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Diffstat (limited to 'src/libpng/pngrutil.c')
| -rw-r--r-- | src/libpng/pngrutil.c | 3390 |
1 files changed, 3390 insertions, 0 deletions
diff --git a/src/libpng/pngrutil.c b/src/libpng/pngrutil.c new file mode 100644 index 0000000..45e7ddd --- /dev/null +++ b/src/libpng/pngrutil.c @@ -0,0 +1,3390 @@ + +/* pngrutil.c - utilities to read a PNG file + * + * Last changed in libpng 1.2.45 [July 7, 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 +#define PNG_NO_PEDANTIC_WARNINGS +#include "png.h" +#ifdef PNG_READ_SUPPORTED + +#if defined(_WIN32_WCE) && (_WIN32_WCE<0x500) +# define WIN32_WCE_OLD +#endif + +#ifdef PNG_FLOATING_POINT_SUPPORTED +# ifdef WIN32_WCE_OLD +/* The strtod() function is not supported on WindowsCE */ +__inline double png_strtod(png_structp png_ptr, PNG_CONST char *nptr, + char **endptr) +{ + double result = 0; + int len; + wchar_t *str, *end; + + len = MultiByteToWideChar(CP_ACP, 0, nptr, -1, NULL, 0); + str = (wchar_t *)png_malloc(png_ptr, len * png_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); + png_free(png_ptr, str); + } + return result; +} +# else +# define png_strtod(p,a,b) strtod(a,b) +# endif +#endif + +png_uint_32 PNGAPI +png_get_uint_31(png_structp png_ptr, png_bytep buf) +{ +#ifdef PNG_READ_BIG_ENDIAN_SUPPORTED + png_uint_32 i = png_get_uint_32(buf); +#else + /* Avoid an extra function call by inlining the result. */ + 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)); +#endif + if (i > PNG_UINT_31_MAX) + png_error(png_ptr, "PNG unsigned integer out of range."); + return (i); +} +#ifndef PNG_READ_BIG_ENDIAN_SUPPORTED +/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */ +png_uint_32 PNGAPI +png_get_uint_32(png_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)); + + return (i); +} + +/* 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 PNGAPI +png_get_int_32(png_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)); + + return (i); +} + +/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */ +png_uint_16 PNGAPI +png_get_uint_16(png_bytep buf) +{ + png_uint_16 i = (png_uint_16)(((png_uint_16)(*buf) << 8) + + (png_uint_16)(*(buf + 1))); + + return (i); +} +#endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */ + +/* 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_byte buf[8]; + png_uint_32 length; + + /* Read the length and the chunk name */ + 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_memcpy(png_ptr->chunk_name, buf + 4, 4); + + png_debug2(0, "Reading %s chunk, length = %lu", + png_ptr->chunk_name, length); + + /* Reset the crc and run it over the chunk name */ + png_reset_crc(png_ptr); + png_calculate_crc(png_ptr, png_ptr->chunk_name, 4); + + /* Check to see if chunk name is valid */ + png_check_chunk_name(png_ptr, png_ptr->chunk_name); + + return length; +} + +/* 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. + */ +int /* PRIVATE */ +png_crc_finish(png_structp png_ptr, png_uint_32 skip) +{ + png_size_t i; + png_size_t istop = png_ptr->zbuf_size; + + for (i = (png_size_t)skip; i > istop; i -= istop) + { + png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); + } + if (i) + { + png_crc_read(png_ptr, png_ptr->zbuf, i); + } + + 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))) + { + png_chunk_warning(png_ptr, "CRC error"); + } + else + { + png_chunk_error(png_ptr, "CRC error"); + } + return (1); + } + + return (0); +} + +/* Compare the CRC stored in the PNG file with that calculated by libpng from + * the data it has read thus far. + */ +int /* PRIVATE */ +png_crc_error(png_structp png_ptr) +{ + png_byte crc_bytes[4]; + png_uint_32 crc; + int need_crc = 1; + + if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ + { + if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == + (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) + need_crc = 0; + } + else /* critical */ + { + if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) + need_crc = 0; + } + + png_read_data(png_ptr, crc_bytes, 4); + + if (need_crc) + { + crc = png_get_uint_32(crc_bytes); + return ((int)(crc != png_ptr->crc)); + } + else + return (0); +} + +#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \ + defined(PNG_READ_iCCP_SUPPORTED) +static png_size_t +png_inflate(png_structp png_ptr, const png_byte *data, png_size_t size, + png_bytep output, png_size_t output_size) +{ + png_size_t count = 0; + + png_ptr->zstream.next_in = (png_bytep)data; /* const_cast: VALID */ + png_ptr->zstream.avail_in = size; + + while (1) + { + int ret, avail; + + /* 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 = png_ptr->zbuf_size; + + ret = inflate(&png_ptr->zstream, Z_NO_FLUSH); + avail = png_ptr->zbuf_size - png_ptr->zstream.avail_out; + + /* 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) + { + if (output != 0 && output_size > count) + { + int copy = output_size - count; + if (avail < copy) copy = avail; + png_memcpy(output + count, png_ptr->zbuf, copy); + } + count += avail; + } + + 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. + */ + { + PNG_CONST char *msg; + if (png_ptr->zstream.msg != 0) + msg = png_ptr->zstream.msg; + else + { +#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE) + char umsg[52]; + + switch (ret) + { + case Z_BUF_ERROR: + msg = "Buffer error in compressed datastream in %s chunk"; + break; + case Z_DATA_ERROR: + msg = "Data error in compressed datastream in %s chunk"; + break; + default: + msg = "Incomplete compressed datastream in %s chunk"; + break; + } + + png_snprintf(umsg, sizeof umsg, msg, png_ptr->chunk_name); + msg = umsg; +#else + msg = "Damaged compressed datastream in chunk other than IDAT"; +#endif + } + + png_warning(png_ptr, msg); + } + + /* 0 means an error - notice that this code simple 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 +# 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 + 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 +#endif + if (expanded_size > 0) + { + /* Success (maybe) - really uncompress the chunk. */ + png_size_t new_size = 0; + png_charp text = png_malloc_warn(png_ptr, + prefix_size + expanded_size + 1); + + if (text != NULL) + { + 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); + } + else + png_warning(png_ptr, "Not enough memory to decompress chunk."); + } + } + + else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */ + { +#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE) + char umsg[50]; + + png_snprintf(umsg, sizeof umsg, "Unknown zTXt compression type %d", + comp_type); + png_warning(png_ptr, umsg); +#else + png_warning(png_ptr, "Unknown zTXt compression type"); +#endif + + /* The recovery is to simply drop the data. */ + } + + /* Generic error return - leave the prefix, delete the compressed + * data, reallocate the chunkdata to remove the potentially large + * amount of compressed data. + */ + { + png_charp text = png_malloc_warn(png_ptr, prefix_size + 1); + if (text != NULL) + { + if (prefix_size > 0) + png_memcpy(text, png_ptr->chunkdata, prefix_size); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = text; + + /* This is an extra zero in the 'uncompressed' part. */ + *(png_ptr->chunkdata + prefix_size) = 0x00; + } + /* Ignore a malloc error here - it is safe. */ + } + + *newlength = prefix_size; +} +#endif + +/* Read and check the IDHR chunk */ +void /* PRIVATE */ +png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[13]; + png_uint_32 width, height; + int bit_depth, color_type, compression_type, filter_type; + int interlace_type; + + png_debug(1, "in png_handle_IHDR"); + + if (png_ptr->mode & PNG_HAVE_IHDR) + png_error(png_ptr, "Out of place IHDR"); + + /* Check the length */ + if (length != 13) + png_error(png_ptr, "Invalid IHDR chunk"); + + png_ptr->mode |= PNG_HAVE_IHDR; + + png_crc_read(png_ptr, buf, 13); + png_crc_finish(png_ptr, 0); + + width = png_get_uint_31(png_ptr, buf); + height = png_get_uint_31(png_ptr, buf + 4); + bit_depth = buf[8]; + color_type = buf[9]; + compression_type = buf[10]; + filter_type = buf[11]; + interlace_type = buf[12]; + + /* Set internal variables */ + png_ptr->width = width; + png_ptr->height = height; + png_ptr->bit_depth = (png_byte)bit_depth; + png_ptr->interlaced = (png_byte)interlace_type; + png_ptr->color_type = (png_byte)color_type; +#ifdef PNG_MNG_FEATURES_SUPPORTED + png_ptr->filter_type = (png_byte)filter_type; +#endif + png_ptr->compression_type = (png_byte)compression_type; + + /* Find number of channels */ + switch (png_ptr->color_type) + { + case PNG_COLOR_TYPE_GRAY: + case PNG_COLOR_TYPE_PALETTE: + png_ptr->channels = 1; + break; + + case PNG_COLOR_TYPE_RGB: + png_ptr->channels = 3; + break; + + case PNG_COLOR_TYPE_GRAY_ALPHA: + png_ptr->channels = 2; + break; + + case PNG_COLOR_TYPE_RGB_ALPHA: + png_ptr->channels = 4; + break; + } + + /* Set up other useful info */ + png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * + png_ptr->channels); + png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width); + png_debug1(3, "bit_depth = %d", png_ptr->bit_depth); + png_debug1(3, "channels = %d", png_ptr->channels); + png_debug1(3, "rowbytes = %lu", png_ptr->rowbytes); + png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, + color_type, interlace_type, compression_type, filter_type); +} + +/* Read and check the palette */ +void /* PRIVATE */ +png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_color palette[PNG_MAX_PALETTE_LENGTH]; + int num, i; +#ifdef PNG_POINTER_INDEXING_SUPPORTED + png_colorp pal_ptr; +#endif + + png_debug(1, "in png_handle_PLTE"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before PLTE"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid PLTE after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (png_ptr->mode & PNG_HAVE_PLTE) + png_error(png_ptr, "Duplicate PLTE chunk"); + + png_ptr->mode |= PNG_HAVE_PLTE; + + if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR)) + { + png_warning(png_ptr, + "Ignoring PLTE chunk in grayscale PNG"); + png_crc_finish(png_ptr, length); + return; + } +#ifndef PNG_READ_OPT_PLTE_SUPPORTED + if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) + { + png_crc_finish(png_ptr, length); + return; + } +#endif + + if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3) + { + if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) + { + png_warning(png_ptr, "Invalid palette chunk"); + png_crc_finish(png_ptr, length); + return; + } + + else + { + png_error(png_ptr, "Invalid palette chunk"); + } + } + + num = (int)length / 3; + +#ifdef PNG_POINTER_INDEXING_SUPPORTED + for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++) + { + png_byte buf[3]; + + png_crc_read(png_ptr, buf, 3); + pal_ptr->red = buf[0]; + pal_ptr->green = buf[1]; + pal_ptr->blue = buf[2]; + } +#else + for (i = 0; i < num; i++) + { + png_byte buf[3]; + + png_crc_read(png_ptr, buf, 3); + /* Don't depend upon png_color being any order */ + palette[i].red = buf[0]; + palette[i].green = buf[1]; + palette[i].blue = buf[2]; + } +#endif + + /* If we actually NEED the PLTE chunk (ie for a paletted image), we do + * whatever the normal CRC configuration tells us. However, if we + * have an RGB image, the PLTE can be considered ancillary, so + * we will act as though it is. + */ +#ifndef PNG_READ_OPT_PLTE_SUPPORTED + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) +#endif + { + png_crc_finish(png_ptr, 0); + } +#ifndef PNG_READ_OPT_PLTE_SUPPORTED + else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */ + { + /* If we don't want to use the data from an ancillary chunk, + we have two options: an error abort, or a warning and we + ignore the data in this chunk (which should be OK, since + it's considered ancillary for a RGB or RGBA image). */ + if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE)) + { + if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) + { + png_chunk_error(png_ptr, "CRC error"); + } + else + { + png_chunk_warning(png_ptr, "CRC error"); + return; + } + } + /* Otherwise, we (optionally) emit a warning and use the chunk. */ + else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) + { + png_chunk_warning(png_ptr, "CRC error"); + } + } +#endif + + png_set_PLTE(png_ptr, info_ptr, palette, num); + +#ifdef PNG_READ_tRNS_SUPPORTED + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS)) + { + if (png_ptr->num_trans > (png_uint_16)num) + { + png_warning(png_ptr, "Truncating incorrect tRNS chunk length"); + png_ptr->num_trans = (png_uint_16)num; + } + if (info_ptr->num_trans > (png_uint_16)num) + { + png_warning(png_ptr, "Truncating incorrect info tRNS chunk length"); + info_ptr->num_trans = (png_uint_16)num; + } + } + } +#endif + +} + +void /* PRIVATE */ +png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_debug(1, "in png_handle_IEND"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT)) + { + png_error(png_ptr, "No image in file"); + } + + png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND); + + if (length != 0) + { + png_warning(png_ptr, "Incorrect IEND chunk length"); + } + png_crc_finish(png_ptr, length); + + info_ptr = info_ptr; /* Quiet compiler warnings about unused info_ptr */ +} + +#ifdef PNG_READ_gAMA_SUPPORTED +void /* PRIVATE */ +png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_fixed_point igamma; +#ifdef PNG_FLOATING_POINT_SUPPORTED + float file_gamma; +#endif + png_byte buf[4]; + + png_debug(1, "in png_handle_gAMA"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before gAMA"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid gAMA after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (png_ptr->mode & PNG_HAVE_PLTE) + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Out of place gAMA chunk"); + + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA) +#ifdef PNG_READ_sRGB_SUPPORTED + && !(info_ptr->valid & PNG_INFO_sRGB) +#endif + ) + { + png_warning(png_ptr, "Duplicate gAMA chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 4) + { + png_warning(png_ptr, "Incorrect gAMA chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 4); + if (png_crc_finish(png_ptr, 0)) + return; + + igamma = (png_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; + } + +#ifdef PNG_READ_sRGB_SUPPORTED + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)) + if (PNG_OUT_OF_RANGE(igamma, 45500L, 500)) + { + png_warning(png_ptr, + "Ignoring incorrect gAMA value when sRGB is also present"); +#ifdef PNG_CONSOLE_IO_SUPPORTED + fprintf(stderr, "gamma = (%d/100000)", (int)igamma); +#endif + return; + } +#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; +# endif + png_set_gAMA(png_ptr, info_ptr, file_gamma); +#endif +#ifdef PNG_FIXED_POINT_SUPPORTED + png_set_gAMA_fixed(png_ptr, info_ptr, igamma); +#endif +} +#endif + +#ifdef PNG_READ_sBIT_SUPPORTED +void /* PRIVATE */ +png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_size_t truelen; + png_byte buf[4]; + + png_debug(1, "in png_handle_sBIT"); + + buf[0] = buf[1] = buf[2] = buf[3] = 0; + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before sBIT"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid sBIT after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (png_ptr->mode & PNG_HAVE_PLTE) + { + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Out of place sBIT chunk"); + } + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)) + { + png_warning(png_ptr, "Duplicate sBIT chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + truelen = 3; + else + truelen = (png_size_t)png_ptr->channels; + + if (length != truelen || length > 4) + { + png_warning(png_ptr, "Incorrect sBIT chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, truelen); + if (png_crc_finish(png_ptr, 0)) + return; + + if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) + { + png_ptr->sig_bit.red = buf[0]; + png_ptr->sig_bit.green = buf[1]; + png_ptr->sig_bit.blue = buf[2]; + png_ptr->sig_bit.alpha = buf[3]; + } + else + { + png_ptr->sig_bit.gray = buf[0]; + png_ptr->sig_bit.red = buf[0]; + png_ptr->sig_bit.green = buf[0]; + png_ptr->sig_bit.blue = buf[0]; + png_ptr->sig_bit.alpha = buf[1]; + } + png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit)); +} +#endif + +#ifdef PNG_READ_cHRM_SUPPORTED +void /* PRIVATE */ +png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[32]; +#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_uint_32 uint_x, uint_y; + + png_debug(1, "in png_handle_cHRM"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before cHRM"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid cHRM after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (png_ptr->mode & PNG_HAVE_PLTE) + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Missing PLTE before cHRM"); + + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM) +#ifdef PNG_READ_sRGB_SUPPORTED + && !