lisp/gnus/mml2015.el

   1 ;;; mml2015.el --- MIME Security with Pretty Good Privacy (PGP)
   2
   3 ;; Copyright (C) 2000-2014 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   (if (locate-library "password-cache")
  32       (require 'password-cache)
  33     (require 'password)))
  34
  35 (eval-when-compile (require 'cl))
  36 (require 'mm-decode)
  37 (require 'mm-util)
  38 (require 'mml)
  39 (require 'mml-sec)
  40
  41 (defvar mc-pgp-always-sign)
  42
  43 (declare-function epg-check-configuration "ext:epg-config"
  44                   (config &optional minimum-version))
  45 (declare-function epg-configuration "ext:epg-config" ())
  46
  47 ;; Maybe this should be in eg mml-sec.el (and have a different name).
  48 ;; Then mml1991 would not need to require mml2015, and mml1991-use
  49 ;; could be removed.
  50 (defvar mml2015-use (or
  51                      (progn
  52                        (ignore-errors (require 'epg-config))
  53                        (and (fboundp 'epg-check-configuration)
  54                            'epg))
  55                      (progn
  56                        (let ((abs-file (locate-library "pgg")))
  57                          ;; Don't load PGG if it is marked as obsolete
  58                          ;; (Emacs 24).
  59                          (when (and abs-file
  60                                     (not (string-match "/obsolete/[^/]*\\'"
  61                                                        abs-file)))
  62                            (ignore-errors (require 'pgg))
  63                            (and (fboundp 'pgg-sign-region)
  64                                 'pgg))))
  65                      (progn (ignore-errors
  66                               (load "mc-toplev"))
  67                             (and (fboundp 'mc-encrypt-generic)
  68                                  (fboundp 'mc-sign-generic)
  69                                  (fboundp 'mc-cleanup-recipient-headers)
  70                                  'mailcrypt)))
  71   "The package used for PGP/MIME.
  72 Valid packages include `epg', `pgg' and `mailcrypt'.")
  73
  74 ;; Something is not RFC2015.
  75 (defvar mml2015-function-alist
  76   '((mailcrypt mml2015-mailcrypt-sign
  77                mml2015-mailcrypt-encrypt
  78                mml2015-mailcrypt-verify
  79                mml2015-mailcrypt-decrypt
  80                mml2015-mailcrypt-clear-verify
  81                mml2015-mailcrypt-clear-decrypt)
  82     (pgg mml2015-pgg-sign
  83          mml2015-pgg-encrypt
  84          mml2015-pgg-verify
  85          mml2015-pgg-decrypt
  86          mml2015-pgg-clear-verify
  87          mml2015-pgg-clear-decrypt)
  88     (epg mml2015-epg-sign
  89          mml2015-epg-encrypt
  90          mml2015-epg-verify
  91          mml2015-epg-decrypt
  92          mml2015-epg-clear-verify
  93          mml2015-epg-clear-decrypt))
  94   "Alist of PGP/MIME functions.")
  95
  96 (defvar mml2015-result-buffer nil)
  97
  98 (defcustom mml2015-unabbrev-trust-alist
  99   '(("TRUST_UNDEFINED" . nil)
 100     ("TRUST_NEVER"     . nil)
 101     ("TRUST_MARGINAL"  . t)
 102     ("TRUST_FULLY"     . t)
 103     ("TRUST_ULTIMATE"  . t))
 104   "Map GnuPG trust output values to a boolean saying if you trust the key."
 105   :version "22.1"
 106   :group 'mime-security
 107   :type '(repeat (cons (regexp :tag "GnuPG output regexp")
 108                        (boolean :tag "Trust key"))))
 109
 110 (defcustom mml2015-cache-passphrase mml-secure-cache-passphrase
 111   "If t, cache passphrase."
 112   :group 'mime-security
 113   :type 'boolean)
 114
 115 (defcustom mml2015-passphrase-cache-expiry mml-secure-passphrase-cache-expiry
 116   "How many seconds the passphrase is cached.
 117 Whether the passphrase is cached at all is controlled by
 118 `mml2015-cache-passphrase'."
 119   :group 'mime-security
 120   :type 'integer)
 121
 122 (defcustom mml2015-signers nil
 123   "A list of your own key ID(s) which will be used to sign a message.
 124 If set, it overrides the setting of `mml2015-sign-with-sender'."
 125   :group 'mime-security
 126   :type '(repeat (string :tag "Key ID")))
 127
 128 (defcustom mml2015-sign-with-sender nil
 129   "If t, use message sender so find a key to sign with."
 130   :group 'mime-security
 131   :type 'boolean
 132   :version "24.1")
 133
 134 (defcustom mml2015-encrypt-to-self nil
 135   "If t, add your own key ID to recipient list when encryption."
 136   :group 'mime-security
 137   :type 'boolean)
 138
 139 (defcustom mml2015-always-trust t
 140   "If t, GnuPG skip key validation on encryption."
 141   :group 'mime-security
 142   :type 'boolean)
 143
 144 (defcustom mml2015-maximum-key-image-dimension 64
 145   "The maximum dimension (width or height) of any key images."
 146   :version "24.4"
 147   :group 'mime-security
 148   :type 'integer)
 149
 150 ;; Extract plaintext from cleartext signature.  IMO, this kind of task
 151 ;; should be done by GnuPG rather than Elisp, but older PGP backends
 152 ;; (such as Mailcrypt, and PGG) discard the output from GnuPG.
 153 (defun mml2015-extract-cleartext-signature ()
 154   ;; Daiki Ueno in
 155   ;; <54a15d860801080142l70b95d7dkac4bf51a86196011@mail.gmail.com>: ``I still
 156   ;; believe that the right way is to use the plaintext output from GnuPG as
 157   ;; it is, and mml2015-extract-cleartext-signature is just a kludge for
 158   ;; misdesigned libraries like PGG, which have no ability to do that.  So, I
 159   ;; think it should not have descriptive documentation.''
 160   ;;
 161   ;; This function doesn't handle NotDashEscaped correctly.  EasyPG handles it
 162   ;; correctly.
 163   ;; http://thread.gmane.org/gmane.emacs.gnus.general/66062/focus=66082
 164   ;; http://thread.gmane.org/gmane.emacs.gnus.general/65087/focus=65109
 165   (goto-char (point-min))
 166   (forward-line)
 167   ;; We need to be careful not to strip beyond the armor headers.
 168   ;; Previously, an attacker could replace the text inside our
 169   ;; markup with trailing garbage by injecting whitespace into the
 170   ;; message.
 171   (while (looking-at "Hash:")           ; The only header allowed in cleartext
 172     (forward-line))                     ; signatures according to RFC2440.
