code.delx.au - gnu-emacs/blob - lisp/gnus/mml2015.el

   1 ;;; mml2015.el --- MIME Security with Pretty Good Privacy (PGP)
   2
   3 ;; Copyright (C) 2000-2013 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 ;; Extract plaintext from cleartext signature.  IMO, this kind of task
 150 ;; should be done by GnuPG rather than Elisp, but older PGP backends
 151 ;; (such as Mailcrypt, and PGG) discard the output from GnuPG.
 152 (defun mml2015-extract-cleartext-signature ()
 153   ;; Daiki Ueno in
 154   ;; <54a15d860801080142l70b95d7dkac4bf51a86196011@mail.gmail.com>: ``I still
 155   ;; believe that the right way is to use the plaintext output from GnuPG as
 156   ;; it is, and mml2015-extract-cleartext-signature is just a kludge for
 157   ;; misdesigned libraries like PGG, which have no ability to do that.  So, I
 158   ;; think it should not have descriptive documentation.''
 159   ;;
 160   ;; This function doesn't handle NotDashEscaped correctly.  EasyPG handles it
 161   ;; correctly.
 162   ;; http://thread.gmane.org/gmane.emacs.gnus.general/66062/focus=66082
 163   ;; http://thread.gmane.org/gmane.emacs.gnus.general/65087/focus=65109
 164   (goto-char (point-min))
 165   (forward-line)
 166   ;; We need to be careful not to strip beyond the armor headers.
 167   ;; Previously, an attacker could replace the text inside our
 168   ;; markup with trailing garbage by injecting whitespace into the
 169   ;; message.
 170   (while (looking-at "Hash:")           ; The only header allowed in cleartext
 171     (forward-line))                     ; signatures according to RFC2440.
 172   (when (looking-at "[\t ]*$")
 173     (forward-line))
 174   (delete-region (point-min) (point))
 175   (if (re-search-forward "^-----BEGIN PGP SIGNATURE-----" nil t)
 176       (delete-region (match-beginning 0) (point-max)))
 177   (goto-char (point-min))
 178   (while (re-search-forward "^- " nil t)
 179     (replace-match "" t t)
 180     (forward-line 1)))
 181
 182 ;;; mailcrypt wrapper
 183
 184 (autoload 'mailcrypt-decrypt "mailcrypt")
 185 (autoload 'mailcrypt-verify "mailcrypt")
 186 (autoload 'mc-pgp-always-sign "mailcrypt")
 187 (autoload 'mc-encrypt-generic "mc-toplev")
 188 (autoload 'mc-cleanup-recipient-headers "mc-toplev")
 189 (autoload 'mc-sign-generic "mc-toplev")
 190
 191 (defvar mml2015-decrypt-function 'mailcrypt-decrypt)
 192 (defvar mml2015-verify-function 'mailcrypt-verify)
 193
 194 (defun mml2015-format-error (err)
 195   (if (stringp (cadr err))
 196       (cadr err)
 197     (format "%S" (cdr err))))
 198
 199 (defun mml2015-mailcrypt-decrypt (handle ctl)
 200   (catch 'error
 201     (let (child handles result)
 202       (unless (setq child (mm-find-part-by-type
 203                            (cdr handle)
 204                            "application/octet-stream" nil t))
 205         (mm-set-handle-multipart-parameter
 206          mm-security-handle 'gnus-info "Corrupted")
 207         (throw 'error handle))
 208       (with-temp-buffer
 209         (mm-insert-part child)
 210         (setq result
 211               (condition-case err
 212                   (funcall mml2015-decrypt-function)
 213                 (error
 214                  (mm-set-handle-multipart-parameter
 215                   mm-security-handle 'gnus-details (mml2015-format-error err))
 216                  nil)
 217                 (quit
 218                  (mm-set-handle-multipart-parameter
 219                   mm-security-handle 'gnus-details "Quit.")
 220                  nil)))
 221         (unless (car result)
 222           (mm-set-handle-multipart-parameter
 223            mm-security-handle 'gnus-info "Failed")
 224           (throw 'error handle))
 225         (setq handles (mm-dissect-buffer t)))
 226       (mm-destroy-parts handle)
 227       (mm-set-handle-multipart-parameter
 228        mm-security-handle 'gnus-info
 229        (concat "OK"
 230                (let ((sig (with-current-buffer mml2015-result-buffer
 231                             (mml2015-gpg-extract-signature-details))))
 232                  (concat ", Signer: " sig))))
 233       (if (listp (car handles))
 234           handles
 235         (list handles)))))
 236
 237 (defun mml2015-gpg-pretty-print-fpr (fingerprint)
 238   (let* ((result "")
 239          (fpr-length (string-width fingerprint))
 240          (n-slice 0)
 241          slice)
 242     (setq fingerprint (string-to-list fingerprint))
 243     (while fingerprint
 244       (setq fpr-length (- fpr-length 4))
 245       (setq slice (butlast fingerprint fpr-length))
 246       (setq fingerprint (nthcdr 4 fingerprint))
 247       (setq n-slice (1+ n-slice))
 248       (setq result
 249             (concat
 250              result
 251              (case n-slice
 252                (1  slice)
 253                (otherwise (concat " " slice))))))
 254     result))
 255
 256 (defun mml2015-gpg-extract-signature-details ()
 257   (goto-char (point-min))
 258   (let* ((expired (re-search-forward
 259                    "^\\[GNUPG:\\] SIGEXPIRED$"
 260                    nil t))
 261          (signer (and (re-search-forward
 262                        "^\\[GNUPG:\\] GOODSIG \\([0-9A-Za-z]*\\) \\(.*\\)$"
 263                        nil t)
 264                       (cons (match-string 1) (match-string 2))))
 265          (fprint (and (re-search-forward
 266                        "^\\[GNUPG:\\] VALIDSIG \\([0-9a-zA-Z]*\\) "
 267                        nil t)
 268                       (match-string 1)))
 269          (trust  (and (re-search-forward
 270                        "^\\[GNUPG:\\] \\(TRUST_.*\\)$"
 271                        nil t)
 272                       (match-string 1)))
 273          (trust-good-enough-p
 274           (cdr (assoc trust mml2015-unabbrev-trust-alist))))
 275     (cond ((and signer fprint)
 276            (concat (cdr signer)
 277                    (unless trust-good-enough-p
 278                      (concat "\nUntrusted, Fingerprint: "
 279                              (mml2015-gpg-pretty-print-fpr fprint)))
 280                    (when expired
 281                      (format "\nWARNING: Signature from expired key (%s)"
 282                              (car signer)))))
 283           ((re-search-forward
 284             "^\\(gpg: \\)?Good signature from \"\\(.*\\)\"$" nil t)
 285            (match-string 2))
 286           (t
 287            "From unknown user"))))
 288
 289 (defun mml2015-mailcrypt-clear-decrypt ()
 290   (let (result)
 291     (setq result
 292           (condition-case err
 293               (funcall mml2015-decrypt-function)
 294             (error
 295              (mm-set-handle-multipart-parameter
 296               mm-security-handle 'gnus-details (mml2015-format-error err))
 297              nil)
 298             (quit
 299              (mm-set-handle-multipart-parameter
 300               mm-security-handle 'gnus-details "Quit.")
