lisp/gnus/mml2015.el

   1 ;;; mml2015.el --- MIME Security with Pretty Good Privacy (PGP)
   2
   3 ;; Copyright (C) 2000-2011 Free Software Foundation, Inc.
   4
   5 ;; Author: Shenghuo Zhu <zsh@cs.rochester.edu>
   6 ;; Keywords: PGP MIME MML
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;; RFC 2015 is updated by RFC 3156, this file should be compatible
  26 ;; with both.
  27
  28 ;;; Code:
  29
  30 (eval-and-compile
  31   ;; For Emacs <22.2 and XEmacs.
  32   (unless (fboundp 'declare-function) (defmacro declare-function (&rest r)))
  33
  34   (if (locate-library "password-cache")
  35       (require 'password-cache)
  36     (require 'password)))
  37
  38 (eval-when-compile (require 'cl))
  39 (require 'mm-decode)
  40 (require 'mm-util)
  41 (require 'mml)
  42 (require 'mml-sec)
  43
  44 (defvar mc-pgp-always-sign)
  45
  46 (declare-function epg-check-configuration "ext:epg-config"
  47                   (config &optional minimum-version))
  48 (declare-function epg-configuration "ext:epg-config" ())
  49
  50 (defvar mml2015-use (or
  51                      (condition-case nil
  52                          (progn
  53                            (require 'epg-config)
  54                            (epg-check-configuration (epg-configuration))
  55                            'epg)
  56                        (error))
  57                      (progn
  58                        (ignore-errors (require 'pgg))
  59                        (and (fboundp 'pgg-sign-region)
  60                             'pgg))
  61                      (progn (ignore-errors
  62                               (load "mc-toplev"))
  63                             (and (fboundp 'mc-encrypt-generic)
  64                                  (fboundp 'mc-sign-generic)
  65                                  (fboundp 'mc-cleanup-recipient-headers)
  66                                  'mailcrypt)))
  67   "The package used for PGP/MIME.
  68 Valid packages include `epg', `pgg' and `mailcrypt'.")
  69
  70 ;; Something is not RFC2015.
  71 (defvar mml2015-function-alist
  72   '((mailcrypt mml2015-mailcrypt-sign
  73                mml2015-mailcrypt-encrypt
  74                mml2015-mailcrypt-verify
  75                mml2015-mailcrypt-decrypt
  76                mml2015-mailcrypt-clear-verify
  77                mml2015-mailcrypt-clear-decrypt)
  78     (pgg mml2015-pgg-sign
  79          mml2015-pgg-encrypt
  80          mml2015-pgg-verify
  81          mml2015-pgg-decrypt
  82          mml2015-pgg-clear-verify
  83          mml2015-pgg-clear-decrypt)
  84     (epg mml2015-epg-sign
  85          mml2015-epg-encrypt
  86          mml2015-epg-verify
  87          mml2015-epg-decrypt
  88          mml2015-epg-clear-verify
  89          mml2015-epg-clear-decrypt))
  90   "Alist of PGP/MIME functions.")
  91
  92 (defvar mml2015-result-buffer nil)
  93
  94 (defcustom mml2015-unabbrev-trust-alist
  95   '(("TRUST_UNDEFINED" . nil)
  96     ("TRUST_NEVER"     . nil)
  97     ("TRUST_MARGINAL"  . t)
  98     ("TRUST_FULLY"     . t)
  99     ("TRUST_ULTIMATE"  . t))
 100   "Map GnuPG trust output values to a boolean saying if you trust the key."
 101   :version "22.1"
 102   :group 'mime-security
 103   :type '(repeat (cons (regexp :tag "GnuPG output regexp")
 104                        (boolean :tag "Trust key"))))
 105
 106 (defcustom mml2015-cache-passphrase mml-secure-cache-passphrase
 107   "If t, cache passphrase."
 108   :group 'mime-security
 109   :type 'boolean)
 110
 111 (defcustom mml2015-passphrase-cache-expiry mml-secure-passphrase-cache-expiry
 112   "How many seconds the passphrase is cached.
 113 Whether the passphrase is cached at all is controlled by
 114 `mml2015-cache-passphrase'."
 115   :group 'mime-security
 116   :type 'integer)
 117
 118 (defcustom mml2015-signers nil
 119   "A list of your own key ID which will be used to sign a message."
 120   :group 'mime-security
 121   :type '(repeat (string :tag "Key ID")))
 122
 123 (defcustom mml2015-encrypt-to-self nil
 124   "If t, add your own key ID to recipient list when encryption."
 125   :group 'mime-security
 126   :type 'boolean)
 127
 128 (defcustom mml2015-always-trust t
 129   "If t, GnuPG skip key validation on encryption."
 130   :group 'mime-security
 131   :type 'boolean)
 132
 133 ;; Extract plaintext from cleartext signature.  IMO, this kind of task
 134 ;; should be done by GnuPG rather than Elisp, but older PGP backends
 135 ;; (such as Mailcrypt, and PGG) discard the output from GnuPG.
 136 (defun mml2015-extract-cleartext-signature ()
 137   ;; Daiki Ueno in
 138   ;; <54a15d860801080142l70b95d7dkac4bf51a86196011@mail.gmail.com>: ``I still
 139   ;; believe that the right way is to use the plaintext output from GnuPG as
 140   ;; it is, and mml2015-extract-cleartext-signature is just a kludge for
 141   ;; misdesigned libraries like PGG, which have no ability to do that.  So, I
 142   ;; think it should not have descriptive documentation.''
 143   ;;
 144   ;; This function doesn't handle NotDashEscaped correctly.  EasyPG handles it
 145   ;; correctly.
 146   ;; http://thread.gmane.org/gmane.emacs.gnus.general/66062/focus=66082
 147   ;; http://thread.gmane.org/gmane.emacs.gnus.general/65087/focus=65109
 148   (goto-char (point-min))
 149   (forward-line)
 150   ;; We need to be careful not to strip beyond the armor headers.
 151   ;; Previously, an attacker could replace the text inside our
 152   ;; markup with trailing garbage by injecting whitespace into the
 153   ;; message.
 154   (while (looking-at "Hash:")           ; The only header allowed in cleartext
 155     (forward-line))                     ; signatures according to RFC2440.
