lisp/gnus/mml1991.el

   1 ;;; mml1991.el --- Old PGP message format (RFC 1991) support for MML
   2
   3 ;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   4 ;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.
   5
   6 ;; Author: Sascha Ldecke <sascha@meta-x.de>,
   7 ;;      Simon Josefsson <simon@josefsson.org> (Mailcrypt interface, Gnus glue)
   8 ;; Keywords PGP
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 3, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  25 ;; Boston, MA 02110-1301, USA.
  26
  27 ;;; Commentary:
  28
  29 ;;; Code:
  30
  31 ;; For Emacs < 22.2.
  32 (eval-and-compile
  33   (unless (fboundp 'declare-function) (defmacro declare-function (&rest r))))
  34
  35 (eval-when-compile
  36   (require 'cl)
  37   (require 'mm-util))
  38
  39 (require 'mml-sec)
  40
  41 (defvar mc-pgp-always-sign)
  42
  43 (autoload 'quoted-printable-decode-region "qp")
  44 (autoload 'quoted-printable-encode-region "qp")
  45
  46 (autoload 'mm-decode-content-transfer-encoding "mm-bodies")
  47 (autoload 'mm-encode-content-transfer-encoding "mm-bodies")
  48 (autoload 'message-options-get "message")
  49 (autoload 'message-options-set "message")
  50
  51 (defvar mml1991-use mml2015-use
  52   "The package used for PGP.")
  53
  54 (defvar mml1991-function-alist
  55   '((mailcrypt mml1991-mailcrypt-sign
  56                mml1991-mailcrypt-encrypt)
  57     (gpg mml1991-gpg-sign
  58          mml1991-gpg-encrypt)
  59     (pgg mml1991-pgg-sign
  60          mml1991-pgg-encrypt)
  61     (epg mml1991-epg-sign
  62          mml1991-epg-encrypt))
  63   "Alist of PGP functions.")
  64
  65 (defvar mml1991-verbose mml-secure-verbose
  66   "If non-nil, ask the user about the current operation more verbosely.")
  67
  68 (defvar mml1991-cache-passphrase mml-secure-cache-passphrase
  69   "If t, cache passphrase.")
  70
  71 (defvar mml1991-passphrase-cache-expiry mml-secure-passphrase-cache-expiry
  72   "How many seconds the passphrase is cached.
  73 Whether the passphrase is cached at all is controlled by
  74 `mml1991-cache-passphrase'.")
  75
  76 (defvar mml1991-signers nil
  77   "A list of your own key ID which will be used to sign a message.")
  78
  79 (defvar mml1991-encrypt-to-self nil
  80   "If t, add your own key ID to recipient list when encryption.")
  81
  82 ;;; mailcrypt wrapper
  83
  84 (eval-and-compile
  85   (autoload 'mc-sign-generic "mc-toplev"))
  86
  87 (defvar mml1991-decrypt-function 'mailcrypt-decrypt)
  88 (defvar mml1991-verify-function 'mailcrypt-verify)
  89
  90 (defun mml1991-mailcrypt-sign (cont)
  91   (let ((text (current-buffer))
  92         headers signature
  93         (result-buffer (get-buffer-create "*GPG Result*")))
  94     ;; Save MIME Content[^ ]+: headers from signing
  95     (goto-char (point-min))
  96     (while (looking-at "^Content[^ ]+:") (forward-line))
  97     (unless (bobp)
  98       (setq headers (buffer-string))
  99       (delete-region (point-min) (point)))
 100     (goto-char (point-max))
 101     (unless (bolp)
 102       (insert "\n"))
 103     (quoted-printable-decode-region (point-min) (point-max))
 104     (with-temp-buffer
 105       (setq signature (current-buffer))
 106       (insert-buffer-substring text)
 107       (unless (mc-sign-generic (message-options-get 'message-sender)
 108                                nil nil nil nil)
 109         (unless (> (point-max) (point-min))
 110           (pop-to-buffer result-buffer)
 111           (error "Sign error")))
 112       (goto-char (point-min))
 113       (while (re-search-forward "\r+$" nil t)
 114         (replace-match "" t t))
 115       (quoted-printable-encode-region (point-min) (point-max))
 116       (set-buffer text)
 117       (delete-region (point-min) (point-max))
 118       (if headers (insert headers))
 119       (insert "\n")
 120       (insert-buffer-substring signature)
 121       (goto-char (point-max)))))
 122
 123 (declare-function mc-encrypt-generic "ext:mc-toplev"
