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Apache > HTTP Server > Documentation > Version 2.5 > Modules

Apache Module mod_authnz_ldap

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Description:Allows an LDAP directory to be used to store the database for HTTP Basic authentication.
Status:Extension
Module Identifier:authnz_ldap_module
Source File:mod_authnz_ldap.c

Summary

This module allows authentication front-ends such as mod_auth_basic to authenticate users through an ldap directory.

mod_authnz_ldap supports the following features:

When using mod_auth_basic, this module is invoked via the AuthBasicProvider directive with the ldap value.

Directives

Topics

See also

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Contents

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Operation

There are two phases in granting access to a user. The first phase is authentication, in which the mod_authnz_ldap authentication provider verifies that the user's credentials are valid. This is also called the search/bind phase. The second phase is authorization, in which mod_authnz_ldap determines if the authenticated user is allowed access to the resource in question. This is also known as the compare phase.

mod_authnz_ldap registers both an authn_ldap authentication provider and an authz_ldap authorization handler. The authn_ldap authentication provider can be enabled through the AuthBasicProvider directive using the ldap value. The authz_ldap handler extends the Require directive's authorization types by adding ldap-user, ldap-dn and ldap-group values.

The Authentication Phase

During the authentication phase, mod_authnz_ldap searches for an entry in the directory that matches the username that the HTTP client passes. If a single unique match is found, then mod_authnz_ldap attempts to bind to the directory server using the DN of the entry plus the password provided by the HTTP client. Because it does a search, then a bind, it is often referred to as the search/bind phase. Here are the steps taken during the search/bind phase.

  1. Generate a search filter by combining the attribute and filter provided in the AuthLDAPURL directive with the username passed by the HTTP client.
  2. Search the directory using the generated filter. If the search does not return exactly one entry, deny or decline access.
  3. Fetch the distinguished name of the entry retrieved from the search and attempt to bind to the LDAP server using that DN and the password passed by the HTTP client. If the bind is unsuccessful, deny or decline access.

The following directives are used during the search/bind phase

AuthLDAPURL Specifies the LDAP server, the base DN, the attribute to use in the search, as well as the extra search filter to use.
AuthLDAPBindDN An optional DN to bind with during the search phase.
AuthLDAPBindPassword An optional password to bind with during the search phase.

The Authorization Phase

During the authorization phase, mod_authnz_ldap attempts to determine if the user is authorized to access the resource. Many of these checks require mod_authnz_ldap to do a compare operation on the LDAP server. This is why this phase is often referred to as the compare phase. mod_authnz_ldap accepts the following Require directives to determine if the credentials are acceptable:

Other Require values may also be used which may require loading additional authorization modules.

mod_authnz_ldap uses the following directives during the compare phase:

AuthLDAPURL The attribute specified in the URL is used in compare operations for the Require ldap-user operation.
AuthLDAPCompareDNOnServer Determines the behavior of the Require ldap-dn directive.
AuthLDAPGroupAttribute Determines the attribute to use for comparisons in the Require ldap-group directive.
AuthLDAPGroupAttributeIsDN Specifies whether to use the user DN or the username when doing comparisons for the Require ldap-group directive.
AuthLDAPMaxSubGroupDepth Determines the maximum depth of sub-groups that will be evaluated during comparisons in the Require ldap-group directive.
AuthLDAPSubGroupAttribute Determines the attribute to use when obtaining sub-group members of the current group during comparisons in the Require ldap-group directive.
AuthLDAPSubGroupClass Specifies the LDAP objectClass values used to identify if queried directory objects really are group objects (as opposed to user objects) during the Require ldap-group directive's sub-group processing.
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The Require Directives

Apache's Require directives are used during the authorization phase to ensure that a user is allowed to access a resource. mod_authnz_ldap extends the authorization types with ldap-user, ldap-dn, ldap-group, ldap-attribute and ldap-filter. Other authorization types may also be used but may require that additional authorization modules be loaded.

Since v2.4.8, expressions are supported within the LDAP require directives.

