| <?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: FAQ - 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: FAQ</h1> |
| <div class="toplang"> |
| <p><span>Available Languages: </span><a href="../en/ssl/ssl_faq.html" title="English"> en </a> | |
| <a href="../fr/ssl/ssl_faq.html" hreflang="fr" rel="alternate" title="Français"> fr </a></p> |
| </div> |
| |
| <blockquote> |
| <p>The wise man doesn't give the right answers, |
| he poses the right questions.</p> |
| <p class="cite">-- <cite>Claude Levi-Strauss</cite></p> |
| |
| </blockquote> |
| </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="#installation">Installation</a></li> |
| <li><img alt="" src="../images/down.gif" /> <a href="#aboutconfig">Configuration</a></li> |
| <li><img alt="" src="../images/down.gif" /> <a href="#aboutcerts">Certificates</a></li> |
| <li><img alt="" src="../images/down.gif" /> <a href="#aboutssl">The SSL Protocol</a></li> |
| <li><img alt="" src="../images/down.gif" /> <a href="#support">mod_ssl Support</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="installation" id="installation">Installation</a></h2> |
| <ul> |
| <li><a href="#mutex">Why do I get permission errors related to |
| SSLMutex when I start Apache?</a></li> |
| <li><a href="#entropy">Why does mod_ssl stop with the error "Failed to |
| generate temporary 512 bit RSA private key" when I start Apache?</a></li> |
| </ul> |
| |
| <h3><a name="mutex" id="mutex">Why do I get permission errors related to |
| SSLMutex when I start Apache?</a></h3> |
| <p>Errors such as ``<code>mod_ssl: Child could not open |
| SSLMutex lockfile /opt/apache/logs/ssl_mutex.18332 (System error follows) |
| [...] System: Permission denied (errno: 13)</code>'' are usually |
| caused by overly restrictive permissions on the <em>parent</em> directories. |
| Make sure that all parent directories (here <code>/opt</code>, |
| <code>/opt/apache</code> and <code>/opt/apache/logs</code>) have the x-bit |
| set for, at minimum, the UID under which Apache's children are running (see |
| the <code class="directive"><a href="../mod/mod_unixd.html#user">User</a></code> directive).</p> |
| |
| |
| <h3><a name="entropy" id="entropy">Why does mod_ssl stop with the error |
| "Failed to generate temporary 512 bit RSA private key" when I start |
| Apache?</a></h3> |
| <p>Cryptographic software needs a source of unpredictable data |
| to work correctly. Many open source operating systems provide |
| a "randomness device" that serves this purpose (usually named |
| <code>/dev/random</code>). On other systems, applications have to |
| seed the OpenSSL Pseudo Random Number Generator (PRNG) manually with |
| appropriate data before generating keys or performing public key |
| encryption. As of version 0.9.5, the OpenSSL functions that need |
| randomness report an error if the PRNG has not been seeded with |
| at least 128 bits of randomness.</p> |
| <p>To prevent this error, <code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code> has to provide |
| enough entropy to the PRNG to allow it to work correctly. This can |
| be done via the <code class="directive"><a href="../mod/mod_ssl.html#sslrandomseed">SSLRandomSeed</a></code> |
| directive.</p> |
| |
| </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> |
| <div class="section"> |
| <h2><a name="aboutconfig" id="aboutconfig">Configuration</a></h2> |
| <ul> |
| <li><a href="#parallel">Is it possible to provide HTTP and HTTPS from |
| the same server?</a></li> |
| <li><a href="#ports">Which port does HTTPS use?</a></li> |
| <li><a href="#httpstest">How do I speak HTTPS manually for testing |
| purposes?</a></li> |
| <li><a href="#hang">Why does the connection hang when I connect to my |
| SSL-aware Apache server?</a></li> |
| <li><a href="#refused">Why do I get ``Connection Refused'' errors, when |
| trying to access my newly installed Apache+mod_ssl server via HTTPS?</a></li> |
| <li><a href="#envvars">Why are the <code>SSL_XXX</code> variables not |
| available to my CGI & SSI scripts?</a></li> |
| <li><a href="#relative">How can I switch between HTTP and HTTPS in |
| relative hyperlinks?</a></li> |
| </ul> |
| |
| <h3><a name="parallel" id="parallel">Is it possible to provide HTTP and HTTPS |
| from the same server?</a></h3> |
| <p>Yes. HTTP and HTTPS use different server ports (HTTP binds to |
| port 80, HTTPS to port 443), so there is no direct conflict between |
| them. You can either run two separate server instances bound to |
| these ports, or use Apache's elegant virtual hosting facility to |
| create two virtual servers, both served by the same instance of Apache |
| - one responding over HTTP to requests on port 80, and the other |
| responding over HTTPS to requests on port 443.</p> |
| |
| |
| <h3><a name="ports" id="ports">Which port does HTTPS use?</a></h3> |
| <p>You can run HTTPS on any port, but the standards specify port 443, which |
| is where any HTTPS compliant browser will look by default. You can force |
| your browser to look on a different port by specifying it in the URL. For |
| example, if your server is set up to serve pages over HTTPS on port 8080, |
| you can access them at <code>https://example.com:8080/</code></p> |
| |
| |
| <h3><a name="httpstest" id="httpstest">How do I speak HTTPS manually for testing purposes?</a></h3> |
| <p>While you usually just use</p> |
| |
| <div class="example"><p><code>$ telnet localhost 80<br /> |
| GET / HTTP/1.0</code></p></div> |
| |
| <p>for simple testing of Apache via HTTP, it's not so easy for |
| HTTPS because of the SSL protocol between TCP and HTTP. With the |
| help of OpenSSL's <code>s_client</code> command, however, you can |
| do a similar check via HTTPS:</p> |
| |
