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23 <modulesynopsis metafile="mod_authnz_ldap.xml.meta">
25 <name>mod_authnz_ldap</name>
26 <description>Allows an LDAP directory to be used to store the database
27 for HTTP Basic authentication.</description>
28 <status>Extension</status>
29 <sourcefile>mod_authnz_ldap.c</sourcefile>
30 <identifier>authnz_ldap_module</identifier>
33 <p>This module allows authentication front-ends such as
34 <module>mod_auth_basic</module> to authenticate users through
35 an ldap directory.</p>
37 <p><module>mod_authnz_ldap</module> supports the following features:</p>
40 <li>Known to support the <a
41 href="http://www.openldap.org/">OpenLDAP SDK</a> (both 1.x
42 and 2.x), <a href="http://developer.novell.com/ndk/cldap.htm">
43 Novell LDAP SDK</a> and the <a
44 href="http://www.iplanet.com/downloads/developer/">iPlanet
45 (Netscape)</a> SDK.</li>
47 <li>Complex authorization policies can be implemented by
48 representing the policy with LDAP filters.</li>
50 <li>Uses extensive caching of LDAP operations via <a
51 href="mod_ldap.html">mod_ldap</a>.</li>
53 <li>Support for LDAP over SSL (requires the Netscape SDK) or
54 TLS (requires the OpenLDAP 2.x SDK or Novell LDAP SDK).</li>
57 <p>When using <module>mod_auth_basic</module>, this module is invoked
58 via the <directive module="mod_auth_basic">AuthBasicProvider</directive>
59 directive with the <code>ldap</code> value.</p>
62 <seealso><module>mod_ldap</module></seealso>
63 <seealso><module>mod_auth_basic</module></seealso>
64 <seealso><module>mod_authz_user</module></seealso>
65 <seealso><module>mod_authz_groupfile</module></seealso>
67 <section id="contents"><title>Contents</title>
71 <a href="#operation">Operation</a>
74 <li><a href="#authenphase">The Authentication
77 <li><a href="#authorphase">The Authorization
83 <a href="#requiredirectives">The Require Directives</a>
86 <li><a href="#requser">Require ldap-user</a></li>
87 <li><a href="#reqgroup">Require ldap-group</a></li>
88 <li><a href="#reqdn">Require ldap-dn</a></li>
89 <li><a href="#reqattribute">Require ldap-attribute</a></li>
90 <li><a href="#reqfilter">Require ldap-filter</a></li>
94 <li><a href="#examples">Examples</a></li>
95 <li><a href="#usingtls">Using TLS</a></li>
96 <li><a href="#usingssl">Using SSL</a></li>
97 <li><a href="#exposed">Exposing Login Information</a></li>
98 <li><a href="#activedirectory">Using Active Directory</a></li>
100 <a href="#frontpage">Using Microsoft FrontPage with
101 <module>mod_authnz_ldap</module></a>
104 <li><a href="#howitworks">How It Works</a></li>
105 <li><a href="#fpcaveats">Caveats</a></li>
111 <section id="operation"><title>Operation</title>
113 <p>There are two phases in granting access to a user. The first
114 phase is authentication, in which the <module>mod_authnz_ldap</module>
115 authentication provider verifies that the user's credentials are valid.
116 This is also called the <em>search/bind</em> phase. The second phase is
117 authorization, in which <module>mod_authnz_ldap</module> determines
118 if the authenticated user is allowed access to the resource in
119 question. This is also known as the <em>compare</em>
122 <p><module>mod_authnz_ldap</module> registers both an authn_ldap authentication
123 provider and an authz_ldap authorization handler. The authn_ldap
124 authentication provider can be enabled through the
125 <directive module="mod_auth_basic">AuthBasicProvider</directive> directive
126 using the <code>ldap</code> value. The authz_ldap handler extends the
127 <directive module="mod_authz_core">Require</directive> directive's authorization types
128 by adding <code>ldap-user</code>, <code>ldap-dn</code> and <code>ldap-group</code>
131 <section id="authenphase"><title>The Authentication
134 <p>During the authentication phase, <module>mod_authnz_ldap</module>
135 searches for an entry in the directory that matches the username
136 that the HTTP client passes. If a single unique match is found,
137 then <module>mod_authnz_ldap</module> attempts to bind to the
138 directory server using the DN of the entry plus the password
139 provided by the HTTP client. Because it does a search, then a
140 bind, it is often referred to as the search/bind phase. Here are
141 the steps taken during the search/bind phase.</p>
144 <li>Generate a search filter by combining the attribute and
145 filter provided in the <directive module="mod_authnz_ldap"
146 >AuthLDAPURL</directive> directive with
147 the username passed by the HTTP client.</li>
149 <li>Search the directory using the generated filter. If the
150 search does not return exactly one entry, deny or decline
153 <li>Fetch the distinguished name of the entry retrieved from
154 the search and attempt to bind to the LDAP server using that
155 DN and the password passed by the HTTP client. If the bind is
156 unsuccessful, deny or decline access.</li>
159 <p>The following directives are used during the search/bind
163 <columnspec><column width=".3"/><column width=".7"/></columnspec>
165 <td><directive module="mod_authnz_ldap">AuthLDAPURL</directive></td>
167 <td>Specifies the LDAP server, the
168 base DN, the attribute to use in the search, as well as the
169 extra search filter to use.</td>
173 <td><directive module="mod_authnz_ldap">AuthLDAPBindDN</directive></td>
175 <td>An optional DN to bind with
176 during the search phase.</td>
181 module="mod_authnz_ldap">AuthLDAPBindPassword</directive></td>
183 <td>An optional password to bind
184 with during the search phase.</td>
189 <section id="authorphase"><title>The Authorization Phase</title>
191 <p>During the authorization phase, <module>mod_authnz_ldap</module>
192 attempts to determine if the user is authorized to access the
193 resource. Many of these checks require
194 <module>mod_authnz_ldap</module> to do a compare operation on the
195 LDAP server. This is why this phase is often referred to as the
196 compare phase. <module>mod_authnz_ldap</module> accepts the
197 following <directive module="mod_authz_core">Require</directive>
198 directives to determine if the credentials are acceptable:</p>