Require ldap-user

The Require ldap-user directive specifies what usernames can access the resource. Once mod_authnz_ldap has retrieved a unique DN from the directory, it does an LDAP compare operation using the username specified in the Require ldap-user to see if that username is part of the just-fetched LDAP entry. Multiple users can be granted access by putting multiple usernames on the line, separated with spaces. If a username has a space in it, then it must be surrounded with double quotes. Multiple users can also be granted access by using multiple Require ldap-user directives, with one user per line. For example, with a AuthLDAPURL of ldap://ldap/o=Example?cn (i.e., cn is used for searches), the following Require directives could be used to restrict access:

Require ldap-user "Barbara Jenson"
Require ldap-user "Fred User"
Require ldap-user "Joe Manager"

Because of the way that mod_authnz_ldap handles this directive, Barbara Jenson could sign on as Barbara Jenson, Babs Jenson or any other cn that she has in her LDAP entry. Only the single Require ldap-user line is needed to support all values of the attribute in the user's entry.

If the uid attribute was used instead of the cn attribute in the URL above, the above three lines could be condensed to

Require ldap-user bjenson fuser jmanager

Require ldap-group

This directive specifies an LDAP group whose members are allowed access. It takes the distinguished name of the LDAP group. Note: Do not surround the group name with quotes. For example, assume that the following entry existed in the LDAP directory:

dn: cn=Administrators, o=Example
objectClass: groupOfUniqueNames
uniqueMember: cn=Barbara Jenson, o=Example
uniqueMember: cn=Fred User, o=Example

The following directive would grant access to both Fred and Barbara:

Require ldap-group cn=Administrators, o=Example

Members can also be found within sub-groups of a specified LDAP group if AuthLDAPMaxSubGroupDepth is set to a value greater than 0. For example, assume the following entries exist in the LDAP directory:

dn: cn=Employees, o=Example
objectClass: groupOfUniqueNames
uniqueMember: cn=Managers, o=Example
uniqueMember: cn=Administrators, o=Example
uniqueMember: cn=Users, o=Example

dn: cn=Managers, o=Example
objectClass: groupOfUniqueNames
uniqueMember: cn=Bob Ellis, o=Example
uniqueMember: cn=Tom Jackson, o=Example

dn: cn=Administrators, o=Example
objectClass: groupOfUniqueNames
uniqueMember: cn=Barbara Jenson, o=Example
uniqueMember: cn=Fred User, o=Example

dn: cn=Users, o=Example
objectClass: groupOfUniqueNames
uniqueMember: cn=Allan Jefferson, o=Example
uniqueMember: cn=Paul Tilley, o=Example
uniqueMember: cn=Temporary Employees, o=Example

dn: cn=Temporary Employees, o=Example
objectClass: groupOfUniqueNames
uniqueMember: cn=Jim Swenson, o=Example
uniqueMember: cn=Elliot Rhodes, o=Example

The following directives would allow access for Bob Ellis, Tom Jackson, Barbara Jenson, Fred User, Allan Jefferson, and Paul Tilley but would not allow access for Jim Swenson, or Elliot Rhodes (since they are at a sub-group depth of 2):

Require ldap-group cn=Employees, o=Example
AuthLDAPMaxSubGroupDepth 1

Behavior of this directive is modified by the AuthLDAPGroupAttribute, AuthLDAPGroupAttributeIsDN, AuthLDAPMaxSubGroupDepth, AuthLDAPSubGroupAttribute, and AuthLDAPSubGroupClass directives.

Require ldap-dn

The Require ldap-dn directive allows the administrator to grant access based on distinguished names. It specifies a DN that must match for access to be granted. If the distinguished name that was retrieved from the directory server matches the distinguished name in the Require ldap-dn, then authorization is granted. Note: do not surround the distinguished name with quotes.

The following directive would grant access to a specific DN:

Require ldap-dn cn=Barbara Jenson, o=Example

Behavior of this directive is modified by the AuthLDAPCompareDNOnServer directive.