| <div class="example"><p><code>$ openssl s_client -connect localhost:443 -state -debug<br /> |
| GET / HTTP/1.0</code></p></div> |
| |
| <p>Before the actual HTTP response you will receive detailed |
| information about the SSL handshake. For a more general command |
| line client which directly understands both HTTP and HTTPS, can |
| perform GET and POST operations, can use a proxy, supports byte |
| ranges, etc. you should have a look at the nifty |
| <a href="http://curl.haxx.se/">cURL</a> tool. Using this, you can |
| check that Apache is responding correctly to requests via HTTP and |
| HTTPS as follows:</p> |
| |
| <div class="example"><p><code>$ curl http://localhost/<br /> |
| $ curl https://localhost/</code></p></div> |
| |
| |
| <h3><a name="hang" id="hang">Why does the connection hang when I connect |
| to my SSL-aware Apache server?</a></h3> |
| |
| <p>This can happen when you try to connect to a HTTPS server (or virtual |
| server) via HTTP (eg, using <code>http://example.com/</code> instead of |
| <code>https://example.com</code>). It can also happen when trying to |
| connect via HTTPS to a HTTP server (eg, using |
| <code>https://example.com/</code> on a server which doesn't support HTTPS, |
| or which supports it on a non-standard port). Make sure that you're |
| connecting to a (virtual) server that supports SSL.</p> |
| |
| <h3><a name="refused" id="refused">Why do I get ``Connection Refused'' messages, |
| when trying to access my newly installed Apache+mod_ssl server via HTTPS?</a></h3> |
| <p> |
| This error can be caused by an incorrect configuration. |
| Please make sure that your <code class="directive"><a href="../mod/mpm_common.html#listen">Listen</a></code> directives match your |
| <code class="directive"><a href="../mod/core.html#virtualhost"><VirtualHost></a></code> |
| directives. If all else fails, please start afresh, using the default |
| configuration provided by <code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code>.</p> |
| |
| |
| <h3><a name="envvars" id="envvars">Why are the <code>SSL_XXX</code> variables |
| not available to my CGI & SSI scripts?</a></h3> |
| <p>Please make sure you have ``<code>SSLOptions +StdEnvVars</code>'' |
| enabled for the context of your CGI/SSI requests.</p> |
| |
| |
| <h3><a name="relative" id="relative">How can I switch between HTTP and HTTPS in relative |
| hyperlinks?</a></h3> |
| |
| <p>Usually, to switch between HTTP and HTTPS, you have to use |
| fully-qualified hyperlinks (because you have to change the URL |
| scheme). Using <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code> however, you can |
| manipulate relative hyperlinks, to achieve the same effect.</p> |
| <pre class="prettyprint lang-config">RewriteEngine on |
| RewriteRule "^/(.*)_SSL$" "https://%{SERVER_NAME}/$1" [R,L] |
| RewriteRule "^/(.*)_NOSSL$" "http://%{SERVER_NAME}/$1" [R,L]</pre> |
| |
| |
| <p>This rewrite ruleset lets you use hyperlinks of the form |
| <code><a href="document.html_SSL"></code>, to switch to HTTPS |
| in a relative link. (Replace SSL with NOSSL to switch to HTTP.)</p> |
| |
| </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> |
| <div class="section"> |
| <h2><a name="aboutcerts" id="aboutcerts">Certificates</a></h2> |
| <ul> |
| <li><a href="#keyscerts">What are RSA Private Keys, CSRs and |
| Certificates?</a></li> |
| <li><a href="#startup">Is there a difference on startup between |
| a non-SSL-aware Apache and an SSL-aware Apache?</a></li> |
| <li><a href="#selfcert">How do I create a self-signed SSL |
| Certificate for testing purposes?</a></li> |
| <li><a href="#realcert">How do I create a real SSL Certificate?</a></li> |
| <li><a href="#ownca">How do I create and use my own Certificate |
| Authority (CA)?</a></li> |
| <li><a href="#passphrase">How can I change the pass-phrase on my private |
| key file?</a></li> |
| <li><a href="#removepassphrase">How can I get rid of the pass-phrase |
| dialog at Apache startup time?</a></li> |
| <li><a href="#verify">How do I verify that a private key matches its |
| Certificate?</a></li> |
| <li><a href="#pemder">How can I convert a certificate from PEM to DER |
| format?</a></li> |
| <li><a href="#gid">Why do browsers complain that they cannot |
| verify my server certificate?</a></li> |
| </ul> |
| |
| <h3><a name="keyscerts" id="keyscerts">What are RSA Private Keys, CSRs and Certificates?</a></h3> |
| <p>An RSA private key file is a digital file that you can use to decrypt |
| messages sent to you. It has a public component which you distribute (via |
| your Certificate file) which allows people to encrypt those messages to |
| you.</p> |
| <p>A Certificate Signing Request (CSR) is a digital file which contains |
| your public key and your name. You send the CSR to a Certifying Authority |
| (CA), who will convert it into a real Certificate, by signing it.</p> |
| <p>A Certificate contains your |
| RSA public key, your name, the name of the CA, and is digitally signed by |
| the CA. Browsers that know the CA can verify the signature on that |
| Certificate, thereby obtaining your RSA public key. That enables them to |
| send messages which only you can decrypt.</p> |
| <p>See the <a href="ssl_intro.html">Introduction</a> chapter for a general |
| description of the SSL protocol.</p> |
| |
| |
| <h3><a name="startup" id="startup">Is there a difference on startup between |
| a non-SSL-aware Apache and an SSL-aware Apache?</a></h3> |
| <p>Yes. In general, starting Apache with |
| <code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code> built-in is just like starting Apache |
| without it. However, if you have a passphrase on your SSL private |
| key file, a startup dialog will pop up which asks you to enter the |
| pass phrase.</p> |
| |
| <p>Having to manually enter the passphrase when starting the server |
