- Do not close NULL stream

diff --git a/programs/aes/aescrypt2.c b/programs/aes/aescrypt2.c
index c291c18..e761554 100644
--- a/programs/aes/aescrypt2.c
+++ b/programs/aes/aescrypt2.c
@@ -390,8 +390,10 @@
     ret = 0;
 
 exit:
-    fclose( fin );
-    fclose( fout );
+    if( fin )
+        fclose( fin );
+    if( fout )
+        fclose( fout );
 
     memset( buffer, 0, sizeof( buffer ) );
     memset( digest, 0, sizeof( digest ) );