lisp/gnus/mml2015.el

   1 ;;; mml2015.el --- MIME Security with Pretty Good Privacy (PGP)
   2
   3 ;; Copyright (C) 2000-2015 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 ;; Maybe this should be in eg mml-sec.el (and have a different name).
  51 ;; Then mml1991 would not need to require mml2015, and mml1991-use
  52 ;; could be removed.
  53 (defvar mml2015-use (or
  54                      (condition-case nil
  55                          (progn
  56                            (require 'epg-config)
  57                            (epg-check-configuration (epg-configuration))
  58                            'epg)
  59                        (error))
  60                      (progn
  61                        (let ((abs-file (locate-library "pgg")))
  62                          ;; Don't load PGG if it is marked as obsolete
  63                          ;; (Emacs 24).
  64                          (when (and abs-file
  65                                     (not (string-match "/obsolete/[^/]*\\'"
  66                                                        abs-file)))
  67                            (ignore-errors (require 'pgg))
  68                            (and (fboundp 'pgg-sign-region)
  69                                 'pgg))))
  70                      (progn (ignore-errors
  71                               (load "mc-toplev"))
  72                             (and (fboundp 'mc-encrypt-generic)
  73                                  (fboundp 'mc-sign-generic)
  74                                  (fboundp 'mc-cleanup-recipient-headers)
  75                                  'mailcrypt)))
  76   "The package used for PGP/MIME.
  77 Valid packages include `epg', `pgg' and `mailcrypt'.")
  78
  79 ;; Something is not RFC2015.
  80 (defvar mml2015-function-alist
  81   '((mailcrypt mml2015-mailcrypt-sign
  82                mml2015-mailcrypt-encrypt
  83                mml2015-mailcrypt-verify
  84                mml2015-mailcrypt-decrypt
  85                mml2015-mailcrypt-clear-verify
  86                mml2015-mailcrypt-clear-decrypt)
  87     (pgg mml2015-pgg-sign
  88          mml2015-pgg-encrypt
  89          mml2015-pgg-verify
  90          mml2015-pgg-decrypt
  91          mml2015-pgg-clear-verify
  92          mml2015-pgg-clear-decrypt)
  93     (epg mml2015-epg-sign
  94          mml2015-epg-encrypt
  95          mml2015-epg-verify
  96          mml2015-epg-decrypt
  97          mml2015-epg-clear-verify
  98          mml2015-epg-clear-decrypt))
  99   "Alist of PGP/MIME functions.")
 100
 101 (defvar mml2015-result-buffer nil)
 102
 103 (defcustom mml2015-unabbrev-trust-alist
 104   '(("TRUST_UNDEFINED" . nil)
 105     ("TRUST_NEVER"     . nil)
 106     ("TRUST_MARGINAL"  . t)
 107     ("TRUST_FULLY"     . t)
 108     ("TRUST_ULTIMATE"  . t))
 109   "Map GnuPG trust output values to a boolean saying if you trust the key."
 110   :version "22.1"
 111   :group 'mime-security
 112   :type '(repeat (cons (regexp :tag "GnuPG output regexp")
 113                        (boolean :tag "Trust key"))))
 114
 115 (defcustom mml2015-cache-passphrase mml-secure-cache-passphrase
 116   "If t, cache passphrase."
 117   :group 'mime-security
 118   :type 'boolean)
 119
 120 (defcustom mml2015-passphrase-cache-expiry mml-secure-passphrase-cache-expiry
 121   "How many seconds the passphrase is cached.
 122 Whether the passphrase is cached at all is controlled by
 123 `mml2015-cache-passphrase'."
 124   :group 'mime-security
 125   :type 'integer)
 126
 127 (defcustom mml2015-signers nil
 128   "A list of your own key ID(s) which will be used to sign a message.
 129 If set, it overrides the setting of `mml2015-sign-with-sender'."
 130   :group 'mime-security
 131   :type '(repeat (string :tag "Key ID")))
 132
 133 (defcustom mml2015-sign-with-sender nil
 134   "If t, use message sender so find a key to sign with."
 135   :group 'mime-security
 136   :type 'boolean
 137   :version "24.1")
 138
 139 (defcustom mml2015-encrypt-to-self nil
 140   "If t, add your own key ID to recipient list when encryption."
 141   :group 'mime-security
 142   :type 'boolean)
 143
 144 (defcustom mml2015-always-trust t
 145   "If t, GnuPG skip key validation on encryption."
 146   :group 'mime-security
 147   :type 'boolean)
 148
 149 (defcustom mml2015-maximum-key-image-dimension 64
 150   "The maximum dimension (width or height) of any key images."
 151   :version "24.4"
 152   :group 'mime-security
 153   :type 'integer)
 154
 155 (defcustom mml2015-display-key-image t
 156   "If t, try to display key images."
 157   :version "24.5"
 158   :group 'mime-security
 159   :type 'boolean)
 160
 161 ;; Extract plaintext from cleartext signature.  IMO, this kind of task
 162 ;; should be done by GnuPG rather than Elisp, but older PGP backends
 163 ;; (such as Mailcrypt, and PGG) discard the output from GnuPG.
 164 (defun mml2015-extract-cleartext-signature ()
 165   ;; Daiki Ueno in
 166   ;; <54a15d860801080142l70b95d7dkac4bf51a86196011@mail.gmail.com>: ``I still
 167   ;; believe that the right way is to use the plaintext output from GnuPG as
 168   ;; it is, and mml2015-extract-cleartext-signature is just a kludge for
 169   ;; misdesigned libraries like PGG, which have no ability to do that.  So, I
 170   ;; think it should not have descriptive documentation.''
 171   ;;
 172   ;; This function doesn't handle NotDashEscaped correctly.  EasyPG handles it
 173   ;; correctly.
 174   ;; http://thread.gmane.org/gmane.emacs.gnus.general/66062/focus=66082
 175   ;; http://thread.gmane.org/gmane.emacs.gnus.general/65087/focus=65109
 176   (goto-char (point-min))
 177   (forward-line)
 178   ;; We need to be careful not to strip beyond the armor headers.
 179   ;; Previously, an attacker could replace the text inside our
 180   ;; markup with trailing garbage by injecting whitespace into the
 181   ;; message.
 182   (while (looking-at "Hash:")           ; The only header allowed in cleartext
 183     (forward-line))                     ; signatures according to RFC2440.
