lisp/gnus/mml2015.el

   1 ;;; mml2015.el --- MIME Security with Pretty Good Privacy (PGP)
   2
   3 ;; Copyright (C) 2000-2018 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 <https://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-when-compile (require 'cl))
  31 (require 'mm-decode)
  32 (require 'mm-util)
  33 (require 'mml)
  34 (require 'mml-sec)
  35 (require 'epg-config)
  36
  37 (defvar mc-pgp-always-sign)
  38
  39 (declare-function epg-check-configuration "ext:epg-config"
  40                   (config &optional minimum-version))
  41 (declare-function epg-configuration "ext:epg-config" ())
  42
  43 ;; Maybe this should be in eg mml-sec.el (and have a different name).
  44 ;; Then mml1991 would not need to require mml2015, and mml1991-use
  45 ;; could be removed.
  46 (defvar mml2015-use 'epg
  47   "The package used for PGP/MIME.
  48 Valid packages include `epg', `pgg' and `mailcrypt'.")
  49
  50 ;; Something is not RFC2015.
  51 (defvar mml2015-function-alist
  52   '((mailcrypt mml2015-mailcrypt-sign
  53                mml2015-mailcrypt-encrypt
  54                mml2015-mailcrypt-verify
  55                mml2015-mailcrypt-decrypt
  56                mml2015-mailcrypt-clear-verify
  57                mml2015-mailcrypt-clear-decrypt)
  58     (pgg mml2015-pgg-sign
  59          mml2015-pgg-encrypt
  60          mml2015-pgg-verify
  61          mml2015-pgg-decrypt
  62          mml2015-pgg-clear-verify
  63          mml2015-pgg-clear-decrypt)
  64     (epg mml2015-epg-sign
  65          mml2015-epg-encrypt
  66          mml2015-epg-verify
  67          mml2015-epg-decrypt
  68          mml2015-epg-clear-verify
  69          mml2015-epg-clear-decrypt))
  70   "Alist of PGP/MIME functions.")
  71
  72 (defvar mml2015-result-buffer nil)
  73
  74 (defcustom mml2015-unabbrev-trust-alist
  75   '(("TRUST_UNDEFINED" . nil)
  76     ("TRUST_NEVER"     . nil)
  77     ("TRUST_MARGINAL"  . t)
  78     ("TRUST_FULLY"     . t)
  79     ("TRUST_ULTIMATE"  . t))
  80   "Map GnuPG trust output values to a boolean saying if you trust the key."
  81   :version "22.1"
  82   :group 'mime-security
  83   :type '(repeat (cons (regexp :tag "GnuPG output regexp")
  84                        (boolean :tag "Trust key"))))
  85
  86 (defcustom mml2015-cache-passphrase mml-secure-cache-passphrase
  87   "If t, cache passphrase."
  88   :group 'mime-security
  89   :type 'boolean)
  90 (make-obsolete-variable 'mml2015-cache-passphrase
  91                         'mml-secure-cache-passphrase
  92                         "25.1")
  93
  94 (defcustom mml2015-passphrase-cache-expiry mml-secure-passphrase-cache-expiry
  95   "How many seconds the passphrase is cached.
  96 Whether the passphrase is cached at all is controlled by
  97 `mml2015-cache-passphrase'."
  98   :group 'mime-security
  99   :type 'integer)
 100 (make-obsolete-variable 'mml2015-passphrase-cache-expiry
 101                         'mml-secure-passphrase-cache-expiry
 102                         "25.1")
 103
 104 (defcustom mml2015-signers nil
 105   "A list of your own key ID(s) which will be used to sign a message.
 106 If set, it overrides the setting of `mml2015-sign-with-sender'."
 107   :group 'mime-security
 108   :type '(repeat (string :tag "Key ID")))
 109
 110 (defcustom mml2015-sign-with-sender nil
 111   "If t, use message sender so find a key to sign with."
 112   :group 'mime-security
 113   :type 'boolean
 114   :version "24.1")
 115
 116 (defcustom mml2015-encrypt-to-self nil
 117   "If t, add your own key ID to recipient list when encryption."
 118   :group 'mime-security
 119   :type 'boolean)
 120
 121 (defcustom mml2015-always-trust t
 122   "If t, GnuPG skip key validation on encryption."
 123   :group 'mime-security
 124   :type 'boolean)
 125
 126 (defcustom mml2015-maximum-key-image-dimension 64
 127   "The maximum dimension (width or height) of any key images."
 128   :version "24.4"
 129   :group 'mime-security
 130   :type 'integer)
 131
 132 (defcustom mml2015-display-key-image t
 133   "If t, try to display key images."
 134   :version "24.5"
 135   :group 'mime-security
 136   :type 'boolean)
 137
 138 ;; Extract plaintext from cleartext signature.  IMO, this kind of task
 139 ;; should be done by GnuPG rather than Elisp, but older PGP backends
 140 ;; (such as Mailcrypt, and PGG) discard the output from GnuPG.
 141 (defun mml2015-extract-cleartext-signature ()
 142   ;; Daiki Ueno in
 143   ;; <54a15d860801080142l70b95d7dkac4bf51a86196011@mail.gmail.com>: ``I still
 144   ;; believe that the right way is to use the plaintext output from GnuPG as
 145   ;; it is, and mml2015-extract-cleartext-signature is just a kludge for
 146   ;; misdesigned libraries like PGG, which have no ability to do that.  So, I
 147   ;; think it should not have descriptive documentation.''
 148   ;;
 149   ;; This function doesn't handle NotDashEscaped correctly.  EasyPG handles it
 150   ;; correctly.
 151   ;; http://thread.gmane.org/gmane.emacs.gnus.general/66062/focus=66082
 152   ;; http://thread.gmane.org/gmane.emacs.gnus.general/65087/focus=65109
 153   (goto-char (point-min))
 154   (forward-line)
 155   ;; We need to be careful not to strip beyond the armor headers.
