sharing-gallery/etc/authentication.php

<?php
$realm = "MY REALM HERE";
$ldaphost = "my.ldap.host";
$ldaptls = "yes";
$ldapbase = "dc=my,dc=server,dc=com";
$checkuser = "cn";
function basicAuth() {
    header('WWW-Authenticate: Basic realm="'.$realm.'"');
    header('HTTP/1.0 401 Unauthorized');
    exit;
}
if (!isset($_SERVER['PHP_AUTH_USER'])) {
    basicAuth();
} else {
    $tstusername = preg_replace('/[^a-z]/', '-', $_SERVER['PHP_AUTH_USER']);
    $password = $_SERVER['PHP_AUTH_PW'];
    $ldapconn = ldap_connect($ldaphost, 389) 
        or error_die("connection to LDAP host failed");
    ldap_set_option($ldapconn, LDAP_OPT_PROTOCOL_VERSION, 3)
        or error_die("failed to set LDAP protocol version 3");
    if ($ldaptls!="no" && $ldaptls!=0 && $ldaptlS)
        ldap_start_tls($ldapconn)
            or error_die($ldapconn, "cannot start LDAP TLS");
    $ldapbind = @ldap_bind($ldapconn, $checkuser.'='.$tstusername.','.$ldapbase, $password)
        or basicAuth();
    $username = $tstuserbname;
}
?>