d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder<?xml version='1.0' encoding='UTF-8' ?>

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder<!DOCTYPE manualpage SYSTEM "/style/manualpage.dtd">

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder<?xml-stylesheet type="text/xsl" href="/style/manual.en.xsl"?>

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder

02a2037f53b925617df45eb62ca743d777672265Klaus Luettich

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder<manualpage metafile="auth.xml.meta">

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder<parentdocument href="./">How-To / Tutorials</parentdocument>

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder<title>Authentication, Authorization and Access Control</title>

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder<summary>

7b27b67b1c8516d7ccf1610a17fec93662d6a93fChristian Maeder <p>Authentication is any process by which you verify that

b7b2eb9d574f5ed3ac3e9e1d7a5f168ed78a0604Till Mossakowski someone is who they claim they are. Authorization is any

0678d323bee844db79af13113ae252546629a594Christian Maeder process by which someone is allowed to be where they want to

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder go, or to have information that they want to have.</p>

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder</summary>

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder<section id="related"><title>Related Modules and Directives</title>

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder

7b27b67b1c8516d7ccf1610a17fec93662d6a93fChristian Maeder<p>There are three types of modules involved in the authentication and

7b27b67b1c8516d7ccf1610a17fec93662d6a93fChristian Maederauthorization process. You will usually need to choose at least one

7b27b67b1c8516d7ccf1610a17fec93662d6a93fChristian Maedermodule from each group.</p>

7b27b67b1c8516d7ccf1610a17fec93662d6a93fChristian Maeder

7b27b67b1c8516d7ccf1610a17fec93662d6a93fChristian Maeder<ul>

7b27b67b1c8516d7ccf1610a17fec93662d6a93fChristian Maeder <li>Authentication type (see the

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <directive module="mod_authn_core">AuthType</directive> directive)

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <ul>

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <li><module>mod_auth_basic</module></li>

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <li><module>mod_auth_digest</module></li>

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder </ul>

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder </li>

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <li>Authentication provider (see the

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <directive module="mod_auth_basic">AuthBasicProvider</directive> and

7b27b67b1c8516d7ccf1610a17fec93662d6a93fChristian Maeder <directive module="mod_auth_digest">AuthDigestProvider</directive> directives)

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder <ul>

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder <li><module>mod_authn_anon</module></li>

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder <li><module>mod_authn_dbd</module></li>

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder <li><module>mod_authn_dbm</module></li>

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder <li><module>mod_authn_file</module></li>

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder <li><module>mod_authnz_ldap</module></li>

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder </ul>

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder </li>

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <li>Authorization (see the

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <directive module="mod_authz_core">Require</directive> directive)

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <ul>

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <li><module>mod_authnz_ldap</module></li>

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <li><module>mod_authz_dbd</module></li>

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <li><module>mod_authz_dbm</module></li>

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <li><module>mod_authz_groupfile</module></li>

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <li><module>mod_authz_host</module></li>

bec7e681b0ba4d085638ec7af0cf7ae5068840caChristian Maeder <li><module>mod_authz_owner</module></li>

a255351561838b3743d03c1629d335cfb8b83804Christian Maeder <li><module>mod_authz_user</module></li>

a255351561838b3743d03c1629d335cfb8b83804Christian Maeder </ul>

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder </li>

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder</ul>

a255351561838b3743d03c1629d335cfb8b83804Christian Maeder

a255351561838b3743d03c1629d335cfb8b83804Christian Maeder <p>In addition to these modules, there are also

a255351561838b3743d03c1629d335cfb8b83804Christian Maeder <module>mod_authn_core</module> and

a255351561838b3743d03c1629d335cfb8b83804Christian Maeder <module>mod_authz_core</module>. These module implement core

f7d2e793728bbb7fd185e027eb9dfd7b9dd11c21Christian Maeder directives that are core to all auth modules.</p>

a255351561838b3743d03c1629d335cfb8b83804Christian Maeder

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder <p>The module <module>mod_authnz_ldap</module> is both an

f7d2e793728bbb7fd185e027eb9dfd7b9dd11c21Christian Maeder authentication and authorization provider. The module

02a2037f53b925617df45eb62ca743d777672265Klaus Luettich <module>mod_authz_host</module> provides authorization

02a2037f53b925617df45eb62ca743d777672265Klaus Luettich and access control based on hostname, IP address or characteristics