 156   ;; Previously, an attacker could replace the text inside our
 157   ;; markup with trailing garbage by injecting whitespace into the
 158   ;; message.
 159   (while (looking-at "Hash:")           ; The only header allowed in cleartext
 160     (forward-line))                     ; signatures according to RFC2440.
 161   (when (looking-at "[\t ]*$")
 162     (forward-line))
 163   (delete-region (point-min) (point))
 164   (if (re-search-forward "^-----BEGIN PGP SIGNATURE-----" nil t)
 165       (delete-region (match-beginning 0) (point-max)))
 166   (goto-char (point-min))
 167   (while (re-search-forward "^- " nil t)
 168     (replace-match "" t t)
 169     (forward-line 1)))
 170
 171 ;;; mailcrypt wrapper
 172
 173 (autoload 'mailcrypt-decrypt "mailcrypt")
 174 (autoload 'mailcrypt-verify "mailcrypt")
 175 (autoload 'mc-pgp-always-sign "mailcrypt")
 176 (autoload 'mc-encrypt-generic "mc-toplev")
 177 (autoload 'mc-cleanup-recipient-headers "mc-toplev")
 178 (autoload 'mc-sign-generic "mc-toplev")
 179
 180 (defvar mml2015-decrypt-function 'mailcrypt-decrypt)
 181 (defvar mml2015-verify-function 'mailcrypt-verify)
 182
 183 (defun mml2015-format-error (err)
 184   (if (stringp (cadr err))
 185       (cadr err)
 186     (format "%S" (cdr err))))
 187
 188 (defun mml2015-mailcrypt-decrypt (handle ctl)
 189   (catch 'error
 190     (let (child handles result)
 191       (unless (setq child (mm-find-part-by-type
 192                            (cdr handle)
 193                            "application/octet-stream" nil t))
 194         (mm-set-handle-multipart-parameter
 195          mm-security-handle 'gnus-info "Corrupted")
 196         (throw 'error handle))
 197       (with-temp-buffer
 198         (mm-insert-part child)
 199         (setq result
 200               (condition-case err
 201                   (funcall mml2015-decrypt-function)
 202                 (error
 203                  (mm-set-handle-multipart-parameter
 204                   mm-security-handle 'gnus-details (mml2015-format-error err))
 205                  nil)
 206                 (quit
 207                  (mm-set-handle-multipart-parameter
 208                   mm-security-handle 'gnus-details "Quit.")
 209                  nil)))
 210         (unless (car result)
 211           (mm-set-handle-multipart-parameter
 212            mm-security-handle 'gnus-info "Failed")
 213           (throw 'error handle))
 214         (setq handles (mm-dissect-buffer t)))
 215       (mm-destroy-parts handle)
 216       (mm-set-handle-multipart-parameter
 217        mm-security-handle 'gnus-info
 218        (concat "OK"
 219                (let ((sig (with-current-buffer mml2015-result-buffer
 220                             (mml2015-gpg-extract-signature-details))))
 221                  (concat ", Signer: " sig))))
 222       (if (listp (car handles))
 223           handles
 224         (list handles)))))
 225
 226 (defun mml2015-gpg-pretty-print-fpr (fingerprint)
 227   (let* ((result "")
 228          (fpr-length (string-width fingerprint))
 229          (n-slice 0)
 230          slice)
 231     (setq fingerprint (string-to-list fingerprint))
 232     (while fingerprint
 233       (setq fpr-length (- fpr-length 4))
 234       (setq slice (butlast fingerprint fpr-length))
 235       (setq fingerprint (nthcdr 4 fingerprint))
 236       (setq n-slice (1+ n-slice))
 237       (setq result
 238             (concat
 239              result
 240              (case n-slice
 241                (1  slice)
 242                (otherwise (concat " " slice))))))
 243     result))
 244
 245 (defun mml2015-gpg-extract-signature-details ()
 246   (goto-char (point-min))
 247   (let* ((expired (re-search-forward
 248                    "^\\[GNUPG:\\] SIGEXPIRED$"
 249                    nil t))
 250          (signer (and (re-search-forward
 251                        "^\\[GNUPG:\\] GOODSIG \\([0-9A-Za-z]*\\) \\(.*\\)$"
 252                        nil t)
 253                       (cons (match-string 1) (match-string 2))))
 254          (fprint (and (re-search-forward
 255                        "^\\[GNUPG:\\] VALIDSIG \\([0-9a-zA-Z]*\\) "
 256                        nil t)
 257                       (match-string 1)))
 258          (trust  (and (re-search-forward
 259                        "^\\[GNUPG:\\] \\(TRUST_.*\\)$"
 260                        nil t)
 261                       (match-string 1)))
 262          (trust-good-enough-p
 263           (cdr (assoc trust mml2015-unabbrev-trust-alist))))
 264     (cond ((and signer fprint)
 265            (concat (cdr signer)
 266                    (unless trust-good-enough-p
 267                      (concat "\nUntrusted, Fingerprint: "
 268                              (mml2015-gpg-pretty-print-fpr fprint)))
 269                    (when expired
 270                      (format "\nWARNING: Signature from expired key (%s)"
 271                              (car signer)))))
 272           ((re-search-forward
 273             "^\\(gpg: \\)?Good signature from \"\\(.*\\)\"$" nil t)
 274            (match-string 2))
 275           (t
 276            "From unknown user"))))
 277
 278 (defun mml2015-mailcrypt-clear-decrypt ()
 279   (let (result)
 280     (setq result
 281           (condition-case err
 282               (funcall mml2015-decrypt-function)
 283             (error
 284              (mm-set-handle-multipart-parameter
 285               mm-security-handle 'gnus-details (mml2015-format-error err))
 286              nil)
 287             (quit
 288              (mm-set-handle-multipart-parameter
 289               mm-security-handle 'gnus-details "Quit.")