201 <li>Grant access if there is a <a
202 href="#reqgroup"><code>Require ldap-user</code></a> directive, and the
203 username in the directive matches the username passed by the
206 <li>Grant access if there is a <a href="#reqdn"><code>Require
207 ldap-dn</code></a> directive, and the DN in the directive matches
208 the DN fetched from the LDAP directory.</li>
210 <li>Grant access if there is a <a
211 href="#reqgroup"><code>Require ldap-group</code></a> directive, and
212 the DN fetched from the LDAP directory (or the username
213 passed by the client) occurs in the LDAP group or, potentially, in
214 one of its sub-groups.</li>
216 <li>Grant access if there is a <a href="#reqattribute">
217 <code>Require ldap-attribute</code></a>
218 directive, and the attribute fetched from the LDAP directory
219 matches the given value.</li>
221 <li>Grant access if there is a <a href="#reqfilter">
222 <code>Require ldap-filter</code></a>
223 directive, and the search filter successfully finds a single user
224 object that matches the dn of the authenticated user.</li>
226 <li>otherwise, deny or decline access</li>
229 <p>Other <directive module="mod_authz_core">Require</directive> values may also
230 be used which may require loading additional authorization modules.</p>
233 <li>Grant access to all successfully authenticated users if
234 there is a <a href="#requser"><code>Require valid-user</code></a>
235 directive. (requires <module>mod_authz_user</module>)</li>
237 <li>Grant access if there is a <a
238 href="#reqgroup"><code>Require group</code></a> directive, and
239 <module>mod_authz_groupfile</module> has been loaded with the
240 <directive module="mod_authz_groupfile">AuthGroupFile</directive>
247 <p><module>mod_authnz_ldap</module> uses the following directives during the
251 <columnspec><column width=".4"/><column width=".6"/></columnspec>
253 <td><directive module="mod_authnz_ldap">AuthLDAPURL</directive> </td>
255 <td>The attribute specified in the
256 URL is used in compare operations for the <code>Require
257 ldap-user</code> operation.</td>
262 module="mod_authnz_ldap">AuthLDAPCompareDNOnServer</directive></td>
264 <td>Determines the behavior of the
265 <code>Require ldap-dn</code> directive.</td>
270 module="mod_authnz_ldap">AuthLDAPGroupAttribute</directive></td>
272 <td>Determines the attribute to
273 use for comparisons in the <code>Require ldap-group</code>
279 module="mod_authnz_ldap">AuthLDAPGroupAttributeIsDN</directive></td>
281 <td>Specifies whether to use the
282 user DN or the username when doing comparisons for the
283 <code>Require ldap-group</code> directive.</td>
288 module="mod_authnz_ldap">AuthLDAPMaxSubGroupDepth</directive></td>
290 <td>Determines the maximum depth of sub-groups that will be evaluated
291 during comparisons in the <code>Require ldap-group</code> directive.</td>
296 module="mod_authnz_ldap">AuthLDAPSubGroupAttribute</directive></td>
298 <td>Determines the attribute to use when obtaining sub-group members
299 of the current group during comparisons in the <code>Require ldap-group</code>
305 module="mod_authnz_ldap">AuthLDAPSubGroupClass</directive></td>
307 <td>Specifies the LDAP objectClass values used to identify if queried directory
308 objects really are group objects (as opposed to user objects) during the
309 <code>Require ldap-group</code> directive's sub-group processing.</td>
315 <section id="requiredirectives"><title>The Require Directives</title>
317 <p>Apache's <directive module="mod_authz_core">Require</directive>
318 directives are used during the authorization phase to ensure that
319 a user is allowed to access a resource. mod_authnz_ldap extends the
320 authorization types with <code>ldap-user</code>, <code>ldap-dn</code>,
321 <code>ldap-group</code>, <code>ldap-attribute</code> and
322 <code>ldap-filter</code>. Other authorization types may also be
323 used but may require that additional authorization modules be loaded.</p>
325 <p>Since v2.4.8, <a href="../expr.html">expressions</a> are supported
326 within the LDAP require directives.</p>
328 <section id="requser"><title>Require ldap-user</title>
330 <p>The <code>Require ldap-user</code> directive specifies what
331 usernames can access the resource. Once
332 <module>mod_authnz_ldap</module> has retrieved a unique DN from the
333 directory, it does an LDAP compare operation using the username
334 specified in the <code>Require ldap-user</code> to see if that username
335 is part of the just-fetched LDAP entry. Multiple users can be
336 granted access by putting multiple usernames on the line,
337 separated with spaces. If a username has a space in it, then it
338 must be surrounded with double quotes. Multiple users can also be
339 granted access by using multiple <code>Require ldap-user</code>
340 directives, with one user per line. For example, with a <directive
341 module="mod_authnz_ldap">AuthLDAPURL</directive> of
342 <code>ldap://ldap/o=Example?cn</code> (i.e., <code>cn</code> is
343 used for searches), the following Require directives could be used
344 to restrict access:</p>
345 <highlight language="config">
346 Require ldap-user "Barbara Jenson"
347 Require ldap-user "Fred User"
348 Require ldap-user "Joe Manager"
351 <p>Because of the way that <module>mod_authnz_ldap</module> handles this
352 directive, Barbara Jenson could sign on as <em>Barbara
353 Jenson</em>, <em>Babs Jenson</em> or any other <code>cn</code> that
354 she has in her LDAP entry. Only the single <code>Require
355 ldap-user</code> line is needed to support all values of the attribute
356 in the user's entry.</p>
358 <p>If the <code>uid</code> attribute was used instead of the
359 <code>cn</code> attribute in the URL above, the above three lines
360 could be condensed to</p>
361 <highlight language="config">Require ldap-user bjenson fuser jmanager</highlight>
364 <section id="reqgroup"><title>Require ldap-group</title>
366 <p>This directive specifies an LDAP group whose members are
367 allowed access. It takes the distinguished name of the LDAP
368 group. Note: Do not surround the group name with quotes.