Require ldap-attribute

The Require ldap-attribute directive allows the administrator to grant access based on attributes of the authenticated user in the LDAP directory. If the attribute in the directory matches the value given in the configuration, access is granted.

The following directive would grant access to anyone with the attribute employeeType = active

Require ldap-attribute employeeType=active

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

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

Require ldap-attribute city="San Jose" status=active

Require ldap-filter

The Require ldap-filter directive allows the administrator to grant access based on a complex LDAP search filter. If the dn returned by the filter search matches the authenticated user dn, access is granted.

The following directive would grant access to anyone having a cell phone and is in the marketing department

Require ldap-filter &(cell=*)(department=marketing)

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

When using an expression within the filter, care must be taken to ensure that LDAP filters are escaped correctly to guard against LDAP injection. The ldap function can be used for this purpose.

<LocationMatch ^/dav/(?<SITENAME>[^/]+)/>
  Require ldap-filter (memberOf=cn=%{ldap:%{unescape:%{env:MATCH_SITENAME}},ou=Websites,o=Example)
</LocationMatch>

Require ldap-search

The Require ldap-search directive allows the administrator to grant access based on a generic LDAP search filter using an expression. If there is exactly one match to the search filter, regardless of the distinguished name, access is granted.

The following directive would grant access to URLs that match the given objects in the LDAP server:

<LocationMatch ^/dav/(?<SITENAME>[^/]+)/>
Require ldap-search (cn=%{ldap:%{unescape:%{env:MATCH_SITENAME}} Website)
</LocationMatch>

Note: care must be taken to ensure that any expressions are properly escaped to guard against LDAP injection. The ldap function can be used as per the example above.

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Examples

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Using TLS

To use TLS, see the mod_ldap directives LDAPTrustedClientCert, LDAPTrustedGlobalCert and LDAPTrustedMode.

An optional second parameter can be added to the AuthLDAPURL to override the default connection type set by LDAPTrustedMode. This will allow the connection established by an ldap:// Url to be upgraded to a secure connection on the same port.

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Using SSL

To use SSL, see the mod_ldap directives LDAPTrustedClientCert, LDAPTrustedGlobalCert and LDAPTrustedMode.

To specify a secure LDAP server, use ldaps:// in the AuthLDAPURL directive, instead of ldap://.

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Exposing Login Information

when this module performs authentication, ldap attributes specified in the authldapurl directive are placed in environment variables with the prefix "AUTHENTICATE_".

when this module performs authorization, ldap attributes specified in the authldapurl directive are placed in environment variables with the prefix "AUTHORIZE_".

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

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

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Using Active Directory

An Active Directory installation may support multiple domains at the same time. To distinguish users between domains, an identifier called a User Principle Name (UPN) can be added to a user's entry in the directory. This UPN usually takes the form of the user's account name, followed by the domain components of the particular domain, for example somebody@nz.example.com.

You may wish to configure the mod_authnz_ldap module to authenticate users present in any of the domains making up the Active Directory forest. In this way both somebody@nz.example.com and someone@au.example.com can be authenticated using the same query at the same time.

To make this practical, Active Directory supports the concept of a Global Catalog. This Global Catalog is a read only copy of selected attributes of all the Active Directory servers within the Active Directory forest. Querying the Global Catalog allows all the domains to be queried in a single query, without the query spanning servers over potentially slow links.

If enabled, the Global Catalog is an independent directory server that runs on port 3268 (3269 for SSL). To search for a user, do a subtree search for the attribute userPrincipalName, with an empty search root, like so:

AuthLDAPBindDN apache@example.com
AuthLDAPBindPassword password
AuthLDAPURL ldap://10.0.0.1:3268/?userPrincipalName?sub

Users will need to enter their User Principal Name as a login, in the form somebody@nz.example.com.

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Using Microsoft FrontPage with mod_authnz_ldap

Normally, FrontPage uses FrontPage-web-specific user/group files (i.e., the mod_authn_file and mod_authz_groupfile modules) to handle all authentication. Unfortunately, it is not possible to just change to LDAP authentication by adding the proper directives, because it will break the Permissions forms in the FrontPage client, which attempt to modify the standard text-based authorization files.