 156   (when (looking-at "[\t ]*$")
 157     (forward-line))
 158   (delete-region (point-min) (point))
 159   (if (re-search-forward "^-----BEGIN PGP SIGNATURE-----" nil t)
 160       (delete-region (match-beginning 0) (point-max)))
 161   (goto-char (point-min))
 162   (while (re-search-forward "^- " nil t)
 163     (replace-match "" t t)
 164     (forward-line 1)))
 165
 166 ;;; mailcrypt wrapper
 167
 168 (autoload 'mailcrypt-decrypt "mailcrypt")
 169 (autoload 'mailcrypt-verify "mailcrypt")
 170 (autoload 'mc-pgp-always-sign "mailcrypt")
 171 (autoload 'mc-encrypt-generic "mc-toplev")
 172 (autoload 'mc-cleanup-recipient-headers "mc-toplev")
 173 (autoload 'mc-sign-generic "mc-toplev")
 174
 175 (defvar mml2015-decrypt-function 'mailcrypt-decrypt)
 176 (defvar mml2015-verify-function 'mailcrypt-verify)
 177
 178 (defun mml2015-format-error (err)
 179   (if (stringp (cadr err))
 180       (cadr err)
 181     (format "%S" (cdr err))))
 182
 183 (defun mml2015-mailcrypt-decrypt (handle ctl)
 184   (catch 'error
 185     (let (child handles result)
 186       (unless (setq child (mm-find-part-by-type
 187                            (cdr handle)
 188                            "application/octet-stream" nil t))
 189         (mm-set-handle-multipart-parameter
 190          mm-security-handle 'gnus-info "Corrupted")
 191         (throw 'error handle))
 192       (with-temp-buffer
 193         (mm-insert-part child)
 194         (setq result
 195               (condition-case err
 196                   (funcall mml2015-decrypt-function)
 197                 (error
 198                  (mm-set-handle-multipart-parameter
 199                   mm-security-handle 'gnus-details (mml2015-format-error err))
 200                  nil)
 201                 (quit
 202                  (mm-set-handle-multipart-parameter
 203                   mm-security-handle 'gnus-details "Quit.")
 204                  nil)))
 205         (unless (car result)
 206           (mm-set-handle-multipart-parameter
 207            mm-security-handle 'gnus-info "Failed")
 208           (throw 'error handle))
 209         (setq handles (mm-dissect-buffer t)))
 210       (mm-destroy-parts handle)
 211       (mm-set-handle-multipart-parameter
 212        mm-security-handle 'gnus-info
 213        (concat "OK"
 214                (let ((sig (with-current-buffer mml2015-result-buffer
 215                             (mml2015-gpg-extract-signature-details))))
 216                  (concat ", Signer: " sig))))
 217       (if (listp (car handles))
 218           handles
 219         (list handles)))))
 220
 221 (defun mml2015-gpg-pretty-print-fpr (fingerprint)
 222   (let* ((result "")
 223          (fpr-length (string-width fingerprint))
 224          (n-slice 0)
 225          slice)
 226     (setq fingerprint (string-to-list fingerprint))
 227     (while fingerprint
 228       (setq fpr-length (- fpr-length 4))
 229       (setq slice (butlast fingerprint fpr-length))
 230       (setq fingerprint (nthcdr 4 fingerprint))
 231       (setq n-slice (1+ n-slice))
 232       (setq result
 233             (concat
 234              result
 235              (case n-slice
 236                (1  slice)
 237                (otherwise (concat " " slice))))))
 238     result))
 239
 240 (defun mml2015-gpg-extract-signature-details ()
 241   (goto-char (point-min))
 242   (let* ((expired (re-search-forward
 243                    "^\\[GNUPG:\\] SIGEXPIRED$"
 244                    nil t))
 245          (signer (and (re-search-forward
 246                        "^\\[GNUPG:\\] GOODSIG \\([0-9A-Za-z]*\\) \\(.*\\)$"
 247                        nil t)
 248                       (cons (match-string 1) (match-string 2))))
 249          (fprint (and (re-search-forward
 250                        "^\\[GNUPG:\\] VALIDSIG \\([0-9a-zA-Z]*\\) "
 251                        nil t)
 252                       (match-string 1)))
 253          (trust  (and (re-search-forward
 254                        "^\\[GNUPG:\\] \\(TRUST_.*\\)$"
 255                        nil t)
 256                       (match-string 1)))
 257          (trust-good-enough-p
 258           (cdr (assoc trust mml2015-unabbrev-trust-alist))))
 259     (cond ((and signer fprint)
 260            (concat (cdr signer)
 261                    (unless trust-good-enough-p
 262                      (concat "\nUntrusted, Fingerprint: "
 263                              (mml2015-gpg-pretty-print-fpr fprint)))
 264                    (when expired
 265                      (format "\nWARNING: Signature from expired key (%s)"
 266                              (car signer)))))
 267           ((re-search-forward
 268             "^\\(gpg: \\)?Good signature from \"\\(.*\\)\"$" nil t)
 269            (match-string 2))
 270           (t
 271            "From unknown user"))))
 272
 273 (defun mml2015-mailcrypt-clear-decrypt ()
 274   (let (result)
 275     (setq result
 276           (condition-case err
 277               (funcall mml2015-decrypt-function)
 278             (error
 279              (mm-set-handle-multipart-parameter
 280               mm-security-handle 'gnus-details (mml2015-format-error err))
 281              nil)
 282             (quit
 283              (mm-set-handle-multipart-parameter
 284               mm-security-handle 'gnus-details "Quit.")
