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<div id="preamble"><h1>Apache Module mod_authnz_ldap</h1>
<div class="toplang">
<p><span>Available Languages: </span><a href="../en/mod/mod_authnz_ldap.html" title="English">&nbsp;en&nbsp;</a></p>
</div>
<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Allows an LDAP directory to be used to store the database
for HTTP Basic authentication.</td></tr>
<tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>authnz_ldap_module</td></tr>
<tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>mod_authnz_ldap.c</td></tr>
<tr><th><a href="module-dict.html#Compatibility">Compatibility:</a></th><td>Available in version 2.1 and later</td></tr></table>
<h3>Summary</h3>

    <p>This module provides authentication front-ends such as
    <code class="module"><a href="../mod/mod_auth_basic.html">mod_auth_basic</a></code> to authenticate users through 
    an ldap directory.</p>
    
    <p><code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> 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>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>

    <p>When using <code class="module"><a href="../mod/mod_auth_basic.html">mod_auth_basic</a></code>, this module is invoked
    via the <code class="directive"><a href="../mod/mod_auth_basic.html#authbasicprovider">AuthBasicProvider</a></code>
    directive with the <code>ldap</code> value.</p>
</div>
<div id="quickview"><h3 class="directives">Directives</h3>
<ul id="toc">
<li><img alt="" src="../images/down.gif" /> <a href="#authldapbinddn">AuthLDAPBindDN</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#authldapbindpassword">AuthLDAPBindPassword</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#authldapcharsetconfig">AuthLDAPCharsetConfig</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#authldapcomparednonserver">AuthLDAPCompareDNOnServer</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#authldapdereferencealiases">AuthLDAPDereferenceAliases</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#authldapgroupattribute">AuthLDAPGroupAttribute</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#authldapgroupattributeisdn">AuthLDAPGroupAttributeIsDN</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#authldapremoteuserattribute">AuthLDAPRemoteUserAttribute</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#authldapremoteuserisdn">AuthLDAPRemoteUserIsDN</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#authldapurl">AuthLDAPUrl</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#authzldapauthoritative">AuthzLDAPAuthoritative</a></li>
</ul>
<h3>Topics</h3>
<ul id="topics">
<li><img alt="" src="../images/down.gif" /> <a href="#contents">Contents</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#operation">Operation</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#requiredirectives">The Require Directives</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#examples">Examples</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#usingtls">Using TLS</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#usingssl">Using SSL</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#exposed">Exposing Login Information</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#frontpage">Using Microsoft
    FrontPage with mod_authnz_ldap</a></li>
</ul><h3>See also</h3>
<ul class="seealso">
<li><code class="module"><a href="../mod/mod_ldap.html">mod_ldap</a></code></li>
<li><code class="module"><a href="../mod/mod_auth_basic.html">mod_auth_basic</a></code></li>
<li><code class="module"><a href="../mod/mod_authz_user.html">mod_authz_user</a></code></li>
<li><code class="module"><a href="../mod/mod_authz_groupfile.html">mod_authz_groupfile</a></code></li>
</ul></div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="contents" id="contents">Contents</a></h2>

    <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 ldap-user</a></li>
          <li><a href="#reqgroup">Require ldap-group</a></li>
          <li><a href="#reqdn">Require ldap-dn</a></li>
          <li><a href="#reqattribute">Require ldap-attribute</a></li>
          <li><a href="#reqfilter">Require ldap-filter</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="#exposed">Exposing Login Information</a></li>
      <li>
        <a href="#frontpage">Using Microsoft FrontPage with
        <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code></a> 

        <ul>
          <li><a href="#howitworks">How It Works</a></li>
          <li><a href="#fpcaveats">Caveats</a></li>
        </ul>
      </li>
    </ul>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="operation" id="operation">Operation</a></h2>

    <p>There are two phases in granting access to a user. The first
    phase is authentication, in which the <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code>
    authentication provider verifies that the user's credentials are valid. 
    This is also called the <em>search/bind</em> phase. The second phase is
    authorization, in which <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> determines
    if the authenticated user is allowed access to the resource in
    question. This is also known as the <em>compare</em>
    phase.</p>

