1 ;;; mml-smime.el --- S/MIME support for MML
2 ;; Copyright (c) 2000, 2001, 2003 Free Software Foundation, Inc.
4 ;; Author: Simon Josefsson <simon@josefsson.org>
5 ;; Keywords: Gnus, MIME, S/MIME, MML
7 ;; This file is part of GNU Emacs.
9 ;; GNU Emacs is free software; you can redistribute it and/or modify
10 ;; it under the terms of the GNU General Public License as published
11 ;; by the Free Software Foundation; either version 2, or (at your
12 ;; option) any later version.
14 ;; GNU Emacs is distributed in the hope that it will be useful, but
15 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 ;; General Public License for more details.
19 ;; You should have received a copy of the GNU General Public License
20 ;; along with GNU Emacs; see the file COPYING. If not, write to the
21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
22 ;; Boston, MA 02111-1307, USA.
28 (eval-when-compile (require 'cl))
32 (autoload 'message-narrow-to-headers "message")
33 (autoload 'message-fetch-field "message")
35 (defun mml-smime-sign (cont)
36 (when (null smime-keys)
37 (customize-variable 'smime-keys)
38 (error "No S/MIME keys configured, use customize to add your key"))
39 (smime-sign-buffer (cdr (assq 'keyfile cont)))
40 (goto-char (point-min))
41 (while (search-forward "\r\n" nil t)
42 (replace-match "\n" t t))
43 (goto-char (point-max)))
45 (defun mml-smime-encrypt (cont)
46 (let (certnames certfiles tmp file tmpfiles)
47 ;; xxx tmp files are always an security issue
48 (while (setq tmp (pop cont))
49 (if (and (consp tmp) (eq (car tmp) 'certfile))
50 (push (cdr tmp) certnames)))
51 (while (setq tmp (pop certnames))
52 (if (not (and (not (file-exists-p tmp))
55 (setq file (mm-make-temp-file (expand-file-name "mml."
57 (with-current-buffer tmp
58 (write-region (point-min) (point-max) file))
60 (push file tmpfiles)))
61 (if (smime-encrypt-buffer certfiles)
63 (while (setq tmp (pop tmpfiles))
66 (while (setq tmp (pop tmpfiles))
69 (goto-char (point-max)))
71 (defun mml-smime-sign-query ()
72 ;; query information (what certificate) from user when MML tag is
73 ;; added, for use later by the signing process
74 (when (null smime-keys)
75 (customize-variable 'smime-keys)
76 (error "No S/MIME keys configured, use customize to add your key"))
78 (if (= (length smime-keys) 1)
80 (or (let ((from (cadr (funcall gnus-extract-address-components
83 (message-narrow-to-headers)
84 (message-fetch-field "from")))
86 (and from (smime-get-key-by-email from)))
87 (smime-get-key-by-email
88 (completing-read "Sign this part with what signature? "
90 (and (listp (car-safe smime-keys))
91 (caar smime-keys))))))))
93 (defun mml-smime-get-file-cert ()
95 (list 'certfile (read-file-name
96 "File with recipient's S/MIME certificate: "
97 smime-certificate-directory nil t ""))))
99 (defun mml-smime-get-dns-cert ()
100 ;; todo: deal with comma separated multiple recipients
101 (let (result who bad cert)
104 (setq who (read-from-minibuffer
105 (format "%sLookup certificate for: " (or bad ""))
106 (cadr (funcall gnus-extract-address-components
109 (message-narrow-to-headers)
110 (message-fetch-field "to")))
112 (if (setq cert (smime-cert-by-dns who))
113 (setq result (list 'certfile (buffer-name cert)))
114 (setq bad (format "`%s' not found. " who))))
118 (defun mml-smime-encrypt-query ()
119 ;; todo: add ldap support (xemacs ldap api?)
120 ;; todo: try dns/ldap automatically first, before prompting user
123 (ecase (read (gnus-completing-read-with-default
124 "dns" "Fetch certificate from"
125 '(("dns") ("file")) nil t))
126 (dns (setq certs (append certs
127 (mml-smime-get-dns-cert))))
128 (file (setq certs (append certs
129 (mml-smime-get-file-cert)))))
130 (setq done (not (y-or-n-p "Add more recipients? "))))
133 (defun mml-smime-verify (handle ctl)
135 (insert-buffer-substring (mm-handle-multipart-original-buffer ctl))
136 (goto-char (point-min))
137 (insert (format "Content-Type: %s; " (mm-handle-media-type ctl)))
138 (insert (format "protocol=\"%s\"; "
139 (mm-handle-multipart-ctl-parameter ctl 'protocol)))
140 (insert (format "micalg=\"%s\"; "
141 (mm-handle-multipart-ctl-parameter ctl 'micalg)))
142 (insert (format "boundary=\"%s\"\n\n"
143 (mm-handle-multipart-ctl-parameter ctl 'boundary)))
144 (when (get-buffer smime-details-buffer)
145 (kill-buffer smime-details-buffer))
146 (let ((buf (current-buffer))
147 (good-signature (smime-noverify-buffer))
148 (good-certificate (and (or smime-CA-file smime-CA-directory)
149 (smime-verify-buffer)))
150 addresses openssl-output)
151 (setq openssl-output (with-current-buffer smime-details-buffer
153 (if (not good-signature)
155 ;; we couldn't verify message, fail with openssl output as message
156 (mm-set-handle-multipart-parameter
157 mm-security-handle 'gnus-info "Failed")
158 (mm-set-handle-multipart-parameter
159 mm-security-handle 'gnus-details
160 (concat "OpenSSL failed to verify message integrity:\n"
161 "-------------------------------------------\n"
163 ;; verify mail addresses in mail against those in certificate
164 (when (and (smime-pkcs7-region (point-min) (point-max))
165 (smime-pkcs7-certificates-region (point-min) (point-max)))
167 (insert-buffer-substring buf)
168 (goto-char (point-min))
169 (while (re-search-forward "-----END CERTIFICATE-----" nil t)
170 (when (smime-pkcs7-email-region (point-min) (point))
171 (setq addresses (append (smime-buffer-as-string-region
172 (point-min) (point)) addresses)))
173 (delete-region (point-min) (point)))
174 (setq addresses (mapcar 'downcase addresses))))
175 (if (not (member (downcase (or (mm-handle-multipart-from ctl) "")) addresses))
176 (mm-set-handle-multipart-parameter
177 mm-security-handle 'gnus-info "Sender address forged")
179 (mm-set-handle-multipart-parameter
180 mm-security-handle 'gnus-info "Ok (sender authenticated)")
181 (mm-set-handle-multipart-parameter
182 mm-security-handle 'gnus-info "Ok (sender not trusted)")))
183 (mm-set-handle-multipart-parameter
184 mm-security-handle 'gnus-details
185 (concat "Sender claimed to be: " (mm-handle-multipart-from ctl) "\n"
187 (concat "Addresses in certificate: "
188 (mapconcat 'identity addresses ", "))
189 "No addresses found in certificate. (Requires OpenSSL 0.9.6 or later.)")
192 "---------------\n" openssl-output "\n"
193 "Certificate(s) inside S/MIME signature:\n"
194 "---------------------------------------\n"
195 (buffer-string) "\n")))))
198 (defun mml-smime-verify-test (handle ctl)
199 smime-openssl-program)
203 ;;; mml-smime.el ends here