 173   (when (looking-at "[\t ]*$")
 174     (forward-line))
 175   (delete-region (point-min) (point))
 176   (if (re-search-forward "^-----BEGIN PGP SIGNATURE-----" nil t)
 177       (delete-region (match-beginning 0) (point-max)))
 178   (goto-char (point-min))
 179   (while (re-search-forward "^- " nil t)
 180     (replace-match "" t t)
 181     (forward-line 1)))
 182
 183 ;;; mailcrypt wrapper
 184
 185 (autoload 'mailcrypt-decrypt "mailcrypt")
 186 (autoload 'mailcrypt-verify "mailcrypt")
 187 (autoload 'mc-pgp-always-sign "mailcrypt")
 188 (autoload 'mc-encrypt-generic "mc-toplev")
 189 (autoload 'mc-cleanup-recipient-headers "mc-toplev")
 190 (autoload 'mc-sign-generic "mc-toplev")
 191
 192 (defvar mml2015-decrypt-function 'mailcrypt-decrypt)
 193 (defvar mml2015-verify-function 'mailcrypt-verify)
 194
 195 (defun mml2015-format-error (err)
 196   (if (stringp (cadr err))
 197       (cadr err)
 198     (format "%S" (cdr err))))
 199
 200 (defun mml2015-mailcrypt-decrypt (handle ctl)
 201   (catch 'error
 202     (let (child handles result)
 203       (unless (setq child (mm-find-part-by-type
 204                            (cdr handle)
 205                            "application/octet-stream" nil t))
 206         (mm-set-handle-multipart-parameter
 207          mm-security-handle 'gnus-info "Corrupted")
 208         (throw 'error handle))
 209       (with-temp-buffer
 210         (mm-insert-part child)
 211         (setq result
 212               (condition-case err
 213                   (funcall mml2015-decrypt-function)
 214                 (error
 215                  (mm-set-handle-multipart-parameter
 216                   mm-security-handle 'gnus-details (mml2015-format-error err))
 217                  nil)
 218                 (quit
 219                  (mm-set-handle-multipart-parameter
 220                   mm-security-handle 'gnus-details "Quit.")
 221                  nil)))
 222         (unless (car result)
 223           (mm-set-handle-multipart-parameter
 224            mm-security-handle 'gnus-info "Failed")
 225           (throw 'error handle))
 226         (setq handles (mm-dissect-buffer t)))
 227       (mm-destroy-parts handle)
 228       (mm-set-handle-multipart-parameter
 229        mm-security-handle 'gnus-info
 230        (concat "OK"
 231                (let ((sig (with-current-buffer mml2015-result-buffer
 232                             (mml2015-gpg-extract-signature-details))))
 233                  (concat ", Signer: " sig))))
 234       (if (listp (car handles))
 235           handles
 236         (list handles)))))
 237
 238 (defun mml2015-gpg-pretty-print-fpr (fingerprint)
 239   (let* ((result "")
 240          (fpr-length (string-width fingerprint))
 241          (n-slice 0)
 242          slice)
 243     (setq fingerprint (string-to-list fingerprint))
 244     (while fingerprint
 245       (setq fpr-length (- fpr-length 4))
 246       (setq slice (butlast fingerprint fpr-length))
 247       (setq fingerprint (nthcdr 4 fingerprint))
 248       (setq n-slice (1+ n-slice))
 249       (setq result
 250             (concat
 251              result
 252              (case n-slice
 253                (1  slice)
 254                (otherwise (concat " " slice))))))
 255     result))
 256
 257 (defun mml2015-gpg-extract-signature-details ()
 258   (goto-char (point-min))
 259   (let* ((expired (re-search-forward
 260                    "^\\[GNUPG:\\] SIGEXPIRED$"
 261                    nil t))
 262          (signer (and (re-search-forward
 263                        "^\\[GNUPG:\\] GOODSIG \\([0-9A-Za-z]*\\) \\(.*\\)$"
 264                        nil t)
 265                       (cons (match-string 1) (match-string 2))))
 266          (fprint (and (re-search-forward
 267                        "^\\[GNUPG:\\] VALIDSIG \\([0-9a-zA-Z]*\\) "
 268                        nil t)
 269                       (match-string 1)))
 270          (trust  (and (re-search-forward
 271                        "^\\[GNUPG:\\] \\(TRUST_.*\\)$"
 272                        nil t)
 273                       (match-string 1)))
 274          (trust-good-enough-p
 275           (cdr (assoc trust mml2015-unabbrev-trust-alist))))
 276     (cond ((and signer fprint)
 277            (concat (cdr signer)
 278                    (unless trust-good-enough-p
 279                      (concat "\nUntrusted, Fingerprint: "
 280                              (mml2015-gpg-pretty-print-fpr fprint)))
 281                    (when expired
 282                      (format "\nWARNING: Signature from expired key (%s)"
 283                              (car signer)))))
 284           ((re-search-forward
 285             "^\\(gpg: \\)?Good signature from \"\\(.*\\)\"$" nil t)
 286            (match-string 2))
 287           (t
 288            "From unknown user"))))
 289
 290 (defun mml2015-mailcrypt-clear-decrypt ()
 291   (let (result)
 292     (setq result
 293           (condition-case err
 294               (funcall mml2015-decrypt-function)
 295             (error
 296              (mm-set-handle-multipart-parameter
 297               mm-security-handle 'gnus-details (mml2015-format-error err))
 298              nil)
 299             (quit
 300              (mm-set-handle-multipart-parameter
 301               mm-security-handle 'gnus-details "Quit.")
 302              nil)))
 303     (if (car result)
 304         (mm-set-handle-multipart-parameter
 305          mm-security-handle 'gnus-info "OK")
 306       (mm-set-handle-multipart-parameter
 307        mm-security-handle 'gnus-info "Failed"))))
 308
 309 (defun mml2015-fix-micalg (alg)
 310   (and alg
 311        ;; Mutt/1.2.5i has seen sending micalg=php-sha1
 312        (upcase (if (string-match "^p[gh]p-" alg)
 313                    (substring alg (match-end 0))
 314                  alg))))
 315
 316 (defun mml2015-mailcrypt-verify (handle ctl)
 317   (catch 'error
 318     (let (part)
 319       (unless (setq part (mm-find-raw-part-by-type
 320                           ctl (or (mm-handle-multipart-ctl-parameter
 321                                    ctl 'protocol)
 322                                   "application/pgp-signature")
 323                           t))
 324         (mm-set-handle-multipart-parameter
 325          mm-security-handle 'gnus-info "Corrupted")
 326         (throw 'error handle))
 327       (with-temp-buffer
 328         (insert "-----BEGIN PGP SIGNED MESSAGE-----\n")
 329         (insert (format "Hash: %s\n\n"
 330                         (or (mml2015-fix-micalg
 331                              (mm-handle-multipart-ctl-parameter
 332                               ctl 'micalg))
 333                             "SHA1")))
 334         (save-restriction
 335           (narrow-to-region (point) (point))
 336           (insert part "\n")
 337           (goto-char (point-min))
 338           (while (not (eobp))
 339             (if (looking-at "^-")
 340                 (insert "- "))
 341             (forward-line)))
 342         (unless (setq part (mm-find-part-by-type
 343                             (cdr handle) "application/pgp-signature" nil t))
 344           (mm-set-handle-multipart-parameter
 345            mm-security-handle 'gnus-info "Corrupted")
 346           (throw 'error handle))
 347         (save-restriction
 348           (narrow-to-region (point) (point))
 349           (mm-insert-part part)
 350           (goto-char (point-min))
 351           (if (re-search-forward "^-----BEGIN PGP [^-]+-----\r?$" nil t)
 352               (replace-match "-----BEGIN PGP SIGNATURE-----" t t))
 353           (if (re-search-forward "^-----END PGP [^-]+-----\r?$" nil t)
 354               (replace-match "-----END PGP SIGNATURE-----" t t)))
 355         (let ((mc-gpg-debug-buffer (get-buffer-create " *gnus gpg debug*")))
 356           (unless (condition-case err
 357                       (prog1
 358                           (funcall mml2015-verify-function)
 359                         (if (get-buffer " *mailcrypt stderr temp")
 360                             (mm-set-handle-multipart-parameter
 361                              mm-security-handle 'gnus-details
 362                              (with-current-buffer " *mailcrypt stderr temp"
 363                                (buffer-string))))
 364                         (if (get-buffer " *mailcrypt stdout temp")
 365                             (kill-buffer " *mailcrypt stdout temp"))
 366                         (if (get-buffer " *mailcrypt stderr temp")
 367                             (kill-buffer " *mailcrypt stderr temp"))
 368                         (if (get-buffer " *mailcrypt status temp")
 369                             (kill-buffer " *mailcrypt status temp"))
 370                         (if (get-buffer mc-gpg-debug-buffer)
 371                             (kill-buffer mc-gpg-debug-buffer)))
 372                     (error
 373                      (mm-set-handle-multipart-parameter
 374                       mm-security-handle 'gnus-details (mml2015-format-error err))
 375                      nil)
 376                     (quit
 377                      (mm-set-handle-multipart-parameter
 378                       mm-security-handle 'gnus-details "Quit.")
