diff options
Diffstat (limited to 'png/pngread.c')
| -rw-r--r-- | png/pngread.c | 548 |
1 files changed, 326 insertions, 222 deletions
diff --git a/png/pngread.c b/png/pngread.c index 87a789157..8fa7d9f16 100644 --- a/png/pngread.c +++ b/png/pngread.c @@ -1,10 +1,10 @@ /* pngread.c - read a PNG file * - * Last changed in libpng 1.6.15 [November 20, 2014] - * Copyright (c) 1998-2014 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.) + * Copyright (c) 2018-2019 Cosmin Truta + * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson + * Copyright (c) 1996-1997 Andreas Dilger + * 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 @@ -28,10 +28,10 @@ png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr, { #ifndef PNG_USER_MEM_SUPPORTED png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr, - error_fn, warn_fn, NULL, NULL, NULL); + error_fn, warn_fn, NULL, NULL, NULL); #else return png_create_read_struct_2(user_png_ver, error_ptr, error_fn, - warn_fn, NULL, NULL, NULL); + warn_fn, NULL, NULL, NULL); } /* Alternate create PNG structure for reading, and allocate any memory @@ -43,7 +43,7 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) { png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr, - error_fn, warn_fn, mem_ptr, malloc_fn, free_fn); + error_fn, warn_fn, mem_ptr, malloc_fn, free_fn); #endif /* USER_MEM */ if (png_ptr != NULL) @@ -63,7 +63,7 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, /* In stable builds only warn if an application error can be completely * handled. */ -# if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC +# if PNG_RELEASE_BUILD png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN; # endif # endif @@ -127,7 +127,10 @@ png_read_info(png_structrp png_ptr, png_inforp info_ptr) } else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; png_ptr->mode |= PNG_AFTER_IDAT; + } /* This should be a binary subdivision search or a hash for * matching the chunk name rather than a linear search. @@ -172,6 +175,11 @@ png_read_info(png_structrp png_ptr, png_inforp info_ptr) png_handle_cHRM(png_ptr, info_ptr, length); #endif +#ifdef PNG_READ_eXIf_SUPPORTED + else if (chunk_name == png_eXIf) + png_handle_eXIf(png_ptr, info_ptr, length); +#endif + #ifdef PNG_READ_gAMA_SUPPORTED else if (chunk_name == png_gAMA) png_handle_gAMA(png_ptr, info_ptr, length); @@ -249,7 +257,7 @@ png_read_info(png_structrp png_ptr, png_inforp info_ptr) else png_handle_unknown(png_ptr, info_ptr, length, - PNG_HANDLE_CHUNK_AS_DEFAULT); + PNG_HANDLE_CHUNK_AS_DEFAULT); } } #endif /* SEQUENTIAL_READ */ @@ -276,7 +284,7 @@ png_read_update_info(png_structrp png_ptr, png_inforp info_ptr) /* New in 1.6.0 this avoids the bug of doing the initializations twice */ else png_app_error(png_ptr, - "png_read_update_info/png_start_read_image: duplicate call"); + "png_read_update_info/png_start_read_image: duplicate call"); } } @@ -299,7 +307,7 @@ png_start_read_image(png_structrp png_ptr) /* New in 1.6.0 this avoids the bug of doing the initializations twice */ else png_app_error(png_ptr, - "png_start_read_image/png_read_update_info: duplicate call"); + "png_start_read_image/png_read_update_info: duplicate call"); } } #endif /* SEQUENTIAL_READ */ @@ -356,9 +364,9 @@ png_do_read_intrapixel(png_row_infop row_info, png_bytep row) for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) { - png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); - png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); - png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); + png_uint_32 s0 = (png_uint_32)(*(rp ) << 8) | *(rp + 1); + png_uint_32 s1 = (png_uint_32)(*(rp + 2) << 8) | *(rp + 3); + png_uint_32 s2 = (png_uint_32)(*(rp + 4) << 8) | *(rp + 5); png_uint_32 red = (s0 + s1 + 65536) & 0xffff; png_uint_32 blue = (s2 + s1 + 65536) & 0xffff; *(rp ) = (png_byte)((red >> 8) & 0xff); @@ -531,13 +539,14 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row) png_error(png_ptr, "Invalid attempt to read row data"); /* Fill the row with IDAT data: */ + png_ptr->row_buf[0]=255; /* to force error if no data was found */ png_read_IDAT_data(png_ptr, png_ptr->row_buf, row_info.rowbytes + 1); if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE) { if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST) png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1, - png_ptr->prev_row + 1, png_ptr->row_buf[0]); + png_ptr->prev_row + 1, png_ptr->row_buf[0]); else png_error(png_ptr, "bad adaptive filter value"); } @@ -581,7 +590,7 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row) { if (png_ptr->pass < 6) png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass, - png_ptr->transformations); + png_ptr->transformations); if (dsp_row != NULL) png_combine_row(png_ptr, dsp_row, 1/*display*/); @@ -716,7 +725,7 @@ png_read_image(png_structrp png_ptr, png_bytepp image) * but the caller should do it! */ png_warning(png_ptr, "Interlace handling should be turned on when " - "using png_read_image"); + "using png_read_image"); /* Make sure this is set correctly */ png_ptr->num_rows = png_ptr->height; } @@ -776,8 +785,8 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr) #ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED /* Report invalid palette index; added at libng-1.5.10 */ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && - png_ptr->num_palette_max > png_ptr->num_palette) - png_benign_error(png_ptr, "Read palette index exceeding num_palette"); + png_ptr->num_palette_max > png_ptr->num_palette) + png_benign_error(png_ptr, "Read palette index exceeding num_palette"); #endif do @@ -785,6 +794,9 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr) png_uint_32 length = png_read_chunk_header(png_ptr); png_uint_32 chunk_name = png_ptr->chunk_name; + if (chunk_name != png_IDAT) + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; + if (chunk_name == png_IEND) png_handle_IEND(png_ptr, info_ptr, length); @@ -799,9 +811,9 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr) { if (chunk_name == png_IDAT) { - if ((length > 0) || - (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0) - png_benign_error(png_ptr, "Too many IDATs found"); + if ((length > 0 && !