    <p><code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> registers both an authn_ldap authentication
    provider and an authz_ldap authorization handler.  The authn_ldap
    authentication provider can be enabled through the 
    <code class="directive"><a href="../mod/mod_auth_basic.html#authbasicprovider">AuthBasicProvider</a></code> directive 
    using the <code>ldap</code> value. The authz_ldap handler extends the 
    <code class="directive"><a href="../mod/core.html#require">Require</a></code> directive's authorization types
    by adding <code>ldap-user</code>, <code>ldap-dn</code> and <code>ldap-group</code> 
    values.</p>

<h3><a name="authenphase" id="authenphase">The Authentication
    Phase</a></h3>

    <p>During the authentication phase, <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code>
    searches for an entry in the directory that matches the username
    that the HTTP client passes. If a single unique match is found,
    then <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> 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 <code class="directive"><a href="#authldapurl">AuthLDAPURL</a></code> 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><code class="directive"><a href="#authldapurl">AuthLDAPURL</a></code></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><code class="directive"><a href="#authldapbinddn">AuthLDAPBindDN</a></code></td>

        <td>An optional DN to bind with
        during the search phase.</td>
      </tr>

      <tr>
        <td><code class="directive"><a href="#authldapbindpassword">AuthLDAPBindPassword</a></code></td>

        <td>An optional password to bind
        with during the search phase.</td>
      </tr>
    </table>


<h3><a name="authorphase" id="authorphase">The Authorization Phase</a></h3>

    <p>During the authorization phase, <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code>
    attempts to determine if the user is authorized to access the
    resource.  Many of these checks require
    <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> to do a compare operation on the
    LDAP server. This is why this phase is often referred to as the
    compare phase. <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> accepts the
    following <code class="directive"><a href="../mod/core.html#require">Require</a></code>
    directives to determine if the credentials are acceptable:</p>

    <ul>
      <li>Grant access if there is a <a href="#reqgroup"><code>Require ldap-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
      ldap-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 ldap-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>Grant access if there is a <a href="#reqattribute">
      <code>Require ldap-attribute</code></a> 
      directive, and the attribute fetched from the LDAP directory
      matches the given value.</li> 

      <li>Grant access if there is a <a href="#reqfilter">
      <code>Require ldap-filter</code></a> 
      directive, and the search filter successfully finds a single user
      object that matches the dn of the authenticated user.</li> 

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

    <p>Other <code class="directive"><a href="../mod/core.html#require">Require</a></code> values may also
    be used which may require loading additional authorization modules.
    Note that if you use a <code class="directive"><a href="../mod/core.html#require">Require</a></code>
    value from another authorization module, you will need to ensure that
    <code class="directive"><a href="#authzldapauthoritative">AuthzLDAPAuthoritative</a></code>
    is set to <code>off</code> to allow the authorization phase to fall
    back to the module providing the alternate
    <code class="directive"><a href="../mod/core.html#require">Require</a></code> value. When no 
    LDAP-specific <code class="directive"><a href="../mod/core.html#require">Require</a></code>  directives
    are used, authorization is allowed to fall back to other modules
    as if <code class="directive"><a href="#authzldapauthoritative">AuthzLDAPAuthoritative</a></code>
    was set to <code>off</code>. </p>

    <ul>
        <li>Grant access if there is a <a href="#requser"><code>Require
        valid-user</code></a> directive. (requires 
        <code class="module"><a href="../mod/mod_authz_user.html">mod_authz_user</a></code>)</li>

        <li>Grant access if there is a <a href="#reqgroup"><code>Require group</code></a> directive, and
        <code class="module"><a href="../mod/mod_authz_groupfile.html">mod_authz_groupfile</a></code> has been loaded with the 
        <code class="directive"><a href="../mod/mod_authz_groupfile.html#authgroupfile">AuthGroupFile</a></code> 
        directive set.</li>
    
        <li>others...</li>
     </ul>


    <p><code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> uses the following directives during the
    compare phase:</p>

    <table>
      
      <tr>
        <td><code class="directive"><a href="#authldapurl">AuthLDAPURL</a></code> </td>

        <td>The attribute specified in the
        URL is used in compare operations for the <code>Require
        ldap-user</code> operation.</td>
      </tr>

      <tr>
        <td><code class="directive"><a href="#authldapcomparednonserver">AuthLDAPCompareDNOnServer</a></code></td>

        <td>Determines the behavior of the
        <code>Require ldap-dn</code> directive.</td>
      </tr>

