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

<name>mod_authnz_ldap</name>

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

for HTTP Basic authentication.</description>

<status>Extension</status>

<sourcefile>mod_authnz_ldap.c</sourcefile>

<identifier>authnz_ldap_module</identifier>

<compatibility>Available in version 2.1 and later</compatibility>

<summary>

<p>This module provides authentication front-ends such as

<module>mod_auth_basic</module> to authenticate users through

an ldap directory.</p>

<p><module>mod_authnz_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>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 <module>mod_auth_basic</module>, this module is invoked

via the <directive module="mod_auth_basic">AuthBasicProvider</directive>

directive with the <code>ldap</code> value.</p>

</summary>

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

<seealso><module>mod_auth_basic</module></seealso>

<seealso><module>mod_authz_user</module></seealso>

<seealso><module>mod_authz_groupfile</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="#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="#activedirectory">Using Active Directory</a></li>

<li>

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

<module>mod_authnz_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 the <module>mod_authnz_ldap</module>

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 <module>mod_authnz_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>

<p><module>mod_authnz_ldap</module> registers both an authn_ldap authentication

provider and an authz_ldap authorization handler. The authn_ldap

authentication provider can be enabled through the

<directive module="mod_auth_basic">AuthBasicProvider</directive> directive

using the <code>ldap</code> value. The authz_ldap handler extends the

<directive module="mod_authz_core">Require</directive> directive's authorization types

by adding <code>ldap-user</code>, <code>ldap-dn</code> and <code>ldap-group</code>

values.</p>

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

Phase</title>

<p>During the authentication phase, <module>mod_authnz_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_authnz_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_authnz_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 that

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>

<columnspec><column width=".3"/><column width=".7"/></columnspec>

<tr>

<td><directive module="mod_authnz_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_authnz_ldap">AuthLDAPBindDN</directive></td>

<td>An optional DN to bind with

during the search phase.</td>

</tr>

<tr>

<td><directive

module="mod_authnz_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_authnz_ldap</module>

attempts to determine if the user is authorized to access the

resource. Many of these checks require

<module>mod_authnz_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_authnz_ldap</module> accepts the

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

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 or, potentially, in

one of its sub-groups.</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 <directive module="mod_authz_core">Require</directive> values may also

be used which may require loading additional authorization modules.</p>

<ul>

<li>Grant access to all successfully authenticated users if

there is a <a href="#requser"><code>Require valid-user</code></a>

directive. (requires <module>mod_authz_user</module>)</li>

<li>Grant access if there is a <a

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

<module>mod_authz_groupfile</module> has been loaded with the

<directive module="mod_authz_groupfile">AuthGroupFile</directive>

directive set.</li>

<li>others...</li>

</ul>

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

compare phase:</p>

<table>

<columnspec><column width=".4"/><column width=".6"/></columnspec>

<tr>

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

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

<td>Determines the behavior of the

<code>Require ldap-dn</code> directive.</td>

</tr>

<tr>

<td><directive

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

<td>Determines the attribute to

use for comparisons in the <code>Require ldap-group</code>

directive.</td>

</tr>

<tr>

<td><directive

module="mod_authnz_ldap">AuthLDAPGroupAttributeIsDN</directive></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>

<tr>

<td><directive

module="mod_authnz_ldap">AuthLDAPMaxSubGroupDepth</directive></td>

<td>Determines the maximum depth of sub-groups that will be evaluated

during comparisons in the <code>Require ldap-group</code> directive.</td>

</tr>

<tr>

<td><directive

module="mod_authnz_ldap">AuthLDAPSubGroupAttribute</directive></td>

<td>Determines the attribute to use when obtaining sub-group members

of the current group during comparisons in the <code>Require ldap-group</code>

directive.</td>

</tr>

<tr>

<td><directive

module="mod_authnz_ldap">AuthLDAPSubGroupClass</directive></td>

<td>Specifies the LDAP objectClass values used to identify if queried directory

objects really are group objects (as opposed to user objects) during the

<code>Require ldap-group</code> directive's sub-group processing.</td>

</tr>

</table>

</section>

</section>

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

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

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>

<section id="requser"><title>Require ldap-user</title>

<p>The <code>Require ldap-user</code> directive specifies what

usernames can access the resource. Once

<module>mod_authnz_ldap</module> 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 <directive