369 For example, assume that the following entry existed in
370 the LDAP directory:</p>
372 dn: cn=Administrators, o=Example
373 objectClass: groupOfUniqueNames
374 uniqueMember: cn=Barbara Jenson, o=Example
375 uniqueMember: cn=Fred User, o=Example
378 <p>The following directive would grant access to both Fred and
380 <highlight language="config">Require ldap-group cn=Administrators, o=Example</highlight>
382 <p>Members can also be found within sub-groups of a specified LDAP group
383 if <directive module="mod_authnz_ldap">AuthLDAPMaxSubGroupDepth</directive>
384 is set to a value greater than 0. For example, assume the following entries
385 exist in the LDAP directory:</p>
387 dn: cn=Employees, o=Example
388 objectClass: groupOfUniqueNames
389 uniqueMember: cn=Managers, o=Example
390 uniqueMember: cn=Administrators, o=Example
391 uniqueMember: cn=Users, o=Example
393 dn: cn=Managers, o=Example
394 objectClass: groupOfUniqueNames
395 uniqueMember: cn=Bob Ellis, o=Example
396 uniqueMember: cn=Tom Jackson, o=Example
398 dn: cn=Administrators, o=Example
399 objectClass: groupOfUniqueNames
400 uniqueMember: cn=Barbara Jenson, o=Example
401 uniqueMember: cn=Fred User, o=Example
403 dn: cn=Users, o=Example
404 objectClass: groupOfUniqueNames
405 uniqueMember: cn=Allan Jefferson, o=Example
406 uniqueMember: cn=Paul Tilley, o=Example
407 uniqueMember: cn=Temporary Employees, o=Example
409 dn: cn=Temporary Employees, o=Example
410 objectClass: groupOfUniqueNames
411 uniqueMember: cn=Jim Swenson, o=Example
412 uniqueMember: cn=Elliot Rhodes, o=Example
415 <p>The following directives would allow access for Bob Ellis, Tom Jackson,
416 Barbara Jensen, Fred User, Allan Jefferson, and Paul Tilley but would not
417 allow access for Jim Swenson, or Elliot Rhodes (since they are at a
418 sub-group depth of 2):</p>
419 <highlight language="config">
420 Require ldap-group cn=Employees, o-Example
421 AuthLDAPMaxSubGroupDepth 1
424 <p>Behavior of this directive is modified by the <directive
425 module="mod_authnz_ldap">AuthLDAPGroupAttribute</directive>, <directive
426 module="mod_authnz_ldap">AuthLDAPGroupAttributeIsDN</directive>, <directive
427 module="mod_authnz_ldap">AuthLDAPMaxSubGroupDepth</directive>, <directive
428 module="mod_authnz_ldap">AuthLDAPSubGroupAttribute</directive>, and <directive
429 module="mod_authnz_ldap">AuthLDAPSubGroupClass</directive>
433 <section id="reqdn"><title>Require ldap-dn</title>
435 <p>The <code>Require ldap-dn</code> directive allows the administrator
436 to grant access based on distinguished names. It specifies a DN
437 that must match for access to be granted. If the distinguished
438 name that was retrieved from the directory server matches the
439 distinguished name in the <code>Require ldap-dn</code>, then
440 authorization is granted. Note: do not surround the distinguished
441 name with quotes.</p>
443 <p>The following directive would grant access to a specific
445 <highlight language="config">Require ldap-dn cn=Barbara Jenson, o=Example</highlight>
447 <p>Behavior of this directive is modified by the <directive
448 module="mod_authnz_ldap">AuthLDAPCompareDNOnServer</directive>
452 <section id="reqattribute"><title>Require ldap-attribute</title>
454 <p>The <code>Require ldap-attribute</code> directive allows the
455 administrator to grant access based on attributes of the authenticated
456 user in the LDAP directory. If the attribute in the directory
457 matches the value given in the configuration, access is granted.</p>
459 <p>The following directive would grant access to anyone with
460 the attribute employeeType = active</p>
462 <highlight language="config">Require ldap-attribute employeeType=active</highlight>
464 <p>Multiple attribute/value pairs can be specified on the same line
465 separated by spaces or they can be specified in multiple
466 <code>Require ldap-attribute</code> directives. The effect of listing
467 multiple attribute/values pairs is an OR operation. Access will be
468 granted if any of the listed attribute values match the value of the
469 corresponding attribute in the user object. If the value of the
470 attribute contains a space, only the value must be within double quotes.</p>
472 <p>The following directive would grant access to anyone with
473 the city attribute equal to "San Jose" or status equal to "Active"</p>
475 <highlight language="config">Require ldap-attribute city="San Jose" status=active</highlight>
479 <section id="reqfilter"><title>Require ldap-filter</title>
481 <p>The <code>Require ldap-filter</code> directive allows the
482 administrator to grant access based on a complex LDAP search filter.
483 If the dn returned by the filter search matches the authenticated user
484 dn, access is granted.</p>
486 <p>The following directive would grant access to anyone having a cell phone
487 and is in the marketing department</p>
489 <highlight language="config">Require ldap-filter &(cell=*)(department=marketing)</highlight>
491 <p>The difference between the <code>Require ldap-filter</code> directive and the
492 <code>Require ldap-attribute</code> directive is that <code>ldap-filter</code>
493 performs a search operation on the LDAP directory using the specified search
494 filter rather than a simple attribute comparison. If a simple attribute
495 comparison is all that is required, the comparison operation performed by
496 <code>ldap-attribute</code> will be faster than the search operation
497 used by <code>ldap-filter</code> especially within a large directory.</p>
503 <section id="examples"><title>Examples</title>
507 Grant access to anyone who exists in the LDAP directory,
508 using their UID for searches.
509 <highlight language="config">
510 AuthLDAPURL "ldap://ldap1.example.com:389/ou=People, o=Example?uid?sub?(objectClass=*)"
516 The next example is the same as above; but with the fields
517 that have useful defaults omitted. Also, note the use of a
518 redundant LDAP server.
519 <highlight language="config">AuthLDAPURL "ldap://ldap1.example.com ldap2.example.com/ou=People, o=Example"
525 The next example is similar to the previous one, but it
526 uses the common name instead of the UID. Note that this
527 could be problematical if multiple people in the directory
528 share the same <code>cn</code>, because a search on <code>cn</code>
529 <strong>must</strong> return exactly one entry. That's why
530 this approach is not recommended: it's a better idea to
531 choose an attribute that is guaranteed unique in your
532 directory, such as <code>uid</code>.
533 <highlight language="config">
534 AuthLDAPURL "ldap://ldap.example.com/ou=People, o=Example?cn"
540 Grant access to anybody in the Administrators group. The
541 users must authenticate using their UID.
542 <highlight language="config">
543 AuthLDAPURL ldap://ldap.example.com/o=Example?uid
544 Require ldap-group cn=Administrators, o=Example
549 Grant access to anybody in the group whose name matches the
550 hostname of the virtual host. In this example an
551 <a href="../expr.html">expression</a> is used to build the filter.
552 <highlight language="config">
553 AuthLDAPURL ldap://ldap.example.com/o=Example?uid
554 Require ldap-group cn=%{SERVER_NAME}, o=Example
559 The next example assumes that everyone at Example who
560 carries an alphanumeric pager will have an LDAP attribute
561 of <code>qpagePagerID</code>. The example will grant access
562 only to people (authenticated via their UID) who have
564 <highlight language="config">
565 AuthLDAPURL ldap://ldap.example.com/o=Example?uid??(qpagePagerID=*)
571 <p>The next example demonstrates the power of using filters
572 to accomplish complicated administrative requirements.
