--- /dev/null
+<?php
+
+/**
+ * Licensed to Jasig under one or more contributor license
+ * agreements. See the NOTICE file distributed with this work for
+ * additional information regarding copyright ownership.
+ *
+ * Jasig licenses this file to you under the Apache License,
+ * Version 2.0 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * PHP Version 5
+ *
+ * @file CAS/ProxyChain/Trusted.php
+ * @category Authentication
+ * @package PhpCAS
+ * @author Adam Franco <afranco@middlebury.edu>
+ * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License 2.0
+ * @link https://wiki.jasig.org/display/CASC/phpCAS
+ */
+
+/**
+ * A proxy-chain definition that defines a chain up to a trusted proxy and
+ * delegates the resposibility of validating the rest of the chain to that
+ * trusted proxy.
+ *
+ * @class CAS_ProxyChain_Trusted
+ * @category Authentication
+ * @package PhpCAS
+ * @author Adam Franco <afranco@middlebury.edu>
+ * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License 2.0
+ * @link https://wiki.jasig.org/display/CASC/phpCAS
+ */
+class CAS_ProxyChain_Trusted
+extends CAS_ProxyChain
+implements CAS_ProxyChain_Interface
+{
+
+ /**
+ * Validate the size of the the list as compared to our chain.
+ *
+ * @param array $list list of proxies
+ *
+ * @return bool
+ */
+ protected function isSizeValid (array $list)
+ {
+ return (sizeof($this->chain) <= sizeof($list));
+ }
+
+}