/* Read the information before the actual image data. This has been * changed in v0.90 to allow reading a file that already has the magic * bytes read from the stream. You can tell libpng how many bytes have * been read from the beginning of the stream (up to the maximum of 8) * via png_set_sig_bytes(), and we will only check the remaining bytes * here. The application can then have access to the signature bytes we * read if it is determined that this isn't a valid PNG file. */ void PNGAPI png_read_info(png_structp png_ptr, png_infop info_ptr) { if (png_ptr == NULL || info_ptr == NULL) return; png_debug(1, "in png_read_info\n"); /* If we haven't checked all of the PNG signature bytes, do so now. */ if (png_ptr->sig_bytes < 8) { png_size_t num_checked = png_ptr->sig_bytes, num_to_check = 8 - num_checked; png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); png_ptr->sig_bytes = 8; 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"); } if (num_checked < 3) png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; } for (;;) { #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_sPLT_SUPPORTED) PNG_CONST PNG_sPLT; #endif #if defined(PNG_READ_sRGB_SUPPORTED) PNG_CONST PNG_sRGB; #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 */ png_uint_32 length = png_read_chunk_header(png_ptr); PNG_CONST png_bytep chunk_name = png_ptr->chunk_name; /* This should be a binary subdivision search or a hash for * matching the chunk name rather than a linear search. */ if (!png_memcmp(chunk_name, png_IDAT, 4)) if (png_ptr->mode & PNG_AFTER_IDAT) png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; 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)) png_ptr->mode |= PNG_HAVE_IDAT; png_handle_unknown(png_ptr, info_ptr, length); if (!png_memcmp(chunk_name, png_PLTE, 4)) png_ptr->mode |= PNG_HAVE_PLTE; else if (!png_memcmp(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"); break; } } #endif else if (!png_memcmp(chunk_name, png_PLTE, 4)) png_handle_PLTE(png_ptr, info_ptr, length); else if (!png_memcmp(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"); png_ptr->idat_size = length; png_ptr->mode |= PNG_HAVE_IDAT; break; } #if defined(PNG_READ_bKGD_SUPPORTED) else if (!png_memcmp(chunk_name, png_bKGD, 4)) png_handle_bKGD(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_cHRM_SUPPORTED) else if (!png_memcmp(chunk_name, png_cHRM, 4)) png_handle_cHRM(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_gAMA_SUPPORTED) else if (!png_memcmp(chunk_name, png_gAMA, 4)) png_handle_gAMA(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_hIST_SUPPORTED) else if (!png_memcmp(chunk_name, png_hIST, 4)) png_handle_hIST(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_oFFs_SUPPORTED) else if (!png_memcmp(chunk_name, png_oFFs, 4)) png_handle_oFFs(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_pCAL_SUPPORTED) else if (!png_memcmp(chunk_name, png_pCAL, 4)) png_handle_pCAL(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sCAL_SUPPORTED) else if (!png_memcmp(chunk_name, png_sCAL, 4)) png_handle_sCAL(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_pHYs_SUPPORTED) else if (!png_memcmp(chunk_name, png_pHYs, 4)) png_handle_pHYs(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sBIT_SUPPORTED) else if (!png_memcmp(chunk_name, png_sBIT, 4)) png_handle_sBIT(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sRGB_SUPPORTED) else if (!png_memcmp(chunk_name, png_sRGB, 4)) png_handle_sRGB(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_iCCP_SUPPORTED) else if (!png_memcmp(chunk_name, png_iCCP, 4)) png_handle_iCCP(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sPLT_SUPPORTED) else if (!png_memcmp(chunk_name, png_sPLT, 4)) png_handle_sPLT(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tEXt_SUPPORTED) else if (!png_memcmp(chunk_name, png_tEXt, 4)) png_handle_tEXt(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tIME_SUPPORTED) else if (!png_memcmp(chunk_name, png_tIME, 4)) png_handle_tIME(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tRNS_SUPPORTED) else if (!png_memcmp(chunk_name, png_tRNS, 4)) png_handle_tRNS(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_zTXt_SUPPORTED) else if (!png_memcmp(chunk_name, png_zTXt, 4)) png_handle_zTXt(png_ptr, info_ptr, length); #endif #if defined(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); } }
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; 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->mode |= PNG_HAVE_IDAT; png_ptr->process_mode = PNG_READ_IDAT_MODE; if ((png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) == 0) if (png_ptr->push_length == 0) return; 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) { 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 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_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; }
/* 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)); }
/* 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 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; }
