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

<name>mod_auth_ldap</name>

<description>Allows an LDAP directory to be used to store the database

for HTTP Basic authentication.</description>

<status>Experimental</status>

<sourcefile>mod_auth_ldap.c</sourcefile>

<identifier>auth_ldap_module</identifier>

<compatibility>Available in version 2.0.41 and later</compatibility>

<summary>

<p><module>mod_auth_ldap</module> supports the following features:</p>

<ul>

<li>Known to support the <a

href="http://www.openldap.org/">OpenLDAP SDK</a> (both 1.x

and 2.x), <a href="http://developer.novell.com/ndk/cldap.htm">

Novell LDAP SDK</a> and the <a

href="http://www.iplanet.com/downloads/developer/">iPlanet

(Netscape)</a> SDK.</li>

<li>Complex authorization policies can be implemented by

representing the policy with LDAP filters.</li>

<li>Support for Microsoft FrontPage allows FrontPage users to

control access to their webs, while retaining LDAP for user

authentication.</li>

<li>Uses extensive caching of LDAP operations via <a

href="mod_ldap.html">mod_ldap</a>.</li>

<li>Support for LDAP over SSL (requires the Netscape SDK) or

TLS (requires the OpenLDAP 2.x SDK or Novell LDAP SDK).</li>

</ul>

</summary>

<seealso><module>mod_ldap</module></seealso>

<section id="contents"><title>Contents</title>

<ul>

<li>

<a href="#operation">Operation</a>

<ul>

<li><a href="#authenphase">The Authentication

Phase</a></li>

<li><a href="#authorphase">The Authorization

Phase</a></li>

</ul>

</li>

<li>

<a href="#requiredirectives">The require Directives</a>

<ul>

<li><a href="#reqvaliduser">require valid-user</a></li>

<li><a href="#requser">require user</a></li>

<li><a href="#reqgroup">require group</a></li>

<li><a href="#reqdn">require dn</a></li>

</ul>

</li>

<li><a href="#examples">Examples</a></li>

<li><a href="#usingtls">Using TLS</a></li>

<li><a href="#usingssl">Using SSL</a></li>

<li>

<a href="#frontpage">Using Microsoft FrontPage with

<module>mod_auth_ldap</module></a>

<ul>

<li><a href="#howitworks">How It Works</a></li>

<li><a href="#fpcaveats">Caveats</a></li>

</ul>

</li>

</ul>

</section>

<section id="operation"><title>Operation</title>

<p>There are two phases in granting access to a user. The first

phase is authentication, in which <module>mod_auth_ldap</module>

verifies that the user's credentials are valid. This also called

the <em>search/bind</em> phase. The second phase is

authorization, in which <module>mod_auth_ldap</module> determines

if the authenticated user is allowed access to the resource in

question. This is also known as the <em>compare</em>

phase.</p>

<section id="authenphase"><title>The Authentication

Phase</title>

<p>During the authentication phase, <module>mod_auth_ldap</module>

searches for an entry in the directory that matches the username

that the HTTP client passes. If a single unique match is found,

then <module>mod_auth_ldap</module> attempts to bind to the

directory server using the DN of the entry plus the password

provided by the HTTP client. Because it does a search, then a

bind, it is often referred to as the search/bind phase. Here are

the steps taken during the search/bind phase.</p>

<ol>

<li>Generate a search filter by combining the attribute and

filter provided in the <directive module="mod_auth_ldap"

