diff --git a/3d-viewer/3d_cache/3d_cache.cpp b/3d-viewer/3d_cache/3d_cache.cpp
index 33c04d0..1abc22c 100644
--- a/3d-viewer/3d_cache/3d_cache.cpp
+++ b/3d-viewer/3d_cache/3d_cache.cpp
@@ -345,7 +345,7 @@ SCENEGRAPH* S3D_CACHE::checkCache( const wxString& aFileName, S3D_CACHE_ENTRY**
 }
 
 
-bool S3D_CACHE::getSHA1( const wxString& aFileName, unsigned char* aSHA1Sum )
+bool S3D_CACHE::getSHA1( const wxString& aFileName, unsigned char (&aSHA1Sum)[20] )
 {
     if( aFileName.empty() )
     {
@@ -380,22 +380,7 @@ bool S3D_CACHE::getSHA1( const wxString& aFileName, unsigned char* aSHA1Sum )
         dblock.process_bytes( block, bsize );
 
     fclose( fp );
-    unsigned int digest[5];
-    dblock.get_digest( digest );
-
-    // ensure MSB order
-    for( int i = 0; i < 5; ++i )
-    {
-        int idx = i << 2;
-        unsigned int tmp = digest[i];
-        aSHA1Sum[idx+3] = tmp & 0xff;
-        tmp >>= 8;
-        aSHA1Sum[idx+2] = tmp & 0xff;
-        tmp >>= 8;
-        aSHA1Sum[idx+1] = tmp & 0xff;
-        tmp >>= 8;
-        aSHA1Sum[idx] = tmp & 0xff;
-    }
+    dblock.get_digest( aSHA1Sum );
 
     return true;
 }
@@ -696,4 +681,4 @@ void S3D_CACHE::CleanCacheDir( int aNumDaysOld )
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/3d-viewer/3d_cache/3d_cache.h b/3d-viewer/3d_cache/3d_cache.h
index 4abc62e..fd5076e 100644
--- a/3d-viewer/3d_cache/3d_cache.h
+++ b/3d-viewer/3d_cache/3d_cache.h
@@ -156,7 +156,7 @@ private:
      * @param aSHA1Sum a 20 byte character array to hold the SHA1 hash.
      * @return true on  success, otherwise false.
      */
-    bool getSHA1( const wxString& aFileName, unsigned char* aSHA1Sum );
+    bool getSHA1( const wxString& aFileName, unsigned char (&aSHA1Sum)[20] );
 
     // load scene data from a cache file
     bool loadCacheData( S3D_CACHE_ENTRY* aCacheItem );