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         (inline (mm-disable-multibyte))
 149         (setq cipher (current-buffer))
 150         (insert-buffer-substring text)
 151         (unless (mc-encrypt-generic
 152                  (or
 153                   (message-options-get 'message-recipients)
 154                   (message-options-set 'message-recipients
 155                                        (read-string "Recipients: ")))
 156                  nil
 157                  (point-min) (point-max)
 158                  (message-options-get 'message-sender)
 159                  'sign)
 160           (unless (> (point-max) (point-min))
 161             (pop-to-buffer result-buffer)
 162             (error "Encrypt error")))
 163         (goto-char (point-min))
 164         (while (re-search-forward "\r+$" nil t)
 165           (replace-match "" t t))
 166         (set-buffer text)
 167         (delete-region (point-min) (point-max))
 168         ;;(insert "Content-Type: application/pgp-encrypted\n\n")
 169         ;;(insert "Version: 1\n\n")
 170         (insert "\n")
 171         (insert-buffer-substring cipher)
 172         (goto-char (point-max))))))
 173
 174 ;;; gpg wrapper
 175
 176 (autoload 'gpg-sign-cleartext "gpg")
 177
 178 (declare-function gpg-sign-encrypt "ext:gpg"
 179                   (plaintext ciphertext result recipients &optional
 180                              passphrase sign-with-key armor textmode))
 181 (declare-function gpg-encrypt "ext:gpg"
 182                   (plaintext ciphertext result recipients &optional
 183                              passphrase armor textmode))
 184
 185 (defun mml1991-gpg-sign (cont)
 186   (let ((text (current-buffer))
 187         headers signature
 188         (result-buffer (get-buffer-create "*GPG Result*")))
 189     ;; Save MIME Content[^ ]+: headers from signing
 190     (goto-char (point-min))
 191     (while (looking-at "^Content[^ ]+:") (forward-line))
 192     (unless (bobp)
 193       (setq headers (buffer-string))
 194       (delete-region (point-min) (point)))
 195     (goto-char (point-max))
 196     (unless (bolp)
 197       (insert "\n"))
 198     (quoted-printable-decode-region (point-min) (point-max))
 199     (with-temp-buffer
 200       (unless (gpg-sign-cleartext text (setq signature (current-buffer))
 201                                   result-buffer
 202                                   nil
 203                                   (message-options-get 'message-sender))
 204         (unless (> (point-max) (point-min))
 205           (pop-to-buffer result-buffer)
 206           (error "Sign error")))
 207       (goto-char (point-min))
 208       (while (re-search-forward "\r+$" nil t)
 209         (replace-match "" t t))
 210       (quoted-printable-encode-region (point-min) (point-max))
 211       (set-buffer text)
 212       (delete-region (point-min) (point-max))
 213       (if headers (insert headers))
 214       (insert "\n")
 215       (insert-buffer-substring signature)
 216       (goto-char (point-max)))))
 217
 218 (defun mml1991-gpg-encrypt (cont &optional sign)
 219   (let ((text (current-buffer))
 220         cipher
 221         (result-buffer (get-buffer-create "*GPG Result*")))
 222     ;; Strip MIME Content[^ ]: headers since it will be ASCII ARMORED
 223     (goto-char (point-min))
 224     (while (looking-at "^Content[^ ]+:") (forward-line))
 225     (unless (bobp)
 226       (delete-region (point-min) (point)))
 227     (mm-with-unibyte-current-buffer
 228       (with-temp-buffer
 229         (inline (mm-disable-multibyte))