>AuthLDAPURL</directive> directive with

the username passed by the HTTP client.</li>

<li>Search the directory using the generated filter. If the

search does not return exactly one entry, deny or decline

access.</li>

<li>Fetch the distinguished name of the entry retrieved from

the search and attempt to bind to the LDAP server using the

DN and the password passed by the HTTP client. If the bind is

unsuccessful, deny or decline access.</li>

</ol>

<p>The following directives are used during the search/bind

phase</p>

<table>

<tr>

<td><directive module="mod_auth_ldap">AuthLDAPURL</directive></td>

<td>Specifies the LDAP server, the

base DN, the attribute to use in the search, as well as the

extra search filter to use.</td>

</tr>

<tr>

<td><directive module="mod_auth_ldap">AuthLDAPBindDN</directive></td>

<td>An optional DN to bind with

during the search phase.</td>

</tr>

<tr>

<td><directive

module="mod_auth_ldap">AuthLDAPBindPassword</directive></td>

<td>An optional password to bind

with during the search phase.</td>

</tr>

</table>

</section>

<section id="authorphase"><title>The Authorization

Phase</title>

<p>During the authorization phase, <module>mod_auth_ldap</module>

attempts to determine if the user is authorized to access the

resource. Many of these checks require

<module>mod_auth_ldap</module> to do a compare operation on the

LDAP server. This is why this phase is often referred to as the

compare phase. <module>mod_auth_ldap</module> accepts the

following <directive module="core">Require</directive>

directives to determine if the credentials are acceptable:</p>

<ul>

<li>Grant access if there is a <a href="#requser"><code>require

valid-user</code></a> directive.</li>

<li>Grant access if there is a <a

href="#reqgroup"><code>require user</code></a> directive, and the

username in the directive matches the username passed by the

client.</li>

<li>Grant access if there is a <a href="#reqdn"><code>require

dn</code></a> directive, and the DN in the directive matches

the DN fetched from the LDAP directory.</li>

<li>Grant access if there is a <a

href="#reqgroup"><code>require group</code></a> directive, and

the DN fetched from the LDAP directory (or the username

passed by the client) occurs in the LDAP group.</li>

<li>otherwise, deny or decline access</li>

</ul>

<p><module>mod_auth_ldap</module> uses the following directives during the

compare phase:</p>

<table>

<tr>

<td><directive module="mod_auth_ldap">AuthLDAPURL</directive> </td>

<td>The attribute specified in the

URL is used in compare operations for the <code>require

user</code> operation.</td>

</tr>

<tr>

<td><directive

module="mod_auth_ldap">AuthLDAPCompareDNOnServer</directive></td>

<td>Determines the behavior of the

<code>require dn</code> directive.</td>

</tr>

<tr>

<td><directive

module="mod_auth_ldap">AuthLDAPGroupAttribute</directive></td>

<td>Determines the attribute to

use for comparisons in the <code>require group</code>

directive.</td>

</tr>

<tr>

<td><directive

module="mod_auth_ldap">AuthLDAPGroupAttributeIsDN</directive></td>

<td>Specifies whether to use the

user DN or the username when doing comparisons for the

<code>require group</code> directive.</td>

</tr>

</table>

</section>

</section>

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

<p>Apache's <directive module="core">Require</directive>

directives are used during the authorization phase to ensure that

a user is allowed to access a resource.</p>

<section id="reqvaliduser"><title>require

valid-user</title>

<p>If this directive exists, <module>mod_auth_ldap</module> grants

access to any user that has successfully authenticated during the

search/bind phase.</p>

</section>

<section id="requser"><title>require user</title>

<p>The <code>require user</code> directive specifies what

usernames can access the resource. Once

<module>mod_auth_ldap</module> has retrieved a unique DN from the

directory, it does an LDAP compare operation using the username

specified in the <code>require user</code> to see if that username

is part of the just-fetched LDAP entry. Multiple users can be

granted access by putting multiple usernames on the line,

separated with spaces. If a username has a space in it, then it

must be surrounded with double quotes. Multiple users can also be

granted access by using multiple <code>require user</code>

directives, with one user per line. For example, with a <directive

module="mod_auth_ldap">AuthLDAPURL</directive> of

<code>ldap://ldap/o=Airius?cn</code> (i.e., <code>cn</code> is

