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[apache] / docs / manual / mod / mod_authz_host.xml

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<modulesynopsis metafile="mod_authz_host.xml.meta">

<name>mod_authz_host</name> 
<description>Group authorizations based on host (name or IP
address)</description>
<status>Base</status>
<sourcefile>mod_authz_host.c</sourcefile>
<identifier>authz_host_module</identifier>
<compatibility>Available in Apache 2.3 and later</compatibility>

<summary>
    <p>The authorization providers implemented by <module>mod_authz_host</module> are
    registered using the <directive module="mod_authz_core">Require</directive>
    directive. The directive can be referenced within a 
    <directive module="core" type="section">Directory</directive>,
    <directive module="core" type="section">Files</directive>, 
    or <directive module="core" type="section">Location</directive> section
    as well as <code><a href="core.html#accessfilename">.htaccess</a>
    </code> files to control access to particular parts of the server.
    Access can be controlled based on the client hostname, IP address, or
    other characteristics of the client request, as captured in <a
    href="../env.html">environment variables</a>.</p>

    <p>In general, access restriction directives apply to all
    access methods (<code>GET</code>, <code>PUT</code>,
    <code>POST</code>, etc). This is the desired behavior in most
    cases. However, it is possible to restrict some methods, while
    leaving other methods unrestricted, by enclosing the directives
    in a <directive module="core" type="section">Limit</directive> section.</p>
</summary>

<seealso><a href="../howto/auth.html">Authentication, Authorization,
    and Access Control</a></seealso> 
<seealso><directive module="mod_authz_core">Require</directive></seealso>

<section id="requiredirectives"><title>The Require Directives</title>

    <p>Apache's <directive module="mod_authz_core">Require</directive> 
    directive is used during the authorization phase to ensure that a user is allowed or
    denied access to a resource.  mod_authz_host extends the 
    authorization types with <code>env</code>, <code>ip</code>, 
    <code>host</code> and <code>all</code>.  Other authorization types may also be 
    used but may require that additional authorization modules be loaded.</p>

    <p>These authorization providers affect which hosts can
    access an area of the server. Access can be controlled by
    hostname, IP Address, IP Address range, or by other
    characteristics of the client request captured in environment
    variables.</p>

<section id="reqenv"><title>Require env</title>

    <p>The <code>env</code> provider allows access to the server
    to be controlled based on the existence of an <a
    href="../env.html">environment variable</a>. When <code>Require 
    env <var>env-variable</var></code> is specified, then the request is
    allowed access if the environment variable <var>env-variable</var>
    exists. The server provides the ability to set environment
    variables in a flexible way based on characteristics of the client
    request using the directives provided by
    <module>mod_setenvif</module>. Therefore, this directive can be
    used to allow access based on such factors as the clients
    <code>User-Agent</code> (browser type), <code>Referer</code>, or
    other HTTP request header fields.</p>
    
    <example><title>Example:</title>
      SetEnvIf User-Agent ^KnockKnock/2\.0 let_me_in<br />
      &lt;Directory /docroot&gt;<br />
      <indent>
        Require env let_me_in<br />
      </indent>
      &lt;/Directory&gt;
    </example>
    
    <p>In this case, browsers with a user-agent string beginning
    with <code>KnockKnock/2.0</code> will be allowed access, and all
    others will be denied.</p>

</section>

<section id="reqip"><title>Require ip</title>

    <p>The <code>ip</code> provider allows access to the server
    to be controlled based on the IP address of the remote client. 
    When <code>Require ip <var>ip-address</var></code> is specified, 
    then the request is allowed access if the IP address matches.</p>

    <p>A full IP address:</p>
    
    <example>
      Require ip 10.1.2.3<br />
      Require ip 192.168.1.104 192.168.1.205
    </example>

    <p>An IP address of a host allowed access</p>
    
    <p>A partial IP address:</p>
    
    <example>
      Require ip 10.1<br />
      Require ip 10 172.20 192.168.2
    </example>
    <p>The first 1 to 3 bytes of an IP address, for subnet
    restriction.</p>
    
    <p>A network/netmask pair:</p>
    
    <example>
      Require ip 10.1.0.0/255.255.0.0
    </example>
    <p>A network a.b.c.d, and a netmask w.x.y.z. For more
    fine-grained subnet restriction.</p>
    
    <p>A network/nnn CIDR specification:</p>
    
    <example>
      Require ip 10.1.0.0/16
    </example>
    <p>Similar to the previous case, except the netmask consists of
    nnn high-order 1 bits.</p>
    
    <p>Note that the last three examples above match exactly the
    same set of hosts.</p>
    
    <p>IPv6 addresses and IPv6 subnets can be specified as shown
    below:</p>
    
    <example>
     Require ip 2001:db8::a00:20ff:fea7:ccea<br />
     Require ip 2001:db8::a00:20ff:fea7:ccea/10
    </example>


</section>

<section id="reqhost"><title>Require host</title>

    <p>The <code>host</code> provider allows access to the server
    to be controlled based on the host name of the remote client. 
    When <code>Require host <var>host-name</var></code> is specified, 
    then the request is allowed access if the host name matches.</p>

    <p>A (partial) domain-name</p>
    
    <example>
    Require host apache.org<br />
    Require host .net example.edu
    </example>
    
    <p>Hosts whose names match, or end in, this string are allowed
    access. Only complete components are matched, so the above
    example will match <code>foo.apache.org</code> but it will not
    match <code>fooapache.org</code>. This configuration will cause
    Apache to perform a double reverse DNS lookup on the client IP
    address, regardless of the setting of the <directive
    module="core">HostnameLookups</directive> directive.  It will do
    a reverse DNS lookup on the IP address to find the associated
    hostname, and then do a forward lookup on the hostname to assure
    that it matches the original IP address.  Only if the forward
    and reverse DNS are consistent and the hostname matches will
    access be allowed.</p>

</section>

<section id="reqall"><title>Require all</title>

    <p>The <code>all</code> provider mimics the functionality the
    was previously provided by the 'Allow from all' and 'Deny from all'
    directives.  This provider can take one of two arguments which are 
    'granted' or 'denied'.  The following examples will grant or deny 
    access to all requests.</p>

    <example>
    Require all granted<br />
    </example>

    <example>
    Require all denied<br />
    </example>

</section>


</section>


</modulesynopsis>