 285              nil)))
 286     (if (car result)
 287         (mm-set-handle-multipart-parameter
 288          mm-security-handle 'gnus-info "OK")
 289       (mm-set-handle-multipart-parameter
 290        mm-security-handle 'gnus-info "Failed"))))
 291
 292 (defun mml2015-fix-micalg (alg)
 293   (and alg
 294        ;; Mutt/1.2.5i has seen sending micalg=php-sha1
 295        (upcase (if (string-match "^p[gh]p-" alg)
 296                    (substring alg (match-end 0))
 297                  alg))))
 298
 299 (defun mml2015-mailcrypt-verify (handle ctl)
 300   (catch 'error
 301     (let (part)
 302       (unless (setq part (mm-find-raw-part-by-type
 303                           ctl (or (mm-handle-multipart-ctl-parameter
 304                                    ctl 'protocol)
 305                                   "application/pgp-signature")
 306                           t))
 307         (mm-set-handle-multipart-parameter
 308          mm-security-handle 'gnus-info "Corrupted")
 309         (throw 'error handle))
 310       (with-temp-buffer
 311         (insert "-----BEGIN PGP SIGNED MESSAGE-----\n")
 312         (insert (format "Hash: %s\n\n"
 313                         (or (mml2015-fix-micalg
 314                              (mm-handle-multipart-ctl-parameter
 315                               ctl 'micalg))
 316                             "SHA1")))
 317         (save-restriction
 318           (narrow-to-region (point) (point))
 319           (insert part "\n")
 320           (goto-char (point-min))
 321           (while (not (eobp))
 322             (if (looking-at "^-")
 323                 (insert "- "))
 324             (forward-line)))
 325         (unless (setq part (mm-find-part-by-type
 326                             (cdr handle) "application/pgp-signature" nil t))
 327           (mm-set-handle-multipart-parameter
 328            mm-security-handle 'gnus-info "Corrupted")
 329           (throw 'error handle))
 330         (save-restriction
 331           (narrow-to-region (point) (point))
 332           (mm-insert-part part)
 333           (goto-char (point-min))
 334           (if (re-search-forward "^-----BEGIN PGP [^-]+-----\r?$" nil t)
 335               (replace-match "-----BEGIN PGP SIGNATURE-----" t t))
 336           (if (re-search-forward "^-----END PGP [^-]+-----\r?$" nil t)
 337               (replace-match "-----END PGP SIGNATURE-----" t t)))
 338         (let ((mc-gpg-debug-buffer (get-buffer-create " *gnus gpg debug*")))
 339           (unless (condition-case err
 340                       (prog1
 341                           (funcall mml2015-verify-function)
 342                         (if (get-buffer " *mailcrypt stderr temp")
 343                             (mm-set-handle-multipart-parameter
 344                              mm-security-handle 'gnus-details
 345                              (with-current-buffer " *mailcrypt stderr temp"
 346                                (buffer-string))))
 347                         (if (get-buffer " *mailcrypt stdout temp")
 348                             (kill-buffer " *mailcrypt stdout temp"))
 349                         (if (get-buffer " *mailcrypt stderr temp")
 350                             (kill-buffer " *mailcrypt stderr temp"))
 351                         (if (get-buffer " *mailcrypt status temp")
 352                             (kill-buffer " *mailcrypt status temp"))
 353                         (if (get-buffer mc-gpg-debug-buffer)
 354                             (kill-buffer mc-gpg-debug-buffer)))
 355                     (error
 356                      (mm-set-handle-multipart-parameter
 357                       mm-security-handle 'gnus-details (mml2015-format-error err))
 358                      nil)
 359                     (quit
 360                      (mm-set-handle-multipart-parameter
 361                       mm-security-handle 'gnus-details "Quit.")
 362                      nil))
 363             (mm-set-handle-multipart-parameter
 364              mm-security-handle 'gnus-info "Failed")
 365             (throw 'error handle))))
 366       (mm-set-handle-multipart-parameter
 367        mm-security-handle 'gnus-info "OK")
 368       handle)))
 369
 370 (defun mml2015-mailcrypt-clear-verify ()
 371   (let ((mc-gpg-debug-buffer (get-buffer-create " *gnus gpg debug*")))
 372     (if (condition-case err
 373             (prog1
 374                 (funcall mml2015-verify-function)
 375               (if (get-buffer " *mailcrypt stderr temp")
 376                   (mm-set-handle-multipart-parameter
 377                    mm-security-handle 'gnus-details
 378                    (with-current-buffer " *mailcrypt stderr temp"
 379                      (buffer-string))))
 380               (if (get-buffer " *mailcrypt stdout temp")
 381                   (kill-buffer " *mailcrypt stdout temp"))
 382               (if (get-buffer " *mailcrypt stderr temp")
 383                   (kill-buffer " *mailcrypt stderr temp"))
 384               (if (get-buffer " *mailcrypt status temp")
 385                   (kill-buffer " *mailcrypt status temp"))
 386               (if (get-buffer mc-gpg-debug-buffer)
 387                   (kill-buffer mc-gpg-debug-buffer)))
 388           (error
 389            (mm-set-handle-multipart-parameter
 390             mm-security-handle 'gnus-details (mml2015-format-error err))
 391            nil)
 392           (quit
 393            (mm-set-handle-multipart-parameter
 394             mm-security-handle 'gnus-details "Quit.")
 395            nil))
 396         (mm-set-handle-multipart-parameter
 397          mm-security-handle 'gnus-info "OK")
 398       (mm-set-handle-multipart-parameter
 399        mm-security-handle 'gnus-info "Failed")))
 400   (mml2015-extract-cleartext-signature))
 401
 402 (defun mml2015-mailcrypt-sign (cont)
 403   (mc-sign-generic (message-options-get 'message-sender)
 404                    nil nil nil nil)
 405   (let ((boundary (mml-compute-boundary cont))
 406         hash point)
 407     (goto-char (point-min))
 408     (unless (re-search-forward "^-----BEGIN PGP SIGNED MESSAGE-----\r?$" nil t)
 409       (error "Cannot find signed begin line"))
 410     (goto-char (match-beginning 0))
 411     (forward-line 1)
 412     (unless (looking-at "Hash:[ \t]*\\([a-zA-Z0-9]+\\)")
 413       (error "Cannot not find PGP hash"))
 414     (setq hash (match-string 1))
 415     (unless (re-search-forward "^$" nil t)
 416       (error "Cannot not find PGP message"))
 417     (forward-line 1)
 418     (delete-region (point-min) (point))
 419     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
 420                     boundary))
 421     (insert (format "\tmicalg=pgp-%s; protocol=\"application/pgp-signature\"\n"
 422                     (downcase hash)))
 423     (insert (format "\n--%s\n" boundary))
 424     (setq point (point))
 425     (goto-char (point-max))
 426     (unless (re-search-backward "^-----END PGP SIGNATURE-----\r?$" nil t)
 427       (error "Cannot find signature part"))
 428     (replace-match "-----END PGP MESSAGE-----" t t)
 429     (goto-char (match-beginning 0))
 430     (unless (re-search-backward "^-----BEGIN PGP SIGNATURE-----\r?$"
 431                                 nil t)
 432       (error "Cannot find signature part"))
 433     (replace-match "-----BEGIN PGP MESSAGE-----" t t)
 434     (goto-char (match-beginning 0))
 435     (save-restriction
 436       (narrow-to-region point (point))
 437       (goto-char point)
 438       (while (re-search-forward "^- -" nil t)
 439         (replace-match "-" t t))
 440       (goto-char (point-max)))
 441     (insert (format "--%s\n" boundary))
 442     (insert "Content-Type: application/pgp-signature\n\n")
 443     (goto-char (point-max))
 444     (insert (format "--%s--\n" boundary))
 445     (goto-char (point-max))))
 446
 447 ;; We require mm-decode, which requires mm-bodies, which autoloads
 448 ;; message-options-get (!).