 124                   (&optional recipients scheme start end from sign))
 125
 126 (defun mml1991-mailcrypt-encrypt (cont &optional sign)
 127   (let ((text (current-buffer))
 128         (mc-pgp-always-sign
 129          (or mc-pgp-always-sign
 130              sign
 131              (eq t (or (message-options-get 'message-sign-encrypt)
 132                        (message-options-set
 133                         'message-sign-encrypt
 134                         (or (y-or-n-p "Sign the message? ")
 135                             'not))))
 136              'never))
 137         cipher
 138         (result-buffer (get-buffer-create "*GPG Result*")))
 139     ;; Strip MIME Content[^ ]: headers since it will be ASCII ARMOURED
 140     (goto-char (point-min))
 141     (while (looking-at "^Content[^ ]+:") (forward-line))
 142     (unless (bobp)
 143       (delete-region (point-min) (point)))
 144     (mm-with-unibyte-current-buffer
 145       (with-temp-buffer
 146         (setq cipher (current-buffer))
 147         (insert-buffer-substring text)
 148         (unless (mc-encrypt-generic
 149                  (or
 150                   (message-options-get 'message-recipients)
 151                   (message-options-set 'message-recipients
 152                                        (read-string "Recipients: ")))
 153                  nil
 154                  (point-min) (point-max)
 155                  (message-options-get 'message-sender)
 156                  'sign)
 157           (unless (> (point-max) (point-min))
 158             (pop-to-buffer result-buffer)
 159             (error "Encrypt error")))
 160         (goto-char (point-min))
 161         (while (re-search-forward "\r+$" nil t)
 162           (replace-match "" t t))
 163         (set-buffer text)
 164         (delete-region (point-min) (point-max))
 165         ;;(insert "Content-Type: application/pgp-encrypted\n\n")
 166         ;;(insert "Version: 1\n\n")
 167         (insert "\n")
 168         (insert-buffer-substring cipher)
 169         (goto-char (point-max))))))
 170
 171 ;;; gpg wrapper
 172
 173 (eval-and-compile
 174   (autoload 'gpg-sign-cleartext "gpg"))
 175
 176 (declare-function gpg-sign-encrypt "ext:gpg"
 177                   (plaintext ciphertext result recipients &optional
 178                              passphrase sign-with-key armor textmode))
 179 (declare-function gpg-encrypt "ext:gpg"
 180                   (plaintext ciphertext result recipients &optional
 181                              passphrase armor textmode))
 182
 183 (defun mml1991-gpg-sign (cont)
 184   (let ((text (current-buffer))
 185         headers signature
 186         (result-buffer (get-buffer-create "*GPG Result*")))
 187     ;; Save MIME Content[^ ]+: headers from signing
 188     (goto-char (point-min))
 189     (while (looking-at "^Content[^ ]+:") (forward-line))
 190     (unless (bobp)
 191       (setq headers (buffer-string))
 192       (delete-region (point-min) (point)))
 193     (goto-char (point-max))
 194     (unless (bolp)
 195       (insert "\n"))
 196     (quoted-printable-decode-region (point-min) (point-max))
 197     (with-temp-buffer
 198       (unless (gpg-sign-cleartext text (setq signature (current-buffer))
 199                                   result-buffer
 200                                   nil
 201                                   (message-options-get 'message-sender))
 202         (unless (> (point-max) (point-min))
 203           (pop-to-buffer result-buffer)
 204           (error "Sign error")))
 205       (goto-char (point-min))
 206       (while (re-search-forward "\r+$" nil t)
 207         (replace-match "" t t))
 208       (quoted-printable-encode-region (point-min) (point-max))
 209       (set-buffer text)
 210       (delete-region (point-min) (point-max))
 211       (if headers (insert headers))
 212       (insert "\n")
 213       (insert-buffer-substring signature)
 214       (goto-char (point-max)))))
 215
 216 (defun mml1991-gpg-encrypt (cont &optional sign)
 217   (let ((text (current-buffer))
