| |
| /* pngpread.c - read a png file in push mode |
| * |
| * Last changed in libpng 1.2.44 [June 26, 2010] |
| * Copyright (c) 1998-2010 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 |
| #define PNG_NO_PEDANTIC_WARNINGS |
| #include "png.h" |
| #ifdef PNG_PROGRESSIVE_READ_SUPPORTED |
| |
| /* 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_structp png_ptr, png_infop 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) |
| { |
| png_process_some_data(png_ptr, info_ptr); |
| } |
| } |
| |
| /* What we do with the incoming data depends on what we were previously |
| * doing before we ran out of data... |
| */ |
| void /* PRIVATE */ |
| png_process_some_data(png_structp png_ptr, png_infop info_ptr) |
| { |
| if (png_ptr == NULL) |
| return; |
| |
| switch (png_ptr->process_mode) |
| { |
| case PNG_READ_SIG_MODE: |
| { |
| 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; |
| } |
| |
| #ifdef PNG_READ_tEXt_SUPPORTED |
| case PNG_READ_tEXt_MODE: |
| { |
| png_push_read_tEXt(png_ptr, info_ptr); |
| break; |
| } |
| |
| #endif |
| #ifdef PNG_READ_zTXt_SUPPORTED |
| case PNG_READ_zTXt_MODE: |
| { |
| png_push_read_zTXt(png_ptr, info_ptr); |
| break; |
| } |
| |
| #endif |
| #ifdef PNG_READ_iTXt_SUPPORTED |
| case PNG_READ_iTXt_MODE: |
| { |
| png_push_read_iTXt(png_ptr, info_ptr); |
| break; |
| } |
| |
| #endif |
| case PNG_SKIP_MODE: |
| { |
| png_push_crc_finish(png_ptr); |
| break; |
| } |
| |
| default: |
| { |
| png_ptr->buffer_size = 0; |
| break; |
| } |
| } |
| } |
| |
| /* 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, either because they have been |
| * checked by the calling application, or because of multiple calls to this |
| * routine. |
| */ |
| void /* PRIVATE */ |
| png_push_read_sig(png_structp png_ptr, png_infop info_ptr) |
| { |
| png_size_t num_checked = png_ptr->sig_bytes, |
| num_to_check = 8 - num_checked; |
| |
| if (png_ptr->buffer_size < num_to_check) |
| { |
| 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 = (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"); |
| } |
| else |
| { |
| if (png_ptr->sig_bytes >= 8) |
| { |
| png_ptr->process_mode = PNG_READ_CHUNK_MODE; |
| } |
| } |
| } |
| |
| void /* PRIVATE */ |
| png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) |
| { |
| #ifdef PNG_USE_LOCAL_ARRAYS |
| PNG_CONST PNG_IHDR; |
| PNG_CONST PNG_IDAT; |
| PNG_CONST PNG_IEND; |
| PNG_CONST PNG_PLTE; |
| #ifdef PNG_READ_bKGD_SUPPORTED |
| PNG_CONST PNG_bKGD; |
| #endif |
| #ifdef PNG_READ_cHRM_SUPPORTED |
| PNG_CONST PNG_cHRM; |
| #endif |
| #ifdef PNG_READ_gAMA_SUPPORTED |
| PNG_CONST PNG_gAMA; |
| #endif |
| #ifdef PNG_READ_hIST_SUPPORTED |
| PNG_CONST PNG_hIST; |
| #endif |
| #ifdef PNG_READ_iCCP_SUPPORTED |
| PNG_CONST PNG_iCCP; |
| #endif |
| #ifdef PNG_READ_iTXt_SUPPORTED |
| PNG_CONST PNG_iTXt; |
| #endif |
| #ifdef PNG_READ_oFFs_SUPPORTED |
| PNG_CONST PNG_oFFs; |
| #endif |
| #ifdef PNG_READ_pCAL_SUPPORTED |
| PNG_CONST PNG_pCAL; |
| #endif |
| #ifdef PNG_READ_pHYs_SUPPORTED |
| PNG_CONST PNG_pHYs; |
| #endif |
| #ifdef PNG_READ_sBIT_SUPPORTED |
| PNG_CONST PNG_sBIT; |
| #endif |
| #ifdef PNG_READ_sCAL_SUPPORTED |
| PNG_CONST PNG_sCAL; |
| #endif |
| #ifdef PNG_READ_sRGB_SUPPORTED |
| PNG_CONST PNG_sRGB; |
| #endif |
| #ifdef PNG_READ_sPLT_SUPPORTED |
| PNG_CONST PNG_sPLT; |
| #endif |
| #ifdef PNG_READ_tEXt_SUPPORTED |
| PNG_CONST PNG_tEXt; |
| #endif |
| #ifdef PNG_READ_tIME_SUPPORTED |
| PNG_CONST PNG_tIME; |
| #endif |
| #ifdef PNG_READ_tRNS_SUPPORTED |
| PNG_CONST PNG_tRNS; |
| #endif |
| #ifdef PNG_READ_zTXt_SUPPORTED |
| PNG_CONST PNG_zTXt; |
| #endif |
| #endif /* PNG_USE_LOCAL_ARRAYS */ |
| |
| /* 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->mode & PNG_HAVE_CHUNK_HEADER)) |
| { |
| png_byte chunk_length[4]; |
| |