573 Without filters, it would have been necessary to create a
574 new LDAP group and ensure that the group's members remain
575 synchronized with the pager users. This becomes trivial
576 with filters. The goal is to grant access to anyone who has
577 a pager, plus grant access to Joe Manager, who doesn't
578 have a pager, but does need to access the same
580 <highlight language="config">
581 AuthLDAPURL ldap://ldap.example.com/o=Example?uid??(|(qpagePagerID=*)(uid=jmanager))
585 <p>This last may look confusing at first, so it helps to
586 evaluate what the search filter will look like based on who
587 connects, as shown below. If
588 Fred User connects as <code>fuser</code>, the filter would look
591 <example>(&(|(qpagePagerID=*)(uid=jmanager))(uid=fuser))</example>
593 <p>The above search will only succeed if <em>fuser</em> has a
594 pager. When Joe Manager connects as <em>jmanager</em>, the
595 filter looks like</p>
597 <example>(&(|(qpagePagerID=*)(uid=jmanager))(uid=jmanager))</example>
599 <p>The above search will succeed whether <em>jmanager</em>
600 has a pager or not.</p>
605 <section id="usingtls"><title>Using TLS</title>
607 <p>To use TLS, see the <module>mod_ldap</module> directives <directive
608 module="mod_ldap">LDAPTrustedClientCert</directive>, <directive
609 module="mod_ldap">LDAPTrustedGlobalCert</directive> and <directive
610 module="mod_ldap">LDAPTrustedMode</directive>.</p>
612 <p>An optional second parameter can be added to the
613 <directive module="mod_authnz_ldap">AuthLDAPURL</directive> to override
614 the default connection type set by <directive module="mod_ldap">LDAPTrustedMode</directive>.
615 This will allow the connection established by an <em>ldap://</em> Url
616 to be upgraded to a secure connection on the same port.</p>
619 <section id="usingssl"><title>Using SSL</title>
621 <p>To use SSL, see the <module>mod_ldap</module> directives <directive
622 module="mod_ldap">LDAPTrustedClientCert</directive>, <directive
623 module="mod_ldap">LDAPTrustedGlobalCert</directive> and <directive
624 module="mod_ldap">LDAPTrustedMode</directive>.</p>
626 <p>To specify a secure LDAP server, use <em>ldaps://</em> in the
627 <directive module="mod_authnz_ldap">AuthLDAPURL</directive>
628 directive, instead of <em>ldap://</em>.</p>
631 <section id="exposed"><title>Exposing Login Information</title>
633 <p>when this module performs <em>authentication</em>, ldap attributes specified
634 in the <directive module="mod_authnz_ldap">authldapurl</directive>
635 directive are placed in environment variables with the prefix "AUTHENTICATE_".</p>
637 <p>when this module performs <em>authorization</em>, ldap attributes specified
638 in the <directive module="mod_authnz_ldap">authldapurl</directive>
639 directive are placed in environment variables with the prefix "AUTHORIZE_".</p>
641 <p>If the attribute field contains the username, common name
642 and telephone number of a user, a CGI program will have access to
643 this information without the need to make a second independent LDAP
644 query to gather this additional information.</p>
646 <p>This has the potential to dramatically simplify the coding and
647 configuration required in some web applications.</p>
651 <section id="activedirectory"><title>Using Active Directory</title>
653 <p>An Active Directory installation may support multiple domains at the
654 same time. To distinguish users between domains, an identifier called
655 a User Principle Name (UPN) can be added to a user's entry in the
656 directory. This UPN usually takes the form of the user's account
657 name, followed by the domain components of the particular domain,
658 for example <em>somebody@nz.example.com</em>.</p>
660 <p>You may wish to configure the <module>mod_authnz_ldap</module>
661 module to authenticate users present in any of the domains making up
662 the Active Directory forest. In this way both
663 <em>somebody@nz.example.com</em> and <em>someone@au.example.com</em>
664 can be authenticated using the same query at the same time.</p>
666 <p>To make this practical, Active Directory supports the concept of
667 a Global Catalog. This Global Catalog is a read only copy of selected
668 attributes of all the Active Directory servers within the Active
669 Directory forest. Querying the Global Catalog allows all the domains
670 to be queried in a single query, without the query spanning servers
671 over potentially slow links.</p>
673 <p>If enabled, the Global Catalog is an independent directory server
674 that runs on port 3268 (3269 for SSL). To search for a user, do a
675 subtree search for the attribute <em>userPrincipalName</em>, with
676 an empty search root, like so:</p>
678 <highlight language="config">
679 AuthLDAPBindDN apache@example.com
680 AuthLDAPBindPassword password
681 AuthLDAPURL ldap://10.0.0.1:3268/?userPrincipalName?sub
684 <p>Users will need to enter their User Principal Name as a login, in
685 the form <em>somebody@nz.example.com</em>.</p>
689 <section id="frontpage"><title>Using Microsoft
690 FrontPage with mod_authnz_ldap</title>
692 <p>Normally, FrontPage uses FrontPage-web-specific user/group
693 files (i.e., the <module>mod_authn_file</module> and
694 <module>mod_authz_groupfile</module> modules) to handle all
695 authentication. Unfortunately, it is not possible to just
696 change to LDAP authentication by adding the proper directives,
697 because it will break the <em>Permissions</em> forms in
698 the FrontPage client, which attempt to modify the standard
699 text-based authorization files.</p>
701 <p>Once a FrontPage web has been created, adding LDAP
702 authentication to it is a matter of adding the following
703 directives to <em>every</em> <code>.htaccess</code> file
704 that gets created in the web</p>
705 <highlight language="config">
706 AuthLDAPURL "the url"
707 AuthGroupFile mygroupfile
708 Require group mygroupfile
711 <section id="howitworks"><title>How It Works</title>
713 <p>FrontPage restricts access to a web by adding the <code>Require
714 valid-user</code> directive to the <code>.htaccess</code>
715 files. The <code>Require valid-user</code> directive will succeed for
716 any user who is valid <em>as far as LDAP is
717 concerned</em>. This means that anybody who has an entry in
718 the LDAP directory is considered a valid user, whereas FrontPage
719 considers only those people in the local user file to be
720 valid. By substituting the ldap-group with group file authorization,
721 Apache is allowed to consult the local user file (which is managed by
722 FrontPage) - instead of LDAP - when handling authorizing the user.</p>
724 <p>Once directives have been added as specified above,
725 FrontPage users will be able to perform all management
726 operations from the FrontPage client.</p>
729 <section id="fpcaveats"><title>Caveats</title>
732 <li>When choosing the LDAP URL, the attribute to use for
733 authentication should be something that will also be valid
734 for putting into a <module>mod_authn_file</module> user file.