 218         cipher
 219         (result-buffer (get-buffer-create "*GPG Result*")))
 220     ;; Strip MIME Content[^ ]: headers since it will be ASCII ARMOURED
 221     (goto-char (point-min))
 222     (while (looking-at "^Content[^ ]+:") (forward-line))
 223     (unless (bobp)
 224       (delete-region (point-min) (point)))
 225     (mm-with-unibyte-current-buffer
 226       (with-temp-buffer
 227         (flet ((gpg-encrypt-func
 228                 (sign plaintext ciphertext result recipients &optional
 229                       passphrase sign-with-key armor textmode)
 230                 (if sign
 231                     (gpg-sign-encrypt
 232                      plaintext ciphertext result recipients passphrase
 233                      sign-with-key armor textmode)
 234                   (gpg-encrypt
 235                    plaintext ciphertext result recipients passphrase
 236                    armor textmode))))
 237           (unless (gpg-encrypt-func
 238                    sign
 239                    text (setq cipher (current-buffer))
 240                    result-buffer
 241                    (split-string
 242                     (or
 243                      (message-options-get 'message-recipients)
 244                      (message-options-set 'message-recipients
 245                                           (read-string "Recipients: ")))
 246                     "[ \f\t\n\r\v,]+")
 247                    nil
 248                    (message-options-get 'message-sender)
 249                    t t) ; armor & textmode
 250             (unless (> (point-max) (point-min))
 251               (pop-to-buffer result-buffer)
 252               (error "Encrypt error"))))
 253         (goto-char (point-min))
 254         (while (re-search-forward "\r+$" nil t)
 255           (replace-match "" t t))
 256         (set-buffer text)
 257         (delete-region (point-min) (point-max))
 258         ;;(insert "Content-Type: application/pgp-encrypted\n\n")
 259         ;;(insert "Version: 1\n\n")
 260         (insert "\n")
 261         (insert-buffer-substring cipher)
 262         (goto-char (point-max))))))
 263
 264 ;; pgg wrapper
 265
 266 (defvar pgg-default-user-id)
 267 (defvar pgg-errors-buffer)
 268 (defvar pgg-output-buffer)
 269
 270 (defun mml1991-pgg-sign (cont)
 271   (let ((pgg-text-mode t)
 272         (pgg-default-user-id (or (message-options-get 'mml-sender)
 273                                  pgg-default-user-id))
 274         headers cte)
 275     ;; Don't sign headers.
 276     (goto-char (point-min))
 277     (when (re-search-forward "^$" nil t)
 278       (setq headers (buffer-substring (point-min) (point)))
 279       (save-restriction
 280         (narrow-to-region (point-min) (point))
 281         (setq cte (mail-fetch-field "content-transfer-encoding")))
 282       (forward-line 1)
 283       (delete-region (point-min) (point))
 284       (when cte
 285         (setq cte (intern (downcase cte)))
 286         (mm-decode-content-transfer-encoding cte)))
 287     (unless (pgg-sign-region (point-min) (point-max) t)
 288       (pop-to-buffer pgg-errors-buffer)
 289       (error "Encrypt error"))
 290     (delete-region (point-min) (point-max))
 291     (mm-with-unibyte-current-buffer
 292       (insert-buffer-substring pgg-output-buffer)
 293       (goto-char (point-min))
 294       (while (re-search-forward "\r+$" nil t)
 295         (replace-match "" t t))
 296       (when cte
 297         (mm-encode-content-transfer-encoding cte))
 298       (goto-char (point-min))
 299       (when headers
 300         (insert headers))
 301       (insert "\n"))
 302     t))
 303
 304 (defun mml1991-pgg-encrypt (cont &optional sign)
 305   (goto-char (point-min))
 306   (when (re-search-forward "^$" nil t)
 307     (let ((cte (save-restriction
 308                  (narrow-to-region (point-min) (point))
 309                  (mail-fetch-field "content-transfer-encoding"))))
 310       ;; Strip MIME headers since it will be ASCII armoured.