used for searches), the following require directives could be used

to restrict access:</p>

<example>

require user "Barbara Jenson"<br />

require user "Fred User"<br />

require user "Joe Manager"<br />

</example>

<p>Because of the way that <module>mod_auth_ldap</module> handles this

directive, Barbara Jenson could sign on as <em>Barbara

Jenson</em>, <em>Babs Jenson</em> or any other <code>cn</code> that

she has in her LDAP entry. Only the single <code>require

user</code> line is needed to support all values of the attribute

in the user's entry.</p>

<p>If the <code>uid</code> attribute was used instead of the

<code>cn</code> attribute in the URL above, the above three lines

could be condensed to</p>

<example>require user bjenson fuser jmanager</example>

</section>

<section id="reqgroup"><title>require group</title>

<p>This directive specifies an LDAP group whose members are

allowed access. It takes the distinguished name of the LDAP

group. For example, assume that the following entry existed in

the LDAP directory:</p>

<example>

dn: cn=Administrators, o=Airius<br />

objectClass: groupOfUniqueNames<br />

uniqueMember: cn=Barbara Jenson, o=Airius<br />

uniqueMember: cn=Fred User, o=Airius<br />

</example>

<p>The following directive would grant access to both Fred and

Barbara:</p>

<example>require group "cn=Administrators, o=Airius"</example>

<p>Behavior of this directive is modified by the <directive

module="mod_auth_ldap">AuthLDAPGroupAttribute</directive> and

<directive

module="mod_auth_ldap">AuthLDAPGroupAttributeIsDN</directive>

directives.</p>

</section>

<section id="reqdn"><title>require dn</title>

<p>The <code>require dn</code> directive allows the administrator

to grant access based on distinguished names. It specifies a DN

that must match for access to be granted. If the distinguished

name that was retrieved from the directory server matches the

distinguished name in the <code>require dn</code>, then

authorization is granted.</p>

<p>The following directive would grant access to a specific

DN:</p>

<example>require dn "cn=Barbara Jenson, o=Airius"</example>

<p>Behavior of this directive is modified by the <directive

module="mod_auth_ldap">AuthLDAPCompareDNOnServer</directive>

directive.</p>

</section>

</section>

<section id="examples"><title>Examples</title>

<ul>

<li>

Grant access to anyone who exists in the LDAP directory,

using their UID for searches.

<example>

AuthLDAPURL "ldap://ldap1.airius.com:389/ou=People, o=Airius?uid?sub?(objectClass=*)"<br />

require valid-user

</example>

</li>

<li>

The next example is the same as above; but with the fields

that have useful defaults omitted. Also, note the use of a

redundant LDAP server.

<example>AuthLDAPURL "ldap://ldap1.airius.com ldap2.airius.com/ou=People, o=Airius"<br />

require valid-user

</example>

</li>

<li>

The next example is similar to the previous one, but is

uses the common name instead of the UID. Note that this

could be problematical if multiple people in the directory

share the same <code>cn</code>, because a search on <code>cn</code>

<strong>must</strong> return exactly one entry. That's why

this approach is not recommended: it's a better idea to

choose an attribute that is guaranteed unique in your

directory, such as <code>uid</code>.

<example>

AuthLDAPURL "ldap://ldap.airius.com/ou=People, o=Airius?cn"<br />

require valid-user

</example>

</li>

<li>

Grant access to anybody in the Administrators group. The

users must authenticate using their UID.

<example>

AuthLDAPURL "ldap://ldap.airius.com/o=Airius?uid"<br />

require group cn=Administrators, o=Airius

</example>

</li>

<li>

The next example assumes that everyone at Airius who

carries an alphanumeric pager will have an LDAP attribute

of <code>qpagePagerID</code>. The example will grant access

only to people (authenticated via their UID) who have

alphanumeric pagers:

<example>

AuthLDAPURL "ldap://ldap.airius.com/o=Airius?uid??(qpagePagerID=*)"<br />

require valid-user

</example>

</li>

<li>

<p>The next example demonstrates the power of using filters

to accomplish complicated administrative requirements.

Without filters, it would have been necessary to create a

new LDAP group and ensure that the group's members remain

synchronized with the pager users. This becomes trivial

with filters. The goal is to grant access to anyone who has

a filter, plus grant access to Joe Manager, who doesn't

have a pager, but does need to access the same

resource:</p>

<example>

AuthLDAPURL "ldap://ldap.airius.com/o=Airius?uid??(|(qpagePagerID=*)(uid=jmanager))"<br />

