Proper initialization and checks for rare cases
diff --git a/programs/pkey/key_app_writer.c b/programs/pkey/key_app_writer.c
index d8465ca..0055319 100644
--- a/programs/pkey/key_app_writer.c
+++ b/programs/pkey/key_app_writer.c
@@ -97,6 +97,9 @@
     c = base_buf;
 
     f = fopen( output_file, "w" );
+    if( f == NULL )
+        return;
+
     fprintf(f, "-----BEGIN PUBLIC KEY-----\n");
     while (olen)
     {