 311       (forward-line 1)
 312       (delete-region (point-min) (point))
 313       (when cte
 314         (mm-decode-content-transfer-encoding (intern (downcase cte))))))
 315   (unless (let ((pgg-text-mode t))
 316             (pgg-encrypt-region
 317              (point-min) (point-max)
 318              (split-string
 319               (or
 320                (message-options-get 'message-recipients)
 321                (message-options-set 'message-recipients
 322                                     (read-string "Recipients: ")))
 323               "[ \f\t\n\r\v,]+")
 324              sign))
 325     (pop-to-buffer pgg-errors-buffer)
 326     (error "Encrypt error"))
 327   (delete-region (point-min) (point-max))
 328   (insert "\n")
 329   (insert-buffer-substring pgg-output-buffer)
 330   t)
 331
 332 ;; epg wrapper
 333
 334 (defvar epg-user-id-alist)
 335 (defvar password-cache-expiry)
 336
 337 (eval-and-compile
 338   (autoload 'epg-make-context "epg")
 339   (autoload 'epg-passphrase-callback-function "epg")
 340   (autoload 'epa-select-keys "epa")
 341   (autoload 'epg-list-keys "epg")
 342   (autoload 'epg-context-set-armor "epg")
 343   (autoload 'epg-context-set-textmode "epg")
 344   (autoload 'epg-context-set-signers "epg")
 345   (autoload 'epg-context-set-passphrase-callback "epg")
 346   (autoload 'epg-sign-string "epg")
 347   (autoload 'epg-encrypt-string "epg")
 348   (autoload 'epg-configuration "epg-config")
 349   (autoload 'epg-expand-group "epg-config"))
 350
 351 (defvar mml1991-epg-secret-key-id-list nil)
 352
 353 (defun mml1991-epg-passphrase-callback (context key-id ignore)
 354   (if (eq key-id 'SYM)
 355       (epg-passphrase-callback-function context key-id nil)
 356     (let* ((entry (assoc key-id epg-user-id-alist))
 357            (passphrase
 358             (password-read
 359              (format "GnuPG passphrase for %s: "
 360                      (if entry
 361                          (cdr entry)
 362                        key-id))
 363              (if (eq key-id 'PIN)
 364                  "PIN"
 365                key-id))))
 366       (when passphrase
 367         (let ((password-cache-expiry mml1991-passphrase-cache-expiry))
 368           (password-cache-add key-id passphrase))
 369         (setq mml1991-epg-secret-key-id-list
 370               (cons key-id mml1991-epg-secret-key-id-list))
 371         (copy-sequence passphrase)))))
 372
 373 (defun mml1991-epg-sign (cont)
 374   (let ((context (epg-make-context))
 375         headers cte signers signature)
 376     (if mml1991-verbose
 377         (setq signers (epa-select-keys context "Select keys for signing.
 378 If no one is selected, default secret key is used.  "
 379                                        mml1991-signers t))
 380       (if mml1991-signers
 381           (setq signers (mapcar (lambda (name)
 382                                   (car (epg-list-keys context name t)))
 383                                 mml1991-signers))))
 384     (epg-context-set-armor context t)
 385     (epg-context-set-textmode context t)
 386     (epg-context-set-signers context signers)
 387     (if mml1991-cache-passphrase
 388         (epg-context-set-passphrase-callback
 389          context
 390          #'mml1991-epg-passphrase-callback))
 391     ;; Don't sign headers.
 392     (goto-char (point-min))
 393     (when (re-search-forward "^$" nil t)
 394       (setq headers (buffer-substring (point-min) (point)))
 395       (save-restriction
 396         (narrow-to-region (point-min) (point))
 397         (setq cte (mail-fetch-field "content-transfer-encoding")))
 398       (forward-line 1)
 399       (delete-region (point-min) (point))
 400       (when cte
 401         (setq cte (intern (downcase cte)))
 402         (mm-decode-content-transfer-encoding cte)))
 403     (condition-case error
 404         (setq signature (epg-sign-string context (buffer-string) 'clear)
 405               mml1991-epg-secret-key-id-list nil)
 406       (error
 407        (while mml1991-epg-secret-key-id-list
 408          (password-cache-remove (car mml1991-epg-secret-key-id-list))
 409          (setq mml1991-epg-secret-key-id-list
 410                (cdr mml1991-epg-secret-key-id-list)))
 411        (signal (car error) (cdr error))))
 412     (delete-region (point-min) (point-max))
 413     (mm-with-unibyte-current-buffer
 414       (insert signature)
 415       (goto-char (point-min))
 416       (while (re-search-forward "\r+$" nil t)
 417         (replace-match "" t t))
 418       (when cte
 419         (mm-encode-content-transfer-encoding cte))
 420       (goto-char (point-min))
 421       (when headers
 422         (insert headers))
 423       (insert "\n"))
 424     t))
 425
 426 (defun mml1991-epg-encrypt (cont &optional sign)
 427   (goto-char (point-min))
 428   (when (re-search-forward "^$" nil t)
 429     (let ((cte (save-restriction
 430                  (narrow-to-region (point-min) (point))
 431                  (mail-fetch-field "content-transfer-encoding"))))
 432       ;; Strip MIME headers since it will be ASCII armoured.
