;;; org-crypt.el --- Public key encryption for org-mode entries
-;; Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
+;; Copyright (C) 2007-2016 Free Software Foundation, Inc.
;; Emacs Lisp Archive Entry
;; Filename: org-crypt.el
-;; Version: 7.4
;; Keywords: org-mode
;; Author: John Wiegley <johnw@gnu.org>
;; Maintainer: Peter Jones <pjones@pmade.com>
;; 4. To automatically encrypt all necessary entries when saving a
;; file, call `org-crypt-use-before-save-magic' after loading
;; org-crypt.el.
-;;
-;; TODO:
-;; - Allow symmetric encryption as well
;;; Thanks:
compress-algorithm))
(declare-function epg-encrypt-string "epg"
(context plain recipients &optional sign always-trust))
+(defvar epg-context)
+
(defgroup org-crypt nil
- "Org Crypt"
- :tag "Org Crypt" :group 'org)
+ "Org Crypt."
+ :tag "Org Crypt"
+ :group 'org)
(defcustom org-crypt-tag-matcher "crypt"
"The tag matcher used to find headings whose contents should be encrypted.
See the \"Match syntax\" section of the org manual for more details."
- :type 'string :group 'org-crypt)
+ :type 'string
+ :group 'org-crypt)
-(defcustom org-crypt-key nil
+(defcustom org-crypt-key ""
"The default key to use when encrypting the contents of a heading.
This setting can also be overridden in the CRYPTKEY property."
- :type 'string :group 'org-crypt)
+ :type 'string
+ :group 'org-crypt)
+
+(defcustom org-crypt-disable-auto-save 'ask
+ "What org-decrypt should do if `auto-save-mode' is enabled.
+
+t : Disable auto-save-mode for the current buffer
+ prior to decrypting an entry.
+
+nil : Leave auto-save-mode enabled.
+ This may cause data to be written to disk unencrypted!
+
+'ask : Ask user whether or not to disable auto-save-mode
+ for the current buffer.
+
+'encrypt : Leave auto-save-mode enabled for the current buffer,
+ but automatically re-encrypt all decrypted entries
+ *before* auto-saving.
+ NOTE: This only works for entries which have a tag
+ that matches `org-crypt-tag-matcher'."
+ :group 'org-crypt
+ :version "24.1"
+ :type '(choice (const :tag "Always" t)
+ (const :tag "Never" nil)
+ (const :tag "Ask" ask)
+ (const :tag "Encrypt" encrypt)))
+
+(defun org-crypt-check-auto-save ()
+ "Check whether auto-save-mode is enabled for the current buffer.
+
+`auto-save-mode' may cause leakage when decrypting entries, so
+check whether it's enabled, and decide what to do about it.
+
+See `org-crypt-disable-auto-save'."
+ (when buffer-auto-save-file-name
+ (cond
+ ((or
+ (eq org-crypt-disable-auto-save t)
+ (and
+ (eq org-crypt-disable-auto-save 'ask)
+ (y-or-n-p "org-decrypt: auto-save-mode may cause leakage. Disable it for current buffer? ")))
+ (message "org-decrypt: Disabling auto-save-mode for %s"
+ (or (buffer-file-name) (current-buffer)))
+ ;; The argument to auto-save-mode has to be "-1", since
+ ;; giving a "nil" argument toggles instead of disabling.
+ (auto-save-mode -1))
+ ((eq org-crypt-disable-auto-save nil)
+ (message "org-decrypt: Decrypting entry with auto-save-mode enabled. This may cause leakage."))
+ ((eq org-crypt-disable-auto-save 'encrypt)
+ (message "org-decrypt: Enabling re-encryption on auto-save.")
+ (org-add-hook 'auto-save-hook
+ (lambda ()
+ (message "org-crypt: Re-encrypting all decrypted entries due to auto-save.")
+ (org-encrypt-entries))
+ nil t))
+ (t nil))))
(defun org-crypt-key-for-heading ()
"Return the encryption key for the current heading."
(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)
+ (set (make-local-variable '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)
(require 'epg)
(save-excursion
(org-back-to-heading t)
+ (set (make-local-variable 'epg-context) (epg-make-context nil t t))
(let ((start-heading (point)))
(forward-line)
(when (not (looking-at "-----BEGIN PGP MESSAGE-----"))
- (let ((folded (org-invisible-p))
- (epg-context (epg-make-context nil t t))
+ (let ((folded (outline-invisible-p))
(crypt-key (org-crypt-key-for-heading))
(beg (point))
end encrypted-text)
(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
(unless (org-before-first-heading-p)
(save-excursion
(org-back-to-heading t)
- (forward-line)
- (when (looking-at "-----BEGIN PGP MESSAGE-----")
- (let* ((beg (point))
- (end (save-excursion
- (search-forward "-----END PGP MESSAGE-----")
- (forward-line)
- (point)))
- (epg-context (epg-make-context nil t t))
- (decrypted-text
- (decode-coding-string
- (epg-decrypt-string
- epg-context
- (buffer-substring-no-properties beg end))
- 'utf-8)))
- (delete-region beg end)
- (insert decrypted-text)
- nil)))))
+ (let ((heading-point (point))
+ (heading-was-invisible-p
+ (save-excursion
+ (outline-end-of-heading)
+ (outline-invisible-p))))
+ (forward-line)
+ (when (looking-at "-----BEGIN PGP MESSAGE-----")
+ (org-crypt-check-auto-save)
+ (set (make-local-variable 'epg-context) (epg-make-context nil t t))
+ (let* ((end (save-excursion
+ (search-forward "-----END PGP MESSAGE-----")
+ (forward-line)
+ (point)))
+ (encrypted-text (buffer-substring-no-properties (point) end))
+ (decrypted-text
+ (decode-coding-string
+ (epg-decrypt-string
+ epg-context
+ 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)
+ ;; Store a checksum of the decrypted and the encrypted
+ ;; text value. This allow reusing 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))
+ nil))))))
(defun org-encrypt-entries ()
"Encrypt all top-level entries in the current buffer."
(interactive)
- (org-scan-tags
- 'org-encrypt-entry
- (cdr (org-make-tags-matcher org-crypt-tag-matcher))))
+ (let (todo-only)
+ (org-scan-tags
+ 'org-encrypt-entry
+ (cdr (org-make-tags-matcher org-crypt-tag-matcher))
+ todo-only)))
(defun org-decrypt-entries ()
"Decrypt all entries in the current buffer."
(interactive)
- (org-scan-tags
- 'org-decrypt-entry
- (cdr (org-make-tags-matcher org-crypt-tag-matcher))))
+ (let (todo-only)
+ (org-scan-tags
+ 'org-decrypt-entry
+ (cdr (org-make-tags-matcher org-crypt-tag-matcher))
+ todo-only)))
+
+(defun org-at-encrypted-entry-p ()
+ "Is the current entry encrypted?"
+ (unless (org-before-first-heading-p)
+ (save-excursion
+ (org-back-to-heading t)
+ (search-forward "-----BEGIN PGP MESSAGE-----"
+ (save-excursion (outline-next-heading)) t))))
(defun org-crypt-use-before-save-magic ()
"Add a hook to automatically encrypt entries before a file is saved to disk."
(add-hook
'org-mode-hook
- (lambda () (add-hook 'before-save-hook 'org-encrypt-entries nil t))))
+ (lambda () (org-add-hook 'before-save-hook 'org-encrypt-entries nil t))))
(add-hook 'org-reveal-start-hook 'org-decrypt-entry)
(provide 'org-crypt)
-
;;; org-crypt.el ends here