 301              nil)))
 302     (if (car result)
 303         (mm-set-handle-multipart-parameter
 304          mm-security-handle 'gnus-info "OK")
 305       (mm-set-handle-multipart-parameter
 306        mm-security-handle 'gnus-info "Failed"))))
 307
 308 (defun mml2015-fix-micalg (alg)
 309   (and alg
 310        ;; Mutt/1.2.5i has seen sending micalg=php-sha1
 311        (upcase (if (string-match "^p[gh]p-" alg)
 312                    (substring alg (match-end 0))
 313                  alg))))
 314
 315 (defun mml2015-mailcrypt-verify (handle ctl)
 316   (catch 'error
 317     (let (part)
 318       (unless (setq part (mm-find-raw-part-by-type
 319                           ctl (or (mm-handle-multipart-ctl-parameter
 320                                    ctl 'protocol)
 321                                   "application/pgp-signature")
 322                           t))
 323         (mm-set-handle-multipart-parameter
 324          mm-security-handle 'gnus-info "Corrupted")
 325         (throw 'error handle))
 326       (with-temp-buffer
 327         (insert "-----BEGIN PGP SIGNED MESSAGE-----\n")
 328         (insert (format "Hash: %s\n\n"
 329                         (or (mml2015-fix-micalg
 330                              (mm-handle-multipart-ctl-parameter
 331                               ctl 'micalg))
 332                             "SHA1")))
 333         (save-restriction
 334           (narrow-to-region (point) (point))
 335           (insert part "\n")
 336           (goto-char (point-min))
 337           (while (not (eobp))
 338             (if (looking-at "^-")
 339                 (insert "- "))
 340             (forward-line)))
 341         (unless (setq part (mm-find-part-by-type
 342                             (cdr handle) "application/pgp-signature" nil t))
 343           (mm-set-handle-multipart-parameter
 344            mm-security-handle 'gnus-info "Corrupted")
 345           (throw 'error handle))
 346         (save-restriction
 347           (narrow-to-region (point) (point))
 348           (mm-insert-part part)
 349           (goto-char (point-min))
 350           (if (re-search-forward "^-----BEGIN PGP [^-]+-----\r?$" nil t)
 351               (replace-match "-----BEGIN PGP SIGNATURE-----" t t))
 352           (if (re-search-forward "^-----END PGP [^-]+-----\r?$" nil t)
 353               (replace-match "-----END PGP SIGNATURE-----" t t)))
 354         (let ((mc-gpg-debug-buffer (get-buffer-create " *gnus gpg debug*")))
 355           (unless (condition-case err
 356                       (prog1
 357                           (funcall mml2015-verify-function)
 358                         (if (get-buffer " *mailcrypt stderr temp")
 359                             (mm-set-handle-multipart-parameter
 360                              mm-security-handle 'gnus-details
 361                              (with-current-buffer " *mailcrypt stderr temp"
 362                                (buffer-string))))
 363                         (if (get-buffer " *mailcrypt stdout temp")
 364                             (kill-buffer " *mailcrypt stdout temp"))
 365                         (if (get-buffer " *mailcrypt stderr temp")
 366                             (kill-buffer " *mailcrypt stderr temp"))
 367                         (if (get-buffer " *mailcrypt status temp")
 368                             (kill-buffer " *mailcrypt status temp"))
 369                         (if (get-buffer mc-gpg-debug-buffer)
 370                             (kill-buffer mc-gpg-debug-buffer)))
 371                     (error
 372                      (mm-set-handle-multipart-parameter
 373                       mm-security-handle 'gnus-details (mml2015-format-error err))
 374                      nil)
 375                     (quit
 376                      (mm-set-handle-multipart-parameter
 377                       mm-security-handle 'gnus-details "Quit.")
 378                      nil))
 379             (mm-set-handle-multipart-parameter
 380              mm-security-handle 'gnus-info "Failed")
 381             (throw 'error handle))))
 382       (mm-set-handle-multipart-parameter
 383        mm-security-handle 'gnus-info "OK")
 384       handle)))
 385
 386 (defun mml2015-mailcrypt-clear-verify ()
 387   (let ((mc-gpg-debug-buffer (get-buffer-create " *gnus gpg debug*")))
 388     (if (condition-case err
 389             (prog1
 390                 (funcall mml2015-verify-function)
 391               (if (get-buffer " *mailcrypt stderr temp")
 392                   (mm-set-handle-multipart-parameter
 393                    mm-security-handle 'gnus-details
 394                    (with-current-buffer " *mailcrypt stderr temp"
 395                      (buffer-string))))
 396               (if (get-buffer " *mailcrypt stdout temp")
 397                   (kill-buffer " *mailcrypt stdout temp"))
 398               (if (get-buffer " *mailcrypt stderr temp")
 399                   (kill-buffer " *mailcrypt stderr temp"))
 400               (if (get-buffer " *mailcrypt status temp")
 401                   (kill-buffer " *mailcrypt status temp"))
 402               (if (get-buffer mc-gpg-debug-buffer)
 403                   (kill-buffer mc-gpg-debug-buffer)))
 404           (error
 405            (mm-set-handle-multipart-parameter
 406             mm-security-handle 'gnus-details (mml2015-format-error err))
 407            nil)
 408           (quit
 409            (mm-set-handle-multipart-parameter
 410             mm-security-handle 'gnus-details "Quit.")