      <tr>
        <td><code class="directive"><a href="#authldapgroupattribute">AuthLDAPGroupAttribute</a></code></td>

        <td>Determines the attribute to
        use for comparisons in the <code>Require ldap-group</code>
        directive.</td>
      </tr>

      <tr>
        <td><code class="directive"><a href="#authldapgroupattributeisdn">AuthLDAPGroupAttributeIsDN</a></code></td>

        <td>Specifies whether to use the
        user DN or the username when doing comparisons for the
        <code>Require ldap-group</code> directive.</td>
      </tr>
    </table>

</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="requiredirectives" id="requiredirectives">The Require Directives</a></h2>

    <p>Apache's <code class="directive"><a href="../mod/core.html#require">Require</a></code>
    directives are used during the authorization phase to ensure that
    a user is allowed to access a resource.  mod_authnz_ldap extends the 
    authorization types with <code>ldap-user</code>, <code>ldap-dn</code>, 
    <code>ldap-group</code>, <code>ldap-attribute</code> and 
    <code>ldap-filter</code>.  Other authorization types may also be 
    used but may require that additional authorization modules be loaded.</p>

<h3><a name="reqvaliduser" id="reqvaliduser">Require valid-user</a></h3>

    <p>If this directive exists, <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> grants
    access to any user that has successfully authenticated during the
    search/bind phase.  Requires that <code class="module"><a href="../mod/mod_authz_user.html">mod_authz_user</a></code> be 
    loaded.</p>


<h3><a name="requser" id="requser">Require ldap-user</a></h3>

    <p>The <code>Require ldap-user</code> directive specifies what
    usernames can access the resource. Once
    <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> has retrieved a unique DN from the
    directory, it does an LDAP compare operation using the username
    specified in the <code>Require ldap-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 ldap-user</code>
    directives, with one user per line. For example, with a <code class="directive"><a href="#authldapurl">AuthLDAPURL</a></code> 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>
<div class="example"><p><code>
Require ldap-user "Barbara Jenson"<br />
Require ldap-user "Fred User"<br />
Require ldap-user "Joe Manager"<br />
</code></p></div>

    <p>Because of the way that <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> 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
    ldap-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>
<div class="example"><p><code>Require ldap-user bjenson fuser jmanager</code></p></div>


<h3><a name="reqgroup" id="reqgroup">Require ldap-group</a></h3>

    <p>This directive specifies an LDAP group whose members are
    allowed access. It takes the distinguished name of the LDAP
    group. Note: Do not surround the group name with quotes.
    For example, assume that the following entry existed in
    the LDAP directory:</p>
<div class="example"><p><code>
dn: cn=Administrators, o=Airius<br />
objectClass: groupOfUniqueNames<br />
uniqueMember: cn=Barbara Jenson, o=Airius<br />
uniqueMember: cn=Fred User, o=Airius<br />
</code></p></div>

    <p>The following directive would grant access to both Fred and
    Barbara:</p>
<div class="example"><p><code>Require ldap-group cn=Administrators, o=Airius</code></p></div>

    <p>Behavior of this directive is modified by the <code class="directive"><a href="#authldapgroupattribute">AuthLDAPGroupAttribute</a></code> and
    <code class="directive"><a href="#authldapgroupattributeisdn">AuthLDAPGroupAttributeIsDN</a></code>
    directives.</p>


<h3><a name="reqdn" id="reqdn">Require ldap-dn</a></h3>

    <p>The <code>Require ldap-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 ldap-dn</code>, then
    authorization is granted. Note: do not surround the distinguished
    name with quotes.</p>

    <p>The following directive would grant access to a specific
    DN:</p>
<div class="example"><p><code>Require ldap-dn cn=Barbara Jenson, o=Airius</code></p></div>

    <p>Behavior of this directive is modified by the <code class="directive"><a href="#authldapcomparednonserver">AuthLDAPCompareDNOnServer</a></code>
    directive.</p>


<h3><a name="reqattribute" id="reqattribute">Require ldap-attribute</a></h3>

    <p>The <code>Require ldap-attribute</code> directive allows the
    administrator to grant access based on attributes of the authenticated
    user in the LDAP directory.  If the attribute in the directory
    matches the value given in the configuration, access is granted.</p>
    
