1 ;;; mml-smime.el --- S/MIME support for MML
3 ;; Copyright (C) 2000, 2001, 2002, 2003, 2004,
4 ;; 2005 Free Software Foundation, Inc.
6 ;; Author: Simon Josefsson <simon@josefsson.org>
7 ;; Keywords: Gnus, MIME, S/MIME, MML
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software; you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published
13 ;; by the Free Software Foundation; either version 2, or (at your
14 ;; option) any later version.
16 ;; GNU Emacs is distributed in the hope that it will be useful, but
17 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 ;; General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs; see the file COPYING. If not, write to the
23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24 ;; Boston, MA 02110-1301, USA.
30 (eval-when-compile (require 'cl))
34 (autoload 'message-narrow-to-headers "message")
35 (autoload 'message-fetch-field "message")
37 (defun mml-smime-sign (cont)
38 (when (null smime-keys)
39 (customize-variable 'smime-keys)
40 (error "No S/MIME keys configured, use customize to add your key"))
41 (smime-sign-buffer (cdr (assq 'keyfile cont)))
42 (goto-char (point-min))
43 (while (search-forward "\r\n" nil t)
44 (replace-match "\n" t t))
45 (goto-char (point-max)))
47 (defun mml-smime-encrypt (cont)
48 (let (certnames certfiles tmp file tmpfiles)
49 ;; xxx tmp files are always an security issue
50 (while (setq tmp (pop cont))
51 (if (and (consp tmp) (eq (car tmp) 'certfile))
52 (push (cdr tmp) certnames)))
53 (while (setq tmp (pop certnames))
54 (if (not (and (not (file-exists-p tmp))
57 (setq file (mm-make-temp-file (expand-file-name "mml."
59 (with-current-buffer tmp
60 (write-region (point-min) (point-max) file))
62 (push file tmpfiles)))
63 (if (smime-encrypt-buffer certfiles)
65 (while (setq tmp (pop tmpfiles))
68 (while (setq tmp (pop tmpfiles))
71 (goto-char (point-max)))
73 (defun mml-smime-sign-query ()
74 ;; query information (what certificate) from user when MML tag is
75 ;; added, for use later by the signing process
76 (when (null smime-keys)
77 (customize-variable 'smime-keys)
78 (error "No S/MIME keys configured, use customize to add your key"))
80 (if (= (length smime-keys) 1)
82 (or (let ((from (cadr (funcall gnus-extract-address-components
85 (message-narrow-to-headers)
86 (message-fetch-field "from")))
88 (and from (smime-get-key-by-email from)))
89 (smime-get-key-by-email
90 (completing-read "Sign this part with what signature? "
92 (and (listp (car-safe smime-keys))
93 (caar smime-keys))))))))
95 (defun mml-smime-get-file-cert ()
97 (list 'certfile (read-file-name
98 "File with recipient's S/MIME certificate: "
99 smime-certificate-directory nil t ""))))
101 (defun mml-smime-get-dns-cert ()
102 ;; todo: deal with comma separated multiple recipients
103 (let (result who bad cert)
106 (setq who (read-from-minibuffer
107 (format "%sLookup certificate for: " (or bad ""))
108 (cadr (funcall gnus-extract-address-components
111 (message-narrow-to-headers)
112 (message-fetch-field "to")))
114 (if (setq cert (smime-cert-by-dns who))
115 (setq result (list 'certfile (buffer-name cert)))
116 (setq bad (format "`%s' not found. " who))))
120 (defun mml-smime-get-ldap-cert ()
121 ;; todo: deal with comma separated multiple recipients
122 (let (result who bad cert)
125 (setq who (read-from-minibuffer
126 (format "%sLookup certificate for: " (or bad ""))
127 (cadr (funcall gnus-extract-address-components
130 (message-narrow-to-headers)