| can be problematic - for example, when starting the server from the |
| system boot scripts. In this case, you can follow the steps |
| <a href="#removepassphrase">below</a> to remove the passphrase from |
| your private key. Bear in mind that doing so brings additional security |
| risks - proceed with caution!</p> |
| |
| |
| <h3><a name="selfcert" id="selfcert">How do I create a self-signed SSL |
| Certificate for testing purposes?</a></h3> |
| <ol> |
| <li>Make sure OpenSSL is installed and in your <code>PATH</code>.<br /> |
| <br /> |
| </li> |
| <li>Run the following command, to create <code>server.key</code> and |
| <code>server.crt</code> files:<br /> |
| <code><strong>$ openssl req -new -x509 -nodes -out server.crt |
| -keyout server.key</strong></code><br /> |
| These can be used as follows in your <code>httpd.conf</code> |
| file: |
| <pre class="prettyprint lang-config">SSLCertificateFile "/path/to/this/server.crt" |
| SSLCertificateKeyFile "/path/to/this/server.key"</pre> |
| |
| </li> |
| <li>It is important that you are aware that this |
| <code>server.key</code> does <em>not</em> have any passphrase. |
| To add a passphrase to the key, you should run the following |
| command, and enter & verify the passphrase as requested.<br /> |
| <p><code><strong>$ openssl rsa -des3 -in server.key -out |
| server.key.new</strong></code><br /> |
| <code><strong>$ mv server.key.new server.key</strong></code><br /></p> |
| Please backup the <code>server.key</code> file, and the passphrase |
| you entered, in a secure location. |
| </li> |
| </ol> |
| |
| |
| <h3><a name="realcert" id="realcert">How do I create a real SSL Certificate?</a></h3> |
| <p>Here is a step-by-step description:</p> |
| <ol> |
| <li>Make sure OpenSSL is installed and in your <code>PATH</code>. |
| <br /> |
| <br /> |
| </li> |
| <li>Create a RSA private key for your Apache server |
| (will be Triple-DES encrypted and PEM formatted):<br /> |
| <br /> |
| <code><strong>$ openssl genrsa -des3 -out server.key 2048</strong></code><br /> |
| <br /> |
| Please backup this <code>server.key</code> file and the |
| pass-phrase you entered in a secure location. |
| You can see the details of this RSA private key by using the command:<br /> |
| |
| <br /> |
| <code><strong>$ openssl rsa -noout -text -in server.key</strong></code><br /> |
| <br /> |
| If necessary, you can also create a decrypted PEM version (not |
| recommended) of this RSA private key with:<br /> |
| <br /> |
| <code><strong>$ openssl rsa -in server.key -out server.key.unsecure</strong></code><br /> |
| <br /> |
| |
| </li> |
| <li>Create a Certificate Signing Request (CSR) with the server RSA private |
| key (output will be PEM formatted):<br /> |
| <br /> |
| <code><strong>$ openssl req -new -key server.key -out server.csr</strong></code><br /> |
| <br /> |
| Make sure you enter the FQDN ("Fully Qualified Domain Name") of the |
| server when OpenSSL prompts you for the "CommonName", i.e. when you |
| generate a CSR for a website which will be later accessed via |
| <code>https://www.foo.dom/</code>, enter "www.foo.dom" here. |
| You can see the details of this CSR by using<br /> |
| |
| <br /> |
| <code><strong>$ openssl req -noout -text -in server.csr</strong></code><br /> |
| <br /> |
| </li> |
| <li>You now have to send this Certificate Signing Request (CSR) to |
| a Certifying Authority (CA) to be signed. Once the CSR has been |
| signed, you will have a real Certificate, which can be used by |
| Apache. You can have a CSR signed by a commercial CA, or you can |
| create your own CA to sign it.<br /> |
| Commercial CAs usually ask you to post the CSR into a web form, |
| pay for the signing, and then send a signed Certificate, which |
| you can store in a server.crt file.<br /> |
| |
| For details on how to create your own CA, and use this to sign |
| a CSR, see <a href="#ownca">below</a>.<br /> |
| |
| Once your CSR has been signed, you can see the details of the |
| Certificate as follows:<br /> |
| <br /> |
| <code><strong>$ openssl x509 -noout -text -in server.crt</strong></code><br /> |
| |
| </li> |
| <li>You should now have two files: <code>server.key</code> and |
| <code>server.crt</code>. These can be used as follows in your |
| <code>httpd.conf</code> file: |
| <pre class="prettyprint lang-config">SSLCertificateFile "/path/to/this/server.crt" |
| SSLCertificateKeyFile "/path/to/this/server.key"</pre> |
| |
| The <code>server.csr</code> file is no longer needed. |
| </li> |
| |
| </ol> |
| |
| |
| <h3><a name="ownca" id="ownca">How do I create and use my own Certificate Authority (CA)?</a></h3> |
| <p>The short answer is to use the <code>CA.sh</code> or <code>CA.pl</code> |
| script provided by OpenSSL. Unless you have a good reason not to, |
| you should use these for preference. If you cannot, you can create a |
| self-signed certificate as follows:</p> |
| |
| <ol> |
| <li>Create a RSA private key for your server |
| (will be Triple-DES encrypted and PEM formatted):<br /> |
| <br /> |
| <code><strong>$ openssl genrsa -des3 -out server.key 2048</strong></code><br /> |
| <br /> |
| Please backup this <code>server.key</code> file and the |
| pass-phrase you entered in a secure location. |
| You can see the details of this RSA private key by using the |
| command:<br /> |
| <br /> |
| <code><strong>$ openssl rsa -noout -text -in server.key</strong></code><br /> |
| <br /> |
| If necessary, you can also create a decrypted PEM version (not |
| recommended) of this RSA private key with:<br /> |
| <br /> |
| <code><strong>$ openssl rsa -in server.key -out server.key.unsecure</strong></code><br /> |
| <br /> |
| </li> |
| <li>Create a self-signed certificate (X509 structure) |
