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 (eval-and-compile
  30   ;; For Emacs <22.2 and XEmacs.
  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 (autoload 'pgg-sign-region "pgg")
 172 (autoload 'pgg-encrypt-region "pgg")
 173
 174 (defvar pgg-default-user-id)
 175 (defvar pgg-errors-buffer)
 176 (defvar pgg-output-buffer)
 177
 178 (defun mml1991-pgg-sign (cont)
 179   (let ((pgg-text-mode t)
 180         (pgg-default-user-id (or (message-options-get 'mml-sender)
 181                                  pgg-default-user-id))
 182         headers cte)
 183     ;; Don't sign headers.
 184     (goto-char (point-min))
 185     (when (re-search-forward "^$" nil t)
 186       (setq headers (buffer-substring (point-min) (point)))
 187       (save-restriction
 188         (narrow-to-region (point-min) (point))
 189         (setq cte (mail-fetch-field "content-transfer-encoding")))
 190       (forward-line 1)
 191       (delete-region (point-min) (point))
 192       (when cte
 193         (setq cte (intern (downcase cte)))
 194         (mm-decode-content-transfer-encoding cte)))
 195     (unless (pgg-sign-region (point-min) (point-max) t)
 196       (pop-to-buffer pgg-errors-buffer)
 197       (error "Encrypt error"))
 198     (delete-region (point-min) (point-max))
 199     (mm-with-unibyte-current-buffer
 200       (insert-buffer-substring pgg-output-buffer)
 201       (goto-char (point-min))
 202       (while (re-search-forward "\r+$" nil t)
 203         (replace-match "" t t))
 204       (when cte
 205         (mm-encode-content-transfer-encoding cte))
 206       (goto-char (point-min))
 207       (when headers
 208         (insert headers))
 209       (insert "\n"))
 210     t))
 211
 212 (defun mml1991-pgg-encrypt (cont &optional sign)
 213   (goto-char (point-min))
 214   (when (re-search-forward "^$" nil t)
 215     (let ((cte (save-restriction
 216                  (narrow-to-region (point-min) (point))
 217                  (mail-fetch-field "content-transfer-encoding"))))
 218       ;; Strip MIME headers since it will be ASCII armored.
 219       (forward-line 1)
 220       (delete-region (point-min) (point))
 221       (when cte
 222         (mm-decode-content-transfer-encoding (intern (downcase cte))))))
 223   (unless (let ((pgg-text-mode t))
 224             (pgg-encrypt-region
 225              (point-min) (point-max)
 226              (split-string
 227               (or
 228                (message-options-get 'message-recipients)
 229                (message-options-set 'message-recipients
 230                                     (read-string "Recipients: ")))
 231               "[ \f\t\n\r\v,]+")
 232              sign))
 233     (pop-to-buffer pgg-errors-buffer)
 234     (error "Encrypt error"))
 235   (delete-region (point-min) (point-max))
 236   (insert "\n")
 237   (insert-buffer-substring pgg-output-buffer)
 238   t)
 239
 240 ;; epg wrapper
 241
 242 (defvar epg-user-id-alist)
 243
 244 (autoload 'epg-make-context "epg")
 245 (autoload 'epg-passphrase-callback-function "epg")
 246 (autoload 'epa-select-keys "epa")
 247 (autoload 'epg-list-keys "epg")
 248 (autoload 'epg-context-set-armor "epg")
 249 (autoload 'epg-context-set-textmode "epg")
 250 (autoload 'epg-context-set-signers "epg")
 251 (autoload 'epg-context-set-passphrase-callback "epg")
 252 (autoload 'epg-sign-string "epg")
 253 (autoload 'epg-encrypt-string "epg")
 254 (autoload 'epg-configuration "epg-config")
 255 (autoload 'epg-expand-group "epg-config")
 256
 257 (defvar mml1991-epg-secret-key-id-list nil)
 258
 259 (defun mml1991-epg-passphrase-callback (context key-id ignore)
 260   (if (eq key-id 'SYM)
 261       (epg-passphrase-callback-function context key-id nil)
 262     (let* ((entry (assoc key-id epg-user-id-alist))
 263            (passphrase
 264             (password-read
 265              (format "GnuPG passphrase for %s: "
 266                      (if entry
 267                          (cdr entry)
 268                        key-id))
 269              (if (eq key-id 'PIN)
 270                  "PIN"
 271                key-id))))
 272       (when passphrase
 273         (let ((password-cache-expiry mml1991-passphrase-cache-expiry))
 274           (password-cache-add key-id passphrase))
 275         (setq mml1991-epg-secret-key-id-list
 276               (cons key-id mml1991-epg-secret-key-id-list))
 277         (copy-sequence passphrase)))))
 278
 279 (defun mml1991-epg-sign (cont)
 280   (let ((context (epg-make-context))
 281         headers cte signers signature)
 282     (if (eq mm-sign-option 'guided)
 283         (setq signers (epa-select-keys context "Select keys for signing.
 284 If no one is selected, default secret key is used.  "
 285                                        mml1991-signers t))
 286       (if mml1991-signers
 287           (setq signers (mapcar (lambda (name)
 288                                   (car (epg-list-keys context name t)))
 289                                 mml1991-signers))))
 290     (epg-context-set-armor context t)
 291     (epg-context-set-textmode context t)
 292     (epg-context-set-signers context signers)
 293     (if mml1991-cache-passphrase
 294         (epg-context-set-passphrase-callback
 295          context
 296          #'mml1991-epg-passphrase-callback))
 297     ;; Don't sign headers.