Once a FrontPage web has been created, adding LDAP authentication to it is a matter of adding the following directives to every .htaccess file that gets created in the web

AuthLDAPURL       "the url"
AuthGroupFile     mygroupfile
Require group     mygroupfile

How It Works

FrontPage restricts access to a web by adding the Require valid-user directive to the .htaccess files. The Require valid-user directive will succeed for any user who is valid as far as LDAP is concerned. This means that anybody who has an entry in the LDAP directory is considered a valid user, whereas FrontPage considers only those people in the local user file to be valid. By substituting the ldap-group with group file authorization, Apache is allowed to consult the local user file (which is managed by FrontPage) - instead of LDAP - when handling authorizing the user.

Once directives have been added as specified above, FrontPage users will be able to perform all management operations from the FrontPage client.

Caveats

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AuthLDAPAuthorizePrefix Directive

Description:Specifies the prefix for environment variables set during authorization
Syntax:AuthLDAPAuthorizePrefix prefix
Default:AuthLDAPAuthorizePrefix AUTHORIZE_
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap
Compatibility:Available in version 2.3.6 and later

This directive allows you to override the prefix used for environment variables set during LDAP authorization. If AUTHENTICATE_ is specified, consumers of these environment variables see the same information whether LDAP has performed authentication, authorization, or both.

Note

No authorization variables are set when a user is authorized on the basis of Require valid-user.
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AuthLDAPBindAuthoritative Directive

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.
Syntax:AuthLDAPBindAuthoritativeoff|on
Default:AuthLDAPBindAuthoritative on
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap

By default, subsequent authentication providers are only queried if a user cannot be mapped to a DN, but not if the user can be mapped to a DN and their password cannot be verified with an LDAP bind. If AuthLDAPBindAuthoritative is set to off, other configured authentication modules will have a chance to validate the user if the LDAP bind (with the current user's credentials) fails for any reason.

This allows users present in both LDAP and AuthUserFile to authenticate when the LDAP server is available but the user's account is locked or password is otherwise unusable.

See also

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AuthLDAPBindDN Directive

Description:Optional DN to use in binding to the LDAP server
Syntax:AuthLDAPBindDN distinguished-name
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap

An optional DN used to bind to the server when searching for entries. If not provided, mod_authnz_ldap will use an anonymous bind.

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AuthLDAPBindPassword Directive

Description:Password used in conjuction with the bind DN
Syntax:AuthLDAPBindPassword password
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap
Compatibility:exec: was added in 2.4.5.

A bind password to use in conjunction with the bind DN. Note that the bind password is probably sensitive data, and should be properly protected. You should only use the AuthLDAPBindDN and AuthLDAPBindPassword if you absolutely need them to search the directory.

If the value begins with exec: the resulting command will be executed and the first line returned to standard output by the program will be used as the password.

#Password used as-is
AuthLDAPBindPassword secret

#Run /path/to/program to get my password
AuthLDAPBindPassword exec:/path/to/program

#Run /path/to/otherProgram and provide arguments
AuthLDAPBindPassword "exec:/path/to/otherProgram argument1"
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AuthLDAPCharsetConfig Directive

Description:Language to charset conversion configuration file
Syntax:AuthLDAPCharsetConfig file-path
Context:server config
Status:Extension
Module:mod_authnz_ldap

The AuthLDAPCharsetConfig directive sets the location of the language to charset conversion configuration file. File-path is relative to the ServerRoot. This file specifies the list of language extensions to character sets. Most administrators use the provided charset.conv file, which associates common language extensions to character sets.

The file contains lines in the following format:

Language-Extension charset [Language-String] ...

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

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AuthLDAPCompareAsUser Directive

Description:Use the authenticated user's credentials to perform authorization comparisons
Syntax:AuthLDAPCompareAsUser on|off
Default:AuthLDAPCompareAsUser off
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap
Compatibility:Available in version 2.3.6 and later

When set, and mod_authnz_ldap has authenticated the user, LDAP comparisons for authorization use the queried distinguished name (DN) and HTTP basic authentication password of the authenticated user instead of the servers configured credentials.