require valid-user

</example>

<p>This last may look confusing at first, so it helps to

evaluate what the search filter will look like based on who

connects, as shown below. The text in blue is the part that

is filled in using the attribute specified in the URL. The

text in red is the part that is filled in using the filter

specified in the URL. The text in green is filled in using

the information that is retrieved from the HTTP client. If

Fred User connects as <code>fuser</code>, the filter would look

like</p>

<example>(&amp;(|(qpagePagerID=*)(uid=jmanager))(uid=fuser))</example>

<p>The above search will only succeed if <em>fuser</em> has a

pager. When Joe Manager connects as <em>jmanager</em>, the

filter looks like</p>

<example>(&amp;(|(qpagePagerID=*)(uid=jmanager))(uid=jmanager))</example>

<p>The above search will succeed whether <em>jmanager</em>

has a pager or not.</p>

</li>

</ul>

</section>

<section id="usingtls"><title>Using TLS</title>

<p>To use TLS, see the <module>mod_ldap</module> directives <directive

module="mod_ldap">LDAPTrustedCA</directive> and <directive

module="mod_ldap">LDAPTrustedCAType</directive>.</p>

</section>

<section id="usingssl"><title>Using SSL</title>

<p>To use SSL, see the <module>mod_ldap</module> directives <directive

module="mod_ldap">LDAPTrustedCA</directive> and <directive

module="mod_ldap">LDAPTrustedCAType</directive>.</p>

<p>To specify a secure LDAP server, use <em>ldaps://</em> in the

<directive module="mod_auth_ldap">AuthLDAPURL</directive>

directive, instead of <em>ldap://</em>.</p>

</section>

<section id="frontpage"><title>Using Microsoft

FrontPage with mod_auth_ldap</title>

<p>Normally, FrontPage uses FrontPage-web-specific user/group

files (i.e., the <module>mod_authn_file</module> and

<module>mod_authz_groupfile</module> modules) to handle all

authentication. Unfortunately, it is not possible to just

change to LDAP authentication by adding the proper directives,

because it will break the <em>Permissions</em> forms in

the FrontPage client, which attempt to modify the standard

text-based authorization files.</p>

<p>Once a FrontPage web has been created, adding LDAP

authentication to it is a matter of adding the following

directives to <em>every</em> <code>.htaccess</code> file

that gets created in the web</p>

<example><pre>

AuthLDAPURL "the url"

AuthLDAPAuthoritative off

AuthLDAPFrontPageHack on

</pre></example>

<p><directive

module="mod_auth_ldap">AuthLDAPAuthoritative</directive> must be

off to allow <module>mod_auth_ldap</module> to decline group

authentication so that Apache will fall back to file

authentication for checking group membership. This allows the

FrontPage-managed group file to be used.</p>

<section id="howitworks"><title>How It Works</title>

<p>FrontPage restricts access to a web by adding the <code>require

valid-user</code> directive to the <code>.htaccess</code>

files. If <directive

module="mod_auth_ldap">AuthLDAPFrontPageHack</directive> is not

on, the <code>require valid-user</code> directive will succeed for

any user who is valid <em>as far as LDAP is

concerned</em>. This means that anybody who has an entry in

the LDAP directory is considered a valid user, whereas FrontPage

considers only those people in the local user file to be

valid. The purpose of the hack is to force Apache to consult the

local user file (which is managed by FrontPage) - instead of LDAP

- when handling the <code>require valid-user</code> directive.</p>

<p>Once directives have been added as specified above,

FrontPage users will be able to perform all management

operations from the FrontPage client.</p>

</section>

<section id="fpcaveats"><title>Caveats</title>

<ul>

<li>When choosing the LDAP URL, the attribute to use for

authentication should be something that will also be valid

for putting into a <module>mod_authn_file</module> user file.

The user ID is ideal for this.</li>

<li>When adding users via FrontPage, FrontPage administrators

should choose usernames that already exist in the LDAP

directory (for obvious reasons). Also, the password that the

administrator enters into the form is ignored, since Apache

will actually be authenticating against the password in the

LDAP database, and not against the password in the local user

file. This could cause confusion for web administrators.</li>

<!-- XXX is that true? was mod_auth before the aaa change -->

<li>Apache must be compiled with <module>mod_auth_basic</module>,

<module>mod_authn_file</module> and

<module>mod_authz_groupfile</module> in order to

use FrontPage support. This is because Apache will still use

the <module>mod_authz_groupfile</module> group file for determine the extent of a

user's access to the FrontPage web.</li>

<li>The directives must be put in the <code>.htaccess</code>

files. Attempting to put them inside <directive module="core"

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

type="section">Directory</directive> directives won't work. This

is because <module>mod_auth_ldap</module> has to be able to grab

the <directive module="mod_authn_file">AuthUserFile</directive>

directive that is found in FrontPage <code>.htaccess</code>

files so that it knows where to look for the valid user list. If

the <module>mod_auth_ldap</module> directives aren't in the same

<code>.htaccess</code> file as the FrontPage directives, then

the hack won't work, because <module>mod_auth_ldap</module> will

never get a chance to process the <code>.htaccess</code> file,

and won't be able to find the FrontPage-managed user file.</li>

</ul>

</section>

</section>

<directivesynopsis>

<name>AuthLDAPAuthoritative</name>

<description>Prevent other authentication modules from

authenticating the user if this one fails</description>

<syntax>AuthLDAPAuthoritative on|off</syntax>

<default>AuthLDAPAuthoritative on</default>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>Set to <code>off</code> if this module should let other

authentication modules attempt to authenticate the user, should

authentication with this module fail. Control is only passed on

to lower modules if there is no DN or rule that matches the

supplied user name (as passed by the client).</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPBindDN</name>

