, but we can cope with it */
|
|
png_warning(png_ptr, "Out of place sRGB chunk");
|
|
|
|
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
|
|
{
|
|
png_warning(png_ptr, "Duplicate sRGB chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (length != 1)
|
|
{
|
|
png_warning(png_ptr, "Incorrect sRGB chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, 1);
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
return;
|
|
|
|
intent = buf[0];
|
|
|
|
/* Check for bad intent */
|
|
if (intent >= PNG_sRGB_INTENT_LAST)
|
|
{
|
|
png_warning(png_ptr, "Unknown sRGB intent");
|
|
return;
|
|
}
|
|
|
|
#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
|
|
{
|
|
if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500L, 500))
|
|
{
|
|
PNG_WARNING_PARAMETERS(p)
|
|
|
|
png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed,
|
|
info_ptr->gamma);
|
|
|
|
png_formatted_warning(png_ptr, p,
|
|
"Ignoring incorrect gAMA value @1 when sRGB is also present");
|
|
}
|
|
}
|
|
#endif /* PNG_READ_gAMA_SUPPORTED */
|
|
|
|
#ifdef PNG_READ_cHRM_SUPPORTED
|
|
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
|
|
if (PNG_OUT_OF_RANGE(info_ptr->x_white, 31270, 1000) ||
|
|
PNG_OUT_OF_RANGE(info_ptr->y_white, 32900, 1000) ||
|
|
PNG_OUT_OF_RANGE(info_ptr->x_red, 64000L, 1000) ||
|
|
PNG_OUT_OF_RANGE(info_ptr->y_red, 33000, 1000) ||
|
|
PNG_OUT_OF_RANGE(info_ptr->x_green, 30000, 1000) ||
|
|
PNG_OUT_OF_RANGE(info_ptr->y_green, 60000L, 1000) ||
|
|
PNG_OUT_OF_RANGE(info_ptr->x_blue, 15000, 1000) ||
|
|
PNG_OUT_OF_RANGE(info_ptr->y_blue, 6000, 1000))
|
|
{
|
|
png_warning(png_ptr,
|
|
"Ignoring incorrect cHRM value when sRGB is also present");
|
|
}
|
|
#endif /* PNG_READ_cHRM_SUPPORTED */
|
|
|
|
png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
|
|
}
|
|
#endif /* PNG_READ_sRGB_SUPPORTED */
|
|
|
|
#ifdef PNG_READ_iCCP_SUPPORTED
|
|
void /* PRIVATE */
|
|
png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
/* Note: this does not properly handle chunks that are > 64K under DOS */
|
|
{
|
|
png_byte compression_type;
|
|
png_bytep pC;
|
|
png_charp profile;
|
|
png_uint_32 skip = 0;
|
|
png_uint_32 profile_size;
|
|
png_alloc_size_t profile_length;
|
|
png_size_t slength, prefix_length, data_length;
|
|
|
|
png_debug(1, "in png_handle_iCCP");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before iCCP");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid iCCP after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_PLTE)
|
|
/* Should be an error, but we can cope with it */
|
|
png_warning(png_ptr, "Out of place iCCP chunk");
|
|
|
|
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP))
|
|
{
|
|
png_warning(png_ptr, "Duplicate iCCP chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
#ifdef PNG_MAX_MALLOC_64K
|
|
if (length > (png_uint_32)65535L)
|
|
{
|
|
png_warning(png_ptr, "iCCP chunk too large to fit in memory");
|
|
skip = length - (png_uint_32)65535L;
|
|
length = (png_uint_32)65535L;
|
|
}
|
|
#endif
|
|
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
|
|
slength = (png_size_t)length;
|
|
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
|
|
|
|
if (png_crc_finish(png_ptr, skip))
|
|
{
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
png_ptr->chunkdata[slength] = 0x00;
|
|
|
|
for (profile = png_ptr->chunkdata; *profile; profile++)
|
|
/* Empty loop to find end of name */ ;
|
|
|
|
++profile;
|
|
|
|
/* There should be at least one zero (the compression type byte)
|
|
* following the separator, and we should be on it
|
|
*/
|
|
if (profile >= png_ptr->chunkdata + slength - 1)
|
|
{
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
png_warning(png_ptr, "Malformed iCCP chunk");
|
|
return;
|
|
}
|
|
|
|
/* Compression_type should always be zero */
|
|
compression_type = *profile++;
|
|
|
|
if (compression_type)
|
|
{
|
|
png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk");
|
|
compression_type = 0x00; /* Reset it to zero (libpng-1.0.6 through 1.0.8
|
|
wrote nonzero) */
|
|
}
|
|
|
|
prefix_length = profile - png_ptr->chunkdata;
|
|
png_decompress_chunk(png_ptr, compression_type,
|
|
slength, prefix_length, &data_length);
|
|
|
|
profile_length = data_length - prefix_length;
|
|
|
|
if (prefix_length > data_length || profile_length < 4)
|
|
{
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
png_warning(png_ptr, "Profile size field missing from iCCP chunk");
|
|
return;
|
|
}
|
|
|
|
/* Check the profile_size recorded in the first 32 bits of the ICC profile */
|
|
pC = (png_bytep)(png_ptr->chunkdata + prefix_length);
|
|
profile_size = ((*(pC )) << 24) |
|
|
((*(pC + 1)) << 16) |
|
|
((*(pC + 2)) << 8) |
|
|
((*(pC + 3)) );
|
|
|
|
/* NOTE: the following guarantees that 'profile_length' fits into 32 bits,
|
|
* because profile_size is a 32 bit value.
|
|
*/
|
|
if (profile_size < profile_length)
|
|
profile_length = profile_size;
|
|
|
|
/* And the following guarantees that profile_size == profile_length. */
|
|
if (profile_size > profile_length)
|
|
{
|
|
PNG_WARNING_PARAMETERS(p)
|
|
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
|
|
png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_u, profile_size);
|
|
png_warning_parameter_unsigned(p, 2, PNG_NUMBER_FORMAT_u, profile_length);
|
|
png_formatted_warning(png_ptr, p,
|
|
"Ignoring iCCP chunk with declared size = @1 and actual length = @2");
|
|
return;
|
|
}
|
|
|
|
png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata,
|
|
compression_type, (png_bytep)png_ptr->chunkdata + prefix_length,
|
|
profile_size);
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
}
|
|
#endif /* PNG_READ_iCCP_SUPPORTED */
|
|
|
|
#ifdef PNG_READ_sPLT_SUPPORTED
|
|
void /* PRIVATE */
|
|
png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
/* Note: this does not properly handle chunks that are > 64K under DOS */
|
|
{
|
|
png_bytep entry_start;
|
|
png_sPLT_t new_palette;
|
|
png_sPLT_entryp pp;
|
|
png_uint_32 data_length;
|
|
int entry_size, i;
|
|
png_uint_32 skip = 0;
|
|
png_size_t slength;
|
|
png_uint_32 dl;
|
|
png_size_t max_dl;
|
|
|
|
png_debug(1, "in png_handle_sPLT");
|
|
|
|
#ifdef PNG_USER_LIMITS_SUPPORTED
|
|
|
|
if (png_ptr->user_chunk_cache_max != 0)
|
|
{
|
|
if (png_ptr->user_chunk_cache_max == 1)
|
|
{
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (--png_ptr->user_chunk_cache_max == 1)
|
|
{
|
|
png_warning(png_ptr, "No space in chunk cache for sPLT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before sPLT");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid sPLT after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
#ifdef PNG_MAX_MALLOC_64K
|
|
if (length > (png_uint_32)65535L)
|
|
{
|
|
png_warning(png_ptr, "sPLT chunk too large to fit in memory");
|
|
skip = length - (png_uint_32)65535L;
|
|
length = (png_uint_32)65535L;
|
|
}
|
|
#endif
|
|
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
|
|
|
|
/* 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.
