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Edit File: mod_ldap.html

<!DOCTYPE html>
<html>
<head>
<title>ProFTPD module mod_ldap</title>
</head>

<hr> 
<center>
<h2>ProFTPD module <code>mod_ldap</code></h2>
</center>
<hr>

This module is contained in the <code>mod_ldap.c</code> file for ProFTPD 1.2.x/1.3.x, and is not compiled by default. Installation instructions
are discussed <a href="#Installation">here</a>.

The most current version of <code>mod_ldap</code> is distributed with the
ProFTPD source code.

<h2>Author</h2>

Please contact John Morrissey &lt;jwm at horde.net&gt; with any
questions, concerns, or suggestions regarding this module.

<h2>Directives</h2>
<ul>
 <li><a href="#LDAPAliasDereference">LDAPAliasDereference</a>
 <li><a href="#LDAPAttr">LDAPAttr</a>
 <li><a href="#LDAPAuthBinds">LDAPAuthBinds</a>
 <li><a href="#LDAPBindDN">LDAPBindDN</a>
 <li><a href="#LDAPDefaultAuthScheme">LDAPDefaultAuthScheme</a>
 <li><a href="#LDAPDefaultGID">LDAPDefaultGID</a>
 <li><a href="#LDAPDefaultQuota">LDAPDefaultQuota</a>
 <li><a href="#LDAPDefaultUID">LDAPDefaultUID</a>
 <li><a href="#LDAPForceDefaultGID">LDAPForceDefaultGID</a>
 <li><a href="#LDAPForceDefaultUID">LDAPForceDefaultUID</a>
 <li><a href="#LDAPForceGeneratedHomedir">LDAPForceGeneratedHomedir</a>
 <li><a href="#LDAPGenerateHomedir">LDAPGenerateHomedir</a>
 <li><a href="#LDAPGenerateHomedirPrefix">LDAPGenerateHomedirPrefix</a>
 <li><a href="#LDAPGenerateHomedirPrefixNoUsername">LDAPGenerateHomedirPrefixNoUsername</a>
 <li><a href="#LDAPGroups">LDAPGroups</a>
 <li><a href="#LDAPLog">LDAPLog</a>
 <li><a href="#LDAPProtocolVersion">LDAPProtocolVersion</a>
 <li><a href="#LDAPQueryTimeout">LDAPQueryTimeout</a>
 <li><a href="#LDAPSearchScope">LDAPSearchScope</a>
 <li><a href="#LDAPServer">LDAPServer</a>
 <li><a href="#LDAPUsers">LDAPUsers</a>
 <li><a href="#LDAPUseTLS">LDAPUseTLS</a>
</ul>

<hr>
<h3><a name="LDAPAliasDereference">LDAPAliasDereference</a></h3>
Syntax: LDAPAliasDereference never|always|search|find 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

The <code>LDAPAliasDereference</code> directive configures how aliases are
handled. The possible values have the following behaviors:
<ul>
 <li>never
 
 Never dereference aliases
 </li>

<li>always
 
 Always dereference aliases
 </li>

<li>search
 
 Dereference aliases only when searching
 </li>

<li>find
 
 Dereference aliases only when locating the base object for the search
 </li>
</ul>

The default is "never", e.g.:
<pre>
 &lt;IfModule mod_ldap.c&gt;
 LDAPAliasDeference never
 &lt;/IfModule&gt;
</pre>

<hr>
<h3><a name="LDAPAttr">LDAPAttr</a></h3>
Syntax: LDAPAttr old-attr-name new-attr-name 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

The <code>LDAPAttr</code> directive is used to map, or to associate, a standard
attribute name to a non-standard attribute name. If, for example, your
LDAP directory schema used different names for some of the attributes used
by <code>mod_ldap</code>, you would use this directive to tell
<code>mod_ldap</code> what new attribute names to use.