<description>Optional DN to use in binding to the LDAP server</description>

<syntax>AuthLDAPBindDN <em>distinguished-name</em></syntax>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>An optional DN used to bind to the server when searching for

entries. If not provided, <module>mod_auth_ldap</module> will use

an anonymous bind.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPBindPassword</name>

<description>Password used in conjuction with the bind DN</description>

<syntax>AuthLDAPBindPassword <em>password</em></syntax>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>A bind password to use in conjunction with the bind DN. Note

that the bind password is probably sensitive data, and should be

properly protected. You should only use the <directive

module="mod_auth_ldap">AuthLDAPBindDN</directive> and <directive

module="mod_auth_ldap">AuthLDAPBindPassword</directive> if you

absolutely need them to search the directory.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPCharsetConfig</name>

<description>Language to charset conversion configuration file</description>

<syntax>AuthLDAPCharsetConfig <em>file-path</em></syntax>

<contextlist><context>server config</context>

</contextlist>

<usage>

<p>The <directive>AuthLDAPCharsetConfig</directive> directive sets the location

of the language to charset conversion configuration file. <var>File-path</var> is relative

to the <directive module="core">ServerRoot</directive>. This file specifies

the list of language extensions to character sets.

Most administrators use the provided <code>charset.conv</code>

file, which associates common language extensions to character sets.</p>

<p>The file contains lines in the following format:</p>

<example>

<var>Language-Extension</var> <var>charset</var> [<var>Language-String</var>] ...

</example>

<p>The case of the extension does not matter. Blank lines, and lines

beginning with a hash character (<code>#</code>) are ignored.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPCompareDNOnServer</name>

<description>Use the LDAP server to compare the DNs</description>

<syntax>AuthLDAPCompareDNOnServer on|off</syntax>

<default>AuthLDAPCompareDNOnServer on</default>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>When set, <module>mod_auth_ldap</module> will use the LDAP

server to compare the DNs. This is the only foolproof way to

compare DNs. <module>mod_auth_ldap</module> will search the

directory for the DN specified with the <a

href="#reqdn"><code>require dn</code></a> directive, then,

retrieve the DN and compare it with the DN retrieved from the user

entry. If this directive is not set,

<module>mod_auth_ldap</module> simply does a string comparison. It

is possible to get false negatives with this approach, but it is

much faster. Note the <module>mod_ldap</module> cache can speed up

DN comparison in most situations.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPDereferenceAliases</name>

<description>When will the module de-reference aliases</description>

<syntax>AuthLDAPDereferenceAliases never|searching|finding|always</syntax>

<default>AuthLDAPDereferenceAliases Always</default>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>This directive specifies when <module>mod_auth_ldap</module> will

de-reference aliases during LDAP operations. The default is

<code>always</code>.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPEnabled</name>

<description>Turn on or off LDAP authentication</description>

<syntax> AuthLDAPEnabled on|off</syntax>

<default>AuthLDAPEnabled on</default>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>Set to <code>off</code> to disable

<module>mod_auth_ldap</module> in certain directories. This is

useful if you have <module>mod_auth_ldap</module> enabled at or

near the top of your tree, but want to disable it completely in

certain locations.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPFrontPageHack</name>

<description>Allow LDAP authentication to work with MS FrontPage</description>

<syntax>AuthLDAPFrontPageHack on|off</syntax>

<default>AuthLDAPFrontPageHack off</default>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>See the section on <a href="#frontpage">using Microsoft

FrontPage</a> with <module>mod_auth_ldap</module>.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPGroupAttribute</name>

<description>LDAP attributes used to check for group membership</description>

<syntax>AuthLDAPGroupAttribute <em>attribute</em></syntax>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>This directive specifies which LDAP attributes are used to

check for group membership. Multiple attributes can be used by

specifying this directive multiple times. If not specified,

then <module>mod_auth_ldap</module> uses the <code>member</code> and

<code>uniquemember</code> attributes.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPGroupAttributeIsDN</name>