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED)) + || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0) + png_benign_error(png_ptr, ".Too many IDATs found"); } png_handle_unknown(png_ptr, info_ptr, length, keep); if (chunk_name == png_PLTE) @@ -812,11 +824,14 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr) else if (chunk_name == png_IDAT) { /* Zero length IDATs are legal after the last IDAT has been - * read, but not after other chunks have been read. + * read, but not after other chunks have been read. 1.6 does not + * always read all the deflate data; specifically it cannot be relied + * upon to read the Adler32 at the end. If it doesn't ignore IDAT + * chunks which are longer than zero as well: */ - if ((length > 0) || - (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0) - png_benign_error(png_ptr, "Too many IDATs found"); + if ((length > 0 && !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED)) + || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0) + png_benign_error(png_ptr, "..Too many IDATs found"); png_crc_finish(png_ptr, length); } @@ -833,6 +848,11 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr) png_handle_cHRM(png_ptr, info_ptr, length); #endif +#ifdef PNG_READ_eXIf_SUPPORTED + else if (chunk_name == png_eXIf) + png_handle_eXIf(png_ptr, info_ptr, length); +#endif + #ifdef PNG_READ_gAMA_SUPPORTED else if (chunk_name == png_gAMA) png_handle_gAMA(png_ptr, info_ptr, length); @@ -910,7 +930,7 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr) else png_handle_unknown(png_ptr, info_ptr, length, - PNG_HANDLE_CHUNK_AS_DEFAULT); + PNG_HANDLE_CHUNK_AS_DEFAULT); } while ((png_ptr->mode & PNG_HAVE_IEND) == 0); } #endif /* SEQUENTIAL_READ */ @@ -974,6 +994,12 @@ png_read_destroy(png_structrp png_ptr) png_ptr->chunk_list = NULL; #endif +#if defined(PNG_READ_EXPAND_SUPPORTED) && \ + defined(PNG_ARM_NEON_IMPLEMENTATION) + png_free(png_ptr, png_ptr->riffled_palette); + png_ptr->riffled_palette = NULL; +#endif + /* NOTE: the 'setjmp' buffer may still be allocated and the memory and error * callbacks are still set at this point. They are required to complete the * destruction of the png_struct itself. @@ -1021,8 +1047,7 @@ png_set_read_status_fn(png_structrp png_ptr, png_read_status_ptr read_row_fn) #ifdef PNG_INFO_IMAGE_SUPPORTED void PNGAPI png_read_png(png_structrp png_ptr, png_inforp info_ptr, - int transforms, - voidp params) + int transforms, voidp params) { if (png_ptr == NULL || info_ptr == NULL) return; @@ -1044,9 +1069,9 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr, /* Tell libpng to strip 16-bit/color files down to 8 bits per color. */ if ((transforms & PNG_TRANSFORM_SCALE_16) != 0) - /* Added at libpng-1.5.4. "strip_16" produces the same result that it - * did in earlier versions, while "scale_16" is now more accurate. - */ + /* Added at libpng-1.5.4. "strip_16" produces the same result that it + * did in earlier versions, while "scale_16" is now more accurate. + */ #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED png_set_scale_16(png_ptr); #else @@ -1210,7 +1235,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr, for (iptr = 0; iptr < info_ptr->height; iptr++) info_ptr->row_pointers[iptr] = png_voidcast(png_bytep, - png_malloc(png_ptr, info_ptr->rowbytes)); + png_malloc(png_ptr, info_ptr->rowbytes)); } png_read_image(png_ptr, info_ptr->row_pointers); @@ -1298,7 +1323,7 @@ png_image_read_init(png_imagep image) if (info_ptr != NULL) { png_controlp control = png_voidcast(png_controlp, - png_malloc_warn(png_ptr, (sizeof *control))); + png_malloc_warn(png_ptr, (sizeof *control))); if (control != NULL) { @@ -1385,7 +1410,9 @@ png_image_read_header(png_voidp argument) png_structrp png_ptr = image->opaque->png_ptr; png_inforp info_ptr = image->opaque->info_ptr; +#ifdef PNG_BENIGN_ERRORS_SUPPORTED png_set_benign_errors(png_ptr, 1/*warn*/); +#endif png_read_info(png_ptr, info_ptr); /* Do this the fast way; just read directly out of png_struct. */ @@ -1423,7 +1450,7 @@ png_image_read_header(png_voidp argument) break; case PNG_COLOR_TYPE_PALETTE: - cmap_entries = png_ptr->num_palette; + cmap_entries = (png_uint_32)png_ptr->num_palette; break; default: @@ -1461,12 +1488,12 @@ png_image_begin_read_from_stdio(png_imagep image, FILE* file) else return png_image_error(image, - "png_image_begin_read_from_stdio: invalid argument"); + "png_image_begin_read_from_stdio: invalid argument"); } else if (image != NULL) return png_image_error(image, - "png_image_begin_read_from_stdio: incorrect PNG_IMAGE_VERSION"); + "png_image_begin_read_from_stdio: incorrect PNG_IMAGE_VERSION"); return 0; } @@ -1499,19 +1526,19 @@ png_image_begin_read_from_file(png_imagep image, const char *file_name) else return png_image_error(image, - "png_image_begin_read_from_file: invalid argument"); + "png_image_begin_read_from_file: invalid argument"); } else if (image != NULL) return