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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:01:30 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:01:30 +0000 |
| commit | 6beeb1b708550be0d4a53b272283e17e5e35fe17 (patch) | |
| tree | 1ce8673d4aaa948e5554000101f46536a1e4cc29 /docs/manual/ssl/ssl_howto.html.en | |
| parent | Initial commit. (diff) | |
| download | apache2-6beeb1b708550be0d4a53b272283e17e5e35fe17.tar.xz apache2-6beeb1b708550be0d4a53b272283e17e5e35fe17.zip | |
Adding upstream version 2.4.57.upstream/2.4.57
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'docs/manual/ssl/ssl_howto.html.en')
| -rw-r--r-- | docs/manual/ssl/ssl_howto.html.en | 449 |
1 files changed, 449 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 0000000..d5c2075 --- /dev/null +++ b/docs/manual/ssl/ssl_howto.html.en @@ -0,0 +1,449 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!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> +<meta content="text/html; charset=UTF-8" http-equiv="Content-Type" /> +<!-- + XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX + This file is generated from xml source: DO NOT EDIT + XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX + --> +<title>SSL/TLS Strong Encryption: How-To - Apache HTTP Server Version 2.4</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.min.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 2.4</p> +<img alt="" src="../images/feather.png" /></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 2.4</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 document 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"><a href="https://www.apache.org/foundation/contributing.html" class="badge"><img src="https://www.apache.org/images/SupportApache-small.png" alt="Support Apache!" /></a><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="#ocspstapling">OCSP Stapling</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><h3>See also</h3><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">LoadModule ssl_module modules/mod_ssl.so + +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="ocspstapling" id="ocspstapling">OCSP Stapling</a></h2> + + +<p>The Online Certificate Status Protocol (OCSP) is a mechanism for +determining whether or not a server certificate has been revoked, and OCSP +Stapling is a special form of this in which the server, such as httpd and +mod_ssl, maintains current OCSP responses for its certificates and sends +them to clients which communicate with the server. Most certificates +contain the address of an OCSP responder maintained by the issuing +Certificate Authority, and mod_ssl can communicate with that responder to +obtain a signed response that can be sent to clients communicating with +the server.</p> + +<p>Because the client can obtain the certificate revocation status from +the server, without requiring an extra connection from the client to the +Certificate Authority, OCSP Stapling is the preferred way for the +revocation status to be obtained. Other benefits of eliminating the +communication between clients and the Certificate Authority are that the +client browsing history is not exposed to the Certificate Authority and +obtaining status is more reliable by not depending on potentially heavily +loaded Certificate Authority servers.</p> + +<p>Because the response obtained by the server can be reused for all clients +using the same certificate during the time that the response is valid, the +overhead for the server is minimal.</p> + +<p>Once general SSL support has been configured properly, enabling OCSP +Stapling generally requires only very minor modifications to the httpd +configuration — the addition of these two directives:</p> + + <pre class="prettyprint lang-config">SSLUseStapling On +SSLStaplingCache "shmcb:logs/ssl_stapling(32768)"</pre> + + +<p>These directives are placed at global scope (i.e., not within a virtual +host definition) wherever other global SSL configuration directives are +placed, such as in <code>conf/extra/httpd-ssl.conf</code> for normal +open source builds of httpd, <code>/etc/apache2/mods-enabled/ssl.conf</code> +for the Ubuntu or Debian-bundled httpd, etc.</p> + +<p>The path on the <code class="directive">SSLStaplingCache</code> directive +(e.g., <code>logs/</code>) should match the one on the +<code class="directive">SSLSessionCache</code> directive. This path is relative +to <code class="directive">ServerRoot</code>.</p> + +<p>This particular <code class="directive">SSLStaplingCache</code> directive requires +<code class="module"><a href="../mod/mod_socache_shmcb.html">mod_socache_shmcb</a></code> (from the <code>shmcb</code> prefix on the +directive's argument). This module is usually enabled already for +<code class="directive">SSLSessionCache</code> or on behalf of some module other than +<code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code>. If you enabled an SSL session cache using a +mechanism other than <code class="module"><a href="../mod/mod_socache_shmcb.html">mod_socache_shmcb</a></code>, use that alternative +mechanism for <code class="directive">SSLStaplingCache</code> as well. For example:</p> + + <pre class="prettyprint lang-config">SSLSessionCache "dbm:logs/ssl_scache" +SSLStaplingCache "dbm:logs/ssl_stapling"</pre> + + +<p>You can use the openssl command-line program to verify that an OCSP response +is sent by your server:</p> + +<pre>$ openssl s_client -connect www.example.com:443 -status -servername www.example.com +... +OCSP response: +====================================== +OCSP Response Data: + OCSP Response Status: successful (0x0) + Response Type: Basic OCSP Response +... + Cert Status: Good +...