 298     (goto-char (point-min))
 299     (when (re-search-forward "^$" nil t)
 300       (setq headers (buffer-substring (point-min) (point)))
 301       (save-restriction
 302         (narrow-to-region (point-min) (point))
 303         (setq cte (mail-fetch-field "content-transfer-encoding")))
 304       (forward-line 1)
 305       (delete-region (point-min) (point))
 306       (when cte
 307         (setq cte (intern (downcase cte)))
 308         (mm-decode-content-transfer-encoding cte)))
 309     (condition-case error
 310         (setq signature (epg-sign-string context (buffer-string) 'clear)
 311               mml1991-epg-secret-key-id-list nil)
 312       (error
 313        (while mml1991-epg-secret-key-id-list
 314          (password-cache-remove (car mml1991-epg-secret-key-id-list))
 315          (setq mml1991-epg-secret-key-id-list
 316                (cdr mml1991-epg-secret-key-id-list)))
 317        (signal (car error) (cdr error))))
 318     (delete-region (point-min) (point-max))
 319     (mm-with-unibyte-current-buffer
 320       (insert signature)
 321       (goto-char (point-min))
 322       (while (re-search-forward "\r+$" nil t)
 323         (replace-match "" t t))
 324       (when cte
 325         (mm-encode-content-transfer-encoding cte))
 326       (goto-char (point-min))
 327       (when headers
 328         (insert headers))
 329       (insert "\n"))
 330     t))
 331
 332 (defun mml1991-epg-encrypt (cont &optional sign)
 333   (goto-char (point-min))
 334   (when (re-search-forward "^$" nil t)
 335     (let ((cte (save-restriction
 336                  (narrow-to-region (point-min) (point))
 337                  (mail-fetch-field "content-transfer-encoding"))))
 338       ;; Strip MIME headers since it will be ASCII armored.
 339       (forward-line 1)
 340       (delete-region (point-min) (point))
 341       (when cte
 342         (mm-decode-content-transfer-encoding (intern (downcase cte))))))
 343   (let ((context (epg-make-context))
 344         (recipients
 345          (if (message-options-get 'message-recipients)
 346              (split-string
 347               (message-options-get 'message-recipients)
 348               "[ \f\t\n\r\v,]+")))
 349         cipher signers config)
 350     ;; We should remove this check if epg-0.0.6 is released.
 351     (if (and (condition-case nil
 352                  (require 'epg-config)
 353                (error))
 354              (functionp #'epg-expand-group))
 355         (setq config (epg-configuration)
 356               recipients
 357               (apply #'nconc
 358                      (mapcar (lambda (recipient)
 359                                (or (epg-expand-group config recipient)
 360                                    (list recipient)))
 361                              recipients))))
 362     (if (eq mm-encrypt-option 'guided)
 363         (setq recipients
 364               (epa-select-keys context "Select recipients for encryption.
 365 If no one is selected, symmetric encryption will be performed.  "
 366                                recipients))
 367       (setq recipients
 368             (delq nil (mapcar (lambda (name)
 369                                 (car (epg-list-keys context name)))
 370                               recipients))))
 371     (if mml1991-encrypt-to-self
 372         (if mml1991-signers
 373             (setq recipients
 374                   (nconc recipients
 375                          (mapcar (lambda (name)
 376                                    (car (epg-list-keys context name)))
 377                                  mml1991-signers)))
 378           (error "mml1991-signers not set")))
 379     (when sign
 380       (if (eq mm-sign-option 'guided)
 381           (setq signers (epa-select-keys context "Select keys for signing.
 382 If no one is selected, default secret key is used.  "
 383                                          mml1991-signers t))
 384         (if mml1991-signers
 385             (setq signers (mapcar (lambda (name)
 386                                     (car (epg-list-keys context name t)))
 387                                   mml1991-signers))))
 388       (epg-context-set-signers context signers))
 389     (epg-context-set-armor context t)
 390     (epg-context-set-textmode context t)
 391     (if mml1991-cache-passphrase
 392         (epg-context-set-passphrase-callback
 393          context
 394          #'mml1991-epg-passphrase-callback))
 395     (condition-case error
 396         (setq cipher
 397               (epg-encrypt-string context (buffer-string) recipients sign)
 398               mml1991-epg-secret-key-id-list nil)
 399       (error
 400        (while mml1991-epg-secret-key-id-list
 401          (password-cache-remove (car mml1991-epg-secret-key-id-list))
 402          (setq mml1991-epg-secret-key-id-list
 403                (cdr mml1991-epg-secret-key-id-list)))
 404        (signal (car error) (cdr error))))
 405     (delete-region (point-min) (point-max))
 406     (insert "\n" cipher))
 407   t)
 408
 409 ;;;###autoload
 410 (defun mml1991-encrypt (cont &optional sign)
 411   (let ((func (nth 2 (assq mml1991-use mml1991-function-alist))))
 412     (if func
 413         (funcall func cont sign)
 414       (error "Cannot find encrypt function"))))
 415
 416 ;;;###autoload
 417 (defun mml1991-sign (cont)
 418   (let ((func (nth 1 (assq mml1991-use mml1991-function-alist))))
 419     (if func
 420         (funcall func cont)
 421       (error "Cannot find sign function"))))
 422
 423 (provide 'mml1991)
 424
 425 ;; Local Variables:
 426 ;; coding: iso-8859-1
 427 ;; End:
 428
 429 ;;; mml1991.el ends here