png_image_error(image, - "png_image_begin_read_from_file: incorrect PNG_IMAGE_VERSION"); + "png_image_begin_read_from_file: incorrect PNG_IMAGE_VERSION"); return 0; } #endif /* STDIO */ static void PNGCBAPI -png_image_memory_read(png_structp png_ptr, png_bytep out, png_size_t need) +png_image_memory_read(png_structp png_ptr, png_bytep out, size_t need) { if (png_ptr != NULL) { @@ -1522,7 +1549,7 @@ png_image_memory_read(png_structp png_ptr, png_bytep out, png_size_t need) if (cp != NULL) { png_const_bytep memory = cp->memory; - png_size_t size = cp->size; + size_t size = cp->size; if (memory != NULL && size >= need) { @@ -1541,7 +1568,7 @@ png_image_memory_read(png_structp png_ptr, png_bytep out, png_size_t need) } int PNGAPI png_image_begin_read_from_memory(png_imagep image, - png_const_voidp memory, png_size_t size) + png_const_voidp memory, size_t size) { if (image != NULL && image->version == PNG_IMAGE_VERSION) { @@ -1564,12 +1591,12 @@ int PNGAPI png_image_begin_read_from_memory(png_imagep image, else return png_image_error(image, - "png_image_begin_read_from_memory: invalid argument"); + "png_image_begin_read_from_memory: invalid argument"); } else if (image != NULL) return png_image_error(image, - "png_image_begin_read_from_memory: incorrect PNG_IMAGE_VERSION"); + "png_image_begin_read_from_memory: incorrect PNG_IMAGE_VERSION"); return 0; } @@ -1600,7 +1627,7 @@ png_image_skip_unused_chunks(png_structrp png_ptr) * errors (which are unfortunately quite common.) */ { - static PNG_CONST png_byte chunks_to_process[] = { + static const png_byte chunks_to_process[] = { 98, 75, 71, 68, '\0', /* bKGD */ 99, 72, 82, 77, '\0', /* cHRM */ 103, 65, 77, 65, '\0', /* gAMA */ @@ -1615,12 +1642,12 @@ png_image_skip_unused_chunks(png_structrp png_ptr) * IHDR, PLTE, tRNS, IDAT, and IEND chunks. */ png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_NEVER, - NULL, -1); + NULL, -1); /* But do not ignore image data handling chunks */ png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_AS_DEFAULT, - chunks_to_process, (int)/*SAFE*/(sizeof chunks_to_process)/5); - } + chunks_to_process, (int)/*SAFE*/(sizeof chunks_to_process)/5); + } } # define PNG_SKIP_CHUNKS(p) png_image_skip_unused_chunks(p) @@ -1684,10 +1711,11 @@ decode_gamma(png_image_read_control *display, png_uint_32 value, int encoding) value *= 257; break; +#ifdef __GNUC__ default: png_error(display->image->opaque->png_ptr, - "unexpected encoding (internal error)"); - break; + "unexpected encoding (internal error)"); +#endif } return value; @@ -1695,8 +1723,8 @@ decode_gamma(png_image_read_control *display, png_uint_32 value, int encoding) static png_uint_32 png_colormap_compose(png_image_read_control *display, - png_uint_32 foreground, int foreground_encoding, png_uint_32 alpha, - png_uint_32 background, int encoding) + png_uint_32 foreground, int foreground_encoding, png_uint_32 alpha, + png_uint_32 background, int encoding) { /* The file value is composed on the background, the background has the given * encoding and so does the result, the file is encoded with P_FILE and the @@ -1732,14 +1760,14 @@ png_colormap_compose(png_image_read_control *display, */ static void png_create_colormap_entry(png_image_read_control *display, - png_uint_32 ip, png_uint_32 red, png_uint_32 green, png_uint_32 blue, - png_uint_32 alpha, int encoding) + png_uint_32 ip, png_uint_32 red, png_uint_32 green, png_uint_32 blue, + png_uint_32 alpha, int encoding) { png_imagep image = display->image; - const int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) != 0 ? - P_LINEAR : P_sRGB; - const int convert_to_Y = (image->format & PNG_FORMAT_FLAG_COLOR) == 0 && - (red != green || green != blue); + int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) != 0 ? + P_LINEAR : P_sRGB; + int convert_to_Y = (image->format & PNG_FORMAT_FLAG_COLOR) == 0 && + (red != green || green != blue); if (ip > 255) png_error(image->opaque->png_ptr, "color-map index out of range"); @@ -1824,6 +1852,7 @@ png_create_colormap_entry(png_image_read_control *display, y = (y + 128) >> 8; y *= 255; y = PNG_sRGB_FROM_LINEAR((y + 64) >> 7); + alpha = PNG_DIV257(alpha); encoding = P_sRGB; } @@ -1846,13 +1875,13 @@ png_create_colormap_entry(png_image_read_control *display, /* Store the value. */ { # ifdef PNG_FORMAT_AFIRST_SUPPORTED - const int afirst = (image->format & PNG_FORMAT_FLAG_AFIRST) != 0 && + int afirst = (image->format & PNG_FORMAT_FLAG_AFIRST) != 0 && (image->format & PNG_FORMAT_FLAG_ALPHA) != 0; # else # define afirst 0 # endif # ifdef PNG_FORMAT_BGR_SUPPORTED - const int bgr = (image->format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0; + int bgr = (image->format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0; # else # define bgr 0 # endif @@ -1871,7 +1900,7 @@ png_create_colormap_entry(png_image_read_control *display, { case 4: entry[afirst ? 0 : 3] = (png_uint_16)alpha; - /* FALL THROUGH */ + /* FALLTHROUGH */ case 3: if (alpha < 65535) @@ -1893,7 +1922,7 @@ png_create_colormap_entry(png_image_read_control *display, case 2: entry[1 ^ afirst] = (png_uint_16)alpha; - /* FALL THROUGH */ + /* FALLTHROUGH */ case 1: if (alpha < 65535) @@ -1922,6 +1951,7 @@ png_create_colormap_entry(png_image_read_control *display, { case 4: entry[afirst ? 