|
|
*/
|
|
slength = (png_size_t)length;
|
|
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
|
|
|
|
if (png_crc_finish(png_ptr, skip))
|
|
{
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
png_ptr->chunkdata[slength] = 0x00;
|
|
|
|
for (entry_start = (png_bytep)png_ptr->chunkdata; *entry_start;
|
|
entry_start++)
|
|
/* Empty loop to find end of name */ ;
|
|
|
|
++entry_start;
|
|
|
|
/* A sample depth should follow the separator, and we should be on it */
|
|
if (entry_start > (png_bytep)png_ptr->chunkdata + slength - 2)
|
|
{
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
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 (and use 'length', not 'slength' here for clarity -
|
|
* they are guaranteed to be the same, see the tests above.)
|
|
*/
|
|
data_length = length - (png_uint_32)(entry_start -
|
|
(png_bytep)png_ptr->chunkdata);
|
|
|
|
/* Integrity-check the data length */
|
|
if (data_length % entry_size)
|
|
{
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
png_warning(png_ptr, "sPLT chunk has bad length");
|
|
return;
|
|
}
|
|
|
|
dl = (png_int_32)(data_length / entry_size);
|
|
max_dl = PNG_SIZE_MAX / png_sizeof(png_sPLT_entry);
|
|
|
|
if (dl > max_dl)
|
|
{
|
|
png_warning(png_ptr, "sPLT chunk too long");
|
|
return;
|
|
}
|
|
|
|
new_palette.nentries = (png_int_32)(data_length / entry_size);
|
|
|
|
new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
|
|
png_ptr, new_palette.nentries * png_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_ptr->chunkdata;
|
|
|
|
png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
|
|
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
png_free(png_ptr, new_palette.entries);
|
|
}
|
|
#endif /* PNG_READ_sPLT_SUPPORTED */
|
|
|
|
#ifdef PNG_READ_tRNS_SUPPORTED
|
|
void /* PRIVATE */
|
|
png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
|
|
|
|
png_debug(1, "in png_handle_tRNS");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before tRNS");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid tRNS after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
|
|
{
|
|
png_warning(png_ptr, "Duplicate tRNS chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
|
|
{
|
|
png_byte buf[2];
|
|
|
|
if (length != 2)
|
|
{
|
|
png_warning(png_ptr, "Incorrect tRNS chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
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_warning(png_ptr, "Incorrect tRNS chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, (png_size_t)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))
|
|
{
|
|
/* Should be an error, but we can cope with it. */
|
|
png_warning(png_ptr, "Missing PLTE before tRNS");
|
|
}
|
|
|
|
if (length > (png_uint_32)png_ptr->num_palette ||
|
|
length > PNG_MAX_PALETTE_LENGTH)
|
|
{
|
|
png_warning(png_ptr, "Incorrect tRNS chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (length == 0)
|
|
{
|
|
png_warning(png_ptr, "Zero length tRNS chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, readbuf, (png_size_t)length);
|
|
png_ptr->num_trans = (png_uint_16)length;
|
|
}
|
|
|
|
else
|
|
{
|
|
png_warning(png_ptr, "tRNS chunk not allowed with alpha channel");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
{
|
|
png_ptr->num_trans = 0;
|
|
return;
|
|
}
|
|
|
|
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_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_size_t truelen;
|
|
png_byte buf[6];
|
|
png_color_16 background;
|
|
|
|
png_debug(1, "in png_handle_bKGD");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before bKGD");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid bKGD after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
|
|
!(png_ptr->mode & PNG_HAVE_PLTE))
|
|
{
|
|
png_warning(png_ptr, "Missing PLTE before bKGD");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD))
|
|
{
|
|
png_warning(png_ptr, "Duplicate bKGD chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
truelen = 1;
|
|
|
|
else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
|
|
truelen = 6;
|
|
|
|
else
|
|
truelen = 2;
|
|
|
|
if (length != truelen)
|
|
{
|
|
png_warning(png_ptr, "Incorrect bKGD chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, truelen);
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
return;
|
|
|
|
/* We convert the index value into RGB components so that we can allow
|
|
* arbitrary RGB values for background when we have transparency, and
|
|
* so it is easy to determine the RGB values of the background color
|
|
* from the info_ptr struct.
|
|
*/
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
background.index = buf[0];
|
|
|
|
if (info_ptr && info_ptr->num_palette)
|
|
{
|
|
if (buf[0] >= info_ptr->num_palette)
|
|
{
|
|
png_warning(png_ptr, "Incorrect bKGD chunk index value");
|
|
return;
|
|
}
|
|
|
|
background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
|
|
background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
|
|
background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
|
|
}
|
|
|
|
else
|
|
background.red = background.green = background.blue = 0;
|
|
|
|
background.gray = 0;
|
|
}
|
|
|
|
else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
|
|
{
|
|
background.index = 0;
|
|
background.red =
|
|
background.green =
|
|
background.blue =
|
|
background.gray = png_get_uint_16(buf);
|
|
}
|
|
|
|
else
|
|
{
|
|
background.index = 0;
|
|
background.red = png_get_uint_16(buf);
|
|
background.green = png_get_uint_16(buf + 2);
|
|
background.blue = png_get_uint_16(buf + 4);
|
|
background.gray = 0;
|
|
}
|
|
|
|
png_set_bKGD(png_ptr, info_ptr, &background);
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_hIST_SUPPORTED
|
|
void /* PRIVATE */
|
|
png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
unsigned int num, i;
|
|
png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
|
|
|
|
png_debug(1, "in png_handle_hIST");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before hIST");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid hIST after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (!(png_ptr->mode & PNG_HAVE_PLTE))
|
|
{
|
|
png_warning(png_ptr, "Missing PLTE before hIST");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST))
|
|
{
|
|
png_warning(png_ptr, "Duplicate hIST chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
num = length / 2 ;
|
|
|
|
if (num != (unsigned int)png_ptr->num_palette || num >
|
|
(unsigned int)PNG_MAX_PALETTE_LENGTH)
|
|
{
|
|
png_warning(png_ptr, "Incorrect hIST chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
for (i = 0; i < num; i++)
|
|
{
|
|
png_byte buf[2];
|
|
|
|
png_crc_read(png_ptr, buf, 2);
|
|
readbuf[i] = png_get_uint_16(buf);
|
|
}
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
return;
|
|
|
|
png_set_hIST(png_ptr, info_ptr, readbuf);
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_pHYs_SUPPORTED
|
|
void /* PRIVATE */
|
|
png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_byte buf[9];
|
|
png_uint_32 res_x, res_y;
|
|
int unit_type;
|
|
|
|
png_debug(1, "in png_handle_pHYs");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before pHYs");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid pHYs after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
|
|
{
|
|
png_warning(png_ptr, "Duplicate pHYs chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (length != 9)
|
|
{
|
|
png_warning(png_ptr, "Incorrect pHYs chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, 9);
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
return;
|
|
|
|
res_x = png_get_uint_32(buf);
|
|
res_y = png_get_uint_32(buf + 4);
|
|
unit_type = buf[8];
|
|
png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_oFFs_SUPPORTED
|
|
void /* PRIVATE */
|
|
png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_byte buf[9];
|
|
png_int_32 offset_x, offset_y;
|
|
int unit_type;
|
|
|
|
png_debug(1, "in png_handle_oFFs");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before oFFs");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid oFFs after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
|
|
{
|
|
png_warning(png_ptr, "Duplicate oFFs chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (length != 9)
|
|
{
|
|
png_warning(png_ptr, "Incorrect oFFs chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, 9);
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
return;
|
|
|
|
offset_x = png_get_int_32(buf);
|
|
offset_y = png_get_int_32(buf + 4);
|
|
unit_type = buf[8];
|
|
png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_pCAL_SUPPORTED
|
|
/* Read the pCAL chunk (described in the PNG Extensions document) */
|
|
void /* PRIVATE */
|
|
png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_int_32 X0, X1;
|
|
png_byte type, nparams;
|
|
png_charp buf, units, endptr;
|
|
png_charpp params;
|
|
png_size_t slength;
|
|
int i;
|
|
|
|
png_debug(1, "in png_handle_pCAL");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before pCAL");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid pCAL after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL))
|
|
{
|
|
png_warning(png_ptr, "Duplicate pCAL chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)",
|
|
length + 1);
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
|
|
|
|
if (png_ptr->chunkdata == NULL)
|
|
{
|
|
png_warning(png_ptr, "No memory for pCAL purpose");
|
|
return;
|
|
}
|
|
|
|
slength = (png_size_t)length;
|
|
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
{
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
|
|
|
|
png_debug(3, "Finding end of pCAL purpose string");
|
|
for (buf = png_ptr->chunkdata; *buf; buf++)
|
|
/* Empty loop */ ;
|
|
|
|
endptr = png_ptr->chunkdata + slength;
|
|
|
|
/* We need to have at least 12 bytes after the purpose string
|
|
* in order to get the parameter information.