| if (png_ptr->buffer_size < 8) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_push_fill_buffer(png_ptr, chunk_length, 4); |
| 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_check_chunk_name(png_ptr, png_ptr->chunk_name); |
| png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; |
| } |
| |
| if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
| if (png_ptr->mode & PNG_AFTER_IDAT) |
| png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; |
| |
| if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) |
| { |
| 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); |
| return; |
| } |
| |
| png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_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); |
| } |
| |
| #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED |
| else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
| png_ptr->mode |= PNG_HAVE_IDAT; |
| |
| png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); |
| |
| if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) |
| png_ptr->mode |= PNG_HAVE_PLTE; |
| |
| else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
| { |
| 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"); |
| } |
| } |
| |
| #endif |
| else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) |
| { |
| 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 (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
| { |
| /* 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"); |
| |
| if (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_error(png_ptr, "Too many IDAT's found"); |
| } |
| |
| 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_ROWBYTES(png_ptr->pixel_depth, |
| png_ptr->iwidth) + 1; |
| png_ptr->zstream.next_out = png_ptr->row_buf; |
| return; |
| } |
| |
| #ifdef PNG_READ_gAMA_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| #ifdef PNG_READ_sBIT_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| #ifdef PNG_READ_cHRM_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| #ifdef PNG_READ_sRGB_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| #ifdef PNG_READ_iCCP_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| #ifdef PNG_READ_sPLT_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4)) |
| { |
| 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 |
| #ifdef PNG_READ_tRNS_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| #ifdef PNG_READ_bKGD_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| #ifdef PNG_READ_hIST_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| #ifdef PNG_READ_pHYs_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| #ifdef PNG_READ_oFFs_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| #endif |
| |
| #ifdef PNG_READ_pCAL_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| #ifdef PNG_READ_sCAL_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4)) |
| { |
| 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 |
| #ifdef PNG_READ_tIME_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| #ifdef PNG_READ_tEXt_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| #ifdef PNG_READ_zTXt_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| #ifdef PNG_READ_iTXt_SUPPORTED |
| else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4)) |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| #endif |
| else |
| { |
| if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; |
| } |
| |
| void /* PRIVATE */ |
| png_push_crc_skip(png_structp png_ptr, png_uint_32 skip) |
| { |
| png_ptr->process_mode = PNG_SKIP_MODE; |
| png_ptr->skip_length = skip; |
| } |
| |
| void /* PRIVATE */ |
| png_push_crc_finish(png_structp png_ptr) |
| { |
| if (png_ptr->skip_length && png_ptr->save_buffer_size) |
| { |
| png_size_t save_size; |
| |
| 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; |
| |
| png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); |