(info_ptr->valid & PNG_INFO_sRGB) +#endif + ) + { + png_warning(png_ptr, "Duplicate cHRM chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 32) + { + png_warning(png_ptr, "Incorrect cHRM chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 32); + if (png_crc_finish(png_ptr, 0)) + return; + + uint_x = png_get_uint_32(buf); + uint_y = png_get_uint_32(buf + 4); + int_x_white = (png_fixed_point)uint_x; + int_y_white = (png_fixed_point)uint_y; + + uint_x = png_get_uint_32(buf + 8); + uint_y = png_get_uint_32(buf + 12); + int_x_red = (png_fixed_point)uint_x; + int_y_red = (png_fixed_point)uint_y; + + uint_x = png_get_uint_32(buf + 16); + uint_y = png_get_uint_32(buf + 20); + int_x_green = (png_fixed_point)uint_x; + int_y_green = (png_fixed_point)uint_y; + + uint_x = png_get_uint_32(buf + 24); + uint_y = png_get_uint_32(buf + 28); + 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 + +#ifdef PNG_READ_sRGB_SUPPORTED + if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB)) + { + if (PNG_OUT_OF_RANGE(int_x_white, 31270, 1000) || + PNG_OUT_OF_RANGE(int_y_white, 32900, 1000) || + PNG_OUT_OF_RANGE(int_x_red, 64000L, 1000) || + PNG_OUT_OF_RANGE(int_y_red, 33000, 1000) || + PNG_OUT_OF_RANGE(int_x_green, 30000, 1000) || + PNG_OUT_OF_RANGE(int_y_green, 60000L, 1000) || + PNG_OUT_OF_RANGE(int_x_blue, 15000, 1000) || + PNG_OUT_OF_RANGE(int_y_blue, 6000, 1000)) + { + png_warning(png_ptr, + "Ignoring incorrect cHRM value when sRGB is also present"); +#ifdef PNG_CONSOLE_IO_SUPPORTED +#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", + (long)int_x_white, (long)int_y_white, + (long)int_x_red, (long)int_y_red); + fprintf(stderr, "gx=%ld, gy=%ld, bx=%ld, by=%ld\n", + (long)int_x_green, (long)int_y_green, + (long)int_x_blue, (long)int_y_blue); +#endif +#endif /* PNG_CONSOLE_IO_SUPPORTED */ + } + 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 +} +#endif + +#ifdef PNG_READ_sRGB_SUPPORTED +void /* PRIVATE */ +png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + int intent; + png_byte buf[1]; + + png_debug(1, "in png_handle_sRGB"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before sRGB"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid sRGB after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (png_ptr->mode & PNG_HAVE_PLTE) + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Out of place sRGB chunk"); + + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)) + { + png_warning(png_ptr, "Duplicate sRGB chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 1) + { + png_warning(png_ptr, "Incorrect sRGB chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 1); + if (png_crc_finish(png_ptr, 0)) + return; + + intent = buf[0]; + /* Check for bad intent */ + if (intent >= PNG_sRGB_INTENT_LAST) + { + png_warning(png_ptr, "Unknown sRGB intent"); + return; + } + +#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)) + { + png_fixed_point igamma; +#ifdef PNG_FIXED_POINT_SUPPORTED + igamma=info_ptr->int_gamma; +#else +# ifdef PNG_FLOATING_POINT_SUPPORTED + igamma=(png_fixed_point)(info_ptr->gamma * 100000.); +# endif +#endif + if (PNG_OUT_OF_RANGE(igamma, 45500L, 500)) + { + png_warning(png_ptr, + "Ignoring incorrect gAMA value when sRGB is also present"); +#ifdef PNG_CONSOLE_IO_SUPPORTED +# 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 + } + } +#endif /* PNG_READ_gAMA_SUPPORTED */ + +#ifdef PNG_READ_cHRM_SUPPORTED +#ifdef PNG_FIXED_POINT_SUPPORTED + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)) + if (PNG_OUT_OF_RANGE(info_ptr->int_x_white, 31270, 1000) || + PNG_OUT_OF_RANGE(info_ptr->int_y_white, 32900, 1000) || + PNG_OUT_OF_RANGE(info_ptr->int_x_red, 64000L, 1000) || + PNG_OUT_OF_RANGE(info_ptr->int_y_red, 33000, 1000) || + PNG_OUT_OF_RANGE(info_ptr->int_x_green, 30000, 1000) || + PNG_OUT_OF_RANGE(info_ptr->int_y_green, 60000L, 1000) || + PNG_OUT_OF_RANGE(info_ptr->int_x_blue, 15000, 1000) || + PNG_OUT_OF_RANGE(info_ptr->int_y_blue, 6000, 1000)) + { + png_warning(png_ptr, + "Ignoring incorrect cHRM value when sRGB is also present"); + } +#endif /* PNG_FIXED_POINT_SUPPORTED */ +#endif /* PNG_READ_cHRM_SUPPORTED */ + + png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent); +} +#endif /* PNG_READ_sRGB_SUPPORTED */ + +#ifdef PNG_READ_iCCP_SUPPORTED +void /* PRIVATE */ +png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +/* Note: this does not properly handle chunks that are > 64K under DOS */ +{ + png_byte compression_type; + png_bytep pC; + png_charp profile; + png_uint_32 skip = 0; + png_uint_32 profile_size, profile_length; + png_size_t slength, prefix_length, data_length; + + png_debug(1, "in png_handle_iCCP"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before iCCP"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid iCCP after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (png_ptr->mode & PNG_HAVE_PLTE) + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Out of place iCCP chunk"); + + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)) + { + png_warning(png_ptr, "Duplicate iCCP chunk"); + png_crc_finish(png_ptr, length); + return; + } + +#ifdef PNG_MAX_MALLOC_64K + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "iCCP chunk too large to fit in memory"); + skip = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; + } +#endif + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1); + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + + if (png_crc_finish(png_ptr, skip)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + png_ptr->chunkdata[slength] = 0x00; + + for (profile = png_ptr->chunkdata; *profile; profile++) + /* Empty loop to find end of name */ ; + + ++profile; + + /* There should be at least one zero (the compression type byte) + * following the separator, and we should be on it + */ + if ( profile >= png_ptr->chunkdata + slength - 1) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_warning(png_ptr, "Malformed iCCP chunk"); + return; + } + + /* Compression_type should always be zero */ + compression_type = *profile++; + if (compression_type) + { + png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk"); + compression_type = 0x00; /* Reset it to zero (libpng-1.0.6 through 1.0.8 + wrote nonzero) */ + } + + prefix_length = profile - png_ptr->chunkdata; + png_decompress_chunk(png_ptr, compression_type, + slength, prefix_length, &data_length); + + profile_length = data_length - prefix_length; + + if ( prefix_length > data_length || profile_length < 4) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_warning(png_ptr, "Profile size field missing from iCCP chunk"); + return; + } + + /* Check the profile_size recorded in the first 32 bits of the ICC profile */ + pC = (png_bytep)(png_ptr->chunkdata + prefix_length); + profile_size = ((*(pC ))<<24) | + ((*(pC + 1))<<16) | + ((*(pC + 2))<< 8) | + ((*(pC + 3)) ); + + if (profile_size < profile_length) + profile_length = profile_size; + + if (profile_size > profile_length) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_warning(png_ptr, "Ignoring truncated iCCP profile."); + return; + } + + png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata, + compression_type, png_ptr->chunkdata + prefix_length, profile_length); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; +} +#endif /* PNG_READ_iCCP_SUPPORTED */ + +#ifdef PNG_READ_sPLT_SUPPORTED +void /* PRIVATE */ +png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +/* Note: this does not properly handle chunks that are > 64K under DOS */ +{ + png_bytep entry_start; + png_sPLT_t new_palette; +#ifdef PNG_POINTER_INDEXING_SUPPORTED + png_sPLT_entryp pp; +#endif + int data_length, entry_size, i; + png_uint_32 skip = 0; + png_size_t slength; + + png_debug(1, "in png_handle_sPLT"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + if (--png_ptr->user_chunk_cache_max == 1) + { + png_warning(png_ptr, "No space in chunk cache for sPLT"); + png_crc_finish(png_ptr, length); + return; + } + } +#endif + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before sPLT"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid sPLT after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + +#ifdef PNG_MAX_MALLOC_64K + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "sPLT chunk too large to fit in memory"); + skip = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; + } +#endif + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1); + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + + if (png_crc_finish(png_ptr, skip)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + png_ptr->chunkdata[slength] = 0x00; + + for (entry_start = (png_bytep)png_ptr->chunkdata; *entry_start; + entry_start++) + /* Empty loop to find end of name */ ; + ++entry_start; + + /* A sample depth should follow the separator, and we should be on it */ + if (entry_start > (png_bytep)png_ptr->chunkdata + slength - 2) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_warning(png_ptr, "malformed sPLT chunk"); + return; + } + + new_palette.depth = *entry_start++; + entry_size = (new_palette.depth == 8 ? 