mime-pgp.el

   1 ;;; mime-pgp.el --- mime-view internal methods for PGP.
   2
   3 ;; Copyright (C) 1995,1996,1997,1998,1999,2000 Free Software Foundation, Inc.
   4
   5 ;; Author: MORIOKA Tomohiko <tomo@m17n.org>
   6 ;;      Daiki Ueno <ueno@unixuser.org>
   7 ;; Created: 1995/12/7
   8 ;;      Renamed: 1997/2/27 from tm-pgp.el
   9 ;; Keywords: PGP, security, MIME, multimedia, mail, news
  10
  11 ;; This file is part of SEMI (Secure Emacs MIME Interface).
  12
  13 ;; This program is free software; you can redistribute it and/or
  14 ;; modify it under the terms of the GNU General Public License as
  15 ;; published by the Free Software Foundation; either version 2, or (at
  16 ;; your option) any later version.
  17
  18 ;; This program is distributed in the hope that it will be useful, but
  19 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21 ;; General Public License for more details.
  22
  23 ;; You should have received a copy of the GNU General Public License
  24 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  25 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  26 ;; Boston, MA 02111-1307, USA.
  27
  28 ;;; Commentary:
  29
  30 ;;    This module is based on
  31
  32 ;;      [security-multipart] RFC 1847: "Security Multiparts for MIME:
  33 ;;          Multipart/Signed and Multipart/Encrypted" by
  34 ;;          Jim Galvin <galvin@tis.com>, Sandy Murphy <sandy@tis.com>,
  35 ;;          Steve Crocker <crocker@cybercash.com> and
  36 ;;          Ned Freed <ned@innosoft.com> (1995/10)
  37
  38 ;;      [PGP/MIME] RFC 2015: "MIME Security with Pretty Good Privacy
  39 ;;          (PGP)" by Michael Elkins <elkins@aero.org> (1996/6)
  40
  41 ;;      [PGP-kazu] draft-kazu-pgp-mime-00.txt: "PGP MIME Integration"
  42 ;;          by Kazuhiko Yamamoto <kazu@is.aist-nara.ac.jp> (1995/10;
  43 ;;          expired)
  44
  45 ;;      [OpenPGP/MIME] draft-ietf-openpgp-mime-02.txt: "MIME
  46 ;;          Security with OpenPGP" by
  47 ;;          John W. Noerenberg II <jwn2@qualcomm.com>,
  48 ;;          Dave Del Torto <ddt@cryptorights.org> and
  49 ;;          Michael Elkins <michael_elkins@nai.com> (2000/8)
  50
  51 ;;; Code:
  52
  53 (require 'mime-play)
  54 (require 'pgg-def)
  55
  56 (autoload 'pgg-decrypt-region "pgg"
  57   "PGP decryption of current region." t)
  58 (autoload 'pgg-verify-region "pgg"
  59   "PGP verification of current region." t)
  60 (autoload 'pgg-snarf-keys-region "pgg"
  61   "Snarf PGP public keys in current region." t)
  62
  63 ;;; @ Internal method for multipart/signed
  64 ;;;
  65 ;;; It is based on RFC 1847 (security-multipart).
  66
  67 (defun mime-verify-multipart/signed (entity situation)
  68   "Internal method to verify multipart/signed."
  69   (mime-play-entity
  70    (nth 1 (mime-entity-children entity)) ; entity-info of signature
  71    (list (assq 'mode situation)) ; play-mode
  72    ))
  73
  74
  75 ;;; @ internal method for application/pgp
  76 ;;;
  77 ;;; It is based on draft-kazu-pgp-mime-00.txt (PGP-kazu).
