X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/2b5f62a0b2db198609b45dec622a018dae37008e..6619c4af1b03055fc130d72077186867fbdd7340:/src/png/pngrutil.c diff --git a/src/png/pngrutil.c b/src/png/pngrutil.c index d0a4964cd1..52a73cfc39 100644 --- a/src/png/pngrutil.c +++ b/src/png/pngrutil.c @@ -1,95 +1,205 @@ /* pngrutil.c - utilities to read a PNG file * - * libpng 1.2.5rc3 - September 18, 2002 - * For conditions of distribution and use, see copyright notice in png.h - * Copyright (c) 1998-2002 Glenn Randers-Pehrson + * Last changed in libpng 1.5.7 [December 15, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * * This file contains routines that are only called from within * libpng itself during the course of reading an image. */ -#define PNG_INTERNAL -#include "png.h" +#include "pngpriv.h" + +#ifdef PNG_READ_SUPPORTED -#if defined(_WIN32_WCE) -/* strtod() function is not supported on WindowsCE */ -# ifdef PNG_FLOATING_POINT_SUPPORTED -__inline double strtod(const char *nptr, char **endptr) +#define png_strtod(p,a,b) strtod(a,b) + +png_uint_32 PNGAPI +png_get_uint_31(png_structp png_ptr, png_const_bytep buf) { - double result = 0; - int len; - wchar_t *str, *end; + png_uint_32 uval = png_get_uint_32(buf); - len = MultiByteToWideChar(CP_ACP, 0, nptr, -1, NULL, 0); - str = (wchar_t *)malloc(len * sizeof(wchar_t)); - if ( NULL != str ) - { - MultiByteToWideChar(CP_ACP, 0, nptr, -1, str, len); - result = wcstod(str, &end); - len = WideCharToMultiByte(CP_ACP, 0, end, -1, NULL, 0, NULL, NULL); - *endptr = (char *)nptr + (png_strlen(nptr) - len + 1); - free(str); - } - return result; + if (uval > PNG_UINT_31_MAX) + png_error(png_ptr, "PNG unsigned integer out of range"); + + return (uval); +} + +#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED) +/* The following is a variation on the above for use with the fixed + * point values used for gAMA and cHRM. Instead of png_error it + * issues a warning and returns (-1) - an invalid value because both + * gAMA and cHRM use *unsigned* integers for fixed point values. + */ +#define PNG_FIXED_ERROR (-1) + +static png_fixed_point /* PRIVATE */ +png_get_fixed_point(png_structp png_ptr, png_const_bytep buf) +{ + png_uint_32 uval = png_get_uint_32(buf); + + if (uval <= PNG_UINT_31_MAX) + return (png_fixed_point)uval; /* known to be in range */ + + /* The caller can turn off the warning by passing NULL. */ + if (png_ptr != NULL) + png_warning(png_ptr, "PNG fixed point integer out of range"); + + return PNG_FIXED_ERROR; } -# endif #endif -#ifndef PNG_READ_BIG_ENDIAN_SUPPORTED +#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED +/* NOTE: the read macros will obscure these definitions, so that if + * PNG_USE_READ_MACROS is set the library will not use them internally, + * but the APIs will still be available externally. + * + * The parentheses around "PNGAPI function_name" in the following three + * functions are necessary because they allow the macros to co-exist with + * these (unused but exported) functions. + */ + /* Grab an unsigned 32-bit integer from a buffer in big-endian format. */ -png_uint_32 /* PRIVATE */ -png_get_uint_32(png_bytep buf) +png_uint_32 (PNGAPI +png_get_uint_32)(png_const_bytep buf) { - png_uint_32 i = ((png_uint_32)(*buf) << 24) + - ((png_uint_32)(*(buf + 1)) << 16) + - ((png_uint_32)(*(buf + 2)) << 8) + - (png_uint_32)(*(buf + 3)); + png_uint_32 uval = + ((png_uint_32)(*(buf )) << 24) + + ((png_uint_32)(*(buf + 1)) << 16) + + ((png_uint_32)(*(buf + 2)) << 8) + + ((png_uint_32)(*(buf + 3)) ) ; - return (i); + return uval; } -#if defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_oFFs_SUPPORTED) /* Grab a signed 32-bit integer from a buffer in big-endian format. The - * data is stored in the PNG file in two's complement format, and it is - * assumed that the machine format for signed integers is the same. */ -png_int_32 /* PRIVATE */ -png_get_int_32(png_bytep buf) + * data is stored in the PNG file in two's complement format and there + * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore + * the following code does a two's complement to native conversion. + */ +png_int_32 (PNGAPI +png_get_int_32)(png_const_bytep buf) { - png_int_32 i = ((png_int_32)(*buf) << 24) + - ((png_int_32)(*(buf + 1)) << 16) + - ((png_int_32)(*(buf + 2)) << 8) + - (png_int_32)(*(buf + 3)); + png_uint_32 uval = png_get_uint_32(buf); + if ((uval & 0x80000000) == 0) /* non-negative */ + return uval; - return (i); + uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */ + return -(png_int_32)uval; } -#endif /* PNG_READ_pCAL_SUPPORTED */ /* Grab an unsigned 16-bit integer from a buffer in big-endian format. */ -png_uint_16 /* PRIVATE */ -png_get_uint_16(png_bytep buf) +png_uint_16 (PNGAPI +png_get_uint_16)(png_const_bytep buf) +{ + /* ANSI-C requires an int value to accomodate at least 16 bits so this + * works and allows the compiler not to worry about possible narrowing + * on 32 bit systems. (Pre-ANSI systems did not make integers smaller + * than 16 bits either.) + */ + unsigned int val = + ((unsigned int)(*buf) << 8) + + ((unsigned int)(*(buf + 1))); + + return (png_uint_16)val; +} + +#endif /* PNG_READ_INT_FUNCTIONS_SUPPORTED */ + +/* Read and check the PNG file signature */ +void /* PRIVATE */ +png_read_sig(png_structp png_ptr, png_infop info_ptr) +{ + png_size_t num_checked, num_to_check; + + /* Exit if the user application does not expect a signature. */ + if (png_ptr->sig_bytes >= 8) + return; + + num_checked = png_ptr->sig_bytes; + num_to_check = 8 - num_checked; + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE; +#endif + + /* The signature must be serialized in a single I/O call. */ + png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); + png_ptr->sig_bytes = 8; + + if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) + { + if (num_checked < 4 && + png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) + png_error(png_ptr, "Not a PNG file"); + else + png_error(png_ptr, "PNG file corrupted by ASCII conversion"); + } + if (num_checked < 3) + png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; +} + +/* Read the chunk header (length + type name). + * Put the type name into png_ptr->chunk_name, and return the length. + */ +png_uint_32 /* PRIVATE */ +png_read_chunk_header(png_structp png_ptr) { - png_uint_16 i = (png_uint_16)(((png_uint_16)(*buf) << 8) + - (png_uint_16)(*(buf + 1))); + png_byte buf[8]; + png_uint_32 length; + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR; +#endif + + /* Read the length and the chunk name. + * This must be performed in a single I/O call. + */ + png_read_data(png_ptr, buf, 8); + length = png_get_uint_31(png_ptr, buf); + + /* Put the chunk name into png_ptr->chunk_name. */ + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4); + + png_debug2(0, "Reading %lx chunk, length = %lu", + (unsigned long)png_ptr->chunk_name, (unsigned long)length); + + /* Reset the crc and run it over the chunk name. */ + png_reset_crc(png_ptr); + png_calculate_crc(png_ptr, buf + 4, 4); + + /* Check to see if chunk name is valid. */ + png_check_chunk_name(png_ptr, png_ptr->chunk_name); - return (i); +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA; +#endif + + return length; } -#endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */ /* Read data, and (optionally) run it through the CRC. */ void /* PRIVATE */ png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length) { + if (png_ptr == NULL) + return; + png_read_data(png_ptr, buf, length); png_calculate_crc(png_ptr, buf, length); } /* Optionally skip data and then check the CRC. Depending on whether we - are reading a ancillary or critical chunk, and how the program has set - things up, we may calculate the CRC on the data and print a message. - Returns '1' if there was a CRC error, '0' otherwise. */ + * are reading a ancillary or critical chunk, and how the program has set + * things up, we may calculate the CRC on the data and print a message. + * Returns '1' if there was a CRC error, '0' otherwise. + */ int /* PRIVATE */ png_crc_finish(png_structp png_ptr, png_uint_32 skip) { @@ -100,6 +210,7 @@ png_crc_finish(png_structp png_ptr, png_uint_32 skip) { png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); } + if (i) { png_crc_read(png_ptr, png_ptr->zbuf, i); @@ -107,17 +218,19 @@ png_crc_finish(png_structp png_ptr, png_uint_32 skip) if (png_crc_error(png_ptr)) { - if (((png_ptr->chunk_name[0] & 0x20) && /* Ancillary */ - !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) || - (!(png_ptr->chunk_name[0] & 0x20) && /* Critical */ - (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))) + if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name) ? + !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) : + (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)) { png_chunk_warning(png_ptr, "CRC error"); } + else { - png_chunk_error(png_ptr, "CRC error"); + png_chunk_benign_error(png_ptr, "CRC error"); + return (0); } + return (1); } @@ -125,7 +238,8 @@ png_crc_finish(png_structp png_ptr, png_uint_32 skip) } /* Compare the CRC stored in the PNG file with that calculated by libpng from - the data it has read thus far. */ + * the data it has read thus far. + */ int /* PRIVATE */ png_crc_error(png_structp png_ptr) { @@ -133,18 +247,24 @@ png_crc_error(png_structp png_ptr) png_uint_32 crc; int need_crc = 1; - if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ + if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name)) { if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) need_crc = 0; } - else /* critical */ + + else /* critical */ { if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) need_crc = 0; } +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC; +#endif + + /* The chunk CRC must be serialized in a single I/O call. */ png_read_data(png_ptr, crc_bytes, 4); if (need_crc) @@ -152,178 +272,255 @@ png_crc_error(png_structp png_ptr) crc = png_get_uint_32(crc_bytes); return ((int)(crc != png_ptr->crc)); } + else return (0); } -#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \ - defined(PNG_READ_iCCP_SUPPORTED) -/* - * Decompress trailing data in a chunk. The assumption is that chunkdata - * points at an allocated area holding the contents of a chunk with a - * trailing compressed part. What we get back is an allocated area - * holding the original prefix part and an uncompressed version of the - * trailing part (the malloc area passed in is freed). - */ -png_charp /* PRIVATE */ -png_decompress_chunk(png_structp png_ptr, int comp_type, - png_charp chunkdata, png_size_t chunklength, - png_size_t prefix_size, png_size_t *newlength) +#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED +static png_size_t +png_inflate(png_structp png_ptr, png_bytep data, png_size_t size, + png_bytep output, png_size_t output_size) { - static char msg[] = "Error decoding compressed text"; - png_charp text = NULL; - png_size_t text_size; + png_size_t count = 0; + + /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it can't + * even necessarily handle 65536 bytes) because the type uInt is "16 bits or + * more". Consequently it is necessary to chunk the input to zlib. This + * code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the maximum value + * that can be stored in a uInt.) It is possible to set ZLIB_IO_MAX to a + * lower value in pngpriv.h and this may sometimes have a performance + * advantage, because it forces access of the input data to be separated from + * at least some of the use by some period of time. + */ + png_ptr->zstream.next_in = data; + /* avail_in is set below from 'size' */ + png_ptr->zstream.avail_in = 0; - if (comp_type == PNG_COMPRESSION_TYPE_BASE) + while (1) { - int ret = Z_OK; - png_ptr->zstream.next_in = (png_bytep)(chunkdata + prefix_size); - png_ptr->zstream.avail_in = (uInt)(chunklength - prefix_size); + int ret, avail; + + /* The setting of 'avail_in' used to be outside the loop; by setting it + * inside it is possible to chunk the input to zlib and simply rely on + * zlib to advance the 'next_in' pointer. This allows arbitrary amounts o + * data to be passed through zlib at the unavoidable cost of requiring a + * window save (memcpy of up to 32768 output bytes) every ZLIB_IO_MAX + * input bytes. + */ + if (png_ptr->zstream.avail_in == 0 && size > 0) + { + if (size <= ZLIB_IO_MAX) + { + /* The value is less than ZLIB_IO_MAX so the cast is safe: */ + png_ptr->zstream.avail_in = (uInt)size; + size = 0; + } + + else + { + png_ptr->zstream.avail_in = ZLIB_IO_MAX; + size -= ZLIB_IO_MAX; + } + } + + /* Reset the output buffer each time round - we empty it + * after every inflate call. + */ png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.avail_out = png_ptr->zbuf_size; - text_size = 0; - text = NULL; + ret = inflate(&png_ptr->zstream, Z_NO_FLUSH); + avail = png_ptr->zbuf_size - png_ptr->zstream.avail_out; - while (png_ptr->zstream.avail_in) + /* First copy/count any new output - but only if we didn't + * get an error code. + */ + if ((ret == Z_OK || ret == Z_STREAM_END) && avail > 0) { - ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); - if (ret != Z_OK && ret != Z_STREAM_END) - { - if (png_ptr->zstream.msg != NULL) - png_warning(png_ptr, png_ptr->zstream.msg); - else - png_warning(png_ptr, msg); - inflateReset(&png_ptr->zstream); - png_ptr->zstream.avail_in = 0; + png_size_t space = avail; /* > 0, see above */ - if (text == NULL) - { - text_size = prefix_size + sizeof(msg) + 1; - text = (png_charp)png_malloc_warn(png_ptr, text_size); - if (text == NULL) - { - png_free(png_ptr,chunkdata); - png_error(png_ptr,"Not enough memory to decompress chunk"); - } - png_memcpy(text, chunkdata, prefix_size); - } + if (output != 0 && output_size > count) + { + png_size_t copy = output_size - count; - text[text_size - 1] = 0x00; + if (space < copy) + copy = space; - /* Copy what we can of the error message into the text chunk */ - text_size = (png_size_t)(chunklength - (text - chunkdata) - 1); - text_size = sizeof(msg) > text_size ? text_size : sizeof(msg); - png_memcpy(text + prefix_size, msg, text_size + 1); - break; + png_memcpy(output + count, png_ptr->zbuf, copy); } - if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END) + count += space; + } + + if (ret == Z_OK) + continue; + + /* Termination conditions - always reset the zstream, it + * must be left in inflateInit state. + */ + png_ptr->zstream.avail_in = 0; + inflateReset(&png_ptr->zstream); + + if (ret == Z_STREAM_END) + return count; /* NOTE: may be zero. */ + + /* Now handle the error codes - the API always returns 0 + * and the error message is dumped into the uncompressed + * buffer if available. + */ +# ifdef PNG_WARNINGS_SUPPORTED + { + png_const_charp msg; + + if (png_ptr->zstream.msg != 0) + msg = png_ptr->zstream.msg; + + else switch (ret) { - if (text == NULL) - { - text_size = prefix_size + - png_ptr->zbuf_size - png_ptr->zstream.avail_out; - text = (png_charp)png_malloc_warn(png_ptr, text_size + 1); - if (text == NULL) - { - png_free(png_ptr,chunkdata); - png_error(png_ptr,"Not enough memory to decompress chunk."); - } - png_memcpy(text + prefix_size, png_ptr->zbuf, - text_size - prefix_size); - png_memcpy(text, chunkdata, prefix_size); - *(text + text_size) = 0x00; - } - else - { - png_charp tmp; + case Z_BUF_ERROR: + msg = "Buffer error in compressed datastream"; + break; - tmp = text; - text = (png_charp)png_malloc_warn(png_ptr, - (png_uint_32)(text_size + - png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1)); - if (text == NULL) - { - png_free(png_ptr, tmp); - png_free(png_ptr, chunkdata); - png_error(png_ptr,"Not enough memory to decompress chunk.."); - } - png_memcpy(text, tmp, text_size); - png_free(png_ptr, tmp); - png_memcpy(text + text_size, png_ptr->zbuf, - (png_ptr->zbuf_size - png_ptr->zstream.avail_out)); - text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out; - *(text + text_size) = 0x00; - } - if (ret == Z_STREAM_END) + case Z_DATA_ERROR: + msg = "Data error in compressed datastream"; + break; + + default: + msg = "Incomplete compressed datastream"; break; - else - { - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - } } + + png_chunk_warning(png_ptr, msg); } - if (ret != Z_STREAM_END) - { -#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE) - char umsg[50]; - - if (ret == Z_BUF_ERROR) - sprintf(umsg,"Buffer error in compressed datastream in %s chunk", - png_ptr->chunk_name); - else if (ret == Z_DATA_ERROR) - sprintf(umsg,"Data error in compressed datastream in %s chunk", - png_ptr->chunk_name); - else - sprintf(umsg,"Incomplete compressed datastream in %s chunk", - png_ptr->chunk_name); - png_warning(png_ptr, umsg); +# endif + + /* 0 means an error - notice that this code simply ignores + * zero length compressed chunks as a result. + */ + return 0; + } +} + +/* + * Decompress trailing data in a chunk. The assumption is that chunkdata + * points at an allocated area holding the contents of a chunk with a + * trailing compressed part. What we get back is an allocated area + * holding the original prefix part and an uncompressed version of the + * trailing part (the malloc area passed in is freed). + */ +void /* PRIVATE */ +png_decompress_chunk(png_structp png_ptr, int comp_type, + png_size_t chunklength, + png_size_t prefix_size, png_size_t *newlength) +{ + /* The caller should guarantee this */ + if (prefix_size > chunklength) + { + /* The recovery is to delete the chunk. */ + png_warning(png_ptr, "invalid chunklength"); + prefix_size = 0; /* To delete everything */ + } + + else if (comp_type == PNG_COMPRESSION_TYPE_BASE) + { + png_size_t expanded_size = png_inflate(png_ptr, + (png_bytep)(png_ptr->chunkdata + prefix_size), + chunklength - prefix_size, + 0, /* output */ + 0); /* output size */ + + /* Now check the limits on this chunk - if the limit fails the + * compressed data will be removed, the prefix will remain. + */ +#ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED + if (png_ptr->user_chunk_malloc_max && + (prefix_size + expanded_size >= png_ptr->user_chunk_malloc_max - 1)) #else - png_warning(png_ptr, - "Incomplete compressed datastream in chunk other than IDAT"); +# ifdef PNG_USER_CHUNK_MALLOC_MAX + if ((PNG_USER_CHUNK_MALLOC_MAX > 0) && + prefix_size + expanded_size >= PNG_USER_CHUNK_MALLOC_MAX - 1) +# endif #endif - text_size=prefix_size; - if (text == NULL) + png_warning(png_ptr, "Exceeded size limit while expanding chunk"); + + /* If the size is zero either there was an error and a message + * has already been output (warning) or the size really is zero + * and we have nothing to do - the code will exit through the + * error case below. + */ +#if defined(PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED) || \ + defined(PNG_USER_CHUNK_MALLOC_MAX) + else if (expanded_size > 0) +#else + if (expanded_size > 0) +#endif + { + /* Success (maybe) - really uncompress the chunk. */ + png_size_t new_size = 0; + png_charp text = (png_charp)png_malloc_warn(png_ptr, + prefix_size + expanded_size + 1); + + if (text != NULL) { - text = (png_charp)png_malloc_warn(png_ptr, text_size+1); - if (text == NULL) - { - png_free(png_ptr, chunkdata); - png_error(png_ptr,"Not enough memory for text."); - } - png_memcpy(text, chunkdata, prefix_size); + png_memcpy(text, png_ptr->chunkdata, prefix_size); + new_size = png_inflate(png_ptr, + (png_bytep)(png_ptr->chunkdata + prefix_size), + chunklength - prefix_size, + (png_bytep)(text + prefix_size), expanded_size); + text[prefix_size + expanded_size] = 0; /* just in case */ + + if (new_size == expanded_size) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = text; + *newlength = prefix_size + expanded_size; + return; /* The success return! */ + } + + png_warning(png_ptr, "png_inflate logic error"); + png_free(png_ptr, text); } - *(text + text_size) = 0x00; + + else + png_warning(png_ptr, "Not enough memory to decompress chunk"); } + } - inflateReset(&png_ptr->zstream); - png_ptr->zstream.avail_in = 0; + else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */ + { + PNG_WARNING_PARAMETERS(p) + png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, comp_type); + png_formatted_warning(png_ptr, p, "Unknown compression type @1"); - png_free(png_ptr, chunkdata); - chunkdata = text; - *newlength=text_size; + /* The recovery is to simply drop the data. */ } - else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */ + + /* Generic error return - leave the prefix, delete the compressed + * data, reallocate the chunkdata to remove the potentially large + * amount of compressed data. + */ { -#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE) - char umsg[50]; + png_charp text = (png_charp)png_malloc_warn(png_ptr, prefix_size + 1); - sprintf(umsg, "Unknown zTXt compression type %d", comp_type); - png_warning(png_ptr, umsg); -#else - png_warning(png_ptr, "Unknown zTXt compression type"); -#endif + 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; - *(chunkdata + prefix_size) = 0x00; - *newlength=prefix_size; + /* This is an extra zero in the 'uncompressed' part. */ + *(png_ptr->chunkdata + prefix_size) = 0x00; + } + /* Ignore a malloc error here - it is safe. */ } - return chunkdata; + *newlength = prefix_size; } -#endif +#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */ -/* read and check the IDHR chunk */ +/* Read and check the IDHR chunk */ void /* PRIVATE */ png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { @@ -332,12 +529,12 @@ png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) int bit_depth, color_type, compression_type, filter_type; int interlace_type; - png_debug(1, "in png_handle_IHDR\n"); + 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 */ + /* Check the length */ if (length != 13) png_error(png_ptr, "Invalid IHDR chunk"); @@ -346,75 +543,80 @@ png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_crc_read(png_ptr, buf, 13); png_crc_finish(png_ptr, 0); - width = png_get_uint_32(buf); - height = png_get_uint_32(buf + 4); + 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 */ + /* 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; -#if defined(PNG_MNG_FEATURES_SUPPORTED) +#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 */ + /* 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 */ + /* Set up other useful info */ png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * png_ptr->channels); - png_ptr->rowbytes = ((png_ptr->width * - (png_uint_32)png_ptr->pixel_depth + 7) >> 3); - png_debug1(3,"bit_depth = %d\n", png_ptr->bit_depth); - png_debug1(3,"channels = %d\n", png_ptr->channels); - png_debug1(3,"rowbytes = %lu\n", png_ptr->rowbytes); + 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); + color_type, interlace_type, compression_type, filter_type); } -/* read and check the palette */ +/* 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; -#ifndef PNG_NO_POINTER_INDEXING +#ifdef PNG_POINTER_INDEXING_SUPPORTED png_colorp pal_ptr; #endif - png_debug(1, "in png_handle_PLTE\n"); + 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"); @@ -423,11 +625,12 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR)) { png_warning(png_ptr, - "Ignoring PLTE chunk in grayscale PNG"); + "Ignoring PLTE chunk in grayscale PNG"); png_crc_finish(png_ptr, length); return; } -#if !defined(PNG_READ_OPT_PLTE_SUPPORTED) + +#ifndef PNG_READ_OPT_PLTE_SUPPORTED if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) { png_crc_finish(png_ptr, length); @@ -443,6 +646,7 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_crc_finish(png_ptr, length); return; } + else { png_error(png_ptr, "Invalid palette chunk"); @@ -451,7 +655,7 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) num = (int)length / 3; -#ifndef PNG_NO_POINTER_INDEXING +#ifdef PNG_POINTER_INDEXING_SUPPORTED for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++) { png_byte buf[3]; @@ -467,42 +671,47 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_byte buf[3]; png_crc_read(png_ptr, buf, 3); - /* don't depend upon png_color being any order */ + /* 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. */ -#if !defined(PNG_READ_OPT_PLTE_SUPPORTED) + /* 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); } -#if !defined(PNG_READ_OPT_PLTE_SUPPORTED) + +#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). */ + * 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_error(png_ptr, "CRC error"); + 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)) { @@ -513,7 +722,7 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_set_PLTE(png_ptr, info_ptr, palette, num); -#if defined(PNG_READ_tRNS_SUPPORTED) +#ifdef PNG_READ_tRNS_SUPPORTED if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS)) @@ -523,6 +732,7 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) 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"); @@ -537,13 +747,11 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) void /* PRIVATE */ png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { - png_debug(1, "in png_handle_IEND\n"); + 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"); - - info_ptr = info_ptr; /* quiet compiler warnings about unused info_ptr */ } png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND); @@ -552,38 +760,40 @@ png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { 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 */ } -#if defined(PNG_READ_gAMA_SUPPORTED) +#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; -#ifdef PNG_FLOATING_POINT_SUPPORTED - float file_gamma; -#endif png_byte buf[4]; - png_debug(1, "in png_handle_gAMA\n"); + 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"); - else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA) -#if defined(PNG_READ_sRGB_SUPPORTED) - && !