|
|
*/
|
|
if (endptr <= buf + 12)
|
|
{
|
|
png_warning(png_ptr, "Invalid pCAL data");
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
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_warning(png_ptr, "Invalid pCAL parameters for equation type");
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
else if (type >= PNG_EQUATION_LAST)
|
|
{
|
|
png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
|
|
}
|
|
|
|
for (buf = units; *buf; buf++)
|
|
/* Empty loop to move past the units string. */ ;
|
|
|
|
png_debug(3, "Allocating pCAL parameters array");
|
|
|
|
params = (png_charpp)png_malloc_warn(png_ptr,
|
|
(png_size_t)(nparams * png_sizeof(png_charp)));
|
|
|
|
if (params == NULL)
|
|
{
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
png_warning(png_ptr, "No memory for pCAL params");
|
|
return;
|
|
}
|
|
|
|
/* Get pointers to the start of each parameter string. */
|
|
for (i = 0; i < (int)nparams; i++)
|
|
{
|
|
buf++; /* Skip the null string terminator from previous parameter. */
|
|
|
|
png_debug1(3, "Reading pCAL parameter %d", i);
|
|
|
|
for (params[i] = buf; buf <= endptr && *buf != 0x00; buf++)
|
|
/* Empty loop to move past each parameter string */ ;
|
|
|
|
/* Make sure we haven't run out of data yet */
|
|
if (buf > endptr)
|
|
{
|
|
png_warning(png_ptr, "Invalid pCAL data");
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
png_free(png_ptr, params);
|
|
return;
|
|
}
|
|
}
|
|
|
|
png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams,
|
|
units, params);
|
|
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
png_free(png_ptr, params);
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_sCAL_SUPPORTED
|
|
/* Read the sCAL chunk */
|
|
void /* PRIVATE */
|
|
png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_size_t slength, i;
|
|
int state;
|
|
|
|
png_debug(1, "in png_handle_sCAL");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before sCAL");
|
|
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid sCAL after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL))
|
|
{
|
|
png_warning(png_ptr, "Duplicate sCAL chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
/* Need unit type, width, \0, height: minimum 4 bytes */
|
|
else if (length < 4)
|
|
{
|
|
png_warning(png_ptr, "sCAL chunk too short");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
|
|
length + 1);
|
|
|
|
png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
|
|
|
|
if (png_ptr->chunkdata == NULL)
|
|
{
|
|
png_warning(png_ptr, "Out of memory while processing sCAL chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
slength = (png_size_t)length;
|
|
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
|
|
png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
{
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
/* Validate the unit. */
|
|
if (png_ptr->chunkdata[0] != 1 && png_ptr->chunkdata[0] != 2)
|
|
{
|
|
png_warning(png_ptr, "Invalid sCAL ignored: invalid unit");
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
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_ptr->chunkdata[1] == 45 /* negative width */ ||
|
|
!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
|
|
i >= slength || png_ptr->chunkdata[i++] != 0)
|
|
png_warning(png_ptr, "Invalid sCAL chunk ignored: bad width format");
|
|
|
|
else
|
|
{
|
|
png_size_t heighti = i;
|
|
|
|
state = 0;
|
|
if (png_ptr->chunkdata[i] == 45 /* negative height */ ||
|
|
!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
|
|
i != slength)
|
|
png_warning(png_ptr, "Invalid sCAL chunk ignored: bad height format");
|
|
|
|
else
|
|
/* This is the (only) success case. */
|
|
png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0],
|
|
png_ptr->chunkdata+1, png_ptr->chunkdata+heighti);
|
|
}
|
|
|
|
/* Clean up - just free the temporarily allocated buffer. */
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_tIME_SUPPORTED
|
|
void /* PRIVATE */
|
|
png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_byte buf[7];
|
|
png_time mod_time;
|
|
|
|
png_debug(1, "in png_handle_tIME");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Out of place tIME chunk");
|
|
|
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME))
|
|
{
|
|
png_warning(png_ptr, "Duplicate tIME chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
png_ptr->mode |= PNG_AFTER_IDAT;
|
|
|
|
if (length != 7)
|
|
{
|
|
png_warning(png_ptr, "Incorrect tIME chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, 7);
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
return;
|
|
|
|
mod_time.second = buf[6];
|
|
mod_time.minute = buf[5];
|
|
mod_time.hour = buf[4];
|
|
mod_time.day = buf[3];
|
|
mod_time.month = buf[2];
|
|
mod_time.year = png_get_uint_16(buf);
|
|
|
|
png_set_tIME(png_ptr, info_ptr, &mod_time);
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_tEXt_SUPPORTED
|
|
/* Note: this does not properly handle chunks that are > 64K under DOS */
|
|
void /* PRIVATE */
|
|
png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_textp text_ptr;
|
|
png_charp key;
|
|
png_charp text;
|
|
png_uint_32 skip = 0;
|
|
png_size_t slength;
|
|
int ret;
|
|
|
|
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_warning(png_ptr, "No space in chunk cache for tEXt");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before tEXt");
|
|
|
|
if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
png_ptr->mode |= PNG_AFTER_IDAT;
|
|
|
|
#ifdef PNG_MAX_MALLOC_64K
|
|
if (length > (png_uint_32)65535L)
|
|
{
|
|
png_warning(png_ptr, "tEXt chunk too large to fit in memory");
|
|
skip = length - (png_uint_32)65535L;
|
|
length = (png_uint_32)65535L;
|
|
}
|
|
#endif
|
|
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
|
|
png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
|
|
|
|
if (png_ptr->chunkdata == NULL)
|
|
{
|
|
png_warning(png_ptr, "No memory to process text chunk");
|
|
return;
|
|
}
|
|
|
|
slength = (png_size_t)length;
|
|
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
|
|
|
|
if (png_crc_finish(png_ptr, skip))
|
|
{
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
key = png_ptr->chunkdata;
|
|
|
|
key[slength] = 0x00;
|
|
|
|
for (text = key; *text; text++)
|
|
/* Empty loop to find end of key */ ;
|
|
|
|
if (text != key + slength)
|
|
text++;
|
|
|
|
text_ptr = (png_textp)png_malloc_warn(png_ptr,
|
|
png_sizeof(png_text));
|
|
|
|
if (text_ptr == NULL)
|
|
{
|
|
png_warning(png_ptr, "Not enough memory to process text chunk");
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
|
|
text_ptr->key = key;
|
|
text_ptr->lang = NULL;
|
|
text_ptr->lang_key = NULL;
|
|
text_ptr->itxt_length = 0;
|
|
text_ptr->text = text;
|
|
text_ptr->text_length = png_strlen(text);
|
|
|
|
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
|
|
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
png_free(png_ptr, text_ptr);
|
|
|
|
if (ret)
|
|
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_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_textp text_ptr;
|
|
png_charp text;
|
|
int comp_type;
|
|
int ret;
|
|
png_size_t slength, prefix_len, data_len;
|
|
|
|
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_warning(png_ptr, "No space in chunk cache for zTXt");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before zTXt");
|
|
|
|
if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
png_ptr->mode |= PNG_AFTER_IDAT;
|
|
|
|
#ifdef PNG_MAX_MALLOC_64K
|
|
/* We will no doubt have problems with chunks even half this size, but
|
|
* there is no hard and fast rule to tell us where to stop.