    <p>The following directive would grant access to anyone with
    the attribute employeeType = active</p>

    <div class="example"><p><code>Require ldap-attribute employeeType=active</code></p></div>

    <p>Multiple attribute/value pairs can be specified on the same line
    separated by spaces or they can be specified in multiple 
    <code>Require ldap-attribute</code> directives. The effect of listing 
    multiple attribute/values pairs is an OR operation. Access will be 
    granted if any of the listed attribute values match the value of the 
    corresponding attribute in the user object. If the value of the 
    attribute contains a space, only the value must be within double quotes.</p>

    <p>The following directive would grant access to anyone with
    the city attribute equal to "San Jose" or status equal to "Active"</p>

    <div class="example"><p><code>Require ldap-attribute city="San Jose" status=active</code></p></div>



<h3><a name="reqfilter" id="reqfilter">Require ldap-filter</a></h3>

    <p>The <code>Require ldap-filter</code> directive allows the
    administrator to grant access based on a complex LDAP search filter.
    If the dn returned by the filter search matches the authenticated user
    dn, access is granted.</p>
    
    <p>The following directive would grant access to anyone having a cell phone
    and is in the marketing department</p>

    <div class="example"><p><code>Require ldap-filter &amp;(cell=*)(department=marketing)</code></p></div>

    <p>The difference between the <code>Require ldap-filter</code> directive and the 
    <code>Require ldap-attribute</code> directive is that <code>ldap-filter</code> 
    performs a search operation on the LDAP directory using the specified search 
    filter rather than a simple attribute comparison. If a simple attribute 
    comparison is all that is required, the comparison operation performed by 
    <code>ldap-attribute</code> will be faster than the search operation 
    used by <code>ldap-filter</code> especially within a large directory.</p>



</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="examples" id="examples">Examples</a></h2>

    <ul>
      <li>
        Grant access to anyone who exists in the LDAP directory,
        using their UID for searches. 
<div class="example"><p><code>
AuthLDAPURL "ldap://ldap1.airius.com:389/ou=People, o=Airius?uid?sub?(objectClass=*)"<br />
Require valid-user
</code></p></div>
      </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. 
<div class="example"><p><code>AuthLDAPURL "ldap://ldap1.airius.com ldap2.airius.com/ou=People, o=Airius"<br />
Require valid-user
</code></p></div>
      </li>

      <li>
        The next example is similar to the previous one, but it
        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>. 
<div class="example"><p><code>
AuthLDAPURL "ldap://ldap.airius.com/ou=People, o=Airius?cn"<br />
Require valid-user
</code></p></div>
      </li>

      <li>
        Grant access to anybody in the Administrators group. The
        users must authenticate using their UID. 
<div class="example"><p><code>
AuthLDAPURL ldap://ldap.airius.com/o=Airius?uid<br />
Require ldap-group cn=Administrators, o=Airius
</code></p></div>
      </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: 
<div class="example"><p><code>
AuthLDAPURL ldap://ldap.airius.com/o=Airius?uid??(qpagePagerID=*)<br />
Require valid-user
</code></p></div>
      </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 pager, plus grant access to Joe Manager, who doesn't
        have a pager, but does need to access the same
        resource:</p>
<div class="example"><p><code>
AuthLDAPURL ldap://ldap.airius.com/o=Airius?uid??(|(qpagePagerID=*)(uid=jmanager))<br />
Require valid-user
</code></p></div>

        <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.  If
        Fred User connects as <code>fuser</code>, the filter would look
        like</p>

        <div class="example"><p><code>(&amp;(|(qpagePagerID=*)(uid=jmanager))(uid=fuser))</code></p></div>

        <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>

        <div class="example"><p><code>(&amp;(|(qpagePagerID=*)(uid=jmanager))(uid=jmanager))</code></p></div>

        <p>The above search will succeed whether <em>jmanager</em>
        has a pager or not.</p>
      </li>
    </ul>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="usingtls" id="usingtls">Using TLS</a></h2>

    <p>To use TLS, see the <code class="module"><a href="../mod/mod_ldap.html">mod_ldap</a></code> directives <code class="directive"><a href="../mod/mod_ldap.html#ldaptrustedclientcert">LDAPTrustedClientCert</a></code>, <code class="directive"><a href="../mod/mod_ldap.html#ldaptrustedglobalcert">LDAPTrustedGlobalCert</a></code> and <code class="directive"><a href="../mod/mod_ldap.html#ldaptrustedmode">LDAPTrustedMode</a></code>.</p>