(info_ptr->valid & PNG_INFO_sRGB) + 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); @@ -598,69 +808,72 @@ png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } png_crc_read(png_ptr, buf, 4); + if (png_crc_finish(png_ptr, 0)) return; - igamma = (png_fixed_point)png_get_uint_32(buf); - /* check for zero gamma */ - if (igamma == 0) - { - png_warning(png_ptr, - "Ignoring gAMA chunk with gamma=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; + } -#if defined(PNG_READ_sRGB_SUPPORTED) - if (info_ptr->valid & PNG_INFO_sRGB) - if(igamma < 45000L || igamma > 46000L) +# ifdef PNG_READ_sRGB_SUPPORTED + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)) + { + if (PNG_OUT_OF_RANGE(igamma, 45500, 500)) { - png_warning(png_ptr, - "Ignoring incorrect gAMA value when sRGB is also present"); -#ifndef PNG_NO_CONSOLE_IO - fprintf(stderr, "gamma = (%d/100000)\n", (int)igamma); -#endif + 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 */ + } +# endif /* PNG_READ_sRGB_SUPPORTED */ -#ifdef PNG_FLOATING_POINT_SUPPORTED - file_gamma = (float)igamma / (float)100000.0; # ifdef PNG_READ_GAMMA_SUPPORTED - png_ptr->gamma = file_gamma; + /* Gamma correction on read is supported. */ + png_ptr->gamma = igamma; # endif - png_set_gAMA(png_ptr, info_ptr, file_gamma); -#endif -#ifdef PNG_FIXED_POINT_SUPPORTED + /* And set the 'info' structure members. */ png_set_gAMA_fixed(png_ptr, info_ptr, igamma); -#endif } #endif -#if defined(PNG_READ_sBIT_SUPPORTED) +#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\n"); + 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"); } - else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)) + + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)) { png_warning(png_ptr, "Duplicate sBIT chunk"); png_crc_finish(png_ptr, length); @@ -669,10 +882,11 @@ png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) truelen = 3; + else truelen = (png_size_t)png_ptr->channels; - if (length != truelen) + if (length != truelen || length > 4) { png_warning(png_ptr, "Incorrect sBIT chunk length"); png_crc_finish(png_ptr, length); @@ -680,6 +894,7 @@ png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } png_crc_read(png_ptr, buf, truelen); + if (png_crc_finish(png_ptr, 0)) return; @@ -690,6 +905,7 @@ png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_ptr->sig_bit.blue = buf[2]; png_ptr->sig_bit.alpha = buf[3]; } + else { png_ptr->sig_bit.gray = buf[0]; @@ -698,41 +914,39 @@ png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) 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 -#if defined(PNG_READ_cHRM_SUPPORTED) +#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[4]; -#ifdef PNG_FLOATING_POINT_SUPPORTED - float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y; -#endif - png_fixed_point int_x_white, int_y_white, int_x_red, int_y_red, int_x_green, - int_y_green, int_x_blue, int_y_blue; + png_byte buf[32]; + png_fixed_point x_white, y_white, x_red, y_red, x_green, y_green, x_blue, + y_blue; - png_uint_32 uint_x, uint_y; - - png_debug(1, "in png_handle_cHRM\n"); + 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"); + png_warning(png_ptr, "Out of place cHRM chunk"); - else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM) -#if defined(PNG_READ_sRGB_SUPPORTED) - && !(info_ptr->valid & PNG_INFO_sRGB) -#endif + 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"); @@ -747,151 +961,173 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - png_crc_read(png_ptr, buf, 4); - uint_x = png_get_uint_32(buf); - - png_crc_read(png_ptr, buf, 4); - uint_y = png_get_uint_32(buf); + png_crc_read(png_ptr, buf, 32); - if (uint_x > 80000L || uint_y > 80000L || - uint_x + uint_y > 100000L) - { - png_warning(png_ptr, "Invalid cHRM white point"); - png_crc_finish(png_ptr, 24); + if (png_crc_finish(png_ptr, 0)) return; - } - int_x_white = (png_fixed_point)uint_x; - int_y_white = (png_fixed_point)uint_y; - - png_crc_read(png_ptr, buf, 4); - uint_x = png_get_uint_32(buf); - - png_crc_read(png_ptr, buf, 4); - uint_y = png_get_uint_32(buf); - if (uint_x > 80000L || uint_y > 80000L || - uint_x + uint_y > 100000L) + 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, "Invalid cHRM red point"); - png_crc_finish(png_ptr, 16); + png_warning(png_ptr, "Ignoring cHRM chunk with negative chromaticities"); return; } - int_x_red = (png_fixed_point)uint_x; - int_y_red = (png_fixed_point)uint_y; - - png_crc_read(png_ptr, buf, 4); - uint_x = png_get_uint_32(buf); - - png_crc_read(png_ptr, buf, 4); - uint_y = png_get_uint_32(buf); - if (uint_x > 80000L || uint_y > 80000L || - uint_x + uint_y > 100000L) +#ifdef PNG_READ_sRGB_SUPPORTED + if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB)) { - png_warning(png_ptr, "Invalid cHRM green point"); - png_crc_finish(png_ptr, 8); + if (PNG_OUT_OF_RANGE(x_white, 31270, 1000) || + PNG_OUT_OF_RANGE(y_white, 32900, 1000) || + PNG_OUT_OF_RANGE(x_red, 64000, 1000) || + PNG_OUT_OF_RANGE(y_red, 33000, 1000) || + PNG_OUT_OF_RANGE(x_green, 30000, 1000) || + PNG_OUT_OF_RANGE(y_green, 60000, 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; } - int_x_green = (png_fixed_point)uint_x; - int_y_green = (png_fixed_point)uint_y; - - png_crc_read(png_ptr, buf, 4); - uint_x = png_get_uint_32(buf); - - png_crc_read(png_ptr, buf, 4); - uint_y = png_get_uint_32(buf); +#endif /* PNG_READ_sRGB_SUPPORTED */ - if (uint_x > 80000L || uint_y > 80000L || - uint_x + uint_y > 100000L) +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* Store the _white values as default coefficients for the rgb to gray + * operation if it is supported. Check if the transform is already set to + * avoid destroying the transform values. + */ + if (!png_ptr->rgb_to_gray_coefficients_set) { - png_warning(png_ptr, "Invalid cHRM blue point"); - png_crc_finish(png_ptr, 0); - return; - } - int_x_blue = (png_fixed_point)uint_x; - int_y_blue = (png_fixed_point)uint_y; - -#ifdef PNG_FLOATING_POINT_SUPPORTED - white_x = (float)int_x_white / (float)100000.0; - white_y = (float)int_y_white / (float)100000.0; - red_x = (float)int_x_red / (float)100000.0; - red_y = (float)int_y_red / (float)100000.0; - green_x = (float)int_x_green / (float)100000.0; - green_y = (float)int_y_green / (float)100000.0; - blue_x = (float)int_x_blue / (float)100000.0; - blue_y = (float)int_y_blue / (float)100000.0; -#endif - -#if defined(PNG_READ_sRGB_SUPPORTED) - if (info_ptr->valid & PNG_INFO_sRGB) + /* png_set_background has not been called and we haven't seen an sRGB + * chunk yet. Find the XYZ of the three end points. + */ + png_XYZ XYZ; + png_xy xy; + + xy.redx = x_red; + xy.redy = y_red; + xy.greenx = x_green; + xy.greeny = y_green; + xy.bluex = x_blue; + xy.bluey = y_blue; + xy.whitex = x_white; + xy.whitey = y_white; + + if (png_XYZ_from_xy_checked(png_ptr, &XYZ, xy)) { - if (abs(int_x_white - 31270L) > 1000 || - abs(int_y_white - 32900L) > 1000 || - abs(int_x_red - 64000L) > 1000 || - abs(int_y_red - 33000L) > 1000 || - abs(int_x_green - 30000L) > 1000 || - abs(int_y_green - 60000L) > 1000 || - abs(int_x_blue - 15000L) > 1000 || - abs(int_y_blue - 6000L) > 1000) + /* The success case, because XYZ_from_xy normalises to a reference + * white Y of 1.0 we just need to scale the numbers. This should + * always work just fine. It is an internal error if this overflows. + */ { + png_fixed_point r, g, b; + if (png_muldiv(&r, XYZ.redY, 32768, PNG_FP_1) && + r >= 0 && r <= 32768 && + png_muldiv(&g, XYZ.greenY, 32768, PNG_FP_1) && + g >= 0 && g <= 32768 && + png_muldiv(&b, XYZ.blueY, 32768, PNG_FP_1) && + b >= 0 && b <= 32768 && + r+g+b <= 32769) + { + /* We allow 0 coefficients here. r+g+b may be 32769 if two or + * all of the coefficients were rounded up. Handle this by + * reducing the *largest* coefficient by 1; this matches the + * approach used for the default coefficients in pngrtran.c + */ + int add = 0; + + if (r+g+b > 32768) + add = -1; + else if (r+g+b < 32768) + add = 1; + + if (add != 0) + { + if (g >= r && g >= b) + g += add; + else if (r >= g && r >= b) + r += add; + else + b += add; + } - png_warning(png_ptr, - "Ignoring incorrect cHRM value when sRGB is also present"); -#ifndef PNG_NO_CONSOLE_IO -#ifdef PNG_FLOATING_POINT_SUPPORTED - fprintf(stderr,"wx=%f, wy=%f, rx=%f, ry=%f\n", - white_x, white_y, red_x, red_y); - fprintf(stderr,"gx=%f, gy=%f, bx=%f, by=%f\n", - green_x, green_y, blue_x, blue_y); -#else - fprintf(stderr,"wx=%ld, wy=%ld, rx=%ld, ry=%ld\n", - int_x_white, int_y_white, int_x_red, int_y_red); - fprintf(stderr,"gx=%ld, gy=%ld, bx=%ld, by=%ld\n", - int_x_green, int_y_green, int_x_blue, int_y_blue); -#endif -#endif /* PNG_NO_CONSOLE_IO */ + /* Check for an internal error. */ + if (r+g+b != 32768) + png_error(png_ptr, + "internal error handling cHRM coefficients"); + + png_ptr->rgb_to_gray_red_coeff = (png_uint_16)r; + png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g; + } + + /* This is a png_error at present even though it could be ignored - + * it should never happen, but it is important that if it does, the + * bug is fixed. + */ + else + png_error(png_ptr, "internal error handling cHRM->XYZ"); } - png_crc_finish(png_ptr, 0); - return; } -#endif /* PNG_READ_sRGB_SUPPORTED */ - -#ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_cHRM(png_ptr, info_ptr, - white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y); -#endif -#ifdef PNG_FIXED_POINT_SUPPORTED - png_set_cHRM_fixed(png_ptr, info_ptr, - int_x_white, int_y_white, int_x_red, int_y_red, int_x_green, - int_y_green, int_x_blue, int_y_blue); + } #endif - if (png_crc_finish(png_ptr, 0)) - return; + + 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 -#if defined(PNG_READ_sRGB_SUPPORTED) +#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\n"); + 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"); - else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)) + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)) { png_warning(png_ptr, "Duplicate sRGB chunk"); png_crc_finish(png_ptr, length); @@ -906,11 +1142,13 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } png_crc_read(png_ptr, buf, 1); + if (png_crc_finish(png_ptr, 0)) return; intent = buf[0]; - /* check for bad intent */ + + /* Check for bad intent */ if (intent >= PNG_sRGB_INTENT_LAST) { png_warning(png_ptr, "Unknown sRGB intent"); @@ -918,84 +1156,112 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } #if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) - if ((info_ptr->valid & PNG_INFO_gAMA)) + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)) { - int igamma; -#ifdef PNG_FIXED_POINT_SUPPORTED - igamma=(int)info_ptr->int_gamma; -#else -# ifdef PNG_FLOATING_POINT_SUPPORTED - igamma=(int)(info_ptr->gamma * 100000.); -# endif -#endif - if(igamma < 45000L || igamma > 46000L) + if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500, 500)) { - png_warning(png_ptr, - "Ignoring incorrect gAMA value when sRGB is also present"); -#ifndef PNG_NO_CONSOLE_IO -# ifdef PNG_FIXED_POINT_SUPPORTED - fprintf(stderr,"incorrect gamma=(%d/100000)\n",(int)png_ptr->int_gamma); -# else -# ifdef PNG_FLOATING_POINT_SUPPORTED - fprintf(stderr,"incorrect gamma=%f\n",png_ptr->gamma); -# endif -# endif -#endif + 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 -#ifdef PNG_FIXED_POINT_SUPPORTED - if (info_ptr->valid & PNG_INFO_cHRM) - if (abs(info_ptr->int_x_white - 31270L) > 1000 || - abs(info_ptr->int_y_white - 32900L) > 1000 || - abs(info_ptr->int_x_red - 64000L) > 1000 || - abs(info_ptr->int_y_red - 33000L) > 1000 || - abs(info_ptr->int_x_green - 30000L) > 1000 || - abs(info_ptr->int_y_green - 60000L) > 1000 || - abs(info_ptr->int_x_blue - 15000L) > 1000 || - abs(info_ptr->int_y_blue - 6000L) > 1000) - { - png_warning(png_ptr, - "Ignoring incorrect cHRM value when sRGB is also present"); - } -#endif /* PNG_FIXED_POINT_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, 64000, 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, 60000, 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 */ + /* This is recorded for use when handling the cHRM chunk above. An sRGB + * chunk unconditionally overwrites the coefficients for grayscale conversion + * too. + */ + png_ptr->is_sRGB = 1; + +# ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* Don't overwrite user supplied values: */ + if (!png_ptr->rgb_to_gray_coefficients_set) + { + /* These numbers come from the sRGB specification (or, since one has to + * pay much money to get a copy, the wikipedia sRGB page) the + * chromaticity values quoted have been inverted to get the reverse + * transformation from RGB to XYZ and the 'Y' coefficients scaled by + * 32768 (then rounded). + * + * sRGB and ITU Rec-709 both truncate the values for the D65 white + * point to four digits and, even though it actually stores five + * digits, the PNG spec gives the truncated value. + * + * This means that when the chromaticities are converted back to XYZ + * end points we end up with (6968,23435,2366), which, as described in + * pngrtran.c, would overflow. If the five digit precision and up is + * used we get, instead: + * + * 6968*R + 23435*G + 2365*B + * + * (Notice that this rounds the blue coefficient down, rather than the + * choice used in pngrtran.c which is to round the green one down.) + */ + png_ptr->rgb_to_gray_red_coeff = 6968; /* 0.212639005871510 */ + png_ptr->rgb_to_gray_green_coeff = 23434; /* 0.715168678767756 */ + /* png_ptr->rgb_to_gray_blue_coeff = 2366; 0.072192315360734 */ + + /* The following keeps the cHRM chunk from destroying the + * coefficients again in the event that it follows the sRGB chunk. + */ + png_ptr->rgb_to_gray_coefficients_set = 1; + } +# endif + png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent); } #endif /* PNG_READ_sRGB_SUPPORTED */ -#if defined(PNG_READ_iCCP_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_charp