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, 2005, 2006,
   4 ;;   2007, 2008, 2009, 2010  Free Software Foundation, Inc.
   5
   6 ;; Author: Sascha Lüdecke <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 of the License, or
  15 ;; (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;;; Code:
  28
  29 ;; For Emacs < 22.2.
  30 (eval-and-compile
  31   (unless (fboundp 'declare-function) (defmacro declare-function (&rest r)))
  32
  33   (if (locate-library "password-cache")
  34       (require 'password-cache)
  35     (require 'password)))
  36
  37 (eval-when-compile
  38   (require 'cl)
  39   (require 'mm-util))
  40
  41 (require 'mm-encode)
  42 (require 'mml-sec)
  43
  44 (defvar mc-pgp-always-sign)
  45
  46 (autoload 'quoted-printable-decode-region "qp")
  47 (autoload 'quoted-printable-encode-region "qp")
  48
  49 (autoload 'mm-decode-content-transfer-encoding "mm-bodies")
  50 (autoload 'mm-encode-content-transfer-encoding "mm-bodies")
  51 (autoload 'message-options-get "message")
  52 (autoload 'message-options-set "message")
  53
  54 (defvar mml1991-use mml2015-use
  55   "The package used for PGP.")
  56
  57 (defvar mml1991-function-alist
  58   '((mailcrypt mml1991-mailcrypt-sign
  59                mml1991-mailcrypt-encrypt)
  60     (gpg mml1991-gpg-sign
  61          mml1991-gpg-encrypt)
  62     (pgg mml1991-pgg-sign
  63          mml1991-pgg-encrypt)
  64     (epg mml1991-epg-sign
  65          mml1991-epg-encrypt))
  66   "Alist of PGP functions.")
  67
  68 (defvar mml1991-verbose mml-secure-verbose
  69   "If non-nil, ask the user about the current operation more verbosely.")
  70
  71 (defvar mml1991-cache-passphrase mml-secure-cache-passphrase
  72   "If t, cache passphrase.")
  73
  74 (defvar mml1991-passphrase-cache-expiry mml-secure-passphrase-cache-expiry
  75   "How many seconds the passphrase is cached.
  76 Whether the passphrase is cached at all is controlled by
  77 `mml1991-cache-passphrase'.")
  78
  79 (defvar mml1991-signers nil
  80   "A list of your own key ID which will be used to sign a message.")
  81
  82 (defvar mml1991-encrypt-to-self nil
  83   "If t, add your own key ID to recipient list when encryption.")
  84
  85 ;;; mailcrypt wrapper
  86
  87 (autoload 'mc-sign-generic "mc-toplev")
  88
  89 (defvar mml1991-decrypt-function 'mailcrypt-decrypt)
  90 (defvar mml1991-verify-function 'mailcrypt-verify)
  91
  92 (defun mml1991-mailcrypt-sign (cont)
  93   (let ((text (current-buffer))
  94         headers signature
  95         (result-buffer (get-buffer-create "*GPG Result*")))
  96     ;; Save MIME Content[^ ]+: headers from signing
  97     (goto-char (point-min))
  98     (while (looking-at "^Content[^ ]+:") (forward-line))
  99     (unless (bobp)
 100       (setq headers (buffer-string))
 101       (delete-region (point-min) (point)))
 102     (goto-char (point-max))
 103     (unless (bolp)
 104       (insert "\n"))
 105     (quoted-printable-decode-region (point-min) (point-max))
 106     (with-temp-buffer
 107       (setq signature (current-buffer))
 108       (insert-buffer-substring text)
 109       (unless (mc-sign-generic (message-options-get 'message-sender)
 110                                nil nil nil nil)
 111         (unless (> (point-max) (point-min))
 112           (pop-to-buffer result-buffer)
 113           (error "Sign error")))
 114       (goto-char (point-min))
 115       (while (re-search-forward "\r+$" nil t)
 116         (replace-match "" t t))
 117       (quoted-printable-encode-region (point-min) (point-max))
 118       (set-buffer text)
 119       (delete-region (point-min) (point-max))
 120       (if headers (insert headers))
 121       (insert "\n")
 122       (insert-buffer-substring signature)
 123       (goto-char (point-max)))))
 124
 125 (declare-function mc-encrypt-generic "ext:mc-toplev"
 126                   (&optional recipients scheme start end from sign))
 127
 128 (defun mml1991-mailcrypt-encrypt (cont &optional sign)