| |
| png_ptr->skip_length -= save_size; |
| 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; |
| |
| 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; |
| |
| png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); |
| |
| png_ptr->skip_length -= save_size; |
| png_ptr->buffer_size -= save_size; |
| png_ptr->current_buffer_size -= save_size; |
| png_ptr->current_buffer_ptr += save_size; |
| } |
| if (!png_ptr->skip_length) |
| { |
| if (png_ptr->buffer_size < 4) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_crc_finish(png_ptr, 0); |
| png_ptr->process_mode = PNG_READ_CHUNK_MODE; |
| } |
| } |
| |
| void PNGAPI |
| 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) |
| { |
| png_size_t save_size; |
| |
| 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); |
| length -= save_size; |
| ptr += save_size; |
| png_ptr->buffer_size -= save_size; |
| png_ptr->save_buffer_size -= save_size; |
| png_ptr->save_buffer_ptr += save_size; |
| } |
| if (length && png_ptr->current_buffer_size) |
| { |
| png_size_t save_size; |
| |
| 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); |
| png_ptr->buffer_size -= save_size; |
| png_ptr->current_buffer_size -= save_size; |
| png_ptr->current_buffer_ptr += save_size; |
| } |
| } |
| |
| void /* PRIVATE */ |
| png_push_save_buffer(png_structp png_ptr) |
| { |
| if (png_ptr->save_buffer_size) |
| { |
| if (png_ptr->save_buffer_ptr != png_ptr->save_buffer) |
| { |
| 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 < istop; i++, sp++, dp++) |
| { |
| *dp = *sp; |
| } |
| } |
| } |
| if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > |
| 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_warn(png_ptr, |
| (png_uint_32)new_max); |
| if (png_ptr->save_buffer == NULL) |
| { |
| png_free(png_ptr, old_buffer); |
| png_error(png_ptr, "Insufficient memory for save_buffer"); |
| } |
| png_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, |
| 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; |
| } |
| png_ptr->save_buffer_ptr = png_ptr->save_buffer; |
| png_ptr->buffer_size = 0; |
| } |
| |
| void /* PRIVATE */ |
| png_push_restore_buffer(png_structp png_ptr, png_bytep buffer, |
| png_size_t buffer_length) |
| { |
| png_ptr->current_buffer = buffer; |
| png_ptr->current_buffer_size = buffer_length; |
| png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size; |
| png_ptr->current_buffer_ptr = png_ptr->current_buffer; |
| } |
| |
| void /* PRIVATE */ |
| png_push_read_IDAT(png_structp png_ptr) |
| { |
| #ifdef PNG_USE_LOCAL_ARRAYS |
| PNG_CONST PNG_IDAT; |
| #endif |
| if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) |
| { |
| png_byte chunk_length[4]; |
| |
| if (png_ptr->buffer_size < 8) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_push_fill_buffer(png_ptr, chunk_length, 4); |
| 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->mode |= PNG_HAVE_CHUNK_HEADER; |
| |
| if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
| { |
| png_ptr->process_mode = PNG_READ_CHUNK_MODE; |
| if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) |
| 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; |
| |
| 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; |
| |
| 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->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; |
| |
| 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; |
| |
| 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->buffer_size -= save_size; |
| png_ptr->current_buffer_size -= save_size; |
| png_ptr->current_buffer_ptr += save_size; |
| } |
| if (!png_ptr->idat_size) |
| { |
| if (png_ptr->buffer_size < 4) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_crc_finish(png_ptr, 0); |
| png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; |
