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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="#reqvaliduser">Require valid-user</a></li>
88 <li><a href="#requser">Require ldap-user</a></li>
89 <li><a href="#reqgroup">Require ldap-group</a></li>
90 <li><a href="#reqdn">Require ldap-dn</a></li>
91 <li><a href="#reqattribute">Require ldap-attribute</a></li>
92 <li><a href="#reqfilter">Require ldap-filter</a></li>
96 <li><a href="#examples">Examples</a></li>
97 <li><a href="#usingtls">Using TLS</a></li>
98 <li><a href="#usingssl">Using SSL</a></li>
99 <li><a href="#exposed">Exposing Login Information</a></li>
100 <li><a href="#activedirectory">Using Active Directory</a></li>
102 <a href="#frontpage">Using Microsoft FrontPage with
103 <module>mod_authnz_ldap</module></a>
106 <li><a href="#howitworks">How It Works</a></li>
107 <li><a href="#fpcaveats">Caveats</a></li>
113 <section id="operation"><title>Operation</title>
115 <p>There are two phases in granting access to a user. The first
116 phase is authentication, in which the <module>mod_authnz_ldap</module>
117 authentication provider verifies that the user's credentials are valid.
118 This is also called the <em>search/bind</em> phase. The second phase is
119 authorization, in which <module>mod_authnz_ldap</module> determines
120 if the authenticated user is allowed access to the resource in
121 question. This is also known as the <em>compare</em>
124 <p><module>mod_authnz_ldap</module> registers both an authn_ldap authentication
125 provider and an authz_ldap authorization handler. The authn_ldap
126 authentication provider can be enabled through the
127 <directive module="mod_auth_basic">AuthBasicProvider</directive> directive
128 using the <code>ldap</code> value. The authz_ldap handler extends the
129 <directive module="mod_authz_core">Require</directive> directive's authorization types
130 by adding <code>ldap-user</code>, <code>ldap-dn</code> and <code>ldap-group</code>
133 <section id="authenphase"><title>The Authentication
136 <p>During the authentication phase, <module>mod_authnz_ldap</module>
137 searches for an entry in the directory that matches the username
138 that the HTTP client passes. If a single unique match is found,
139 then <module>mod_authnz_ldap</module> attempts to bind to the
140 directory server using the DN of the entry plus the password
141 provided by the HTTP client. Because it does a search, then a
142 bind, it is often referred to as the search/bind phase. Here are
143 the steps taken during the search/bind phase.</p>
146 <li>Generate a search filter by combining the attribute and
147 filter provided in the <directive module="mod_authnz_ldap"
148 >AuthLDAPURL</directive> directive with
149 the username passed by the HTTP client.</li>
151 <li>Search the directory using the generated filter. If the
152 search does not return exactly one entry, deny or decline
155 <li>Fetch the distinguished name of the entry retrieved from
156 the search and attempt to bind to the LDAP server using the
157 DN and the password passed by the HTTP client. If the bind is
158 unsuccessful, deny or decline access.</li>
161 <p>The following directives are used during the search/bind
165 <columnspec><column width=".3"/><column width=".7"/></columnspec>
167 <td><directive module="mod_authnz_ldap">AuthLDAPURL</directive></td>
169 <td>Specifies the LDAP server, the
170 base DN, the attribute to use in the search, as well as the
171 extra search filter to use.</td>
175 <td><directive module="mod_authnz_ldap">AuthLDAPBindDN</directive></td>
177 <td>An optional DN to bind with
178 during the search phase.</td>
183 module="mod_authnz_ldap">AuthLDAPBindPassword</directive></td>
185 <td>An optional password to bind
186 with during the search phase.</td>
191 <section id="authorphase"><title>The Authorization Phase</title>
193 <p>During the authorization phase, <module>mod_authnz_ldap</module>
194 attempts to determine if the user is authorized to access the
195 resource. Many of these checks require
196 <module>mod_authnz_ldap</module> to do a compare operation on the
197 LDAP server. This is why this phase is often referred to as the
198 compare phase. <module>mod_authnz_ldap</module> accepts the
199 following <directive module="mod_authz_core">Require</directive>
200 directives to determine if the credentials are acceptable:</p>
203 <li>Grant access if there is a <a
204 href="#reqgroup"><code>Require ldap-user</code></a> directive, and the
205 username in the directive matches the username passed by the
208 <li>Grant access if there is a <a href="#reqdn"><code>Require
209 ldap-dn</code></a> directive, and the DN in the directive matches
210 the DN fetched from the LDAP directory.</li>
212 <li>Grant access if there is a <a
213 href="#reqgroup"><code>Require ldap-group</code></a> directive, and
214 the DN fetched from the LDAP directory (or the username
215 passed by the client) occurs in the LDAP group or, potentially, in
216 one of its sub-groups.</li>
218 <li>Grant access if there is a <a href="#reqattribute">
219 <code>Require ldap-attribute</code></a>
220 directive, and the attribute fetched from the LDAP directory
221 matches the given value.</li>
223 <li>Grant access if there is a <a href="#reqfilter">
224 <code>Require ldap-filter</code></a>
225 directive, and the search filter successfully finds a single user
226 object that matches the dn of the authenticated user.</li>
228 <li>otherwise, deny or decline access</li>
231 <p>Other <directive module="mod_authz_core">Require</directive> values may also
232 be used which may require loading additional authorization modules.