 129   (let ((text (current-buffer))
 130         (mc-pgp-always-sign
 131          (or mc-pgp-always-sign
 132              sign
 133              (eq t (or (message-options-get 'message-sign-encrypt)
 134                        (message-options-set
 135                         'message-sign-encrypt
 136                         (or (y-or-n-p "Sign the message? ")
 137                             'not))))
 138              'never))
 139         cipher
 140         (result-buffer (get-buffer-create "*GPG Result*")))
 141     ;; Strip MIME Content[^ ]: headers since it will be ASCII ARMORED
 142     (goto-char (point-min))
 143     (while (looking-at "^Content[^ ]+:") (forward-line))
 144     (unless (bobp)
 145       (delete-region (point-min) (point)))
 146     (mm-with-unibyte-current-buffer
 147       (with-temp-buffer
 148         (setq cipher (current-buffer))
 149         (insert-buffer-substring text)
 150         (unless (mc-encrypt-generic
 151                  (or
 152                   (message-options-get 'message-recipients)
 153                   (message-options-set 'message-recipients
 154                                        (read-string "Recipients: ")))
 155                  nil
 156                  (point-min) (point-max)
 157                  (message-options-get 'message-sender)
 158                  'sign)
 159           (unless (> (point-max) (point-min))
 160             (pop-to-buffer result-buffer)
 161             (error "Encrypt error")))
 162         (goto-char (point-min))
 163         (while (re-search-forward "\r+$" nil t)
 164           (replace-match "" t t))
 165         (set-buffer text)
 166         (delete-region (point-min) (point-max))
 167         ;;(insert "Content-Type: application/pgp-encrypted\n\n")
 168         ;;(insert "Version: 1\n\n")
 169         (insert "\n")
 170         (insert-buffer-substring cipher)
 171         (goto-char (point-max))))))
 172
 173 ;;; gpg wrapper
 174
 175 (autoload 'gpg-sign-cleartext "gpg")
 176
 177 (declare-function gpg-sign-encrypt "ext:gpg"
 178                   (plaintext ciphertext result recipients &optional
 179                              passphrase sign-with-key armor textmode))
 180 (declare-function gpg-encrypt "ext:gpg"
 181                   (plaintext ciphertext result recipients &optional
 182                              passphrase armor textmode))
 183
 184 (defun mml1991-gpg-sign (cont)
 185   (let ((text (current-buffer))
 186         headers signature
 187         (result-buffer (get-buffer-create "*GPG Result*")))
 188     ;; Save MIME Content[^ ]+: headers from signing
 189     (goto-char (point-min))
 190     (while (looking-at "^Content[^ ]+:") (forward-line))
 191     (unless (bobp)
 192       (setq headers (buffer-string))
 193       (delete-region (point-min) (point)))
 194     (goto-char (point-max))
 195     (unless (bolp)
 196       (insert "\n"))
 197     (quoted-printable-decode-region (point-min) (point-max))
 198     (with-temp-buffer
 199       (unless (gpg-sign-cleartext text (setq signature (current-buffer))
 200                                   result-buffer
 201                                   nil
 202                                   (message-options-get 'message-sender))
 203         (unless (> (point-max) (point-min))
 204           (pop-to-buffer result-buffer)
 205           (error "Sign error")))
 206       (goto-char (point-min))
 207       (while (re-search-forward "\r+$" nil t)
 208         (replace-match "" t t))
 209       (quoted-printable-encode-region (point-min) (point-max))
 210       (set-buffer text)
 211       (delete-region (point-min) (point-max))
 212       (if headers (insert headers))
 213       (insert "\n")
 214       (insert-buffer-substring signature)
 215       (goto-char (point-max)))))
 216
 217 (defun mml1991-gpg-encrypt (cont &optional sign)
 218   (let ((text (current-buffer))
 219         cipher