 449 (declare-function message-options-set "message" (symbol value))
 450
 451 (defun mml2015-mailcrypt-encrypt (cont &optional sign)
 452   (let ((mc-pgp-always-sign
 453          (or mc-pgp-always-sign
 454              sign
 455              (eq t (or (message-options-get 'message-sign-encrypt)
 456                        (message-options-set
 457                         'message-sign-encrypt
 458                         (or (y-or-n-p "Sign the message? ")
 459                             'not))))
 460              'never)))
 461     (mm-with-unibyte-current-buffer
 462       (mc-encrypt-generic
 463        (or (message-options-get 'message-recipients)
 464            (message-options-set 'message-recipients
 465                               (mc-cleanup-recipient-headers
 466                                (read-string "Recipients: "))))
 467        nil nil nil
 468        (message-options-get 'message-sender))))
 469   (goto-char (point-min))
 470   (unless (looking-at "-----BEGIN PGP MESSAGE-----")
 471     (error "Fail to encrypt the message"))
 472   (let ((boundary (mml-compute-boundary cont)))
 473     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
 474                     boundary))
 475     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
 476     (insert (format "--%s\n" boundary))
 477     (insert "Content-Type: application/pgp-encrypted\n\n")
 478     (insert "Version: 1\n\n")
 479     (insert (format "--%s\n" boundary))
 480     (insert "Content-Type: application/octet-stream\n\n")
 481     (goto-char (point-max))
 482     (insert (format "--%s--\n" boundary))
 483     (goto-char (point-max))))
 484
 485 ;;; pgg wrapper
 486
 487 (defvar pgg-default-user-id)
 488 (defvar pgg-errors-buffer)
 489 (defvar pgg-output-buffer)
 490
 491 (autoload 'pgg-decrypt-region "pgg")
 492 (autoload 'pgg-verify-region "pgg")
 493 (autoload 'pgg-sign-region "pgg")
 494 (autoload 'pgg-encrypt-region "pgg")
 495 (autoload 'pgg-parse-armor "pgg-parse")
 496
 497 (defun mml2015-pgg-decrypt (handle ctl)
 498   (catch 'error
 499     (let ((pgg-errors-buffer mml2015-result-buffer)
 500           child handles result decrypt-status)
 501       (unless (setq child (mm-find-part-by-type
 502                            (cdr handle)
 503                            "application/octet-stream" nil t))
 504         (mm-set-handle-multipart-parameter
 505          mm-security-handle 'gnus-info "Corrupted")
 506         (throw 'error handle))
 507       (with-temp-buffer
 508         (mm-insert-part child)
 509         (if (condition-case err
 510                 (prog1
 511                     (pgg-decrypt-region (point-min) (point-max))
 512                   (setq decrypt-status
 513                         (with-current-buffer mml2015-result-buffer
 514                           (buffer-string)))
 515                   (mm-set-handle-multipart-parameter
 516                    mm-security-handle 'gnus-details
 517                    decrypt-status))
 518               (error
 519                (mm-set-handle-multipart-parameter
 520                 mm-security-handle 'gnus-details (mml2015-format-error err))
 521                nil)
 522               (quit
 523                (mm-set-handle-multipart-parameter
 524                 mm-security-handle 'gnus-details "Quit.")
 525                nil))
 526             (with-current-buffer pgg-output-buffer
 527               (goto-char (point-min))
 528               (while (search-forward "\r\n" nil t)
 529                 (replace-match "\n" t t))
 530               (setq handles (mm-dissect-buffer t))
 531               (mm-destroy-parts handle)
 532               (mm-set-handle-multipart-parameter
 533                mm-security-handle 'gnus-info "OK")
 534               (mm-set-handle-multipart-parameter
 535                mm-security-handle 'gnus-details
 536                (concat decrypt-status
 537                        (when (stringp (car handles))
 538                          "\n" (mm-handle-multipart-ctl-parameter
 539                                handles 'gnus-details))))
 540               (if (listp (car handles))
 541                   handles
 542                 (list handles)))
 543           (mm-set-handle-multipart-parameter
 544            mm-security-handle 'gnus-info "Failed")
 545           (throw 'error handle))))))
 546
 547 (defun mml2015-pgg-clear-decrypt ()
 548   (let ((pgg-errors-buffer mml2015-result-buffer))
 549     (if (prog1
 550             (pgg-decrypt-region (point-min) (point-max))
 551           (mm-set-handle-multipart-parameter
 552            mm-security-handle 'gnus-details
 553            (with-current-buffer mml2015-result-buffer
 554              (buffer-string))))
 555         (progn
 556           (erase-buffer)
 557           ;; Treat data which pgg returns as a unibyte string.
 558           (mm-disable-multibyte)
 559           (insert-buffer-substring pgg-output-buffer)
 560           (goto-char (point-min))
 561           (while (search-forward "\r\n" nil t)
 562             (replace-match "\n" t t))
 563           (mm-set-handle-multipart-parameter
 564            mm-security-handle 'gnus-info "OK"))
 565       (mm-set-handle-multipart-parameter
 566        mm-security-handle 'gnus-info "Failed"))))
 567
 568 (defun mml2015-pgg-verify (handle ctl)
 569   (let ((pgg-errors-buffer mml2015-result-buffer)
 570         signature-file part signature)
 571     (if (or (null (setq part (mm-find-raw-part-by-type
 572                               ctl (or (mm-handle-multipart-ctl-parameter
 573                                        ctl 'protocol)
 574                                       "application/pgp-signature")
 575                               t)))
 576             (null (setq signature (mm-find-part-by-type
 577                                    (cdr handle) "application/pgp-signature" nil t))))
 578         (progn
 579           (mm-set-handle-multipart-parameter
 580            mm-security-handle 'gnus-info "Corrupted")
 581           handle)
 582       (with-temp-buffer
 583         (insert part)
 584         ;; Convert <LF> to <CR><LF> in signed text.  If --textmode is
 585         ;; specified when signing, the conversion is not necessary.
 586         (goto-char (point-min))
 587         (end-of-line)
 588         (while (not (eobp))
 589           (unless (eq (char-before) ?\r)
 590             (insert "\r"))
 591           (forward-line)
 592           (end-of-line))
 593         (with-temp-file (setq signature-file (mm-make-temp-file "pgg"))
 594           (mm-insert-part signature))
 595         (if (condition-case err
 596                 (prog1
 597                     (pgg-verify-region (point-min) (point-max)
 598                                        signature-file t)
 599                   (goto-char (point-min))
 600                   (while (search-forward "\r\n" nil t)
 601                     (replace-match "\n" t t))
 602                   (mm-set-handle-multipart-parameter
 603                    mm-security-handle 'gnus-details
 604                    (concat (with-current-buffer pgg-output-buffer
 605                              (buffer-string))
 606                            (with-current-buffer pgg-errors-buffer
 607                              (buffer-string)))))
 608               (error
 609                (mm-set-handle-multipart-parameter
 610                 mm-security-handle 'gnus-details (mml2015-format-error err))
 611                nil)
 612               (quit
 613                (mm-set-handle-multipart-parameter
 614                 mm-security-handle 'gnus-details "Quit.")