02a2037f53b925617df45eb62ca743d777672265Klaus Luettich of the request, but is not part of the authentication provider

02a2037f53b925617df45eb62ca743d777672265Klaus Luettich system. For backwards compatibility with the mod_access, there is

02a2037f53b925617df45eb62ca743d777672265Klaus Luettich a new module <module>mod_access_compat</module>.</p>

f7d2e793728bbb7fd185e027eb9dfd7b9dd11c21Christian Maeder

5908cc06d7a3f4dd46d2d7c7fe0fad43b6cd921fChristian Maeder <p>You probably also want to take a look at the <a

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder href="access.html">Access Control</a> howto, which discusses the

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder various ways to control access to your server.</p>

5908cc06d7a3f4dd46d2d7c7fe0fad43b6cd921fChristian Maeder

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder</section>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder

02a2037f53b925617df45eb62ca743d777672265Klaus Luettich<section id="introduction"><title>Introduction</title>

a255351561838b3743d03c1629d335cfb8b83804Christian Maeder <p>If you have information on your web site that is sensitive

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder or intended for only a small group of people, the techniques in

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder this article will help you make sure that the people that see

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder those pages are the people that you wanted to see them.</p>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder <p>This article covers the "standard" way of protecting parts

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder of your web site that most of you are going to use.</p>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder <note><title>Note:</title>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder <p>If your data really needs to be secure, consider using

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder <module>mod_ssl</module> in addition to any authentication.</p>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder </note>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder</section>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder<section id="theprerequisites"><title>The Prerequisites</title>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder <p>The directives discussed in this article will need to go

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder either in your main server configuration file (typically in a

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder <directive module="core" type="section">Directory</directive> section), or

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder in per-directory configuration files (<code>.htaccess</code> files).</p>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder <p>If you plan to use <code>.htaccess</code> files, you will

f7d2e793728bbb7fd185e027eb9dfd7b9dd11c21Christian Maeder need to have a server configuration that permits putting

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder authentication directives in these files. This is done with the

a255351561838b3743d03c1629d335cfb8b83804Christian Maeder <directive module="core">AllowOverride</directive> directive, which

f7d2e793728bbb7fd185e027eb9dfd7b9dd11c21Christian Maeder specifies which directives, if any, may be put in per-directory

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder configuration files.</p>

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder <p>Since we're talking here about authentication, you will need

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder an <directive module="core">AllowOverride</directive> directive like the

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder following:</p>

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder <example>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder AllowOverride AuthConfig

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder </example>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder <p>Or, if you are just going to put the directives directly in

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder your main server configuration file, you will of course need to

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder have write permission to that file.</p>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder <p>And you'll need to know a little bit about the directory

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder structure of your server, in order to know where some files are

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder kept. This should not be terribly difficult, and I'll try to

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder make this clear when we come to that point.</p>

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder <p>You will also need to make sure that the modules

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder <module>mod_authn_core</module> and <module>mod_authz_core</module>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder have either been built into the httpd binary or loaded by the

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder httpd.conf configuration file. Both of these modules provide core

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder directives and functionality that are critical to the configuration

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder and use of authentication and authorization in the web server.</p>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder</section>

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder<section id="gettingitworking"><title>Getting it working</title>

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder <p>Here's the basics of password protecting a directory on your

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder server.</p>

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder <p>First, you need to create a password file. Exactly how you do

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder this will vary depending on what authentication provider you have

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder chosen. More on that later. To start with, we'll use a text password

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder file.</p>

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder <p>This file should be

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder placed somewhere not accessible from the web. This is so that

91f4f0335ac32768d819e202263f713aef5d7fe6Christian Maeder folks cannot download the password file. For example, if your

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder documents are served out of <code>/usr/local/apache/htdocs</code> you

36fcac4cf0f6a1f8a0fee696ac7f4b91d769843cChristian Maeder might want to put the password file(s) in

0678d323bee844db79af13113ae252546629a594Christian Maeder <code>/usr/local/apache/passwd</code>.</p>

0678d323bee844db79af13113ae252546629a594Christian Maeder

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder <p>To create the file, use the <program>htpasswd</program> utility that

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder came with Apache. This will be located in the <code>bin</code> directory

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder of wherever you installed Apache. If you have installed Apache from