| with the RSA key you just created (output will be PEM formatted):<br /> |
| <br /> |
| <code><strong>$ openssl req -new -x509 -nodes -sha1 -days 365 |
| -key server.key -out server.crt -extensions usr_cert</strong></code><br /> |
| <br /> |
| This signs the server CSR and results in a <code>server.crt</code> file.<br /> |
| You can see the details of this Certificate using:<br /> |
| <br /> |
| <code><strong>$ openssl x509 -noout -text -in server.crt</strong></code><br /> |
| <br /> |
| </li> |
| </ol> |
| |
| |
| <h3><a name="passphrase" id="passphrase">How can I change the pass-phrase on my private key file?</a></h3> |
| <p>You simply have to read it with the old pass-phrase and write it again, |
| specifying the new pass-phrase. You can accomplish this with the following |
| commands:</p> |
| |
| |
| <p><code><strong>$ openssl rsa -des3 -in server.key -out server.key.new</strong></code><br /> |
| <code><strong>$ mv server.key.new server.key</strong></code><br /></p> |
| |
| <p>The first time you're asked for a PEM pass-phrase, you should |
| enter the old pass-phrase. After that, you'll be asked again to |
| enter a pass-phrase - this time, use the new pass-phrase. If you |
| are asked to verify the pass-phrase, you'll need to enter the new |
| pass-phrase a second time.</p> |
| |
| |
| <h3><a name="removepassphrase" id="removepassphrase">How can I get rid of the pass-phrase dialog at Apache startup time?</a></h3> |
| <p>The reason this dialog pops up at startup and every re-start |
| is that the RSA private key inside your server.key file is stored in |
| encrypted format for security reasons. The pass-phrase is needed to decrypt |
| this file, so it can be read and parsed. Removing the pass-phrase |
| removes a layer of security from your server - proceed with caution!</p> |
| <ol> |
| <li>Remove the encryption from the RSA private key (while |
| keeping a backup copy of the original file):<br /> |
| <br /> |
| <code><strong>$ cp server.key server.key.org</strong></code><br /> |
| <code><strong>$ openssl rsa -in server.key.org -out server.key</strong></code><br /> |
| |
| <br /> |
| </li> |
| <li>Make sure the server.key file is only readable by root:<br /> |
| <br /> |
| <code><strong>$ chmod 400 server.key</strong></code><br /> |
| <br /> |
| </li> |
| </ol> |
| |
| <p>Now <code>server.key</code> contains an unencrypted copy of the key. |
| If you point your server at this file, it will not prompt you for a |
| pass-phrase. HOWEVER, if anyone gets this key they will be able to |
| impersonate you on the net. PLEASE make sure that the permissions on this |
| file are such that only root or the web server user can read it |
| (preferably get your web server to start as root but run as another |
| user, and have the key readable only by root).</p> |
| |
| <p>As an alternative approach you can use the ``<code>SSLPassPhraseDialog |
| exec:/path/to/program</code>'' facility. Bear in mind that this is |
| neither more nor less secure, of course.</p> |
| |
| |
| <h3><a name="verify" id="verify">How do I verify that a private key matches its Certificate?</a></h3> |
| <p>A private key contains a series of numbers. Two of these numbers form |
| the "public key", the others are part of the "private key". The "public |
| key" bits are included when you generate a CSR, and subsequently form |
| part of the associated Certificate.</p> |
| <p>To check that the public key in your Certificate matches the public |
| portion of your private key, you simply need to compare these numbers. |
| To view the Certificate and the key run the commands:</p> |
| |
| <p><code><strong>$ openssl x509 -noout -text -in server.crt</strong></code><br /> |
| <code><strong>$ openssl rsa -noout -text -in server.key</strong></code></p> |
| |
| <p>The `modulus' and the `public exponent' portions in the key and the |
| Certificate must match. As the public exponent is usually 65537 |
| and it's difficult to visually check that the long modulus numbers |
| are the same, you can use the following approach:</p> |
| |
| <p><code><strong>$ openssl x509 -noout -modulus -in server.crt | openssl md5</strong></code><br /> |
| <code><strong>$ openssl rsa -noout -modulus -in server.key | openssl md5</strong></code></p> |
| |
| <p>This leaves you with two rather shorter numbers to compare. It is, |
| in theory, possible that these numbers may be the same, without the |
| modulus numbers being the same, but the chances of this are |
| overwhelmingly remote.</p> |
| <p>Should you wish to check to which key or certificate a particular |
| CSR belongs you can perform the same calculation on the CSR as |
| follows:</p> |
| |
| <p><code><strong>$ openssl req -noout -modulus -in server.csr | openssl md5</strong></code></p> |
| |
| |
| <h3><a name="pemder" id="pemder">How can I convert a certificate from PEM to DER format?</a></h3> |
| <p>The default certificate format for OpenSSL is PEM, which is simply |
| Base64 encoded DER, with header and footer lines. For some applications |
| (e.g. Microsoft Internet Explorer) you need the certificate in plain DER |
| format. You can convert a PEM file <code>cert.pem</code> into the |
| corresponding DER file <code>cert.der</code> using the following command: |
| <code><strong>$ openssl x509 -in cert.pem -out cert.der -outform DER</strong></code></p> |
| |
| |
| <h3><a name="gid" id="gid">Why do browsers complain that they cannot verify my server certificate?</a></h3> |
| |
| <p>One reason this might happen is because your server certificate is signed |
| by an intermediate CA. Various CAs, such as Verisign or Thawte, have started |
| signing certificates not with their root certificate but with intermediate |
| certificates.</p> |
| |
| <p>Intermediate CA certificates lie between the root CA certificate (which is |