 615                nil))
 616             (progn
 617               (delete-file signature-file)
 618               (mm-set-handle-multipart-parameter
 619                mm-security-handle 'gnus-info
 620                (with-current-buffer pgg-errors-buffer
 621                  (mml2015-gpg-extract-signature-details))))
 622           (delete-file signature-file)
 623           (mm-set-handle-multipart-parameter
 624            mm-security-handle 'gnus-info "Failed")))))
 625   handle)
 626
 627 (defun mml2015-pgg-clear-verify ()
 628   (let ((pgg-errors-buffer mml2015-result-buffer)
 629         (text (buffer-string))
 630         (coding-system buffer-file-coding-system))
 631     (if (condition-case err
 632             (prog1
 633                 (mm-with-unibyte-buffer
 634                   (insert (mm-encode-coding-string text coding-system))
 635                   (pgg-verify-region (point-min) (point-max) nil t))
 636               (goto-char (point-min))
 637               (while (search-forward "\r\n" nil t)
 638                 (replace-match "\n" t t))
 639               (mm-set-handle-multipart-parameter
 640                mm-security-handle 'gnus-details
 641                (concat (with-current-buffer pgg-output-buffer
 642                          (buffer-string))
 643                        (with-current-buffer pgg-errors-buffer
 644                          (buffer-string)))))
 645           (error
 646            (mm-set-handle-multipart-parameter
 647             mm-security-handle 'gnus-details (mml2015-format-error err))
 648            nil)
 649           (quit
 650            (mm-set-handle-multipart-parameter
 651             mm-security-handle 'gnus-details "Quit.")
 652            nil))
 653         (mm-set-handle-multipart-parameter
 654          mm-security-handle 'gnus-info
 655          (with-current-buffer pgg-errors-buffer
 656            (mml2015-gpg-extract-signature-details)))
 657       (mm-set-handle-multipart-parameter
 658        mm-security-handle 'gnus-info "Failed")))
 659   (mml2015-extract-cleartext-signature))
 660
 661 (defun mml2015-pgg-sign (cont)
 662   (let ((pgg-errors-buffer mml2015-result-buffer)
 663         (boundary (mml-compute-boundary cont))
 664         (pgg-default-user-id (or (message-options-get 'mml-sender)
 665                                  pgg-default-user-id))
 666         (pgg-text-mode t)
 667         entry)
 668     (unless (pgg-sign-region (point-min) (point-max))
 669       (pop-to-buffer mml2015-result-buffer)
 670       (error "Sign error"))
 671     (goto-char (point-min))
 672     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
 673                     boundary))
 674     (if (setq entry (assq 2 (pgg-parse-armor
 675                              (with-current-buffer pgg-output-buffer
 676                                (buffer-string)))))
 677         (setq entry (assq 'hash-algorithm (cdr entry))))
 678     (insert (format "\tmicalg=%s; "
 679                     (if (cdr entry)
 680                         (downcase (format "pgp-%s" (cdr entry)))
 681                       "pgp-sha1")))
 682     (insert "protocol=\"application/pgp-signature\"\n")
 683     (insert (format "\n--%s\n" boundary))
 684     (goto-char (point-max))
 685     (insert (format "\n--%s\n" boundary))
 686     (insert "Content-Type: application/pgp-signature\n\n")
 687     (insert-buffer-substring pgg-output-buffer)
 688     (goto-char (point-max))
 689     (insert (format "--%s--\n" boundary))
 690     (goto-char (point-max))))
 691
 692 (defun mml2015-pgg-encrypt (cont &optional sign)
 693   (let ((pgg-errors-buffer mml2015-result-buffer)
 694         (pgg-text-mode t)
 695         (boundary (mml-compute-boundary cont)))
 696     (unless (pgg-encrypt-region (point-min) (point-max)
 697                                 (split-string
 698                                  (or
 699                                   (message-options-get 'message-recipients)
 700                                   (message-options-set 'message-recipients
 701                                                        (read-string "Recipients: ")))
 702                                  "[ \f\t\n\r\v,]+")
 703                                 sign)
 704       (pop-to-buffer mml2015-result-buffer)
 705       (error "Encrypt error"))
 706     (delete-region (point-min) (point-max))
 707     (goto-char (point-min))
 708     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
 709                     boundary))
 710     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
 711     (insert (format "--%s\n" boundary))
 712     (insert "Content-Type: application/pgp-encrypted\n\n")
 713     (insert "Version: 1\n\n")
 714     (insert (format "--%s\n" boundary))
 715     (insert "Content-Type: application/octet-stream\n\n")
 716     (insert-buffer-substring pgg-output-buffer)
 717     (goto-char (point-max))
 718     (insert (format "--%s--\n" boundary))
 719     (goto-char (point-max))))
 720
 721 ;;; epg wrapper
 722
 723 (defvar epg-user-id-alist)
 724 (defvar epg-digest-algorithm-alist)
 725 (defvar inhibit-redisplay)
 726
 727 (autoload 'epg-make-context "epg")
 728 (autoload 'epg-context-set-armor "epg")
 729 (autoload 'epg-context-set-textmode "epg")
 730 (autoload 'epg-context-set-signers "epg")
 731 (autoload 'epg-context-result-for "epg")
 732 (autoload 'epg-new-signature-digest-algorithm "epg")
 733 (autoload 'epg-verify-result-to-string "epg")
 734 (autoload 'epg-list-keys "epg")
 735 (autoload 'epg-decrypt-string "epg")
 736 (autoload 'epg-verify-string "epg")
 737 (autoload 'epg-sign-string "epg")
 738 (autoload 'epg-encrypt-string "epg")
 739 (autoload 'epg-passphrase-callback-function "epg")
 740 (autoload 'epg-context-set-passphrase-callback "epg")
 741 (autoload 'epg-key-sub-key-list "epg")
 742 (autoload 'epg-sub-key-capability "epg")
 743 (autoload 'epg-sub-key-validity "epg")
 744 (autoload 'epg-sub-key-fingerprint "epg")
 745 (autoload 'epg-configuration "epg-config")
 746 (autoload 'epg-expand-group "epg-config")
 747 (autoload 'epa-select-keys "epa")
 748
 749 (defvar mml2015-epg-secret-key-id-list nil)
 750
 751 (defun mml2015-epg-passphrase-callback (context key-id ignore)
 752   (if (eq key-id 'SYM)
