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     (pgg mml1991-pgg-sign
  61          mml1991-pgg-encrypt)
  62     (epg mml1991-epg-sign
  63          mml1991-epg-encrypt))
  64   "Alist of PGP functions.")
  65
  66 (defvar mml1991-cache-passphrase mml-secure-cache-passphrase
  67   "If t, cache passphrase.")
  68
  69 (defvar mml1991-passphrase-cache-expiry mml-secure-passphrase-cache-expiry
  70   "How many seconds the passphrase is cached.
  71 Whether the passphrase is cached at all is controlled by
  72 `mml1991-cache-passphrase'.")
  73
  74 (defvar mml1991-signers nil
  75   "A list of your own key ID which will be used to sign a message.")
  76
  77 (defvar mml1991-encrypt-to-self nil
  78   "If t, add your own key ID to recipient list when encryption.")
  79
  80 ;;; mailcrypt wrapper
  81
  82 (autoload 'mc-sign-generic "mc-toplev")
  83
  84 (defvar mml1991-decrypt-function 'mailcrypt-decrypt)
  85 (defvar mml1991-verify-function 'mailcrypt-verify)
  86
  87 (defun mml1991-mailcrypt-sign (cont)
  88   (let ((text (current-buffer))
  89         headers signature
  90         (result-buffer (get-buffer-create "*GPG Result*")))
  91     ;; Save MIME Content[^ ]+: headers from signing
  92     (goto-char (point-min))
  93     (while (looking-at "^Content[^ ]+:") (forward-line))
  94     (unless (bobp)
  95       (setq headers (buffer-string))
  96       (delete-region (point-min) (point)))
  97     (goto-char (point-max))
  98     (unless (bolp)
  99       (insert "\n"))
 100     (quoted-printable-decode-region (point-min) (point-max))
 101     (with-temp-buffer
 102       (setq signature (current-buffer))
 103       (insert-buffer-substring text)
 104       (unless (mc-sign-generic (message-options-get 'message-sender)
 105                                nil nil nil nil)
 106         (unless (> (point-max) (point-min))
 107           (pop-to-buffer result-buffer)
 108           (error "Sign error")))
 109       (goto-char (point-min))
 110       (while (re-search-forward "\r+$" nil t)
 111         (replace-match "" t t))
 112       (quoted-printable-encode-region (point-min) (point-max))
 113       (set-buffer text)
 114       (delete-region (point-min) (point-max))
 115       (if headers (insert headers))
 116       (insert "\n")
 117       (insert-buffer-substring signature)
 118       (goto-char (point-max)))))
 119
 120 (declare-function mc-encrypt-generic "ext:mc-toplev"
 121                   (&optional recipients scheme start end from sign))
 122
 123 (defun mml1991-mailcrypt-encrypt (cont &optional sign)
 124   (let ((text (current-buffer))
 125         (mc-pgp-always-sign
 126          (or mc-pgp-always-sign
 127              sign
 128              (eq t (or (message-options-get 'message-sign-encrypt)
 129                        (message-options-set
 130                         'message-sign-encrypt
 131                         (or (y-or-n-p "Sign the message? ")
 132                             'not))))
 133              'never))
 134         cipher
 135         (result-buffer (get-buffer-create "*GPG Result*")))
 136     ;; Strip MIME Content[^ ]: headers since it will be ASCII ARMORED
 137     (goto-char (point-min))
 138     (while (looking-at "^Content[^ ]+:") (forward-line))
 139     (unless (bobp)
 140       (delete-region (point-min) (point)))
 141     (mm-with-unibyte-current-buffer
 142       (with-temp-buffer
 143         (inline (mm-disable-multibyte))
 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 ;; pgg wrapper
 170
 171 (defvar pgg-default-user-id)
 172 (defvar pgg-errors-buffer)
 173 (defvar pgg-output-buffer)
 174
 175 (defun mml1991-pgg-sign (cont)
 176   (let ((pgg-text-mode t)
 177         (pgg-default-user-id (or (message-options-get 'mml-sender)
 178                                  pgg-default-user-id))
 179         headers cte)
 180     ;; Don't sign headers.
