mirror of
https://github.com/apache/httpd.git
synced 2025-05-30 01:07:09 +03:00
5347b4715f
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@421086 13f79535-47bb-0310-9956-ffa450edef68
294 lines
14 KiB
XML
294 lines
14 KiB
XML
<?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 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="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>
|
|
<p class="apache">Apache HTTP Server Version 2.3</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 2.3</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></p>
|
|
</div>
|
|
|
|
<blockquote>
|
|
<p>The solution to this problem is trivial
|
|
and is left as an exercise for the reader.</p>
|
|
|
|
<p class="cite">-- <cite>Standard textbook cookie</cite></p>
|
|
</blockquote>
|
|
|
|
<p>How to solve particular security problems for an SSL-aware
|
|
webserver is not always obvious because of the interactions between SSL,
|
|
HTTP and Apache's way of processing requests. This chapter gives
|
|
instructions on how to solve some typical situations. Treat it as a first
|
|
step to find out the final solution, but always try to understand the
|
|
stuff before you use it. Nothing is worse than using a security solution
|
|
without knowing its restrictions and how it interacts with other systems.</p>
|
|
</div>
|
|
<div id="quickview"><ul id="toc"><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>
|
|
</ul></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="#realssl">How can I create a real SSLv2-only server?</a></li>
|
|
<li><a href="#onlystrong">How can I create an SSL server which accepts strong encryption only?</a></li>
|
|
<li><a href="#upgradeenc">How can I create an SSL server which accepts strong encryption only, but allows
|
|
export browsers to upgrade to stronger encryption?</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="realssl" id="realssl">How can I create a real SSLv2-only server?</a></h3>
|
|
|
|
<p>The following creates an SSL server which speaks only the SSLv2 protocol and
|
|
its ciphers.</p>
|
|
|
|
<div class="example"><h3>httpd.conf</h3><p><code>
|
|
SSLProtocol -all +SSLv2<br />
|
|
SSLCipherSuite SSLv2:+HIGH:+MEDIUM:+LOW:+EXP<br />
|
|
</code></p></div>
|
|
|
|
|
|
<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 seven strongest ciphers:</p>
|
|
<div class="example"><h3>httpd.conf</h3><p><code>
|
|
SSLProtocol all<br />
|
|
SSLCipherSuite HIGH:MEDIUM<br />
|
|
</code></p></div>
|
|
|
|
|
|
<h3><a name="upgradeenc" id="upgradeenc">How can I create an SSL server which accepts strong encryption
|
|
only, but allows export browsers to upgrade to stronger encryption?</a></h3>
|
|
|
|
<p>This facility is called Server Gated Cryptography (SGC) and requires
|
|
a Global ID server certificate, signed by a special CA certificate
|
|
from Verisign. This enables strong encryption in 'export' versions of
|
|
browsers, which traditionally could not support it (because of US export
|
|
restrictions).</p>
|
|
<p>When a browser connects with an export cipher, the server sends its Global
|
|
ID certificate. The browser verifies this, and can then upgrade its
|
|
cipher suite before any HTTP communication takes place. The problem
|
|
lies in allowing browsers to upgrade in this fashion, but still requiring
|
|
strong encryption. In other words, we want browsers to either start a
|
|
connection with strong encryption, or to start with export ciphers but
|
|
upgrade to strong encryption before beginning HTTP communication.</p>
|
|
<p>This can be done as follows:</p>
|
|
<div class="example"><h3>httpd.conf</h3><p><code>
|
|
# allow all ciphers for the initial handshake,<br />
|
|
# so export browsers can upgrade via SGC facility<br />
|
|
SSLCipherSuite ALL:!ADH:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP:+eNULL<br />
|
|
<br />
|
|
<Directory /usr/local/apache2/htdocs><br />
|
|
# but finally deny all browsers which haven't upgraded<br />
|
|
SSLRequire %{SSL_CIPHER_USEKEYSIZE} >= 128<br />
|
|
</Directory>
|
|
</code></p></div>
|
|
|
|
|
|
<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>
|
|
<div class="example"><p><code>
|
|
# be liberal in general<br />
|
|
SSLCipherSuite ALL:!ADH:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP:+eNULL<br />
|
|
<br />
|
|
<Location /strong/area><br />
|
|
# but https://hostname/strong/area/ and below<br />
|
|
# requires strong ciphers<br />
|
|
SSLCipherSuite HIGH:MEDIUM<br />
|
|
</Location>
|
|
</code></p></div>
|
|
|
|
</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>
|
|
<div class="example"><h3>httpd.conf</h3><p><code>
|
|
# require a client certificate which has to be directly<br />
|
|
# signed by our CA certificate in ca.crt<br />
|
|
SSLVerifyClient require<br />
|
|
SSLVerifyDepth 1<br />
|
|
SSLCACertificateFile conf/ssl.crt/ca.crt
|
|
</code></p></div>
|
|
|
|
|
|
<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>
|
|
|
|
<div class="example"><h3>httpd.conf</h3><p><code>
|
|
SSLVerifyClient none<br />
|
|
SSLCACertificateFile conf/ssl.crt/ca.crt<br />
|
|
<br />
|
|
<Location /secure/area><br />
|
|
SSLVerifyClient require<br />
|
|
SSLVerifyDepth 1<br />
|
|
</Location><br />
|
|
</code></p></div>
|
|
|
|
|
|
<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>
|
|
|
|
<div class="example"><h3>httpd.conf</h3><pre>
|
|
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></div>
|
|
|
|
<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>
|
|
|
|
|
|
<div class="example"><h3>httpd.conf</h3><pre>
|
|
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></div>
|
|
|
|
|
|
<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
|
|
192.160.1.0/24, 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>
|
|
|
|
<div class="example"><h3>httpd.conf</h3><pre>
|
|
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></div>
|
|
<div class="bottomlang">
|
|
<p><span>Available Languages: </span><a href="../en/ssl/ssl_howto.html" title="English"> en </a></p>
|
|
</div><div id="footer">
|
|
<p class="apache">Copyright 2006 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="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div>
|
|
</body></html> |