 411            nil))
 412         (mm-set-handle-multipart-parameter
 413          mm-security-handle 'gnus-info "OK")
 414       (mm-set-handle-multipart-parameter
 415        mm-security-handle 'gnus-info "Failed")))
 416   (mml2015-extract-cleartext-signature))
 417
 418 (defun mml2015-mailcrypt-sign (cont)
 419   (mc-sign-generic (message-options-get 'message-sender)
 420                    nil nil nil nil)
 421   (let ((boundary (mml-compute-boundary cont))
 422         hash point)
 423     (goto-char (point-min))
 424     (unless (re-search-forward "^-----BEGIN PGP SIGNED MESSAGE-----\r?$" nil t)
 425       (error "Cannot find signed begin line"))
 426     (goto-char (match-beginning 0))
 427     (forward-line 1)
 428     (unless (looking-at "Hash:[ \t]*\\([a-zA-Z0-9]+\\)")
 429       (error "Cannot not find PGP hash"))
 430     (setq hash (match-string 1))
 431     (unless (re-search-forward "^$" nil t)
 432       (error "Cannot not find PGP message"))
 433     (forward-line 1)
 434     (delete-region (point-min) (point))
 435     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
 436                     boundary))
 437     (insert (format "\tmicalg=pgp-%s; protocol=\"application/pgp-signature\"\n"
 438                     (downcase hash)))
 439     (insert (format "\n--%s\n" boundary))
 440     (setq point (point))
 441     (goto-char (point-max))
 442     (unless (re-search-backward "^-----END PGP SIGNATURE-----\r?$" nil t)
 443       (error "Cannot find signature part"))
 444     (replace-match "-----END PGP MESSAGE-----" t t)
 445     (goto-char (match-beginning 0))
 446     (unless (re-search-backward "^-----BEGIN PGP SIGNATURE-----\r?$"
 447                                 nil t)
 448       (error "Cannot find signature part"))
 449     (replace-match "-----BEGIN PGP MESSAGE-----" t t)
 450     (goto-char (match-beginning 0))
 451     (save-restriction
 452       (narrow-to-region point (point))
 453       (goto-char point)
 454       (while (re-search-forward "^- -" nil t)
 455         (replace-match "-" t t))
 456       (goto-char (point-max)))
 457     (insert (format "--%s\n" boundary))
 458     (insert "Content-Type: application/pgp-signature\n\n")
 459     (goto-char (point-max))
 460     (insert (format "--%s--\n" boundary))
 461     (goto-char (point-max))))
 462
 463 ;; We require mm-decode, which requires mm-bodies, which autoloads
 464 ;; message-options-get (!).
 465 (declare-function message-options-set "message" (symbol value))
 466
 467 (defun mml2015-mailcrypt-encrypt (cont &optional sign)
 468   (let ((mc-pgp-always-sign
 469          (or mc-pgp-always-sign
 470              sign
 471              (eq t (or (message-options-get 'message-sign-encrypt)
 472                        (message-options-set
 473                         'message-sign-encrypt
 474                         (or (y-or-n-p "Sign the message? ")
 475                             'not))))
 476              'never)))
 477     (mm-with-unibyte-current-buffer
 478       (mc-encrypt-generic
 479        (or (message-options-get 'message-recipients)
 480            (message-options-set 'message-recipients
 481                               (mc-cleanup-recipient-headers
 482                                (read-string "Recipients: "))))
 483        nil nil nil
 484        (message-options-get 'message-sender))))
 485   (goto-char (point-min))
 486   (unless (looking-at "-----BEGIN PGP MESSAGE-----")
 487     (error "Fail to encrypt the message"))
 488   (let ((boundary (mml-compute-boundary cont)))
 489     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
 490                     boundary))
 491     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
 492     (insert (format "--%s\n" boundary))
 493     (insert "Content-Type: application/pgp-encrypted\n\n")
 494     (insert "Version: 1\n\n")
 495     (insert (format "--%s\n" boundary))
 496     (insert "Content-Type: application/octet-stream\n\n")
 497     (goto-char (point-max))
 498     (insert (format "--%s--\n" boundary))
 499     (goto-char (point-max))))
 500
 501 ;;; pgg wrapper
 502
 503 (defvar pgg-default-user-id)
 504 (defvar pgg-errors-buffer)
 505 (defvar pgg-output-buffer)
 506
 507 (autoload 'pgg-decrypt-region "pgg")
 508 (autoload 'pgg-verify-region "pgg")
 509 (autoload 'pgg-sign-region "pgg")
 510 (autoload 'pgg-encrypt-region "pgg")
 511 (autoload 'pgg-parse-armor "pgg-parse")
 512
 513 (defun mml2015-pgg-decrypt (handle ctl)
 514   (catch 'error
 515     (let ((pgg-errors-buffer mml2015-result-buffer)
 516           child handles result decrypt-status)
 517       (unless (setq child (mm-find-part-by-type
 518                            (cdr handle)
 519                            "application/octet-stream" nil t))
 520         (mm-set-handle-multipart-parameter
 521          mm-security-handle 'gnus-info "Corrupted")
 522         (throw 'error handle))
 523       (with-temp-buffer
 524         (mm-insert-part child)
 525         (if (condition-case err
 526                 (prog1
 527                     (pgg-decrypt-region (point-min) (point-max))
 528                   (setq decrypt-status
 529                         (with-current-buffer mml2015-result-buffer
 530                           (buffer-string)))
 531                   (mm-set-handle-multipart-parameter
 532                    mm-security-handle 'gnus-details
 533                    decrypt-status))
 534               (error
 535                (mm-set-handle-multipart-parameter
 536                 mm-security-handle 'gnus-details (mml2015-format-error err))
 537                nil)
 538               (quit
 539                (mm-set-handle-multipart-parameter
 540                 mm-security-handle 'gnus-details "Quit.")
 541                nil))
 542             (with-current-buffer pgg-output-buffer
 543               (goto-char (point-min))
 544               (while (search-forward "\r\n" nil t)
 545                 (replace-match "\n" t t))
 546               (setq handles (mm-dissect-buffer t))
 547               (mm-destroy-parts handle)
 548               (mm-set-handle-multipart-parameter
 549                mm-security-handle 'gnus-info "OK")
 550               (mm-set-handle-multipart-parameter
 551                mm-security-handle 'gnus-details
 552                (concat decrypt-status
 553                        (when (stringp (car handles))
 554                          "\n" (mm-handle-multipart-ctl-parameter
 555                                handles 'gnus-details))))
 556               (if (listp (car handles))
 557                   handles
 558                 (list handles)))
 559           (mm-set-handle-multipart-parameter
 560            mm-security-handle 'gnus-info "Failed")
 561           (throw 'error handle))))))
 562
 563 (defun mml2015-pgg-clear-decrypt ()
 564   (let ((pgg-errors-buffer mml2015-result-buffer))
 565     (if (prog1
 566             (pgg-decrypt-region (point-min) (point-max))
 567           (mm-set-handle-multipart-parameter
 568            mm-security-handle 'gnus-details
 569            (with-current-buffer mml2015-result-buffer
 570              (buffer-string))))
 571         (progn
 572           (erase-buffer)
 573           ;; Treat data which pgg returns as a unibyte string.