 181     (goto-char (point-min))
 182     (when (re-search-forward "^$" nil t)
 183       (setq headers (buffer-substring (point-min) (point)))
 184       (save-restriction
 185         (narrow-to-region (point-min) (point))
 186         (setq cte (mail-fetch-field "content-transfer-encoding")))
 187       (forward-line 1)
 188       (delete-region (point-min) (point))
 189       (when cte
 190         (setq cte (intern (downcase cte)))
 191         (mm-decode-content-transfer-encoding cte)))
 192     (unless (pgg-sign-region (point-min) (point-max) t)
 193       (pop-to-buffer pgg-errors-buffer)
 194       (error "Encrypt error"))
 195     (delete-region (point-min) (point-max))
 196     (mm-with-unibyte-current-buffer
 197       (insert-buffer-substring pgg-output-buffer)
 198       (goto-char (point-min))
 199       (while (re-search-forward "\r+$" nil t)
 200         (replace-match "" t t))
 201       (when cte
 202         (mm-encode-content-transfer-encoding cte))
 203       (goto-char (point-min))
 204       (when headers
 205         (insert headers))
 206       (insert "\n"))
 207     t))
 208
 209 (defun mml1991-pgg-encrypt (cont &optional sign)
 210   (goto-char (point-min))
 211   (when (re-search-forward "^$" nil t)
 212     (let ((cte (save-restriction
 213                  (narrow-to-region (point-min) (point))
 214                  (mail-fetch-field "content-transfer-encoding"))))
 215       ;; Strip MIME headers since it will be ASCII armored.
 216       (forward-line 1)
 217       (delete-region (point-min) (point))
 218       (when cte
 219         (mm-decode-content-transfer-encoding (intern (downcase cte))))))
 220   (unless (let ((pgg-text-mode t))
 221             (pgg-encrypt-region
 222              (point-min) (point-max)
 223              (split-string
 224               (or
 225                (message-options-get 'message-recipients)
 226                (message-options-set 'message-recipients
 227                                     (read-string "Recipients: ")))
 228               "[ \f\t\n\r\v,]+")
 229              sign))
 230     (pop-to-buffer pgg-errors-buffer)
 231     (error "Encrypt error"))
 232   (delete-region (point-min) (point-max))
 233   (insert "\n")
 234   (insert-buffer-substring pgg-output-buffer)
 235   t)
 236
 237 ;; epg wrapper
 238
 239 (defvar epg-user-id-alist)
 240
 241 (autoload 'epg-make-context "epg")
 242 (autoload 'epg-passphrase-callback-function "epg")
 243 (autoload 'epa-select-keys "epa")
 244 (autoload 'epg-list-keys "epg")
 245 (autoload 'epg-context-set-armor "epg")
 246 (autoload 'epg-context-set-textmode "epg")
 247 (autoload 'epg-context-set-signers "epg")
 248 (autoload 'epg-context-set-passphrase-callback "epg")
 249 (autoload 'epg-sign-string "epg")
 250 (autoload 'epg-encrypt-string "epg")
 251 (autoload 'epg-configuration "epg-config")
 252 (autoload 'epg-expand-group "epg-config")
 253
 254 (defvar mml1991-epg-secret-key-id-list nil)
 255
 256 (defun mml1991-epg-passphrase-callback (context key-id ignore)
 257   (if (eq key-id 'SYM)
 258       (epg-passphrase-callback-function context key-id nil)
 259     (let* ((entry (assoc key-id epg-user-id-alist))
 260            (passphrase
 261             (password-read
 262              (format "GnuPG passphrase for %s: "
 263                      (if entry
 264                          (cdr entry)
 265                        key-id))
 266              (if (eq key-id 'PIN)
 267                  "PIN"
 268                key-id))))
 269       (when passphrase
 270         (let ((password-cache-expiry mml1991-passphrase-cache-expiry))
 271           (password-cache-add key-id passphrase))
 272         (setq mml1991-epg-secret-key-id-list
 273               (cons key-id mml1991-epg-secret-key-id-list))
 274         (copy-sequence passphrase)))))
 275
 276 (defun mml1991-epg-sign (cont)
 277   (let ((context (epg-make-context))
 278         headers cte signers signature)
 279     (if (eq mm-sign-option 'guided)
 280         (setq signers (epa-select-keys context "Select keys for signing.
 281 If no one is selected, default secret key is used.  "
 282                                        mml1991-signers t))
 283       (if mml1991-signers
 284           (setq signers (mapcar (lambda (name)
 285                                   (car (epg-list-keys context name t)))
 286                                 mml1991-signers))))
 287     (epg-context-set-armor context t)
 288     (epg-context-set-textmode context t)
 289     (epg-context-set-signers context signers)
 290     (if mml1991-cache-passphrase
 291         (epg-context-set-passphrase-callback
 292          context
 293          #'mml1991-epg-passphrase-callback))
 294     ;; Don't sign headers.