131 (message-fetch-field "to")))
133 (if (setq cert (smime-cert-by-ldap who))
134 (setq result (list 'certfile (buffer-name cert)))
135 (setq bad (format "`%s' not found. " who))))
139 (defun mml-smime-encrypt-query ()
140 ;; todo: try dns/ldap automatically first, before prompting user
143 (ecase (read (gnus-completing-read-with-default
144 "ldap" "Fetch certificate from"
145 '(("dns") ("ldap") ("file")) nil t))
146 (dns (setq certs (append certs
147 (mml-smime-get-dns-cert))))
148 (ldap (setq certs (append certs
149 (mml-smime-get-ldap-cert))))
150 (file (setq certs (append certs
151 (mml-smime-get-file-cert)))))
152 (setq done (not (y-or-n-p "Add more recipients? "))))
155 (defun mml-smime-verify (handle ctl)
157 (insert-buffer-substring (mm-handle-multipart-original-buffer ctl))
158 (goto-char (point-min))
159 (insert (format "Content-Type: %s; " (mm-handle-media-type ctl)))
160 (insert (format "protocol=\"%s\"; "
161 (mm-handle-multipart-ctl-parameter ctl 'protocol)))
162 (insert (format "micalg=\"%s\"; "
163 (mm-handle-multipart-ctl-parameter ctl 'micalg)))
164 (insert (format "boundary=\"%s\"\n\n"
165 (mm-handle-multipart-ctl-parameter ctl 'boundary)))
166 (when (get-buffer smime-details-buffer)
167 (kill-buffer smime-details-buffer))
168 (let ((buf (current-buffer))
169 (good-signature (smime-noverify-buffer))
170 (good-certificate (and (or smime-CA-file smime-CA-directory)
171 (smime-verify-buffer)))
172 addresses openssl-output)
173 (setq openssl-output (with-current-buffer smime-details-buffer
175 (if (not good-signature)
177 ;; we couldn't verify message, fail with openssl output as message
178 (mm-set-handle-multipart-parameter
179 mm-security-handle 'gnus-info "Failed")
180 (mm-set-handle-multipart-parameter
181 mm-security-handle 'gnus-details
182 (concat "OpenSSL failed to verify message integrity:\n"
183 "-------------------------------------------\n"
185 ;; verify mail addresses in mail against those in certificate
186 (when (and (smime-pkcs7-region (point-min) (point-max))
187 (smime-pkcs7-certificates-region (point-min) (point-max)))
189 (insert-buffer-substring buf)
190 (goto-char (point-min))
191 (while (re-search-forward "-----END CERTIFICATE-----" nil t)
192 (when (smime-pkcs7-email-region (point-min) (point))
193 (setq addresses (append (smime-buffer-as-string-region
194 (point-min) (point)) addresses)))
195 (delete-region (point-min) (point)))
196 (setq addresses (mapcar 'downcase addresses))))
197 (if (not (member (downcase (or (mm-handle-multipart-from ctl) "")) addresses))
198 (mm-set-handle-multipart-parameter
199 mm-security-handle 'gnus-info "Sender address forged")
201 (mm-set-handle-multipart-parameter
202 mm-security-handle 'gnus-info "Ok (sender authenticated)")
203 (mm-set-handle-multipart-parameter
204 mm-security-handle 'gnus-info "Ok (sender not trusted)")))
205 (mm-set-handle-multipart-parameter
206 mm-security-handle 'gnus-details
207 (concat "Sender claimed to be: " (mm-handle-multipart-from ctl) "\n"
209 (concat "Addresses in certificate: "
210 (mapconcat 'identity addresses ", "))
211 "No addresses found in certificate. (Requires OpenSSL 0.9.6 or later.)")
214 "---------------\n" openssl-output "\n"
215 "Certificate(s) inside S/MIME signature:\n"
216 "---------------------------------------\n"
217 (buffer-string) "\n")))))
220 (defun mml-smime-verify-test (handle ctl)
221 smime-openssl-program)
225 ;;; arch-tag: f1bf94d4-f2cd-4c6f-b059-ad69492817e2
226 ;;; mml-smime.el ends here