  78
  79 (defun mime-view-application/pgp (entity situation)
  80   (let* ((p-win (or (get-buffer-window (current-buffer))
  81                     (get-largest-window)))
  82          (new-name
  83           (format "%s-%s" (buffer-name) (mime-entity-number entity)))
  84          (mother (current-buffer))
  85          (preview-buffer (concat "*Preview-" (buffer-name) "*"))
  86          representation-type message-buf)
  87     (set-buffer (setq message-buf (get-buffer-create new-name)))
  88     (erase-buffer)
  89     (mime-insert-entity entity)
  90     (cond ((progn
  91              (goto-char (point-min))
  92              (re-search-forward "^-+BEGIN PGP SIGNED MESSAGE-+$" nil t))
  93            (pgg-verify-region (match-beginning 0)(point-max) nil 'fetch)
  94            (goto-char (point-min))
  95            (delete-region
  96             (point-min)
  97             (and
  98              (re-search-forward "^-+BEGIN PGP SIGNED MESSAGE-+\n\n")
  99              (match-end 0)))
 100            (delete-region
 101             (and (re-search-forward "^-+BEGIN PGP SIGNATURE-+")
 102                  (match-beginning 0))
 103             (point-max))
 104            (goto-char (point-min))
 105            (while (re-search-forward "^- -" nil t)
 106              (replace-match "-"))
 107            (setq representation-type (if (mime-entity-cooked-p entity)
 108                                          'cooked)))
 109           ((progn
 110              (goto-char (point-min))
 111              (re-search-forward "^-+BEGIN PGP MESSAGE-+$" nil t))
 112            (pgg-decrypt-region (point-min)(point-max))
 113            (delete-region (point-min)(point-max))
 114            (insert-buffer pgg-output-buffer)
 115            (setq representation-type 'binary)))
 116     (setq major-mode 'mime-show-message-mode)
 117     (save-window-excursion
 118       (mime-view-buffer nil preview-buffer mother
 119                         nil representation-type)
 120       (make-local-variable 'mime-view-temp-message-buffer)
 121       (setq mime-view-temp-message-buffer message-buf))
 122     (set-window-buffer p-win preview-buffer)))
 123
 124
 125 ;;; @ Internal method for application/pgp-signature
 126 ;;;
 127 ;;; It is based on RFC 2015 (PGP/MIME) and
 128 ;;; draft-ietf-openpgp-mime-02.txt (OpenPGP/MIME).
 129
 130 (defun mime-verify-application/pgp-signature (entity situation)
 131   "Internal method to check PGP/MIME signature."
 132   (let* ((entity-node-id (mime-entity-node-id entity))
 133          (mother (mime-entity-parent entity))
 134          (knum (car entity-node-id))
 135          (onum (if (> knum 0)
 136                    (1- knum)
 137                  (1+ knum)))
 138          (orig-entity (nth onum (mime-entity-children mother)))
 139          (basename (expand-file-name "tm" temporary-file-directory))
 140          (sig-file (concat (make-temp-name basename) ".asc"))
 141          status)
 142     (save-excursion
 143       (mime-show-echo-buffer)
 144       (set-buffer mime-echo-buffer-name)
 145       (set-window-start
 146        (get-buffer-window mime-echo-buffer-name)
 147        (point-max)))
 148     (mime-write-entity-content entity sig-file)
 149     (unwind-protect
 150         (with-temp-buffer
 151           (mime-insert-entity orig-entity)
 152           (goto-char (point-min))
 153           (while (progn (end-of-line) (not (eobp)))
 154             (insert "\r")
 155             (forward-line 1))
 156           (setq status (pgg-verify-region (point-min)(point-max)
 157                                           sig-file 'fetch))
 158           (save-excursion
 159             (set-buffer mime-echo-buffer-name)
 160             (insert-buffer-substring (if status pgg-output-buffer
 161                                        pgg-errors-buffer))))
 162       (delete-file sig-file))))
 163
 164
 165 ;;; @ Internal method for application/pgp-encrypted
 166 ;;;
 167 ;;; It is based on RFC 2015 (PGP/MIME) and
 168 ;;; draft-ietf-openpgp-mime-02.txt (OpenPGP/MIME).
 169
 170 (defun mime-decrypt-application/pgp-encrypted (entity situation)
 171   (let* ((entity-node-id (mime-entity-node-id entity))
 172          (mother (mime-entity-parent entity))
 173          (knum (car entity-node-id))
 174          (onum (if (> knum 0)
 175                    (1- knum)
 176                  (1+ knum)))
 177          (orig-entity (nth onum (mime-entity-children mother))))
 178     (mime-view-application/pgp orig-entity situation)))
 179
 180
 181 ;;; @ Internal method for application/pgp-keys
 182 ;;;
 183 ;;; It is based on RFC 2015 (PGP/MIME) and
 184 ;;; draft-ietf-openpgp-mime-02.txt (OpenPGP/MIME).
 185
 186 (defun mime-add-application/pgp-keys (entity situation)
 187   (save-excursion
 188     (mime-show-echo-buffer)
 189     (set-buffer mime-echo-buffer-name)
 190     (set-window-start
 191      (get-buffer-window mime-echo-buffer-name)
 192      (point-max)))
 193   (with-temp-buffer
 194     (mime-insert-entity-content entity)
 195     (mime-decode-region (point-min) (point-max)
 196                         (cdr (assq 'encoding situation)))
 197     (let ((status (pgg-snarf-keys-region (point-min)(point-max))))
 198       (save-excursion
 199         (set-buffer mime-echo-buffer-name)
 200         (insert-buffer-substring (if status pgg-output-buffer
 201                                    pgg-errors-buffer))))))
 202
 203
 204 ;;; @ Internal method for application/pkcs7-signature
 205 ;;;
 206 ;;; It is based on the S/MIME user interface in Gnus.
 207
 208 (defun mime-verify-application/pkcs7-signature (entity situation)
 209   "Internal method to check S/MIME signature."
 210   (with-temp-buffer
 211     (mime-insert-entity (mime-find-root-entity entity))
 212     (let ((good-signature (smime-noverify-buffer))
 213           (good-certificate
 214            (and (or smime-CA-file smime-CA-directory)
 215                 (smime-verify-buffer))))
 216       (if (not good-signature)
 217           ;; we couldn't verify message, fail with openssl output as message
 218           (save-excursion
 219             (mime-show-echo-buffer)
 220             (set-buffer mime-echo-buffer-name)
 221             (set-window-start
 222              (get-buffer-window mime-echo-buffer-name)
 223              (point-max))
 224             (insert-buffer-substring smime-details-buffer))
 225         ;; verify mail addresses in mail against those in certificate
 226         (when (and (smime-pkcs7-region (point-min)(point-max))
 227                    (smime-pkcs7-certificates-region (point-min)(point-max)))
 228           (if (not (member
 229                     (downcase
 230                      (nth 1 (std11-extract-address-components
 231                              (mime-entity-fetch-field
 232                               (mime-find-root-entity entity) "From"))))
 233                     (mime-smime-pkcs7-email-buffer (current-buffer))))
 234               (message "Sender address forged")
 235             (if good-certificate
 236                 (message "Ok (sender authenticated)")
 237               (message "Integrity OK (sender unknown)"))))))))
 238
 239 (defun mime-smime-pkcs7-email-buffer (buffer)
 240   (with-temp-buffer
 241     (insert-buffer-substring buffer)
 242     (goto-char (point-min))
 243     (let (addresses)
 244       (while (re-search-forward "-----END CERTIFICATE-----" nil t)
 245         (if (smime-pkcs7-email-region (point-min)(point))
 246             (setq addresses (append (split-string
 247                                      (buffer-substring (point-min)(point))
 248                                      "[\n\r]+")
 249                                     addresses)))
 250         (delete-region (point-min)(point)))
 251       (mapcar #'downcase addresses))))
 252
 253
 254 ;;; @ Internal method for application/pkcs7-mime
 255 ;;;
 256 ;;; It is based on RFC 2633 (S/MIME version 3).
 257
 258 (defun mime-view-application/pkcs7-mime (entity situation)
 259   (let* ((p-win (or (get-buffer-window (current-buffer))
 260                     (get-largest-window)))
 261          (new-name
 262           (format "%s-%s" (buffer-name) (mime-entity-number entity)))
 263          (mother (current-buffer))
 264          (preview-buffer (concat "*Preview-" (buffer-name) "*"))
 265          message-buf)
 266     (when (memq (or (cdr (assq 'smime-type situation)) 'enveloped-data)
 267                 '(enveloped-data signed-data))
 268       (set-buffer (setq message-buf (get-buffer-create new-name)))
 269       (let ((inhibit-read-only t)
 270             buffer-read-only)
 271         (erase-buffer)
 272         (mime-insert-entity entity)
 273         (smime-decrypt-buffer))
 274       (setq major-mode 'mime-show-message-mode)
 275       (save-window-excursion
 276         (mime-view-buffer nil preview-buffer mother
 277                           nil 'binary)
 278         (make-local-variable 'mime-view-temp-message-buffer)
 279         (setq mime-view-temp-message-buffer message-buf))
 280       (set-window-buffer p-win preview-buffer))))
 281
 282
 283 ;;; @ end
 284 ;;;
 285
 286 (provide 'mime-pgp)
 287
 288 (run-hooks 'mime-pgp-load-hook)
 289
 290 ;;; mime-pgp.el ends here