1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
|
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
This file is generated from xml source: DO NOT EDIT
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
-->
<title>SSL/TLS Strong Encryption: How-To - Apache HTTP Server</title>
<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /><link rel="stylesheet" type="text/css" href="../style/css/prettify.css" />
<script src="../style/scripts/prettify.js" type="text/javascript">
</script>
<link href="../images/favicon.ico" rel="shortcut icon" /></head>
<body id="manual-page"><div id="page-header">
<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="http://wiki.apache.org/httpd/FAQ">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>
<p class="apache">Apache HTTP Server Version 2.5</p>
<img alt="" src="../images/feather.gif" /></div>
<div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div>
<div id="path">
<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.5</a> > <a href="./">SSL/TLS</a></div><div id="page-content"><div id="preamble"><h1>SSL/TLS Strong Encryption: How-To</h1>
<div class="toplang">
<p><span>Available Languages: </span><a href="../en/ssl/ssl_howto.html" title="English"> en </a> |
<a href="../fr/ssl/ssl_howto.html" hreflang="fr" rel="alternate" title="Français"> fr </a></p>
</div>
<p>This documented is intended to get you started, and get a few things
working. You are strongly encouraged to read the rest of the SSL
documentation, and arrive at a deeper understanding of the material,
before progressing to the advanced techniques.</p>
</div>
<div id="quickview"><ul id="toc"><li><img alt="" src="../images/down.gif" /> <a href="#configexample">Basic Configuration Example</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#ciphersuites">Cipher Suites and Enforcing Strong Security</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#accesscontrol">Client Authentication and Access Control</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#logging">Logging</a></li>
</ul><ul class="seealso"><li><a href="#comments_section">Comments</a></li></ul></div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="configexample" id="configexample">Basic Configuration Example</a></h2>
<p>Your SSL configuration will need to contain, at minimum, the
following directives.</p>
<pre class="prettyprint lang-config">
Listen 443
<VirtualHost *:443>
ServerName www.example.com
SSLEngine on
SSLCertificateFile /path/to/www.example.com.cert
SSLCertificateKeyFile /path/to/www.example.com.key
</VirtualHost>
</pre>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="ciphersuites" id="ciphersuites">Cipher Suites and Enforcing Strong Security</a></h2>
<ul>
<li><a href="#onlystrong">How can I create an SSL server which accepts strong encryption only?</a></li>
<li><a href="#strongurl">How can I create an SSL server which accepts all types of ciphers in general, but
requires a strong cipher for access to a particular URL?</a></li>
</ul>
<h3><a name="onlystrong" id="onlystrong">How can I create an SSL server which accepts strong encryption
only?</a></h3>
<p>The following enables only the strongest ciphers:</p>
<pre class="prettyprint lang-config">
SSLCipherSuite HIGH:!aNULL:!MD5
</pre>
<p>While with the following configuration you specify a preference
for specific speed-optimized ciphers (which will be selected by
mod_ssl, provided that they are supported by the client):</p>
<pre class="prettyprint lang-config">
SSLCipherSuite RC4-SHA:AES128-SHA:HIGH:!aNULL:!MD5
SSLHonorCipherOrder on
</pre>
<h3><a name="strongurl" id="strongurl">How can I create an SSL server which accepts all types of ciphers
in general, but requires a strong ciphers for access to a particular
URL?</a></h3>
<p>Obviously, a server-wide <code class="directive"><a href="../mod/mod_ssl.html#sslciphersuite">SSLCipherSuite</a></code> which restricts
ciphers to the strong variants, isn't the answer here. However,
<code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code> can be reconfigured within <code>Location</code>
blocks, to give a per-directory solution, and can automatically force
a renegotiation of the SSL parameters to meet the new configuration.