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

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

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

to restrict access:</p>

<example>

Require ldap-user "Barbara Jenson"<br />

Require ldap-user "Fred User"<br />

Require ldap-user "Joe Manager"<br />

</example>

<p>Because of the way that <module>mod_authnz_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

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>

<example>Require ldap-user bjenson fuser jmanager</example>

</section>

<section id="reqgroup"><title>Require ldap-group</title>

<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>

<example>

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

objectClass: groupOfUniqueNames<br />

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

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

</example>

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

Barbara:</p>

<example>Require ldap-group cn=Administrators, o=Example</example>

<p>Members can also be found within sub-groups of a specified LDAP group

if <directive module="mod_authnz_ldap">AuthLDAPMaxSubGroupDepth</directive>

is set to a value greater than 0. For example, assume the following entries

exist in the LDAP directory:</p>

<example>

dn: cn=Employees, o=Example<br />

objectClass: groupOfUniqueNames<br />

uniqueMember: cn=Managers, o=Example<br />

uniqueMember: cn=Administrators, o=Example<br />

uniqueMember: cn=Users, o=Example<br />

<br />

dn: cn=Managers, o=Example<br />

objectClass: groupOfUniqueNames<br />

uniqueMember: cn=Bob Ellis, o=Example<br />

uniqueMember: cn=Tom Jackson, o=Example<br />

<br />

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

objectClass: groupOfUniqueNames<br />

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

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

<br />

dn: cn=Users, o=Example<br />

objectClass: groupOfUniqueNames<br />

uniqueMember: cn=Allan Jefferson, o=Example<br />

uniqueMember: cn=Paul Tilley, o=Example<br />

uniqueMember: cn=Temporary Employees, o=Example<br />

<br />

dn: cn=Temporary Employees, o=Example<br />

objectClass: groupOfUniqueNames<br />

uniqueMember: cn=Jim Swenson, o=Example<br />

uniqueMember: cn=Elliot Rhodes, o=Example<br />

</example>

<p>The following directives would allow access for Bob Ellis, Tom Jackson,

Barbara Jensen, Fred User, Allan Jefferson, and Paul Tilley but would not

allow access for Jim Swenson, or Elliot Rhodes (since they are at a

sub-group depth of 2):</p>

<example>

Require ldap-group cn=Employees, o-Example<br />

AuthLDAPSubGroupDepth 1<br />

</example>

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

module="mod_authnz_ldap">AuthLDAPGroupAttribute</directive>, <directive

module="mod_authnz_ldap">AuthLDAPGroupAttributeIsDN</directive>, <directive

module="mod_authnz_ldap">AuthLDAPMaxSubGroupDepth</directive>, <directive

module="mod_authnz_ldap">AuthLDAPSubGroupAttribute</directive>, and <directive

module="mod_authnz_ldap">AuthLDAPSubGroupClass</directive>

directives.</p>

</section>

<section id="reqdn"><title>Require ldap-dn</title>

<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>

<example>Require ldap-dn cn=Barbara Jenson, o=Example</example>

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

module="mod_authnz_ldap">AuthLDAPCompareDNOnServer</directive>

directive.</p>

</section>

<section id="reqattribute"><title>Require ldap-attribute</title>

<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>

<example>Require ldap-attribute employeeType=active</example>

<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>

<example>Require ldap-attribute city="San Jose" status=active</example>

</section>

<section id="reqfilter"><title>Require ldap-filter</title>

<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>

<example>Require ldap-filter &amp;(cell=*)(department=marketing)</example>

<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>

</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.example.com:389/ou=People, o=Example?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.example.com ldap2.example.com/ou=People, o=Example"<br />

Require valid-user

</example>

</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>.

