Index: auth/ldap/auth.php
===================================================================
--- auth/ldap/auth.php	(revision 290)
+++ auth/ldap/auth.php	(working copy)
@@ -57,13 +57,13 @@
                 $this->config->{$key} = $value[$this->config->user_type];
             }
         }
+
         //hack prefix to objectclass
         if (empty($this->config->objectclass)) {        // Can't send empty filter
             $this->config->objectclass='objectClass=*';
         } else if (stripos($this->config->objectclass, 'objectClass=') !== 0) {
             $this->config->objectclass = 'objectClass='.$this->config->objectclass;
         }
-
     }
 
     /**
@@ -1558,6 +1558,10 @@
                 ldap_set_option($connresult, LDAP_OPT_PROTOCOL_VERSION, $this->config->version);
             }
 
+            if ($this->config->tls) {
+                ldap_start_tls($connresult);
+            }
+
             // Fix MDL-10921
             if ($this->config->user_type == 'ad') {
                  ldap_set_option($connresult, LDAP_OPT_REFERRALS, 0);
@@ -1917,6 +1921,8 @@
         // set to defaults if undefined
         if (!isset($config->host_url))
             { $config->host_url = ''; }
+        if (!isset($config->tls))
+            { $config->tls = 0; }
         if (empty($config->ldapencoding))
             { $config->ldapencoding = 'utf-8'; }
         if (!isset($config->contexts))
@@ -1976,8 +1982,8 @@
 
         // save settings
         set_config('host_url', $config->host_url, 'auth/ldap');
+        set_config('tls', $config->tls, 'auth/ldap');
         set_config('ldapencoding', $config->ldapencoding, 'auth/ldap');
-        set_config('host_url', $config->host_url, 'auth/ldap');
         set_config('contexts', $config->contexts, 'auth/ldap');
         set_config('user_type', $config->user_type, 'auth/ldap');
         set_config('user_attribute', $config->user_attribute, 'auth/ldap');
Index: auth/ldap/config.html
===================================================================
--- auth/ldap/config.html	(revision 290)
+++ auth/ldap/config.html	(working copy)
@@ -3,6 +3,8 @@
     // set to defaults if undefined
     if (!isset($config->host_url))
         { $config->host_url = ''; }
+    if (!isset($config->tls))
+        { $config->tls = 0; }
     if (empty($config->ldapencoding))
         { $config->ldapencoding = 'utf-8'; }
     if (!isset($config->contexts))
@@ -87,10 +89,24 @@
 </tr>
 
 <tr valign="top" class="required">
+    <td align="right"><label for="menutls"><?php print_string('auth_ldap_tls_key','auth') ?></label></td>
+    <td>
+    <?php
+       $yesno = array(0 => get_string('no'), 1 => get_string('yes'));
+       choose_from_menu($yesno, 'tls', $config->tls, '');
+       if (isset($err['tls'])) formerr($err['tls']);
+    ?>
+    </td>
+    <td>
+    <?php print_string('auth_ldap_tls','auth') ?>
+    </td>
+</tr>
+
+<tr valign="top" class="required">
     <td align="right"><label for="menuversion"><?php print_string('auth_ldap_version_key','auth') ?></label></td>
     <td>
     <?php
-       $varsions = array();
+       $versions = array();
        $versions[2] = '2';
        $versions[3] = '3';
        choose_from_menu($versions, 'version', $config->version, '');
Index: lang/en_utf8/auth.php
===================================================================
--- lang/en_utf8/auth.php	(revision 220)
+++ lang/en_utf8/auth.php	(working copy)
@@ -174,6 +174,7 @@
 $string['auth_ldap_groupecreators'] = 'List of groups or contexts whose members are allowed to create groups. Separate multiple groups with \';\'. Usually something like \'cn=teachers,ou=staff,o=myorg\'';
 $string['auth_ldap_groupecreators_key'] = 'Group creators';
 $string['auth_ldap_host_url'] = 'Specify LDAP host in URL-form like \'ldap://ldap.myorg.com/\' or \'ldaps://ldap.myorg.com/\' Separate multipleservers with \';\' to get failover support.';
+$string['auth_ldap_tls'] = 'Encrypt communication';
 $string['auth_ldap_ldap_encoding'] = 'Specify encoding used by LDAP server. Most probably utf-8, MS AD v2 uses default platform encoding such as cp1252, cp1250, etc.';
 $string['auth_ldap_login_settings'] = 'Login settings';
 $string['auth_ldap_memberattribute'] = 'Optional: Overrides user member attribute, when users belongs to a group. Usually \'member\'';
@@ -203,6 +204,7 @@
                                   password are checked.';
 $string['auth_ldap_ldap_encoding_key'] = 'LDAP encoding';
 $string['auth_ldap_host_url_key'] = 'Host URL';
+$string['auth_ldap_tls_key'] = 'Use TLS';
 $string['auth_ldap_version_key'] = 'Version';
 $string['auth_ldap_preventpassindb_key'] = 'Hide passwords';
 $string['auth_ldap_bind_dn_key'] = 'Distinguished Name';