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

<name>mod_access_compat</name>

<description>Group authorizations based on host (name or IP

address)</description>

<status>Extension</status>

<sourcefile>mod_access_compat.c</sourcefile>

<identifier>access_compat_module</identifier>

<compatibility>Available in Apache HTTP Server 2.3 as a compatibility module with

previous versions of Apache httpd 2.x. The directives provided by this module

have been deprecated by the new authz refactoring. Please see

<module>mod_authz_host</module></compatibility>

<summary>

<p>The directives provided by <module>mod_access_compat</module> are

used in <directive module="core" type="section">Directory</directive>,

<directive module="core" type="section">Files</directive>, and

<directive module="core" type="section">Location</directive> sections

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>. The <directive

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

module="mod_access_compat">Deny</directive> directives are used to

specify which clients are or are not allowed access to the server,

while the <directive module="mod_access_compat">Order</directive>

directive sets the default access state, and configures how the

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

module="mod_access_compat">Deny</directive> directives interact with each

other.</p>

<p>Both host-based access restrictions and password-based

authentication may be implemented simultaneously. In that case,

the <directive module="mod_access_compat">Satisfy</directive> directive is used

to determine how the two sets of restrictions interact.</p>

<note type="warning"><title>Note</title>

<p>The directives provided by <module>mod_access_compat</module> have

been deprecated by the new authz refactoring. Please see

<module>mod_authz_host</module>.</p>

</note>

<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>

<note> <title>Merging of configuration sections</title>

<p>When any directive provided by this module is used in a new

configuration section, no directives provided by this module are

inherited from previous configuration sections.</p>

</note>

</summary>

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

<seealso><module>mod_authz_host</module></seealso>

<seealso><module>mod_authz_core</module></seealso>

<directivesynopsis>

<name>Allow</name>

<description>Controls which hosts can access an area of the

server</description>

<syntax> Allow from all|<var>host</var>|env=[!]<var>env-variable</var>

[<var>host</var>|env=[!]<var>env-variable</var>] ...</syntax>

<contextlist><context>directory</context><context>.htaccess</context>

</contextlist>

<override>Limit</override>

<usage>

<p>The <directive>Allow</directive> directive affects 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>

<p>The first argument to this directive is always

<code>from</code>. The subsequent arguments can take three

different forms. If <code>Allow from all</code> is specified, then

all hosts are allowed access, subject to the configuration of the

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

module="mod_access_compat">Order</directive> directives as discussed

below. To allow only particular hosts or groups of hosts to access

the server, the <em>host</em> can be specified in any of the

following formats:</p>

<dl>

<dt>A (partial) domain-name</dt>

<dd>

<highlight language="config">

Allow from example.org

Allow from .net example.edu

</highlight>

<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.example.org</code> but it will not

match <code>fooexample.org</code>. This configuration will cause

Apache httpd to perform a double 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></dd>

<dt>A full IP address</dt>

<dd>

<highlight language="config">

Allow from 10.1.2.3

Allow from 192.168.1.104 192.168.1.205

</highlight>

<p>An IP address of a host allowed access</p></dd>

<dt>A partial IP address</dt>

<dd>

<highlight language="config">

Allow from 10.1

Allow from 10 172.20 192.168.2

</highlight>

<p>The first 1 to 3 bytes of an IP address, for subnet

restriction.</p></dd>

<dt>A network/netmask pair</dt>

<dd>

<highlight language="config">

Allow from 10.1.0.0/255.255.0.0

</highlight>

<p>A network a.b.c.d, and a netmask w.x.y.z. For more

fine-grained subnet restriction.</p></dd>

<dt>A network/nnn CIDR specification</dt>

<dd>

<highlight language="config">

Allow from 10.1.0.0/16

</highlight>

<p>Similar to the previous case, except the netmask consists of

nnn high-order 1 bits.</p></dd>

</dl>

<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>

<highlight language="config">

Allow from 2001:db8::a00:20ff:fea7:ccea

Allow from 2001:db8::a00:20ff:fea7:ccea/10

</highlight>

<p>The third format of the arguments to the

<directive>Allow</directive> directive allows access to the server

to be controlled based on the existence of an <a

href="/env.html">environment variable</a>. When <code>Allow from

env=<var>env-variable</var></code> is specified, then the request is

allowed access if the environment variable <var>env-variable</var>

exists. When <code>Allow from env=!<var>env-variable</var></code> is

specified, then the request is allowed access if the environment

variable <var>env-variable</var> doesn't exist.