/* Read the information before the actual image data. This has been * changed in v0.90 to allow reading a file that already has the magic * bytes read from the stream. You can tell libpng how many bytes have * been read from the beginning of the stream (up to the maximum of 8) * via png_set_sig_bytes(), and we will only check the remaining bytes * here. The application can then have access to the signature bytes we * read if it is determined that this isn't a valid PNG file. */ void PNGAPI png_read_info(png_structp png_ptr, png_infop info_ptr) { png_debug(1, "in png_read_info"); if (png_ptr == NULL || info_ptr == NULL) return; /* Read and check the PNG file signature. */ png_read_sig(png_ptr, info_ptr); for (;;) { 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; /* This should be a binary subdivision search or a hash for * matching the chunk name rather than a linear search. */ if (!png_memcmp(chunk_name, png_IDAT, 4)) if (png_ptr->mode & PNG_AFTER_IDAT) png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; 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)) png_ptr->mode |= PNG_HAVE_IDAT; png_handle_unknown(png_ptr, info_ptr, length); if (!png_memcmp(chunk_name, png_PLTE, 4)) png_ptr->mode |= PNG_HAVE_PLTE; else if (!png_memcmp(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"); break; } } #endif else if (!png_memcmp(chunk_name, png_PLTE, 4)) png_handle_PLTE(png_ptr, info_ptr, length); else if (!png_memcmp(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"); png_ptr->idat_size = length; png_ptr->mode |= PNG_HAVE_IDAT; break; } #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); } }
void /* PRIVATE */ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr) { png_uint_32 chunk_name; #ifdef PNG_SET_UNKNOWN_CHUNKS_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)) { png_byte chunk_length[4]; png_byte chunk_tag[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, 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 || png_ptr->num_frames_read > 1) png_error(png_ptr, "out of place IDAT"); if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_push_crc_skip(png_ptr, png_ptr->push_length); png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; return; } else if (chunk_name == png_fdAT) { if (png_ptr->buffer_size < 4) { png_push_save_buffer(png_ptr); return; } png_ensure_sequence_number(png_ptr, 4); if (!(png_ptr->mode & PNG_HAVE_fcTL)) { /* Discard trailing fdATs for frames other than the first */ if (png_ptr->num_frames_read < 2) png_error(png_ptr, "out of place fdAT"); if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_push_crc_skip(png_ptr, png_ptr->push_length); png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; return; } 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; return; } } else if (chunk_name == png_fcTL) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } 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)) 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; return; } else { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_warning(png_ptr, "Skipped (ignored) a chunk " "between APNG chunks"); png_push_crc_skip(png_ptr, png_ptr->push_length); png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; return; } return; } #endif /* PNG_READ_APNG_SUPPORTED */ if (chunk_name == png_IDAT) { if (png_ptr->mode & PNG_AFTER_IDAT) png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; /* If we reach an IDAT chunk, this means we have read all of the * header chunks, and we can start reading the image (or if this * is called after the image has been read - we have an error). */ if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before IDAT"); else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && !(png_ptr->mode & PNG_HAVE_PLTE)) png_error(png_ptr, "Missing PLTE before IDAT"); png_ptr->mode |= PNG_HAVE_IDAT; if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) if (png_ptr->push_length == 0) return; if (png_ptr->mode & PNG_AFTER_IDAT) png_benign_error(png_ptr, "Too many IDATs found"); } if (chunk_name == png_IHDR) { if (png_ptr->push_length != 13) png_error(png_ptr, "Invalid IHDR length"); if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); } else if (chunk_name == png_IEND) { 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_SET_UNKNOWN_CHUNKS_SUPPORTED else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep); if (chunk_name == png_PLTE) png_ptr->mode |= PNG_HAVE_PLTE; } #endif else if (chunk_name == png_PLTE) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); } else if (chunk_name == png_IDAT) { #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) { 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_ptr->chunk_name == png_sBIT) { 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_ptr->chunk_name == png_cHRM) { 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 (chunk_name == png_sRGB) { 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_ptr->chunk_name == png_iCCP) { 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 (chunk_name == png_sPLT) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_tRNS_SUPPORTED else if (chunk_name == png_tRNS) { 