 290              nil)))
 291     (if (car result)
 292         (mm-set-handle-multipart-parameter
 293          mm-security-handle 'gnus-info "OK")
 294       (mm-set-handle-multipart-parameter
 295        mm-security-handle 'gnus-info "Failed"))))
 296
 297 (defun mml2015-fix-micalg (alg)
 298   (and alg
 299        ;; Mutt/1.2.5i has seen sending micalg=php-sha1
 300        (upcase (if (string-match "^p[gh]p-" alg)
 301                    (substring alg (match-end 0))
 302                  alg))))
 303
 304 (defun mml2015-mailcrypt-verify (handle ctl)
 305   (catch 'error
 306     (let (part)
 307       (unless (setq part (mm-find-raw-part-by-type
 308                           ctl (or (mm-handle-multipart-ctl-parameter
 309                                    ctl 'protocol)
 310                                   "application/pgp-signature")
 311                           t))
 312         (mm-set-handle-multipart-parameter
 313          mm-security-handle 'gnus-info "Corrupted")
 314         (throw 'error handle))
 315       (with-temp-buffer
 316         (insert "-----BEGIN PGP SIGNED MESSAGE-----\n")
 317         (insert (format "Hash: %s\n\n"
 318                         (or (mml2015-fix-micalg
 319                              (mm-handle-multipart-ctl-parameter
 320                               ctl 'micalg))
 321                             "SHA1")))
 322         (save-restriction
 323           (narrow-to-region (point) (point))
 324           (insert part "\n")
 325           (goto-char (point-min))
 326           (while (not (eobp))
 327             (if (looking-at "^-")
 328                 (insert "- "))
 329             (forward-line)))
 330         (unless (setq part (mm-find-part-by-type
 331                             (cdr handle) "application/pgp-signature" nil t))
 332           (mm-set-handle-multipart-parameter
 333            mm-security-handle 'gnus-info "Corrupted")
 334           (throw 'error handle))
 335         (save-restriction
 336           (narrow-to-region (point) (point))
 337           (mm-insert-part part)
 338           (goto-char (point-min))
 339           (if (re-search-forward "^-----BEGIN PGP [^-]+-----\r?$" nil t)
 340               (replace-match "-----BEGIN PGP SIGNATURE-----" t t))
 341           (if (re-search-forward "^-----END PGP [^-]+-----\r?$" nil t)
 342               (replace-match "-----END PGP SIGNATURE-----" t t)))
 343         (let ((mc-gpg-debug-buffer (get-buffer-create " *gnus gpg debug*")))
 344           (unless (condition-case err
 345                       (prog1
 346                           (funcall mml2015-verify-function)
 347                         (if (get-buffer " *mailcrypt stderr temp")
 348                             (mm-set-handle-multipart-parameter
 349                              mm-security-handle 'gnus-details
 350                              (with-current-buffer " *mailcrypt stderr temp"
 351                                (buffer-string))))
 352                         (if (get-buffer " *mailcrypt stdout temp")
 353                             (kill-buffer " *mailcrypt stdout temp"))
 354                         (if (get-buffer " *mailcrypt stderr temp")
 355                             (kill-buffer " *mailcrypt stderr temp"))
 356                         (if (get-buffer " *mailcrypt status temp")
 357                             (kill-buffer " *mailcrypt status temp"))
 358                         (if (get-buffer mc-gpg-debug-buffer)
 359                             (kill-buffer mc-gpg-debug-buffer)))
 360                     (error
 361                      (mm-set-handle-multipart-parameter
 362                       mm-security-handle 'gnus-details (mml2015-format-error err))
 363                      nil)
 364                     (quit
 365                      (mm-set-handle-multipart-parameter
 366                       mm-security-handle 'gnus-details "Quit.")
 367                      nil))
 368             (mm-set-handle-multipart-parameter
 369              mm-security-handle 'gnus-info "Failed")
 370             (throw 'error handle))))
 371       (mm-set-handle-multipart-parameter
 372        mm-security-handle 'gnus-info "OK")
 373       handle)))
 374
 375 (defun mml2015-mailcrypt-clear-verify ()
 376   (let ((mc-gpg-debug-buffer (get-buffer-create " *gnus gpg debug*")))
 377     (if (condition-case err
 378             (prog1
 379                 (funcall mml2015-verify-function)
 380               (if (get-buffer " *mailcrypt stderr temp")
 381                   (mm-set-handle-multipart-parameter
 382                    mm-security-handle 'gnus-details
 383                    (with-current-buffer " *mailcrypt stderr temp"
 384                      (buffer-string))))
 385               (if (get-buffer " *mailcrypt stdout temp")
 386                   (kill-buffer " *mailcrypt stdout temp"))
 387               (if (get-buffer " *mailcrypt stderr temp")
 388                   (kill-buffer " *mailcrypt stderr temp"))
 389               (if (get-buffer " *mailcrypt status temp")
 390                   (kill-buffer " *mailcrypt status temp"))
 391               (if (get-buffer mc-gpg-debug-buffer)
 392                   (kill-buffer mc-gpg-debug-buffer)))
 393           (error
 394            (mm-set-handle-multipart-parameter
 395             mm-security-handle 'gnus-details (mml2015-format-error err))
 396            nil)
 397           (quit
 398            (mm-set-handle-multipart-parameter
 399             mm-security-handle 'gnus-details "Quit.")