|
|
*/
|
|
if (length > (png_uint_32)65535L)
|
|
{
|
|
png_warning(png_ptr, "zTXt chunk too large to fit in memory");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
|
|
|
|
if (png_ptr->chunkdata == NULL)
|
|
{
|
|
png_warning(png_ptr, "Out of memory processing zTXt chunk");
|
|
return;
|
|
}
|
|
|
|
slength = (png_size_t)length;
|
|
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
{
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
png_ptr->chunkdata[slength] = 0x00;
|
|
|
|
for (text = png_ptr->chunkdata; *text; text++)
|
|
/* Empty loop */ ;
|
|
|
|
/* zTXt must have some text after the chunkdataword */
|
|
if (text >= png_ptr->chunkdata + slength - 2)
|
|
{
|
|
png_warning(png_ptr, "Truncated zTXt chunk");
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
else
|
|
{
|
|
comp_type = *(++text);
|
|
|
|
if (comp_type != PNG_TEXT_COMPRESSION_zTXt)
|
|
{
|
|
png_warning(png_ptr, "Unknown compression type in zTXt chunk");
|
|
comp_type = PNG_TEXT_COMPRESSION_zTXt;
|
|
}
|
|
|
|
text++; /* Skip the compression_method byte */
|
|
}
|
|
|
|
prefix_len = text - png_ptr->chunkdata;
|
|
|
|
png_decompress_chunk(png_ptr, comp_type,
|
|
(png_size_t)length, prefix_len, &data_len);
|
|
|
|
text_ptr = (png_textp)png_malloc_warn(png_ptr,
|
|
png_sizeof(png_text));
|
|
|
|
if (text_ptr == NULL)
|
|
{
|
|
png_warning(png_ptr, "Not enough memory to process zTXt chunk");
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
text_ptr->compression = comp_type;
|
|
text_ptr->key = png_ptr->chunkdata;
|
|
text_ptr->lang = NULL;
|
|
text_ptr->lang_key = NULL;
|
|
text_ptr->itxt_length = 0;
|
|
text_ptr->text = png_ptr->chunkdata + prefix_len;
|
|
text_ptr->text_length = data_len;
|
|
|
|
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
|
|
|
|
png_free(png_ptr, text_ptr);
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
|
|
if (ret)
|
|
png_error(png_ptr, "Insufficient memory to store zTXt chunk");
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_iTXt_SUPPORTED
|
|
/* Note: this does not correctly handle chunks that are > 64K under DOS */
|
|
void /* PRIVATE */
|
|
png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_textp text_ptr;
|
|
png_charp key, lang, text, lang_key;
|
|
int comp_flag;
|
|
int comp_type = 0;
|
|
int ret;
|
|
png_size_t slength, prefix_len, data_len;
|
|
|
|
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_warning(png_ptr, "No space in chunk cache for iTXt");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before iTXt");
|
|
|
|
if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
png_ptr->mode |= PNG_AFTER_IDAT;
|
|
|
|
#ifdef PNG_MAX_MALLOC_64K
|
|
/* We will no doubt have problems with chunks even half this size, but
|
|
* there is no hard and fast rule to tell us where to stop.
|
|
*/
|
|
if (length > (png_uint_32)65535L)
|
|
{
|
|
png_warning(png_ptr, "iTXt chunk too large to fit in memory");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
|
|
|
|
if (png_ptr->chunkdata == NULL)
|
|
{
|
|
png_warning(png_ptr, "No memory to process iTXt chunk");
|
|
return;
|
|
}
|
|
|
|
slength = (png_size_t)length;
|
|
png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
{
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
png_ptr->chunkdata[slength] = 0x00;
|
|
|
|
for (lang = png_ptr->chunkdata; *lang; lang++)
|
|
/* Empty loop */ ;
|
|
|
|
lang++; /* Skip NUL separator */
|
|
|
|
/* iTXt must have a language tag (possibly empty), two compression bytes,
|
|
* translated keyword (possibly empty), and possibly some text after the
|
|
* keyword
|
|
*/
|
|
|
|
if (lang >= png_ptr->chunkdata + slength - 3)
|
|
{
|
|
png_warning(png_ptr, "Truncated iTXt chunk");
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
else
|
|
{
|
|
comp_flag = *lang++;
|
|
comp_type = *lang++;
|
|
}
|
|
|
|
for (lang_key = lang; *lang_key; lang_key++)
|
|
/* Empty loop */ ;
|
|
|
|
lang_key++; /* Skip NUL separator */
|
|
|
|
if (lang_key >= png_ptr->chunkdata + slength)
|
|
{
|
|
png_warning(png_ptr, "Truncated iTXt chunk");
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
for (text = lang_key; *text; text++)
|
|
/* Empty loop */ ;
|
|
|
|
text++; /* Skip NUL separator */
|
|
|
|
if (text >= png_ptr->chunkdata + slength)
|
|
{
|
|
png_warning(png_ptr, "Malformed iTXt chunk");
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
prefix_len = text - png_ptr->chunkdata;
|
|
|
|
key=png_ptr->chunkdata;
|
|
|
|
if (comp_flag)
|
|
png_decompress_chunk(png_ptr, comp_type,
|
|
(size_t)length, prefix_len, &data_len);
|
|
|
|
else
|
|
data_len = png_strlen(png_ptr->chunkdata + prefix_len);
|
|
|
|
text_ptr = (png_textp)png_malloc_warn(png_ptr,
|
|
png_sizeof(png_text));
|
|
|
|
if (text_ptr == NULL)
|
|
{
|
|
png_warning(png_ptr, "Not enough memory to process iTXt chunk");
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
return;
|
|
}
|
|
|
|
text_ptr->compression = (int)comp_flag + 1;
|
|
text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key);
|
|
text_ptr->lang = png_ptr->chunkdata + (lang - key);
|
|
text_ptr->itxt_length = data_len;
|
|
text_ptr->text_length = 0;
|
|
text_ptr->key = png_ptr->chunkdata;
|
|
text_ptr->text = png_ptr->chunkdata + prefix_len;
|
|
|
|
ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
|
|
|
|
png_free(png_ptr, text_ptr);
|
|
png_free(png_ptr, png_ptr->chunkdata);
|
|
png_ptr->chunkdata = NULL;
|
|
|
|
if (ret)
|
|
png_error(png_ptr, "Insufficient memory to store iTXt chunk");
|
|
}
|
|
#endif
|
|
|
|
/* This function is called when we haven't found a handler for a
|
|
* chunk. If there isn't a problem with the chunk itself (ie bad
|
|
* chunk name, CRC, or a critical chunk), the chunk is silently ignored
|
|
* -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
|
|
* case it will be saved away to be written out later.
