1 ;;; mml-smime.el --- S/MIME support for MML
2 ;; Copyright (c) 2000, 2001, 2003, 2005 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., 51 Franklin Street, Fifth Floor,
22 ;; Boston, MA 02110-1301, USA.
28 (eval-when-compile (require 'cl))
30 ;; EMIKO doesn't provide the smime.el module.
35 (autoload 'message-narrow-to-headers "message")
36 (autoload 'message-fetch-field "message")
38 (defun mml-smime-sign (cont)
39 (when (null smime-keys)
40 (customize-variable 'smime-keys)
41 (error "No S/MIME keys configured, use customize to add your key"))
42 (smime-sign-buffer (cdr (assq 'keyfile cont)))
43 (goto-char (point-min))
44 (while (search-forward "\r\n" nil t)
45 (replace-match "\n" t t))
46 (goto-char (point-max)))
48 (defun mml-smime-encrypt (cont)
49 (let (certnames certfiles tmp file tmpfiles)
50 ;; xxx tmp files are always an security issue
51 (while (setq tmp (pop cont))
52 (if (and (consp tmp) (eq (car tmp) 'certfile))
53 (push (cdr tmp) certnames)))
54 (while (setq tmp (pop certnames))
55 (if (not (and (not (file-exists-p tmp))
58 (setq file (mm-make-temp-file (expand-file-name "mml."
60 (with-current-buffer tmp
61 (write-region (point-min) (point-max) file))
63 (push file tmpfiles)))
64 (if (smime-encrypt-buffer certfiles)
66 (while (setq tmp (pop tmpfiles))
69 (while (setq tmp (pop tmpfiles))
72 (goto-char (point-max)))
74 (defun mml-smime-sign-query ()
75 ;; query information (what certificate) from user when MML tag is
76 ;; added, for use later by the signing process
77 (when (null smime-keys)
78 (customize-variable 'smime-keys)
79 (error "No S/MIME keys configured, use customize to add your key"))
81 (if (= (length smime-keys) 1)
83 (or (let ((from (cadr (funcall (if (boundp
84 'gnus-extract-address-components)
85 gnus-extract-address-components
86 'mail-extract-address-components)
89 (message-narrow-to-headers)
90 (message-fetch-field "from")))
92 (and from (smime-get-key-by-email from)))
93 (smime-get-key-by-email
94 (completing-read "Sign this part with what signature? "
96 (and (listp (car-safe smime-keys))
97 (caar smime-keys))))))))
99 (defun mml-smime-get-file-cert ()
101 (list 'certfile (read-file-name
102 "File with recipient's S/MIME certificate: "
103 smime-certificate-directory nil t ""))))
105 (defun mml-smime-get-dns-cert ()
106 ;; todo: deal with comma separated multiple recipients
107 (let (result who bad cert)
110 (setq who (read-from-minibuffer
111 (format "%sLookup certificate for: " (or bad ""))
112 (cadr (funcall (if (boundp
113 'gnus-extract-address-components)
114 gnus-extract-address-components
115 'mail-extract-address-components)
118 (message-narrow-to-headers)
119 (message-fetch-field "to")))
121 (if (setq cert (smime-cert-by-dns who))
122 (setq result (list 'certfile (buffer-name cert)))
123 (setq bad (format "`%s' not found. " who))))
127 (defun mml-smime-get-ldap-cert ()
128 ;; todo: deal with comma separated multiple recipients
129 (let (result who bad cert)
132 (setq who (read-from-minibuffer
133 (format "%sLookup certificate for: " (or bad ""))
134 (cadr (funcall gnus-extract-address-components
137 (message-narrow-to-headers)
138 (message-fetch-field "to")))
140 (if (setq cert (smime-cert-by-ldap who))
141 (setq result (list 'certfile (buffer-name cert)))
142 (setq bad (format "`%s' not found. " who))))
146 (defun mml-smime-encrypt-query ()
147 ;; todo: add ldap support (xemacs ldap api?)
148 ;; todo: try dns/ldap automatically first, before prompting user
151 (ecase (read (gnus-completing-read-with-default
152 "ldap" "Fetch certificate from"
153 '(("dns") ("ldap") ("file")) nil t))
154 (dns (setq certs (append certs
155 (mml-smime-get-dns-cert))))
156 (ldap (setq certs (append certs
157 (mml-smime-get-ldap-cert))))
158 (file (setq certs (append certs
159 (mml-smime-get-file-cert)))))
160 (setq done (not (y-or-n-p "Add more recipients? "))))
163 (defun mml-smime-verify (handle ctl)
165 (insert-buffer-substring (mm-handle-multipart-original-buffer ctl))
166 (goto-char (point-min))
167 (insert (format "Content-Type: %s; " (mm-handle-media-type ctl)))
168 (insert (format "protocol=\"%s\"; "
169 (mm-handle-multipart-ctl-parameter ctl 'protocol)))
170 (insert (format "micalg=\"%s\"; "
171 (mm-handle-multipart-ctl-parameter ctl 'micalg)))
172 (insert (format "boundary=\"%s\"\n\n"
173 (mm-handle-multipart-ctl-parameter ctl 'boundary)))
174 (when (get-buffer smime-details-buffer)
175 (kill-buffer smime-details-buffer))
176 (let ((buf (current-buffer))
177 (good-signature (smime-noverify-buffer))
178 (good-certificate (and (or smime-CA-file smime-CA-directory)
179 (smime-verify-buffer)))
180 addresses openssl-output)
181 (setq openssl-output (with-current-buffer smime-details-buffer
183 (if (not good-signature)
185 ;; we couldn't verify message, fail with openssl output as message
186 (mm-set-handle-multipart-parameter
187 mm-security-handle 'gnus-info "Failed")
188 (mm-set-handle-multipart-parameter
189 mm-security-handle 'gnus-details
190 (concat "OpenSSL failed to verify message integrity:\n"
191 "-------------------------------------------\n"
193 ;; verify mail addresses in mail against those in certificate
194 (when (and (smime-pkcs7-region (point-min) (point-max))
195 (smime-pkcs7-certificates-region (point-min) (point-max)))
197 (insert-buffer-substring buf)
198 (goto-char (point-min))
199 (while (re-search-forward "-----END CERTIFICATE-----" nil t)
200 (when (smime-pkcs7-email-region (point-min) (point))
201 (setq addresses (append (smime-buffer-as-string-region
202 (point-min) (point)) addresses)))
203 (delete-region (point-min) (point)))
204 (setq addresses (mapcar 'downcase addresses))))
205 (if (not (member (downcase (or (mm-handle-multipart-from ctl) "")) addresses))
206 (mm-set-handle-multipart-parameter
207 mm-security-handle 'gnus-info "Sender address forged")
209 (mm-set-handle-multipart-parameter
210 mm-security-handle 'gnus-info "Ok (sender authenticated)")
211 (mm-set-handle-multipart-parameter
212 mm-security-handle 'gnus-info "Ok (sender not trusted)")))
213 (mm-set-handle-multipart-parameter
214 mm-security-handle 'gnus-details
215 (concat "Sender claimed to be: " (mm-handle-multipart-from ctl) "\n"
217 (concat "Addresses in certificate: "
218 (mapconcat 'identity addresses ", "))
219 "No addresses found in certificate. (Requires OpenSSL 0.9.6 or later.)")
222 "---------------\n" openssl-output "\n"
223 "Certificate(s) inside S/MIME signature:\n"
224 "---------------------------------------\n"
225 (buffer-string) "\n")))))
228 (defun mml-smime-verify-test (handle ctl)
229 smime-openssl-program)
233 ;;; mml-smime.el ends here