    <p>An optional second parameter can be added to the 
    <code class="directive"><a href="#authldapurl">AuthLDAPURL</a></code> to override
    the default connection type set by <code class="directive"><a href="../mod/mod_ldap.html#ldaptrustedmode">LDAPTrustedMode</a></code>.
    This will allow the connection established by an <em>ldap://</em> Url 
    to be upgraded to a secure connection on the same port.</p>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="usingssl" id="usingssl">Using SSL</a></h2>

    <p>To use SSL, see the <code class="module"><a href="../mod/mod_ldap.html">mod_ldap</a></code> directives <code class="directive"><a href="../mod/mod_ldap.html#ldaptrustedclientcert">LDAPTrustedClientCert</a></code>, <code class="directive"><a href="../mod/mod_ldap.html#ldaptrustedglobalcert">LDAPTrustedGlobalCert</a></code> and <code class="directive"><a href="../mod/mod_ldap.html#ldaptrustedmode">LDAPTrustedMode</a></code>.</p>

    <p>To specify a secure LDAP server, use <em>ldaps://</em> in the
    <code class="directive"><a href="#authldapurl">AuthLDAPURL</a></code>
    directive, instead of <em>ldap://</em>.</p>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="exposed" id="exposed">Exposing Login Information</a></h2>

    <p>When this module performs authentication, LDAP attributes specified
    in the <code class="directive"><a href="#authldapurl">AuthLDAPUrl</a></code> 
    directive are placed in environment variables with the prefix "AUTHENTICATE_".</p>

    <p>If the attribute field contains the username, common name
    and telephone number of a user, a CGI program will have access to
    this information without the need to make a second independent LDAP
    query to gather this additional information.</p>

    <p>This has the potential to dramatically simplify the coding and
    configuration required in some web applications.</p>

</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="frontpage" id="frontpage">Using Microsoft
    FrontPage with mod_authnz_ldap</a></h2>

    <p>Normally, FrontPage uses FrontPage-web-specific user/group
    files (i.e., the <code class="module"><a href="../mod/mod_authn_file.html">mod_authn_file</a></code> and
    <code class="module"><a href="../mod/mod_authz_groupfile.html">mod_authz_groupfile</a></code> 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>
<div class="example"><pre>
AuthLDAPURL            "the url"
AuthGroupFile <em>mygroupfile</em>
Require group <em>mygroupfile</em>
</pre></div>

<h3><a name="howitworks" id="howitworks">How It Works</a></h3>

    <p>FrontPage restricts access to a web by adding the <code>Require
    valid-user</code> directive to the <code>.htaccess</code>
    files. 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. By substituting the ldap-group with group file authorization,
    Apache is allowed to consult the local user file (which is managed by 
    FrontPage) - instead of LDAP - when handling authorizing the user.</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>


<h3><a name="fpcaveats" id="fpcaveats">Caveats</a></h3>

    <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 <code class="module"><a href="../mod/mod_authn_file.html">mod_authn_file</a></code> 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>

      
      <li>Apache must be compiled with <code class="module"><a href="../mod/mod_auth_basic.html">mod_auth_basic</a></code>,
      <code class="module"><a href="../mod/mod_authn_file.html">mod_authn_file</a></code> and
      <code class="module"><a href="../mod/mod_authz_groupfile.html">mod_authz_groupfile</a></code> in order to
      use FrontPage support. This is because Apache will still use
      the <code class="module"><a href="../mod/mod_authz_groupfile.html">mod_authz_groupfile</a></code> 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 <code class="directive"><a href="../mod/core.html#location">&lt;Location&gt;</a></code> or <code class="directive"><a href="../mod/core.html#directory">&lt;Directory&gt;</a></code> directives won't work. This
      is because <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> has to be able to grab
      the <code class="directive"><a href="../mod/mod_authn_file.html#authgroupfile">AuthGroupFile</a></code>
      directive that is found in FrontPage <code>.htaccess</code>
      files so that it knows where to look for the valid user list. If
      the <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> directives aren't in the same
      <code>.htaccess</code> file as the FrontPage directives, then
      the hack won't work, because <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> 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>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="AuthLDAPBindDN" id="AuthLDAPBindDN">AuthLDAPBindDN</a> <a name="authldapbinddn" id="authldapbinddn">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Optional DN to use in binding to the LDAP server</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthLDAPBindDN <em>distinguished-name</em></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_authnz_ldap</td></tr>
</table>
    <p>An optional DN used to bind to the server when searching for
    entries. If not provided, <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> will use
    an anonymous bind.</p>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="AuthLDAPBindPassword" id="AuthLDAPBindPassword">AuthLDAPBindPassword</a> <a name="authldapbindpassword" id="authldapbindpassword">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Password used in conjuction with the bind DN</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthLDAPBindPassword <em>password</em></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_authnz_ldap</td></tr>
</table>
    <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 <code class="directive"><a href="#authldapbinddn">AuthLDAPBindDN</a></code> and <code class="directive"><a href="#authldapbindpassword">AuthLDAPBindPassword</a></code> if you
    absolutely need them to search the directory.</p> 