 433       (forward-line 1)
 434       (delete-region (point-min) (point))
 435       (when cte
 436         (mm-decode-content-transfer-encoding (intern (downcase cte))))))
 437   (let ((context (epg-make-context))
 438         (recipients
 439          (if (message-options-get 'message-recipients)
 440              (split-string
 441               (message-options-get 'message-recipients)
 442               "[ \f\t\n\r\v,]+")))
 443         cipher signers config)
 444     ;; We should remove this check if epg-0.0.6 is released.
 445     (if (and (condition-case nil
 446                  (require 'epg-config)
 447                (error))
 448              (functionp #'epg-expand-group))
 449         (setq config (epg-configuration)
 450               recipients
 451               (apply #'nconc
 452                      (mapcar (lambda (recipient)
 453                                (or (epg-expand-group config recipient)
 454                                    (list recipient)))
 455                              recipients))))
 456     (if mml1991-verbose
 457         (setq recipients
 458               (epa-select-keys context "Select recipients for encryption.
 459 If no one is selected, symmetric encryption will be performed.  "
 460                                recipients))
 461       (setq recipients
 462             (delq nil (mapcar (lambda (name)
 463                                 (car (epg-list-keys context name)))
 464                               recipients))))
 465     (if mml1991-encrypt-to-self
 466         (if mml1991-signers
 467             (setq recipients
 468                   (nconc recipients
 469                          (mapcar (lambda (name)
 470                                    (car (epg-list-keys context name)))
 471                                  mml1991-signers)))
 472           (error "mml1991-signers not set")))
 473     (when sign
 474       (if mml1991-verbose
 475           (setq signers (epa-select-keys context "Select keys for signing.
 476 If no one is selected, default secret key is used.  "
 477                                          mml1991-signers t))
 478         (if mml1991-signers
 479             (setq signers (mapcar (lambda (name)
 480                                     (car (epg-list-keys context name t)))
 481                                   mml1991-signers))))
 482       (epg-context-set-signers context signers))
 483     (epg-context-set-armor context t)
 484     (epg-context-set-textmode context t)
 485     (if mml1991-cache-passphrase
 486         (epg-context-set-passphrase-callback
 487          context
 488          #'mml1991-epg-passphrase-callback))
 489     (condition-case error
 490         (setq cipher
 491               (epg-encrypt-string context (buffer-string) recipients sign)
 492               mml1991-epg-secret-key-id-list nil)
 493       (error
 494        (while mml1991-epg-secret-key-id-list
 495          (password-cache-remove (car mml1991-epg-secret-key-id-list))
 496          (setq mml1991-epg-secret-key-id-list
 497                (cdr mml1991-epg-secret-key-id-list)))
 498        (signal (car error) (cdr error))))
 499     (delete-region (point-min) (point-max))
 500     (insert "\n" cipher))
 501   t)
 502
 503 ;;;###autoload
 504 (defun mml1991-encrypt (cont &optional sign)
 505   (let ((func (nth 2 (assq mml1991-use mml1991-function-alist))))
 506     (if func
 507         (funcall func cont sign)
 508       (error "Cannot find encrypt function"))))
 509
 510 ;;;###autoload
 511 (defun mml1991-sign (cont)
 512   (let ((func (nth 1 (assq mml1991-use mml1991-function-alist))))
 513     (if func
 514         (funcall func cont)
 515       (error "Cannot find sign function"))))
 516
 517 (provide 'mml1991)
 518
 519 ;; Local Variables:
 520 ;; coding: iso-8859-1
 521 ;; End:
 522
 523 ;; arch-tag: e542be18-ab28-4393-9b33-97fe9cf30706
 524 ;;; mml1991.el ends here