code.delx.au - gnu-emacs/blob - 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, 2011  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 (eval-when-compile
  34   (require 'cl)
  35   (require 'mm-util))
  36
  37 (require 'mm-encode)
  38 (require 'mml-sec)
  39
  40 (defvar mc-pgp-always-sign)
  41
  42 (autoload 'quoted-printable-decode-region "qp")
  43 (autoload 'quoted-printable-encode-region "qp")
  44
  45 (autoload 'mm-decode-content-transfer-encoding "mm-bodies")
  46 (autoload 'mm-encode-content-transfer-encoding "mm-bodies")
  47 (autoload 'message-options-get "message")
  48 (autoload 'message-options-set "message")
  49
  50 (defvar mml1991-use mml2015-use
  51   "The package used for PGP.")
  52
  53 (defvar mml1991-function-alist
  54   '((mailcrypt mml1991-mailcrypt-sign
  55                mml1991-mailcrypt-encrypt)
  56     (gpg mml1991-gpg-sign
  57          mml1991-gpg-encrypt)
  58     (pgg mml1991-pgg-sign
  59          mml1991-pgg-encrypt)
  60     (epg mml1991-epg-sign
  61          mml1991-epg-encrypt))
  62   "Alist of PGP functions.")
  63
  64 (defvar mml1991-verbose mml-secure-verbose
  65   "If non-nil, ask the user about the current operation more verbosely.")
  66
  67 (defvar mml1991-cache-passphrase mml-secure-cache-passphrase
  68   "If t, cache passphrase.")
  69
  70 (defvar mml1991-passphrase-cache-expiry mml-secure-passphrase-cache-expiry
  71   "How many seconds the passphrase is cached.
  72 Whether the passphrase is cached at all is controlled by
  73 `mml1991-cache-passphrase'.")
  74
  75 (defvar mml1991-signers nil
  76   "A list of your own key ID which will be used to sign a message.")
  77
  78 (defvar mml1991-encrypt-to-self nil
  79   "If t, add your own key ID to recipient list when encryption.")
  80
  81 ;;; mailcrypt wrapper
  82
  83 (autoload 'mc-sign-generic "mc-toplev")
  84
  85 (defvar mml1991-decrypt-function 'mailcrypt-decrypt)
  86 (defvar mml1991-verify-function 'mailcrypt-verify)
  87
  88 (defun mml1991-mailcrypt-sign (cont)
  89   (let ((text (current-buffer))
  90         headers signature
  91         (result-buffer (get-buffer-create "*GPG Result*")))
  92     ;; Save MIME Content[^ ]+: headers from signing
  93     (goto-char (point-min))
  94     (while (looking-at "^Content[^ ]+:") (forward-line))
  95     (unless (bobp)
  96       (setq headers (buffer-string))
  97       (delete-region (point-min) (point)))
  98     (goto-char (point-max))
  99     (unless (bolp)
 100       (insert "\n"))
 101     (quoted-printable-decode-region (point-min) (point-max))
 102     (with-temp-buffer
 103       (setq signature (current-buffer))
 104       (insert-buffer-substring text)
 105       (unless (mc-sign-generic (message-options-get 'message-sender)
 106                                nil nil nil nil)
 107         (unless (> (point-max) (point-min))
 108           (pop-to-buffer result-buffer)
 109           (error "Sign error")))
 110       (goto-char (point-min))
 111       (while (re-search-forward "\r+$" nil t)
 112         (replace-match "" t t))
 113       (quoted-printable-encode-region (point-min) (point-max))
 114       (set-buffer text)
 115       (delete-region (point-min) (point-max))
 116       (if headers (insert headers))
 117       (insert "\n")
 118       (insert-buffer-substring signature)
 119       (goto-char (point-max)))))
 120
 121 (declare-function mc-encrypt-generic "ext:mc-toplev"
 122                   (&optional recipients scheme start end from sign))
 123
 124 (defun mml1991-mailcrypt-encrypt (cont &optional sign)
 125   (let ((text (current-buffer))
 126         (mc-pgp-always-sign
 127          (or mc-pgp-always-sign
 128              sign
 129              (eq t (or (message-options-get 'message-sign-encrypt)
 130                        (message-options-set