 400            nil))
 401         (mm-set-handle-multipart-parameter
 402          mm-security-handle 'gnus-info "OK")
 403       (mm-set-handle-multipart-parameter
 404        mm-security-handle 'gnus-info "Failed")))
 405   (mml2015-extract-cleartext-signature))
 406
 407 (defun mml2015-mailcrypt-sign (cont)
 408   (mc-sign-generic (message-options-get 'message-sender)
 409                    nil nil nil nil)
 410   (let ((boundary (mml-compute-boundary cont))
 411         hash point)
 412     (goto-char (point-min))
 413     (unless (re-search-forward "^-----BEGIN PGP SIGNED MESSAGE-----\r?$" nil t)
 414       (error "Cannot find signed begin line"))
 415     (goto-char (match-beginning 0))
 416     (forward-line 1)
 417     (unless (looking-at "Hash:[ \t]*\\([a-zA-Z0-9]+\\)")
 418       (error "Cannot not find PGP hash"))
 419     (setq hash (match-string 1))
 420     (unless (re-search-forward "^$" nil t)
 421       (error "Cannot not find PGP message"))
 422     (forward-line 1)
 423     (delete-region (point-min) (point))
 424     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
 425                     boundary))
 426     (insert (format "\tmicalg=pgp-%s; protocol=\"application/pgp-signature\"\n"
 427                     (downcase hash)))
 428     (insert (format "\n--%s\n" boundary))
 429     (setq point (point))
 430     (goto-char (point-max))
 431     (unless (re-search-backward "^-----END PGP SIGNATURE-----\r?$" nil t)
 432       (error "Cannot find signature part"))
 433     (replace-match "-----END PGP MESSAGE-----" t t)
 434     (goto-char (match-beginning 0))
 435     (unless (re-search-backward "^-----BEGIN PGP SIGNATURE-----\r?$"
 436                                 nil t)
 437       (error "Cannot find signature part"))
 438     (replace-match "-----BEGIN PGP MESSAGE-----" t t)
 439     (goto-char (match-beginning 0))
 440     (save-restriction
 441       (narrow-to-region point (point))
 442       (goto-char point)
 443       (while (re-search-forward "^- -" nil t)
 444         (replace-match "-" t t))
 445       (goto-char (point-max)))
 446     (insert (format "--%s\n" boundary))
 447     (insert "Content-Type: application/pgp-signature\n\n")
 448     (goto-char (point-max))
 449     (insert (format "--%s--\n" boundary))
 450     (goto-char (point-max))))
 451
 452 ;; We require mm-decode, which requires mm-bodies, which autoloads
 453 ;; message-options-get (!).
 454 (declare-function message-options-set "message" (symbol value))
 455
 456 (defun mml2015-mailcrypt-encrypt (cont &optional sign)
 457   (let ((mc-pgp-always-sign
 458          (or mc-pgp-always-sign
 459              sign
 460              (eq t (or (message-options-get 'message-sign-encrypt)
 461                        (message-options-set
 462                         'message-sign-encrypt
 463                         (or (y-or-n-p "Sign the message? ")
 464                             'not))))
 465              'never)))
 466     (insert
 467      (with-temp-buffer
 468        (set-buffer-multibyte nil)
 469        (mc-encrypt-generic
 470         (or (message-options-get 'message-recipients)
 471             (message-options-set 'message-recipients
 472                                  (mc-cleanup-recipient-headers
 473                                   (read-string "Recipients: "))))
 474         nil nil nil
 475         (message-options-get 'message-sender))
 476        (buffer-string))))
 477   (goto-char (point-min))
 478   (unless (looking-at "-----BEGIN PGP MESSAGE-----")
 479     (error "Fail to encrypt the message"))
 480   (let ((boundary (mml-compute-boundary cont)))
 481     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
 482                     boundary))
 483     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
 484     (insert (format "--%s\n" boundary))
 485     (insert "Content-Type: application/pgp-encrypted\n\n")
 486     (insert "Version: 1\n\n")
 487     (insert (format "--%s\n" boundary))
 488     (insert "Content-Type: application/octet-stream\n\n")
 489     (goto-char (point-max))
 490     (insert (format "--%s--\n" boundary))
 491     (goto-char (point-max))))
 492
 493 ;;; pgg wrapper
 494
 495 (defvar pgg-default-user-id)
 496 (defvar pgg-errors-buffer)
 497 (defvar pgg-output-buffer)
 498
 499 (autoload 'pgg-decrypt-region "pgg")
 500 (autoload 'pgg-verify-region "pgg")
 501 (autoload 'pgg-sign-region "pgg")
 502 (autoload 'pgg-encrypt-region "pgg")
 503 (autoload 'pgg-parse-armor "pgg-parse")
 504
 505 (defun mml2015-pgg-decrypt (handle ctl)
 506   (catch 'error
 507     (let ((pgg-errors-buffer mml2015-result-buffer)
 508           child handles result decrypt-status)
 509       (unless (setq child (mm-find-part-by-type
 510                            (cdr handle)
 511                            "application/octet-stream" nil t))
 512         (mm-set-handle-multipart-parameter
 513          mm-security-handle 'gnus-info "Corrupted")
 514         (throw 'error handle))
 515       (with-temp-buffer
 516         (mm-insert-part child)
 517         (if (condition-case err
 518                 (prog1
 519                     (pgg-decrypt-region (point-min) (point-max))
 520                   (setq decrypt-status
 521                         (with-current-buffer mml2015-result-buffer
 522                           (buffer-string)))
 523                   (mm-set-handle-multipart-parameter
 524                    mm-security-handle 'gnus-details
 525                    decrypt-status))
 526               (error
 527                (mm-set-handle-multipart-parameter
 528                 mm-security-handle 'gnus-details (mml2015-format-error err))
 529                nil)
 530               (quit
 531                (mm-set-handle-multipart-parameter
 532                 mm-security-handle 'gnus-details "Quit.")