233 Note that if you use a <directive module="mod_authz_core">Require</directive>
234 value from another authorization module, you will need to ensure that
235 <directive module="mod_authnz_ldap">AuthzLDAPAuthoritative</directive>
236 is set to <code>off</code> to allow the authorization phase to fall
237 back to the module providing the alternate
238 <directive module="mod_authz_core">Require</directive> value.</p>
241 <li>Grant access if there is a <a href="#requser"><code>Require
242 valid-user</code></a> directive. (requires
243 <module>mod_authz_user</module>)</li>
245 <li>Grant access if there is a <a
246 href="#reqgroup"><code>Require group</code></a> directive, and
247 <module>mod_authz_groupfile</module> has been loaded with the
248 <directive module="mod_authz_groupfile">AuthGroupFile</directive>
255 <p><module>mod_authnz_ldap</module> uses the following directives during the
259 <columnspec><column width=".4"/><column width=".6"/></columnspec>
261 <td><directive module="mod_authnz_ldap">AuthLDAPURL</directive> </td>
263 <td>The attribute specified in the
264 URL is used in compare operations for the <code>Require
265 ldap-user</code> operation.</td>
270 module="mod_authnz_ldap">AuthLDAPCompareDNOnServer</directive></td>
272 <td>Determines the behavior of the
273 <code>Require ldap-dn</code> directive.</td>
278 module="mod_authnz_ldap">AuthLDAPGroupAttribute</directive></td>
280 <td>Determines the attribute to
281 use for comparisons in the <code>Require ldap-group</code>
287 module="mod_authnz_ldap">AuthLDAPGroupAttributeIsDN</directive></td>
289 <td>Specifies whether to use the
290 user DN or the username when doing comparisons for the
291 <code>Require ldap-group</code> directive.</td>
296 module="mod_authnz_ldap">AuthLDAPMaxSubGroupDepth</directive></td>
298 <td>Determines the maximum depth of sub-groups that will be evaluated
299 during comparisons in the <code>Require ldap-group</code> directive.</td>
304 module="mod_authnz_ldap">AuthLDAPSubGroupAttribute</directive></td>
306 <td>Determines the attribute to use when obtaining sub-group members
307 of the current group during comparisons in the <code>Require ldap-group</code>
313 module="mod_authnz_ldap">AuthLDAPSubGroupClass</directive></td>
315 <td>Specifies the LDAP objectClass values used to identify if queried directory
316 objects really are group objects (as opposed to user objects) during the
317 <code>Require ldap-group</code> directive's sub-group processing.</td>
323 <section id="requiredirectives"><title>The Require Directives</title>
325 <p>Apache's <directive module="mod_authz_core">Require</directive>
326 directives are used during the authorization phase to ensure that
327 a user is allowed to access a resource. mod_authnz_ldap extends the
328 authorization types with <code>ldap-user</code>, <code>ldap-dn</code>,
329 <code>ldap-group</code>, <code>ldap-attribute</code> and
330 <code>ldap-filter</code>. Other authorization types may also be
331 used but may require that additional authorization modules be loaded.</p>
333 <section id="reqvaliduser"><title>Require valid-user</title>
335 <p>If this directive exists, <module>mod_authnz_ldap</module> grants
336 access to any user that has successfully authenticated during the
337 search/bind phase. Requires that <module>mod_authz_user</module> be
341 <section id="requser"><title>Require ldap-user</title>
343 <p>The <code>Require ldap-user</code> directive specifies what
344 usernames can access the resource. Once
345 <module>mod_authnz_ldap</module> has retrieved a unique DN from the
346 directory, it does an LDAP compare operation using the username
347 specified in the <code>Require ldap-user</code> to see if that username
348 is part of the just-fetched LDAP entry. Multiple users can be
349 granted access by putting multiple usernames on the line,
350 separated with spaces. If a username has a space in it, then it
351 must be surrounded with double quotes. Multiple users can also be
352 granted access by using multiple <code>Require ldap-user</code>
353 directives, with one user per line. For example, with a <directive
354 module="mod_authnz_ldap">AuthLDAPURL</directive> of
355 <code>ldap://ldap/o=Airius?cn</code> (i.e., <code>cn</code> is
356 used for searches), the following Require directives could be used
357 to restrict access:</p>
359 Require ldap-user "Barbara Jenson"<br />
360 Require ldap-user "Fred User"<br />
361 Require ldap-user "Joe Manager"<br />
364 <p>Because of the way that <module>mod_authnz_ldap</module> handles this
365 directive, Barbara Jenson could sign on as <em>Barbara
366 Jenson</em>, <em>Babs Jenson</em> or any other <code>cn</code> that
367 she has in her LDAP entry. Only the single <code>Require
368 ldap-user</code> line is needed to support all values of the attribute
369 in the user's entry.</p>
371 <p>If the <code>uid</code> attribute was used instead of the
372 <code>cn</code> attribute in the URL above, the above three lines
373 could be condensed to</p>
374 <example>Require ldap-user bjenson fuser jmanager</example>
377 <section id="reqgroup"><title>Require ldap-group</title>
379 <p>This directive specifies an LDAP group whose members are
380 allowed access. It takes the distinguished name of the LDAP
381 group. Note: Do not surround the group name with quotes.
