--- /dev/null
+;;; rfc2015.el --- MIME Security with Pretty Good Privacy (PGP)
+;; Copyright (c) 2000 Free Software Foundation, Inc.
+
+;; Author: Shenghuo Zhu <zsh@cs.rochester.edu>
+;; Keywords: PGP MIME
+
+;; This file is a part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published
+;; by the Free Software Foundation; either version 2, or (at your
+;; option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING. If not, write to the
+;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;; Commentary:
+
+;; Usage:
+;; (rfc2015-setup)
+;;
+;; Insert an attribute, postprocess=pgp-sign (or pgp-encrypt), into
+;; the mml tag to be signed (or encrypted).
+
+;;; Code:
+
+(defvar rfc2015-decrypt-function 'mailcrypt-decrypt)
+(defvar rfc2015-verify-function 'mailcrypt-verify)
+
+(defun rfc2015-decrypt (handle)
+ (let (child)
+ (cond
+ ((setq child (mm-find-part-by-type (cdr handle)
+ "application/octet-stream"))
+ (let (handles result)
+ (with-temp-buffer
+ (mm-insert-part child)
+ (setq result (funcall rfc2015-decrypt-function))
+ (unless (car result)
+ (error "Decrypting error."))
+ (setq handles (mm-dissect-buffer t)))
+ (setq gnus-article-mime-handles
+ (append (if (listp (car gnus-article-mime-handles))
+ gnus-article-mime-handles
+ (list gnus-article-mime-handles))
+ (if (listp (car handles))
+ handles
+ (list handles))))
+ (gnus-mime-display-part handles)))
+ (t
+ (if (y-or-n-p "Corrupted pgp-encrypted part. Abort?" )
+ (error "Corrupted pgp-encrypted part.")
+ (gnus-mime-display-mixed (cdr handle)))))))
+
+;; FIXME: mm-dissect-buffer loses information of micalg and the
+;; original header of signed part.
+
+(defun rfc2015-verify (handle)
+ (if (y-or-n-p "Verify signed part?" )
+ (let (child result hash)
+ (with-temp-buffer
+ (unless (setq child (mm-find-part-by-type
+ (cdr handle) "application/pgp-signature" t))
+ (error "Corrupted pgp-signature part."))
+ (insert "-----BEGIN PGP SIGNED MESSAGE-----\n")
+ (insert (format "Hash: %s\n\n" (read-string "Hash: " "SHA1")))
+ (mm-insert-part child)
+ (goto-char (point-max))
+ (unless (bolp)
+ (insert "\n"))
+ (unless (setq child (mm-find-part-by-type
+ (cdr handle) "application/pgp-signature"))
+ (error "Corrupted pgp-signature part."))
+ (mm-insert-part child)
+ (setq result (funcall rfc2015-verify-function))
+ (unless result
+ (error "Verify error.")))))
+ (gnus-mime-display-part
+ (mm-find-part-by-type
+ (cdr handle) "application/pgp-signature" t)))
+
+(defvar rfc2015-mailcrypt-prefix 0)
+
+(defun rfc2015-mailcrypt-sign (cont)
+ (mailcrypt-sign rfc2015-mailcrypt-prefix)
+ (let ((boundary
+ (funcall mml-boundary-function (incf mml-multipart-number)))
+ (scheme-alist (funcall (or mc-default-scheme
+ (cdr (car mc-schemes)))))
+ hash)
+ (goto-char (point-min))
+ (unless (re-search-forward (cdr (assq 'signed-begin-line scheme-alist)))
+ (error "Cannot find signed begin line." ))
+ (goto-char (match-beginning 0))
+ (forward-line 1)
+ (unless (looking-at "Hash:[ \t]*\\([a-zA-Z0-9]+\\)")
+ (error "Cannot not find PGP hash." ))
+ (setq hash (match-string 1))
+ (unless (re-search-forward "^$" nil t)
+ (error "Cannot not find PGP message." ))
+ (forward-line 1)
+ (delete-region (point-min) (point))
+ (insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
+ boundary))
+ (insert (format "\tmicalg=pgp-%s; protocol=\"application/pgp-signature\"\n"
+ hash))
+ (insert "\n")
+ (insert (format "--%s\n" boundary))
+ (unless (re-search-forward (cdr (assq 'signed-end-line scheme-alist)))
+ (error "Cannot find signature part." ))
+ (goto-char (match-beginning 0))
+ (unless (re-search-backward "^-+BEGIN" nil t)
+ (error "Cannot find signature part." ))
+ (goto-char (match-beginning 0))
+ (insert (format "--%s\n" boundary))
+ (insert "Content-Type: application/pgp-signature\n\n")
+ (goto-char (point-max))
+ (insert (format "--%s--\n" boundary))
+ (goto-char (point-max))))
+
+(defun rfc2015-mailcrypt-encrypt (cont)
+ ;; FIXME:
+ ;; You have to input the receiptant.
+ (mailcrypt-encrypt rfc2015-mailcrypt-prefix)
+ (let ((boundary
+ (funcall mml-boundary-function (incf mml-multipart-number))))
+ (goto-char (point-min))
+ (insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
+ boundary))
+ (insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
+ (insert (format "--%s\n" boundary))
+ (insert "Content-Type: application/pgp-encrypted\n\n")
+ (insert "Version: 1\n\n")
+ (insert (format "--%s\n" boundary))
+ (insert "Content-Type: application/octet-stream\n\n")
+ (goto-char (point-max))
+ (insert (format "--%s--\n" boundary))
+ (goto-char (point-max))))
+
+;; The following code might be moved into mml.el or gnus-art.el.
+
+(defvar mml-postprocess-alist
+ '(("pgp-sign" . rfc2015-mailcrypt-sign)
+ ("pgp-encrypt" . rfc2015-mailcrypt-encrypt))
+ "Alist of postprocess functions.")
+
+(defun mml-postprocess (cont)
+ (let ((pp (cdr (or (assq 'postprocess cont)
+ (assq 'pp cont))))
+ item)
+ (if (and pp (setq item (assoc pp mml-postprocess-alist)))
+ (funcall (cdr item) cont))))
+
+(defun rfc2015-setup ()
+ (setq mml-generate-mime-postprocess-function 'mml-postprocess)
+; (push '("multipart/signed" . rfc2015-verify)
+; gnus-mime-multipart-functions)
+ (push '("multipart/encrypted" . rfc2015-decrypt)
+ gnus-mime-multipart-functions))
+
+;; The following code might be moved into mm-decode.el.
+
+(defun mm-find-part-by-type (handles type &optional notp)
+ (let (handle)
+ (while handles
+ (if (if notp
+ (not (equal (mm-handle-media-type (car handles)) type))
+ (equal (mm-handle-media-type (car handles)) type))
+ (setq handle (car handles)
+ handles nil))
+ (setq handles (cdr handles)))
+ handle))
+
+(provide 'rfc2015)
+
+;;; rfc2015.el ends here
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