 379                      nil))
 380             (mm-set-handle-multipart-parameter
 381              mm-security-handle 'gnus-info "Failed")
 382             (throw 'error handle))))
 383       (mm-set-handle-multipart-parameter
 384        mm-security-handle 'gnus-info "OK")
 385       handle)))
 386
 387 (defun mml2015-mailcrypt-clear-verify ()
 388   (let ((mc-gpg-debug-buffer (get-buffer-create " *gnus gpg debug*")))
 389     (if (condition-case err
 390             (prog1
 391                 (funcall mml2015-verify-function)
 392               (if (get-buffer " *mailcrypt stderr temp")
 393                   (mm-set-handle-multipart-parameter
 394                    mm-security-handle 'gnus-details
 395                    (with-current-buffer " *mailcrypt stderr temp"
 396                      (buffer-string))))
 397               (if (get-buffer " *mailcrypt stdout temp")
 398                   (kill-buffer " *mailcrypt stdout temp"))
 399               (if (get-buffer " *mailcrypt stderr temp")
 400                   (kill-buffer " *mailcrypt stderr temp"))
 401               (if (get-buffer " *mailcrypt status temp")
 402                   (kill-buffer " *mailcrypt status temp"))
 403               (if (get-buffer mc-gpg-debug-buffer)
 404                   (kill-buffer mc-gpg-debug-buffer)))
 405           (error
 406            (mm-set-handle-multipart-parameter
 407             mm-security-handle 'gnus-details (mml2015-format-error err))
 408            nil)
 409           (quit
 410            (mm-set-handle-multipart-parameter
 411             mm-security-handle 'gnus-details "Quit.")
 412            nil))
 413         (mm-set-handle-multipart-parameter
 414          mm-security-handle 'gnus-info "OK")
 415       (mm-set-handle-multipart-parameter
 416        mm-security-handle 'gnus-info "Failed")))
 417   (mml2015-extract-cleartext-signature))
 418
 419 (defun mml2015-mailcrypt-sign (cont)
 420   (mc-sign-generic (message-options-get 'message-sender)
 421                    nil nil nil nil)
 422   (let ((boundary (mml-compute-boundary cont))
 423         hash point)
 424     (goto-char (point-min))
 425     (unless (re-search-forward "^-----BEGIN PGP SIGNED MESSAGE-----\r?$" nil t)
 426       (error "Cannot find signed begin line"))
 427     (goto-char (match-beginning 0))
 428     (forward-line 1)
 429     (unless (looking-at "Hash:[ \t]*\\([a-zA-Z0-9]+\\)")
 430       (error "Cannot not find PGP hash"))
 431     (setq hash (match-string 1))
 432     (unless (re-search-forward "^$" nil t)
 433       (error "Cannot not find PGP message"))
 434     (forward-line 1)
 435     (delete-region (point-min) (point))
 436     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
 437                     boundary))
 438     (insert (format "\tmicalg=pgp-%s; protocol=\"application/pgp-signature\"\n"
 439                     (downcase hash)))
 440     (insert (format "\n--%s\n" boundary))
 441     (setq point (point))
 442     (goto-char (point-max))
 443     (unless (re-search-backward "^-----END PGP SIGNATURE-----\r?$" nil t)
 444       (error "Cannot find signature part"))
 445     (replace-match "-----END PGP MESSAGE-----" t t)
 446     (goto-char (match-beginning 0))
 447     (unless (re-search-backward "^-----BEGIN PGP SIGNATURE-----\r?$"
 448                                 nil t)
 449       (error "Cannot find signature part"))
 450     (replace-match "-----BEGIN PGP MESSAGE-----" t t)
 451     (goto-char (match-beginning 0))
 452     (save-restriction
 453       (narrow-to-region point (point))
 454       (goto-char point)
 455       (while (re-search-forward "^- -" nil t)
 456         (replace-match "-" t t))
 457       (goto-char (point-max)))
 458     (insert (format "--%s\n" boundary))
 459     (insert "Content-Type: application/pgp-signature\n\n")
 460     (goto-char (point-max))
 461     (insert (format "--%s--\n" boundary))
 462     (goto-char (point-max))))
 463
 464 ;; We require mm-decode, which requires mm-bodies, which autoloads
 465 ;; message-options-get (!).