382 For example, assume that the following entry existed in
383 the LDAP directory:</p>
385 dn: cn=Administrators, o=Airius<br />
386 objectClass: groupOfUniqueNames<br />
387 uniqueMember: cn=Barbara Jenson, o=Airius<br />
388 uniqueMember: cn=Fred User, o=Airius<br />
391 <p>The following directive would grant access to both Fred and
393 <example>Require ldap-group cn=Administrators, o=Airius</example>
395 <p>Members can also be found within sub-groups of a specified LDAP group
396 if <directive module="mod_authnz_ldap">AuthLDAPMaxSubGroupDepth</directive>
397 is set to a value greater than 0. For example, assume the following entries
398 exist in the LDAP directory:</p>
400 dn: cn=Employees, o=Airius<br />
401 objectClass: groupOfUniqueNames<br />
402 uniqueMember: cn=Managers, o=Airius<br />
403 uniqueMember: cn=Administrators, o=Airius<br />
404 uniqueMember: cn=Users, o=Airius<br />
406 dn: cn=Managers, o=Airius<br />
407 objectClass: groupOfUniqueNames<br />
408 uniqueMember: cn=Bob Ellis, o=Airius<br />
409 uniqueMember: cn=Tom Jackson, o=Airius<br />
411 dn: cn=Administrators, o=Airius<br />
412 objectClass: groupOfUniqueNames<br />
413 uniqueMember: cn=Barbara Jenson, o=Airius<br />
414 uniqueMember: cn=Fred User, o=Airius<br />
416 dn: cn=Users, o=Airius<br />
417 objectClass: groupOfUniqueNames<br />
418 uniqueMember: cn=Allan Jefferson, o=Airius<br />
419 uniqueMember: cn=Paul Tilley, o=Airius<br />
420 uniqueMember: cn=Temporary Employees, o=Airius<br />
422 dn: cn=Temporary Employees, o=Airius<br />
423 objectClass: groupOfUniqueNames<br />
424 uniqueMember: cn=Jim Swenson, o=Airius<br />
425 uniqueMember: cn=Elliot Rhodes, o=Airius<br />
428 <p>The following directives would allow access for Bob Ellis, Tom Jackson,
429 Barbara Jensen, Fred User, Allan Jefferson, and Paul Tilley but would not
430 allow access for Jim Swenson, or Elliot Rhodes (since they are at a
431 sub-group depth of 2):</p>
433 Require ldap-group cn=Employees, o-Airius<br />
434 AuthLDAPSubGroupDepth 1<br />
437 <p>Behavior of this directive is modified by the <directive
438 module="mod_authnz_ldap">AuthLDAPGroupAttribute</directive>, <directive
439 module="mod_authnz_ldap">AuthLDAPGroupAttributeIsDN</directive>, <directive
440 module="mod_authnz_ldap">AuthLDAPMaxSubGroupDepth</directive>, <directive
441 module="mod_authnz_ldap">AuthLDAPSubGroupAttribute</directive>, and <directive
442 module="mod_authnz_ldap">AuthLDAPSubGroupClass</directive>
446 <section id="reqdn"><title>Require ldap-dn</title>
448 <p>The <code>Require ldap-dn</code> directive allows the administrator
449 to grant access based on distinguished names. It specifies a DN
450 that must match for access to be granted. If the distinguished
451 name that was retrieved from the directory server matches the
452 distinguished name in the <code>Require ldap-dn</code>, then
453 authorization is granted. Note: do not surround the distinguished
454 name with quotes.</p>
456 <p>The following directive would grant access to a specific
458 <example>Require ldap-dn cn=Barbara Jenson, o=Airius</example>
460 <p>Behavior of this directive is modified by the <directive
461 module="mod_authnz_ldap">AuthLDAPCompareDNOnServer</directive>
465 <section id="reqattribute"><title>Require ldap-attribute</title>
467 <p>The <code>Require ldap-attribute</code> directive allows the
468 administrator to grant access based on attributes of the authenticated
469 user in the LDAP directory. If the attribute in the directory
470 matches the value given in the configuration, access is granted.</p>
472 <p>The following directive would grant access to anyone with
473 the attribute employeeType = active</p>
475 <example>Require ldap-attribute employeeType=active</example>
477 <p>Multiple attribute/value pairs can be specified on the same line
478 separated by spaces or they can be specified in multiple
479 <code>Require ldap-attribute</code> directives. The effect of listing
480 multiple attribute/values pairs is an OR operation. Access will be
481 granted if any of the listed attribute values match the value of the
482 corresponding attribute in the user object. If the value of the
483 attribute contains a space, only the value must be within double quotes.</p>
485 <p>The following directive would grant access to anyone with
486 the city attribute equal to "San Jose" or status equal to "Active"</p>
488 <example>Require ldap-attribute city="San Jose" status=active</example>
492 <section id="reqfilter"><title>Require ldap-filter</title>
494 <p>The <code>Require ldap-filter</code> directive allows the
495 administrator to grant access based on a complex LDAP search filter.