 230         (flet ((gpg-encrypt-func
 231                 (sign plaintext ciphertext result recipients &optional
 232                       passphrase sign-with-key armor textmode)
 233                 (if sign
 234                     (gpg-sign-encrypt
 235                      plaintext ciphertext result recipients passphrase
 236                      sign-with-key armor textmode)
 237                   (gpg-encrypt
 238                    plaintext ciphertext result recipients passphrase
 239                    armor textmode))))
 240           (unless (gpg-encrypt-func
 241                    sign
 242                    text (setq cipher (current-buffer))
 243                    result-buffer
 244                    (split-string
 245                     (or
 246                      (message-options-get 'message-recipients)
 247                      (message-options-set 'message-recipients
 248                                           (read-string "Recipients: ")))
 249                     "[ \f\t\n\r\v,]+")
 250                    nil
 251                    (message-options-get 'message-sender)
 252                    t t) ; armor & textmode
 253             (unless (> (point-max) (point-min))
 254               (pop-to-buffer result-buffer)
 255               (error "Encrypt error"))))
 256         (goto-char (point-min))
 257         (while (re-search-forward "\r+$" nil t)
 258           (replace-match "" t t))
 259         (set-buffer text)
 260         (delete-region (point-min) (point-max))
 261         ;;(insert "Content-Type: application/pgp-encrypted\n\n")
 262         ;;(insert "Version: 1\n\n")
 263         (insert "\n")
 264         (insert-buffer-substring cipher)
 265         (goto-char (point-max))))))
 266
 267 ;; pgg wrapper
 268
 269 (defvar pgg-default-user-id)
 270 (defvar pgg-errors-buffer)
 271 (defvar pgg-output-buffer)
 272
 273 (defun mml1991-pgg-sign (cont)
 274   (let ((pgg-text-mode t)
 275         (pgg-default-user-id (or (message-options-get 'mml-sender)
 276                                  pgg-default-user-id))
 277         headers cte)
 278     ;; Don't sign headers.
 279     (goto-char (point-min))
 280     (when (re-search-forward "^$" nil t)
 281       (setq headers (buffer-substring (point-min) (point)))
 282       (save-restriction
 283         (narrow-to-region (point-min) (point))
 284         (setq cte (mail-fetch-field "content-transfer-encoding")))
 285       (forward-line 1)
 286       (delete-region (point-min) (point))
 287       (when cte
 288         (setq cte (intern (downcase cte)))
 289         (mm-decode-content-transfer-encoding cte)))
 290     (unless (pgg-sign-region (point-min) (point-max) t)
 291       (pop-to-buffer pgg-errors-buffer)
 292       (error "Encrypt error"))
 293     (delete-region (point-min) (point-max))
 294     (mm-with-unibyte-current-buffer
 295       (insert-buffer-substring pgg-output-buffer)
 296       (goto-char (point-min))
 297       (while (re-search-forward "\r+$" nil t)
 298         (replace-match "" t t))
 299       (when cte
 300         (mm-encode-content-transfer-encoding cte))
 301       (goto-char (point-min))
 302       (when headers
 303         (insert headers))
 304       (insert "\n"))
 305     t))
 306
 307 (defun mml1991-pgg-encrypt (cont &optional sign)
 308   (goto-char (point-min))
 309   (when (re-search-forward "^$" nil t)
 310     (let ((cte (save-restriction
 311                  (narrow-to-region (point-min) (point))
 312                  (mail-fetch-field "content-transfer-encoding"))))
 313       ;; Strip MIME headers since it will be ASCII armored.
