This module allows authentication front-ends such as
When using ldap value.
This module caches authentication and authorization results based
on the configuration of
There are two phases in granting access to a user. The first
phase is authentication, in which the
ldap value. The authz_ldap handler extends the
ldap-user, ldap-dn and ldap-group
values.
During the authentication phase,
The following directives are used during the search/bind phase
| Specifies the LDAP server, the base DN, the attribute to use in the search, as well as the extra search filter to use. | |
| An optional DN to bind with during the search phase. | |
| An optional password to bind with during the search phase. |
Apache's 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.
The Require ldap-user directive specifies what
usernames can access the resource. Once
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 ldap://ldap/o=Example?cn (i.e., cn is
used for searches), the following Require directives could be used
to restrict access:
Because of the way that 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
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:
Members can also be found within sub-groups of a specified LDAP group
if
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):
Behavior of this directive is modified by the
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:
Behavior of this directive is modified by the
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
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"
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
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.
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:
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.
cn, because a search on cn
must return exactly one entry. That's why
this approach is not recommended: it's a better idea to
choose an attribute that is guaranteed unique in your
directory, such as uid.
qpagePagerID. The example will grant access
only to people (authenticated via their UID) who have
alphanumeric pagers:
The next example demonstrates the power of using filters to accomplish complicated administrative requirements. Without filters, it would have been necessary to create a new LDAP group and ensure that the group's members remain synchronized with the pager users. This becomes trivial with filters. The goal is to grant access to anyone who has a pager, plus grant access to Joe Manager, who doesn't have a pager, but does need to access the same resource:
This last may look confusing at first, so it helps to
evaluate what the search filter will look like based on who
connects, as shown below. If
Fred User connects as fuser, the filter would look
like
The above search will only succeed if fuser has a pager. When Joe Manager connects as jmanager, the filter looks like
The above search will succeed whether jmanager has a pager or not.
To use TLS, see the
An optional second parameter can be added to the
To use SSL, see the
To specify a secure LDAP server, use ldaps:// in the
when this module performs authentication, ldap attributes specified
in the
when this module performs authorization, ldap attributes specified
in the
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.
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
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:
Users will need to enter their User Principal Name as a login, in the form somebody@nz.example.com.
Normally, FrontPage uses FrontPage-web-specific user/group
files (i.e., the
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
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.
.htaccess
files. Attempting to put them inside .htaccess
files so that it knows where to look for the valid user list. If
the .htaccess file as the FrontPage directives, then
the hack won't work, because .htaccess file,
and won't be able to find the FrontPage-managed user file.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.
Require valid-user.
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
This allows users present in both LDAP and
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
This directive should only be used when your LDAP server doesn't
accept anonymous searches and you cannot use a dedicated
If
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
An optional DN used to bind to the server when searching for
entries. If not provided,
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
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.
The charset.conv
file, which associates common language extensions to character sets.
The file contains lines in the following format:
The case of the extension does not matter. Blank lines, and lines
beginning with a hash character (#) are ignored.
When set, and
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
This directive should only be used when your LDAP server doesn't
accept anonymous comparisons and you cannot use a dedicated
When set, Require dn directive, then,
retrieve the DN and compare it with the DN retrieved from the user
entry. If this directive is not set,
This directive specifies when always.
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 member and
uniquemember attributes.
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,
cn=Babs Jenson, o=Example as a member. If this
directive is not set, then bjenson as a member.
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.
When
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
This directive only has effect when this module is used for authentication.
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.
When set, and
The ldap-filter and ldap-dn authorization checks use searches.
This directive only has effect on the comparisons performed during
nested group processing when
This directive should only be used when your LDAP server doesn't
accept anonymous searches and you cannot use a dedicated
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 member and uniqueMember attributes.
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 groupOfNames and groupOfUniqueNames values.
An RFC 2255 URL which specifies the LDAP search parameters to use. The syntax of the URL is
If you want to specify more than one LDAP URL that Apache should try in turn, the syntax is:
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 secure LDAP, use ldaps
instead. Secure LDAP is only available if Apache was linked
to an LDAP library with SSL support.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.
Once a connection has been made to a server, that
connection remains active for the life of the
If the LDAP server goes down and breaks an existing
connection,
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.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.(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:
ldap:// on port 389.ldaps://See above for examples of