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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>
31 <compatibility>Available in version 2.1 and later</compatibility>
34 <p>This module provides authentication front-ends such as
35 <module>mod_auth_basic</module> to authenticate users through
36 an ldap directory.</p>
38 <p><module>mod_authnz_ldap</module> supports the following features:</p>
41 <li>Known to support the <a
42 href="http://www.openldap.org/">OpenLDAP SDK</a> (both 1.x
43 and 2.x), <a href="http://developer.novell.com/ndk/cldap.htm">
44 Novell LDAP SDK</a> and the <a
45 href="http://www.iplanet.com/downloads/developer/">iPlanet
46 (Netscape)</a> SDK.</li>
48 <li>Complex authorization policies can be implemented by
49 representing the policy with LDAP filters.</li>
51 <li>Uses extensive caching of LDAP operations via <a
52 href="mod_ldap.html">mod_ldap</a>.</li>
54 <li>Support for LDAP over SSL (requires the Netscape SDK) or
55 TLS (requires the OpenLDAP 2.x SDK or Novell LDAP SDK).</li>
58 <p>When using <module>mod_auth_basic</module>, this module is invoked
59 via the <directive module="mod_auth_basic">AuthBasicProvider</directive>
60 directive with the <code>ldap</code> value.</p>
63 <seealso><module>mod_ldap</module></seealso>
64 <seealso><module>mod_auth_basic</module></seealso>
65 <seealso><module>mod_authz_user</module></seealso>
66 <seealso><module>mod_authz_groupfile</module></seealso>
68 <section id="contents"><title>Contents</title>
72 <a href="#operation">Operation</a>
75 <li><a href="#authenphase">The Authentication
78 <li><a href="#authorphase">The Authorization
84 <a href="#requiredirectives">The Require Directives</a>
87 <li><a href="#requser">Require ldap-user</a></li>
88 <li><a href="#reqgroup">Require ldap-group</a></li>
89 <li><a href="#reqdn">Require ldap-dn</a></li>
90 <li><a href="#reqattribute">Require ldap-attribute</a></li>
91 <li><a href="#reqfilter">Require ldap-filter</a></li>
95 <li><a href="#examples">Examples</a></li>
96 <li><a href="#usingtls">Using TLS</a></li>
97 <li><a href="#usingssl">Using SSL</a></li>
98 <li><a href="#exposed">Exposing Login Information</a></li>
99 <li><a href="#activedirectory">Using Active Directory</a></li>
101 <a href="#frontpage">Using Microsoft FrontPage with
102 <module>mod_authnz_ldap</module></a>
105 <li><a href="#howitworks">How It Works</a></li>
106 <li><a href="#fpcaveats">Caveats</a></li>
112 <section id="operation"><title>Operation</title>
114 <p>There are two phases in granting access to a user. The first
115 phase is authentication, in which the <module>mod_authnz_ldap</module>
116 authentication provider verifies that the user's credentials are valid.
117 This is also called the <em>search/bind</em> phase. The second phase is
118 authorization, in which <module>mod_authnz_ldap</module> determines
119 if the authenticated user is allowed access to the resource in
120 question. This is also known as the <em>compare</em>
123 <p><module>mod_authnz_ldap</module> registers both an authn_ldap authentication
124 provider and an authz_ldap authorization handler. The authn_ldap
125 authentication provider can be enabled through the
126 <directive module="mod_auth_basic">AuthBasicProvider</directive> directive
127 using the <code>ldap</code> value. The authz_ldap handler extends the
128 <directive module="mod_authz_core">Require</directive> directive's authorization types
129 by adding <code>ldap-user</code>, <code>ldap-dn</code> and <code>ldap-group</code>
132 <section id="authenphase"><title>The Authentication
135 <p>During the authentication phase, <module>mod_authnz_ldap</module>
136 searches for an entry in the directory that matches the username
137 that the HTTP client passes. If a single unique match is found,
138 then <module>mod_authnz_ldap</module> attempts to bind to the
139 directory server using the DN of the entry plus the password
140 provided by the HTTP client. Because it does a search, then a
141 bind, it is often referred to as the search/bind phase. Here are
142 the steps taken during the search/bind phase.</p>
145 <li>Generate a search filter by combining the attribute and
146 filter provided in the <directive module="mod_authnz_ldap"
147 >AuthLDAPURL</directive> directive with
148 the username passed by the HTTP client.</li>
150 <li>Search the directory using the generated filter. If the
151 search does not return exactly one entry, deny or decline
154 <li>Fetch the distinguished name of the entry retrieved from
155 the search and attempt to bind to the LDAP server using that
156 DN and the password passed by the HTTP client. If the bind is
157 unsuccessful, deny or decline access.</li>
160 <p>The following directives are used during the search/bind
164 <columnspec><column width=".3"/><column width=".7"/></columnspec>
166 <td><directive module="mod_authnz_ldap">AuthLDAPURL</directive></td>
168 <td>Specifies the LDAP server, the
169 base DN, the attribute to use in the search, as well as the
170 extra search filter to use.</td>
174 <td><directive module="mod_authnz_ldap">AuthLDAPBindDN</directive></td>
176 <td>An optional DN to bind with
177 during the search phase.</td>
182 module="mod_authnz_ldap">AuthLDAPBindPassword</directive></td>
184 <td>An optional password to bind
185 with during the search phase.</td>
190 <section id="authorphase"><title>The Authorization Phase</title>
192 <p>During the authorization phase, <module>mod_authnz_ldap</module>
193 attempts to determine if the user is authorized to access the
194 resource. Many of these checks require
195 <module>mod_authnz_ldap</module> to do a compare operation on the
196 LDAP server. This is why this phase is often referred to as the
197 compare phase. <module>mod_authnz_ldap</module> accepts the
198 following <directive module="mod_authz_core">Require</directive>
199 directives to determine if the credentials are acceptable:</p>