0678d323bee844db79af13113ae252546629a594Christian Maeder a third-party package, it may be in your execution path.</p>

0678d323bee844db79af13113ae252546629a594Christian Maeder

0678d323bee844db79af13113ae252546629a594Christian Maeder <p>To create the file, type:</p>

0678d323bee844db79af13113ae252546629a594Christian Maeder

0e2ae85e2453466d03c1fc5884a3d693235bb9d9Christian Maeder <example>

36fcac4cf0f6a1f8a0fee696ac7f4b91d769843cChristian Maeder htpasswd -c /usr/local/apache/passwd/passwords rbowen

0678d323bee844db79af13113ae252546629a594Christian Maeder </example>

0678d323bee844db79af13113ae252546629a594Christian Maeder

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder <p><program>htpasswd</program> will ask you for the password, and

b7b2eb9d574f5ed3ac3e9e1d7a5f168ed78a0604Till Mossakowski then ask you to type it again to confirm it:</p>

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder

0678d323bee844db79af13113ae252546629a594Christian Maeder <example>

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder # htpasswd -c /usr/local/apache/passwd/passwords rbowen<br />

0678d323bee844db79af13113ae252546629a594Christian Maeder New password: mypassword<br />

0678d323bee844db79af13113ae252546629a594Christian Maeder Re-type new password: mypassword<br />

0678d323bee844db79af13113ae252546629a594Christian Maeder Adding password for user rbowen

0678d323bee844db79af13113ae252546629a594Christian Maeder </example>

0678d323bee844db79af13113ae252546629a594Christian Maeder

0678d323bee844db79af13113ae252546629a594Christian Maeder <p>If <program>htpasswd</program> is not in your path, of course

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder you'll have to type the full path to the file to get it to run.

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder With a default installation, it's located at

b7b2eb9d574f5ed3ac3e9e1d7a5f168ed78a0604Till Mossakowski <code>/usr/local/apache2/bin/htpasswd</code></p>

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder

0678d323bee844db79af13113ae252546629a594Christian Maeder <p>Next, you'll need to configure the server to request a

0678d323bee844db79af13113ae252546629a594Christian Maeder password and tell the server which users are allowed access.

0678d323bee844db79af13113ae252546629a594Christian Maeder You can do this either by editing the <code>httpd.conf</code>

0678d323bee844db79af13113ae252546629a594Christian Maeder file or using an <code>.htaccess</code> file. For example, if

0678d323bee844db79af13113ae252546629a594Christian Maeder you wish to protect the directory

d183a4514d8a5b6a5d48d15a8dff52d0c96691eaChristian Maeder <code>/usr/local/apache/htdocs/secret</code>, you can use the

0678d323bee844db79af13113ae252546629a594Christian Maeder following directives, either placed in the file

0678d323bee844db79af13113ae252546629a594Christian Maeder <code>/usr/local/apache/htdocs/secret/.htaccess</code>, or

0678d323bee844db79af13113ae252546629a594Christian Maeder placed in <code>httpd.conf</code> inside a &lt;Directory

0678d323bee844db79af13113ae252546629a594Christian Maeder /usr/local/apache/htdocs/secret&gt; section.</p>

0678d323bee844db79af13113ae252546629a594Christian Maeder

0678d323bee844db79af13113ae252546629a594Christian Maeder <example>

0678d323bee844db79af13113ae252546629a594Christian Maeder AuthType Basic<br />

0678d323bee844db79af13113ae252546629a594Christian Maeder AuthName "Restricted Files"<br />

0678d323bee844db79af13113ae252546629a594Christian Maeder # (Following line optional)<br />

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder AuthBasicProvider file<br />

fe216849cef7b87c6800aad21178d1e686575d8fChristian Maeder AuthUserFile /usr/local/apache/passwd/passwords<br />

0678d323bee844db79af13113ae252546629a594Christian Maeder Require user rbowen

0678d323bee844db79af13113ae252546629a594Christian Maeder </example>

0678d323bee844db79af13113ae252546629a594Christian Maeder

0678d323bee844db79af13113ae252546629a594Christian Maeder <p>Let's examine each of those directives individually. The <directive

0678d323bee844db79af13113ae252546629a594Christian Maeder module="mod_authn_core">AuthType</directive> directive selects

