X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/c801d85f158c4cba50b588807daabdcbd0ed3853..0d53638f7147c18153f63fdfc096b17be6e22a27:/src/png/pngpread.c?ds=sidebyside diff --git a/src/png/pngpread.c b/src/png/pngpread.c index 0f0d466fa2..f132ce6004 100644 --- a/src/png/pngpread.c +++ b/src/png/pngpread.c @@ -1,23 +1,38 @@ /* pngpread.c - read a png file in push mode * - * libpng 1.0.1 - * For conditions of distribution and use, see copyright notice in png.h - * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - * Copyright (c) 1996, 1997 Andreas Dilger - * Copyright (c) 1998, Glenn Randers-Pehrson - * March 15, 1998 + * Last changed in libpng 1.6.0 [February 14, 2013] + * Copyright (c) 1998-2013 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 */ -#define PNG_INTERNAL -#include "png.h" +#include "pngpriv.h" #ifdef PNG_PROGRESSIVE_READ_SUPPORTED -void -png_process_data(png_structp png_ptr, png_infop info_ptr, - png_bytep buffer, png_size_t buffer_size) +/* Push model modes */ +#define PNG_READ_SIG_MODE 0 +#define PNG_READ_CHUNK_MODE 1 +#define PNG_READ_IDAT_MODE 2 +#define PNG_SKIP_MODE 3 +#define PNG_READ_tEXt_MODE 4 +#define PNG_READ_zTXt_MODE 5 +#define PNG_READ_DONE_MODE 6 +#define PNG_READ_iTXt_MODE 7 +#define PNG_ERROR_MODE 8 + +void PNGAPI +png_process_data(png_structrp png_ptr, png_inforp info_ptr, + png_bytep buffer, png_size_t buffer_size) { + if (png_ptr == NULL || info_ptr == NULL) + return; + png_push_restore_buffer(png_ptr, buffer, buffer_size); while (png_ptr->buffer_size) @@ -26,12 +41,73 @@ png_process_data(png_structp png_ptr, png_infop info_ptr, } } +png_size_t PNGAPI +png_process_data_pause(png_structrp png_ptr, int save) +{ + if (png_ptr != NULL) + { + /* It's easiest for the caller if we do the save, then the caller doesn't + * have to supply the same data again: + */ + if (save) + png_push_save_buffer(png_ptr); + else + { + /* This includes any pending saved bytes: */ + png_size_t remaining = png_ptr->buffer_size; + png_ptr->buffer_size = 0; + + /* So subtract the saved buffer size, unless all the data + * is actually 'saved', in which case we just return 0 + */ + if (png_ptr->save_buffer_size < remaining) + return remaining - png_ptr->save_buffer_size; + } + } + + return 0; +} + +png_uint_32 PNGAPI +png_process_data_skip(png_structrp png_ptr) +{ + png_uint_32 remaining = 0; + + if (png_ptr != NULL && png_ptr->process_mode == PNG_SKIP_MODE && + png_ptr->skip_length > 0) + { + /* At the end of png_process_data the buffer size must be 0 (see the loop + * above) so we can detect a broken call here: + */ + if (png_ptr->buffer_size != 0) + png_error(png_ptr, + "png_process_data_skip called inside png_process_data"); + + /* If is impossible for there to be a saved buffer at this point - + * otherwise we could not be in SKIP mode. This will also happen if + * png_process_skip is called inside png_process_data (but only very + * rarely.) + */ + if (png_ptr->save_buffer_size != 0) + png_error(png_ptr, "png_process_data_skip called with saved data"); + + remaining = png_ptr->skip_length; + png_ptr->skip_length = 0; + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + } + + return remaining; +} + /* What we do with the incoming data depends on what we were previously * doing before we ran out of data... */ -void -png_process_some_data(png_structp png_ptr, png_infop info_ptr) +void /* PRIVATE */ +png_process_some_data(png_structrp png_ptr, png_inforp info_ptr) { + if (png_ptr == NULL) + return; + switch (png_ptr->process_mode) { case PNG_READ_SIG_MODE: @@ -39,35 +115,25 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr) png_push_read_sig(png_ptr, info_ptr); break; } + case PNG_READ_CHUNK_MODE: { png_push_read_chunk(png_ptr, info_ptr); break; } + case PNG_READ_IDAT_MODE: { png_push_read_IDAT(png_ptr); break; } -#if defined(PNG_READ_tEXt_SUPPORTED) - case PNG_READ_tEXt_MODE: - { - png_push_read_tEXt(png_ptr, info_ptr); - break; - } -#endif -#if defined(PNG_READ_zTXt_SUPPORTED) - case PNG_READ_zTXt_MODE: - { - png_push_read_zTXt(png_ptr, info_ptr); - break; - } -#endif + case PNG_SKIP_MODE: { png_push_crc_finish(png_ptr); break; } + default: { png_ptr->buffer_size = 0; @@ -78,11 +144,12 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr) /* Read any remaining signature bytes from the stream and compare them with * the correct PNG signature. It is possible that this routine is called - * with bytes already read from the signature, whether because they have been - * checked by the calling application, or from multiple calls to this routine. + * with bytes already read from the signature, either because they have been + * checked by the calling application, or because of multiple calls to this + * routine. */ -void -png_push_read_sig(png_structp png_ptr, png_infop info_ptr) +void /* PRIVATE */ +png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr) { png_size_t num_checked = png_ptr->sig_bytes, num_to_check = 8 - num_checked; @@ -92,15 +159,16 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr) num_to_check = png_ptr->buffer_size; } - png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]), - num_to_check); - png_ptr->sig_bytes += num_to_check; + png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]), + num_to_check); + png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check); if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) { if (num_checked < 4 && png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) png_error(png_ptr, "Not a PNG file"); + else png_error(png_ptr, "PNG file corrupted by ASCII conversion"); } @@ -113,18 +181,24 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr) } } -void -png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) +void /* PRIVATE */ +png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr) { + png_uint_32 chunk_name; +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + int keep; /* unknown handling method */ +#endif + /* First we make sure we have enough data for the 4 byte chunk name * and the 4 byte chunk length before proceeding with decoding the * chunk data. To fully decode each of these chunks, we also make * sure we have enough data in the buffer for the 4 byte CRC at the * end of every chunk (except IDAT, which is handled separately). */ - if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER)) + if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) { png_byte chunk_length[4]; + png_byte chunk_tag[4]; if (png_ptr->buffer_size < 8) { @@ -133,14 +207,47 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) } png_push_fill_buffer(png_ptr, chunk_length, 4); - png_ptr->push_length = png_get_uint_32(chunk_length); + png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); png_reset_crc(png_ptr); - png_crc_read(png_ptr, png_ptr->chunk_name, 4); - png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER; + png_crc_read(png_ptr, chunk_tag, 4); + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); + png_check_chunk_name(png_ptr, png_ptr->chunk_name); + png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; } - if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) + chunk_name = png_ptr->chunk_name; + + if (chunk_name == png_IDAT) { + if (png_ptr->mode & PNG_AFTER_IDAT) + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; + + /* If we reach an IDAT chunk, this means we have read all of the + * header chunks, and we can start reading the image (or if this + * is called after the image has been read - we have an error). + */ + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before IDAT"); + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + !(png_ptr->mode & PNG_HAVE_PLTE)) + png_error(png_ptr, "Missing PLTE before IDAT"); + + png_ptr->mode |= PNG_HAVE_IDAT; + + if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) + if (png_ptr->push_length == 0) + return; + + if (png_ptr->mode & PNG_AFTER_IDAT) + png_benign_error(png_ptr, "Too many IDATs found"); + } + + if (chunk_name == png_IHDR) + { + if (png_ptr->push_length != 13) + png_error(png_ptr, "Invalid IHDR length"); + if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); @@ -149,7 +256,8 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); } - else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + + else if (chunk_name == png_IEND) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -157,32 +265,52 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) return; } - png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); + png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length); + + png_ptr->process_mode = PNG_READ_DONE_MODE; + png_push_have_end(png_ptr, info_ptr); } - else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0) { - /* If we reach an IDAT chunk, this means we have read all of the - * header chunks, and we can start reading the image (or if this - * is called after the image has been read - we have an error). - */ - if (png_ptr->mode & PNG_HAVE_IDAT) + if (png_ptr->push_length + 4 > png_ptr->buffer_size) { - if (png_ptr->push_length == 0) - return; + png_push_save_buffer(png_ptr); + return; + } + + png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep); + + if (chunk_name == png_PLTE) + png_ptr->mode |= PNG_HAVE_PLTE; + } - if (png_ptr->mode & PNG_AFTER_IDAT) - png_error(png_ptr, "Too many IDAT's found"); +#endif + else if (chunk_name == png_PLTE) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; } + png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); + } + else if (chunk_name == png_IDAT) + { png_ptr->idat_size = png_ptr->push_length; - png_ptr->mode |= PNG_HAVE_IDAT; png_ptr->process_mode = PNG_READ_IDAT_MODE; png_push_have_info(png_ptr, info_ptr); - png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; + png_ptr->zstream.avail_out = + (uInt) PNG_ROWBYTES(png_ptr->pixel_depth, + png_ptr->iwidth) + 1; png_ptr->zstream.next_out = png_ptr->row_buf; return; } - else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) + +#ifdef PNG_READ_gAMA_SUPPORTED + else if (png_ptr->chunk_name == png_gAMA) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -190,12 +318,12 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) return; } - png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length); - png_ptr->process_mode = PNG_READ_DONE_MODE; - png_push_have_end(png_ptr, info_ptr); + png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length); } -#if defined(PNG_READ_gAMA_SUPPORTED) - else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) + +#endif +#ifdef PNG_READ_sBIT_SUPPORTED + else if (png_ptr->chunk_name == png_sBIT) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -203,11 +331,12 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) return; } - png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length); + png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length); } + #endif -#if defined(PNG_READ_sBIT_SUPPORTED) - else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) +#ifdef PNG_READ_cHRM_SUPPORTED + else if (png_ptr->chunk_name == png_cHRM) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -215,11 +344,12 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) return; } - png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length); + png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); } + #endif -#if defined(PNG_READ_cHRM_SUPPORTED) - else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) +#ifdef PNG_READ_sRGB_SUPPORTED + else if (chunk_name == png_sRGB) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -227,11 +357,12 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) return; } - png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); + png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); } + #endif -#if defined(PNG_READ_sRGB_SUPPORTED) - else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) +#ifdef PNG_READ_iCCP_SUPPORTED + else if (png_ptr->chunk_name == png_iCCP) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -239,11 +370,25 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) return; } - png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); + png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sPLT_SUPPORTED + else if (chunk_name == png_sPLT) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length); } + #endif -#if defined(PNG_READ_tRNS_SUPPORTED) - else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) +#ifdef PNG_READ_tRNS_SUPPORTED + else if (chunk_name == png_tRNS) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -253,9 +398,10 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length); } + #endif -#if defined(PNG_READ_bKGD_SUPPORTED) - else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) +#ifdef PNG_READ_bKGD_SUPPORTED + else if (chunk_name == png_bKGD) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -265,9 +411,10 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length); } + #endif -#if defined(PNG_READ_hIST_SUPPORTED) - else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) +#ifdef PNG_READ_hIST_SUPPORTED + else if (chunk_name == png_hIST) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -277,9 +424,10 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length); } + #endif -#if defined(PNG_READ_pHYs_SUPPORTED) - else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) +#ifdef PNG_READ_pHYs_SUPPORTED + else if (chunk_name == png_pHYs) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -289,9 +437,10 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length); } + #endif -#if defined(PNG_READ_oFFs_SUPPORTED) - else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) +#ifdef PNG_READ_oFFs_SUPPORTED + else if (chunk_name == png_oFFs) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -302,8 +451,9 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length); } #endif -#if defined(PNG_READ_pCAL_SUPPORTED) - else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) + +#ifdef PNG_READ_pCAL_SUPPORTED + else if (chunk_name == png_pCAL) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -313,9 +463,23 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length); } + +#endif +#ifdef PNG_READ_sCAL_SUPPORTED + else if (chunk_name == png_sCAL) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length); + } + #endif -#if defined(PNG_READ_tIME_SUPPORTED) - else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) +#ifdef PNG_READ_tIME_SUPPORTED + else if (chunk_name == png_tIME) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { @@ -325,65 +489,112 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length); } + +#endif +#ifdef PNG_READ_tEXt_SUPPORTED + else if (chunk_name == png_tEXt) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); + } + #endif -#if defined(PNG_READ_tEXt_SUPPORTED) - else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) +#ifdef PNG_READ_zTXt_SUPPORTED + else if (chunk_name == png_zTXt) { - png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); } + #endif -#if defined(PNG_READ_zTXt_SUPPORTED) - else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) +#ifdef PNG_READ_iTXt_SUPPORTED + else if (chunk_name == png_iTXt) { - png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); } + #endif else { - png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, + PNG_HANDLE_CHUNK_AS_DEFAULT); } - png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER; + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; } -void -png_push_crc_skip(png_structp png_ptr, png_uint_32 skip) +void /* PRIVATE */ +png_push_crc_skip(png_structrp png_ptr, png_uint_32 skip) { png_ptr->process_mode = PNG_SKIP_MODE; png_ptr->skip_length = skip; } -void -png_push_crc_finish(png_structp png_ptr) +void /* PRIVATE */ +png_push_crc_finish(png_structrp png_ptr) { if (png_ptr->skip_length && png_ptr->save_buffer_size) { - png_size_t save_size; + png_size_t save_size = png_ptr->save_buffer_size; + png_uint_32 skip_length = png_ptr->skip_length; + + /* We want the smaller of 'skip_length' and 'save_buffer_size', but + * they are of different types and we don't know which variable has the + * fewest bits. Carefully select the smaller and cast it to the type of + * the larger - this cannot overflow. Do not cast in the following test + * - it will break on either 16 or 64 bit platforms. + */ + if (skip_length < save_size) + save_size = (png_size_t)skip_length; - if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size) - save_size = (png_size_t)png_ptr->skip_length; else - save_size = png_ptr->save_buffer_size; + skip_length = (png_uint_32)save_size; png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); - png_ptr->skip_length -= save_size; + png_ptr->skip_length -= skip_length; png_ptr->buffer_size -= save_size; png_ptr->save_buffer_size -= save_size; png_ptr->save_buffer_ptr += save_size; } if (png_ptr->skip_length && png_ptr->current_buffer_size) { - png_size_t save_size; + png_size_t save_size = png_ptr->current_buffer_size; + png_uint_32 skip_length = png_ptr->skip_length; + + /* We want the smaller of 'skip_length' and 'current_buffer_size', here, + * the same problem exists as above and the same solution. + */ + if (skip_length < save_size) + save_size = (png_size_t)skip_length; - if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size) - save_size = (png_size_t)png_ptr->skip_length; else - save_size = png_ptr->current_buffer_size; + skip_length = (png_uint_32)save_size; png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); - png_ptr->skip_length -= save_size; + png_ptr->skip_length -= skip_length; png_ptr->buffer_size -= save_size; png_ptr->current_buffer_size -= save_size; png_ptr->current_buffer_ptr += save_size; @@ -401,11 +612,14 @@ png_push_crc_finish(png_structp png_ptr) } } -void +void PNGCBAPI png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) { png_bytep ptr; + if (png_ptr == NULL) + return; + ptr = buffer; if (png_ptr->save_buffer_size) { @@ -413,10 +627,11 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) if (length < png_ptr->save_buffer_size) save_size = length; + else save_size = png_ptr->save_buffer_size; - png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size); + memcpy(ptr, png_ptr->save_buffer_ptr, save_size); length -= save_size; ptr += save_size; png_ptr->buffer_size -= save_size; @@ -429,52 +644,66 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) if (length < png_ptr->current_buffer_size) save_size = length; + else save_size = png_ptr->current_buffer_size; - png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size); + memcpy(ptr, png_ptr->current_buffer_ptr, save_size); png_ptr->buffer_size -= save_size; png_ptr->current_buffer_size -= save_size; png_ptr->current_buffer_ptr += save_size; } } -void -png_push_save_buffer(png_structp png_ptr) +void /* PRIVATE */ +png_push_save_buffer(png_structrp png_ptr) { if (png_ptr->save_buffer_size) { if (png_ptr->save_buffer_ptr != png_ptr->save_buffer) { - png_size_t i; + png_size_t i, istop; png_bytep sp; png_bytep dp; + istop = png_ptr->save_buffer_size; for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer; - i < png_ptr->save_buffer_size; - i++, sp++, dp++) + i < istop; i++, sp++, dp++) { *dp = *sp; } } } if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > - png_ptr->save_buffer_max) + png_ptr->save_buffer_max) { png_size_t new_max; png_bytep old_buffer; + if (png_ptr->save_buffer_size > PNG_SIZE_MAX - + (png_ptr->current_buffer_size + 256)) + { + png_error(png_ptr, "Potential overflow of save_buffer"); + } + new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256; old_buffer = png_ptr->save_buffer; - png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr, - (png_uint_32)new_max); - png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); + png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, + (png_size_t)new_max); + + if (png_ptr->save_buffer == NULL) + { + png_free(png_ptr, old_buffer); + png_error(png_ptr, "Insufficient memory for save_buffer"); + } + + memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); png_free(png_ptr, old_buffer); png_ptr->save_buffer_max = new_max; } if (png_ptr->current_buffer_size) { - png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size, + memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size, png_ptr->current_buffer_ptr, png_ptr->current_buffer_size); png_ptr->save_buffer_size += png_ptr->current_buffer_size; png_ptr->current_buffer_size = 0; @@ -483,8 +712,8 @@ png_push_save_buffer(png_structp png_ptr) png_ptr->buffer_size = 0; } -void -png_push_restore_buffer(png_structp png_ptr, png_bytep buffer, +void /* PRIVATE */ +png_push_restore_buffer(png_structrp png_ptr, png_bytep buffer, png_size_t buffer_length) { png_ptr->current_buffer = buffer; @@ -493,13 +722,15 @@ png_push_restore_buffer(png_structp png_ptr, png_bytep buffer, png_ptr->current_buffer_ptr = png_ptr->current_buffer; } -void -png_push_read_IDAT(png_structp png_ptr) +void /* PRIVATE */ +png_push_read_IDAT(png_structrp png_ptr) { - if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER)) + if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) { png_byte chunk_length[4]; + png_byte chunk_tag[4]; + /* TODO: this code can be commoned up with the same code in push_read */ if (png_ptr->buffer_size < 8) { png_push_save_buffer(png_ptr); @@ -507,62 +738,73 @@ png_push_read_IDAT(png_structp png_ptr) } png_push_fill_buffer(png_ptr, chunk_length, 4); - png_ptr->push_length = png_get_uint_32(chunk_length); - + png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); png_reset_crc(png_ptr); - png_crc_read(png_ptr, png_ptr->chunk_name, 4); - png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER; + png_crc_read(png_ptr, chunk_tag, 4); + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); + png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; - if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + if (png_ptr->chunk_name != png_IDAT) { png_ptr->process_mode = PNG_READ_CHUNK_MODE; - if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) + + if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED)) png_error(png_ptr, "Not enough compressed data"); + return; } png_ptr->idat_size = png_ptr->push_length; } + if (png_ptr->idat_size && png_ptr->save_buffer_size) { - png_size_t save_size; + png_size_t save_size = png_ptr->save_buffer_size; + png_uint_32 idat_size = png_ptr->idat_size; + + /* We want the smaller of 'idat_size' and 'current_buffer_size', but they + * are of different types and we don't know which variable has the fewest + * bits. Carefully select the smaller and cast it to the type of the + * larger - this cannot overflow. Do not cast in the following test - it + * will break on either 16 or 64 bit platforms. + */ + if (idat_size < save_size) + save_size = (png_size_t)idat_size; - if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size) - { - save_size = (png_size_t)png_ptr->idat_size; - /* check for overflow */ - if((png_uint_32)save_size != png_ptr->idat_size) - png_error(png_ptr, "save_size overflowed in pngpread"); - } else - save_size = png_ptr->save_buffer_size; + idat_size = (png_uint_32)save_size; png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); + png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size); - png_ptr->idat_size -= save_size; + png_ptr->idat_size -= idat_size; png_ptr->buffer_size -= save_size; png_ptr->save_buffer_size -= save_size; png_ptr->save_buffer_ptr += save_size; } + if (png_ptr->idat_size && png_ptr->current_buffer_size) { - png_size_t save_size; + png_size_t save_size = png_ptr->current_buffer_size; + png_uint_32 idat_size = png_ptr->idat_size; + + /* We want the smaller of 'idat_size' and 'current_buffer_size', but they + * are of different types and we don't know which variable has the fewest + * bits. Carefully select the smaller and cast it to the type of the + * larger - this cannot overflow. + */ + if (idat_size < save_size) + save_size = (png_size_t)idat_size; - if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size) - { - save_size = (png_size_t)png_ptr->idat_size; - /* check for overflow */ - if((png_uint_32)save_size != png_ptr->idat_size) - png_error(png_ptr, "save_size overflowed in pngpread"); - } else - save_size = png_ptr->current_buffer_size; + idat_size = (png_uint_32)save_size; png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); + png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size); - png_ptr->idat_size -= save_size; + png_ptr->idat_size -= idat_size; png_ptr->buffer_size -= save_size; png_ptr->current_buffer_size -= save_size; png_ptr->current_buffer_ptr += save_size; @@ -576,94 +818,211 @@ png_push_read_IDAT(png_structp png_ptr) } png_crc_finish(png_ptr, 0); - png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER; + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->zowner = 0; } } -void -png_process_IDAT_data(png_structp png_ptr, png_bytep buffer, +void /* PRIVATE */ +png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer, png_size_t buffer_length) { - int ret; - - if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length) - png_error(png_ptr, "Extra compression data"); + /* The caller checks for a non-zero buffer length. */ + if (!(buffer_length > 0) || buffer == NULL) + png_error(png_ptr, "No IDAT data (internal error)"); + /* This routine must process all the data it has been given + * before returning, calling the row callback as required to + * handle the uncompressed results. + */ png_ptr->zstream.next_in = buffer; + /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */ png_ptr->zstream.avail_in = (uInt)buffer_length; - for(;;) + + /* Keep going until the decompressed data is all processed + * or the stream marked as finished. + */ + while (png_ptr->zstream.avail_in > 0 && + !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED)) { - ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); - if (ret == Z_STREAM_END) + int ret; + + /* We have data for zlib, but we must check that zlib + * has someplace to put the results. It doesn't matter + * if we don't expect any results -- it may be the input + * data is just the LZ end code. + */ + if (!(png_ptr->zstream.avail_out > 0)) { - if (png_ptr->zstream.avail_in) - png_error(png_ptr, "Extra compressed data"); - if (!(png_ptr->zstream.avail_out)) - { - png_push_process_row(png_ptr); - } + /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */ + png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth, + png_ptr->iwidth) + 1); - png_ptr->mode |= PNG_AFTER_IDAT; - png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; - break; + png_ptr->zstream.next_out = png_ptr->row_buf; } - else if (ret == Z_BUF_ERROR) - break; - else if (ret != Z_OK) - png_error(png_ptr, "Decompression Error"); - if (!(png_ptr->zstream.avail_out)) + + /* Using Z_SYNC_FLUSH here means that an unterminated + * LZ stream (a stream with a missing end code) can still + * be handled, otherwise (Z_NO_FLUSH) a future zlib + * implementation might defer output and therefore + * change the current behavior (see comments in inflate.c + * for why this doesn't happen at present with zlib 1.2.5). + */ + ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH); + + /* Check for any failure before proceeding. */ + if (ret != Z_OK && ret != Z_STREAM_END) { - png_push_process_row(png_ptr); - png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; - png_ptr->zstream.next_out = png_ptr->row_buf; + /* Terminate the decompression. */ + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; + png_ptr->zowner = 0; + + /* This may be a truncated stream (missing or + * damaged end code). Treat that as a warning. + */ + if (png_ptr->row_number >= png_ptr->num_rows || + png_ptr->pass > 6) + png_warning(png_ptr, "Truncated compressed data in IDAT"); + + else + png_error(png_ptr, "Decompression error in IDAT"); + + /* Skip the check on unprocessed input */ + return; } - else - break; + + /* Did inflate output any data? */ + if (png_ptr->zstream.next_out != png_ptr->row_buf) + { + /* Is this unexpected data after the last row? + * If it is, artificially terminate the LZ output + * here. + */ + if (png_ptr->row_number >= png_ptr->num_rows || + png_ptr->pass > 6) + { + /* Extra data. */ + png_warning(png_ptr, "Extra compressed data in IDAT"); + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; + png_ptr->zowner = 0; + + /* Do no more processing; skip the unprocessed + * input check below. + */ + return; + } + + /* Do we have a complete row? */ + if (png_ptr->zstream.avail_out == 0) + png_push_process_row(png_ptr); + } + + /* And check for the end of the stream. */ + if (ret == Z_STREAM_END) + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; } + + /* All