|
|
*/
|
|
void /* PRIVATE */
|
|
png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_uint_32 skip = 0;
|
|
|
|
png_debug(1, "in png_handle_unknown");
|
|
|
|
#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 unknown chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
PNG_IDAT;
|
|
|
|
if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) /* Not an IDAT */
|
|
png_ptr->mode |= PNG_AFTER_IDAT;
|
|
}
|
|
|
|
if (!(png_ptr->chunk_name[0] & 0x20))
|
|
{
|
|
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
|
|
if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
|
|
PNG_HANDLE_CHUNK_ALWAYS
|
|
#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
|
|
&& png_ptr->read_user_chunk_fn == NULL
|
|
#endif
|
|
)
|
|
#endif
|
|
png_chunk_error(png_ptr, "unknown critical chunk");
|
|
}
|
|
|
|
#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
|
|
if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
|
|
#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
|
|
|| (png_ptr->read_user_chunk_fn != NULL)
|
|
#endif
|
|
)
|
|
{
|
|
#ifdef PNG_MAX_MALLOC_64K
|
|
if (length > (png_uint_32)65535L)
|
|
{
|
|
png_warning(png_ptr, "unknown chunk too large to fit in memory");
|
|
skip = length - (png_uint_32)65535L;
|
|
length = (png_uint_32)65535L;
|
|
}
|
|
#endif
|
|
|
|
png_memcpy((png_charp)png_ptr->unknown_chunk.name,
|
|
(png_charp)png_ptr->chunk_name,
|
|
png_sizeof(png_ptr->unknown_chunk.name));
|
|
|
|
png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1]
|
|
= '\0';
|
|
|
|
png_ptr->unknown_chunk.size = (png_size_t)length;
|
|
|
|
if (length == 0)
|
|
png_ptr->unknown_chunk.data = NULL;
|
|
|
|
else
|
|
{
|
|
png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
|
|
png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
|
|
}
|
|
|
|
#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
|
|
if (png_ptr->read_user_chunk_fn != NULL)
|
|
{
|
|
/* Callback to user unknown chunk handler */
|
|
int ret;
|
|
|
|
ret = (*(png_ptr->read_user_chunk_fn))
|
|
(png_ptr, &png_ptr->unknown_chunk);
|
|
|
|
if (ret < 0)
|
|
png_chunk_error(png_ptr, "error in user chunk");
|
|
|
|
if (ret == 0)
|
|
{
|
|
if (!(png_ptr->chunk_name[0] & 0x20))
|
|
{
|
|
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
|
|
if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
|
|
PNG_HANDLE_CHUNK_ALWAYS)
|
|
#endif
|
|
png_chunk_error(png_ptr, "unknown critical chunk");
|
|
}
|
|
|
|
png_set_unknown_chunks(png_ptr, info_ptr,
|
|
&png_ptr->unknown_chunk, 1);
|
|
}
|
|
}
|
|
|
|
else
|
|
#endif
|
|
png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
|
|
|
|
png_free(png_ptr, png_ptr->unknown_chunk.data);
|
|
png_ptr->unknown_chunk.data = NULL;
|
|
}
|
|
|
|
else
|
|
#endif
|
|
skip = length;
|
|
|
|
png_crc_finish(png_ptr, skip);
|
|
|
|
#ifndef PNG_READ_USER_CHUNKS_SUPPORTED
|
|
PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */
|
|
#endif
|
|
}
|
|
|
|
/* 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.
|
|
*/
|
|
|
|
#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
|
|
|
|
void /* PRIVATE */
|
|
png_check_chunk_name(png_structp png_ptr, png_const_bytep chunk_name)
|
|
{
|
|
png_debug(1, "in png_check_chunk_name");
|
|
if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) ||
|
|
isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3]))
|
|
{
|
|
png_chunk_error(png_ptr, "invalid chunk type");
|
|
}
|
|
}
|
|
|
|
/* 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 mask value.
|
|
* The mask value describes which pixels are to be combined with
|
|
* the row. The pattern always repeats every 8 pixels, so just 8
|
|
* bits are needed. A one indicates the pixel is to be combined,
|
|
* a zero indicates the pixel is to be skipped. This is in addition
|
|
* to any alpha or transparency value associated with the pixel. If
|
|
* you want all pixels to be combined, pass 0xff (255) in mask.
|
|
*/
|
|
|
|
void /* PRIVATE */
|
|
png_combine_row(png_structp png_ptr, png_bytep row, int mask)
|
|
{
|
|
png_debug(1, "in png_combine_row");
|
|
|
|
/* Added in 1.5.3: the row_info 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(png_ptr->row_info.pixel_depth, png_ptr->width))
|
|
png_error(png_ptr, "internal row size calculation error");
|
|
|
|
if (mask == 0xff)
|
|
{
|
|
png_memcpy(row, png_ptr->row_buf + 1,
|
|
PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width));
|
|
}
|
|
|
|
else
|
|
{
|
|
switch (png_ptr->row_info.pixel_depth)
|
|
{
|
|
case 1:
|
|
{
|
|
png_bytep sp = png_ptr->row_buf + 1;
|
|
png_bytep dp = row;
|
|
int s_inc, s_start, s_end;
|
|
int m = 0x80;
|
|
int shift;
|
|
png_uint_32 i;
|
|
png_uint_32 row_width = png_ptr->width;
|
|
|
|
#ifdef PNG_READ_PACKSWAP_SUPPORTED
|
|
if (png_ptr->transformations & PNG_PACKSWAP)
|
|
{
|
|
s_start = 0;
|
|
s_end = 7;
|
|
s_inc = 1;
|
|
}
|
|
|
|
else
|
|
#endif
|
|
{
|
|
s_start = 7;
|
|
s_end = 0;
|
|
s_inc = -1;
|
|
}
|
|
|
|
shift = s_start;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if (m & mask)
|
|
{
|
|
int value;
|
|
|
|
value = (*sp >> shift) & 0x01;
|
|
*dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
|
|
*dp |= (png_byte)(value << shift);
|
|
}
|
|
|
|
if (shift == s_end)
|
|
{
|
|
shift = s_start;
|
|
sp++;
|
|
dp++;
|
|
}
|
|
|
|
else
|
|
shift += s_inc;
|
|
|
|
if (m == 1)
|
|
m = 0x80;
|
|
|
|
else
|
|
m >>= 1;
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 2:
|
|
{
|
|
png_bytep sp = png_ptr->row_buf + 1;
|
|
png_bytep dp = row;
|
|
int s_start, s_end, s_inc;
|
|
int m = 0x80;
|
|
int shift;
|
|
png_uint_32 i;
|
|
png_uint_32 row_width = png_ptr->width;
|
|
int value;
|
|
|
|
#ifdef PNG_READ_PACKSWAP_SUPPORTED
|
|
if (png_ptr->transformations & PNG_PACKSWAP)
|
|
{
|
|
s_start = 0;
|
|
s_end = 6;
|
|
s_inc = 2;
|
|
}
|
|
|
|
else
|
|
#endif
|
|
{
|
|
s_start = 6;
|
|
s_end = 0;
|
|
s_inc = -2;
|
|
}
|
|
|
|
shift = s_start;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if (m & mask)
|
|
{
|
|
value = (*sp >> shift) & 0x03;
|
|
*dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
|
|
*dp |= (png_byte)(value << shift);
|
|
}
|
|
|
|
if (shift == s_end)
|
|
{
|
|
shift = s_start;
|
|
sp++;
|
|
dp++;
|
|
}
|
|
|
|
else
|
|
shift += s_inc;
|
|
|
|
if (m == 1)
|
|
m = 0x80;
|
|
|
|
else
