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_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; else skip_length = (png_uint_32)save_size; png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, 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_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; else skip_length = (png_uint_32)save_size; png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, 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; } 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 /* 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; } }
/* Read the end of the PNG file. Will not read past the end of the * file, will verify the end is accurate, and will read any comments * or time information at the end of the file, if info is not NULL. */ void PNGAPI png_read_end(png_structp png_ptr, png_infop info_ptr) { png_debug(1, "in png_read_end"); if (png_ptr == NULL) return; png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */ do { PNG_IHDR; PNG_IDAT; PNG_IEND; PNG_PLTE; #ifdef PNG_READ_bKGD_SUPPORTED PNG_bKGD; #endif #ifdef PNG_READ_cHRM_SUPPORTED PNG_cHRM; #endif #ifdef PNG_READ_gAMA_SUPPORTED PNG_gAMA; #endif #ifdef PNG_READ_hIST_SUPPORTED PNG_hIST; #endif #ifdef PNG_READ_iCCP_SUPPORTED PNG_iCCP; #endif #ifdef PNG_READ_iTXt_SUPPORTED PNG_iTXt; #endif #ifdef PNG_READ_oFFs_SUPPORTED PNG_oFFs; #endif #ifdef PNG_READ_pCAL_SUPPORTED PNG_pCAL; #endif #ifdef PNG_READ_pHYs_SUPPORTED PNG_pHYs; #endif #ifdef PNG_READ_sBIT_SUPPORTED PNG_sBIT; #endif #ifdef PNG_READ_sCAL_SUPPORTED PNG_sCAL; #endif #ifdef PNG_READ_sPLT_SUPPORTED PNG_sPLT; #endif #ifdef PNG_READ_sRGB_SUPPORTED PNG_sRGB; #endif #ifdef PNG_READ_tEXt_SUPPORTED PNG_tEXt; #endif #ifdef PNG_READ_tIME_SUPPORTED PNG_tIME; #endif #ifdef PNG_READ_tRNS_SUPPORTED PNG_tRNS; #endif #ifdef PNG_READ_zTXt_SUPPORTED PNG_zTXt; #endif png_uint_32 length = png_read_chunk_header(png_ptr); PNG_CONST png_bytep chunk_name = png_ptr->chunk_name; if (!png_memcmp(chunk_name, png_IHDR, 4)) png_handle_IHDR(png_ptr, info_ptr, length); else if (!png_memcmp(chunk_name, png_IEND, 4)) png_handle_IEND(png_ptr, info_ptr, length); #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED else if (png_handle_as_unknown(png_ptr, chunk_name)) { if (!png_memcmp(chunk_name, png_IDAT, 4)) { if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) png_benign_error(png_ptr, "Too many IDATs found"); } png_handle_unknown(png_ptr, info_ptr, length); if (!png_memcmp(chunk_name, png_PLTE, 4)) png_ptr->mode |= PNG_HAVE_PLTE; } #endif else if (!png_memcmp(chunk_name, png_IDAT, 4)) { /* Zero length IDATs are legal after the last IDAT has been * read, but not after other chunks have been read. */ if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) png_benign_error(png_ptr, "Too many IDATs found"); png_crc_finish(png_ptr, length); } else if (!png_memcmp(chunk_name, png_PLTE, 4)) png_handle_PLTE(png_ptr, info_ptr, length); #ifdef PNG_READ_bKGD_SUPPORTED else if (!png_memcmp(chunk_name, png_bKGD, 4)) png_handle_bKGD(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_cHRM_SUPPORTED else if (!png_memcmp(chunk_name, png_cHRM, 4)) png_handle_cHRM(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_gAMA_SUPPORTED else if (!png_memcmp(chunk_name, png_gAMA, 4)) png_handle_gAMA(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_hIST_SUPPORTED else if (!png_memcmp(chunk_name, png_hIST, 4)) png_handle_hIST(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_oFFs_SUPPORTED else if (!png_memcmp(chunk_name, png_oFFs, 4)) png_handle_oFFs(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_pCAL_SUPPORTED else if (!png_memcmp(chunk_name, png_pCAL, 4)) png_handle_pCAL(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_sCAL_SUPPORTED else if (!png_memcmp(chunk_name, png_sCAL, 4)) png_handle_sCAL(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_pHYs_SUPPORTED else if (!png_memcmp(chunk_name, png_pHYs, 4)) png_handle_pHYs(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_sBIT_SUPPORTED else if (!png_memcmp(chunk_name, png_sBIT, 4)) png_handle_sBIT(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_sRGB_SUPPORTED else if (!png_memcmp(chunk_name, png_sRGB, 4)) png_handle_sRGB(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_iCCP_SUPPORTED else if (!png_memcmp(chunk_name, png_iCCP, 4)) png_handle_iCCP(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_sPLT_SUPPORTED else if (!png_memcmp(chunk_name, png_sPLT, 4)) png_handle_sPLT(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_tEXt_SUPPORTED else if (!png_memcmp(chunk_name, png_tEXt, 4)) png_handle_tEXt(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_tIME_SUPPORTED else if (!png_memcmp(chunk_name, png_tIME, 4)) png_handle_tIME(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_tRNS_SUPPORTED else if (!png_memcmp(chunk_name, png_tRNS, 4)) png_handle_tRNS(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_zTXt_SUPPORTED else if (!png_memcmp(chunk_name, png_zTXt, 4)) png_handle_zTXt(png_ptr, info_ptr, length); #endif #ifdef PNG_READ_iTXt_SUPPORTED else if (!png_memcmp(chunk_name, png_iTXt, 4)) png_handle_iTXt(png_ptr, info_ptr, length); #endif else png_handle_unknown(png_ptr, info_ptr, length); } while (!(png_ptr->mode & PNG_HAVE_IEND)); }