chunkdata; png_byte compression_type; png_bytep pC; png_charp profile; png_uint_32 skip = 0; - png_uint_32 profile_size = 0; - png_uint_32 profile_length = 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\n"); + 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"); - else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)) + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)) { png_warning(png_ptr, "Duplicate iCCP chunk"); png_crc_finish(png_ptr, length); @@ -1011,96 +1277,135 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } #endif - chunkdata = (png_charp)png_malloc(png_ptr, length + 1); + 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)chunkdata, slength); + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, skip)) { - png_free(png_ptr, chunkdata); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; return; } - chunkdata[slength] = 0x00; + png_ptr->chunkdata[slength] = 0x00; - for (profile = chunkdata; *profile; profile++) - /* empty loop to find end of name */ ; + 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 >= chunkdata + slength) + /* 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, chunkdata); + 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 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 + compression_type = 0x00; /* Reset it to zero (libpng-1.0.6 through 1.0.8 wrote nonzero) */ } - prefix_length = profile - chunkdata; - chunkdata = png_decompress_chunk(png_ptr, compression_type, chunkdata, - slength, prefix_length, &data_length); + 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) + if (prefix_length > data_length || profile_length < 4) { - png_free(png_ptr, chunkdata); + 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)(chunkdata+prefix_length); - profile_size = ((*(pC ))<<24) | - ((*(pC+1))<<16) | - ((*(pC+2))<< 8) | - ((*(pC+3)) ); - - if(profile_size < profile_length) + 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; - if(profile_size > profile_length) + /* And the following guarantees that profile_size == profile_length. */ + if (profile_size > profile_length) { - png_free(png_ptr, chunkdata); - png_warning(png_ptr, "Ignoring truncated iCCP profile.\n"); + 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, chunkdata, compression_type, - chunkdata + prefix_length, profile_length); - png_free(png_ptr, chunkdata); + 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 */ -#if defined(PNG_READ_sPLT_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 chunkdata; png_bytep entry_start; png_sPLT_t new_palette; -#ifdef PNG_NO_POINTER_INDEXING png_sPLT_entryp pp; -#endif - int data_length, entry_size, i; + 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; + } - png_debug(1, "in png_handle_sPLT\n"); + 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"); @@ -1117,116 +1422,156 @@ png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } #endif - chunkdata = (png_bytep)png_malloc(png_ptr, length + 1); + 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)chunkdata, slength); + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, skip)) { - png_free(png_ptr, chunkdata); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; return; } - chunkdata[slength] = 0x00; + png_ptr->chunkdata[slength] = 0x00; + + for (entry_start = (png_bytep)png_ptr->chunkdata; *entry_start; + entry_start++) + /* Empty loop to find end of name */ ; - for (entry_start = 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 > chunkdata + slength) + /* 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, chunkdata); + 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); - data_length = (slength - (entry_start - chunkdata)); - - /* integrity-check the data length */ + /* 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, chunkdata); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; png_warning(png_ptr, "sPLT chunk has bad length"); return; } - new_palette.nentries = data_length / entry_size; - new_palette.entries = (png_sPLT_entryp)png_malloc( - png_ptr, new_palette.nentries * sizeof(png_sPLT_entry)); + 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; + } -#ifndef PNG_NO_POINTER_INDEXING +#ifdef PNG_POINTER_INDEXING_SUPPORTED for (i = 0; i < new_palette.nentries; i++) { - png_sPLT_entryp pp = new_palette.entries + 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++; + 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->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++; + 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].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->frequency = png_get_uint_16(entry_start); entry_start += 2; + + pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2; } #endif - /* discard all chunk data except the name and stash that */ - new_palette.name = (png_charp)chunkdata; + /* 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, chunkdata); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; png_free(png_ptr, new_palette.entries); } #endif /* PNG_READ_sPLT_SUPPORTED */ -#if defined(PNG_READ_tRNS_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\n"); + 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"); @@ -1234,29 +1579,22 @@ png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) { - 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"); - } - else if (length > (png_uint_32)png_ptr->num_palette) + png_byte buf[2]; + + if (length != 2) { 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; + 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]; @@ -1270,25 +1608,38 @@ png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_crc_read(png_ptr, buf, (png_size_t)length); png_ptr->num_trans = 1; - png_ptr->trans_values.red = png_get_uint_16(buf); - png_ptr->trans_values.green = png_get_uint_16(buf + 2); - png_ptr->trans_values.blue = png_get_uint_16(buf + 4); + 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_GRAY) + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { - png_byte buf[6]; + 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 != 2) + 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; } - png_crc_read(png_ptr, buf, 2); - png_ptr->num_trans = 1; - png_ptr->trans_values.gray = png_get_uint_16(buf); + 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"); @@ -1297,37 +1648,44 @@ png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } 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_values)); + &(png_ptr->trans_color)); } #endif -#if defined(PNG_READ_bKGD_SUPPORTED) +#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\n"); + 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_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"); @@ -1337,8 +1695,10 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) 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; @@ -1350,72 +1710,86 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } 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. */ + * from the info_ptr struct. + */ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { - png_ptr->background.index = buf[0]; - if(info_ptr->num_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; - } - png_ptr->background.red = - (png_uint_16)png_ptr->palette[buf[0]].red; - png_ptr->background.green = - (png_uint_16)png_ptr->palette[buf[0]].green; - png_ptr->background.blue = - (png_uint_16)png_ptr->palette[buf[0]].blue; + 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 */ { - png_ptr->background.red = - png_ptr->background.green = - png_ptr->background.blue = - png_ptr->background.gray = png_get_uint_16(buf); + background.index = 0; + background.red = + background.green = + background.blue = + background.gray = png_get_uint_16(buf); } + else { - png_ptr->background.red = png_get_uint_16(buf); - png_ptr->background.green = png_get_uint_16(buf + 2); - png_ptr->background.blue = png_get_uint_16(buf + 4); + 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, &(png_ptr->background)); + png_set_bKGD(png_ptr, info_ptr, &background); } #endif -#if defined(PNG_READ_hIST_SUPPORTED) +#ifdef PNG_READ_hIST_SUPPORTED void /* PRIVATE */ png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { - int num, i; + unsigned int num, i; png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH]; - png_debug(1, "in png_handle_hIST\n"); + 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"); @@ -1423,8 +1797,10 @@ png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - num = (int)length / 2 ; - if (num != png_ptr->num_palette) + 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); @@ -1446,7 +1822,7 @@ png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } #endif -#if defined(PNG_READ_pHYs_SUPPORTED) +#ifdef PNG_READ_pHYs_SUPPORTED void /* PRIVATE */ png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { @@ -1454,16 +1830,18 @@ png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_uint_32 res_x, res_y; int unit_type; - png_debug(1, "in png_handle_pHYs\n"); + 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"); @@ -1479,6 +1857,7 @@ png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } png_crc_read(png_ptr, buf, 9); + if (png_crc_finish(png_ptr, 0)) return; @@ -1489,7 +1868,7 @@ png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } #endif -#if defined(PNG_READ_oFFs_SUPPORTED) +#ifdef PNG_READ_oFFs_SUPPORTED void /* PRIVATE */ png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { @@ -1497,16 +1876,18 @@ png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_int_32 offset_x, offset_y; int unit_type; - png_debug(1, "in png_handle_oFFs\n"); + 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"); @@ -1522,6 +1903,7 @@ png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } png_crc_read(png_ptr, buf, 9); + if (png_crc_finish(png_ptr, 0)) return; @@ -1532,12 +1914,11 @@ png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } #endif -#if defined(PNG_READ_pCAL_SUPPORTED) -/* read the pCAL chunk (described in the PNG Extensions document) */ +#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_charp purpose; png_int_32 X0, X1; png_byte type, nparams; png_charp buf, units, endptr; @@ -1545,16 +1926,18 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_size_t slength; int i; - png_debug(1, "in png_handle_pCAL\n"); + 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"); @@ -1562,59 +1945,68 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - png_debug1(2, "Allocating and reading pCAL chunk data (%lu bytes)\n", - length + 1); - purpose = (png_charp)png_malloc_warn(png_ptr, length + 1); - if (purpose == NULL) - { - png_warning(png_ptr, "No memory for pCAL purpose."); - 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)purpose, slength); + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, 0)) { - png_free(png_ptr, purpose); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; return; } - purpose[slength] = 0x00; /* null terminate the last string */ + png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */ - png_debug(3, "Finding end of pCAL purpose string\n"); - for (buf = purpose; *buf; buf++) - /* empty loop */ ; + png_debug(3, "Finding end of pCAL purpose string"); + for (buf = png_ptr->chunkdata; *buf; buf++) + /* Empty loop */ ; - endptr = purpose + slength; + endptr = png_ptr->chunkdata + slength; /* We need to have at least 12 bytes after the purpose string - in order to get the parameter information. */ + * in order to get the parameter information. + */ if (endptr <= buf + 12) { png_warning(png_ptr, "Invalid pCAL data"); - png_free(png_ptr, purpose); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; return; } - png_debug(3, "Reading pCAL X0, X1, type, nparams, and units\n"); + 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\n"); + png_debug(3, "Checking pCAL equation type and number of parameters"); /* Check that we have the right number of parameters for known - equation types. */ + * 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, purpose); + 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"); @@ -1623,69 +2015,69 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) for (buf = units; *buf; buf++) /* Empty loop to move past the units string. */ ; - png_debug(3, "Allocating pCAL parameters array\n"); - params = (png_charpp)png_malloc_warn(png_ptr, (png_uint_32)(nparams - *sizeof(png_charp))) ; + 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, purpose); - png_warning(png_ptr, "No memory for pCAL params."); - return; - } + { + 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\n", i); - for (params[i] = buf; *buf != 0x00 && buf <= endptr; buf++) + 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, purpose); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; png_free(png_ptr, params); return; } } - png_set_pCAL(png_ptr, info_ptr, purpose, X0, X1, type, nparams, + png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams, units, params); - png_free(png_ptr, purpose); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; png_free(png_ptr, params); } #endif -#if defined(PNG_READ_sCAL_SUPPORTED) -/* read the sCAL chunk */ +#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_charp buffer, ep; -#ifdef PNG_FLOATING_POINT_SUPPORTED - double width, height; - png_charp