1 ;;; tls.el --- TLS/SSL support via wrapper around GnuTLS
3 ;; Copyright (C) 1996, 1997, 1998, 1999, 2002, 2003, 2004,
4 ;; 2005, 2006, 2007 Free Software Foundation, Inc.
6 ;; Author: Simon Josefsson <simon@josefsson.org>
7 ;; Keywords: comm, tls, gnutls, ssl
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 by
13 ;; the Free Software Foundation; either version 3, or (at your option)
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU 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.
28 ;; This package implements a simple wrapper around "gnutls-cli" to
29 ;; make Emacs support TLS/SSL.
31 ;; Usage is the same as `open-network-stream', i.e.:
33 ;; (setq tmp (open-tls-stream "test" (current-buffer) "news.mozilla.org" 563))
36 ;; (process-send-string tmp "mode reader\n")
37 ;; 200 secnews.netscape.com Netscape-Collabra/3.52 03615 NNRP ready ...
39 ;; (process-send-string tmp "quit\n")
43 ;; To use this package as a replacement for ssl.el by William M. Perry
44 ;; <wmperry@cs.indiana.edu>, you need to evaluate the following:
46 ;; (defalias 'open-ssl-stream 'open-tls-stream)
51 (autoload 'format-spec "format-spec")
52 (autoload 'format-spec-make "format-spec"))
55 "Transport Layer Security (TLS) parameters."
58 (defcustom tls-program '("gnutls-cli -p %p %h"
59 "gnutls-cli -p %p %h --protocols ssl3"
60 "openssl s_client -connect %h:%p -no_ssl2")
61 "List of strings containing commands to start TLS stream to a host.
62 Each entry in the list is tried until a connection is successful.
63 %h is replaced with server hostname, %p with port to connect to.
64 The program should read input on stdin and write output to
67 See `tls-checktrust' on how to check trusted root certs.
69 Also see `tls-success' for what the program should output after
70 successful negotiation."
73 (list :tag "Choose commands"
75 ("gnutls-cli -p %p %h"
76 "gnutls-cli -p %p %h --protocols ssl3"
77 "openssl s_client -connect %h:%p -no_ssl2")
79 ;; FIXME: add brief `:tag "..."' descriptions.
80 ;; (repeat :inline t :tag "Other" (string))
81 ;; See `tls-checktrust':
82 (const "gnutls-cli --x509cafile /etc/ssl/certs/ca-certificates.crt -p %p %h")
83 (const "gnutls-cli --x509cafile /etc/ssl/certs/ca-certificates.crt -p %p %h --protocols ssl3")
84 (const "openssl s_client -connect %h:%p -CAfile /etc/ssl/certs/ca-certificates.crt -no_ssl2")
86 (const "gnutls-cli -p %p %h")
87 (const "gnutls-cli -p %p %h --protocols ssl3")
88 (const "openssl s_client -connect %h:%p -no_ssl2"))
89 (repeat :inline t :tag "Other" (string)))
90 (const :tag "Default list of commands"
91 ("gnutls-cli -p %p %h"
92 "gnutls-cli -p %p %h --protocols ssl3"
93 "openssl s_client -connect %h:%p -no_ssl2"))
94 (list :tag "List of commands"
95 (repeat :tag "Command" (string))))
99 (defcustom tls-process-connection-type nil
100 "Value for `process-connection-type' to use when starting TLS process."
105 (defcustom tls-success "- Handshake was completed\\|SSL handshake has read "
106 "Regular expression indicating completed TLS handshakes.
107 The default is what GNUTLS's \"gnutls-cli\" or OpenSSL's
108 \"openssl s_client\" outputs."
113 (defcustom tls-checktrust nil
114 "Indicate if certificates should be checked against trusted root certs.
115 If this is `ask', the user can decide whether to accept an
116 untrusted certificate. You may have to adapt `tls-program' in
117 order to make this feature work properly, i.e., to ensure that
118 the external program knows about the root certificates you
119 consider trustworthy, e.g.:
122 '(\"gnutls-cli --x509cafile /etc/ssl/certs/ca-certificates.crt -p %p %h\"
123 \"gnutls-cli --x509cafile /etc/ssl/certs/ca-certificates.crt -p %p %h --protocols ssl3\"
124 \"openssl s_client -connect %h:%p -CAfile /etc/ssl/certs/ca-certificates.crt -no_ssl2\"))"
125 :type '(choice (const :tag "Always" t)
126 (const :tag "Never" nil)
127 (const :tag "Ask" ask))
128 :version "23.0" ;; No Gnus
131 (defcustom tls-untrusted
132 "- Peer's certificate is NOT trusted\\|Verify return code: \\([^0] \\|.[^ ]\\)"
133 "Regular expression indicating failure of TLS certificate verification.