 314       (forward-line 1)
 315       (delete-region (point-min) (point))
 316       (when cte
 317         (mm-decode-content-transfer-encoding (intern (downcase cte))))))
 318   (unless (let ((pgg-text-mode t))
 319             (pgg-encrypt-region
 320              (point-min) (point-max)
 321              (split-string
 322               (or
 323                (message-options-get 'message-recipients)
 324                (message-options-set 'message-recipients
 325                                     (read-string "Recipients: ")))
 326               "[ \f\t\n\r\v,]+")
 327              sign))
 328     (pop-to-buffer pgg-errors-buffer)
 329     (error "Encrypt error"))
 330   (delete-region (point-min) (point-max))
 331   (insert "\n")
 332   (insert-buffer-substring pgg-output-buffer)
 333   t)
 334
 335 ;; epg wrapper
 336
 337 (defvar epg-user-id-alist)
 338
 339 (autoload 'epg-make-context "epg")
 340 (autoload 'epg-passphrase-callback-function "epg")
 341 (autoload 'epa-select-keys "epa")
 342 (autoload 'epg-list-keys "epg")
 343 (autoload 'epg-context-set-armor "epg")
 344 (autoload 'epg-context-set-textmode "epg")
 345 (autoload 'epg-context-set-signers "epg")
 346 (autoload 'epg-context-set-passphrase-callback "epg")
 347 (autoload 'epg-sign-string "epg")
 348 (autoload 'epg-encrypt-string "epg")
 349 (autoload 'epg-configuration "epg-config")
 350 (autoload 'epg-expand-group "epg-config")
 351
 352 (defvar mml1991-epg-secret-key-id-list nil)
 353
 354 (defun mml1991-epg-passphrase-callback (context key-id ignore)
 355   (if (eq key-id 'SYM)
 356       (epg-passphrase-callback-function context key-id nil)
 357     (let* ((entry (assoc key-id epg-user-id-alist))
 358            (passphrase
 359             (password-read
 360              (format "GnuPG passphrase for %s: "
 361                      (if entry
 362                          (cdr entry)
 363                        key-id))
 364              (if (eq key-id 'PIN)
 365                  "PIN"
 366                key-id))))
 367       (when passphrase
 368         (let ((password-cache-expiry mml1991-passphrase-cache-expiry))
 369           (password-cache-add key-id passphrase))
 370         (setq mml1991-epg-secret-key-id-list
 371               (cons key-id mml1991-epg-secret-key-id-list))
 372         (copy-sequence passphrase)))))
 373
 374 (defun mml1991-epg-sign (cont)
 375   (let ((context (epg-make-context))
 376         headers cte signers signature)
 377     (if (eq mm-sign-option 'guided)
 378         (setq signers (epa-select-keys context "Select keys for signing.
 379 If no one is selected, default secret key is used.  "
 380                                        mml1991-signers t))
 381       (if mml1991-signers
 382           (setq signers (mapcar (lambda (name)
 383                                   (car (epg-list-keys context name t)))
 384                                 mml1991-signers))))
 385     (epg-context-set-armor context t)
 386     (epg-context-set-textmode context t)
 387     (epg-context-set-signers context signers)
 388     (if mml1991-cache-passphrase
 389         (epg-context-set-passphrase-callback
 390          context
 391          #'mml1991-epg-passphrase-callback))
 392     ;; Don't sign headers.
 393     (goto-char (point-min))
 394     (when (re-search-forward "^$" nil t)
 395       (setq headers (buffer-substring (point-min) (point)))
 396       (save-restriction
 397         (narrow-to-region (point-min) (point))
 398         (setq cte (mail-fetch-field "content-transfer-encoding")))
 399       (forward-line 1)
 400       (delete-region (point-min) (point))
 401       (when cte
 402         (setq cte (intern (downcase cte)))
 403         (mm-decode-content-transfer-encoding cte)))
 404     (condition-case error
 405         (setq signature (epg-sign-string context (buffer-string) 'clear)
 406               mml1991-epg-secret-key-id-list nil)
 407       (error
 408        (while mml1991-epg-secret-key-id-list
 409          (password-cache-remove (car mml1991-epg-secret-key-id-list))
 410          (setq mml1991-epg-secret-key-id-list
 411                (cdr mml1991-epg-secret-key-id-list)))
 412        (signal (car error) (cdr error))))
 413     (delete-region (point-min) (point-max))
 414     (mm-with-unibyte-current-buffer
 415       (insert signature)
 416       (goto-char (point-min))
 417       (while (re-search-forward "\r+$" nil t)
 418         (replace-match "" t t))
 419       (when cte
 420         (mm-encode-content-transfer-encoding cte))
 421       (goto-char (point-min))
 422       (when headers
 423         (insert headers))
 424       (insert "\n"))
 425     t))
 426
 427 (defun mml1991-epg-encrypt (cont &optional sign)
 428   (goto-char (point-min))
 429   (when (re-search-forward "^$" nil t)
 430     (let ((cte (save-restriction
 431                  (narrow-to-region (point-min) (point))
 432                  (mail-fetch-field "content-transfer-encoding"))))
 433       ;; Strip MIME headers since it will be ASCII armored.