 131                         'message-sign-encrypt
 132                         (or (y-or-n-p "Sign the message? ")
 133                             'not))))
 134              'never))
 135         cipher
 136         (result-buffer (get-buffer-create "*GPG Result*")))
 137     ;; Strip MIME Content[^ ]: headers since it will be ASCII ARMORED
 138     (goto-char (point-min))
 139     (while (looking-at "^Content[^ ]+:") (forward-line))
 140     (unless (bobp)
 141       (delete-region (point-min) (point)))
 142     (mm-with-unibyte-current-buffer
 143       (with-temp-buffer
 144         (setq cipher (current-buffer))
 145         (insert-buffer-substring text)
 146         (unless (mc-encrypt-generic
 147                  (or
 148                   (message-options-get 'message-recipients)
 149                   (message-options-set 'message-recipients
 150                                        (read-string "Recipients: ")))
 151                  nil
 152                  (point-min) (point-max)
 153                  (message-options-get 'message-sender)
 154                  'sign)
 155           (unless (> (point-max) (point-min))
 156             (pop-to-buffer result-buffer)
 157             (error "Encrypt error")))
 158         (goto-char (point-min))
 159         (while (re-search-forward "\r+$" nil t)
 160           (replace-match "" t t))
 161         (set-buffer text)
 162         (delete-region (point-min) (point-max))
 163         ;;(insert "Content-Type: application/pgp-encrypted\n\n")
 164         ;;(insert "Version: 1\n\n")
 165         (insert "\n")
 166         (insert-buffer-substring cipher)
 167         (goto-char (point-max))))))
 168
 169 ;;; gpg wrapper
 170
 171 (autoload 'gpg-sign-cleartext "gpg")
 172
 173 (declare-function gpg-sign-encrypt "ext:gpg"
 174                   (plaintext ciphertext result recipients &optional
 175                              passphrase sign-with-key armor textmode))
 176 (declare-function gpg-encrypt "ext:gpg"
 177                   (plaintext ciphertext result recipients &optional
 178                              passphrase armor textmode))
 179
 180 (defun mml1991-gpg-sign (cont)
 181   (let ((text (current-buffer))
 182         headers signature
 183         (result-buffer (get-buffer-create "*GPG Result*")))
 184     ;; Save MIME Content[^ ]+: headers from signing
 185     (goto-char (point-min))
 186     (while (looking-at "^Content[^ ]+:") (forward-line))
 187     (unless (bobp)
 188       (setq headers (buffer-string))
 189       (delete-region (point-min) (point)))
 190     (goto-char (point-max))
 191     (unless (bolp)
 192       (insert "\n"))
 193     (quoted-printable-decode-region (point-min) (point-max))
 194     (with-temp-buffer
 195       (unless (gpg-sign-cleartext text (setq signature (current-buffer))
 196                                   result-buffer
 197                                   nil
 198                                   (message-options-get 'message-sender))
 199         (unless (> (point-max) (point-min))
 200           (pop-to-buffer result-buffer)
 201           (error "Sign error")))
 202       (goto-char (point-min))
 203       (while (re-search-forward "\r+$" nil t)
 204         (replace-match "" t t))
 205       (quoted-printable-encode-region (point-min) (point-max))
 206       (set-buffer text)
 207       (delete-region (point-min) (point-max))
 208       (if headers (insert headers))
 209       (insert "\n")
 210       (insert-buffer-substring signature)
 211       (goto-char (point-max)))))
 212
 213 (defun mml1991-gpg-encrypt (cont &optional sign)
 214   (let ((text (current-buffer))
 215         cipher
 216         (result-buffer (get-buffer-create "*GPG Result*")))
 217     ;; Strip MIME Content[^ ]: headers since it will be ASCII ARMORED
 218     (goto-char (point-min))