0 : 3] = (png_byte)alpha; + /* FALLTHROUGH */ case 3: entry[afirst + (2 ^ bgr)] = (png_byte)blue; entry[afirst + 1] = (png_byte)green; @@ -1930,6 +1960,7 @@ png_create_colormap_entry(png_image_read_control *display, case 2: entry[1 ^ afirst] = (png_byte)alpha; + /* FALLTHROUGH */ case 1: entry[afirst] = (png_byte)green; break; @@ -1956,7 +1987,7 @@ make_gray_file_colormap(png_image_read_control *display) for (i=0; i<256; ++i) png_create_colormap_entry(display, i, i, i, i, 255, P_FILE); - return i; + return (int)i; } static int @@ -1967,7 +1998,7 @@ make_gray_colormap(png_image_read_control *display) for (i=0; i<256; ++i) png_create_colormap_entry(display, i, i, i, i, 255, P_sRGB); - return i; + return (int)i; } #define PNG_GRAY_COLORMAP_ENTRIES 256 @@ -2018,10 +2049,10 @@ make_ga_colormap(png_image_read_control *display) for (g=0; g<6; ++g) png_create_colormap_entry(display, i++, g*51, g*51, g*51, a*51, - P_sRGB); + P_sRGB); } - return i; + return (int)i; } #define PNG_GA_COLORMAP_ENTRIES 256 @@ -2042,11 +2073,11 @@ make_rgb_colormap(png_image_read_control *display) for (b=0; b<6; ++b) png_create_colormap_entry(display, i++, r*51, g*51, b*51, 255, - P_sRGB); + P_sRGB); } } - return i; + return (int)i; } #define PNG_RGB_COLORMAP_ENTRIES 216 @@ -2060,11 +2091,11 @@ png_image_read_colormap(png_voidp argument) { png_image_read_control *display = png_voidcast(png_image_read_control*, argument); - const png_imagep image = display->image; + png_imagep image = display->image; - const png_structrp png_ptr = image->opaque->png_ptr; - const png_uint_32 output_format = image->format; - const int output_encoding = (output_format & PNG_FORMAT_FLAG_LINEAR) != 0 ? + png_structrp png_ptr = image->opaque->png_ptr; + png_uint_32 output_format = image->format; + int output_encoding = (output_format & PNG_FORMAT_FLAG_LINEAR) != 0 ? P_LINEAR : P_sRGB; unsigned int cmap_entries; @@ -2094,7 +2125,7 @@ png_image_read_colormap(png_voidp argument) else if (display->background == NULL /* no way to remove it */) png_error(png_ptr, - "a background color must be supplied to remove alpha/transparency"); + "background color must be supplied to remove alpha/transparency"); /* Get a copy of the background color (this avoids repeating the checks * below.) The encoding is 8-bit sRGB or 16-bit linear, depending on the @@ -2189,7 +2220,7 @@ png_image_read_colormap(png_voidp argument) */ if (i != trans) png_create_colormap_entry(display, i, val, val, val, 255, - P_FILE/*8-bit with file gamma*/); + P_FILE/*8-bit with file gamma*/); /* Else this entry is transparent. The colors don't matter if * there is an alpha channel (back_alpha == 0), but it does no @@ -2201,7 +2232,7 @@ png_image_read_colormap(png_voidp argument) */ else png_create_colormap_entry(display, i, back_r, back_g, back_b, - back_alpha, output_encoding); + back_alpha, output_encoding); } /* We need libpng to preserve the original encoding. */ @@ -2239,7 +2270,7 @@ png_image_read_colormap(png_voidp argument) if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries) png_error(png_ptr, "gray[16] color-map: too few entries"); - cmap_entries = make_gray_colormap(display); + cmap_entries = (unsigned int)make_gray_colormap(display); if (png_ptr->num_trans > 0) { @@ -2266,7 +2297,7 @@ png_image_read_colormap(png_voidp argument) * matches. */ png_create_colormap_entry(display, gray, back_g, back_g, - back_g, 65535, P_LINEAR); + back_g, 65535, P_LINEAR); } /* The background passed to libpng, however, must be the @@ -2280,14 +2311,20 @@ png_image_read_colormap(png_voidp argument) * doesn't. */ png_set_background_fixed(png_ptr, &c, - PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, - 0/*gamma: not used*/); + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); output_processing = PNG_CMAP_NONE; break; } - +#ifdef __COVERITY__ + /* Coverity claims that output_encoding cannot be 2 (P_LINEAR) + * here. + */ + back_alpha = 255; +#else back_alpha = output_encoding == P_LINEAR ? 65535 : 255; +#endif } /* output_processing means that the libpng-processed row will be @@ -2305,7 +2342,7 @@ png_image_read_colormap(png_voidp argument) * background color at full precision. */ png_create_colormap_entry(display, 254, back_r, back_g, back_b, - back_alpha, output_encoding); + back_alpha, output_encoding); } else @@ -2331,7 +2368,7 @@ png_image_read_colormap(png_voidp argument) if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries) png_error(png_ptr, "gray+alpha color-map: too few entries"); - cmap_entries = make_ga_colormap(display); + cmap_entries = (unsigned int)make_ga_colormap(display); background_index = PNG_CMAP_GA_BACKGROUND; output_processing = PNG_CMAP_GA; @@ -2365,7 +2402,7 @@ png_image_read_colormap(png_voidp argument) if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries) png_error(png_ptr, "gray-alpha color-map: too few entries"); - cmap_entries = make_gray_colormap(display); + cmap_entries = (unsigned int)make_gray_colormap(display); if (output_encoding == P_LINEAR) { @@ -2373,7 +2410,7 @@ png_image_read_colormap(png_voidp argument) /* And make sure the corresponding palette entry matches. */ png_create_colormap_entry(display, gray, back_g, back_g, - back_g, 65535, P_LINEAR); + back_g, 65535, P_LINEAR); } /* The background passed to libpng, however, must be the sRGB @@ -2383,8 +2420,8 @@ png_image_read_colormap(png_voidp argument) c.gray = c.red = c.green = c.blue = (png_uint_16)gray; png_set_background_fixed(png_ptr, &c, - PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, - 0/*gamma: not used*/); + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); output_processing = PNG_CMAP_NONE; } @@ -2404,7 +2441,7 @@ png_image_read_colormap(png_voidp argument) { png_uint_32 gray = (i * 256 + 115) / 231; png_create_colormap_entry(display, i++, gray, gray, gray, - 255, P_sRGB); + 255, P_sRGB); } /* NOTE: this preserves the full precision of the application @@ -2412,7 +2449,14 @@ png_image_read_colormap(png_voidp argument) */ background_index = i; png_create_colormap_entry(display, i++, back_r, back_g, back_b, - output_encoding == P_LINEAR ? 