 466 (declare-function message-options-set "message" (symbol value))
 467
 468 (defun mml2015-mailcrypt-encrypt (cont &optional sign)
 469   (let ((mc-pgp-always-sign
 470          (or mc-pgp-always-sign
 471              sign
 472              (eq t (or (message-options-get 'message-sign-encrypt)
 473                        (message-options-set
 474                         'message-sign-encrypt
 475                         (or (y-or-n-p "Sign the message? ")
 476                             'not))))
 477              'never)))
 478     (mm-with-unibyte-current-buffer
 479       (mc-encrypt-generic
 480        (or (message-options-get 'message-recipients)
 481            (message-options-set 'message-recipients
 482                               (mc-cleanup-recipient-headers
 483                                (read-string "Recipients: "))))
 484        nil nil nil
 485        (message-options-get 'message-sender))))
 486   (goto-char (point-min))
 487   (unless (looking-at "-----BEGIN PGP MESSAGE-----")
 488     (error "Fail to encrypt the message"))
 489   (let ((boundary (mml-compute-boundary cont)))
 490     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
 491                     boundary))
 492     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
 493     (insert (format "--%s\n" boundary))
 494     (insert "Content-Type: application/pgp-encrypted\n\n")
 495     (insert "Version: 1\n\n")
 496     (insert (format "--%s\n" boundary))
 497     (insert "Content-Type: application/octet-stream\n\n")
 498     (goto-char (point-max))
 499     (insert (format "--%s--\n" boundary))
 500     (goto-char (point-max))))
 501
 502 ;;; pgg wrapper
 503
 504 (defvar pgg-default-user-id)
 505 (defvar pgg-errors-buffer)
 506 (defvar pgg-output-buffer)
 507
 508 (autoload 'pgg-decrypt-region "pgg")
 509 (autoload 'pgg-verify-region "pgg")
 510 (autoload 'pgg-sign-region "pgg")
 511 (autoload 'pgg-encrypt-region "pgg")
 512 (autoload 'pgg-parse-armor "pgg-parse")
 513
 514 (defun mml2015-pgg-decrypt (handle ctl)
 515   (catch 'error
 516     (let ((pgg-errors-buffer mml2015-result-buffer)
 517           child handles result decrypt-status)
 518       (unless (setq child (mm-find-part-by-type
 519                            (cdr handle)
 520                            "application/octet-stream" nil t))
 521         (mm-set-handle-multipart-parameter
 522          mm-security-handle 'gnus-info "Corrupted")
 523         (throw 'error handle))
 524       (with-temp-buffer
 525         (mm-insert-part child)
 526         (if (condition-case err
 527                 (prog1
 528                     (pgg-decrypt-region (point-min) (point-max))
 529                   (setq decrypt-status
 530                         (with-current-buffer mml2015-result-buffer
 531                           (buffer-string)))
 532                   (mm-set-handle-multipart-parameter
 533                    mm-security-handle 'gnus-details
 534                    decrypt-status))
 535               (error
 536                (mm-set-handle-multipart-parameter
 537                 mm-security-handle 'gnus-details (mml2015-format-error err))
 538                nil)
 539               (quit
 540                (mm-set-handle-multipart-parameter
 541                 mm-security-handle 'gnus-details "Quit.")
 542                nil))
 543             (with-current-buffer pgg-output-buffer
 544               (goto-char (point-min))
 545               (while (search-forward "\r\n" nil t)
 546                 (replace-match "\n" t t))
 547               (setq handles (mm-dissect-buffer t))
 548               (mm-destroy-parts handle)
 549               (mm-set-handle-multipart-parameter
 550                mm-security-handle 'gnus-info "OK")
 551               (mm-set-handle-multipart-parameter
 552                mm-security-handle 'gnus-details
 553                (concat decrypt-status
 554                        (when (stringp (car handles))
 555                          "\n" (mm-handle-multipart-ctl-parameter
 556                                handles 'gnus-details))))
 557               (if (listp (car handles))
 558                   handles
 559                 (list handles)))
 560           (mm-set-handle-multipart-parameter
 561            mm-security-handle 'gnus-info "Failed")
 562           (throw 'error handle))))))
 563
 564 (defun mml2015-pgg-clear-decrypt ()
 565   (let ((pgg-errors-buffer mml2015-result-buffer))
 566     (if (prog1
 567             (pgg-decrypt-region (point-min) (point-max))
 568           (mm-set-handle-multipart-parameter
 569            mm-security-handle 'gnus-details
 570            (with-current-buffer mml2015-result-buffer
 571              (buffer-string))))
 572         (progn
 573           (erase-buffer)
 574           ;; Treat data which pgg returns as a unibyte string.
 575           (mm-disable-multibyte)
 576           (insert-buffer-substring pgg-output-buffer)
 577           (goto-char (point-min))
 578           (while (search-forward "\r\n" nil t)
 579             (replace-match "\n" t t))
 580           (mm-set-handle-multipart-parameter
 581            mm-security-handle 'gnus-info "OK"))
 582       (mm-set-handle-multipart-parameter
 583        mm-security-handle 'gnus-info "Failed"))))
 584
 585 (defun mml2015-pgg-verify (handle ctl)
 586   (let ((pgg-errors-buffer mml2015-result-buffer)
 587         signature-file part signature)
 588     (if (or (null (setq part (mm-find-raw-part-by-type
 589                               ctl (or (mm-handle-multipart-ctl-parameter
 590                                        ctl 'protocol)
 591                                       "application/pgp-signature")
 592                               t)))
 593             (null (setq signature (mm-find-part-by-type
 594                                    (cdr handle) "application/pgp-signature" nil t))))
 595         (progn
 596           (mm-set-handle-multipart-parameter
 597            mm-security-handle 'gnus-info "Corrupted")
 598           handle)
 599       (with-temp-buffer
 600         (insert part)
 601         ;; Convert <LF> to <CR><LF> in signed text.  If --textmode is
 602         ;; specified when signing, the conversion is not necessary.
 603         (goto-char (point-min))
 604         (end-of-line)
 605         (while (not (eobp))
 606           (unless (eq (char-before) ?\r)
 607             (insert "\r"))
 608           (forward-line)
 609           (end-of-line))
 610         (with-temp-file (setq signature-file (mm-make-temp-file "pgg"))
 611           (mm-insert-part signature))
 612         (if (condition-case err
 613                 (prog1
 614                     (pgg-verify-region (point-min) (point-max)
 615                                        signature-file t)
 616                   (goto-char (point-min))
 617                   (while (search-forward "\r\n" nil t)
 618                     (replace-match "\n" t t))
 619                   (mm-set-handle-multipart-parameter
 620                    mm-security-handle 'gnus-details
 621                    (concat (with-current-buffer pgg-output-buffer
 622                              (buffer-string))
 623                            (with-current-buffer pgg-errors-buffer
 624                              (buffer-string)))))
 625               (error
 626                (mm-set-handle-multipart-parameter
 627                 mm-security-handle 'gnus-details (mml2015-format-error err))
 628                nil)
 629               (quit
 630                (mm-set-handle-multipart-parameter
 631                 mm-security-handle 'gnus-details "Quit.")
 632                nil))
 633             (progn
 634               (delete-file signature-file)
 635               (mm-set-handle-multipart-parameter
 636                mm-security-handle 'gnus-info
 637                (with-current-buffer pgg-errors-buffer
 638                  (mml2015-gpg-extract-signature-details))))
 639           (delete-file signature-file)
 640           (mm-set-handle-multipart-parameter
 641            mm-security-handle 'gnus-info "Failed")))))
 642   handle)
 643
 644 (defun mml2015-pgg-clear-verify ()
 645   (let ((pgg-errors-buffer mml2015-result-buffer)
 646         (text (buffer-string))
 647         (coding-system buffer-file-coding-system))
 648     (if (condition-case err
 649             (prog1
 650                 (mm-with-unibyte-buffer
 651                   (insert (mm-encode-coding-string text coding-system))
 652                   (pgg-verify-region (point-min) (point-max) nil t))
 653               (goto-char (point-min))
 654               (while (search-forward "\r\n" nil t)
 655                 (replace-match "\n" t t))
 656               (mm-set-handle-multipart-parameter
 657                mm-security-handle 'gnus-details
 658                (concat (with-current-buffer pgg-output-buffer
 659                          (buffer-string))
 660                        (with-current-buffer pgg-errors-buffer
 661                          (buffer-string)))))
 662           (error
 663            (mm-set-handle-multipart-parameter
 664             mm-security-handle 'gnus-details (mml2015-format-error err))
 665            nil)
 666           (quit
 667            (mm-set-handle-multipart-parameter
 668             mm-security-handle 'gnus-details "Quit.")