| installed in the browsers) and the server certificate (which you installed |
| on the server). In order for the browser to be able to traverse and verify |
| the trust chain from the server certificate to the root certificate it |
| needs need to be given the intermediate certificates. The CAs should |
| be able to provide you such intermediate certificate packages that can be |
| installed on the server.</p> |
| |
| <p>You need to include those intermediate certificates with the |
| <code class="directive"><a href="../mod/mod_ssl.html#sslcertificatechainfile">SSLCertificateChainFile</a></code> |
| directive.</p> |
| |
| </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> |
| <div class="section"> |
| <h2><a name="aboutssl" id="aboutssl">The SSL Protocol</a></h2> |
| <ul> |
| <li><a href="#random">Why do I get lots of random SSL protocol |
| errors under heavy server load?</a></li> |
| <li><a href="#load">Why does my webserver have a higher load, now |
| that it serves SSL encrypted traffic?</a></li> |
| <li><a href="#establishing">Why do HTTPS connections to my server |
| sometimes take up to 30 seconds to establish a connection?</a></li> |
| <li><a href="#ciphers">What SSL Ciphers are supported by mod_ssl?</a></li> |
| <li><a href="#adh">Why do I get ``no shared cipher'' errors, when |
| trying to use Anonymous Diffie-Hellman (ADH) ciphers?</a></li> |
| <li><a href="#sharedciphers">Why do I get a 'no shared ciphers' |
| error when connecting to my newly installed server?</a></li> |
| <li><a href="#vhosts">Why can't I use SSL with name-based/non-IP-based |
| virtual hosts?</a></li> |
| <li><a href="#vhosts2">Is it possible to use Name-Based Virtual |
| Hosting to identify different SSL virtual hosts?</a></li> |
| <li><a href="#comp">How do I get SSL compression working?</a></li> |
| <li><a href="#lockicon">When I use Basic Authentication over HTTPS |
| the lock icon in Netscape browsers stays unlocked when the dialog pops up. |
| Does this mean the username/password is being sent unencrypted?</a></li> |
| <li><a href="#msie">Why do I get I/O errors when connecting via |
| HTTPS to an Apache+mod_ssl server with Microsoft Internet Explorer |
| (MSIE)?</a></li> |
| <li><a href="#srp">How do I enable TLS-SRP?</a></li> |
| <li><a href="#javadh">Why do I get handshake failures with Java-based clients when using a certificate with more than 1024 bits?</a></li> |
| </ul> |
| |
| <h3><a name="random" id="random">Why do I get lots of random SSL protocol |
| errors under heavy server load?</a></h3> |
| <p>There can be a number of reasons for this, but the main one |
| is problems with the SSL session Cache specified by the |
| <code class="directive"><a href="../mod/mod_ssl.html#sslsessioncache">SSLSessionCache</a></code> directive. The DBM session |
| cache is the most likely source of the problem, so using the SHM session cache (or |
| no cache at all) may help.</p> |
| |
| |
| <h3><a name="load" id="load">Why does my webserver have a higher load, now |
| that it serves SSL encrypted traffic?</a></h3> |
| <p>SSL uses strong cryptographic encryption, which necessitates a lot of |
| number crunching. When you request a webpage via HTTPS, everything (even |
| the images) is encrypted before it is transferred. So increased HTTPS |
| traffic leads to load increases.</p> |
| |
| |
| <h3><a name="establishing" id="establishing">Why do HTTPS connections to my server |
| sometimes take up to 30 seconds to establish a connection?</a></h3> |
| <p>This is usually caused by a <code>/dev/random</code> device for |
| <code class="directive"><a href="../mod/mod_ssl.html#sslrandomseed">SSLRandomSeed</a></code> which blocks the |
| read(2) call until enough entropy is available to service the |
| request. More information is available in the reference |
| manual for the <code class="directive"><a href="../mod/mod_ssl.html#sslrandomseed">SSLRandomSeed</a></code> |
| directive.</p> |
| |
| |
| <h3><a name="ciphers" id="ciphers">What SSL Ciphers are supported by mod_ssl?</a></h3> |
| <p>Usually, any SSL ciphers supported by the version of OpenSSL in use, |
| are also supported by <code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code>. Which ciphers are |
| available can depend on the way you built OpenSSL. Typically, at |
| least the following ciphers are supported:</p> |
| |
| <ol> |
| <li>RC4 with SHA1</li> |
| <li>AES with SHA1</li> |
| <li>Triple-DES with SHA1</li> |
| </ol> |
| |
| <p>To determine the actual list of ciphers available, you should run |
| the following:</p> |
| <div class="example"><p><code>$ openssl ciphers -v</code></p></div> |
| |
| |
| <h3><a name="adh" id="adh">Why do I get ``no shared cipher'' errors, when |
| trying to use Anonymous Diffie-Hellman (ADH) ciphers?</a></h3> |
| <p>By default, OpenSSL does <em>not</em> allow ADH ciphers, for security |
| reasons. Please be sure you are aware of the potential side-effects |
| if you choose to enable these ciphers.</p> |
| <p>In order to use Anonymous Diffie-Hellman (ADH) ciphers, you must |
| build OpenSSL with ``<code>-DSSL_ALLOW_ADH</code>'', and then add |
| ``<code>ADH</code>'' into your <code class="directive"><a href="../mod/mod_ssl.html#sslciphersuite">SSLCipherSuite</a></code>.</p> |
| |
| |
| <h3><a name="sharedciphers" id="sharedciphers">Why do I get a 'no shared ciphers' |
| error when connecting to my newly installed server?</a></h3> |
| <p>Either you have made a mistake with your |
| <code class="directive"><a href="../mod/mod_ssl.html#sslciphersuite">SSLCipherSuite</a></code> |
| directive (compare it with the pre-configured example in |
| <code>extra/httpd-ssl.conf</code>) or you chose to use DSA/DH |
| algorithms instead of RSA when you generated your private key |