496 If the dn returned by the filter search matches the authenticated user
497 dn, access is granted.</p>
499 <p>The following directive would grant access to anyone having a cell phone
500 and is in the marketing department</p>
502 <example>Require ldap-filter &(cell=*)(department=marketing)</example>
504 <p>The difference between the <code>Require ldap-filter</code> directive and the
505 <code>Require ldap-attribute</code> directive is that <code>ldap-filter</code>
506 performs a search operation on the LDAP directory using the specified search
507 filter rather than a simple attribute comparison. If a simple attribute
508 comparison is all that is required, the comparison operation performed by
509 <code>ldap-attribute</code> will be faster than the search operation
510 used by <code>ldap-filter</code> especially within a large directory.</p>
516 <section id="examples"><title>Examples</title>
520 Grant access to anyone who exists in the LDAP directory,
521 using their UID for searches.
523 AuthLDAPURL ldap://ldap1.airius.com:389/ou=People, o=Airius?uid?sub?(objectClass=*)<br />
529 The next example is the same as above; but with the fields
530 that have useful defaults omitted. Also, note the use of a
531 redundant LDAP server.
532 <example>AuthLDAPURL ldap://ldap1.airius.com ldap2.airius.com/ou=People, o=Airius<br />
538 The next example is similar to the previous one, but it
539 uses the common name instead of the UID. Note that this
540 could be problematical if multiple people in the directory
541 share the same <code>cn</code>, because a search on <code>cn</code>
542 <strong>must</strong> return exactly one entry. That's why
543 this approach is not recommended: it's a better idea to
544 choose an attribute that is guaranteed unique in your
545 directory, such as <code>uid</code>.
547 AuthLDAPURL ldap://ldap.airius.com/ou=People, o=Airius?cn<br />
553 Grant access to anybody in the Administrators group. The
554 users must authenticate using their UID.
556 AuthLDAPURL ldap://ldap.airius.com/o=Airius?uid<br />
557 Require ldap-group cn=Administrators, o=Airius
562 The next example assumes that everyone at Airius who
563 carries an alphanumeric pager will have an LDAP attribute
564 of <code>qpagePagerID</code>. The example will grant access
565 only to people (authenticated via their UID) who have
568 AuthLDAPURL ldap://ldap.airius.com/o=Airius?uid??(qpagePagerID=*)<br />
574 <p>The next example demonstrates the power of using filters
575 to accomplish complicated administrative requirements.
576 Without filters, it would have been necessary to create a
577 new LDAP group and ensure that the group's members remain
578 synchronized with the pager users. This becomes trivial
579 with filters. The goal is to grant access to anyone who has
580 a pager, plus grant access to Joe Manager, who doesn't
581 have a pager, but does need to access the same
584 AuthLDAPURL ldap://ldap.airius.com/o=Airius?uid??(|(qpagePagerID=*)(uid=jmanager))<br />
588 <p>This last may look confusing at first, so it helps to
589 evaluate what the search filter will look like based on who
590 connects, as shown below. If
591 Fred User connects as <code>fuser</code>, the filter would look
594 <example>(&(|(qpagePagerID=*)(uid=jmanager))(uid=fuser))</example>
596 <p>The above search will only succeed if <em>fuser</em> has a
597 pager. When Joe Manager connects as <em>jmanager</em>, the
598 filter looks like</p>
600 <example>(&(|(qpagePagerID=*)(uid=jmanager))(uid=jmanager))</example>
602 <p>The above search will succeed whether <em>jmanager</em>
603 has a pager or not.</p>
608 <section id="usingtls"><title>Using TLS</title>
610 <p>To use TLS, see the <module>mod_ldap</module> directives <directive
611 module="mod_ldap">LDAPTrustedClientCert</directive>, <directive
612 module="mod_ldap">LDAPTrustedGlobalCert</directive> and <directive
613 module="mod_ldap">LDAPTrustedMode</directive>.</p>
615 <p>An optional second parameter can be added to the
616 <directive module="mod_authnz_ldap">AuthLDAPURL</directive> to override
617 the default connection type set by <directive module="mod_ldap">LDAPTrustedMode</directive>.