 295     (goto-char (point-min))
 296     (when (re-search-forward "^$" nil t)
 297       (setq headers (buffer-substring (point-min) (point)))
 298       (save-restriction
 299         (narrow-to-region (point-min) (point))
 300         (setq cte (mail-fetch-field "content-transfer-encoding")))
 301       (forward-line 1)
 302       (delete-region (point-min) (point))
 303       (when cte
 304         (setq cte (intern (downcase cte)))
 305         (mm-decode-content-transfer-encoding cte)))
 306     (condition-case error
 307         (setq signature (epg-sign-string context (buffer-string) 'clear)
 308               mml1991-epg-secret-key-id-list nil)
 309       (error
 310        (while mml1991-epg-secret-key-id-list
 311          (password-cache-remove (car mml1991-epg-secret-key-id-list))
 312          (setq mml1991-epg-secret-key-id-list
 313                (cdr mml1991-epg-secret-key-id-list)))
 314        (signal (car error) (cdr error))))
 315     (delete-region (point-min) (point-max))
 316     (mm-with-unibyte-current-buffer
 317       (insert signature)
 318       (goto-char (point-min))
 319       (while (re-search-forward "\r+$" nil t)
 320         (replace-match "" t t))
 321       (when cte
 322         (mm-encode-content-transfer-encoding cte))
 323       (goto-char (point-min))
 324       (when headers
 325         (insert headers))
 326       (insert "\n"))
 327     t))
 328
 329 (defun mml1991-epg-encrypt (cont &optional sign)
 330   (goto-char (point-min))
 331   (when (re-search-forward "^$" nil t)
 332     (let ((cte (save-restriction
 333                  (narrow-to-region (point-min) (point))
 334                  (mail-fetch-field "content-transfer-encoding"))))
 335       ;; Strip MIME headers since it will be ASCII armored.
 336       (forward-line 1)
 337       (delete-region (point-min) (point))
 338       (when cte
 339         (mm-decode-content-transfer-encoding (intern (downcase cte))))))
 340   (let ((context (epg-make-context))
 341         (recipients
 342          (if (message-options-get 'message-recipients)
 343              (split-string
 344               (message-options-get 'message-recipients)
 345               "[ \f\t\n\r\v,]+")))
 346         cipher signers config)
 347     ;; We should remove this check if epg-0.0.6 is released.
 348     (if (and (condition-case nil
 349                  (require 'epg-config)
 350                (error))
 351              (functionp #'epg-expand-group))
 352         (setq config (epg-configuration)
 353               recipients
 354               (apply #'nconc
 355                      (mapcar (lambda (recipient)
 356                                (or (epg-expand-group config recipient)
 357                                    (list recipient)))
 358                              recipients))))
 359     (if (eq mm-encrypt-option 'guided)
 360         (setq recipients
 361               (epa-select-keys context "Select recipients for encryption.
 362 If no one is selected, symmetric encryption will be performed.  "
 363                                recipients))
 364       (setq recipients
 365             (delq nil (mapcar (lambda (name)
 366                                 (car (epg-list-keys context name)))
 367                               recipients))))
 368     (if mml1991-encrypt-to-self
 369         (if mml1991-signers
 370             (setq recipients
 371                   (nconc recipients
 372                          (mapcar (lambda (name)
 373                                    (car (epg-list-keys context name)))
 374                                  mml1991-signers)))
 375           (error "mml1991-signers not set")))
 376     (when sign
 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-signers context signers))
 386     (epg-context-set-armor context t)
 387     (epg-context-set-textmode context t)
 388     (if mml1991-cache-passphrase
 389         (epg-context-set-passphrase-callback
 390          context
 391          #'mml1991-epg-passphrase-callback))
 392     (condition-case error
 393         (setq cipher
 394               (epg-encrypt-string context (buffer-string) recipients sign)
 395               mml1991-epg-secret-key-id-list nil)
 396       (error
 397        (while mml1991-epg-secret-key-id-list
 398          (password-cache-remove (car mml1991-epg-secret-key-id-list))
 399          (setq mml1991-epg-secret-key-id-list
 400                (cdr mml1991-epg-secret-key-id-list)))
 401        (signal (car error) (cdr error))))
 402     (delete-region (point-min) (point-max))
 403     (insert "\n" cipher))
 404   t)
 405
 406 ;;;###autoload
 407 (defun mml1991-encrypt (cont &optional sign)
 408   (let ((func (nth 2 (assq mml1991-use mml1991-function-alist))))
 409     (if func
 410         (funcall func cont sign)
 411       (error "Cannot find encrypt function"))))
 412
 413 ;;;###autoload
 414 (defun mml1991-sign (cont)
 415   (let ((func (nth 1 (assq mml1991-use mml1991-function-alist))))
 416     (if func
 417         (funcall func cont)
 418       (error "Cannot find sign function"))))
 419
 420 (provide 'mml1991)
 421
 422 ;; Local Variables:
 423 ;; coding: iso-8859-1
 424 ;; End:
 425
 426 ;;; mml1991.el ends here