 574           (mm-disable-multibyte)
 575           (insert-buffer-substring pgg-output-buffer)
 576           (goto-char (point-min))
 577           (while (search-forward "\r\n" nil t)
 578             (replace-match "\n" t t))
 579           (mm-set-handle-multipart-parameter
 580            mm-security-handle 'gnus-info "OK"))
 581       (mm-set-handle-multipart-parameter
 582        mm-security-handle 'gnus-info "Failed"))))
 583
 584 (defun mml2015-pgg-verify (handle ctl)
 585   (let ((pgg-errors-buffer mml2015-result-buffer)
 586         signature-file part signature)
 587     (if (or (null (setq part (mm-find-raw-part-by-type
 588                               ctl (or (mm-handle-multipart-ctl-parameter
 589                                        ctl 'protocol)
 590                                       "application/pgp-signature")
 591                               t)))
 592             (null (setq signature (mm-find-part-by-type
 593                                    (cdr handle) "application/pgp-signature" nil t))))
 594         (progn
 595           (mm-set-handle-multipart-parameter
 596            mm-security-handle 'gnus-info "Corrupted")
 597           handle)
 598       (with-temp-buffer
 599         (insert part)
 600         ;; Convert <LF> to <CR><LF> in signed text.  If --textmode is
 601         ;; specified when signing, the conversion is not necessary.
 602         (goto-char (point-min))
 603         (end-of-line)
 604         (while (not (eobp))
 605           (unless (eq (char-before) ?\r)
 606             (insert "\r"))
 607           (forward-line)
 608           (end-of-line))
 609         (with-temp-file (setq signature-file (mm-make-temp-file "pgg"))
 610           (mm-insert-part signature))
 611         (if (condition-case err
 612                 (prog1
 613                     (pgg-verify-region (point-min) (point-max)
 614                                        signature-file t)
 615                   (goto-char (point-min))
 616                   (while (search-forward "\r\n" nil t)
 617                     (replace-match "\n" t t))
 618                   (mm-set-handle-multipart-parameter
 619                    mm-security-handle 'gnus-details
 620                    (concat (with-current-buffer pgg-output-buffer
 621                              (buffer-string))
 622                            (with-current-buffer pgg-errors-buffer
 623                              (buffer-string)))))
 624               (error
 625                (mm-set-handle-multipart-parameter
 626                 mm-security-handle 'gnus-details (mml2015-format-error err))
 627                nil)
 628               (quit
 629                (mm-set-handle-multipart-parameter
 630                 mm-security-handle 'gnus-details "Quit.")
 631                nil))
 632             (progn
 633               (delete-file signature-file)
 634               (mm-set-handle-multipart-parameter
 635                mm-security-handle 'gnus-info
 636                (with-current-buffer pgg-errors-buffer
 637                  (mml2015-gpg-extract-signature-details))))
 638           (delete-file signature-file)
 639           (mm-set-handle-multipart-parameter
 640            mm-security-handle 'gnus-info "Failed")))))
 641   handle)
 642
 643 (defun mml2015-pgg-clear-verify ()
 644   (let ((pgg-errors-buffer mml2015-result-buffer)
 645         (text (buffer-string))
 646         (coding-system buffer-file-coding-system))
 647     (if (condition-case err
 648             (prog1
 649                 (mm-with-unibyte-buffer
 650                   (insert (mm-encode-coding-string text coding-system))
 651                   (pgg-verify-region (point-min) (point-max) nil t))
 652               (goto-char (point-min))
 653               (while (search-forward "\r\n" nil t)
 654                 (replace-match "\n" t t))
 655               (mm-set-handle-multipart-parameter
 656                mm-security-handle 'gnus-details
 657                (concat (with-current-buffer pgg-output-buffer
 658                          (buffer-string))
 659                        (with-current-buffer pgg-errors-buffer
 660                          (buffer-string)))))
 661           (error
 662            (mm-set-handle-multipart-parameter
 663             mm-security-handle 'gnus-details (mml2015-format-error err))
 664            nil)
 665           (quit
 666            (mm-set-handle-multipart-parameter
 667             mm-security-handle 'gnus-details "Quit.")