 219     (while (looking-at "^Content[^ ]+:") (forward-line))
 220     (unless (bobp)
 221       (delete-region (point-min) (point)))
 222     (mm-with-unibyte-current-buffer
 223       (with-temp-buffer
 224         (flet ((gpg-encrypt-func
 225                 (sign plaintext ciphertext result recipients &optional
 226                       passphrase sign-with-key armor textmode)
 227                 (if sign
 228                     (gpg-sign-encrypt
 229                      plaintext ciphertext result recipients passphrase
 230                      sign-with-key armor textmode)
 231                   (gpg-encrypt
 232                    plaintext ciphertext result recipients passphrase
 233                    armor textmode))))
 234           (unless (gpg-encrypt-func
 235                    sign
 236                    text (setq cipher (current-buffer))
 237                    result-buffer
 238                    (split-string
 239                     (or
 240                      (message-options-get 'message-recipients)
 241                      (message-options-set 'message-recipients
 242                                           (read-string "Recipients: ")))
 243                     "[ \f\t\n\r\v,]+")
 244                    nil
 245                    (message-options-get 'message-sender)
 246                    t t) ; armor & textmode
 247             (unless (> (point-max) (point-min))
 248               (pop-to-buffer result-buffer)
 249               (error "Encrypt error"))))
 250         (goto-char (point-min))
 251         (while (re-search-forward "\r+$" nil t)
 252           (replace-match "" t t))
 253         (set-buffer text)
 254         (delete-region (point-min) (point-max))
 255         ;;(insert "Content-Type: application/pgp-encrypted\n\n")
 256         ;;(insert "Version: 1\n\n")
 257         (insert "\n")
 258         (insert-buffer-substring cipher)
 259         (goto-char (point-max))))))
 260
 261 ;; pgg wrapper
 262
 263 (defvar pgg-default-user-id)
 264 (defvar pgg-errors-buffer)
 265 (defvar pgg-output-buffer)
 266
 267 (defun mml1991-pgg-sign (cont)
 268   (let ((pgg-text-mode t)
 269         (pgg-default-user-id (or (message-options-get 'mml-sender)
 270                                  pgg-default-user-id))
 271         headers cte)
 272     ;; Don't sign headers.
 273     (goto-char (point-min))
 274     (when (re-search-forward "^$" nil t)
 275       (setq headers (buffer-substring (point-min) (point)))
 276       (save-restriction
 277         (narrow-to-region (point-min) (point))
 278         (setq cte (mail-fetch-field "content-transfer-encoding")))
 279       (forward-line 1)
 280       (delete-region (point-min) (point))
 281       (when cte
 282         (setq cte (intern (downcase cte)))
 283         (mm-decode-content-transfer-encoding cte)))
 284     (unless (pgg-sign-region (point-min) (point-max) t)
 285       (pop-to-buffer pgg-errors-buffer)
 286       (error "Encrypt error"))
 287     (delete-region (point-min) (point-max))
 288     (mm-with-unibyte-current-buffer
 289       (insert-buffer-substring pgg-output-buffer)
 290       (goto-char (point-min))
 291       (while (re-search-forward "\r+$" nil t)
 292         (replace-match "" t t))
 293       (when cte
 294         (mm-encode-content-transfer-encoding cte))
 295       (goto-char (point-min))
 296       (when headers
 297         (insert headers))
 298       (insert "\n"))
 299     t))
 300
 301 (defun mml1991-pgg-encrypt (cont &optional sign)
 302   (goto-char (point-min))
 303   (when (re-search-forward "^$" nil t)
 304     (let ((cte (save-restriction
 305                  (narrow-to-region (point-min) (point))
 306                  (mail-fetch-field "content-transfer-encoding"))))
 307       ;; Strip MIME headers since it will be ASCII armored.