vp; -#else -#ifdef PNG_FIXED_POINT_SUPPORTED - png_charp swidth, sheight; -#endif -#endif - png_size_t slength; + png_size_t slength, i; + int state; - png_debug(1, "in png_handle_sCAL\n"); + 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"); @@ -1693,112 +2085,96 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - png_debug1(2, "Allocating and reading sCAL chunk data (%lu bytes)\n", - length + 1); - buffer = (png_charp)png_malloc_warn(png_ptr, length + 1); - if (buffer == NULL) - { - png_warning(png_ptr, "Out of memory while processing sCAL chunk"); - return; - } - slength = (png_size_t)length; - png_crc_read(png_ptr, (png_bytep)buffer, slength); - - if (png_crc_finish(png_ptr, 0)) + /* Need unit type, width, \0, height: minimum 4 bytes */ + else if (length < 4) { - png_free(png_ptr, buffer); + png_warning(png_ptr, "sCAL chunk too short"); + png_crc_finish(png_ptr, length); return; } - buffer[slength] = 0x00; /* null terminate the last string */ + png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)", + length + 1); - ep = buffer + 1; /* skip unit byte */ + png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); -#ifdef PNG_FLOATING_POINT_SUPPORTED - width = strtod(ep, &vp); - if (*vp) + if (png_ptr->chunkdata == NULL) { - png_warning(png_ptr, "malformed width string in sCAL chunk"); - return; + png_warning(png_ptr, "Out of memory while processing sCAL chunk"); + png_crc_finish(png_ptr, length); + return; } -#else -#ifdef PNG_FIXED_POINT_SUPPORTED - swidth = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1); - if (swidth == NULL) - { - png_warning(png_ptr, "Out of memory while processing sCAL chunk width"); - return; - } - png_memcpy(swidth, ep, (png_size_t)png_strlen(ep)); -#endif -#endif - for (ep = buffer; *ep; ep++) - /* empty loop */ ; - ep++; + 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 */ -#ifdef PNG_FLOATING_POINT_SUPPORTED - height = strtod(ep, &vp); - if (*vp) + if (png_crc_finish(png_ptr, 0)) { - png_warning(png_ptr, "malformed height string in sCAL chunk"); - return; + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; } -#else -#ifdef PNG_FIXED_POINT_SUPPORTED - sheight = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1); - if (swidth == NULL) - { - png_warning(png_ptr, "Out of memory while processing sCAL chunk height"); - return; - } - png_memcpy(sheight, ep, (png_size_t)png_strlen(ep)); -#endif -#endif - if (buffer + slength < ep -#ifdef PNG_FLOATING_POINT_SUPPORTED - || width <= 0. || height <= 0. -#endif - ) + /* Validate the unit. */ + if (png_ptr->chunkdata[0] != 1 && png_ptr->chunkdata[0] != 2) { - png_warning(png_ptr, "Invalid sCAL data"); - png_free(png_ptr, buffer); -#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) - png_free(png_ptr, swidth); - png_free(png_ptr, sheight); -#endif + 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; -#ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_sCAL(png_ptr, info_ptr, buffer[0], width, height); -#else -#ifdef PNG_FIXED_POINT_SUPPORTED - png_set_sCAL_s(png_ptr, info_ptr, buffer[0], swidth, sheight); -#endif -#endif + if (!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"); - png_free(png_ptr, buffer); -#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) - png_free(png_ptr, swidth); - png_free(png_ptr, sheight); -#endif + else if (!PNG_FP_IS_POSITIVE(state)) + png_warning(png_ptr, "Invalid sCAL chunk ignored: non-positive width"); + + else + { + png_size_t heighti = i; + + state = 0; + if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) || + i != slength) + png_warning(png_ptr, "Invalid sCAL chunk ignored: bad height format"); + + else if (!PNG_FP_IS_POSITIVE(state)) + png_warning(png_ptr, + "Invalid sCAL chunk ignored: non-positive height"); + + 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 -#if defined(PNG_READ_tIME_SUPPORTED) +#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\n"); + 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"); @@ -1817,6 +2193,7 @@ png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } png_crc_read(png_ptr, buf, 7); + if (png_crc_finish(png_ptr, 0)) return; @@ -1831,7 +2208,7 @@ png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } #endif -#if defined(PNG_READ_tEXt_SUPPORTED) +#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) @@ -1843,7 +2220,25 @@ png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_size_t slength; int ret; - png_debug(1, "in png_handle_tEXt\n"); + 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"); @@ -1860,68 +2255,97 @@ png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } #endif - key = (png_charp)png_malloc_warn(png_ptr, length + 1); - if (key == NULL) + 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."); + png_warning(png_ptr, "No memory to process text chunk"); return; } + slength = (png_size_t)length; - png_crc_read(png_ptr, (png_bytep)key, slength); + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, skip)) { - png_free(png_ptr, key); + 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 */ ; + /* Empty loop to find end of key */ ; if (text != key + slength) text++; - text_ptr = (png_textp)png_malloc_warn(png_ptr, (png_uint_32)sizeof(png_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, key); - return; + 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; -#ifdef PNG_iTXt_SUPPORTED text_ptr->lang = NULL; text_ptr->lang_key = NULL; text_ptr->itxt_length = 0; -#endif text_ptr->text = text; text_ptr->text_length = png_strlen(text); - ret=png_set_text_2(png_ptr, info_ptr, text_ptr, 1); + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); - png_free(png_ptr, key); + 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."); + png_warning(png_ptr, "Insufficient memory to process text chunk"); } #endif -#if defined(PNG_READ_zTXt_SUPPORTED) -/* note: this does not correctly handle chunks that are > 64K under DOS */ +#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 chunkdata; png_charp text; int comp_type; int ret; png_size_t slength, prefix_len, data_len; - png_debug(1, "in png_handle_zTXt\n"); + 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"); @@ -1930,95 +2354,128 @@ png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) #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. */ + * 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; + png_warning(png_ptr, "zTXt chunk too large to fit in memory"); + png_crc_finish(png_ptr, length); + return; } #endif - chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); - if (chunkdata == NULL) + 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; + png_warning(png_ptr, "Out of memory processing zTXt chunk"); + return; } + slength = (png_size_t)length; - png_crc_read(png_ptr, (png_bytep)chunkdata, slength); + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + if (png_crc_finish(png_ptr, 0)) { - png_free(png_ptr, chunkdata); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; return; } - chunkdata[slength] = 0x00; + png_ptr->chunkdata[slength] = 0x00; - for (text = chunkdata; *text; text++) - /* empty loop */ ; + for (text = png_ptr->chunkdata; *text; text++) + /* Empty loop */ ; /* zTXt must have some text after the chunkdataword */ - if (text == chunkdata + slength) + if (text >= png_ptr->chunkdata + slength - 2) { - comp_type = PNG_TEXT_COMPRESSION_NONE; - png_warning(png_ptr, "Zero length zTXt chunk"); + 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 */ + + text++; /* Skip the compression_method byte */ } - prefix_len = text - chunkdata; - chunkdata = (png_charp)png_decompress_chunk(png_ptr, comp_type, chunkdata, - (png_size_t)length, prefix_len, &data_len); + 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)); - text_ptr = (png_textp)png_malloc_warn(png_ptr, (png_uint_32)sizeof(png_text)); if (text_ptr == NULL) { - png_warning(png_ptr,"Not enough memory to process zTXt chunk."); - png_free(png_ptr, chunkdata); - return; + 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 = chunkdata; -#ifdef PNG_iTXt_SUPPORTED + text_ptr->key = png_ptr->chunkdata; text_ptr->lang = NULL; text_ptr->lang_key = NULL; text_ptr->itxt_length = 0; -#endif - text_ptr->text = chunkdata + prefix_len; + 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); + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); png_free(png_ptr, text_ptr); - png_free(png_ptr, chunkdata); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + if (ret) - png_error(png_ptr, "Insufficient memory to store zTXt chunk."); + png_error(png_ptr, "Insufficient memory to store zTXt chunk"); } #endif -#if defined(PNG_READ_iTXt_SUPPORTED) -/* note: this does not correctly handle chunks that are > 64K under DOS */ +#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 chunkdata; 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\n"); + 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"); @@ -2028,428 +2485,792 @@ png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) #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. */ + * 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; + png_warning(png_ptr, "iTXt chunk too large to fit in memory"); + png_crc_finish(png_ptr, length); + return; } #endif - chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); - if (chunkdata == NULL) + 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; + png_warning(png_ptr, "No memory to process iTXt chunk"); + return; } + slength = (png_size_t)length; - png_crc_read(png_ptr, (png_bytep)chunkdata, slength); + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + if (png_crc_finish(png_ptr, 0)) { - png_free(png_ptr, chunkdata); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; return; } - chunkdata[slength] = 0x00; + png_ptr->chunkdata[slength] = 0x00; - for (lang = chunkdata; *lang; lang++) - /* empty loop */ ; - lang++; /* skip NUL separator */ + 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 */ + * translated keyword (possibly empty), and possibly some text after the + * keyword + */ - if (lang >= chunkdata + slength) + if (lang >= png_ptr->chunkdata + slength - 3) { - comp_flag = PNG_TEXT_COMPRESSION_NONE; - png_warning(png_ptr, "Zero length iTXt chunk"); + 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++; + comp_flag = *lang++; + comp_type = *lang++; + } + + if (comp_type || (comp_flag && comp_flag != PNG_TEXT_COMPRESSION_zTXt)) + { + png_warning(png_ptr, "Unknown iTXt compression type or method"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; } for (lang_key = lang; *lang_key; lang_key++) - /* empty loop */ ; - lang_key++; /* skip NUL separator */ + /* 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 */ + /* 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; - prefix_len = text - chunkdata; + key=png_ptr->chunkdata; - key=chunkdata; if (comp_flag) - chunkdata = png_decompress_chunk(png_ptr, comp_type, chunkdata, + png_decompress_chunk(png_ptr, comp_type, (size_t)length, prefix_len, &data_len); + else - data_len=png_strlen(chunkdata + prefix_len); - text_ptr = (png_textp)png_malloc_warn(png_ptr, (png_uint_32)sizeof(png_text)); + 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, chunkdata); - return; + 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 = chunkdata+(lang_key-key); - text_ptr->lang = chunkdata+(lang-key); + 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 = chunkdata; - text_ptr->text = chunkdata + prefix_len; + 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); + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); png_free(png_ptr, text_ptr); - png_free(png_ptr, chunkdata); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + if (ret) - png_error(png_ptr, "Insufficient memory to store iTXt chunk."); + 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. */ + * 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\n"); + png_debug(1, "in png_handle_unknown"); - if (png_ptr->mode & PNG_HAVE_IDAT) +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) { -#ifdef PNG_USE_LOCAL_ARRAYS - PNG_IDAT; + 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_memcmp(png_ptr->chunk_name, png_IDAT, 4)) /* not an IDAT */ + + if (png_ptr->mode & PNG_HAVE_IDAT) + { + if (png_ptr->chunk_name != png_IDAT) png_ptr->mode |= PNG_AFTER_IDAT; } - png_check_chunk_name(png_ptr, png_ptr->chunk_name); - - if (!(png_ptr->chunk_name[0] & 0x20)) + if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name)) { -#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) - if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != - HANDLE_CHUNK_ALWAYS -#if defined(PNG_READ_USER_CHUNKS_SUPPORTED) - && png_ptr->read_user_chunk_fn == NULL +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + if (png_chunk_unknown_handling(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"); + png_chunk_error(png_ptr, "unknown critical chunk"); } -#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) - if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) +#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 + ) { - png_unknown_chunk chunk; - #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; - } + if (length > 65535) + { + png_warning(png_ptr, "unknown chunk too large to fit in memory"); + skip = length - 65535; + length = 65535; + } #endif - png_strcpy((png_charp)chunk.name, (png_charp)png_ptr->chunk_name); - chunk.data = (png_bytep)png_malloc(png_ptr, length); - chunk.size = (png_size_t)length; - png_crc_read(png_ptr, (png_bytep)chunk.data, length); -#if defined(PNG_READ_USER_CHUNKS_SUPPORTED) - if(png_ptr->read_user_chunk_fn != NULL) - { - /* callback to user unknown chunk handler */ - if ((*(png_ptr->read_user_chunk_fn)) (png_ptr, &chunk) <= 0) - { - if (!