 184   (when (looking-at "[\t ]*$")
 185     (forward-line))
 186   (delete-region (point-min) (point))
 187   (if (re-search-forward "^-----BEGIN PGP SIGNATURE-----" nil t)
 188       (delete-region (match-beginning 0) (point-max)))
 189   (goto-char (point-min))
 190   (while (re-search-forward "^- " nil t)
 191     (replace-match "" t t)
 192     (forward-line 1)))
 193
 194 ;;; mailcrypt wrapper
 195
 196 (autoload 'mailcrypt-decrypt "mailcrypt")
 197 (autoload 'mailcrypt-verify "mailcrypt")
 198 (autoload 'mc-pgp-always-sign "mailcrypt")
 199 (autoload 'mc-encrypt-generic "mc-toplev")
 200 (autoload 'mc-cleanup-recipient-headers "mc-toplev")
 201 (autoload 'mc-sign-generic "mc-toplev")
 202
 203 (defvar mml2015-decrypt-function 'mailcrypt-decrypt)
 204 (defvar mml2015-verify-function 'mailcrypt-verify)
 205
 206 (defun mml2015-format-error (err)
 207   (if (stringp (cadr err))
 208       (cadr err)
 209     (format "%S" (cdr err))))
 210
 211 (defun mml2015-mailcrypt-decrypt (handle ctl)
 212   (catch 'error
 213     (let (child handles result)
 214       (unless (setq child (mm-find-part-by-type
 215                            (cdr handle)
 216                            "application/octet-stream" nil t))
 217         (mm-set-handle-multipart-parameter
 218          mm-security-handle 'gnus-info "Corrupted")
 219         (throw 'error handle))
 220       (with-temp-buffer
 221         (mm-insert-part child)
 222         (setq result
 223               (condition-case err
 224                   (funcall mml2015-decrypt-function)
 225                 (error
 226                  (mm-set-handle-multipart-parameter
 227                   mm-security-handle 'gnus-details (mml2015-format-error err))
 228                  nil)
 229                 (quit
 230                  (mm-set-handle-multipart-parameter
 231                   mm-security-handle 'gnus-details "Quit.")
 232                  nil)))
 233         (unless (car result)
 234           (mm-set-handle-multipart-parameter
 235            mm-security-handle 'gnus-info "Failed")
 236           (throw 'error handle))
 237         (setq handles (mm-dissect-buffer t)))
 238       (mm-destroy-parts handle)
 239       (mm-set-handle-multipart-parameter
 240        mm-security-handle 'gnus-info
 241        (concat "OK"
 242                (let ((sig (with-current-buffer mml2015-result-buffer
 243                             (mml2015-gpg-extract-signature-details))))
 244                  (concat ", Signer: " sig))))
 245       (if (listp (car handles))
 246           handles
 247         (list handles)))))
 248
 249 (defun mml2015-gpg-pretty-print-fpr (fingerprint)
 250   (let* ((result "")
 251          (fpr-length (string-width fingerprint))
 252          (n-slice 0)
 253          slice)
 254     (setq fingerprint (string-to-list fingerprint))
 255     (while fingerprint
 256       (setq fpr-length (- fpr-length 4))
 257       (setq slice (butlast fingerprint fpr-length))
 258       (setq fingerprint (nthcdr 4 fingerprint))
 259       (setq n-slice (1+ n-slice))
 260       (setq result
 261             (concat
 262              result
 263              (case n-slice
 264                (1  slice)
 265                (otherwise (concat " " slice))))))
 266     result))
 267
 268 (defun mml2015-gpg-extract-signature-details ()
 269   (goto-char (point-min))
 270   (let* ((expired (re-search-forward
 271                    "^\\[GNUPG:\\] SIGEXPIRED$"
 272                    nil t))
 273          (signer (and (re-search-forward
 274                        "^\\[GNUPG:\\] GOODSIG \\([0-9A-Za-z]*\\) \\(.*\\)$"
 275                        nil t)
 276                       (cons (match-string 1) (match-string 2))))
 277          (fprint (and (re-search-forward
 278                        "^\\[GNUPG:\\] VALIDSIG \\([0-9a-zA-Z]*\\) "
 279                        nil t)
 280                       (match-string 1)))
 281          (trust  (and (re-search-forward
 282                        "^\\[GNUPG:\\] \\(TRUST_.*\\)$"
 283                        nil t)
 284                       (match-string 1)))
 285          (trust-good-enough-p
 286           (cdr (assoc trust mml2015-unabbrev-trust-alist))))
 287     (cond ((and signer fprint)
 288            (concat (cdr signer)
 289                    (unless trust-good-enough-p
 290                      (concat "\nUntrusted, Fingerprint: "
 291                              (mml2015-gpg-pretty-print-fpr fprint)))
 292                    (when expired
 293                      (format "\nWARNING: Signature from expired key (%s)"
 294                              (car signer)))))
 295           ((re-search-forward
 296             "^\\(gpg: \\)?Good signature from \"\\(.*\\)\"$" nil t)
 297            (match-string 2))
 298           (t
 299            "From unknown user"))))
 300
 301 (defun mml2015-mailcrypt-clear-decrypt ()
 302   (let (result)
 303     (setq result
 304           (condition-case err
 305               (funcall mml2015-decrypt-function)
 306             (error
 307              (mm-set-handle-multipart-parameter
 308               mm-security-handle 'gnus-details (mml2015-format-error err))
 309              nil)
 310             (quit
 311              (mm-set-handle-multipart-parameter
 312               mm-security-handle 'gnus-details "Quit.")
 313              nil)))
 314     (if (car result)
 315         (mm-set-handle-multipart-parameter
 316          mm-security-handle 'gnus-info "OK")
 317       (mm-set-handle-multipart-parameter
 318        mm-security-handle 'gnus-info "Failed"))))
 319
 320 (defun mml2015-fix-micalg (alg)
 321   (and alg
 322        ;; Mutt/1.2.5i has seen sending micalg=php-sha1
 323        (upcase (if (string-match "^p[gh]p-" alg)
 324                    (substring alg (match-end 0))
 325                  alg))))
 326
 327 (defun mml2015-mailcrypt-verify (handle ctl)
 328   (catch 'error
 329     (let (part)
 330       (unless (setq part (mm-find-raw-part-by-type
 331                           ctl (or (mm-handle-multipart-ctl-parameter
 332                                    ctl 'protocol)
 333                                   "application/pgp-signature")
 334                           t))
 335         (mm-set-handle-multipart-parameter
 336          mm-security-handle 'gnus-info "Corrupted")
 337         (throw 'error handle))
 338       (with-temp-buffer
 339         (insert "-----BEGIN PGP SIGNED MESSAGE-----\n")
 340         (insert (format "Hash: %s\n\n"
 341                         (or (mml2015-fix-micalg
 342                              (mm-handle-multipart-ctl-parameter
 343                               ctl 'micalg))
 344                             "SHA1")))
 345         (save-restriction
 346           (narrow-to-region (point) (point))
 347           (insert part "\n")
 348           (goto-char (point-min))
 349           (while (not (eobp))
 350             (if (looking-at "^-")
 351                 (insert "- "))
 352             (forward-line)))
 353         (unless (setq part (mm-find-part-by-type
 354                             (cdr handle) "application/pgp-signature" nil t))
 355           (mm-set-handle-multipart-parameter
 356            mm-security-handle 'gnus-info "Corrupted")
 357           (throw 'error handle))
 358         (save-restriction
 359           (narrow-to-region (point) (point))
 360           (mm-insert-part part)
 361           (goto-char (point-min))
 362           (if (re-search-forward "^-----BEGIN PGP [^-]+-----\r?$" nil t)
 363               (replace-match "-----BEGIN PGP SIGNATURE-----" t t))
 364           (if (re-search-forward "^-----END PGP [^-]+-----\r?$" nil t)
 365               (replace-match "-----END PGP SIGNATURE-----" t t)))
 366         (let ((mc-gpg-debug-buffer (get-buffer-create " *gnus gpg debug*")))
 367           (unless (condition-case err
 368                       (prog1
 369                           (funcall mml2015-verify-function)
 370                         (if (get-buffer " *mailcrypt stderr temp")
 371                             (mm-set-handle-multipart-parameter
 372                              mm-security-handle 'gnus-details
 373                              (with-current-buffer " *mailcrypt stderr temp"
 374                                (buffer-string))))
 375                         (if (get-buffer " *mailcrypt stdout temp")
 376                             (kill-buffer " *mailcrypt stdout temp"))
 377                         (if (get-buffer " *mailcrypt stderr temp")
 378                             (kill-buffer " *mailcrypt stderr temp"))
 379                         (if (get-buffer " *mailcrypt status temp")
 380                             (kill-buffer " *mailcrypt status temp"))
 381                         (if (get-buffer mc-gpg-debug-buffer)
 382                             (kill-buffer mc-gpg-debug-buffer)))
 383                     (error
 384                      (mm-set-handle-multipart-parameter
 385                       mm-security-handle 'gnus-details (mml2015-format-error err))
 386                      nil)
 387                     (quit
 388                      (mm-set-handle-multipart-parameter
 389                       mm-security-handle 'gnus-details "Quit.")