 753       (epg-passphrase-callback-function context key-id nil)
 754     (let* ((password-cache-key-id
 755             (if (eq key-id 'PIN)
 756                 "PIN"
 757                key-id))
 758            entry
 759            (passphrase
 760             (password-read
 761              (if (eq key-id 'PIN)
 762                  "Passphrase for PIN: "
 763                (if (setq entry (assoc key-id epg-user-id-alist))
 764                    (format "Passphrase for %s %s: " key-id (cdr entry))
 765                  (format "Passphrase for %s: " key-id)))
 766              password-cache-key-id)))
 767       (when passphrase
 768         (let ((password-cache-expiry mml2015-passphrase-cache-expiry))
 769           (password-cache-add password-cache-key-id passphrase))
 770         (setq mml2015-epg-secret-key-id-list
 771               (cons password-cache-key-id mml2015-epg-secret-key-id-list))
 772         (copy-sequence passphrase)))))
 773
 774 (defun mml2015-epg-find-usable-key (keys usage)
 775   (catch 'found
 776     (while keys
 777       (let ((pointer (epg-key-sub-key-list (car keys))))
 778         (while pointer
 779           (if (and (memq usage (epg-sub-key-capability (car pointer)))
 780                    (not (memq 'disabled (epg-sub-key-capability (car pointer))))
 781                    (not (memq (epg-sub-key-validity (car pointer))
 782                               '(revoked expired))))
 783               (throw 'found (car keys)))
 784           (setq pointer (cdr pointer))))
 785       (setq keys (cdr keys)))))
 786
 787 ;; XXX: since gpg --list-secret-keys does not return validity of each
 788 ;; key, `mml2015-epg-find-usable-key' defined above is not enough for
 789 ;; secret keys.  The function `mml2015-epg-find-usable-secret-key'
 790 ;; below looks at appropriate public keys to check usability.
 791 (defun mml2015-epg-find-usable-secret-key (context name usage)
 792   (let ((secret-keys (epg-list-keys context name t))
 793         secret-key)
 794     (while (and (not secret-key) secret-keys)
 795       (if (mml2015-epg-find-usable-key
 796            (epg-list-keys context (epg-sub-key-fingerprint
 797                                    (car (epg-key-sub-key-list
 798                                          (car secret-keys)))))
 799            usage)
 800           (setq secret-key (car secret-keys)
 801                 secret-keys nil)
 802         (setq secret-keys (cdr secret-keys))))
 803     secret-key))
 804
 805 (defun mml2015-epg-decrypt (handle ctl)
 806   (catch 'error
 807     (let ((inhibit-redisplay t)
 808           context plain child handles result decrypt-status)
 809       (unless (setq child (mm-find-part-by-type
 810                            (cdr handle)
 811                            "application/octet-stream" nil t))
 812         (mm-set-handle-multipart-parameter
 813          mm-security-handle 'gnus-info "Corrupted")
 814         (throw 'error handle))
 815       (setq context (epg-make-context))
 816       (if mml2015-cache-passphrase
 817           (epg-context-set-passphrase-callback
 818            context
 819            #'mml2015-epg-passphrase-callback))
 820       (condition-case error
 821           (setq plain (epg-decrypt-string context (mm-get-part child))
 822                 mml2015-epg-secret-key-id-list nil)
 823         (error
 824          (while mml2015-epg-secret-key-id-list
 825            (password-cache-remove (car mml2015-epg-secret-key-id-list))
 826            (setq mml2015-epg-secret-key-id-list
 827                  (cdr mml2015-epg-secret-key-id-list)))
 828          (mm-set-handle-multipart-parameter
 829           mm-security-handle 'gnus-info "Failed")
 830          (if (eq (car error) 'quit)
 831              (mm-set-handle-multipart-parameter
 832               mm-security-handle 'gnus-details "Quit.")
 833            (mm-set-handle-multipart-parameter
 834             mm-security-handle 'gnus-details (mml2015-format-error error)))
 835          (throw 'error handle)))
 836       (with-temp-buffer
 837         (insert plain)
 838         (goto-char (point-min))
 839         (while (search-forward "\r\n" nil t)
 840           (replace-match "\n" t t))
 841         (setq handles (mm-dissect-buffer t))
 842         (mm-destroy-parts handle)
 843         (if (epg-context-result-for context 'verify)
 844             (mm-set-handle-multipart-parameter
 845              mm-security-handle 'gnus-info
 846              (concat "OK\n"
 847                      (epg-verify-result-to-string
 848                       (epg-context-result-for context 'verify))))
 849           (mm-set-handle-multipart-parameter
 850            mm-security-handle 'gnus-info "OK"))
 851         (if (stringp (car handles))
 852             (mm-set-handle-multipart-parameter
 853              mm-security-handle 'gnus-details
 854              (mm-handle-multipart-ctl-parameter handles 'gnus-details))))
 855         (if (listp (car handles))
 856             handles
 857           (list handles)))))
 858
 859 (defun mml2015-epg-clear-decrypt ()
 860   (let ((inhibit-redisplay t)
 861         (context (epg-make-context))
 862         plain)
 863     (if mml2015-cache-passphrase
 864         (epg-context-set-passphrase-callback
 865          context
 866          #'mml2015-epg-passphrase-callback))
 867     (condition-case error
 868         (setq plain (epg-decrypt-string context (buffer-string))
 869               mml2015-epg-secret-key-id-list nil)
 870       (error
 871        (while mml2015-epg-secret-key-id-list
 872          (password-cache-remove (car mml2015-epg-secret-key-id-list))
 873          (setq mml2015-epg-secret-key-id-list
 874                (cdr mml2015-epg-secret-key-id-list)))
 875        (mm-set-handle-multipart-parameter
 876         mm-security-handle 'gnus-info "Failed")
 877        (if (eq (car error) 'quit)
 878            (mm-set-handle-multipart-parameter
 879             mm-security-handle 'gnus-details "Quit.")
 880          (mm-set-handle-multipart-parameter
 881           mm-security-handle 'gnus-details (mml2015-format-error error)))))
 882     (when plain
 883       (erase-buffer)
 884       ;; Treat data which epg returns as a unibyte string.
