Heavily Encrypted

02/12/2015
(if (and netrc-cache
         (equal (car netrc-cache) (nth 5 (file-attributes file))))
    (insert (base64-decode-string (rot13-string (cdr netrc-cache))))
  (insert-file-contents file)
  (when (string-match "\\.gpg\\'" file)
    ;; Store the contents of the file heavily encrypted in memory.
    (setq netrc-cache (cons (nth 5 (file-attributes file))
                            (rot13-string
                             (base64-encode-string
                              (buffer-string)))))))

Whenever I see such code, a number of questions comes to my mind:

  • Is this a joke?
  • Why is this “encryption” only applied to GPG-encrypted file contents?
  • Why is this caching only applied to GPG-encrypted file contents?
  • Which scenario does this apply to? I mean, scrambling a buffer representation doesn’t make any sense on my Linux box, simply because root access is necessary for accessing other process memory. Windows systems have more grave issues than any process being able to read the memory of other processes.
  • Who the hell wrote this?

At least the last one is easy to answer. Lars splitted this one out from Gnus, our favourite Emacs mail program. It hardly is alone in this department, I’m aware of Thunderbird storing permanently cached credentials properly encrypted, but leaving the key in a base64-encoded file.