|
|
m >>= 1;
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 4:
|
|
{
|
|
png_bytep sp = png_ptr->row_buf + 1;
|
|
png_bytep dp = row;
|
|
int s_start, s_end, s_inc;
|
|
int m = 0x80;
|
|
int shift;
|
|
png_uint_32 i;
|
|
png_uint_32 row_width = png_ptr->width;
|
|
int value;
|
|
|
|
#ifdef PNG_READ_PACKSWAP_SUPPORTED
|
|
if (png_ptr->transformations & PNG_PACKSWAP)
|
|
{
|
|
s_start = 0;
|
|
s_end = 4;
|
|
s_inc = 4;
|
|
}
|
|
|
|
else
|
|
#endif
|
|
{
|
|
s_start = 4;
|
|
s_end = 0;
|
|
s_inc = -4;
|
|
}
|
|
shift = s_start;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if (m & mask)
|
|
{
|
|
value = (*sp >> shift) & 0xf;
|
|
*dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
|
|
*dp |= (png_byte)(value << shift);
|
|
}
|
|
|
|
if (shift == s_end)
|
|
{
|
|
shift = s_start;
|
|
sp++;
|
|
dp++;
|
|
}
|
|
|
|
else
|
|
shift += s_inc;
|
|
|
|
if (m == 1)
|
|
m = 0x80;
|
|
|
|
else
|
|
m >>= 1;
|
|
}
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
png_bytep sp = png_ptr->row_buf + 1;
|
|
png_bytep dp = row;
|
|
png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
|
|
png_uint_32 i;
|
|
png_uint_32 row_width = png_ptr->width;
|
|
png_byte m = 0x80;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if (m & mask)
|
|
{
|
|
png_memcpy(dp, sp, pixel_bytes);
|
|
}
|
|
|
|
sp += pixel_bytes;
|
|
dp += pixel_bytes;
|
|
|
|
if (m == 1)
|
|
m = 0x80;
|
|
|
|
else
|
|
m >>= 1;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#ifdef PNG_READ_INTERLACING_SUPPORTED
|
|
void /* PRIVATE */
|
|
png_do_read_interlace(png_structp png_ptr)
|
|
{
|
|
png_row_infop row_info = &(png_ptr->row_info);
|
|
png_bytep row = png_ptr->row_buf + 1;
|
|
int pass = png_ptr->pass;
|
|
png_uint_32 transformations = png_ptr->transformations;
|
|
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
|
|
/* Offset to next interlace block */
|
|
PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
|
|
|
|
png_debug(1, "in png_do_read_interlace");
|
|
if (row != NULL && row_info != NULL)
|
|
{
|
|
png_uint_32 final_width;
|
|
|
|
final_width = row_info->width * png_pass_inc[pass];
|
|
|
|
switch (row_info->pixel_depth)
|
|
{
|
|
case 1:
|
|
{
|
|
png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
|
|
png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
|
|
int sshift, dshift;
|
|
int s_start, s_end, s_inc;
|
|
int jstop = png_pass_inc[pass];
|
|
png_byte v;
|
|
png_uint_32 i;
|
|
int j;
|
|
|
|
#ifdef PNG_READ_PACKSWAP_SUPPORTED
|
|
if (transformations & PNG_PACKSWAP)
|
|
{
|
|
sshift = (int)((row_info->width + 7) & 0x07);
|
|
dshift = (int)((final_width + 7) & 0x07);
|
|
s_start = 7;
|
|
s_end = 0;
|
|
s_inc = -1;
|
|
}
|
|
|
|
else
|
|
#endif
|
|
{
|
|
sshift = 7 - (int)((row_info->width + 7) & 0x07);
|
|
dshift = 7 - (int)((final_width + 7) & 0x07);
|
|
s_start = 0;
|
|
s_end = 7;
|
|
s_inc = 1;
|
|
}
|
|
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
v = (png_byte)((*sp >> sshift) & 0x01);
|
|
for (j = 0; j < jstop; j++)
|
|
{
|
|
*dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
|
|
*dp |= (png_byte)(v << dshift);
|
|
|
|
if (dshift == s_end)
|
|
{
|
|
dshift = s_start;
|
|
dp--;
|
|
}
|
|
|
|
else
|
|
dshift += s_inc;
|
|
}
|
|
|
|
if (sshift == s_end)
|
|
{
|
|
sshift = s_start;
|
|
sp--;
|
|
}
|
|
|
|
else
|
|
sshift += s_inc;
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 2:
|
|
{
|
|
png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
|
|
png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
|
|
int sshift, dshift;
|
|
int s_start, s_end, s_inc;
|
|
int jstop = png_pass_inc[pass];
|
|
png_uint_32 i;
|
|
|
|
#ifdef PNG_READ_PACKSWAP_SUPPORTED
|
|
if (transformations & PNG_PACKSWAP)
|
|
{
|
|
sshift = (int)(((row_info->width + 3) & 0x03) << 1);
|
|
dshift = (int)(((final_width + 3) & 0x03) << 1);
|
|
s_start = 6;
|
|
s_end = 0;
|
|
s_inc = -2;
|
|
}
|
|
|
|
else
|
|
#endif
|
|
{
|
|
sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
|
|
dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
|
|
s_start = 0;
|
|
s_end = 6;
|
|
s_inc = 2;
|
|
}
|
|
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
png_byte v;
|
|
int j;
|
|
|
|
v = (png_byte)((*sp >> sshift) & 0x03);
|
|
for (j = 0; j < jstop; j++)
|
|
{
|
|
*dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
|
|
*dp |= (png_byte)(v << dshift);
|
|
|
|
if (dshift == s_end)
|
|
{
|
|
dshift = s_start;
|
|
dp--;
|
|
}
|
|
|
|
else
|
|
dshift += s_inc;
|
|
}
|
|
|
|
if (sshift == s_end)
|
|
{
|
|
sshift = s_start;
|
|
sp--;
|
|
}
|
|
|
|
else
|
|
sshift += s_inc;
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 4:
|
|
{
|
|
png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
|
|
png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
|
|
int sshift, dshift;
|
|
int s_start, s_end, s_inc;
|
|
png_uint_32 i;
|
|
int jstop = png_pass_inc[pass];
|
|
|
|
#ifdef PNG_READ_PACKSWAP_SUPPORTED
|
|
if (transformations & PNG_PACKSWAP)
|
|
{
|
|
sshift = (int)(((row_info->width + 1) & 0x01) << 2);
|
|
dshift = (int)(((final_width + 1) & 0x01) << 2);
|
|
s_start = 4;
|
|
s_end = 0;
|
|
s_inc = -4;
|
|
}
|
|
|
|
else
|
|
#endif
|
|
{
|
|
sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
|
|
dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
|
|
s_start = 0;
|
|
s_end = 4;
|
|
s_inc = 4;
|
|
}
|
|
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
png_byte v = (png_byte)((*sp >> sshift) & 0xf);
|
|
int j;
|
|
|
|
for (j = 0; j < jstop; j++)
|
|
{
|
|
*dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
|
|
*dp |= (png_byte)(v << dshift);
|
|
|
|
if (dshift == s_end)
|
|
{
|
|
dshift = s_start;
|
|
dp--;
|
|
}
|
|
|
|
else
|
|
dshift += s_inc;
|
|
}
|
|
|
|
if (sshift == s_end)
|
|
{
|
|
sshift = s_start;
|
|
sp--;
|
|
}
|
|
|
|
else
|
|
sshift += s_inc;
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
{
|
|
png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
|
|
|
|
png_bytep sp = row + (png_size_t)(row_info->width - 1)
|
|
* pixel_bytes;
|
|
|
|
png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
|
|
|
|
int jstop = png_pass_inc[pass];
|
|
png_uint_32 i;
|
|
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
png_byte v[8];
|
|
int j;
|
|
|
|
png_memcpy(v, sp, pixel_bytes);
|
|
|
|