The following LDAP attributes can be renamed in this manner:
<ul>
 <li><code>uid</code>
 <li><code>uidNumber</code>
 <li><code>gidNumber</code>
 <li><code>homeDirectory</code>
 <li><code>userPassword</code>
 <li><code>loginShell</code>
 <li><code>cn</code>
 <li><code>memberUid</code>
 <li><code>ftpQuota</code>
</ul>

<hr>
<h3><a name="LDAPAuthBinds">LDAPAuthBinds</a></h3>
Syntax: LDAPAuthBinds on|off 
Default: LDAPAuthBinds on 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

By default, the DN specified by the
<a href="#LDAPBindDNo"><code>LDAPBindDN</code></a> will be used to bind to the
LDAP server to obtain user information, including the <code>userPassword</code>
attribute. If <code>LDAPAuthBinds</code> is set to on, the DN
specified by <code>LDAPDNInfo</code> will be used to fetch all user information
except the <code>userPassword</code> attribute. Then, the
<code>mod_ldap</code> module will bind to the LDAP server as the user who is
logging in via FTP with the user-supplied password. If this bind succeeds,
the user is considered authenticated and is allowed to log in. This method of
LDAP authentication has the added benefit of supporting any password encryption
scheme that your LDAP server supports.

In versions of <code>mod_ldap</code> up to 2.7.6, the default for
<code>LDAPAuthBinds</code> was off. After <code>mod_ldap</code> 2.8,
the default value for <code>LDAPAuthBinds</code> is on.

<hr>
<h3><a name="LDAPBindDN">LDAPBindDN</a></h3>
Syntax: LDAPBindDN dn password 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.3.5rc1 and later

The <code>LDAPBindDN</code> directive configures the DN and the
password that <code>mod_ldap</code> will use when binding to the LDAP
directory. If this configuration directive is missing, then anonymous binds
are used.

The default is:
<pre>
 &lt;IfModule mod_ldap.c&gt;
 # Use anonymous binds
 LDAPBindDN "" ""
 &lt;/IfModule&gt;
</pre>

See also: <a href="#LDAPServer"><code>LDAPServer</code></a>

<hr>
<h3><a name="LDAPDefaultAuthScheme">LDAPDefaultAuthScheme</a></h3>
Syntax: LDAPDefaultAuthScheme crypt|clear 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

The <code>LDAPDefaultAuthScheme</code> directive specifies the authentication
scheme used for passwords which have no "{hashname}" prefix in the LDAP
directory. For example, if you are:
<pre>
 userPassword mypass
</pre>
in your directory, you would want to set <code>LDAPDefaultAuthScheme</code>
to clear.

The default value is crypt.

<hr>
<h3><a name="LDAPDefaultGID">LDAPDefaultGID</a></h3>
Syntax: LDAPDefaultGID gid 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

The <code>LDAPDefaultGID</code> directive sets the default GID to be used
for users when no <code>gidNumber</code> attribute is found for that user.

This directive is useful primarily in virtual user environments common in
large-scale ISPs and hosting organizations. If a user does not have an LDAP
<code>gidNumber</code> attribute, the <code>LDAPDefaultGID</code> is used.
This allows one to have a large number of users in an LDAP directory without
<code>gidNumber</code> attributes; setting this configuration directive will
automatically assign those users a single GID.

See also: <a href="#LDAPDefaultUID"><code>LDAPDefaultUID</code></a>

<hr>
<h3><a name="LDAPDefaultQuota">LDAPDefaultQuota</a></h3>
Syntax: LDAPDefaultQuota default-quota 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.3.5rc1 and later

The <code>LDAPDefaultQuota</code> directive configures a default-quota
to use if a user does not have an <code>ftpQuota</code> attribute. This
parameter is formatted the same way as the <code>ftpQuota</code> LDAP attribute.

<hr>
<h3><a name="LDAPDefaultUID">LDAPDefaultUID</a></h3>
Syntax: LDAPDefaultUID uid 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

The <code>LDAPDefaultUID</code> directive sets the default UID to be used
for users when no <code>uidNumber</code> attribute is found for that user.

This directive is useful primarily in virtual user environments common in
large-scale ISPs and hosting organizations. If a user does not have an LDAP
<code>uidNumber</code> attribute, the <code>LDAPDefaultGID</code> is used.
This allows one to have a large number of users in an LDAP directory without
<code>uidNumber</code> attributes; setting this configuration directive will
automatically assign those users a single UID.