The ldap-attribute, ldap-user, and ldap-group (single-level only) authorization checks use comparisons.

This directive only has effect on the comparisons performed during nested group processing when AuthLDAPSearchAsUser is also enabled.

This directive should only be used when your LDAP server doesn't accept anonymous comparisons and you cannot use a dedicated AuthLDAPBindDN.

See also

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AuthLDAPCompareDNOnServer Directive

Description:Use the LDAP server to compare the DNs
Syntax:AuthLDAPCompareDNOnServer on|off
Default:AuthLDAPCompareDNOnServer on
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap

When set, mod_authnz_ldap will use the LDAP server to compare the DNs. This is the only foolproof way to compare DNs. mod_authnz_ldap will search the directory for the DN specified with the Require dn directive, then, retrieve the DN and compare it with the DN retrieved from the user entry. If this directive is not set, mod_authnz_ldap simply does a string comparison. It is possible to get false negatives with this approach, but it is much faster. Note the mod_ldap cache can speed up DN comparison in most situations.

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AuthLDAPDereferenceAliases Directive

Description:When will the module de-reference aliases
Syntax:AuthLDAPDereferenceAliases never|searching|finding|always
Default:AuthLDAPDereferenceAliases always
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap

This directive specifies when mod_authnz_ldap will de-reference aliases during LDAP operations. The default is always.

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AuthLDAPGroupAttribute Directive

Description:LDAP attributes used to identify the user members of groups.
Syntax:AuthLDAPGroupAttribute attribute
Default:AuthLDAPGroupAttribute member uniquemember
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap

This directive specifies which LDAP attributes are used to check for user members within groups. Multiple attributes can be used by specifying this directive multiple times. If not specified, then mod_authnz_ldap uses the member and uniquemember attributes.

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AuthLDAPGroupAttributeIsDN Directive

Description:Use the DN of the client username when checking for group membership
Syntax:AuthLDAPGroupAttributeIsDN on|off
Default:AuthLDAPGroupAttributeIsDN on
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap

When set on, this directive says to use the distinguished name of the client username when checking for group membership. Otherwise, the username will be used. For example, assume that the client sent the username bjenson, which corresponds to the LDAP DN cn=Babs Jenson, o=Example. If this directive is set, mod_authnz_ldap will check if the group has cn=Babs Jenson, o=Example as a member. If this directive is not set, then mod_authnz_ldap will check if the group has bjenson as a member.

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AuthLDAPInitialBindAsUser Directive

Description:Determines if the server does the initial DN lookup using the basic authentication users' own username, instead of anonymously or with hard-coded credentials for the server
Syntax:AuthLDAPInitialBindAsUser off|on
Default:AuthLDAPInitialBindAsUser off
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap
Compatibility:Available in version 2.3.6 and later

By default, the server either anonymously, or with a dedicated user and password, converts the basic authentication username into an LDAP distinguished name (DN). This directive forces the server to use the verbatim username and password provided by the incoming user to perform the initial DN search.

If the verbatim username can't directly bind, but needs some cosmetic transformation, see AuthLDAPInitialBindPattern.

This directive should only be used when your LDAP server doesn't accept anonymous searches and you cannot use a dedicated AuthLDAPBindDN.

Not available with authorization-only

This directive can only be used if this module authenticates the user, and has no effect when this module is used exclusively for authorization.

See also

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AuthLDAPInitialBindPattern Directive

Description:Specifies the transformation of the basic authentication username to be used when binding to the LDAP server to perform a DN lookup
Syntax:AuthLDAPInitialBindPatternregex substitution
Default:AuthLDAPInitialBindPattern (.*) $1 (remote username used verbatim)
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap
Compatibility:Available in version 2.3.6 and later

If AuthLDAPInitialBindAsUser is set to ON, the basic authentication username will be transformed according to the regular expression and substituion arguments.