0678d323bee844db79af13113ae252546629a594Christian Maeder that method that is used to authenticate the user. The most

0678d323bee844db79af13113ae252546629a594Christian Maeder common method is <code>Basic</code>, and this is the method

0678d323bee844db79af13113ae252546629a594Christian Maeder implemented by <module>mod_auth_basic</module>. It is important to be aware,

0678d323bee844db79af13113ae252546629a594Christian Maeder however, that Basic authentication sends the password from the client to

0678d323bee844db79af13113ae252546629a594Christian Maeder the server unencrypted. This method should therefore not be used for

0678d323bee844db79af13113ae252546629a594Christian Maeder highly sensitive data, unless accompanied by <module>mod_ssl</module>.

0678d323bee844db79af13113ae252546629a594Christian Maeder Apache supports one other authentication method:

0678d323bee844db79af13113ae252546629a594Christian Maeder <code>AuthType Digest</code>. This method is implemented by <module

0678d323bee844db79af13113ae252546629a594Christian Maeder >mod_auth_digest</module> and is much more secure. Most recent

0678d323bee844db79af13113ae252546629a594Christian Maeder browsers support Digest authentication.</p>

0678d323bee844db79af13113ae252546629a594Christian Maeder

0678d323bee844db79af13113ae252546629a594Christian Maeder <p>The <directive module="mod_authn_core">AuthName</directive> directive sets

0678d323bee844db79af13113ae252546629a594Christian Maeder the <dfn>Realm</dfn> to be used in the authentication. The realm serves

0678d323bee844db79af13113ae252546629a594Christian Maeder two major functions. First, the client often presents this information to

0678d323bee844db79af13113ae252546629a594Christian Maeder the user as part of the password dialog box. Second, it is used by the

0678d323bee844db79af13113ae252546629a594Christian Maeder client to determine what password to send for a given authenticated

0678d323bee844db79af13113ae252546629a594Christian Maeder area.</p>

0678d323bee844db79af13113ae252546629a594Christian Maeder

0678d323bee844db79af13113ae252546629a594Christian Maeder <p>So, for example, once a client has authenticated in the

f7d2e793728bbb7fd185e027eb9dfd7b9dd11c21Christian Maeder <code>"Restricted Files"</code> area, it will automatically

0678d323bee844db79af13113ae252546629a594Christian Maeder retry the same password for any area on the same server that is

0678d323bee844db79af13113ae252546629a594Christian Maeder marked with the <code>"Restricted Files"</code> Realm.

0678d323bee844db79af13113ae252546629a594Christian Maeder Therefore, you can prevent a user from being prompted more than

0678d323bee844db79af13113ae252546629a594Christian Maeder once for a password by letting multiple restricted areas share

0678d323bee844db79af13113ae252546629a594Christian Maeder the same realm. Of course, for security reasons, the client

0678d323bee844db79af13113ae252546629a594Christian Maeder will always need to ask again for the password whenever the

0678d323bee844db79af13113ae252546629a594Christian Maeder hostname of the server changes.</p>

0678d323bee844db79af13113ae252546629a594Christian Maeder

0678d323bee844db79af13113ae252546629a594Christian Maeder <p>The <directive

0678d323bee844db79af13113ae252546629a594Christian Maeder module="mod_auth_basic">AuthBasicProvider</directive> is,

0678d323bee844db79af13113ae252546629a594Christian Maeder in this case, optional, since <code>file</code> is the default value

0678d323bee844db79af13113ae252546629a594Christian Maeder for this directive. You'll need to use this directive if you are

0678d323bee844db79af13113ae252546629a594Christian Maeder choosing a different source for authentication, such as

0678d323bee844db79af13113ae252546629a594Christian Maeder <module>mod_authn_dbm</module> or <module>mod_authn_dbd</module>.</p>

0678d323bee844db79af13113ae252546629a594Christian Maeder

0678d323bee844db79af13113ae252546629a594Christian Maeder <p>The <directive module="mod_authn_file">AuthUserFile</directive>

0678d323bee844db79af13113ae252546629a594Christian Maeder directive sets the path to the password file that we just

0678d323bee844db79af13113ae252546629a594Christian Maeder created with <program>htpasswd</program>. If you have a large number

0678d323bee844db79af13113ae252546629a594Christian Maeder of users, it can be quite slow to search through a plain text

0678d323bee844db79af13113ae252546629a594Christian Maeder file to authenticate the user on each request. Apache also has

0678d323bee844db79af13113ae252546629a594Christian Maeder the ability to store user information in fast database files.