See also: <a href="#LDAPDefaultGID"><code>LDAPDefaultGID</code></a>

DoAuth

By default, the search filter template used is:
<pre>
 (&amp;(uid=%v)(objectclass=posixAccount))
</pre>
The uid for the the search filter is taken from the
<code>LDAPAttr</code> directive. Search filter templates are only supported
in versions of <code>mod_ldap</code> 2.7 and later.

See also: <a href="#LDAPAttr"><code>LDAPAttr</code></a>

<hr>
<h3><a name="LDAPForceDefaultGID">LDAPForceDefaultGID</a></h3>
Syntax: LDAPForceDefaultGID on|off 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

Even when a <a href="#LDAPDefaultGID"><code>LDAPDefaultGID</code></a> is
configured, the <code>mod_ldap</code> module will allow individual users to
have <code>gidNumber</code> attributes that will override this default GID.
With <code>LDAPForceDefaultGID</code> directive configured to be on,
all LDAP-authenticated users are given the default GID; GIDs may not be
overridden by <code>gidNumber</code> attributes.

<hr>
<h3><a name="LDAPForceDefaultUID">LDAPForceDefaultUID</a></h3>
Syntax: LDAPForceDefaultUID on|off 
Default: None 
Context: server config 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

Even when a <a href="#LDAPDefaultUID"><code>LDAPDefaultUID</code></a> is
configured, the <code>mod_ldap</code> module will allow individual users to
have <code>uidNumber</code> attributes that will override this default UID.
With <code>LDAPForceDefaultUID</code> directive configured to be on,
all LDAP-authenticated users are given the default UID; UIDs may not be
overridden by <code>uidNumber</code> attributes.

<hr>
<h3><a name="LDAPForceGeneratedHomedir">LDAPForceGeneratedHomedir</a></h3>
Syntax: LDAPForceGeneratedHomedir off|on 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code
>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

When no <code>homeDirectory</code> attribute is found, the <code>mod_ldap</code>
module can be configured to generate a home directory using the
<a href="#LDAPGenerateHomedir"><code>LDAPGenerateHomedir</code></a> directive.
If there is a <code>homeDirectory</code> attribute present, however,
the <code>mod_ldap</code> module will use that attribute value as the home
directory.

However, there may be cases where the administrator wishes to override
the <code>homeDirectory</code> attribute, and thus to always use the
home directory value that <code>mod_ldap</code> would generate. The
<code>LDAPForceGeneratedHomedir</code> directive is used in such cases.

For example, assume that the user logging in is named "tj", and has an
LDAP object whose <code>homeDirectory</code> attribute value is "/home/tj".
To force the use of <code>mod_ldap</code>'s generated home directory
instead of that <code>homeDirectory</code> value, the configuration might
look like:
<pre>
 LDAPForceGeneratedHomedir on
 LDAPGenerateHomedir on
 LDAPGenerateHomedirPrefix /var/ftp
</pre>
Using the above configuration, the home directory that the
<code>mod_ldap</code> module would use is <code>/var/ftp/tj</code>, despite
what <code>homeDirectory</code> attribute may be in the LDAP directory.

Note that if <code>LDAPForceGeneratedHomedir</code> is enabled, then
<code>LDAPGenerateHomedir</code> must also be enabled. It is an error
to enable <code>LDAPForceGeneratedHomedir</code> without also enabling
<code>LDAPGenerateHomdir</code>.

See also: <a href="#LDAPGenerateHomedir"><code>LDAPGenerateHomedir</code></a>, <a href="#LDAPGenerateHomedirPrefix"><code>LDAPGenerateHomedirPrefix</code></a>, <a href="#LDAPGenerateHomedirPrefixNoUsername"><code>LDAPGenerateHomedirPrefixNoUsername</code></a>

<hr>
<h3><a name="LDAPGenerateHomedir">LDAPGenerateHomedir</a></h3>
Syntax: LDAPGenerateHomedir on|off 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

By default, the <code>mod_ldap</code> module uses the <code>homeDirectory</code>
attribute to determine what home directory to use for the session. Sometimes,
however, an administrator will want to use a different home directory
for these FTP/SFTP sessions, something other than the path in the
<code>homeDirectory</code> attribute. The <code>LDAPGenerateHomedir</code>
directive is used for situations like this.