The regular expression argument is compared against the current basic authentication username. The substitution argument may contain backreferences, but has no other variable interpolation.

This directive should only be used when your LDAP server doesn't accept anonymous searches and you cannot use a dedicated AuthLDAPBindDN.

AuthLDAPInitialBindPattern (.+) $1@example.com
AuthLDAPInitialBindPattern (.+) cn=$1,dc=example,dc=com

Not available with authorization-only

This directive can only be used if this module authenticates the user, and has no effect when this module is used exclusively for authorization.

debugging

The substituted DN is recorded in the environment variable LDAP_BINDASUSER. If the regular expression does not match the input, the verbatim username is used.

See also

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AuthLDAPMaxSubGroupDepth Directive

Description:Specifies the maximum sub-group nesting depth that will be evaluated before the user search is discontinued.
Syntax:AuthLDAPMaxSubGroupDepth Number
Default:AuthLDAPMaxSubGroupDepth 0
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap
Compatibility:Available in version 2.3.0 and later, defaulted to 10 in 2.4.x and early 2.5

When this directive is set to a non-zero value X combined with use of the Require ldap-group someGroupDN directive, the provided user credentials will be searched for as a member of the someGroupDN directory object or of any group member of the current group up to the maximum nesting level X specified by this directive.

See the Require ldap-group section for a more detailed example.

Nested groups performance

When AuthLDAPSubGroupAttribute overlaps with AuthLDAPGroupAttribute (as it does by default and as required by common LDAP schemas), uncached searching for subgroups in large groups can be very slow. If you use large, non-nested groups, keep AuthLDAPMaxSubGroupDepth set to zero.

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AuthLDAPRemoteUserAttribute Directive

Description:Use the value of the attribute returned during the user query to set the REMOTE_USER environment variable
Syntax:AuthLDAPRemoteUserAttribute uid
Default:none
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap

If this directive is set, the value of the REMOTE_USER environment variable will be set to the value of the attribute specified. Make sure that this attribute is included in the list of attributes in the AuthLDAPUrl definition, otherwise this directive will have no effect. This directive, if present, takes precedence over AuthLDAPRemoteUserIsDN. This directive is useful should you want people to log into a website using an email address, but a backend application expects the username as a userid.

This directive only has effect when this module is used for authentication.

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AuthLDAPRemoteUserIsDN Directive

Description:Use the DN of the client username to set the REMOTE_USER environment variable
Syntax:AuthLDAPRemoteUserIsDN on|off
Default:AuthLDAPRemoteUserIsDN off
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap

If this directive is set to on, the value of the REMOTE_USER environment variable will be set to the full distinguished name of the authenticated user, rather than just the username that was passed by the client. It is turned off by default.

This directive only has effect when this module is used for authentication.

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AuthLDAPSearchAsUser Directive

Description:Use the authenticated user's credentials to perform authorization searches
Syntax:AuthLDAPSearchAsUser on|off
Default:AuthLDAPSearchAsUser off
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap
Compatibility:Available in version 2.3.6 and later

When set, and mod_authnz_ldap has authenticated the user, LDAP searches for authorization use the queried distinguished name (DN) and HTTP basic authentication password of the authenticated user instead of the servers configured credentials.

The ldap-filter and ldap-dn authorization checks use searches.

This directive only has effect on the comparisons performed during nested group processing when AuthLDAPCompareAsUser is also enabled.

This directive should only be used when your LDAP server doesn't accept anonymous searches and you cannot use a dedicated AuthLDAPBindDN.

See also

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AuthLDAPSubGroupAttribute Directive

Description:Specifies the attribute labels, one value per directive line, used to distinguish the members of the current group that are groups.
Syntax:AuthLDAPSubGroupAttribute attribute
Default:AuthLDAPSubgroupAttribute member uniquemember
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap
Compatibility:Available in version 2.3.0 and later

An LDAP group object may contain members that are users and members that are groups (called nested or sub groups). The AuthLDAPSubGroupAttribute directive identifies the labels of group members and the AuthLDAPGroupAttribute directive identifies the labels of the user members. Multiple attributes can be used by specifying this directive multiple times. If not specified, then mod_authnz_ldap uses the member and uniqueMember attributes.