 885       (mm-disable-multibyte)
 886       (insert plain)
 887       (goto-char (point-min))
 888       (while (search-forward "\r\n" nil t)
 889         (replace-match "\n" t t))
 890       (mm-set-handle-multipart-parameter
 891        mm-security-handle 'gnus-info "OK")
 892       (if (epg-context-result-for context 'verify)
 893           (mm-set-handle-multipart-parameter
 894            mm-security-handle 'gnus-details
 895            (epg-verify-result-to-string
 896             (epg-context-result-for context 'verify)))))))
 897
 898 (defun mml2015-epg-verify (handle ctl)
 899   (catch 'error
 900     (let ((inhibit-redisplay t)
 901           context plain signature-file part signature)
 902       (when (or (null (setq part (mm-find-raw-part-by-type
 903                                   ctl (or (mm-handle-multipart-ctl-parameter
 904                                            ctl 'protocol)
 905                                           "application/pgp-signature")
 906                                   t)))
 907                 (null (setq signature (mm-find-part-by-type
 908                                        (cdr handle) "application/pgp-signature"
 909                                        nil t))))
 910         (mm-set-handle-multipart-parameter
 911          mm-security-handle 'gnus-info "Corrupted")
 912         (throw 'error handle))
 913       (setq part (mm-replace-in-string part "\n" "\r\n" t)
 914             signature (mm-get-part signature)
 915             context (epg-make-context))
 916       (condition-case error
 917           (setq plain (epg-verify-string context signature part))
 918         (error
 919          (mm-set-handle-multipart-parameter
 920           mm-security-handle 'gnus-info "Failed")
 921          (if (eq (car error) 'quit)
 922              (mm-set-handle-multipart-parameter
 923               mm-security-handle 'gnus-details "Quit.")
 924            (mm-set-handle-multipart-parameter
 925             mm-security-handle 'gnus-details (mml2015-format-error error)))
 926          (throw 'error handle)))
 927       (mm-set-handle-multipart-parameter
 928        mm-security-handle 'gnus-info
 929        (epg-verify-result-to-string (epg-context-result-for context 'verify)))
 930       handle)))
 931
 932 (defun mml2015-epg-clear-verify ()
 933   (let ((inhibit-redisplay t)
 934         (context (epg-make-context))
 935         (signature (mm-encode-coding-string (buffer-string)
 936                                             coding-system-for-write))
 937         plain)
 938     (condition-case error
 939         (setq plain (epg-verify-string context signature))
 940       (error
 941        (mm-set-handle-multipart-parameter
 942         mm-security-handle 'gnus-info "Failed")
 943        (if (eq (car error) 'quit)
 944            (mm-set-handle-multipart-parameter
 945             mm-security-handle 'gnus-details "Quit.")
 946          (mm-set-handle-multipart-parameter
 947           mm-security-handle 'gnus-details (mml2015-format-error error)))))
 948     (if plain
 949         (progn
 950           (mm-set-handle-multipart-parameter
 951            mm-security-handle 'gnus-info
 952            (epg-verify-result-to-string
 953             (epg-context-result-for context 'verify)))
 954           (delete-region (point-min) (point-max))
 955           (insert (mm-decode-coding-string plain coding-system-for-read)))
 956       (mml2015-extract-cleartext-signature))))
 957
 958 (defun mml2015-epg-sign (cont)
 959   (let* ((inhibit-redisplay t)
 960          (context (epg-make-context))
 961          (boundary (mml-compute-boundary cont))
 962          (sender (message-options-get 'message-sender))
 963          signer-key
 964          (signers
 965           (or (message-options-get 'mml2015-epg-signers)
 966               (message-options-set
 967                'mml2015-epg-signers
 968                (if (eq mm-sign-option 'guided)
 969                    (epa-select-keys context "\
 970 Select keys for signing.
 971 If no one is selected, default secret key is used.  "
 972                                     (if sender
 973                                         (cons (concat "<" sender ">")
 974                                               mml2015-signers)
 975                                       mml2015-signers)
 976                                     t)
 977                  (if (or sender mml2015-signers)
 978                      (delq nil
 979                            (mapcar
 980                             (lambda (signer)
 981                               (setq signer-key
 982                                     (mml2015-epg-find-usable-secret-key
 983                                      context signer 'sign))
 984                               (unless (or signer-key
 985                                           (y-or-n-p
 986                                            (format
 987                                             "No secret key for %s; skip it? "
 988                                             signer)))
 989                                 (error "No secret key for %s" signer))
 990                               signer-key)
 991                             (if sender
 992                                 (cons (concat "<" sender ">")
 993                                       mml2015-signers)
 994                               mml2015-signers))))))))
 995          signature micalg)
 996     (epg-context-set-armor context t)
 997     (epg-context-set-textmode context t)
 998     (epg-context-set-signers context signers)
 999     (if mml2015-cache-passphrase
1000         (epg-context-set-passphrase-callback
1001          context
1002          #'mml2015-epg-passphrase-callback))
1003     (condition-case error
1004         (setq signature (epg-sign-string context (buffer-string) t)
1005               mml2015-epg-secret-key-id-list nil)
1006       (error
1007        (while mml2015-epg-secret-key-id-list
1008          (password-cache-remove (car mml2015-epg-secret-key-id-list))
1009          (setq mml2015-epg-secret-key-id-list
1010                (cdr mml2015-epg-secret-key-id-list)))
1011        (signal (car error) (cdr error))))
1012     (if (epg-context-result-for context 'sign)
1013         (setq micalg (epg-new-signature-digest-algorithm
1014                       (car (epg-context-result-for context 'sign)))))
1015     (goto-char (point-min))
1016     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
1017                     boundary))
1018     (if micalg
1019         (insert (format "\tmicalg=pgp-%s; "
1020                         (downcase
1021                          (cdr (assq micalg
1022                                     epg-digest-algorithm-alist))))))
1023     (insert "protocol=\"application/pgp-signature\"\n")
1024     (insert (format "\n--%s\n" boundary))
1025     (goto-char (point-max))
1026     (insert (format "\n--%s\n" boundary))
1027     (insert "Content-Type: application/pgp-signature\n\n")
1028     (insert signature)
1029     (goto-char (point-max))
1030     (insert (format "--%s--\n" boundary))
1031     (goto-char (point-max))))
1032
1033 (defun mml2015-epg-encrypt (cont &optional sign)
1034   (let ((inhibit-redisplay t)
1035         (context (epg-make-context))
1036         (config (epg-configuration))
1037         (sender (message-options-get 'message-sender))
1038         (recipients (message-options-get 'mml2015-epg-recipients))
1039         cipher signers
1040         (boundary (mml-compute-boundary cont))
1041         recipient-key signer-key)
1042     (unless recipients
1043       (setq recipients
1044             (apply #'nconc
1045                    (mapcar
1046                     (lambda (recipient)
1047                       (or (epg-expand-group config recipient)
1048                           (list (concat "<" recipient ">"))))
1049                     (split-string
1050                      (or (message-options-get 'message-recipients)
1051                          (message-options-set 'message-recipients
1052                                               (read-string "Recipients: ")))
1053                      "[ \f\t\n\r\v,]+"))))
1054       (when mml2015-encrypt-to-self
1055         (unless (or sender mml2015-signers)
1056           (error "Message sender and mml2015-signers not set"))
1057         (setq recipients (nconc recipients (if sender
1058                                                (cons (concat "<" sender ">")
1059                                                      mml2015-signers)
1060                                              mml2015-signers))))
1061       (if (eq mm-encrypt-option 'guided)
