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
65 stdout. Also see `tls-success' for what the program should output
66 after successful negotiation."
67 :type '(repeat string)
71 (defcustom tls-process-connection-type nil
72 "*Value for `process-connection-type' to use when starting TLS process."
77 (defcustom tls-success "- Handshake was completed\\|SSL handshake has read "
78 "*Regular expression indicating completed TLS handshakes.
79 The default is what GNUTLS's \"gnutls-cli\" or OpenSSL's
80 \"openssl s_client\" outputs."
85 (defcustom tls-checktrust nil
86 "Indicate if certificates should be checked against trusted root certs.
87 If this is `ask', the user can decide whether to accept an untrusted
88 certificate. You may have to adapt `tls-program' in order to make this feature
89 work properly, i.e., to ensure that the external program knows about the
90 root certificates you consider trustworthy. An appropriate entry in .emacs
93 '(\"gnutls-cli --x509cafile /etc/ssl/certs/ca-certificates.crt -p %p %h\"
94 \"gnutls-cli --x509cafile /etc/ssl/certs/ca-certificates.crt -p %p %h --protocols ssl3\"
95 \"openssl s_client -connect %h:%p -CAfile /etc/ssl/certs/ca-certificates.crt -no_ssl2\"))"
96 :type '(choice (const :tag "Always" t)
97 (const :tag "Never" nil)
98 (const :tag "Ask" ask))
101 (defcustom tls-untrusted "- Peer's certificate is NOT trusted\\|Verify return code: \\([^0] \\|.[^ ]\\)"
102 "*Regular expression indicating failure of TLS certificate verification.
103 The default is what GNUTLS's \"gnutls-cli\" or OpenSSL's
104 \"openssl s_client\" return in the event of unsuccessful verification."
108 (defcustom tls-hostmismatch "# The hostname in the certificate does NOT match"
109 "*Regular expression indicating a host name mismatch in certificate.
110 When the host name specified in the certificate doesn't match the name of the
111 host you are connecting to, gnutls-cli issues a warning to this effect. There
112 is no such feature in openssl. Set this to nil if you want to ignore host name
117 (defcustom tls-certtool-program (executable-find "certtool")
118 "Name of GnuTLS certtool.
119 Used by `tls-certificate-information'."
124 (defun tls-certificate-information (der)
125 "Parse X.509 certificate in DER format into an assoc list."
126 (let ((certificate (concat "-----BEGIN CERTIFICATE-----\n"
127 (base64-encode-string der)
128 "\n-----END CERTIFICATE-----\n"))
130 (with-current-buffer (get-buffer-create " *certtool*")
133 (setq exit-code (condition-case ()
134 (call-process-region (point-min) (point-max)
136 t (list (current-buffer) nil) t
137 "--certificate-info")
142 (goto-char (point-min))
143 (while (re-search-forward "^\\([^:]+\\): \\(.*\\)" nil t)
144 (push (cons (match-string 1) (match-string 2)) vals))
147 (defun open-tls-stream (name buffer host port)
148 "Open a TLS connection for a port to a host.
149 Returns a subprocess-object to represent the connection.
150 Input and output work as for subprocesses; `delete-process' closes it.
151 Args are NAME BUFFER HOST PORT.
152 NAME is name for process. It is modified if necessary to make it unique.
153 BUFFER is the buffer (or buffer-name) to associate with the process.
154 Process output goes at end of that buffer, unless you specify
155 an output stream or filter function to handle the output.
156 BUFFER may be also nil, meaning that this process is not associated
158 Third arg is name of the host to connect to, or its IP address.
159 Fourth arg PORT is an integer specifying a port to connect to."
160 (let ((cmds tls-program)
161 (use-temp-buffer (null buffer))
164 (setq buffer (generate-new-buffer " TLS")))
165 (message "Opening TLS connection to `%s'..." host)
166 (while (and (not done) (setq cmd (pop cmds)))
167 (message "Opening TLS connection with `%s'..." cmd)
168 (let ((process-connection-type tls-process-connection-type)
170 (setq process (start-process
171 name buffer shell-file-name shell-command-switch
176 ?p (if (integerp port)
180 (memq (process-status process) '(open run))
182 (set-buffer buffer) ;; XXX "blue moon" nntp.el bug
183 (goto-char (point-min))
184 (not (setq done (re-search-forward tls-success nil t)))))
185 (unless (accept-process-output process 1)
187 (message "Opening TLS connection with `%s'...%s" cmd
188 (if done "done" "failed"))
191 (delete-process process))))
199 (goto-char (point-min))
200 (re-search-forward tls-untrusted nil t))
202 (format "The certificate presented by `%s' is NOT trusted. Accept anyway? " host))))
203 (and tls-hostmismatch
205 (goto-char (point-min))
206 (re-search-forward tls-hostmismatch nil t))
208 (format "Host name in certificate doesn't match `%s'. Connect anyway? " host)))))
210 (delete-process process))))
211 (message "Opening TLS connection to `%s'...%s"
212 host (if done "done" "failed"))
213 (when use-temp-buffer
214 (if done (set-process-buffer process nil))
215 (kill-buffer buffer))
220 ;;; arch-tag: 5596d1c4-facc-4bc4-94a9-9863b928d7ac