This can be done as follows:</p>
<pre class="prettyprint lang-config">
# be liberal in general
SSLCipherSuite ALL:!aNULL:RC4+RSA:+HIGH:+MEDIUM:+LOW:+EXP:+eNULL
<Location /strong/area>
# but https://hostname/strong/area/ and below
# requires strong ciphers
SSLCipherSuite HIGH:!aNULL:!MD5
</Location>
</pre>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="accesscontrol" id="accesscontrol">Client Authentication and Access Control</a></h2>
<ul>
<li><a href="#allclients">How can I force clients to authenticate using certificates?</a></li>
<li><a href="#arbitraryclients">How can I force clients to authenticate using certificates for a
particular URL, but still allow arbitrary clients to access the rest of the server?</a></li>
<li><a href="#certauthenticate">How can I allow only clients who have certificates to access a
particular URL, but allow all clients to access the rest of the server?</a></li>
<li><a href="#intranet">How can I require HTTPS with strong ciphers, and either
basic authentication or client certificates, for access to part of the
Intranet website, for clients coming from the Internet?</a></li>
</ul>
<h3><a name="allclients" id="allclients">How can I force clients to authenticate using certificates?</a></h3>
<p>When you know all of your users (eg, as is often the case on a corporate
Intranet), you can require plain certificate authentication. All you
need to do is to create client certificates signed by your own CA
certificate (<code>ca.crt</code>) and then verify the clients against this
certificate.</p>
<pre class="prettyprint lang-config">
# require a client certificate which has to be directly
# signed by our CA certificate in ca.crt
SSLVerifyClient require
SSLVerifyDepth 1
SSLCACertificateFile conf/ssl.crt/ca.crt
</pre>
<h3><a name="arbitraryclients" id="arbitraryclients">How can I force clients to authenticate using certificates for a
particular URL, but still allow arbitrary clients to access the rest of the server?</a></h3>
<p>To force clients to authenticate using certificates for a particular URL,
you can use the per-directory reconfiguration features of
<code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code>:</p>
<pre class="prettyprint lang-config">
SSLVerifyClient none
SSLCACertificateFile conf/ssl.crt/ca.crt
<Location /secure/area>
SSLVerifyClient require
SSLVerifyDepth 1
</Location>
</pre>
<h3><a name="certauthenticate" id="certauthenticate">How can I allow only clients who have certificates to access a
particular URL, but allow all clients to access the rest of the server?</a></h3>
<p>The key to doing this is checking that part of the client certificate
matches what you expect. Usually this means checking all or part of the
Distinguished Name (DN), to see if it contains some known string.
There are two ways to do this, using either <code class="module"><a href="../mod/mod_auth_basic.html">mod_auth_basic</a></code> or
<code class="directive"><a href="../mod/mod_ssl.html#sslrequire">SSLRequire</a></code>.</p>
<p>The <code class="module"><a href="../mod/mod_auth_basic.html">mod_auth_basic</a></code> method is generally required when
the certificates are completely arbitrary, or when their DNs have
no common fields (usually the organisation, etc.). In this case,
you should establish a password database containing <em>all</em>
clients allowed, as follows:</p>
<pre class="prettyprint lang-config">
SSLVerifyClient none
<Directory /usr/local/apache2/htdocs/secure/area>
SSLVerifyClient require
SSLVerifyDepth 5
SSLCACertificateFile conf/ssl.crt/ca.crt
SSLCACertificatePath conf/ssl.crt
SSLOptions +FakeBasicAuth
SSLRequireSSL
AuthName "Snake Oil Authentication"
AuthType Basic
AuthBasicProvider file
AuthUserFile /usr/local/apache2/conf/httpd.passwd
Require valid-user
</Directory>
</pre>
<p>The password used in this example is the DES encrypted string "password".
See the <code class="directive"><a href="../mod/mod_ssl.html#ssloptions">SSLOptions</a></code> docs for more
information.</p>
<div class="example"><h3>httpd.passwd</h3><pre>
/C=DE/L=Munich/O=Snake Oil, Ltd./OU=Staff/CN=Foo:xxj31ZMTZzkVA
/C=US/L=S.F./O=Snake Oil, Ltd./OU=CA/CN=Bar:xxj31ZMTZzkVA
/C=US/L=L.A./O=Snake Oil, Ltd./OU=Dev/CN=Quux:xxj31ZMTZzkVA</pre></div>
<p>When your clients are all part of a common hierarchy, which is encoded
into the DN, you can match them more easily using <code class="directive"><a href="../mod/mod_ssl.html#sslrequire">SSLRequire</a></code>, as follows:</p>
<pre class="prettyprint lang-config">
SSLVerifyClient none
<Directory /usr/local/apache2/htdocs/secure/area>
SSLVerifyClient require
SSLVerifyDepth 5
SSLCACertificateFile conf/ssl.crt/ca.crt
SSLCACertificatePath conf/ssl.crt
SSLOptions +FakeBasicAuth
SSLRequireSSL
SSLRequire %{SSL_CLIENT_S_DN_O} eq "Snake Oil, Ltd." \
and %{SSL_CLIENT_S_DN_OU} in {"Staff", "CA", "Dev"}
</Directory>
</pre>
<h3><a name="intranet" id="intranet">How can I require HTTPS with strong ciphers, and either basic
authentication or client certificates, for access to part of the
Intranet website, for clients coming from the Internet? I still want to allow
plain HTTP access for clients on the Intranet.</a></h3>
<p>These examples presume that clients on the Intranet have IPs in the range
192.168.1.0/24, and that the part of the Intranet website you want to allow
internet access to is <code>/usr/local/apache2/htdocs/subarea</code>.