<example>

AuthLDAPURL "ldap://ldap.example.com/ou=People, o=Example?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.example.com/o=Example?uid<br />

Require ldap-group cn=Administrators, o=Example

</example>

</li>

<li>

The next example assumes that everyone at Example 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.example.com/o=Example?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 pager, 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.example.com/o=Example?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. 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">LDAPTrustedClientCert</directive>, <directive

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

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

<p>An optional second parameter can be added to the

<directive module="mod_authnz_ldap">AuthLDAPURL</directive> to override

the default connection type set by <directive module="mod_ldap">LDAPTrustedMode</directive>.

This will allow the connection established by an <em>ldap://</em> Url

to be upgraded to a secure connection on the same port.</p>

</section>

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

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

module="mod_ldap">LDAPTrustedClientCert</directive>, <directive

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

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

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

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

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

</section>

<section id="exposed"><title>Exposing Login Information</title>

<p>when this module performs <em>authentication</em>, ldap attributes specified

in the <directive module="mod_authnz_ldap">authldapurl</directive>

directive are placed in environment variables with the prefix "AUTHENTICATE_".</p>

<p>when this module performs <em>authorization</em>, ldap attributes specified

in the <directive module="mod_authnz_ldap">authldapurl</directive>

directive are placed in environment variables with the prefix "AUTHORIZE_".</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>

</section>

<section id="activedirectory"><title>Using Active Directory</title>

<p>An Active Directory installation may support multiple domains at the

same time. To distinguish users between domains, an identifier called

a User Principle Name (UPN) can be added to a user's entry in the

directory. This UPN usually takes the form of the user's account

name, followed by the domain components of the particular domain,

for example <em>somebody@nz.example.com</em>.</p>

<p>You may wish to configure the <module>mod_authnz_ldap</module>

module to authenticate users present in any of the domains making up

the Active Directory forest. In this way both

<em>somebody@nz.example.com</em> and <em>someone@au.example.com</em>

can be authenticated using the same query at the same time.</p>

<p>To make this practical, Active Directory supports the concept of

a Global Catalog. This Global Catalog is a read only copy of selected

attributes of all the Active Directory servers within the Active

Directory forest. Querying the Global Catalog allows all the domains

to be queried in a single query, without the query spanning servers

over potentially slow links.</p>

<p>If enabled, the Global Catalog is an independent directory server

that runs on port 3268 (3269 for SSL). To search for a user, do a

subtree search for the attribute <em>userPrincipalName</em>, with

an empty search root, like so:</p>

<example>

AuthLDAPBindDN apache@example.com<br />

AuthLDAPBindPassword password<br />

AuthLDAPURL ldap://10.0.0.1:3268/?userPrincipalName?sub

</example>

<p>Users will need to enter their User Principal Name as a login, in

the form <em>somebody@nz.example.com</em>.</p>

</section>

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

FrontPage with mod_authnz_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"

AuthGroupFile <em>mygroupfile</em>

Require group <em>mygroupfile</em>

</pre></example>

<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. 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>

</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_authnz_ldap</module> has to be able to grab

the <directive module="mod_authn_file">AuthGroupFile</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_authnz_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_authnz_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>AuthLDAPAuthorizePrefix</name>

<description>Specifies the prefix for environment variables set during

authorization</description>

<syntax>AuthLDAPAuthorizePrefix <em>prefix</em></syntax>

<default>AuthLDAPAuthorizePrefix AUTHORIZE_</default>

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

</contextlist>

<override>AuthConfig</override>

<compatibility>Available in version 2.3.6 and later</compatibility>

<usage>

<p>This directive allows you to override the prefix used for environment

variables set during LDAP authorization. If <em>AUTHENTICATE_</em> is

specified, consumers of these environment variables see the same information

whether LDAP has performed authentication, authorization, or both.</p>

<note><title>Note</title>

No authorization variables are set when a user is authorized on the basis of

<code>Require valid-user</code>.