(png_ptr->chunk_name[0] & 0x20)) - if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != - HANDLE_CHUNK_ALWAYS) - { - png_free(png_ptr, chunk.data); - png_chunk_error(png_ptr, "unknown critical chunk"); - } - png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1); - } - } - else + + /* TODO: this code is very close to the unknown handling in pngpread.c, + * maybe it can be put into a common utility routine? + * png_struct::unknown_chunk is just used as a temporary variable, along + * with the data into which the chunk is read. These can be eliminated. + */ + PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name); + 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_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_CHUNK_CRITICAL(png_ptr->chunk_name)) + { +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + if (png_chunk_unknown_handling(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, &chunk, 1); - png_free(png_ptr, chunk.data); + 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); -#if !defined(PNG_READ_USER_CHUNKS_SUPPORTED) - info_ptr = info_ptr; /* quiet compiler warnings about unused info_ptr */ +#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. */ + * 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) < 41 || (c) > 122 || ((c) > 90 && (c) < 97)) +/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is: + * + * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) + */ void /* PRIVATE */ -png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name) +png_check_chunk_name(png_structp png_ptr, png_uint_32 chunk_name) { - png_debug(1, "in png_check_chunk_name\n"); - if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) || - isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3])) + int i; + + png_debug(1, "in png_check_chunk_name"); + + for (i=1; i<=4; ++i) { - png_chunk_error(png_ptr, "invalid chunk type"); + int c = chunk_name & 0xff; + + if (c < 65 || c > 122 || (c > 90 && c < 97)) + png_chunk_error(png_ptr, "invalid chunk type"); + + chunk_name >>= 8; } } -/* Combines the row recently read in with the existing pixels in the - row. This routine takes care of alpha and transparency if requested. - This routine also handles the two methods of progressive display - of interlaced images, depending on the 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. */ -#ifndef PNG_HAVE_ASSEMBLER_COMBINE_ROW +/* Combines the row recently read in with the existing pixels in the row. This + * routine takes care of alpha and transparency if requested. This routine also + * handles the two methods of progressive display of interlaced images, + * depending on the 'display' value; if 'display' is true then the whole row + * (dp) is filled from the start by replicating the available pixels. If + * 'display' is false only those pixels present in the pass are filled in. + */ void /* PRIVATE */ -png_combine_row(png_structp png_ptr, png_bytep row, int mask) +png_combine_row(png_structp png_ptr, png_bytep dp, int display) { - png_debug(1,"in png_combine_row\n"); - if (mask == 0xff) + unsigned int pixel_depth = png_ptr->transformed_pixel_depth; + png_const_bytep sp = png_ptr->row_buf + 1; + png_uint_32 row_width = png_ptr->width; + unsigned int pass = png_ptr->pass; + png_bytep end_ptr = 0; + png_byte end_byte = 0; + unsigned int end_mask; + + png_debug(1, "in png_combine_row"); + + /* Added in 1.5.6: it should not be possible to enter this routine until at + * least one row has been read from the PNG data and transformed. + */ + if (pixel_depth == 0) + png_error(png_ptr, "internal row logic error"); + + /* Added in 1.5.4: the pixel depth should match the information returned by + * any call to png_read_update_info at this point. Do not continue if we got + * this wrong. + */ + if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes != + PNG_ROWBYTES(pixel_depth, row_width)) + png_error(png_ptr, "internal row size calculation error"); + + /* Don't expect this to ever happen: */ + if (row_width == 0) + png_error(png_ptr, "internal row width error"); + + /* Preserve the last byte in cases where only part of it will be overwritten, + * the multiply below may overflow, we don't care because ANSI-C guarantees + * we get the low bits. + */ + end_mask = (pixel_depth * row_width) & 7; + if (end_mask != 0) { - png_memcpy(row, png_ptr->row_buf + 1, - (png_size_t)((png_ptr->width * - png_ptr->row_info.pixel_depth + 7) >> 3)); + /* end_ptr == NULL is a flag to say do nothing */ + end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1; + end_byte = *end_ptr; +# ifdef PNG_READ_PACKSWAP_SUPPORTED + if (png_ptr->transformations & PNG_PACKSWAP) /* little-endian byte */ + end_mask = 0xff << end_mask; + + else /* big-endian byte */ +# endif + end_mask = 0xff >> end_mask; + /* end_mask is now the bits to *keep* from the destination row */ } - else + + /* For non-interlaced images this reduces to a png_memcpy(). A png_memcpy() + * will also happen if interlacing isn't supported or if the application + * does not call png_set_interlace_handling(). In the latter cases the + * caller just gets a sequence of the unexpanded rows from each interlace + * pass. + */ +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE) && + pass < 6 && (display == 0 || + /* The following copies everything for 'display' on passes 0, 2 and 4. */ + (display == 1 && (pass & 1) != 0))) { - switch (png_ptr->row_info.pixel_depth) + /* Narrow images may have no bits in a pass; the caller should handle + * this, but this test is cheap: + */ + if (row_width <= PNG_PASS_START_COL(pass)) + return; + + if (pixel_depth < 8) { - case 1: + /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit + * into 32 bits, then a single loop over the bytes using the four byte + * values in the 32-bit mask can be used. For the 'display' option the + * expanded mask may also not require any masking within a byte. To + * make this work the PACKSWAP option must be taken into account - it + * simply requires the pixels to be reversed in each byte. + * + * The 'regular' case requires a mask for each of the first 6 passes, + * the 'display' case does a copy for the even passes in the range + * 0..6. This has already been handled in the test above. + * + * The masks are arranged as four bytes with the first byte to use in + * the lowest bits (little-endian) regardless of the order (PACKSWAP or + * not) of the pixels in each byte. + * + * NOTE: the whole of this logic depends on the caller of this function + * only calling it on rows appropriate to the pass. This function only + * understands the 'x' logic; the 'y' logic is handled by the caller. + * + * The following defines allow generation of compile time constant bit + * masks for each pixel depth and each possibility of swapped or not + * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index, + * is in the range 0..7; and the result is 1 if the pixel is to be + * copied in the pass, 0 if not. 'S' is for the sparkle method, 'B' + * for the block method. + * + * With some compilers a compile time expression of the general form: + * + * (shift >= 32) ? (a >> (shift-32)) : (b >> shift) + * + * Produces warnings with values of 'shift' in the range 33 to 63 + * because the right hand side of the ?: expression is evaluated by + * the compiler even though it isn't used. Microsoft Visual C (various + * versions) and the Intel C compiler are known to do this. To avoid + * this the following macros are used in 1.5.6. This is a temporary + * solution to avoid destabilizing the code during the release process. + */ +# if PNG_USE_COMPILE_TIME_MASKS +# define PNG_LSR(x,s) ((x)>>((s) & 0x1f)) +# define PNG_LSL(x,s) ((x)<<((s) & 0x1f)) +# else +# define PNG_LSR(x,s) ((x)>>(s)) +# define PNG_LSL(x,s) ((x)<<(s)) +# endif +# define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\ + PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1) +# define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\ + PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1) + + /* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is + * little endian - the first pixel is at bit 0 - however the extra + * parameter 's' can be set to cause the mask position to be swapped + * within each byte, to match the PNG format. This is done by XOR of + * the shift with 7, 6 or 4 for bit depths 1, 2 and 4. + */ +# define PIXEL_MASK(p,x,d,s) \ + (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0)))) + + /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask. + */ +# define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) +# define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) + + /* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp + * cases the result needs replicating, for the 4-bpp case the above + * generates a full 32 bits. + */ +# define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1))) + +# define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\ + S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\ + S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d) + +# define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\ + B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\ + B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d) + +#if PNG_USE_COMPILE_TIME_MASKS + /* Utility macros to construct all the masks for a depth/swap + * combination. The 's' parameter says whether the format is PNG + * (big endian bytes) or not. Only the three odd-numbered passes are + * required for the display/block algorithm. + */ +# define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\ + S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) } + +# define B_MASKS(d,s) { B_MASK(1,d,s), S_MASK(3,d,s), S_MASK(5,d,s) } + +# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2)) + + /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and + * then pass: + */ + static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] = { - 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; - -#if defined(PNG_READ_PACKSWAP_SUPPORTED) + /* Little-endian byte masks for PACKSWAP */ + { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) }, + /* Normal (big-endian byte) masks - PNG format */ + { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) } + }; + + /* display_mask has only three entries for the odd passes, so index by + * pass>>1. + */ + static PNG_CONST png_uint_32 display_mask[2][3][3] = + { + /* Little-endian byte masks for PACKSWAP */ + { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) }, + /* Normal (big-endian byte) masks - PNG format */ + { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) } + }; + +# define MASK(pass,depth,display,png)\ + ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\ + row_mask[png][DEPTH_INDEX(depth)][pass]) + +#else /* !PNG_USE_COMPILE_TIME_MASKS */ + /* This is the runtime alternative: it seems unlikely that this will + * ever be either smaller or faster than the compile time approach. + */ +# define MASK(pass,depth,display,png)\ + ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png)) +#endif /* !PNG_USE_COMPILE_TIME_MASKS */ + + /* Use the appropriate mask to copy the required bits. In some cases + * the byte mask will be 0 or 0xff, optimize these cases. row_width is + * the number of pixels, but the code copies bytes, so it is necessary + * to special case the end. + */ + png_uint_32 pixels_per_byte = 8 / pixel_depth; + png_uint_32 mask; + +# ifdef PNG_READ_PACKSWAP_SUPPORTED if (png_ptr->transformations & PNG_PACKSWAP) - { - s_start = 0; - s_end = 7; - s_inc = 1; - } + mask = MASK(pass, pixel_depth, display, 0); + else -#endif +# endif + mask = MASK(pass, pixel_depth, display, 1); + + for (;;) + { + png_uint_32 m; + + /* It doesn't matter in the following if png_uint_32 has more than + * 32 bits because the high bits always match those in m<<24; it is, + * however, essential to use OR here, not +, because of this. + */ + m = mask; + mask = (m >> 8) | (m << 24); /* rotate right to good compilers */ + m &= 0xff; + + if (m != 0) /* something to copy */ { - s_start = 7; - s_end = 0; - s_inc = -1; + if (m != 0xff) + *dp = (png_byte)((*dp & ~m) | (*sp & m)); + else + *dp = *sp; } - shift = s_start; + /* NOTE: this may overwrite the last byte with garbage if the image + * is not an exact number of bytes wide; libpng has always done + * this. + */ + if (row_width <= pixels_per_byte) + break; /* May need to restore part of the last byte */ - for (i = 0; i < row_width; i++) - { - if (m & mask) - { - int value; + row_width -= pixels_per_byte; + ++dp; + ++sp; + } + } - value = (*sp >> shift) & 0x01; - *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); - *dp |= (png_byte)(value << shift); - } + else /* pixel_depth >= 