>From 64bf9c2f6b15e82b5d077b1428408237ad1d1e74 Mon Sep 17 00:00:00 2001 From: Damien Cassou Date: Tue, 27 Mar 2018 16:57:51 +0200 Subject: [PATCH] Detect if a message can be encrypted and add an MML tag * lisp/gnus/message.el (message-recipients): Return a list of pairs, one for each recipient in To, Cc, Bcc. (message-all-epg-keys-available-p): Check that there is a public key in epg for each recipient of the current message. (message-sign-encrypt-if-all-keys-available): Add MML tag to sign and encrypt current message if there is a public key for every recipient in current message. * test/lisp/gnus/message-tests.el (message-recipients): Test for message-recipients. --- etc/NEWS | 8 +++++++ lisp/gnus/message.el | 30 +++++++++++++++++++++++++++ test/lisp/gnus/message-tests.el | 46 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 84 insertions(+) diff --git a/etc/NEWS b/etc/NEWS index baff9664cf..02b31ecff4 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -337,6 +337,14 @@ or NextCloud hosted files and directories. It was obsolete since Emacs 22.1, replaced by customize. +** Message + ++++ +*** Messages can now be systematically encrypted +when the PGP keyring contains a public key for every recipient. To +achieve this, add 'message-add-encrypt-tag-if-can-encrypt' to +'message-send-hook'. + * New Modes and Packages in Emacs 27.1 +++ diff --git a/lisp/gnus/message.el b/lisp/gnus/message.el index 37b994de99..fdb296fc24 100644 --- a/lisp/gnus/message.el +++ b/lisp/gnus/message.el @@ -2582,6 +2582,36 @@ message-info (t 'message))))) +(defun message-all-recipients () + "Return a list of all recipients in the message, looking at TO, CC and BCC. + +Each recipient is in the format of `mail-extract-address-components'." + (mapcan (lambda (header) + (let ((header-value (message-fetch-field header))) + (and + header-value + (mail-extract-address-components header-value t)))) + '("To" "Cc" "Bcc"))) + +(defun message-all-epg-keys-available-p () + "Return non-nil if the pgp keyring has a public key for each recipient." + (require 'epa) + (let ((context (epg-make-context epa-protocol))) + (catch 'break + (dolist (recipient (message-all-recipients)) + (let ((recipient-email (cadr recipient))) + (when (and recipient-email (not (epg-list-keys context recipient-email))) + (throw 'break nil)))) + t))) + +(defun message-sign-encrypt-if-all-keys-available () + "Add MML tag to encrypt message when there is a key for each recipient. + +Consider adding this function to `message-send-hook' to +systematically send encrypted emails when possible." + (when (message-all-epg-keys-available-p) + (mml-secure-message-sign-encrypt))) + ;;; diff --git a/test/lisp/gnus/message-tests.el b/test/lisp/gnus/message-tests.el index ec1f247020..9124dcf77a 100644 --- a/test/lisp/gnus/message-tests.el +++ b/test/lisp/gnus/message-tests.el @@ -29,6 +29,8 @@ (require 'ert) (require 'ert-x) +(require 'cl-lib) + (ert-deftest message-mode-propertize () (with-temp-buffer (unwind-protect @@ -97,6 +99,50 @@ (should (string= stripped-was (message-strip-subject-trailing-was with-was))))))) +(ert-deftest message-all-recipients () + (ert-with-test-buffer (:name "message") + (insert "To: Person 1 , Person 2 \n") + (insert "CC: Person 3 , Person 4 \n") + (insert "BCC: Person 5 , Person 6 \n") + (should (equal (message-all-recipients) + '(("Person 1" "p1@p1.org") + ("Person 2" "p2@p2.org") + ("Person 3" "p3@p3.org") + ("Person 4" "p4@p4.org") + ("Person 5" "p5@p5.org") + ("Person 6" "p6@p6.org")))))) + +(ert-deftest message-all-epg-keys-available-p () + (let ((person1 '("Person 1" "p1@p1.org")) + (person2 '("Person 2" "p2@p2.org")) + (person3 '("Person 3" "p3@p3.org")) + (recipients nil) + (keyring '("p1@p1.org" "p2@p2.org"))) + (cl-letf (((symbol-function 'epg-list-keys) + (lambda (_ email) (cl-find email keyring :test #'string=))) + ((symbol-function 'message-all-recipients) + (lambda () recipients))) + + (setq recipients (list)) + (should (message-all-epg-keys-available-p)) + + (setq recipients (list person1)) + (should (message-all-epg-keys-available-p)) + + (setq recipients (list person1 person2)) + (should (message-all-epg-keys-available-p)) + + (setq recipients (list person3)) + (should-not (message-all-epg-keys-available-p)) + + (setq recipients (list person1 person3)) + (should-not (message-all-epg-keys-available-p)) + + (setq recipients (list person3 person1)) + (should-not (message-all-epg-keys-available-p)) + + (setq recipients (list person1 person2 person3)) + (should-not (message-all-epg-keys-available-p))))) (provide 'message-mode-tests) -- 2.14.3