 308       (forward-line 1)
 309       (delete-region (point-min) (point))
 310       (when cte
 311         (mm-decode-content-transfer-encoding (intern (downcase cte))))))
 312   (unless (let ((pgg-text-mode t))
 313             (pgg-encrypt-region
 314              (point-min) (point-max)
 315              (split-string
 316               (or
 317                (message-options-get 'message-recipients)
 318                (message-options-set 'message-recipients
 319                                     (read-string "Recipients: ")))
 320               "[ \f\t\n\r\v,]+")
 321              sign))
 322     (pop-to-buffer pgg-errors-buffer)
 323     (error "Encrypt error"))
 324   (delete-region (point-min) (point-max))
 325   (insert "\n")
 326   (insert-buffer-substring pgg-output-buffer)
 327   t)
 328
 329 ;; epg wrapper
 330
 331 (defvar epg-user-id-alist)
 332 (defvar password-cache-expiry)
 333
 334 (autoload 'epg-make-context "epg")
 335 (autoload 'epg-passphrase-callback-function "epg")
 336 (autoload 'epa-select-keys "epa")
 337 (autoload 'epg-list-keys "epg")
 338 (autoload 'epg-context-set-armor "epg")
 339 (autoload 'epg-context-set-textmode "epg")
 340 (autoload 'epg-context-set-signers "epg")
 341 (autoload 'epg-context-set-passphrase-callback "epg")
 342 (autoload 'epg-sign-string "epg")
 343 (autoload 'epg-encrypt-string "epg")
 344 (autoload 'epg-configuration "epg-config")
 345 (autoload 'epg-expand-group "epg-config")
 346
 347 (defvar mml1991-epg-secret-key-id-list nil)
 348
 349 (defun mml1991-epg-passphrase-callback (context key-id ignore)
 350   (if (eq key-id 'SYM)
 351       (epg-passphrase-callback-function context key-id nil)
 352     (let* ((entry (assoc key-id epg-user-id-alist))
 353            (passphrase
 354             (password-read
 355              (format "GnuPG passphrase for %s: "
 356                      (if entry
 357                          (cdr entry)
 358                        key-id))
 359              (if (eq key-id 'PIN)
 360                  "PIN"
 361                key-id))))
 362       (when passphrase
 363         (let ((password-cache-expiry mml1991-passphrase-cache-expiry))
 364           (password-cache-add key-id passphrase))
 365         (setq mml1991-epg-secret-key-id-list
 366               (cons key-id mml1991-epg-secret-key-id-list))
 367         (copy-sequence passphrase)))))
 368
 369 (defun mml1991-epg-sign (cont)
 370   (let ((context (epg-make-context))
 371         headers cte signers signature)
 372     (if (eq mm-sign-option 'guided)
 373         (setq signers (epa-select-keys context "Select keys for signing.
 374 If no one is selected, default secret key is used.  "
 375                                        mml1991-signers t))
 376       (if mml1991-signers
 377           (setq signers (mapcar (lambda (name)
 378                                   (car (epg-list-keys context name t)))
 379                                 mml1991-signers))))
 380     (epg-context-set-armor context t)
 381     (epg-context-set-textmode context t)
 382     (epg-context-set-signers context signers)
 383     (if mml1991-cache-passphrase
 384         (epg-context-set-passphrase-callback
 385          context
 386          #'mml1991-epg-passphrase-callback))
 387     ;; Don't sign headers.
 388     (goto-char (point-min))
 389     (when (re-search-forward "^$" nil t)
 390       (setq headers (buffer-substring (point-min) (point)))
 391       (save-restriction
 392         (narrow-to-region (point-min) (point))
 393         (setq cte (mail-fetch-field "content-transfer-encoding")))
 394       (forward-line 1)
 395       (delete-region (point-min) (point))
 396       (when cte
 397         (setq cte (intern (downcase cte)))
 398         (mm-decode-content-transfer-encoding cte)))
 399     (condition-case error
 400         (setq signature (epg-sign-string context (buffer-string) 'clear)
 401               mml1991-epg-secret-key-id-list nil)
 402       (error
 403        (while mml1991-epg-secret-key-id-list
 404          (password-cache-remove (car mml1991-epg-secret-key-id-list))
 405          (setq mml1991-epg-secret-key-id-list
 406                (cdr mml1991-epg-secret-key-id-list)))
 407        (signal (car error) (cdr error))))
 408     (delete-region (point-min) (point-max))
 409     (mm-with-unibyte-current-buffer
 410       (insert signature)
 411       (goto-char (point-min))
 412       (while (re-search-forward "\r+$" nil t)
 413         (replace-match "" t t))
 414       (when cte
 415         (mm-encode-content-transfer-encoding cte))
 416       (goto-char (point-min))
 417       (when headers
 418         (insert headers))
 419       (insert "\n"))
 420     t))
 421
 422 (defun mml1991-epg-encrypt (cont &optional sign)
 423   (goto-char (point-min))
 424   (when (re-search-forward "^$" nil t)
 425     (let ((cte (save-restriction
 426                  (narrow-to-region (point-min) (point))
 427                  (mail-fetch-field "content-transfer-encoding"))))
 428       ;; Strip MIME headers since it will be ASCII armored.