65535U : 255U, output_encoding); +#ifdef __COVERITY__ + /* Coverity claims that output_encoding + * cannot be 2 (P_LINEAR) here. + */ 255U, +#else + output_encoding == P_LINEAR ? 65535U : 255U, +#endif + output_encoding); /* For non-opaque input composite on the sRGB background - this * requires inverting the encoding for each component. The input @@ -2450,9 +2494,9 @@ png_image_read_colormap(png_voidp argument) png_uint_32 gray = png_sRGB_table[g*51] * alpha; png_create_colormap_entry(display, i++, - PNG_sRGB_FROM_LINEAR(gray + back_rx), - PNG_sRGB_FROM_LINEAR(gray + back_gx), - PNG_sRGB_FROM_LINEAR(gray + back_bx), 255, P_sRGB); + PNG_sRGB_FROM_LINEAR(gray + back_rx), + PNG_sRGB_FROM_LINEAR(gray + back_gx), + PNG_sRGB_FROM_LINEAR(gray + back_bx), 255, P_sRGB); } } @@ -2478,7 +2522,7 @@ png_image_read_colormap(png_voidp argument) * png_set_tRNS_to_alpha before png_set_background_fixed. */ png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, -1, - -1); + -1); data_encoding = P_sRGB; /* The output will now be one or two 8-bit gray or gray+alpha @@ -2497,7 +2541,7 @@ png_image_read_colormap(png_voidp argument) if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries) png_error(png_ptr, "rgb[ga] color-map: too few entries"); - cmap_entries = make_ga_colormap(display); + cmap_entries = (unsigned int)make_ga_colormap(display); background_index = PNG_CMAP_GA_BACKGROUND; output_processing = PNG_CMAP_GA; } @@ -2523,12 +2567,12 @@ png_image_read_colormap(png_voidp argument) png_ptr->num_trans > 0) && png_gamma_not_sRGB(png_ptr->colorspace.gamma) != 0) { - cmap_entries = make_gray_file_colormap(display); + cmap_entries = (unsigned int)make_gray_file_colormap(display); data_encoding = P_FILE; } else - cmap_entries = make_gray_colormap(display); + cmap_entries = (unsigned int)make_gray_colormap(display); /* But if the input has alpha or transparency it must be removed */ @@ -2554,13 +2598,13 @@ png_image_read_colormap(png_voidp argument) gray = png_sRGB_table[gray]; /* now P_LINEAR */ gray = PNG_DIV257(png_gamma_16bit_correct(gray, - png_ptr->colorspace.gamma)); /* now P_FILE */ + png_ptr->colorspace.gamma)); /* now P_FILE */ /* And make sure the corresponding palette entry contains * exactly the required sRGB value. */ png_create_colormap_entry(display, gray, back_g, back_g, - back_g, 0/*unused*/, output_encoding); + back_g, 0/*unused*/, output_encoding); } else if (output_encoding == P_LINEAR) @@ -2585,8 +2629,8 @@ png_image_read_colormap(png_voidp argument) */ expand_tRNS = 1; png_set_background_fixed(png_ptr, &c, - PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, - 0/*gamma: not used*/); + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); } output_processing = PNG_CMAP_NONE; @@ -2616,11 +2660,11 @@ png_image_read_colormap(png_voidp argument) if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries) png_error(png_ptr, "rgb+alpha color-map: too few entries"); - cmap_entries = make_rgb_colormap(display); + cmap_entries = (unsigned int)make_rgb_colormap(display); /* Add a transparent entry. */ png_create_colormap_entry(display, cmap_entries, 255, 255, - 255, 0, P_sRGB); + 255, 0, P_sRGB); /* This is stored as the background index for the processing * algorithm. @@ -2641,7 +2685,7 @@ png_image_read_colormap(png_voidp argument) */ for (b=0; b<256; b = (b << 1) | 0x7f) png_create_colormap_entry(display, cmap_entries++, - r, g, b, 128, P_sRGB); + r, g, b, 128, P_sRGB); } } @@ -2665,10 +2709,10 @@ png_image_read_colormap(png_voidp argument) if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries) png_error(png_ptr, "rgb-alpha color-map: too few entries"); - cmap_entries = make_rgb_colormap(display); + cmap_entries = (unsigned int)make_rgb_colormap(display); png_create_colormap_entry(display, cmap_entries, back_r, - back_g, back_b, 0/*unused*/, output_encoding); + back_g, back_b, 0/*unused*/, output_encoding); if (output_encoding == P_LINEAR) { @@ -2690,9 +2734,9 @@ png_image_read_colormap(png_voidp argument) * index. */ if (memcmp((png_const_bytep)display->colormap + - sample_size * cmap_entries, - (png_const_bytep)display->colormap + - sample_size * PNG_RGB_INDEX(r,g,b), + sample_size * cmap_entries, + (png_const_bytep)display->colormap + + sample_size * PNG_RGB_INDEX(r,g,b), sample_size) != 0) { /* The background color must be added. */ @@ -2710,13 +2754,13 @@ png_image_read_colormap(png_voidp argument) */ for (b=0; b<256; b = (b << 1) | 0x7f) png_create_colormap_entry(display, cmap_entries++, - png_colormap_compose(display, r, P_sRGB, 128, - back_r, output_encoding), - png_colormap_compose(display, g, P_sRGB, 128, - back_g, output_encoding), - png_colormap_compose(display, b, P_sRGB, 128, - back_b, output_encoding), - 0/*unused*/, output_encoding); + png_colormap_compose(display, r, P_sRGB, 128, + back_r, output_encoding), + png_colormap_compose(display, g, P_sRGB, 128, + back_g, output_encoding), + png_colormap_compose(display, b, P_sRGB, 128, + back_b, output_encoding), + 0/*unused*/, output_encoding); } } @@ -2734,8 +2778,8 @@ png_image_read_colormap(png_voidp argument) c.blue = (png_uint_16)back_b; png_set_background_fixed(png_ptr, &c, - PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, - 0/*gamma: not used*/); + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); output_processing = PNG_CMAP_RGB; } @@ -2750,7 +2794,7 @@ png_image_read_colormap(png_voidp argument) if (PNG_RGB_COLORMAP_ENTRIES > image->colormap_entries) png_error(png_ptr, "rgb color-map: too few entries"); - cmap_entries = make_rgb_colormap(display); + cmap_entries = (unsigned int)make_rgb_colormap(display); output_processing = PNG_CMAP_RGB; } } @@ -2764,7 +2808,7 @@ png_image_read_colormap(png_voidp argument) unsigned int num_trans = png_ptr->num_trans; png_const_bytep trans = num_trans > 0 ? png_ptr->trans_alpha : NULL; png_const_colorp colormap = png_ptr->palette; - const int do_background = trans != NULL && + int do_background = trans != NULL && (output_format & PNG_FORMAT_FLAG_ALPHA) == 0; unsigned int i; @@ -2774,11 +2818,11 @@ png_image_read_colormap(png_voidp argument) output_processing = PNG_CMAP_NONE; data_encoding = P_FILE; /* Don't change from color-map indices */ - cmap_entries = png_ptr->num_palette; + cmap_entries = (unsigned int)png_ptr->num_palette; if (cmap_entries > 256) cmap_entries = 256; - if (cmap_entries > image->colormap_entries) + if (cmap_entries > (unsigned int)image->colormap_entries) png_error(png_ptr, "palette color-map: too few entries"); for (i=0; i < cmap_entries; ++i) @@ -2787,7 +2831,7 @@ png_image_read_colormap(png_voidp argument) { if (trans[i] == 0) png_create_colormap_entry(display, i, back_r, back_g, - back_b, 0, output_encoding); + back_b, 0, output_encoding); else { @@ -2795,22 +2839,22 @@ png_image_read_colormap(png_voidp argument) * on the sRGB color in 'back'. */ png_create_colormap_entry(display, i, - png_colormap_compose(display, colormap[i].red, P_FILE, - trans[i], back_r, output_encoding), - png_colormap_compose(display, colormap[i].green, P_FILE, - trans[i], back_g, output_encoding), - png_colormap_compose(display, colormap[i].blue, P_FILE, - trans[i], back_b, output_encoding), - output_encoding == P_LINEAR ? trans[i] * 257U : - trans[i], - output_encoding); + png_colormap_compose(display, colormap[i].red, + P_FILE, trans[i], back_r, output_encoding), + png_colormap_compose(display, colormap[i].green, + P_FILE, trans[i], back_g, output_encoding), + png_colormap_compose(display, colormap[i].blue, + P_FILE, trans[i], back_b, output_encoding), + output_encoding == P_LINEAR ? trans[i] * 257U : + trans[i], + output_encoding); } } else png_create_colormap_entry(display, i, colormap[i].red, - colormap[i].green, colormap[i].blue, - i < num_trans ? trans[i] : 255U, P_FILE/*8-bit*/); + colormap[i].green, colormap[i].blue, + i < num_trans ? trans[i] : 255U, P_FILE/*8-bit*/); } /* The PNG data may have indices packed in fewer than 8 bits, it @@ -2824,7 +2868,6 @@ png_image_read_colormap(png_voidp argument) default: png_error(png_ptr, "invalid PNG color type"); /*NOT REACHED*/ - break; } /* Now deal with the output processing */ @@ -2834,19 +2877,20 @@ png_image_read_colormap(png_voidp argument) switch (data_encoding) { - default: - png_error(png_ptr, "bad data option (internal error)"); - break; - case P_sRGB: /* Change to 8-bit sRGB */ png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, PNG_GAMMA_sRGB); - /* FALL THROUGH */ + /* FALLTHROUGH */ case P_FILE: if (png_ptr->bit_depth > 8) png_set_scale_16(png_ptr); break; + +#ifdef __GNUC__ + default: + png_error(png_ptr, "bad data option (internal error)"); +#endif } if (cmap_entries > 256 || cmap_entries > image->colormap_entries) @@ -2890,7 +2934,7 @@ png_image_read_colormap(png_voidp argument) png_error(png_ptr, "bad background index (internal error)"); } - display->colormap_processing = output_processing; + display->colormap_processing = (int)output_processing; return 1/*ok*/; } @@ -2900,7 +2944,7 @@ static int png_image_read_and_map(png_voidp argument) { png_image_read_control *display = png_voidcast(png_image_read_control*, - argument); + argument); png_imagep image = display->image; png_structrp png_ptr = image->opaque->png_ptr; int passes; @@ -3037,7 +3081,7 @@ png_image_read_and_map(png_voidp argument) if (alpha >= 196) *outrow = PNG_RGB_INDEX(inrow[0], inrow[1], - inrow[2]); + inrow[2]); else if (alpha < 64) *outrow = PNG_CMAP_RGB_ALPHA_BACKGROUND; @@ -3089,7 +3133,7 @@ static int png_image_read_colormapped(png_voidp argument) { png_image_read_control *display = png_voidcast(png_image_read_control*, - argument); + argument); png_imagep image = display->image; png_controlp control = image->opaque; png_structrp png_ptr = control->png_ptr; @@ -3154,8 +3198,7 @@ png_image_read_colormapped(png_voidp argument) image->colormap_entries == 244 /* 216 + 1 + 27 */) break; - /* goto bad_output; */ - /* FALL THROUGH */ + goto bad_output; default: bad_output: @@ -3199,14 +3242,14 @@ png_image_read_colormapped(png_voidp argument) else { - png_alloc_size_t row_bytes = display->row_bytes; + png_alloc_size_t row_bytes = (png_alloc_size_t)display->row_bytes; while (--passes >= 0) { png_uint_32 y = image->height; png_bytep row = png_voidcast(png_bytep, display->first_row); - while (y-- > 0) + for (; y > 0; --y) { png_read_row(png_ptr, row, NULL); row += row_bytes; @@ -3222,7 +3265,7 @@ static int png_image_read_composite(png_voidp argument) { png_image_read_control *display = png_voidcast(png_image_read_control*, - argument); + argument); png_imagep image = display->image; png_structrp png_ptr = image->opaque->png_ptr; int passes; @@ -3246,7 +3289,7 @@ png_image_read_composite(png_voidp argument) png_uint_32 width = image->width; ptrdiff_t step_row = display->row_bytes; unsigned int channels = - (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1; + (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1; int pass; for (pass = 0; pass < passes; ++pass) @@ -3349,7 +3392,7 @@ static int png_image_read_background(png_voidp argument) { png_image_read_control *display = png_voidcast(png_image_read_control*, - argument); + argument); png_imagep image = display->image; png_structrp png_ptr = image->opaque->png_ptr; png_inforp info_ptr = image->opaque->info_ptr; @@ -3397,10 +3440,6 @@ png_image_read_background(png_voidp argument) */ switch (info_ptr->bit_depth) { - default: - png_error(png_ptr, "unexpected bit depth"); - break; - case 8: /* 8-bit sRGB gray values with an alpha channel; the alpha channel is * to be removed by composing on a background: either the row if @@ -3413,8 +3452,7 @@ png_image_read_background(png_voidp argument) for (pass = 0; pass < passes; ++pass) { - png_bytep row = png_voidcast(png_bytep, - display->first_row); + png_bytep row = png_voidcast(png_bytep, display->first_row); unsigned int startx, stepx, stepy; png_uint_32 y; @@ -3442,7 +3480,7 @@ png_image_read_background(png_voidp argument) for (; y<height; y += stepy) { png_bytep inrow = png_voidcast(png_bytep, - display->local_row); + display->local_row); png_bytep outrow = first_row + y * step_row; png_const_bytep end_row = outrow + width; @@ -3487,7 +3525,7 @@ png_image_read_background(png_voidp argument) for (; y<height; y += stepy) { png_bytep inrow = png_voidcast(png_bytep, - display->local_row); + display->local_row); png_bytep outrow = first_row + y * step_row; png_const_bytep end_row = outrow + width; @@ -3534,13 +3572,14 @@ png_image_read_background(png_voidp argument) */ { png_uint_16p first_row = png_voidcast(png_uint_16p, - display->first_row); + display->first_row); /* The division by two is safe because the caller passed in a * stride which was multiplied by 2 (below) to get row_bytes. */ ptrdiff_t step_row = display->row_bytes / 2; - int preserve_alpha = (image->format & PNG_FORMAT_FLAG_ALPHA) != 0; - unsigned int outchannels = 1+preserve_alpha; + unsigned int preserve_alpha = (image->format & + PNG_FORMAT_FLAG_ALPHA) != 0; + unsigned int outchannels = 1U+preserve_alpha; int swap_alpha = 0; # ifdef PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED @@ -3584,7 +3623,7 @@ png_image_read_background(png_voidp argument) /* Read the row, which is packed: */ png_read_row(png_ptr, png_voidcast(png_bytep, - display->local_row), NULL); + display->local_row), NULL); inrow = png_voidcast(png_const_uint_16p, display->local_row); /* Now do the pre-multiplication on each pixel in this row. @@ -3618,6 +3657,11 @@ png_image_read_background(png_voidp argument) } } break; + +#ifdef __GNUC__ + default: + png_error(png_ptr, "unexpected bit depth"); +#endif } return 1; @@ -3628,7 +3672,7 @@ static int png_image_read_direct(png_voidp argument) { png_image_read_control *display = png_voidcast(png_image_read_control*, - argument); + argument); png_imagep image = display->image; png_structrp png_ptr = image->opaque->png_ptr; png_inforp info_ptr = image->opaque->info_ptr; @@ -3679,7 +3723,7 @@ png_image_read_direct(png_voidp argument) do_local_background = 1/*maybe*/; png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, - PNG_RGB_TO_GRAY_DEFAULT, PNG_RGB_TO_GRAY_DEFAULT); + PNG_RGB_TO_GRAY_DEFAULT, PNG_RGB_TO_GRAY_DEFAULT); } change &= ~PNG_FORMAT_FLAG_COLOR; @@ -3721,7 +3765,13 @@ png_image_read_direct(png_voidp argument) mode = PNG_ALPHA_PNG; output_gamma = PNG_DEFAULT_sRGB; } - + + if ((change & PNG_FORMAT_FLAG_ASSOCIATED_ALPHA) != 0) + { + mode = PNG_ALPHA_OPTIMIZED; + change &= ~PNG_FORMAT_FLAG_ASSOCIATED_ALPHA; + } + /* If 'do_local_background' is set check for the presence of gamma * correction; this is part of the work-round for the libpng bug * described above. @@ -3738,7 +3788,7 @@ png_image_read_direct(png_voidp argument) * final value. */ if (png_muldiv(>est, output_gamma, png_ptr->colorspace.gamma, - PNG_FP_1) != 0 && png_gamma_significant(gtest) == 0) + PNG_FP_1) != 0 && png_gamma_significant(gtest) == 0) do_local_background = 0; else if (mode == PNG_ALPHA_STANDARD) @@ -3801,8 +3851,8 @@ png_image_read_direct(png_voidp argument) * pixels. */ png_set_background_fixed(png_ptr, &c, - PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, - 0/*gamma: not used*/); + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); } else /* compose on row: implemented below. */ @@ -3833,16 +3883,16 @@ png_image_read_direct(png_voidp argument) else filler = 255; -# ifdef PNG_FORMAT_AFIRST_SUPPORTED - if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) - { - where = PNG_FILLER_BEFORE; - change &= ~PNG_FORMAT_FLAG_AFIRST; - } +#ifdef PNG_FORMAT_AFIRST_SUPPORTED + if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) + { + where = PNG_FILLER_BEFORE; + change &= ~PNG_FORMAT_FLAG_AFIRST; + } - else -# endif - where = PNG_FILLER_AFTER; + else +#endif + where = PNG_FILLER_AFTER; png_set_add_alpha(png_ptr, filler, where); } @@ -3902,7 +3952,7 @@ png_image_read_direct(png_voidp argument) */ if (linear != 0) { - PNG_CONST png_uint_16 le = 0x0001; + png_uint_16 le = 0x0001; if ((*(png_const_bytep) & le) != 0) png_set_swap(png_ptr); @@ -3947,15 +3997,19 @@ png_image_read_direct(png_voidp argument) else if (do_local_compose != 0) /* internal error */ png_error(png_ptr, "png_image_read: alpha channel lost"); + if ((format & PNG_FORMAT_FLAG_ASSOCIATED_ALPHA) != 0) { + info_format |= PNG_FORMAT_FLAG_ASSOCIATED_ALPHA; + } + if (info_ptr->bit_depth == 16) info_format |= PNG_FORMAT_FLAG_LINEAR; -# ifdef PNG_FORMAT_BGR_SUPPORTED - if ((png_ptr->transformations & PNG_BGR) != 0) - info_format |= PNG_FORMAT_FLAG_BGR; -# endif +#ifdef PNG_FORMAT_BGR_SUPPORTED + if ((png_ptr->transformations & PNG_BGR) != 0) + info_format |= PNG_FORMAT_FLAG_BGR; +#endif -# ifdef PNG_FORMAT_AFIRST_SUPPORTED +#ifdef PNG_FORMAT_AFIRST_SUPPORTED if (do_local_background == 2) { if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) @@ -4032,14 +4086,14 @@ png_image_read_direct(png_voidp argument) else { - png_alloc_size_t row_bytes = display->row_bytes; + png_alloc_size_t row_bytes = (png_alloc_size_t)display->row_bytes; while (--passes >= 0) { png_uint_32 y = image->height; png_bytep row = png_voidcast(png_bytep, display->first_row); - while (y-- > 0) + for (; y > 0; --y) { png_read_row(png_ptr, row, NULL); row += row_bytes; @@ -4052,67 +4106,117 @@ png_image_read_direct(png_voidp argument) int PNGAPI png_image_finish_read(png_imagep image, png_const_colorp background, - void *buffer, png_int_32 row_stride, void *colormap) + void *buffer, png_int_32 row_stride, void *colormap) { if (image != NULL && image->version == PNG_IMAGE_VERSION) { - png_uint_32 check; + /* Check for row_stride overflow. This check is not performed on the + * original PNG format because it may not occur in the output PNG format + * and libpng deals with the issues of reading the original. + */ + unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format); - if (row_stride == 0) - row_stride = PNG_IMAGE_ROW_STRIDE(*image); + /* The following checks just the 'row_stride' calculation to ensure it + * fits in a signed 32-bit value. Because channels/components can be + * either 1 or 2 bytes in size the length of a row can still overflow 32 + * bits; this is just to verify that the 'row_stride' argument can be + * represented. + */ + if (image->width <= 0x7fffffffU/channels) /* no overflow */ + { + png_uint_32 check; + png_uint_32 png_row_stride = image->width * channels; - if (row_stride < 0) - check = -row_stride; + if (row_stride == 0) + row_stride = (png_int_32)/*SAFE*/png_row_stride; - else - check = row_stride; + if (row_stride < 0) + check = (png_uint_32)(-row_stride); - if (image->opaque != NULL && buffer != NULL && - check >= PNG_IMAGE_ROW_STRIDE(*image)) - { - if ((image->format & PNG_FORMAT_FLAG_COLORMAP) == 0 || - (image->colormap_entries > 0 && colormap != NULL)) + else + check = (png_uint_32)row_stride; + + /* This verifies 'check', the absolute value of the actual stride + * passed in and detects overflow in the application calculation (i.e. + * if the app did actually pass in a non-zero 'row_stride'. + */ + if (image->opaque != NULL && buffer != NULL && check >= png_row_stride) { - int result; - png_image_read_control display; - - memset(&display, 0, (sizeof display)); - display.image = image; - display.buffer = buffer; - display.row_stride = row_stride; - display.colormap = colormap; - display.background = background; - display.local_row = NULL; - - /* Choose the correct 'end' routine; for the color-map case all the - * setup has already been done. + /* Now check for overflow of the image buffer calculation; this + * limits the whole image size to 32 bits for API compatibility with + * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro. + * + * The PNG_IMAGE_BUFFER_SIZE macro is: + * + * (PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)*height*(row_stride)) + * + * And the component size is always 1 or 2, so make sure that the + * number of *bytes* that the application is saying are available + * does actually fit into a 32-bit number. + * + * NOTE: this will be changed in 1.7 because PNG_IMAGE_BUFFER_SIZE + * will be changed to use png_alloc_size_t; bigger images can be + * accommodated on 64-bit systems. */ - if ((image->format & PNG_FORMAT_FLAG_COLORMAP) != 0) - result = - png_safe_execute(image, png_image_read_colormap, &display) && - png_safe_execute(image, png_image_read_colormapped, &display); + if (image->height <= + 0xffffffffU/PNG_IMAGE_PIXEL_COMPONENT_SIZE(image->format)/check) + { + if ((image->format & PNG_FORMAT_FLAG_COLORMAP) == 0 || + (image->colormap_entries > 0 && colormap != NULL)) + { + int result; + png_image_read_control display; + + memset(&display, 0, (sizeof display)); + display.image = image; + display.buffer = buffer; + display.row_stride = row_stride; + display.colormap = colormap; + display.background = background; + display.local_row = NULL; + + /* Choose the correct 'end' routine; for the color-map case + * all the setup has already been done. + */ + if ((image->format & PNG_FORMAT_FLAG_COLORMAP) != 0) + result = + png_safe_execute(image, + png_image_read_colormap, &display) && + png_safe_execute(image, + png_image_read_colormapped, &display); - else - result = - png_safe_execute(image, png_image_read_direct, &display); + else + result = + png_safe_execute(image, + png_image_read_direct, &display); + + png_image_free(image); + return result; + } - png_image_free(image); - return result; + else + return png_image_error(image, + "png_image_finish_read[color-map]: no color-map"); + } + + else + return png_image_error(image, + "png_image_finish_read: image too large"); } else return png_image_error(image, - "png_image_finish_read[color-map]: no color-map"); + "png_image_finish_read: invalid argument"); } else return png_image_error(image, - "png_image_finish_read: invalid argument"); + "png_image_finish_read: row_stride too large"); } else if (image != NULL) return png_image_error(image, - "png_image_finish_read: damaged PNG_IMAGE_VERSION"); + "png_image_finish_read: damaged PNG_IMAGE_VERSION"); return 0; } |