 668            nil))
 669         (mm-set-handle-multipart-parameter
 670          mm-security-handle 'gnus-info
 671          (with-current-buffer pgg-errors-buffer
 672            (mml2015-gpg-extract-signature-details)))
 673       (mm-set-handle-multipart-parameter
 674        mm-security-handle 'gnus-info "Failed")))
 675   (mml2015-extract-cleartext-signature))
 676
 677 (defun mml2015-pgg-sign (cont)
 678   (let ((pgg-errors-buffer mml2015-result-buffer)
 679         (boundary (mml-compute-boundary cont))
 680         (pgg-default-user-id (or (message-options-get 'mml-sender)
 681                                  pgg-default-user-id))
 682         (pgg-text-mode t)
 683         entry)
 684     (unless (pgg-sign-region (point-min) (point-max))
 685       (pop-to-buffer mml2015-result-buffer)
 686       (error "Sign error"))
 687     (goto-char (point-min))
 688     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
 689                     boundary))
 690     (if (setq entry (assq 2 (pgg-parse-armor
 691                              (with-current-buffer pgg-output-buffer
 692                                (buffer-string)))))
 693         (setq entry (assq 'hash-algorithm (cdr entry))))
 694     (insert (format "\tmicalg=%s; "
 695                     (if (cdr entry)
 696                         (downcase (format "pgp-%s" (cdr entry)))
 697                       "pgp-sha1")))
 698     (insert "protocol=\"application/pgp-signature\"\n")
 699     (insert (format "\n--%s\n" boundary))
 700     (goto-char (point-max))
 701     (insert (format "\n--%s\n" boundary))
 702     (insert "Content-Type: application/pgp-signature\n\n")
 703     (insert-buffer-substring pgg-output-buffer)
 704     (goto-char (point-max))
 705     (insert (format "--%s--\n" boundary))
 706     (goto-char (point-max))))
 707
 708 (defun mml2015-pgg-encrypt (cont &optional sign)
 709   (let ((pgg-errors-buffer mml2015-result-buffer)
 710         (pgg-text-mode t)
 711         (boundary (mml-compute-boundary cont)))
 712     (unless (pgg-encrypt-region (point-min) (point-max)
 713                                 (split-string
 714                                  (or
 715                                   (message-options-get 'message-recipients)
 716                                   (message-options-set 'message-recipients
 717                                                        (read-string "Recipients: ")))
 718                                  "[ \f\t\n\r\v,]+")
 719                                 sign)
 720       (pop-to-buffer mml2015-result-buffer)
 721       (error "Encrypt error"))
 722     (delete-region (point-min) (point-max))
 723     (goto-char (point-min))
 724     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
 725                     boundary))
 726     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
 727     (insert (format "--%s\n" boundary))
 728     (insert "Content-Type: application/pgp-encrypted\n\n")
 729     (insert "Version: 1\n\n")
 730     (insert (format "--%s\n" boundary))
 731     (insert "Content-Type: application/octet-stream\n\n")
 732     (insert-buffer-substring pgg-output-buffer)
 733     (goto-char (point-max))
 734     (insert (format "--%s--\n" boundary))
 735     (goto-char (point-max))))
 736
 737 ;;; epg wrapper
 738
 739 (defvar epg-user-id-alist)
 740 (defvar epg-digest-algorithm-alist)
 741 (defvar epg-gpg-program)
 742 (defvar inhibit-redisplay)
 743
 744 (autoload 'epg-make-context "epg")
 745 (autoload 'epg-context-set-armor "epg")
 746 (autoload 'epg-context-set-textmode "epg")
 747 (autoload 'epg-context-set-signers "epg")
 748 (autoload 'epg-context-result-for "epg")
 749 (autoload 'epg-new-signature-digest-algorithm "epg")
 750 (autoload 'epg-list-keys "epg")
 751 (autoload 'epg-decrypt-string "epg")
 752 (autoload 'epg-verify-string "epg")
 753 (autoload 'epg-sign-string "epg")
 754 (autoload 'epg-encrypt-string "epg")
 755 (autoload 'epg-passphrase-callback-function "epg")
 756 (autoload 'epg-context-set-passphrase-callback "epg")
 757 (autoload 'epg-key-sub-key-list "epg")
 758 (autoload 'epg-sub-key-capability "epg")
 759 (autoload 'epg-sub-key-validity "epg")
 760 (autoload 'epg-sub-key-fingerprint "epg")
 761 (autoload 'epg-signature-key-id "epg")
 762 (autoload 'epg-signature-to-string "epg")
 763 (autoload 'epg-key-user-id-list "epg")
 764 (autoload 'epg-user-id-string "epg")
 765 (autoload 'epg-user-id-validity "epg")
 766 (autoload 'epg-configuration "epg-config")
 767 (autoload 'epg-expand-group "epg-config")
 768 (autoload 'epa-select-keys "epa")
 769
 770 (defvar mml2015-epg-secret-key-id-list nil)
 771
 772 (defun mml2015-epg-passphrase-callback (context key-id ignore)
 773   (if (eq key-id 'SYM)
 774       (epg-passphrase-callback-function context key-id nil)
 775     (let* ((password-cache-key-id
 776             (if (eq key-id 'PIN)
 777                 "PIN"
 778                key-id))
 779            entry
 780            (passphrase
 781             (password-read
 782              (if (eq key-id 'PIN)
 783                  "Passphrase for PIN: "
 784                (if (setq entry (assoc key-id epg-user-id-alist))
 785                    (format "Passphrase for %s %s: " key-id (cdr entry))
 786                  (format "Passphrase for %s: " key-id)))
 787              password-cache-key-id)))
 788       (when passphrase
 789         (let ((password-cache-expiry mml2015-passphrase-cache-expiry))
 790           (password-cache-add password-cache-key-id passphrase))
 791         (setq mml2015-epg-secret-key-id-list
 792               (cons password-cache-key-id mml2015-epg-secret-key-id-list))
 793         (copy-sequence passphrase)))))
 794
 795 (defun mml2015-epg-check-user-id (key recipient)
 796   (let ((pointer (epg-key-user-id-list key))
 797         result)
 798     (while pointer
 799       (if (and (equal (car (mail-header-parse-address
 800                             (epg-user-id-string (car pointer))))
 801                       (car (mail-header-parse-address
 802                             recipient)))
 803                (not (memq (epg-user-id-validity (car pointer))
 804                           '(revoked expired))))
 805           (setq result t
 806                 pointer nil)
 807         (setq pointer (cdr pointer))))
 808     result))
 809
 810 (defun mml2015-epg-check-sub-key (key usage)
 811   (let ((pointer (epg-key-sub-key-list key))
 812         result)
 813     ;; The primary key will be marked as disabled, when the entire
 814     ;; key is disabled (see 12 Field, Format of colon listings, in
 815     ;; gnupg/doc/DETAILS)
 816     (unless (memq 'disabled (epg-sub-key-capability (car pointer)))
 817       (while pointer
 818         (if (and (memq usage (epg-sub-key-capability (car pointer)))
 819                  (not (memq (epg-sub-key-validity (car pointer))
 820                             '(revoked expired))))
 821             (setq result t
 822                   pointer nil)
 823           (setq pointer (cdr pointer)))))
 824     result))
 825
 826 (defun mml2015-epg-find-usable-key (context name usage
 827                                             &optional name-is-key-id)
 828   (let ((keys (epg-list-keys context name))
 829         key)
 830     (while keys
 831       (if (and (or name-is-key-id
 832                    ;; Non email user-id can be supplied through
 833                    ;; mml2015-signers if mml2015-encrypt-to-self is set.
 834                    ;; Treat it as valid, as it is user's intention.
 835                    (not (string-match "\\`<" name))
 836                    (mml2015-epg-check-user-id (car keys) name))
 837                (mml2015-epg-check-sub-key (car keys) usage))
 838           (setq key (car keys)
 839                 keys nil)
 840         (setq keys (cdr keys))))
 841     key))
 842
 843 ;; XXX: since gpg --list-secret-keys does not return validity of each
 844 ;; key, `mml2015-epg-find-usable-key' defined above is not enough for
 845 ;; secret keys.  The function `mml2015-epg-find-usable-secret-key'
 846 ;; below looks at appropriate public keys to check usability.