618 This will allow the connection established by an <em>ldap://</em> Url
619 to be upgraded to a secure connection on the same port.</p>
622 <section id="usingssl"><title>Using SSL</title>
624 <p>To use SSL, see the <module>mod_ldap</module> directives <directive
625 module="mod_ldap">LDAPTrustedClientCert</directive>, <directive
626 module="mod_ldap">LDAPTrustedGlobalCert</directive> and <directive
627 module="mod_ldap">LDAPTrustedMode</directive>.</p>
629 <p>To specify a secure LDAP server, use <em>ldaps://</em> in the
630 <directive module="mod_authnz_ldap">AuthLDAPURL</directive>
631 directive, instead of <em>ldap://</em>.</p>
634 <section id="exposed"><title>Exposing Login Information</title>
636 <p>Whenever a query is made to the LDAP server, all LDAP attributes
637 returned by the query are placed in the environment, using environment
638 variables with the prefix "AUTHENTICATE_".</p>
640 <p>If an LDAP query for example returned the username, common name
641 and telephone number of a user, a CGI program will have access to
642 this information without the need to make a second independent LDAP
643 query to gather this additional information.</p>
645 <p>This has the potential to dramatically simplify the coding and
646 configuration required in some web applications.</p>
650 <section id="activedirectory"><title>Using Active Directory</title>
652 <p>An Active Directory installation may support multiple domains at the
653 same time. To distinguish users between domains, an identifier called
654 a User Principle Name (UPN) can be added to a user's entry in the
655 directory. This UPN usually takes the form of the user's account
656 name, followed by the domain components of the particular domain,
657 for example <em>somebody@nz.somedomain.com</em>.</p>
659 <p>You may wish to configure the <module>mod_authnz_ldap</module>
660 module to authenticate users present in any of the domains making up
661 the Active Directory forest. In this way both
662 <em>somebody@nz.somedomain.com</em> and <em>someone@au.somedomain.com</em>
663 can be authenticated using the same query at the same time.</p>
665 <p>To make this practical, Active Directory supports the concept of
666 a Global Catalog. This Global Catalog is a read only copy of selected
667 attributes of all the Active Directory servers within the Active
668 Directory forest. Querying the Global Catalog allows all the domains
669 to be queried in a single query, without the query spanning servers
670 over potentially slow links.</p>
672 <p>If enabled, the Global Catalog is an independent directory server
673 that runs on port 3268 (3269 for SSL). To search for a user, do a
674 subtree search for the attribute <em>userPrincipalName</em>, with
675 an empty search root, like so:</p>
678 AuthLDAPBindDN <em>apache@somedomain.com</em>
679 AuthLDAPBindPassword <em>password</em>
680 AuthLDAPURL <em>ldap://10.0.0.1:3268/>userPrincipalName?sub</em>
683 <p>Users will need to enter their User Principal Name as a login, in
684 the form <em>somebody@nz.somedomain.com</em>.</p>
688 <section id="frontpage"><title>Using Microsoft
689 FrontPage with mod_authnz_ldap</title>
691 <p>Normally, FrontPage uses FrontPage-web-specific user/group
692 files (i.e., the <module>mod_authn_file</module> and
693 <module>mod_authz_groupfile</module> modules) to handle all
694 authentication. Unfortunately, it is not possible to just
695 change to LDAP authentication by adding the proper directives,
696 because it will break the <em>Permissions</em> forms in
697 the FrontPage client, which attempt to modify the standard
698 text-based authorization files.</p>
700 <p>Once a FrontPage web has been created, adding LDAP
701 authentication to it is a matter of adding the following
702 directives to <em>every</em> <code>.htaccess</code> file
703 that gets created in the web</p>
705 AuthLDAPURL "the url"
706 AuthGroupFile <em>mygroupfile</em>
707 Require group <em>mygroupfile</em>
710 <section id="howitworks"><title>How It Works</title>
712 <p>FrontPage restricts access to a web by adding the <code>Require
713 valid-user</code> directive to the <code>.htaccess</code>
714 files. The <code>Require valid-user</code> directive will succeed for
715 any user who is valid <em>as far as LDAP is
716 concerned</em>. This means that anybody who has an entry in
717 the LDAP directory is considered a valid user, whereas FrontPage
718 considers only those people in the local user file to be
719 valid. By substituting the ldap-group with group file authorization,
720 Apache is allowed to consult the local user file (which is managed by
721 FrontPage) - instead of LDAP - when handling authorizing the user.</p>
723 <p>Once directives have been added as specified above,
724 FrontPage users will be able to perform all management
725 operations from the FrontPage client.</p>
728 <section id="fpcaveats"><title>Caveats</title>
731 <li>When choosing the LDAP URL, the attribute to use for
732 authentication should be something that will also be valid
733 for putting into a <module>mod_authn_file</module> user file.