 533                nil))
 534             (with-current-buffer pgg-output-buffer
 535               (goto-char (point-min))
 536               (while (search-forward "\r\n" nil t)
 537                 (replace-match "\n" t t))
 538               (setq handles (mm-dissect-buffer t))
 539               (mm-destroy-parts handle)
 540               (mm-set-handle-multipart-parameter
 541                mm-security-handle 'gnus-info "OK")
 542               (mm-set-handle-multipart-parameter
 543                mm-security-handle 'gnus-details
 544                (concat decrypt-status
 545                        (when (stringp (car handles))
 546                          "\n" (mm-handle-multipart-ctl-parameter
 547                                handles 'gnus-details))))
 548               (if (listp (car handles))
 549                   handles
 550                 (list handles)))
 551           (mm-set-handle-multipart-parameter
 552            mm-security-handle 'gnus-info "Failed")
 553           (throw 'error handle))))))
 554
 555 (defun mml2015-pgg-clear-decrypt ()
 556   (let ((pgg-errors-buffer mml2015-result-buffer))
 557     (if (prog1
 558             (pgg-decrypt-region (point-min) (point-max))
 559           (mm-set-handle-multipart-parameter
 560            mm-security-handle 'gnus-details
 561            (with-current-buffer mml2015-result-buffer
 562              (buffer-string))))
 563         (progn
 564           (erase-buffer)
 565           ;; Treat data which pgg returns as a unibyte string.
 566           (mm-disable-multibyte)
 567           (insert-buffer-substring pgg-output-buffer)
 568           (goto-char (point-min))
 569           (while (search-forward "\r\n" nil t)
 570             (replace-match "\n" t t))
 571           (mm-set-handle-multipart-parameter
 572            mm-security-handle 'gnus-info "OK"))
 573       (mm-set-handle-multipart-parameter
 574        mm-security-handle 'gnus-info "Failed"))))
 575
 576 (defun mml2015-pgg-verify (handle ctl)
 577   (let ((pgg-errors-buffer mml2015-result-buffer)
 578         signature-file part signature)
 579     (if (or (null (setq part (mm-find-raw-part-by-type
 580                               ctl (or (mm-handle-multipart-ctl-parameter
 581                                        ctl 'protocol)
 582                                       "application/pgp-signature")
 583                               t)))
 584             (null (setq signature (mm-find-part-by-type
 585                                    (cdr handle) "application/pgp-signature" nil t))))
 586         (progn
 587           (mm-set-handle-multipart-parameter
 588            mm-security-handle 'gnus-info "Corrupted")
 589           handle)
 590       (with-temp-buffer
 591         (insert part)
 592         ;; Convert <LF> to <CR><LF> in signed text.  If --textmode is
 593         ;; specified when signing, the conversion is not necessary.
 594         (goto-char (point-min))
 595         (end-of-line)
 596         (while (not (eobp))
 597           (unless (eq (char-before) ?\r)
 598             (insert "\r"))
 599           (forward-line)
 600           (end-of-line))
 601         (with-temp-file (setq signature-file (make-temp-file "pgg"))
 602           (mm-insert-part signature))
 603         (if (condition-case err
 604                 (prog1
 605                     (pgg-verify-region (point-min) (point-max)
 606                                        signature-file t)
 607                   (goto-char (point-min))
 608                   (while (search-forward "\r\n" nil t)
 609                     (replace-match "\n" t t))
 610                   (mm-set-handle-multipart-parameter
 611                    mm-security-handle 'gnus-details
 612                    (concat (with-current-buffer pgg-output-buffer
 613                              (buffer-string))
 614                            (with-current-buffer pgg-errors-buffer
 615                              (buffer-string)))))
 616               (error
 617                (mm-set-handle-multipart-parameter
 618                 mm-security-handle 'gnus-details (mml2015-format-error err))
 619                nil)
 620               (quit
 621                (mm-set-handle-multipart-parameter
 622                 mm-security-handle 'gnus-details "Quit.")
 623                nil))
 624             (progn
 625               (delete-file signature-file)
 626               (mm-set-handle-multipart-parameter
 627                mm-security-handle 'gnus-info
 628                (with-current-buffer pgg-errors-buffer
 629                  (mml2015-gpg-extract-signature-details))))
 630           (delete-file signature-file)
 631           (mm-set-handle-multipart-parameter
 632            mm-security-handle 'gnus-info "Failed")))))
 633   handle)
 634
 635 (defun mml2015-pgg-clear-verify ()
 636   (let ((pgg-errors-buffer mml2015-result-buffer)
 637         (text (buffer-string))
 638         (coding-system buffer-file-coding-system))
 639     (if (condition-case err
 640             (prog1
 641                 (mm-with-unibyte-buffer
 642                   (insert (encode-coding-string text coding-system))
 643                   (pgg-verify-region (point-min) (point-max) nil t))
 644               (goto-char (point-min))
 645               (while (search-forward "\r\n" nil t)
 646                 (replace-match "\n" t t))
 647               (mm-set-handle-multipart-parameter
 648                mm-security-handle 'gnus-details
 649                (concat (with-current-buffer pgg-output-buffer
 650                          (buffer-string))
 651                        (with-current-buffer pgg-errors-buffer
 652                          (buffer-string)))))
 653           (error
 654            (mm-set-handle-multipart-parameter
 655             mm-security-handle 'gnus-details (mml2015-format-error err))
 656            nil)
 657           (quit
 658            (mm-set-handle-multipart-parameter
 659             mm-security-handle 'gnus-details "Quit.")