6 : 10); + data_length = (slength - (entry_start - (png_bytep)png_ptr->chunkdata)); + + /* Integrity-check the data length */ + if (data_length % entry_size) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_warning(png_ptr, "sPLT chunk has bad length"); + return; + } + + new_palette.nentries = (png_int_32) ( data_length / entry_size); + if ((png_uint_32) new_palette.nentries > + (png_uint_32) (PNG_SIZE_MAX / png_sizeof(png_sPLT_entry))) + { + png_warning(png_ptr, "sPLT chunk too long"); + return; + } + new_palette.entries = (png_sPLT_entryp)png_malloc_warn( + png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry)); + if (new_palette.entries == NULL) + { + png_warning(png_ptr, "sPLT chunk requires too much memory"); + return; + } + +#ifdef PNG_POINTER_INDEXING_SUPPORTED + for (i = 0; i < new_palette.nentries; i++) + { + pp = new_palette.entries + i; + + if (new_palette.depth == 8) + { + pp->red = *entry_start++; + pp->green = *entry_start++; + pp->blue = *entry_start++; + pp->alpha = *entry_start++; + } + else + { + pp->red = png_get_uint_16(entry_start); entry_start += 2; + pp->green = png_get_uint_16(entry_start); entry_start += 2; + pp->blue = png_get_uint_16(entry_start); entry_start += 2; + pp->alpha = png_get_uint_16(entry_start); entry_start += 2; + } + pp->frequency = png_get_uint_16(entry_start); entry_start += 2; + } +#else + pp = new_palette.entries; + for (i = 0; i < new_palette.nentries; i++) + { + + if (new_palette.depth == 8) + { + pp[i].red = *entry_start++; + pp[i].green = *entry_start++; + pp[i].blue = *entry_start++; + pp[i].alpha = *entry_start++; + } + else + { + pp[i].red = png_get_uint_16(entry_start); entry_start += 2; + pp[i].green = png_get_uint_16(entry_start); entry_start += 2; + pp[i].blue = png_get_uint_16(entry_start); entry_start += 2; + pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2; + } + pp->frequency = png_get_uint_16(entry_start); entry_start += 2; + } +#endif + + /* Discard all chunk data except the name and stash that */ + new_palette.name = png_ptr->chunkdata; + + png_set_sPLT(png_ptr, info_ptr, &new_palette, 1); + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_free(png_ptr, new_palette.entries); +} +#endif /* PNG_READ_sPLT_SUPPORTED */ + +#ifdef PNG_READ_tRNS_SUPPORTED +void /* PRIVATE */ +png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte readbuf[PNG_MAX_PALETTE_LENGTH]; + + png_debug(1, "in png_handle_tRNS"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before tRNS"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid tRNS after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS)) + { + png_warning(png_ptr, "Duplicate tRNS chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + png_byte buf[2]; + + if (length != 2) + { + png_warning(png_ptr, "Incorrect tRNS chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 2); + png_ptr->num_trans = 1; + png_ptr->trans_values.gray = png_get_uint_16(buf); + } + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + { + png_byte buf[6]; + + if (length != 6) + { + png_warning(png_ptr, "Incorrect tRNS chunk length"); + png_crc_finish(png_ptr, length); + return; + } + png_crc_read(png_ptr, buf, (png_size_t)length); + png_ptr->num_trans = 1; + png_ptr->trans_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); + } + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (!(png_ptr->mode & PNG_HAVE_PLTE)) + { + /* Should be an error, but we can cope with it. */ + png_warning(png_ptr, "Missing PLTE before tRNS"); + } + if (length > (png_uint_32)png_ptr->num_palette || + length > PNG_MAX_PALETTE_LENGTH) + { + png_warning(png_ptr, "Incorrect tRNS chunk length"); + png_crc_finish(png_ptr, length); + return; + } + if (length == 0) + { + png_warning(png_ptr, "Zero length tRNS chunk"); + png_crc_finish(png_ptr, length); + return; + } + png_crc_read(png_ptr, readbuf, (png_size_t)length); + png_ptr->num_trans = (png_uint_16)length; + } + else + { + png_warning(png_ptr, "tRNS chunk not allowed with alpha channel"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_crc_finish(png_ptr, 0)) + { + png_ptr->num_trans = 0; + return; + } + + png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans, + &(png_ptr->trans_values)); +} +#endif + +#ifdef PNG_READ_bKGD_SUPPORTED +void /* PRIVATE */ +png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_size_t truelen; + png_byte buf[6]; + + png_debug(1, "in png_handle_bKGD"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before bKGD"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid bKGD after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + !(png_ptr->mode & PNG_HAVE_PLTE)) + { + png_warning(png_ptr, "Missing PLTE before bKGD"); + png_crc_finish(png_ptr, length); + return; + } + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)) + { + png_warning(png_ptr, "Duplicate bKGD chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + truelen = 1; + else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) + truelen = 6; + else + truelen = 2; + + if (length != truelen) + { + png_warning(png_ptr, "Incorrect bKGD chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, truelen); + if (png_crc_finish(png_ptr, 0)) + return; + + /* We convert the index value into RGB components so that we can allow + * arbitrary RGB values for background when we have transparency, and + * so it is easy to determine the RGB values of the background color + * from the info_ptr struct. */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + png_ptr->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; + } + } + 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); + } + 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); + } + + png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background)); +} +#endif + +#ifdef PNG_READ_hIST_SUPPORTED +void /* PRIVATE */ +png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + unsigned int num, i; + png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH]; + + png_debug(1, "in png_handle_hIST"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before hIST"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid hIST after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (!(png_ptr->mode & PNG_HAVE_PLTE)) + { + png_warning(png_ptr, "Missing PLTE before hIST"); + png_crc_finish(png_ptr, length); + return; + } + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)) + { + png_warning(png_ptr, "Duplicate hIST chunk"); + png_crc_finish(png_ptr, length); + return; + } + + num = length / 2 ; + if (num != (unsigned int) png_ptr->num_palette || num > + (unsigned int) PNG_MAX_PALETTE_LENGTH) + { + png_warning(png_ptr, "Incorrect hIST chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + for (i = 0; i < num; i++) + { + png_byte buf[2]; + + png_crc_read(png_ptr, buf, 2); + readbuf[i] = png_get_uint_16(buf); + } + + if (png_crc_finish(png_ptr, 0)) + return; + + png_set_hIST(png_ptr, info_ptr, readbuf); +} +#endif + +#ifdef PNG_READ_pHYs_SUPPORTED +void /* PRIVATE */ +png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[9]; + png_uint_32 res_x, res_y; + int unit_type; + + png_debug(1, "in png_handle_pHYs"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before pHYs"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid pHYs after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) + { + png_warning(png_ptr, "Duplicate pHYs chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 9) + { + png_warning(png_ptr, "Incorrect pHYs chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 9); + if (png_crc_finish(png_ptr, 0)) + return; + + res_x = png_get_uint_32(buf); + res_y = png_get_uint_32(buf + 4); + unit_type = buf[8]; + png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type); +} +#endif + +#ifdef PNG_READ_oFFs_SUPPORTED +void /* PRIVATE */ +png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[9]; + png_int_32 offset_x, offset_y; + int unit_type; + + png_debug(1, "in png_handle_oFFs"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before oFFs"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid oFFs after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) + { + png_warning(png_ptr, "Duplicate oFFs chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 9) + { + png_warning(png_ptr, "Incorrect oFFs chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 9); + if (png_crc_finish(png_ptr, 0)) + return; + + offset_x = png_get_int_32(buf); + offset_y = png_get_int_32(buf + 4); + unit_type = buf[8]; + png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type); +} +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED +/* Read the pCAL chunk (described in the PNG Extensions document) */ +void /* PRIVATE */ +png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_int_32 X0, X1; + png_byte type, nparams; + png_charp buf, units, endptr; + png_charpp params; + png_size_t slength; + int i; + + png_debug(1, "in png_handle_pCAL"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before pCAL"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid pCAL after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL)) + { + png_warning(png_ptr, "Duplicate pCAL chunk"); + png_crc_finish(png_ptr, length); + return; + } + + png_debug1(2, "Allocating and reading pCAL chunk data (%lu bytes)", + length + 1); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); + if (png_ptr->chunkdata == NULL) + { + png_warning(png_ptr, "No memory for pCAL purpose."); + return; + } + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + + if (png_crc_finish(png_ptr, 0)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */ + + png_debug(3, "Finding