202 <li>Grant access if there is a <a
203 href="#reqgroup"><code>Require ldap-user</code></a> directive, and the
204 username in the directive matches the username passed by the
207 <li>Grant access if there is a <a href="#reqdn"><code>Require
208 ldap-dn</code></a> directive, and the DN in the directive matches
209 the DN fetched from the LDAP directory.</li>
211 <li>Grant access if there is a <a
212 href="#reqgroup"><code>Require ldap-group</code></a> directive, and
213 the DN fetched from the LDAP directory (or the username
214 passed by the client) occurs in the LDAP group or, potentially, in
215 one of its sub-groups.</li>
217 <li>Grant access if there is a <a href="#reqattribute">
218 <code>Require ldap-attribute</code></a>
219 directive, and the attribute fetched from the LDAP directory
220 matches the given value.</li>
222 <li>Grant access if there is a <a href="#reqfilter">
223 <code>Require ldap-filter</code></a>
224 directive, and the search filter successfully finds a single user
225 object that matches the dn of the authenticated user.</li>
227 <li>otherwise, deny or decline access</li>
230 <p>Other <directive module="mod_authz_core">Require</directive> values may also
231 be used which may require loading additional authorization modules.</p>
234 <li>Grant access to all successfully authenticated users if
235 there is a <a href="#requser"><code>Require valid-user</code></a>
236 directive. (requires <module>mod_authz_user</module>)</li>
238 <li>Grant access if there is a <a
239 href="#reqgroup"><code>Require group</code></a> directive, and
240 <module>mod_authz_groupfile</module> has been loaded with the
241 <directive module="mod_authz_groupfile">AuthGroupFile</directive>
248 <p><module>mod_authnz_ldap</module> uses the following directives during the
252 <columnspec><column width=".4"/><column width=".6"/></columnspec>
254 <td><directive module="mod_authnz_ldap">AuthLDAPURL</directive> </td>
256 <td>The attribute specified in the
257 URL is used in compare operations for the <code>Require
258 ldap-user</code> operation.</td>
263 module="mod_authnz_ldap">AuthLDAPCompareDNOnServer</directive></td>
265 <td>Determines the behavior of the
266 <code>Require ldap-dn</code> directive.</td>
271 module="mod_authnz_ldap">AuthLDAPGroupAttribute</directive></td>
273 <td>Determines the attribute to
274 use for comparisons in the <code>Require ldap-group</code>
280 module="mod_authnz_ldap">AuthLDAPGroupAttributeIsDN</directive></td>
282 <td>Specifies whether to use the
283 user DN or the username when doing comparisons for the
284 <code>Require ldap-group</code> directive.</td>
289 module="mod_authnz_ldap">AuthLDAPMaxSubGroupDepth</directive></td>
291 <td>Determines the maximum depth of sub-groups that will be evaluated
292 during comparisons in the <code>Require ldap-group</code> directive.</td>
297 module="mod_authnz_ldap">AuthLDAPSubGroupAttribute</directive></td>
299 <td>Determines the attribute to use when obtaining sub-group members
300 of the current group during comparisons in the <code>Require ldap-group</code>
306 module="mod_authnz_ldap">AuthLDAPSubGroupClass</directive></td>
308 <td>Specifies the LDAP objectClass values used to identify if queried directory
309 objects really are group objects (as opposed to user objects) during the
310 <code>Require ldap-group</code> directive's sub-group processing.</td>
316 <section id="requiredirectives"><title>The Require Directives</title>
318 <p>Apache's <directive module="mod_authz_core">Require</directive>
319 directives are used during the authorization phase to ensure that
320 a user is allowed to access a resource. mod_authnz_ldap extends the
321 authorization types with <code>ldap-user</code>, <code>ldap-dn</code>,
322 <code>ldap-group</code>, <code>ldap-attribute</code> and
323 <code>ldap-filter</code>. Other authorization types may also be
324 used but may require that additional authorization modules be loaded.</p>
326 <section id="requser"><title>Require ldap-user</title>
328 <p>The <code>Require ldap-user</code> directive specifies what
329 usernames can access the resource. Once
330 <module>mod_authnz_ldap</module> has retrieved a unique DN from the
331 directory, it does an LDAP compare operation using the username
332 specified in the <code>Require ldap-user</code> to see if that username
333 is part of the just-fetched LDAP entry. Multiple users can be
334 granted access by putting multiple usernames on the line,
335 separated with spaces. If a username has a space in it, then it
336 must be surrounded with double quotes. Multiple users can also be
337 granted access by using multiple <code>Require ldap-user</code>
338 directives, with one user per line. For example, with a <directive
339 module="mod_authnz_ldap">AuthLDAPURL</directive> of
340 <code>ldap://ldap/o=Airius?cn</code> (i.e., <code>cn</code> is
341 used for searches), the following Require directives could be used
342 to restrict access:</p>
344 Require ldap-user "Barbara Jenson"<br />
345 Require ldap-user "Fred User"<br />
346 Require ldap-user "Joe Manager"<br />
349 <p>Because of the way that <module>mod_authnz_ldap</module> handles this
350 directive, Barbara Jenson could sign on as <em>Barbara
351 Jenson</em>, <em>Babs Jenson</em> or any other <code>cn</code> that
352 she has in her LDAP entry. Only the single <code>Require
353 ldap-user</code> line is needed to support all values of the attribute
354 in the user's entry.</p>
356 <p>If the <code>uid</code> attribute was used instead of the
357 <code>cn</code> attribute in the URL above, the above three lines
358 could be condensed to</p>
359 <example>Require ldap-user bjenson fuser jmanager</example>
362 <section id="reqgroup"><title>Require ldap-group</title>
364 <p>This directive specifies an LDAP group whose members are
365 allowed access. It takes the distinguished name of the LDAP
366 group. Note: Do not surround the group name with quotes.