 434       (forward-line 1)
 435       (delete-region (point-min) (point))
 436       (when cte
 437         (mm-decode-content-transfer-encoding (intern (downcase cte))))))
 438   (let ((context (epg-make-context))
 439         (recipients
 440          (if (message-options-get 'message-recipients)
 441              (split-string
 442               (message-options-get 'message-recipients)
 443               "[ \f\t\n\r\v,]+")))
 444         cipher signers config)
 445     ;; We should remove this check if epg-0.0.6 is released.
 446     (if (and (condition-case nil
 447                  (require 'epg-config)
 448                (error))
 449              (functionp #'epg-expand-group))
 450         (setq config (epg-configuration)
 451               recipients
 452               (apply #'nconc
 453                      (mapcar (lambda (recipient)
 454                                (or (epg-expand-group config recipient)
 455                                    (list recipient)))
 456                              recipients))))
 457     (if (eq mm-encrypt-option 'guided)
 458         (setq recipients
 459               (epa-select-keys context "Select recipients for encryption.
 460 If no one is selected, symmetric encryption will be performed.  "
 461                                recipients))
 462       (setq recipients
 463             (delq nil (mapcar (lambda (name)
 464                                 (car (epg-list-keys context name)))
 465                               recipients))))
 466     (if mml1991-encrypt-to-self
 467         (if mml1991-signers
 468             (setq recipients
 469                   (nconc recipients
 470                          (mapcar (lambda (name)
 471                                    (car (epg-list-keys context name)))
 472                                  mml1991-signers)))
 473           (error "mml1991-signers not set")))
 474     (when sign
 475       (if (eq mm-sign-option 'guided)
 476           (setq signers (epa-select-keys context "Select keys for signing.
 477 If no one is selected, default secret key is used.  "
 478                                          mml1991-signers t))
 479         (if mml1991-signers
 480             (setq signers (mapcar (lambda (name)
 481                                     (car (epg-list-keys context name t)))
 482                                   mml1991-signers))))
 483       (epg-context-set-signers context signers))
 484     (epg-context-set-armor context t)
 485     (epg-context-set-textmode context t)
 486     (if mml1991-cache-passphrase
 487         (epg-context-set-passphrase-callback
 488          context
 489          #'mml1991-epg-passphrase-callback))
 490     (condition-case error
 491         (setq cipher
 492               (epg-encrypt-string context (buffer-string) recipients sign)
 493               mml1991-epg-secret-key-id-list nil)
 494       (error
 495        (while mml1991-epg-secret-key-id-list
 496          (password-cache-remove (car mml1991-epg-secret-key-id-list))
 497          (setq mml1991-epg-secret-key-id-list
 498                (cdr mml1991-epg-secret-key-id-list)))
 499        (signal (car error) (cdr error))))
 500     (delete-region (point-min) (point-max))
 501     (insert "\n" cipher))
 502   t)
 503
 504 ;;;###autoload
 505 (defun mml1991-encrypt (cont &optional sign)
 506   (let ((func (nth 2 (assq mml1991-use mml1991-function-alist))))
 507     (if func
 508         (funcall func cont sign)
 509       (error "Cannot find encrypt function"))))
 510
 511 ;;;###autoload
 512 (defun mml1991-sign (cont)
 513   (let ((func (nth 1 (assq mml1991-use mml1991-function-alist))))
 514     (if func
 515         (funcall func cont)
 516       (error "Cannot find sign function"))))
 517
 518 (provide 'mml1991)
 519
 520 ;; Local Variables:
 521 ;; coding: iso-8859-1
 522 ;; End:
 523
 524 ;; arch-tag: e542be18-ab28-4393-9b33-97fe9cf30706
 525 ;;; mml1991.el ends here