| png_ptr->mode |= PNG_AFTER_IDAT; |
| } |
| } |
| |
| void /* PRIVATE */ |
| png_process_IDAT_data(png_structp png_ptr, png_bytep buffer, |
| png_size_t buffer_length) |
| { |
| /* 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; |
| png_ptr->zstream.avail_in = (uInt)buffer_length; |
| |
| /* 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_ZLIB_FINISHED)) |
| { |
| int ret; |
| |
| /* We have data for zlib, but we must check that zlib |
| * has somewhere 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)) |
| { |
| 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; |
| } |
| |
| /* Using Z_SYNC_FLUSH here means that an unterminated |
| * LZ stream can still be handled (a stream with a missing |
| * end code), 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) |
| { |
| /* Terminate the decompression. */ |
| png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; |
| |
| /* 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; |
| } |
| |
| /* 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_ZLIB_FINISHED; |
| /* 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_ZLIB_FINISHED; |
| } |
| |
| /* 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"); |
| } |
| |
| void /* PRIVATE */ |
| png_push_process_row(png_structp 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_ROWBYTES(png_ptr->row_info.pixel_depth, |
| png_ptr->row_info.width); |
| |
| 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); |
| |
| if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) |
| png_do_read_transformations(png_ptr); |
| |
| #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) |
| /* old interface (pre-1.0.9): |
| png_do_read_interlace(&(png_ptr->row_info), |
| png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); |
| */ |
| png_do_read_interlace(png_ptr); |
| |
| 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); /* 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, png_bytep_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, png_bytep_NULL); |
| png_read_push_finish_row(png_ptr); |
| } |
| } |
| |
| if (png_ptr->pass == 6 && png_ptr->height <= 4) |
| { |
| png_push_have_row(png_ptr, png_bytep_NULL); |
| png_read_push_finish_row(png_ptr); |
| } |
| |
| break; |
| } |
| |
| case 1: |
| { |
| int i; |
| for (i = 0; i < 8 && png_ptr->pass == 1; i++) |
| { |
| png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
| png_read_push_finish_row(png_ptr); |
| } |
| |
| if (png_ptr->pass == 2) /* Skip top 4 generated rows */ |
| { |
| for (i = 0; i < 4 && png_ptr->pass == 2; i++) |
| { |
| png_push_have_row(png_ptr, png_bytep_NULL); |
| 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, png_bytep_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, png_bytep_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) /* Skip top two generated rows */ |
| { |
| for (i = 0; i < 2 && png_ptr->pass == 4; i++) |
| { |
| png_push_have_row(png_ptr, png_bytep_NULL); |
| 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, png_bytep_NULL); |
| png_read_push_finish_row(png_ptr); |
| } |
| |
| if (png_ptr->pass == 6) /* Pass 5 might be empty */ |
| { |
| png_push_have_row(png_ptr, png_bytep_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) /* Skip top generated row */ |
| { |
| png_push_have_row(png_ptr, png_bytep_NULL); |
| png_read_push_finish_row(png_ptr); |
| } |
| |
| break; |
| } |
| 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, png_bytep_NULL); |
| png_read_push_finish_row(png_ptr); |
| } |
| } |
| } |
| else |
| #endif |
| { |
| png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
| png_read_push_finish_row(png_ptr); |
| } |
| } |
| |
| void /* PRIVATE */ |
| png_read_push_finish_row(png_structp png_ptr) |
| { |
| #ifdef PNG_USE_LOCAL_ARRAYS |
| /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
| |