</note>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPBindAuthoritative</name>

<description>Determines if other authentication providers are used when a user can be mapped to a DN but the server cannot successfully bind with the user's credentials.</description>

<syntax>AuthLDAPBindAuthoritative<em>off|on</em></syntax>

<default>AuthLDAPBindAuthoritative on</default>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>By default, subsequent authentication providers are only queried if a

user cannot be mapped to a DN, but not if the user can be mapped to a DN and their

password cannot be verified with an LDAP bind.

If <directive module="mod_authnz_ldap">AuthLDAPBindAuthoritative</directive>

is set to <em>off</em>, other configured authentication modules will have

a chance to validate the user if the LDAP bind (with the current user's credentials)

fails for any reason.</p>

<p> This allows users present in both LDAP and

<directive module="mod_authn_file">AuthUserFile</directive> to authenticate

when the LDAP server is available but the user's account is locked or password

is otherwise unusable.</p>

</usage>

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

<seealso><directive module="mod_auth_basic">AuthBasicProvider</directive></seealso>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPInitialBindAsUser</name>

<description>Determines if the server does the initial DN lookup using the basic authentication users'

own username, instead of anonymously or with hard-coded credentials for the server</description>

<syntax>AuthLDAPInitialBindAsUser <em>off|on</em></syntax>

<default>AuthLDAPInitialBindAsUser off</default>

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

</contextlist>

<override>AuthConfig</override>

<compatibility>Available in version 2.3.6 and later</compatibility>

<usage>

<p>By default, the server either anonymously, or with a dedicated user and

password, converts the basic authentication username into an LDAP

distinguished name (DN). This directive forces the server to use the verbatim username

and password provided by the incoming user to perform the initial DN

search.</p>

<p> If the verbatim username can't directly bind, but needs some

cosmetic transformation, see <directive module="mod_authnz_ldap">

AuthLDAPInitialBindPattern</directive>.</p>

<p> This directive should only be used when your LDAP server doesn't

accept anonymous searches and you cannot use a dedicated

<directive module="mod_authnz_ldap">AuthLDAPBindDN</directive>.

</p>

<note><title>Not available with authorization-only</title>

This directive can only be used if this module authenticates the user, and

has no effect when this module is used exclusively for authorization.

</note>

</usage>

<seealso><directive module="mod_authnnz_ldap">AuthLDAPInitialBindPattern</directive></seealso>

<seealso><directive module="mod_authnnz_ldap">AuthLDAPBindDN</directive></seealso>

<seealso><directive module="mod_authnz_ldap">AuthLDAPCompareAsUser</directive></seealso>

<seealso><directive module="mod_authnz_ldap">AuthLDAPSearchAsUser</directive></seealso>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPInitialBindPattern</name>

<description>Specifies the transformation of the basic authentication username to be used when binding to the LDAP server

to perform a DN lookup</description>

<syntax>AuthLDAPInitialBindPattern<em><var>regex</var> <var>substitution</var></em></syntax>

<default>AuthLDAPInitialBindPattern (.*) $1 (remote username used verbatim)</default>

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

</contextlist>

<override>AuthConfig</override>

<compatibility>Available in version 2.3.6 and later</compatibility>

<usage>

<p>If <directive module="mod_authnz_ldap">AuthLDAPInitialBindAsUser</directive> is set to

<em>ON</em>, the basic authentication username will be transformed according to the

regular expression and substituion arguments.</p>

<p> The regular expression argument is compared against the current basic authentication username.

The substitution argument may contain backreferences, but has no other variable interpolation.</p>

<p> This directive should only be used when your LDAP server doesn't

accept anonymous searches and you cannot use a dedicated

<directive module="mod_authnz_ldap">AuthLDAPBindDN</directive>.

</p>

<example> AuthLDAPInitialBindPattern (.+) $1@example.com </example>

<example> AuthLDAPInitialBindPattern (.+) cn=$1,dc=example,dc=com</example>

<note><title>Not available with authorization-only</title>

This directive can only be used if this module authenticates the user, and

has no effect when this module is used exclusively for authorization.

