transparent encryption with crypt++, gpg and xemacs-21.4.15 ?

[Adrian Aichner]

The following message is a courtesy copy of an article
that has been posted to comp.emacs.xemacs as well.

>>>>> "Manfred" == Manfred Bartz <spamhere at dev.null> writes:

    Manfred> crypt++ just ignores me!
    Manfred> I have added this to my init.el file:

    Manfred> (setq crypt-encryption-type 'gpg
    Manfred>       crypt-encryption-file-extension "\\(\\.e\\)$"
    Manfred>       crypt-bind-insert-file nil
    Manfred>       crypt-freeze-vs-fortran nil)
    Manfred> (require 'crypt)

    Manfred> crypt.el is a symlink to crypt++.el

    Manfred> I don't get any passphrase prompt when saving a file with the ".e"
    Manfred> extension, it just saves the file without error message.
    Manfred> When I change the 'gpg to 'pgp crypt++ asks for a passphrase but 
    Manfred> then it cannot find pgp (because I use gpg).

Manfred, Karl, xemacs-beta,

I just debugged in the area today.

Part of my problem was that sample.init.el sheipped with XEmacs (which
I load in site-start.el) loads crypt.el, which I have not symlinked to
crypt++.el.

Secondly, at least in native Windows crypt++ destroys file content on
decryption due to use of

   (let ((coding-system-for-write 'no-conversion)
	 (coding-system-for-read 'no-conversion)

in

(defun crypt-encrypt-region (start end key &optional decrypt)

I changed the above to
   (let ((coding-system-for-write 'binary)
	 (coding-system-for-read 'binary)

My .emacs bit currently looks as follows:

;;; APA:
;;; crypt is already loaded by sample.init.el, therefor we have to
;;; force loading crypt++ and rebuild the tables here!
(setq crypt-encryption-type 'gpg
      crypt-encryption-file-extension nil
      crypt-bind-insert-file nil
      crypt-freeze-vs-fortran nil)
(load "crypt++")
(crypt-rebuild-tables)
(crypt-bind-insert-file)
(modify-coding-system-alist 'file "\\.gpg$" 'binary)
(modify-coding-system-alist 'process "gpg" 'binary)

And things are now in working order, except for following warning,
which even gets written into the encrypted file itself!

gpg: WARNING: message was not integrity protected

Karl, am I making sense?

Best regards,

Adrian

    Manfred> The parameters in the crypt-build-encryption-alist for gpg look
    Manfred> reasonable AFAICS.

    Manfred> If anyone has this working, could you please post your init.el
    Manfred> settings?

    Manfred> Or maybe I should use another method or package?

    Manfred> -- 
    Manfred> Manfred

-- 
Adrian Aichner
 mailto:adrian at xemacs.org
 http://www.xemacs.org/