735 The user ID is ideal for this.</li>
737 <li>When adding users via FrontPage, FrontPage administrators
738 should choose usernames that already exist in the LDAP
739 directory (for obvious reasons). Also, the password that the
740 administrator enters into the form is ignored, since Apache
741 will actually be authenticating against the password in the
742 LDAP database, and not against the password in the local user
743 file. This could cause confusion for web administrators.</li>
745 <!-- XXX is that true? was mod_auth before the aaa change -->
746 <li>Apache must be compiled with <module>mod_auth_basic</module>,
747 <module>mod_authn_file</module> and
748 <module>mod_authz_groupfile</module> in order to
749 use FrontPage support. This is because Apache will still use
750 the <module>mod_authz_groupfile</module> group file for determine
751 the extent of a user's access to the FrontPage web.</li>
753 <li>The directives must be put in the <code>.htaccess</code>
754 files. Attempting to put them inside <directive module="core"
755 type="section">Location</directive> or <directive module="core"
756 type="section">Directory</directive> directives won't work. This
757 is because <module>mod_authnz_ldap</module> has to be able to grab
758 the <directive module="mod_authz_groupfile">AuthGroupFile</directive>
759 directive that is found in FrontPage <code>.htaccess</code>
760 files so that it knows where to look for the valid user list. If
761 the <module>mod_authnz_ldap</module> directives aren't in the same
762 <code>.htaccess</code> file as the FrontPage directives, then
763 the hack won't work, because <module>mod_authnz_ldap</module> will
764 never get a chance to process the <code>.htaccess</code> file,
765 and won't be able to find the FrontPage-managed user file.</li>
771 <name>AuthLDAPAuthorizePrefix</name>
772 <description>Specifies the prefix for environment variables set during
773 authorization</description>
774 <syntax>AuthLDAPAuthorizePrefix <em>prefix</em></syntax>
775 <default>AuthLDAPAuthorizePrefix AUTHORIZE_</default>
776 <contextlist><context>directory</context><context>.htaccess</context>
778 <override>AuthConfig</override>
779 <compatibility>Available in version 2.3.6 and later</compatibility>
781 <p>This directive allows you to override the prefix used for environment
782 variables set during LDAP authorization. If <em>AUTHENTICATE_</em> is
783 specified, consumers of these environment variables see the same information
784 whether LDAP has performed authentication, authorization, or both.</p>
786 <note><title>Note</title>
787 No authorization variables are set when a user is authorized on the basis of
788 <code>Require valid-user</code>.
795 <name>AuthLDAPBindAuthoritative</name>
796 <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>
797 <syntax>AuthLDAPBindAuthoritative<em>off|on</em></syntax>
798 <default>AuthLDAPBindAuthoritative on</default>
799 <contextlist><context>directory</context><context>.htaccess</context>
801 <override>AuthConfig</override>
803 <p>By default, subsequent authentication providers are only queried if a
804 user cannot be mapped to a DN, but not if the user can be mapped to a DN and their
805 password cannot be verified with an LDAP bind.
806 If <directive module="mod_authnz_ldap">AuthLDAPBindAuthoritative</directive>
807 is set to <em>off</em>, other configured authentication modules will have
808 a chance to validate the user if the LDAP bind (with the current user's credentials)
809 fails for any reason.</p>
810 <p> This allows users present in both LDAP and
811 <directive module="mod_authn_file">AuthUserFile</directive> to authenticate
812 when the LDAP server is available but the user's account is locked or password
813 is otherwise unusable.</p>
815 <seealso><directive module="mod_authn_file">AuthUserFile</directive></seealso>
816 <seealso><directive module="mod_auth_basic">AuthBasicProvider</directive></seealso>
820 <name>AuthLDAPInitialBindAsUser</name>
821 <description>Determines if the server does the initial DN lookup using the basic authentication users'
822 own username, instead of anonymously or with hard-coded credentials for the server</description>
823 <syntax>AuthLDAPInitialBindAsUser <em>off|on</em></syntax>
824 <default>AuthLDAPInitialBindAsUser off</default>
825 <contextlist><context>directory</context><context>.htaccess</context>
827 <override>AuthConfig</override>
828 <compatibility>Available in version 2.3.6 and later</compatibility>
830 <p>By default, the server either anonymously, or with a dedicated user and
831 password, converts the basic authentication username into an LDAP
832 distinguished name (DN). This directive forces the server to use the verbatim username
833 and password provided by the incoming user to perform the initial DN
836 <p> If the verbatim username can't directly bind, but needs some
837 cosmetic transformation, see <directive module="mod_authnz_ldap">
838 AuthLDAPInitialBindPattern</directive>.</p>
840 <p> This directive should only be used when your LDAP server doesn't
841 accept anonymous searches and you cannot use a dedicated
842 <directive module="mod_authnz_ldap">AuthLDAPBindDN</directive>.
845 <note><title>Not available with authorization-only</title>
846 This directive can only be used if this module authenticates the user, and
847 has no effect when this module is used exclusively for authorization.
850 <seealso><directive module="mod_authnz_ldap">AuthLDAPInitialBindPattern</directive></seealso>
851 <seealso><directive module="mod_authnz_ldap">AuthLDAPBindDN</directive></seealso>
852 <seealso><directive module="mod_authnz_ldap">AuthLDAPCompareAsUser</directive></seealso>
853 <seealso><directive module="mod_authnz_ldap">AuthLDAPSearchAsUser</directive></seealso>
857 <name>AuthLDAPInitialBindPattern</name>
858 <description>Specifies the transformation of the basic authentication username to be used when binding to the LDAP server
859 to perform a DN lookup</description>
860 <syntax>AuthLDAPInitialBindPattern<em><var>regex</var> <var>substitution</var></em></syntax>
861 <default>AuthLDAPInitialBindPattern (.*) $1 (remote username used verbatim)</default>
862 <contextlist><context>directory</context><context>.htaccess</context>
864 <override>AuthConfig</override>
865 <compatibility>Available in version 2.3.6 and later</compatibility>
867 <p>If <directive module="mod_authnz_ldap">AuthLDAPInitialBindAsUser</directive> is set to
868 <em>ON</em>, the basic authentication username will be transformed according to the
869 regular expression and substituion arguments.</p>
871 <p> The regular expression argument is compared against the current basic authentication username.
872 The substitution argument may contain backreferences, but has no other variable interpolation.</p>
874 <p> This directive should only be used when your LDAP server doesn't
875 accept anonymous searches and you cannot use a dedicated
876 <directive module="mod_authnz_ldap">AuthLDAPBindDN</directive>.
879 <highlight language="config"> AuthLDAPInitialBindPattern (.+) $1@example.com </highlight>
880 <highlight language="config"> AuthLDAPInitialBindPattern (.+) cn=$1,dc=example,dc=com</highlight>
882 <note><title>Not available with authorization-only</title>
883 This directive can only be used if this module authenticates the user, and
884 has no effect when this module is used exclusively for authorization.
886 <note><title>debugging</title>
887 The substituted DN is recorded in the environment variable
888 <em>LDAP_BINDASUSER</em>. If the regular expression does not match the input,
889 the verbatim username is used.