8 */ + { + unsigned int bytes_to_copy, bytes_to_jump; - if (shift == s_end) - { - shift = s_start; - sp++; - dp++; - } - else - shift += s_inc; + /* Validate the depth - it must be a multiple of 8 */ + if (pixel_depth & 7) + png_error(png_ptr, "invalid user transform pixel depth"); - if (m == 1) - m = 0x80; - else - m >>= 1; - } - break; - } - case 2: + pixel_depth >>= 3; /* now in bytes */ + row_width *= pixel_depth; + + /* Regardless of pass number the Adam 7 interlace always results in a + * fixed number of pixels to copy then to skip. There may be a + * different number of pixels to skip at the start though. + */ { - 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; + unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth; -#if defined(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; - } + row_width -= offset; + dp += offset; + sp += offset; + } - shift = s_start; + /* Work out the bytes to copy. */ + if (display) + { + /* When doing the 'block' algorithm the pixel in the pass gets + * replicated to adjacent pixels. This is why the even (0,2,4,6) + * passes are skipped above - the entire expanded row is copied. + */ + bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth; - for (i = 0; i < row_width; i++) - { - if (m & mask) + /* But don't allow this number to exceed the actual row width. */ + if (bytes_to_copy > row_width) + bytes_to_copy = row_width; + } + + else /* normal row; Adam7 only ever gives us one pixel to copy. */ + bytes_to_copy = pixel_depth; + + /* In Adam7 there is a constant offset between where the pixels go. */ + bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth; + + /* And simply copy these bytes. Some optimization is possible here, + * depending on the value of 'bytes_to_copy'. Special case the low + * byte counts, which we know to be frequent. + * + * Notice that these cases all 'return' rather than 'break' - this + * avoids an unnecessary test on whether to restore the last byte + * below. + */ + switch (bytes_to_copy) + { + case 1: + for (;;) { - value = (*sp >> shift) & 0x03; - *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); - *dp |= (png_byte)(value << shift); + *dp = *sp; + + if (row_width <= bytes_to_jump) + return; + + dp += bytes_to_jump; + sp += bytes_to_jump; + row_width -= bytes_to_jump; } - if (shift == s_end) + case 2: + /* There is a possibility of a partial copy at the end here; this + * slows the code down somewhat. + */ + do { - shift = s_start; - sp++; - dp++; + dp[0] = sp[0], dp[1] = sp[1]; + + if (row_width <= bytes_to_jump) + return; + + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; } - 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; + while (row_width > 1); -#if defined(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; + /* And there can only be one byte left at this point: */ + *dp = *sp; + return; - for (i = 0; i < row_width; i++) - { - if (m & mask) + case 3: + /* This can only be the RGB case, so each copy is exactly one + * pixel and it is not necessary to check for a partial copy. + */ + for(;;) { - value = (*sp >> shift) & 0xf; - *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); - *dp |= (png_byte)(value << shift); + dp[0] = sp[0], dp[1] = sp[1], dp[2] = sp[2]; + + if (row_width <= bytes_to_jump) + return; + + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; } - if (shift == s_end) + default: +#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE + /* Check for double byte alignment and, if possible, use a + * 16-bit copy. Don't attempt this for narrow images - ones that + * are less than an interlace panel wide. Don't attempt it for + * wide bytes_to_copy either - use the png_memcpy there. + */ + if (bytes_to_copy < 16 /*else use png_memcpy*/ && + png_isaligned(dp, png_uint_16) && + png_isaligned(sp, png_uint_16) && + bytes_to_copy % sizeof (png_uint_16) == 0 && + bytes_to_jump % sizeof (png_uint_16) == 0) { - 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; + /* Everything is aligned for png_uint_16 copies, but try for + * png_uint_32 first. + */ + if (png_isaligned(dp, png_uint_32) && + png_isaligned(sp, png_uint_32) && + bytes_to_copy % sizeof (png_uint_32) == 0 && + bytes_to_jump % sizeof (png_uint_32) == 0) + { + png_uint_32p dp32 = (png_uint_32p)dp; + png_const_uint_32p sp32 = (png_const_uint_32p)sp; + unsigned int skip = (bytes_to_jump-bytes_to_copy) / + sizeof (png_uint_32); + + do + { + size_t c = bytes_to_copy; + do + { + *dp32++ = *sp32++; + c -= sizeof (png_uint_32); + } + while (c > 0); + + if (row_width <= bytes_to_jump) + return; + + dp32 += skip; + sp32 += skip; + row_width -= bytes_to_jump; + } + while (bytes_to_copy <= row_width); + + /* Get to here when the row_width truncates the final copy. + * There will be 1-3 bytes left to copy, so don't try the + * 16-bit loop below. + */ + dp = (png_bytep)dp32; + sp = (png_const_bytep)sp32; + do + *dp++ = *sp++; + while (--row_width > 0); + return; + } + /* Else do it in 16-bit quantities, but only if the size is + * not too large. + */ + else + { + png_uint_16p dp16 = (png_uint_16p)dp; + png_const_uint_16p sp16 = (png_const_uint_16p)sp; + unsigned int skip = (bytes_to_jump-bytes_to_copy) / + sizeof (png_uint_16); + + do + { + size_t c = bytes_to_copy; + do + { + *dp16++ = *sp16++; + c -= sizeof (png_uint_16); + } + while (c > 0); + + if (row_width <= bytes_to_jump) + return; + + dp16 += skip; + sp16 += skip; + row_width -= bytes_to_jump; + } + while (bytes_to_copy <= row_width); + + /* End of row - 1 byte left, bytes_to_copy > row_width: */ + dp = (png_bytep)dp16; + sp = (png_const_bytep)sp16; + do + *dp++ = *sp++; + while (--row_width > 0); + return; + } + } +#endif /* PNG_ALIGN_ code */ - for (i = 0; i < row_width; i++) - { - if (m & mask) + /* The true default - use a png_memcpy: */ + for (;;) { - png_memcpy(dp, sp, pixel_bytes); - } + png_memcpy(dp, sp, bytes_to_copy); - sp += pixel_bytes; - dp += pixel_bytes; + if (row_width <= bytes_to_jump) + return; - if (m == 1) - m = 0x80; - else - m >>= 1; - } - break; + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; + if (bytes_to_copy > row_width) + bytes_to_copy = row_width; + } } - } + + /* NOT REACHED*/ + } /* pixel_depth >= 8 */ + + /* Here if pixel_depth < 8 to check 'end_ptr' below. */ } + else +#endif + + /* If here then the switch above wasn't used so just png_memcpy the whole row + * from the temporary row buffer (notice that this overwrites the end of the + * destination row if it is a partial byte.) + */ + png_memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width)); + + /* Restore the overwritten bits from the last byte if necessary. */ + if (end_ptr != NULL) + *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask)); } -#endif /* !PNG_HAVE_ASSEMBLER_COMBINE_ROW */ #ifdef PNG_READ_INTERLACING_SUPPORTED -#ifndef PNG_HAVE_ASSEMBLER_READ_INTERLACE /* else in pngvcrd.c, pnggccrd.c */ -/* OLD pre-1.0.9 interface: -void png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass, - png_uint_32 transformations) - */ void /* PRIVATE */ -png_do_read_interlace(png_structp png_ptr) +png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass, + png_uint_32 transformations /* Because these may affect the byte layout */) { - 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; -#ifdef PNG_USE_LOCAL_ARRAYS - /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - /* offset to next interlace block */ - const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; -#endif + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + /* Offset to next interlace block */ + static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - png_debug(1,"in png_do_read_interlace (stock C version)\n"); + png_debug(1, "in png_do_read_interlace"); if (row != NULL && row_info != NULL) { png_uint_32 final_width; @@ -2469,7 +3290,7 @@ png_do_read_interlace(png_structp png_ptr) png_uint_32 i; int j; -#if defined(PNG_READ_PACKSWAP_SUPPORTED) +#ifdef PNG_READ_PACKSWAP_SUPPORTED if (transformations & PNG_PACKSWAP) { sshift = (int)((row_info->width + 7) & 0x07); @@ -2478,6 +3299,7 @@ png_do_read_interlace(png_structp png_ptr) s_end = 0; s_inc = -1; } + else #endif { @@ -2495,24 +3317,29 @@ png_do_read_interlace(png_structp png_ptr) { *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); @@ -2522,7 +3349,7 @@ png_do_read_interlace(png_structp png_ptr) int jstop = png_pass_inc[pass]; png_uint_32 i; -#if defined(PNG_READ_PACKSWAP_SUPPORTED) +#ifdef PNG_READ_PACKSWAP_SUPPORTED if (transformations & PNG_PACKSWAP) { sshift = (int)(((row_info->width + 3) & 0x03) << 1); @@ -2531,6 +3358,7 @@ png_do_read_interlace(png_structp png_ptr) s_end = 0; s_inc = -2; } + else #endif { @@ -2551,24 +3379,29 @@ png_do_read_interlace(png_structp png_ptr) { *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); @@ -2578,7 +3411,7 @@ png_do_read_interlace(png_structp png_ptr) png_uint_32 i; int jstop = png_pass_inc[pass]; -#if defined(PNG_READ_PACKSWAP_SUPPORTED) +#ifdef PNG_READ_PACKSWAP_SUPPORTED if (transformations & PNG_PACKSWAP) { sshift = (int)(((row_info->width + 1) & 0x01) << 2); @@ -2587,6 +3420,7 @@ png_do_read_interlace(png_structp png_ptr) s_end = 0; s_inc = -4; } + else #endif { @@ -2599,35 +3433,43 @@ png_do_read_interlace(png_structp png_ptr) for (i = 0; i < row_info->width; i++) { - png_byte v = (png_byte)((*sp >> sshift) & 0xf); + png_byte v = (png_byte)((*sp >> sshift) & 0x0f); 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 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]; @@ -2639,262 +3481,391 @@ png_do_read_interlace(png_structp png_ptr) 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 = ((final_width * - (png_uint_32)row_info->pixel_depth + 7) >> 3); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width); } -#if !defined(PNG_READ_PACKSWAP_SUPPORTED) - transformations = transformations; /* silence compiler warning */ +#ifndef PNG_READ_PACKSWAP_SUPPORTED + PNG_UNUSED(transformations) /* Silence compiler warning */ #endif } -#endif /* !PNG_HAVE_ASSEMBLER_READ_INTERLACE */ #endif /* PNG_READ_INTERLACING_SUPPORTED */ -#ifndef PNG_HAVE_ASSEMBLER_READ_FILTER_ROW -void /* PRIVATE */ -png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row, - png_bytep prev_row, int filter) +static void +png_read_filter_row_sub(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) { - png_debug(1, "in png_read_filter_row\n"); - png_debug2(2,"row = %lu, filter = %d\n", png_ptr->row_number, filter); - switch (filter) + png_size_t i; + png_size_t istop = row_info->rowbytes; + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + png_bytep rp = row + bpp; + + PNG_UNUSED(prev_row) + + for (i = bpp; i < istop; i++) { - case PNG_FILTER_VALUE_NONE: - break; - case PNG_FILTER_VALUE_SUB: - { - png_uint_32 i; - png_uint_32 istop = row_info->rowbytes; - png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3; - png_bytep rp = row + bpp; - png_bytep lp = row; + *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); + rp++; + } +} - for (i = bpp; i < istop; i++) - { - *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff); - rp++; - } - break; - } - case PNG_FILTER_VALUE_UP: - { - png_uint_32 i; - png_uint_32 istop = row_info->rowbytes; - png_bytep rp = row; - png_bytep pp = prev_row; +static void +png_read_filter_row_up(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_size_t i; + png_size_t istop = row_info->rowbytes; + png_bytep rp = row; + png_const_bytep pp = prev_row; - for (i = 0; i < istop; i++) - { - *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); - rp++; - } - break; - } - case PNG_FILTER_VALUE_AVG: - { - png_uint_32 i; - png_bytep rp = row; - png_bytep pp = prev_row; - png_bytep lp = row; - png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3; - png_uint_32 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++)) & 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_uint_32 i; - png_bytep rp = row; - png_bytep pp = prev_row; - png_bytep lp = row; - png_bytep cp = prev_row; - png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3; - png_uint_32 istop=row_info->rowbytes - bpp; - - for (i = 0; i < bpp; i++) - { - *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); - rp++; - } +static void +png_read_filter_row_avg(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_size_t i; + png_bytep rp = row; + png_const_bytep pp = prev_row; + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + png_size_t istop = row_info->rowbytes - bpp; - for (i = 0; i < istop; i++) /* use leftover rp,pp */ - { - int a, b, c, pa, pb, pc, p; + for (i = 0; i < bpp; i++) + { + *rp = (png_byte)(((int)(*rp) + + ((int)(*pp++) / 2 )) & 0xff); - a = *lp++; - b = *pp++; - c = *cp++; + rp++; + } - p = b - c; - pc = a - c; + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + + (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); -#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 + rp++; + } +} - /* - if (pa <= pb && pa <= pc) - p = a; - else if (pb <= pc) - p = b; - else - p = c; - */ +static void +png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp_end = row + row_info->rowbytes; + int a, c; - p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; + /* First pixel/byte */ + c = *prev_row++; + a = *row + c; + *row++ = (png_byte)a; - *rp = (png_byte)(((int)(*rp) + p) & 0xff); - rp++; - } + /* Remainder */ + while (row < rp_end) + { + int b, pa, pb, pc, p; + + a &= 0xff; /* From previous iteration or start */ + b = *prev_row++; + + p = b - c; + pc = a - c; + +# ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +# else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +# endif + + /* Find the best predictor, the least of pa, pb, pc favoring the earlier + * ones in the case of a tie. + */ + if (pb < pa) pa = pb, a = b; + if (pc < pa) a = c; + + /* Calculate the current pixel in a, and move the previous row pixel to c + * for the next time round the loop + */ + c = b; + a += *row; + *row++ = (png_byte)a; + } +} + +static void +png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + int bpp = (row_info->pixel_depth + 7) >> 3; + png_bytep rp_end = row + bpp; + + /* Process the first pixel in the row completely (this is the same as 'up' + * because there is only one candidate predictor for the first row). + */ + while (row < rp_end) + { + int a = *row + *prev_row++; + *row++ = (png_byte)a; + } + + /* Remainder */ + rp_end += row_info->rowbytes - bpp; + + while (row < rp_end) + { + int a, b, c, pa, pb, pc, p; + + c = *(prev_row - bpp); + a = *(row - bpp); + b = *prev_row++; + + p = b - c; + pc = a - c; + +# ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +# else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +# endif + + if (pb < pa) pa = pb, a = b; + if (pc < pa) a = c; + + c = b; + a += *row; + *row++ = (png_byte)a; + } +} + +#ifdef PNG_ARM_NEON + +#ifdef __linux__ +#include +#include +#include + +static int png_have_hwcap(unsigned cap) +{ + FILE *f = fopen("/proc/self/auxv", "r"); + Elf32_auxv_t aux; + int have_cap = 0; + + if (!f) + return 0; + + while (fread(&aux, sizeof(aux), 1, f) > 0) + { + if (aux.a_type == AT_HWCAP && + aux.a_un.a_val & cap) + { + have_cap = 1; break; } - default: - png_warning(png_ptr, "Ignoring bad adaptive filter type"); - *row=0; - break; } + + fclose(f); + + return have_cap; +} +#endif /* __linux__ */ + +static void +png_init_filter_functions_neon(png_structp pp, unsigned int bpp) +{ +#ifdef __linux__ + if (!png_have_hwcap(HWCAP_NEON)) + return; +#endif + + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon; + + if (bpp == 3) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth3_neon; + } + + else if (bpp == 4) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth4_neon; + } +} +#endif /* PNG_ARM_NEON */ + +static void +png_init_filter_functions(png_structp pp) +{ + unsigned int bpp = (pp->pixel_depth + 7) >> 3; + + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub; + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg; + if (bpp == 1) + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth_1byte_pixel; + else + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth_multibyte_pixel; + +#ifdef PNG_ARM_NEON + png_init_filter_functions_neon(pp, bpp); +#endif } -#endif /* !PNG_HAVE_ASSEMBLER_READ_FILTER_ROW */ +void /* PRIVATE */ +png_read_filter_row(png_structp pp, png_row_infop row_info, png_bytep row, + png_const_bytep prev_row, int filter) +{ + if (pp->read_filter[0] == NULL) + png_init_filter_functions(pp); + if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST) + pp->read_filter[filter-1](row_info, row, prev_row); +} + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED void /* PRIVATE */ png_read_finish_row(png_structp png_ptr) { -#ifdef PNG_USE_LOCAL_ARRAYS - /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - /* start of interlace block */ - const int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + /* Start of interlace block */ + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - /* offset to next interlace block */ - const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + /* Offset to next interlace block */ + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - /* start of interlace block in the y direction */ - const int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + /* Start of interlace block in the y direction */ + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; - /* offset to next interlace block in the y direction */ - const int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; -#endif + /* Offset to next interlace block in the y direction */ + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif /* PNG_READ_INTERLACING_SUPPORTED */ - png_debug(1, "in png_read_finish_row\n"); + 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_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1); + + /* TO DO: don't do this if prev_row isn't needed (requires + * read-ahead of the next row's filter byte. + */ + 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]; - png_ptr->irowbytes = ((png_ptr->iwidth * - (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1; 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]; - if (!(png_ptr->num_rows)) - continue; + 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; - } while (png_ptr->iwidth == 0); + 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)) { -#ifdef PNG_USE_LOCAL_ARRAYS - PNG_IDAT; -#endif char extra; int ret; png_ptr->zstream.next_out = (Byte *)&extra; png_ptr->zstream.avail_out = (uInt)1; - for(;;) + + for (;;) { if (!(png_ptr->zstream.avail_in)) { while (!png_ptr->idat_size) { - png_byte chunk_length[4]; - png_crc_finish(png_ptr, 0); - - png_read_data(png_ptr, chunk_length, 4); - png_ptr->idat_size = png_get_uint_32(chunk_length); - - png_reset_crc(png_ptr); - png_crc_read(png_ptr, png_ptr->chunk_name, 4); - if (png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4)) + png_ptr->idat_size = png_read_chunk_header(png_ptr); + if (png_ptr->chunk_name != png_IDAT) 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_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"); + "Decompression Error"); if (!(png_ptr->zstream.avail_out)) { - png_warning(png_ptr, "Extra compressed data."); + png_warning(png_ptr, "Extra compressed data"); png_ptr->mode |= PNG_AFTER_IDAT; png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; break; @@ -2911,81 +3882,96 @@ png_read_finish_row(png_structp png_ptr) png_ptr->mode |= PNG_AFTER_IDAT; } +#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ void /* PRIVATE */ png_read_start_row(png_structp png_ptr) { -#ifdef PNG_USE_LOCAL_ARRAYS - /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - /* start of interlace block */ - const int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + /* Start of interlace block */ + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - /* offset to next interlace block */ - const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + /* Offset to next interlace block */ + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - /* start of interlace block in the y direction */ - const int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + /* Start of interlace block in the y direction */ + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; - /* offset to next interlace block in the y direction */ - const int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; + /* Offset to next interlace block in the y direction */ + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; #endif int max_pixel_depth; - png_uint_32 row_bytes; + png_size_t row_bytes; - png_debug(1, "in png_read_start_row\n"); + 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]; + 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]; - - row_bytes = ((png_ptr->iwidth * - (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1; - png_ptr->irowbytes = (png_size_t)row_bytes; - if((png_uint_32)png_ptr->irowbytes != row_bytes) - png_error(png_ptr, "Rowbytes overflow in png_read_start_row"); + 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; - png_ptr->irowbytes = png_ptr->rowbytes + 1; } + max_pixel_depth = png_ptr->pixel_depth; -#if defined(PNG_READ_PACK_SUPPORTED) + /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpliar set of + * calculations to calculate the final pixel depth, then + * png_do_read_transforms actually does the transforms. This means that the + * code which effectively calculates this value is actually repeated in three + * separate places. They must all match. Innocent changes to the order of + * transformations can and will break libpng in a way that causes memory + * overwrites. + * + * TODO: fix this. + */ +#ifdef PNG_READ_PACK_SUPPORTED if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8) max_pixel_depth = 8; #endif -#if defined(PNG_READ_EXPAND_SUPPORTED) +#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) @@ -2997,56 +3983,81 @@ png_read_start_row(png_structp png_ptr) } #endif -#if defined(PNG_READ_FILLER_SUPPORTED) +#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 (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) + + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB || + png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { if (max_pixel_depth <= 32) max_pixel_depth = 32; + else max_pixel_depth = 64; } } #endif -#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED if (png_ptr->transformations & PNG_GRAY_TO_RGB) { if ( -#if defined(PNG_READ_EXPAND_SUPPORTED) - (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) || +#ifdef PNG_READ_EXPAND_SUPPORTED + (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) || #endif -#if defined(PNG_READ_FILLER_SUPPORTED) - (png_ptr->transformations & (PNG_FILLER)) || +#ifdef PNG_READ_FILLER_SUPPORTED + (png_ptr->transformations & (PNG_FILLER)) || #endif - png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + 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) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) max_pixel_depth = 32; - else + + 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; } @@ -3055,47 +4066,95 @@ png_read_start_row(png_structp png_ptr) #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* + 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; - } + + 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 */ + /* This value is stored in png_struct and double checked in the row read + * code. + */ + png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth; + png_ptr->transformed_pixel_depth = 0; /* calculated on demand */ + + /* Align the width on the next larger 8 pixels. Mainly used + * for interlacing + */ row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7)); - /* calculate the maximum bytes needed, adding a byte and a pixel - for safety's sake */ - row_bytes = ((row_bytes * (png_uint_32)max_pixel_depth + 7) >> 3) + - 1 + ((max_pixel_depth + 7) >> 3); + /* 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 - png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes+64); - png_ptr->row_buf = png_ptr->big_row_buf+32; -#if defined(PNG_DEBUG) && defined(PNG_USE_PNGGCCRD) - png_ptr->row_buf_size = row_bytes; + + if (row_bytes + 48 > png_ptr->old_big_row_buf_size) + { + png_free(png_ptr, png_ptr->big_row_buf); + png_free(png_ptr, png_ptr->big_prev_row); + + if (png_ptr->interlaced) + png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr, + row_bytes + 48); + + else + png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48); + + png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48); + +#ifdef PNG_ALIGNED_MEMORY_SUPPORTED + /* Use 16-byte aligned memory for row_buf with at least 16 bytes + * of padding before and after row_buf; treat prev_row similarly. + * NOTE: the alignment is to the start of the pixels, one beyond the start + * of the buffer, because of the filter byte. Prior to libpng 1.5.6 this + * was incorrect; the filter byte was aligned, which had the exact + * opposite effect of that intended. + */ + { + png_bytep temp = png_ptr->big_row_buf + 32; + int extra = (int)((temp - (png_bytep)0) & 0x0f); + png_ptr->row_buf = temp - extra - 1/*filter byte*/; + + temp = png_ptr->big_prev_row + 32; + extra = (int)((temp - (png_bytep)0) & 0x0f); + png_ptr->prev_row = temp - extra - 1/*filter byte*/; + } + +#else + /* Use 31 bytes of padding before and 17 bytes after row_buf. */ + png_ptr->row_buf = png_ptr->big_row_buf + 31; + png_ptr->prev_row = png_ptr->big_prev_row + 31; #endif + png_ptr->old_big_row_buf_size = row_bytes + 48; + } #ifdef PNG_MAX_MALLOC_64K - if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L) + if (png_ptr->rowbytes > 65535) png_error(png_ptr, "This image requires a row greater than 64KB"); + #endif - png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)( - png_ptr->rowbytes + 1)); + if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1)) + png_error(png_ptr, "Row has too many bytes to allocate in memory"); - png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1); + png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); - png_debug1(3, "width = %lu,\n", png_ptr->width); - png_debug1(3, "height = %lu,\n", png_ptr->height); - png_debug1(3, "iwidth = %lu,\n", png_ptr->iwidth); - png_debug1(3, "num_rows = %lu\n", png_ptr->num_rows); - png_debug1(3, "rowbytes = %lu,\n", png_ptr->rowbytes); - png_debug1(3, "irowbytes = %lu,\n", png_ptr->irowbytes); + 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 */