for (j = 0; j < jstop; j++)
|
|
{
|
|
png_memcpy(dp, v, pixel_bytes);
|
|
dp -= pixel_bytes;
|
|
}
|
|
|
|
sp -= pixel_bytes;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
row_info->width = final_width;
|
|
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
|
|
}
|
|
#ifndef PNG_READ_PACKSWAP_SUPPORTED
|
|
PNG_UNUSED(transformations) /* Silence compiler warning */
|
|
#endif
|
|
}
|
|
#endif /* PNG_READ_INTERLACING_SUPPORTED */
|
|
|
|
void /* PRIVATE */
|
|
png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
|
|
png_const_bytep prev_row, int filter)
|
|
{
|
|
png_debug(1, "in png_read_filter_row");
|
|
png_debug2(2, "row = %u, filter = %d", png_ptr->row_number, filter);
|
|
switch (filter)
|
|
{
|
|
case PNG_FILTER_VALUE_NONE:
|
|
break;
|
|
|
|
case PNG_FILTER_VALUE_SUB:
|
|
{
|
|
png_size_t i;
|
|
png_size_t istop = row_info->rowbytes;
|
|
unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
|
|
png_bytep rp = row + bpp;
|
|
png_bytep lp = row;
|
|
|
|
for (i = bpp; i < istop; i++)
|
|
{
|
|
*rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff);
|
|
rp++;
|
|
}
|
|
break;
|
|
}
|
|
case PNG_FILTER_VALUE_UP:
|
|
{
|
|
png_size_t i;
|
|
png_size_t istop = row_info->rowbytes;
|
|
png_bytep rp = row;
|
|
png_const_bytep pp = prev_row;
|
|
|
|
for (i = 0; i < istop; i++)
|
|
{
|
|
*rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
|
|
rp++;
|
|
}
|
|
break;
|
|
}
|
|
case PNG_FILTER_VALUE_AVG:
|
|
{
|
|
png_size_t i;
|
|
png_bytep rp = row;
|
|
png_const_bytep pp = prev_row;
|
|
png_bytep lp = row;
|
|
unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
|
|
png_size_t istop = row_info->rowbytes - bpp;
|
|
|
|
for (i = 0; i < bpp; i++)
|
|
{
|
|
*rp = (png_byte)(((int)(*rp) +
|
|
((int)(*pp++) / 2 )) & 0xff);
|
|
|
|
rp++;
|
|
}
|
|
|
|
for (i = 0; i < istop; i++)
|
|
{
|
|
*rp = (png_byte)(((int)(*rp) +
|
|
(int)(*pp++ + *lp++) / 2 ) & 0xff);
|
|
|
|
rp++;
|
|
}
|
|
break;
|
|
}
|
|
case PNG_FILTER_VALUE_PAETH:
|
|
{
|
|
png_size_t i;
|
|
png_bytep rp = row;
|
|
png_const_bytep pp = prev_row;
|
|
png_bytep lp = row;
|
|
png_const_bytep cp = prev_row;
|
|
unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
|
|
png_size_t istop=row_info->rowbytes - bpp;
|
|
|
|
for (i = 0; i < bpp; i++)
|
|
{
|
|
*rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
|
|
rp++;
|
|
}
|
|
|
|
for (i = 0; i < istop; i++) /* Use leftover rp,pp */
|
|
{
|
|
int a, b, c, pa, pb, pc, p;
|
|
|
|
a = *lp++;
|
|
b = *pp++;
|
|
c = *cp++;
|
|
|
|
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 (pa <= pb && pa <= pc)
|
|
p = a;
|
|
|
|
else if (pb <= pc)
|
|
p = b;
|
|
|
|
else
|
|
p = c;
|
|
*/
|
|
|
|
p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c;
|
|
|
|
*rp = (png_byte)(((int)(*rp) + p) & 0xff);
|
|
rp++;
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
png_error(png_ptr, "Ignoring bad adaptive filter type");
|
|
/*NOT REACHED */
|
|
break;
|
|
}
|
|
}
|
|
|
|
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
|
|
void /* PRIVATE */
|
|
png_read_finish_row(png_structp png_ptr)
|
|
{
|
|
#ifdef PNG_READ_INTERLACING_SUPPORTED
|
|
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
|
|
|
|
/* Start of interlace block */
|
|
PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
|
|
|
|
/* Offset to next interlace block */
|
|
PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
|
|
|
|
/* Start of interlace block in the y direction */
|
|
PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
|
|
|
|
/* Offset to next interlace block in the y direction */
|
|
PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
|
|
#endif /* PNG_READ_INTERLACING_SUPPORTED */
|
|
|
|
png_debug(1, "in png_read_finish_row");
|
|
png_ptr->row_number++;
|
|
if (png_ptr->row_number < png_ptr->num_rows)
|
|
return;
|
|
|
|
#ifdef PNG_READ_INTERLACING_SUPPORTED
|
|
if (png_ptr->interlaced)
|
|
{
|
|
png_ptr->row_number = 0;
|
|
|
|
png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
|
|
|
|
do
|
|
{
|
|
png_ptr->pass++;
|
|
|
|
if (png_ptr->pass >= 7)
|
|
break;
|
|
|
|
png_ptr->iwidth = (png_ptr->width +
|
|
png_pass_inc[png_ptr->pass] - 1 -
|
|
png_pass_start[png_ptr->pass]) /
|
|
png_pass_inc[png_ptr->pass];
|
|
|
|
if (!(png_ptr->transformations & PNG_INTERLACE))
|
|
{
|
|
png_ptr->num_rows = (png_ptr->height +
|
|
png_pass_yinc[png_ptr->pass] - 1 -
|
|
png_pass_ystart[png_ptr->pass]) /
|
|
png_pass_yinc[png_ptr->pass];
|
|
}
|
|
|
|
else /* if (png_ptr->transformations & PNG_INTERLACE) */
|
|
break; /* libpng deinterlacing sees every row */
|
|
|
|
} while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0);
|
|
|
|
if (png_ptr->pass < 7)
|
|
return;
|
|
}
|
|
#endif /* PNG_READ_INTERLACING_SUPPORTED */
|
|
|
|
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
|
|
{
|
|
PNG_IDAT;
|
|
char extra;
|
|
int ret;
|
|
|
|
png_ptr->zstream.next_out = (Byte *)&extra;
|
|
png_ptr->zstream.avail_out = (uInt)1;
|
|
|
|
for (;;)
|
|
{
|
|
if (!(png_ptr->zstream.avail_in))
|
|
{
|
|
while (!png_ptr->idat_size)
|
|
{
|
|
png_crc_finish(png_ptr, 0);
|
|
png_ptr->idat_size = png_read_chunk_header(png_ptr);
|
|
if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
|
|
png_error(png_ptr, "Not enough image data");
|
|
}
|
|
|
|
png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
|
|
png_ptr->zstream.next_in = png_ptr->zbuf;
|
|
|
|
if (png_ptr->zbuf_size > png_ptr->idat_size)
|
|
png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
|
|
|
|
png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in);
|
|
png_ptr->idat_size -= png_ptr->zstream.avail_in;
|
|
}
|
|
|
|
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
|
|
|
|
if (ret == Z_STREAM_END)
|
|
{
|
|
if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in ||
|
|
png_ptr->idat_size)
|
|
png_warning(png_ptr, "Extra compressed data");
|
|
|
|
png_ptr->mode |= PNG_AFTER_IDAT;
|
|
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
|
|
break;
|
|
}
|
|
|
|
if (ret != Z_OK)
|
|
png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
|
|
"Decompression Error");
|
|
|
|
if (!(png_ptr->zstream.avail_out))
|
|
{
|
|
png_warning(png_ptr, "Extra compressed data");
|
|
png_ptr->mode |= PNG_AFTER_IDAT;
|
|
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