</note>

<note><title>debugging</title>

The substituted DN is recorded in the environment variable

<em>LDAP_BINDASUSER</em>. If the regular expression does not match the input,

the verbatim username is used.

</note>

</usage>

<seealso><directive module="mod_authnnz_ldap">AuthLDAPInitialBindAsUser</directive></seealso>

<seealso><directive module="mod_authnnz_ldap">AuthLDAPBindDN</directive></seealso>

</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_authnz_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_authnz_ldap">AuthLDAPBindDN</directive> and <directive

module="mod_authnz_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>AuthLDAPCompareAsUser</name>

<description>Use the authenticated user's credentials to perform authorization comparisons</description>

<syntax>AuthLDAPCompareAsUser on|off</syntax>

<default>AuthLDAPCompareAsUser off</default>

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

</contextlist>

<override>AuthConfig</override>

<compatibility>Available in version 2.3.6 and later</compatibility>

<usage>

<p>When set, and <module>mod_authnz_ldap</module> has authenticated the

user, LDAP comparisons for authorization use the queried distinguished name (DN)

and HTTP basic authentication password of the authenticated user instead of

the servers configured credentials.</p>

<p> The <em>ldap-attribute</em>, <em>ldap-user</em>, and <em>ldap-group</em> (single-level only)

authorization checks use comparisons.</p>

<p>This directive only has effect on the comparisons performed during

nested group processing when <directive module="mod_authnz_ldap">

AuthLDAPSearchAsUser</directive> is also enabled.</p>

<p> This directive should only be used when your LDAP server doesn't

accept anonymous comparisons and you cannot use a dedicated

<directive module="mod_authnz_ldap">AuthLDAPBindDN</directive>.

</p>

</usage>

<seealso><directive module="mod_authnz_ldap">AuthLDAPInitialBindAsUser</directive></seealso>

<seealso><directive module="mod_authnz_ldap">AuthLDAPSearchAsUser</directive></seealso>

</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_authnz_ldap</module> will use the LDAP

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

compare DNs. <module>mod_authnz_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_authnz_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_authnz_ldap</module> will

de-reference aliases during LDAP operations. The default is

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

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPGroupAttribute</name>

<description>LDAP attributes used to identify the user members of

groups.</description>

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

<default>AuthLDAPGroupAttribute member uniquemember</default>

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

</contextlist>

<override>AuthConfig</override>

<usage>

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

check for user members within groups. Multiple attributes can be used

by specifying this directive multiple times. If not specified,

then <module>mod_authnz_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=Example</code>. If this directive is set,

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

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

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

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

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPMaxSubGroupDepth</name>

<description>Specifies the maximum sub-group nesting depth that will be

evaluated before the user search is discontinued.</description>

<syntax>AuthLDAPMaxSubGroupDepth <var>Number</var></syntax>

<default>AuthLDAPMaxSubGroupDepth 10</default>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>When this directive is set to a non-zero value <code>X</code>

combined with use of the <code>Require ldap-group someGroupDN</code>

directive, the provided user credentials will be searched for

as a member of the <code>someGroupDN</code> directory object or of

any group member of the current group up to the maximum nesting

level <code>X</code> specified by this directive.</p>

<p>See the <a href="#reqgroup"><code>Require ldap-group</code></a>

section for a more detailed example.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPRemoteUserAttribute</name>

<description>Use the value of the attribute returned during the user

query to set the REMOTE_USER environment variable</description>

<syntax>AuthLDAPRemoteUserAttribute uid</syntax>

<default>none</default>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<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>

</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>AuthLDAPSearchAsUser</name>

<description>Use the authenticated user's credentials to perform authorization searches</description>

