1 /*
2 * Copyright 2002-2009 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package net.sf.json.util;
18
19 /**
20 * Defines base implementations for preventing WebHijack in AJAX applications.
21 * The default implementations are:
22 * <ul>
23 * <li>COMMENTS - wraps the string with /* *\/</li>
24 * <li>INFINITE_LOOP - prepends "while(1);"</li>
25 * </ul>
26 *
27 * @author Andres Almiray <aalmiray@users.sourceforge.net>
28 */
29 public abstract class WebHijackPreventionStrategy {
30 /** Wraps the string with /* *\/ */
31 public static final WebHijackPreventionStrategy COMMENTS = new CommentWebHijackPreventionStrategy();
32 /** Prepends "while(1);" */
33 public static final WebHijackPreventionStrategy INFINITE_LOOP = new InfiniteLoopWebHijackPreventionStrategy();
34
35 /**
36 * Transforms the input with the desired strategy.<br>
37 *
38 * @param str a json string
39 * @return String - the transformed json string
40 */
41 public abstract String protect( String str );
42
43 private static final class CommentWebHijackPreventionStrategy extends
44 WebHijackPreventionStrategy {
45 public String protect( String str ) {
46 return "/*" + str + "*/";
47 }
48 }
49
50 private static final class InfiniteLoopWebHijackPreventionStrategy extends
51 WebHijackPreventionStrategy {
52 public String protect( String str ) {
53 return "while(1);" + str;
54 }
55 }
56 }