<description>Use the DN of the client username when checking for

group membership</description>

<syntax>AuthLDAPGroupAttributeIsDN on|off</syntax>

<default>AuthLDAPGroupAttributeIsDN on</default>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>When set <code>on</code>, this directive says to use the

distinguished name of the client username when checking for group

membership. Otherwise, the username will be used. For example,

assume that the client sent the username <code>bjenson</code>,

which corresponds to the LDAP DN <code>cn=Babs Jenson,

o=Airius</code>. If this directive is set,

<module>mod_auth_ldap</module> will check if the group has

<code>cn=Babs Jenson, o=Airius</code> as a member. If this

directive is not set, then <module>mod_auth_ldap</module> will

check if the group has <code>bjenson</code> as a member.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPRemoteUserIsDN</name>

<description>Use the DN of the client username to set the REMOTE_USER

environment variable</description>

<syntax>AuthLDAPRemoteUserIsDN on|off</syntax>

<default>AuthLDAPRemoteUserIsDN off</default>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>If this directive is set to on, the value of the

<code>REMOTE_USER</code> environment variable will be set to the full

distinguished name of the authenticated user, rather than just

the username that was passed by the client. It is turned off by

default.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPUrl</name>

<description>URL specifying the LDAP search parameters</description>

<syntax>AuthLDAPUrl <em>url</em></syntax>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>An RFC 2255 URL which specifies the LDAP search parameters

to use. The syntax of the URL is</p>

<example>ldap://host:port/basedn?attribute?scope?filter</example>

<dl>

<dt>ldap</dt>

<dd>For regular ldap, use the

string <code>ldap</code>. For secure LDAP, use <code>ldaps</code>

instead. Secure LDAP is only available if Apache was linked

to an LDAP library with SSL support.</dd>

<dt>host:port</dt>

<dd>

<p>The name/port of the ldap server (defaults to

<code>localhost:389</code> for <code>ldap</code>, and

<code>localhost:636</code> for <code>ldaps</code>). To

specify multiple, redundant LDAP servers, just list all

servers, separated by spaces. <module>mod_auth_ldap</module>

will try connecting to each server in turn, until it makes a

successful connection.</p>

<p>Once a connection has been made to a server, that

connection remains active for the life of the

<code>httpd</code> process, or until the LDAP server goes

down.</p>

<p>If the LDAP server goes down and breaks an existing

connection, <module>mod_auth_ldap</module> will attempt to

re-connect, starting with the primary server, and trying

each redundant server in turn. Note that this is different

than a true round-robin search.</p>

</dd>

<dt>basedn</dt>

<dd>The DN of the branch of the

directory where all searches should start from. At the very

least, this must be the top of your directory tree, but

could also specify a subtree in the directory.</dd>

<dt>attribute</dt>

<dd>The attribute to search for.

Although RFC 2255 allows a comma-separated list of

attributes, only the first attribute will be used, no

matter how many are provided. If no attributes are

provided, the default is to use <code>uid</code>. It's a good

idea to choose an attribute that will be unique across all

entries in the subtree you will be using.</dd>

<dt>scope</dt>

<dd>The scope of the search. Can be either <code>one</code> or

<code>sub</code>. Note that a scope of <code>base</code> is

also supported by RFC 2255, but is not supported by this

module. If the scope is not provided, or if <code>base</code> scope

is specified, the default is to use a scope of

<code>sub</code>.</dd>

<dt>filter</dt>

<dd>A valid LDAP search filter. If

not provided, defaults to <code>(objectClass=*)</code>, which

will search for all objects in the tree. Filters are

limited to approximately 8000 characters (the definition of

<code>MAX_STRING_LEN</code> in the Apache source code). This

should be than sufficient for any application.</dd>

</dl>

<p>When doing searches, the attribute, filter and username passed

by the HTTP client are combined to create a search filter that

looks like

<code>(&amp;(<em>filter</em>)(<em>attribute</em>=<em>username</em>))</code>.</p>

<p>For example, consider an URL of

<code>ldap://ldap.airius.com/o=Airius?cn?sub?(posixid=*)</code>. When

a client attempts to connect using a username of <code>Babs

Jenson</code>, the resulting search filter will be

<code>(&amp;(posixid=*)(cn=Babs Jenson))</code>.</p>

<p>See above for examples of <directive

module="mod_auth_ldap">AuthLDAPURL</directive> URLs.</p>

</usage>

</directivesynopsis>

</modulesynopsis>