367 For example, assume that the following entry existed in
368 the LDAP directory:</p>
370 dn: cn=Administrators, o=Airius<br />
371 objectClass: groupOfUniqueNames<br />
372 uniqueMember: cn=Barbara Jenson, o=Airius<br />
373 uniqueMember: cn=Fred User, o=Airius<br />
376 <p>The following directive would grant access to both Fred and
378 <example>Require ldap-group cn=Administrators, o=Airius</example>
380 <p>Members can also be found within sub-groups of a specified LDAP group
381 if <directive module="mod_authnz_ldap">AuthLDAPMaxSubGroupDepth</directive>
382 is set to a value greater than 0. For example, assume the following entries
383 exist in the LDAP directory:</p>
385 dn: cn=Employees, o=Airius<br />
386 objectClass: groupOfUniqueNames<br />
387 uniqueMember: cn=Managers, o=Airius<br />
388 uniqueMember: cn=Administrators, o=Airius<br />
389 uniqueMember: cn=Users, o=Airius<br />
391 dn: cn=Managers, o=Airius<br />
392 objectClass: groupOfUniqueNames<br />
393 uniqueMember: cn=Bob Ellis, o=Airius<br />
394 uniqueMember: cn=Tom Jackson, o=Airius<br />
396 dn: cn=Administrators, o=Airius<br />
397 objectClass: groupOfUniqueNames<br />
398 uniqueMember: cn=Barbara Jenson, o=Airius<br />
399 uniqueMember: cn=Fred User, o=Airius<br />
401 dn: cn=Users, o=Airius<br />
402 objectClass: groupOfUniqueNames<br />
403 uniqueMember: cn=Allan Jefferson, o=Airius<br />
404 uniqueMember: cn=Paul Tilley, o=Airius<br />
405 uniqueMember: cn=Temporary Employees, o=Airius<br />
407 dn: cn=Temporary Employees, o=Airius<br />
408 objectClass: groupOfUniqueNames<br />
409 uniqueMember: cn=Jim Swenson, o=Airius<br />
410 uniqueMember: cn=Elliot Rhodes, o=Airius<br />
413 <p>The following directives would allow access for Bob Ellis, Tom Jackson,
414 Barbara Jensen, Fred User, Allan Jefferson, and Paul Tilley but would not
415 allow access for Jim Swenson, or Elliot Rhodes (since they are at a
416 sub-group depth of 2):</p>
418 Require ldap-group cn=Employees, o-Airius<br />
419 AuthLDAPSubGroupDepth 1<br />
422 <p>Behavior of this directive is modified by the <directive
423 module="mod_authnz_ldap">AuthLDAPGroupAttribute</directive>, <directive
424 module="mod_authnz_ldap">AuthLDAPGroupAttributeIsDN</directive>, <directive
425 module="mod_authnz_ldap">AuthLDAPMaxSubGroupDepth</directive>, <directive
426 module="mod_authnz_ldap">AuthLDAPSubGroupAttribute</directive>, and <directive
427 module="mod_authnz_ldap">AuthLDAPSubGroupClass</directive>
431 <section id="reqdn"><title>Require ldap-dn</title>
433 <p>The <code>Require ldap-dn</code> directive allows the administrator
434 to grant access based on distinguished names. It specifies a DN
435 that must match for access to be granted. If the distinguished
436 name that was retrieved from the directory server matches the
437 distinguished name in the <code>Require ldap-dn</code>, then
438 authorization is granted. Note: do not surround the distinguished
439 name with quotes.</p>
441 <p>The following directive would grant access to a specific
443 <example>Require ldap-dn cn=Barbara Jenson, o=Airius</example>
445 <p>Behavior of this directive is modified by the <directive
446 module="mod_authnz_ldap">AuthLDAPCompareDNOnServer</directive>
450 <section id="reqattribute"><title>Require ldap-attribute</title>
452 <p>The <code>Require ldap-attribute</code> directive allows the
453 administrator to grant access based on attributes of the authenticated
454 user in the LDAP directory. If the attribute in the directory
455 matches the value given in the configuration, access is granted.</p>
457 <p>The following directive would grant access to anyone with
458 the attribute employeeType = active</p>
460 <example>Require ldap-attribute employeeType=active</example>
462 <p>Multiple attribute/value pairs can be specified on the same line
463 separated by spaces or they can be specified in multiple
464 <code>Require ldap-attribute</code> directives. The effect of listing
465 multiple attribute/values pairs is an OR operation. Access will be
466 granted if any of the listed attribute values match the value of the
467 corresponding attribute in the user object. If the value of the
468 attribute contains a space, only the value must be within double quotes.</p>
470 <p>The following directive would grant access to anyone with
471 the city attribute equal to "San Jose" or status equal to "Active"</p>
473 <example>Require ldap-attribute city="San Jose" status=active</example>
477 <section id="reqfilter"><title>Require ldap-filter</title>
479 <p>The <code>Require ldap-filter</code> directive allows the
480 administrator to grant access based on a complex LDAP search filter.