 660            nil))
 661         (mm-set-handle-multipart-parameter
 662          mm-security-handle 'gnus-info
 663          (with-current-buffer pgg-errors-buffer
 664            (mml2015-gpg-extract-signature-details)))
 665       (mm-set-handle-multipart-parameter
 666        mm-security-handle 'gnus-info "Failed")))
 667   (mml2015-extract-cleartext-signature))
 668
 669 (defun mml2015-pgg-sign (cont)
 670   (let ((pgg-errors-buffer mml2015-result-buffer)
 671         (boundary (mml-compute-boundary cont))
 672         (pgg-default-user-id (or (message-options-get 'mml-sender)
 673                                  pgg-default-user-id))
 674         (pgg-text-mode t)
 675         entry)
 676     (unless (pgg-sign-region (point-min) (point-max))
 677       (pop-to-buffer mml2015-result-buffer)
 678       (error "Sign error"))
 679     (goto-char (point-min))
 680     (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
 681                     boundary))
 682     (if (setq entry (assq 2 (pgg-parse-armor
 683                              (with-current-buffer pgg-output-buffer
 684                                (buffer-string)))))
 685         (setq entry (assq 'hash-algorithm (cdr entry))))
 686     (insert (format "\tmicalg=%s; "
 687                     (if (cdr entry)
 688                         (downcase (format "pgp-%s" (cdr entry)))
 689                       "pgp-sha1")))
 690     (insert "protocol=\"application/pgp-signature\"\n")
 691     (insert (format "\n--%s\n" boundary))
 692     (goto-char (point-max))
 693     (insert (format "\n--%s\n" boundary))
 694     (insert "Content-Type: application/pgp-signature\n\n")
 695     (insert-buffer-substring pgg-output-buffer)
 696     (goto-char (point-max))
 697     (insert (format "--%s--\n" boundary))
 698     (goto-char (point-max))))
 699
 700 (defun mml2015-pgg-encrypt (cont &optional sign)
 701   (let ((pgg-errors-buffer mml2015-result-buffer)
 702         (pgg-text-mode t)
 703         (boundary (mml-compute-boundary cont)))
 704     (unless (pgg-encrypt-region (point-min) (point-max)
 705                                 (split-string
 706                                  (or
 707                                   (message-options-get 'message-recipients)
 708                                   (message-options-set 'message-recipients
 709                                                        (read-string "Recipients: ")))
 710                                  "[ \f\t\n\r\v,]+")
 711                                 sign)
 712       (pop-to-buffer mml2015-result-buffer)
 713       (error "Encrypt error"))
 714     (delete-region (point-min) (point-max))
 715     (goto-char (point-min))
 716     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
 717                     boundary))
 718     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
 719     (insert (format "--%s\n" boundary))
 720     (insert "Content-Type: application/pgp-encrypted\n\n")
 721     (insert "Version: 1\n\n")
 722     (insert (format "--%s\n" boundary))
 723     (insert "Content-Type: application/octet-stream\n\n")
 724     (insert-buffer-substring pgg-output-buffer)
 725     (goto-char (point-max))
 726     (insert (format "--%s--\n" boundary))
 727     (goto-char (point-max))))
 728
 729 ;;; epg wrapper
 730
 731 (defvar epg-user-id-alist)
 732 (defvar epg-digest-algorithm-alist)
 733 (defvar epg-gpg-program)
 734 (defvar inhibit-redisplay)
 735
 736 (autoload 'epg-make-context "epg")
 737 (autoload 'epg-context-set-armor "epg")
 738 (autoload 'epg-context-set-textmode "epg")
 739 (autoload 'epg-context-set-signers "epg")
 740 (autoload 'epg-context-result-for "epg")
 741 (autoload 'epg-new-signature-digest-algorithm "epg")
 742 (autoload 'epg-list-keys "epg")
 743 (autoload 'epg-decrypt-string "epg")
 744 (autoload 'epg-verify-string "epg")
 745 (autoload 'epg-sign-string "epg")
 746 (autoload 'epg-encrypt-string "epg")
 747 (autoload 'epg-passphrase-callback-function "epg")
 748 (autoload 'epg-context-set-passphrase-callback "epg")
 749 (autoload 'epg-key-sub-key-list "epg")
 750 (autoload 'epg-sub-key-capability "epg")
 751 (autoload 'epg-sub-key-validity "epg")
 752 (autoload 'epg-sub-key-fingerprint "epg")
 753 (autoload 'epg-signature-key-id "epg")
 754 (autoload 'epg-signature-to-string "epg")
 755 (autoload 'epg-key-user-id-list "epg")
 756 (autoload 'epg-user-id-string "epg")
 757 (autoload 'epg-user-id-validity "epg")
 758 (autoload 'epg-configuration "epg-config")
 759 (autoload 'epg-expand-group "epg-config")
 760 (autoload 'epa-select-keys "epa")
 761
 762 (defun mml2015-epg-key-image (key-id)
 763   "Return the image of a key, if any"
 764   (with-temp-buffer
 765     (set-buffer-multibyte nil)
 766     (let* ((coding-system-for-write 'binary)
 767            (coding-system-for-read 'binary)
 768            (data (shell-command-to-string
 769                   (format "%s --list-options no-show-photos --attribute-fd 3 --list-keys %s 3>&1 >/dev/null 2>&1"
 770                           (shell-quote-argument epg-gpg-program) key-id))))
 771       (when (> (length data) 0)
 772         (insert (substring data 16))
 773         (condition-case nil
 774             (gnus-create-image (buffer-string) nil t)
 775           (error))))))
 776
 777 (autoload 'gnus-rescale-image "gnus-util")
 778
 779 (defun mml2015-epg-key-image-to-string (key-id)
 780   "Return a string with the image of a key, if any"
 781   (let ((key-image (mml2015-epg-key-image key-id)))
 782     (if (not key-image)
 783         ""
 784       (condition-case error
 785           (let ((result "  "))
 786             (put-text-property
 787              1 2 'display
 788              (gnus-rescale-image key-image
 789                                  (cons mml2015-maximum-key-image-dimension
 790                                        mml2015-maximum-key-image-dimension))
 791              result)
 792             result)
 793         (error "")))))
 794
 795 (defun mml2015-epg-signature-to-string (signature)
 796   (concat (epg-signature-to-string signature)
 797           (when mml2015-display-key-image
 798             (mml2015-epg-key-image-to-string (epg-signature-key-id signature)))))
 799
 800 (defun mml2015-epg-verify-result-to-string (verify-result)
 801   (mapconcat #'mml2015-epg-signature-to-string verify-result "\n"))
 802
 803 (defun mml2015-epg-decrypt (handle ctl)
 804   (catch 'error
 805     (let ((inhibit-redisplay t)
 806           context plain child handles result decrypt-status)
 807       (unless (setq child (mm-find-part-by-type
 808                            (cdr handle)
 809                            "application/octet-stream" nil t))
 810         (mm-set-handle-multipart-parameter
 811          mm-security-handle 'gnus-info "Corrupted")
 812         (throw 'error handle))
 813       (setq context (epg-make-context))
 814       (if (or mml2015-cache-passphrase mml-secure-cache-passphrase)
 815           (epg-context-set-passphrase-callback
 816            context
 817            (cons 'mml-secure-passphrase-callback 'OpenPGP)))
 818       (condition-case error
 819           (setq plain (epg-decrypt-string context (mm-get-part child))
 820                 mml-secure-secret-key-id-list nil)
 821         (error
 822          (mml-secure-clear-secret-key-id-list)
 823          (mm-set-handle-multipart-parameter
 824           mm-security-handle 'gnus-info "Failed")
 825          (if (eq (car error) 'quit)
 826              (mm-set-handle-multipart-parameter
 827               mm-security-handle 'gnus-details "Quit.")
