From: Sebastian Fieber Date: Fri, 24 Dec 2021 09:43:52 +0000 (+0100) Subject: verify signed content in smime encrypted and signed message X-Git-Tag: emacs-29.0.90~3474 X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=b6fac9aaaf21c12a25e1cbec9cb8b8d14d2dc8a8;p=emacs.git verify signed content in smime encrypted and signed message * lisp/gnus/gnus-art.el (gnus-mime-display-part): Parse pkcs7 parts (bug#40397). (gnus-mime-security-verify-or-decrypt): (gnus-insert-mime-security-button): Handle these parts. * lisp/gnus/mm-decode.el (mm-verify-function-alist): Add pkcs7 functions. (mm-decrypt-function-alist): Handle them. (mm-possibly-verify-or-decrypt): Ditto. * lisp/gnus/mm-view.el (mm-view-pkcs7-decrypt): Handle pkcs7. Changes: - structure the result of mm-dissect-buffer of application/pkcs7-mime like a multipart mail so there is no loosing of information of verification and decryption results which can now be displayed by gnus-mime-display-security - adjust gnus-mime-display-part to handle application/pkcs7-mime like multipart/encrypted or multipart/signed - add dummy entries to mm-verify-function-alist and mm-decrypt-function-alist so gnus-mime-display-security correctly displays "S/MIME" and not "unknown protocol" - don't just check for multipart/signed in gnus-insert-mime-security-button but also for the pkcs7-mime mimetypes to print "Encrypted" or "Signed" accordingly in the security button - adjust mm-possibly-verify-or-decrypt to check for smime-type to ask wether to verify or decrypt the part and not to always ask to decrypt - adjust mm-view-pkcs7-decrypt and verify to call mm-sec-status so success information can be displayed by gnus-mime-display-security - adjust gnus-mime-security-verify-or-decrypt to handle pkcs7-mime right with the done changes --- diff --git a/lisp/gnus/gnus-art.el b/lisp/gnus/gnus-art.el index b7701f10a5e..3b3564fc30a 100644 --- a/lisp/gnus/gnus-art.el +++ b/lisp/gnus/gnus-art.el @@ -6084,6 +6084,34 @@ If nil, don't show those extra buttons." ((equal (car handle) "multipart/encrypted") (gnus-add-wash-type 'encrypted) (gnus-mime-display-security handle)) + ;; pkcs7-mime handling: + ;; + ;; although not really multipart these are structured internally by + ;; mm-dissect-buffer like multipart to not discard the decryption + ;; and verification results + ;; + ;; application/pkcs7-mime + ((and (equal (car handle) "application/pkcs7-mime") + (equal (mm-handle-multipart-ctl-parameter handle 'protocol) + "application/pkcs7-mime_signed-data")) + (gnus-add-wash-type 'signed) + (gnus-mime-display-security handle)) + ((and (equal (car handle) "application/pkcs7-mime") + (equal (mm-handle-multipart-ctl-parameter handle 'protocol) + "application/pkcs7-mime_enveloped-data")) + (gnus-add-wash-type 'encrypted) + (gnus-mime-display-security handle)) + ;; application/x-pkcs7-mime + ((and (equal (car handle) "application/x-pkcs7-mime") + (equal (mm-handle-multipart-ctl-parameter handle 'protocol) + "application/x-pkcs7-mime_signed-data")) + (gnus-add-wash-type 'signed) + (gnus-mime-display-security handle)) + ((and (equal (car handle) "application/x-pkcs7-mime") + (equal (mm-handle-multipart-ctl-parameter handle 'protocol) + "application/x-pkcs7-mime_enveloped-data")) + (gnus-add-wash-type 'encrypted) + (gnus-mime-display-security handle)) ;; Other multiparts are handled like multipart/mixed. (t (gnus-mime-display-mixed (cdr handle))))) @@ -8833,11 +8861,19 @@ For example: (setq point (point)) (with-current-buffer (mm-handle-multipart-original-buffer handle) (let* ((mm-verify-option 'known) - (mm-decrypt-option 'known) - (nparts (mm-possibly-verify-or-decrypt (cdr handle) handle))) - (unless (eq nparts (cdr handle)) - (mm-destroy-parts (cdr handle)) - (setcdr handle nparts)))) + (mm-decrypt-option 'known) + (pkcs7-mime-p (or (equal (car handle) "application/pkcs7-mime") + (equal (car handle) "application/x-pkcs7-mime"))) + (nparts (if pkcs7-mime-p + (list (mm-possibly-verify-or-decrypt + (cadr handle) (cadadr handle))) + (mm-possibly-verify-or-decrypt (cdr handle) handle)))) + (unless (eq nparts (cdr handle)) + ;; if pkcs7-mime don't destroy the parts as the buffer in + ;; the cdr still needs to be accessible + (when (not pkcs7-mime-p) + (mm-destroy-parts (cdr handle))) + (setcdr handle nparts)))) (gnus-mime-display-security handle) (when region (delete-region (point) (cdr region)) @@ -8891,14 +8927,35 @@ For example: (let* ((protocol (mm-handle-multipart-ctl-parameter handle 'protocol)) (gnus-tmp-type (concat - (or (nth 2 (assoc protocol mm-verify-function-alist)) - (nth 2 (assoc protocol mm-decrypt-function-alist)) - "Unknown") - (if (equal (car handle) "multipart/signed") - " Signed" " Encrypted") - " Part")) - (gnus-tmp-info - (or (mm-handle-multipart-ctl-parameter handle 'gnus-info) + (or (nth 2 (assoc protocol mm-verify-function-alist)) + (nth 2 (assoc protocol mm-decrypt-function-alist)) + "Unknown") + (cond ((equal (car handle) "multipart/signed") " Signed") + ((equal (car handle) "multipart/encrypted") " Encrypted") + ((and (equal (car handle) "application/pkcs7-mime") + (equal + (mm-handle-multipart-ctl-parameter handle 'protocol) + "application/pkcs7-mime_signed-data")) + " Signed") + ((and (equal (car handle) "application/pkcs7-mime") + (equal + (mm-handle-multipart-ctl-parameter handle 'protocol) + "application/pkcs7-mime_enveloped-data")) + " Encrypted") + ;; application/x-pkcs7-mime + ((and (equal (car handle) "application/x-pkcs7-mime") + (equal + (mm-handle-multipart-ctl-parameter handle 'protocol) + "application/x-pkcs7-mime_signed-data")) + " Signed") + ((and (equal (car handle) "application/x-pkcs7-mime") + (equal + (mm-handle-multipart-ctl-parameter handle 'protocol) + "application/x-pkcs7-mime_enveloped-data")) + " Encrypted")) + " Part")) + (gnus-tmp-info + (or (mm-handle-multipart-ctl-parameter handle 'gnus-info) "Undecided")) (gnus-tmp-details (mm-handle-multipart-ctl-parameter handle 'gnus-details)) diff --git a/lisp/gnus/mm-decode.el b/lisp/gnus/mm-decode.el index d781407cdcd..d2889a50c0a 100644 --- a/lisp/gnus/mm-decode.el +++ b/lisp/gnus/mm-decode.el @@ -474,6 +474,7 @@ The file will be saved in the directory `mm-tmp-directory'.") (autoload 'mml2015-verify-test "mml2015") (autoload 'mml-smime-verify "mml-smime") (autoload 'mml-smime-verify-test "mml-smime") +(autoload 'mm-view-pkcs7-verify "mm-view") (defvar mm-verify-function-alist '(("application/pgp-signature" mml2015-verify "PGP" mml2015-verify-test) @@ -482,7 +483,15 @@ The file will be saved in the directory `mm-tmp-directory'.") ("application/pkcs7-signature" mml-smime-verify "S/MIME" mml-smime-verify-test) ("application/x-pkcs7-signature" mml-smime-verify "S/MIME" - mml-smime-verify-test))) + mml-smime-verify-test) + ("application/x-pkcs7-signature" mml-smime-verify "S/MIME" + mml-smime-verify-test) + ;; these are only used for security-buttons and contain the + ;; smime-type after the underscore + ("application/pkcs7-mime_signed-data" mm-view-pkcs7-verify "S/MIME" + nil) + ("application/x-pkcs7-mime_signed-data" mml-view-pkcs7-verify "S/MIME" + nil))) (defcustom mm-verify-option 'never "Option of verifying signed parts. @@ -501,11 +510,17 @@ result of the verification." (autoload 'mml2015-decrypt "mml2015") (autoload 'mml2015-decrypt-test "mml2015") +(autoload 'mm-view-pkcs7-decrypt "mm-view") (defvar mm-decrypt-function-alist '(("application/pgp-encrypted" mml2015-decrypt "PGP" mml2015-decrypt-test) ("application/x-gnus-pgp-encrypted" mm-uu-pgp-encrypted-extract-1 "PGP" - mm-uu-pgp-encrypted-test))) + mm-uu-pgp-encrypted-test) + ;; these are only used for security-buttons and contain the + ;; smime-type after the underscore + ("application/pkcs7-mime_enveloped-data" mm-view-pkcs7-decrypt "S/MIME" nil) + ("application/x-pkcs7-mime_enveloped-data" + mm-view-pkcs7-decrypt "S/MIME" nil))) (defcustom mm-decrypt-option nil "Option of decrypting encrypted parts. @@ -682,18 +697,35 @@ MIME-Version header before proceeding." 'start start) (car ctl)) (cons (car ctl) (mm-dissect-multipart ctl from)))) - (t - (mm-possibly-verify-or-decrypt - (mm-dissect-singlepart - ctl - (and cte (intern (downcase (mail-header-strip-cte cte)))) - no-strict-mime - (and cd (mail-header-parse-content-disposition cd)) - description id) - ctl from)))) - (when id - (when (string-match " *<\\(.*\\)> *" id) - (setq id (match-string 1 id))) + (t + (let* ((handle + (mm-dissect-singlepart + ctl + (and cte (intern (downcase (mail-header-strip-cte cte)))) + no-strict-mime + (and cd (mail-header-parse-content-disposition cd)) + description id)) + (intermediate-result + (mm-possibly-verify-or-decrypt handle ctl from))) + (when (and (equal type "application") + (or (equal subtype "pkcs7-mime") + (equal subtype "x-pkcs7-mime"))) + (add-text-properties + 0 (length (car ctl)) + (list 'protocol + (concat (substring-no-properties (car ctl)) + "_" + (cdr (assoc 'smime-type ctl)))) + (car ctl)) + ;; If this is a pkcs7-mime lets treat this special and + ;; more like multipart so the pkcs7-mime part does not + ;; get ignored. + (setq intermediate-result + (cons (car ctl) (list intermediate-result)))) + intermediate-result)))) + (when id + (when (string-match " *<\\(.*\\)> *" id) + (setq id (match-string 1 id))) (push (cons id result) mm-content-id-alist)) result)))) @@ -1677,43 +1709,40 @@ If RECURSIVE, search recursively." (cond ((or (equal type "application/x-pkcs7-mime") (equal type "application/pkcs7-mime")) - (with-temp-buffer - (when (and (cond - ((equal smime-type "signed-data") t) - ((eq mm-decrypt-option 'never) nil) - ((eq mm-decrypt-option 'always) t) - ((eq mm-decrypt-option 'known) t) - (t (y-or-n-p "Decrypt (S/MIME) part? "))) - (mm-view-pkcs7 parts from)) - (goto-char (point-min)) - ;; The encrypted document is a MIME part, and may use either - ;; CRLF (Outlook and the like) or newlines for end-of-line - ;; markers. Translate from CRLF. - (while (search-forward "\r\n" nil t) - (replace-match "\n")) - ;; Normally there will be a Content-type header here, but - ;; some mailers don't add that to the encrypted part, which - ;; makes the subsequent re-dissection fail here. - (save-restriction - (mail-narrow-to-head) - (unless (mail-fetch-field "content-type") - (goto-char (point-max)) - (insert "Content-type: text/plain\n\n"))) - (setq parts - (if (equal smime-type "signed-data") - (list (propertize - "multipart/signed" - 'protocol "application/pkcs7-signature" - 'gnus-info - (format - "%s:%s" - (get-text-property 0 'gnus-info - (car mm-security-handle)) - (get-text-property 0 'gnus-details - (car mm-security-handle)))) - (mm-dissect-buffer t) - parts) - (mm-dissect-buffer t)))))) + (add-text-properties 0 (length (car ctl)) + (list 'buffer (car parts)) + (car ctl)) + (let* ((envelope-p (string= smime-type "enveloped-data")) + (decrypt-or-verify-option (if envelope-p + mm-decrypt-option + mm-verify-option)) + (question (if envelope-p + "Decrypt (S/MIME) part? " + "Verify signed (S/MIME) part? "))) + (with-temp-buffer + (when (and (cond + ((equal smime-type "signed-data") t) + ((eq decrypt-or-verify-option 'never) nil) + ((eq decrypt-or-verify-option 'always) t) + ((eq decrypt-or-verify-option 'known) t) + (t (y-or-n-p (format question)))) + (mm-view-pkcs7 parts from)) + + (goto-char (point-min)) + ;; The encrypted document is a MIME part, and may use either + ;; CRLF (Outlook and the like) or newlines for end-of-line + ;; markers. Translate from CRLF. + (while (search-forward "\r\n" nil t) + (replace-match "\n")) + ;; Normally there will be a Content-type header here, but + ;; some mailers don't add that to the encrypted part, which + ;; makes the subsequent re-dissection fail here. + (save-restriction + (mail-narrow-to-head) + (unless (mail-fetch-field "content-type") + (goto-char (point-max)) + (insert "Content-type: text/plain\n\n"))) + (setq parts (mm-dissect-buffer t)))))) ((equal subtype "signed") (unless (and (setq protocol (mm-handle-multipart-ctl-parameter ctl 'protocol)) diff --git a/lisp/gnus/mm-view.el b/lisp/gnus/mm-view.el index d2a6d2cf5d3..319bc745ff8 100644 --- a/lisp/gnus/mm-view.el +++ b/lisp/gnus/mm-view.el @@ -634,12 +634,9 @@ If MODE is not set, try to find mode automatically." (context (epg-make-context 'CMS))) (prog1 (epg-verify-string context part) - (let ((result (car (epg-context-result-for context 'verify)))) + (let ((result (epg-context-result-for context 'verify))) (mm-sec-status - 'gnus-info (epg-signature-status result) - 'gnus-details - (format "%s:%s" (epg-signature-validity result) - (epg-signature-key-id result)))))))) + 'gnus-info (epg-verify-result-to-string result))))))) (with-temp-buffer (insert "MIME-Version: 1.0\n") (mm-insert-headers "application/pkcs7-mime" "base64" "smime.p7m") @@ -659,7 +656,11 @@ If MODE is not set, try to find mode automatically." ;; Use EPG/gpgsm (let ((part (base64-decode-string (buffer-string)))) (erase-buffer) - (insert (epg-decrypt-string (epg-make-context 'CMS) part))) + (insert + (let ((context (epg-make-context 'CMS))) + (prog1 + (epg-decrypt-string context part) + (mm-sec-status 'gnus-info "OK"))))) ;; Use openssl (insert "MIME-Version: 1.0\n") (mm-insert-headers "application/pkcs7-mime" "base64" "smime.p7m")