481 If the dn returned by the filter search matches the authenticated user
482 dn, access is granted.</p>
484 <p>The following directive would grant access to anyone having a cell phone
485 and is in the marketing department</p>
487 <example>Require ldap-filter &(cell=*)(department=marketing)</example>
489 <p>The difference between the <code>Require ldap-filter</code> directive and the
490 <code>Require ldap-attribute</code> directive is that <code>ldap-filter</code>
491 performs a search operation on the LDAP directory using the specified search
492 filter rather than a simple attribute comparison. If a simple attribute
493 comparison is all that is required, the comparison operation performed by
494 <code>ldap-attribute</code> will be faster than the search operation
495 used by <code>ldap-filter</code> especially within a large directory.</p>
501 <section id="examples"><title>Examples</title>
505 Grant access to anyone who exists in the LDAP directory,
506 using their UID for searches.
508 AuthLDAPURL "ldap://ldap1.airius.com:389/ou=People, o=Airius?uid?sub?(objectClass=*)"<br />
514 The next example is the same as above; but with the fields
515 that have useful defaults omitted. Also, note the use of a
516 redundant LDAP server.
517 <example>AuthLDAPURL "ldap://ldap1.airius.com ldap2.airius.com/ou=People, o=Airius"<br />
523 The next example is similar to the previous one, but it
524 uses the common name instead of the UID. Note that this
525 could be problematical if multiple people in the directory
526 share the same <code>cn</code>, because a search on <code>cn</code>
527 <strong>must</strong> return exactly one entry. That's why
528 this approach is not recommended: it's a better idea to
529 choose an attribute that is guaranteed unique in your
530 directory, such as <code>uid</code>.
532 AuthLDAPURL "ldap://ldap.airius.com/ou=People, o=Airius?cn"<br />
538 Grant access to anybody in the Administrators group. The
539 users must authenticate using their UID.
541 AuthLDAPURL ldap://ldap.airius.com/o=Airius?uid<br />
542 Require ldap-group cn=Administrators, o=Airius
547 The next example assumes that everyone at Airius who
548 carries an alphanumeric pager will have an LDAP attribute
549 of <code>qpagePagerID</code>. The example will grant access
550 only to people (authenticated via their UID) who have
553 AuthLDAPURL ldap://ldap.airius.com/o=Airius?uid??(qpagePagerID=*)<br />
559 <p>The next example demonstrates the power of using filters
560 to accomplish complicated administrative requirements.
561 Without filters, it would have been necessary to create a
562 new LDAP group and ensure that the group's members remain
563 synchronized with the pager users. This becomes trivial
564 with filters. The goal is to grant access to anyone who has
565 a pager, plus grant access to Joe Manager, who doesn't
566 have a pager, but does need to access the same
569 AuthLDAPURL ldap://ldap.airius.com/o=Airius?uid??(|(qpagePagerID=*)(uid=jmanager))<br />
573 <p>This last may look confusing at first, so it helps to
574 evaluate what the search filter will look like based on who
575 connects, as shown below. If
576 Fred User connects as <code>fuser</code>, the filter would look
579 <example>(&(|(qpagePagerID=*)(uid=jmanager))(uid=fuser))</example>
581 <p>The above search will only succeed if <em>fuser</em> has a
582 pager. When Joe Manager connects as <em>jmanager</em>, the
583 filter looks like</p>
585 <example>(&(|(qpagePagerID=*)(uid=jmanager))(uid=jmanager))</example>
587 <p>The above search will succeed whether <em>jmanager</em>
588 has a pager or not.</p>
593 <section id="usingtls"><title>Using TLS</title>
595 <p>To use TLS, see the <module>mod_ldap</module> directives <directive
596 module="mod_ldap">LDAPTrustedClientCert</directive>, <directive
597 module="mod_ldap">LDAPTrustedGlobalCert</directive> and <directive
598 module="mod_ldap">LDAPTrustedMode</directive>.</p>
600 <p>An optional second parameter can be added to the
601 <directive module="mod_authnz_ldap">AuthLDAPURL</directive> to override
602 the default connection type set by <directive module="mod_ldap">LDAPTrustedMode</directive>.