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AuthLDAPSubGroupClass Directive

Description:Specifies which LDAP objectClass values identify directory objects that are groups during sub-group processing.
Syntax:AuthLDAPSubGroupClass LdapObjectClass
Default:AuthLDAPSubGroupClass groupOfNames groupOfUniqueNames
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap
Compatibility:Available in version 2.3.0 and later

An LDAP group object may contain members that are users and members that are groups (called nested or sub groups). The AuthLDAPSubGroupAttribute directive identifies the labels of members that may be sub-groups of the current group (as opposed to user members). The AuthLDAPSubGroupClass directive specifies the LDAP objectClass values used in verifying that these potential sub-groups are in fact group objects. Verified sub-groups can then be searched for more user or sub-group members. Multiple attributes can be used by specifying this directive multiple times. If not specified, then mod_authnz_ldap uses the groupOfNames and groupOfUniqueNames values.

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AuthLDAPUrl Directive

Description:URL specifying the LDAP search parameters
Syntax:AuthLDAPUrl url [NONE|SSL|TLS|STARTTLS]
Context:directory, .htaccess
Override:AuthConfig
Status:Extension
Module:mod_authnz_ldap

An RFC 2255 URL which specifies the LDAP search parameters to use. The syntax of the URL is

ldap://host:port/basedn?attribute?scope?filter

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

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

Caveat: If you specify multiple servers, you need to enclose the entire URL string in quotes; otherwise you will get an error: "AuthLDAPURL takes one argument, URL to define LDAP connection.." You can of course use search parameters on each of these.

ldap
For regular ldap, use the string ldap. For secure LDAP, use ldaps instead. Secure LDAP is only available if Apache was linked to an LDAP library with SSL support.
host:port

The name/port of the ldap server (defaults to localhost:389 for ldap, and localhost:636 for ldaps). To specify multiple, redundant LDAP servers, just list all servers, separated by spaces. mod_authnz_ldap will try connecting to each server in turn, until it makes a successful connection. If multiple ldap servers are specified, then entire LDAP URL must be encapsulated in double quotes.

Once a connection has been made to a server, that connection remains active for the life of the httpd process, or until the LDAP server goes down.

If the LDAP server goes down and breaks an existing connection, mod_authnz_ldap will attempt to re-connect, starting with the primary server, and trying each redundant server in turn. Note that this is different than a true round-robin search.

basedn
The DN of the branch of the directory where all searches should start from. At the very least, this must be the top of your directory tree, but could also specify a subtree in the directory.
attribute
The attribute to search for. Although RFC 2255 allows a comma-separated list of attributes, only the first attribute will be used, no matter how many are provided. If no attributes are provided, the default is to use uid. It's a good idea to choose an attribute that will be unique across all entries in the subtree you will be using. All attributes listed will be put into the environment with an AUTHENTICATE_ prefix for use by other modules.
scope
The scope of the search. Can be either one or sub. Note that a scope of base is also supported by RFC 2255, but is not supported by this module. If the scope is not provided, or if base scope is specified, the default is to use a scope of sub.
filter
A valid LDAP search filter. If not provided, defaults to (objectClass=*), which will search for all objects in the tree. Filters are limited to approximately 8000 characters (the definition of MAX_STRING_LEN in the Apache source code). This should be more than sufficient for any application. The keyword none disables the use of a filter; this is required by some primitive LDAP servers.

When doing searches, the attribute, filter and username passed by the HTTP client are combined to create a search filter that looks like (&(filter)(attribute=username)).

For example, consider an URL of ldap://ldap.example.com/o=Example?cn?sub?(posixid=*). When a client attempts to connect using a username of Babs Jenson, the resulting search filter will be (&(posixid=*)(cn=Babs Jenson)).

An optional parameter can be added to allow the LDAP Url to override the connection type. This parameter can be one of the following:

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

See above for examples of AuthLDAPURL URLs.

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