the data should have been processed, if anything + * is left at this point we have bytes of IDAT data + * after the zlib end code. + */ + if (png_ptr->zstream.avail_in > 0) + png_warning(png_ptr, "Extra compression data in IDAT"); } -void -png_push_process_row(png_structp png_ptr) +void /* PRIVATE */ +png_push_process_row(png_structrp png_ptr) { - png_ptr->row_info.color_type = png_ptr->color_type; - png_ptr->row_info.width = png_ptr->iwidth; - png_ptr->row_info.channels = png_ptr->channels; - png_ptr->row_info.bit_depth = png_ptr->bit_depth; - png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; - - png_ptr->row_info.rowbytes = ((png_ptr->row_info.width * - (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3); - - png_read_filter_row(png_ptr, &(png_ptr->row_info), - png_ptr->row_buf + 1, png_ptr->prev_row + 1, - (int)(png_ptr->row_buf[0])); - - png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf, - png_ptr->rowbytes + 1); + /* 1.5.6: row_info moved out of png_struct to a local here. */ + png_row_info row_info; + + row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */ + row_info.color_type = png_ptr->color_type; + row_info.bit_depth = png_ptr->bit_depth; + row_info.channels = png_ptr->channels; + row_info.pixel_depth = png_ptr->pixel_depth; + row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); + + 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]); + else + png_error(png_ptr, "bad adaptive filter value"); + } + /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before + * 1.5.6, while the buffer really is this big in current versions of libpng + * it may not be in the future, so this was changed just to copy the + * interlaced row count: + */ + memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1); + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED if (png_ptr->transformations) - png_do_read_transformations(png_ptr); + png_do_read_transformations(png_ptr, &row_info); +#endif + + /* The transformed pixel depth should match the depth now in row_info. */ + if (png_ptr->transformed_pixel_depth == 0) + { + png_ptr->transformed_pixel_depth = row_info.pixel_depth; + if (row_info.pixel_depth > png_ptr->maximum_pixel_depth) + png_error(png_ptr, "progressive row overflow"); + } + + else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth) + png_error(png_ptr, "internal progressive row size calculation error"); -#if defined(PNG_READ_INTERLACING_SUPPORTED) - /* blow up interlaced rows to full size */ + +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Blow up interlaced rows to full size */ if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) { if (png_ptr->pass < 6) - png_do_read_interlace(&(png_ptr->row_info), - png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); + png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass, + png_ptr->transformations); - switch (png_ptr->pass) - { + switch (png_ptr->pass) + { case 0: { int i; for (i = 0; i < 8 && png_ptr->pass == 0; i++) { png_push_have_row(png_ptr, png_ptr->row_buf + 1); - png_read_push_finish_row(png_ptr); + png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */ + } + + if (png_ptr->pass == 2) /* Pass 1 might be empty */ + { + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + if (png_ptr->pass == 4 && png_ptr->height <= 4) + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + if (png_ptr->pass == 6 && png_ptr->height <= 4) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); } + break; } + case 1: { int i; @@ -672,7 +1031,8 @@ png_push_process_row(png_structp png_ptr) png_push_have_row(png_ptr, png_ptr->row_buf + 1); png_read_push_finish_row(png_ptr); } - if (png_ptr->pass == 2) + + if (png_ptr->pass == 2) /* Skip top 4 generated rows */ { for (i = 0; i < 4 && png_ptr->pass == 2; i++) { @@ -680,32 +1040,49 @@ png_push_process_row(png_structp png_ptr) png_read_push_finish_row(png_ptr); } } + break; } + case 2: { int i; + for (i = 0; i < 4 && png_ptr->pass == 2; i++) { png_push_have_row(png_ptr, png_ptr->row_buf + 1); png_read_push_finish_row(png_ptr); } + for (i = 0; i < 4 && png_ptr->pass == 2; i++) { png_push_have_row(png_ptr, NULL); png_read_push_finish_row(png_ptr); } + + if (png_ptr->pass == 4) /* Pass 3 might be empty */ + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + break; } + case 3: { int i; + for (i = 0; i < 4 && png_ptr->pass == 3; i++) { png_push_have_row(png_ptr, png_ptr->row_buf + 1); png_read_push_finish_row(png_ptr); } - if (png_ptr->pass == 4) + + if (png_ptr->pass == 4) /* Skip top two generated rows */ { for (i = 0; i < 2 && png_ptr->pass == 4; i++) { @@ -713,44 +1090,63 @@ png_push_process_row(png_structp png_ptr) png_read_push_finish_row(png_ptr); } } + break; } + case 4: { int i; + for (i = 0; i < 2 && png_ptr->pass == 4; i++) { png_push_have_row(png_ptr, png_ptr->row_buf + 1); png_read_push_finish_row(png_ptr); } + for (i = 0; i < 2 && png_ptr->pass == 4; i++) { png_push_have_row(png_ptr, NULL); png_read_push_finish_row(png_ptr); } + + if (png_ptr->pass == 6) /* Pass 5 might be empty */ + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + break; } + case 5: { int i; + for (i = 0; i < 2 && png_ptr->pass == 5; i++) { png_push_have_row(png_ptr, png_ptr->row_buf + 1); png_read_push_finish_row(png_ptr); } - if (png_ptr->pass == 6) + + if (png_ptr->pass == 6) /* Skip top generated row */ { png_push_have_row(png_ptr, NULL); png_read_push_finish_row(png_ptr); } + break; } + + default: case 6: { png_push_have_row(png_ptr, png_ptr->row_buf + 1); png_read_push_finish_row(png_ptr); + if (png_ptr->pass != 6) break; + png_push_have_row(png_ptr, NULL); png_read_push_finish_row(png_ptr); } @@ -764,368 +1160,119 @@ png_push_process_row(png_structp png_ptr) } } -void -png_read_push_finish_row(png_structp png_ptr) -{ - png_ptr->row_number++; - if (png_ptr->row_number < png_ptr->num_rows) - return; - - 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]; - - png_ptr->irowbytes = ((png_ptr->iwidth * - png_ptr->pixel_depth + 7) >> 3) + 1; - - if (!