 390                      nil))
 391             (mm-set-handle-multipart-parameter
 392              mm-security-handle 'gnus-info "Failed")
 393             (throw 'error handle))))
 394       (mm-set-handle-multipart-parameter
 395        mm-security-handle 'gnus-info "OK")
 396       handle)))
 397
 398 (defun mml2015-mailcrypt-clear-verify ()
 399   (let ((mc-gpg-debug-buffer (get-buffer-create " *gnus gpg debug*")))
 400     (if (condition-case err
 401             (prog1
 402                 (funcall mml2015-verify-function)
 403               (if (get-buffer " *mailcrypt stderr temp")
 404                   (mm-set-handle-multipart-parameter
 405                    mm-security-handle 'gnus-details
 406                    (with-current-buffer " *mailcrypt stderr temp"
 407                      (buffer-string))))
 408               (if (get-buffer " *mailcrypt stdout temp")
 409                   (kill-buffer " *mailcrypt stdout temp"))
 410               (if (get-buffer " *mailcrypt stderr temp")
 411                   (kill-buffer " *mailcrypt stderr temp"))
 412               (if (get-buffer " *mailcrypt status temp")
 413                   (kill-buffer " *mailcrypt status temp"))
 414               (if (get-buffer mc-gpg-debug-buffer)
 415                   (kill-buffer mc-gpg-debug-buffer)))
 416           (error
 417            (mm-set-handle-multipart-parameter
 418             mm-security-handle 'gnus-details (mml2015-format-error err))
 419            nil)
 420           (quit
 421            (mm-set-handle-multipart-parameter
 422             mm-security-handle 'gnus-details "Quit.")
 423            nil))
 424         (mm-set-handle-multipart-parameter
 425          mm-security-handle 'gnus-info "OK")
 426       (mm-set-handle-multipart-parameter
 427        mm-security-handle 'gnus-info "Failed")))
 428   (mml2015-extract-cleartext-signature))
 429
 430 (defun mml2015-mailcrypt-sign (cont)
 431   (mc-sign-generic (message-options-get 'message-sender)
 432                    nil nil nil nil)
 433   (let ((boundary (mml-compute-boundary cont))
 434         hash point)
 435     (goto-char (point-min))
 436     (unless (re-search-forward "^-----BEGIN PGP SIGNED MESSAGE-----\r?$" nil t)
 437       (error "Cannot find signed begin line"))
 438     (goto-char (match-beginning 0))
 439     (forward-line 1)
 440     (unless (looking-at "Hash:[ \t]*\\([a-zA-Z0-9]+\\)")
 441       (error "Cannot not find PGP hash"))
 442     (setq hash (match-string 1))
 443     (unless (re-search-forward "^$" nil t)
 444       (error "Cannot not find PGP message"))
 445     (forward-line 1)
 446     (delete-region (point-min) (point))
 447     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
 448                     boundary))
 449     (insert (format "\tmicalg=pgp-%s; protocol=\"application/pgp-signature\"\n"
 450                     (downcase hash)))
 451     (insert (format "\n--%s\n" boundary))
 452     (setq point (point))
 453     (goto-char (point-max))
 454     (unless (re-search-backward "^-----END PGP SIGNATURE-----\r?$" nil t)
 455       (error "Cannot find signature part"))
 456     (replace-match "-----END PGP MESSAGE-----" t t)
 457     (goto-char (match-beginning 0))
 458     (unless (re-search-backward "^-----BEGIN PGP SIGNATURE-----\r?$"
 459                                 nil t)
 460       (error "Cannot find signature part"))
 461     (replace-match "-----BEGIN PGP MESSAGE-----" t t)
 462     (goto-char (match-beginning 0))
 463     (save-restriction
 464       (narrow-to-region point (point))
 465       (goto-char point)
 466       (while (re-search-forward "^- -" nil t)
 467         (replace-match "-" t t))
 468       (goto-char (point-max)))
 469     (insert (format "--%s\n" boundary))
 470     (insert "Content-Type: application/pgp-signature\n\n")
 471     (goto-char (point-max))
 472     (insert (format "--%s--\n" boundary))
 473     (goto-char (point-max))))
 474
 475 ;; We require mm-decode, which requires mm-bodies, which autoloads
 476 ;; message-options-get (!).