The <code>LDAPGenerateHomedir</code> directive configures the
<code>mod_ldap</code> module to "generate" a new home directory value,
overriding the value from the <code>homeDirectory</code> attribute.
The generated home directory value requires that a starting point
for the new home directory, a "prefix", also be provided using the
<a href="#LDAPGenerateHomedirPrefix"><code>LDAPGenerateHomedirPrefix</code></a>
directive.

The <code>LDAPGenerateHomedir</code> directives does not cause the
new home directory to be created on the filesystem. It only changes
the home directory value that the <code>mod_ldap</code> module provides to
the ProFTPD engine. The creation of the home directory, if it does
not already exist, is done using the
<a href="../howto/CreateHome.html"><code>CreateHome</code></a> directive.

See also: <a href="#LDAPGenerateHomedirPrefix"><code>LDAPGenerateHomedirPrefix</code></a>, <a href="#LDAPGenerateHomedirPrefixNoUsername"><code>LDAPGenerateHomedirPrefixNoUsername</code></a>

<hr>
<h3><a name="LDAPGenerateHomedirPrefix">LDAPGenerateHomedirPrefix</a></h3>
Syntax: LDAPGenerateHomedirPrefix prefix 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

The <code>LDAPGenerateHomedirPrefix</code> directive is used when
<code>LDAPGenerateHomedir</code> is enabled, causing the <code>mod_ldap</code>
module to generate a default home directory, when the
<code>homeDirectory</code> attribute value is not present. The generated home
directory value like this:
<pre>
 prefix/username
</pre>
The configured prefix string has the username (from the
<code>uid</code> attribute) appended to generate the home directory value for
the user.

For example:
<pre>
 LDAPGenerateHomedir on
 LDAPGenerateHomedirPrefix /var/ftp
</pre>
Using the above configuration, and assuming a user name of "tj", the home
directory that the <code>mod_ldap</code> module would use is
<code>/var/ftp/tj</code>, no matter what the <code>homeDirectory</code>
attribute may be in the LDAP directory.

See also: <a href="#LDAPForceGeneratedHomedir"><code>LDAPForceGeneratedHomedir</code></a>, <a href="#LDAPGenerateHomedir"><code>LDAPGenerateHomedir</code></a>, <a href="#LDAPGenerateHomedirPrefixNoUsername"><code>LDAPGenerateHomedirPrefixNoUsername</code></a>

<hr>
<h3><a name="LDAPGenerateHomedirPrefixNoUsername">LDAPGenerateHomedirPrefixNoUsername</a></h3>
Syntax: LDAPGenerateHomedirPrefixNoUsername on|off 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

When the <a href="#LDAPGenerateHomedir"><code>LDAPGenerateHomedir</code></a>
and <a href="#LDAPGenerateHomedirPrefix"><code>LDAPGenerateHomedirPrefix</code></a> directives are used, the generated home directory value for
the session is:
<pre>
 prefix/username
</pre>
However, there may be cases where the administrator does not want
the username automatically appended to the generated value, and instead wishes
to use just the prefix as the home directory. For these use cases,
use the <code>LDAPGenerateHomedirPrefixNoUsername</code> directive.

For example:
<pre>
 LDAPGenerateHomedir on
 LDAPGenerateHomedirPrefix /var/ftp
 LDAPGenerateHomedirPrefixNoUsername on
</pre>
Using the above configuration, and assuming a user name of "tj", the home
directory that the <code>mod_ldap</code> module would use is
<code>/var/ftp</code>, no matter what the <code>homeDirectory</code> attribute
may be in the LDAP directory.

See also: <a href="#LDAPGenerateHomedir"><code>LDAPGenerateHomedir</code></a>, <a href="#LDAPGenerateHomedirPrefix"><code>LDAPGenerateHomedirPrefix</code></a>

<hr>
<h3><a name="LDAPGroups">LDAPGroups</a></h3>
Syntax: LDAPGroups base-dn cn-filter-template gid-number-filter-template member-uid-filter-template 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.3.5rc1 and later

The <code>LDAPGroups</code> directive activates LDAP GID-to-name lookups for
directory listings. The first parameter to this directive is the LDAP
base DN to use for GID-to-name lookups. The second through fourth
optional parameters are templates to be used for the search filter;
<code>%v</code> will be replaced with the GID that is being looked up.