| and ignored or overlooked the warnings. If you have chosen |
| DSA/DH, then your server cannot communicate using RSA-based SSL |
| ciphers (at least until you configure an additional RSA-based |
| certificate/key pair). Modern browsers like NS or IE can only |
| communicate over SSL using RSA ciphers. The result is the |
| "no shared ciphers" error. To fix this, regenerate your server |
| certificate/key pair, using the RSA algorithm.</p> |
| |
| |
| <h3><a name="vhosts" id="vhosts">Why can't I use SSL with name-based/non-IP-based virtual hosts?</a></h3> |
| <p>The reason is very technical, and a somewhat "chicken and egg" problem. |
| The SSL protocol layer stays below the HTTP protocol layer and |
| encapsulates HTTP. When an SSL connection (HTTPS) is established |
| Apache/mod_ssl has to negotiate the SSL protocol parameters with the |
| client. For this, mod_ssl has to consult the configuration of the virtual |
| server (for instance it has to look for the cipher suite, the server |
| certificate, etc.). But in order to go to the correct virtual server |
| Apache has to know the <code>Host</code> HTTP header field. To do this, the |
| HTTP request header has to be read. This cannot be done before the SSL |
| handshake is finished, but the information is needed in order to |
| complete the SSL handshake phase. See the next question for how to |
| circumvent this issue.</p> |
| |
| <p>Note that if you have a wildcard SSL certificate, or a |
| certificate that has multiple hostnames on it using subjectAltName |
| fields, you can use SSL on name-based virtual hosts without further |
| workarounds.</p> |
| |
| |
| <h3><a name="vhosts2" id="vhosts2">Is it possible to use Name-Based |
| Virtual Hosting to identify different SSL virtual hosts?</a></h3> |
| <p>Name-Based Virtual Hosting is a very popular method of identifying |
| different virtual hosts. It allows you to use the same IP address and |
| the same port number for many different sites. When people move on to |
| SSL, it seems natural to assume that the same method can be used to have |
| lots of different SSL virtual hosts on the same server.</p> |
| |
| <p>It is possible, but only if using a 2.2.12 or later web server, |
| built with 0.9.8j or later OpenSSL. This is because it requires a |
| feature that only the most recent revisions of the SSL |
| specification added, called Server Name Indication (SNI).</p> |
| |
| <p>Note that if you have a wildcard SSL certificate, or a |
| certificate that has multiple hostnames on it using subjectAltName |
| fields, you can use SSL on name-based virtual hosts without further |
| workarounds.</p> |
| |
| <p>The reason is that the SSL protocol is a separate layer which |
| encapsulates the HTTP protocol. So the SSL session is a separate |
| transaction, that takes place before the HTTP session has begun. |
| The server receives an SSL request on IP address X and port Y |
| (usually 443). Since the SSL request did not contain any Host: |
| field, the server had no way to decide which SSL virtual host to use. |
| Usually, it just used the first one it found which matched the |
| port and IP address specified.</p> |
| |
| <p>If you are using a version of the web server and OpenSSL that |
| support SNI, though, and the client's browser also supports SNI, |
| then the hostname is included in the original SSL request, and the |
| web server can select the correct SSL virtual host.</p> |
| |
| <p>You can, of course, use Name-Based Virtual Hosting to identify many |
| non-SSL virtual hosts (all on port 80, for example) and then |
| have a single SSL virtual host (on port 443). But if you do this, |
| you must make sure to put the non-SSL port number on the NameVirtualHost |
| directive, e.g.</p> |
| |
| <pre class="prettyprint lang-config">NameVirtualHost 192.168.1.1:80</pre> |
| |
| |
| <p>Other workaround solutions include: </p> |
| |
| <p>Using separate IP addresses for different SSL hosts. |
| Using different port numbers for different SSL hosts.</p> |
| |
| |
| <h3><a name="comp" id="comp">How do I get SSL compression working?</a></h3> |
| <p>Although SSL compression negotiation was defined in the specification |
| of SSLv2 and TLS, it took until May 2004 for RFC 3749 to define DEFLATE as |
| a negotiable standard compression method. |
| </p> |
| <p>OpenSSL 0.9.8 started to support this by default when compiled with the |
| <code>zlib</code> option. If both the client and the server support compression, |
| it will be used. However, most clients still try to initially connect with an |
| SSLv2 Hello. As SSLv2 did not include an array of preferred compression algorithms |
| in its handshake, compression cannot be negotiated with these clients. |
| If the client disables support for SSLv2, either an SSLv3 or TLS Hello |
| may be sent, depending on which SSL library is used, and compression may |
| be set up. You can verify whether clients make use of SSL compression by |
| logging the <code>%{SSL_COMPRESS_METHOD}x</code> variable. |
| </p> |
| |
| |
| <h3><a name="lockicon" id="lockicon">When I use Basic Authentication over HTTPS |
| the lock icon in Netscape browsers stays unlocked when the dialog pops up. |
| Does this mean the username/password is being sent unencrypted?</a></h3> |
| <p>No, the username/password is transmitted encrypted. The icon in |
| Netscape browsers is not actually synchronized with the SSL/TLS layer. |
| It only toggles to the locked state when the first part of the actual |
| webpage data is transferred, which may confuse people. The Basic |
| Authentication facility is part of the HTTP layer, which is above |
| the SSL/TLS layer in HTTPS. Before any HTTP data communication takes |
| place in HTTPS, the SSL/TLS layer has already completed its handshake |