 477 (declare-function message-options-set "message" (symbol value))
 478
 479 (defun mml2015-mailcrypt-encrypt (cont &optional sign)
 480   (let ((mc-pgp-always-sign
 481          (or mc-pgp-always-sign
 482              sign
 483              (eq t (or (message-options-get 'message-sign-encrypt)
 484                        (message-options-set
 485                         'message-sign-encrypt
 486                         (or (y-or-n-p "Sign the message? ")
 487                             'not))))
 488              'never)))
 489     (mm-with-unibyte-current-buffer
 490       (mc-encrypt-generic
 491        (or (message-options-get 'message-recipients)
 492            (message-options-set 'message-recipients
 493                               (mc-cleanup-recipient-headers
 494                                (read-string "Recipients: "))))
 495        nil nil nil
 496        (message-options-get 'message-sender))))
 497   (goto-char (point-min))
 498   (unless (looking-at "-----BEGIN PGP MESSAGE-----")
 499     (error "Fail to encrypt the message"))
 500   (let ((boundary (mml-compute-boundary cont)))
 501     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
 502                     boundary))
 503     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
 504     (insert (format "--%s\n" boundary))
 505     (insert "Content-Type: application/pgp-encrypted\n\n")
 506     (insert "Version: 1\n\n")
 507     (insert (format "--%s\n" boundary))
 508     (insert "Content-Type: application/octet-stream\n\n")
 509     (goto-char (point-max))
 510     (insert (format "--%s--\n" boundary))
 511     (goto-char (point-max))))
 512
 513 ;;; pgg wrapper
 514
 515 (defvar pgg-default-user-id)
 516 (defvar pgg-errors-buffer)
 517 (defvar pgg-output-buffer)
 518
 519 (autoload 'pgg-decrypt-region "pgg")
 520 (autoload 'pgg-verify-region "pgg")
 521 (autoload 'pgg-sign-region "pgg")
 522 (autoload 'pgg-encrypt-region "pgg")
 523 (autoload 'pgg-parse-armor "pgg-parse")
 524
 525 (defun mml2015-pgg-decrypt (handle ctl)
 526   (catch 'error
 527     (let ((pgg-errors-buffer mml2015-result-buffer)
 528           child handles result decrypt-status)
 529       (unless (setq child (mm-find-part-by-type
 530                            (cdr handle)
 531                            "application/octet-stream" nil t))
 532         (mm-set-handle-multipart-parameter
 533          mm-security-handle 'gnus-info "Corrupted")
 534         (throw 'error handle))
 535       (with-temp-buffer
 536         (mm-insert-part child)
 537         (if (condition-case err
 538                 (prog1
 539                     (pgg-decrypt-region (point-min) (point-max))
 540                   (setq decrypt-status
 541                         (with-current-buffer mml2015-result-buffer
 542                           (buffer-string)))
 543                   (mm-set-handle-multipart-parameter
 544                    mm-security-handle 'gnus-details
 545                    decrypt-status))
 546               (error
 547                (mm-set-handle-multipart-parameter
 548                 mm-security-handle 'gnus-details (mml2015-format-error err))
 549                nil)
 550               (quit
 551                (mm-set-handle-multipart-parameter
 552                 mm-security-handle 'gnus-details "Quit.")
 553                nil))
 554             (with-current-buffer pgg-output-buffer
 555               (goto-char (point-min))
 556               (while (search-forward "\r\n" nil t)
 557                 (replace-match "\n" t t))
 558               (setq handles (mm-dissect-buffer t))
 559               (mm-destroy-parts handle)
 560               (mm-set-handle-multipart-parameter
 561                mm-security-handle 'gnus-info "OK")
 562               (mm-set-handle-multipart-parameter
 563                mm-security-handle 'gnus-details
 564                (concat decrypt-status
 565                        (when (stringp (car handles))
 566                          "\n" (mm-handle-multipart-ctl-parameter
 567                                handles 'gnus-details))))
 568               (if (listp (car handles))
 569                   handles
 570                 (list handles)))
 571           (mm-set-handle-multipart-parameter
 572            mm-security-handle 'gnus-info "Failed")
 573           (throw 'error handle))))))
 574
 575 (defun mml2015-pgg-clear-decrypt ()
 576   (let ((pgg-errors-buffer mml2015-result-buffer))
 577     (if (prog1
 578             (pgg-decrypt-region (point-min) (point-max))
 579           (mm-set-handle-multipart-parameter
 580            mm-security-handle 'gnus-details
 581            (with-current-buffer mml2015-result-buffer
 582              (buffer-string))))
 583         (progn
 584           (erase-buffer)
 585           ;; Treat data which pgg returns as a unibyte string.
 586           (mm-disable-multibyte)
 587           (insert-buffer-substring pgg-output-buffer)
 588           (goto-char (point-min))
 589           (while (search-forward "\r\n" nil t)
 590             (replace-match "\n" t t))
 591           (mm-set-handle-multipart-parameter
 592            mm-security-handle 'gnus-info "OK"))
 593       (mm-set-handle-multipart-parameter
 594        mm-security-handle 'gnus-info "Failed"))))
 595
 596 (defun mml2015-pgg-verify (handle ctl)
 597   (let ((pgg-errors-buffer mml2015-result-buffer)
 598         signature-file part signature)
 599     (if (or (null (setq part (mm-find-raw-part-by-type
 600                               ctl (or (mm-handle-multipart-ctl-parameter
 601                                        ctl 'protocol)
 602                                       "application/pgp-signature")
 603                               t)))
 604             (null (setq signature (mm-find-part-by-type
 605                                    (cdr handle) "application/pgp-signature" nil t))))
 606         (progn
 607           (mm-set-handle-multipart-parameter
 608            mm-security-handle 'gnus-info "Corrupted")
 609           handle)
 610       (with-temp-buffer
 611         (insert part)
 612         ;; Convert <LF> to <CR><LF> in signed text.  If --textmode is
 613         ;; specified when signing, the conversion is not necessary.
 614         (goto-char (point-min))
 615         (end-of-line)
 616         (while (not (eobp))
 617           (unless (eq (char-before) ?\r)
 618             (insert "\r"))
 619           (forward-line)
 620           (end-of-line))
 621         (with-temp-file (setq signature-file (mm-make-temp-file "pgg"))
 622           (mm-insert-part signature))
 623         (if (condition-case err
 624                 (prog1
 625                     (pgg-verify-region (point-min) (point-max)
 626                                        signature-file t)
 627                   (goto-char (point-min))
 628                   (while (search-forward "\r\n" nil t)
 629                     (replace-match "\n" t t))
 630                   (mm-set-handle-multipart-parameter
 631                    mm-security-handle 'gnus-details
 632                    (concat (with-current-buffer pgg-output-buffer
 633                              (buffer-string))
 634                            (with-current-buffer pgg-errors-buffer
 635                              (buffer-string)))))
 636               (error
 637                (mm-set-handle-multipart-parameter
 638                 mm-security-handle 'gnus-details (mml2015-format-error err))
 639                nil)
 640               (quit
 641                (mm-set-handle-multipart-parameter
 642                 mm-security-handle 'gnus-details "Quit.")
 643                nil))
 644             (progn
 645               (delete-file signature-file)
 646               (mm-set-handle-multipart-parameter
 647                mm-security-handle 'gnus-info
 648                (with-current-buffer pgg-errors-buffer
 649                  (mml2015-gpg-extract-signature-details))))
 650           (delete-file signature-file)
 651           (mm-set-handle-multipart-parameter
 652            mm-security-handle 'gnus-info "Failed")))))
 653   handle)
 654
 655 (defun mml2015-pgg-clear-verify ()
 656   (let ((pgg-errors-buffer mml2015-result-buffer)
 657         (text (buffer-string))
 658         (coding-system buffer-file-coding-system))
 659     (if (condition-case err
 660             (prog1
 661                 (mm-with-unibyte-buffer
 662                   (insert (mm-encode-coding-string text coding-system))
 663                   (pgg-verify-region (point-min) (point-max) nil t))
 664               (goto-char (point-min))
 665               (while (search-forward "\r\n" nil t)
 666                 (replace-match "\n" t t))
 667               (mm-set-handle-multipart-parameter
 668                mm-security-handle 'gnus-details
 669                (concat (with-current-buffer pgg-output-buffer
 670                          (buffer-string))
 671                        (with-current-buffer pgg-errors-buffer
 672                          (buffer-string)))))
 673           (error
 674            (mm-set-handle-multipart-parameter
 675             mm-security-handle 'gnus-details (mml2015-format-error err))
 676            nil)
 677           (quit
 678            (mm-set-handle-multipart-parameter
 679             mm-security-handle 'gnus-details "Quit.")