 847 (defun mml2015-epg-find-usable-secret-key (context name usage)
 848   (let ((secret-keys (epg-list-keys context name t))
 849         secret-key)
 850     (while (and (not secret-key) secret-keys)
 851       (if (mml2015-epg-find-usable-key
 852            context
 853            (epg-sub-key-fingerprint
 854             (car (epg-key-sub-key-list
 855                   (car secret-keys))))
 856            usage
 857            t)
 858           (setq secret-key (car secret-keys)
 859                 secret-keys nil)
 860         (setq secret-keys (cdr secret-keys))))
 861     secret-key))
 862
 863 (defun mml2015-epg-key-image (key-id)
 864   "Return the image of a key, if any"
 865   (with-temp-buffer
 866     (mm-set-buffer-multibyte nil)
 867     (let* ((coding-system-for-write 'binary)
 868            (coding-system-for-read 'binary)
 869            (data (shell-command-to-string
 870                   (format "%s --list-options no-show-photos --attribute-fd 3 --list-keys %s 3>&1 >/dev/null 2>&1"
 871                           (shell-quote-argument epg-gpg-program) key-id))))
 872       (when (> (length data) 0)
 873         (insert (substring data 16))
 874         (create-image (buffer-string) nil t)))))
 875
 876 (defun mml2015-epg-key-image-to-string (key-id)
 877   "Return a string with the image of a key, if any"
 878   (let* ((result "")
 879          (key-image (mml2015-epg-key-image key-id)))
 880     (when key-image
 881       (setq result "  ")
 882       (put-text-property 1 2 'display key-image result))
 883     result))
 884
 885 (defun mml2015-epg-signature-to-string (signature)
 886   (concat (epg-signature-to-string signature)
 887           (mml2015-epg-key-image-to-string (epg-signature-key-id signature))))
 888
 889 (defun mml2015-epg-verify-result-to-string (verify-result)
 890   (mapconcat #'mml2015-epg-signature-to-string verify-result "\n"))
 891
 892 (defun mml2015-epg-decrypt (handle ctl)
 893   (catch 'error
 894     (let ((inhibit-redisplay t)
 895           context plain child handles result decrypt-status)
 896       (unless (setq child (mm-find-part-by-type
 897                            (cdr handle)
 898                            "application/octet-stream" nil t))
 899         (mm-set-handle-multipart-parameter
 900          mm-security-handle 'gnus-info "Corrupted")
 901         (throw 'error handle))
 902       (setq context (epg-make-context))
 903       (if mml2015-cache-passphrase
 904           (epg-context-set-passphrase-callback
 905            context
 906            #'mml2015-epg-passphrase-callback))
 907       (condition-case error
 908           (setq plain (epg-decrypt-string context (mm-get-part child))
 909                 mml2015-epg-secret-key-id-list nil)
 910         (error
 911          (while mml2015-epg-secret-key-id-list
 912            (password-cache-remove (car mml2015-epg-secret-key-id-list))
 913            (setq mml2015-epg-secret-key-id-list
 914                  (cdr mml2015-epg-secret-key-id-list)))
 915          (mm-set-handle-multipart-parameter
 916           mm-security-handle 'gnus-info "Failed")
 917          (if (eq (car error) 'quit)
 918              (mm-set-handle-multipart-parameter
 919               mm-security-handle 'gnus-details "Quit.")
 920            (mm-set-handle-multipart-parameter
 921             mm-security-handle 'gnus-details (mml2015-format-error error)))
 922          (throw 'error handle)))
 923       (with-temp-buffer
 924         (insert plain)
 925         (goto-char (point-min))
 926         (while (search-forward "\r\n" nil t)
 927           (replace-match "\n" t t))
 928         (setq handles (mm-dissect-buffer t))
 929         (mm-destroy-parts handle)
 930         (if (epg-context-result-for context 'verify)
 931             (mm-set-handle-multipart-parameter
 932              mm-security-handle 'gnus-info
 933              (concat "OK\n"
 934                      (mml2015-epg-verify-result-to-string
 935                       (epg-context-result-for context 'verify))))
 936           (mm-set-handle-multipart-parameter
 937            mm-security-handle 'gnus-info "OK"))
 938         (if (stringp (car handles))
 939             (mm-set-handle-multipart-parameter
 940              mm-security-handle 'gnus-details
 941              (mm-handle-multipart-ctl-parameter handles 'gnus-details))))
 942         (if (listp (car handles))
 943             handles
 944           (list handles)))))
 945
 946 (defun mml2015-epg-clear-decrypt ()
 947   (let ((inhibit-redisplay t)
 948         (context (epg-make-context))
 949         plain)
 950     (if mml2015-cache-passphrase
 951         (epg-context-set-passphrase-callback
 952          context
 953          #'mml2015-epg-passphrase-callback))
 954     (condition-case error
 955         (setq plain (epg-decrypt-string context (buffer-string))
 956               mml2015-epg-secret-key-id-list nil)
 957       (error
 958        (while mml2015-epg-secret-key-id-list
 959          (password-cache-remove (car mml2015-epg-secret-key-id-list))
 960          (setq mml2015-epg-secret-key-id-list
 961                (cdr mml2015-epg-secret-key-id-list)))
 962        (mm-set-handle-multipart-parameter
 963         mm-security-handle 'gnus-info "Failed")
 964        (if (eq (car error) 'quit)
 965            (mm-set-handle-multipart-parameter
 966             mm-security-handle 'gnus-details "Quit.")
 967          (mm-set-handle-multipart-parameter
 968           mm-security-handle 'gnus-details (mml2015-format-error error)))))
 969     (when plain
 970       (erase-buffer)
 971       ;; Treat data which epg returns as a unibyte string.