 669            nil))
 670         (mm-set-handle-multipart-parameter
 671          mm-security-handle 'gnus-info
 672          (with-current-buffer pgg-errors-buffer
 673            (mml2015-gpg-extract-signature-details)))
 674       (mm-set-handle-multipart-parameter
 675        mm-security-handle 'gnus-info "Failed")))
 676   (mml2015-extract-cleartext-signature))
 677
 678 (defun mml2015-pgg-sign (cont)
 679   (let ((pgg-errors-buffer mml2015-result-buffer)
 680         (boundary (mml-compute-boundary cont))
 681         (pgg-default-user-id (or (message-options-get 'mml-sender)
 682                                  pgg-default-user-id))
 683         (pgg-text-mode t)
 684         entry)
 685     (unless (pgg-sign-region (point-min) (point-max))
 686       (pop-to-buffer mml2015-result-buffer)
 687       (error "Sign error"))
 688     (goto-char (point-min))
 689     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
 690                     boundary))
 691     (if (setq entry (assq 2 (pgg-parse-armor
 692                              (with-current-buffer pgg-output-buffer
 693                                (buffer-string)))))
 694         (setq entry (assq 'hash-algorithm (cdr entry))))
 695     (insert (format "\tmicalg=%s; "
 696                     (if (cdr entry)
 697                         (downcase (format "pgp-%s" (cdr entry)))
 698                       "pgp-sha1")))
 699     (insert "protocol=\"application/pgp-signature\"\n")
 700     (insert (format "\n--%s\n" boundary))
 701     (goto-char (point-max))
 702     (insert (format "\n--%s\n" boundary))
 703     (insert "Content-Type: application/pgp-signature\n\n")
 704     (insert-buffer-substring pgg-output-buffer)
 705     (goto-char (point-max))
 706     (insert (format "--%s--\n" boundary))
 707     (goto-char (point-max))))
 708
 709 (defun mml2015-pgg-encrypt (cont &optional sign)
 710   (let ((pgg-errors-buffer mml2015-result-buffer)
 711         (pgg-text-mode t)
 712         (boundary (mml-compute-boundary cont)))
 713     (unless (pgg-encrypt-region (point-min) (point-max)
 714                                 (split-string
 715                                  (or
 716                                   (message-options-get 'message-recipients)
 717                                   (message-options-set 'message-recipients
 718                                                        (read-string "Recipients: ")))
 719                                  "[ \f\t\n\r\v,]+")
 720                                 sign)
 721       (pop-to-buffer mml2015-result-buffer)
 722       (error "Encrypt error"))
 723     (delete-region (point-min) (point-max))
 724     (goto-char (point-min))
 725     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
 726                     boundary))
 727     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
 728     (insert (format "--%s\n" boundary))
 729     (insert "Content-Type: application/pgp-encrypted\n\n")
 730     (insert "Version: 1\n\n")
 731     (insert (format "--%s\n" boundary))
 732     (insert "Content-Type: application/octet-stream\n\n")
 733     (insert-buffer-substring pgg-output-buffer)
 734     (goto-char (point-max))
 735     (insert (format "--%s--\n" boundary))
 736     (goto-char (point-max))))
 737
 738 ;;; epg wrapper
 739
 740 (defvar epg-user-id-alist)
 741 (defvar epg-digest-algorithm-alist)
 742 (defvar epg-gpg-program)
 743 (defvar inhibit-redisplay)
 744
 745 (autoload 'epg-make-context "epg")
 746 (autoload 'epg-context-set-armor "epg")
 747 (autoload 'epg-context-set-textmode "epg")
 748 (autoload 'epg-context-set-signers "epg")
 749 (autoload 'epg-context-result-for "epg")
 750 (autoload 'epg-new-signature-digest-algorithm "epg")
 751 (autoload 'epg-list-keys "epg")
 752 (autoload 'epg-decrypt-string "epg")
 753 (autoload 'epg-verify-string "epg")
 754 (autoload 'epg-sign-string "epg")
 755 (autoload 'epg-encrypt-string "epg")
 756 (autoload 'epg-passphrase-callback-function "epg")
 757 (autoload 'epg-context-set-passphrase-callback "epg")
 758 (autoload 'epg-key-sub-key-list "epg")
 759 (autoload 'epg-sub-key-capability "epg")
 760 (autoload 'epg-sub-key-validity "epg")
 761 (autoload 'epg-sub-key-fingerprint "epg")
 762 (autoload 'epg-signature-key-id "epg")
 763 (autoload 'epg-signature-to-string "epg")
 764 (autoload 'epg-key-user-id-list "epg")
 765 (autoload 'epg-user-id-string "epg")
 766 (autoload 'epg-user-id-validity "epg")
 767 (autoload 'epg-configuration "epg-config")
 768 (autoload 'epg-expand-group "epg-config")
 769 (autoload 'epa-select-keys "epa")
 770
 771 (defvar mml2015-epg-secret-key-id-list nil)
 772
 773 (defun mml2015-epg-passphrase-callback (context key-id ignore)
 774   (if (eq key-id 'SYM)
 775       (epg-passphrase-callback-function context key-id nil)
 776     (let* ((password-cache-key-id
 777             (if (eq key-id 'PIN)
 778                 "PIN"
 779                key-id))
 780            entry
 781            (passphrase
 782             (password-read
 783              (if (eq key-id 'PIN)
 784                  "Passphrase for PIN: "
 785                (if (setq entry (assoc key-id epg-user-id-alist))
 786                    (format "Passphrase for %s %s: " key-id (cdr entry))
 787                  (format "Passphrase for %s: " key-id)))
 788              password-cache-key-id)))
 789       (when passphrase
 790         (let ((password-cache-expiry mml2015-passphrase-cache-expiry))
 791           (password-cache-add password-cache-key-id passphrase))
 792         (setq mml2015-epg-secret-key-id-list
 793               (cons password-cache-key-id mml2015-epg-secret-key-id-list))
 794         (copy-sequence passphrase)))))
 795
 796 (defun mml2015-epg-check-user-id (key recipient)
 797   (let ((pointer (epg-key-user-id-list key))
 798         result)
 799     (while pointer
 800       (if (and (equal (car (mail-header-parse-address
 801                             (epg-user-id-string (car pointer))))
 802                       (car (mail-header-parse-address
 803                             recipient)))
 804                (not (memq (epg-user-id-validity (car pointer))
 805                           '(revoked expired))))
 806           (setq result t
 807                 pointer nil)
 808         (setq pointer (cdr pointer))))
 809     result))
 810
 811 (defun mml2015-epg-check-sub-key (key usage)
 812   (let ((pointer (epg-key-sub-key-list key))
 813         result)
 814     ;; The primary key will be marked as disabled, when the entire
 815     ;; key is disabled (see 12 Field, Format of colon listings, in
 816     ;; gnupg/doc/DETAILS)
 817     (unless (memq 'disabled (epg-sub-key-capability (car pointer)))
 818       (while pointer
 819         (if (and (memq usage (epg-sub-key-capability (car pointer)))
 820                  (not (memq (epg-sub-key-validity (car pointer))
 821                             '(revoked expired))))
 822             (setq result t
 823                   pointer nil)
 824           (setq pointer (cdr pointer)))))
 825     result))
 826
 827 (defun mml2015-epg-find-usable-key (context name usage
 828                                             &optional name-is-key-id)
 829   (let ((keys (epg-list-keys context name))
 830         key)
 831     (while keys
 832       (if (and (or name-is-key-id
 833                    ;; Non email user-id can be supplied through
 834                    ;; mml2015-signers if mml2015-encrypt-to-self is set.