 680            nil))
 681         (mm-set-handle-multipart-parameter
 682          mm-security-handle 'gnus-info
 683          (with-current-buffer pgg-errors-buffer
 684            (mml2015-gpg-extract-signature-details)))
 685       (mm-set-handle-multipart-parameter
 686        mm-security-handle 'gnus-info "Failed")))
 687   (mml2015-extract-cleartext-signature))
 688
 689 (defun mml2015-pgg-sign (cont)
 690   (let ((pgg-errors-buffer mml2015-result-buffer)
 691         (boundary (mml-compute-boundary cont))
 692         (pgg-default-user-id (or (message-options-get 'mml-sender)
 693                                  pgg-default-user-id))
 694         (pgg-text-mode t)
 695         entry)
 696     (unless (pgg-sign-region (point-min) (point-max))
 697       (pop-to-buffer mml2015-result-buffer)
 698       (error "Sign error"))
 699     (goto-char (point-min))
 700     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
 701                     boundary))
 702     (if (setq entry (assq 2 (pgg-parse-armor
 703                              (with-current-buffer pgg-output-buffer
 704                                (buffer-string)))))
 705         (setq entry (assq 'hash-algorithm (cdr entry))))
 706     (insert (format "\tmicalg=%s; "
 707                     (if (cdr entry)
 708                         (downcase (format "pgp-%s" (cdr entry)))
 709                       "pgp-sha1")))
 710     (insert "protocol=\"application/pgp-signature\"\n")
 711     (insert (format "\n--%s\n" boundary))
 712     (goto-char (point-max))
 713     (insert (format "\n--%s\n" boundary))
 714     (insert "Content-Type: application/pgp-signature\n\n")
 715     (insert-buffer-substring pgg-output-buffer)
 716     (goto-char (point-max))
 717     (insert (format "--%s--\n" boundary))
 718     (goto-char (point-max))))
 719
 720 (defun mml2015-pgg-encrypt (cont &optional sign)
 721   (let ((pgg-errors-buffer mml2015-result-buffer)
 722         (pgg-text-mode t)
 723         (boundary (mml-compute-boundary cont)))
 724     (unless (pgg-encrypt-region (point-min) (point-max)
 725                                 (split-string
 726                                  (or
 727                                   (message-options-get 'message-recipients)
 728                                   (message-options-set 'message-recipients
 729                                                        (read-string "Recipients: ")))
 730                                  "[ \f\t\n\r\v,]+")
 731                                 sign)
 732       (pop-to-buffer mml2015-result-buffer)
 733       (error "Encrypt error"))
 734     (delete-region (point-min) (point-max))
 735     (goto-char (point-min))
 736     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
 737                     boundary))
 738     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
 739     (insert (format "--%s\n" boundary))
 740     (insert "Content-Type: application/pgp-encrypted\n\n")
 741     (insert "Version: 1\n\n")
 742     (insert (format "--%s\n" boundary))
 743     (insert "Content-Type: application/octet-stream\n\n")
 744     (insert-buffer-substring pgg-output-buffer)
 745     (goto-char (point-max))
 746     (insert (format "--%s--\n" boundary))
 747     (goto-char (point-max))))
 748
 749 ;;; epg wrapper
 750
 751 (defvar epg-user-id-alist)
 752 (defvar epg-digest-algorithm-alist)
 753 (defvar epg-gpg-program)
 754 (defvar inhibit-redisplay)
 755
 756 (autoload 'epg-make-context "epg")
 757 (autoload 'epg-context-set-armor "epg")
 758 (autoload 'epg-context-set-textmode "epg")
 759 (autoload 'epg-context-set-signers "epg")
 760 (autoload 'epg-context-result-for "epg")
 761 (autoload 'epg-new-signature-digest-algorithm "epg")
 762 (autoload 'epg-list-keys "epg")
 763 (autoload 'epg-decrypt-string "epg")
 764 (autoload 'epg-verify-string "epg")
 765 (autoload 'epg-sign-string "epg")
 766 (autoload 'epg-encrypt-string "epg")
 767 (autoload 'epg-passphrase-callback-function "epg")
 768 (autoload 'epg-context-set-passphrase-callback "epg")
 769 (autoload 'epg-key-sub-key-list "epg")
 770 (autoload 'epg-sub-key-capability "epg")
 771 (autoload 'epg-sub-key-validity "epg")
 772 (autoload 'epg-sub-key-fingerprint "epg")
 773 (autoload 'epg-signature-key-id "epg")
 774 (autoload 'epg-signature-to-string "epg")
 775 (autoload 'epg-key-user-id-list "epg")
 776 (autoload 'epg-user-id-string "epg")
 777 (autoload 'epg-user-id-validity "epg")
 778 (autoload 'epg-configuration "epg-config")
 779 (autoload 'epg-expand-group "epg-config")
 780 (autoload 'epa-select-keys "epa")
 781
 782 (defvar mml2015-epg-secret-key-id-list nil)
 783
 784 (defun mml2015-epg-passphrase-callback (context key-id ignore)
 785   (if (eq key-id 'SYM)
 786       (epg-passphrase-callback-function context key-id nil)
 787     (let* ((password-cache-key-id
 788             (if (eq key-id 'PIN)
 789                 "PIN"
 790                key-id))
 791            entry
 792            (passphrase
 793             (password-read
 794              (if (eq key-id 'PIN)
 795                  "Passphrase for PIN: "
 796                (if (setq entry (assoc key-id epg-user-id-alist))
 797                    (format "Passphrase for %s %s: " key-id (cdr entry))
 798                  (format "Passphrase for %s: " key-id)))
 799              password-cache-key-id)))
 800       (when passphrase
 801         (let ((password-cache-expiry mml2015-passphrase-cache-expiry))
 802           (password-cache-add password-cache-key-id passphrase))
 803         (setq mml2015-epg-secret-key-id-list
 804               (cons password-cache-key-id mml2015-epg-secret-key-id-list))
 805         (copy-sequence passphrase)))))
 806
 807 (defun mml2015-epg-check-user-id (key recipient)
 808   (let ((pointer (epg-key-user-id-list key))
 809         result)
 810     (while pointer
 811       (if (and (equal (car (mail-header-parse-address
 812                             (epg-user-id-string (car pointer))))
 813                       (car (mail-header-parse-address
 814                             recipient)))
 815                (not (memq (epg-user-id-validity (car pointer))
 816                           '(revoked expired))))
 817           (setq result t
 818                 pointer nil)
 819         (setq pointer (cdr pointer))))
 820     result))
 821
 822 (defun mml2015-epg-check-sub-key (key usage)
 823   (let ((pointer (epg-key-sub-key-list key))
 824         result)
 825     ;; The primary key will be marked as disabled, when the entire
 826     ;; key is disabled (see 12 Field, Format of colon listings, in
 827     ;; gnupg/doc/DETAILS)
 828     (unless (memq 'disabled (epg-sub-key-capability (car pointer)))
 829       (while pointer
 830         (if (and (memq usage (epg-sub-key-capability (car pointer)))
 831                  (not (memq (epg-sub-key-validity (car pointer))
 832                             '(revoked expired))))
 833             (setq result t
 834                   pointer nil)
 835           (setq pointer (cdr pointer)))))
 836     result))
 837
 838 (defun mml2015-epg-find-usable-key (context name usage
 839                                             &optional name-is-key-id)
 840   (let ((keys (epg-list-keys context name))
 841         key)
 842     (while keys
 843       (if (and (or name-is-key-id
 844                    ;; Non email user-id can be supplied through
 845                    ;; mml2015-signers if mml2015-encrypt-to-self is set.