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="AuthLDAPCharsetConfig" id="AuthLDAPCharsetConfig">AuthLDAPCharsetConfig</a> <a name="authldapcharsetconfig" id="authldapcharsetconfig">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Language to charset conversion configuration file</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthLDAPCharsetConfig <em>file-path</em></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_authnz_ldap</td></tr>
</table>
    <p>The <code class="directive">AuthLDAPCharsetConfig</code> directive sets the location
    of the language to charset conversion configuration file. <var>File-path</var> is relative
    to the <code class="directive"><a href="../mod/core.html#serverroot">ServerRoot</a></code>. 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>

    <div class="example"><p><code>
      <var>Language-Extension</var> <var>charset</var> [<var>Language-String</var>] ...
    </code></p></div>

    <p>The case of the extension does not matter. Blank lines, and lines
    beginning with a hash character (<code>#</code>) are ignored.</p>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="AuthLDAPCompareDNOnServer" id="AuthLDAPCompareDNOnServer">AuthLDAPCompareDNOnServer</a> <a name="authldapcomparednonserver" id="authldapcomparednonserver">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use the LDAP server to compare the DNs</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthLDAPCompareDNOnServer on|off</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AuthLDAPCompareDNOnServer on</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_authnz_ldap</td></tr>
</table>
    <p>When set, <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> will use the LDAP
    server to compare the DNs. This is the only foolproof way to
    compare DNs.  <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> 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,
    <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> simply does a string comparison. It
    is possible to get false negatives with this approach, but it is
    much faster. Note the <code class="module"><a href="../mod/mod_ldap.html">mod_ldap</a></code> cache can speed up
    DN comparison in most situations.</p>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="AuthLDAPDereferenceAliases" id="AuthLDAPDereferenceAliases">AuthLDAPDereferenceAliases</a> <a name="authldapdereferencealiases" id="authldapdereferencealiases">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>When will the module de-reference aliases</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthLDAPDereferenceAliases never|searching|finding|always</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AuthLDAPDereferenceAliases Always</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_authnz_ldap</td></tr>
</table>
    <p>This directive specifies when <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> will
    de-reference aliases during LDAP operations. The default is
    <code>always</code>.</p>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="AuthLDAPGroupAttribute" id="AuthLDAPGroupAttribute">AuthLDAPGroupAttribute</a> <a name="authldapgroupattribute" id="authldapgroupattribute">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>LDAP attributes used to check for group membership</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthLDAPGroupAttribute <em>attribute</em></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_authnz_ldap</td></tr>
</table>
    <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 <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> uses the <code>member</code> and
    <code>uniquemember</code> attributes.</p>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="AuthLDAPGroupAttributeIsDN" id="AuthLDAPGroupAttributeIsDN">AuthLDAPGroupAttributeIsDN</a> <a name="authldapgroupattributeisdn" id="authldapgroupattributeisdn">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use the DN of the client username when checking for
group membership</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthLDAPGroupAttributeIsDN on|off</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AuthLDAPGroupAttributeIsDN on</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_authnz_ldap</td></tr>
</table>
    <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,
    <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> will check if the group has
    <code>cn=Babs Jenson, o=Airius</code> as a member. If this
    directive is not set, then <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> will
    check if the group has <code>bjenson</code> as a member.</p>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="AuthLDAPRemoteUserAttribute" id="AuthLDAPRemoteUserAttribute">AuthLDAPRemoteUserAttribute</a> <a name="authldapremoteuserattribute" id="authldapremoteuserattribute">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use the value of the attribute returned during the user
query to set the REMOTE_USER environment variable</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthLDAPRemoteUserAttribute uid</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>none</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_authnz_ldap</td></tr>
</table>
    <p>If this directive is set, the value of the 
    <code>REMOTE_USER</code> environment variable will be set to the
    value of the attribute specified. Make sure that this attribute is
    included in the list of attributes in the AuthLDAPUrl definition,
    otherwise this directive will have no effect. This directive, if
    present, takes precedence over AuthLDAPRemoteUserIsDN. This
    directive is useful should you want people to log into a website
    using an email address, but a backend application expects the
    username as a userid.</p>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="AuthLDAPRemoteUserIsDN" id="AuthLDAPRemoteUserIsDN">AuthLDAPRemoteUserIsDN</a> <a name="authldapremoteuserisdn" id="authldapremoteuserisdn">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use the DN of the client username to set the REMOTE_USER
environment variable</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthLDAPRemoteUserIsDN on|off</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AuthLDAPRemoteUserIsDN off</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_authnz_ldap</td></tr>
</table>
    <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>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="AuthLDAPUrl" id="AuthLDAPUrl">AuthLDAPUrl</a> <a name="authldapurl" id="authldapurl">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>URL specifying the LDAP search parameters</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthLDAPUrl <em>url [NONE|SSL|TLS|STARTTLS]</em></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_authnz_ldap</td></tr>
</table>
    <p>An RFC 2255 URL which specifies the LDAP search parameters
    to use. The syntax of the URL is</p>
<div class="example"><p><code>ldap://host:port/basedn?attribute?scope?filter</code></p></div>