| /* Start of interlace block */ |
| PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; |
| |
| /* Offset to next interlace block */ |
| PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; |
| |
| /* Start of interlace block in the y direction */ |
| PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; |
| |
| /* Offset to next interlace block in the y direction */ |
| PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; |
| |
| /* Height of interlace block. This is not currently used - if you need |
| * it, uncomment it here and in png.h |
| PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; |
| */ |
| #endif |
| |
| png_ptr->row_number++; |
| if (png_ptr->row_number < png_ptr->num_rows) |
| return; |
| |
| #ifdef PNG_READ_INTERLACING_SUPPORTED |
| if (png_ptr->interlaced) |
| { |
| png_ptr->row_number = 0; |
| png_memset_check(png_ptr, png_ptr->prev_row, 0, |
| png_ptr->rowbytes + 1); |
| do |
| { |
| png_ptr->pass++; |
| if ((png_ptr->pass == 1 && png_ptr->width < 5) || |
| (png_ptr->pass == 3 && png_ptr->width < 3) || |
| (png_ptr->pass == 5 && png_ptr->width < 2)) |
| png_ptr->pass++; |
| |
| if (png_ptr->pass > 7) |
| png_ptr->pass--; |
| |
| if (png_ptr->pass >= 7) |
| break; |
| |
| png_ptr->iwidth = (png_ptr->width + |
| png_pass_inc[png_ptr->pass] - 1 - |
| png_pass_start[png_ptr->pass]) / |
| png_pass_inc[png_ptr->pass]; |
| |
| if (png_ptr->transformations & PNG_INTERLACE) |
| break; |
| |
| 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]; |
| |
| } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0); |
| } |
| #endif /* PNG_READ_INTERLACING_SUPPORTED */ |
| } |
| |
| #ifdef PNG_READ_tEXt_SUPPORTED |
| void /* PRIVATE */ |
| png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 |
| length) |
| { |
| if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) |
| { |
| png_error(png_ptr, "Out of place tEXt"); |
| info_ptr = info_ptr; /* To quiet some compiler warnings */ |
| } |
| |
| #ifdef PNG_MAX_MALLOC_64K |
| png_ptr->skip_length = 0; /* This may not be necessary */ |
| |
| if (length > (png_uint_32)65535L) /* Can't hold 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 /* PRIVATE */ |
| png_push_read_tEXt(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_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; |
| int ret; |
| |
| if (png_ptr->buffer_size < 4) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_push_crc_finish(png_ptr); |
| |
| #ifdef PNG_MAX_MALLOC_64K |
| if (png_ptr->skip_length) |
| return; |
| #endif |
| |
| key = png_ptr->current_text; |
| |
| for (text = key; *text; text++) |
| /* Empty loop */ ; |
| |
| if (text < key + png_ptr->current_text_size) |
| text++; |
| |
| text_ptr = (png_textp)png_malloc(png_ptr, |
| (png_uint_32)png_sizeof(png_text)); |
| text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; |
| text_ptr->key = key; |
| #ifdef PNG_iTXt_SUPPORTED |
| text_ptr->lang = NULL; |
| text_ptr->lang_key = NULL; |
| #endif |
| text_ptr->text = text; |
| |
| ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); |
| |
| png_free(png_ptr, key); |
| png_free(png_ptr, text_ptr); |
| png_ptr->current_text = NULL; |
| |
| if (ret) |
| png_warning(png_ptr, "Insufficient memory to store text chunk."); |
| } |
| } |
| #endif |
| |
| #ifdef PNG_READ_zTXt_SUPPORTED |
| void /* PRIVATE */ |
| png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 |
| length) |
| { |
| if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) |
| { |
| png_error(png_ptr, "Out of place zTXt"); |
| info_ptr = info_ptr; /* To quiet some compiler warnings */ |
| } |
| |
| #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); |
| 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 /* PRIVATE */ |
| 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)) |
| { |
| 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; |