 220         (result-buffer (get-buffer-create "*GPG Result*")))
 221     ;; Strip MIME Content[^ ]: headers since it will be ASCII ARMORED
 222     (goto-char (point-min))
 223     (while (looking-at "^Content[^ ]+:") (forward-line))
 224     (unless (bobp)
 225       (delete-region (point-min) (point)))
 226     (mm-with-unibyte-current-buffer
 227       (with-temp-buffer
 228         (flet ((gpg-encrypt-func
 229                 (sign plaintext ciphertext result recipients &optional
 230                       passphrase sign-with-key armor textmode)
 231                 (if sign
 232                     (gpg-sign-encrypt
 233                      plaintext ciphertext result recipients passphrase
 234                      sign-with-key armor textmode)
 235                   (gpg-encrypt
 236                    plaintext ciphertext result recipients passphrase
 237                    armor textmode))))
 238           (unless (gpg-encrypt-func
 239                    sign
 240                    text (setq cipher (current-buffer))
 241                    result-buffer
 242                    (split-string
 243                     (or
 244                      (message-options-get 'message-recipients)
 245                      (message-options-set 'message-recipients
 246                                           (read-string "Recipients: ")))
 247                     "[ \f\t\n\r\v,]+")
 248                    nil
 249                    (message-options-get 'message-sender)
 250                    t t) ; armor & textmode
 251             (unless (> (point-max) (point-min))
 252               (pop-to-buffer result-buffer)
 253               (error "Encrypt error"))))
 254         (goto-char (point-min))
 255         (while (re-search-forward "\r+$" nil t)
 256           (replace-match "" t t))
 257         (set-buffer text)
 258         (delete-region (point-min) (point-max))
 259         ;;(insert "Content-Type: application/pgp-encrypted\n\n")
 260         ;;(insert "Version: 1\n\n")
 261         (insert "\n")
 262         (insert-buffer-substring cipher)
 263         (goto-char (point-max))))))
 264
 265 ;; pgg wrapper
 266
 267 (defvar pgg-default-user-id)
 268 (defvar pgg-errors-buffer)
 269 (defvar pgg-output-buffer)
 270
 271 (defun mml1991-pgg-sign (cont)
 272   (let ((pgg-text-mode t)
 273         (pgg-default-user-id (or (message-options-get 'mml-sender)
 274                                  pgg-default-user-id))
 275         headers cte)
 276     ;; Don't sign headers.
 277     (goto-char (point-min))
 278     (when (re-search-forward "^$" nil t)
 279       (setq headers (buffer-substring (point-min) (point)))
 280       (save-restriction
 281         (narrow-to-region (point-min) (point))
 282         (setq cte (mail-fetch-field "content-transfer-encoding")))
 283       (forward-line 1)
 284       (delete-region (point-min) (point))
 285       (when cte
 286         (setq cte (intern (downcase cte)))
 287         (mm-decode-content-transfer-encoding cte)))
 288     (unless (pgg-sign-region (point-min) (point-max) t)
 289       (pop-to-buffer pgg-errors-buffer)
 290       (error "Encrypt error"))
 291     (delete-region (point-min) (point-max))
 292     (mm-with-unibyte-current-buffer
 293       (insert-buffer-substring pgg-output-buffer)
 294       (goto-char (point-min))
 295       (while (re-search-forward "\r+$" nil t)
 296         (replace-match "" t t))
 297       (when cte
 298         (mm-encode-content-transfer-encoding cte))
 299       (goto-char (point-min))
 300       (when headers
 301         (insert headers))
 302       (insert "\n"))
 303     t))
 304
 305 (defun mml1991-pgg-encrypt (cont &optional sign)
 306   (goto-char (point-min))
 307   (when (re-search-forward "^$" nil t)
 308     (let ((cte (save-restriction
 309                  (narrow-to-region (point-min) (point))
 310                  (mail-fetch-field "content-transfer-encoding"))))
 311       ;; Strip MIME headers since it will be ASCII armored.