void PNGAPI png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) { PNG_IDAT; PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff}; int ret; if (png_ptr == NULL) return; png_debug2(1, "in png_read_row (row %lu, pass %d)", (unsigned long) png_ptr->row_number, png_ptr->pass); if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) png_read_start_row(png_ptr); if (png_ptr->row_number == 0 && png_ptr->pass == 0) { /* Check for transforms that have been set but were defined out */ #if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED) if (png_ptr->transformations & PNG_INVERT_MONO) png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined"); #endif #if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED) if (png_ptr->transformations & PNG_FILLER) png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined"); #endif #if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \ !defined(PNG_READ_PACKSWAP_SUPPORTED) if (png_ptr->transformations & PNG_PACKSWAP) png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined"); #endif #if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED) if (png_ptr->transformations & PNG_PACK) png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined"); #endif #if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) if (png_ptr->transformations & PNG_SHIFT) png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined"); #endif #if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED) if (png_ptr->transformations & PNG_BGR) png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined"); #endif #if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED) if (png_ptr->transformations & PNG_SWAP_BYTES) png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined"); #endif } #ifdef PNG_READ_INTERLACING_SUPPORTED /* If interlaced and we do not need a new row, combine row and return */ if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) { switch (png_ptr->pass) { case 0: if (png_ptr->row_number & 0x07) { if (dsp_row != NULL) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); png_read_finish_row(png_ptr); return; } break; case 1: if ((png_ptr->row_number & 0x07) || png_ptr->width < 5) { if (dsp_row != NULL) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); png_read_finish_row(png_ptr); return; } break; case 2: if ((png_ptr->row_number & 0x07) != 4) { if (dsp_row != NULL && (png_ptr->row_number & 4)) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); png_read_finish_row(png_ptr); return; } break; case 3: if ((png_ptr->row_number & 3) || png_ptr->width < 3) { if (dsp_row != NULL) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); png_read_finish_row(png_ptr); return; } break; case 4: if ((png_ptr->row_number & 3) != 2) { if (dsp_row != NULL && (png_ptr->row_number & 2)) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); png_read_finish_row(png_ptr); return; } break; case 5: if ((png_ptr->row_number & 1) || png_ptr->width < 2) { if (dsp_row != NULL) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); png_read_finish_row(png_ptr); return; } break; default: case 6: if (!(png_ptr->row_number & 1)) { png_read_finish_row(png_ptr); return; } break; } } #endif if (!(png_ptr->mode & PNG_HAVE_IDAT)) png_error(png_ptr, "Invalid attempt to read row data"); png_ptr->zstream.next_out = png_ptr->row_buf; png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1); do { if (!(png_ptr->zstream.avail_in)) { while (!png_ptr->idat_size) { png_crc_finish(png_ptr, 0); png_ptr->idat_size = png_read_chunk_header(png_ptr); if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) png_error(png_ptr, "Not enough image data"); } png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; png_ptr->zstream.next_in = png_ptr->zbuf; if (png_ptr->zbuf_size > png_ptr->idat_size) png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size; png_crc_read(png_ptr, png_ptr->zbuf, (png_size_t)png_ptr->zstream.avail_in); png_ptr->idat_size -= png_ptr->zstream.avail_in; } ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); if (ret == Z_STREAM_END) { if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in || png_ptr->idat_size) png_benign_error(png_ptr, "Extra compressed data"); png_ptr->mode |= PNG_AFTER_IDAT; png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; break; } if (ret != Z_OK) png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : "Decompression error"); } while (png_ptr->zstream.avail_out); 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); if (png_ptr->row_buf[0]) 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(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1); #ifdef PNG_MNG_FEATURES_SUPPORTED if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) { /* Intrapixel differencing */ png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1); } #endif 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); if (dsp_row != NULL) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); if (row != NULL) png_combine_row(png_ptr, row, png_pass_mask[png_ptr->pass]); } else #endif { if (row != NULL) png_combine_row(png_ptr, row, 0xff); if (dsp_row != NULL) png_combine_row(png_ptr, dsp_row, 0xff); } png_read_finish_row(png_ptr); if (png_ptr->read_row_fn != NULL) (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); }
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); if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) 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); if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) 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; } }
/* Read the end of the PNG file. Will not read past the end of the * file, will verify the end is accurate, and will read any comments * or time information at the end of the file, if info is not NULL. */ void PNGAPI png_read_end(png_structp png_ptr, png_infop info_ptr) { png_byte chunk_length[4]; png_uint_32 length; png_debug(1, "in png_read_end\n"); png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */ do { #ifdef PNG_USE_LOCAL_ARRAYS PNG_IHDR; PNG_IDAT; PNG_IEND; PNG_PLTE; #if defined(PNG_READ_bKGD_SUPPORTED) PNG_bKGD; #endif #if defined(PNG_READ_cHRM_SUPPORTED) PNG_cHRM; #endif #if defined(PNG_READ_gAMA_SUPPORTED) PNG_gAMA; #endif #if defined(PNG_READ_hIST_SUPPORTED) PNG_hIST; #endif #if defined(PNG_READ_iCCP_SUPPORTED) PNG_iCCP; #endif #if defined(PNG_READ_iTXt_SUPPORTED) PNG_iTXt; #endif #if defined(PNG_READ_oFFs_SUPPORTED) PNG_oFFs; #endif #if defined(PNG_READ_pCAL_SUPPORTED) PNG_pCAL; #endif #if defined(PNG_READ_pHYs_SUPPORTED) PNG_pHYs; #endif #if defined(PNG_READ_sBIT_SUPPORTED) PNG_sBIT; #endif #if defined(PNG_READ_sCAL_SUPPORTED) PNG_sCAL; #endif #if defined(PNG_READ_sPLT_SUPPORTED) PNG_sPLT; #endif #if defined(PNG_READ_sRGB_SUPPORTED) PNG_sRGB; #endif #if defined(PNG_READ_tEXt_SUPPORTED) PNG_tEXt; #endif #if defined(PNG_READ_tIME_SUPPORTED) PNG_tIME; #endif #if defined(PNG_READ_tRNS_SUPPORTED) PNG_tRNS; #endif #if defined(PNG_READ_zTXt_SUPPORTED) PNG_zTXt; #endif #endif /* PNG_USE_LOCAL_ARRAYS */ png_read_data(png_ptr, chunk_length, 4); 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_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name); if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) png_handle_IHDR(png_ptr, info_ptr, length); else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) png_handle_IEND(png_ptr, info_ptr, length); #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name)) { if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) { if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT) png_error(png_ptr, "Too many IDAT's found"); } else png_ptr->mode |= PNG_AFTER_IDAT; png_handle_unknown(png_ptr, info_ptr, length); if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) png_ptr->mode |= PNG_HAVE_PLTE; } #endif else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) { /* Zero length IDATs are legal after the last IDAT has been * read, but not after other chunks have been read. */ if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT) png_error(png_ptr, "Too many IDAT's found"); png_crc_finish(png_ptr, length); } else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) png_handle_PLTE(png_ptr, info_ptr, length); #if defined(PNG_READ_bKGD_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) png_handle_bKGD(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_cHRM_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) png_handle_cHRM(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_gAMA_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) png_handle_gAMA(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_hIST_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) png_handle_hIST(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_oFFs_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) png_handle_oFFs(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_pCAL_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) png_handle_pCAL(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sCAL_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4)) png_handle_sCAL(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_pHYs_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) png_handle_pHYs(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sBIT_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) png_handle_sBIT(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sRGB_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) png_handle_sRGB(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_iCCP_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4)) png_handle_iCCP(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sPLT_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4)) png_handle_sPLT(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tEXt_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) png_handle_tEXt(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tIME_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) png_handle_tIME(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tRNS_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) png_handle_tRNS(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_zTXt_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) png_handle_zTXt(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_iTXt_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4)) png_handle_iTXt(png_ptr, info_ptr, length); #endif else png_handle_unknown(png_ptr, info_ptr, length); } while (!(png_ptr->mode & PNG_HAVE_IEND)); }
void /* PRIVATE */ png_push_read_IDAT(png_structrp png_ptr) { if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0) { png_byte chunk_length[4]; png_byte chunk_tag[4]; /* TODO: this code can be commoned up with the same code in push_read */ PNG_PUSH_SAVE_BUFFER_IF_LT(8) 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, chunk_tag, 4); png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; if (png_ptr->chunk_name != png_IDAT) { png_ptr->process_mode = PNG_READ_CHUNK_MODE; if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) png_error(png_ptr, "Not enough compressed data"); return; } png_ptr->idat_size = png_ptr->push_length; } if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0) { 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-bit or 64-bit platforms. */ if (idat_size < save_size) save_size = (png_size_t)idat_size; else 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 -= 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 != 0 && png_ptr->current_buffer_size != 0) { 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; else 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 -= idat_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 == 0) { PNG_PUSH_SAVE_BUFFER_IF_LT(4) png_crc_finish(png_ptr, 0); png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; png_ptr->mode |= PNG_AFTER_IDAT; png_ptr->zowner = 0; } }
void /* PRIVATE */ png_push_read_IDAT(png_structrp png_ptr) { if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0) { png_byte chunk_length[4]; png_byte chunk_tag[4]; /* TODO: this code can be commoned up with the same code in push_read */ #ifdef PNG_READ_APNG_SUPPORTED PNG_PUSH_SAVE_BUFFER_IF_LT(12) #else PNG_PUSH_SAVE_BUFFER_IF_LT(8) #endif 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, chunk_tag, 4); png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; #ifdef PNG_READ_APNG_SUPPORTED if (png_ptr->chunk_name != png_fdAT && png_ptr->num_frames_read > 0) { if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) != 0) { png_ptr->process_mode = PNG_READ_CHUNK_MODE; if (png_ptr->frame_end_fn != NULL) (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read); png_ptr->num_frames_read++; return; } else { if (png_ptr->chunk_name == png_IEND) png_error(png_ptr, "Not enough image data"); PNG_PUSH_SAVE_BUFFER_IF_FULL png_warning(png_ptr, "Skipping (ignoring) a chunk between " "APNG chunks"); png_crc_finish(png_ptr, png_ptr->push_length); png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; return; } } else #endif #ifdef PNG_READ_APNG_SUPPORTED if (png_ptr->chunk_name != png_IDAT && png_ptr->num_frames_read == 0) #else if (png_ptr->chunk_name != png_IDAT) #endif { png_ptr->process_mode = PNG_READ_CHUNK_MODE; if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) png_error(png_ptr, "Not enough compressed data"); #ifdef PNG_READ_APNG_SUPPORTED if (png_ptr->frame_end_fn != NULL) (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read); png_ptr->num_frames_read++; #endif return; } png_ptr->idat_size = png_ptr->push_length; #ifdef PNG_READ_APNG_SUPPORTED if (png_ptr->num_frames_read > 0) { png_ensure_sequence_number(png_ptr, 4); png_ptr->idat_size -= 4; } #endif } if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0) { 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-bit or 64-bit platforms. */ if (idat_size < save_size) save_size = (png_size_t)idat_size; else 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 -= 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 != 0 && png_ptr->current_buffer_size != 0) { 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; else 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 -= idat_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 == 0) { PNG_PUSH_SAVE_BUFFER_IF_LT(4) png_crc_finish(png_ptr, 0); png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; png_ptr->mode |= PNG_AFTER_IDAT; png_ptr->zowner = 0; } }
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->mode & PNG_HAVE_CHUNK_HEADER) == 0) { png_byte chunk_length[4]; png_byte chunk_tag[4]; PNG_PUSH_SAVE_BUFFER_IF_LT(8) 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, 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; } chunk_name = png_ptr->chunk_name; #ifdef PNG_READ_APNG_SUPPORTED if (png_ptr->num_frames_read > 0 && png_ptr->num_frames_read < info_ptr->num_frames) { if (chunk_name == png_IDAT) { /* Discard trailing IDATs for the first frame */ if ((png_ptr->mode & PNG_HAVE_fcTL) != 0 || png_ptr->num_frames_read > 1) png_error(png_ptr, "out of place IDAT"); PNG_PUSH_SAVE_BUFFER_IF_FULL png_crc_finish(png_ptr, png_ptr->push_length); png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; } else if (chunk_name == png_fdAT) { PNG_PUSH_SAVE_BUFFER_IF_LT(4) png_ensure_sequence_number(png_ptr, 4); if ((png_ptr->mode & PNG_HAVE_fcTL) == 0) { /* Discard trailing fdATs for frames other than the first */ if (png_ptr->num_frames_read < 2) png_error(png_ptr, "out of place fdAT"); PNG_PUSH_SAVE_BUFFER_IF_FULL png_crc_finish(png_ptr, png_ptr->push_length); png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; } else { /* frame data follows */ png_ptr->idat_size = png_ptr->push_length - 4; png_ptr->mode |= PNG_HAVE_IDAT; png_ptr->process_mode = PNG_READ_IDAT_MODE; } } else if (chunk_name == png_fcTL) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_read_reset(png_ptr); png_ptr->mode &= ~PNG_HAVE_fcTL; png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length); if ((png_ptr->mode & PNG_HAVE_fcTL) == 0) png_error(png_ptr, "missing required fcTL chunk"); png_read_reinit(png_ptr, info_ptr); png_progressive_read_reset(png_ptr); if (png_ptr->frame_info_fn != NULL) (*(png_ptr->frame_info_fn))(png_ptr, png_ptr->num_frames_read); png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; } else if (chunk_name == png_IEND) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_warning(png_ptr, "Number of actual frames fewer than expected"); png_crc_finish(png_ptr, png_ptr->push_length); png_ptr->process_mode = PNG_READ_DONE_MODE; png_push_have_end(png_ptr, info_ptr); } else { PNG_PUSH_SAVE_BUFFER_IF_FULL png_warning(png_ptr, "Skipped (ignored) a chunk " "between APNG chunks"); png_crc_finish(png_ptr, png_ptr->push_length); png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; } return; } #endif /* READ_APNG */ if (chunk_name == png_IDAT) { if ((png_ptr->mode & PNG_AFTER_IDAT) != 0) 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) == 0) png_error(png_ptr, "Missing IHDR before IDAT"); else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && (png_ptr->mode & PNG_HAVE_PLTE) == 0) png_error(png_ptr, "Missing PLTE before IDAT"); png_ptr->process_mode = PNG_READ_IDAT_MODE; if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) if ((png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) == 0) if (png_ptr->push_length == 0) return; png_ptr->mode |= PNG_HAVE_IDAT; if ((png_ptr->mode & PNG_AFTER_IDAT) != 0) 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"); PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); } else if (chunk_name == png_IEND) { PNG_PUSH_SAVE_BUFFER_IF_FULL 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 ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep); if (chunk_name == png_PLTE) png_ptr->mode |= PNG_HAVE_PLTE; } #endif else if (chunk_name == png_PLTE) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); } else if (chunk_name == png_IDAT) { #ifdef PNG_READ_APNG_SUPPORTED png_have_info(png_ptr, info_ptr); #endif png_ptr->idat_size = png_ptr->push_length; 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_ptr->chunk_name == png_gAMA) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_sBIT_SUPPORTED else if (png_ptr->chunk_name == png_sBIT) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_cHRM_SUPPORTED else if (png_ptr->chunk_name == png_cHRM) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_sRGB_SUPPORTED else if (chunk_name == png_sRGB) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_iCCP_SUPPORTED else if (png_ptr->chunk_name == png_iCCP) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_sPLT_SUPPORTED else if (chunk_name == png_sPLT) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_tRNS_SUPPORTED else if (chunk_name == png_tRNS) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_bKGD_SUPPORTED else if (chunk_name == png_bKGD) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_hIST_SUPPORTED else if (chunk_name == png_hIST) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_pHYs_SUPPORTED else if (chunk_name == png_pHYs) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_oFFs_SUPPORTED else if (chunk_name == png_oFFs) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_pCAL_SUPPORTED else if (chunk_name == png_pCAL) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_sCAL_SUPPORTED else if (chunk_name == png_sCAL) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_tIME_SUPPORTED else if (chunk_name == png_tIME) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_tEXt_SUPPORTED else if (chunk_name == png_tEXt) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_zTXt_SUPPORTED else if (chunk_name == png_zTXt) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_iTXt_SUPPORTED else if (chunk_name == png_iTXt) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_APNG_SUPPORTED else if (chunk_name == png_acTL) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_acTL(png_ptr, info_ptr, png_ptr->push_length); } else if (chunk_name == png_fcTL) { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length); } #endif /* READ_APNG */ else { PNG_PUSH_SAVE_BUFFER_IF_FULL png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, PNG_HANDLE_CHUNK_AS_DEFAULT); } png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; }
void /* PRIVATE */ png_push_read_IDAT(png_structp png_ptr) { PNG_IDAT; 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 = 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; else 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 -= 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_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; else 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 -= idat_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; } }
/* Read the end of the PNG file. Will not read past the end of the * file, will verify the end is accurate, and will read any comments * or time information at the end of the file, if info is not NULL. */ void png_read_end(png_structp png_ptr, png_infop info_ptr) { png_byte chunk_length[4]; png_uint_32 length; png_debug(1, "in png_read_end\n"); /* save jump buffer and error functions */ png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */ do { png_read_data(png_ptr, chunk_length, 4); length = png_get_uint_32(chunk_length); png_reset_crc(png_ptr); png_crc_read(png_ptr, png_ptr->chunk_name, 4); png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name); if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) png_handle_IHDR(png_ptr, info_ptr, length); else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) { /* Zero length IDATs are legal after the last IDAT has been * read, but not after other chunks have been read. */ if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT) png_error(png_ptr, "Too many IDAT's found"); else png_crc_finish(png_ptr, 0); } else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) png_handle_PLTE(png_ptr, info_ptr, length); else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) png_handle_IEND(png_ptr, info_ptr, length); #if defined(PNG_READ_bKGD_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) png_handle_bKGD(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_cHRM_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) png_handle_cHRM(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_gAMA_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) png_handle_gAMA(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_hIST_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) png_handle_hIST(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_oFFs_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) png_handle_oFFs(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_pCAL_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) png_handle_pCAL(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_pHYs_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) png_handle_pHYs(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sBIT_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) png_handle_sBIT(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sRGB_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) png_handle_sRGB(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tEXt_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) png_handle_tEXt(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tIME_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) png_handle_tIME(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tRNS_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) png_handle_tRNS(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_zTXt_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) png_handle_zTXt(png_ptr, info_ptr, length); #endif else png_handle_unknown(png_ptr, info_ptr, length); } while (!(png_ptr->mode & PNG_HAVE_IEND)); }
void png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) { int ret; png_debug2(1, "in png_read_row (row %d, pass %d)\n", png_ptr->row_number, png_ptr->pass); /* save jump buffer and error functions */ if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) png_read_start_row(png_ptr); if (png_ptr->row_number == 0 && png_ptr->pass == 0) { /* check for transforms that have been set but were defined out */ #if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED) if (png_ptr->transformations & PNG_INVERT_MONO) png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined."); #endif #if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED) if (png_ptr->transformations & PNG_FILLER) png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined."); #endif #if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && !defined(PNG_READ_PACKSWAP_SUPPORTED) if (png_ptr->transformations & PNG_PACKSWAP) png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined."); #endif #if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED) if (png_ptr->transformations & PNG_PACK) png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined."); #endif #if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) if (png_ptr->transformations & PNG_SHIFT) png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined."); #endif #if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED) if (png_ptr->transformations & PNG_BGR) png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined."); #endif #if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED) if (png_ptr->transformations & PNG_SWAP_BYTES) png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined."); #endif } #if defined(PNG_READ_INTERLACING_SUPPORTED) /* if interlaced and we do not need a new row, combine row and return */ if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) { switch (png_ptr->pass) { case 0: if (png_ptr->row_number & 7) { if (dsp_row != NULL) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); png_read_finish_row(png_ptr); return; } break; case 1: if ((png_ptr->row_number & 7) || png_ptr->width < 5) { if (dsp_row != NULL) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); png_read_finish_row(png_ptr); return; } break; case 2: if ((png_ptr->row_number & 7) != 4) { if (dsp_row != NULL && (png_ptr->row_number & 4)) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); png_read_finish_row(png_ptr); return; } break; case 3: if ((png_ptr->row_number & 3) || png_ptr->width < 3) { if (dsp_row != NULL) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); png_read_finish_row(png_ptr); return; } break; case 4: if ((png_ptr->row_number & 3) != 2) { if (dsp_row != NULL && (png_ptr->row_number & 2)) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); png_read_finish_row(png_ptr); return; } break; case 5: if ((png_ptr->row_number & 1) || png_ptr->width < 2) { if (dsp_row != NULL) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); png_read_finish_row(png_ptr); return; } break; case 6: if (!(png_ptr->row_number & 1)) { png_read_finish_row(png_ptr); return; } break; } } #endif if (!(png_ptr->mode & PNG_HAVE_IDAT)) png_error(png_ptr, "Invalid attempt to read row data"); png_ptr->zstream.next_out = png_ptr->row_buf; png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; do { if (!(png_ptr->zstream.avail_in)) { while (!png_ptr->idat_size) { png_byte chunk_length[4]; png_crc_finish(png_ptr, 0); png_read_data(png_ptr, chunk_length, 4); png_ptr->idat_size = png_get_uint_32(chunk_length); png_reset_crc(png_ptr); png_crc_read(png_ptr, png_ptr->chunk_name, 4); if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) png_error(png_ptr, "Not enough image data"); } png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; png_ptr->zstream.next_in = png_ptr->zbuf; if (png_ptr->zbuf_size > png_ptr->idat_size) png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size; png_crc_read(png_ptr, png_ptr->zbuf, (png_size_t)png_ptr->zstream.avail_in); png_ptr->idat_size -= png_ptr->zstream.avail_in; } ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); if (ret == Z_STREAM_END) { if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in || png_ptr->idat_size) png_error(png_ptr, "Extra compressed data"); png_ptr->mode |= PNG_AFTER_IDAT; png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; break; } if (ret != Z_OK) png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : "Decompression error"); } while (png_ptr->zstream.avail_out); 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); if (png_ptr->transformations) png_do_read_transformations(png_ptr); #if defined(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); if (dsp_row != NULL) png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); if (row != NULL) png_combine_row(png_ptr, row, png_pass_mask[png_ptr->pass]); } else #endif { if (row != NULL) png_combine_row(png_ptr, row, 0xff); if (dsp_row != NULL) png_combine_row(png_ptr, dsp_row, 0xff); } png_read_finish_row(png_ptr); if (png_ptr->read_row_fn != NULL) (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); }