end of pCAL purpose string"); + for (buf = png_ptr->chunkdata; *buf; buf++) + /* Empty loop */ ; + + endptr = png_ptr->chunkdata + slength; + + /* We need to have at least 12 bytes after the purpose string + in order to get the parameter information. */ + if (endptr <= buf + 12) + { + png_warning(png_ptr, "Invalid pCAL data"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + png_debug(3, "Reading pCAL X0, X1, type, nparams, and units"); + X0 = png_get_int_32((png_bytep)buf+1); + X1 = png_get_int_32((png_bytep)buf+5); + type = buf[9]; + nparams = buf[10]; + units = buf + 11; + + png_debug(3, "Checking pCAL equation type and number of parameters"); + /* Check that we have the right number of parameters for known + equation types. */ + if ((type == PNG_EQUATION_LINEAR && nparams != 2) || + (type == PNG_EQUATION_BASE_E && nparams != 3) || + (type == PNG_EQUATION_ARBITRARY && nparams != 3) || + (type == PNG_EQUATION_HYPERBOLIC && nparams != 4)) + { + png_warning(png_ptr, "Invalid pCAL parameters for equation type"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + else if (type >= PNG_EQUATION_LAST) + { + png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); + } + + for (buf = units; *buf; buf++) + /* Empty loop to move past the units string. */ ; + + png_debug(3, "Allocating pCAL parameters array"); + params = (png_charpp)png_malloc_warn(png_ptr, + (png_uint_32)(nparams * png_sizeof(png_charp))) ; + if (params == NULL) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_warning(png_ptr, "No memory for pCAL params."); + return; + } + + /* Get pointers to the start of each parameter string. */ + for (i = 0; i < (int)nparams; i++) + { + buf++; /* Skip the null string terminator from previous parameter. */ + + png_debug1(3, "Reading pCAL parameter %d", i); + for (params[i] = buf; buf <= endptr && *buf != 0x00; buf++) + /* Empty loop to move past each parameter string */ ; + + /* Make sure we haven't run out of data yet */ + if (buf > endptr) + { + png_warning(png_ptr, "Invalid pCAL data"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_free(png_ptr, params); + return; + } + } + + png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams, + units, params); + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_free(png_ptr, params); +} +#endif + +#ifdef PNG_READ_sCAL_SUPPORTED +/* Read the sCAL chunk */ +void /* PRIVATE */ +png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_charp 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_debug(1, "in png_handle_sCAL"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before sCAL"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid sCAL after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL)) + { + png_warning(png_ptr, "Duplicate sCAL chunk"); + png_crc_finish(png_ptr, length); + return; + } + + /* Need unit type, width, \0, height: minimum 4 bytes */ + else if (length < 4) + { + png_warning(png_ptr, "sCAL chunk too short"); + png_crc_finish(png_ptr, length); + return; + } + + png_debug1(2, "Allocating and reading sCAL chunk data (%lu bytes)", + length + 1); + png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); + if (png_ptr->chunkdata == NULL) + { + png_warning(png_ptr, "Out of memory while processing sCAL chunk"); + png_crc_finish(png_ptr, length); + return; + } + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + + if (png_crc_finish(png_ptr, 0)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */ + + ep = png_ptr->chunkdata + 1; /* Skip unit byte */ + +#ifdef PNG_FLOATING_POINT_SUPPORTED + width = png_strtod(png_ptr, ep, &vp); + if (*vp) + { + png_warning(png_ptr, "malformed width string in sCAL chunk"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + 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"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + png_memcpy(swidth, ep, (png_size_t)png_strlen(ep)); +#endif +#endif + + for (ep = png_ptr->chunkdata; *ep; ep++) + /* Empty loop */ ; + ep++; + + if (png_ptr->chunkdata + slength < ep) + { + png_warning(png_ptr, "Truncated sCAL chunk"); +#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) + png_free(png_ptr, swidth); +#endif + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + +#ifdef PNG_FLOATING_POINT_SUPPORTED + height = png_strtod(png_ptr, ep, &vp); + if (*vp) + { + png_warning(png_ptr, "malformed height string in sCAL chunk"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; +#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) + png_free(png_ptr, swidth); +#endif + return; + } +#else +#ifdef PNG_FIXED_POINT_SUPPORTED + sheight = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1); + if (sheight == NULL) + { + png_warning(png_ptr, "Out of memory while processing sCAL chunk height"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; +#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) + png_free(png_ptr, swidth); +#endif + return; + } + png_memcpy(sheight, ep, (png_size_t)png_strlen(ep)); +#endif +#endif + + if (png_ptr->chunkdata + slength < ep +#ifdef PNG_FLOATING_POINT_SUPPORTED + || width <= 0. || height <= 0. +#endif + ) + { + png_warning(png_ptr, "Invalid sCAL data"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; +#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) + png_free(png_ptr, swidth); + png_free(png_ptr, sheight); +#endif + return; + } + + +#ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_sCAL(png_ptr, info_ptr, png_ptr->chunkdata[0], width, height); +#else +#ifdef PNG_FIXED_POINT_SUPPORTED + png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0], swidth, sheight); +#endif +#endif + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; +#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) + png_free(png_ptr, swidth); + png_free(png_ptr, sheight); +#endif +} +#endif + +#ifdef PNG_READ_tIME_SUPPORTED +void /* PRIVATE */ +png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[7]; + png_time mod_time; + + png_debug(1, "in png_handle_tIME"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Out of place tIME chunk"); + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME)) + { + png_warning(png_ptr, "Duplicate tIME chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_ptr->mode & PNG_HAVE_IDAT) + png_ptr->mode |= PNG_AFTER_IDAT; + + if (length != 7) + { + png_warning(png_ptr, "Incorrect tIME chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 7); + if (png_crc_finish(png_ptr, 0)) + return; + + mod_time.second = buf[6]; + mod_time.minute = buf[5]; + mod_time.hour = buf[4]; + mod_time.day = buf[3]; + mod_time.month = buf[2]; + mod_time.year = png_get_uint_16(buf); + + png_set_tIME(png_ptr, info_ptr, &mod_time); +} +#endif + +#ifdef PNG_READ_tEXt_SUPPORTED +/* Note: this does not properly handle chunks that are > 64K under DOS */ +void /* PRIVATE */ +png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_textp text_ptr; + png_charp key; + png_charp text; + png_uint_32 skip = 0; + png_size_t slength; + int ret; + + png_debug(1, "in png_handle_tEXt"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + if (--png_ptr->user_chunk_cache_max == 1) + { + png_warning(png_ptr, "No space in chunk cache for tEXt"); + png_crc_finish(png_ptr, length); + return; + } + } +#endif + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before tEXt"); + + if (png_ptr->mode & PNG_HAVE_IDAT) + png_ptr->mode |= PNG_AFTER_IDAT; + +#ifdef PNG_MAX_MALLOC_64K + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "tEXt chunk too large to fit in memory"); + skip = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; + } +#endif + + png_free(png_ptr, png_ptr->chunkdata); + + png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); + if (png_ptr->chunkdata == NULL) + { + png_warning(png_ptr, "No memory to process text chunk."); + return; + } + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + + if (png_crc_finish(png_ptr, skip)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + key = png_ptr->chunkdata; + + key[slength] = 0x00; + + for (text = key; *text; text++) + /* Empty loop to find end of key */ ; + + if (text != key + slength) + text++; + + text_ptr = (png_textp)png_malloc_warn(png_ptr, + (png_uint_32)png_sizeof(png_text)); + if (text_ptr == NULL) + { + png_warning(png_ptr, "Not enough memory to process text chunk."); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; + text_ptr->key = key; +#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); + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_free(png_ptr, text_ptr); + if (ret) + png_warning(png_ptr, "Insufficient memory to process text chunk."); +} +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED +/* Note: this does not correctly handle chunks that are > 64K under DOS */ +void /* PRIVATE */ +png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_textp text_ptr; + png_charp text; + int comp_type; + int