diff --git a/tools/tiffcrop.c b/tools/tiffcrop.c

index ea4f7a1..f04e2eb 100644

--- a/tools/tiffcrop.c

+++ b/tools/tiffcrop.c

@@ -798,6 +798,11 @@ static int readContigTilesIntoBuffer (TIFF* in, uint8* buf,

     }

   tile_buffsize = tilesize;

+  if (tilesize == 0 || tile_rowsize == 0)

+  {

+     TIFFError("readContigTilesIntoBuffer", "Tile size or tile rowsize is zero");

+     exit(-1);

+  }

   if (tilesize < (tsize_t)(tl * tile_rowsize))

     {

@@ -807,7 +812,12 @@ static int readContigTilesIntoBuffer (TIFF* in, uint8* buf,

               tilesize, tl * tile_rowsize);

 #endif

     tile_buffsize = tl * tile_rowsize;

-    } 

+    if (tl != (tile_buffsize / tile_rowsize))

+    {

+    	TIFFError("readContigTilesIntoBuffer", "Integer overflow when calculating buffer size.");

+        exit(-1);

+    }

+    }

   tilebuf = _TIFFmalloc(tile_buffsize);

   if (tilebuf == 0)

@@ -1210,6 +1220,12 @@ static int writeBufferToContigTiles (TIFF* out, uint8* buf, uint32 imagelength,

       !TIFFGetField(out, TIFFTAG_BITSPERSAMPLE, &bps) )

       return 1;

+  if (tilesize == 0 || tile_rowsize == 0 || tl == 0 || tw == 0)

+  {

+    TIFFError("writeBufferToContigTiles", "Tile size, tile row size, tile width, or tile length is zero");

+    exit(-1);

+  }

+  

   tile_buffsize = tilesize;

   if (tilesize < (tsize_t)(tl * tile_rowsize))

     {

@@ -1219,6 +1235,11 @@ static int writeBufferToContigTiles (TIFF* out, uint8* buf, uint32 imagelength,

               tilesize, tl * tile_rowsize);

 #endif

     tile_buffsize = tl * tile_rowsize;

+    if (tl != tile_buffsize / tile_rowsize)

+    {

+	TIFFError("writeBufferToContigTiles", "Integer overflow when calculating buffer size");

+	exit(-1);

+    }

     }

   tilebuf = _TIFFmalloc(tile_buffsize);

@@ -5931,12 +5952,27 @@ loadImage(TIFF* in, struct image_data *image, struct dump_opts *dump, unsigned c

     TIFFGetField(in, TIFFTAG_TILELENGTH, &tl;;

     tile_rowsize  = TIFFTileRowSize(in);      

+    if (ntiles == 0 || tlsize == 0 || tile_rowsize == 0)

+    {

+	TIFFError("loadImage", "File appears to be tiled, but the number of tiles, tile size, or tile rowsize is zero.");

+	exit(-1);

+    }

     buffsize = tlsize * ntiles;

+    if (tlsize != (buffsize / ntiles))

+    {

+	TIFFError("loadImage", "Integer overflow when calculating buffer size");

+	exit(-1);

+    }

-        

     if (buffsize < (uint32)(ntiles * tl * tile_rowsize))

       {

       buffsize = ntiles * tl * tile_rowsize;

+      if (ntiles != (buffsize / tl / tile_rowsize))

+      {

+	TIFFError("loadImage", "Integer overflow when calculating buffer size");

+	exit(-1);

+      }

+      

 #ifdef DEBUG2

       TIFFError("loadImage",

 	        "Tilesize %u is too small, using ntiles * tilelength * tilerowsize %lu",

@@ -5955,8 +5991,25 @@ loadImage(TIFF* in, struct image_data *image, struct dump_opts *dump, unsigned c

     TIFFGetFieldDefaulted(in, TIFFTAG_ROWSPERSTRIP, &rowsperstrip);

     stsize = TIFFStripSize(in);

     nstrips = TIFFNumberOfStrips(in);

+    if (nstrips == 0 || stsize == 0)

+    {

+	TIFFError("loadImage", "File appears to be striped, but the number of stipes or stripe size is zero.");

+	exit(-1);

+    }

+

     buffsize = stsize * nstrips;

-    

+    if (stsize != (buffsize / nstrips))

+    {

+	TIFFError("loadImage", "Integer overflow when calculating buffer size");

+	exit(-1);

+    }

+    uint32 buffsize_check;

+    buffsize_check = ((length * width * spp * bps) + 7);

+    if (length != ((buffsize_check - 7) / width / spp / bps))

+    {

+	TIFFError("loadImage", "Integer overflow detected.");

+	exit(-1);

+    }

     if (buffsize < (uint32) (((length * width * spp * bps) + 7) / 8))

       {

       buffsize =  ((length * width * spp * bps) + 7) / 8;