 828            (mm-set-handle-multipart-parameter
 829             mm-security-handle 'gnus-details (mml2015-format-error error)))
 830          (throw 'error handle)))
 831       (with-temp-buffer
 832         (insert plain)
 833         (goto-char (point-min))
 834         (while (search-forward "\r\n" nil t)
 835           (replace-match "\n" t t))
 836         (setq handles (mm-dissect-buffer t))
 837         (mm-destroy-parts handle)
 838         (if (epg-context-result-for context 'verify)
 839             (mm-set-handle-multipart-parameter
 840              mm-security-handle 'gnus-info
 841              (concat "OK\n"
 842                      (mml2015-epg-verify-result-to-string
 843                       (epg-context-result-for context 'verify))))
 844           (mm-set-handle-multipart-parameter
 845            mm-security-handle 'gnus-info "OK"))
 846         (if (stringp (car handles))
 847             (mm-set-handle-multipart-parameter
 848              mm-security-handle 'gnus-details
 849              (mm-handle-multipart-ctl-parameter handles 'gnus-details))))
 850         (if (listp (car handles))
 851             handles
 852           (list handles)))))
 853
 854 (defun mml2015-epg-clear-decrypt ()
 855   (let ((inhibit-redisplay t)
 856         (context (epg-make-context))
 857         plain)
 858     (if (or mml2015-cache-passphrase mml-secure-cache-passphrase)
 859         (epg-context-set-passphrase-callback
 860          context
 861          (cons 'mml-secure-passphrase-callback 'OpenPGP)))
 862     (condition-case error
 863         (setq plain (epg-decrypt-string context (buffer-string))
 864               mml-secure-secret-key-id-list nil)
 865       (error
 866        (mml-secure-clear-secret-key-id-list)
 867        (mm-set-handle-multipart-parameter
 868         mm-security-handle 'gnus-info "Failed")
 869        (if (eq (car error) 'quit)
 870            (mm-set-handle-multipart-parameter
 871             mm-security-handle 'gnus-details "Quit.")
 872          (mm-set-handle-multipart-parameter
 873           mm-security-handle 'gnus-details (mml2015-format-error error)))))
 874     (when plain
 875       (erase-buffer)
 876       ;; Treat data which epg returns as a unibyte string.
 877       (mm-disable-multibyte)
 878       (insert plain)
 879       (goto-char (point-min))
 880       (while (search-forward "\r\n" nil t)
 881         (replace-match "\n" t t))
 882       (mm-set-handle-multipart-parameter
 883        mm-security-handle 'gnus-info "OK")
 884       (if (epg-context-result-for context 'verify)
 885           (mm-set-handle-multipart-parameter
 886            mm-security-handle 'gnus-details
 887            (mml2015-epg-verify-result-to-string
 888             (epg-context-result-for context 'verify)))))))
 889
 890 (defun mml2015-epg-verify (handle ctl)
 891   (catch 'error
 892     (let ((inhibit-redisplay t)
 893           context plain signature-file part signature)
 894       (when (or (null (setq part (mm-find-raw-part-by-type
 895                                   ctl (or (mm-handle-multipart-ctl-parameter
 896                                            ctl 'protocol)
 897                                           "application/pgp-signature")
 898                                   t)))
 899                 (null (setq signature (mm-find-part-by-type
 900                                        (cdr handle) "application/pgp-signature"
 901                                        nil t))))
 902         (mm-set-handle-multipart-parameter
 903          mm-security-handle 'gnus-info "Corrupted")
 904         (throw 'error handle))
 905       (setq part (replace-regexp-in-string "\n" "\r\n" part)
 906             signature (mm-get-part signature)
 907             context (epg-make-context))
 908       (condition-case error
 909           (setq plain (epg-verify-string context signature part))
 910         (error
 911          (mm-set-handle-multipart-parameter
 912           mm-security-handle 'gnus-info "Failed")
 913          (if (eq (car error) 'quit)
 914              (mm-set-handle-multipart-parameter
 915               mm-security-handle 'gnus-details "Quit.")