 835                    ;; Treat it as valid, as it is user's intention.
 836                    (not (string-match "\\`<" name))
 837                    (mml2015-epg-check-user-id (car keys) name))
 838                (mml2015-epg-check-sub-key (car keys) usage))
 839           (setq key (car keys)
 840                 keys nil)
 841         (setq keys (cdr keys))))
 842     key))
 843
 844 ;; XXX: since gpg --list-secret-keys does not return validity of each
 845 ;; key, `mml2015-epg-find-usable-key' defined above is not enough for
 846 ;; secret keys.  The function `mml2015-epg-find-usable-secret-key'
 847 ;; below looks at appropriate public keys to check usability.
 848 (defun mml2015-epg-find-usable-secret-key (context name usage)
 849   (let ((secret-keys (epg-list-keys context name t))
 850         secret-key)
 851     (while (and (not secret-key) secret-keys)
 852       (if (mml2015-epg-find-usable-key
 853            context
 854            (epg-sub-key-fingerprint
 855             (car (epg-key-sub-key-list
 856                   (car secret-keys))))
 857            usage
 858            t)
 859           (setq secret-key (car secret-keys)
 860                 secret-keys nil)
 861         (setq secret-keys (cdr secret-keys))))
 862     secret-key))
 863
 864 (autoload 'gnus-create-image "gnus-ems")
 865
 866 (defun mml2015-epg-key-image (key-id)
 867   "Return the image of a key, if any"
 868   (with-temp-buffer
 869     (mm-set-buffer-multibyte nil)
 870     (let* ((coding-system-for-write 'binary)
 871            (coding-system-for-read 'binary)
 872            (data (shell-command-to-string
 873                   (format "%s --list-options no-show-photos --attribute-fd 3 --list-keys %s 3>&1 >/dev/null 2>&1"
 874                           (shell-quote-argument epg-gpg-program) key-id))))
 875       (when (> (length data) 0)
 876         (insert (substring data 16))
 877         (condition-case nil
 878             (gnus-create-image (buffer-string) nil t)
 879           (error))))))
 880
 881 (autoload 'gnus-rescale-image "gnus-util")
 882
 883 (defun mml2015-epg-key-image-to-string (key-id)
 884   "Return a string with the image of a key, if any"
 885   (let ((key-image (mml2015-epg-key-image key-id)))
 886     (if (not key-image)
 887         ""
 888       (condition-case error
 889           (let ((result "  "))
 890             (put-text-property
 891              1 2 'display
 892              (gnus-rescale-image key-image
 893                                  (cons mml2015-maximum-key-image-dimension
 894                                        mml2015-maximum-key-image-dimension))
 895              result)
 896             result)
 897         (error "")))))
 898
 899 (defun mml2015-epg-signature-to-string (signature)
 900   (concat (epg-signature-to-string signature)
 901           (mml2015-epg-key-image-to-string (epg-signature-key-id signature))))
 902
 903 (defun mml2015-epg-verify-result-to-string (verify-result)
 904   (mapconcat #'mml2015-epg-signature-to-string verify-result "\n"))
 905
 906 (defun mml2015-epg-decrypt (handle ctl)
 907   (catch 'error
 908     (let ((inhibit-redisplay t)
 909           context plain child handles result decrypt-status)
 910       (unless (setq child (mm-find-part-by-type
 911                            (cdr handle)
 912                            "application/octet-stream" nil t))
 913         (mm-set-handle-multipart-parameter
 914          mm-security-handle 'gnus-info "Corrupted")
 915         (throw 'error handle))
 916       (setq context (epg-make-context))
 917       (if mml2015-cache-passphrase
 918           (epg-context-set-passphrase-callback
 919            context
 920            #'mml2015-epg-passphrase-callback))
 921       (condition-case error
 922           (setq plain (epg-decrypt-string context (mm-get-part child))
 923                 mml2015-epg-secret-key-id-list nil)
 924         (error
 925          (while mml2015-epg-secret-key-id-list
 926            (password-cache-remove (car mml2015-epg-secret-key-id-list))
 927            (setq mml2015-epg-secret-key-id-list
 928                  (cdr mml2015-epg-secret-key-id-list)))
 929          (mm-set-handle-multipart-parameter
 930           mm-security-handle 'gnus-info "Failed")
 931          (if (eq (car error) 'quit)
 932              (mm-set-handle-multipart-parameter
 933               mm-security-handle 'gnus-details "Quit.")
 934            (mm-set-handle-multipart-parameter
 935             mm-security-handle 'gnus-details (mml2015-format-error error)))
 936          (throw 'error handle)))
 937       (with-temp-buffer
 938         (insert plain)
 939         (goto-char (point-min))
 940         (while (search-forward "\r\n" nil t)
 941           (replace-match "\n" t t))
 942         (setq handles (mm-dissect-buffer t))
 943         (mm-destroy-parts handle)
 944         (if (epg-context-result-for context 'verify)
 945             (mm-set-handle-multipart-parameter
 946              mm-security-handle 'gnus-info
 947              (concat "OK\n"
 948                      (mml2015-epg-verify-result-to-string
 949                       (epg-context-result-for context 'verify))))
 950           (mm-set-handle-multipart-parameter
 951            mm-security-handle 'gnus-info "OK"))
 952         (if (stringp (car handles))
 953             (mm-set-handle-multipart-parameter
 954              mm-security-handle 'gnus-details
 955              (mm-handle-multipart-ctl-parameter handles 'gnus-details))))
 956         (if (listp (car handles))
 957             handles
 958           (list handles)))))
 959
 960 (defun mml2015-epg-clear-decrypt ()
 961   (let ((inhibit-redisplay t)
 962         (context (epg-make-context))
 963         plain)
 964     (if mml2015-cache-passphrase
 965         (epg-context-set-passphrase-callback
 966          context
 967          #'mml2015-epg-passphrase-callback))
 968     (condition-case error
 969         (setq plain (epg-decrypt-string context (buffer-string))
 970               mml2015-epg-secret-key-id-list nil)
 971       (error
 972        (while mml2015-epg-secret-key-id-list
 973          (password-cache-remove (car mml2015-epg-secret-key-id-list))
 974          (setq mml2015-epg-secret-key-id-list
 975                (cdr mml2015-epg-secret-key-id-list)))
 976        (mm-set-handle-multipart-parameter
 977         mm-security-handle 'gnus-info "Failed")
 978        (if (eq (car error) 'quit)
 979            (mm-set-handle-multipart-parameter
 980             mm-security-handle 'gnus-details "Quit.")