603 This will allow the connection established by an <em>ldap://</em> Url
604 to be upgraded to a secure connection on the same port.</p>
607 <section id="usingssl"><title>Using SSL</title>
609 <p>To use SSL, see the <module>mod_ldap</module> directives <directive
610 module="mod_ldap">LDAPTrustedClientCert</directive>, <directive
611 module="mod_ldap">LDAPTrustedGlobalCert</directive> and <directive
612 module="mod_ldap">LDAPTrustedMode</directive>.</p>
614 <p>To specify a secure LDAP server, use <em>ldaps://</em> in the
615 <directive module="mod_authnz_ldap">AuthLDAPURL</directive>
616 directive, instead of <em>ldap://</em>.</p>
619 <section id="exposed"><title>Exposing Login Information</title>
621 <p>When this module performs authentication, LDAP attributes specified
622 in the <directive module="mod_authnz_ldap">AuthLDAPUrl</directive>
623 directive are placed in environment variables with the prefix "AUTHENTICATE_".</p>
625 <p>If the attribute field contains the username, common name
626 and telephone number of a user, a CGI program will have access to
627 this information without the need to make a second independent LDAP
628 query to gather this additional information.</p>
630 <p>This has the potential to dramatically simplify the coding and
631 configuration required in some web applications.</p>
635 <section id="activedirectory"><title>Using Active Directory</title>
637 <p>An Active Directory installation may support multiple domains at the
638 same time. To distinguish users between domains, an identifier called
639 a User Principle Name (UPN) can be added to a user's entry in the
640 directory. This UPN usually takes the form of the user's account
641 name, followed by the domain components of the particular domain,
642 for example <em>somebody@nz.example.com</em>.</p>
644 <p>You may wish to configure the <module>mod_authnz_ldap</module>
645 module to authenticate users present in any of the domains making up
646 the Active Directory forest. In this way both
647 <em>somebody@nz.example.com</em> and <em>someone@au.example.com</em>
648 can be authenticated using the same query at the same time.</p>
650 <p>To make this practical, Active Directory supports the concept of
651 a Global Catalog. This Global Catalog is a read only copy of selected
652 attributes of all the Active Directory servers within the Active
653 Directory forest. Querying the Global Catalog allows all the domains
654 to be queried in a single query, without the query spanning servers
655 over potentially slow links.</p>
657 <p>If enabled, the Global Catalog is an independent directory server
658 that runs on port 3268 (3269 for SSL). To search for a user, do a
659 subtree search for the attribute <em>userPrincipalName</em>, with
660 an empty search root, like so:</p>
663 AuthLDAPBindDN apache@example.com<br />
664 AuthLDAPBindPassword password<br />
665 AuthLDAPURL ldap://10.0.0.1:3268/?userPrincipalName?sub
668 <p>Users will need to enter their User Principal Name as a login, in
669 the form <em>somebody@nz.example.com</em>.</p>
673 <section id="frontpage"><title>Using Microsoft
674 FrontPage with mod_authnz_ldap</title>
676 <p>Normally, FrontPage uses FrontPage-web-specific user/group
677 files (i.e., the <module>mod_authn_file</module> and
678 <module>mod_authz_groupfile</module> modules) to handle all
679 authentication. Unfortunately, it is not possible to just
680 change to LDAP authentication by adding the proper directives,
681 because it will break the <em>Permissions</em> forms in
682 the FrontPage client, which attempt to modify the standard
683 text-based authorization files.</p>
685 <p>Once a FrontPage web has been created, adding LDAP
686 authentication to it is a matter of adding the following
687 directives to <em>every</em> <code>.htaccess</code> file
688 that gets created in the web</p>
690 AuthLDAPURL "the url"
691 AuthGroupFile <em>mygroupfile</em>
692 Require group <em>mygroupfile</em>
695 <section id="howitworks"><title>How It Works</title>
697 <p>FrontPage restricts access to a web by adding the <code>Require
698 valid-user</code> directive to the <code>.htaccess</code>
699 files. The <code>Require valid-user</code> directive will succeed for
700 any user who is valid <em>as far as LDAP is
701 concerned</em>. This means that anybody who has an entry in
702 the LDAP directory is considered a valid user, whereas FrontPage
703 considers only those people in the local user file to be
704 valid. By substituting the ldap-group with group file authorization,
705 Apache is allowed to consult the local user file (which is managed by
706 FrontPage) - instead of LDAP - when handling authorizing the user.</p>
708 <p>Once directives have been added as specified above,
709 FrontPage users will be able to perform all management
710 operations from the FrontPage client.</p>
713 <section id="fpcaveats"><title>Caveats</title>
716 <li>When choosing the LDAP URL, the attribute to use for
717 authentication should be something that will also be valid
718 for putting into a <module>mod_authn_file</module> user file.
719 The user ID is ideal for this.</li>
721 <li>When adding users via FrontPage, FrontPage administrators
722 should choose usernames that already exist in the LDAP
723 directory (for obvious reasons). Also, the password that the
724 administrator enters into the form is ignored, since Apache
725 will actually be authenticating against the password in the
726 LDAP database, and not against the password in the local user
727 file. This could cause confusion for web administrators.</li>
729 <!-- XXX is that true? was mod_auth before the aaa change -->
730 <li>Apache must be compiled with <module>mod_auth_basic</module>,
731 <module>mod_authn_file</module> and
732 <module>mod_authz_groupfile</module> in order to
733 use FrontPage support. This is because Apache will still use
734 the <module>mod_authz_groupfile</module> group file for determine
735 the extent of a user's access to the FrontPage web.</li>
737 <li>The directives must be put in the <code>.htaccess</code>
738 files. Attempting to put them inside <directive module="core"
739 type="section">Location</directive> or <directive module="core"
740 type="section">Directory</directive> directives won't work. This
741 is because <module>mod_authnz_ldap</module> has to be able to grab
742 the <directive module="mod_authn_file">AuthGroupFile</directive>
743 directive that is found in FrontPage <code>.htaccess</code>
744 files so that it knows where to look for the valid user list. If
745 the <module>mod_authnz_ldap</module> directives aren't in the same
746 <code>.htaccess</code> file as the FrontPage directives, then
747 the hack won't work, because <module>mod_authnz_ldap</module> will
748 never get a chance to process the <code>.htaccess</code> file,
749 and won't be able to find the FrontPage-managed user file.</li>
755 <name>AuthLDAPBindAuthoritative</name>
756 <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 users credentials.</description>
757 <syntax>AuthLDAPBindAuthoritative<em>off|on</em></syntax>
758 <default>AuthLDAPBindAuthoritative on</default>
759 <contextlist><context>directory</context><context>.htaccess</context>
761 <override>AuthConfig</override>
763 <p>By default, subsequent authentication providers are only queried if a
764 user cannot be mapped to a DN, but not if the user can be mapped to a DN and their
765 password cannot be verified with an LDAP bind.