<syntax>AuthLDAPSearchAsUser on|off</syntax>

<default>AuthLDAPSearchAsUser off</default>

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

</contextlist>

<override>AuthConfig</override>

<compatibility>Available in version 2.3.6 and later</compatibility>

<usage>

<p>When set, and <module>mod_authnz_ldap</module> has authenticated the

user, LDAP searches for authorization use the queried distinguished name (DN)

and HTTP basic authentication password of the authenticated user instead of

the servers configured credentials.</p>

<p> The <em>ldap-filter</em> and <em>ldap-dn</em> authorization

checks use searches.</p>

<p>This directive only has effect on the comparisons performed during

nested group processing when <directive module="mod_authnz_ldap">

AuthLDAPCompareAsUser</directive> is also enabled.</p>

<p> This directive should only be used when your LDAP server doesn't

accept anonymous searches and you cannot use a dedicated

<directive module="mod_authnz_ldap">AuthLDAPBindDN</directive>.

</p>

</usage>

<seealso><directive module="mod_authnz_ldap">AuthLDAPInitialBindAsUser</directive></seealso>

<seealso><directive module="mod_authnz_ldap">AuthLDAPCompareAsUser</directive></seealso>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPSubGroupAttribute</name>

<description>Specifies the attribute labels, one value per

directive line, used to distinguish the members of the current group that

are groups.</description>

<syntax>AuthLDAPSubGroupAttribute <em>attribute</em></syntax>

<default>AuthLDAPSubgroupAttribute member uniquemember</default>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>An LDAP group object may contain members that are users and

members that are groups (called nested or sub groups). The

<code>AuthLDAPSubGroupAttribute</code> directive identifies the

labels of group members and the <code>AuthLDAPGroupAttribute</code>

directive identifies the labels of the user members. Multiple

attributes can be used by specifying this directive multiple times.

If not specified, then <module>mod_authnz_ldap</module> uses the

<code>member</code> and <code>uniqueMember</code> attributes.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPSubGroupClass</name>

<description>Specifies which LDAP objectClass values identify directory

objects that are groups during sub-group processing.</description>

<syntax>AuthLDAPSubGroupClass <em>LdapObjectClass</em></syntax>

<default>AuthLDAPSubGroupClass groupOfNames groupOfUniqueNames</default>

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

</contextlist>

<override>AuthConfig</override>

<usage>

<p>An LDAP group object may contain members that are users and

members that are groups (called nested or sub groups). The

<code>AuthLDAPSubGroupAttribute</code> directive identifies the

labels of members that may be sub-groups of the current group

(as opposed to user members). The <code>AuthLDAPSubGroupClass</code>

directive specifies the LDAP objectClass values used in verifying that

these potential sub-groups are in fact group objects. Verified sub-groups

can then be searched for more user or sub-group members. Multiple

attributes can be used by specifying this directive multiple times.

If not specified, then <module>mod_authnz_ldap</module> uses the

<code>groupOfNames</code> and <code>groupOfUniqueNames</code> values.</p>

</usage>

</directivesynopsis>

<directivesynopsis>

<name>AuthLDAPUrl</name>

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

<syntax>AuthLDAPUrl <em>url [NONE|SSL|TLS|STARTTLS]</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>

<p>If you want to specify more than one LDAP URL that Apache should try in turn, the syntax is:</p>

<example>AuthLDAPUrl "ldap://ldap1.example.com ldap2.example.com/dc=..."</example>

<p><em><strong>Caveat: </strong>If you specify multiple servers, you need to enclose the entire URL string in quotes;

otherwise you will get an error: "AuthLDAPURL takes one argument, URL to define LDAP connection.." </em>

You can of course use search parameters on each of these.</p>

<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_authnz_ldap</module>

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

successful connection. If multiple ldap servers are specified,

then entire LDAP URL must be encapsulated in double quotes.</p>

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

connection remains active for the life of the

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

down.</p>

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

connection, <module>mod_authnz_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. All attributes

listed will be put into the environment with an AUTHENTICATE_ prefix

for use by other modules.</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.example.com/o=Example?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 <directive

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

</usage>

</directivesynopsis>

</modulesynopsis>