org.apache.log4j.net.HardenedObjectInputStream Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.
*/
package org.apache.log4j.net;
import java.io.IOException;
import java.io.InputStream;
import java.io.InvalidClassException;
import java.io.ObjectInputStream;
import java.io.ObjectStreamClass;
import java.util.ArrayList;
import java.util.List;
/**
* HardenedObjectInputStream restricts the set of classes that can be
* deserialized to a set of explicitly whitelisted classes. This prevents
* certain type of attacks from being successful.
*
*
* It is assumed that classes in the "java.lang" and "java.util" packages are
* always authorized.
*
*
* @author Ceki Gülcü
* @since 1.2.18
*
* === Copied from the logback project with permission ==
*/
public class HardenedObjectInputStream extends ObjectInputStream {
static final String ARRAY_CLASS_PREFIX = "[L";
final List whitelistedClassNames;
final static String[] JAVA_PACKAGES = new String[] { "java.lang", "java.util", ARRAY_CLASS_PREFIX + "java.lang" };
public HardenedObjectInputStream(InputStream in, String[] whilelist) throws IOException {
super(in);
this.whitelistedClassNames = new ArrayList();
if (whilelist != null) {
for (int i = 0; i < whilelist.length; i++) {
this.whitelistedClassNames.add(whilelist[i]);
}
}
}
public HardenedObjectInputStream(InputStream in, List whitelist) throws IOException {
super(in);
this.whitelistedClassNames = new ArrayList();
this.whitelistedClassNames.addAll(whitelist);
}
@Override
protected Class resolveClass(ObjectStreamClass anObjectStreamClass) throws IOException, ClassNotFoundException {
String incomingClassName = anObjectStreamClass.getName();
if (!isWhitelisted(incomingClassName)) {
throw new InvalidClassException("Unauthorized deserialization attempt", incomingClassName);
}
return super.resolveClass(anObjectStreamClass);
}
private boolean isWhitelisted(String incomingClassName) {
for (int i = 0; i < JAVA_PACKAGES.length; i++) {
if (incomingClassName.startsWith(JAVA_PACKAGES[i]))
return true;
}
for (String whiteListed : whitelistedClassNames) {
if (incomingClassName.equals(whiteListed))
return true;
}
return false;
}
protected void addToWhitelist(List additionalAuthorizedClasses) {
whitelistedClassNames.addAll(additionalAuthorizedClasses);
}
}