| |
| for (text = key; *text; text++) |
| /* Empty loop */ ; |
| |
| /* zTXt can't have zero text */ |
| if (text >= key + png_ptr->current_text_size) |
| { |
| png_ptr->current_text = NULL; |
| png_free(png_ptr, key); |
| return; |
| } |
| |
| text++; |
| |
| if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */ |
| { |
| png_ptr->current_text = NULL; |
| 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; |
| |
| 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_ptr->current_text = NULL; |
| 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 (ret == Z_STREAM_END) |
| break; |
| } |
| |
| inflateReset(&png_ptr->zstream); |
| png_ptr->zstream.avail_in = 0; |
| |
| if (ret != Z_STREAM_END) |
| { |
| png_ptr->current_text = NULL; |
| png_free(png_ptr, key); |
| png_free(png_ptr, text); |
| return; |
| } |
| |
| png_ptr->current_text = NULL; |
| png_free(png_ptr, key); |
| key = text; |
| text += key_size; |
| |
| text_ptr = (png_textp)png_malloc(png_ptr, |
| (png_uint_32)png_sizeof(png_text)); |
| text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt; |
| text_ptr->key = key; |
| #ifdef PNG_iTXt_SUPPORTED |
| text_ptr->lang = NULL; |
| text_ptr->lang_key = NULL; |
| #endif |
| text_ptr->text = text; |
| |
| ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); |
| |
| png_free(png_ptr, key); |
| png_free(png_ptr, text_ptr); |
| |
| if (ret) |
| png_warning(png_ptr, "Insufficient memory to store text chunk."); |
| } |
| } |
| #endif |
| |
| #ifdef PNG_READ_iTXt_SUPPORTED |
| void /* PRIVATE */ |
| png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 |
| length) |
| { |
| if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) |
| { |
| png_error(png_ptr, "Out of place iTXt"); |
| info_ptr = info_ptr; /* To quiet some compiler warnings */ |
| } |
| |
| #ifdef PNG_MAX_MALLOC_64K |
| png_ptr->skip_length = 0; /* This may not be necessary */ |
| |
| if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */ |
| { |
| png_warning(png_ptr, "iTXt 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_iTXt_MODE; |
| } |
| |
| void /* PRIVATE */ |
| png_push_read_iTXt(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_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 key; |
| int comp_flag; |
| png_charp lang; |
| png_charp lang_key; |
| png_charp text; |
| int ret; |
| |
| if (png_ptr->buffer_size < 4) |
| { |
| png_push_save_buffer(png_ptr); |
| return; |
| } |
| |
| png_push_crc_finish(png_ptr); |
| |
| #ifdef PNG_MAX_MALLOC_64K |
| if (png_ptr->skip_length) |
| return; |
| #endif |
| |
| key = png_ptr->current_text; |
| |
| for (lang = key; *lang; lang++) |
| /* Empty loop */ ; |
| |
| if (lang < key + png_ptr->current_text_size - 3) |
| lang++; |
| |
| comp_flag = *lang++; |
| lang++; /* Skip comp_type, always zero */ |
| |
| for (lang_key = lang; *lang_key; lang_key++) |
| /* Empty loop */ ; |
| |
| lang_key++; /* Skip NUL separator */ |
| |
| text=lang_key; |
| |
| if (lang_key < key + png_ptr->current_text_size - 1) |
| { |
| for (; *text; text++) |
| /* Empty loop */ ; |
| } |
| |
| if (text < key + png_ptr->current_text_size) |
| text++; |
| |
| text_ptr = (png_textp)png_malloc(png_ptr, |
| (png_uint_32)png_sizeof(png_text)); |
| |
| text_ptr->compression = comp_flag + 2; |
| text_ptr->key = key; |
| text_ptr->lang = lang; |
| text_ptr->lang_key = lang_key; |
| text_ptr->text = text; |
| text_ptr->text_length = 0; |
| text_ptr->itxt_length = png_strlen(text); |
| |
| ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); |
| |
| png_ptr->current_text = NULL; |
| |
| png_free(png_ptr, text_ptr); |
| if (ret) |
| png_warning(png_ptr, "Insufficient memory to store iTXt chunk."); |
| } |
| } |
| #endif |
| |
| /* This function is called when we haven't found a handler for this |
