Example #1
0
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;
   }
}
Example #2
0
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);
}
Example #5
0
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;
   }
}
Example #6
0
/* 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));
}
Example #7
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 */
      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;
   }
}
Example #8
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;
    }
}
Example #9
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;
}
Example #10
0
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;
   }
}
Example #11
0
/* 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));
}
Example #12
0
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);
}