892 <seealso><directive module="mod_authnz_ldap">AuthLDAPInitialBindAsUser</directive></seealso>
893 <seealso><directive module="mod_authnz_ldap">AuthLDAPBindDN</directive></seealso>
897 <name>AuthLDAPBindDN</name>
898 <description>Optional DN to use in binding to the LDAP server</description>
899 <syntax>AuthLDAPBindDN <em>distinguished-name</em></syntax>
900 <contextlist><context>directory</context><context>.htaccess</context>
902 <override>AuthConfig</override>
905 <p>An optional DN used to bind to the server when searching for
906 entries. If not provided, <module>mod_authnz_ldap</module> will use
907 an anonymous bind.</p>
912 <name>AuthLDAPBindPassword</name>
913 <description>Password used in conjuction with the bind DN</description>
914 <syntax>AuthLDAPBindPassword <em>password</em></syntax>
915 <contextlist><context>directory</context><context>.htaccess</context>
917 <override>AuthConfig</override>
918 <compatibility><em>exec:</em> was added in 2.4.5.</compatibility>
921 <p>A bind password to use in conjunction with the bind DN. Note
922 that the bind password is probably sensitive data, and should be
923 properly protected. You should only use the <directive
924 module="mod_authnz_ldap">AuthLDAPBindDN</directive> and <directive
925 module="mod_authnz_ldap">AuthLDAPBindPassword</directive> if you
926 absolutely need them to search the directory.</p>
928 <p>If the value begins with exec: the resulting command will be
929 executed and the first line returned to standard output by the
930 program will be used as the password.</p>
931 <highlight language="config">
933 AuthLDAPBindPassword secret
935 #Run /path/to/program to get my password
936 AuthLDAPBindPassword exec:/path/to/program
938 #Run /path/to/otherProgram and provide arguments
939 AuthLDAPBindPassword "exec:/path/to/otherProgram argument1"
946 <name>AuthLDAPCharsetConfig</name>
947 <description>Language to charset conversion configuration file</description>
948 <syntax>AuthLDAPCharsetConfig <em>file-path</em></syntax>
949 <contextlist><context>server config</context>
953 <p>The <directive>AuthLDAPCharsetConfig</directive> directive sets the location
954 of the language to charset conversion configuration file. <var>File-path</var> is relative
955 to the <directive module="core">ServerRoot</directive>. This file specifies
956 the list of language extensions to character sets.
957 Most administrators use the provided <code>charset.conv</code>
958 file, which associates common language extensions to character sets.</p>
960 <p>The file contains lines in the following format:</p>
963 <var>Language-Extension</var> <var>charset</var> [<var>Language-String</var>] ...
966 <p>The case of the extension does not matter. Blank lines, and lines
967 beginning with a hash character (<code>#</code>) are ignored.</p>
972 <name>AuthLDAPCompareAsUser</name>
973 <description>Use the authenticated user's credentials to perform authorization comparisons</description>
974 <syntax>AuthLDAPCompareAsUser on|off</syntax>
975 <default>AuthLDAPCompareAsUser off</default>
976 <contextlist><context>directory</context><context>.htaccess</context>
978 <override>AuthConfig</override>
979 <compatibility>Available in version 2.3.6 and later</compatibility>
982 <p>When set, and <module>mod_authnz_ldap</module> has authenticated the
983 user, LDAP comparisons for authorization use the queried distinguished name (DN)
984 and HTTP basic authentication password of the authenticated user instead of
985 the servers configured credentials.</p>
987 <p> The <em>ldap-attribute</em>, <em>ldap-user</em>, and <em>ldap-group</em> (single-level only)
988 authorization checks use comparisons.</p>
990 <p>This directive only has effect on the comparisons performed during
991 nested group processing when <directive module="mod_authnz_ldap">
992 AuthLDAPSearchAsUser</directive> is also enabled.</p>
994 <p> This directive should only be used when your LDAP server doesn't
995 accept anonymous comparisons and you cannot use a dedicated
996 <directive module="mod_authnz_ldap">AuthLDAPBindDN</directive>.
999 <seealso><directive module="mod_authnz_ldap">AuthLDAPInitialBindAsUser</directive></seealso>
1000 <seealso><directive module="mod_authnz_ldap">AuthLDAPSearchAsUser</directive></seealso>
1001 </directivesynopsis>
1004 <name>AuthLDAPCompareDNOnServer</name>
1005 <description>Use the LDAP server to compare the DNs</description>
1006 <syntax>AuthLDAPCompareDNOnServer on|off</syntax>
1007 <default>AuthLDAPCompareDNOnServer on</default>
1008 <contextlist><context>directory</context><context>.htaccess</context>
1010 <override>AuthConfig</override>
1013 <p>When set, <module>mod_authnz_ldap</module> will use the LDAP
1014 server to compare the DNs. This is the only foolproof way to
1015 compare DNs. <module>mod_authnz_ldap</module> will search the
1016 directory for the DN specified with the <a
1017 href="#reqdn"><code>Require dn</code></a> directive, then,
1018 retrieve the DN and compare it with the DN retrieved from the user
1019 entry. If this directive is not set,
1020 <module>mod_authnz_ldap</module> simply does a string comparison. It
1021 is possible to get false negatives with this approach, but it is
1022 much faster. Note the <module>mod_ldap</module> cache can speed up
1023 DN comparison in most situations.</p>
1025 </directivesynopsis>
1028 <name>AuthLDAPDereferenceAliases</name>
1029 <description>When will the module de-reference aliases</description>
1030 <syntax>AuthLDAPDereferenceAliases never|searching|finding|always</syntax>
1031 <default>AuthLDAPDereferenceAliases always</default>
1032 <contextlist><context>directory</context><context>.htaccess</context>
1034 <override>AuthConfig</override>
1037 <p>This directive specifies when <module>mod_authnz_ldap</module> will
1038 de-reference aliases during LDAP operations. The default is
1039 <code>always</code>.</p>
1041 </directivesynopsis>
1044 <name>AuthLDAPGroupAttribute</name>
1045 <description>LDAP attributes used to identify the user members of
1046 groups.</description>
1047 <syntax>AuthLDAPGroupAttribute <em>attribute</em></syntax>
1048 <default>AuthLDAPGroupAttribute member uniquemember</default>
1049 <contextlist><context>directory</context><context>.htaccess</context>
1051 <override>AuthConfig</override>
1054 <p>This directive specifies which LDAP attributes are used to
1055 check for user members within groups. Multiple attributes can be used
1056 by specifying this directive multiple times. If not specified,
1057 then <module>mod_authnz_ldap</module> uses the <code>member</code> and
1058 <code>uniquemember</code> attributes.</p>
1060 </directivesynopsis>
1063 <name>AuthLDAPGroupAttributeIsDN</name>