 916            (mm-set-handle-multipart-parameter
 917             mm-security-handle 'gnus-details (mml2015-format-error error)))
 918          (throw 'error handle)))
 919       (mm-set-handle-multipart-parameter
 920        mm-security-handle 'gnus-info
 921        (mml2015-epg-verify-result-to-string
 922         (epg-context-result-for context 'verify)))
 923       handle)))
 924
 925 (defun mml2015-epg-clear-verify ()
 926   (let ((inhibit-redisplay t)
 927         (context (epg-make-context))
 928         (signature (encode-coding-string (buffer-string)
 929                                          coding-system-for-write))
 930         plain)
 931     (condition-case error
 932         (setq plain (epg-verify-string context signature))
 933       (error
 934        (mm-set-handle-multipart-parameter
 935         mm-security-handle 'gnus-info "Failed")
 936        (if (eq (car error) 'quit)
 937            (mm-set-handle-multipart-parameter
 938             mm-security-handle 'gnus-details "Quit.")
 939          (mm-set-handle-multipart-parameter
 940           mm-security-handle 'gnus-details (mml2015-format-error error)))))
 941     (if plain
 942         (progn
 943           (mm-set-handle-multipart-parameter
 944            mm-security-handle 'gnus-info
 945            (mml2015-epg-verify-result-to-string
 946             (epg-context-result-for context 'verify)))
 947           (delete-region (point-min) (point-max))
 948           (insert (decode-coding-string plain coding-system-for-read)))
 949       (mml2015-extract-cleartext-signature))))
 950
 951 (defun mml2015-epg-sign (cont)
 952   (let ((inhibit-redisplay t)
 953         (boundary (mml-compute-boundary cont)))
 954     ;; Signed data must end with a newline (RFC 3156, 5).
 955     (goto-char (point-max))
 956     (unless (bolp)
 957       (insert "\n"))
 958     (let* ((pair (mml-secure-epg-sign 'OpenPGP t))
 959            (signature (car pair))
 960            (micalg (cdr pair)))
 961       (goto-char (point-min))
 962       (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
 963                       boundary))
 964       (if micalg
 965           (insert (format "\tmicalg=pgp-%s; "
 966                           (downcase
 967                            (cdr (assq micalg
 968                                       epg-digest-algorithm-alist))))))
 969       (insert "protocol=\"application/pgp-signature\"\n")
 970       (insert (format "\n--%s\n" boundary))
 971       (goto-char (point-max))
 972       (insert (format "\n--%s\n" boundary))
 973       (insert "Content-Type: application/pgp-signature; name=\"signature.asc\"\n\n")
 974       (insert signature)
 975       (goto-char (point-max))
 976       (insert (format "--%s--\n" boundary))
 977       (goto-char (point-max)))))
 978
 979 (defun mml2015-epg-encrypt (cont &optional sign)
 980   (let* ((inhibit-redisplay t)
 981          (boundary (mml-compute-boundary cont))
 982          (cipher (mml-secure-epg-encrypt 'OpenPGP cont sign)))
 983     (delete-region (point-min) (point-max))
 984     (goto-char (point-min))
 985     (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
 986                     boundary))
 987     (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
 988     (insert (format "--%s\n" boundary))
 989     (insert "Content-Type: application/pgp-encrypted\n\n")
 990     (insert "Version: 1\n\n")
 991     (insert (format "--%s\n" boundary))
 992     (insert "Content-Type: application/octet-stream\n\n")
 993     (insert cipher)
 994     (goto-char (point-max))
 995     (insert (format "--%s--\n" boundary))
 996     (goto-char (point-max))))
 997
 998 ;;; General wrapper
 999
1000 (autoload 'gnus-buffer-live-p "gnus-util")
1001 (autoload 'gnus-get-buffer-create "gnus")
1002
1003 (defun mml2015-clean-buffer ()
1004   (if (gnus-buffer-live-p mml2015-result-buffer)
1005       (with-current-buffer mml2015-result-buffer
1006         (erase-buffer)
1007         t)
1008     (setq mml2015-result-buffer
1009           (gnus-get-buffer-create " *MML2015 Result*"))
1010     nil))
1011
1012 (defsubst mml2015-clear-decrypt-function ()
1013   (nth 6 (assq mml2015-use mml2015-function-alist)))
1014
1015 (defsubst mml2015-clear-verify-function ()
1016   (nth 5 (assq mml2015-use mml2015-function-alist)))
1017
1018 ;;;###autoload
1019 (defun mml2015-decrypt (handle ctl)
1020   (mml2015-clean-buffer)
1021   (let ((func (nth 4 (assq mml2015-use mml2015-function-alist))))
1022     (if func
1023         (funcall func handle ctl)
1024       handle)))
1025
1026 ;;;###autoload
1027 (defun mml2015-decrypt-test (handle ctl)
1028   mml2015-use)
1029
1030 ;;;###autoload
1031 (defun mml2015-verify (handle ctl)
1032   (mml2015-clean-buffer)
1033   (let ((func (nth 3 (assq mml2015-use mml2015-function-alist))))
1034     (if func
1035         (funcall func handle ctl)
1036       handle)))
1037
1038 ;;;###autoload
1039 (defun mml2015-verify-test (handle ctl)
1040   mml2015-use)
1041
1042 ;;;###autoload
1043 (defun mml2015-encrypt (cont &optional sign)
1044   (mml2015-clean-buffer)
1045   (let ((func (nth 2 (assq mml2015-use mml2015-function-alist))))
1046     (if func
1047         (funcall func cont sign)
1048       (error "Cannot find encrypt function"))))
1049
1050 ;;;###autoload
1051 (defun mml2015-sign (cont)
1052   (mml2015-clean-buffer)
1053   (let ((func (nth 1 (assq mml2015-use mml2015-function-alist))))
1054     (if func
1055         (funcall func cont)
1056       (error "Cannot find sign function"))))
1057
1058 ;;;###autoload
1059 (defun mml2015-self-encrypt ()
1060   (mml2015-encrypt nil))
1061
1062 (provide 'mml2015)
1063
1064 ;;; mml2015.el ends here