1;;; mml-smime.el --- S/MIME support for MML 2 3;; Copyright (C) 2000, 2001, 2002, 2003, 2004, 4;; 2005, 2006, 2007 Free Software Foundation, Inc. 5 6;; Author: Simon Josefsson <simon@josefsson.org> 7;; Keywords: Gnus, MIME, S/MIME, MML 8 9;; This file is part of GNU Emacs. 10 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. 15 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. 20 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. 25 26;;; Commentary: 27 28;;; Code: 29 30(eval-when-compile (require 'cl)) 31 32(require 'smime) 33(require 'mm-decode) 34(autoload 'message-narrow-to-headers "message") 35(autoload 'message-fetch-field "message") 36 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))) 46 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)) 55 (get-buffer tmp))) 56 (push tmp certfiles) 57 (setq file (mm-make-temp-file (expand-file-name "mml." 58 mm-tmp-directory))) 59 (with-current-buffer tmp 60 (write-region (point-min) (point-max) file)) 61 (push file certfiles) 62 (push file tmpfiles))) 63 (if (smime-encrypt-buffer certfiles) 64 (progn 65 (while (setq tmp (pop tmpfiles)) 66 (delete-file tmp)) 67 t) 68 (while (setq tmp (pop tmpfiles)) 69 (delete-file tmp)) 70 nil)) 71 (goto-char (point-max))) 72 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")) 79 (list 'keyfile 80 (if (= (length smime-keys) 1) 81 (cadar smime-keys) 82 (or (let ((from (cadr (funcall (if (boundp 83 'gnus-extract-address-components) 84 gnus-extract-address-components 85 'mail-extract-address-components) 86 (or (save-excursion 87 (save-restriction 88 (message-narrow-to-headers) 89 (message-fetch-field "from"))) 90 ""))))) 91 (and from (smime-get-key-by-email from))) 92 (smime-get-key-by-email 93 (completing-read "Sign this part with what signature? " 94 smime-keys nil nil 95 (and (listp (car-safe smime-keys)) 96 (caar smime-keys)))))))) 97 98(defun mml-smime-get-file-cert () 99 (ignore-errors 100 (list 'certfile (read-file-name 101 "File with recipient's S/MIME certificate: " 102 smime-certificate-directory nil t "")))) 103 104(defun mml-smime-get-dns-cert () 105 ;; todo: deal with comma separated multiple recipients 106 (let (result who bad cert) 107 (condition-case () 108 (while (not result) 109 (setq who (read-from-minibuffer 110 (format "%sLookup certificate for: " (or bad "")) 111 (cadr (funcall (if (boundp 112 'gnus-extract-address-components) 113 gnus-extract-address-components 114 'mail-extract-address-components) 115 (or (save-excursion 116 (save-restriction 117 (message-narrow-to-headers) 118 (message-fetch-field "to"))) 119 ""))))) 120 (if (setq cert (smime-cert-by-dns who)) 121 (setq result (list 'certfile (buffer-name cert))) 122 (setq bad (format "`%s' not found. " who)))) 123 (quit)) 124 result)) 125 126(defun mml-smime-encrypt-query () 127 ;; todo: add ldap support (xemacs ldap api?) 128 ;; todo: try dns/ldap automatically first, before prompting user 129 (let (certs done) 130 (while (not done) 131 (ecase (read (gnus-completing-read-with-default 132 "dns" "Fetch certificate from" 133 '(("dns") ("file")) nil t)) 134 (dns (setq certs (append certs 135 (mml-smime-get-dns-cert)))) 136 (file (setq certs (append certs 137 (mml-smime-get-file-cert))))) 138 (setq done (not (y-or-n-p "Add more recipients? ")))) 139 certs)) 140 141(defun mml-smime-verify (handle ctl) 142 (with-temp-buffer 143 (insert-buffer-substring (mm-handle-multipart-original-buffer ctl)) 144 (goto-char (point-min)) 145 (insert (format "Content-Type: %s; " (mm-handle-media-type ctl))) 146 (insert (format "protocol=\"%s\"; " 147 (mm-handle-multipart-ctl-parameter ctl 'protocol))) 148 (insert (format "micalg=\"%s\"; " 149 (mm-handle-multipart-ctl-parameter ctl 'micalg))) 150 (insert (format "boundary=\"%s\"\n\n" 151 (mm-handle-multipart-ctl-parameter ctl 'boundary))) 152 (when (get-buffer smime-details-buffer) 153 (kill-buffer smime-details-buffer)) 154 (let ((buf (current-buffer)) 155 (good-signature (smime-noverify-buffer)) 156 (good-certificate (and (or smime-CA-file smime-CA-directory) 157 (smime-verify-buffer))) 158 addresses openssl-output) 159 (setq openssl-output (with-current-buffer smime-details-buffer 160 (buffer-string))) 161 (if (not good-signature) 162 (progn 163 ;; we couldn't verify message, fail with openssl output as message 164 (mm-set-handle-multipart-parameter 165 mm-security-handle 'gnus-info "Failed") 166 (mm-set-handle-multipart-parameter 167 mm-security-handle 'gnus-details 168 (concat "OpenSSL failed to verify message integrity:\n" 169 "-------------------------------------------\n" 170 openssl-output))) 171 ;; verify mail addresses in mail against those in certificate 172 (when (and (smime-pkcs7-region (point-min) (point-max)) 173 (smime-pkcs7-certificates-region (point-min) (point-max))) 174 (with-temp-buffer 175 (insert-buffer-substring buf) 176 (goto-char (point-min)) 177 (while (re-search-forward "-----END CERTIFICATE-----" nil t) 178 (when (smime-pkcs7-email-region (point-min) (point)) 179 (setq addresses (append (smime-buffer-as-string-region 180 (point-min) (point)) addresses))) 181 (delete-region (point-min) (point))) 182 (setq addresses (mapcar 'downcase addresses)))) 183 (if (not (member (downcase (or (mm-handle-multipart-from ctl) "")) addresses)) 184 (mm-set-handle-multipart-parameter 185 mm-security-handle 'gnus-info "Sender address forged") 186 (if good-certificate 187 (mm-set-handle-multipart-parameter 188 mm-security-handle 'gnus-info "Ok (sender authenticated)") 189 (mm-set-handle-multipart-parameter 190 mm-security-handle 'gnus-info "Ok (sender not trusted)"))) 191 (mm-set-handle-multipart-parameter 192 mm-security-handle 'gnus-details 193 (concat "Sender claimed to be: " (mm-handle-multipart-from ctl) "\n" 194 (if addresses 195 (concat "Addresses in certificate: " 196 (mapconcat 'identity addresses ", ")) 197 "No addresses found in certificate. (Requires OpenSSL 0.9.6 or later.)") 198 "\n" "\n" 199 "OpenSSL output:\n" 200 "---------------\n" openssl-output "\n" 201 "Certificate(s) inside S/MIME signature:\n" 202 "---------------------------------------\n" 203 (buffer-string) "\n"))))) 204 handle) 205 206(defun mml-smime-verify-test (handle ctl) 207 smime-openssl-program) 208 209(provide 'mml-smime) 210 211;;; arch-tag: f1bf94d4-f2cd-4c6f-b059-ad69492817e2 212;;; mml-smime.el ends here 213