1062           (setq recipients
1063                 (epa-select-keys context "\
1064 Select recipients for encryption.
1065 If no one is selected, symmetric encryption will be performed.  "
1066                                  recipients))
1067         (setq recipients
1068               (delq nil
1069                     (mapcar
1070                      (lambda (recipient)
1071                        (setq recipient-key (mml2015-epg-find-usable-key
1072                                             (epg-list-keys context recipient)
1073                                             'encrypt))
1074                        (unless (or recipient-key
1075                                    (y-or-n-p
1076                                     (format "No public key for %s; skip it? "
1077                                             recipient)))
1078                          (error "No public key for %s" recipient))
1079                        recipient-key)
1080                      recipients)))
1081         (unless recipients
1082           (error "No recipient specified")))
1083       (message-options-set 'mml2015-epg-recipients recipients))
1084     (when sign
1085       (setq signers
1086             (or (message-options-get 'mml2015-epg-signers)
1087                 (message-options-set
1088                  'mml2015-epg-signers
1089                  (if (eq mm-sign-option 'guided)
1090                      (epa-select-keys context "\
1091 Select keys for signing.
1092 If no one is selected, default secret key is used.  "
1093                                       (if sender
1094                                           (cons (concat "<" sender ">")
1095                                                 mml2015-signers)
1096                                         mml2015-signers)
1097                                       t)
1098                    (if (or sender mml2015-signers)
1099                        (delq nil
1100                              (mapcar
1101                               (lambda (signer)
1102                                 (setq signer-key
1103                                       (mml2015-epg-find-usable-secret-key
1104                                        context signer 'sign))
1105                                 (unless (or signer-key
1106                                             (y-or-n-p
1107                                              (format
1108                                               "No secret key for %s; skip it? "
1109                                               signer)))
1110                                   (error "No secret key for %s" signer))
1111                                 signer-key)
1112                               (if sender
1113                                   (cons (concat "<" sender ">") mml2015-signers)
1114                                 mml2015-signers))))))))
1115       (epg-context-set-signers context signers))
1116     (epg-context-set-armor context t)
1117     (epg-context-set-textmode context t)
1118     (if mml2015-cache-passphrase
1119         (epg-context-set-passphrase-callback
1120          context
1121          #'mml2015-epg-passphrase-callback))
1122     (condition-case error
1123         (setq cipher
1124               (epg-encrypt-string context (buffer-string) recipients sign
1125                                   mml2015-always-trust)
1126               mml2015-epg-secret-key-id-list nil)
1127       (error
1128        (while mml2015-epg-secret-key-id-list
1129          (password-cache-remove (car mml2015-epg-secret-key-id-list))
1130          (setq mml2015-epg-secret-key-id-list
1131                (cdr mml2015-epg-secret-key-id-list)))
1132        (signal (car error) (cdr error))))
1133     (delete-region (point-min) (point-max))
1134     (goto-char (point-min))
1135     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
1136                     boundary))
1137     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
1138     (insert (format "--%s\n" boundary))
1139     (insert "Content-Type: application/pgp-encrypted\n\n")
1140     (insert "Version: 1\n\n")
1141     (insert (format "--%s\n" boundary))
1142     (insert "Content-Type: application/octet-stream\n\n")
1143     (insert cipher)
1144     (goto-char (point-max))
1145     (insert (format "--%s--\n" boundary))
1146     (goto-char (point-max))))
1147
1148 ;;; General wrapper
1149
1150 (autoload 'gnus-buffer-live-p "gnus-util")
1151 (autoload 'gnus-get-buffer-create "gnus")
1152
1153 (defun mml2015-clean-buffer ()
1154   (if (gnus-buffer-live-p mml2015-result-buffer)
1155       (with-current-buffer mml2015-result-buffer
1156         (erase-buffer)
1157         t)
1158     (setq mml2015-result-buffer
1159           (gnus-get-buffer-create " *MML2015 Result*"))
1160     nil))
1161
1162 (defsubst mml2015-clear-decrypt-function ()
1163   (nth 6 (assq mml2015-use mml2015-function-alist)))
1164
1165 (defsubst mml2015-clear-verify-function ()
1166   (nth 5 (assq mml2015-use mml2015-function-alist)))
1167
1168 ;;;###autoload
1169 (defun mml2015-decrypt (handle ctl)
1170   (mml2015-clean-buffer)
1171   (let ((func (nth 4 (assq mml2015-use mml2015-function-alist))))
1172     (if func
1173         (funcall func handle ctl)
1174       handle)))
1175
1176 ;;;###autoload
1177 (defun mml2015-decrypt-test (handle ctl)
1178   mml2015-use)
1179
1180 ;;;###autoload
1181 (defun mml2015-verify (handle ctl)
1182   (mml2015-clean-buffer)
1183   (let ((func (nth 3 (assq mml2015-use mml2015-function-alist))))
1184     (if func
1185         (funcall func handle ctl)
1186       handle)))
1187
1188 ;;;###autoload
1189 (defun mml2015-verify-test (handle ctl)
1190   mml2015-use)
1191
1192 ;;;###autoload
1193 (defun mml2015-encrypt (cont &optional sign)
1194   (mml2015-clean-buffer)
1195   (let ((func (nth 2 (assq mml2015-use mml2015-function-alist))))
1196     (if func
1197         (funcall func cont sign)
1198       (error "Cannot find encrypt function"))))
1199
1200 ;;;###autoload
1201 (defun mml2015-sign (cont)
1202   (mml2015-clean-buffer)
1203   (let ((func (nth 1 (assq mml2015-use mml2015-function-alist))))
1204     (if func
1205         (funcall func cont)
1206       (error "Cannot find sign function"))))
1207
1208 ;;;###autoload
1209 (defun mml2015-self-encrypt ()
1210   (mml2015-encrypt nil))
1211
1212 (provide 'mml2015)
1213
1214 ;;; mml2015.el ends here