 972       (mm-disable-multibyte)
 973       (insert plain)
 974       (goto-char (point-min))
 975       (while (search-forward "\r\n" nil t)
 976         (replace-match "\n" t t))
 977       (mm-set-handle-multipart-parameter
 978        mm-security-handle 'gnus-info "OK")
 979       (if (epg-context-result-for context 'verify)
 980           (mm-set-handle-multipart-parameter
 981            mm-security-handle 'gnus-details
 982            (mml2015-epg-verify-result-to-string
 983             (epg-context-result-for context 'verify)))))))
 984
 985 (defun mml2015-epg-verify (handle ctl)
 986   (catch 'error
 987     (let ((inhibit-redisplay t)
 988           context plain signature-file part signature)
 989       (when (or (null (setq part (mm-find-raw-part-by-type
 990                                   ctl (or (mm-handle-multipart-ctl-parameter
 991                                            ctl 'protocol)
 992                                           "application/pgp-signature")
 993                                   t)))
 994                 (null (setq signature (mm-find-part-by-type
 995                                        (cdr handle) "application/pgp-signature"
 996                                        nil t))))
 997         (mm-set-handle-multipart-parameter
 998          mm-security-handle 'gnus-info "Corrupted")
 999         (throw 'error handle))
1000       (setq part (mm-replace-in-string part "\n" "\r\n")
1001             signature (mm-get-part signature)
1002             context (epg-make-context))
1003       (condition-case error
1004           (setq plain (epg-verify-string context signature part))
1005         (error
1006          (mm-set-handle-multipart-parameter
1007           mm-security-handle 'gnus-info "Failed")
1008          (if (eq (car error) 'quit)
1009              (mm-set-handle-multipart-parameter
1010               mm-security-handle 'gnus-details "Quit.")
1011            (mm-set-handle-multipart-parameter
1012             mm-security-handle 'gnus-details (mml2015-format-error error)))
1013          (throw 'error handle)))
1014       (mm-set-handle-multipart-parameter
1015        mm-security-handle 'gnus-info
1016        (mml2015-epg-verify-result-to-string
1017         (epg-context-result-for context 'verify)))
1018       handle)))
1019
1020 (defun mml2015-epg-clear-verify ()
1021   (let ((inhibit-redisplay t)
1022         (context (epg-make-context))
1023         (signature (mm-encode-coding-string (buffer-string)
1024                                             coding-system-for-write))
1025         plain)
1026     (condition-case error
1027         (setq plain (epg-verify-string context signature))
1028       (error
1029        (mm-set-handle-multipart-parameter
1030         mm-security-handle 'gnus-info "Failed")
1031        (if (eq (car error) 'quit)
1032            (mm-set-handle-multipart-parameter
1033             mm-security-handle 'gnus-details "Quit.")
1034          (mm-set-handle-multipart-parameter
1035           mm-security-handle 'gnus-details (mml2015-format-error error)))))
1036     (if plain
1037         (progn
1038           (mm-set-handle-multipart-parameter
1039            mm-security-handle 'gnus-info
1040            (mml2015-epg-verify-result-to-string
1041             (epg-context-result-for context 'verify)))
1042           (delete-region (point-min) (point-max))
1043           (insert (mm-decode-coding-string plain coding-system-for-read)))
1044       (mml2015-extract-cleartext-signature))))
1045
1046 (defun mml2015-epg-sign (cont)
1047   (let* ((inhibit-redisplay t)
1048          (context (epg-make-context))
1049          (boundary (mml-compute-boundary cont))
1050          (sender (message-options-get 'message-sender))
1051          (signer-names (or mml2015-signers
1052                            (if (and mml2015-sign-with-sender sender)
1053                                (list (concat "<" sender ">")))))
1054          signer-key
1055          (signers
1056           (or (message-options-get 'mml2015-epg-signers)
1057               (message-options-set
1058                'mml2015-epg-signers
1059                (if (eq mm-sign-option 'guided)
1060                    (epa-select-keys context "\
1061 Select keys for signing.
1062 If no one is selected, default secret key is used.  "
1063                                     signer-names
1064                                     t)
1065                  (if (or sender mml2015-signers)
1066                      (delq nil
1067                            (mapcar
1068                             (lambda (signer)
1069                               (setq signer-key
1070                                     (mml2015-epg-find-usable-secret-key
1071                                      context signer 'sign))
1072                               (unless (or signer-key
1073                                           (y-or-n-p
1074                                            (format
1075                                             "No secret key for %s; skip it? "
1076                                             signer)))
1077                                 (error "No secret key for %s" signer))
1078                               signer-key)
1079                             signer-names)))))))
1080          signature micalg)
1081     (epg-context-set-armor context t)
1082     (epg-context-set-textmode context t)
1083     (epg-context-set-signers context signers)
1084     (if mml2015-cache-passphrase
1085         (epg-context-set-passphrase-callback
1086          context
1087          #'mml2015-epg-passphrase-callback))
1088     ;; Signed data must end with a newline (RFC 3156, 5).
1089     (goto-char (point-max))
1090     (unless (bolp)
1091       (insert "\n"))
1092     (condition-case error
1093         (setq signature (epg-sign-string context (buffer-string) t)
1094               mml2015-epg-secret-key-id-list nil)
1095       (error
1096        (while mml2015-epg-secret-key-id-list
1097          (password-cache-remove (car mml2015-epg-secret-key-id-list))
1098          (setq mml2015-epg-secret-key-id-list
1099                (cdr mml2015-epg-secret-key-id-list)))
1100        (signal (car error) (cdr error))))
1101     (if (epg-context-result-for context 'sign)
1102         (setq micalg (epg-new-signature-digest-algorithm
1103                       (car (epg-context-result-for context 'sign)))))
1104     (goto-char (point-min))
1105     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
1106                     boundary))
1107     (if micalg
1108         (insert (format "\tmicalg=pgp-%s; "
1109                         (downcase
1110                          (cdr (assq micalg
1111                                     epg-digest-algorithm-alist))))))
1112     (insert "protocol=\"application/pgp-signature\"\n")
1113     (insert (format "\n--%s\n" boundary))
1114     (goto-char (point-max))
1115     (insert (format "\n--%s\n" boundary))
1116     (insert "Content-Type: application/pgp-signature; name=\"signature.asc\"\n\n")
1117     (insert signature)
1118     (goto-char (point-max))
1119     (insert (format "--%s--\n" boundary))
1120     (goto-char (point-max))))
1121
1122 (defun mml2015-epg-encrypt (cont &optional sign)
1123   (let* ((inhibit-redisplay t)
1124          (context (epg-make-context))
1125          (boundary (mml-compute-boundary cont))
1126          (config (epg-configuration))
1127          (recipients (message-options-get 'mml2015-epg-recipients))
1128          cipher
1129          (sender (message-options-get 'message-sender))
1130          (signer-names (or mml2015-signers
1131                            (if (and mml2015-sign-with-sender sender)
1132                                (list (concat "<" sender ">")))))
1133          signers
1134          recipient-key signer-key)
1135     (unless recipients
1136       (setq recipients
1137             (apply #'nconc
1138                    (mapcar
1139                     (lambda (recipient)
1140                       (or (epg-expand-group config recipient)
1141                           (list (concat "<" recipient ">"))))
1142                     (split-string
1143                      (or (message-options-get 'message-recipients)
1144                          (message-options-set 'message-recipients
1145                                               (read-string "Recipients: ")))
1146                      "[ \f\t\n\r\v,]+"))))
1147       (when mml2015-encrypt-to-self
1148         (unless signer-names
1149           (error "Neither message sender nor mml2015-signers are set"))
1150         (setq recipients (nconc recipients signer-names)))
1151       (if (eq mm-encrypt-option 'guided)
