;;; mml-smime.el --- S/MIME support for MML
-;; Copyright (C) 2000-2011 Free Software Foundation, Inc.
+;; Copyright (C) 2000-2016 Free Software Foundation, Inc.
;; Author: Simon Josefsson <simon@josefsson.org>
;; Keywords: Gnus, MIME, S/MIME, MML
;;; Code:
-;; For Emacs <22.2 and XEmacs.
-(eval-and-compile
- (unless (fboundp 'declare-function) (defmacro declare-function (&rest r))))
-
(eval-when-compile (require 'cl))
(require 'smime)
(autoload 'message-narrow-to-headers "message")
(autoload 'message-fetch-field "message")
+;; Prefer epg over openssl if it is available as epg uses GnuPG's gpgsm,
+;; which features full-fledged certificate management, while openssl requires
+;; major manual efforts for certificate revocation and expiry and has bugs
+;; as documented under man smime(1).
+(ignore-errors (require 'epg))
+
(defcustom mml-smime-use (if (featurep 'epg) 'epg 'openssl)
- "Whether to use OpenSSL or EPG to decrypt S/MIME messages.
-Defaults to EPG if it's loaded."
+ "Whether to use OpenSSL or EasyPG (EPG) to handle S/MIME messages.
+Defaults to EPG if it's available.
+If you think about using OpenSSL, please read the BUGS section in the manual
+for the `smime' command coming with OpenSSL first. EasyPG is recommended."
:group 'mime-security
:type '(choice (const :tag "EPG" epg)
(const :tag "OpenSSL" openssl)))
"If t, cache passphrase."
:group 'mime-security
:type 'boolean)
+(make-obsolete-variable 'mml-smime-cache-passphrase
+ 'mml-secure-cache-passphrase
+ "25.1")
(defcustom mml-smime-passphrase-cache-expiry mml-secure-passphrase-cache-expiry
"How many seconds the passphrase is cached.
`mml-smime-cache-passphrase'."
:group 'mime-security
:type 'integer)
+(make-obsolete-variable 'mml-smime-passphrase-cache-expiry
+ 'mml-secure-passphrase-cache-expiry
+ "25.1")
(defcustom mml-smime-signers nil
"A list of your own key ID which will be used to sign a message."
:group 'mime-security
:type '(repeat (string :tag "Key ID")))
+(defcustom mml-smime-sign-with-sender nil
+ "If t, use message sender so find a key to sign with."
+ :group 'mime-security
+ :version "24.4"
+ :type 'boolean)
+
+(defcustom mml-smime-encrypt-to-self nil
+ "If t, add your own key ID to recipient list when encryption."
+ :group 'mime-security
+ :version "24.4"
+ :type 'boolean)
+
(defun mml-smime-sign (cont)
(let ((func (nth 1 (assq mml-smime-use mml-smime-function-alist))))
(if func
(autoload 'epg-encrypt-string "epg")
(autoload 'epg-passphrase-callback-function "epg")
(autoload 'epg-context-set-passphrase-callback "epg")
+ (autoload 'epg-sub-key-fingerprint "epg")
(autoload 'epg-configuration "epg-config")
(autoload 'epg-expand-group "epg-config")
(autoload 'epa-select-keys "epa"))
-(defvar mml-smime-epg-secret-key-id-list nil)
-
-(defun mml-smime-epg-passphrase-callback (context key-id ignore)
- (if (eq key-id 'SYM)
- (epg-passphrase-callback-function context key-id nil)
- (let* (entry
- (passphrase
- (password-read
- (if (eq key-id 'PIN)
- "Passphrase for PIN: "
- (if (setq entry (assoc key-id epg-user-id-alist))
- (format "Passphrase for %s %s: " key-id (cdr entry))
- (format "Passphrase for %s: " key-id)))
- (if (eq key-id 'PIN)
- "PIN"
- key-id))))
- (when passphrase
- (let ((password-cache-expiry mml-smime-passphrase-cache-expiry))
- (password-cache-add key-id passphrase))
- (setq mml-smime-epg-secret-key-id-list
- (cons key-id mml-smime-epg-secret-key-id-list))
- (copy-sequence passphrase)))))
-
(declare-function epg-key-sub-key-list "ext:epg" (key))
(declare-function epg-sub-key-capability "ext:epg" (sub-key))
(declare-function epg-sub-key-validity "ext:epg" (sub-key))
-(defun mml-smime-epg-find-usable-key (keys usage)
- (catch 'found
- (while keys
- (let ((pointer (epg-key-sub-key-list (car keys))))
- (while pointer
- (if (and (memq usage (epg-sub-key-capability (car pointer)))
- (not (memq (epg-sub-key-validity (car pointer))
- '(revoked expired))))
- (throw 'found (car keys)))
- (setq pointer (cdr pointer))))
- (setq keys (cdr keys)))))
-
(autoload 'mml-compute-boundary "mml")
;; We require mm-decode, which requires mm-bodies, which autoloads
(declare-function message-options-set "message" (symbol value))
(defun mml-smime-epg-sign (cont)
- (let* ((inhibit-redisplay t)
- (context (epg-make-context 'CMS))
- (boundary (mml-compute-boundary cont))
- signer-key
- (signers
- (or (message-options-get 'mml-smime-epg-signers)
- (message-options-set
- 'mml-smime-epg-signers
- (if (eq mm-sign-option 'guided)
- (epa-select-keys context "\
-Select keys for signing.
-If no one is selected, default secret key is used. "
- mml-smime-signers t)
- (if mml-smime-signers
- (mapcar
- (lambda (signer)
- (setq signer-key (mml-smime-epg-find-usable-key
- (epg-list-keys context signer t)
- 'sign))
- (unless (or signer-key
- (y-or-n-p
- (format "No secret key for %s; skip it? "
- signer)))
- (error "No secret key for %s" signer))
- signer-key)
- mml-smime-signers))))))
- signature micalg)
- (epg-context-set-signers context signers)
- (if mml-smime-cache-passphrase
- (epg-context-set-passphrase-callback
- context
- #'mml-smime-epg-passphrase-callback))
- (condition-case error
- (setq signature (epg-sign-string context
- (mm-replace-in-string (buffer-string)
- "\n" "\r\n")
- t)
- mml-smime-epg-secret-key-id-list nil)
- (error
- (while mml-smime-epg-secret-key-id-list
- (password-cache-remove (car mml-smime-epg-secret-key-id-list))
- (setq mml-smime-epg-secret-key-id-list
- (cdr mml-smime-epg-secret-key-id-list)))
- (signal (car error) (cdr error))))
- (if (epg-context-result-for context 'sign)
- (setq micalg (epg-new-signature-digest-algorithm
- (car (epg-context-result-for context 'sign)))))
+ (let ((inhibit-redisplay t)
+ (boundary (mml-compute-boundary cont)))
(goto-char (point-min))
- (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
- boundary))
- (if micalg
- (insert (format "\tmicalg=%s; "
- (downcase
- (cdr (assq micalg
- epg-digest-algorithm-alist))))))
- (insert "protocol=\"application/pkcs7-signature\"\n")
- (insert (format "\n--%s\n" boundary))
- (goto-char (point-max))
- (insert (format "\n--%s\n" boundary))
- (insert "Content-Type: application/pkcs7-signature; name=smime.p7s
+ (let* ((pair (mml-secure-epg-sign 'CMS cont))
+ (signature (car pair))
+ (micalg (cdr pair)))
+ (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
+ boundary))
+ (if micalg
+ (insert (format "\tmicalg=%s; "
+ (downcase
+ (cdr (assq micalg
+ epg-digest-algorithm-alist))))))
+ (insert "protocol=\"application/pkcs7-signature\"\n")
+ (insert (format "\n--%s\n" boundary))
+ (goto-char (point-max))
+ (insert (format "\n--%s\n" boundary))
+ (insert "Content-Type: application/pkcs7-signature; name=smime.p7s
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=smime.p7s
")
- (insert (base64-encode-string signature) "\n")
- (goto-char (point-max))
- (insert (format "--%s--\n" boundary))
- (goto-char (point-max))))
+ (insert (base64-encode-string signature) "\n")
+ (goto-char (point-max))
+ (insert (format "--%s--\n" boundary))
+ (goto-char (point-max)))))
(defun mml-smime-epg-encrypt (cont)
- (let ((inhibit-redisplay t)
- (context (epg-make-context 'CMS))
- (config (epg-configuration))
- (recipients (message-options-get 'mml-smime-epg-recipients))
- cipher signers
- (boundary (mml-compute-boundary cont))
- recipient-key)
- (unless recipients
- (setq recipients
- (apply #'nconc
- (mapcar
- (lambda (recipient)
- (or (epg-expand-group config recipient)
- (list recipient)))
- (split-string
- (or (message-options-get 'message-recipients)
- (message-options-set 'message-recipients
- (read-string "Recipients: ")))
- "[ \f\t\n\r\v,]+"))))
- (if (eq mm-encrypt-option 'guided)
- (setq recipients
- (epa-select-keys context "\
-Select recipients for encryption.
-If no one is selected, symmetric encryption will be performed. "
- recipients))
- (setq recipients
- (mapcar
- (lambda (recipient)
- (setq recipient-key (mml-smime-epg-find-usable-key
- (epg-list-keys context recipient)
- 'encrypt))
- (unless (or recipient-key
- (y-or-n-p
- (format "No public key for %s; skip it? "
- recipient)))
- (error "No public key for %s" recipient))
- recipient-key)
- recipients))
- (unless recipients
- (error "No recipient specified")))
- (message-options-set 'mml-smime-epg-recipients recipients))
- (if mml-smime-cache-passphrase
- (epg-context-set-passphrase-callback
- context
- #'mml-smime-epg-passphrase-callback))
- (condition-case error
- (setq cipher
- (epg-encrypt-string context (buffer-string) recipients)
- mml-smime-epg-secret-key-id-list nil)
- (error
- (while mml-smime-epg-secret-key-id-list
- (password-cache-remove (car mml-smime-epg-secret-key-id-list))
- (setq mml-smime-epg-secret-key-id-list
- (cdr mml-smime-epg-secret-key-id-list)))
- (signal (car error) (cdr error))))
+ (let* ((inhibit-redisplay t)
+ (boundary (mml-compute-boundary cont))
+ (cipher (mml-secure-epg-encrypt 'CMS cont)))
(delete-region (point-min) (point-max))
(goto-char (point-min))
(insert "\
(mm-set-handle-multipart-parameter
mm-security-handle 'gnus-info "Corrupted")
(throw 'error handle))
- (setq part (mm-replace-in-string part "\n" "\r\n" t)
+ (setq part (mm-replace-in-string part "\n" "\r\n")
context (epg-make-context 'CMS))
(condition-case error
(setq plain (epg-verify-string context (mm-get-part signature) part))
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