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| author | Stefan Fritsch <sf@sfritsch.de> | 2011-12-27 19:42:03 +0100 |
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| committer | Stefan Fritsch <sf@sfritsch.de> | 2011-12-27 19:42:03 +0100 |
| commit | 80db94fff6a9620fb469ee911347ed973e3f7735 (patch) | |
| tree | 35ccde4018b7e6b84103e5e85dc1085ef9e7d6c2 /docs/manual/ssl/ssl_howto.html.en | |
| download | apache2-upstream/2.2.3.tar.gz | |
Upstream tarball 2.2.3upstream/2.2.3
Diffstat (limited to 'docs/manual/ssl/ssl_howto.html.en')
| -rw-r--r-- | docs/manual/ssl/ssl_howto.html.en | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/docs/manual/ssl/ssl_howto.html.en b/docs/manual/ssl/ssl_howto.html.en new file mode 100644 index 00000000..8c514409 --- /dev/null +++ b/docs/manual/ssl/ssl_howto.html.en @@ -0,0 +1,294 @@ +<?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 2.2</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 2.2</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>
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