(png_ptr->transformations & PNG_INTERLACE)) - { - png_ptr->num_rows = (png_ptr->height + - png_pass_yinc[png_ptr->pass] - 1 - - png_pass_ystart[png_ptr->pass]) / - png_pass_yinc[png_ptr->pass]; - if (!(png_ptr->num_rows)) - continue; - } - if (png_ptr->transformations & PNG_INTERLACE) - break; - } while (png_ptr->iwidth == 0); - } -} - -#if defined(PNG_READ_tEXt_SUPPORTED) -void -png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) -{ - if (png_ptr->mode == PNG_BEFORE_IHDR || png_ptr->mode & PNG_HAVE_IEND) - { - png_error(png_ptr, "Out of place tEXt"); - /* to quiet some compiler warnings */ - if(info_ptr == NULL) return; - } - -#ifdef PNG_MAX_MALLOC_64K - png_ptr->skip_length = 0; /* This may not be necessary */ - - if (length > (png_uint_32)65535L) /* Can't hold the entire string in memory */ - { - png_warning(png_ptr, "tEXt chunk too large to fit in memory"); - png_ptr->skip_length = length - (png_uint_32)65535L; - length = (png_uint_32)65535L; - } -#endif - - png_ptr->current_text = (png_charp)png_malloc(png_ptr, - (png_uint_32)(length+1)); - png_ptr->current_text[length] = '\0'; - png_ptr->current_text_ptr = png_ptr->current_text; - png_ptr->current_text_size = (png_size_t)length; - png_ptr->current_text_left = (png_size_t)length; - png_ptr->process_mode = PNG_READ_tEXt_MODE; -} - -void -png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr) +void /* PRIVATE */ +png_read_push_finish_row(png_structrp png_ptr) { - if (png_ptr->buffer_size && png_ptr->current_text_left) - { - png_size_t text_size; - - if (png_ptr->buffer_size < png_ptr->current_text_left) - text_size = png_ptr->buffer_size; - else - text_size = png_ptr->current_text_left; - png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); - png_ptr->current_text_left -= text_size; - png_ptr->current_text_ptr += text_size; - } - if (!(png_ptr->current_text_left)) - { - png_textp text_ptr; - png_charp text; - png_charp key; +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - if (png_ptr->buffer_size < 4) - { - png_push_save_buffer(png_ptr); - return; - } - - png_push_crc_finish(png_ptr); - -#if defined(PNG_MAX_MALLOC_64K) - if (png_ptr->skip_length) - return; -#endif - - key = png_ptr->current_text; - png_ptr->current_text = 0; - - for (text = key; *text; text++) - /* empty loop */ ; + /* Start of interlace block */ + static PNG_CONST png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; - if (text != key + png_ptr->current_text_size) - text++; + /* Offset to next interlace block */ + static PNG_CONST png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; - text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); - text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; - text_ptr->key = key; - text_ptr->text = text; + /* Start of interlace block in the y direction */ + static PNG_CONST png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; - png_set_text(png_ptr, info_ptr, text_ptr, 1); + /* Offset to next interlace block in the y direction */ + static PNG_CONST png_byte png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; - png_free(png_ptr, text_ptr); - } -} + /* Height of interlace block. This is not currently used - if you need + * it, uncomment it here and in png.h + static PNG_CONST png_byte png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; + */ #endif -#if defined(PNG_READ_zTXt_SUPPORTED) -void -png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) -{ - if (png_ptr->mode == PNG_BEFORE_IHDR || png_ptr->mode & PNG_HAVE_IEND) - { - png_error(png_ptr, "Out of place zTXt"); - /* to quiet some compiler warnings */ - if(info_ptr == NULL) return; - } - -#ifdef PNG_MAX_MALLOC_64K - /* We can't handle zTXt chunks > 64K, since we don't have enough space - * to be able to store the uncompressed data. Actually, the threshold - * is probably around 32K, but it isn't as definite as 64K is. - */ - if (length > (png_uint_32)65535L) - { - png_warning(png_ptr, "zTXt chunk too large to fit in memory"); - png_push_crc_skip(png_ptr, length); + png_ptr->row_number++; + if (png_ptr->row_number < png_ptr->num_rows) return; - } -#endif - - png_ptr->current_text = (png_charp)png_malloc(png_ptr, - (png_uint_32)(length+1)); - png_ptr->current_text[length] = '\0'; - png_ptr->current_text_ptr = png_ptr->current_text; - png_ptr->current_text_size = (png_size_t)length; - png_ptr->current_text_left = (png_size_t)length; - png_ptr->process_mode = PNG_READ_zTXt_MODE; -} - -void -png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr) -{ - if (png_ptr->buffer_size && png_ptr->current_text_left) - { - png_size_t text_size; - if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left) - text_size = png_ptr->buffer_size; - else - text_size = png_ptr->current_text_left; - png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); - png_ptr->current_text_left -= text_size; - png_ptr->current_text_ptr += text_size; - } - if (!