134 The default is what GNUTLS's \"gnutls-cli\" or OpenSSL's
135 \"openssl s_client\" return in the event of unsuccessful
138 :version "23.0" ;; No Gnus
141 (defcustom tls-hostmismatch
142 "# The hostname in the certificate does NOT match"
143 "Regular expression indicating a host name mismatch in certificate.
144 When the host name specified in the certificate doesn't match the
145 name of the host you are connecting to, gnutls-cli issues a
146 warning to this effect. There is no such feature in openssl. Set
147 this to nil if you want to ignore host name mismatches."
149 :version "23.0" ;; No Gnus
152 (defcustom tls-certtool-program (executable-find "certtool")
153 "Name of GnuTLS certtool.
154 Used by `tls-certificate-information'."
159 (defun tls-certificate-information (der)
160 "Parse X.509 certificate in DER format into an assoc list."
161 (let ((certificate (concat "-----BEGIN CERTIFICATE-----\n"
162 (base64-encode-string der)
163 "\n-----END CERTIFICATE-----\n"))
165 (with-current-buffer (get-buffer-create " *certtool*")
168 (setq exit-code (condition-case ()
169 (call-process-region (point-min) (point-max)
171 t (list (current-buffer) nil) t
172 "--certificate-info")
177 (goto-char (point-min))
178 (while (re-search-forward "^\\([^:]+\\): \\(.*\\)" nil t)
179 (push (cons (match-string 1) (match-string 2)) vals))
182 (defun open-tls-stream (name buffer host port)
183 "Open a TLS connection for a port to a host.
184 Returns a subprocess-object to represent the connection.
185 Input and output work as for subprocesses; `delete-process' closes it.
186 Args are NAME BUFFER HOST PORT.
187 NAME is name for process. It is modified if necessary to make it unique.
188 BUFFER is the buffer (or buffer-name) to associate with the process.
189 Process output goes at end of that buffer, unless you specify
190 an output stream or filter function to handle the output.
191 BUFFER may be also nil, meaning that this process is not associated
193 Third arg is name of the host to connect to, or its IP address.
194 Fourth arg PORT is an integer specifying a port to connect to."
195 (let ((cmds tls-program)
196 (use-temp-buffer (null buffer))
199 (setq buffer (generate-new-buffer " TLS")))
200 (message "Opening TLS connection to `%s'..." host)
201 (while (and (not done) (setq cmd (pop cmds)))
202 (message "Opening TLS connection with `%s'..." cmd)
203 (let ((process-connection-type tls-process-connection-type)
205 (setq process (start-process
206 name buffer shell-file-name shell-command-switch
211 ?p (if (integerp port)
215 (memq (process-status process) '(open run))
217 (set-buffer buffer) ;; XXX "blue moon" nntp.el bug
218 (goto-char (point-min))
219 (not (setq done (re-search-forward tls-success nil t)))))
220 (unless (accept-process-output process 1)
222 (message "Opening TLS connection with `%s'...%s" cmd
223 (if done "done" "failed"))
226 (delete-process process))))
234 (goto-char (point-min))
235 (re-search-forward tls-untrusted nil t))
237 (and (not (eq tls-checktrust 'ask))
238 (message "The certificate presented by `%s' is NOT trusted." host))
240 (format "The certificate presented by `%s' is NOT trusted. Accept anyway? " host)))))
241 (and tls-hostmismatch
243 (goto-char (point-min))
244 (re-search-forward tls-hostmismatch nil t))
246 (format "Host name in certificate doesn't match `%s'. Connect anyway? " host)))))
248 (delete-process process))))
249 (message "Opening TLS connection to `%s'...%s"
250 host (if done "done" "failed"))
251 (when use-temp-buffer
252 (if done (set-process-buffer process nil))
253 (kill-buffer buffer))
258 ;;; arch-tag: 5596d1c4-facc-4bc4-94a9-9863b928d7ac