766 If <directive module="mod_authnz_ldap">AuthLDAPBindAuthoritative</directive>
767 is set to <em>off</em>, other configured authentication modules will have
768 a chance to validate the user if the LDAP bind (with the current users credentials)
769 fails for any reason.</p>
770 <p> This allows users present in both LDAP and
771 <directive module="mod_authn_file">AuthUserFile</directive> to authenticate
772 when the LDAP server is available but the users account is locked or password
773 is otherwise unusable.</p>
775 <seealso><directive module="mod_authn_file">AuthUserFile</directive></seealso>
776 <seealso><directive module="mod_auth_basic">AuthBasicProvider</directive></seealso>
780 <name>AuthLDAPBindDN</name>
781 <description>Optional DN to use in binding to the LDAP server</description>
782 <syntax>AuthLDAPBindDN <em>distinguished-name</em></syntax>
783 <contextlist><context>directory</context><context>.htaccess</context>
785 <override>AuthConfig</override>
788 <p>An optional DN used to bind to the server when searching for
789 entries. If not provided, <module>mod_authnz_ldap</module> will use
790 an anonymous bind.</p>
795 <name>AuthLDAPBindPassword</name>
796 <description>Password used in conjuction with the bind DN</description>
797 <syntax>AuthLDAPBindPassword <em>password</em></syntax>
798 <contextlist><context>directory</context><context>.htaccess</context>
800 <override>AuthConfig</override>
803 <p>A bind password to use in conjunction with the bind DN. Note
804 that the bind password is probably sensitive data, and should be
805 properly protected. You should only use the <directive
806 module="mod_authnz_ldap">AuthLDAPBindDN</directive> and <directive
807 module="mod_authnz_ldap">AuthLDAPBindPassword</directive> if you
808 absolutely need them to search the directory.</p>
813 <name>AuthLDAPCharsetConfig</name>
814 <description>Language to charset conversion configuration file</description>
815 <syntax>AuthLDAPCharsetConfig <em>file-path</em></syntax>
816 <contextlist><context>server config</context>
820 <p>The <directive>AuthLDAPCharsetConfig</directive> directive sets the location
821 of the language to charset conversion configuration file. <var>File-path</var> is relative
822 to the <directive module="core">ServerRoot</directive>. This file specifies
823 the list of language extensions to character sets.
824 Most administrators use the provided <code>charset.conv</code>
825 file, which associates common language extensions to character sets.</p>
827 <p>The file contains lines in the following format:</p>
830 <var>Language-Extension</var> <var>charset</var> [<var>Language-String</var>] ...
833 <p>The case of the extension does not matter. Blank lines, and lines
834 beginning with a hash character (<code>#</code>) are ignored.</p>
839 <name>AuthLDAPCompareDNOnServer</name>
840 <description>Use the LDAP server to compare the DNs</description>
841 <syntax>AuthLDAPCompareDNOnServer on|off</syntax>
842 <default>AuthLDAPCompareDNOnServer on</default>
843 <contextlist><context>directory</context><context>.htaccess</context>
845 <override>AuthConfig</override>
848 <p>When set, <module>mod_authnz_ldap</module> will use the LDAP
849 server to compare the DNs. This is the only foolproof way to
850 compare DNs. <module>mod_authnz_ldap</module> will search the
851 directory for the DN specified with the <a
852 href="#reqdn"><code>Require dn</code></a> directive, then,
853 retrieve the DN and compare it with the DN retrieved from the user
854 entry. If this directive is not set,
855 <module>mod_authnz_ldap</module> simply does a string comparison. It
856 is possible to get false negatives with this approach, but it is
857 much faster. Note the <module>mod_ldap</module> cache can speed up
858 DN comparison in most situations.</p>
863 <name>AuthLDAPDereferenceAliases</name>
864 <description>When will the module de-reference aliases</description>
865 <syntax>AuthLDAPDereferenceAliases never|searching|finding|always</syntax>
866 <default>AuthLDAPDereferenceAliases always</default>
867 <contextlist><context>directory</context><context>.htaccess</context>
869 <override>AuthConfig</override>
872 <p>This directive specifies when <module>mod_authnz_ldap</module> will
873 de-reference aliases during LDAP operations. The default is
874 <code>always</code>.</p>
879 <name>AuthLDAPGroupAttribute</name>
880 <description>LDAP attributes used to identify the user members of
881 groups.</description>
882 <syntax>AuthLDAPGroupAttribute <em>attribute</em></syntax>
883 <default>AuthLDAPGroupAttribute member uniquemember</default>
884 <contextlist><context>directory</context><context>.htaccess</context>
886 <override>AuthConfig</override>
889 <p>This directive specifies which LDAP attributes are used to
890 check for user members within groups. Multiple attributes can be used
891 by specifying this directive multiple times. If not specified,
892 then <module>mod_authnz_ldap</module> uses the <code>member</code> and
893 <code>uniquemember</code> attributes.</p>
898 <name>AuthLDAPGroupAttributeIsDN</name>
899 <description>Use the DN of the client username when checking for
900 group membership</description>
901 <syntax>AuthLDAPGroupAttributeIsDN on|off</syntax>