|
|
break;
|
|
}
|
|
|
|
}
|
|
png_ptr->zstream.avail_out = 0;
|
|
}
|
|
|
|
if (png_ptr->idat_size || png_ptr->zstream.avail_in)
|
|
png_warning(png_ptr, "Extra compression data");
|
|
|
|
inflateReset(&png_ptr->zstream);
|
|
|
|
png_ptr->mode |= PNG_AFTER_IDAT;
|
|
}
|
|
#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
|
|
|
|
void /* PRIVATE */
|
|
png_read_start_row(png_structp png_ptr)
|
|
{
|
|
#ifdef PNG_READ_INTERLACING_SUPPORTED
|
|
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
|
|
|
|
/* Start of interlace block */
|
|
PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
|
|
|
|
/* Offset to next interlace block */
|
|
PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
|
|
|
|
/* Start of interlace block in the y direction */
|
|
PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
|
|
|
|
/* Offset to next interlace block in the y direction */
|
|
PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
|
|
#endif
|
|
|
|
int max_pixel_depth;
|
|
png_size_t row_bytes;
|
|
|
|
png_debug(1, "in png_read_start_row");
|
|
png_ptr->zstream.avail_in = 0;
|
|
#ifdef PNG_READ_TRANSFORMS_SUPPORTED
|
|
png_init_read_transformations(png_ptr);
|
|
#endif
|
|
#ifdef PNG_READ_INTERLACING_SUPPORTED
|
|
if (png_ptr->interlaced)
|
|
{
|
|
if (!(png_ptr->transformations & PNG_INTERLACE))
|
|
png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
|
|
png_pass_ystart[0]) / png_pass_yinc[0];
|
|
|
|
else
|
|
png_ptr->num_rows = png_ptr->height;
|
|
|
|
png_ptr->iwidth = (png_ptr->width +
|
|
png_pass_inc[png_ptr->pass] - 1 -
|
|
png_pass_start[png_ptr->pass]) /
|
|
png_pass_inc[png_ptr->pass];
|
|
}
|
|
|
|
else
|
|
#endif /* PNG_READ_INTERLACING_SUPPORTED */
|
|
{
|
|
png_ptr->num_rows = png_ptr->height;
|
|
png_ptr->iwidth = png_ptr->width;
|
|
}
|
|
|
|
max_pixel_depth = png_ptr->pixel_depth;
|
|
|
|
#ifdef PNG_READ_PACK_SUPPORTED
|
|
if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8)
|
|
max_pixel_depth = 8;
|
|
#endif
|
|
|
|
#ifdef PNG_READ_EXPAND_SUPPORTED
|
|
if (png_ptr->transformations & PNG_EXPAND)
|
|
{
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
if (png_ptr->num_trans)
|
|
max_pixel_depth = 32;
|
|
|
|
else
|
|
max_pixel_depth = 24;
|
|
}
|
|
|
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
|
|
{
|
|
if (max_pixel_depth < 8)
|
|
max_pixel_depth = 8;
|
|
|
|
if (png_ptr->num_trans)
|
|
max_pixel_depth *= 2;
|
|
}
|
|
|
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
|
|
{
|
|
if (png_ptr->num_trans)
|
|
{
|
|
max_pixel_depth *= 4;
|
|
max_pixel_depth /= 3;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_EXPAND_16_SUPPORTED
|
|
if (png_ptr->transformations & PNG_EXPAND_16)
|
|
{
|
|
# ifdef PNG_READ_EXPAND_SUPPORTED
|
|
/* In fact it is an error if it isn't supported, but checking is
|
|
* the safe way.
|
|
*/
|
|
if (png_ptr->transformations & PNG_EXPAND)
|
|
{
|
|
if (png_ptr->bit_depth < 16)
|
|
max_pixel_depth *= 2;
|
|
}
|
|
else
|
|
# endif
|
|
png_ptr->transformations &= ~PNG_EXPAND_16;
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_FILLER_SUPPORTED
|
|
if (png_ptr->transformations & (PNG_FILLER))
|
|
{
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
max_pixel_depth = 32;
|
|
|
|
else 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)
|
|
{
|
|
if (max_pixel_depth <= 32)
|
|
max_pixel_depth = 32;
|
|
|
|
else
|
|
max_pixel_depth = 64;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
|
if (png_ptr->transformations & PNG_GRAY_TO_RGB)
|
|
{
|
|
if (
|
|
#ifdef PNG_READ_EXPAND_SUPPORTED
|
|
(png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
|
|
#endif
|
|
#ifdef PNG_READ_FILLER_SUPPORTED
|
|
(png_ptr->transformations & (PNG_FILLER)) ||
|
|
#endif
|
|
png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
|
|
{
|
|
if (max_pixel_depth <= 16)
|
|
max_pixel_depth = 32;
|
|
|
|
else
|
|
max_pixel_depth = 64;
|
|
}
|
|
|
|
else
|
|
{
|
|
if (max_pixel_depth <= 8)
|
|
{
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
|
|
max_pixel_depth = 32;
|
|
|
|
else
|
|
max_pixel_depth = 24;
|
|
}
|
|
|
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
|
|
max_pixel_depth = 64;
|
|
|
|
else
|
|
max_pixel_depth = 48;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
|
|
defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_USER_TRANSFORM)
|
|
{
|
|
int user_pixel_depth = png_ptr->user_transform_depth*
|
|
png_ptr->user_transform_channels;
|
|
|
|
if (user_pixel_depth > max_pixel_depth)
|
|
max_pixel_depth=user_pixel_depth;
|
|
}
|
|
#endif
|
|
|
|
/* Align the width on the next larger 8 pixels. Mainly used
|
|
* for interlacing
|
|
*/
|
|
row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
|
|
/* Calculate the maximum bytes needed, adding a byte and a pixel
|
|
* for safety's sake
|
|
*/
|
|
row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
|
|
1 + ((max_pixel_depth + 7) >> 3);
|
|
|
|
#ifdef PNG_MAX_MALLOC_64K
|
|
if (row_bytes > (png_uint_32)65536L)
|
|
png_error(png_ptr, "This image requires a row greater than 64KB");
|
|
#endif
|
|
|
|
if (row_bytes + 48 > png_ptr->old_big_row_buf_size)
|
|
{
|
|
png_free(png_ptr, png_ptr->big_row_buf);
|
|
|
|
if (png_ptr->interlaced)
|
|
png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr,
|
|
row_bytes + 48);
|
|
|
|
else
|
|
png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr,
|
|
row_bytes + 48);
|
|
|
|
png_ptr->old_big_row_buf_size = 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.
|
|
*/
|
|
png_ptr->row_buf = png_ptr->big_row_buf + 32 -
|
|
(((png_alloc_size_t)png_ptr->big_row_buf + 15) & 0x0F);
|
|
|
|
png_ptr->old_big_row_buf_size = row_bytes + 48;
|
|
#else
|
|
/* Use 32 bytes of padding before and 16 bytes after row_buf. */
|
|
png_ptr->row_buf = png_ptr->big_row_buf + 32;
|
|
#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");
|
|
|
|
if (png_ptr->rowbytes + 1 > png_ptr->old_prev_row_size)
|
|
{
|
|
png_free(png_ptr, png_ptr->prev_row);
|
|
|
|
png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1);
|
|
|
|
png_ptr->old_prev_row_size = png_ptr->rowbytes + 1;
|
|
}
|
|
|
|
png_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);
|
|
|
|
png_ptr->flags |= PNG_FLAG_ROW_INIT;
|
|
}
|
|
#endif /* PNG_READ_SUPPORTED */
|