 429       (forward-line 1)
 430       (delete-region (point-min) (point))
 431       (when cte
 432         (mm-decode-content-transfer-encoding (intern (downcase cte))))))
 433   (let ((context (epg-make-context))
 434         (recipients
 435          (if (message-options-get 'message-recipients)
 436              (split-string
 437               (message-options-get 'message-recipients)
 438               "[ \f\t\n\r\v,]+")))
 439         cipher signers config)
 440     ;; We should remove this check if epg-0.0.6 is released.
 441     (if (and (condition-case nil
 442                  (require 'epg-config)
 443                (error))
 444              (functionp #'epg-expand-group))
 445         (setq config (epg-configuration)
 446               recipients
 447               (apply #'nconc
 448                      (mapcar (lambda (recipient)
 449                                (or (epg-expand-group config recipient)
 450                                    (list recipient)))
 451                              recipients))))
 452     (if (eq mm-encrypt-option 'guided)
 453         (setq recipients
 454               (epa-select-keys context "Select recipients for encryption.
 455 If no one is selected, symmetric encryption will be performed.  "
 456                                recipients))
 457       (setq recipients
 458             (delq nil (mapcar (lambda (name)
 459                                 (car (epg-list-keys context name)))
 460                               recipients))))
 461     (if mml1991-encrypt-to-self
 462         (if mml1991-signers
 463             (setq recipients
 464                   (nconc recipients
 465                          (mapcar (lambda (name)
 466                                    (car (epg-list-keys context name)))
 467                                  mml1991-signers)))
 468           (error "mml1991-signers not set")))
 469     (when sign
 470       (if (eq mm-sign-option 'guided)
 471           (setq signers (epa-select-keys context "Select keys for signing.
 472 If no one is selected, default secret key is used.  "
 473                                          mml1991-signers t))
 474         (if mml1991-signers
 475             (setq signers (mapcar (lambda (name)
 476                                     (car (epg-list-keys context name t)))
 477                                   mml1991-signers))))
 478       (epg-context-set-signers context signers))
 479     (epg-context-set-armor context t)
 480     (epg-context-set-textmode context t)
 481     (if mml1991-cache-passphrase
 482         (epg-context-set-passphrase-callback
 483          context
 484          #'mml1991-epg-passphrase-callback))
 485     (condition-case error
 486         (setq cipher
 487               (epg-encrypt-string context (buffer-string) recipients sign)
 488               mml1991-epg-secret-key-id-list nil)
 489       (error
 490        (while mml1991-epg-secret-key-id-list
 491          (password-cache-remove (car mml1991-epg-secret-key-id-list))
 492          (setq mml1991-epg-secret-key-id-list
 493                (cdr mml1991-epg-secret-key-id-list)))
 494        (signal (car error) (cdr error))))
 495     (delete-region (point-min) (point-max))
 496     (insert "\n" cipher))
 497   t)
 498
 499 ;;;###autoload
 500 (defun mml1991-encrypt (cont &optional sign)
 501   (let ((func (nth 2 (assq mml1991-use mml1991-function-alist))))
 502     (if func
 503         (funcall func cont sign)
 504       (error "Cannot find encrypt function"))))
 505
 506 ;;;###autoload
 507 (defun mml1991-sign (cont)
 508   (let ((func (nth 1 (assq mml1991-use mml1991-function-alist))))
 509     (if func
 510         (funcall func cont)
 511       (error "Cannot find sign function"))))
 512
 513 (provide 'mml1991)
 514
 515 ;; Local Variables:
 516 ;; coding: iso-8859-1
 517 ;; End:
 518
 519 ;; arch-tag: e542be18-ab28-4393-9b33-97fe9cf30706
 520 ;;; mml1991.el ends here