3ef9708a35cddb7ba66458ad4a065de549ce7db6Till Mossakowski The <module>mod_authn_dbm</module> module provides the <directive

0678d323bee844db79af13113ae252546629a594Christian Maeder module="mod_authn_dbm">AuthDBMUserFile</directive> directive. These

0678d323bee844db79af13113ae252546629a594Christian Maeder files can be created and manipulated with the <program>

0678d323bee844db79af13113ae252546629a594Christian Maeder dbmmanage</program> program. Many

0678d323bee844db79af13113ae252546629a594Christian Maeder other types of authentication options are available from third

0678d323bee844db79af13113ae252546629a594Christian Maeder party modules in the <a

0678d323bee844db79af13113ae252546629a594Christian Maeder href="http://modules.apache.org/">Apache Modules

0678d323bee844db79af13113ae252546629a594Christian Maeder Database</a>.</p>

0678d323bee844db79af13113ae252546629a594Christian Maeder

0678d323bee844db79af13113ae252546629a594Christian Maeder <p>Finally, the <directive module="mod_authz_core">Require</directive>

f7d2e793728bbb7fd185e027eb9dfd7b9dd11c21Christian Maeder directive provides the authorization part of the process by

0678d323bee844db79af13113ae252546629a594Christian Maeder setting the user that is allowed to access this region of the

0678d323bee844db79af13113ae252546629a594Christian Maeder server. In the next section, we discuss various ways to use the

0678d323bee844db79af13113ae252546629a594Christian Maeder <directive module="mod_authz_core">Require</directive> directive.</p>

0678d323bee844db79af13113ae252546629a594Christian Maeder</section>

<section id="lettingmorethanonepersonin"><title>Letting more than one

person in</title>

<p>The directives above only let one person (specifically

someone with a username of <code>rbowen</code>) into the

directory. In most cases, you'll want to let more than one

person in. This is where the <directive module="mod_authz_groupfile"

>AuthGroupFile</directive> comes in.</p>

<p>If you want to let more than one person in, you'll need to

create a group file that associates group names with a list of

users in that group. The format of this file is pretty simple,

and you can create it with your favorite editor. The contents

of the file will look like this:</p>

<example>

GroupName: rbowen dpitts sungo rshersey

</example>

<p>That's just a list of the members of the group in a long

line separated by spaces.</p>

<p>To add a user to your already existing password file,

type:</p>

<example>

htpasswd /usr/local/apache/passwd/passwords dpitts

</example>

<p>You'll get the same response as before, but it will be

appended to the existing file, rather than creating a new file.