By default, the CN filter template look like this:
<pre>
 (&amp;(LDAPAttr_cn=%v)(objectclass=posixGroup))
</pre>
The <code>gidNumber</code> filter template is:
<pre>
 (&amp;(LDAPAttr_gidNumber=%v)(objectclass=posixGroup))
</pre>
and the <code>memberUid</code> filter template used is:
<pre>
 (&amp;(LDAPAttr_memberUid=%v)(objectclass=posixGroup))
</pre>
Note that filter templates are only supported in <code>mod_ldap</code>
version 2.8.3 and later.

The attribute names used in the default search filters are taken from the
<a href="#LDAPAttr"><code>LDAPAttr</code></a> directive.

<hr>
<h3><a name="LDAPLog">LDAPLog</a></h3>
Syntax: LDAPLog file|"none" 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.3.5rc4 and later

The <code>LDAPLog</code> directive is used to specify a log file for
<code>mod_ldap</code>'s reporting on a per-server basis. The file
parameter given must be the full path to the file to use for logging.

Note that this path must not be to a world-writable directory and,
unless <code>AllowLogSymlinks</code> is explicitly set to on
(generally a bad idea), the path must not be a symbolic link.

<hr>
<h3><a name="LDAPProtocolVersion">LDAPProtocolVersion</a></h3>
Syntax: LDAPProtocolVersion 2|3 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

The <code>LDAPProtocolVersion</code> directive configures the version of
the LDAP protocol that <code>mod_ldap</code> will use when talking to the
LDAP servers. The default protocol version used is 3.

<hr>
<h3><a name="LDAPQueryTimeout">LDAPQueryTimeout</a></h3>
Syntax: LDAPQueryTimeout secs 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

The <code>LDAPQueryTimeout</code> directive configures the timeout value,
in seconds, that will be used for LDAP directory queries. The default timeout
value is determined by your LDAP API.

<hr>
<h3><a name="LDAPSearchScope">LDAPSearchScope</a></h3>
Syntax: LDAPSearchScope base|onelevel|subtree 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

The <code>LDAPSearchScope</code> directive is used to set the scope used for
LDAP searches. The default setting, subtree, searches for all entries
in the tree from the current level down. Setting this directive to
onelevel searches only one level deep in the LDAP tree.

Note that the <code>LDAPSearchScope</code> directive cannot be
used when the LDAP URL syntax, rather than hostname/port, is used for your
<a href="#LDAPServer"><code>LDAPServer</code></a> configuration. Why not?
The search scope can be specified as part of the URL itself. This, combined
with the fact that the <code>LDAPServer</code> directive can take
multiple hosts/URLs, makes it clear to include the search scope in the
URLs as needed.

If you are not using the LDAP URL syntax, then the following will
use the subtree search scope:
<pre>
 LDAPServer ldap.example.com
</pre>
or, to make it explicit in your configuration:
<pre>
 LDAPServer ldap.example.com
 LDAPSearchScope subtree
</pre>
On the other hand, if you are using LDAP URLs, then you specify the
search scope as part of the URL:
<pre>
 LDAPServer ldap://ldap.example.com/??sub
</pre>
It is important that the "/" after the hostname/port be part of your
LDAP URL when specifying the search scope. That is, using:
<pre>
 LDAPServer ldap://ldap.example.com??sub
</pre>
will not work as expected; see
<a href="https://tools.ietf.org/html/rfc2255">RFC 2255</a>, Section 3. LDAP
URL parameters are not like HTTP URL query parameters; LDAP URL
parameters are order-specific. And the "/" before any of the
optional parameters is required.

<hr>
<h3><a name="LDAPServer">LDAPServer</a></h3>
Syntax: LDAPServer &quot;url1|host1:port1 url2|host2:port2&quot; 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

The <code>LDAPServer</code> directive allows you to to specify the hostname(s)
and port(s) of the LDAP server(s) to use for LDAP authentication. If no
<code>LDAPServer</code> configuration directive is present, the default LDAP
servers specified by your LDAP library will be used. Note that the LDAP
URL syntax may also be used.

