Add 2FA form element to CP Users form

interface/web/admin/form/users.tform.php

@@ -94,6 +94,11 @@ while ($file = @readdir($handle)) {
 	}
 }
 
+$otp_method_list = array(
+	'none' => 'none',
+	'email' => 'email',
+);
+
 //* Load themes
 $themes_list = array();
 $handle = @opendir(ISPC_THEMES_PATH);
@@ -254,6 +259,25 @@ $form['tabs']['users'] = array (
 			'rows'  => '',
 			'cols'  => ''
 		),
+		'otp_type' => array(
+				'datatype' => 'VARCHAR',
+				'formtype' => 'SELECT',
+				'validators' => array (  0 => array (    'type' => 'NOTEMPTY',
+						'errmsg'=> 'otp_auth_empty'),
+					1 => array (    'type' => 'REGEX',
+						'regex' => '/^[a-z0-9\_]{0,64}$/',
+						'errmsg'=> 'otp_auth_regex'),
+					),
+				'regex'  => '',
+				'errmsg' => '',
+				'default' => '',
+				'value'  => $otp_method_list,
+				'separator' => '',
+				'width'  => '30',
+				'maxlength' => '255',
+				'rows'  => '',
+				'cols'  => ''
+				),
 		'language' => array (
 			'datatype' => 'VARCHAR',
 			'formtype' => 'SELECT',

interface/web/admin/lib/lang/en_users.lng

@@ -38,4 +38,5 @@ $wb['startmodule_empty'] = 'Startmodule empty.';
 $wb['startmodule_regex'] = 'Invalid chars in Startmodule.';
 $wb['app_theme_empty'] = 'App theme empty.';
 $wb['app_theme_regex'] = 'Invalid chars in App theme.';
+$wb['otp_auth_txt'] = '2-Factor Authentication';
 ?>

interface/web/admin/templates/users_user_edit.htm

@@ -28,6 +28,15 @@
 					<div id="confirmpasswordOK" style="display:none;" class="confirmpasswordok">{tmpl_var name='password_match_txt'}</div>
 				</div>
 			</div>
+            <div class="form-group">
+              <label for="2fa" class="col-sm-3 control-label">{tmpl_var name='otp_auth_txt'}</label>
+              <div class="col-sm-9">
+                <select name="otp_type" id="otp_type" class="form-control">
+                  {tmpl_var name='otp_type'}
+                </select>
+              </div>
+            </div>
+
             <div class="form-group">
                 <label class="col-sm-3 control-label">{tmpl_var name='modules_txt'}</label>
                 <div class="col-sm-9">