(add-to-list 'load-path "<path-to-auto-save>") ; add auto-save to your load-path
(require 'auto-save)
(auto-save-enable)

(setq auto-save-silent t)   ; quietly save
(setq auto-save-delete-trailing-whitespace t)  ; automatically delete spaces at the end of the line when saving

;;; custom predicates if you don't want auto save.
;;; disable auto save mode when current filetype is an gpg file.
(setq auto-save-disable-predicates
      '((lambda ()
      (string-suffix-p
      "gpg"
      (file-name-extension (buffer-name)) t))))