| phase, and switched to encrypted communication. So don't be |
| confused by this icon.</p> |
| |
| |
| <h3><a name="msie" id="msie">Why do I get I/O errors when connecting via |
| HTTPS to an Apache+mod_ssl server with older versions of Microsoft Internet |
| Explorer (MSIE)?</a></h3> |
| <p>The first reason is that the SSL implementation in some MSIE versions has |
| some subtle bugs related to the HTTP keep-alive facility and the SSL close |
| notify alerts on socket connection close. Additionally the interaction |
| between SSL and HTTP/1.1 features are problematic in some MSIE versions. |
| You can work around these problems by forcing Apache not to use HTTP/1.1, |
| keep-alive connections or send the SSL close notify messages to MSIE clients. |
| This can be done by using the following directive in your SSL-aware |
| virtual host section:</p> |
| <pre class="prettyprint lang-config">SetEnvIf User-Agent "MSIE [2-5]" \ |
| nokeepalive ssl-unclean-shutdown \ |
| downgrade-1.0 force-response-1.0</pre> |
| |
| <p>Further, some MSIE versions have problems with particular ciphers. |
| Unfortunately, it is not possible to implement a MSIE-specific |
| workaround for this, because the ciphers are needed as early as the |
| SSL handshake phase. So a MSIE-specific |
| <code class="directive"><a href="../mod/mod_setenvif.html#setenvif">SetEnvIf</a></code> won't solve these |
| problems. Instead, you will have to make more drastic |
| adjustments to the global parameters. Before you decide to do |
| this, make sure your clients really have problems. If not, do not |
| make these changes - they will affect <em>all</em> your clients, MSIE |
| or otherwise.</p> |
| |
| |
| <h3><a name="srp" id="srp">How do I enable TLS-SRP?</a></h3> |
| <p>TLS-SRP (Secure Remote Password key exchange for TLS, specified in RFC 5054) |
| can supplement or replace certificates in authenticating an SSL connection. |
| To use TLS-SRP, set the |
| <code class="directive"><a href="../mod/mod_ssl.html#sslsrpverifierfile">SSLSRPVerifierFile</a></code> directive to |
| point to an OpenSSL SRP verifier file. To create the verifier file, use the |
| <code>openssl</code> tool:</p> |
| <div class="example"><p><code> |
| openssl srp -srpvfile passwd.srpv -add username |
| </code></p></div> |
| <p>After creating this file, specify it in the SSL server configuration:</p> |
| <div class="example"><p><code> |
| SSLSRPVerifierFile /path/to/passwd.srpv |
| </code></p></div> |
| <p>To force clients to use non-certificate TLS-SRP cipher suites, use the |
| following directive:</p> |
| <div class="example"><p><code> |
| SSLCipherSuite "!DSS:!aRSA:SRP" |
| </code></p></div> |
| |
| |
| <h3><a name="javadh" id="javadh">Why do I get handshake failures with Java-based clients when using a certificate with more than 1024 bits?</a></h3> |
| <p>Beginning with version 2.4.7, |
| <code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code> will use DH parameters which include primes |
| with lengths of more than 1024 bits. Java 7 and earlier limit their |
| support for DH prime sizes to a maximum of 1024 bits, however.</p> |
| |
| <p>If your Java-based client aborts with exceptions such as |
| <code>java.lang.RuntimeException: Could not generate DH keypair</code> and |
| <code>java.security.InvalidAlgorithmParameterException: Prime size must be |
| multiple of 64, and can only range from 512 to 1024 (inclusive)</code>, |
| and httpd logs <code>tlsv1 alert internal error (SSL alert number 80)</code> |
| (at <code class="directive"><a href="../mod/core.html#loglevel">LogLevel</a></code> <code>info</code> |
| or higher), you can either rearrange mod_ssl's cipher list with |
| <code class="directive"><a href="../mod/mod_ssl.html#sslciphersuite">SSLCipherSuite</a></code> |
| (possibly in conjunction with <code class="directive"><a href="../mod/mod_ssl.html#sslhonorcipherorder">SSLHonorCipherOrder</a></code>), |
| or you can use custom DH parameters with a 1024-bit prime, which |
| will always have precedence over any of the built-in DH parameters.</p> |
| |
| <p>To generate custom DH parameters, use the <code>openssl dhparam 1024</code> |
| command. Alternatively, you can use the following standard 1024-bit DH |
| parameters from <a href="http://www.ietf.org/rfc/rfc2409.txt">RFC 2409</a>, |
| section 6.2:</p> |
| <div class="example"><pre>-----BEGIN DH PARAMETERS----- |
| MIGHAoGBAP//////////yQ/aoiFowjTExmKLgNwc0SkCTgiKZ8x0Agu+pjsTmyJR |
| Sgh5jjQE3e+VGbPNOkMbMCsKbfJfFDdP4TVtbVHCReSFtXZiXn7G9ExC6aY37WsL |
| /1y29Aa37e44a/taiZ+lrp8kEXxLH+ZJKGZR7OZTgf//////////AgEC |
| -----END DH PARAMETERS-----</pre></div> |
| <p>Add the custom parameters including the "BEGIN DH PARAMETERS" and |
| "END DH PARAMETERS" lines to the end of the first certificate file |
| you have configured using the |
| <code class="directive"><a href="../mod/mod_ssl.html#sslcertificatefile">SSLCertificateFile</a></code> directive.</p> |
| |
| |
| </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> |
| <div class="section"> |
| <h2><a name="support" id="support">mod_ssl Support</a></h2> |
| <ul> |
| <li><a href="#resources">What information resources are available in |
| case of mod_ssl problems?</a></li> |
| <li><a href="#contact">What support contacts are available in case of |
| mod_ssl problems?</a></li> |
| <li><a href="#reportdetails">What information should I |
| provide when writing a bug report?</a></li> |
| <li><a href="#coredumphelp">I had a core dump, can you help me?</a></li> |
| <li><a href="#backtrace">How do I get a backtrace, to help find the reason |
| for my core dump?</a></li> |
| </ul> |
| |
| <h3><a name="resources" id="resources">What information resources are available in case of mod_ssl problems?</a></h3> |