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>

<highlight language="config">

SetEnvIf User-Agent ^KnockKnock/2\.0 let_me_in

&lt;Directory "/docroot"&gt;

Order Deny,Allow

Deny from all

Allow from env=let_me_in

&lt;/Directory&gt;

</highlight>

<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>

<note> <title>Merging of configuration sections</title>

<p>When any directive provided by this module is used in a new

configuration section, no directives provided by this module are

inherited from previous configuration sections.</p>

</note>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>Deny</name>

<description>Controls which hosts are denied access to the

server</description>

<syntax> Deny from all|<var>host</var>|env=[!]<var>env-variable</var>

[<var>host</var>|env=[!]<var>env-variable</var>] ...</syntax>

<contextlist><context>directory</context><context>.htaccess</context>

</contextlist>

<override>Limit</override>

<usage>

<p>This directive allows access to the server to be restricted

based on hostname, IP address, or environment variables. The

arguments for the <directive>Deny</directive> directive are

identical to the arguments for the <directive

module="mod_access_compat">Allow</directive> directive.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>Order</name>

<description>Controls the default access state and the order in which

<directive>Allow</directive> and <directive>Deny</directive> are

evaluated.</description>

<syntax> Order <var>ordering</var></syntax>

<default>Order Deny,Allow</default>

<contextlist><context>directory</context><context>.htaccess</context>

</contextlist>

<override>Limit</override>

<usage>

<p>The <directive>Order</directive> directive, along with the

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

<directive module="mod_access_compat">Deny</directive> directives,

controls a three-pass access control system. The first pass

processes either all <directive

module="mod_access_compat">Allow</directive> or all <directive

module="mod_access_compat">Deny</directive> directives, as specified

by the <directive module="mod_access_compat">Order</directive>

directive. The second pass parses the rest of the directives

(<directive module="mod_access_compat">Deny</directive> or

<directive module="mod_access_compat">Allow</directive>). The third

pass applies to all requests which do not match either of the first

two.</p>

<p>Note that all <directive

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

module="mod_access_compat">Deny</directive> directives are

processed, unlike a typical firewall, where only the first match is

used. The last match is effective (also unlike a typical firewall).

Additionally, the order in which lines appear in the configuration

files is not significant -- all <directive

module="mod_access_compat">Allow</directive> lines are processed as

one group, all <directive

module="mod_access_compat">Deny</directive> lines are considered as

another, and the default state is considered by itself.</p>

<p><em>Ordering</em> is one of:</p>

<dl>

<dt><code>Allow,Deny</code></dt>

<dd>First, all <directive

module="mod_access_compat">Allow</directive> directives are

evaluated; at least one must match, or the request is rejected.

Next, all <directive module="mod_access_compat">Deny</directive>

directives are evaluated. If any matches, the request is rejected.

