Bugfix: avoid opening CAfile when it's NULL.
diff --git a/apps/s_server.c b/apps/s_server.c
index 3ed008c..e54593d 100644
--- a/apps/s_server.c
+++ b/apps/s_server.c
@@ -699,7 +699,8 @@
 	SSL_CTX_set_session_id_context(ctx,(void*)&s_server_session_id_context,
 		sizeof s_server_session_id_context);
 
-	SSL_CTX_set_client_CA_list(ctx,SSL_load_client_CA_file(CAfile));
+	if (CAfile != NULL)
+	    SSL_CTX_set_client_CA_list(ctx,SSL_load_client_CA_file(CAfile));
 
 	BIO_printf(bio_s_out,"ACCEPT\n");
 	if (www)