| * chunk. 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 /* PRIVATE */ |
| png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 |
| length) |
| { |
| png_uint_32 skip = 0; |
| |
| if (!(png_ptr->chunk_name[0] & 0x20)) |
| { |
| #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED |
| if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != |
| PNG_HANDLE_CHUNK_ALWAYS |
| #ifdef PNG_READ_USER_CHUNKS_SUPPORTED |
| && png_ptr->read_user_chunk_fn == NULL |
| #endif |
| ) |
| #endif |
| png_chunk_error(png_ptr, "unknown critical chunk"); |
| |
| info_ptr = info_ptr; /* To quiet some compiler warnings */ |
| } |
| |
| #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED |
| if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) |
| { |
| #ifdef PNG_MAX_MALLOC_64K |
| if (length > (png_uint_32)65535L) |
| { |
| png_warning(png_ptr, "unknown chunk too large to fit in memory"); |
| skip = length - (png_uint_32)65535L; |
| length = (png_uint_32)65535L; |
| } |
| #endif |
| png_memcpy((png_charp)png_ptr->unknown_chunk.name, |
| (png_charp)png_ptr->chunk_name, |
| png_sizeof(png_ptr->unknown_chunk.name)); |
| png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1] |
| = '\0'; |
| |
| png_ptr->unknown_chunk.size = (png_size_t)length; |
| |
| if (length == 0) |
| png_ptr->unknown_chunk.data = NULL; |
| |
| else |
| { |
| png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, |
| (png_uint_32)length); |
| png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length); |
| } |
| |
| #ifdef PNG_READ_USER_CHUNKS_SUPPORTED |
| if (png_ptr->read_user_chunk_fn != NULL) |
| { |
| /* Callback to user unknown chunk handler */ |
| int ret; |
| ret = (*(png_ptr->read_user_chunk_fn)) |
| (png_ptr, &png_ptr->unknown_chunk); |
| |
| if (ret < 0) |
| png_chunk_error(png_ptr, "error in user chunk"); |
| |
| if (ret == 0) |
| { |
| if (!(png_ptr->chunk_name[0] & 0x20)) |
| if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != |
| PNG_HANDLE_CHUNK_ALWAYS) |
| png_chunk_error(png_ptr, "unknown critical chunk"); |
| png_set_unknown_chunks(png_ptr, info_ptr, |
| &png_ptr->unknown_chunk, 1); |
| } |
| } |
| |
| else |
| #endif |
| png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1); |
| png_free(png_ptr, png_ptr->unknown_chunk.data); |
| png_ptr->unknown_chunk.data = NULL; |
| } |
| |
| else |
| #endif |
| skip=length; |
| png_push_crc_skip(png_ptr, skip); |
| } |
| |
| void /* PRIVATE */ |
| png_push_have_info(png_structp png_ptr, png_infop info_ptr) |
| { |
| if (png_ptr->info_fn != NULL) |
| (*(png_ptr->info_fn))(png_ptr, info_ptr); |
| } |
| |
| void /* PRIVATE */ |
| png_push_have_end(png_structp png_ptr, png_infop info_ptr) |
| { |
| if (png_ptr->end_fn != NULL) |
| (*(png_ptr->end_fn))(png_ptr, info_ptr); |
| } |
| |
| void /* PRIVATE */ |
| png_push_have_row(png_structp 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 PNGAPI |
| png_progressive_combine_row (png_structp png_ptr, |
| png_bytep old_row, png_bytep new_row) |
| { |
| #ifdef PNG_USE_LOCAL_ARRAYS |
| PNG_CONST int FARDATA png_pass_dsp_mask[7] = |
| {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; |
| #endif |
| |
| if (png_ptr == NULL) |
| return; |
| |
| if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */ |
| png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]); |
| } |
| |
| void PNGAPI |
| 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) |
| { |
| if (png_ptr == NULL) |
| return; |
| |
| png_ptr->info_fn = info_fn; |
| png_ptr->row_fn = row_fn; |
| png_ptr->end_fn = end_fn; |
| |
| png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer); |
| } |
| |
| png_voidp PNGAPI |
| png_get_progressive_ptr(png_structp png_ptr) |
| { |
| if (png_ptr == NULL) |
| return (NULL); |
| |
| return png_ptr->io_ptr; |
| } |
| #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ |
