mml2015: make key image extraction robuster
[gnus] / lisp / mml2015.el
index a35e206..2c2187a 100644 (file)
@@ -1,27 +1,24 @@
 ;;; mml2015.el --- MIME Security with Pretty Good Privacy (PGP)
 
-;; Copyright (C) 2000, 2001, 2002, 2003, 2004,
-;;   2005, 2006 Free Software Foundation, Inc.
+;; Copyright (C) 2000-2013 Free Software Foundation, Inc.
 
 ;; Author: Shenghuo Zhu <zsh@cs.rochester.edu>
 ;; Keywords: PGP MIME MML
 
 ;; This file is part of GNU Emacs.
 
-;; GNU Emacs is free software; you can redistribute it and/or modify
-;; it under the terms of the GNU General Public License as published
-;; by the Free Software Foundation; either version 2, or (at your
-;; option) any later version.
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
 
-;; GNU Emacs is distributed in the hope that it will be useful, but
-;; WITHOUT ANY WARRANTY; without even the implied warranty of
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-;; General Public License for more details.
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
 
 ;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING.  If not, write to the
-;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-;; Boston, MA 02110-1301, USA.
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
 
 ;;; Commentary:
 
 
 ;;; Code:
 
+(eval-and-compile
+  ;; For Emacs <22.2 and XEmacs.
+  (unless (fboundp 'declare-function) (defmacro declare-function (&rest r)))
+
+  (if (locate-library "password-cache")
+      (require 'password-cache)
+    (require 'password)))
+
 (eval-when-compile (require 'cl))
 (require 'mm-decode)
 (require 'mm-util)
 (require 'mml)
+(require 'mml-sec)
 
 (defvar mc-pgp-always-sign)
 
+(declare-function epg-check-configuration "ext:epg-config"
+                  (config &optional minimum-version))
+(declare-function epg-configuration "ext:epg-config" ())
+
+;; Maybe this should be in eg mml-sec.el (and have a different name).
+;; Then mml1991 would not need to require mml2015, and mml1991-use
+;; could be removed.
 (defvar mml2015-use (or
+                    (condition-case nil
+                        (progn
+                          (require 'epg-config)
+                          (epg-check-configuration (epg-configuration))
+                          'epg)
+                      (error))
                     (progn
-                      (ignore-errors
-                       ;; Avoid the "Recursive load suspected" error
-                       ;; in Emacs 21.1.
-                       (let ((recursive-load-depth-limit 100))
-                         (require 'pgg)))
-                      (and (fboundp 'pgg-sign-region)
-                           'pgg))
-                    (progn
-                      (ignore-errors
-                        (require 'gpg))
-                      (and (fboundp 'gpg-sign-detached)
-                           'gpg))
+                      (let ((abs-file (locate-library "pgg")))
+                        ;; Don't load PGG if it is marked as obsolete
+                        ;; (Emacs 24).
+                        (when (and abs-file
+                                   (not (string-match "/obsolete/[^/]*\\'"
+                                                      abs-file)))
+                          (ignore-errors (require 'pgg))
+                          (and (fboundp 'pgg-sign-region)
+                               'pgg))))
                     (progn (ignore-errors
                              (load "mc-toplev"))
                            (and (fboundp 'mc-encrypt-generic)
@@ -58,7 +74,7 @@
                                 (fboundp 'mc-cleanup-recipient-headers)
                                 'mailcrypt)))
   "The package used for PGP/MIME.
-Valid packages include `pgg', `gpg' and `mailcrypt'.")
+Valid packages include `epg', `pgg' and `mailcrypt'.")
 
 ;; Something is not RFC2015.
 (defvar mml2015-function-alist
@@ -68,18 +84,18 @@ Valid packages include `pgg', `gpg' and `mailcrypt'.")
               mml2015-mailcrypt-decrypt
               mml2015-mailcrypt-clear-verify
               mml2015-mailcrypt-clear-decrypt)
-    (gpg mml2015-gpg-sign
-        mml2015-gpg-encrypt
-        mml2015-gpg-verify
-        mml2015-gpg-decrypt
-        mml2015-gpg-clear-verify
-        mml2015-gpg-clear-decrypt)
-  (pgg mml2015-pgg-sign
-       mml2015-pgg-encrypt
-       mml2015-pgg-verify
-       mml2015-pgg-decrypt
-       mml2015-pgg-clear-verify
-       mml2015-pgg-clear-decrypt))
+    (pgg mml2015-pgg-sign
+        mml2015-pgg-encrypt
+        mml2015-pgg-verify
+        mml2015-pgg-decrypt
+        mml2015-pgg-clear-verify
+        mml2015-pgg-clear-decrypt)
+    (epg mml2015-epg-sign
+        mml2015-epg-encrypt
+        mml2015-epg-verify
+        mml2015-epg-decrypt
+        mml2015-epg-clear-verify
+        mml2015-epg-clear-decrypt))
   "Alist of PGP/MIME functions.")
 
 (defvar mml2015-result-buffer nil)
@@ -96,19 +112,87 @@ Valid packages include `pgg', `gpg' and `mailcrypt'.")
   :type '(repeat (cons (regexp :tag "GnuPG output regexp")
                       (boolean :tag "Trust key"))))
 
-;;; mailcrypt wrapper
+(defcustom mml2015-cache-passphrase mml-secure-cache-passphrase
+  "If t, cache passphrase."
+  :group 'mime-security
+  :type 'boolean)
 
-(eval-and-compile
-  (autoload 'mailcrypt-decrypt "mailcrypt")
-  (autoload 'mailcrypt-verify "mailcrypt")
-  (autoload 'mc-pgp-always-sign "mailcrypt")
-  (autoload 'mc-encrypt-generic "mc-toplev")
-  (autoload 'mc-cleanup-recipient-headers "mc-toplev")
-  (autoload 'mc-sign-generic "mc-toplev"))
+(defcustom mml2015-passphrase-cache-expiry mml-secure-passphrase-cache-expiry
+  "How many seconds the passphrase is cached.
+Whether the passphrase is cached at all is controlled by
+`mml2015-cache-passphrase'."
+  :group 'mime-security
+  :type 'integer)
 
-(eval-when-compile
-  (defvar mc-default-scheme)
-  (defvar mc-schemes))
+(defcustom mml2015-signers nil
+  "A list of your own key ID(s) which will be used to sign a message.
+If set, it overrides the setting of `mml2015-sign-with-sender'."
+  :group 'mime-security
+  :type '(repeat (string :tag "Key ID")))
+
+(defcustom mml2015-sign-with-sender nil
+  "If t, use message sender so find a key to sign with."
+  :group 'mime-security
+  :type 'boolean
+  :version "24.1")
+
+(defcustom mml2015-encrypt-to-self nil
+  "If t, add your own key ID to recipient list when encryption."
+  :group 'mime-security
+  :type 'boolean)
+
+(defcustom mml2015-always-trust t
+  "If t, GnuPG skip key validation on encryption."
+  :group 'mime-security
+  :type 'boolean)
+
+(defcustom mml2015-maximum-key-image-dimension 64
+  "The maximum dimension (width or height) of any key images."
+  :version "24.4"
+  :group 'mime-security
+  :type 'integer)
+
+;; Extract plaintext from cleartext signature.  IMO, this kind of task
+;; should be done by GnuPG rather than Elisp, but older PGP backends
+;; (such as Mailcrypt, and PGG) discard the output from GnuPG.
+(defun mml2015-extract-cleartext-signature ()
+  ;; Daiki Ueno in
+  ;; <54a15d860801080142l70b95d7dkac4bf51a86196011@mail.gmail.com>: ``I still
+  ;; believe that the right way is to use the plaintext output from GnuPG as
+  ;; it is, and mml2015-extract-cleartext-signature is just a kludge for
+  ;; misdesigned libraries like PGG, which have no ability to do that.  So, I
+  ;; think it should not have descriptive documentation.''
+  ;;
+  ;; This function doesn't handle NotDashEscaped correctly.  EasyPG handles it
+  ;; correctly.
+  ;; http://thread.gmane.org/gmane.emacs.gnus.general/66062/focus=66082
+  ;; http://thread.gmane.org/gmane.emacs.gnus.general/65087/focus=65109
+  (goto-char (point-min))
+  (forward-line)
+  ;; We need to be careful not to strip beyond the armor headers.
+  ;; Previously, an attacker could replace the text inside our
+  ;; markup with trailing garbage by injecting whitespace into the
+  ;; message.
+  (while (looking-at "Hash:")          ; The only header allowed in cleartext
+    (forward-line))                    ; signatures according to RFC2440.
+  (when (looking-at "[\t ]*$")
+    (forward-line))
+  (delete-region (point-min) (point))
+  (if (re-search-forward "^-----BEGIN PGP SIGNATURE-----" nil t)
+      (delete-region (match-beginning 0) (point-max)))
+  (goto-char (point-min))
+  (while (re-search-forward "^- " nil t)
+    (replace-match "" t t)
+    (forward-line 1)))
+
+;;; mailcrypt wrapper
+
+(autoload 'mailcrypt-decrypt "mailcrypt")
+(autoload 'mailcrypt-verify "mailcrypt")
+(autoload 'mc-pgp-always-sign "mailcrypt")
+(autoload 'mc-encrypt-generic "mc-toplev")
+(autoload 'mc-cleanup-recipient-headers "mc-toplev")
+(autoload 'mc-sign-generic "mc-toplev")
 
 (defvar mml2015-decrypt-function 'mailcrypt-decrypt)
 (defvar mml2015-verify-function 'mailcrypt-verify)
@@ -156,6 +240,58 @@ Valid packages include `pgg', `gpg' and `mailcrypt'.")
          handles
        (list handles)))))
 
+(defun mml2015-gpg-pretty-print-fpr (fingerprint)
+  (let* ((result "")
+        (fpr-length (string-width fingerprint))
+        (n-slice 0)
+        slice)
+    (setq fingerprint (string-to-list fingerprint))
+    (while fingerprint
+      (setq fpr-length (- fpr-length 4))
+      (setq slice (butlast fingerprint fpr-length))
+      (setq fingerprint (nthcdr 4 fingerprint))
+      (setq n-slice (1+ n-slice))
+      (setq result
+           (concat
+            result
+            (case n-slice
+              (1  slice)
+              (otherwise (concat " " slice))))))
+    result))
+
+(defun mml2015-gpg-extract-signature-details ()
+  (goto-char (point-min))
+  (let* ((expired (re-search-forward
+                  "^\\[GNUPG:\\] SIGEXPIRED$"
+                  nil t))
+        (signer (and (re-search-forward
+                      "^\\[GNUPG:\\] GOODSIG \\([0-9A-Za-z]*\\) \\(.*\\)$"
+                      nil t)
+                     (cons (match-string 1) (match-string 2))))
+        (fprint (and (re-search-forward
+                      "^\\[GNUPG:\\] VALIDSIG \\([0-9a-zA-Z]*\\) "
+                      nil t)
+                     (match-string 1)))
+        (trust  (and (re-search-forward
+                      "^\\[GNUPG:\\] \\(TRUST_.*\\)$"
+                      nil t)
+                     (match-string 1)))
+        (trust-good-enough-p
+         (cdr (assoc trust mml2015-unabbrev-trust-alist))))
+    (cond ((and signer fprint)
+          (concat (cdr signer)
+                  (unless trust-good-enough-p
+                    (concat "\nUntrusted, Fingerprint: "
+                            (mml2015-gpg-pretty-print-fpr fprint)))
+                  (when expired
+                    (format "\nWARNING: Signature from expired key (%s)"
+                            (car signer)))))
+         ((re-search-forward
+           "^\\(gpg: \\)?Good signature from \"\\(.*\\)\"$" nil t)
+          (match-string 2))
+         (t
+          "From unknown user"))))
+
 (defun mml2015-mailcrypt-clear-decrypt ()
   (let (result)
     (setq result
@@ -282,7 +418,8 @@ Valid packages include `pgg', `gpg' and `mailcrypt'.")
        (mm-set-handle-multipart-parameter
         mm-security-handle 'gnus-info "OK")
       (mm-set-handle-multipart-parameter
-       mm-security-handle 'gnus-info "Failed"))))
+       mm-security-handle 'gnus-info "Failed")))
+  (mml2015-extract-cleartext-signature))
 
 (defun mml2015-mailcrypt-sign (cont)
   (mc-sign-generic (message-options-get 'message-sender)
@@ -329,6 +466,10 @@ Valid packages include `pgg', `gpg' and `mailcrypt'.")
     (insert (format "--%s--\n" boundary))
     (goto-char (point-max))))
 
+;; We require mm-decode, which requires mm-bodies, which autoloads
+;; message-options-get (!).
+(declare-function message-options-set "message" (symbol value))
+
 (defun mml2015-mailcrypt-encrypt (cont &optional sign)
   (let ((mc-pgp-always-sign
         (or mc-pgp-always-sign
@@ -363,293 +504,17 @@ Valid packages include `pgg', `gpg' and `mailcrypt'.")
     (insert (format "--%s--\n" boundary))
     (goto-char (point-max))))
 
-;;; gpg wrapper
-
-(eval-and-compile
-  (autoload 'gpg-decrypt "gpg")
-  (autoload 'gpg-verify "gpg")
-  (autoload 'gpg-verify-cleartext "gpg")
-  (autoload 'gpg-sign-detached "gpg")
-  (autoload 'gpg-sign-encrypt "gpg")
-  (autoload 'gpg-encrypt "gpg")
-  (autoload 'gpg-passphrase-read "gpg"))
-
-(defun mml2015-gpg-passphrase ()
-  (or (message-options-get 'gpg-passphrase)
-      (message-options-set 'gpg-passphrase (gpg-passphrase-read))))
-
-(defun mml2015-gpg-decrypt-1 ()
-  (let ((cipher (current-buffer)) plain result)
-    (if (with-temp-buffer
-         (prog1
-             (gpg-decrypt cipher (setq plain (current-buffer))
-                          mml2015-result-buffer nil)
-           (mm-set-handle-multipart-parameter
-            mm-security-handle 'gnus-details
-            (with-current-buffer mml2015-result-buffer
-              (buffer-string)))
-           (set-buffer cipher)
-           (erase-buffer)
-           (insert-buffer-substring plain)
-           (goto-char (point-min))
-           (while (search-forward "\r\n" nil t)
-             (replace-match "\n" t t))))
-       '(t)
-      ;; Some wrong with the return value, check plain text buffer.
-      (if (> (point-max) (point-min))
-         '(t)
-       nil))))
-
-(defun mml2015-gpg-decrypt (handle ctl)
-  (let ((mml2015-decrypt-function 'mml2015-gpg-decrypt-1))
-    (mml2015-mailcrypt-decrypt handle ctl)))
-
-(defun mml2015-gpg-clear-decrypt ()
-  (let (result)
-    (setq result (mml2015-gpg-decrypt-1))
-    (if (car result)
-       (mm-set-handle-multipart-parameter
-        mm-security-handle 'gnus-info "OK")
-      (mm-set-handle-multipart-parameter
-       mm-security-handle 'gnus-info "Failed"))))
-
-(defun mml2015-gpg-pretty-print-fpr (fingerprint)
-  (let* ((result "")
-        (fpr-length (string-width fingerprint))
-        (n-slice 0)
-        slice)
-    (setq fingerprint (string-to-list fingerprint))
-    (while fingerprint
-      (setq fpr-length (- fpr-length 4))
-      (setq slice (butlast fingerprint fpr-length))
-      (setq fingerprint (nthcdr 4 fingerprint))
-      (setq n-slice (1+ n-slice))
-      (setq result
-           (concat
-            result
-            (case n-slice
-              (1  slice)
-              (otherwise (concat " " slice))))))
-    result))
-
-(defun mml2015-gpg-extract-signature-details ()
-  (goto-char (point-min))
-  (let* ((expired (re-search-forward
-                  "^\\[GNUPG:\\] SIGEXPIRED$"
-                  nil t))
-        (signer (and (re-search-forward
-                      "^\\[GNUPG:\\] GOODSIG \\([0-9A-Za-z]*\\) \\(.*\\)$"
-                      nil t)
-                     (cons (match-string 1) (match-string 2))))
-        (fprint (and (re-search-forward
-                      "^\\[GNUPG:\\] VALIDSIG \\([0-9a-zA-Z]*\\) "
-                      nil t)
-                     (match-string 1)))
-        (trust  (and (re-search-forward
-                      "^\\[GNUPG:\\] \\(TRUST_.*\\)$"
-                      nil t)
-                     (match-string 1)))
-        (trust-good-enough-p
-         (cdr (assoc trust mml2015-unabbrev-trust-alist))))
-    (cond ((and signer fprint)
-          (concat (cdr signer)
-                  (unless trust-good-enough-p
-                    (concat "\nUntrusted, Fingerprint: "
-                            (mml2015-gpg-pretty-print-fpr fprint)))
-                  (when expired
-                    (format "\nWARNING: Signature from expired key (%s)"
-                            (car signer)))))
-         ((re-search-forward
-           "^\\(gpg: \\)?Good signature from \"\\(.*\\)\"$" nil t)
-          (match-string 2))
-         (t
-          "From unknown user"))))
-
-(defun mml2015-gpg-verify (handle ctl)
-  (catch 'error
-    (let (part message signature info-is-set-p)
-      (unless (setq part (mm-find-raw-part-by-type
-                         ctl (or (mm-handle-multipart-ctl-parameter
-                                  ctl 'protocol)
-                                 "application/pgp-signature")
-                         t))
-       (mm-set-handle-multipart-parameter
-        mm-security-handle 'gnus-info "Corrupted")
-       (throw 'error handle))
-      (with-temp-buffer
-       (setq message (current-buffer))
-       (insert part)
-       ;; Convert <LF> to <CR><LF> in verify mode.  Sign and
-       ;; clearsign use --textmode. The conversion is not necessary.
-       ;; In clearverify, the conversion is not necessary either.
-       (goto-char (point-min))
-       (end-of-line)
-       (while (not (eobp))
-         (unless (eq (char-before) ?\r)
-           (insert "\r"))
-         (forward-line)
-         (end-of-line))
-       (with-temp-buffer
-         (setq signature (current-buffer))
-         (unless (setq part (mm-find-part-by-type
-                             (cdr handle) "application/pgp-signature" nil t))
-           (mm-set-handle-multipart-parameter
-            mm-security-handle 'gnus-info "Corrupted")
-           (throw 'error handle))
-         (mm-insert-part part)
-         (unless (condition-case err
-                     (prog1
-                         (gpg-verify message signature mml2015-result-buffer)
-                       (mm-set-handle-multipart-parameter
-                        mm-security-handle 'gnus-details
-                        (with-current-buffer mml2015-result-buffer
-                          (buffer-string))))
-                   (error
-                    (mm-set-handle-multipart-parameter
-                     mm-security-handle 'gnus-details (mml2015-format-error err))
-                    (mm-set-handle-multipart-parameter
-                     mm-security-handle 'gnus-info "Error.")
-                    (setq info-is-set-p t)
-                    nil)
-                   (quit
-                    (mm-set-handle-multipart-parameter
-                     mm-security-handle 'gnus-details "Quit.")
-                    (mm-set-handle-multipart-parameter
-                     mm-security-handle 'gnus-info "Quit.")
-                    (setq info-is-set-p t)
-                    nil))
-           (unless info-is-set-p
-             (mm-set-handle-multipart-parameter
-              mm-security-handle 'gnus-info "Failed"))
-           (throw 'error handle)))
-       (mm-set-handle-multipart-parameter
-        mm-security-handle 'gnus-info
-        (with-current-buffer mml2015-result-buffer
-          (mml2015-gpg-extract-signature-details))))
-      handle)))
-
-(defun mml2015-gpg-clear-verify ()
-  (if (condition-case err
-         (prog1
-             (gpg-verify-cleartext (current-buffer) mml2015-result-buffer)
-           (mm-set-handle-multipart-parameter
-            mm-security-handle 'gnus-details
-            (with-current-buffer mml2015-result-buffer
-              (buffer-string))))
-       (error
-        (mm-set-handle-multipart-parameter
-         mm-security-handle 'gnus-details (mml2015-format-error err))
-        nil)
-       (quit
-        (mm-set-handle-multipart-parameter
-         mm-security-handle 'gnus-details "Quit.")
-        nil))
-      (mm-set-handle-multipart-parameter
-       mm-security-handle 'gnus-info
-       (with-current-buffer mml2015-result-buffer
-        (mml2015-gpg-extract-signature-details)))
-    (mm-set-handle-multipart-parameter
-     mm-security-handle 'gnus-info "Failed")))
-
-(defun mml2015-gpg-sign (cont)
-  (let ((boundary (mml-compute-boundary cont))
-       (text (current-buffer)) signature)
-    (goto-char (point-max))
-    (unless (bolp)
-      (insert "\n"))
-    (with-temp-buffer
-      (unless (gpg-sign-detached text (setq signature (current-buffer))
-                                mml2015-result-buffer
-                                nil
-                                (message-options-get 'message-sender)
-                                t t) ; armor & textmode
-       (unless (> (point-max) (point-min))
-         (pop-to-buffer mml2015-result-buffer)
-         (error "Sign error")))
-      (goto-char (point-min))
-      (while (re-search-forward "\r+$" nil t)
-       (replace-match "" t t))
-      (set-buffer text)
-      (goto-char (point-min))
-      (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
-                     boundary))
-      ;;; FIXME: what is the micalg?
-      (insert "\tmicalg=pgp-sha1; protocol=\"application/pgp-signature\"\n")
-      (insert (format "\n--%s\n" boundary))
-      (goto-char (point-max))
-      (insert (format "\n--%s\n" boundary))
-      (insert "Content-Type: application/pgp-signature\n\n")
-      (insert-buffer-substring signature)
-      (goto-char (point-max))
-      (insert (format "--%s--\n" boundary))
-      (goto-char (point-max)))))
-
-(defun mml2015-gpg-encrypt (cont &optional sign)
-  (let ((boundary (mml-compute-boundary cont))
-       (text (current-buffer))
-       cipher)
-    (mm-with-unibyte-current-buffer
-      (with-temp-buffer
-       ;; set up a function to call the correct gpg encrypt routine
-       ;; with the right arguments. (FIXME: this should be done
-       ;; differently.)
-       (flet ((gpg-encrypt-func
-                (sign plaintext ciphertext result recipients &optional
-                      passphrase sign-with-key armor textmode)
-                (if sign
-                    (gpg-sign-encrypt
-                     plaintext ciphertext result recipients passphrase
-                     sign-with-key armor textmode)
-                  (gpg-encrypt
-                   plaintext ciphertext result recipients passphrase
-                   armor textmode))))
-         (unless (gpg-encrypt-func
-                   sign ; passed in when using signencrypt
-                   text (setq cipher (current-buffer))
-                   mml2015-result-buffer
-                   (split-string
-                    (or
-                     (message-options-get 'message-recipients)
-                     (message-options-set 'message-recipients
-                                          (read-string "Recipients: ")))
-                    "[ \f\t\n\r\v,]+")
-                   nil
-                   (message-options-get 'message-sender)
-                   t t) ; armor & textmode
-           (unless (> (point-max) (point-min))
-             (pop-to-buffer mml2015-result-buffer)
-             (error "Encrypt error"))))
-       (goto-char (point-min))
-       (while (re-search-forward "\r+$" nil t)
-         (replace-match "" t t))
-       (set-buffer text)
-       (delete-region (point-min) (point-max))
-       (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
-                       boundary))
-       (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
-       (insert (format "--%s\n" boundary))
-       (insert "Content-Type: application/pgp-encrypted\n\n")
-       (insert "Version: 1\n\n")
-       (insert (format "--%s\n" boundary))
-       (insert "Content-Type: application/octet-stream\n\n")
-       (insert-buffer-substring cipher)
-       (goto-char (point-max))
-       (insert (format "--%s--\n" boundary))
-       (goto-char (point-max))))))
-
 ;;; pgg wrapper
 
-(eval-when-compile
-  (defvar pgg-default-user-id)
-  (defvar pgg-errors-buffer)
-  (defvar pgg-output-buffer))
+(defvar pgg-default-user-id)
+(defvar pgg-errors-buffer)
+(defvar pgg-output-buffer)
 
-(eval-and-compile
-  (autoload 'pgg-decrypt-region "pgg")
-  (autoload 'pgg-verify-region "pgg")
-  (autoload 'pgg-sign-region "pgg")
-  (autoload 'pgg-encrypt-region "pgg")
-  (autoload 'pgg-parse-armor "pgg-parse"))
+(autoload 'pgg-decrypt-region "pgg")
+(autoload 'pgg-verify-region "pgg")
+(autoload 'pgg-sign-region "pgg")
+(autoload 'pgg-encrypt-region "pgg")
+(autoload 'pgg-parse-armor "pgg-parse")
 
 (defun mml2015-pgg-decrypt (handle ctl)
   (catch 'error
@@ -738,9 +603,8 @@ Valid packages include `pgg', `gpg' and `mailcrypt'.")
          handle)
       (with-temp-buffer
        (insert part)
-       ;; Convert <LF> to <CR><LF> in verify mode.  Sign and
-       ;; clearsign use --textmode. The conversion is not necessary.
-       ;; In clearverify, the conversion is not necessary either.
+       ;; Convert <LF> to <CR><LF> in signed text.  If --textmode is
+       ;; specified when signing, the conversion is not necessary.
        (goto-char (point-min))
        (end-of-line)
        (while (not (eobp))
@@ -789,7 +653,7 @@ Valid packages include `pgg', `gpg' and `mailcrypt'.")
     (if (condition-case err
            (prog1
                (mm-with-unibyte-buffer
-                 (insert (encode-coding-string text coding-system))
+                 (insert (mm-encode-coding-string text coding-system))
                  (pgg-verify-region (point-min) (point-max) nil t))
              (goto-char (point-min))
              (while (search-forward "\r\n" nil t)
@@ -813,7 +677,8 @@ Valid packages include `pgg', `gpg' and `mailcrypt'.")
         (with-current-buffer pgg-errors-buffer
           (mml2015-gpg-extract-signature-details)))
       (mm-set-handle-multipart-parameter
-       mm-security-handle 'gnus-info "Failed"))))
+       mm-security-handle 'gnus-info "Failed")))
+  (mml2015-extract-cleartext-signature))
 
 (defun mml2015-pgg-sign (cont)
   (let ((pgg-errors-buffer mml2015-result-buffer)
@@ -875,8 +740,515 @@ Valid packages include `pgg', `gpg' and `mailcrypt'.")
     (insert (format "--%s--\n" boundary))
     (goto-char (point-max))))
 
+;;; epg wrapper
+
+(defvar epg-user-id-alist)
+(defvar epg-digest-algorithm-alist)
+(defvar epg-gpg-program)
+(defvar inhibit-redisplay)
+
+(autoload 'epg-make-context "epg")
+(autoload 'epg-context-set-armor "epg")
+(autoload 'epg-context-set-textmode "epg")
+(autoload 'epg-context-set-signers "epg")
+(autoload 'epg-context-result-for "epg")
+(autoload 'epg-new-signature-digest-algorithm "epg")
+(autoload 'epg-list-keys "epg")
+(autoload 'epg-decrypt-string "epg")
+(autoload 'epg-verify-string "epg")
+(autoload 'epg-sign-string "epg")
+(autoload 'epg-encrypt-string "epg")
+(autoload 'epg-passphrase-callback-function "epg")
+(autoload 'epg-context-set-passphrase-callback "epg")
+(autoload 'epg-key-sub-key-list "epg")
+(autoload 'epg-sub-key-capability "epg")
+(autoload 'epg-sub-key-validity "epg")
+(autoload 'epg-sub-key-fingerprint "epg")
+(autoload 'epg-signature-key-id "epg")
+(autoload 'epg-signature-to-string "epg")
+(autoload 'epg-key-user-id-list "epg")
+(autoload 'epg-user-id-string "epg")
+(autoload 'epg-user-id-validity "epg")
+(autoload 'epg-configuration "epg-config")
+(autoload 'epg-expand-group "epg-config")
+(autoload 'epa-select-keys "epa")
+
+(defvar mml2015-epg-secret-key-id-list nil)
+
+(defun mml2015-epg-passphrase-callback (context key-id ignore)
+  (if (eq key-id 'SYM)
+      (epg-passphrase-callback-function context key-id nil)
+    (let* ((password-cache-key-id
+           (if (eq key-id 'PIN)
+               "PIN"
+              key-id))
+          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)))
+            password-cache-key-id)))
+      (when passphrase
+       (let ((password-cache-expiry mml2015-passphrase-cache-expiry))
+         (password-cache-add password-cache-key-id passphrase))
+       (setq mml2015-epg-secret-key-id-list
+             (cons password-cache-key-id mml2015-epg-secret-key-id-list))
+       (copy-sequence passphrase)))))
+
+(defun mml2015-epg-check-user-id (key recipient)
+  (let ((pointer (epg-key-user-id-list key))
+       result)
+    (while pointer
+      (if (and (equal (car (mail-header-parse-address
+                           (epg-user-id-string (car pointer))))
+                     (car (mail-header-parse-address
+                           recipient)))
+              (not (memq (epg-user-id-validity (car pointer))
+                         '(revoked expired))))
+         (setq result t
+               pointer nil)
+       (setq pointer (cdr pointer))))
+    result))
+
+(defun mml2015-epg-check-sub-key (key usage)
+  (let ((pointer (epg-key-sub-key-list key))
+       result)
+    ;; The primary key will be marked as disabled, when the entire
+    ;; key is disabled (see 12 Field, Format of colon listings, in
+    ;; gnupg/doc/DETAILS)
+    (unless (memq 'disabled (epg-sub-key-capability (car pointer)))
+      (while pointer
+       (if (and (memq usage (epg-sub-key-capability (car pointer)))
+                (not (memq (epg-sub-key-validity (car pointer))
+                           '(revoked expired))))
+           (setq result t
+                 pointer nil)
+         (setq pointer (cdr pointer)))))
+    result))
+
+(defun mml2015-epg-find-usable-key (context name usage
+                                           &optional name-is-key-id)
+  (let ((keys (epg-list-keys context name))
+       key)
+    (while keys
+      (if (and (or name-is-key-id
+                  ;; Non email user-id can be supplied through
+                  ;; mml2015-signers if mml2015-encrypt-to-self is set.
+                  ;; Treat it as valid, as it is user's intention.
+                  (not (string-match "\\`<" name))
+                  (mml2015-epg-check-user-id (car keys) name))
+              (mml2015-epg-check-sub-key (car keys) usage))
+         (setq key (car keys)
+               keys nil)
+       (setq keys (cdr keys))))
+    key))
+
+;; XXX: since gpg --list-secret-keys does not return validity of each
+;; key, `mml2015-epg-find-usable-key' defined above is not enough for
+;; secret keys.  The function `mml2015-epg-find-usable-secret-key'
+;; below looks at appropriate public keys to check usability.
+(defun mml2015-epg-find-usable-secret-key (context name usage)
+  (let ((secret-keys (epg-list-keys context name t))
+       secret-key)
+    (while (and (not secret-key) secret-keys)
+      (if (mml2015-epg-find-usable-key
+          context
+          (epg-sub-key-fingerprint
+           (car (epg-key-sub-key-list
+                 (car secret-keys))))
+          usage
+          t)
+         (setq secret-key (car secret-keys)
+               secret-keys nil)
+       (setq secret-keys (cdr secret-keys))))
+    secret-key))
+
+(defun mml2015-epg-key-image (key-id)
+  "Return the image of a key, if any"
+  (with-temp-buffer
+    (mm-set-buffer-multibyte nil)
+    (let* ((coding-system-for-write 'binary)
+           (coding-system-for-read 'binary)
+           (data (shell-command-to-string
+                  (format "%s --list-options no-show-photos --attribute-fd 3 --list-keys %s 3>&1 >/dev/null 2>&1"
+                          (shell-quote-argument epg-gpg-program) key-id))))
+      (when (> (length data) 0)
+        (insert (substring data 16))
+       (condition-case nil
+           (gnus-create-image (buffer-string) nil t)
+         (error))))))
+
+(autoload 'gnus-rescale-image "gnus-util")
+
+(defun mml2015-epg-key-image-to-string (key-id)
+  "Return a string with the image of a key, if any"
+  (let* ((result "")
+         (key-image (mml2015-epg-key-image key-id)))
+    (when key-image
+      (setq result "  ")
+      (put-text-property
+       1 2 'display
+       (gnus-rescale-image key-image
+                          (cons mml2015-maximum-key-image-dimension
+                                mml2015-maximum-key-image-dimension))
+       result))
+    result))
+
+(defun mml2015-epg-signature-to-string (signature)
+  (concat (epg-signature-to-string signature)
+         (mml2015-epg-key-image-to-string (epg-signature-key-id signature))))
+
+(defun mml2015-epg-verify-result-to-string (verify-result)
+  (mapconcat #'mml2015-epg-signature-to-string verify-result "\n"))
+
+(defun mml2015-epg-decrypt (handle ctl)
+  (catch 'error
+    (let ((inhibit-redisplay t)
+         context plain child handles result decrypt-status)
+      (unless (setq child (mm-find-part-by-type
+                          (cdr handle)
+                          "application/octet-stream" nil t))
+       (mm-set-handle-multipart-parameter
+        mm-security-handle 'gnus-info "Corrupted")
+       (throw 'error handle))
+      (setq context (epg-make-context))
+      (if mml2015-cache-passphrase
+         (epg-context-set-passphrase-callback
+          context
+          #'mml2015-epg-passphrase-callback))
+      (condition-case error
+         (setq plain (epg-decrypt-string context (mm-get-part child))
+               mml2015-epg-secret-key-id-list nil)
+       (error
+        (while mml2015-epg-secret-key-id-list
+          (password-cache-remove (car mml2015-epg-secret-key-id-list))
+          (setq mml2015-epg-secret-key-id-list
+                (cdr mml2015-epg-secret-key-id-list)))
+        (mm-set-handle-multipart-parameter
+         mm-security-handle 'gnus-info "Failed")
+        (if (eq (car error) 'quit)
+            (mm-set-handle-multipart-parameter
+             mm-security-handle 'gnus-details "Quit.")
+          (mm-set-handle-multipart-parameter
+           mm-security-handle 'gnus-details (mml2015-format-error error)))
+        (throw 'error handle)))
+      (with-temp-buffer
+       (insert plain)
+       (goto-char (point-min))
+       (while (search-forward "\r\n" nil t)
+         (replace-match "\n" t t))
+       (setq handles (mm-dissect-buffer t))
+       (mm-destroy-parts handle)
+       (if (epg-context-result-for context 'verify)
+           (mm-set-handle-multipart-parameter
+            mm-security-handle 'gnus-info
+            (concat "OK\n"
+                    (mml2015-epg-verify-result-to-string
+                     (epg-context-result-for context 'verify))))
+         (mm-set-handle-multipart-parameter
+          mm-security-handle 'gnus-info "OK"))
+       (if (stringp (car handles))
+           (mm-set-handle-multipart-parameter
+            mm-security-handle 'gnus-details
+            (mm-handle-multipart-ctl-parameter handles 'gnus-details))))
+       (if (listp (car handles))
+           handles
+         (list handles)))))
+
+(defun mml2015-epg-clear-decrypt ()
+  (let ((inhibit-redisplay t)
+       (context (epg-make-context))
+       plain)
+    (if mml2015-cache-passphrase
+       (epg-context-set-passphrase-callback
+        context
+        #'mml2015-epg-passphrase-callback))
+    (condition-case error
+       (setq plain (epg-decrypt-string context (buffer-string))
+             mml2015-epg-secret-key-id-list nil)
+      (error
+       (while mml2015-epg-secret-key-id-list
+        (password-cache-remove (car mml2015-epg-secret-key-id-list))
+        (setq mml2015-epg-secret-key-id-list
+              (cdr mml2015-epg-secret-key-id-list)))
+       (mm-set-handle-multipart-parameter
+       mm-security-handle 'gnus-info "Failed")
+       (if (eq (car error) 'quit)
+          (mm-set-handle-multipart-parameter
+           mm-security-handle 'gnus-details "Quit.")
+        (mm-set-handle-multipart-parameter
+         mm-security-handle 'gnus-details (mml2015-format-error error)))))
+    (when plain
+      (erase-buffer)
+      ;; Treat data which epg returns as a unibyte string.
+      (mm-disable-multibyte)
+      (insert plain)
+      (goto-char (point-min))
+      (while (search-forward "\r\n" nil t)
+       (replace-match "\n" t t))
+      (mm-set-handle-multipart-parameter
+       mm-security-handle 'gnus-info "OK")
+      (if (epg-context-result-for context 'verify)
+         (mm-set-handle-multipart-parameter
+          mm-security-handle 'gnus-details
+          (mml2015-epg-verify-result-to-string
+           (epg-context-result-for context 'verify)))))))
+
+(defun mml2015-epg-verify (handle ctl)
+  (catch 'error
+    (let ((inhibit-redisplay t)
+         context plain signature-file part signature)
+      (when (or (null (setq part (mm-find-raw-part-by-type
+                                 ctl (or (mm-handle-multipart-ctl-parameter
+                                          ctl 'protocol)
+                                         "application/pgp-signature")
+                                 t)))
+               (null (setq signature (mm-find-part-by-type
+                                      (cdr handle) "application/pgp-signature"
+                                      nil t))))
+       (mm-set-handle-multipart-parameter
+        mm-security-handle 'gnus-info "Corrupted")
+       (throw 'error handle))
+      (setq part (mm-replace-in-string part "\n" "\r\n")
+           signature (mm-get-part signature)
+           context (epg-make-context))
+      (condition-case error
+         (setq plain (epg-verify-string context signature part))
+       (error
+        (mm-set-handle-multipart-parameter
+         mm-security-handle 'gnus-info "Failed")
+        (if (eq (car error) 'quit)
+            (mm-set-handle-multipart-parameter
+             mm-security-handle 'gnus-details "Quit.")
+          (mm-set-handle-multipart-parameter
+           mm-security-handle 'gnus-details (mml2015-format-error error)))
+        (throw 'error handle)))
+      (mm-set-handle-multipart-parameter
+       mm-security-handle 'gnus-info
+       (mml2015-epg-verify-result-to-string
+       (epg-context-result-for context 'verify)))
+      handle)))
+
+(defun mml2015-epg-clear-verify ()
+  (let ((inhibit-redisplay t)
+       (context (epg-make-context))
+       (signature (mm-encode-coding-string (buffer-string)
+                                           coding-system-for-write))
+       plain)
+    (condition-case error
+       (setq plain (epg-verify-string context signature))
+      (error
+       (mm-set-handle-multipart-parameter
+       mm-security-handle 'gnus-info "Failed")
+       (if (eq (car error) 'quit)
+          (mm-set-handle-multipart-parameter
+           mm-security-handle 'gnus-details "Quit.")
+        (mm-set-handle-multipart-parameter
+         mm-security-handle 'gnus-details (mml2015-format-error error)))))
+    (if plain
+       (progn
+         (mm-set-handle-multipart-parameter
+          mm-security-handle 'gnus-info
+          (mml2015-epg-verify-result-to-string
+           (epg-context-result-for context 'verify)))
+         (delete-region (point-min) (point-max))
+         (insert (mm-decode-coding-string plain coding-system-for-read)))
+      (mml2015-extract-cleartext-signature))))
+
+(defun mml2015-epg-sign (cont)
+  (let* ((inhibit-redisplay t)
+        (context (epg-make-context))
+        (boundary (mml-compute-boundary cont))
+        (sender (message-options-get 'message-sender))
+        (signer-names (or mml2015-signers
+                          (if (and mml2015-sign-with-sender sender)
+                              (list (concat "<" sender ">")))))
+        signer-key
+        (signers
+         (or (message-options-get 'mml2015-epg-signers)
+             (message-options-set
+              'mml2015-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.  "
+                                   signer-names
+                                   t)
+                (if (or sender mml2015-signers)
+                    (delq nil
+                          (mapcar
+                           (lambda (signer)
+                             (setq signer-key
+                                   (mml2015-epg-find-usable-secret-key
+                                    context signer '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)
+                           signer-names)))))))
+        signature micalg)
+    (epg-context-set-armor context t)
+    (epg-context-set-textmode context t)
+    (epg-context-set-signers context signers)
+    (if mml2015-cache-passphrase
+       (epg-context-set-passphrase-callback
+        context
+        #'mml2015-epg-passphrase-callback))
+    ;; Signed data must end with a newline (RFC 3156, 5).
+    (goto-char (point-max))
+    (unless (bolp)
+      (insert "\n"))
+    (condition-case error
+       (setq signature (epg-sign-string context (buffer-string) t)
+             mml2015-epg-secret-key-id-list nil)
+      (error
+       (while mml2015-epg-secret-key-id-list
+        (password-cache-remove (car mml2015-epg-secret-key-id-list))
+        (setq mml2015-epg-secret-key-id-list
+              (cdr mml2015-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)))))
+    (goto-char (point-min))
+    (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
+                   boundary))
+    (if micalg
+       (insert (format "\tmicalg=pgp-%s; "
+                       (downcase
+                        (cdr (assq micalg
+                                   epg-digest-algorithm-alist))))))
+    (insert "protocol=\"application/pgp-signature\"\n")
+    (insert (format "\n--%s\n" boundary))
+    (goto-char (point-max))
+    (insert (format "\n--%s\n" boundary))
+    (insert "Content-Type: application/pgp-signature; name=\"signature.asc\"\n\n")
+    (insert signature)
+    (goto-char (point-max))
+    (insert (format "--%s--\n" boundary))
+    (goto-char (point-max))))
+
+(defun mml2015-epg-encrypt (cont &optional sign)
+  (let* ((inhibit-redisplay t)
+        (context (epg-make-context))
+        (boundary (mml-compute-boundary cont))
+        (config (epg-configuration))
+        (recipients (message-options-get 'mml2015-epg-recipients))
+        cipher
+        (sender (message-options-get 'message-sender))
+        (signer-names (or mml2015-signers
+                          (if (and mml2015-sign-with-sender sender)
+                              (list (concat "<" sender ">")))))
+        signers
+        recipient-key signer-key)
+    (unless recipients
+      (setq recipients
+           (apply #'nconc
+                  (mapcar
+                   (lambda (recipient)
+                     (or (epg-expand-group config recipient)
+                         (list (concat "<" recipient ">"))))
+                   (split-string
+                    (or (message-options-get 'message-recipients)
+                        (message-options-set 'message-recipients
+                                             (read-string "Recipients: ")))
+                    "[ \f\t\n\r\v,]+"))))
+      (when mml2015-encrypt-to-self
+       (unless signer-names
+         (error "Neither message sender nor mml2015-signers are set"))
+       (setq recipients (nconc recipients signer-names)))
+      (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
+             (delq nil
+                   (mapcar
+                    (lambda (recipient)
+                      (setq recipient-key (mml2015-epg-find-usable-key
+                                           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 'mml2015-epg-recipients recipients))
+    (when sign
+      (setq signers
+           (or (message-options-get 'mml2015-epg-signers)
+               (message-options-set
+                'mml2015-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.  "
+                                     signer-names
+                                     t)
+                  (if (or sender mml2015-signers)
+                      (delq nil
+                            (mapcar
+                             (lambda (signer)
+                               (setq signer-key
+                                     (mml2015-epg-find-usable-secret-key
+                                      context signer '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)
+                             signer-names)))))))
+      (epg-context-set-signers context signers))
+    (epg-context-set-armor context t)
+    (epg-context-set-textmode context t)
+    (if mml2015-cache-passphrase
+       (epg-context-set-passphrase-callback
+        context
+        #'mml2015-epg-passphrase-callback))
+    (condition-case error
+       (setq cipher
+             (epg-encrypt-string context (buffer-string) recipients sign
+                                 mml2015-always-trust)
+             mml2015-epg-secret-key-id-list nil)
+      (error
+       (while mml2015-epg-secret-key-id-list
+        (password-cache-remove (car mml2015-epg-secret-key-id-list))
+        (setq mml2015-epg-secret-key-id-list
+              (cdr mml2015-epg-secret-key-id-list)))
+       (signal (car error) (cdr error))))
+    (delete-region (point-min) (point-max))
+    (goto-char (point-min))
+    (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
+                   boundary))
+    (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
+    (insert (format "--%s\n" boundary))
+    (insert "Content-Type: application/pgp-encrypted\n\n")
+    (insert "Version: 1\n\n")
+    (insert (format "--%s\n" boundary))
+    (insert "Content-Type: application/octet-stream\n\n")
+    (insert cipher)
+    (goto-char (point-max))
+    (insert (format "--%s--\n" boundary))
+    (goto-char (point-max))))
+
 ;;; General wrapper
 
+(autoload 'gnus-buffer-live-p "gnus-util")
+(autoload 'gnus-get-buffer-create "gnus")
+
 (defun mml2015-clean-buffer ()
   (if (gnus-buffer-live-p mml2015-result-buffer)
       (with-current-buffer mml2015-result-buffer
@@ -938,5 +1310,4 @@ Valid packages include `pgg', `gpg' and `mailcrypt'.")
 
 (provide 'mml2015)
 
-;;; arch-tag: b04701d5-0b09-44d8-bed8-de901bf435f2
 ;;; mml2015.el ends here