902 <default>AuthLDAPGroupAttributeIsDN on</default>
903 <contextlist><context>directory</context><context>.htaccess</context>
905 <override>AuthConfig</override>
908 <p>When set <code>on</code>, this directive says to use the
909 distinguished name of the client username when checking for group
910 membership. Otherwise, the username will be used. For example,
911 assume that the client sent the username <code>bjenson</code>,
912 which corresponds to the LDAP DN <code>cn=Babs Jenson,
913 o=Airius</code>. If this directive is set,
914 <module>mod_authnz_ldap</module> will check if the group has
915 <code>cn=Babs Jenson, o=Airius</code> as a member. If this
916 directive is not set, then <module>mod_authnz_ldap</module> will
917 check if the group has <code>bjenson</code> as a member.</p>
922 <name>AuthLDAPMaxSubGroupDepth</name>
923 <description>Specifies the maximum sub-group nesting depth that will be
924 evaluated before the user search is discontinued.</description>
925 <syntax>AuthLDAPMaxSubGroupDepth <var>Number</var></syntax>
926 <default>AuthLDAPMaxSubGroupDepth 10</default>
927 <contextlist><context>directory</context><context>.htaccess</context>
929 <override>AuthConfig</override>
932 <p>When this directive is set to a non-zero value <code>X</code>
933 combined with use of the <code>Require ldap-group someGroupDN</code>
934 directive, the provided user credentials will be searched for
935 as a member of the <code>someGroupDN</code> directory object or of
936 any group member of the current group up to the maximum nesting
937 level <code>X</code> specified by this directive.</p>
938 <p>See the <a href="#reqgroup"><code>Require ldap-group</code></a>
939 section for a more detailed example.</p>
944 <name>AuthLDAPRemoteUserAttribute</name>
945 <description>Use the value of the attribute returned during the user
946 query to set the REMOTE_USER environment variable</description>
947 <syntax>AuthLDAPRemoteUserAttribute uid</syntax>
948 <default>none</default>
949 <contextlist><context>directory</context><context>.htaccess</context>
951 <override>AuthConfig</override>
954 <p>If this directive is set, the value of the
955 <code>REMOTE_USER</code> environment variable will be set to the
956 value of the attribute specified. Make sure that this attribute is
957 included in the list of attributes in the AuthLDAPUrl definition,
958 otherwise this directive will have no effect. This directive, if
959 present, takes precedence over AuthLDAPRemoteUserIsDN. This
960 directive is useful should you want people to log into a website
961 using an email address, but a backend application expects the
962 username as a userid.</p>
967 <name>AuthLDAPRemoteUserIsDN</name>
968 <description>Use the DN of the client username to set the REMOTE_USER
969 environment variable</description>
970 <syntax>AuthLDAPRemoteUserIsDN on|off</syntax>
971 <default>AuthLDAPRemoteUserIsDN off</default>
972 <contextlist><context>directory</context><context>.htaccess</context>
974 <override>AuthConfig</override>
977 <p>If this directive is set to on, the value of the
978 <code>REMOTE_USER</code> environment variable will be set to the full
979 distinguished name of the authenticated user, rather than just
980 the username that was passed by the client. It is turned off by
986 <name>AuthLDAPSubGroupAttribute</name>
987 <description>Specifies the attribute labels, one value per
988 directive line, used to distinguish the members of the current group that
989 are groups.</description>
990 <syntax>AuthLDAPSubGroupAttribute <em>attribute</em></syntax>
991 <contextlist><context>directory</context><context>.htaccess</context>
993 <override>AuthConfig</override>
996 <p>An LDAP group object may contain members that are users and
997 members that are groups (called nested or sub groups). The
998 <code>AuthLDAPSubGroupAttribute</code> directive identifies the
999 labels of group members and the <code>AuthLDAPGroupAttribute</code>
1000 directive identifies the labels of the user members. Multiple
1001 attributes can be used by specifying this directive multiple times.
1002 If not specified, then <module>mod_authnz_ldap</module> uses the
1003 <code>member</code> and <code>uniqueMember</code> attributes.</p>
1005 </directivesynopsis>
1008 <name>AuthLDAPSubGroupClass</name>
1009 <description>Specifies which LDAP objectClass values identify directory
1010 objects that are groups during sub-group processing.</description>
1011 <syntax>AuthLDAPSubGroupClass <em>LdapObjectClass</em></syntax>
1012 <contextlist><context>directory</context><context>.htaccess</context>
1014 <override>AuthConfig</override>
1017 <p>An LDAP group object may contain members that are users and
1018 members that are groups (called nested or sub groups). The
1019 <code>AuthLDAPSubGroupAttribute</code> directive identifies the
1020 labels of members that may be sub-groups of the current group
1021 (as opposed to user members). The <code>AuthLDAPSubGroupClass</code>
1022 directive specifies the LDAP objectClass values used in verifying that
1023 these potential sub-groups are in fact group objects. Verified sub-groups
1024 can then be searched for more user or sub-group members. Multiple
1025 attributes can be used by specifying this directive multiple times.