1064 <description>Use the DN of the client username when checking for
1065 group membership</description>
1066 <syntax>AuthLDAPGroupAttributeIsDN on|off</syntax>
1067 <default>AuthLDAPGroupAttributeIsDN on</default>
1068 <contextlist><context>directory</context><context>.htaccess</context>
1070 <override>AuthConfig</override>
1073 <p>When set <code>on</code>, this directive says to use the
1074 distinguished name of the client username when checking for group
1075 membership. Otherwise, the username will be used. For example,
1076 assume that the client sent the username <code>bjenson</code>,
1077 which corresponds to the LDAP DN <code>cn=Babs Jenson,
1078 o=Example</code>. If this directive is set,
1079 <module>mod_authnz_ldap</module> will check if the group has
1080 <code>cn=Babs Jenson, o=Example</code> as a member. If this
1081 directive is not set, then <module>mod_authnz_ldap</module> will
1082 check if the group has <code>bjenson</code> as a member.</p>
1084 </directivesynopsis>
1087 <name>AuthLDAPMaxSubGroupDepth</name>
1088 <description>Specifies the maximum sub-group nesting depth that will be
1089 evaluated before the user search is discontinued.</description>
1090 <syntax>AuthLDAPMaxSubGroupDepth <var>Number</var></syntax>
1091 <default>AuthLDAPMaxSubGroupDepth 0</default>
1092 <contextlist><context>directory</context><context>.htaccess</context>
1094 <override>AuthConfig</override>
1095 <compatibility>Available in version 2.3.0 and later, defaulted to 10 in 2.4.x and early 2.5</compatibility>
1098 <p>When this directive is set to a non-zero value <code>X</code>
1099 combined with use of the <code>Require ldap-group someGroupDN</code>
1100 directive, the provided user credentials will be searched for
1101 as a member of the <code>someGroupDN</code> directory object or of
1102 any group member of the current group up to the maximum nesting
1103 level <code>X</code> specified by this directive.</p>
1104 <p>See the <a href="#reqgroup"><code>Require ldap-group</code></a>
1105 section for a more detailed example.</p>
1107 <note><title>Nested groups performance</title>
1108 <p> When <directive>AuthLDAPSubGroupAttribute</directive> overlaps with
1109 <directive>AuthLDAPGroupAttribute</directive> (as it does by default and
1110 as required by common LDAP schemas), uncached searching for subgroups in
1111 large groups can be very slow. If you use large, non-nested groups, keep
1112 <directive>AuthLDAPMaxSubGroupDepth</directive> set to zero.</p>
1116 </directivesynopsis>
1119 <name>AuthLDAPRemoteUserAttribute</name>
1120 <description>Use the value of the attribute returned during the user
1121 query to set the REMOTE_USER environment variable</description>
1122 <syntax>AuthLDAPRemoteUserAttribute uid</syntax>
1123 <default>none</default>
1124 <contextlist><context>directory</context><context>.htaccess</context>
1126 <override>AuthConfig</override>
1129 <p>If this directive is set, the value of the
1130 <code>REMOTE_USER</code> environment variable will be set to the
1131 value of the attribute specified. Make sure that this attribute is
1132 included in the list of attributes in the AuthLDAPUrl definition,
1133 otherwise this directive will have no effect. This directive, if
1134 present, takes precedence over <directive module="mod_authnz_ldap"
1135 >AuthLDAPRemoteUserIsDN</directive>. This
1136 directive is useful should you want people to log into a website
1137 using an email address, but a backend application expects the
1138 username as a userid.</p>
1139 <p> This directive only has effect when this module is used for
1142 </directivesynopsis>
1145 <name>AuthLDAPRemoteUserIsDN</name>
1146 <description>Use the DN of the client username to set the REMOTE_USER
1147 environment variable</description>
1148 <syntax>AuthLDAPRemoteUserIsDN on|off</syntax>
1149 <default>AuthLDAPRemoteUserIsDN off</default>
1150 <contextlist><context>directory</context><context>.htaccess</context>
1152 <override>AuthConfig</override>
1155 <p>If this directive is set to on, the value of the
1156 <code>REMOTE_USER</code> environment variable will be set to the full
1157 distinguished name of the authenticated user, rather than just
1158 the username that was passed by the client. It is turned off by
1160 <p> This directive only has effect when this module is used for
1163 </directivesynopsis>
1166 <name>AuthLDAPSearchAsUser</name>
1167 <description>Use the authenticated user's credentials to perform authorization searches</description>
1168 <syntax>AuthLDAPSearchAsUser on|off</syntax>
1169 <default>AuthLDAPSearchAsUser off</default>
1170 <contextlist><context>directory</context><context>.htaccess</context>
1172 <override>AuthConfig</override>
1173 <compatibility>Available in version 2.3.6 and later</compatibility>
1176 <p>When set, and <module>mod_authnz_ldap</module> has authenticated the
1177 user, LDAP searches for authorization use the queried distinguished name (DN)
1178 and HTTP basic authentication password of the authenticated user instead of
1179 the servers configured credentials.</p>
1181 <p> The <em>ldap-filter</em> and <em>ldap-dn</em> authorization
1182 checks use searches.</p>
1184 <p>This directive only has effect on the comparisons performed during
1185 nested group processing when <directive module="mod_authnz_ldap">
1186 AuthLDAPCompareAsUser</directive> is also enabled.</p>
1188 <p> This directive should only be used when your LDAP server doesn't
1189 accept anonymous searches and you cannot use a dedicated
1190 <directive module="mod_authnz_ldap">AuthLDAPBindDN</directive>.
1193 <seealso><directive module="mod_authnz_ldap">AuthLDAPInitialBindAsUser</directive></seealso>
1194 <seealso><directive module="mod_authnz_ldap">AuthLDAPCompareAsUser</directive></seealso>
1195 </directivesynopsis>
1198 <name>AuthLDAPSubGroupAttribute</name>
1199 <description>Specifies the attribute labels, one value per
1200 directive line, used to distinguish the members of the current group that
1201 are groups.</description>
1202 <syntax>AuthLDAPSubGroupAttribute <em>attribute</em></syntax>
1203 <default>AuthLDAPSubgroupAttribute member uniquemember</default>
1204 <contextlist><context>directory</context><context>.htaccess</context>
1206 <override>AuthConfig</override>
1207 <compatibility>Available in version 2.3.0 and later</compatibility>
1210 <p>An LDAP group object may contain members that are users and
1211 members that are groups (called nested or sub groups). The
1212 <code>AuthLDAPSubGroupAttribute</code> directive identifies the
1213 labels of group members and the <code>AuthLDAPGroupAttribute</code>
1214 directive identifies the labels of the user members. Multiple
1215 attributes can be used by specifying this directive multiple times.