To specify multiple LDAP servers, enclose the entire list of servers in
quotation marks. For example:
<pre>
 LDAPServer &quot;host1:port1 host2:port2&quot;
</pre>
or:
<pre>
 LDAPServer &quot;url1 url2&quot;
</pre>
Th default search scope for LDAP URLs is "base" (unless a scope is explicitly
provided in the URL). This behavior differs from the
<a href="#LDAPSearchScope"><code>LDAPSearchScope</code></a> directive, which
defaults to "subtree".

Note that to use LDAPS (LDAP over SSL), use the URL format,
e.g.:
<pre>
 LDAPServer ldaps://host1:port1 ldaps://host2:port2
</pre>
Alternatively, you can use the <a href="#LDAPUseTLS"><code>LDAPUseTLS</code></a>
directive, e.g.:
<pre>
 LDAPServer ldap://host1:port1 ldap://host2:port2
 LDAPUseTLS on
</pre>
to tell <code>mod_ldap</code> to use LDAP's <a href="https://en.wikipedia.org/wiki/STARTTLS">STARTTLS</a> mechanism.

<hr>
<h3><a name="LDAPUsers">LDAPUsers</a></h3>
Syntax: LDAPUsers base-dn [name-filter-template [uid-filter-template]] 
Default: None 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.3.5rc1 and later

The <code>LDAPUsers</code> directive activates LDAP UID-to-name lookups
for directory listings. The first parameter to this directive is the LDAP
base DN to use for UID-to-name lookups. The optional second parameter
is a template to be used for the search filter for the username; <code>%v</code>
will be replaced with the UID that is being looked up. Similarly, an optional
third parameter is also a template, to be used for the search filter for
the UID.

By default, the name search filter template looks like this:
<pre>
 (&amp;(uid=%v)(objectclass=posixAccount))
</pre>
and the UID search filter template looks like this:
<pre>
 (&amp;(LDAPAttr_uidNumber=%v)(objectclass=posixGroup))
</pre>
The uidNumber attribute name used in the search filter comes from
the <a href="#LDAPAttr"><code>LDAPAttr</code></a> directive.
Note that filter templates are only supported in <code>mod_ldap</code>
version 2.7 and later.

<hr>
<h3><a name="LDAPUseTLS">LDAPUseTLS</a></h3>
Syntax: LDAPUseTLS on|off 
Default: off 
Context: server config, <code>&lt;VirtualHost&gt;</code>, <code>&lt;Global&gt;</code> 
Module: mod_ldap 
Compatibility: 1.2.7rc1 and later

The <code>LDAPUseTLS</code> directive configures whether <code>mod_ldap</code>
will use SSL/TLS via <a href="https://en.wikipedia.org/wiki/STARTTLS">STARTTLS</a> to protect the connections made to the configured LDAP servers.

By default, the <code>mod_ldap</code> module connects to the LDAP server via 
non-encrypted connections. Enabling this option causes <code>mod_ldap</code>
to use an encrypted (TLS/SSL) connection to the LDAP server. If a secure
connection to the LDAP server fails, <code>mod_ldap</code> will not
authenticate users; <code>mod_ldap</code> will not fall back to an
unsecure connection.

<hr>
<h2><a name="Installation">Installation</a></h2>
Follow the normal steps for using third-party modules in ProFTPD:
<pre>
 $ ./configure --with-modules=mod_ldap
 $ make
 $ make install
</pre>
You may need to specify the location of the OpenLDAP header and library files
in your <code>configure</code> command, e.g.:
<pre>
 $ ./configure --with-modules=mod_ldap \
 --with-includes=/usr/local/openldap/include \
 --with-libraries=/usr/local/openldap/lib
</pre>

<hr>
<h2><a name="Usage">Usage</a></h2>

One <code>mod_ldap</code> user submitted the following configuration for
allowing <code>mod_ldap</code> to communicate to a Windows Active Directory
server. Note that this configuration has not been tested; if it works for
you (or not), please let us know:
<pre>
 &lt;IfModule mod_ldap.c&gt;
 LDAPServer ldaps://dc.example.org:3268
 LDAPUseTLS on
 LDAPAuthBinds on
 LDAPBindDN "cn=SRV_ACC_SVN_AUTH,ou=special accounts,ou=Sales,dc=example,dc=org" ******************

