1 ;;; starttls.el --- STARTTLS functions
3 ;; Copyright (C) 1999, 2000, 2003, 2004 Free Software Foundation, Inc.
5 ;; Author: Daiki Ueno <ueno@unixuser.org>
6 ;; Author: Simon Josefsson <simon@josefsson.org>
8 ;; Keywords: TLS, SSL, OpenSSL, GNUTLS, mail, news
10 ;; This file is part of GNU Emacs.
12 ;; GNU Emacs is free software; you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation; either version 2, or (at your option)
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;; GNU General Public License for more details.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs; see the file COPYING. If not, write to the
24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
25 ;; Boston, MA 02111-1307, USA.
29 ;; This module defines some utility functions for STARTTLS profiles.
31 ;; [RFC 2595] "Using TLS with IMAP, POP3 and ACAP"
32 ;; by Chris Newman <chris.newman@innosoft.com> (1999/06)
34 ;; This file now contain a combination of the two previous
35 ;; implementations both called "starttls.el". The first one is Daiki
36 ;; Ueno's starttls.el which uses his own "starttls" command line tool,
37 ;; and the second one is Simon Josefsson's starttls.el which uses
38 ;; "gnutls-cli" from GNUTLS.
40 ;; If "gnutls-cli" is available, it is prefered by the code over
41 ;; "starttls". Use `starttls-use-gnutls' to toggle between
42 ;; implementations if you have both tools installed.
44 ;; The GNUTLS support require GNUTLS 0.9.90 (released 2003-10-08) or
45 ;; later, from <http://www.gnu.org/software/gnutls/>, or "starttls"
46 ;; from <ftp://ftp.opaopa.org/pub/elisp/>.
48 ;; Usage is similar to `open-network-stream'. For example:
50 ;; (when (setq tmp (starttls-open-stream
51 ;; "test" (current-buffer) "yxa.extundo.com" 25))
52 ;; (accept-process-output tmp 15)
53 ;; (process-send-string tmp "STARTTLS\n")
54 ;; (accept-process-output tmp 15)
55 ;; (message "STARTTLS output:\n%s" (starttls-negotiate tmp))
56 ;; (process-send-string tmp "EHLO foo\n"))
58 ;; An example run yield the following output:
60 ;; 220 yxa.extundo.com ESMTP Sendmail 8.12.11/8.12.11/Debian-3; Wed, 26 May 2004 19:12:29 +0200; (No UCE/UBE) logging access from: c494102a.s-bi.bostream.se(OK)-c494102a.s-bi.bostream.se [217.215.27.65]
61 ;; 220 2.0.0 Ready to start TLS
62 ;; 250-yxa.extundo.com Hello c494102a.s-bi.bostream.se [217.215.27.65], pleased to meet you
63 ;; 250-ENHANCEDSTATUSCODES
71 ;; 250-AUTH DIGEST-MD5 CRAM-MD5 PLAIN LOGIN
76 ;; With the message buffer containing:
79 ;; *** Starting TLS handshake
80 ;; - Server's trusted authorities:
81 ;; [0]: C=SE,ST=Stockholm,L=Stockholm,O=YXA,OU=CA,CN=yxa.extundo.com,EMAIL=staff@yxa.extundo.com
82 ;; - Certificate type: X.509
83 ;; - Got a certificate list of 2 certificates.
85 ;; - Certificate[0] info:
86 ;; # The hostname in the certificate matches 'yxa.extundo.com'.
87 ;; # valid since: Wed May 26 12:16:00 CEST 2004
88 ;; # expires at: Wed Jul 26 12:16:00 CEST 2023
89 ;; # serial number: 04
90 ;; # fingerprint: 7c 04 4b c1 fa 26 9b 5d 90 22 52 3c 65 3d 85 3a
92 ;; # public key algorithm: RSA
93 ;; # Modulus: 1024 bits
94 ;; # Subject's DN: C=SE,ST=Stockholm,L=Stockholm,O=YXA,OU=Mail server,CN=yxa.extundo.com,EMAIL=staff@yxa.extundo.com
95 ;; # Issuer's DN: C=SE,ST=Stockholm,L=Stockholm,O=YXA,OU=CA,CN=yxa.extundo.com,EMAIL=staff@yxa.extundo.com
97 ;; - Certificate[1] info:
98 ;; # valid since: Sun May 23 11:35:00 CEST 2004
99 ;; # expires at: Sun Jul 23 11:35:00 CEST 2023
100 ;; # serial number: 00
101 ;; # fingerprint: fc 76 d8 63 1a c9 0b 3b fa 40 fe ed 47 7a 58 ae
103 ;; # public key algorithm: RSA
104 ;; # Modulus: 1024 bits
105 ;; # Subject's DN: C=SE,ST=Stockholm,L=Stockholm,O=YXA,OU=CA,CN=yxa.extundo.com,EMAIL=staff@yxa.extundo.com
106 ;; # Issuer's DN: C=SE,ST=Stockholm,L=Stockholm,O=YXA,OU=CA,CN=yxa.extundo.com,EMAIL=staff@yxa.extundo.com
108 ;; - Peer's certificate issuer is unknown
109 ;; - Peer's certificate is NOT trusted
110 ;; - Version: TLS 1.0
111 ;; - Key Exchange: RSA
112 ;; - Cipher: ARCFOUR 128
114 ;; - Compression: NULL
118 (defgroup starttls nil
119 "Support for `Transport Layer Security' protocol."
123 (defcustom starttls-gnutls-program "gnutls-cli"
124 "Name of GNUTLS command line tool.
125 This program is used when GNUTLS is used, i.e. when
126 `starttls-use-gnutls' is non-nil."