 846                    ;; Treat it as valid, as it is user's intention.
 847                    (not (string-match "\\`<" name))
 848                    (mml2015-epg-check-user-id (car keys) name))
 849                (mml2015-epg-check-sub-key (car keys) usage))
 850           (setq key (car keys)
 851                 keys nil)
 852         (setq keys (cdr keys))))
 853     key))
 854
 855 ;; XXX: since gpg --list-secret-keys does not return validity of each
 856 ;; key, `mml2015-epg-find-usable-key' defined above is not enough for
 857 ;; secret keys.  The function `mml2015-epg-find-usable-secret-key'
 858 ;; below looks at appropriate public keys to check usability.
 859 (defun mml2015-epg-find-usable-secret-key (context name usage)
 860   (let ((secret-keys (epg-list-keys context name t))
 861         secret-key)
 862     (while (and (not secret-key) secret-keys)
 863       (if (mml2015-epg-find-usable-key
 864            context
 865            (epg-sub-key-fingerprint
 866             (car (epg-key-sub-key-list
 867                   (car secret-keys))))
 868            usage
 869            t)
 870           (setq secret-key (car secret-keys)
 871                 secret-keys nil)
 872         (setq secret-keys (cdr secret-keys))))
 873     secret-key))
 874
 875 (autoload 'gnus-create-image "gnus-ems")
 876
 877 (defun mml2015-epg-key-image (key-id)
 878   "Return the image of a key, if any"
 879   (with-temp-buffer
 880     (mm-set-buffer-multibyte nil)
 881     (let* ((coding-system-for-write 'binary)
 882            (coding-system-for-read 'binary)
 883            (data (shell-command-to-string
 884                   (format "%s --list-options no-show-photos --attribute-fd 3 --list-keys %s 3>&1 >/dev/null 2>&1"
 885                           (shell-quote-argument epg-gpg-program) key-id))))
 886       (when (> (length data) 0)
 887         (insert (substring data 16))
 888         (condition-case nil
 889             (gnus-create-image (buffer-string) nil t)
 890           (error))))))
 891
 892 (autoload 'gnus-rescale-image "gnus-util")
 893
 894 (defun mml2015-epg-key-image-to-string (key-id)
 895   "Return a string with the image of a key, if any"
 896   (let ((key-image (mml2015-epg-key-image key-id)))
 897     (if (not key-image)
 898         ""
 899       (condition-case error
 900           (let ((result "  "))
 901             (put-text-property
 902              1 2 'display
 903              (gnus-rescale-image key-image
 904                                  (cons mml2015-maximum-key-image-dimension
 905                                        mml2015-maximum-key-image-dimension))
 906              result)
 907             result)
 908         (error "")))))
 909
 910 (defun mml2015-epg-signature-to-string (signature)
 911   (concat (epg-signature-to-string signature)
 912           (when mml2015-display-key-image
 913             (mml2015-epg-key-image-to-string (epg-signature-key-id signature)))))
 914
 915 (defun mml2015-epg-verify-result-to-string (verify-result)
 916   (mapconcat #'mml2015-epg-signature-to-string verify-result "\n"))
 917
 918 (defun mml2015-epg-decrypt (handle ctl)
 919   (catch 'error
 920     (let ((inhibit-redisplay t)
 921           context plain child handles result decrypt-status)
 922       (unless (setq child (mm-find-part-by-type
 923                            (cdr handle)
 924                            "application/octet-stream" nil t))
 925         (mm-set-handle-multipart-parameter
 926          mm-security-handle 'gnus-info "Corrupted")
 927         (throw 'error handle))
 928       (setq context (epg-make-context))
 929       (if mml2015-cache-passphrase
 930           (epg-context-set-passphrase-callback
 931            context
 932            #'mml2015-epg-passphrase-callback))
 933       (condition-case error
 934           (setq plain (epg-decrypt-string context (mm-get-part child))
 935                 mml2015-epg-secret-key-id-list nil)
 936         (error
 937          (while mml2015-epg-secret-key-id-list
 938            (password-cache-remove (car mml2015-epg-secret-key-id-list))
 939            (setq mml2015-epg-secret-key-id-list
 940                  (cdr mml2015-epg-secret-key-id-list)))
 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          (throw 'error handle)))
 949       (with-temp-buffer
 950         (insert plain)
 951         (goto-char (point-min))
 952         (while (search-forward "\r\n" nil t)
 953           (replace-match "\n" t t))
 954         (setq handles (mm-dissect-buffer t))
 955         (mm-destroy-parts handle)
 956         (if (epg-context-result-for context 'verify)
 957             (mm-set-handle-multipart-parameter
 958              mm-security-handle 'gnus-info
 959              (concat "OK\n"
 960                      (mml2015-epg-verify-result-to-string
 961                       (epg-context-result-for context 'verify))))
 962           (mm-set-handle-multipart-parameter
 963            mm-security-handle 'gnus-info "OK"))
 964         (if (stringp (car handles))
 965             (mm-set-handle-multipart-parameter
 966              mm-security-handle 'gnus-details
 967              (mm-handle-multipart-ctl-parameter handles 'gnus-details))))
 968         (if (listp (car handles))
 969             handles
 970           (list handles)))))
 971
 972 (defun mml2015-epg-clear-decrypt ()
 973   (let ((inhibit-redisplay t)
 974         (context (epg-make-context))
 975         plain)
 976     (if mml2015-cache-passphrase
 977         (epg-context-set-passphrase-callback
 978          context
 979          #'mml2015-epg-passphrase-callback))
 980     (condition-case error
 981         (setq plain (epg-decrypt-string context (buffer-string))
 982               mml2015-epg-secret-key-id-list nil)
 983       (error
 984        (while mml2015-epg-secret-key-id-list
 985          (password-cache-remove (car mml2015-epg-secret-key-id-list))
 986          (setq mml2015-epg-secret-key-id-list
 987                (cdr mml2015-epg-secret-key-id-list)))
 988        (mm-set-handle-multipart-parameter
 989         mm-security-handle 'gnus-info "Failed")
 990        (if (eq (car error) 'quit)
 991            (mm-set-handle-multipart-parameter
 992             mm-security-handle 'gnus-details "Quit.")