1026 If not specified, then <module>mod_authnz_ldap</module> uses the
1027 <code>groupOfNames</code> and <code>groupOfUniqueNames</code> values.</p>
1029 </directivesynopsis>
1032 <name>AuthLDAPUrl</name>
1033 <description>URL specifying the LDAP search parameters</description>
1034 <syntax>AuthLDAPUrl <em>url [NONE|SSL|TLS|STARTTLS]</em></syntax>
1035 <contextlist><context>directory</context><context>.htaccess</context>
1037 <override>AuthConfig</override>
1040 <p>An RFC 2255 URL which specifies the LDAP search parameters
1041 to use. The syntax of the URL is</p>
1042 <example>ldap://host:port/basedn?attribute?scope?filter</example>
1043 <p>If you want to specify more than one LDAP URL that Apache should try in turn, the syntax is:</p>
1044 <example>AuthLDAPUrl "ldap://ldap1.example.com ldap2.example.com/dc=..."</example>
1045 <p><em><strong>Caveat: </strong>If you specify multiple servers, you need to enclose the entire URL string in quotes;
1046 otherwise you will get an error: "AuthLDAPURL takes one argument, URL to define LDAP connection.." </em>
1047 You can of course use search parameters on each of these.</p>
1052 <dd>For regular ldap, use the
1053 string <code>ldap</code>. For secure LDAP, use <code>ldaps</code>
1054 instead. Secure LDAP is only available if Apache was linked
1055 to an LDAP library with SSL support.</dd>
1060 <p>The name/port of the ldap server (defaults to
1061 <code>localhost:389</code> for <code>ldap</code>, and
1062 <code>localhost:636</code> for <code>ldaps</code>). To
1063 specify multiple, redundant LDAP servers, just list all
1064 servers, separated by spaces. <module>mod_authnz_ldap</module>
1065 will try connecting to each server in turn, until it makes a
1066 successful connection. If multiple ldap servers are specified,
1067 then entire LDAP URL must be encapsulated in double quotes.</p>
1069 <p>Once a connection has been made to a server, that
1070 connection remains active for the life of the
1071 <program>httpd</program> process, or until the LDAP server goes
1074 <p>If the LDAP server goes down and breaks an existing
1075 connection, <module>mod_authnz_ldap</module> will attempt to
1076 re-connect, starting with the primary server, and trying
1077 each redundant server in turn. Note that this is different
1078 than a true round-robin search.</p>
1083 <dd>The DN of the branch of the
1084 directory where all searches should start from. At the very
1085 least, this must be the top of your directory tree, but
1086 could also specify a subtree in the directory.</dd>
1090 <dd>The attribute to search for.
1091 Although RFC 2255 allows a comma-separated list of
1092 attributes, only the first attribute will be used, no
1093 matter how many are provided. If no attributes are
1094 provided, the default is to use <code>uid</code>. It's a good
1095 idea to choose an attribute that will be unique across all
1096 entries in the subtree you will be using. All attributes
1097 listed will be put into the environment with an AUTHENTICATE_ prefix
1098 for use by other modules.</dd>
1102 <dd>The scope of the search. Can be either <code>one</code> or
1103 <code>sub</code>. Note that a scope of <code>base</code> is
1104 also supported by RFC 2255, but is not supported by this
1105 module. If the scope is not provided, or if <code>base</code> scope
1106 is specified, the default is to use a scope of
1107 <code>sub</code>.</dd>
1111 <dd>A valid LDAP search filter. If
1112 not provided, defaults to <code>(objectClass=*)</code>, which
1113 will search for all objects in the tree. Filters are
1114 limited to approximately 8000 characters (the definition of
1115 <code>MAX_STRING_LEN</code> in the Apache source code). This
1116 should be more than sufficient for any application.</dd>
1119 <p>When doing searches, the attribute, filter and username passed
1120 by the HTTP client are combined to create a search filter that
1122 <code>(&(<em>filter</em>)(<em>attribute</em>=<em>username</em>))</code>.</p>
1124 <p>For example, consider an URL of
1125 <code>ldap://ldap.airius.com/o=Airius?cn?sub?(posixid=*)</code>. When
1126 a client attempts to connect using a username of <code>Babs
1127 Jenson</code>, the resulting search filter will be
1128 <code>(&(posixid=*)(cn=Babs Jenson))</code>.</p>
1130 <p>An optional parameter can be added to allow the LDAP Url to override
1131 the connection type. This parameter can be one of the following:</p>
1135 <dd>Establish an unsecure connection on the default LDAP port. This
1136 is the same as <code>ldap://</code> on port 389.</dd>
1138 <dd>Establish a secure connection on the default secure LDAP port.
1139 This is the same as <code>ldaps://</code></dd>
1140 <dt>TLS | STARTTLS</dt>
1141 <dd>Establish an upgraded secure connection on the default LDAP port.
1142 This connection will be initiated on port 389 by default and then
1143 upgraded to a secure connection on the same port.</dd>
1146 <p>See above for examples of <directive
1147 module="mod_authnz_ldap">AuthLDAPURL</directive> URLs.</p>
1149 </directivesynopsis>