| <p>The following information resources are available. |
| In case of problems you should search here first.</p> |
| |
| <dl> |
| <dt>Answers in the User Manual's F.A.Q. List (this)</dt> |
| <dd><a href="http://httpd.apache.org/docs/2.4/ssl/ssl_faq.html"> |
| http://httpd.apache.org/docs/2.4/ssl/ssl_faq.html</a><br /> |
| First check the F.A.Q. (this text). If your problem is a common |
| one, it may have been answered several times before, and been included |
| in this doc. |
| </dd> |
| </dl> |
| |
| |
| <h3><a name="contact" id="contact">What support contacts are available in case |
| of mod_ssl problems?</a></h3> |
| <p>The following lists all support possibilities for mod_ssl, in order of |
| preference. Please go through these possibilities |
| <em>in this order</em> - don't just pick the one you like the look of. </p> |
| <ol> |
| |
| <li><em>Send a Problem Report to the Apache httpd Users Support Mailing List</em><br /> |
| <a href="mailto:users@httpd.apache.org"> |
| users@httpd.apache.org</a><br /> |
| This is the second way of submitting your problem report. Again, you must |
| subscribe to the list first, but you can then easily discuss your problem |
| with the whole Apache httpd user community. |
| </li> |
| |
| <li><em>Write a Problem Report in the Bug Database</em><br /> |
| <a href="http://httpd.apache.org/bug_report.html"> |
| http://httpd.apache.org/bug_report.html</a><br /> |
| This is the last way of submitting your problem report. You should only |
| do this if you've already posted to the mailing lists, and had no success. |
| Please follow the instructions on the above page <em>carefully</em>. |
| </li> |
| </ol> |
| |
| |
| <h3><a name="reportdetails" id="reportdetails">What information should I |
| provide when writing a bug report?</a></h3> |
| <p>You should always provide at least the following information:</p> |
| |
| <dl> |
| <dt>Apache httpd and OpenSSL version information</dt> |
| <dd>The Apache version can be determined |
| by running <code>httpd -v</code>. The OpenSSL version can be |
| determined by running <code>openssl version</code>. Alternatively, if |
| you have Lynx installed, you can run the command <code>lynx -mime_header |
| http://localhost/ | grep Server</code> to gather this information in a |
| single step. |
| </dd> |
| |
| <dt>The details on how you built and installed Apache httpd and OpenSSL</dt> |
| <dd>For this you can provide a logfile of your terminal session which shows |
| the configuration and install steps. If this is not possible, you |
| should at least provide the <code class="program"><a href="../programs/configure.html">configure</a></code> command line you used. |
| </dd> |
| |
| <dt>In case of core dumps please include a Backtrace</dt> |
| <dd>If your Apache httpd dumps its core, please attach |
| a stack-frame ``backtrace'' (see <a href="#backtrace">below</a> |
| for information on how to get this). This information is required |
| in order to find a reason for your core dump. |
| </dd> |
| |
| <dt>A detailed description of your problem</dt> |
| <dd>Don't laugh, we really mean it! Many problem reports don't |
| include a description of what the actual problem is. Without this, |
| it's very difficult for anyone to help you. So, it's in your own |
| interest (you want the problem be solved, don't you?) to include as |
| much detail as possible, please. Of course, you should still include |
| all the essentials above too. |
| </dd> |
| </dl> |
| |
| |
| <h3><a name="coredumphelp" id="coredumphelp">I had a core dump, can you help me?</a></h3> |
| <p>In general no, at least not unless you provide more details about the code |
| location where Apache dumped core. What is usually always required in |
| order to help you is a backtrace (see next question). Without this |
| information it is mostly impossible to find the problem and help you in |
| fixing it.</p> |
| |
| |
| <h3><a name="backtrace" id="backtrace">How do I get a backtrace, to help find |
| the reason for my core dump?</a></h3> |
| <p>Following are the steps you will need to complete, to get a backtrace:</p> |
| <ol> |
| <li>Make sure you have debugging symbols available, at least |
| in Apache. On platforms where you use GCC/GDB, you will have to build |
| Apache+mod_ssl with ``<code>OPTIM="-g -ggdb3"</code>'' to get this. On |
| other platforms at least ``<code>OPTIM="-g"</code>'' is needed. |
| </li> |
| |
| <li>Start the server and try to reproduce the core-dump. For this you may |
| want to use a directive like ``<code>CoreDumpDirectory /tmp</code>'' to |
| make sure that the core-dump file can be written. This should result |
| in a <code>/tmp/core</code> or <code>/tmp/httpd.core</code> file. If you |
| don't get one of these, try running your server under a non-root UID. |
| Many modern kernels do not allow a process to dump core after it has |
| done a <code>setuid()</code> (unless it does an <code>exec()</code>) for |
| security reasons (there can be privileged information left over in |
| memory). If necessary, you can run <code>/path/to/httpd -X</code> |
| manually to force Apache to not fork. |
| </li> |
| |
| <li>Analyze the core-dump. For this, run <code>gdb /path/to/httpd |
| /tmp/httpd.core</code> or a similar command. In GDB, all you |
| have to do then is to enter <code>bt</code>, and voila, you get the |
| backtrace. For other debuggers consult your local debugger manual. |
| </li> |
| </ol> |
| |
| </div></div> |
| <div class="bottomlang"> |
| <p><span>Available Languages: </span><a href="../en/ssl/ssl_faq.html" title="English"> en </a> | |
| <a href="../fr/ssl/ssl_faq.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_faq.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 2022 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> |