Enabling LDAP authentication on MediaWiki is fairly straightforward, but there are a couple tricks and gotchas to watch out for.

First, a couple packages are needed: php-ldap (through your packaged manager) and Extension:LDAP Authentication (download and install as instructed).

This assumes that you already have your Linux server working with your LDAP environment.

First, edit /etc/openldap/ldap.conf and add this line to the bottom:

TLS_REQCERT never

After all, we trust our own domain, right?

In your LocalSettings.php, add the following:

require_once ("$IP/extensions/LdapAuthentication/LdapAuthentication.php");

$wgAuth = new LdapAuthenticationPlugin();

$wgLDAPDomainNames = array(
'my.domain.com'
);

$wgLDAPServerNames = array(
'my.domain.com' => 'ldap.domain.com'
);

$wgLDAPSearchAttributes = array(
'my.domain.com' => 'sAMAccountName'
);

$wgLDAPBaseDNs = array(
'my.domain.com' => 'dc=my,dc=domain,dc=com'
);

$wgLDAPEncryptionType = array(
'my.domain.com' => 'ssl'
);

$wgMinimalPasswordLength = 1;

Just change my.domain.com to your FQDN.

After updating both files, on command line run:

/path/to/wiki/maintenance/php update.php

You should now be able to log in with your domain user. I also disabled anonymous editing in my configuration.