1152           (setq recipients
1153                 (epa-select-keys context "\
1154 Select recipients for encryption.
1155 If no one is selected, symmetric encryption will be performed.  "
1156                                  recipients))
1157         (setq recipients
1158               (delq nil
1159                     (mapcar
1160                      (lambda (recipient)
1161                        (setq recipient-key (mml2015-epg-find-usable-key
1162                                             context recipient 'encrypt))
1163                        (unless (or recipient-key
1164                                    (y-or-n-p
1165                                     (format "No public key for %s; skip it? "
1166                                             recipient)))
1167                          (error "No public key for %s" recipient))
1168                        recipient-key)
1169                      recipients)))
1170         (unless recipients
1171           (error "No recipient specified")))
1172       (message-options-set 'mml2015-epg-recipients recipients))
1173     (when sign
1174       (setq signers
1175             (or (message-options-get 'mml2015-epg-signers)
1176                 (message-options-set
1177                  'mml2015-epg-signers
1178                  (if (eq mm-sign-option 'guided)
1179                      (epa-select-keys context "\
1180 Select keys for signing.
1181 If no one is selected, default secret key is used.  "
1182                                       signer-names
1183                                       t)
1184                    (if (or sender mml2015-signers)
1185                        (delq nil
1186                              (mapcar
1187                               (lambda (signer)
1188                                 (setq signer-key
1189                                       (mml2015-epg-find-usable-secret-key
1190                                        context signer 'sign))
1191                                 (unless (or signer-key
1192                                             (y-or-n-p
1193                                              (format
1194                                               "No secret key for %s; skip it? "
1195                                               signer)))
1196                                   (error "No secret key for %s" signer))
1197                                 signer-key)
1198                               signer-names)))))))
1199       (epg-context-set-signers context signers))
1200     (epg-context-set-armor context t)
1201     (epg-context-set-textmode context t)
1202     (if mml2015-cache-passphrase
1203         (epg-context-set-passphrase-callback
1204          context
1205          #'mml2015-epg-passphrase-callback))
1206     (condition-case error
1207         (setq cipher
1208               (epg-encrypt-string context (buffer-string) recipients sign
1209                                   mml2015-always-trust)
1210               mml2015-epg-secret-key-id-list nil)
1211       (error
1212        (while mml2015-epg-secret-key-id-list
1213          (password-cache-remove (car mml2015-epg-secret-key-id-list))
1214          (setq mml2015-epg-secret-key-id-list
1215                (cdr mml2015-epg-secret-key-id-list)))
1216        (signal (car error) (cdr error))))
1217     (delete-region (point-min) (point-max))
1218     (goto-char (point-min))
1219     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
1220                     boundary))
1221     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
1222     (insert (format "--%s\n" boundary))
1223     (insert "Content-Type: application/pgp-encrypted\n\n")
1224     (insert "Version: 1\n\n")
1225     (insert (format "--%s\n" boundary))
1226     (insert "Content-Type: application/octet-stream\n\n")
1227     (insert cipher)
1228     (goto-char (point-max))
1229     (insert (format "--%s--\n" boundary))
1230     (goto-char (point-max))))
1231
1232 ;;; General wrapper
1233
1234 (autoload 'gnus-buffer-live-p "gnus-util")
1235 (autoload 'gnus-get-buffer-create "gnus")
1236
1237 (defun mml2015-clean-buffer ()
1238   (if (gnus-buffer-live-p mml2015-result-buffer)
1239       (with-current-buffer mml2015-result-buffer
1240         (erase-buffer)
1241         t)
1242     (setq mml2015-result-buffer
1243           (gnus-get-buffer-create " *MML2015 Result*"))
1244     nil))
1245
1246 (defsubst mml2015-clear-decrypt-function ()
1247   (nth 6 (assq mml2015-use mml2015-function-alist)))
1248
1249 (defsubst mml2015-clear-verify-function ()
1250   (nth 5 (assq mml2015-use mml2015-function-alist)))
1251
1252 ;;;###autoload
1253 (defun mml2015-decrypt (handle ctl)
1254   (mml2015-clean-buffer)
1255   (let ((func (nth 4 (assq mml2015-use mml2015-function-alist))))
1256     (if func
1257         (funcall func handle ctl)
1258       handle)))
1259
1260 ;;;###autoload
1261 (defun mml2015-decrypt-test (handle ctl)
1262   mml2015-use)
1263
1264 ;;;###autoload
1265 (defun mml2015-verify (handle ctl)
1266   (mml2015-clean-buffer)
1267   (let ((func (nth 3 (assq mml2015-use mml2015-function-alist))))
1268     (if func
1269         (funcall func handle ctl)
1270       handle)))
1271
1272 ;;;###autoload
1273 (defun mml2015-verify-test (handle ctl)
1274   mml2015-use)
1275
1276 ;;;###autoload
1277 (defun mml2015-encrypt (cont &optional sign)
1278   (mml2015-clean-buffer)
1279   (let ((func (nth 2 (assq mml2015-use mml2015-function-alist))))
1280     (if func
1281         (funcall func cont sign)
1282       (error "Cannot find encrypt function"))))
1283
1284 ;;;###autoload
1285 (defun mml2015-sign (cont)
1286   (mml2015-clean-buffer)
1287   (let ((func (nth 1 (assq mml2015-use mml2015-function-alist))))
1288     (if func
1289         (funcall func cont)
1290       (error "Cannot find sign function"))))
1291
1292 ;;;###autoload
1293 (defun mml2015-self-encrypt ()
1294   (mml2015-encrypt nil))
1295
1296 (provide 'mml2015)
1297
1298 ;;; mml2015.el ends here