1 package org.apache.velocity.util.introspection;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.util.Iterator;
23
24 import org.apache.velocity.runtime.RuntimeConstants;
25 import org.apache.velocity.runtime.RuntimeServices;
26 import org.apache.velocity.util.RuntimeServicesAware;
27
28 /**
29 * Use a custom introspector that prevents classloader related method
30 * calls. Use this introspector for situations in which template
31 * writers are numerous or untrusted. Specifically, this introspector
32 * prevents creation of arbitrary objects or reflection on objects.
33 *
34 * <p>To use this introspector, set the following property:
35 * <pre>
36 * runtime.introspector.uberspect = org.apache.velocity.util.introspection.SecureUberspector
37 * </pre>
38 *
39 * @author <a href="mailto:wglass@forio.com">Will Glass-Husain</a>
40 * @version $Id: SecureUberspector.java 718443 2008-11-18 00:01:56Z nbubna $
41 * @since 1.5
42 */
43 public class SecureUberspector extends UberspectImpl implements RuntimeServicesAware
44 {
45 RuntimeServices runtimeServices;
46
47 public SecureUberspector()
48 {
49 super();
50 }
51
52 /**
53 * init - generates the Introspector. As the setup code
54 * makes sure that the log gets set before this is called,
55 * we can initialize the Introspector using the log object.
56 */
57 public void init()
58 {
59 String [] badPackages = runtimeServices.getConfiguration()
60 .getStringArray(RuntimeConstants.INTROSPECTOR_RESTRICT_PACKAGES);
61
62 String [] badClasses = runtimeServices.getConfiguration()
63 .getStringArray(RuntimeConstants.INTROSPECTOR_RESTRICT_CLASSES);
64
65 introspector = new SecureIntrospectorImpl(badClasses, badPackages, log);
66 }
67
68 /**
69 * Get an iterator from the given object. Since the superclass method
70 * this secure version checks for execute permission.
71 *
72 * @param obj object to iterate over
73 * @param i line, column, template info
74 * @return Iterator for object
75 * @throws Exception
76 */
77 public Iterator getIterator(Object obj, Info i)
78 throws Exception
79 {
80 if (obj != null)
81 {
82 SecureIntrospectorControl sic = (SecureIntrospectorControl)introspector;
83 if (sic.checkObjectExecutePermission(obj.getClass(), null))
84 {
85 return super.getIterator(obj, i);
86 }
87 else
88 {
89 log.warn("Cannot retrieve iterator from " + obj.getClass() +
90 " due to security restrictions.");
91 }
92 }
93 return null;
94 }
95
96 /**
97 * Store the RuntimeServices before the object is initialized..
98 * @param rs RuntimeServices object for initialization
99 */
100 public void setRuntimeServices(RuntimeServices rs)
101 {
102 this.runtimeServices = rs;
103 }
104
105
106 }