1216 If not specified, then <module>mod_authnz_ldap</module> uses the
1217 <code>member</code> and <code>uniqueMember</code> attributes.</p>
1219 </directivesynopsis>
1222 <name>AuthLDAPSubGroupClass</name>
1223 <description>Specifies which LDAP objectClass values identify directory
1224 objects that are groups during sub-group processing.</description>
1225 <syntax>AuthLDAPSubGroupClass <em>LdapObjectClass</em></syntax>
1226 <default>AuthLDAPSubGroupClass groupOfNames groupOfUniqueNames</default>
1227 <contextlist><context>directory</context><context>.htaccess</context>
1229 <override>AuthConfig</override>
1230 <compatibility>Available in version 2.3.0 and later</compatibility>
1233 <p>An LDAP group object may contain members that are users and
1234 members that are groups (called nested or sub groups). The
1235 <code>AuthLDAPSubGroupAttribute</code> directive identifies the
1236 labels of members that may be sub-groups of the current group
1237 (as opposed to user members). The <code>AuthLDAPSubGroupClass</code>
1238 directive specifies the LDAP objectClass values used in verifying that
1239 these potential sub-groups are in fact group objects. Verified sub-groups
1240 can then be searched for more user or sub-group members. Multiple
1241 attributes can be used by specifying this directive multiple times.
1242 If not specified, then <module>mod_authnz_ldap</module> uses the
1243 <code>groupOfNames</code> and <code>groupOfUniqueNames</code> values.</p>
1245 </directivesynopsis>
1248 <name>AuthLDAPUrl</name>
1249 <description>URL specifying the LDAP search parameters</description>
1250 <syntax>AuthLDAPUrl <em>url [NONE|SSL|TLS|STARTTLS]</em></syntax>
1251 <contextlist><context>directory</context><context>.htaccess</context>
1253 <override>AuthConfig</override>
1256 <p>An RFC 2255 URL which specifies the LDAP search parameters
1257 to use. The syntax of the URL is</p>
1258 <example>ldap://host:port/basedn?attribute?scope?filter</example>
1259 <p>If you want to specify more than one LDAP URL that Apache should try in turn, the syntax is:</p>
1260 <highlight language="config">AuthLDAPUrl "ldap://ldap1.example.com ldap2.example.com/dc=..."</highlight>
1261 <p><em><strong>Caveat: </strong>If you specify multiple servers, you need to enclose the entire URL string in quotes;
1262 otherwise you will get an error: "AuthLDAPURL takes one argument, URL to define LDAP connection.." </em>
1263 You can of course use search parameters on each of these.</p>
1268 <dd>For regular ldap, use the
1269 string <code>ldap</code>. For secure LDAP, use <code>ldaps</code>
1270 instead. Secure LDAP is only available if Apache was linked
1271 to an LDAP library with SSL support.</dd>
1276 <p>The name/port of the ldap server (defaults to
1277 <code>localhost:389</code> for <code>ldap</code>, and
1278 <code>localhost:636</code> for <code>ldaps</code>). To
1279 specify multiple, redundant LDAP servers, just list all
1280 servers, separated by spaces. <module>mod_authnz_ldap</module>
1281 will try connecting to each server in turn, until it makes a
1282 successful connection. If multiple ldap servers are specified,
1283 then entire LDAP URL must be encapsulated in double quotes.</p>
1285 <p>Once a connection has been made to a server, that
1286 connection remains active for the life of the
1287 <program>httpd</program> process, or until the LDAP server goes
1290 <p>If the LDAP server goes down and breaks an existing
1291 connection, <module>mod_authnz_ldap</module> will attempt to
1292 re-connect, starting with the primary server, and trying
1293 each redundant server in turn. Note that this is different
1294 than a true round-robin search.</p>
1299 <dd>The DN of the branch of the
1300 directory where all searches should start from. At the very
1301 least, this must be the top of your directory tree, but
1302 could also specify a subtree in the directory.</dd>
1306 <dd>The attribute to search for.
1307 Although RFC 2255 allows a comma-separated list of
1308 attributes, only the first attribute will be used, no
1309 matter how many are provided. If no attributes are
1310 provided, the default is to use <code>uid</code>. It's a good
1311 idea to choose an attribute that will be unique across all
1312 entries in the subtree you will be using. All attributes
1313 listed will be put into the environment with an AUTHENTICATE_ prefix
1314 for use by other modules.</dd>
1318 <dd>The scope of the search. Can be either <code>one</code> or
1319 <code>sub</code>. Note that a scope of <code>base</code> is
1320 also supported by RFC 2255, but is not supported by this
1321 module. If the scope is not provided, or if <code>base</code> scope
1322 is specified, the default is to use a scope of
1323 <code>sub</code>.</dd>
1327 <dd>A valid LDAP search filter. If
1328 not provided, defaults to <code>(objectClass=*)</code>, which
1329 will search for all objects in the tree. Filters are
1330 limited to approximately 8000 characters (the definition of
1331 <code>MAX_STRING_LEN</code> in the Apache source code). This
1332 should be more than sufficient for any application. The keyword
1333 <code>none</code> disables the use of a filter; this is required
1334 by some primitive LDAP servers.</dd>
1337 <p>When doing searches, the attribute, filter and username passed
1338 by the HTTP client are combined to create a search filter that
1340 <code>(&(<em>filter</em>)(<em>attribute</em>=<em>username</em>))</code>.</p>
1342 <p>For example, consider an URL of
1343 <code>ldap://ldap.example.com/o=Example?cn?sub?(posixid=*)</code>. When
1344 a client attempts to connect using a username of <code>Babs
1345 Jenson</code>, the resulting search filter will be
1346 <code>(&(posixid=*)(cn=Babs Jenson))</code>.</p>
1348 <p>An optional parameter can be added to allow the LDAP Url to override
1349 the connection type. This parameter can be one of the following:</p>
1353 <dd>Establish an unsecure connection on the default LDAP port. This
1354 is the same as <code>ldap://</code> on port 389.</dd>
1356 <dd>Establish a secure connection on the default secure LDAP port.
1357 This is the same as <code>ldaps://</code></dd>
1358 <dt>TLS | STARTTLS</dt>
1359 <dd>Establish an upgraded secure connection on the default LDAP port.
1360 This connection will be initiated on port 389 by default and then
1361 upgraded to a secure connection on the same port.</dd>
1364 <p>See above for examples of <directive
1365 module="mod_authnz_ldap">AuthLDAPURL</directive> URLs.</p>
1367 </directivesynopsis>