[Accepted] org-crypt: cache encrypted text

[Bastien Guerry <bzg@altern.org>]

Patch 586 (http://patchwork.newartisans.com/patch/586/) is now "Accepted".

Maintainer comment: none

This relates to the following submission:

http://mid.gmane.org/%3C1297102717-5071-1-git-send-email-julien%40danjou.info%3E

Here is the original message containing the patch:

> Content-Type: text/plain; charset="utf-8"
> MIME-Version: 1.0
> Content-Transfer-Encoding: 7bit
> Subject: [Orgmode] org-crypt: cache encrypted text
> Date: Mon, 07 Feb 2011 23:18:37 -0000
> From: Julien Danjou <julien@danjou.info>
> X-Patchwork-Id: 586
> Message-Id: <1297102717-5071-1-git-send-email-julien@danjou.info>
> To: emacs-orgmode@gnu.org
> Cc: Julien Danjou <julien@danjou.info>
> 
> * lisp/org-crypt.el (org-encrypt-string): New function.
> (org-encrypt-entry): Use org-encrypt-string to encrypt, so we use cached
> crypted values.
> (org-decrypt-entry): Store crypted text in decrypted text.
> 
> Signed-off-by: Julien Danjou <julien@danjou.info>
> 
> ---
> lisp/org-crypt.el |   26 ++++++++++++++++++++------
>  1 files changed, 20 insertions(+), 6 deletions(-)
> 
> diff --git a/lisp/org-crypt.el b/lisp/org-crypt.el
> index 7c28d70..291c540 100644
> --- a/lisp/org-crypt.el
> +++ b/lisp/org-crypt.el
> @@ -103,6 +103,15 @@ This setting can also be overridden in the CRYPTKEY property."
>          (and (boundp 'epa-file-encrypt-to) epa-file-encrypt-to)
>          (message "No crypt key set, using symmetric encryption."))))
>  
> +(defun org-encrypt-string (str crypt-key)
> +  "Return STR encrypted with CRYPT-KEY."
> +  ;; Text and key have to be identical, otherwise we re-crypt.
> +  (if (and (string= crypt-key (get-text-property 0 'org-crypt-key str))
> +	   (string= (sha1 str) (get-text-property 0 'org-crypt-checksum str)))
> +      (get-text-property 0 'org-crypt-text str)
> +    (let ((epg-context (epg-make-context nil t t)))
> +      (epg-encrypt-string epg-context str (epg-list-keys epg-context crypt-key)))))
> +
>  (defun org-encrypt-entry ()
>    "Encrypt the content of the current headline."
>    (interactive)
> @@ -122,10 +131,7 @@ This setting can also be overridden in the CRYPTKEY property."
>            (org-back-over-empty-lines)
>            (setq end (point)
>                  encrypted-text
> -                (epg-encrypt-string
> -                 epg-context
> -                 (buffer-substring-no-properties beg end)
> -                 (epg-list-keys epg-context crypt-key)))
> +		(org-encrypt-string (buffer-substring beg end) crypt-key))
>            (delete-region beg end)
>            (insert encrypted-text)
>            (when folded
> @@ -152,16 +158,24 @@ This setting can also be overridden in the CRYPTKEY property."
>  			(forward-line)
>  			(point)))
>  		 (epg-context (epg-make-context nil t t))
> +		 (encrypted-text (buffer-substring-no-properties (point) end))
>  		 (decrypted-text
>  		  (decode-coding-string
>  		   (epg-decrypt-string
>  		    epg-context
> -		    (buffer-substring-no-properties (point) end))
> +		    encrypted-text)
>  		   'utf-8)))
>  	    ;; Delete region starting just before point, because the
>  	    ;; outline property starts at the \n of the heading.
>  	    (delete-region (1- (point)) end)
> -	    (insert "\n" decrypted-text)
> +	    ;; Store a checksum of the decrypted and the encrypted
> +	    ;; text value. This allow to reuse the same encrypted text
> +	    ;; if the text does not change, and therefore avoid a
> +	    ;; re-encryption process.
> +	    (insert "\n" (propertize decrypted-text
> +				     'org-crypt-checksum (sha1 decrypted-text)
> +				     'org-crypt-key (org-crypt-key-for-heading)
> +				     'org-crypt-text encrypted-text))
>  	    (when heading-was-invisible-p
>  	      (goto-char heading-point)
>  	      (org-flag-subtree t))
>