ret; + png_size_t slength, prefix_len, data_len; + + png_debug(1, "in png_handle_zTXt"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + if (--png_ptr->user_chunk_cache_max == 1) + { + png_warning(png_ptr, "No space in chunk cache for zTXt"); + png_crc_finish(png_ptr, length); + return; + } + } +#endif + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before zTXt"); + + if (png_ptr->mode & PNG_HAVE_IDAT) + png_ptr->mode |= PNG_AFTER_IDAT; + +#ifdef PNG_MAX_MALLOC_64K + /* We will no doubt have problems with chunks even half this size, but + there is no hard and fast rule to tell us where to stop. */ + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "zTXt chunk too large to fit in memory"); + png_crc_finish(png_ptr, length); + return; + } +#endif + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); + if (png_ptr->chunkdata == NULL) + { + png_warning(png_ptr, "Out of memory processing zTXt chunk."); + return; + } + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + if (png_crc_finish(png_ptr, 0)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + png_ptr->chunkdata[slength] = 0x00; + + for (text = png_ptr->chunkdata; *text; text++) + /* Empty loop */ ; + + /* zTXt must have some text after the chunkdataword */ + if (text >= png_ptr->chunkdata + slength - 2) + { + png_warning(png_ptr, "Truncated zTXt chunk"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + else + { + comp_type = *(++text); + if (comp_type != PNG_TEXT_COMPRESSION_zTXt) + { + png_warning(png_ptr, "Unknown compression type in zTXt chunk"); + comp_type = PNG_TEXT_COMPRESSION_zTXt; + } + text++; /* Skip the compression_method byte */ + } + prefix_len = text - png_ptr->chunkdata; + + png_decompress_chunk(png_ptr, comp_type, + (png_size_t)length, prefix_len, &data_len); + + text_ptr = (png_textp)png_malloc_warn(png_ptr, + (png_uint_32)png_sizeof(png_text)); + if (text_ptr == NULL) + { + png_warning(png_ptr, "Not enough memory to process zTXt chunk."); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + text_ptr->compression = comp_type; + text_ptr->key = png_ptr->chunkdata; +#ifdef PNG_iTXt_SUPPORTED + text_ptr->lang = NULL; + text_ptr->lang_key = NULL; + text_ptr->itxt_length = 0; +#endif + text_ptr->text = png_ptr->chunkdata + prefix_len; + text_ptr->text_length = data_len; + + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, text_ptr); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + if (ret) + png_error(png_ptr, "Insufficient memory to store zTXt chunk."); +} +#endif + +#ifdef PNG_READ_iTXt_SUPPORTED +/* Note: this does not correctly handle chunks that are > 64K under DOS */ +void /* PRIVATE */ +png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_textp text_ptr; + png_charp key, lang, text, lang_key; + int comp_flag; + int comp_type = 0; + int ret; + png_size_t slength, prefix_len, data_len; + + png_debug(1, "in png_handle_iTXt"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + if (--png_ptr->user_chunk_cache_max == 1) + { + png_warning(png_ptr, "No space in chunk cache for iTXt"); + png_crc_finish(png_ptr, length); + return; + } + } +#endif + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before iTXt"); + + if (png_ptr->mode & PNG_HAVE_IDAT) + png_ptr->mode |= PNG_AFTER_IDAT; + +#ifdef PNG_MAX_MALLOC_64K + /* We will no doubt have problems with chunks even half this size, but + there is no hard and fast rule to tell us where to stop. */ + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "iTXt chunk too large to fit in memory"); + png_crc_finish(png_ptr, length); + return; + } +#endif + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); + if (png_ptr->chunkdata == NULL) + { + png_warning(png_ptr, "No memory to process iTXt chunk."); + return; + } + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + if (png_crc_finish(png_ptr, 0)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + png_ptr->chunkdata[slength] = 0x00; + + for (lang = png_ptr->chunkdata; *lang; lang++) + /* Empty loop */ ; + lang++; /* Skip NUL separator */ + + /* iTXt must have a language tag (possibly empty), two compression bytes, + * translated keyword (possibly empty), and possibly some text after the + * keyword + */ + + if (lang >= png_ptr->chunkdata + slength - 3) + { + png_warning(png_ptr, "Truncated iTXt chunk"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + else + { + comp_flag = *lang++; + comp_type = *lang++; + } + + for (lang_key = lang; *lang_key; lang_key++) + /* Empty loop */ ; + lang_key++; /* Skip NUL separator */ + + if (lang_key >= png_ptr->chunkdata + slength) + { + png_warning(png_ptr, "Truncated iTXt chunk"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + for (text = lang_key; *text; text++) + /* Empty loop */ ; + text++; /* Skip NUL separator */ + if (text >= png_ptr->chunkdata + slength) + { + png_warning(png_ptr, "Malformed iTXt chunk"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + prefix_len = text - png_ptr->chunkdata; + + key=png_ptr->chunkdata; + if (comp_flag) + png_decompress_chunk(png_ptr, comp_type, + (size_t)length, prefix_len, &data_len); + else + data_len = png_strlen(png_ptr->chunkdata + prefix_len); + text_ptr = (png_textp)png_malloc_warn(png_ptr, + (png_uint_32)png_sizeof(png_text)); + if (text_ptr == NULL) + { + png_warning(png_ptr, "Not enough memory to process iTXt chunk."); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + text_ptr->compression = (int)comp_flag + 1; + text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key); + text_ptr->lang = png_ptr->chunkdata + (lang - key); + text_ptr->itxt_length = data_len; + text_ptr->text_length = 0; + text_ptr->key = png_ptr->chunkdata; + text_ptr->text = png_ptr->chunkdata + prefix_len; + + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, text_ptr); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + if (ret) + png_error(png_ptr, "Insufficient memory to store iTXt chunk."); +} +#endif + +/* This function is called when we haven't found a handler for a + chunk. If there isn't a problem with the chunk itself (ie bad + chunk name, CRC, or a critical chunk), the chunk is silently ignored + -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which + case it will be saved away to be written out later. */ +void /* PRIVATE */ +png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_uint_32 skip = 0; + + png_debug(1, "in png_handle_unknown"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + if (--png_ptr->user_chunk_cache_max == 1) + { + png_warning(png_ptr, "No space in chunk cache for unknown chunk"); + png_crc_finish(png_ptr, length); + return; + } + } +#endif + + if (png_ptr->mode & PNG_HAVE_IDAT) + { +#ifdef PNG_USE_LOCAL_ARRAYS + PNG_CONST PNG_IDAT; +#endif + if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) /* Not an IDAT */ + png_ptr->mode |= PNG_AFTER_IDAT; + } + + if (!(png_ptr->chunk_name[0] & 0x20)) + { +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != + PNG_HANDLE_CHUNK_ALWAYS +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED + && png_ptr->read_user_chunk_fn == NULL +#endif + ) +#endif + png_chunk_error(png_ptr, "unknown critical chunk"); + } + +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED + if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED + || (png_ptr->read_user_chunk_fn != NULL) +#endif + ) + { +#ifdef PNG_MAX_MALLOC_64K + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "unknown chunk too large to fit in memory"); + skip = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; + } +#endif + png_memcpy((png_charp)png_ptr->unknown_chunk.name, + (png_charp)png_ptr->chunk_name, + png_sizeof(png_ptr->unknown_chunk.name)); + png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1] + = '\0'; + png_ptr->unknown_chunk.size = (png_size_t)length; + if (length == 0) + png_ptr->unknown_chunk.data = NULL; + else + { + png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length); + png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length); + } +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED + if (png_ptr->read_user_chunk_fn != NULL) + { + /* Callback to user unknown chunk handler */ + int ret; + ret = (*(png_ptr->read_user_chunk_fn)) + (png_ptr, &png_ptr->unknown_chunk); + if (ret < 0) + png_chunk_error(png_ptr, "error in user chunk"); + if (ret == 0) + { + if (!(png_ptr->chunk_name[0] & 0x20)) +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != + PNG_HANDLE_CHUNK_ALWAYS) +#endif + png_chunk_error(png_ptr, "unknown critical chunk"); + png_set_unknown_chunks(png_ptr, info_ptr, + &png_ptr->unknown_chunk, 1); + } + } + else +#endif + png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1); + png_free(png_ptr, png_ptr->unknown_chunk.data); + png_ptr->unknown_chunk.data = NULL; + } + else +#endif + skip = length; + + png_crc_finish(png_ptr, skip); + +#ifndef PNG_READ_USER_CHUNKS_SUPPORTED + info_ptr = info_ptr; /* Quiet compiler warnings about unused info_ptr */ +#endif +} + +/* This function is called to verify that a chunk name is valid. + This function can't have the "critical chunk check" incorporated + into it, since in the future we will need to be able to call user + functions to handle unknown critical chunks after we check that + the chunk name itself is valid. */ + +#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) + +void /* PRIVATE */ +png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name) +{ + png_debug(1, "in png_check_chunk_name"); + if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) || + isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3])) + { + png_chunk_error(png_ptr, "invalid chunk type"); + } +} + +/* Combines the row recently read in with the existing pixels in the + row. This routine takes care of alpha and transparency if requested. + This routine also handles the two methods of progressive display + of interlaced images, depending on the mask value. + The mask value describes which pixels are to be combined with + the row. The pattern always repeats every 8 pixels, so just 8 + bits are needed. A one indicates the pixel is to be combined, + a zero indicates the pixel is to be skipped. This is in addition + to any alpha or transparency value associated with the pixel. If + you want all pixels to be combined, pass 0xff (255) in mask. */ + +void /* PRIVATE */ +png_combine_row(png_structp png_ptr, png_bytep row, int mask) +{ + png_debug(1, "in png_combine_row"); + if (mask == 0xff) + { + png_memcpy(row, png_ptr->row_buf + 1, + PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width)); + } + else + { + switch (png_ptr->row_info.pixel_depth) + { + case 1: + { + png_bytep sp = png_ptr->row_buf + 1; + png_bytep dp = row; + int s_inc, s_start, s_end; + int m = 0x80; + int shift; + png_uint_32 i; + png_uint_32 row_width = png_ptr->width; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if (png_ptr->transformations & PNG_PACKSWAP) + { + s_start = 0; + s_end = 7; + s_inc = 1; + } + else +#endif + { + s_start = 7; + s_end = 0; + s_inc = -1; + } + + shift = s_start; + + for (i = 0; i < row_width; i++) + { + if (m & mask) + { + int value; + + value = (*sp >> shift) & 0x01; + *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); + *dp |= (png_byte)(value << shift); + } + + if (shift == s_end) + { + shift = s_start; + sp++; + dp++; + } + else + shift += s_inc; + + if (m == 1) + m = 0x80; + else + m >>= 1; + } + break; + } + case 2: + { + png_bytep sp = png_ptr->row_buf + 1; + png_bytep dp = row; + int s_start, s_end, s_inc; + int m = 0x80; + int shift; + png_uint_32 i; + png_uint_32 row_width = png_ptr->width; + int value; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if (png_ptr->transformations & PNG_PACKSWAP) + { + s_start = 0; + s_end = 6; + s_inc = 2; + } + else +#endif + { + s_start = 6; + s_end = 0; + s_inc = -2; + } + + shift = s_start; + + for (i = 0; i < row_width; i++) + { + if (m & mask) + { + value = (*sp >> shift) & 0x03; + *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); + *dp |= (png_byte)(value << shift); + } + + if (shift == s_end) + { + shift = s_start; + sp++; + dp++; + } + else + shift += s_inc; + if (m == 1) + m = 0x80; + else + m >>= 1; + } + break; + } + case 4: + { + png_bytep sp = png_ptr->row_buf + 1; + png_bytep dp = row; + int s_start, s_end, s_inc; + int m = 0x80; + int shift; + png_uint_32 i; + png_uint_32 row_width = png_ptr->width; + int value; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if (png_ptr->transformations & PNG_PACKSWAP) + { + s_start = 0; + s_end = 4; + s_inc = 4; + } + else +#endif + { + s_start = 4; + s_end = 0; + s_inc = -4; + } + shift = s_start; + + for (i = 0; i < row_width; i++) + { + if (m & mask) + { + value = (*sp >> shift) & 0xf; + *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); + *dp |= (png_byte)(value << shift); + } + + if (shift == s_end) + { + shift = s_start; + sp++; + dp++; + } + else + shift += s_inc; + if (m == 1) + m = 0x80; + else + m >>= 1; + } + break; + } + default: + { + png_bytep sp = png_ptr->row_buf + 1; + png_bytep dp = row; + png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3); + png_uint_32 i; + png_uint_32 row_width = png_ptr->width; + png_byte m = 0x80; + + + for (i = 0; i < row_width; i++) + { + if (m & mask) + { + png_memcpy(dp, sp, pixel_bytes); + } + + sp += pixel_bytes; + dp += pixel_bytes; + + if (m == 1) + m = 0x80; + else + m >>= 1; + } + break; + } + } + } +} + +#ifdef PNG_READ_INTERLACING_SUPPORTED +/* 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_row_infop row_info = &(png_ptr->row_info); + png_bytep row = png_ptr->row_buf + 1; + int pass = png_ptr->pass; + png_uint_32 transformations = png_ptr->transformations; + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + /* Offset to next interlace block */ + PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + png_debug(1, "in png_do_read_interlace"); + if (row != NULL && row_info != NULL) + { + png_uint_32 final_width; + + final_width = row_info->width * png_pass_inc[pass]; + + switch (row_info->pixel_depth) + { + case 1: + { + png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3); + png_bytep dp = row + (png_size_t)((final_width - 1) >> 3); + int sshift, dshift; + int s_start, s_end, s_inc; + int jstop = png_pass_inc[pass]; + png_byte v; + png_uint_32 i; + int j; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if (transformations & PNG_PACKSWAP) + { + sshift = (int)((row_info->width + 7) & 0x07); + dshift = (int)((final_width + 7) & 0x07); + s_start = 7; + s_end = 0; + s_inc = -1; + } + else +#endif + { + sshift = 7 - (int)((row_info->width + 7) & 0x07); + dshift = 7 - (int)((final_width + 7) & 0x07); + s_start = 0; + s_end = 7; + s_inc = 1; + } + + for (i = 0; i < row_info->width; i++) + { + v = (png_byte)((*sp >> sshift) & 0x01); + for (j = 0; j < jstop; j++) + { + *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff); + *dp |= (png_byte)(v << dshift); + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + else + dshift += s_inc; + } + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + else + sshift += s_inc; + } + break; + } + case 2: + { + png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2); + png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2); + int sshift, dshift; + int s_start, s_end, s_inc; + int jstop = png_pass_inc[pass]; + png_uint_32 i; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if (transformations & PNG_PACKSWAP) + { + sshift = (int)(((row_info->width + 3) & 0x03) << 1); + dshift = (int)(((final_width + 3) & 0x03) << 1); + s_start = 6; + s_end = 0; + s_inc = -2; + } + else +#endif + { + sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1); + dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1); + s_start = 0; + s_end = 6; + s_inc = 2; + } + + for (i = 0; i < row_info->width; i++) + { + png_byte v; + int j; + + v = (png_byte)((*sp >> sshift) & 0x03); + for (j = 0; j < jstop; j++) + { + *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff); + *dp |= (png_byte)(v << dshift); + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + else + dshift += s_inc; + } + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + else + sshift += s_inc; + } + break; + } + case 4: + { + png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1); + png_bytep dp = row + (png_size_t)((final_width - 1) >> 1); + int sshift, dshift; + int s_start, s_end, s_inc; + png_uint_32 i; + int jstop = png_pass_inc[pass]; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if (transformations & PNG_PACKSWAP) + { + sshift = (int)(((row_info->width + 1) & 0x01) << 2); + dshift = (int)(((final_width + 1) & 0x01) << 2); + s_start = 4; + s_end = 0; + s_inc = -4; + } + else +#endif + { + sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2); + dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2); + s_start = 0; + s_end = 4; + s_inc = 4; + } + + for (i = 0; i < row_info->width; i++) + { + png_byte v = (png_byte)((*sp >> sshift) & 0xf); + int j; + + for (j = 0; j < jstop; j++) + { + *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff); + *dp |= (png_byte)(v << dshift); + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + else + dshift += s_inc; + } + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + else + sshift += s_inc; + } + break; + } + default: + { + png_size_t pixel_bytes = (row_info->pixel_depth >> 3); + png_bytep sp = row + (png_size_t)(row_info->width - 1) + * pixel_bytes; + png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes; + + int jstop = png_pass_inc[pass]; + png_uint_32 i; + + for (i = 0; i < row_info->width; i++) + { + png_byte v[8]; + int j; + + png_memcpy(v, sp, pixel_bytes); + for (j = 0; j < jstop; j++) + { + png_memcpy(dp, v, pixel_bytes); + dp -= pixel_bytes; + } + sp -= pixel_bytes; + } + break; + } + } + row_info->width = final_width; + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width); + } +#ifndef PNG_READ_PACKSWAP_SUPPORTED + transformations = transformations; /* Silence compiler warning */ +#endif +} +#endif /* PNG_READ_INTERLACING_SUPPORTED */ + +void /* PRIVATE */ +png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row, + png_bytep prev_row, int filter) +{ + png_debug(1, "in png_read_filter_row"); + png_debug2(2, "row = %lu, filter = %d", png_ptr->row_number, filter); + switch (filter) + { + 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; + + 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; + + 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++ + *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++; + } + + for (i = 0; i < istop; i++) /* Use leftover rp,pp */ + { + int a, b, c, pa, pb, pc, p; + + a = *lp++; + b = *pp++; + c = *cp++; + + p = b - c; + pc = a - c; + +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + + /* + if (pa <= pb && pa <= pc) + p = a; + else if (pb <= pc) + p = b; + else + p = c; + */ + + p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c; + + *rp = (png_byte)(((int)(*rp) + p) & 0xff); + rp++; + } + break; + } + default: + png_warning(png_ptr, "Ignoring bad adaptive filter type"); + *row = 0; + break; + } +} + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +void /* PRIVATE */ +png_read_finish_row(png_structp png_ptr) +{ +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif /* PNG_READ_INTERLACING_SUPPORTED */ + + png_debug(1, "in png_read_finish_row"); + png_ptr->row_number++; + if (png_ptr->row_number < png_ptr->num_rows) + return; + +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (png_ptr->interlaced) + { + png_ptr->row_number = 0; + png_memset_check(png_ptr, png_ptr->prev_row, 0, + png_ptr->rowbytes + 1); + do + { + png_ptr->pass++; + if (png_ptr->pass >= 7) + break; + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + + if (!(png_ptr->transformations & PNG_INTERLACE)) + { + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + if (!(png_ptr->num_rows)) + continue; + } + else /* if (png_ptr->transformations & PNG_INTERLACE) */ + break; + } while (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_CONST PNG_IDAT; +#endif + char extra; + int ret; + + png_ptr->zstream.next_out = (Byte *)&extra; + png_ptr->zstream.avail_out = (uInt)1; + for (;;) + { + if (!(png_ptr->zstream.avail_in)) + { + while (!png_ptr->idat_size) + { + png_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_31(png_ptr, 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_IDAT, 4)) + png_error(png_ptr, "Not enough image data"); + + } + png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_in = png_ptr->zbuf; + if (png_ptr->zbuf_size > png_ptr->idat_size) + png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size; + png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in); + png_ptr->idat_size -= png_ptr->zstream.avail_in; + } + ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); + if (ret == Z_STREAM_END) + { + if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in || + png_ptr->idat_size) + png_warning(png_ptr, "Extra compressed data."); + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + break; + } + if (ret != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : + "Decompression Error"); + + if (!(png_ptr->zstream.avail_out)) + { + png_warning(png_ptr, "Extra compressed data."); + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + break; + } + + } + png_ptr->zstream.avail_out = 0; + } + + if (png_ptr->idat_size || png_ptr->zstream.avail_in) + png_warning(png_ptr, "Extra compression data."); + + inflateReset(&png_ptr->zstream); + + png_ptr->mode |= PNG_AFTER_IDAT; +} +#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ + +void /* PRIVATE */ +png_read_start_row(png_structp png_ptr) +{ +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif + + int max_pixel_depth; + png_size_t row_bytes; + + png_debug(1, "in png_read_start_row"); + png_ptr->zstream.avail_in = 0; + png_init_read_transformations(png_ptr); +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (png_ptr->interlaced) + { + if (!(png_ptr->transformations & PNG_INTERLACE)) + png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - + png_pass_ystart[0]) / png_pass_yinc[0]; + else + png_ptr->num_rows = png_ptr->height; + + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + } + else +#endif /* PNG_READ_INTERLACING_SUPPORTED */ + { + png_ptr->num_rows = png_ptr->height; + png_ptr->iwidth = png_ptr->width; + } + max_pixel_depth = png_ptr->pixel_depth; + +#ifdef PNG_READ_PACK_SUPPORTED + if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8) + max_pixel_depth = 8; +#endif + +#ifdef PNG_READ_EXPAND_SUPPORTED + if (png_ptr->transformations & PNG_EXPAND) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (png_ptr->num_trans) + max_pixel_depth = 32; + else + max_pixel_depth = 24; + } + else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + if (max_pixel_depth < 8) + max_pixel_depth = 8; + if (png_ptr->num_trans) + max_pixel_depth *= 2; + } + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + { + if (png_ptr->num_trans) + { + max_pixel_depth *= 4; + max_pixel_depth /= 3; + } + } + } +#endif + +#ifdef PNG_READ_FILLER_SUPPORTED + if (png_ptr->transformations & (PNG_FILLER)) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + max_pixel_depth = 32; + else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + if (max_pixel_depth <= 8) + max_pixel_depth = 16; + else + max_pixel_depth = 32; + } + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + { + if (max_pixel_depth <= 32) + max_pixel_depth = 32; + else + max_pixel_depth = 64; + } + } +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + if (png_ptr->transformations & PNG_GRAY_TO_RGB) + { + if ( +#ifdef PNG_READ_EXPAND_SUPPORTED + (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) || +#endif +#ifdef PNG_READ_FILLER_SUPPORTED + (png_ptr->transformations & (PNG_FILLER)) || +#endif + png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (max_pixel_depth <= 16) + max_pixel_depth = 32; + else + max_pixel_depth = 64; + } + else + { + if (max_pixel_depth <= 8) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + max_pixel_depth = 32; + else + max_pixel_depth = 24; + } + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + max_pixel_depth = 64; + else + max_pixel_depth = 48; + } + } +#endif + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \ +defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) + if (png_ptr->transformations & PNG_USER_TRANSFORM) + { + int user_pixel_depth = png_ptr->user_transform_depth* + png_ptr->user_transform_channels; + if (user_pixel_depth > max_pixel_depth) + max_pixel_depth=user_pixel_depth; + } +#endif + + /* Align the width on the next larger 8 pixels. Mainly used + * for interlacing + */ + row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7)); + /* Calculate the maximum bytes needed, adding a byte and a pixel + * for safety's sake + */ + row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) + + 1 + ((max_pixel_depth + 7) >> 3); +#ifdef PNG_MAX_MALLOC_64K + if (row_bytes > (png_uint_32)65536L) + png_error(png_ptr, "This image requires a row greater than 64KB"); +#endif + + if (row_bytes + 64 > png_ptr->old_big_row_buf_size) + { + png_free(png_ptr, png_ptr->big_row_buf); + if (png_ptr->interlaced) + png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr, + row_bytes + 64); + else + png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, + row_bytes + 64); + png_ptr->old_big_row_buf_size = row_bytes + 64; + + /* Use 32 bytes of padding before and after row_buf. */ + png_ptr->row_buf = png_ptr->big_row_buf + 32; + png_ptr->old_big_row_buf_size = row_bytes + 64; + } + +#ifdef PNG_MAX_MALLOC_64K + if ((png_uint_32)row_bytes + 1 > (png_uint_32)65536L) + png_error(png_ptr, "This image requires a row greater than 64KB"); +#endif + if ((png_uint_32)row_bytes > (png_uint_32)(PNG_SIZE_MAX - 1)) + png_error(png_ptr, "Row has too many bytes to allocate in memory."); + + if (row_bytes + 1 > png_ptr->old_prev_row_size) + { + png_free(png_ptr, png_ptr->prev_row); + png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)( + row_bytes + 1)); + png_memset_check(png_ptr, png_ptr->prev_row, 0, row_bytes + 1); + png_ptr->old_prev_row_size = row_bytes + 1; + } + + png_ptr->rowbytes = row_bytes; + + png_debug1(3, "width = %lu,", png_ptr->width); + png_debug1(3, "height = %lu,", png_ptr->height); + png_debug1(3, "iwidth = %lu,", png_ptr->iwidth); + png_debug1(3, "num_rows = %lu,", png_ptr->num_rows); + png_debug1(3, "rowbytes = %lu,", png_ptr->rowbytes); + png_debug1(3, "irowbytes = %lu", + PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1); + + png_ptr->flags |= PNG_FLAG_ROW_INIT; +} +#endif /* PNG_READ_SUPPORTED */ |