734 The user ID is ideal for this.</li>
736 <li>When adding users via FrontPage, FrontPage administrators
737 should choose usernames that already exist in the LDAP
738 directory (for obvious reasons). Also, the password that the
739 administrator enters into the form is ignored, since Apache
740 will actually be authenticating against the password in the
741 LDAP database, and not against the password in the local user
742 file. This could cause confusion for web administrators.</li>
744 <!-- XXX is that true? was mod_auth before the aaa change -->
745 <li>Apache must be compiled with <module>mod_auth_basic</module>,
746 <module>mod_authn_file</module> and
747 <module>mod_authz_groupfile</module> in order to
748 use FrontPage support. This is because Apache will still use
749 the <module>mod_authz_groupfile</module> group file for determine
750 the extent of a user's access to the FrontPage web.</li>
752 <li>The directives must be put in the <code>.htaccess</code>
753 files. Attempting to put them inside <directive module="core"
754 type="section">Location</directive> or <directive module="core"
755 type="section">Directory</directive> directives won't work. This
756 is because <module>mod_authnz_ldap</module> has to be able to grab
757 the <directive module="mod_authn_file">AuthGroupFile</directive>
758 directive that is found in FrontPage <code>.htaccess</code>
759 files so that it knows where to look for the valid user list. If
760 the <module>mod_authnz_ldap</module> directives aren't in the same
761 <code>.htaccess</code> file as the FrontPage directives, then
762 the hack won't work, because <module>mod_authnz_ldap</module> will
763 never get a chance to process the <code>.htaccess</code> file,
764 and won't be able to find the FrontPage-managed user file.</li>
770 <name>AuthLDAPBindDN</name>
771 <description>Optional DN to use in binding to the LDAP server</description>
772 <syntax>AuthLDAPBindDN <em>distinguished-name</em></syntax>
773 <contextlist><context>directory</context><context>.htaccess</context>
775 <override>AuthConfig</override>
778 <p>An optional DN used to bind to the server when searching for
779 entries. If not provided, <module>mod_authnz_ldap</module> will use
780 an anonymous bind.</p>
785 <name>AuthLDAPBindPassword</name>
786 <description>Password used in conjuction with the bind DN</description>
787 <syntax>AuthLDAPBindPassword <em>password</em></syntax>
788 <contextlist><context>directory</context><context>.htaccess</context>
790 <override>AuthConfig</override>
793 <p>A bind password to use in conjunction with the bind DN. Note
794 that the bind password is probably sensitive data, and should be
795 properly protected. You should only use the <directive
796 module="mod_authnz_ldap">AuthLDAPBindDN</directive> and <directive
797 module="mod_authnz_ldap">AuthLDAPBindPassword</directive> if you
798 absolutely need them to search the directory.</p>
803 <name>AuthLDAPCharsetConfig</name>
804 <description>Language to charset conversion configuration file</description>
805 <syntax>AuthLDAPCharsetConfig <em>file-path</em></syntax>
806 <contextlist><context>server config</context>
810 <p>The <directive>AuthLDAPCharsetConfig</directive> directive sets the location
811 of the language to charset conversion configuration file. <var>File-path</var> is relative
812 to the <directive module="core">ServerRoot</directive>. This file specifies
813 the list of language extensions to character sets.
814 Most administrators use the provided <code>charset.conv</code>
815 file, which associates common language extensions to character sets.</p>
817 <p>The file contains lines in the following format:</p>
820 <var>Language-Extension</var> <var>charset</var> [<var>Language-String</var>] ...
823 <p>The case of the extension does not matter. Blank lines, and lines
824 beginning with a hash character (<code>#</code>) are ignored.</p>
829 <name>AuthLDAPCompareDNOnServer</name>
830 <description>Use the LDAP server to compare the DNs</description>
831 <syntax>AuthLDAPCompareDNOnServer on|off</syntax>
832 <default>AuthLDAPCompareDNOnServer on</default>
833 <contextlist><context>directory</context><context>.htaccess</context>
835 <override>AuthConfig</override>
838 <p>When set, <module>mod_authnz_ldap</module> will use the LDAP
839 server to compare the DNs. This is the only foolproof way to
840 compare DNs. <module>mod_authnz_ldap</module> will search the
841 directory for the DN specified with the <a
842 href="#reqdn"><code>Require dn</code></a> directive, then,
843 retrieve the DN and compare it with the DN retrieved from the user
844 entry. If this directive is not set,
845 <module>mod_authnz_ldap</module> simply does a string comparison. It
846 is possible to get false negatives with this approach, but it is
847 much faster. Note the <module>mod_ldap</module> cache can speed up
848 DN comparison in most situations.</p>
853 <name>AuthLDAPDereferenceAliases</name>
854 <description>When will the module de-reference aliases</description>
855 <syntax>AuthLDAPDereferenceAliases never|searching|finding|always</syntax>
856 <default>AuthLDAPDereferenceAliases always</default>
857 <contextlist><context>directory</context><context>.htaccess</context>
859 <override>AuthConfig</override>
862 <p>This directive specifies when <module>mod_authnz_ldap</module> will
863 de-reference aliases during LDAP operations. The default is
864 <code>always</code>.</p>
869 <name>AuthLDAPGroupAttribute</name>
870 <description>LDAP attributes used to identify the user members of
871 groups.</description>
872 <syntax>AuthLDAPGroupAttribute <em>attribute</em></syntax>
873 <contextlist><context>directory</context><context>.htaccess</context>
875 <override>AuthConfig</override>