130 (defcustom starttls-program "starttls"
131 "The program to run in a subprocess to open an TLSv1 connection.
132 This program is used when the `starttls' command is used,
133 i.e. when `starttls-use-gnutls' is nil."
137 (defcustom starttls-use-gnutls (not (executable-find starttls-program))
138 "*Whether to use GNUTLS instead of the `starttls' command."
142 (defcustom starttls-extra-args nil
143 "Extra arguments to `starttls-program'.
144 This program is used when the `starttls' command is used,
145 i.e. when `starttls-use-gnutls' is nil."
146 :type '(repeat string)
149 (defcustom starttls-extra-arguments nil
150 "Extra arguments to `starttls-program'.
151 This program is used when GNUTLS is used, i.e. when
152 `starttls-use-gnutls' is non-nil.
154 For example, non-TLS compliant servers may require
155 '(\"--protocols\" \"ssl3\"). Invoke \"gnutls-cli --help\" to
156 find out which parameters are available."
157 :type '(repeat string)
160 (defcustom starttls-process-connection-type nil
161 "*Value for `process-connection-type' to use when starting STARTTLS process."
165 (defcustom starttls-connect "- Simple Client Mode:\n\n"
166 "*Regular expression indicating successful connection.
167 The default is what GNUTLS's \"gnutls-cli\" outputs."
168 ;; GNUTLS cli.c:main() print this string when it is starting to run
169 ;; in the application read/write phase. If the logic, or the string
170 ;; itself, is modified, this must be updated.
174 (defcustom starttls-failure "\\*\\*\\* Handshake has failed"
175 "*Regular expression indicating failed TLS handshake.
176 The default is what GNUTLS's \"gnutls-cli\" outputs."
177 ;; GNUTLS cli.c:do_handshake() print this string on failure. If the
178 ;; logic, or the string itself, is modified, this must be updated.
182 (defcustom starttls-success "- Compression: "
183 "*Regular expression indicating completed TLS handshakes.
184 The default is what GNUTLS's \"gnutls-cli\" outputs."
185 ;; GNUTLS cli.c:do_handshake() calls, on success,
186 ;; common.c:print_info(), that unconditionally print this string
187 ;; last. If that logic, or the string itself, is modified, this
192 (defun starttls-negotiate-gnutls (process)
193 "Negotiate TLS on process opened by `open-starttls-stream'.
194 This should typically only be done once. It typically return a
195 multi-line informational message with information about the
196 handshake, or NIL on failure."
197 (let (buffer info old-max done-ok done-bad)
198 (if (null (setq buffer (process-buffer process)))
199 ;; XXX How to remove/extract the TLS negotiation junk?
200 (signal-process (process-id process) 'SIGALRM)
201 (with-current-buffer buffer
203 (setq old-max (goto-char (point-max)))
204 (signal-process (process-id process) 'SIGALRM)
205 (while (and (processp process)
206 (eq (process-status process) 'run)
209 (not (or (setq done-ok (re-search-forward
210 starttls-success nil t))
211 (setq done-bad (re-search-forward
212 starttls-failure nil t))))))
213 (accept-process-output process 1 100)
215 (setq info (buffer-substring-no-properties old-max (point-max)))
216 (delete-region old-max (point-max))
217 (if (or (and done-ok (not done-bad))
218 ;; Prevent mitm that fake success msg after failure msg.
219 (and done-ok done-bad (< done-ok done-bad)))
221 (message "STARTTLS negotiation failed: %s" info)
224 (defun starttls-negotiate (process)
225 (if starttls-use-gnutls
226 (starttls-negotiate-gnutls process)
227 (signal-process (process-id process) 'SIGALRM)))
229 (defun starttls-open-stream-gnutls (name buffer host service)
230 (message "Opening STARTTLS connection to `%s'..." host)
232 (old-max (with-current-buffer buffer (point-max)))
233 (process-connection-type starttls-process-connection-type)
234 (process (apply #'start-process name buffer
235 starttls-gnutls-program "-s" host
236 "-p" (if (integerp service)
237 (int-to-string service)
239 starttls-extra-arguments)))
240 (process-kill-without-query process)
241 (while (and (processp process)
242 (eq (process-status process) 'run)
246 (not (setq done (re-search-forward
247 starttls-connect nil t)))))
248 (accept-process-output process 0 100)
251 (with-current-buffer buffer
252 (delete-region old-max done))
253 (delete-process process)
255 (message "Opening STARTTLS connection to `%s'...%s"
256 host (if done "done" "failed"))
259 (defun starttls-open-stream (name buffer host service)
260 "Open a TLS connection for a service to a host.
261 Returns a subprocess-object to represent the connection.
262 Input and output work as for subprocesses; `delete-process' closes it.
263 Args are NAME BUFFER HOST SERVICE.
264 NAME is name for process. It is modified if necessary to make it unique.
265 BUFFER is the buffer (or `buffer-name') to associate with the process.
266 Process output goes at end of that buffer, unless you specify
267 an output stream or filter function to handle the output.
268 BUFFER may be also nil, meaning that this process is not associated
270 Third arg is name of the host to connect to, or its IP address.
271 Fourth arg SERVICE is name of the service desired, or an integer
272 specifying a port number to connect to."
273 (if starttls-use-gnutls
274 (starttls-open-stream-gnutls name buffer host service)
275 (let* ((process-connection-type starttls-process-connection-type)
276 (process (apply #'start-process
277 name buffer starttls-program
278 host (format "%s" service)
279 starttls-extra-args)))
280 (process-kill-without-query process)
283 (defun starttls-open-ssl-stream (name buffer host service)
284 (let ((starttls-extra-args (cons "--force" starttls-extra-args)))
285 (starttls-open-stream name buffer host service)))
289 ;;; starttls.el ends here