 312       (forward-line 1)
 313       (delete-region (point-min) (point))
 314       (when cte
 315         (mm-decode-content-transfer-encoding (intern (downcase cte))))))
 316   (unless (let ((pgg-text-mode t))
 317             (pgg-encrypt-region
 318              (point-min) (point-max)
 319              (split-string
 320               (or
 321                (message-options-get 'message-recipients)
 322                (message-options-set 'message-recipients
 323                                     (read-string "Recipients: ")))
 324               "[ \f\t\n\r\v,]+")
 325              sign))
 326     (pop-to-buffer pgg-errors-buffer)
 327     (error "Encrypt error"))
 328   (delete-region (point-min) (point-max))
 329   (insert "\n")
 330   (insert-buffer-substring pgg-output-buffer)
 331   t)
 332
 333 ;; epg wrapper
 334
 335 (defvar epg-user-id-alist)
 336
 337 (autoload 'epg-make-context "epg")
 338 (autoload 'epg-passphrase-callback-function "epg")
 339 (autoload 'epa-select-keys "epa")
 340 (autoload 'epg-list-keys "epg")
 341 (autoload 'epg-context-set-armor "epg")
 342 (autoload 'epg-context-set-textmode "epg")
 343 (autoload 'epg-context-set-signers "epg")
 344 (autoload 'epg-context-set-passphrase-callback "epg")
 345 (autoload 'epg-sign-string "epg")
 346 (autoload 'epg-encrypt-string "epg")
 347 (autoload 'epg-configuration "epg-config")
 348 (autoload 'epg-expand-group "epg-config")
 349
 350 (defvar mml1991-epg-secret-key-id-list nil)
 351
 352 (defun mml1991-epg-passphrase-callback (context key-id ignore)
 353   (if (eq key-id 'SYM)
 354       (epg-passphrase-callback-function context key-id nil)
 355     (let* ((entry (assoc key-id epg-user-id-alist))
 356            (passphrase
 357             (password-read
 358              (format "GnuPG passphrase for %s: "
 359                      (if entry
 360                          (cdr entry)
 361                        key-id))
 362              (if (eq key-id 'PIN)
 363                  "PIN"
 364                key-id))))
 365       (when passphrase
 366         (let ((password-cache-expiry mml1991-passphrase-cache-expiry))
 367           (password-cache-add key-id passphrase))
 368         (setq mml1991-epg-secret-key-id-list
 369               (cons key-id mml1991-epg-secret-key-id-list))
 370         (copy-sequence passphrase)))))
 371
 372 (defun mml1991-epg-sign (cont)
 373   (let ((context (epg-make-context))
 374         headers cte signers signature)
 375     (if (eq mm-sign-option 'guided)
 376         (setq signers (epa-select-keys context "Select keys for signing.
 377 If no one is selected, default secret key is used.  "
 378                                        mml1991-signers t))
 379       (if mml1991-signers
 380           (setq signers (mapcar (lambda (name)
 381                                   (car (epg-list-keys context name t)))
 382                                 mml1991-signers))))
 383     (epg-context-set-armor context t)
 384     (epg-context-set-textmode context t)
 385     (epg-context-set-signers context signers)
 386     (if mml1991-cache-passphrase
 387         (epg-context-set-passphrase-callback
 388          context
 389          #'mml1991-epg-passphrase-callback))
 390     ;; Don't sign headers.
 391     (goto-char (point-min))
 392     (when (re-search-forward "^$" nil t)
 393       (setq headers (buffer-substring (point-min) (point)))
 394       (save-restriction
 395         (narrow-to-region (point-min) (point))
 396         (setq cte (mail-fetch-field "content-transfer-encoding")))
 397       (forward-line 1)
 398       (delete-region (point-min) (point))
 399       (when cte
 400         (setq cte (intern (downcase cte)))
 401         (mm-decode-content-transfer-encoding cte)))
 402     (condition-case error
 403         (setq signature (epg-sign-string context (buffer-string) 'clear)
 404               mml1991-epg-secret-key-id-list nil)
 405       (error
 406        (while mml1991-epg-secret-key-id-list
 407          (password-cache-remove (car mml1991-epg-secret-key-id-list))
 408          (setq mml1991-epg-secret-key-id-list
 409                (cdr mml1991-epg-secret-key-id-list)))
 410        (signal (car error) (cdr error))))
 411     (delete-region (point-min) (point-max))
 412     (mm-with-unibyte-current-buffer
 413       (insert signature)
 414       (goto-char (point-min))
 415       (while (re-search-forward "\r+$" nil t)
 416         (replace-match "" t t))
 417       (when cte
 418         (mm-encode-content-transfer-encoding cte))
 419       (goto-char (point-min))
 420       (when headers
 421         (insert headers))
 422       (insert "\n"))
 423     t))
 424
 425 (defun mml1991-epg-encrypt (cont &optional sign)
 426   (goto-char (point-min))
 427   (when (re-search-forward "^$" nil t)
 428     (let ((cte (save-restriction
 429                  (narrow-to-region (point-min) (point))
 430                  (mail-fetch-field "content-transfer-encoding"))))
 431       ;; Strip MIME headers since it will be ASCII armored.