(png_ptr->current_text_left)) +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (png_ptr->interlaced) { - png_textp text_ptr; - png_charp text; - png_charp key; - int ret; - png_size_t text_size, key_size; - - if (png_ptr->buffer_size < 4) - { - png_push_save_buffer(png_ptr); - return; - } - - png_push_crc_finish(png_ptr); - - key = png_ptr->current_text; - png_ptr->current_text = 0; - - for (text = key; *text; text++) - /* empty loop */ ; - - /* zTXt can't have zero text */ - if (text == key + png_ptr->current_text_size) - { - png_free(png_ptr, key); - return; - } - - text++; + png_ptr->row_number = 0; + memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); - if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */ + do { - png_free(png_ptr, key); - return; - } - - text++; - - png_ptr->zstream.next_in = (png_bytep )text; - png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size - - (text - key)); - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - - key_size = text - key; - text_size = 0; - text = NULL; - ret = Z_STREAM_END; + png_ptr->pass++; + if ((png_ptr->pass == 1 && png_ptr->width < 5) || + (png_ptr->pass == 3 && png_ptr->width < 3) || + (png_ptr->pass == 5 && png_ptr->width < 2)) + png_ptr->pass++; - while (png_ptr->zstream.avail_in) - { - ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); - if (ret != Z_OK && ret != Z_STREAM_END) - { - inflateReset(&png_ptr->zstream); - png_ptr->zstream.avail_in = 0; - png_free(png_ptr, key); - png_free(png_ptr, text); - return; - } - if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END) - { - if (text == NULL) - { - text = (png_charp)png_malloc(png_ptr, - (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out + - key_size + 1)); - png_memcpy(text + key_size, png_ptr->zbuf, - png_ptr->zbuf_size - png_ptr->zstream.avail_out); - png_memcpy(text, key, key_size); - text_size = key_size + png_ptr->zbuf_size - - png_ptr->zstream.avail_out; - *(text + text_size) = '\0'; - } - else - { - png_charp tmp; - - tmp = text; - text = (png_charp)png_malloc(png_ptr, text_size + - (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out - + 1)); - png_memcpy(text, tmp, text_size); - png_free(png_ptr, tmp); - png_memcpy(text + text_size, png_ptr->zbuf, - png_ptr->zbuf_size - png_ptr->zstream.avail_out); - text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out; - *(text + text_size) = '\0'; - } - if (ret != Z_STREAM_END) - { - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - } - } - else - { - break; - } + if (png_ptr->pass > 7) + png_ptr->pass--; - if (ret == Z_STREAM_END) + if (png_ptr->pass >= 7) break; - } - - inflateReset(&png_ptr->zstream); - png_ptr->zstream.avail_in = 0; - - if (ret != Z_STREAM_END) - { - png_free(png_ptr, key); - png_free(png_ptr, text); - return; - } - png_free(png_ptr, key); - key = text; - text += key_size; - - text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); - text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt; - text_ptr->key = key; - text_ptr->text = text; - - png_set_text(png_ptr, info_ptr, text_ptr, 1); + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; - png_free(png_ptr, text_ptr); - } -} -#endif + if (png_ptr->transformations & PNG_INTERLACE) + break; -/* This function is called when we haven't found a handler for this - * chunk. In the future we will have code here which can handle - * user-defined callback functions for unknown chunks before they are - * ignored or cause an error. If there isn't a problem with the - * chunk itself (ie a bad chunk name or a critical chunk), the chunk - * is (currently) silently ignored. - */ -void -png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) -{ - png_check_chunk_name(png_ptr, png_ptr->chunk_name); + 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->chunk_name[0] & 0x20)) - { - png_chunk_error(png_ptr, "unknown critical chunk"); - /* to quiet some compiler warnings */ - if(info_ptr == NULL) return; + } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0); } - - png_push_crc_skip(png_ptr, length); +#endif /* PNG_READ_INTERLACING_SUPPORTED */ } -void -png_push_have_info(png_structp png_ptr, png_infop info_ptr) +void /* PRIVATE */ +png_push_have_info(png_structrp png_ptr, png_inforp info_ptr) { if (png_ptr->info_fn != NULL) (*(png_ptr->info_fn))(png_ptr, info_ptr); } -void -png_push_have_end(png_structp png_ptr, png_infop info_ptr) +void /* PRIVATE */ +png_push_have_end(png_structrp png_ptr, png_inforp info_ptr) { if (png_ptr->end_fn != NULL) (*(png_ptr->end_fn))(png_ptr, info_ptr); } -void -png_push_have_row(png_structp png_ptr, png_bytep row) +void /* PRIVATE */ +png_push_have_row(png_structrp png_ptr, png_bytep row) { if (png_ptr->row_fn != NULL) (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number, (int)png_ptr->pass); } -void -png_progressive_combine_row (png_structp png_ptr, - png_bytep old_row, png_bytep new_row) +#ifdef PNG_READ_INTERLACING_SUPPORTED +void PNGAPI +png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row, + png_const_bytep new_row) { + if (png_ptr == NULL) + return; + + /* new_row is a flag here - if it is NULL then the app callback was called + * from an empty row (see the calls to png_struct::row_fn below), otherwise + * it must be png_ptr->row_buf+1 + */ if (new_row != NULL) - png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]); + png_combine_row(png_ptr, old_row, 1/*display*/); } +#endif /* PNG_READ_INTERLACING_SUPPORTED */ -void -png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr, - png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, - png_progressive_end_ptr end_fn) +void PNGAPI +png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr, + png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, + png_progressive_end_ptr end_fn) { + if (png_ptr == NULL) + return; + png_ptr->info_fn = info_fn; png_ptr->row_fn = row_fn; png_ptr->end_fn = end_fn; @@ -1133,11 +1280,12 @@ png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr, png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer); } -png_voidp -png_get_progressive_ptr(png_structp png_ptr) +png_voidp PNGAPI +png_get_progressive_ptr(png_const_structrp png_ptr) { + if (png_ptr == NULL) + return (NULL); + return png_ptr->io_ptr; } - #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ -