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; #if defined(PNG_READ_bKGD_SUPPORTED) PNG_CONST PNG_bKGD; #endif #if defined(PNG_READ_cHRM_SUPPORTED) PNG_CONST PNG_cHRM; #endif #if defined(PNG_READ_gAMA_SUPPORTED) PNG_CONST PNG_gAMA; #endif #if defined(PNG_READ_hIST_SUPPORTED) PNG_CONST PNG_hIST; #endif #if defined(PNG_READ_iCCP_SUPPORTED) PNG_CONST PNG_iCCP; #endif #if defined(PNG_READ_iTXt_SUPPORTED) PNG_CONST PNG_iTXt; #endif #if defined(PNG_READ_oFFs_SUPPORTED) PNG_CONST PNG_oFFs; #endif #if defined(PNG_READ_pCAL_SUPPORTED) PNG_CONST PNG_pCAL; #endif #if defined(PNG_READ_pHYs_SUPPORTED) PNG_CONST PNG_pHYs; #endif #if defined(PNG_READ_sBIT_SUPPORTED) PNG_CONST PNG_sBIT; #endif #if defined(PNG_READ_sCAL_SUPPORTED) PNG_CONST PNG_sCAL; #endif #if defined(PNG_READ_sRGB_SUPPORTED) PNG_CONST PNG_sRGB; #endif #if defined(PNG_READ_sPLT_SUPPORTED) PNG_CONST PNG_sPLT; #endif #if defined(PNG_READ_tEXt_SUPPORTED) PNG_CONST PNG_tEXt; #endif #if defined(PNG_READ_tIME_SUPPORTED) PNG_CONST PNG_tIME; #endif #if defined(PNG_READ_tRNS_SUPPORTED) PNG_CONST PNG_tRNS; #endif #if defined(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_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 + 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_ptr->irowbytes; png_ptr->zstream.next_out = png_ptr->row_buf; return; } #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) { /* First we make sure we have enough data for the 4 byte chunk name * and the 4 byte chunk length before proceeding with decoding the * chunk data. To fully decode each of these chunks, we also make * sure we have enough data in the buffer for the 4 byte CRC at the * end of every chunk (except IDAT, which is handled separately). */ if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER)) { 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_32(chunk_length); png_reset_crc(png_ptr); png_crc_read(png_ptr, png_ptr->chunk_name, 4); png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER; } if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) { 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_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_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_ptr->irowbytes; png_ptr->zstream.next_out = png_ptr->row_buf; return; } 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); } #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(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 #if defined(PNG_READ_tEXt_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) { png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); } #endif #if defined(PNG_READ_zTXt_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) { png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); } #endif else { png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); } png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER; }