<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. <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code>
          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 class="program"><a href="../programs/httpd.html">httpd</a></code> process, or until the LDAP server goes
          down.</p>

          <p>If the LDAP server goes down and breaks an existing
          connection, <code class="module"><a href="../mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code> 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 more 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>An optional parameter can be added to allow the LDAP Url to override 
    the connection type.  This parameter can be one of the following:</p>

<dl>
    <dt>NONE</dt>
        <dd>Establish an unsecure connection on the default LDAP port. This
        is the same as <code>ldap://</code> on port 389.</dd>
    <dt>SSL</dt>
        <dd>Establish a secure connection on the default secure LDAP port.
        This is the same as <code>ldaps://</code></dd>
    <dt>TLS | STARTTLS</dt>
        <dd>Establish an upgraded secure connection on the default LDAP port.
        This connection will be initiated on port 389 by default and then 
        upgraded to a secure connection on the same port.</dd>
</dl>

    <p>See above for examples of <code class="directive"><a href="#authldapurl">AuthLDAPURL</a></code> URLs.</p>

    <p> When <code class="directive"><a href="#authldapurl">AuthLDAPURL</a></code>
    is enabled in a particular context, but some other module has performed
    authentication for the request, the server will try to map the username to a DN
    during authorization regardless of whether or not LDAP-specific requirements
    are present. To ignore the failures to map a username to a DN during
    authorization, set <code class="directive"><a href="#&#10;    authzldapautoritative">
    AuthzLDAPAutoritative</a></code> to "off".</p>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="AuthzLDAPAuthoritative" id="AuthzLDAPAuthoritative">AuthzLDAPAuthoritative</a> <a name="authzldapauthoritative" id="authzldapauthoritative">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Prevent other authentication modules from
authenticating the user if this one fails</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AuthzLDAPAuthoritative on|off</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AuthzLDAPAuthoritative on</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory, .htaccess</td></tr>
<tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_authnz_ldap</td></tr>
</table>
    <p>Set to <code>off</code> if this module should let other
    authorization modules attempt to authorize the user, should
    authorization 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>
    <p> When no LDAP-specific <code class="directive"><a href="../mod/core.html#require">Require</a></code>  directives
    are used, authorization is allowed to fall back to other modules
    as if <code class="directive"><a href="#authzldapauthoritative">AuthzLDAPAuthoritative</a></code>
    was set to <code>off</code>. </p>

</div>
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