 993          (mm-set-handle-multipart-parameter
 994           mm-security-handle 'gnus-details (mml2015-format-error error)))))
 995     (when plain
 996       (erase-buffer)
 997       ;; Treat data which epg returns as a unibyte string.
 998       (mm-disable-multibyte)
 999       (insert plain)
1000       (goto-char (point-min))
1001       (while (search-forward "\r\n" nil t)
1002         (replace-match "\n" t t))
1003       (mm-set-handle-multipart-parameter
1004        mm-security-handle 'gnus-info "OK")
1005       (if (epg-context-result-for context 'verify)
1006           (mm-set-handle-multipart-parameter
1007            mm-security-handle 'gnus-details
1008            (mml2015-epg-verify-result-to-string
1009             (epg-context-result-for context 'verify)))))))
1010
1011 (defun mml2015-epg-verify (handle ctl)
1012   (catch 'error
1013     (let ((inhibit-redisplay t)
1014           context plain signature-file part signature)
1015       (when (or (null (setq part (mm-find-raw-part-by-type
1016                                   ctl (or (mm-handle-multipart-ctl-parameter
1017                                            ctl 'protocol)
1018                                           "application/pgp-signature")
1019                                   t)))
1020                 (null (setq signature (mm-find-part-by-type
1021                                        (cdr handle) "application/pgp-signature"
1022                                        nil t))))
1023         (mm-set-handle-multipart-parameter
1024          mm-security-handle 'gnus-info "Corrupted")
1025         (throw 'error handle))
1026       (setq part (mm-replace-in-string part "\n" "\r\n")
1027             signature (mm-get-part signature)
1028             context (epg-make-context))
1029       (condition-case error
1030           (setq plain (epg-verify-string context signature part))
1031         (error
1032          (mm-set-handle-multipart-parameter
1033           mm-security-handle 'gnus-info "Failed")
1034          (if (eq (car error) 'quit)
1035              (mm-set-handle-multipart-parameter
1036               mm-security-handle 'gnus-details "Quit.")
1037            (mm-set-handle-multipart-parameter
1038             mm-security-handle 'gnus-details (mml2015-format-error error)))
1039          (throw 'error handle)))
1040       (mm-set-handle-multipart-parameter
1041        mm-security-handle 'gnus-info
1042        (mml2015-epg-verify-result-to-string
1043         (epg-context-result-for context 'verify)))
1044       handle)))
1045
1046 (defun mml2015-epg-clear-verify ()
1047   (let ((inhibit-redisplay t)
1048         (context (epg-make-context))
1049         (signature (mm-encode-coding-string (buffer-string)
1050                                             coding-system-for-write))
1051         plain)
1052     (condition-case error
1053         (setq plain (epg-verify-string context signature))
1054       (error
1055        (mm-set-handle-multipart-parameter
1056         mm-security-handle 'gnus-info "Failed")
1057        (if (eq (car error) 'quit)
1058            (mm-set-handle-multipart-parameter
1059             mm-security-handle 'gnus-details "Quit.")
1060          (mm-set-handle-multipart-parameter
1061           mm-security-handle 'gnus-details (mml2015-format-error error)))))
1062     (if plain
1063         (progn
1064           (mm-set-handle-multipart-parameter
1065            mm-security-handle 'gnus-info
1066            (mml2015-epg-verify-result-to-string
1067             (epg-context-result-for context 'verify)))
1068           (delete-region (point-min) (point-max))
1069           (insert (mm-decode-coding-string plain coding-system-for-read)))
1070       (mml2015-extract-cleartext-signature))))
1071
1072 (defun mml2015-epg-sign (cont)
1073   (let* ((inhibit-redisplay t)
1074          (context (epg-make-context))
1075          (boundary (mml-compute-boundary cont))
1076          (sender (message-options-get 'message-sender))
1077          (signer-names (or mml2015-signers
1078                            (if (and mml2015-sign-with-sender sender)
1079                                (list (concat "<" sender ">")))))
1080          signer-key
1081          (signers
1082           (or (message-options-get 'mml2015-epg-signers)
1083               (message-options-set
1084                'mml2015-epg-signers
1085                (if (eq mm-sign-option 'guided)
1086                    (epa-select-keys context "\
1087 Select keys for signing.
1088 If no one is selected, default secret key is used.  "
1089                                     signer-names
1090                                     t)
1091                  (if (or sender mml2015-signers)
1092                      (delq nil
1093                            (mapcar
1094                             (lambda (signer)
1095                               (setq signer-key
1096                                     (mml2015-epg-find-usable-secret-key
1097                                      context signer 'sign))
1098                               (unless (or signer-key
1099                                           (y-or-n-p
1100                                            (format
1101                                             "No secret key for %s; skip it? "
1102                                             signer)))
1103                                 (error "No secret key for %s" signer))
1104                               signer-key)
1105                             signer-names)))))))
1106          signature micalg)
1107     (epg-context-set-armor context t)
1108     (epg-context-set-textmode context t)
1109     (epg-context-set-signers context signers)
1110     (if mml2015-cache-passphrase
1111         (epg-context-set-passphrase-callback
1112          context
1113          #'mml2015-epg-passphrase-callback))
1114     ;; Signed data must end with a newline (RFC 3156, 5).