</pre> + +<p>The following sections highlight the most common situations which require +further modification to the configuration. Refer also to the +<code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code> reference manual.</p> + +<h3>If more than a few SSL certificates are used for the server</h3> + +<p>OCSP responses are stored in the SSL stapling cache. While the responses +are typically a few hundred to a few thousand bytes in size, mod_ssl +supports OCSP responses up to around 10K bytes in size. With more than a +few certificates, the stapling cache size (32768 bytes in the example above) +may need to be increased. Error message AH01929 will be logged in case of +an error storing a response.</p> + + +<h3>If the certificate does not point to an OCSP responder, or if a +different address must be used</h3> + +<p>Refer to the +<code class="directive"><a href="../mod/mod_ssl.html#sslstaplingforceurl">SSLStaplingForceURL</a></code> directive.</p> + +<p>You can confirm that a server certificate points to an OCSP responder +using the openssl command-line program, as follows:</p> + +<pre>$ openssl x509 -in ./www.example.com.crt -text | grep 'OCSP.*http' +OCSP - URI:http://ocsp.example.com</pre> + +<p>If the OCSP URI is provided and the web server can communicate to it +directly without using a proxy, no configuration is required. Note that +firewall rules that control outbound connections from the web server may +need to be adjusted.</p> + +<p>If no OCSP URI is provided, contact your Certificate Authority to +determine if one is available; if so, configure it with +<code class="directive"><a href="../mod/mod_ssl.html#sslstaplingforceurl">SSLStaplingForceURL</a></code> in the virtual +host that uses the certificate.</p> + + +<h3>If multiple SSL-enabled virtual hosts are configured and OCSP +Stapling should be disabled for some</h3> + + +<p>Add <code>SSLUseStapling Off</code> to the virtual hosts for which OCSP +Stapling should be disabled.</p> + + +<h3>If the OCSP responder is slow or unreliable</h3> + +<p>Several directives are available to handle timeouts and errors. Refer +to the documentation for the +<code class="directive"><a href="../mod/mod_ssl.html#sslstaplingfaketrylater">SSLStaplingFakeTryLater</a></code>, +<code class="directive"><a href="../mod/mod_ssl.html#sslstaplingrespondertimeout">SSLStaplingResponderTimeout</a></code>, and +<code class="directive"><a href="../mod/mod_ssl.html#sslstaplingreturnrespondererrors">SSLStaplingReturnResponderErrors</a></code> +directives.</p> + + +<h3>If mod_ssl logs error AH02217</h3> + +<pre>AH02217: ssl_stapling_init_cert: Can't retrieve issuer certificate!</pre> +<p>In order to support OCSP Stapling when a particular server certificate is +used, the certificate chain for that certificate must be configured. If it +was not configured as part of enabling SSL, the AH02217 error will be issued +when stapling is enabled, and an OCSP response will not be provided for clients +using the certificate.</p> + +<p>Refer to the <code class="directive"><a href="../mod/mod_ssl.html#sslcertificatechainfile">SSLCertificateChainFile</a></code> +and <code class="directive"><a href="../mod/mod_ssl.html#sslcertificatefile">SSLCertificateFile</a></code> for instructions +for configuring the certificate chain.</p> + + +</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 +SSLCACertificateFile "conf/ssl.crt/ca.crt" +SSLCACertificatePath "conf/ssl.crt" + +<Directory "/usr/local/apache2/htdocs/secure/area"> + SSLVerifyClient require + SSLVerifyDepth 5 + 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 +SSLCACertificateFile "conf/ssl.crt/ca.crt" +SSLCACertificatePath "conf/ssl.crt" + +<Directory "/usr/local/apache2/htdocs/secure/area"> + SSLVerifyClient require + SSLVerifyDepth 5 + 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 + Require ip 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 + Require ip 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>Notice:</strong><br />This is not a Q&A section. Comments placed here should be pointed towards suggestions on improving the documentation or server, and may be removed by our moderators if they are either implemented or considered invalid/off-topic. Questions on how to manage the Apache HTTP Server should be directed at either our IRC channel, #httpd, on Libera.chat, or sent to our <a href="https://httpd.apache.org/lists.html">mailing lists</a>.</div> +<script type="text/javascript"><!--//--><![CDATA[//><!-- +var comments_shortname = 'httpd'; +var comments_identifier = 'http://httpd.apache.org/docs/2.4/ssl/ssl_howto.html'; +(function(w, d) { + if (w.location.hostname.toLowerCase() == "httpd.apache.org") { + d.write('<div id="comments_thread"><\/div>'); + var s = d.createElement('script'); + s.type = 'text/javascript'; + s.async = true; + s.src = 'https://comments.apache.org/show_comments.lua?site=' + comments_shortname + '&page=' + comments_identifier; + (d.getElementsByTagName('head')[0] || d.getElementsByTagName('body')[0]).appendChild(s); + } + else { + d.write('<div id="comments_thread">Comments are disabled for this page at the moment.<\/div>'); + } +})(window, document); +//--><!]]></script></div><div id="footer"> +<p class="apache">Copyright 2023 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>
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