LDAPUsers ou=Users,ou=Sales,dc=example,dc=org "(&amp;(sAMAccountName=%u)(objectclass=user)(memberOf=cn=Linux Admins,ou=Groups,ou=Sales,dc=example,dc=com))"
    LDAPSearchScope subtree

# Assign default IDs
    LDAPDefaultUID 106
    LDAPDefaultGID 65534

# Create the home directory
    LDAPGenerateHomedir on
    LDAPGenerateHomedirPrefix /home

# Use different attribute names where necessary
 LDAPAttr uid sAMAccountName
 LDAPAttr gidNumber primaryGroupID
 &lt;/IfModule&gt;
</pre>

Logging 
The <code>mod_ldap</code> module supports <a href="../howto/Tracing.html">trace logging</a>, via the module-specific log channels:
<ul>
 <li>ldap
 <li>ldap.library
</ul>
Thus for trace logging, to aid in debugging, you would use the following in
your <code>proftpd.conf</code>:
<pre>
 TraceLog /path/to/ftpd/trace.log
 Trace ldap:20
</pre>
This trace logging can generate large files; it is intended for debugging use
only, and should be removed from any production configuration.

<a name="FAQ">
Frequently Asked Questions

<a name="ScopesFAQ">
Question: Why is <code>mod_ldap</code> using a "base"
scope by default, rather than "subtree"? I configured:
<pre>
 LDAPSearchScope subtree
</pre>
but it is not working; I see the following in my LDAP server logs:
<pre>
 slapd[31709]: conn=20239 op=1 SRCH base="ou=people,dc=example,dc=com" scope=0 deref=0 filter="(&amp;(uid=tj)(objectClass=posixAccount))"
</pre>
Answer: The use of the "base" scope for searches, in
spite of any <code>LDAPSearchScope</code> directive, happens when a URL, rather
than hostname/port, are used in the <code>LDAPServer</code> directive. <a href="https://tools.ietf.org/html/rfc2255">RFC 2255</a>, Section 3 specifies that the default scope is "base".

Thus instead of:
<pre>
 LDAPServer ldap://ldap.example.com
</pre>
you will need to use:
<pre>
 LDAPServer ldap://ldap.example.com/??sub
</pre>
See the <a href="#LDAPSearchScope"><code>LDAPSearchScope</code></a>
documentation for more details.

<a name="HomedirsFAQ">
Question: How do I use <code>LDAPGenerateHomedir</code>
and <code>CreateHome</code> together successfully? Can I use just
<code>LDAPGenerateHomedir</code>? 
Answer: If you want to have home directories for your
LDAP users automatically created, you do need to use the
<a href="../howto/CreateHome.html"><code>CreateHome</code></a> directive.
Whether you need to use the <a href="#LDAPGenerateHomedir"><code>LDAPGenerateHomedir</code></a> directive is a different (but related) question.

The <code>LDAPGenerateHomedir</code> directive (and its relative <a href="#LDAPForceGeneratedHomedir"><code>LDAPForceGeneratedHomedir</code></a>) should be
used when you want to users to have a different home directory than is
configured for them in LDAP. They are not used for creating these
directories, just generating the paths to use.

Thus to generate a different home directory for your LDAP-defined users,
and to have these different home directories created, you
might use something like this:
<pre>
 &lt;IfModule mod_ldap.c&gt;
 ...
 LDAPGenerateHomedir on
 LDAPGenerateHomedirPrefix /data
 LDAPForceGeneratedHomedir on

# And make sure these home directories are created
 CreateHome on 0770 skel /opt/ProFTPD/etc/skel
 ...
 &lt;/IfModule&gt;
</pre>

<a name="MultipleBindsFAQ">
Question: In my LDAP server logs, I see ProFTPD make
multiple binds for the same client logging in:
<pre>
 slapd[31709]: conn=20239 op=0 BIND dn="cn=admin,dc=example,dc=com" method=128
 slapd[31709]: conn=20239 op=0 BIND dn="cn=admin,dc=example,dc=com" mech=SIMPLE ssf=0
</pre>
I was expecting just one bind. Is this a bug, or is it expected
behavior? 
Answer: Yes, this is the expected behavior.
See the <a href="#LDAPAuthBinds"><code>LDAPAuthBinds</code></a> directive
for details.

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