878 <p>This directive specifies which LDAP attributes are used to
879 check for user members within groups. Multiple attributes can be used
880 by specifying this directive multiple times. If not specified,
881 then <module>mod_authnz_ldap</module> uses the <code>member</code> and
882 <code>uniquemember</code> attributes.</p>
887 <name>AuthLDAPGroupAttributeIsDN</name>
888 <description>Use the DN of the client username when checking for
889 group membership</description>
890 <syntax>AuthLDAPGroupAttributeIsDN on|off</syntax>
891 <default>AuthLDAPGroupAttributeIsDN on</default>
892 <contextlist><context>directory</context><context>.htaccess</context>
894 <override>AuthConfig</override>
897 <p>When set <code>on</code>, this directive says to use the
898 distinguished name of the client username when checking for group
899 membership. Otherwise, the username will be used. For example,
900 assume that the client sent the username <code>bjenson</code>,
901 which corresponds to the LDAP DN <code>cn=Babs Jenson,
902 o=Airius</code>. If this directive is set,
903 <module>mod_authnz_ldap</module> will check if the group has
904 <code>cn=Babs Jenson, o=Airius</code> as a member. If this
905 directive is not set, then <module>mod_authnz_ldap</module> will
906 check if the group has <code>bjenson</code> as a member.</p>
911 <name>AuthLDAPMaxSubGroupDepth</name>
912 <description>Specifies the maximum sub-group nesting depth that will be
913 evaluated before the user search is discontinued.</description>
914 <syntax>AuthLDAPMaxSubGroupDepth <var>Number</var></syntax>
915 <default>AuthLDAPMaxSubGroupDepth 10</default>
916 <contextlist><context>directory</context><context>.htaccess</context>
918 <override>AuthConfig</override>
921 <p>When this directive is set to a non-zero value <code>X</code>
922 combined with use of the <code>Require ldap-group someGroupDN</code>
923 directive, the provided user credentials will be searched for
924 as a member of the <code>someGroupDN</code> directory object or of
925 any group member of the current group up to the maximum nesting
926 level <code>X</code> specified by this directive.</p>
927 <p>See the <a href="#reqgroup"><code>Require ldap-group</code></a>
928 section for a more detailed example.</p>
933 <name>AuthLDAPRemoteUserAttribute</name>
934 <description>Use the value of the attribute returned during the user
935 query to set the REMOTE_USER environment variable</description>
936 <syntax>AuthLDAPRemoteUserAttribute uid</syntax>
937 <default>none</default>
938 <contextlist><context>directory</context><context>.htaccess</context>
940 <override>AuthConfig</override>
943 <p>If this directive is set, the value of the
944 <code>REMOTE_USER</code> environment variable will be set to the
945 value of the attribute specified. Make sure that this attribute is
946 included in the list of attributes in the AuthLDAPUrl definition,
947 otherwise this directive will have no effect. This directive, if
948 present, takes precedence over AuthLDAPRemoteUserIsDN. This
949 directive is useful should you want people to log into a website
950 using an email address, but a backend application expects the
951 username as a userid.</p>
956 <name>AuthLDAPRemoteUserIsDN</name>
957 <description>Use the DN of the client username to set the REMOTE_USER
958 environment variable</description>
959 <syntax>AuthLDAPRemoteUserIsDN on|off</syntax>
960 <default>AuthLDAPRemoteUserIsDN off</default>
961 <contextlist><context>directory</context><context>.htaccess</context>
963 <override>AuthConfig</override>
966 <p>If this directive is set to on, the value of the
967 <code>REMOTE_USER</code> environment variable will be set to the full
968 distinguished name of the authenticated user, rather than just
969 the username that was passed by the client. It is turned off by
975 <name>AuthLDAPSubGroupAttribute</name>
976 <description>Specifies the attribute labels, one value per
977 directive line, used to distinguish the members of the current group that
978 are groups.</description>
979 <syntax>AuthLDAPSubGroupAttribute <em>attribute</em></syntax>
980 <contextlist><context>directory</context><context>.htaccess</context>
982 <override>AuthConfig</override>
985 <p>An LDAP group object may contain members that are users and
986 members that are groups (called nested or sub groups). The
987 <code>AuthLDAPSubGroupAttribute</code> directive identifies the
988 labels of group members and the <code>AuthLDAPGroupAttribute</code>
989 directive identifies the labels of the user members. Multiple
990 attributes can be used by specifying this directive multiple times.
991 If not specified, then <module>mod_authnz_ldap</module> uses the
992 <code>member</code> and <code>uniqueMember</code> attributes.</p>
997 <name>AuthLDAPSubGroupClass</name>
998 <description>Specifies which LDAP objectClass values identify directory
999 objects that are groups during sub-group processing.</description>
1000 <syntax>AuthLDAPSubGroupClass <em>LdapObjectClass</em></syntax>
1001 <contextlist><context>directory</context><context>.htaccess</context>
1003 <override>AuthConfig</override>
1006 <p>An LDAP group object may contain members that are users and
1007 members that are groups (called nested or sub groups). The
1008 <code>AuthLDAPSubGroupAttribute</code> directive identifies the
1009 labels of members that may be sub-groups of the current group
1010 (as opposed to user members). The <code>AuthLDAPSubGroupClass</code>
1011 directive specifies the LDAP objectClass values used in verifying that
1012 these potential sub-groups are in fact group objects. Verified sub-groups
1013 can then be searched for more user or sub-group members. Multiple
1014 attributes can be used by specifying this directive multiple times.