 432       (forward-line 1)
 433       (delete-region (point-min) (point))
 434       (when cte
 435         (mm-decode-content-transfer-encoding (intern (downcase cte))))))
 436   (let ((context (epg-make-context))
 437         (recipients
 438          (if (message-options-get 'message-recipients)
 439              (split-string
 440               (message-options-get 'message-recipients)
 441               "[ \f\t\n\r\v,]+")))
 442         cipher signers config)
 443     ;; We should remove this check if epg-0.0.6 is released.
 444     (if (and (condition-case nil
 445                  (require 'epg-config)
 446                (error))
 447              (functionp #'epg-expand-group))
 448         (setq config (epg-configuration)
 449               recipients
 450               (apply #'nconc
 451                      (mapcar (lambda (recipient)
 452                                (or (epg-expand-group config recipient)
 453                                    (list recipient)))
 454                              recipients))))
 455     (if (eq mm-encrypt-option 'guided)
 456         (setq recipients
 457               (epa-select-keys context "Select recipients for encryption.
 458 If no one is selected, symmetric encryption will be performed.  "
 459                                recipients))
 460       (setq recipients
 461             (delq nil (mapcar (lambda (name)
 462                                 (car (epg-list-keys context name)))
 463                               recipients))))
 464     (if mml1991-encrypt-to-self
 465         (if mml1991-signers
 466             (setq recipients
 467                   (nconc recipients
 468                          (mapcar (lambda (name)
 469                                    (car (epg-list-keys context name)))
 470                                  mml1991-signers)))
 471           (error "mml1991-signers not set")))
 472     (when sign
 473       (if (eq mm-sign-option 'guided)
 474           (setq signers (epa-select-keys context "Select keys for signing.
 475 If no one is selected, default secret key is used.  "
 476                                          mml1991-signers t))
 477         (if mml1991-signers
 478             (setq signers (mapcar (lambda (name)
 479                                     (car (epg-list-keys context name t)))
 480                                   mml1991-signers))))
 481       (epg-context-set-signers context signers))
 482     (epg-context-set-armor context t)
 483     (epg-context-set-textmode context t)
 484     (if mml1991-cache-passphrase
 485         (epg-context-set-passphrase-callback
 486          context
 487          #'mml1991-epg-passphrase-callback))
 488     (condition-case error
 489         (setq cipher
 490               (epg-encrypt-string context (buffer-string) recipients sign)
 491               mml1991-epg-secret-key-id-list nil)
 492       (error
 493        (while mml1991-epg-secret-key-id-list
 494          (password-cache-remove (car mml1991-epg-secret-key-id-list))
 495          (setq mml1991-epg-secret-key-id-list
 496                (cdr mml1991-epg-secret-key-id-list)))
 497        (signal (car error) (cdr error))))
 498     (delete-region (point-min) (point-max))
 499     (insert "\n" cipher))
 500   t)
 501
 502 ;;;###autoload
 503 (defun mml1991-encrypt (cont &optional sign)
 504   (let ((func (nth 2 (assq mml1991-use mml1991-function-alist))))
 505     (if func
 506         (funcall func cont sign)
 507       (error "Cannot find encrypt function"))))
 508
 509 ;;;###autoload
 510 (defun mml1991-sign (cont)
 511   (let ((func (nth 1 (assq mml1991-use mml1991-function-alist))))
 512     (if func
 513         (funcall func cont)
 514       (error "Cannot find sign function"))))
 515
 516 (provide 'mml1991)
 517
 518 ;; Local Variables:
 519 ;; coding: iso-8859-1
 520 ;; End:
 521
 522 ;; arch-tag: e542be18-ab28-4393-9b33-97fe9cf30706
 523 ;;; mml1991.el ends here