 981          (mm-set-handle-multipart-parameter
 982           mm-security-handle 'gnus-details (mml2015-format-error error)))))
 983     (when plain
 984       (erase-buffer)
 985       ;; Treat data which epg returns as a unibyte string.
 986       (mm-disable-multibyte)
 987       (insert plain)
 988       (goto-char (point-min))
 989       (while (search-forward "\r\n" nil t)
 990         (replace-match "\n" t t))
 991       (mm-set-handle-multipart-parameter
 992        mm-security-handle 'gnus-info "OK")
 993       (if (epg-context-result-for context 'verify)
 994           (mm-set-handle-multipart-parameter
 995            mm-security-handle 'gnus-details
 996            (mml2015-epg-verify-result-to-string
 997             (epg-context-result-for context 'verify)))))))
 998
 999 (defun mml2015-epg-verify (handle ctl)
1000   (catch 'error
1001     (let ((inhibit-redisplay t)
1002           context plain signature-file part signature)
1003       (when (or (null (setq part (mm-find-raw-part-by-type
1004                                   ctl (or (mm-handle-multipart-ctl-parameter
1005                                            ctl 'protocol)
1006                                           "application/pgp-signature")
1007                                   t)))
1008                 (null (setq signature (mm-find-part-by-type
1009                                        (cdr handle) "application/pgp-signature"
1010                                        nil t))))
1011         (mm-set-handle-multipart-parameter
1012          mm-security-handle 'gnus-info "Corrupted")
1013         (throw 'error handle))
1014       (setq part (mm-replace-in-string part "\n" "\r\n")
1015             signature (mm-get-part signature)
1016             context (epg-make-context))
1017       (condition-case error
1018           (setq plain (epg-verify-string context signature part))
1019         (error
1020          (mm-set-handle-multipart-parameter
1021           mm-security-handle 'gnus-info "Failed")
1022          (if (eq (car error) 'quit)
1023              (mm-set-handle-multipart-parameter
1024               mm-security-handle 'gnus-details "Quit.")
1025            (mm-set-handle-multipart-parameter
1026             mm-security-handle 'gnus-details (mml2015-format-error error)))
1027          (throw 'error handle)))
1028       (mm-set-handle-multipart-parameter
1029        mm-security-handle 'gnus-info
1030        (mml2015-epg-verify-result-to-string
1031         (epg-context-result-for context 'verify)))
1032       handle)))
1033
1034 (defun mml2015-epg-clear-verify ()
1035   (let ((inhibit-redisplay t)
1036         (context (epg-make-context))
1037         (signature (mm-encode-coding-string (buffer-string)
1038                                             coding-system-for-write))
1039         plain)
1040     (condition-case error
1041         (setq plain (epg-verify-string context signature))
1042       (error
1043        (mm-set-handle-multipart-parameter
1044         mm-security-handle 'gnus-info "Failed")
1045        (if (eq (car error) 'quit)
1046            (mm-set-handle-multipart-parameter
1047             mm-security-handle 'gnus-details "Quit.")
1048          (mm-set-handle-multipart-parameter
1049           mm-security-handle 'gnus-details (mml2015-format-error error)))))
1050     (if plain
1051         (progn
1052           (mm-set-handle-multipart-parameter
1053            mm-security-handle 'gnus-info
1054            (mml2015-epg-verify-result-to-string
1055             (epg-context-result-for context 'verify)))
1056           (delete-region (point-min) (point-max))
1057           (insert (mm-decode-coding-string plain coding-system-for-read)))
1058       (mml2015-extract-cleartext-signature))))
1059
1060 (defun mml2015-epg-sign (cont)
1061   (let* ((inhibit-redisplay t)
1062          (context (epg-make-context))
1063          (boundary (mml-compute-boundary cont))
1064          (sender (message-options-get 'message-sender))
1065          (signer-names (or mml2015-signers
1066                            (if (and mml2015-sign-with-sender sender)
1067                                (list (concat "<" sender ">")))))
1068          signer-key
1069          (signers
1070           (or (message-options-get 'mml2015-epg-signers)
1071               (message-options-set
1072                'mml2015-epg-signers
1073                (if (eq mm-sign-option 'guided)
1074                    (epa-select-keys context "\
1075 Select keys for signing.
1076 If no one is selected, default secret key is used.  "
1077                                     signer-names
1078                                     t)
1079                  (if (or sender mml2015-signers)
1080                      (delq nil
1081                            (mapcar
1082                             (lambda (signer)
1083                               (setq signer-key
1084                                     (mml2015-epg-find-usable-secret-key
1085                                      context signer 'sign))
1086                               (unless (or signer-key
1087                                           (y-or-n-p
1088                                            (format
1089                                             "No secret key for %s; skip it? "
1090                                             signer)))
1091                                 (error "No secret key for %s" signer))
1092                               signer-key)
1093                             signer-names)))))))
1094          signature micalg)
1095     (epg-context-set-armor context t)
1096     (epg-context-set-textmode context t)
1097     (epg-context-set-signers context signers)
1098     (if mml2015-cache-passphrase
1099         (epg-context-set-passphrase-callback
1100          context
1101          #'mml2015-epg-passphrase-callback))
1102     ;; Signed data must end with a newline (RFC 3156, 5).