This configuration should remain outside of your HTTPS virtual host, so
that it applies to both HTTPS and HTTP.</p>
<pre class="prettyprint lang-config">
SSLCACertificateFile conf/ssl.crt/company-ca.crt
<Directory /usr/local/apache2/htdocs>
# Outside the subarea only Intranet access is granted
Order deny,allow
Deny from all
Allow from 192.168.1.0/24
</Directory>
<Directory /usr/local/apache2/htdocs/subarea>
# Inside the subarea any Intranet access is allowed
# but from the Internet only HTTPS + Strong-Cipher + Password
# or the alternative HTTPS + Strong-Cipher + Client-Certificate
# If HTTPS is used, make sure a strong cipher is used.
# Additionally allow client certs as alternative to basic auth.
SSLVerifyClient optional
SSLVerifyDepth 1
SSLOptions +FakeBasicAuth +StrictRequire
SSLRequire %{SSL_CIPHER_USEKEYSIZE} >= 128
# Force clients from the Internet to use HTTPS
RewriteEngine on
RewriteCond %{REMOTE_ADDR} !^192\.168\.1\.[0-9]+$
RewriteCond %{HTTPS} !=on
RewriteRule . - [F]
# Allow Network Access and/or Basic Auth
Satisfy any
# Network Access Control
Order deny,allow
Deny from all
Allow 192.168.1.0/24
# HTTP Basic Authentication
AuthType basic
AuthName "Protected Intranet Area"
AuthBasicProvider file
AuthUserFile conf/protected.passwd
Require valid-user
</Directory>
</pre>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="logging" id="logging">Logging</a></h2>
<p><code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code> can log extremely verbose debugging information
to the error log, when its <code class="directive"><a href="../mod/core.html#loglevel">LogLevel</a></code> is
set to the higher trace levels. On the other hand, on a very busy server,
level <code>info</code> may already be too much. Remember that you can
configure the <code class="directive"><a href="../mod/core.html#loglevel">LogLevel</a></code> per module to
suite your needs.</p>
</div></div>
<div class="bottomlang">
<p><span>Available Languages: </span><a href="../en/ssl/ssl_howto.html" title="English"> en </a> |
<a href="../fr/ssl/ssl_howto.html" hreflang="fr" rel="alternate" title="Français"> fr </a></p>
</div><div class="top"><a href="#page-header"><img src="../images/up.gif" alt="top" /></a></div><div class="section"><h2><a id="comments_section" name="comments_section">Comments</a></h2><div class="warning"><strong>This section is experimental!</strong><br />Comments placed here should not be expected
to last beyond the testing phase of this system, nor do we in any way guarantee that we'll read them.</div>
<script type="text/javascript"><!--//--><![CDATA[//><!--
var disqus_shortname = 'httpd';
var disqus_identifier = 'http://httpd.apache.org/docs/2.4/ssl/ssl_howto.html.en';
(function(w, d) {
var disabled = true;
if (w.location.hostname.toLowerCase() == "httpd.apache.org" && disabled !== true) {
d.write('<div id="disqus_thread"><\/div>');
var s = d.createElement('script');
s.type = 'text/javascript';
s.async = true;
s.src = 'http' + '://' + disqus_shortname + '.disqus.com/embed.js';
(d.getElementsByTagName('head')[0] || d.getElementsByTagName('body')[0]).appendChild(s);
}
else {
d.write('<div id="disqus_thread">Comments are disabled for this page at the moment.<\/div>');
}
})(window, document);
//--><!]]></script></div><div id="footer">
<p class="apache">Copyright 2012 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="http://wiki.apache.org/httpd/FAQ">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div><script type="text/javascript"><!--//--><![CDATA[//><!--
if (typeof(prettyPrint) !== 'undefined') {
prettyPrint();
}
//--><!]]></script>
</body></html>
|