1015 If not specified, then <module>mod_authnz_ldap</module> uses the
1016 <code>groupOfNames</code> and <code>groupOfUniqueNames</code> values.</p>
1018 </directivesynopsis>
1021 <name>AuthLDAPUrl</name>
1022 <description>URL specifying the LDAP search parameters</description>
1023 <syntax>AuthLDAPUrl <em>url [NONE|SSL|TLS|STARTTLS]</em></syntax>
1024 <contextlist><context>directory</context><context>.htaccess</context>
1026 <override>AuthConfig</override>
1029 <p>An RFC 2255 URL which specifies the LDAP search parameters
1030 to use. The syntax of the URL is</p>
1031 <example>ldap://host:port/basedn?attribute?scope?filter</example>
1032 <p>If you want to specify more than one LDAP URL that Apache should try in turn, the syntax is:</p>
1033 <example>AuthLDAPUrl "ldap://ldap1.example.com ldap2.example.com"</example>
1034 <p><em><strong>Caveat: </strong>If you specify multiple servers, you need to enclose the entire URL string in quotes;
1035 otherwise you will get an error: "AuthLDAPURL takes one argument, URL to define LDAP connection.." </em>
1036 You can of course use search parameters on each of these.</p>
1041 <dd>For regular ldap, use the
1042 string <code>ldap</code>. For secure LDAP, use <code>ldaps</code>
1043 instead. Secure LDAP is only available if Apache was linked
1044 to an LDAP library with SSL support.</dd>
1049 <p>The name/port of the ldap server (defaults to
1050 <code>localhost:389</code> for <code>ldap</code>, and
1051 <code>localhost:636</code> for <code>ldaps</code>). To
1052 specify multiple, redundant LDAP servers, just list all
1053 servers, separated by spaces. <module>mod_authnz_ldap</module>
1054 will try connecting to each server in turn, until it makes a
1055 successful connection. If multiple ldap servers are specified,
1056 then entire LDAP URL must be encapsulated in double quotes.</p>
1058 <p>Once a connection has been made to a server, that
1059 connection remains active for the life of the
1060 <program>httpd</program> process, or until the LDAP server goes
1063 <p>If the LDAP server goes down and breaks an existing
1064 connection, <module>mod_authnz_ldap</module> will attempt to
1065 re-connect, starting with the primary server, and trying
1066 each redundant server in turn. Note that this is different
1067 than a true round-robin search.</p>
1072 <dd>The DN of the branch of the
1073 directory where all searches should start from. At the very
1074 least, this must be the top of your directory tree, but
1075 could also specify a subtree in the directory.</dd>
1079 <dd>The attribute to search for.
1080 Although RFC 2255 allows a comma-separated list of
1081 attributes, only the first attribute will be used, no
1082 matter how many are provided. If no attributes are
1083 provided, the default is to use <code>uid</code>. It's a good
1084 idea to choose an attribute that will be unique across all
1085 entries in the subtree you will be using. All attributes
1086 listed will be put into the environment with an AUTHENTICATE_ prefix
1087 for use by other modules.</dd>
1091 <dd>The scope of the search. Can be either <code>one</code> or
1092 <code>sub</code>. Note that a scope of <code>base</code> is
1093 also supported by RFC 2255, but is not supported by this
1094 module. If the scope is not provided, or if <code>base</code> scope
1095 is specified, the default is to use a scope of
1096 <code>sub</code>.</dd>
1100 <dd>A valid LDAP search filter. If
1101 not provided, defaults to <code>(objectClass=*)</code>, which
1102 will search for all objects in the tree. Filters are
1103 limited to approximately 8000 characters (the definition of
1104 <code>MAX_STRING_LEN</code> in the Apache source code). This
1105 should be more than sufficient for any application.</dd>
1108 <p>When doing searches, the attribute, filter and username passed
1109 by the HTTP client are combined to create a search filter that
1111 <code>(&(<em>filter</em>)(<em>attribute</em>=<em>username</em>))</code>.</p>
1113 <p>For example, consider an URL of
1114 <code>ldap://ldap.airius.com/o=Airius?cn?sub?(posixid=*)</code>. When
1115 a client attempts to connect using a username of <code>Babs
1116 Jenson</code>, the resulting search filter will be
1117 <code>(&(posixid=*)(cn=Babs Jenson))</code>.</p>
1119 <p>An optional parameter can be added to allow the LDAP Url to override
1120 the connection type. This parameter can be one of the following:</p>
1124 <dd>Establish an unsecure connection on the default LDAP port. This
1125 is the same as <code>ldap://</code> on port 389.</dd>
1127 <dd>Establish a secure connection on the default secure LDAP port.
1128 This is the same as <code>ldaps://</code></dd>
1129 <dt>TLS | STARTTLS</dt>
1130 <dd>Establish an upgraded secure connection on the default LDAP port.
1131 This connection will be initiated on port 389 by default and then
1132 upgraded to a secure connection on the same port.</dd>
1135 <p>See above for examples of <directive
1136 module="mod_authnz_ldap">AuthLDAPURL</directive> URLs.</p>
1138 </directivesynopsis>