Last, any requests which do not match an <directive

module="mod_access_compat">Allow</directive> or a <directive

module="mod_access_compat">Deny</directive> directive are denied

by default.</dd>

<dt><code>Deny,Allow</code></dt>

<dd>First, all <directive

module="mod_access_compat">Deny</directive> directives are

evaluated; if any match, the request is denied

<strong>unless</strong> it also matches an <directive

module="mod_access_compat">Allow</directive> directive. Any

requests which do not match any <directive

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

module="mod_access_compat">Deny</directive> directives are

permitted.</dd>

<dt><code>Mutual-failure</code></dt>

<dd>This order has the same effect as <code>Order

Allow,Deny</code> and is deprecated in its favor.</dd>

</dl>

<p>Keywords may only be separated by a comma; <em>no whitespace</em>

is allowed between them.</p>

<table border="1">

<tr>

<th>Match</th>

<th>Allow,Deny result</th>

<th>Deny,Allow result</th>

</tr><tr>

<th>Match Allow only</th>

<td>Request allowed</td>

<td>Request allowed</td>

</tr><tr>

<th>Match Deny only</th>

<td>Request denied</td>

<td>Request denied</td>

</tr><tr>

<th>No match</th>

<td>Default to second directive: Denied</td>

<td>Default to second directive: Allowed</td>

</tr><tr>

<th>Match both Allow &amp; Deny</th>

<td>Final match controls: Denied</td>

<td>Final match controls: Allowed</td>

</tr>

</table>

<p>In the following example, all hosts in the example.org domain

are allowed access; all other hosts are denied access.</p>

<highlight language="config">

Order Deny,Allow

Deny from all

Allow from example.org

</highlight>

<p>In the next example, all hosts in the example.org domain are

allowed access, except for the hosts which are in the

foo.example.org subdomain, who are denied access. All hosts not

in the example.org domain are denied access because the default

state is to <directive module="mod_access_compat">Deny</directive>

access to the server.</p>

<highlight language="config">

Order Allow,Deny

Allow from example.org

Deny from foo.example.org

</highlight>

<p>On the other hand, if the <directive>Order</directive> in the

last example is changed to <code>Deny,Allow</code>, all hosts will

be allowed access. This happens because, regardless of the actual

ordering of the directives in the configuration file, the

<code>Allow from example.org</code> will be evaluated last and will

override the <code>Deny from foo.example.org</code>. All hosts not in

the <code>example.org</code> domain will also be allowed access

because the default state is <directive

module="mod_access_compat">Allow</directive>.</p>

<p>The presence of an <directive>Order</directive> directive can

affect access to a part of the server even in the absence of

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

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

directives because of its effect on the default access state. For

example,</p>

<highlight language="config">

&lt;Directory "/www"&gt;

Order Allow,Deny

&lt;/Directory&gt;

</highlight>

<p>will Deny all access to the <code>/www</code> directory

because the default access state is set to

<directive module="mod_access_compat">Deny</directive>.</p>

<p>The <directive>Order</directive> directive controls the order of access

directive processing only within each phase of the server's

configuration processing. This implies, for example, that an

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

module="mod_access_compat">Deny</directive> directive occurring in a

<directive module="core" type="section">Location</directive> section will

always be evaluated after an <directive

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

module="mod_access_compat">Deny</directive> directive occurring in a

<directive module="core" type="section">Directory</directive> section or

<code>.htaccess</code> file, regardless of the setting of the

<directive>Order</directive> directive. For details on the merging

of configuration sections, see the documentation on <a

href="/sections.html">How Directory, Location and Files sections

work</a>.</p>

<note> <title>Merging of configuration sections</title>

<p>When any directive provided by this module is used in a new

configuration section, no directives provided by this module are

inherited from previous configuration sections.</p>

</note>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>Satisfy</name>

<description>Interaction between host-level access control and

user authentication</description>

<syntax>Satisfy Any|All</syntax>

<default>Satisfy All</default>

<contextlist><context>directory</context><context>.htaccess</context>

</contextlist>

<override>AuthConfig</override>

<usage>

<p>Access policy if both <directive

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

module="mod_authz_core">Require</directive> used. The parameter can be

either <code>All</code> or <code>Any</code>. This directive is only

useful if access to a particular area is being restricted by both

username/password <em>and</em> client host address. In this case

the default behavior (<code>All</code>) is to require that the client

passes the address access restriction <em>and</em> enters a valid

username and password. With the <code>Any</code> option the client will be

granted access if they either pass the host restriction or enter a

valid username and password. This can be used to password restrict

an area, but to let clients from particular addresses in without

prompting for a password.</p>

<p>For example, if you wanted to let people on your network have

unrestricted access to a portion of your website, but require that

people outside of your network provide a password, you could use a

configuration similar to the following:</p>

<highlight language="config">

Require valid-user

Allow from 192.168.1

Satisfy Any

</highlight>

<p>

Another frequent use of the <directive>Satisfy</directive> directive

is to relax access restrictions for a subdirectory:

</p>

<highlight language="config">

&lt;Directory "/var/www/private"&gt;

Require valid-user

&lt;/Directory&gt;

&lt;Directory "/var/www/private/public"&gt;

Allow from all

Satisfy Any

&lt;/Directory&gt;

</highlight>

<p>In the above example, authentication will be required for the

<code>/var/www/private</code> directory, but will not be required

for the <code>/var/www/private/public</code> directory.</p>

<p>Since version 2.0.51 <directive>Satisfy</directive> directives can

be restricted to particular methods by <directive module="core"

type="section">Limit</directive> and <directive module="core" type="section"

>LimitExcept</directive> sections.</p>

<note> <title>Merging of configuration sections</title>

<p>When any directive provided by this module is used in a new

configuration section, no directives provided by this module are

inherited from previous configuration sections.</p>

</note>

</usage>

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

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

</directivesynopsis>

</modulesynopsis>