1115     (goto-char (point-max))
1116     (unless (bolp)
1117       (insert "\n"))
1118     (condition-case error
1119         (setq signature (epg-sign-string context (buffer-string) t)
1120               mml2015-epg-secret-key-id-list nil)
1121       (error
1122        (while mml2015-epg-secret-key-id-list
1123          (password-cache-remove (car mml2015-epg-secret-key-id-list))
1124          (setq mml2015-epg-secret-key-id-list
1125                (cdr mml2015-epg-secret-key-id-list)))
1126        (signal (car error) (cdr error))))
1127     (if (epg-context-result-for context 'sign)
1128         (setq micalg (epg-new-signature-digest-algorithm
1129                       (car (epg-context-result-for context 'sign)))))
1130     (goto-char (point-min))
1131     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
1132                     boundary))
1133     (if micalg
1134         (insert (format "\tmicalg=pgp-%s; "
1135                         (downcase
1136                          (cdr (assq micalg
1137                                     epg-digest-algorithm-alist))))))
1138     (insert "protocol=\"application/pgp-signature\"\n")
1139     (insert (format "\n--%s\n" boundary))
1140     (goto-char (point-max))
1141     (insert (format "\n--%s\n" boundary))
1142     (insert "Content-Type: application/pgp-signature; name=\"signature.asc\"\n\n")
1143     (insert signature)
1144     (goto-char (point-max))
1145     (insert (format "--%s--\n" boundary))
1146     (goto-char (point-max))))
1147
1148 (defun mml2015-epg-encrypt (cont &optional sign)
1149   (let* ((inhibit-redisplay t)
1150          (context (epg-make-context))
1151          (boundary (mml-compute-boundary cont))
1152          (config (epg-configuration))
1153          (recipients (message-options-get 'mml2015-epg-recipients))
1154          cipher
1155          (sender (message-options-get 'message-sender))
1156          (signer-names (or mml2015-signers
1157                            (if (and mml2015-sign-with-sender sender)
1158                                (list (concat "<" sender ">")))))
1159          signers
1160          recipient-key signer-key)
1161     (unless recipients
1162       (setq recipients
1163             (apply #'nconc
1164                    (mapcar
1165                     (lambda (recipient)
1166                       (or (epg-expand-group config recipient)
1167                           (list (concat "<" recipient ">"))))
1168                     (split-string
1169                      (or (message-options-get 'message-recipients)
1170                          (message-options-set 'message-recipients
1171                                               (read-string "Recipients: ")))
1172                      "[ \f\t\n\r\v,]+"))))
1173       (when mml2015-encrypt-to-self
1174         (unless signer-names
1175           (error "Neither message sender nor mml2015-signers are set"))
1176         (setq recipients (nconc recipients signer-names)))
1177       (if (eq mm-encrypt-option 'guided)
1178           (setq recipients
1179                 (epa-select-keys context "\
1180 Select recipients for encryption.
1181 If no one is selected, symmetric encryption will be performed.  "
1182                                  recipients))
1183         (setq recipients
1184               (delq nil
1185                     (mapcar
1186                      (lambda (recipient)
1187                        (setq recipient-key (mml2015-epg-find-usable-key
1188                                             context recipient 'encrypt))
1189                        (unless (or recipient-key
1190                                    (y-or-n-p
1191                                     (format "No public key for %s; skip it? "
1192                                             recipient)))
1193                          (error "No public key for %s" recipient))
1194                        recipient-key)
1195                      recipients)))
1196         (unless recipients
1197           (error "No recipient specified")))
1198       (message-options-set 'mml2015-epg-recipients recipients))
1199     (when sign
1200       (setq signers
1201             (or (message-options-get 'mml2015-epg-signers)
1202                 (message-options-set
1203                  'mml2015-epg-signers
1204                  (if (eq mm-sign-option 'guided)
1205                      (epa-select-keys context "\
1206 Select keys for signing.
1207 If no one is selected, default secret key is used.  "
1208                                       signer-names
1209                                       t)
1210                    (if (or sender mml2015-signers)
1211                        (delq nil
1212                              (mapcar
1213                               (lambda (signer)
1214                                 (setq signer-key
1215                                       (mml2015-epg-find-usable-secret-key
1216                                        context signer 'sign))
1217                                 (unless (or signer-key
1218                                             (y-or-n-p
1219                                              (format
1220                                               "No secret key for %s; skip it? "
1221                                               signer)))
1222                                   (error "No secret key for %s" signer))
1223                                 signer-key)
1224                               signer-names)))))))
1225       (epg-context-set-signers context signers))
1226     (epg-context-set-armor context t)
1227     (epg-context-set-textmode context t)
1228     (if mml2015-cache-passphrase
1229         (epg-context-set-passphrase-callback
1230          context
1231          #'mml2015-epg-passphrase-callback))
1232     (condition-case error
1233         (setq cipher
1234               (epg-encrypt-string context (buffer-string) recipients sign
1235                                   mml2015-always-trust)
1236               mml2015-epg-secret-key-id-list nil)
1237       (error
1238        (while mml2015-epg-secret-key-id-list
1239          (password-cache-remove (car mml2015-epg-secret-key-id-list))
1240          (setq mml2015-epg-secret-key-id-list
1241                (cdr mml2015-epg-secret-key-id-list)))
1242        (signal (car error) (cdr error))))
1243     (delete-region (point-min) (point-max))
1244     (goto-char (point-min))
1245     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
1246                     boundary))
1247     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
1248     (insert (format "--%s\n" boundary))
1249     (insert "Content-Type: application/pgp-encrypted\n\n")
1250     (insert "Version: 1\n\n")
1251     (insert (format "--%s\n" boundary))
1252     (insert "Content-Type: application/octet-stream\n\n")
1253     (insert cipher)
1254     (goto-char (point-max))
1255     (insert (format "--%s--\n" boundary))
1256     (goto-char (point-max))))
1257
1258 ;;; General wrapper
1259
1260 (autoload 'gnus-buffer-live-p "gnus-util")
1261 (autoload 'gnus-get-buffer-create "gnus")
1262
1263 (defun mml2015-clean-buffer ()
1264   (if (gnus-buffer-live-p mml2015-result-buffer)
1265       (with-current-buffer mml2015-result-buffer
1266         (erase-buffer)
1267         t)
1268     (setq mml2015-result-buffer
1269           (gnus-get-buffer-create " *MML2015 Result*"))
1270     nil))
1271
1272 (defsubst mml2015-clear-decrypt-function ()
1273   (nth 6 (assq mml2015-use mml2015-function-alist)))
1274
1275 (defsubst mml2015-clear-verify-function ()
1276   (nth 5 (assq mml2015-use mml2015-function-alist)))
1277
1278 ;;;###autoload
1279 (defun mml2015-decrypt (handle ctl)
1280   (mml2015-clean-buffer)
1281   (let ((func (nth 4 (assq mml2015-use mml2015-function-alist))))
1282     (if func
1283         (funcall func handle ctl)
1284       handle)))
1285
1286 ;;;###autoload
1287 (defun mml2015-decrypt-test (handle ctl)
1288   mml2015-use)
1289
1290 ;;;###autoload
1291 (defun mml2015-verify (handle ctl)
1292   (mml2015-clean-buffer)
1293   (let ((func (nth 3 (assq mml2015-use mml2015-function-alist))))
1294     (if func
1295         (funcall func handle ctl)
1296       handle)))
1297
1298 ;;;###autoload
1299 (defun mml2015-verify-test (handle ctl)
1300   mml2015-use)
1301
1302 ;;;###autoload
1303 (defun mml2015-encrypt (cont &optional sign)
1304   (mml2015-clean-buffer)
1305   (let ((func (nth 2 (assq mml2015-use mml2015-function-alist))))
1306     (if func
1307         (funcall func cont sign)
1308       (error "Cannot find encrypt function"))))
1309
1310 ;;;###autoload
1311 (defun mml2015-sign (cont)
1312   (mml2015-clean-buffer)
1313   (let ((func (nth 1 (assq mml2015-use mml2015-function-alist))))
1314     (if func
1315         (funcall func cont)
1316       (error "Cannot find sign function"))))
1317
1318 ;;;###autoload
1319 (defun mml2015-self-encrypt ()
1320   (mml2015-encrypt nil))
1321
1322 (provide 'mml2015)
1323
1324 ;;; mml2015.el ends here