1103     (goto-char (point-max))
1104     (unless (bolp)
1105       (insert "\n"))
1106     (condition-case error
1107         (setq signature (epg-sign-string context (buffer-string) t)
1108               mml2015-epg-secret-key-id-list nil)
1109       (error
1110        (while mml2015-epg-secret-key-id-list
1111          (password-cache-remove (car mml2015-epg-secret-key-id-list))
1112          (setq mml2015-epg-secret-key-id-list
1113                (cdr mml2015-epg-secret-key-id-list)))
1114        (signal (car error) (cdr error))))
1115     (if (epg-context-result-for context 'sign)
1116         (setq micalg (epg-new-signature-digest-algorithm
1117                       (car (epg-context-result-for context 'sign)))))
1118     (goto-char (point-min))
1119     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
1120                     boundary))
1121     (if micalg
1122         (insert (format "\tmicalg=pgp-%s; "
1123                         (downcase
1124                          (cdr (assq micalg
1125                                     epg-digest-algorithm-alist))))))
1126     (insert "protocol=\"application/pgp-signature\"\n")
1127     (insert (format "\n--%s\n" boundary))
1128     (goto-char (point-max))
1129     (insert (format "\n--%s\n" boundary))
1130     (insert "Content-Type: application/pgp-signature; name=\"signature.asc\"\n\n")
1131     (insert signature)
1132     (goto-char (point-max))
1133     (insert (format "--%s--\n" boundary))
1134     (goto-char (point-max))))
1135
1136 (defun mml2015-epg-encrypt (cont &optional sign)
1137   (let* ((inhibit-redisplay t)
1138          (context (epg-make-context))
1139          (boundary (mml-compute-boundary cont))
1140          (config (epg-configuration))
1141          (recipients (message-options-get 'mml2015-epg-recipients))
1142          cipher
1143          (sender (message-options-get 'message-sender))
1144          (signer-names (or mml2015-signers
1145                            (if (and mml2015-sign-with-sender sender)
1146                                (list (concat "<" sender ">")))))
1147          signers
1148          recipient-key signer-key)
1149     (unless recipients
1150       (setq recipients
1151             (apply #'nconc
1152                    (mapcar
1153                     (lambda (recipient)
1154                       (or (epg-expand-group config recipient)
1155                           (list (concat "<" recipient ">"))))
1156                     (split-string
1157                      (or (message-options-get 'message-recipients)
1158                          (message-options-set 'message-recipients
1159                                               (read-string "Recipients: ")))
1160                      "[ \f\t\n\r\v,]+"))))
1161       (when mml2015-encrypt-to-self
1162         (unless signer-names
1163           (error "Neither message sender nor mml2015-signers are set"))
1164         (setq recipients (nconc recipients signer-names)))
1165       (if (eq mm-encrypt-option 'guided)
1166           (setq recipients
1167                 (epa-select-keys context "\
1168 Select recipients for encryption.
1169 If no one is selected, symmetric encryption will be performed.  "
1170                                  recipients))
1171         (setq recipients
1172               (delq nil
1173                     (mapcar
1174                      (lambda (recipient)
1175                        (setq recipient-key (mml2015-epg-find-usable-key
1176                                             context recipient 'encrypt))
1177                        (unless (or recipient-key
1178                                    (y-or-n-p
1179                                     (format "No public key for %s; skip it? "
1180                                             recipient)))
1181                          (error "No public key for %s" recipient))
1182                        recipient-key)
1183                      recipients)))
1184         (unless recipients
1185           (error "No recipient specified")))
1186       (message-options-set 'mml2015-epg-recipients recipients))
1187     (when sign
1188       (setq signers
1189             (or (message-options-get 'mml2015-epg-signers)
1190                 (message-options-set
1191                  'mml2015-epg-signers
1192                  (if (eq mm-sign-option 'guided)
1193                      (epa-select-keys context "\
1194 Select keys for signing.
1195 If no one is selected, default secret key is used.  "
1196                                       signer-names
1197                                       t)
1198                    (if (or sender mml2015-signers)
1199                        (delq nil
1200                              (mapcar
1201                               (lambda (signer)
1202                                 (setq signer-key
1203                                       (mml2015-epg-find-usable-secret-key
1204                                        context signer 'sign))
1205                                 (unless (or signer-key
1206                                             (y-or-n-p
1207                                              (format
1208                                               "No secret key for %s; skip it? "
1209                                               signer)))
1210                                   (error "No secret key for %s" signer))
1211                                 signer-key)
1212                               signer-names)))))))
1213       (epg-context-set-signers context signers))
1214     (epg-context-set-armor context t)
1215     (epg-context-set-textmode context t)
1216     (if mml2015-cache-passphrase
1217         (epg-context-set-passphrase-callback
1218          context
1219          #'mml2015-epg-passphrase-callback))
1220     (condition-case error
1221         (setq cipher
1222               (epg-encrypt-string context (buffer-string) recipients sign
1223                                   mml2015-always-trust)
1224               mml2015-epg-secret-key-id-list nil)
1225       (error
1226        (while mml2015-epg-secret-key-id-list
1227          (password-cache-remove (car mml2015-epg-secret-key-id-list))
1228          (setq mml2015-epg-secret-key-id-list
1229                (cdr mml2015-epg-secret-key-id-list)))
1230        (signal (car error) (cdr error))))
1231     (delete-region (point-min) (point-max))
1232     (goto-char (point-min))
1233     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
1234                     boundary))
1235     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
1236     (insert (format "--%s\n" boundary))
1237     (insert "Content-Type: application/pgp-encrypted\n\n")
1238     (insert "Version: 1\n\n")
1239     (insert (format "--%s\n" boundary))
1240     (insert "Content-Type: application/octet-stream\n\n")
1241     (insert cipher)
1242     (goto-char (point-max))
1243     (insert (format "--%s--\n" boundary))
1244     (goto-char (point-max))))
1245
1246 ;;; General wrapper
1247
1248 (autoload 'gnus-buffer-live-p "gnus-util")
1249 (autoload 'gnus-get-buffer-create "gnus")
1250
1251 (defun mml2015-clean-buffer ()
1252   (if (gnus-buffer-live-p mml2015-result-buffer)
1253       (with-current-buffer mml2015-result-buffer
1254         (erase-buffer)
1255         t)
1256     (setq mml2015-result-buffer
1257           (gnus-get-buffer-create " *MML2015 Result*"))
1258     nil))
1259
1260 (defsubst mml2015-clear-decrypt-function ()
1261   (nth 6 (assq mml2015-use mml2015-function-alist)))
1262
1263 (defsubst mml2015-clear-verify-function ()
1264   (nth 5 (assq mml2015-use mml2015-function-alist)))
1265
1266 ;;;###autoload
1267 (defun mml2015-decrypt (handle ctl)
1268   (mml2015-clean-buffer)
1269   (let ((func (nth 4 (assq mml2015-use mml2015-function-alist))))
1270     (if func
1271         (funcall func handle ctl)
1272       handle)))
1273
1274 ;;;###autoload
1275 (defun mml2015-decrypt-test (handle ctl)
1276   mml2015-use)
1277
1278 ;;;###autoload
1279 (defun mml2015-verify (handle ctl)
1280   (mml2015-clean-buffer)
1281   (let ((func (nth 3 (assq mml2015-use mml2015-function-alist))))
1282     (if func
1283         (funcall func handle ctl)
1284       handle)))
1285
1286 ;;;###autoload
1287 (defun mml2015-verify-test (handle ctl)
1288   mml2015-use)
1289
1290 ;;;###autoload
1291 (defun mml2015-encrypt (cont &optional sign)
1292   (mml2015-clean-buffer)
1293   (let ((func (nth 2 (assq mml2015-use mml2015-function-alist))))
1294     (if func
1295         (funcall func cont sign)
1296       (error "Cannot find encrypt function"))))
1297
1298 ;;;###autoload
1299 (defun mml2015-sign (cont)
1300   (mml2015-clean-buffer)
1301   (let ((func (nth 1 (assq mml2015-use mml2015-function-alist))))
1302     (if func
1303         (funcall func cont)
1304       (error "Cannot find sign function"))))
1305
1306 ;;;###autoload
1307 (defun mml2015-self-encrypt ()
1308   (mml2015-encrypt nil))
1309
1310 (provide 'mml2015)
1311
1312 ;;; mml2015.el ends here