(It's the <code>-c</code> that makes it create a new password

file).</p>

<p>Now, you need to modify your <code>.htaccess</code> file to

look like the following:</p>

<example>

AuthType Basic<br />

AuthName "By Invitation Only"<br />

# Optional line:<br />

AuthBasicProvider file<br />

AuthUserFile /usr/local/apache/passwd/passwords<br />

AuthGroupFile /usr/local/apache/passwd/groups<br />

Require group GroupName

</example>

<p>Now, anyone that is listed in the group <code>GroupName</code>,

and has an entry in the <code>password</code> file, will be let in, if

they type the correct password.</p>

<p>There's another way to let multiple users in that is less

specific. Rather than creating a group file, you can just use

the following directive:</p>

<example>

Require valid-user

</example>

<p>Using that rather than the <code>Require user rbowen</code>

line will allow anyone in that is listed in the password file,

and who correctly enters their password. You can even emulate

the group behavior here, by just keeping a separate password

file for each group. The advantage of this approach is that

Apache only has to check one file, rather than two. The

disadvantage is that you have to maintain a bunch of password

files, and remember to reference the right one in the

<directive module="mod_authn_file">AuthUserFile</directive> directive.</p>

</section>

<section id="possibleproblems"><title>Possible problems</title>

<p>Because of the way that Basic authentication is specified,

your username and password must be verified every time you

request a document from the server. This is even if you're

reloading the same page, and for every image on the page (if

they come from a protected directory). As you can imagine, this

slows things down a little. The amount that it slows things

down is proportional to the size of the password file, because

it has to open up that file, and go down the list of users

until it gets to your name. And it has to do this every time a

page is loaded.</p>

<p>A consequence of this is that there's a practical limit to

how many users you can put in one password file. This limit

will vary depending on the performance of your particular

server machine, but you can expect to see slowdowns once you

get above a few hundred entries, and may wish to consider a

different authentication method at that time.</p>

</section>

<section id="dbmdbd"><title>Alternate password storage</title>

<p>Because storing passwords in plain text files has the above

problems, you may wish to store your passwords somewhere else, such

as in a database.</p>

<p><module>mod_authn_dbm</module> and <module>mod_authn_dbd</module> are two

modules which make this possible. Rather than selecting <code><directive

module="mod_auth_basic">AuthBasicProvider</directive> file</code>, instead

you can choose <code>dbm</code> or <code>dbd</code> as your storage

format.</p>

<p>To select a dbd file rather than a text file, for example:</p>

<example>

&lt;Directory /www/docs/private&gt;<br />

AuthName "Private"<br />

AuthType Basic<br />

AuthBasicProvider dbm<br />

AuthDBMUserFile /www/passwords/passwd.dbm<br />

Require valid-user<br />

&lt;/Directory&gt;

</example>

<p>Other options are available. Consult the

<module>mod_authn_dbm</module> documentation for more details.</p>

</section>

<section id="multprovider"><title>Using multiple providers</title>

<p>With the introduction of the new provider based authentication and

authorization architecture, you are no longer locked into a single

authentication or authorization method. In fact any number of the

providers can be mixed and matched to provide you with exactly the

scheme that meets your needs. In the following example, both the

file and LDAP based authentication providers are being used.</p>

<example>

&lt;Directory /www/docs/private&gt;<br />

AuthName "Private"<br />

AuthType Basic<br />

AuthBasicProvider file ldap<br />

AuthUserFile /usr/local/apache/passwd/passwords<br />

AuthLDAPURL ldap://ldaphost/o=yourorg<br />

Require valid-user<br />

&lt;/Directory&gt;

</example>

<p>In this example the file provider will attempt to authenticate

the user first. If it is unable to authenticate the user, the LDAP

provider will be called. This allows the scope of authentication

to be broadened if your organization implements more than

one type of authentication store. Other authentication and authorization

scenarios may include mixing one type of authentication with a

different type of authorization. For example, authenticating against

a password file yet authorizing against an LDAP directory.</p>

<p>Just as multiple authentication providers can be implemented, multiple

authorization methods can also be used. In this example both file group

authorization as well as LDAP group authorization is being used.</p>

<example>

&lt;Directory /www/docs/private&gt;<br />

AuthName "Private"<br />

AuthType Basic<br />

AuthBasicProvider file<br />

AuthUserFile /usr/local/apache/passwd/passwords<br />

AuthLDAPURL ldap://ldaphost/o=yourorg

AuthGroupFile /usr/local/apache/passwd/groups<br />

Require group GroupName<br />

Require ldap-group cn=mygroup,o=yourorg<br />

&lt;/Directory&gt;

</example>

<p>To take authorization a little further, authorization container

directives such as

<directive module="mod_authz_core" type="section">RequireAll</directive>

and

<directive module="mod_authz_core" type="section">RequireAny</directive>

allow logic to be applied so that the order in which authorization

is handled can be completely controled through the configuration.

See <a href="/mod/mod_authz_core.html#logic">Authorization

Containers</a> for an example of they may be applied.</p>

</section>

<section id="beyond"><title>Beyond just authorization</title>

<p>The way that authorization can be apply is now much more flexible

than just a single check against a single data store. Ordering, logic

and choosing how authorization will be done is now possible.</p>

<section id="authandororder"><title>Applying logic and ordering</title>

<p>Controling how and in what order authorization will be applied

has been a bit of a mystery in the past. In Apache 2.2 a provider-based

authentication mechanism was introduced to decouple the actual

authentication process from authorization and supporting functionality.