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 (chunk_name == png_bKGD) { 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 (chunk_name == png_hIST) { 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 (chunk_name == png_pHYs) { 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 (chunk_name == png_oFFs) { 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 (chunk_name == png_pCAL) { 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 (chunk_name == png_sCAL) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_tIME_SUPPORTED else if (chunk_name == png_tIME) { 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 (chunk_name == png_tEXt) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_zTXt_SUPPORTED else if (chunk_name == png_zTXt) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_iTXt_SUPPORTED else if (chunk_name == png_iTXt) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); } #endif #ifdef PNG_READ_APNG_SUPPORTED else if (chunk_name == png_acTL) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_handle_acTL(png_ptr, info_ptr, png_ptr->push_length); } else if (chunk_name == png_fcTL) { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length); } #endif /* PNG_READ_APNG_SUPPORTED */ else { if (png_ptr->push_length + 4 > png_ptr->buffer_size) { png_push_save_buffer(png_ptr); return; } png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, PNG_HANDLE_CHUNK_AS_DEFAULT); } png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; }
/* 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)); }
/* Read the information before the actual image data. This has been * changed in v0.90 to allow reading a file that already has the magic * bytes read from the stream. You can tell libpng how many bytes have * been read from the beginning of the stream (up to the maximum of 8) * via png_set_sig_bytes(), and we will only check the remaining bytes * here. The application can then have access to the signature bytes we * read if it is determined that this isn't a valid PNG file. */ void png_read_info(png_structp png_ptr, png_infop info_ptr) { png_debug(1, "in png_read_info\n"); /* save jump buffer and error functions */ /* If we haven't checked all of the PNG signature bytes, do so now. */ if (png_ptr->sig_bytes < 8) { png_size_t num_checked = png_ptr->sig_bytes, num_to_check = 8 - num_checked; png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); png_ptr->sig_bytes = 8; 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"); } } for(;;) { png_byte chunk_length[4]; png_uint_32 length; 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_debug2(0, "Reading %s chunk, length=%d.\n", png_ptr->chunk_name, length); /* This should be a binary subdivision search or a hash for * matching the chunk name rather than a linear search. */ 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_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); 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"); png_ptr->idat_size = length; png_ptr->mode |= PNG_HAVE_IDAT; break; } #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); } }
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"); if(png_ptr == NULL) return; png_crc_finish(png_ptr, 0); do { #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_sPLT_SUPPORTED) PNG_CONST PNG_sPLT; #endif #if defined(PNG_READ_sRGB_SUPPORTED) PNG_CONST PNG_sRGB; #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_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_HAVE_CHUNK_AFTER_IDAT)) png_error(png_ptr, "Too many IDAT's found"); } 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)) { if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_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 PNGAPI png_read_info(png_structp png_ptr, png_infop info_ptr) { if(png_ptr == NULL) return; png_debug(1, "in png_read_info\n"); if (png_ptr->sig_bytes < 8) { png_size_t num_checked = png_ptr->sig_bytes, num_to_check = 8 - num_checked; png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); png_ptr->sig_bytes = 8; 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"); } if (num_checked < 3) png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; } for(;;) { #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_sPLT_SUPPORTED) PNG_CONST PNG_sPLT; #endif #if defined(PNG_READ_sRGB_SUPPORTED) PNG_CONST PNG_sRGB; #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_byte chunk_length[4]; png_uint_32 length; 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_debug2(0, "Reading %s chunk, length=%lu.\n", png_ptr->chunk_name, length); if (!png_memcmp(png_ptr->chunk_name, (png_bytep)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)) 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)) png_ptr->mode |= PNG_HAVE_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; 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"); break; } } #endif 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_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"); png_ptr->idat_size = length; png_ptr->mode |= PNG_HAVE_IDAT; break; } #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); } }