One of the side benefits was that authentication providers could be

configured and called in a specific order which didn't depend on the

load order of the auth module itself. This same provider based mechanism

has been brought forward into authorization as well. What this means is

that the <directive module="mod_authz_core">Require</directive> directive

not only specifies which authorization methods should be used, it also

specifies the order in which they are called. Multiple authorization

methods are called in the same order in which the

<directive module="mod_authz_core">Require</directive> directives

appear in the configuration.</p>

<p>With the introduction of authorization container directives

such as

<directive module="mod_authz_core" type="section">RequireAll</directive>

and

<directive module="mod_authz_core" type="section">RequireAny</directive>,

the configuration also has control over when the

authorization methods are called and what criteria determines when

access is granted. See

<a href="/mod/mod_authz_core.html#logic">Authorization Containers</a>

for an example of how they may be used to express complex

authorization logic.</p>

<p>By default all

<directive module="mod_authz_core">Require</directive>

directives are handled as though contained within a

<directive module="mod_authz_core" type="section">RequireAny</directive>

container directive. In other words, if

any of the specified authorization methods succeed, then authorization

is granted.</p>

</section>

<section id="reqaccessctrl"><title>Using authorization providers for access control</title>

<p>Authentication by username and password is only part of the

story. Frequently you want to let people in based on something

other than who they are. Something such as where they are

coming from.</p>

<p>The authorization providers <directive module="mod_authz_host">

all</directive>, <directive module="mod_authz_host">

env</directive>, <directive module="mod_authz_host">

host</directive> and <directive module="mod_authz_host">

ip</directive> let you allow or deny access based other host based

criteria such as host name or ip address of the machine requesting

a document.</p>

<p>The usage of these providers is specified through the

<directive module="mod_authz_core">Require</directive> directive.

This directive registers the authorization providers

that will be called during the authorization stage of the request

processing. For example:</p>

<example>

Require ip <var>address</var>

</example>

<p>where <var>address</var> is an IP address (or a partial IP

address) or:</p>

<example>

Require host <var>domain_name</var>

</example>

<p>where <var>domain_name</var> is a fully qualified domain name

(or a partial domain name); you may provide multiple addresses or

domain names, if desired.</p>

<p>For example, if you have someone spamming your message

board, and you want to keep them out, you could do the

following:</p>

<example>

&lt;RequireAll&gt;

<indent>

Require all granted<br/>

Require not ip 10.252.46.165

</indent>

&lt;/RequireAll&gt;

</example>

<p>Visitors coming from that address will not be able to see

the content covered by this directive. If, instead, you have a

machine name, rather than an IP address, you can use that.</p>

<example>

&lt;RequireAll&gt;

<indent>

Require all granted<br/>

Require not host <var>host.example.com</var>

</indent>

&lt;/RequireAll&gt;

</example>

<p>And, if you'd like to block access from an entire domain,

you can specify just part of an address or domain name:</p>

<example>

&lt;RequireAll&gt;

<indent>

Require all granted<br/>

&lt;RequireNone&gt;

<indent>

Require ip 192.168.205<br />

Require host phishers.example.com moreidiots.example<br />

Require host ke

</indent>

&lt;/RequireNone&gt;

</indent>

&lt;/RequireAll&gt;

</example>

<p>The above example uses the <directive module="mod_authz_core"

type="section">RequireNone</directive> directive

to make sure that none of the

<directive module="mod_authz_core">Require</directive> directives

contained within it

match their parameters before granting access.</p>

</section>

<section id="filesystem"><title>Access Control backwards compatibility</title>

<p>One of the side effects of adopting a provider based mechanism for

authentication is that the need for the previous access control directives

<directive module="mod_access_compat">Order</directive>,

<directive module="mod_access_compat">Allow</directive>,

<directive module="mod_access_compat">Deny</directive> and

<directive module="mod_access_compat">Satisfy</directive> are no longer needed.

However to provide backwards compatibility for older configurations, these

directives have been moved to the <module>mod_access_compat</module> module.</p>

</section>

</section>

<section id="moreinformation"><title>More information</title>

<p>You should also read the documentation for

<module>mod_auth_basic</module> and <module>mod_authz_host</module> which

contain some more information about how this all works.

The directive <directive module="mod_authn_core">&lt;AuthnProviderAlias&gt;</directive>

can also help in simplifying certain authentication configurations.</p>

<p>The various ciphers supported by Apache for authentication data are

explained in <a href="/misc/password_encryptions.html">Password

Encryptions</a>.</p>

<p>And you may want to look at the <a href="access.html">Access

Control</a> howto, which discusses a number of related topics.</p>

</section>

</manualpage>